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irqchip: Fix dependencies for archs w/o HAS_IOMEM
[linux/fpc-iii.git] / fs / btrfs / free-space-cache.c
blobcfe99bec49dedd723e2a7fff04ace299be37ef87
1 /*
2 * Copyright (C) 2008 Red Hat. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/pagemap.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/math64.h>
23 #include <linux/ratelimit.h>
24 #include "ctree.h"
25 #include "free-space-cache.h"
26 #include "transaction.h"
27 #include "disk-io.h"
28 #include "extent_io.h"
29 #include "inode-map.h"
30 #include "volumes.h"
31
32 #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8)
33 #define MAX_CACHE_BYTES_PER_GIG (32 * 1024)
34
35 struct btrfs_trim_range {
36 u64 start;
37 u64 bytes;
38 struct list_head list;
39 };
40
41 static int link_free_space(struct btrfs_free_space_ctl *ctl,
42 struct btrfs_free_space *info);
43 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
44 struct btrfs_free_space *info);
45
46 static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
47 struct btrfs_path *path,
48 u64 offset)
49 {
50 struct btrfs_key key;
51 struct btrfs_key location;
52 struct btrfs_disk_key disk_key;
53 struct btrfs_free_space_header *header;
54 struct extent_buffer *leaf;
55 struct inode *inode = NULL;
56 int ret;
57
58 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
59 key.offset = offset;
60 key.type = 0;
61
62 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
63 if (ret < 0)
64 return ERR_PTR(ret);
65 if (ret > 0) {
66 btrfs_release_path(path);
67 return ERR_PTR(-ENOENT);
68 }
69
70 leaf = path->nodes[0];
71 header = btrfs_item_ptr(leaf, path->slots[0],
72 struct btrfs_free_space_header);
73 btrfs_free_space_key(leaf, header, &disk_key);
74 btrfs_disk_key_to_cpu(&location, &disk_key);
75 btrfs_release_path(path);
76
77 inode = btrfs_iget(root->fs_info->sb, &location, root, NULL);
78 if (!inode)
79 return ERR_PTR(-ENOENT);
80 if (IS_ERR(inode))
81 return inode;
82 if (is_bad_inode(inode)) {
83 iput(inode);
84 return ERR_PTR(-ENOENT);
85 }
86
87 mapping_set_gfp_mask(inode->i_mapping,
88 mapping_gfp_constraint(inode->i_mapping,
89 ~(__GFP_FS | __GFP_HIGHMEM)));
90
91 return inode;
92 }
93
94 struct inode *lookup_free_space_inode(struct btrfs_root *root,
95 struct btrfs_block_group_cache
96 *block_group, struct btrfs_path *path)
97 {
98 struct inode *inode = NULL;
99 u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
100
101 spin_lock(&block_group->lock);
102 if (block_group->inode)
103 inode = igrab(block_group->inode);
104 spin_unlock(&block_group->lock);
105 if (inode)
106 return inode;
107
108 inode = __lookup_free_space_inode(root, path,
109 block_group->key.objectid);
110 if (IS_ERR(inode))
111 return inode;
112
113 spin_lock(&block_group->lock);
114 if (!((BTRFS_I(inode)->flags & flags) == flags)) {
115 btrfs_info(root->fs_info,
116 "Old style space inode found, converting.");
117 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
118 BTRFS_INODE_NODATACOW;
119 block_group->disk_cache_state = BTRFS_DC_CLEAR;
120 }
121
122 if (!block_group->iref) {
123 block_group->inode = igrab(inode);
124 block_group->iref = 1;
125 }
126 spin_unlock(&block_group->lock);
127
128 return inode;
129 }
130
131 static int __create_free_space_inode(struct btrfs_root *root,
132 struct btrfs_trans_handle *trans,
133 struct btrfs_path *path,
134 u64 ino, u64 offset)
135 {
136 struct btrfs_key key;
137 struct btrfs_disk_key disk_key;
138 struct btrfs_free_space_header *header;
139 struct btrfs_inode_item *inode_item;
140 struct extent_buffer *leaf;
141 u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
142 int ret;
143
144 ret = btrfs_insert_empty_inode(trans, root, path, ino);
145 if (ret)
146 return ret;
147
148 /* We inline crc's for the free disk space cache */
149 if (ino != BTRFS_FREE_INO_OBJECTID)
150 flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
151
152 leaf = path->nodes[0];
153 inode_item = btrfs_item_ptr(leaf, path->slots[0],
154 struct btrfs_inode_item);
155 btrfs_item_key(leaf, &disk_key, path->slots[0]);
156 memset_extent_buffer(leaf, 0, (unsigned long)inode_item,
157 sizeof(*inode_item));
158 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
159 btrfs_set_inode_size(leaf, inode_item, 0);
160 btrfs_set_inode_nbytes(leaf, inode_item, 0);
161 btrfs_set_inode_uid(leaf, inode_item, 0);
162 btrfs_set_inode_gid(leaf, inode_item, 0);
163 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
164 btrfs_set_inode_flags(leaf, inode_item, flags);
165 btrfs_set_inode_nlink(leaf, inode_item, 1);
166 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
167 btrfs_set_inode_block_group(leaf, inode_item, offset);
168 btrfs_mark_buffer_dirty(leaf);
169 btrfs_release_path(path);
170
171 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
172 key.offset = offset;
173 key.type = 0;
174 ret = btrfs_insert_empty_item(trans, root, path, &key,
175 sizeof(struct btrfs_free_space_header));
176 if (ret < 0) {
177 btrfs_release_path(path);
178 return ret;
179 }
180
181 leaf = path->nodes[0];
182 header = btrfs_item_ptr(leaf, path->slots[0],
183 struct btrfs_free_space_header);
184 memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header));
185 btrfs_set_free_space_key(leaf, header, &disk_key);
186 btrfs_mark_buffer_dirty(leaf);
187 btrfs_release_path(path);
188
189 return 0;
190 }
191
192 int create_free_space_inode(struct btrfs_root *root,
193 struct btrfs_trans_handle *trans,
194 struct btrfs_block_group_cache *block_group,
195 struct btrfs_path *path)
196 {
197 int ret;
198 u64 ino;
199
200 ret = btrfs_find_free_objectid(root, &ino);
201 if (ret < 0)
202 return ret;
203
204 return __create_free_space_inode(root, trans, path, ino,
205 block_group->key.objectid);
206 }
207
208 int btrfs_check_trunc_cache_free_space(struct btrfs_root *root,
209 struct btrfs_block_rsv *rsv)
210 {
211 u64 needed_bytes;
212 int ret;
213
214 /* 1 for slack space, 1 for updating the inode */
215 needed_bytes = btrfs_calc_trunc_metadata_size(root, 1) +
216 btrfs_calc_trans_metadata_size(root, 1);
217
218 spin_lock(&rsv->lock);
219 if (rsv->reserved < needed_bytes)
220 ret = -ENOSPC;
221 else
222 ret = 0;
223 spin_unlock(&rsv->lock);
224 return ret;
225 }
226
227 int btrfs_truncate_free_space_cache(struct btrfs_root *root,
228 struct btrfs_trans_handle *trans,
229 struct btrfs_block_group_cache *block_group,
230 struct inode *inode)
231 {
232 int ret = 0;
233 struct btrfs_path *path = btrfs_alloc_path();
234 bool locked = false;
235
236 if (!path) {
237 ret = -ENOMEM;
238 goto fail;
239 }
240
241 if (block_group) {
242 locked = true;
243 mutex_lock(&trans->transaction->cache_write_mutex);
244 if (!list_empty(&block_group->io_list)) {
245 list_del_init(&block_group->io_list);
246
247 btrfs_wait_cache_io(root, trans, block_group,
248 &block_group->io_ctl, path,
249 block_group->key.objectid);
250 btrfs_put_block_group(block_group);
251 }
252
253 /*
254 * now that we've truncated the cache away, its no longer
255 * setup or written
256 */
257 spin_lock(&block_group->lock);
258 block_group->disk_cache_state = BTRFS_DC_CLEAR;
259 spin_unlock(&block_group->lock);
260 }
261 btrfs_free_path(path);
262
263 btrfs_i_size_write(inode, 0);
264 truncate_pagecache(inode, 0);
265
266 /*
267 * We don't need an orphan item because truncating the free space cache
268 * will never be split across transactions.
269 * We don't need to check for -EAGAIN because we're a free space
270 * cache inode
271 */
272 ret = btrfs_truncate_inode_items(trans, root, inode,
273 0, BTRFS_EXTENT_DATA_KEY);
274 if (ret)
275 goto fail;
276
277 ret = btrfs_update_inode(trans, root, inode);
278
279 fail:
280 if (locked)
281 mutex_unlock(&trans->transaction->cache_write_mutex);
282 if (ret)
283 btrfs_abort_transaction(trans, root, ret);
284
285 return ret;
286 }
287
288 static int readahead_cache(struct inode *inode)
289 {
290 struct file_ra_state *ra;
291 unsigned long last_index;
292
293 ra = kzalloc(sizeof(*ra), GFP_NOFS);
294 if (!ra)
295 return -ENOMEM;
296
297 file_ra_state_init(ra, inode->i_mapping);
298 last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
299
300 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
301
302 kfree(ra);
303
304 return 0;
305 }
306
307 static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
308 struct btrfs_root *root, int write)
309 {
310 int num_pages;
311 int check_crcs = 0;
312
313 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE);
314
315 if (btrfs_ino(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_CACHE_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->root = root;
331 io_ctl->check_crcs = check_crcs;
332 io_ctl->inode = inode;
333
334 return 0;
335 }
336
337 static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
338 {
339 kfree(io_ctl->pages);
340 io_ctl->pages = NULL;
341 }
342
343 static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
344 {
345 if (io_ctl->cur) {
346 io_ctl->cur = NULL;
347 io_ctl->orig = NULL;
348 }
349 }
350
351 static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
352 {
353 ASSERT(io_ctl->index < io_ctl->num_pages);
354 io_ctl->page = io_ctl->pages[io_ctl->index++];
355 io_ctl->cur = page_address(io_ctl->page);
356 io_ctl->orig = io_ctl->cur;
357 io_ctl->size = PAGE_CACHE_SIZE;
358 if (clear)
359 memset(io_ctl->cur, 0, PAGE_CACHE_SIZE);
360 }
361
362 static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
363 {
364 int i;
365
366 io_ctl_unmap_page(io_ctl);
367
368 for (i = 0; i < io_ctl->num_pages; i++) {
369 if (io_ctl->pages[i]) {
370 ClearPageChecked(io_ctl->pages[i]);
371 unlock_page(io_ctl->pages[i]);
372 page_cache_release(io_ctl->pages[i]);
373 }
374 }
375 }
376
377 static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, struct inode *inode,
378 int uptodate)
379 {
380 struct page *page;
381 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
382 int i;
383
384 for (i = 0; i < io_ctl->num_pages; i++) {
385 page = find_or_create_page(inode->i_mapping, i, mask);
386 if (!page) {
387 io_ctl_drop_pages(io_ctl);
388 return -ENOMEM;
389 }
390 io_ctl->pages[i] = page;
391 if (uptodate && !PageUptodate(page)) {
392 btrfs_readpage(NULL, page);
393 lock_page(page);
394 if (!PageUptodate(page)) {
395 btrfs_err(BTRFS_I(inode)->root->fs_info,
396 "error reading free space cache");
397 io_ctl_drop_pages(io_ctl);
398 return -EIO;
399 }
400 }
401 }
402
403 for (i = 0; i < io_ctl->num_pages; i++) {
404 clear_page_dirty_for_io(io_ctl->pages[i]);
405 set_page_extent_mapped(io_ctl->pages[i]);
406 }
407
408 return 0;
409 }
410
411 static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
412 {
413 __le64 *val;
414
415 io_ctl_map_page(io_ctl, 1);
416
417 /*
418 * Skip the csum areas. If we don't check crcs then we just have a
419 * 64bit chunk at the front of the first page.
420 */
421 if (io_ctl->check_crcs) {
422 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
423 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
424 } else {
425 io_ctl->cur += sizeof(u64);
426 io_ctl->size -= sizeof(u64) * 2;
427 }
428
429 val = io_ctl->cur;
430 *val = cpu_to_le64(generation);
431 io_ctl->cur += sizeof(u64);
432 }
433
434 static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
435 {
436 __le64 *gen;
437
438 /*
439 * Skip the crc area. If we don't check crcs then we just have a 64bit
440 * chunk at the front of the first page.
