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xtensa: fix type conversion in __get_user_[no]check
[linux/fpc-iii.git] / fs / btrfs / free-space-cache.c
blobd54dcd0ab23058cc8fad6ef093ac0a552f00577a
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2008 Red Hat. All rights reserved.
4 */
5
6 #include <linux/pagemap.h>
7 #include <linux/sched.h>
8 #include <linux/sched/signal.h>
9 #include <linux/slab.h>
10 #include <linux/math64.h>
11 #include <linux/ratelimit.h>
12 #include <linux/error-injection.h>
13 #include <linux/sched/mm.h>
14 #include "ctree.h"
15 #include "free-space-cache.h"
16 #include "transaction.h"
17 #include "disk-io.h"
18 #include "extent_io.h"
19 #include "inode-map.h"
20 #include "volumes.h"
21 #include "space-info.h"
22 #include "delalloc-space.h"
23 #include "block-group.h"
24
25 #define BITS_PER_BITMAP (PAGE_SIZE * 8UL)
26 #define MAX_CACHE_BYTES_PER_GIG SZ_32K
27
28 struct btrfs_trim_range {
29 u64 start;
30 u64 bytes;
31 struct list_head list;
32 };
33
34 static int link_free_space(struct btrfs_free_space_ctl *ctl,
35 struct btrfs_free_space *info);
36 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
37 struct btrfs_free_space *info);
38 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
39 struct btrfs_trans_handle *trans,
40 struct btrfs_io_ctl *io_ctl,
41 struct btrfs_path *path);
42
43 static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
44 struct btrfs_path *path,
45 u64 offset)
46 {
47 struct btrfs_fs_info *fs_info = root->fs_info;
48 struct btrfs_key key;
49 struct btrfs_key location;
50 struct btrfs_disk_key disk_key;
51 struct btrfs_free_space_header *header;
52 struct extent_buffer *leaf;
53 struct inode *inode = NULL;
54 unsigned nofs_flag;
55 int ret;
56
57 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
58 key.offset = offset;
59 key.type = 0;
60
61 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
62 if (ret < 0)
63 return ERR_PTR(ret);
64 if (ret > 0) {
65 btrfs_release_path(path);
66 return ERR_PTR(-ENOENT);
67 }
68
69 leaf = path->nodes[0];
70 header = btrfs_item_ptr(leaf, path->slots[0],
71 struct btrfs_free_space_header);
72 btrfs_free_space_key(leaf, header, &disk_key);
73 btrfs_disk_key_to_cpu(&location, &disk_key);
74 btrfs_release_path(path);
75
76 /*
77 * We are often under a trans handle at this point, so we need to make
78 * sure NOFS is set to keep us from deadlocking.
79 */
80 nofs_flag = memalloc_nofs_save();
81 inode = btrfs_iget_path(fs_info->sb, &location, root, NULL, path);
82 btrfs_release_path(path);
83 memalloc_nofs_restore(nofs_flag);
84 if (IS_ERR(inode))
85 return inode;
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(
95 struct btrfs_block_group_cache *block_group,
96 struct btrfs_path *path)
97 {
98 struct btrfs_fs_info *fs_info = block_group->fs_info;
99 struct inode *inode = NULL;
100 u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
101
102 spin_lock(&block_group->lock);
103 if (block_group->inode)
104 inode = igrab(block_group->inode);
105 spin_unlock(&block_group->lock);
106 if (inode)
107 return inode;
108
109 inode = __lookup_free_space_inode(fs_info->tree_root, path,
110 block_group->key.objectid);
111 if (IS_ERR(inode))
112 return inode;
113
114 spin_lock(&block_group->lock);
115 if (!((BTRFS_I(inode)->flags & flags) == flags)) {
116 btrfs_info(fs_info, "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 memzero_extent_buffer(leaf, (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 memzero_extent_buffer(leaf, (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_trans_handle *trans,
193 struct btrfs_block_group_cache *block_group,
194 struct btrfs_path *path)
195 {
196 int ret;
197 u64 ino;
198
199 ret = btrfs_find_free_objectid(trans->fs_info->tree_root, &ino);
200 if (ret < 0)
201 return ret;
202
203 return __create_free_space_inode(trans->fs_info->tree_root, trans, path,
204 ino, block_group->key.objectid);
205 }
206
207 int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
208 struct btrfs_block_rsv *rsv)
209 {
210 u64 needed_bytes;
211 int ret;
212
213 /* 1 for slack space, 1 for updating the inode */
214 needed_bytes = btrfs_calc_insert_metadata_size(fs_info, 1) +
215 btrfs_calc_metadata_size(fs_info, 1);
216
217 spin_lock(&rsv->lock);
218 if (rsv->reserved < needed_bytes)
219 ret = -ENOSPC;
220 else
221 ret = 0;
222 spin_unlock(&rsv->lock);
223 return ret;
224 }
225
226 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
227 struct btrfs_block_group_cache *block_group,
228 struct inode *inode)
229 {
230 struct btrfs_root *root = BTRFS_I(inode)->root;
231 int ret = 0;
232 bool locked = false;
233
234 if (block_group) {
235 struct btrfs_path *path = btrfs_alloc_path();
236
237 if (!path) {
238 ret = -ENOMEM;
239 goto fail;
240 }
241 locked = true;
242 mutex_lock(&trans->transaction->cache_write_mutex);
243 if (!list_empty(&block_group->io_list)) {
244 list_del_init(&block_group->io_list);
245
246 btrfs_wait_cache_io(trans, block_group, path);
247 btrfs_put_block_group(block_group);
248 }
249
250 /*
251 * now that we've truncated the cache away, its no longer
252 * setup or written
253 */
254 spin_lock(&block_group->lock);
255 block_group->disk_cache_state = BTRFS_DC_CLEAR;
256 spin_unlock(&block_group->lock);
257 btrfs_free_path(path);
258 }
259
260 btrfs_i_size_write(BTRFS_I(inode), 0);
261 truncate_pagecache(inode, 0);
262
263 /*
264 * We skip the throttling logic for free space cache inodes, so we don't
265 * need to check for -EAGAIN.
266 */
267 ret = btrfs_truncate_inode_items(trans, root, inode,
268 0, BTRFS_EXTENT_DATA_KEY);
269 if (ret)
270 goto fail;
271
272 ret = btrfs_update_inode(trans, root, inode);
273
274 fail:
275 if (locked)
276 mutex_unlock(&trans->transaction->cache_write_mutex);
277 if (ret)
278 btrfs_abort_transaction(trans, ret);
279
280 return ret;
281 }
282
283 static void readahead_cache(struct inode *inode)
284 {
285 struct file_ra_state *ra;
286 unsigned long last_index;
287
288 ra = kzalloc(sizeof(*ra), GFP_NOFS);
289 if (!ra)
290 return;
291
292 file_ra_state_init(ra, inode->i_mapping);
293 last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
294
295 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
296
297 kfree(ra);
298 }
299
300 static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
301 int write)
302 {
303 int num_pages;
304 int check_crcs = 0;
305
306 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
307
308 if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FREE_INO_OBJECTID)
309 check_crcs = 1;
310
311 /* Make sure we can fit our crcs and generation into the first page */
312 if (write && check_crcs &&
313 (num_pages * sizeof(u32) + sizeof(u64)) > PAGE_SIZE)
314 return -ENOSPC;
315
316 memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
317
318 io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
319 if (!io_ctl->pages)
320 return -ENOMEM;
321
322 io_ctl->num_pages = num_pages;
323 io_ctl->fs_info = btrfs_sb(inode->i_sb);
324 io_ctl->check_crcs = check_crcs;
325 io_ctl->inode = inode;
326
327 return 0;
328 }
329 ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO);
330
331 static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
332 {
333 kfree(io_ctl->pages);
334 io_ctl->pages = NULL;
335 }
336
337 static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
338 {
339 if (io_ctl->cur) {
340 io_ctl->cur = NULL;
341 io_ctl->orig = NULL;
342 }
343 }
344
345 static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
346 {
347 ASSERT(io_ctl->index < io_ctl->num_pages);
348 io_ctl->page = io_ctl->pages[io_ctl->index++];
349 io_ctl->cur = page_address(io_ctl->page);
350 io_ctl->orig = io_ctl->cur;
351 io_ctl->size = PAGE_SIZE;
352 if (clear)
353 clear_page(io_ctl->cur);
354 }
355
356 static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
357 {
358 int i;
359
360 io_ctl_unmap_page(io_ctl);
361
362 for (i = 0; i < io_ctl->num_pages; i++) {
363 if (io_ctl->pages[i]) {
364 ClearPageChecked(io_ctl->pages[i]);
365 unlock_page(io_ctl->pages[i]);
366 put_page(io_ctl->pages[i]);
367 }
368 }
369 }
370
371 static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, struct inode *inode,
372 int uptodate)
373 {
374 struct page *page;
375 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
376 int i;
377
378 for (i = 0; i < io_ctl->num_pages; i++) {
379 page = find_or_create_page(inode->i_mapping, i, mask);
380 if (!page) {
381 io_ctl_drop_pages(io_ctl);
382 return -ENOMEM;
383 }
384 io_ctl->pages[i] = page;
385 if (uptodate && !PageUptodate(page)) {
386 btrfs_readpage(NULL, page);
387 lock_page(page);
388 if (!PageUptodate(page)) {
389 btrfs_err(BTRFS_I(inode)->root->fs_info,
390 "error reading free space cache");
391 io_ctl_drop_pages(io_ctl);
392 return -EIO;
393 }
394 }
395 }
396
397 for (i = 0; i < io_ctl->num_pages; i++) {
398 clear_page_dirty_for_io(io_ctl->pages[i]);
399 set_page_extent_mapped(io_ctl->pages[i]);
400 }
401
402 return 0;
403 }
404
405 static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
406 {
407 __le64 *val;
408
409 io_ctl_map_page(io_ctl, 1);
410
411 /*
412 * Skip the csum areas. If we don't check crcs then we just have a
413 * 64bit chunk at the front of the first page.
414 */
415 if (io_ctl->check_crcs) {
416 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
417 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
418 } else {
419 io_ctl->cur += sizeof(u64);
420 io_ctl->size -= sizeof(u64) * 2;
421 }
422
423 val = io_ctl->cur;
424 *val = cpu_to_le64(generation);
425 io_ctl->cur += sizeof(u64);
426 }
427
428 static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
429 {
430 __le64 *gen;
431
432 /*
433 * Skip the crc area. If we don't check crcs then we just have a 64bit
434 * chunk at the front of the first page.