441 */
442 if (io_ctl->check_crcs) {
443 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
444 io_ctl->size -= sizeof(u64) +
445 (sizeof(u32) * io_ctl->num_pages);
446 } else {
447 io_ctl->cur += sizeof(u64);
448 io_ctl->size -= sizeof(u64) * 2;
449 }
450
451 gen = io_ctl->cur;
452 if (le64_to_cpu(*gen) != generation) {
453 btrfs_err_rl(io_ctl->root->fs_info,
454 "space cache generation (%llu) does not match inode (%llu)",
455 *gen, generation);
456 io_ctl_unmap_page(io_ctl);
457 return -EIO;
458 }
459 io_ctl->cur += sizeof(u64);
460 return 0;
461 }
462
463 static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
464 {
465 u32 *tmp;
466 u32 crc = ~(u32)0;
467 unsigned offset = 0;
468
469 if (!io_ctl->check_crcs) {
470 io_ctl_unmap_page(io_ctl);
471 return;
472 }
473
474 if (index == 0)
475 offset = sizeof(u32) * io_ctl->num_pages;
476
477 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
478 PAGE_CACHE_SIZE - offset);
479 btrfs_csum_final(crc, (char *)&crc);
480 io_ctl_unmap_page(io_ctl);
481 tmp = page_address(io_ctl->pages[0]);
482 tmp += index;
483 *tmp = crc;
484 }
485
486 static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
487 {
488 u32 *tmp, val;
489 u32 crc = ~(u32)0;
490 unsigned offset = 0;
491
492 if (!io_ctl->check_crcs) {
493 io_ctl_map_page(io_ctl, 0);
494 return 0;
495 }
496
497 if (index == 0)
498 offset = sizeof(u32) * io_ctl->num_pages;
499
500 tmp = page_address(io_ctl->pages[0]);
501 tmp += index;
502 val = *tmp;
503
504 io_ctl_map_page(io_ctl, 0);
505 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
506 PAGE_CACHE_SIZE - offset);
507 btrfs_csum_final(crc, (char *)&crc);
508 if (val != crc) {
509 btrfs_err_rl(io_ctl->root->fs_info,
510 "csum mismatch on free space cache");
511 io_ctl_unmap_page(io_ctl);
512 return -EIO;
513 }
514
515 return 0;
516 }
517
518 static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
519 void *bitmap)
520 {
521 struct btrfs_free_space_entry *entry;
522
523 if (!io_ctl->cur)
524 return -ENOSPC;
525
526 entry = io_ctl->cur;
527 entry->offset = cpu_to_le64(offset);
528 entry->bytes = cpu_to_le64(bytes);
529 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
530 BTRFS_FREE_SPACE_EXTENT;
531 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
532 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
533
534 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
535 return 0;
536
537 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
538
539 /* No more pages to map */
540 if (io_ctl->index >= io_ctl->num_pages)
541 return 0;
542
543 /* map the next page */
544 io_ctl_map_page(io_ctl, 1);
545 return 0;
546 }
547
548 static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
549 {
550 if (!io_ctl->cur)
551 return -ENOSPC;
552
553 /*
554 * If we aren't at the start of the current page, unmap this one and
555 * map the next one if there is any left.
556 */
557 if (io_ctl->cur != io_ctl->orig) {
558 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
559 if (io_ctl->index >= io_ctl->num_pages)
560 return -ENOSPC;
561 io_ctl_map_page(io_ctl, 0);
562 }
563
564 memcpy(io_ctl->cur, bitmap, PAGE_CACHE_SIZE);
565 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
566 if (io_ctl->index < io_ctl->num_pages)
567 io_ctl_map_page(io_ctl, 0);
568 return 0;
569 }
570
571 static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
572 {
573 /*
574 * If we're not on the boundary we know we've modified the page and we
575 * need to crc the page.
576 */
577 if (io_ctl->cur != io_ctl->orig)
578 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
579 else
580 io_ctl_unmap_page(io_ctl);
581
582 while (io_ctl->index < io_ctl->num_pages) {
583 io_ctl_map_page(io_ctl, 1);
584 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
585 }
586 }
587
588 static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
589 struct btrfs_free_space *entry, u8 *type)
590 {
591 struct btrfs_free_space_entry *e;
592 int ret;
593
594 if (!io_ctl->cur) {
595 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
596 if (ret)
597 return ret;
598 }
599
600 e = io_ctl->cur;
601 entry->offset = le64_to_cpu(e->offset);
602 entry->bytes = le64_to_cpu(e->bytes);
603 *type = e->type;
604 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
605 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
606
607 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
608 return 0;
609
610 io_ctl_unmap_page(io_ctl);
611
612 return 0;
613 }
614
615 static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
616 struct btrfs_free_space *entry)
617 {
618 int ret;
619
620 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
621 if (ret)
622 return ret;
623
624 memcpy(entry->bitmap, io_ctl->cur, PAGE_CACHE_SIZE);
625 io_ctl_unmap_page(io_ctl);
626
627 return 0;
628 }
629
630 /*
631 * Since we attach pinned extents after the fact we can have contiguous sections
632 * of free space that are split up in entries. This poses a problem with the
633 * tree logging stuff since it could have allocated across what appears to be 2
634 * entries since we would have merged the entries when adding the pinned extents
635 * back to the free space cache. So run through the space cache that we just
636 * loaded and merge contiguous entries. This will make the log replay stuff not
637 * blow up and it will make for nicer allocator behavior.
638 */
639 static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
640 {
641 struct btrfs_free_space *e, *prev = NULL;
642 struct rb_node *n;
643
644 again:
645 spin_lock(&ctl->tree_lock);
646 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
647 e = rb_entry(n, struct btrfs_free_space, offset_index);
648 if (!prev)
649 goto next;
650 if (e->bitmap || prev->bitmap)
651 goto next;
652 if (prev->offset + prev->bytes == e->offset) {
653 unlink_free_space(ctl, prev);
654 unlink_free_space(ctl, e);
655 prev->bytes += e->bytes;
656 kmem_cache_free(btrfs_free_space_cachep, e);
657 link_free_space(ctl, prev);
658 prev = NULL;
659 spin_unlock(&ctl->tree_lock);
660 goto again;
661 }
662 next:
663 prev = e;
664 }
665 spin_unlock(&ctl->tree_lock);
666 }
667
668 static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
669 struct btrfs_free_space_ctl *ctl,
670 struct btrfs_path *path, u64 offset)
671 {
672 struct btrfs_free_space_header *header;
673 struct extent_buffer *leaf;
674 struct btrfs_io_ctl io_ctl;
675 struct btrfs_key key;
676 struct btrfs_free_space *e, *n;
677 LIST_HEAD(bitmaps);
678 u64 num_entries;
679 u64 num_bitmaps;
680 u64 generation;
681 u8 type;
682 int ret = 0;
683
684 /* Nothing in the space cache, goodbye */
685 if (!i_size_read(inode))
686 return 0;
687
688 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
689 key.offset = offset;
690 key.type = 0;
691
692 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
693 if (ret < 0)
694 return 0;
695 else if (ret > 0) {
696 btrfs_release_path(path);
697 return 0;
698 }
699
700 ret = -1;
701
702 leaf = path->nodes[0];
703 header = btrfs_item_ptr(leaf, path->slots[0],
704 struct btrfs_free_space_header);
705 num_entries = btrfs_free_space_entries(leaf, header);
706 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
707 generation = btrfs_free_space_generation(leaf, header);
708 btrfs_release_path(path);
709
710 if (!BTRFS_I(inode)->generation) {
711 btrfs_info(root->fs_info,
712 "The free space cache file (%llu) is invalid. skip it\n",
713 offset);
714 return 0;
715 }
716
717 if (BTRFS_I(inode)->generation != generation) {
718 btrfs_err(root->fs_info,
719 "free space inode generation (%llu) "
720 "did not match free space cache generation (%llu)",
721 BTRFS_I(inode)->generation, generation);
722 return 0;
723 }
724
725 if (!num_entries)
726 return 0;
727
728 ret = io_ctl_init(&io_ctl, inode, root, 0);
729 if (ret)
730 return ret;
731
732 ret = readahead_cache(inode);
733 if (ret)
734 goto out;
735
736 ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
737 if (ret)
738 goto out;
739
740 ret = io_ctl_check_crc(&io_ctl, 0);
741 if (ret)
742 goto free_cache;
743
744 ret = io_ctl_check_generation(&io_ctl, generation);
745 if (ret)
746 goto free_cache;
747
748 while (num_entries) {
749 e = kmem_cache_zalloc(btrfs_free_space_cachep,
750 GFP_NOFS);
751 if (!e)
752 goto free_cache;
753
754 ret = io_ctl_read_entry(&io_ctl, e, &type);
755 if (ret) {
756 kmem_cache_free(btrfs_free_space_cachep, e);
757 goto free_cache;
758 }
759
760 if (!e->bytes) {
761 kmem_cache_free(btrfs_free_space_cachep, e);
762 goto free_cache;
763 }
764
765 if (type == BTRFS_FREE_SPACE_EXTENT) {
766 spin_lock(&ctl->tree_lock);
767 ret = link_free_space(ctl, e);
768 spin_unlock(&ctl->tree_lock);
769 if (ret) {
770 btrfs_err(root->fs_info,
771 "Duplicate entries in free space cache, dumping");
772 kmem_cache_free(btrfs_free_space_cachep, e);
773 goto free_cache;
774 }
775 } else {
776 ASSERT(num_bitmaps);
777 num_bitmaps--;
778 e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
779 if (!e->bitmap) {
780 kmem_cache_free(
781 btrfs_free_space_cachep, e);
782 goto free_cache;
783 }
784 spin_lock(&ctl->tree_lock);
785 ret = link_free_space(ctl, e);
786 ctl->total_bitmaps++;
787 ctl->op->recalc_thresholds(ctl);
788 spin_unlock(&ctl->tree_lock);
789 if (ret) {
790 btrfs_err(root->fs_info,
791 "Duplicate entries in free space cache, dumping");
792 kmem_cache_free(btrfs_free_space_cachep, e);
793 goto free_cache;
794 }
795 list_add_tail(&e->list, &bitmaps);
796 }
797
798 num_entries--;
799 }
800
801 io_ctl_unmap_page(&io_ctl);
802
803 /*
804 * We add the bitmaps at the end of the entries in order that
805 * the bitmap entries are added to the cache.
806 */
807 list_for_each_entry_safe(e, n, &bitmaps, list) {
808 list_del_init(&e->list);
809 ret = io_ctl_read_bitmap(&io_ctl, e);
810 if (ret)
811 goto free_cache;
812 }
813
814 io_ctl_drop_pages(&io_ctl);
815 merge_space_tree(ctl);
816 ret = 1;
817 out:
818 io_ctl_free(&io_ctl);
819 return ret;
820 free_cache:
821 io_ctl_drop_pages(&io_ctl);
822 __btrfs_remove_free_space_cache(ctl);
823 goto out;
824 }
825
826 int load_free_space_cache(struct btrfs_fs_info *fs_info,
827 struct btrfs_block_group_cache *block_group)
828 {
829 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
830 struct btrfs_root *root = fs_info->tree_root;
831 struct inode *inode;
832 struct btrfs_path *path;
833 int ret = 0;
834 bool matched;
835 u64 used = btrfs_block_group_used(&block_group->item);
836
837 /*
838 * If this block group has been marked to be cleared for one reason or
839 * another then we can't trust the on disk cache, so just return.
840 */
841 spin_lock(&block_group->lock);
842 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
843 spin_unlock(&block_group->lock);
844 return 0;
845 }
846 spin_unlock(&block_group->lock);
847
848 path = btrfs_alloc_path();
849 if (!path)
850 return 0;
851 path->search_commit_root = 1;
852 path->skip_locking = 1;
853
854 inode = lookup_free_space_inode(root, block_group, path);
855 if (IS_ERR(inode)) {
856 btrfs_free_path(path);
857 return 0;
858 }
859
860 /* We may have converted the inode and made the cache invalid. */
861 spin_lock(&block_group->lock);
862 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
863 spin_unlock(&block_group->lock);
864 btrfs_free_path(path);
865 goto out;
866 }
867 spin_unlock(&block_group->lock);
868
869 ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
870 path, block_group->key.objectid);
871 btrfs_free_path(path);
872 if (ret <= 0)
873 goto out;
874
875 spin_lock(&ctl->tree_lock);
876 matched = (ctl->free_space == (block_group->key.offset - used -
877 block_group->bytes_super));
878 spin_unlock(&ctl->tree_lock);
879
880 if (!matched) {
881 __btrfs_remove_free_space_cache(ctl);
882 btrfs_warn(fs_info, "block group %llu has wrong amount of free space",
883 block_group->key.objectid);
884 ret = -1;
885 }
886 out:
887 if (ret < 0) {
888 /* This cache is bogus, make sure it gets cleared */
889 spin_lock(&block_group->lock);
890 block_group->disk_cache_state = BTRFS_DC_CLEAR;
891 spin_unlock(&block_group->lock);
892 ret = 0;
893
894 btrfs_warn(fs_info, "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 GFP_NOFS);
1000 goto fail;
1001 }
1002 leaf = path->nodes[0];
1003 if (ret > 0) {
1004 struct btrfs_key found_key;
1005 ASSERT(path->slots[0]);
1006 path->slots[0]--;
1007 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1008 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
1009 found_key.offset != offset) {
1010 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
1011 inode->i_size - 1,
1012 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
1013 NULL, GFP_NOFS);
1014 btrfs_release_path(path);
1015 goto fail;
1016 }
1017 }
1018
1019 BTRFS_I(inode)->generation = trans->transid;
1020 header = btrfs_item_ptr(leaf, path->slots[0],
1021 struct btrfs_free_space_header);
1022 btrfs_set_free_space_entries(leaf, header, entries);
1023 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1024 btrfs_set_free_space_generation(leaf, header, trans->transid);
1025 btrfs_mark_buffer_dirty(leaf);
1026 btrfs_release_path(path);
1027
1028 return 0;
1029
1030 fail:
1031 return -1;
1032 }
1033
1034 static noinline_for_stack int
1035 write_pinned_extent_entries(struct btrfs_root *root,
1036 struct btrfs_block_group_cache *block_group,
1037 struct btrfs_io_ctl *io_ctl,
1038 int *entries)
1039 {
1040 u64 start, extent_start, extent_end, len;
1041 struct extent_io_tree *unpin = NULL;
1042 int ret;
1043
1044 if (!block_group)
1045 return 0;
1046
1047 /*
1048 * We want to add any pinned extents to our free space cache
1049 * so we don't leak the space
1050 *
1051 * We shouldn't have switched the pinned extents yet so this is the
1052 * right one
1053 */
1054 unpin = root->fs_info->pinned_extents;
1055
1056 start = block_group->key.objectid;
1057
1058 while (start < block_group->key.objectid + block_group->key.offset) {
1059 ret = find_first_extent_bit(unpin, start,
1060 &extent_start, &extent_end,
1061 EXTENT_DIRTY, NULL);
1062 if (ret)
1063 return 0;
1064
1065 /* This pinned extent is out of our range */
1066 if (extent_start >= block_group->key.objectid +
1067 block_group->key.offset)
1068 return 0;
1069
1070 extent_start = max(extent_start, start);
1071 extent_end = min(block_group->key.objectid +
1072 block_group->key.offset, extent_end + 1);
1073 len = extent_end - extent_start;
1074
1075 *entries += 1;
1076 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1077 if (ret)
1078 return -ENOSPC;
1079
1080 start = extent_end;
1081 }
1082
1083 return 0;
1084 }
1085
1086 static noinline_for_stack int
1087 write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
1088 {
1089 struct list_head *pos, *n;
1090 int ret;
1091
1092 /* Write out the bitmaps */
1093 list_for_each_safe(pos, n, bitmap_list) {
1094 struct btrfs_free_space *entry =
1095 list_entry(pos, struct btrfs_free_space, list);
1096
1097 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1098 if (ret)
1099 return -ENOSPC;
1100 list_del_init(&entry->list);
1101 }
1102
1103 return 0;
1104 }
1105
1106 static int flush_dirty_cache(struct inode *inode)
1107 {
1108 int ret;
1109
1110 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1111 if (ret)
1112 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1113 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
1114 GFP_NOFS);
1115
1116 return ret;
1117 }
1118
1119 static void noinline_for_stack
1120 cleanup_bitmap_list(struct list_head *bitmap_list)
1121 {
1122 struct list_head *pos, *n;
1123
1124 list_for_each_safe(pos, n, bitmap_list) {
1125 struct btrfs_free_space *entry =
1126 list_entry(pos, struct btrfs_free_space, list);
1127 list_del_init(&entry->list);
1128 }
1129 }
1130
1131 static void noinline_for_stack
1132 cleanup_write_cache_enospc(struct inode *inode,
1133 struct btrfs_io_ctl *io_ctl,
1134 struct extent_state **cached_state,
1135 struct list_head *bitmap_list)
1136 {
1137 io_ctl_drop_pages(io_ctl);
1138 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1139 i_size_read(inode) - 1, cached_state,
1140 GFP_NOFS);
1141 }
1142
1143 int btrfs_wait_cache_io(struct btrfs_root *root,
1144 struct btrfs_trans_handle *trans,
1145 struct btrfs_block_group_cache *block_group,
1146 struct btrfs_io_ctl *io_ctl,
1147 struct btrfs_path *path, u64 offset)
1148 {
1149 int ret;
1150 struct inode *inode = io_ctl->inode;
1151
1152 if (!inode)
1153 return 0;
1154
1155 if (block_group)
1156 root = root->fs_info->tree_root;
1157
1158 /* Flush the dirty pages in the cache file. */
1159 ret = flush_dirty_cache(inode);
1160 if (ret)
1161 goto out;
1162
1163 /* Update the cache item to tell everyone this cache file is valid. */
1164 ret = update_cache_item(trans, root, inode, path, offset,
1165 io_ctl->entries, io_ctl->bitmaps);
1166 out:
1167 io_ctl_free(io_ctl);
1168 if (ret) {
1169 invalidate_inode_pages2(inode->i_mapping);
1170 BTRFS_I(inode)->generation = 0;
1171 if (block_group) {
1172 #ifdef DEBUG
1173 btrfs_err(root->fs_info,
1174 "failed to write free space cache for block group %llu",
1175 block_group->key.objectid);
1176 #endif
1177 }
1178 }
1179 btrfs_update_inode(trans, root, inode);
1180
1181 if (block_group) {
1182 /* the dirty list is protected by the dirty_bgs_lock */
1183 spin_lock(&trans->transaction->dirty_bgs_lock);
1184
1185 /* the disk_cache_state is protected by the block group lock */
1186 spin_lock(&block_group->lock);
1187
1188 /*
1189 * only mark this as written if we didn't get put back on
1190 * the dirty list while waiting for IO. Otherwise our
1191 * cache state won't be right, and we won't get written again
1192 */
1193 if (!ret && list_empty(&block_group->dirty_list))
1194 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1195 else if (ret)
1196 block_group->disk_cache_state = BTRFS_DC_ERROR;
1197
1198 spin_unlock(&block_group->lock);
1199 spin_unlock(&trans->transaction->dirty_bgs_lock);
1200 io_ctl->inode = NULL;
1201 iput(inode);
1202 }
1203
1204 return ret;
1205
1206 }
1207
1208 /**
1209 * __btrfs_write_out_cache - write out cached info to an inode
1210 * @root - the root the inode belongs to
1211 * @ctl - the free space cache we are going to write out
1212 * @block_group - the block_group for this cache if it belongs to a block_group
1213 * @trans - the trans handle
1214 * @path - the path to use
1215 * @offset - the offset for the key we'll insert
1216 *
1217 * This function writes out a free space cache struct to disk for quick recovery
1218 * on mount. This will return 0 if it was successful in writing the cache out,
1219 * or an errno if it was not.
1220 */
1221 static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
1222 struct btrfs_free_space_ctl *ctl,
1223 struct btrfs_block_group_cache *block_group,
1224 struct btrfs_io_ctl *io_ctl,
1225 struct btrfs_trans_handle *trans,
1226 struct btrfs_path *path, u64 offset)
1227 {
1228 struct extent_state *cached_state = NULL;
1229 LIST_HEAD(bitmap_list);
1230 int entries = 0;
1231 int bitmaps = 0;
1232 int ret;
1233 int must_iput = 0;
1234
1235 if (!i_size_read(inode))
1236 return -EIO;
1237
1238 WARN_ON(io_ctl->pages);
1239 ret = io_ctl_init(io_ctl, inode, root, 1);
1240 if (ret)
1241 return ret;
1242
1243 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1244 down_write(&block_group->data_rwsem);
1245 spin_lock(&block_group->lock);
1246 if (block_group->delalloc_bytes) {
1247 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1248 spin_unlock(&block_group->lock);
1249 up_write(&block_group->data_rwsem);
1250 BTRFS_I(inode)->generation = 0;
1251 ret = 0;
1252 must_iput = 1;
1253 goto out;
1254 }
1255 spin_unlock(&block_group->lock);
1256 }
1257
1258 /* Lock all pages first so we can lock the extent safely. */
1259 ret = io_ctl_prepare_pages(io_ctl, inode, 0);
1260 if (ret)
1261 goto out;
1262
1263 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1264 0, &cached_state);
1265
1266 io_ctl_set_generation(io_ctl, trans->transid);
1267
1268 mutex_lock(&ctl->cache_writeout_mutex);
1269 /* Write out the extent entries in the free space cache */
1270 spin_lock(&ctl->tree_lock);
1271 ret = write_cache_extent_entries(io_ctl, ctl,
1272 block_group, &entries, &bitmaps,
1273 &bitmap_list);
1274 if (ret)
1275 goto out_nospc_locked;
1276
1277 /*
1278 * Some spaces that are freed in the current transaction are pinned,
1279 * they will be added into free space cache after the transaction is
1280 * committed, we shouldn't lose them.
1281 *
1282 * If this changes while we are working we'll get added back to
1283 * the dirty list and redo it. No locking needed
1284 */
1285 ret = write_pinned_extent_entries(root, block_group, io_ctl, &entries);
1286 if (ret)
1287 goto out_nospc_locked;
1288
1289 /*
1290 * At last, we write out all the bitmaps and keep cache_writeout_mutex
1291 * locked while doing it because a concurrent trim can be manipulating
1292 * or freeing the bitmap.
1293 */
1294 ret = write_bitmap_entries(io_ctl, &bitmap_list);
1295 spin_unlock(&ctl->tree_lock);
1296 mutex_unlock(&ctl->cache_writeout_mutex);
1297 if (ret)
1298 goto out_nospc;
1299
1300 /* Zero out the rest of the pages just to make sure */
1301 io_ctl_zero_remaining_pages(io_ctl);
1302
1303 /* Everything is written out, now we dirty the pages in the file. */
1304 ret = btrfs_dirty_pages(root, inode, io_ctl->pages, io_ctl->num_pages,
1305 0, i_size_read(inode), &cached_state);
1306 if (ret)
1307 goto out_nospc;
1308
1309 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1310 up_write(&block_group->data_rwsem);
1311 /*
1312 * Release the pages and unlock the extent, we will flush
1313 * them out later
1314 */
1315 io_ctl_drop_pages(io_ctl);
1316
1317 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1318 i_size_read(inode) - 1, &cached_state, GFP_NOFS);
1319
1320 /*
1321 * at this point the pages are under IO and we're happy,
1322 * The caller is responsible for waiting on them and updating the
1323 * the cache and the inode
1324 */
1325 io_ctl->entries = entries;
1326 io_ctl->bitmaps = bitmaps;
1327
1328 ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
1329 if (ret)
1330 goto out;
1331
1332 return 0;
1333
1334 out:
1335 io_ctl->inode = NULL;
1336 io_ctl_free(io_ctl);
1337 if (ret) {
1338 invalidate_inode_pages2(inode->i_mapping);
1339 BTRFS_I(inode)->generation = 0;
1340 }
1341 btrfs_update_inode(trans, root, inode);
1342 if (must_iput)
1343 iput(inode);
1344 return ret;
1345
1346 out_nospc_locked:
1347 cleanup_bitmap_list(&bitmap_list);
1348 spin_unlock(&ctl->tree_lock);
1349 mutex_unlock(&ctl->cache_writeout_mutex);
1350
1351 out_nospc:
1352 cleanup_write_cache_enospc(inode, io_ctl, &cached_state, &bitmap_list);
1353
1354 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1355 up_write(&block_group->data_rwsem);
1356
1357 goto out;
1358 }
1359
1360 int btrfs_write_out_cache(struct btrfs_root *root,
1361 struct btrfs_trans_handle *trans,
1362 struct btrfs_block_group_cache *block_group,
1363 struct btrfs_path *path)
1364 {
1365 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1366 struct inode *inode;
1367 int ret = 0;
1368
1369 root = root->fs_info->tree_root;
1370
1371 spin_lock(&block_group->lock);
1372 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1373 spin_unlock(&block_group->lock);
1374 return 0;
1375 }
1376 spin_unlock(&block_group->lock);
1377
1378 inode = lookup_free_space_inode(root, block_group, path);
1379 if (IS_ERR(inode))
1380 return 0;
1381
1382 ret = __btrfs_write_out_cache(root, inode, ctl, block_group,
1383 &block_group->io_ctl, trans,
1384 path, block_group->key.objectid);
1385 if (ret) {
1386 #ifdef DEBUG
1387 btrfs_err(root->fs_info,
1388 "failed to write free space cache for block group %llu",
1389 block_group->key.objectid);
1390 #endif
1391 spin_lock(&block_group->lock);
1392 block_group->disk_cache_state = BTRFS_DC_ERROR;
1393 spin_unlock(&block_group->lock);
1394
1395 block_group->io_ctl.inode = NULL;
1396 iput(inode);
1397 }
1398
1399 /*
1400 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
1401 * to wait for IO and put the inode
1402 */
1403
1404 return ret;
1405 }
1406
1407 static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1408 u64 offset)
1409 {
1410 ASSERT(offset >= bitmap_start);
1411 offset -= bitmap_start;
1412 return (unsigned long)(div_u64(offset, unit));
1413 }
1414
1415 static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1416 {
1417 return (unsigned long)(div_u64(bytes, unit));
1418 }
1419
1420 static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1421 u64 offset)
1422 {
1423 u64 bitmap_start;
1424 u32 bytes_per_bitmap;
1425
1426 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1427 bitmap_start = offset - ctl->start;
1428 bitmap_start = div_u64(bitmap_start, bytes_per_bitmap);
1429 bitmap_start *= bytes_per_bitmap;
1430 bitmap_start += ctl->start;
1431
1432 return bitmap_start;
1433 }
1434
1435 static int tree_insert_offset(struct rb_root *root, u64 offset,
1436 struct rb_node *node, int bitmap)
1437 {
1438 struct rb_node **p = &root->rb_node;
1439 struct rb_node *parent = NULL;
1440 struct btrfs_free_space *info;
1441
1442 while (*p) {
1443 parent = *p;
1444 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1445
1446 if (offset < info->offset) {
1447 p = &(*p)->rb_left;
1448 } else if (offset > info->offset) {
1449 p = &(*p)->rb_right;
1450 } else {
1451 /*
1452 * we could have a bitmap entry and an extent entry
1453 * share the same offset. If this is the case, we want
1454 * the extent entry to always be found first if we do a
1455 * linear search through the tree, since we want to have
1456 * the quickest allocation time, and allocating from an
1457 * extent is faster than allocating from a bitmap. So
1458 * if we're inserting a bitmap and we find an entry at
1459 * this offset, we want to go right, or after this entry
1460 * logically. If we are inserting an extent and we've
1461 * found a bitmap, we want to go left, or before
1462 * logically.
1463 */
1464 if (bitmap) {
1465 if (info->bitmap) {
1466 WARN_ON_ONCE(1);
1467 return -EEXIST;
1468 }
1469 p = &(*p)->rb_right;
1470 } else {
1471 if (!info->bitmap) {
1472 WARN_ON_ONCE(1);
1473 return -EEXIST;
1474 }
1475 p = &(*p)->rb_left;
1476 }
1477 }
1478 }
1479
1480 rb_link_node(node, parent, p);
1481 rb_insert_color(node, root);
1482
1483 return 0;
1484 }
1485
1486 /*
1487 * searches the tree for the given offset.
1488 *
1489 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1490 * want a section that has at least bytes size and comes at or after the given
1491 * offset.