435 */
436 if (io_ctl->check_crcs) {
437 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
438 io_ctl->size -= sizeof(u64) +
439 (sizeof(u32) * io_ctl->num_pages);
440 } else {
441 io_ctl->cur += sizeof(u64);
442 io_ctl->size -= sizeof(u64) * 2;
443 }
444
445 gen = io_ctl->cur;
446 if (le64_to_cpu(*gen) != generation) {
447 btrfs_err_rl(io_ctl->fs_info,
448 "space cache generation (%llu) does not match inode (%llu)",
449 *gen, generation);
450 io_ctl_unmap_page(io_ctl);
451 return -EIO;
452 }
453 io_ctl->cur += sizeof(u64);
454 return 0;
455 }
456
457 static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
458 {
459 u32 *tmp;
460 u32 crc = ~(u32)0;
461 unsigned offset = 0;
462
463 if (!io_ctl->check_crcs) {
464 io_ctl_unmap_page(io_ctl);
465 return;
466 }
467
468 if (index == 0)
469 offset = sizeof(u32) * io_ctl->num_pages;
470
471 crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
472 btrfs_crc32c_final(crc, (u8 *)&crc);
473 io_ctl_unmap_page(io_ctl);
474 tmp = page_address(io_ctl->pages[0]);
475 tmp += index;
476 *tmp = crc;
477 }
478
479 static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
480 {
481 u32 *tmp, val;
482 u32 crc = ~(u32)0;
483 unsigned offset = 0;
484
485 if (!io_ctl->check_crcs) {
486 io_ctl_map_page(io_ctl, 0);
487 return 0;
488 }
489
490 if (index == 0)
491 offset = sizeof(u32) * io_ctl->num_pages;
492
493 tmp = page_address(io_ctl->pages[0]);
494 tmp += index;
495 val = *tmp;
496
497 io_ctl_map_page(io_ctl, 0);
498 crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
499 btrfs_crc32c_final(crc, (u8 *)&crc);
500 if (val != crc) {
501 btrfs_err_rl(io_ctl->fs_info,
502 "csum mismatch on free space cache");
503 io_ctl_unmap_page(io_ctl);
504 return -EIO;
505 }
506
507 return 0;
508 }
509
510 static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
511 void *bitmap)
512 {
513 struct btrfs_free_space_entry *entry;
514
515 if (!io_ctl->cur)
516 return -ENOSPC;
517
518 entry = io_ctl->cur;
519 entry->offset = cpu_to_le64(offset);
520 entry->bytes = cpu_to_le64(bytes);
521 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
522 BTRFS_FREE_SPACE_EXTENT;
523 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
524 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
525
526 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
527 return 0;
528
529 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
530
531 /* No more pages to map */
532 if (io_ctl->index >= io_ctl->num_pages)
533 return 0;
534
535 /* map the next page */
536 io_ctl_map_page(io_ctl, 1);
537 return 0;
538 }
539
540 static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
541 {
542 if (!io_ctl->cur)
543 return -ENOSPC;
544
545 /*
546 * If we aren't at the start of the current page, unmap this one and
547 * map the next one if there is any left.
548 */
549 if (io_ctl->cur != io_ctl->orig) {
550 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
551 if (io_ctl->index >= io_ctl->num_pages)
552 return -ENOSPC;
553 io_ctl_map_page(io_ctl, 0);
554 }
555
556 copy_page(io_ctl->cur, bitmap);
557 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
558 if (io_ctl->index < io_ctl->num_pages)
559 io_ctl_map_page(io_ctl, 0);
560 return 0;
561 }
562
563 static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
564 {
565 /*
566 * If we're not on the boundary we know we've modified the page and we
567 * need to crc the page.
568 */
569 if (io_ctl->cur != io_ctl->orig)
570 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
571 else
572 io_ctl_unmap_page(io_ctl);
573
574 while (io_ctl->index < io_ctl->num_pages) {
575 io_ctl_map_page(io_ctl, 1);
576 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
577 }
578 }
579
580 static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
581 struct btrfs_free_space *entry, u8 *type)
582 {
583 struct btrfs_free_space_entry *e;
584 int ret;
585
586 if (!io_ctl->cur) {
587 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
588 if (ret)
589 return ret;
590 }
591
592 e = io_ctl->cur;
593 entry->offset = le64_to_cpu(e->offset);
594 entry->bytes = le64_to_cpu(e->bytes);
595 *type = e->type;
596 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
597 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
598
599 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
600 return 0;
601
602 io_ctl_unmap_page(io_ctl);
603
604 return 0;
605 }
606
607 static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
608 struct btrfs_free_space *entry)
609 {
610 int ret;
611
612 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
613 if (ret)
614 return ret;
615
616 copy_page(entry->bitmap, io_ctl->cur);
617 io_ctl_unmap_page(io_ctl);
618
619 return 0;
620 }
621
622 /*
623 * Since we attach pinned extents after the fact we can have contiguous sections
624 * of free space that are split up in entries. This poses a problem with the
625 * tree logging stuff since it could have allocated across what appears to be 2
626 * entries since we would have merged the entries when adding the pinned extents
627 * back to the free space cache. So run through the space cache that we just
628 * loaded and merge contiguous entries. This will make the log replay stuff not
629 * blow up and it will make for nicer allocator behavior.
630 */
631 static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
632 {
633 struct btrfs_free_space *e, *prev = NULL;
634 struct rb_node *n;
635
636 again:
637 spin_lock(&ctl->tree_lock);
638 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
639 e = rb_entry(n, struct btrfs_free_space, offset_index);
640 if (!prev)
641 goto next;
642 if (e->bitmap || prev->bitmap)
643 goto next;
644 if (prev->offset + prev->bytes == e->offset) {
645 unlink_free_space(ctl, prev);
646 unlink_free_space(ctl, e);
647 prev->bytes += e->bytes;
648 kmem_cache_free(btrfs_free_space_cachep, e);
649 link_free_space(ctl, prev);
650 prev = NULL;
651 spin_unlock(&ctl->tree_lock);
652 goto again;
653 }
654 next:
655 prev = e;
656 }
657 spin_unlock(&ctl->tree_lock);
658 }
659
660 static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
661 struct btrfs_free_space_ctl *ctl,
662 struct btrfs_path *path, u64 offset)
663 {
664 struct btrfs_fs_info *fs_info = root->fs_info;
665 struct btrfs_free_space_header *header;
666 struct extent_buffer *leaf;
667 struct btrfs_io_ctl io_ctl;
668 struct btrfs_key key;
669 struct btrfs_free_space *e, *n;
670 LIST_HEAD(bitmaps);
671 u64 num_entries;
672 u64 num_bitmaps;
673 u64 generation;
674 u8 type;
675 int ret = 0;
676
677 /* Nothing in the space cache, goodbye */
678 if (!i_size_read(inode))
679 return 0;
680
681 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
682 key.offset = offset;
683 key.type = 0;
684
685 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
686 if (ret < 0)
687 return 0;
688 else if (ret > 0) {
689 btrfs_release_path(path);
690 return 0;
691 }
692
693 ret = -1;
694
695 leaf = path->nodes[0];
696 header = btrfs_item_ptr(leaf, path->slots[0],
697 struct btrfs_free_space_header);
698 num_entries = btrfs_free_space_entries(leaf, header);
699 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
700 generation = btrfs_free_space_generation(leaf, header);
701 btrfs_release_path(path);
702
703 if (!BTRFS_I(inode)->generation) {
704 btrfs_info(fs_info,
705 "the free space cache file (%llu) is invalid, skip it",
706 offset);
707 return 0;
708 }
709
710 if (BTRFS_I(inode)->generation != generation) {
711 btrfs_err(fs_info,
712 "free space inode generation (%llu) did not match free space cache generation (%llu)",
713 BTRFS_I(inode)->generation, generation);
714 return 0;
715 }
716
717 if (!num_entries)
718 return 0;
719
720 ret = io_ctl_init(&io_ctl, inode, 0);
721 if (ret)
722 return ret;
723
724 readahead_cache(inode);
725
726 ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
727 if (ret)
728 goto out;
729
730 ret = io_ctl_check_crc(&io_ctl, 0);
731 if (ret)
732 goto free_cache;
733
734 ret = io_ctl_check_generation(&io_ctl, generation);
735 if (ret)
736 goto free_cache;
737
738 while (num_entries) {
739 e = kmem_cache_zalloc(btrfs_free_space_cachep,
740 GFP_NOFS);
741 if (!e)
742 goto free_cache;
743
744 ret = io_ctl_read_entry(&io_ctl, e, &type);
745 if (ret) {
746 kmem_cache_free(btrfs_free_space_cachep, e);
747 goto free_cache;
748 }
749
750 if (!e->bytes) {
751 kmem_cache_free(btrfs_free_space_cachep, e);
752 goto free_cache;
753 }
754
755 if (type == BTRFS_FREE_SPACE_EXTENT) {
756 spin_lock(&ctl->tree_lock);
757 ret = link_free_space(ctl, e);
758 spin_unlock(&ctl->tree_lock);
759 if (ret) {
760 btrfs_err(fs_info,
761 "Duplicate entries in free space cache, dumping");
762 kmem_cache_free(btrfs_free_space_cachep, e);
763 goto free_cache;
764 }
765 } else {
766 ASSERT(num_bitmaps);
767 num_bitmaps--;
768 e->bitmap = kmem_cache_zalloc(
769 btrfs_free_space_bitmap_cachep, GFP_NOFS);
770 if (!e->bitmap) {
771 kmem_cache_free(
772 btrfs_free_space_cachep, e);
773 goto free_cache;
774 }
775 spin_lock(&ctl->tree_lock);
776 ret = link_free_space(ctl, e);
777 ctl->total_bitmaps++;
778 ctl->op->recalc_thresholds(ctl);
779 spin_unlock(&ctl->tree_lock);
780 if (ret) {
781 btrfs_err(fs_info,
782 "Duplicate entries in free space cache, dumping");
783 kmem_cache_free(btrfs_free_space_cachep, e);
784 goto free_cache;
785 }
786 list_add_tail(&e->list, &bitmaps);
787 }
788
789 num_entries--;
790 }
791
792 io_ctl_unmap_page(&io_ctl);
793
794 /*
795 * We add the bitmaps at the end of the entries in order that
796 * the bitmap entries are added to the cache.
797 */
798 list_for_each_entry_safe(e, n, &bitmaps, list) {
799 list_del_init(&e->list);
800 ret = io_ctl_read_bitmap(&io_ctl, e);
801 if (ret)
802 goto free_cache;
803 }
804
805 io_ctl_drop_pages(&io_ctl);
806 merge_space_tree(ctl);
807 ret = 1;
808 out:
809 io_ctl_free(&io_ctl);
810 return ret;
811 free_cache:
812 io_ctl_drop_pages(&io_ctl);
813 __btrfs_remove_free_space_cache(ctl);
814 goto out;
815 }
816
817 int load_free_space_cache(struct btrfs_block_group_cache *block_group)
818 {
819 struct btrfs_fs_info *fs_info = block_group->fs_info;
820 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
821 struct inode *inode;
822 struct btrfs_path *path;
823 int ret = 0;
824 bool matched;
825 u64 used = btrfs_block_group_used(&block_group->item);
826
827 /*
828 * If this block group has been marked to be cleared for one reason or
829 * another then we can't trust the on disk cache, so just return.
830 */
831 spin_lock(&block_group->lock);
832 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
833 spin_unlock(&block_group->lock);
834 return 0;
835 }
836 spin_unlock(&block_group->lock);
837
838 path = btrfs_alloc_path();
839 if (!path)
840 return 0;
841 path->search_commit_root = 1;
842 path->skip_locking = 1;
843
844 /*
845 * We must pass a path with search_commit_root set to btrfs_iget in
846 * order to avoid a deadlock when allocating extents for the tree root.