1492 */
1493 static struct btrfs_free_space *
1494 tree_search_offset(struct btrfs_free_space_ctl *ctl,
1495 u64 offset, int bitmap_only, int fuzzy)
1496 {
1497 struct rb_node *n = ctl->free_space_offset.rb_node;
1498 struct btrfs_free_space *entry, *prev = NULL;
1499
1500 /* find entry that is closest to the 'offset' */
1501 while (1) {
1502 if (!n) {
1503 entry = NULL;
1504 break;
1505 }
1506
1507 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1508 prev = entry;
1509
1510 if (offset < entry->offset)
1511 n = n->rb_left;
1512 else if (offset > entry->offset)
1513 n = n->rb_right;
1514 else
1515 break;
1516 }
1517
1518 if (bitmap_only) {
1519 if (!entry)
1520 return NULL;
1521 if (entry->bitmap)
1522 return entry;
1523
1524 /*
1525 * bitmap entry and extent entry may share same offset,
1526 * in that case, bitmap entry comes after extent entry.
1527 */
1528 n = rb_next(n);
1529 if (!n)
1530 return NULL;
1531 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1532 if (entry->offset != offset)
1533 return NULL;
1534
1535 WARN_ON(!entry->bitmap);
1536 return entry;
1537 } else if (entry) {
1538 if (entry->bitmap) {
1539 /*
1540 * if previous extent entry covers the offset,
1541 * we should return it instead of the bitmap entry
1542 */
1543 n = rb_prev(&entry->offset_index);
1544 if (n) {
1545 prev = rb_entry(n, struct btrfs_free_space,
1546 offset_index);
1547 if (!prev->bitmap &&
1548 prev->offset + prev->bytes > offset)
1549 entry = prev;
1550 }
1551 }
1552 return entry;
1553 }
1554
1555 if (!prev)
1556 return NULL;
1557
1558 /* find last entry before the 'offset' */
1559 entry = prev;
1560 if (entry->offset > offset) {
1561 n = rb_prev(&entry->offset_index);
1562 if (n) {
1563 entry = rb_entry(n, struct btrfs_free_space,
1564 offset_index);
1565 ASSERT(entry->offset <= offset);
1566 } else {
1567 if (fuzzy)
1568 return entry;
1569 else
1570 return NULL;
1571 }
1572 }
1573
1574 if (entry->bitmap) {
1575 n = rb_prev(&entry->offset_index);
1576 if (n) {
1577 prev = rb_entry(n, struct btrfs_free_space,
1578 offset_index);
1579 if (!prev->bitmap &&
1580 prev->offset + prev->bytes > offset)
1581 return prev;
1582 }
1583 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1584 return entry;
1585 } else if (entry->offset + entry->bytes > offset)
1586 return entry;
1587
1588 if (!fuzzy)
1589 return NULL;
1590
1591 while (1) {
1592 if (entry->bitmap) {
1593 if (entry->offset + BITS_PER_BITMAP *
1594 ctl->unit > offset)
1595 break;
1596 } else {
1597 if (entry->offset + entry->bytes > offset)
1598 break;
1599 }
1600
1601 n = rb_next(&entry->offset_index);
1602 if (!n)
1603 return NULL;
1604 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1605 }
1606 return entry;
1607 }
1608
1609 static inline void
1610 __unlink_free_space(struct btrfs_free_space_ctl *ctl,
1611 struct btrfs_free_space *info)
1612 {
1613 rb_erase(&info->offset_index, &ctl->free_space_offset);
1614 ctl->free_extents--;
1615 }
1616
1617 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1618 struct btrfs_free_space *info)
1619 {
1620 __unlink_free_space(ctl, info);
1621 ctl->free_space -= info->bytes;
1622 }
1623
1624 static int link_free_space(struct btrfs_free_space_ctl *ctl,
1625 struct btrfs_free_space *info)
1626 {
1627 int ret = 0;
1628
1629 ASSERT(info->bytes || info->bitmap);
1630 ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1631 &info->offset_index, (info->bitmap != NULL));
1632 if (ret)
1633 return ret;
1634
1635 ctl->free_space += info->bytes;
1636 ctl->free_extents++;
1637 return ret;
1638 }
1639
1640 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1641 {
1642 struct btrfs_block_group_cache *block_group = ctl->private;
1643 u64 max_bytes;
1644 u64 bitmap_bytes;
1645 u64 extent_bytes;
1646 u64 size = block_group->key.offset;
1647 u32 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1648 u32 max_bitmaps = div_u64(size + bytes_per_bg - 1, bytes_per_bg);
1649
1650 max_bitmaps = max_t(u32, max_bitmaps, 1);
1651
1652 ASSERT(ctl->total_bitmaps <= max_bitmaps);
1653
1654 /*
1655 * The goal is to keep the total amount of memory used per 1gb of space
1656 * at or below 32k, so we need to adjust how much memory we allow to be
1657 * used by extent based free space tracking
1658 */
1659 if (size < 1024 * 1024 * 1024)
1660 max_bytes = MAX_CACHE_BYTES_PER_GIG;
1661 else
1662 max_bytes = MAX_CACHE_BYTES_PER_GIG *
1663 div_u64(size, 1024 * 1024 * 1024);
1664
1665 /*
1666 * we want to account for 1 more bitmap than what we have so we can make
1667 * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1668 * we add more bitmaps.
1669 */
1670 bitmap_bytes = (ctl->total_bitmaps + 1) * PAGE_CACHE_SIZE;
1671
1672 if (bitmap_bytes >= max_bytes) {
1673 ctl->extents_thresh = 0;
1674 return;
1675 }
1676
1677 /*
1678 * we want the extent entry threshold to always be at most 1/2 the max
1679 * bytes we can have, or whatever is less than that.
1680 */
1681 extent_bytes = max_bytes - bitmap_bytes;
1682 extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
1683
1684 ctl->extents_thresh =
1685 div_u64(extent_bytes, sizeof(struct btrfs_free_space));
1686 }
1687
1688 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1689 struct btrfs_free_space *info,
1690 u64 offset, u64 bytes)
1691 {
1692 unsigned long start, count;
1693
1694 start = offset_to_bit(info->offset, ctl->unit, offset);
1695 count = bytes_to_bits(bytes, ctl->unit);
1696 ASSERT(start + count <= BITS_PER_BITMAP);
1697
1698 bitmap_clear(info->bitmap, start, count);
1699
1700 info->bytes -= bytes;
1701 }
1702
1703 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1704 struct btrfs_free_space *info, u64 offset,
1705 u64 bytes)
1706 {
1707 __bitmap_clear_bits(ctl, info, offset, bytes);
1708 ctl->free_space -= bytes;
1709 }
1710
1711 static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1712 struct btrfs_free_space *info, u64 offset,
1713 u64 bytes)
1714 {
1715 unsigned long start, count;
1716
1717 start = offset_to_bit(info->offset, ctl->unit, offset);
1718 count = bytes_to_bits(bytes, ctl->unit);
1719 ASSERT(start + count <= BITS_PER_BITMAP);
1720
1721 bitmap_set(info->bitmap, start, count);
1722
1723 info->bytes += bytes;
1724 ctl->free_space += bytes;
1725 }
1726
1727 /*
1728 * If we can not find suitable extent, we will use bytes to record
1729 * the size of the max extent.
1730 */
1731 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1732 struct btrfs_free_space *bitmap_info, u64 *offset,
1733 u64 *bytes, bool for_alloc)
1734 {
1735 unsigned long found_bits = 0;
1736 unsigned long max_bits = 0;
1737 unsigned long bits, i;
1738 unsigned long next_zero;
1739 unsigned long extent_bits;
1740
1741 /*
1742 * Skip searching the bitmap if we don't have a contiguous section that
1743 * is large enough for this allocation.
1744 */
1745 if (for_alloc &&
1746 bitmap_info->max_extent_size &&
1747 bitmap_info->max_extent_size < *bytes) {
1748 *bytes = bitmap_info->max_extent_size;
1749 return -1;
1750 }
1751
1752 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1753 max_t(u64, *offset, bitmap_info->offset));
1754 bits = bytes_to_bits(*bytes, ctl->unit);
1755
1756 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1757 if (for_alloc && bits == 1) {
1758 found_bits = 1;
1759 break;
1760 }
1761 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1762 BITS_PER_BITMAP, i);
1763 extent_bits = next_zero - i;
1764 if (extent_bits >= bits) {
1765 found_bits = extent_bits;
1766 break;
1767 } else if (extent_bits > max_bits) {
1768 max_bits = extent_bits;
1769 }
1770 i = next_zero;
1771 }
1772
1773 if (found_bits) {
1774 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1775 *bytes = (u64)(found_bits) * ctl->unit;
1776 return 0;
1777 }
1778
1779 *bytes = (u64)(max_bits) * ctl->unit;
1780 bitmap_info->max_extent_size = *bytes;
1781 return -1;
1782 }
1783
1784 /* Cache the size of the max extent in bytes */
1785 static struct btrfs_free_space *
1786 find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1787 unsigned long align, u64 *max_extent_size)
1788 {
1789 struct btrfs_free_space *entry;
1790 struct rb_node *node;
1791 u64 tmp;
1792 u64 align_off;
1793 int ret;
1794
1795 if (!ctl->free_space_offset.rb_node)
1796 goto out;
1797
1798 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1799 if (!entry)
1800 goto out;
1801
1802 for (node = &entry->offset_index; node; node = rb_next(node)) {
1803 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1804 if (entry->bytes < *bytes) {
1805 if (entry->bytes > *max_extent_size)
1806 *max_extent_size = entry->bytes;
1807 continue;
1808 }
1809
1810 /* make sure the space returned is big enough
1811 * to match our requested alignment
1812 */
1813 if (*bytes >= align) {
1814 tmp = entry->offset - ctl->start + align - 1;
1815 tmp = div64_u64(tmp, align);
1816 tmp = tmp * align + ctl->start;
1817 align_off = tmp - entry->offset;
1818 } else {
1819 align_off = 0;
1820 tmp = entry->offset;
1821 }
1822
1823 if (entry->bytes < *bytes + align_off) {
1824 if (entry->bytes > *max_extent_size)
1825 *max_extent_size = entry->bytes;
1826 continue;
1827 }
1828
1829 if (entry->bitmap) {
1830 u64 size = *bytes;
1831
1832 ret = search_bitmap(ctl, entry, &tmp, &size, true);
1833 if (!ret) {
1834 *offset = tmp;
1835 *bytes = size;
1836 return entry;
1837 } else if (size > *max_extent_size) {
1838 *max_extent_size = size;
1839 }
1840 continue;
1841 }
1842
1843 *offset = tmp;
1844 *bytes = entry->bytes - align_off;
1845 return entry;
1846 }
1847 out:
1848 return NULL;
1849 }
1850
1851 static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1852 struct btrfs_free_space *info, u64 offset)
1853 {
1854 info->offset = offset_to_bitmap(ctl, offset);
1855 info->bytes = 0;
1856 INIT_LIST_HEAD(&info->list);
1857 link_free_space(ctl, info);
1858 ctl->total_bitmaps++;
1859
1860 ctl->op->recalc_thresholds(ctl);
1861 }
1862
1863 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1864 struct btrfs_free_space *bitmap_info)
1865 {
1866 unlink_free_space(ctl, bitmap_info);
1867 kfree(bitmap_info->bitmap);
1868 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1869 ctl->total_bitmaps--;
1870 ctl->op->recalc_thresholds(ctl);
1871 }
1872
1873 static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1874 struct btrfs_free_space *bitmap_info,
1875 u64 *offset, u64 *bytes)
1876 {
1877 u64 end;
1878 u64 search_start, search_bytes;
1879 int ret;
1880
1881 again:
1882 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1883
1884 /*
1885 * We need to search for bits in this bitmap. We could only cover some
1886 * of the extent in this bitmap thanks to how we add space, so we need
1887 * to search for as much as it as we can and clear that amount, and then
1888 * go searching for the next bit.
1889 */
1890 search_start = *offset;
1891 search_bytes = ctl->unit;
1892 search_bytes = min(search_bytes, end - search_start + 1);
1893 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
1894 false);
1895 if (ret < 0 || search_start != *offset)
1896 return -EINVAL;
1897
1898 /* We may have found more bits than what we need */
1899 search_bytes = min(search_bytes, *bytes);
1900
1901 /* Cannot clear past the end of the bitmap */
1902 search_bytes = min(search_bytes, end - search_start + 1);
1903
1904 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
1905 *offset += search_bytes;
1906 *bytes -= search_bytes;
1907
1908 if (*bytes) {
1909 struct rb_node *next = rb_next(&bitmap_info->offset_index);
1910 if (!bitmap_info->bytes)
1911 free_bitmap(ctl, bitmap_info);
1912
1913 /*
1914 * no entry after this bitmap, but we still have bytes to
1915 * remove, so something has gone wrong.
1916 */
1917 if (!next)
1918 return -EINVAL;
1919
1920 bitmap_info = rb_entry(next, struct btrfs_free_space,
1921 offset_index);
1922
1923 /*
1924 * if the next entry isn't a bitmap we need to return to let the
1925 * extent stuff do its work.
1926 */
1927 if (!bitmap_info->bitmap)
1928 return -EAGAIN;
1929
1930 /*
1931 * Ok the next item is a bitmap, but it may not actually hold
1932 * the information for the rest of this free space stuff, so
1933 * look for it, and if we don't find it return so we can try
1934 * everything over again.