847 *
848 * When we are COWing an extent buffer from the tree root, when looking
849 * for a free extent, at extent-tree.c:find_free_extent(), we can find
850 * block group without its free space cache loaded. When we find one
851 * we must load its space cache which requires reading its free space
852 * cache's inode item from the root tree. If this inode item is located
853 * in the same leaf that we started COWing before, then we end up in
854 * deadlock on the extent buffer (trying to read lock it when we
855 * previously write locked it).
856 *
857 * It's safe to read the inode item using the commit root because
858 * block groups, once loaded, stay in memory forever (until they are
859 * removed) as well as their space caches once loaded. New block groups
860 * once created get their ->cached field set to BTRFS_CACHE_FINISHED so
861 * we will never try to read their inode item while the fs is mounted.
862 */
863 inode = lookup_free_space_inode(block_group, path);
864 if (IS_ERR(inode)) {
865 btrfs_free_path(path);
866 return 0;
867 }
868
869 /* We may have converted the inode and made the cache invalid. */
870 spin_lock(&block_group->lock);
871 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
872 spin_unlock(&block_group->lock);
873 btrfs_free_path(path);
874 goto out;
875 }
876 spin_unlock(&block_group->lock);
877
878 ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
879 path, block_group->key.objectid);
880 btrfs_free_path(path);
881 if (ret <= 0)
882 goto out;
883
884 spin_lock(&ctl->tree_lock);
885 matched = (ctl->free_space == (block_group->key.offset - used -
886 block_group->bytes_super));
887 spin_unlock(&ctl->tree_lock);
888
889 if (!matched) {
890 __btrfs_remove_free_space_cache(ctl);
891 btrfs_warn(fs_info,
892 "block group %llu has wrong amount of free space",
893 block_group->key.objectid);
894 ret = -1;
895 }
896 out:
897 if (ret < 0) {
898 /* This cache is bogus, make sure it gets cleared */
899 spin_lock(&block_group->lock);
900 block_group->disk_cache_state = BTRFS_DC_CLEAR;
901 spin_unlock(&block_group->lock);
902 ret = 0;
903
904 btrfs_warn(fs_info,
905 "failed to load free space cache for block group %llu, rebuilding it now",
906 block_group->key.objectid);
907 }
908
909 iput(inode);
910 return ret;
911 }
912
913 static noinline_for_stack
914 int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
915 struct btrfs_free_space_ctl *ctl,
916 struct btrfs_block_group_cache *block_group,
917 int *entries, int *bitmaps,
918 struct list_head *bitmap_list)
919 {
920 int ret;
921 struct btrfs_free_cluster *cluster = NULL;
922 struct btrfs_free_cluster *cluster_locked = NULL;
923 struct rb_node *node = rb_first(&ctl->free_space_offset);
924 struct btrfs_trim_range *trim_entry;
925
926 /* Get the cluster for this block_group if it exists */
927 if (block_group && !list_empty(&block_group->cluster_list)) {
928 cluster = list_entry(block_group->cluster_list.next,
929 struct btrfs_free_cluster,
930 block_group_list);
931 }
932
933 if (!node && cluster) {
934 cluster_locked = cluster;
935 spin_lock(&cluster_locked->lock);
936 node = rb_first(&cluster->root);
937 cluster = NULL;
938 }
939
940 /* Write out the extent entries */
941 while (node) {
942 struct btrfs_free_space *e;
943
944 e = rb_entry(node, struct btrfs_free_space, offset_index);
945 *entries += 1;
946
947 ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
948 e->bitmap);
949 if (ret)
950 goto fail;
951
952 if (e->bitmap) {
953 list_add_tail(&e->list, bitmap_list);
954 *bitmaps += 1;
955 }
956 node = rb_next(node);
957 if (!node && cluster) {
958 node = rb_first(&cluster->root);
959 cluster_locked = cluster;
960 spin_lock(&cluster_locked->lock);
961 cluster = NULL;
962 }
963 }
964 if (cluster_locked) {
965 spin_unlock(&cluster_locked->lock);
966 cluster_locked = NULL;
967 }
968
969 /*
970 * Make sure we don't miss any range that was removed from our rbtree
971 * because trimming is running. Otherwise after a umount+mount (or crash
972 * after committing the transaction) we would leak free space and get
973 * an inconsistent free space cache report from fsck.
974 */
975 list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
976 ret = io_ctl_add_entry(io_ctl, trim_entry->start,
977 trim_entry->bytes, NULL);
978 if (ret)
979 goto fail;
980 *entries += 1;
981 }
982
983 return 0;
984 fail:
985 if (cluster_locked)
986 spin_unlock(&cluster_locked->lock);
987 return -ENOSPC;
988 }
989
990 static noinline_for_stack int
991 update_cache_item(struct btrfs_trans_handle *trans,
992 struct btrfs_root *root,
993 struct inode *inode,
994 struct btrfs_path *path, u64 offset,
995 int entries, int bitmaps)
996 {
997 struct btrfs_key key;
998 struct btrfs_free_space_header *header;
999 struct extent_buffer *leaf;
1000 int ret;
1001
1002 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
1003 key.offset = offset;
1004 key.type = 0;
1005
1006 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1007 if (ret < 0) {
1008 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1009 EXTENT_DELALLOC, 0, 0, NULL);
1010 goto fail;
1011 }
1012 leaf = path->nodes[0];
1013 if (ret > 0) {
1014 struct btrfs_key found_key;
1015 ASSERT(path->slots[0]);
1016 path->slots[0]--;
1017 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1018 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
1019 found_key.offset != offset) {
1020 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
1021 inode->i_size - 1, EXTENT_DELALLOC, 0,
1022 0, NULL);
1023 btrfs_release_path(path);
1024 goto fail;
1025 }
1026 }
1027
1028 BTRFS_I(inode)->generation = trans->transid;
1029 header = btrfs_item_ptr(leaf, path->slots[0],
1030 struct btrfs_free_space_header);
1031 btrfs_set_free_space_entries(leaf, header, entries);
1032 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1033 btrfs_set_free_space_generation(leaf, header, trans->transid);
1034 btrfs_mark_buffer_dirty(leaf);
1035 btrfs_release_path(path);
1036
1037 return 0;
1038
1039 fail:
1040 return -1;
1041 }
1042
1043 static noinline_for_stack int write_pinned_extent_entries(
1044 struct btrfs_block_group_cache *block_group,
1045 struct btrfs_io_ctl *io_ctl,
1046 int *entries)
1047 {
1048 u64 start, extent_start, extent_end, len;
1049 struct extent_io_tree *unpin = NULL;
1050 int ret;
1051
1052 if (!block_group)
1053 return 0;
1054
1055 /*
1056 * We want to add any pinned extents to our free space cache
1057 * so we don't leak the space
1058 *
1059 * We shouldn't have switched the pinned extents yet so this is the
1060 * right one
1061 */
1062 unpin = block_group->fs_info->pinned_extents;
1063
1064 start = block_group->key.objectid;
1065
1066 while (start < block_group->key.objectid + block_group->key.offset) {
1067 ret = find_first_extent_bit(unpin, start,
1068 &extent_start, &extent_end,
1069 EXTENT_DIRTY, NULL);
1070 if (ret)
1071 return 0;
1072
1073 /* This pinned extent is out of our range */
1074 if (extent_start >= block_group->key.objectid +
1075 block_group->key.offset)
1076 return 0;
1077
1078 extent_start = max(extent_start, start);
1079 extent_end = min(block_group->key.objectid +
1080 block_group->key.offset, extent_end + 1);
1081 len = extent_end - extent_start;
1082
1083 *entries += 1;
1084 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1085 if (ret)
1086 return -ENOSPC;
1087
1088 start = extent_end;
1089 }
1090
1091 return 0;
1092 }
1093
1094 static noinline_for_stack int
1095 write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
1096 {
1097 struct btrfs_free_space *entry, *next;
1098 int ret;
1099
1100 /* Write out the bitmaps */
1101 list_for_each_entry_safe(entry, next, bitmap_list, list) {
1102 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1103 if (ret)
1104 return -ENOSPC;
1105 list_del_init(&entry->list);
1106 }
1107
1108 return 0;
1109 }
1110
1111 static int flush_dirty_cache(struct inode *inode)
1112 {
1113 int ret;
1114
1115 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1116 if (ret)
1117 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1118 EXTENT_DELALLOC, 0, 0, NULL);
1119
1120 return ret;
1121 }
1122
1123 static void noinline_for_stack
1124 cleanup_bitmap_list(struct list_head *bitmap_list)
1125 {
1126 struct btrfs_free_space *entry, *next;
1127
1128 list_for_each_entry_safe(entry, next, bitmap_list, list)
1129 list_del_init(&entry->list);
1130 }
1131
1132 static void noinline_for_stack
1133 cleanup_write_cache_enospc(struct inode *inode,
1134 struct btrfs_io_ctl *io_ctl,
1135 struct extent_state **cached_state)
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 }
1141
1142 static int __btrfs_wait_cache_io(struct btrfs_root *root,
1143 struct btrfs_trans_handle *trans,
1144 struct btrfs_block_group_cache *block_group,
1145 struct btrfs_io_ctl *io_ctl,
1146 struct btrfs_path *path, u64 offset)
1147 {
1148 int ret;
1149 struct inode *inode = io_ctl->inode;
1150
1151 if (!inode)
1152 return 0;
1153
1154 /* Flush the dirty pages in the cache file. */
1155 ret = flush_dirty_cache(inode);
1156 if (ret)
1157 goto out;
1158
1159 /* Update the cache item to tell everyone this cache file is valid. */
1160 ret = update_cache_item(trans, root, inode, path, offset,
1161 io_ctl->entries, io_ctl->bitmaps);
1162 out:
1163 io_ctl_free(io_ctl);
1164 if (ret) {
1165 invalidate_inode_pages2(inode->i_mapping);
1166 BTRFS_I(inode)->generation = 0;
1167 if (block_group) {
1168 #ifdef DEBUG
1169 btrfs_err(root->fs_info,
1170 "failed to write free space cache for block group %llu",
1171 block_group->key.objectid);
1172 #endif
1173 }
1174 }
1175 btrfs_update_inode(trans, root, inode);
1176
1177 if (block_group) {
1178 /* the dirty list is protected by the dirty_bgs_lock */
1179 spin_lock(&trans->transaction->dirty_bgs_lock);
1180
1181 /* the disk_cache_state is protected by the block group lock */
1182 spin_lock(&block_group->lock);
1183
1184 /*
1185 * only mark this as written if we didn't get put back on
1186 * the dirty list while waiting for IO. Otherwise our
1187 * cache state won't be right, and we won't get written again
1188 */
1189 if (!ret && list_empty(&block_group->dirty_list))
1190 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1191 else if (ret)
1192 block_group->disk_cache_state = BTRFS_DC_ERROR;
1193
1194 spin_unlock(&block_group->lock);
1195 spin_unlock(&trans->transaction->dirty_bgs_lock);
1196 io_ctl->inode = NULL;
1197 iput(inode);
1198 }
1199
1200 return ret;
1201
1202 }
1203
1204 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
1205 struct btrfs_trans_handle *trans,
1206 struct btrfs_io_ctl *io_ctl,
1207 struct btrfs_path *path)
1208 {
1209 return __btrfs_wait_cache_io(root, trans, NULL, io_ctl, path, 0);
1210 }
1211
1212 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
1213 struct btrfs_block_group_cache *block_group,
1214 struct btrfs_path *path)
1215 {
1216 return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans,
1217 block_group, &block_group->io_ctl,
1218 path, block_group->key.objectid);
1219 }
1220
1221 /**
1222 * __btrfs_write_out_cache - write out cached info to an inode
1223 * @root - the root the inode belongs to
1224 * @ctl - the free space cache we are going to write out
1225 * @block_group - the block_group for this cache if it belongs to a block_group
1226 * @trans - the trans handle
1227 *
1228 * This function writes out a free space cache struct to disk for quick recovery
1229 * on mount. This will return 0 if it was successful in writing the cache out,
1230 * or an errno if it was not.