1935 */
1936 search_start = *offset;
1937 search_bytes = ctl->unit;
1938 ret = search_bitmap(ctl, bitmap_info, &search_start,
1939 &search_bytes, false);
1940 if (ret < 0 || search_start != *offset)
1941 return -EAGAIN;
1942
1943 goto again;
1944 } else if (!bitmap_info->bytes)
1945 free_bitmap(ctl, bitmap_info);
1946
1947 return 0;
1948 }
1949
1950 static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
1951 struct btrfs_free_space *info, u64 offset,
1952 u64 bytes)
1953 {
1954 u64 bytes_to_set = 0;
1955 u64 end;
1956
1957 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
1958
1959 bytes_to_set = min(end - offset, bytes);
1960
1961 bitmap_set_bits(ctl, info, offset, bytes_to_set);
1962
1963 /*
1964 * We set some bytes, we have no idea what the max extent size is
1965 * anymore.
1966 */
1967 info->max_extent_size = 0;
1968
1969 return bytes_to_set;
1970
1971 }
1972
1973 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
1974 struct btrfs_free_space *info)
1975 {
1976 struct btrfs_block_group_cache *block_group = ctl->private;
1977 bool forced = false;
1978
1979 #ifdef CONFIG_BTRFS_DEBUG
1980 if (btrfs_should_fragment_free_space(block_group->fs_info->extent_root,
1981 block_group))
1982 forced = true;
1983 #endif
1984
1985 /*
1986 * If we are below the extents threshold then we can add this as an
1987 * extent, and don't have to deal with the bitmap
1988 */
1989 if (!forced && ctl->free_extents < ctl->extents_thresh) {
1990 /*
1991 * If this block group has some small extents we don't want to
1992 * use up all of our free slots in the cache with them, we want
1993 * to reserve them to larger extents, however if we have plent
1994 * of cache left then go ahead an dadd them, no sense in adding
1995 * the overhead of a bitmap if we don't have to.
1996 */
1997 if (info->bytes <= block_group->sectorsize * 4) {
1998 if (ctl->free_extents * 2 <= ctl->extents_thresh)
1999 return false;
2000 } else {
2001 return false;
2002 }
2003 }
2004
2005 /*
2006 * The original block groups from mkfs can be really small, like 8
2007 * megabytes, so don't bother with a bitmap for those entries. However
2008 * some block groups can be smaller than what a bitmap would cover but
2009 * are still large enough that they could overflow the 32k memory limit,
2010 * so allow those block groups to still be allowed to have a bitmap
2011 * entry.
2012 */
2013 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->key.offset)
2014 return false;
2015
2016 return true;
2017 }
2018
2019 static struct btrfs_free_space_op free_space_op = {
2020 .recalc_thresholds = recalculate_thresholds,
2021 .use_bitmap = use_bitmap,
2022 };
2023
2024 static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
2025 struct btrfs_free_space *info)
2026 {
2027 struct btrfs_free_space *bitmap_info;
2028 struct btrfs_block_group_cache *block_group = NULL;
2029 int added = 0;
2030 u64 bytes, offset, bytes_added;
2031 int ret;
2032
2033 bytes = info->bytes;
2034 offset = info->offset;
2035
2036 if (!ctl->op->use_bitmap(ctl, info))
2037 return 0;
2038
2039 if (ctl->op == &free_space_op)
2040 block_group = ctl->private;
2041 again:
2042 /*
2043 * Since we link bitmaps right into the cluster we need to see if we
2044 * have a cluster here, and if so and it has our bitmap we need to add
2045 * the free space to that bitmap.
2046 */
2047 if (block_group && !list_empty(&block_group->cluster_list)) {
2048 struct btrfs_free_cluster *cluster;
2049 struct rb_node *node;
2050 struct btrfs_free_space *entry;
2051
2052 cluster = list_entry(block_group->cluster_list.next,
2053 struct btrfs_free_cluster,
2054 block_group_list);
2055 spin_lock(&cluster->lock);
2056 node = rb_first(&cluster->root);
2057 if (!node) {
2058 spin_unlock(&cluster->lock);
2059 goto no_cluster_bitmap;
2060 }
2061
2062 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2063 if (!entry->bitmap) {
2064 spin_unlock(&cluster->lock);
2065 goto no_cluster_bitmap;
2066 }
2067
2068 if (entry->offset == offset_to_bitmap(ctl, offset)) {
2069 bytes_added = add_bytes_to_bitmap(ctl, entry,
2070 offset, bytes);
2071 bytes -= bytes_added;
2072 offset += bytes_added;
2073 }
2074 spin_unlock(&cluster->lock);
2075 if (!bytes) {
2076 ret = 1;
2077 goto out;
2078 }
2079 }
2080
2081 no_cluster_bitmap:
2082 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2083 1, 0);
2084 if (!bitmap_info) {
2085 ASSERT(added == 0);
2086 goto new_bitmap;
2087 }
2088
2089 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
2090 bytes -= bytes_added;
2091 offset += bytes_added;
2092 added = 0;
2093
2094 if (!bytes) {
2095 ret = 1;
2096 goto out;
2097 } else
2098 goto again;
2099
2100 new_bitmap:
2101 if (info && info->bitmap) {
2102 add_new_bitmap(ctl, info, offset);
2103 added = 1;
2104 info = NULL;
2105 goto again;
2106 } else {
2107 spin_unlock(&ctl->tree_lock);
2108
2109 /* no pre-allocated info, allocate a new one */
2110 if (!info) {
2111 info = kmem_cache_zalloc(btrfs_free_space_cachep,
2112 GFP_NOFS);
2113 if (!info) {
2114 spin_lock(&ctl->tree_lock);
2115 ret = -ENOMEM;
2116 goto out;
2117 }
2118 }
2119
2120 /* allocate the bitmap */
2121 info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
2122 spin_lock(&ctl->tree_lock);
2123 if (!info->bitmap) {
2124 ret = -ENOMEM;
2125 goto out;
2126 }
2127 goto again;
2128 }
2129
2130 out:
2131 if (info) {
2132 if (info->bitmap)
2133 kfree(info->bitmap);
2134 kmem_cache_free(btrfs_free_space_cachep, info);
2135 }
2136
2137 return ret;
2138 }
2139
2140 static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
2141 struct btrfs_free_space *info, bool update_stat)
2142 {
2143 struct btrfs_free_space *left_info;
2144 struct btrfs_free_space *right_info;
2145 bool merged = false;
2146 u64 offset = info->offset;
2147 u64 bytes = info->bytes;
2148
2149 /*
2150 * first we want to see if there is free space adjacent to the range we
2151 * are adding, if there is remove that struct and add a new one to
2152 * cover the entire range
2153 */
2154 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
2155 if (right_info && rb_prev(&right_info->offset_index))
2156 left_info = rb_entry(rb_prev(&right_info->offset_index),
2157 struct btrfs_free_space, offset_index);
2158 else
2159 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
2160
2161 if (right_info && !right_info->bitmap) {
2162 if (update_stat)
2163 unlink_free_space(ctl, right_info);
2164 else
2165 __unlink_free_space(ctl, right_info);
2166 info->bytes += right_info->bytes;
2167 kmem_cache_free(btrfs_free_space_cachep, right_info);
2168 merged = true;
2169 }
2170
2171 if (left_info && !left_info->bitmap &&
2172 left_info->offset + left_info->bytes == offset) {
2173 if (update_stat)
2174 unlink_free_space(ctl, left_info);
2175 else
2176 __unlink_free_space(ctl, left_info);
2177 info->offset = left_info->offset;
2178 info->bytes += left_info->bytes;
2179 kmem_cache_free(btrfs_free_space_cachep, left_info);
2180 merged = true;
2181 }
2182
2183 return merged;
2184 }
2185
2186 static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2187 struct btrfs_free_space *info,
2188 bool update_stat)
2189 {
2190 struct btrfs_free_space *bitmap;
2191 unsigned long i;
2192 unsigned long j;
2193 const u64 end = info->offset + info->bytes;
2194 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2195 u64 bytes;
2196
2197 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2198 if (!bitmap)
2199 return false;
2200
2201 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2202 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2203 if (j == i)
2204 return false;
2205 bytes = (j - i) * ctl->unit;
2206 info->bytes += bytes;
2207
2208 if (update_stat)
2209 bitmap_clear_bits(ctl, bitmap, end, bytes);
2210 else
2211 __bitmap_clear_bits(ctl, bitmap, end, bytes);
2212
2213 if (!bitmap->bytes)
2214 free_bitmap(ctl, bitmap);
2215
2216 return true;
2217 }
2218
2219 static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2220 struct btrfs_free_space *info,
2221 bool update_stat)
2222 {
2223 struct btrfs_free_space *bitmap;
2224 u64 bitmap_offset;
2225 unsigned long i;
2226 unsigned long j;
2227 unsigned long prev_j;
2228 u64 bytes;
2229
2230 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2231 /* If we're on a boundary, try the previous logical bitmap. */
2232 if (bitmap_offset == info->offset) {
2233 if (info->offset == 0)
2234 return false;
2235 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2236 }
2237
2238 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2239 if (!bitmap)
2240 return false;
2241
2242 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2243 j = 0;
2244 prev_j = (unsigned long)-1;
2245 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2246 if (j > i)
2247 break;
2248 prev_j = j;
2249 }
2250 if (prev_j == i)
2251 return false;
2252
2253 if (prev_j == (unsigned long)-1)
2254 bytes = (i + 1) * ctl->unit;
2255 else
2256 bytes = (i - prev_j) * ctl->unit;
2257
2258 info->offset -= bytes;
2259 info->bytes += bytes;
2260
2261 if (update_stat)
2262 bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2263 else
2264 __bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2265
2266 if (!bitmap->bytes)
2267 free_bitmap(ctl, bitmap);
2268
2269 return true;
2270 }
2271
2272 /*
2273 * We prefer always to allocate from extent entries, both for clustered and
2274 * non-clustered allocation requests. So when attempting to add a new extent
2275 * entry, try to see if there's adjacent free space in bitmap entries, and if
2276 * there is, migrate that space from the bitmaps to the extent.
2277 * Like this we get better chances of satisfying space allocation requests
2278 * because we attempt to satisfy them based on a single cache entry, and never
2279 * on 2 or more entries - even if the entries represent a contiguous free space
2280 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2281 * ends).
2282 */
2283 static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2284 struct btrfs_free_space *info,
2285 bool update_stat)
2286 {
2287 /*
2288 * Only work with disconnected entries, as we can change their offset,
2289 * and must be extent entries.
2290 */
2291 ASSERT(!info->bitmap);
2292 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2293
2294 if (ctl->total_bitmaps > 0) {
2295 bool stole_end;
2296 bool stole_front = false;
2297
2298 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2299 if (ctl->total_bitmaps > 0)
2300 stole_front = steal_from_bitmap_to_front(ctl, info,
2301 update_stat);
2302
2303 if (stole_end || stole_front)
2304 try_merge_free_space(ctl, info, update_stat);
2305 }
2306 }
2307
2308 int __btrfs_add_free_space(struct btrfs_free_space_ctl *ctl,
2309 u64 offset, u64 bytes)
2310 {
2311 struct btrfs_free_space *info;
2312 int ret = 0;
2313
2314 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2315 if (!info)
2316 return -ENOMEM;
2317
2318 info->offset = offset;
2319 info->bytes = bytes;
2320 RB_CLEAR_NODE(&info->offset_index);
2321
2322 spin_lock(&ctl->tree_lock);
2323
2324 if (try_merge_free_space(ctl, info, true))
2325 goto link;
2326
2327 /*
2328 * There was no extent directly to the left or right of this new
2329 * extent then we know we're going to have to allocate a new extent, so
2330 * before we do that see if we need to drop this into a bitmap
2331 */
2332 ret = insert_into_bitmap(ctl, info);
2333 if (ret < 0) {
2334 goto out;
2335 } else if (ret) {
2336 ret = 0;
2337 goto out;
2338 }
2339 link:
2340 /*
2341 * Only steal free space from adjacent bitmaps if we're sure we're not
2342 * going to add the new free space to existing bitmap entries - because
2343 * that would mean unnecessary work that would be reverted. Therefore
2344 * attempt to steal space from bitmaps if we're adding an extent entry.
2345 */
2346 steal_from_bitmap(ctl, info, true);
2347
2348 ret = link_free_space(ctl, info);
2349 if (ret)
2350 kmem_cache_free(btrfs_free_space_cachep, info);
2351 out:
2352 spin_unlock(&ctl->tree_lock);
2353
2354 if (ret) {
2355 printk(KERN_CRIT "BTRFS: unable to add free space :%d\n", ret);
2356 ASSERT(ret != -EEXIST);
2357 }
2358
2359 return ret;
2360 }
2361
2362 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
2363 u64 offset, u64 bytes)
2364 {
2365 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2366 struct btrfs_free_space *info;
2367 int ret;
2368 bool re_search = false;
2369
2370 spin_lock(&ctl->tree_lock);
2371
2372 again:
2373 ret = 0;
2374 if (!bytes)
2375 goto out_lock;
2376
2377 info = tree_search_offset(ctl, offset, 0, 0);
2378 if (!info) {
2379 /*
2380 * oops didn't find an extent that matched the space we wanted
2381 * to remove, look for a bitmap instead
2382 */
2383 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2384 1, 0);
2385 if (!info) {
2386 /*
2387 * If we found a partial bit of our free space in a
2388 * bitmap but then couldn't find the other part this may
2389 * be a problem, so WARN about it.
2390 */
2391 WARN_ON(re_search);
2392 goto out_lock;
2393 }
2394 }
2395
2396 re_search = false;
2397 if (!info->bitmap) {
2398 unlink_free_space(ctl, info);
2399 if (offset == info->offset) {
2400 u64 to_free = min(bytes, info->bytes);
2401
2402 info->bytes -= to_free;
2403 info->offset += to_free;
2404 if (info->bytes) {
2405 ret = link_free_space(ctl, info);
2406 WARN_ON(ret);
2407 } else {
2408 kmem_cache_free(btrfs_free_space_cachep, info);
2409 }
2410
2411 offset += to_free;
2412 bytes -= to_free;
2413 goto again;
2414 } else {
2415 u64 old_end = info->bytes + info->offset;
2416
2417 info->bytes = offset - info->offset;
2418 ret = link_free_space(ctl, info);
2419 WARN_ON(ret);
2420 if (ret)
2421 goto out_lock;
2422
2423 /* Not enough bytes in this entry to satisfy us */
2424 if (old_end < offset + bytes) {
2425 bytes -= old_end - offset;
2426 offset = old_end;
2427 goto again;
2428 } else if (old_end == offset + bytes) {
2429 /* all done */
2430 goto out_lock;
2431 }
2432 spin_unlock(&ctl->tree_lock);
2433
2434 ret = btrfs_add_free_space(block_group, offset + bytes,
2435 old_end - (offset + bytes));
2436 WARN_ON(ret);
2437 goto out;
2438 }
2439 }
2440
2441 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2442 if (ret == -EAGAIN) {
2443 re_search = true;
2444 goto again;
2445 }
2446 out_lock:
2447 spin_unlock(&ctl->tree_lock);
2448 out:
2449 return ret;
2450 }
2451
2452 void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
2453 u64 bytes)
2454 {
2455 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2456 struct btrfs_free_space *info;
2457 struct rb_node *n;
2458 int count = 0;
2459
2460 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2461 info = rb_entry(n, struct btrfs_free_space, offset_index);
2462 if (info->bytes >= bytes && !block_group->ro)
2463 count++;
2464 btrfs_crit(block_group->fs_info,
2465 "entry offset %llu, bytes %llu, bitmap %s",
2466 info->offset, info->bytes,
2467 (info->bitmap) ? "yes" : "no");
2468 }
2469 btrfs_info(block_group->fs_info, "block group has cluster?: %s",
2470 list_empty(&block_group->cluster_list) ? "no" : "yes");
2471 btrfs_info(block_group->fs_info,
2472 "%d blocks of free space at or bigger than bytes is", count);
2473 }
2474
2475 void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
2476 {
2477 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2478
2479 spin_lock_init(&ctl->tree_lock);
2480 ctl->unit = block_group->sectorsize;
2481 ctl->start = block_group->key.objectid;
2482 ctl->private = block_group;
2483 ctl->op = &free_space_op;
2484 INIT_LIST_HEAD(&ctl->trimming_ranges);
2485 mutex_init(&ctl->cache_writeout_mutex);
2486
2487 /*
2488 * we only want to have 32k of ram per block group for keeping
2489 * track of free space, and if we pass 1/2 of that we want to
2490 * start converting things over to using bitmaps
2491 */
2492 ctl->extents_thresh = ((1024 * 32) / 2) /
2493 sizeof(struct btrfs_free_space);
2494 }
2495
2496 /*
2497 * for a given cluster, put all of its extents back into the free
2498 * space cache. If the block group passed doesn't match the block group
2499 * pointed to by the cluster, someone else raced in and freed the
2500 * cluster already. In that case, we just return without changing anything
2501 */
2502 static int
2503 __btrfs_return_cluster_to_free_space(
2504 struct btrfs_block_group_cache *block_group,
2505 struct btrfs_free_cluster *cluster)
2506 {
2507 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2508 struct btrfs_free_space *entry;
2509 struct rb_node *node;
2510
2511 spin_lock(&cluster->lock);
2512 if (cluster->block_group != block_group)
2513 goto out;
2514
2515 cluster->block_group = NULL;
2516 cluster->window_start = 0;
2517 list_del_init(&cluster->block_group_list);
2518
2519 node = rb_first(&cluster->root);
2520 while (node) {
2521 bool bitmap;
2522
2523 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2524 node = rb_next(&entry->offset_index);
2525 rb_erase(&entry->offset_index, &cluster->root);
2526 RB_CLEAR_NODE(&entry->offset_index);
2527
2528 bitmap = (entry->bitmap != NULL);
2529 if (!bitmap) {
2530 try_merge_free_space(ctl, entry, false);
2531 steal_from_bitmap(ctl, entry, false);
2532 }
2533 tree_insert_offset(&ctl->free_space_offset,
2534 entry->offset, &entry->offset_index, bitmap);
2535 }
2536 cluster->root = RB_ROOT;
2537
2538 out:
2539 spin_unlock(&cluster->lock);
2540 btrfs_put_block_group(block_group);
2541 return 0;
2542 }
2543
2544 static void __btrfs_remove_free_space_cache_locked(
2545 struct btrfs_free_space_ctl *ctl)
2546 {
2547 struct btrfs_free_space *info;
2548 struct rb_node *node;
2549
2550 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2551 info = rb_entry(node, struct btrfs_free_space, offset_index);
2552 if (!info->bitmap) {
2553 unlink_free_space(ctl, info);
2554 kmem_cache_free(btrfs_free_space_cachep, info);
2555 } else {
2556 free_bitmap(ctl, info);
2557 }
2558
2559 cond_resched_lock(&ctl->tree_lock);
2560 }
2561 }
2562
2563 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2564 {
2565 spin_lock(&ctl->tree_lock);
2566 __btrfs_remove_free_space_cache_locked(ctl);
2567 spin_unlock(&ctl->tree_lock);
2568 }
2569
2570 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
2571 {
2572 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2573 struct btrfs_free_cluster *cluster;
2574 struct list_head *head;
2575
2576 spin_lock(&ctl->tree_lock);
2577 while ((head = block_group->cluster_list.next) !=
2578 &block_group->cluster_list) {
2579 cluster = list_entry(head, struct btrfs_free_cluster,
2580 block_group_list);
2581
2582 WARN_ON(cluster->block_group != block_group);
2583 __btrfs_return_cluster_to_free_space(block_group, cluster);
2584
2585 cond_resched_lock(&ctl->tree_lock);
2586 }
2587 __btrfs_remove_free_space_cache_locked(ctl);
2588 spin_unlock(&ctl->tree_lock);
2589
2590 }
2591
2592 u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
2593 u64 offset, u64 bytes, u64 empty_size,
2594 u64 *max_extent_size)
2595 {
2596 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2597 struct btrfs_free_space *entry = NULL;
2598 u64 bytes_search = bytes + empty_size;
2599 u64 ret = 0;
2600 u64 align_gap = 0;
2601 u64 align_gap_len = 0;
2602
2603 spin_lock(&ctl->tree_lock);
2604 entry = find_free_space(ctl, &offset, &bytes_search,
2605 block_group->full_stripe_len, max_extent_size);
2606 if (!entry)
2607 goto out;
2608
2609 ret = offset;
2610 if (entry->bitmap) {
2611 bitmap_clear_bits(ctl, entry, offset, bytes);
2612 if (!entry->bytes)
2613 free_bitmap(ctl, entry);
2614 } else {
2615 unlink_free_space(ctl, entry);
2616 align_gap_len = offset - entry->offset;
2617 align_gap = entry->offset;
2618
2619 entry->offset = offset + bytes;
2620 WARN_ON(entry->bytes < bytes + align_gap_len);
2621
2622 entry->bytes -= bytes + align_gap_len;
2623 if (!entry->bytes)
2624 kmem_cache_free(btrfs_free_space_cachep, entry);
2625 else
2626 link_free_space(ctl, entry);
2627 }
2628 out:
2629 spin_unlock(&ctl->tree_lock);
2630
2631 if (align_gap_len)
2632 __btrfs_add_free_space(ctl, align_gap, align_gap_len);
2633 return ret;
2634 }
2635
2636 /*
2637 * given a cluster, put all of its extents back into the free space
2638 * cache. If a block group is passed, this function will only free
2639 * a cluster that belongs to the passed block group.
2640 *
2641 * Otherwise, it'll get a reference on the block group pointed to by the
2642 * cluster and remove the cluster from it.
2643 */
2644 int btrfs_return_cluster_to_free_space(
2645 struct btrfs_block_group_cache *block_group,
2646 struct btrfs_free_cluster *cluster)
2647 {
2648 struct btrfs_free_space_ctl *ctl;
2649 int ret;
2650
2651 /* first, get a safe pointer to the block group */
2652 spin_lock(&cluster->lock);
2653 if (!block_group) {
2654 block_group = cluster->block_group;
2655 if (!block_group) {
2656 spin_unlock(&cluster->lock);
2657 return 0;
2658 }
2659 } else if (cluster->block_group != block_group) {
2660 /* someone else has already freed it don't redo their work */
2661 spin_unlock(&cluster->lock);
2662 return 0;
2663 }
2664 atomic_inc(&block_group->count);
2665 spin_unlock(&cluster->lock);
2666
2667 ctl = block_group->free_space_ctl;
2668
2669 /* now return any extents the cluster had on it */
2670 spin_lock(&ctl->tree_lock);
2671 ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
2672 spin_unlock(&ctl->tree_lock);
2673
2674 /* finally drop our ref */
2675 btrfs_put_block_group(block_group);
2676 return ret;
2677 }
2678
2679 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
2680 struct btrfs_free_cluster *cluster,
2681 struct btrfs_free_space *entry,
2682 u64 bytes, u64 min_start,
2683 u64 *max_extent_size)
2684 {
2685 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2686 int err;
2687 u64 search_start = cluster->window_start;
2688 u64 search_bytes = bytes;
2689 u64 ret = 0;
2690
2691 search_start = min_start;
2692 search_bytes = bytes;
2693
2694 err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
2695 if (err) {
2696 if (search_bytes > *max_extent_size)
2697 *max_extent_size = search_bytes;
2698 return 0;
2699 }
2700
2701 ret = search_start;
2702 __bitmap_clear_bits(ctl, entry, ret, bytes);
2703
2704 return ret;
2705 }
2706
2707 /*
2708 * given a cluster, try to allocate 'bytes' from it, returns 0
2709 * if it couldn't find anything suitably large, or a logical disk offset
2710 * if things worked out
2711 */
2712 u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
2713 struct btrfs_free_cluster *cluster, u64 bytes,
2714 u64 min_start, u64 *max_extent_size)
2715 {
2716 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2717 struct btrfs_free_space *entry = NULL;
2718 struct rb_node *node;
2719 u64 ret = 0;
2720
2721 spin_lock(&cluster->lock);
2722 if (bytes > cluster->max_size)
2723 goto out;
2724
2725 if (cluster->block_group != block_group)
2726 goto out;
2727
2728 node = rb_first(&cluster->root);
2729 if (!node)
2730 goto out;
2731
2732 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2733 while (1) {
2734 if (entry->bytes < bytes && entry->bytes > *max_extent_size)
2735 *max_extent_size = entry->bytes;
2736
2737 if (entry->bytes < bytes ||
2738 (!entry->bitmap && entry->offset < min_start)) {
2739 node = rb_next(&entry->offset_index);
2740 if (!node)
2741 break;
2742 entry = rb_entry(node, struct btrfs_free_space,
2743 offset_index);
2744 continue;
2745 }
2746
2747 if (entry->bitmap) {
2748 ret = btrfs_alloc_from_bitmap(block_group,
2749 cluster, entry, bytes,
2750 cluster->window_start,
2751 max_extent_size);
2752 if (ret == 0) {
2753 node = rb_next(&entry->offset_index);
2754 if (!node)
2755 break;
2756 entry = rb_entry(node, struct btrfs_free_space,
2757 offset_index);
2758 continue;
2759 }
2760 cluster->window_start += bytes;
2761 } else {
2762 ret = entry->offset;
2763
2764 entry->offset += bytes;
2765 entry->bytes -= bytes;
2766 }
2767
2768 if (entry->bytes == 0)
2769 rb_erase(&entry->offset_index, &cluster->root);
2770 break;
2771 }
2772 out:
2773 spin_unlock(&cluster->lock);
2774
2775 if (!ret)
2776 return 0;
2777
2778 spin_lock(&ctl->tree_lock);
2779
2780 ctl->free_space -= bytes;
2781 if (entry->bytes == 0) {
2782 ctl->free_extents--;
2783 if (entry->bitmap) {
2784 kfree(entry->bitmap);
2785 ctl->total_bitmaps--;
2786 ctl->op->recalc_thresholds(ctl);
2787 }
2788 kmem_cache_free(btrfs_free_space_cachep, entry);
2789 }
2790
2791 spin_unlock(&ctl->tree_lock);
2792
2793 return ret;
2794 }
2795
2796 static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
2797 struct btrfs_free_space *entry,
2798 struct btrfs_free_cluster *cluster,
2799 u64 offset, u64 bytes,
2800 u64 cont1_bytes, u64 min_bytes)
2801 {
2802 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2803 unsigned long next_zero;
2804 unsigned long i;
2805 unsigned long want_bits;
2806 unsigned long min_bits;
2807 unsigned long found_bits;
2808 unsigned long max_bits = 0;
2809 unsigned long start = 0;
2810 unsigned long total_found = 0;
2811 int ret;
2812
2813 i = offset_to_bit(entry->offset, ctl->unit,
2814 max_t(u64, offset, entry->offset));
2815 want_bits = bytes_to_bits(bytes, ctl->unit);
2816 min_bits = bytes_to_bits(min_bytes, ctl->unit);
2817
2818 /*
2819 * Don't bother looking for a cluster in this bitmap if it's heavily
2820 * fragmented.