1231 */
1232 static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
1233 struct btrfs_free_space_ctl *ctl,
1234 struct btrfs_block_group_cache *block_group,
1235 struct btrfs_io_ctl *io_ctl,
1236 struct btrfs_trans_handle *trans)
1237 {
1238 struct extent_state *cached_state = NULL;
1239 LIST_HEAD(bitmap_list);
1240 int entries = 0;
1241 int bitmaps = 0;
1242 int ret;
1243 int must_iput = 0;
1244
1245 if (!i_size_read(inode))
1246 return -EIO;
1247
1248 WARN_ON(io_ctl->pages);
1249 ret = io_ctl_init(io_ctl, inode, 1);
1250 if (ret)
1251 return ret;
1252
1253 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1254 down_write(&block_group->data_rwsem);
1255 spin_lock(&block_group->lock);
1256 if (block_group->delalloc_bytes) {
1257 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1258 spin_unlock(&block_group->lock);
1259 up_write(&block_group->data_rwsem);
1260 BTRFS_I(inode)->generation = 0;
1261 ret = 0;
1262 must_iput = 1;
1263 goto out;
1264 }
1265 spin_unlock(&block_group->lock);
1266 }
1267
1268 /* Lock all pages first so we can lock the extent safely. */
1269 ret = io_ctl_prepare_pages(io_ctl, inode, 0);
1270 if (ret)
1271 goto out_unlock;
1272
1273 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1274 &cached_state);
1275
1276 io_ctl_set_generation(io_ctl, trans->transid);
1277
1278 mutex_lock(&ctl->cache_writeout_mutex);
1279 /* Write out the extent entries in the free space cache */
1280 spin_lock(&ctl->tree_lock);
1281 ret = write_cache_extent_entries(io_ctl, ctl,
1282 block_group, &entries, &bitmaps,
1283 &bitmap_list);
1284 if (ret)
1285 goto out_nospc_locked;
1286
1287 /*
1288 * Some spaces that are freed in the current transaction are pinned,
1289 * they will be added into free space cache after the transaction is
1290 * committed, we shouldn't lose them.
1291 *
1292 * If this changes while we are working we'll get added back to
1293 * the dirty list and redo it. No locking needed
1294 */
1295 ret = write_pinned_extent_entries(block_group, io_ctl, &entries);
1296 if (ret)
1297 goto out_nospc_locked;
1298
1299 /*
1300 * At last, we write out all the bitmaps and keep cache_writeout_mutex
1301 * locked while doing it because a concurrent trim can be manipulating
1302 * or freeing the bitmap.
1303 */
1304 ret = write_bitmap_entries(io_ctl, &bitmap_list);
1305 spin_unlock(&ctl->tree_lock);
1306 mutex_unlock(&ctl->cache_writeout_mutex);
1307 if (ret)
1308 goto out_nospc;
1309
1310 /* Zero out the rest of the pages just to make sure */
1311 io_ctl_zero_remaining_pages(io_ctl);
1312
1313 /* Everything is written out, now we dirty the pages in the file. */
1314 ret = btrfs_dirty_pages(inode, io_ctl->pages, io_ctl->num_pages, 0,
1315 i_size_read(inode), &cached_state);
1316 if (ret)
1317 goto out_nospc;
1318
1319 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1320 up_write(&block_group->data_rwsem);
1321 /*
1322 * Release the pages and unlock the extent, we will flush
1323 * them out later
1324 */
1325 io_ctl_drop_pages(io_ctl);
1326
1327 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1328 i_size_read(inode) - 1, &cached_state);
1329
1330 /*
1331 * at this point the pages are under IO and we're happy,
1332 * The caller is responsible for waiting on them and updating the
1333 * the cache and the inode
1334 */
1335 io_ctl->entries = entries;
1336 io_ctl->bitmaps = bitmaps;
1337
1338 ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
1339 if (ret)
1340 goto out;
1341
1342 return 0;
1343
1344 out:
1345 io_ctl->inode = NULL;
1346 io_ctl_free(io_ctl);
1347 if (ret) {
1348 invalidate_inode_pages2(inode->i_mapping);
1349 BTRFS_I(inode)->generation = 0;
1350 }
1351 btrfs_update_inode(trans, root, inode);
1352 if (must_iput)
1353 iput(inode);
1354 return ret;
1355
1356 out_nospc_locked:
1357 cleanup_bitmap_list(&bitmap_list);
1358 spin_unlock(&ctl->tree_lock);
1359 mutex_unlock(&ctl->cache_writeout_mutex);
1360
1361 out_nospc:
1362 cleanup_write_cache_enospc(inode, io_ctl, &cached_state);
1363
1364 out_unlock:
1365 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1366 up_write(&block_group->data_rwsem);
1367
1368 goto out;
1369 }
1370
1371 int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
1372 struct btrfs_block_group_cache *block_group,
1373 struct btrfs_path *path)
1374 {
1375 struct btrfs_fs_info *fs_info = trans->fs_info;
1376 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1377 struct inode *inode;
1378 int ret = 0;
1379
1380 spin_lock(&block_group->lock);
1381 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1382 spin_unlock(&block_group->lock);
1383 return 0;
1384 }
1385 spin_unlock(&block_group->lock);
1386
1387 inode = lookup_free_space_inode(block_group, path);
1388 if (IS_ERR(inode))
1389 return 0;
1390
1391 ret = __btrfs_write_out_cache(fs_info->tree_root, inode, ctl,
1392 block_group, &block_group->io_ctl, trans);
1393 if (ret) {
1394 #ifdef DEBUG
1395 btrfs_err(fs_info,
1396 "failed to write free space cache for block group %llu",
1397 block_group->key.objectid);
1398 #endif
1399 spin_lock(&block_group->lock);
1400 block_group->disk_cache_state = BTRFS_DC_ERROR;
1401 spin_unlock(&block_group->lock);
1402
1403 block_group->io_ctl.inode = NULL;
1404 iput(inode);
1405 }
1406
1407 /*
1408 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
1409 * to wait for IO and put the inode
1410 */
1411
1412 return ret;
1413 }
1414
1415 static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1416 u64 offset)
1417 {
1418 ASSERT(offset >= bitmap_start);
1419 offset -= bitmap_start;
1420 return (unsigned long)(div_u64(offset, unit));
1421 }
1422
1423 static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1424 {
1425 return (unsigned long)(div_u64(bytes, unit));
1426 }
1427
1428 static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1429 u64 offset)
1430 {
1431 u64 bitmap_start;
1432 u64 bytes_per_bitmap;
1433
1434 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1435 bitmap_start = offset - ctl->start;
1436 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1437 bitmap_start *= bytes_per_bitmap;
1438 bitmap_start += ctl->start;
1439
1440 return bitmap_start;
1441 }
1442
1443 static int tree_insert_offset(struct rb_root *root, u64 offset,
1444 struct rb_node *node, int bitmap)
1445 {
1446 struct rb_node **p = &root->rb_node;
1447 struct rb_node *parent = NULL;
1448 struct btrfs_free_space *info;
1449
1450 while (*p) {
1451 parent = *p;
1452 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1453
1454 if (offset < info->offset) {
1455 p = &(*p)->rb_left;
1456 } else if (offset > info->offset) {
1457 p = &(*p)->rb_right;
1458 } else {
1459 /*
1460 * we could have a bitmap entry and an extent entry
1461 * share the same offset. If this is the case, we want
1462 * the extent entry to always be found first if we do a
1463 * linear search through the tree, since we want to have
1464 * the quickest allocation time, and allocating from an
1465 * extent is faster than allocating from a bitmap. So
1466 * if we're inserting a bitmap and we find an entry at
1467 * this offset, we want to go right, or after this entry
1468 * logically. If we are inserting an extent and we've
1469 * found a bitmap, we want to go left, or before
1470 * logically.
1471 */
1472 if (bitmap) {
1473 if (info->bitmap) {
1474 WARN_ON_ONCE(1);
1475 return -EEXIST;
1476 }
1477 p = &(*p)->rb_right;
1478 } else {
1479 if (!info->bitmap) {
1480 WARN_ON_ONCE(1);
1481 return -EEXIST;
1482 }
1483 p = &(*p)->rb_left;
1484 }
1485 }
1486 }
1487
1488 rb_link_node(node, parent, p);
1489 rb_insert_color(node, root);
1490
1491 return 0;
1492 }
1493
1494 /*
1495 * searches the tree for the given offset.
1496 *
1497 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1498 * want a section that has at least bytes size and comes at or after the given
1499 * offset.
1500 */
1501 static struct btrfs_free_space *
1502 tree_search_offset(struct btrfs_free_space_ctl *ctl,
1503 u64 offset, int bitmap_only, int fuzzy)
1504 {
1505 struct rb_node *n = ctl->free_space_offset.rb_node;
1506 struct btrfs_free_space *entry, *prev = NULL;
1507
1508 /* find entry that is closest to the 'offset' */
1509 while (1) {
1510 if (!n) {
1511 entry = NULL;
1512 break;
1513 }
1514
1515 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1516 prev = entry;
1517
1518 if (offset < entry->offset)
1519 n = n->rb_left;
1520 else if (offset > entry->offset)
1521 n = n->rb_right;
1522 else
1523 break;
1524 }
1525
1526 if (bitmap_only) {
1527 if (!entry)
1528 return NULL;
1529 if (entry->bitmap)
1530 return entry;
1531
1532 /*
1533 * bitmap entry and extent entry may share same offset,
1534 * in that case, bitmap entry comes after extent entry.