2821 */
2822 if (entry->max_extent_size &&
2823 entry->max_extent_size < cont1_bytes)
2824 return -ENOSPC;
2825 again:
2826 found_bits = 0;
2827 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
2828 next_zero = find_next_zero_bit(entry->bitmap,
2829 BITS_PER_BITMAP, i);
2830 if (next_zero - i >= min_bits) {
2831 found_bits = next_zero - i;
2832 if (found_bits > max_bits)
2833 max_bits = found_bits;
2834 break;
2835 }
2836 if (next_zero - i > max_bits)
2837 max_bits = next_zero - i;
2838 i = next_zero;
2839 }
2840
2841 if (!found_bits) {
2842 entry->max_extent_size = (u64)max_bits * ctl->unit;
2843 return -ENOSPC;
2844 }
2845
2846 if (!total_found) {
2847 start = i;
2848 cluster->max_size = 0;
2849 }
2850
2851 total_found += found_bits;
2852
2853 if (cluster->max_size < found_bits * ctl->unit)
2854 cluster->max_size = found_bits * ctl->unit;
2855
2856 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
2857 i = next_zero + 1;
2858 goto again;
2859 }
2860
2861 cluster->window_start = start * ctl->unit + entry->offset;
2862 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2863 ret = tree_insert_offset(&cluster->root, entry->offset,
2864 &entry->offset_index, 1);
2865 ASSERT(!ret); /* -EEXIST; Logic error */
2866
2867 trace_btrfs_setup_cluster(block_group, cluster,
2868 total_found * ctl->unit, 1);
2869 return 0;
2870 }
2871
2872 /*
2873 * This searches the block group for just extents to fill the cluster with.
2874 * Try to find a cluster with at least bytes total bytes, at least one
2875 * extent of cont1_bytes, and other clusters of at least min_bytes.
2876 */
2877 static noinline int
2878 setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
2879 struct btrfs_free_cluster *cluster,
2880 struct list_head *bitmaps, u64 offset, u64 bytes,
2881 u64 cont1_bytes, u64 min_bytes)
2882 {
2883 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2884 struct btrfs_free_space *first = NULL;
2885 struct btrfs_free_space *entry = NULL;
2886 struct btrfs_free_space *last;
2887 struct rb_node *node;
2888 u64 window_free;
2889 u64 max_extent;
2890 u64 total_size = 0;
2891
2892 entry = tree_search_offset(ctl, offset, 0, 1);
2893 if (!entry)
2894 return -ENOSPC;
2895
2896 /*
2897 * We don't want bitmaps, so just move along until we find a normal
2898 * extent entry.
2899 */
2900 while (entry->bitmap || entry->bytes < min_bytes) {
2901 if (entry->bitmap && list_empty(&entry->list))
2902 list_add_tail(&entry->list, bitmaps);
2903 node = rb_next(&entry->offset_index);
2904 if (!node)
2905 return -ENOSPC;
2906 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2907 }
2908
2909 window_free = entry->bytes;
2910 max_extent = entry->bytes;
2911 first = entry;
2912 last = entry;
2913
2914 for (node = rb_next(&entry->offset_index); node;
2915 node = rb_next(&entry->offset_index)) {
2916 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2917
2918 if (entry->bitmap) {
2919 if (list_empty(&entry->list))
2920 list_add_tail(&entry->list, bitmaps);
2921 continue;
2922 }
2923
2924 if (entry->bytes < min_bytes)
2925 continue;
2926
2927 last = entry;
2928 window_free += entry->bytes;
2929 if (entry->bytes > max_extent)
2930 max_extent = entry->bytes;
2931 }
2932
2933 if (window_free < bytes || max_extent < cont1_bytes)
2934 return -ENOSPC;
2935
2936 cluster->window_start = first->offset;
2937
2938 node = &first->offset_index;
2939
2940 /*
2941 * now we've found our entries, pull them out of the free space
2942 * cache and put them into the cluster rbtree
2943 */
2944 do {
2945 int ret;
2946
2947 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2948 node = rb_next(&entry->offset_index);
2949 if (entry->bitmap || entry->bytes < min_bytes)
2950 continue;
2951
2952 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2953 ret = tree_insert_offset(&cluster->root, entry->offset,
2954 &entry->offset_index, 0);
2955 total_size += entry->bytes;
2956 ASSERT(!ret); /* -EEXIST; Logic error */
2957 } while (node && entry != last);
2958
2959 cluster->max_size = max_extent;
2960 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
2961 return 0;
2962 }
2963
2964 /*
2965 * This specifically looks for bitmaps that may work in the cluster, we assume
2966 * that we have already failed to find extents that will work.
2967 */
2968 static noinline int
2969 setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
2970 struct btrfs_free_cluster *cluster,
2971 struct list_head *bitmaps, u64 offset, u64 bytes,
2972 u64 cont1_bytes, u64 min_bytes)
2973 {
2974 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2975 struct btrfs_free_space *entry = NULL;
2976 int ret = -ENOSPC;
2977 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
2978
2979 if (ctl->total_bitmaps == 0)
2980 return -ENOSPC;
2981
2982 /*
2983 * The bitmap that covers offset won't be in the list unless offset
2984 * is just its start offset.
2985 */
2986 if (!list_empty(bitmaps))
2987 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
2988
2989 if (!entry || entry->offset != bitmap_offset) {
2990 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
2991 if (entry && list_empty(&entry->list))
2992 list_add(&entry->list, bitmaps);
2993 }
2994
2995 list_for_each_entry(entry, bitmaps, list) {
2996 if (entry->bytes < bytes)
2997 continue;
2998 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
2999 bytes, cont1_bytes, min_bytes);
3000 if (!ret)
3001 return 0;
3002 }
3003
3004 /*
3005 * The bitmaps list has all the bitmaps that record free space
3006 * starting after offset, so no more search is required.
3007 */
3008 return -ENOSPC;
3009 }
3010
3011 /*
3012 * here we try to find a cluster of blocks in a block group. The goal
3013 * is to find at least bytes+empty_size.
3014 * We might not find them all in one contiguous area.
3015 *
3016 * returns zero and sets up cluster if things worked out, otherwise
3017 * it returns -enospc
3018 */
3019 int btrfs_find_space_cluster(struct btrfs_root *root,
3020 struct btrfs_block_group_cache *block_group,
3021 struct btrfs_free_cluster *cluster,
3022 u64 offset, u64 bytes, u64 empty_size)
3023 {
3024 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3025 struct btrfs_free_space *entry, *tmp;
3026 LIST_HEAD(bitmaps);
3027 u64 min_bytes;
3028 u64 cont1_bytes;
3029 int ret;
3030
3031 /*
3032 * Choose the minimum extent size we'll require for this
3033 * cluster. For SSD_SPREAD, don't allow any fragmentation.
3034 * For metadata, allow allocates with smaller extents. For
3035 * data, keep it dense.
3036 */
3037 if (btrfs_test_opt(root, SSD_SPREAD)) {
3038 cont1_bytes = min_bytes = bytes + empty_size;
3039 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
3040 cont1_bytes = bytes;
3041 min_bytes = block_group->sectorsize;
3042 } else {
3043 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
3044 min_bytes = block_group->sectorsize;
3045 }
3046
3047 spin_lock(&ctl->tree_lock);
3048
3049 /*
3050 * If we know we don't have enough space to make a cluster don't even
3051 * bother doing all the work to try and find one.
3052 */
3053 if (ctl->free_space < bytes) {
3054 spin_unlock(&ctl->tree_lock);
3055 return -ENOSPC;
3056 }
3057
3058 spin_lock(&cluster->lock);
3059
3060 /* someone already found a cluster, hooray */
3061 if (cluster->block_group) {
3062 ret = 0;
3063 goto out;
3064 }
3065
3066 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
3067 min_bytes);
3068
3069 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
3070 bytes + empty_size,
3071 cont1_bytes, min_bytes);
3072 if (ret)
3073 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
3074 offset, bytes + empty_size,
3075 cont1_bytes, min_bytes);
3076
3077 /* Clear our temporary list */
3078 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
3079 list_del_init(&entry->list);
3080
3081 if (!ret) {
3082 atomic_inc(&block_group->count);
3083 list_add_tail(&cluster->block_group_list,
3084 &block_group->cluster_list);
3085 cluster->block_group = block_group;
3086 } else {
3087 trace_btrfs_failed_cluster_setup(block_group);
3088 }
3089 out:
3090 spin_unlock(&cluster->lock);
3091 spin_unlock(&ctl->tree_lock);
3092
3093 return ret;
3094 }
3095
3096 /*
3097 * simple code to zero out a cluster
3098 */
3099 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
3100 {
3101 spin_lock_init(&cluster->lock);
3102 spin_lock_init(&cluster->refill_lock);
3103 cluster->root = RB_ROOT;
3104 cluster->max_size = 0;
3105 cluster->fragmented = false;
3106 INIT_LIST_HEAD(&cluster->block_group_list);
3107 cluster->block_group = NULL;
3108 }
3109
3110 static int do_trimming(struct btrfs_block_group_cache *block_group,
3111 u64 *total_trimmed, u64 start, u64 bytes,
3112 u64 reserved_start, u64 reserved_bytes,
3113 struct btrfs_trim_range *trim_entry)
3114 {
3115 struct btrfs_space_info *space_info = block_group->space_info;
3116 struct btrfs_fs_info *fs_info = block_group->fs_info;
3117 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3118 int ret;
3119 int update = 0;
3120 u64 trimmed = 0;
3121
3122 spin_lock(&space_info->lock);
3123 spin_lock(&block_group->lock);
3124 if (!block_group->ro) {
3125 block_group->reserved += reserved_bytes;
3126 space_info->bytes_reserved += reserved_bytes;
3127 update = 1;
3128 }
3129 spin_unlock(&block_group->lock);
3130 spin_unlock(&space_info->lock);
3131
3132 ret = btrfs_discard_extent(fs_info->extent_root,
3133 start, bytes, &trimmed);
3134 if (!ret)
3135 *total_trimmed += trimmed;
3136
3137 mutex_lock(&ctl->cache_writeout_mutex);
3138 btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
3139 list_del(&trim_entry->list);
3140 mutex_unlock(&ctl->cache_writeout_mutex);
3141
3142 if (update) {
3143 spin_lock(&space_info->lock);
3144 spin_lock(&block_group->lock);
3145 if (block_group->ro)
3146 space_info->bytes_readonly += reserved_bytes;
3147 block_group->reserved -= reserved_bytes;
3148 space_info->bytes_reserved -= reserved_bytes;
3149 spin_unlock(&space_info->lock);
3150 spin_unlock(&block_group->lock);
3151 }
3152
3153 return ret;
3154 }
3155
3156 static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
3157 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3158 {
3159 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3160 struct btrfs_free_space *entry;
3161 struct rb_node *node;
3162 int ret = 0;
3163 u64 extent_start;
3164 u64 extent_bytes;
3165 u64 bytes;
3166
3167 while (start < end) {
3168 struct btrfs_trim_range trim_entry;
3169
3170 mutex_lock(&ctl->cache_writeout_mutex);
3171 spin_lock(&ctl->tree_lock);
3172
3173 if (ctl->free_space < minlen) {
3174 spin_unlock(&ctl->tree_lock);
3175 mutex_unlock(&ctl->cache_writeout_mutex);
3176 break;
3177 }
3178
3179 entry = tree_search_offset(ctl, start, 0, 1);
3180 if (!entry) {
3181 spin_unlock(&ctl->tree_lock);
3182 mutex_unlock(&ctl->cache_writeout_mutex);
3183 break;
3184 }
3185
3186 /* skip bitmaps */
3187 while (entry->bitmap) {
3188 node = rb_next(&entry->offset_index);
3189 if (!node) {
3190 spin_unlock(&ctl->tree_lock);
3191 mutex_unlock(&ctl->cache_writeout_mutex);
3192 goto out;
3193 }
3194 entry = rb_entry(node, struct btrfs_free_space,
3195 offset_index);
3196 }
3197
3198 if (entry->offset >= end) {
3199 spin_unlock(&ctl->tree_lock);
3200 mutex_unlock(&ctl->cache_writeout_mutex);
3201 break;
3202 }
3203
3204 extent_start = entry->offset;
3205 extent_bytes = entry->bytes;
3206 start = max(start, extent_start);
3207 bytes = min(extent_start + extent_bytes, end) - start;
3208 if (bytes < minlen) {
3209 spin_unlock(&ctl->tree_lock);
3210 mutex_unlock(&ctl->cache_writeout_mutex);
3211 goto next;
3212 }
3213
3214 unlink_free_space(ctl, entry);
3215 kmem_cache_free(btrfs_free_space_cachep, entry);
3216
3217 spin_unlock(&ctl->tree_lock);
3218 trim_entry.start = extent_start;
3219 trim_entry.bytes = extent_bytes;
3220 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3221 mutex_unlock(&ctl->cache_writeout_mutex);
3222
3223 ret = do_trimming(block_group, total_trimmed, start, bytes,
3224 extent_start, extent_bytes, &trim_entry);
3225 if (ret)
3226 break;
3227 next:
3228 start += bytes;
3229
3230 if (fatal_signal_pending(current)) {
3231 ret = -ERESTARTSYS;
3232 break;
3233 }
3234
3235 cond_resched();
3236 }
3237 out:
3238 return ret;
3239 }
3240
3241 static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
3242 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3243 {
3244 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3245 struct btrfs_free_space *entry;
3246 int ret = 0;
3247 int ret2;
3248 u64 bytes;
3249 u64 offset = offset_to_bitmap(ctl, start);
3250
3251 while (offset < end) {
3252 bool next_bitmap = false;
3253 struct btrfs_trim_range trim_entry;
3254
3255 mutex_lock(&ctl->cache_writeout_mutex);
3256 spin_lock(&ctl->tree_lock);
3257
3258 if (ctl->free_space < minlen) {
3259 spin_unlock(&ctl->tree_lock);
3260 mutex_unlock(&ctl->cache_writeout_mutex);
3261 break;
3262 }
3263
3264 entry = tree_search_offset(ctl, offset, 1, 0);
3265 if (!entry) {
3266 spin_unlock(&ctl->tree_lock);
3267 mutex_unlock(&ctl->cache_writeout_mutex);
3268 next_bitmap = true;
3269 goto next;
3270 }
3271
3272 bytes = minlen;
3273 ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
3274 if (ret2 || start >= end) {
3275 spin_unlock(&ctl->tree_lock);
3276 mutex_unlock(&ctl->cache_writeout_mutex);
3277 next_bitmap = true;
3278 goto next;
3279 }
3280
3281 bytes = min(bytes, end - start);
3282 if (bytes < minlen) {
3283 spin_unlock(&ctl->tree_lock);
3284 mutex_unlock(&ctl->cache_writeout_mutex);
3285 goto next;
3286 }
3287
3288 bitmap_clear_bits(ctl, entry, start, bytes);
3289 if (entry->bytes == 0)
3290 free_bitmap(ctl, entry);
3291
3292 spin_unlock(&ctl->tree_lock);
3293 trim_entry.start = start;
3294 trim_entry.bytes = bytes;
3295 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3296 mutex_unlock(&ctl->cache_writeout_mutex);
3297
3298 ret = do_trimming(block_group, total_trimmed, start, bytes,
3299 start, bytes, &trim_entry);
3300 if (ret)
3301 break;
3302 next:
3303 if (next_bitmap) {
3304 offset += BITS_PER_BITMAP * ctl->unit;
3305 } else {
3306 start += bytes;
3307 if (start >= offset + BITS_PER_BITMAP * ctl->unit)
3308 offset += BITS_PER_BITMAP * ctl->unit;
3309 }
3310
3311 if (fatal_signal_pending(current)) {
3312 ret = -ERESTARTSYS;
3313 break;
3314 }
3315
3316 cond_resched();
3317 }
3318
3319 return ret;
3320 }
3321
3322 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache)
3323 {
3324 atomic_inc(&cache->trimming);
3325 }
3326
3327 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *block_group)
3328 {
3329 struct extent_map_tree *em_tree;
3330 struct extent_map *em;
3331 bool cleanup;
3332
3333 spin_lock(&block_group->lock);
3334 cleanup = (atomic_dec_and_test(&block_group->trimming) &&
3335 block_group->removed);
3336 spin_unlock(&block_group->lock);
3337
3338 if (cleanup) {
3339 lock_chunks(block_group->fs_info->chunk_root);
3340 em_tree = &block_group->fs_info->mapping_tree.map_tree;
3341 write_lock(&em_tree->lock);
3342 em = lookup_extent_mapping(em_tree, block_group->key.objectid,
3343 1);
3344 BUG_ON(!em); /* logic error, can't happen */
3345 /*
3346 * remove_extent_mapping() will delete us from the pinned_chunks
3347 * list, which is protected by the chunk mutex.