1535 */
1536 n = rb_next(n);
1537 if (!n)
1538 return NULL;
1539 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1540 if (entry->offset != offset)
1541 return NULL;
1542
1543 WARN_ON(!entry->bitmap);
1544 return entry;
1545 } else if (entry) {
1546 if (entry->bitmap) {
1547 /*
1548 * if previous extent entry covers the offset,
1549 * we should return it instead of the bitmap entry
1550 */
1551 n = rb_prev(&entry->offset_index);
1552 if (n) {
1553 prev = rb_entry(n, struct btrfs_free_space,
1554 offset_index);
1555 if (!prev->bitmap &&
1556 prev->offset + prev->bytes > offset)
1557 entry = prev;
1558 }
1559 }
1560 return entry;
1561 }
1562
1563 if (!prev)
1564 return NULL;
1565
1566 /* find last entry before the 'offset' */
1567 entry = prev;
1568 if (entry->offset > offset) {
1569 n = rb_prev(&entry->offset_index);
1570 if (n) {
1571 entry = rb_entry(n, struct btrfs_free_space,
1572 offset_index);
1573 ASSERT(entry->offset <= offset);
1574 } else {
1575 if (fuzzy)
1576 return entry;
1577 else
1578 return NULL;
1579 }
1580 }
1581
1582 if (entry->bitmap) {
1583 n = rb_prev(&entry->offset_index);
1584 if (n) {
1585 prev = rb_entry(n, struct btrfs_free_space,
1586 offset_index);
1587 if (!prev->bitmap &&
1588 prev->offset + prev->bytes > offset)
1589 return prev;
1590 }
1591 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1592 return entry;
1593 } else if (entry->offset + entry->bytes > offset)
1594 return entry;
1595
1596 if (!fuzzy)
1597 return NULL;
1598
1599 while (1) {
1600 if (entry->bitmap) {
1601 if (entry->offset + BITS_PER_BITMAP *
1602 ctl->unit > offset)
1603 break;
1604 } else {
1605 if (entry->offset + entry->bytes > offset)
1606 break;
1607 }
1608
1609 n = rb_next(&entry->offset_index);
1610 if (!n)
1611 return NULL;
1612 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1613 }
1614 return entry;
1615 }
1616
1617 static inline void
1618 __unlink_free_space(struct btrfs_free_space_ctl *ctl,
1619 struct btrfs_free_space *info)
1620 {
1621 rb_erase(&info->offset_index, &ctl->free_space_offset);
1622 ctl->free_extents--;
1623 }
1624
1625 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1626 struct btrfs_free_space *info)
1627 {
1628 __unlink_free_space(ctl, info);
1629 ctl->free_space -= info->bytes;
1630 }
1631
1632 static int link_free_space(struct btrfs_free_space_ctl *ctl,
1633 struct btrfs_free_space *info)
1634 {
1635 int ret = 0;
1636
1637 ASSERT(info->bytes || info->bitmap);
1638 ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1639 &info->offset_index, (info->bitmap != NULL));
1640 if (ret)
1641 return ret;
1642
1643 ctl->free_space += info->bytes;
1644 ctl->free_extents++;
1645 return ret;
1646 }
1647
1648 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1649 {
1650 struct btrfs_block_group_cache *block_group = ctl->private;
1651 u64 max_bytes;
1652 u64 bitmap_bytes;
1653 u64 extent_bytes;
1654 u64 size = block_group->key.offset;
1655 u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1656 u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
1657
1658 max_bitmaps = max_t(u64, max_bitmaps, 1);
1659
1660 ASSERT(ctl->total_bitmaps <= max_bitmaps);
1661
1662 /*
1663 * The goal is to keep the total amount of memory used per 1gb of space
1664 * at or below 32k, so we need to adjust how much memory we allow to be
1665 * used by extent based free space tracking
1666 */
1667 if (size < SZ_1G)
1668 max_bytes = MAX_CACHE_BYTES_PER_GIG;
1669 else
1670 max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
1671
1672 /*
1673 * we want to account for 1 more bitmap than what we have so we can make
1674 * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1675 * we add more bitmaps.
1676 */
1677 bitmap_bytes = (ctl->total_bitmaps + 1) * ctl->unit;
1678
1679 if (bitmap_bytes >= max_bytes) {
1680 ctl->extents_thresh = 0;
1681 return;
1682 }
1683
1684 /*
1685 * we want the extent entry threshold to always be at most 1/2 the max
1686 * bytes we can have, or whatever is less than that.
1687 */
1688 extent_bytes = max_bytes - bitmap_bytes;
1689 extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
1690
1691 ctl->extents_thresh =
1692 div_u64(extent_bytes, sizeof(struct btrfs_free_space));
1693 }
1694
1695 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1696 struct btrfs_free_space *info,
1697 u64 offset, u64 bytes)
1698 {
1699 unsigned long start, count;
1700
1701 start = offset_to_bit(info->offset, ctl->unit, offset);
1702 count = bytes_to_bits(bytes, ctl->unit);
1703 ASSERT(start + count <= BITS_PER_BITMAP);
1704
1705 bitmap_clear(info->bitmap, start, count);
1706
1707 info->bytes -= bytes;
1708 if (info->max_extent_size > ctl->unit)
1709 info->max_extent_size = 0;
1710 }
1711
1712 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1713 struct btrfs_free_space *info, u64 offset,
1714 u64 bytes)
1715 {
1716 __bitmap_clear_bits(ctl, info, offset, bytes);
1717 ctl->free_space -= bytes;
1718 }
1719
1720 static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1721 struct btrfs_free_space *info, u64 offset,
1722 u64 bytes)
1723 {
1724 unsigned long start, count;
1725
1726 start = offset_to_bit(info->offset, ctl->unit, offset);
1727 count = bytes_to_bits(bytes, ctl->unit);
1728 ASSERT(start + count <= BITS_PER_BITMAP);
1729
1730 bitmap_set(info->bitmap, start, count);
1731
1732 info->bytes += bytes;
1733 ctl->free_space += bytes;
1734 }
1735
1736 /*
1737 * If we can not find suitable extent, we will use bytes to record
1738 * the size of the max extent.
1739 */
1740 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1741 struct btrfs_free_space *bitmap_info, u64 *offset,
1742 u64 *bytes, bool for_alloc)
1743 {
1744 unsigned long found_bits = 0;
1745 unsigned long max_bits = 0;
1746 unsigned long bits, i;
1747 unsigned long next_zero;
1748 unsigned long extent_bits;
1749
1750 /*
1751 * Skip searching the bitmap if we don't have a contiguous section that
1752 * is large enough for this allocation.
1753 */
1754 if (for_alloc &&
1755 bitmap_info->max_extent_size &&
1756 bitmap_info->max_extent_size < *bytes) {
1757 *bytes = bitmap_info->max_extent_size;
1758 return -1;
1759 }
1760
1761 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1762 max_t(u64, *offset, bitmap_info->offset));
1763 bits = bytes_to_bits(*bytes, ctl->unit);
1764
1765 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1766 if (for_alloc && bits == 1) {
1767 found_bits = 1;
1768 break;
1769 }
1770 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1771 BITS_PER_BITMAP, i);
1772 extent_bits = next_zero - i;
1773 if (extent_bits >= bits) {
1774 found_bits = extent_bits;
1775 break;
1776 } else if (extent_bits > max_bits) {
1777 max_bits = extent_bits;
1778 }
1779 i = next_zero;
1780 }
1781
1782 if (found_bits) {
1783 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1784 *bytes = (u64)(found_bits) * ctl->unit;
1785 return 0;
1786 }
1787
1788 *bytes = (u64)(max_bits) * ctl->unit;
1789 bitmap_info->max_extent_size = *bytes;
1790 return -1;
1791 }
1792
1793 static inline u64 get_max_extent_size(struct btrfs_free_space *entry)
1794 {
1795 if (entry->bitmap)
1796 return entry->max_extent_size;
1797 return entry->bytes;
1798 }
1799
1800 /* Cache the size of the max extent in bytes */
1801 static struct btrfs_free_space *
1802 find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1803 unsigned long align, u64 *max_extent_size)
1804 {
1805 struct btrfs_free_space *entry;
1806 struct rb_node *node;
1807 u64 tmp;
1808 u64 align_off;
1809 int ret;
1810
1811 if (!ctl->free_space_offset.rb_node)
1812 goto out;
1813
1814 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1815 if (!entry)
1816 goto out;
1817
1818 for (node = &entry->offset_index; node; node = rb_next(node)) {
1819 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1820 if (entry->bytes < *bytes) {
1821 *max_extent_size = max(get_max_extent_size(entry),
1822 *max_extent_size);
1823 continue;
1824 }
1825
1826 /* make sure the space returned is big enough
1827 * to match our requested alignment
1828 */
1829 if (*bytes >= align) {
1830 tmp = entry->offset - ctl->start + align - 1;
1831 tmp = div64_u64(tmp, align);
1832 tmp = tmp * align + ctl->start;
1833 align_off = tmp - entry->offset;
1834 } else {
1835 align_off = 0;
1836 tmp = entry->offset;
1837 }
1838
1839 if (entry->bytes < *bytes + align_off) {
1840 *max_extent_size = max(get_max_extent_size(entry),
1841 *max_extent_size);
1842 continue;
1843 }
1844
1845 if (entry->bitmap) {
1846 u64 size = *bytes;
1847
1848 ret = search_bitmap(ctl, entry, &tmp, &size, true);
1849 if (!ret) {
1850 *offset = tmp;
1851 *bytes = size;
1852 return entry;
1853 } else {
1854 *max_extent_size =
1855 max(get_max_extent_size(entry),
1856 *max_extent_size);
1857 }
1858 continue;
1859 }
1860
1861 *offset = tmp;
1862 *bytes = entry->bytes - align_off;
1863 return entry;
1864 }
1865 out:
1866 return NULL;
1867 }
1868
1869 static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1870 struct btrfs_free_space *info, u64 offset)
1871 {
1872 info->offset = offset_to_bitmap(ctl, offset);
1873 info->bytes = 0;
1874 INIT_LIST_HEAD(&info->list);
1875 link_free_space(ctl, info);
1876 ctl->total_bitmaps++;
1877
1878 ctl->op->recalc_thresholds(ctl);
1879 }
1880
1881 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1882 struct btrfs_free_space *bitmap_info)
1883 {
1884 unlink_free_space(ctl, bitmap_info);
1885 kmem_cache_free(btrfs_free_space_bitmap_cachep, bitmap_info->bitmap);
1886 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1887 ctl->total_bitmaps--;
1888 ctl->op->recalc_thresholds(ctl);
1889 }
1890
1891 static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1892 struct btrfs_free_space *bitmap_info,
1893 u64 *offset, u64 *bytes)
1894 {
1895 u64 end;
1896 u64 search_start, search_bytes;
1897 int ret;
1898
1899 again:
1900 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1901
1902 /*
1903 * We need to search for bits in this bitmap. We could only cover some
1904 * of the extent in this bitmap thanks to how we add space, so we need
1905 * to search for as much as it as we can and clear that amount, and then
1906 * go searching for the next bit.
1907 */
1908 search_start = *offset;
1909 search_bytes = ctl->unit;
1910 search_bytes = min(search_bytes, end - search_start + 1);
1911 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
1912 false);
1913 if (ret < 0 || search_start != *offset)
1914 return -EINVAL;
1915
1916 /* We may have found more bits than what we need */
1917 search_bytes = min(search_bytes, *bytes);
1918
1919 /* Cannot clear past the end of the bitmap */
1920 search_bytes = min(search_bytes, end - search_start + 1);
1921
1922 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
1923 *offset += search_bytes;
1924 *bytes -= search_bytes;
1925
1926 if (*bytes) {
1927 struct rb_node *next = rb_next(&bitmap_info->offset_index);
1928 if (!bitmap_info->bytes)
1929 free_bitmap(ctl, bitmap_info);
1930
1931 /*
1932 * no entry after this bitmap, but we still have bytes to
1933 * remove, so something has gone wrong.
1934 */
1935 if (!next)
1936 return -EINVAL;
1937
1938 bitmap_info = rb_entry(next, struct btrfs_free_space,
1939 offset_index);
1940
1941 /*
1942 * if the next entry isn't a bitmap we need to return to let the
1943 * extent stuff do its work.
1944 */
1945 if (!bitmap_info->bitmap)
1946 return -EAGAIN;
1947
1948 /*
1949 * Ok the next item is a bitmap, but it may not actually hold
1950 * the information for the rest of this free space stuff, so
1951 * look for it, and if we don't find it return so we can try
1952 * everything over again.
1953 */
1954 search_start = *offset;
1955 search_bytes = ctl->unit;
1956 ret = search_bitmap(ctl, bitmap_info, &search_start,
1957 &search_bytes, false);
1958 if (ret < 0 || search_start != *offset)
1959 return -EAGAIN;
1960
1961 goto again;
1962 } else if (!bitmap_info->bytes)
1963 free_bitmap(ctl, bitmap_info);
1964
1965 return 0;
1966 }
1967
1968 static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
1969 struct btrfs_free_space *info, u64 offset,
1970 u64 bytes)
1971 {
1972 u64 bytes_to_set = 0;
1973 u64 end;
1974
1975 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
1976
1977 bytes_to_set = min(end - offset, bytes);
1978
1979 bitmap_set_bits(ctl, info, offset, bytes_to_set);
1980
1981 /*
1982 * We set some bytes, we have no idea what the max extent size is
1983 * anymore.
1984 */
1985 info->max_extent_size = 0;
1986
1987 return bytes_to_set;
1988
1989 }
1990
1991 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
1992 struct btrfs_free_space *info)
1993 {
1994 struct btrfs_block_group_cache *block_group = ctl->private;
1995 struct btrfs_fs_info *fs_info = block_group->fs_info;
1996 bool forced = false;
1997
1998 #ifdef CONFIG_BTRFS_DEBUG
1999 if (btrfs_should_fragment_free_space(block_group))
2000 forced = true;
2001 #endif
2002
2003 /*
2004 * If we are below the extents threshold then we can add this as an
2005 * extent, and don't have to deal with the bitmap
2006 */
2007 if (!forced && ctl->free_extents < ctl->extents_thresh) {
2008 /*
2009 * If this block group has some small extents we don't want to
2010 * use up all of our free slots in the cache with them, we want
2011 * to reserve them to larger extents, however if we have plenty
2012 * of cache left then go ahead an dadd them, no sense in adding
2013 * the overhead of a bitmap if we don't have to.
2014 */
2015 if (info->bytes <= fs_info->sectorsize * 4) {
2016 if (ctl->free_extents * 2 <= ctl->extents_thresh)
2017 return false;
2018 } else {
2019 return false;
2020 }
2021 }
2022
2023 /*
2024 * The original block groups from mkfs can be really small, like 8
2025 * megabytes, so don't bother with a bitmap for those entries. However
2026 * some block groups can be smaller than what a bitmap would cover but
2027 * are still large enough that they could overflow the 32k memory limit,
2028 * so allow those block groups to still be allowed to have a bitmap
2029 * entry.
2030 */
2031 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->key.offset)
2032 return false;
2033
2034 return true;
2035 }
2036
2037 static const struct btrfs_free_space_op free_space_op = {
2038 .recalc_thresholds = recalculate_thresholds,
2039 .use_bitmap = use_bitmap,
2040 };
2041
2042 static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
2043 struct btrfs_free_space *info)
2044 {
2045 struct btrfs_free_space *bitmap_info;
2046 struct btrfs_block_group_cache *block_group = NULL;
2047 int added = 0;
2048 u64 bytes, offset, bytes_added;
2049 int ret;
2050
2051 bytes = info->bytes;
2052 offset = info->offset;
2053
2054 if (!ctl->op->use_bitmap(ctl, info))
2055 return 0;
2056
2057 if (ctl->op == &free_space_op)
2058 block_group = ctl->private;
2059 again:
2060 /*
2061 * Since we link bitmaps right into the cluster we need to see if we
2062 * have a cluster here, and if so and it has our bitmap we need to add
2063 * the free space to that bitmap.
2064 */
2065 if (block_group && !list_empty(&block_group->cluster_list)) {
2066 struct btrfs_free_cluster *cluster;
2067 struct rb_node *node;
2068 struct btrfs_free_space *entry;
2069
2070 cluster = list_entry(block_group->cluster_list.next,
2071 struct btrfs_free_cluster,
2072 block_group_list);
2073 spin_lock(&cluster->lock);
2074 node = rb_first(&cluster->root);
2075 if (!node) {
2076 spin_unlock(&cluster->lock);
2077 goto no_cluster_bitmap;
2078 }
2079
2080 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2081 if (!entry->bitmap) {
2082 spin_unlock(&cluster->lock);
2083 goto no_cluster_bitmap;
2084 }
2085
2086 if (entry->offset == offset_to_bitmap(ctl, offset)) {
2087 bytes_added = add_bytes_to_bitmap(ctl, entry,
2088 offset, bytes);
2089 bytes -= bytes_added;
2090 offset += bytes_added;
2091 }
2092 spin_unlock(&cluster->lock);
2093 if (!bytes) {
2094 ret = 1;
2095 goto out;
2096 }
2097 }
2098
2099 no_cluster_bitmap:
2100 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2101 1, 0);
2102 if (!bitmap_info) {
2103 ASSERT(added == 0);
2104 goto new_bitmap;
2105 }
2106
2107 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
2108 bytes -= bytes_added;
2109 offset += bytes_added;
2110 added = 0;
2111
2112 if (!bytes) {
2113 ret = 1;
2114 goto out;
2115 } else
2116 goto again;
2117
2118 new_bitmap:
2119 if (info && info->bitmap) {
2120 add_new_bitmap(ctl, info, offset);
2121 added = 1;
2122 info = NULL;
2123 goto again;
2124 } else {
2125 spin_unlock(&ctl->tree_lock);
2126
2127 /* no pre-allocated info, allocate a new one */
2128 if (!info) {
2129 info = kmem_cache_zalloc(btrfs_free_space_cachep,
2130 GFP_NOFS);
2131 if (!info) {
2132 spin_lock(&ctl->tree_lock);
2133 ret = -ENOMEM;
2134 goto out;
2135 }
2136 }
2137
2138 /* allocate the bitmap */
2139 info->bitmap = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep,
2140 GFP_NOFS);
2141 spin_lock(&ctl->tree_lock);
2142 if (!info->bitmap) {
2143 ret = -ENOMEM;
2144 goto out;
2145 }
2146 goto again;
2147 }
2148
2149 out:
2150 if (info) {
2151 if (info->bitmap)
2152 kmem_cache_free(btrfs_free_space_bitmap_cachep,
2153 info->bitmap);
2154 kmem_cache_free(btrfs_free_space_cachep, info);
2155 }
2156
2157 return ret;
2158 }
2159
2160 static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
2161 struct btrfs_free_space *info, bool update_stat)
2162 {
2163 struct btrfs_free_space *left_info;
2164 struct btrfs_free_space *right_info;
2165 bool merged = false;
2166 u64 offset = info->offset;
2167 u64 bytes = info->bytes;
2168
2169 /*
2170 * first we want to see if there is free space adjacent to the range we
2171 * are adding, if there is remove that struct and add a new one to
2172 * cover the entire range
2173 */
2174 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
2175 if (right_info && rb_prev(&right_info->offset_index))
2176 left_info = rb_entry(rb_prev(&right_info->offset_index),
2177 struct btrfs_free_space, offset_index);
2178 else
2179 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
2180
2181 if (right_info && !right_info->bitmap) {
2182 if (update_stat)
2183 unlink_free_space(ctl, right_info);
2184 else
2185 __unlink_free_space(ctl, right_info);
2186 info->bytes += right_info->bytes;
2187 kmem_cache_free(btrfs_free_space_cachep, right_info);
2188 merged = true;
2189 }
2190
2191 if (left_info && !left_info->bitmap &&
2192 left_info->offset + left_info->bytes == offset) {
2193 if (update_stat)
2194 unlink_free_space(ctl, left_info);
2195 else
2196 __unlink_free_space(ctl, left_info);
2197 info->offset = left_info->offset;
2198 info->bytes += left_info->bytes;
2199 kmem_cache_free(btrfs_free_space_cachep, left_info);
2200 merged = true;
2201 }
2202
2203 return merged;
2204 }
2205
2206 static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2207 struct btrfs_free_space *info,
2208 bool update_stat)
2209 {
2210 struct btrfs_free_space *bitmap;
2211 unsigned long i;
2212 unsigned long j;
2213 const u64 end = info->offset + info->bytes;
2214 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2215 u64 bytes;
2216
2217 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2218 if (!bitmap)
2219 return false;
2220
2221 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2222 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2223 if (j == i)
2224 return false;
2225 bytes = (j - i) * ctl->unit;
2226 info->bytes += bytes;
2227
2228 if (update_stat)
2229 bitmap_clear_bits(ctl, bitmap, end, bytes);
2230 else
2231 __bitmap_clear_bits(ctl, bitmap, end, bytes);
2232
2233 if (!bitmap->bytes)
2234 free_bitmap(ctl, bitmap);
2235
2236 return true;
2237 }
2238
2239 static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2240 struct btrfs_free_space *info,
2241 bool update_stat)
2242 {
2243 struct btrfs_free_space *bitmap;
2244 u64 bitmap_offset;
2245 unsigned long i;
2246 unsigned long j;
2247 unsigned long prev_j;
2248 u64 bytes;
2249
2250 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2251 /* If we're on a boundary, try the previous logical bitmap. */
2252 if (bitmap_offset == info->offset) {
2253 if (info->offset == 0)
2254 return false;
2255 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2256 }
2257
2258 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2259 if (!bitmap)
2260 return false;
2261
2262 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2263 j = 0;
2264 prev_j = (unsigned long)-1;
2265 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2266 if (j > i)
2267 break;
2268 prev_j = j;
2269 }
2270 if (prev_j == i)
2271 return false;
2272
2273 if (prev_j == (unsigned long)-1)
2274 bytes = (i + 1) * ctl->unit;
2275 else
2276 bytes = (i - prev_j) * ctl->unit;
2277
2278 info->offset -= bytes;
2279 info->bytes += bytes;
2280
2281 if (update_stat)
2282 bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2283 else
2284 __bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2285
2286 if (!bitmap->bytes)
2287 free_bitmap(ctl, bitmap);
2288
2289 return true;
2290 }
2291
2292 /*
2293 * We prefer always to allocate from extent entries, both for clustered and
2294 * non-clustered allocation requests. So when attempting to add a new extent
2295 * entry, try to see if there's adjacent free space in bitmap entries, and if
2296 * there is, migrate that space from the bitmaps to the extent.
2297 * Like this we get better chances of satisfying space allocation requests
2298 * because we attempt to satisfy them based on a single cache entry, and never
2299 * on 2 or more entries - even if the entries represent a contiguous free space
2300 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2301 * ends).
2302 */
2303 static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2304 struct btrfs_free_space *info,
2305 bool update_stat)
2306 {
2307 /*
2308 * Only work with disconnected entries, as we can change their offset,
2309 * and must be extent entries.