3348 */
3349 remove_extent_mapping(em_tree, em);
3350 write_unlock(&em_tree->lock);
3351 unlock_chunks(block_group->fs_info->chunk_root);
3352
3353 /* once for us and once for the tree */
3354 free_extent_map(em);
3355 free_extent_map(em);
3356
3357 /*
3358 * We've left one free space entry and other tasks trimming
3359 * this block group have left 1 entry each one. Free them.
3360 */
3361 __btrfs_remove_free_space_cache(block_group->free_space_ctl);
3362 }
3363 }
3364
3365 int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
3366 u64 *trimmed, u64 start, u64 end, u64 minlen)
3367 {
3368 int ret;
3369
3370 *trimmed = 0;
3371
3372 spin_lock(&block_group->lock);
3373 if (block_group->removed) {
3374 spin_unlock(&block_group->lock);
3375 return 0;
3376 }
3377 btrfs_get_block_group_trimming(block_group);
3378 spin_unlock(&block_group->lock);
3379
3380 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
3381 if (ret)
3382 goto out;
3383
3384 ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
3385 out:
3386 btrfs_put_block_group_trimming(block_group);
3387 return ret;
3388 }
3389
3390 /*
3391 * Find the left-most item in the cache tree, and then return the
3392 * smallest inode number in the item.
3393 *
3394 * Note: the returned inode number may not be the smallest one in
3395 * the tree, if the left-most item is a bitmap.
3396 */
3397 u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
3398 {
3399 struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
3400 struct btrfs_free_space *entry = NULL;
3401 u64 ino = 0;
3402
3403 spin_lock(&ctl->tree_lock);
3404
3405 if (RB_EMPTY_ROOT(&ctl->free_space_offset))
3406 goto out;
3407
3408 entry = rb_entry(rb_first(&ctl->free_space_offset),
3409 struct btrfs_free_space, offset_index);
3410
3411 if (!entry->bitmap) {
3412 ino = entry->offset;
3413
3414 unlink_free_space(ctl, entry);
3415 entry->offset++;
3416 entry->bytes--;
3417 if (!entry->bytes)
3418 kmem_cache_free(btrfs_free_space_cachep, entry);
3419 else
3420 link_free_space(ctl, entry);
3421 } else {
3422 u64 offset = 0;
3423 u64 count = 1;
3424 int ret;
3425
3426 ret = search_bitmap(ctl, entry, &offset, &count, true);
3427 /* Logic error; Should be empty if it can't find anything */
3428 ASSERT(!ret);
3429
3430 ino = offset;
3431 bitmap_clear_bits(ctl, entry, offset, 1);
3432 if (entry->bytes == 0)
3433 free_bitmap(ctl, entry);
3434 }
3435 out:
3436 spin_unlock(&ctl->tree_lock);
3437
3438 return ino;
3439 }
3440
3441 struct inode *lookup_free_ino_inode(struct btrfs_root *root,
3442 struct btrfs_path *path)
3443 {
3444 struct inode *inode = NULL;
3445
3446 spin_lock(&root->ino_cache_lock);
3447 if (root->ino_cache_inode)
3448 inode = igrab(root->ino_cache_inode);
3449 spin_unlock(&root->ino_cache_lock);
3450 if (inode)
3451 return inode;
3452
3453 inode = __lookup_free_space_inode(root, path, 0);
3454 if (IS_ERR(inode))
3455 return inode;
3456
3457 spin_lock(&root->ino_cache_lock);
3458 if (!btrfs_fs_closing(root->fs_info))
3459 root->ino_cache_inode = igrab(inode);
3460 spin_unlock(&root->ino_cache_lock);
3461
3462 return inode;
3463 }
3464
3465 int create_free_ino_inode(struct btrfs_root *root,
3466 struct btrfs_trans_handle *trans,
3467 struct btrfs_path *path)
3468 {
3469 return __create_free_space_inode(root, trans, path,
3470 BTRFS_FREE_INO_OBJECTID, 0);
3471 }
3472
3473 int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3474 {
3475 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3476 struct btrfs_path *path;
3477 struct inode *inode;
3478 int ret = 0;
3479 u64 root_gen = btrfs_root_generation(&root->root_item);
3480
3481 if (!btrfs_test_opt(root, INODE_MAP_CACHE))
3482 return 0;
3483
3484 /*
3485 * If we're unmounting then just return, since this does a search on the
3486 * normal root and not the commit root and we could deadlock.
3487 */
3488 if (btrfs_fs_closing(fs_info))
3489 return 0;
3490
3491 path = btrfs_alloc_path();
3492 if (!path)
3493 return 0;
3494
3495 inode = lookup_free_ino_inode(root, path);
3496 if (IS_ERR(inode))
3497 goto out;
3498
3499 if (root_gen != BTRFS_I(inode)->generation)
3500 goto out_put;
3501
3502 ret = __load_free_space_cache(root, inode, ctl, path, 0);
3503
3504 if (ret < 0)
3505 btrfs_err(fs_info,
3506 "failed to load free ino cache for root %llu",
3507 root->root_key.objectid);
3508 out_put:
3509 iput(inode);
3510 out:
3511 btrfs_free_path(path);
3512 return ret;
3513 }
3514
3515 int btrfs_write_out_ino_cache(struct btrfs_root *root,
3516 struct btrfs_trans_handle *trans,
3517 struct btrfs_path *path,
3518 struct inode *inode)
3519 {
3520 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3521 int ret;
3522 struct btrfs_io_ctl io_ctl;
3523 bool release_metadata = true;
3524
3525 if (!btrfs_test_opt(root, INODE_MAP_CACHE))
3526 return 0;
3527
3528 memset(&io_ctl, 0, sizeof(io_ctl));
3529 ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl,
3530 trans, path, 0);
3531 if (!ret) {
3532 /*
3533 * At this point writepages() didn't error out, so our metadata
3534 * reservation is released when the writeback finishes, at
3535 * inode.c:btrfs_finish_ordered_io(), regardless of it finishing
3536 * with or without an error.
3537 */
3538 release_metadata = false;
3539 ret = btrfs_wait_cache_io(root, trans, NULL, &io_ctl, path, 0);
3540 }
3541
3542 if (ret) {
3543 if (release_metadata)
3544 btrfs_delalloc_release_metadata(inode, inode->i_size);
3545 #ifdef DEBUG
3546 btrfs_err(root->fs_info,
3547 "failed to write free ino cache for root %llu",
3548 root->root_key.objectid);
3549 #endif
3550 }
3551
3552 return ret;
3553 }
3554
3555 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3556 /*
3557 * Use this if you need to make a bitmap or extent entry specifically, it
3558 * doesn't do any of the merging that add_free_space does, this acts a lot like
3559 * how the free space cache loading stuff works, so you can get really weird
3560 * configurations.
3561 */
3562 int test_add_free_space_entry(struct btrfs_block_group_cache *cache,
3563 u64 offset, u64 bytes, bool bitmap)
3564 {
3565 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3566 struct btrfs_free_space *info = NULL, *bitmap_info;
3567 void *map = NULL;
3568 u64 bytes_added;
3569 int ret;
3570
3571 again:
3572 if (!info) {
3573 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
3574 if (!info)
3575 return -ENOMEM;
3576 }
3577
3578 if (!bitmap) {
3579 spin_lock(&ctl->tree_lock);
3580 info->offset = offset;
3581 info->bytes = bytes;
3582 info->max_extent_size = 0;
3583 ret = link_free_space(ctl, info);
3584 spin_unlock(&ctl->tree_lock);
3585 if (ret)
3586 kmem_cache_free(btrfs_free_space_cachep, info);
3587 return ret;
3588 }
3589
3590 if (!map) {
3591 map = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
3592 if (!map) {
3593 kmem_cache_free(btrfs_free_space_cachep, info);
3594 return -ENOMEM;
3595 }
3596 }
3597
3598 spin_lock(&ctl->tree_lock);
3599 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3600 1, 0);
3601 if (!bitmap_info) {
3602 info->bitmap = map;
3603 map = NULL;
3604 add_new_bitmap(ctl, info, offset);
3605 bitmap_info = info;
3606 info = NULL;
3607 }
3608
3609 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
3610
3611 bytes -= bytes_added;
3612 offset += bytes_added;
3613 spin_unlock(&ctl->tree_lock);
3614
3615 if (bytes)
3616 goto again;
3617
3618 if (info)
3619 kmem_cache_free(btrfs_free_space_cachep, info);
3620 if (map)
3621 kfree(map);
3622 return 0;
3623 }
3624
3625 /*
3626 * Checks to see if the given range is in the free space cache. This is really
3627 * just used to check the absence of space, so if there is free space in the
3628 * range at all we will return 1.
3629 */
3630 int test_check_exists(struct btrfs_block_group_cache *cache,
3631 u64 offset, u64 bytes)
3632 {
3633 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3634 struct btrfs_free_space *info;
3635 int ret = 0;
3636
3637 spin_lock(&ctl->tree_lock);
3638 info = tree_search_offset(ctl, offset, 0, 0);
3639 if (!info) {
3640 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3641 1, 0);
3642 if (!info)
3643 goto out;
3644 }
3645
3646 have_info:
3647 if (info->bitmap) {
3648 u64 bit_off, bit_bytes;
3649 struct rb_node *n;
3650 struct btrfs_free_space *tmp;
3651
3652 bit_off = offset;
3653 bit_bytes = ctl->unit;
3654 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
3655 if (!ret) {
3656 if (bit_off == offset) {
3657 ret = 1;
3658 goto out;
3659 } else if (bit_off > offset &&
3660 offset + bytes > bit_off) {
3661 ret = 1;
3662 goto out;
3663 }
3664 }
3665
3666 n = rb_prev(&info->offset_index);
3667 while (n) {
3668 tmp = rb_entry(n, struct btrfs_free_space,
3669 offset_index);
3670 if (tmp->offset + tmp->bytes < offset)
3671 break;
3672 if (offset + bytes < tmp->offset) {
3673 n = rb_prev(&info->offset_index);
3674 continue;
3675 }
3676 info = tmp;
3677 goto have_info;
3678 }
3679
3680 n = rb_next(&info->offset_index);
3681 while (n) {
3682 tmp = rb_entry(n, struct btrfs_free_space,
3683 offset_index);
3684 if (offset + bytes < tmp->offset)
3685 break;
3686 if (tmp->offset + tmp->bytes < offset) {
3687 n = rb_next(&info->offset_index);
3688 continue;
3689 }
3690 info = tmp;
3691 goto have_info;
3692 }
3693
3694 ret = 0;
3695 goto out;
3696 }
3697
3698 if (info->offset == offset) {
3699 ret = 1;
3700 goto out;
3701 }
3702
3703 if (offset > info->offset && offset < info->offset + info->bytes)
3704 ret = 1;
3705 out:
3706 spin_unlock(&ctl->tree_lock);
3707 return ret;
3708 }
3709 #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
Linux with added FPC-III support