2310 */
2311 ASSERT(!info->bitmap);
2312 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2313
2314 if (ctl->total_bitmaps > 0) {
2315 bool stole_end;
2316 bool stole_front = false;
2317
2318 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2319 if (ctl->total_bitmaps > 0)
2320 stole_front = steal_from_bitmap_to_front(ctl, info,
2321 update_stat);
2322
2323 if (stole_end || stole_front)
2324 try_merge_free_space(ctl, info, update_stat);
2325 }
2326 }
2327
2328 int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
2329 struct btrfs_free_space_ctl *ctl,
2330 u64 offset, u64 bytes)
2331 {
2332 struct btrfs_free_space *info;
2333 int ret = 0;
2334
2335 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2336 if (!info)
2337 return -ENOMEM;
2338
2339 info->offset = offset;
2340 info->bytes = bytes;
2341 RB_CLEAR_NODE(&info->offset_index);
2342
2343 spin_lock(&ctl->tree_lock);
2344
2345 if (try_merge_free_space(ctl, info, true))
2346 goto link;
2347
2348 /*
2349 * There was no extent directly to the left or right of this new
2350 * extent then we know we're going to have to allocate a new extent, so
2351 * before we do that see if we need to drop this into a bitmap
2352 */
2353 ret = insert_into_bitmap(ctl, info);
2354 if (ret < 0) {
2355 goto out;
2356 } else if (ret) {
2357 ret = 0;
2358 goto out;
2359 }
2360 link:
2361 /*
2362 * Only steal free space from adjacent bitmaps if we're sure we're not
2363 * going to add the new free space to existing bitmap entries - because
2364 * that would mean unnecessary work that would be reverted. Therefore
2365 * attempt to steal space from bitmaps if we're adding an extent entry.
2366 */
2367 steal_from_bitmap(ctl, info, true);
2368
2369 ret = link_free_space(ctl, info);
2370 if (ret)
2371 kmem_cache_free(btrfs_free_space_cachep, info);
2372 out:
2373 spin_unlock(&ctl->tree_lock);
2374
2375 if (ret) {
2376 btrfs_crit(fs_info, "unable to add free space :%d", ret);
2377 ASSERT(ret != -EEXIST);
2378 }
2379
2380 return ret;
2381 }
2382
2383 int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
2384 u64 bytenr, u64 size)
2385 {
2386 return __btrfs_add_free_space(block_group->fs_info,
2387 block_group->free_space_ctl,
2388 bytenr, size);
2389 }
2390
2391 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
2392 u64 offset, u64 bytes)
2393 {
2394 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2395 struct btrfs_free_space *info;
2396 int ret;
2397 bool re_search = false;
2398
2399 spin_lock(&ctl->tree_lock);
2400
2401 again:
2402 ret = 0;
2403 if (!bytes)
2404 goto out_lock;
2405
2406 info = tree_search_offset(ctl, offset, 0, 0);
2407 if (!info) {
2408 /*
2409 * oops didn't find an extent that matched the space we wanted
2410 * to remove, look for a bitmap instead
2411 */
2412 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2413 1, 0);
2414 if (!info) {
2415 /*
2416 * If we found a partial bit of our free space in a
2417 * bitmap but then couldn't find the other part this may
2418 * be a problem, so WARN about it.
2419 */
2420 WARN_ON(re_search);
2421 goto out_lock;
2422 }
2423 }
2424
2425 re_search = false;
2426 if (!info->bitmap) {
2427 unlink_free_space(ctl, info);
2428 if (offset == info->offset) {
2429 u64 to_free = min(bytes, info->bytes);
2430
2431 info->bytes -= to_free;
2432 info->offset += to_free;
2433 if (info->bytes) {
2434 ret = link_free_space(ctl, info);
2435 WARN_ON(ret);
2436 } else {
2437 kmem_cache_free(btrfs_free_space_cachep, info);
2438 }
2439
2440 offset += to_free;
2441 bytes -= to_free;
2442 goto again;
2443 } else {
2444 u64 old_end = info->bytes + info->offset;
2445
2446 info->bytes = offset - info->offset;
2447 ret = link_free_space(ctl, info);
2448 WARN_ON(ret);
2449 if (ret)
2450 goto out_lock;
2451
2452 /* Not enough bytes in this entry to satisfy us */
2453 if (old_end < offset + bytes) {
2454 bytes -= old_end - offset;
2455 offset = old_end;
2456 goto again;
2457 } else if (old_end == offset + bytes) {
2458 /* all done */
2459 goto out_lock;
2460 }
2461 spin_unlock(&ctl->tree_lock);
2462
2463 ret = btrfs_add_free_space(block_group, offset + bytes,
2464 old_end - (offset + bytes));
2465 WARN_ON(ret);
2466 goto out;
2467 }
2468 }
2469
2470 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2471 if (ret == -EAGAIN) {
2472 re_search = true;
2473 goto again;
2474 }
2475 out_lock:
2476 spin_unlock(&ctl->tree_lock);
2477 out:
2478 return ret;
2479 }
2480
2481 void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
2482 u64 bytes)
2483 {
2484 struct btrfs_fs_info *fs_info = block_group->fs_info;
2485 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2486 struct btrfs_free_space *info;
2487 struct rb_node *n;
2488 int count = 0;
2489
2490 spin_lock(&ctl->tree_lock);
2491 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2492 info = rb_entry(n, struct btrfs_free_space, offset_index);
2493 if (info->bytes >= bytes && !block_group->ro)
2494 count++;
2495 btrfs_crit(fs_info, "entry offset %llu, bytes %llu, bitmap %s",
2496 info->offset, info->bytes,
2497 (info->bitmap) ? "yes" : "no");
2498 }
2499 spin_unlock(&ctl->tree_lock);
2500 btrfs_info(fs_info, "block group has cluster?: %s",
2501 list_empty(&block_group->cluster_list) ? "no" : "yes");
2502 btrfs_info(fs_info,
2503 "%d blocks of free space at or bigger than bytes is", count);
2504 }
2505
2506 void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
2507 {
2508 struct btrfs_fs_info *fs_info = block_group->fs_info;
2509 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2510
2511 spin_lock_init(&ctl->tree_lock);
2512 ctl->unit = fs_info->sectorsize;
2513 ctl->start = block_group->key.objectid;
2514 ctl->private = block_group;
2515 ctl->op = &free_space_op;
2516 INIT_LIST_HEAD(&ctl->trimming_ranges);
2517 mutex_init(&ctl->cache_writeout_mutex);
2518
2519 /*
2520 * we only want to have 32k of ram per block group for keeping
2521 * track of free space, and if we pass 1/2 of that we want to
2522 * start converting things over to using bitmaps
2523 */
2524 ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
2525 }
2526
2527 /*
2528 * for a given cluster, put all of its extents back into the free
2529 * space cache. If the block group passed doesn't match the block group
2530 * pointed to by the cluster, someone else raced in and freed the
2531 * cluster already. In that case, we just return without changing anything
2532 */
2533 static int
2534 __btrfs_return_cluster_to_free_space(
2535 struct btrfs_block_group_cache *block_group,
2536 struct btrfs_free_cluster *cluster)
2537 {
2538 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2539 struct btrfs_free_space *entry;
2540 struct rb_node *node;
2541
2542 spin_lock(&cluster->lock);
2543 if (cluster->block_group != block_group)
2544 goto out;
2545
2546 cluster->block_group = NULL;
2547 cluster->window_start = 0;
2548 list_del_init(&cluster->block_group_list);
2549
2550 node = rb_first(&cluster->root);
2551 while (node) {
2552 bool bitmap;
2553
2554 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2555 node = rb_next(&entry->offset_index);
2556 rb_erase(&entry->offset_index, &cluster->root);
2557 RB_CLEAR_NODE(&entry->offset_index);
2558
2559 bitmap = (entry->bitmap != NULL);
2560 if (!bitmap) {
2561 try_merge_free_space(ctl, entry, false);
2562 steal_from_bitmap(ctl, entry, false);
2563 }
2564 tree_insert_offset(&ctl->free_space_offset,
2565 entry->offset, &entry->offset_index, bitmap);
2566 }
2567 cluster->root = RB_ROOT;
2568
2569 out:
2570 spin_unlock(&cluster->lock);
2571 btrfs_put_block_group(block_group);
2572 return 0;
2573 }
2574
2575 static void __btrfs_remove_free_space_cache_locked(
2576 struct btrfs_free_space_ctl *ctl)
2577 {
2578 struct btrfs_free_space *info;
2579 struct rb_node *node;
2580
2581 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2582 info = rb_entry(node, struct btrfs_free_space, offset_index);
2583 if (!info->bitmap) {
2584 unlink_free_space(ctl, info);
2585 kmem_cache_free(btrfs_free_space_cachep, info);
2586 } else {
2587 free_bitmap(ctl, info);
2588 }
2589
2590 cond_resched_lock(&ctl->tree_lock);
2591 }
2592 }
2593
2594 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2595 {
2596 spin_lock(&ctl->tree_lock);
2597 __btrfs_remove_free_space_cache_locked(ctl);
2598 spin_unlock(&ctl->tree_lock);
2599 }
2600
2601 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
2602 {
2603 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2604 struct btrfs_free_cluster *cluster;
2605 struct list_head *head;
2606
2607 spin_lock(&ctl->tree_lock);
2608 while ((head = block_group->cluster_list.next) !=
2609 &block_group->cluster_list) {
2610 cluster = list_entry(head, struct btrfs_free_cluster,
2611 block_group_list);
2612
2613 WARN_ON(cluster->block_group != block_group);
2614 __btrfs_return_cluster_to_free_space(block_group, cluster);
2615
2616 cond_resched_lock(&ctl->tree_lock);
2617 }
2618 __btrfs_remove_free_space_cache_locked(ctl);
2619 spin_unlock(&ctl->tree_lock);
2620
2621 }
2622
2623 u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
2624 u64 offset, u64 bytes, u64 empty_size,
2625 u64 *max_extent_size)
2626 {
2627 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2628 struct btrfs_free_space *entry = NULL;
2629 u64 bytes_search = bytes + empty_size;
2630 u64 ret = 0;
2631 u64 align_gap = 0;
2632 u64 align_gap_len = 0;
2633
2634 spin_lock(&ctl->tree_lock);
2635 entry = find_free_space(ctl, &offset, &bytes_search,
2636 block_group->full_stripe_len, max_extent_size);
2637 if (!entry)
2638 goto out;
2639
2640 ret = offset;
2641 if (entry->bitmap) {
2642 bitmap_clear_bits(ctl, entry, offset, bytes);
2643 if (!entry->bytes)
2644 free_bitmap(ctl, entry);
2645 } else {
2646 unlink_free_space(ctl, entry);
2647 align_gap_len = offset - entry->offset;
2648 align_gap = entry->offset;
2649
2650 entry->offset = offset + bytes;
2651 WARN_ON(entry->bytes < bytes + align_gap_len);
2652
2653 entry->bytes -= bytes + align_gap_len;
2654 if (!entry->bytes)
2655 kmem_cache_free(btrfs_free_space_cachep, entry);
2656 else
2657 link_free_space(ctl, entry);
2658 }
2659 out:
2660 spin_unlock(&ctl->tree_lock);
2661
2662 if (align_gap_len)
2663 __btrfs_add_free_space(block_group->fs_info, ctl,
2664 align_gap, align_gap_len);
2665 return ret;
2666 }
2667
2668 /*
2669 * given a cluster, put all of its extents back into the free space
2670 * cache. If a block group is passed, this function will only free
2671 * a cluster that belongs to the passed block group.
2672 *
2673 * Otherwise, it'll get a reference on the block group pointed to by the
2674 * cluster and remove the cluster from it.
2675 */
2676 int btrfs_return_cluster_to_free_space(
2677 struct btrfs_block_group_cache *block_group,
2678 struct btrfs_free_cluster *cluster)
2679 {
2680 struct btrfs_free_space_ctl *ctl;
2681 int ret;
2682
2683 /* first, get a safe pointer to the block group */
2684 spin_lock(&cluster->lock);
2685 if (!block_group) {
2686 block_group = cluster->block_group;
2687 if (!block_group) {
2688 spin_unlock(&cluster->lock);
2689 return 0;
2690 }
2691 } else if (cluster->block_group != block_group) {
2692 /* someone else has already freed it don't redo their work */
2693 spin_unlock(&cluster->lock);
2694 return 0;
2695 }
2696 atomic_inc(&block_group->count);
2697 spin_unlock(&cluster->lock);
2698
2699 ctl = block_group->free_space_ctl;
2700
2701 /* now return any extents the cluster had on it */
2702 spin_lock(&ctl->tree_lock);
2703 ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
2704 spin_unlock(&ctl->tree_lock);
2705
2706 /* finally drop our ref */
2707 btrfs_put_block_group(block_group);
2708 return ret;
2709 }
2710
2711 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
2712 struct btrfs_free_cluster *cluster,
2713 struct btrfs_free_space *entry,
2714 u64 bytes, u64 min_start,
2715 u64 *max_extent_size)
2716 {
2717 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2718 int err;
2719 u64 search_start = cluster->window_start;
2720 u64 search_bytes = bytes;
2721 u64 ret = 0;
2722
2723 search_start = min_start;
2724 search_bytes = bytes;
2725
2726 err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
2727 if (err) {
2728 *max_extent_size = max(get_max_extent_size(entry),
2729 *max_extent_size);
2730 return 0;
2731 }
2732
2733 ret = search_start;
2734 __bitmap_clear_bits(ctl, entry, ret, bytes);
2735
2736 return ret;
2737 }
2738
2739 /*
2740 * given a cluster, try to allocate 'bytes' from it, returns 0
2741 * if it couldn't find anything suitably large, or a logical disk offset
2742 * if things worked out
2743 */
2744 u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
2745 struct btrfs_free_cluster *cluster, u64 bytes,
2746 u64 min_start, u64 *max_extent_size)
2747 {
2748 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2749 struct btrfs_free_space *entry = NULL;
2750 struct rb_node *node;
2751 u64 ret = 0;
2752
2753 spin_lock(&cluster->lock);
2754 if (bytes > cluster->max_size)
2755 goto out;
2756
2757 if (cluster->block_group != block_group)
2758 goto out;
2759
2760 node = rb_first(&cluster->root);
2761 if (!node)
2762 goto out;
2763
2764 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2765 while (1) {
2766 if (entry->bytes < bytes)
2767 *max_extent_size = max(get_max_extent_size(entry),
2768 *max_extent_size);
2769
2770 if (entry->bytes < bytes ||
2771 (!entry->bitmap && entry->offset < min_start)) {
2772 node = rb_next(&entry->offset_index);
2773 if (!node)
2774 break;
2775 entry = rb_entry(node, struct btrfs_free_space,
2776 offset_index);
2777 continue;
2778 }
2779
2780 if (entry->bitmap) {
2781 ret = btrfs_alloc_from_bitmap(block_group,
2782 cluster, entry, bytes,
2783 cluster->window_start,
2784 max_extent_size);
2785 if (ret == 0) {
2786 node = rb_next(&entry->offset_index);
2787 if (!node)
2788 break;
2789 entry = rb_entry(node, struct btrfs_free_space,
2790 offset_index);
2791 continue;
2792 }
2793 cluster->window_start += bytes;
2794 } else {
2795 ret = entry->offset;
2796
2797 entry->offset += bytes;
2798 entry->bytes -= bytes;
2799 }
2800
2801 if (entry->bytes == 0)
2802 rb_erase(&entry->offset_index, &cluster->root);
2803 break;
2804 }
2805 out:
2806 spin_unlock(&cluster->lock);
2807
2808 if (!ret)
2809 return 0;
2810
2811 spin_lock(&ctl->tree_lock);
2812
2813 ctl->free_space -= bytes;
2814 if (entry->bytes == 0) {
2815 ctl->free_extents--;
2816 if (entry->bitmap) {
2817 kmem_cache_free(btrfs_free_space_bitmap_cachep,
2818 entry->bitmap);
2819 ctl->total_bitmaps--;
2820 ctl->op->recalc_thresholds(ctl);
2821 }
2822 kmem_cache_free(btrfs_free_space_cachep, entry);
2823 }
2824
2825 spin_unlock(&ctl->tree_lock);
2826
2827 return ret;
2828 }
2829
2830 static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
2831 struct btrfs_free_space *entry,
2832 struct btrfs_free_cluster *cluster,
2833 u64 offset, u64 bytes,
2834 u64 cont1_bytes, u64 min_bytes)
2835 {
2836 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2837 unsigned long next_zero;
2838 unsigned long i;
2839 unsigned long want_bits;
2840 unsigned long min_bits;
2841 unsigned long found_bits;
2842 unsigned long max_bits = 0;
2843 unsigned long start = 0;
2844 unsigned long total_found = 0;
2845 int ret;
2846
2847 i = offset_to_bit(entry->offset, ctl->unit,
2848 max_t(u64, offset, entry->offset));
2849 want_bits = bytes_to_bits(bytes, ctl->unit);
2850 min_bits = bytes_to_bits(min_bytes, ctl->unit);
2851
2852 /*
2853 * Don't bother looking for a cluster in this bitmap if it's heavily
2854 * fragmented.
2855 */
2856 if (entry->max_extent_size &&
2857 entry->max_extent_size < cont1_bytes)
2858 return -ENOSPC;
2859 again:
2860 found_bits = 0;
2861 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
2862 next_zero = find_next_zero_bit(entry->bitmap,
2863 BITS_PER_BITMAP, i);
2864 if (next_zero - i >= min_bits) {
2865 found_bits = next_zero - i;
2866 if (found_bits > max_bits)
2867 max_bits = found_bits;
2868 break;
2869 }
2870 if (next_zero - i > max_bits)
2871 max_bits = next_zero - i;
2872 i = next_zero;
2873 }
2874
2875 if (!found_bits) {
2876 entry->max_extent_size = (u64)max_bits * ctl->unit;
2877 return -ENOSPC;
2878 }
2879
2880 if (!total_found) {
2881 start = i;
2882 cluster->max_size = 0;
2883 }
2884
2885 total_found += found_bits;
2886
2887 if (cluster->max_size < found_bits * ctl->unit)
2888 cluster->max_size = found_bits * ctl->unit;
2889
2890 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
2891 i = next_zero + 1;
2892 goto again;
2893 }
2894
2895 cluster->window_start = start * ctl->unit + entry->offset;
2896 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2897 ret = tree_insert_offset(&cluster->root, entry->offset,
2898 &entry->offset_index, 1);
2899 ASSERT(!ret); /* -EEXIST; Logic error */
2900
2901 trace_btrfs_setup_cluster(block_group, cluster,
2902 total_found * ctl->unit, 1);
2903 return 0;
2904 }
2905
2906 /*
2907 * This searches the block group for just extents to fill the cluster with.
2908 * Try to find a cluster with at least bytes total bytes, at least one
2909 * extent of cont1_bytes, and other clusters of at least min_bytes.
2910 */
2911 static noinline int
2912 setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
2913 struct btrfs_free_cluster *cluster,
2914 struct list_head *bitmaps, u64 offset, u64 bytes,
2915 u64 cont1_bytes, u64 min_bytes)
2916 {
2917 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2918 struct btrfs_free_space *first = NULL;
2919 struct btrfs_free_space *entry = NULL;
2920 struct btrfs_free_space *last;
2921 struct rb_node *node;
2922 u64 window_free;
2923 u64 max_extent;
2924 u64 total_size = 0;
2925
2926 entry = tree_search_offset(ctl, offset, 0, 1);
2927 if (!entry)
2928 return -ENOSPC;
2929
2930 /*
2931 * We don't want bitmaps, so just move along until we find a normal
2932 * extent entry.
2933 */
2934 while (entry->bitmap || entry->bytes < min_bytes) {
2935 if (entry->bitmap && list_empty(&entry->list))
2936 list_add_tail(&entry->list, bitmaps);
2937 node = rb_next(&entry->offset_index);
2938 if (!node)
2939 return -ENOSPC;
2940 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2941 }
2942
2943 window_free = entry->bytes;
2944 max_extent = entry->bytes;
2945 first = entry;
2946 last = entry;
2947
2948 for (node = rb_next(&entry->offset_index); node;
2949 node = rb_next(&entry->offset_index)) {
2950 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2951
2952 if (entry->bitmap) {
2953 if (list_empty(&entry->list))
2954 list_add_tail(&entry->list, bitmaps);
2955 continue;
2956 }
2957
2958 if (entry->bytes < min_bytes)
2959 continue;
2960
2961 last = entry;
2962 window_free += entry->bytes;
2963 if (entry->bytes > max_extent)
2964 max_extent = entry->bytes;
2965 }
2966
2967 if (window_free < bytes || max_extent < cont1_bytes)
2968 return -ENOSPC;
2969
2970 cluster->window_start = first->offset;
2971
2972 node = &first->offset_index;
2973
2974 /*
2975 * now we've found our entries, pull them out of the free space
2976 * cache and put them into the cluster rbtree
2977 */
2978 do {
2979 int ret;
2980
2981 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2982 node = rb_next(&entry->offset_index);
2983 if (entry->bitmap || entry->bytes < min_bytes)
2984 continue;
2985
2986 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2987 ret = tree_insert_offset(&cluster->root, entry->offset,
2988 &entry->offset_index, 0);
2989 total_size += entry->bytes;
2990 ASSERT(!ret); /* -EEXIST; Logic error */
2991 } while (node && entry != last);
2992
2993 cluster->max_size = max_extent;
2994 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
2995 return 0;
2996 }
2997
2998 /*
2999 * This specifically looks for bitmaps that may work in the cluster, we assume
3000 * that we have already failed to find extents that will work.
3001 */
3002 static noinline int
3003 setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
3004 struct btrfs_free_cluster *cluster,
3005 struct list_head *bitmaps, u64 offset, u64 bytes,
3006 u64 cont1_bytes, u64 min_bytes)
3007 {
3008 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3009 struct btrfs_free_space *entry = NULL;
3010 int ret = -ENOSPC;
3011 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
3012
3013 if (ctl->total_bitmaps == 0)
3014 return -ENOSPC;
3015
3016 /*
3017 * The bitmap that covers offset won't be in the list unless offset
3018 * is just its start offset.
3019 */
3020 if (!list_empty(bitmaps))
3021 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
3022
3023 if (!entry || entry->offset != bitmap_offset) {
3024 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
3025 if (entry && list_empty(&entry->list))
3026 list_add(&entry->list, bitmaps);
3027 }
3028
3029 list_for_each_entry(entry, bitmaps, list) {
3030 if (entry->bytes < bytes)
3031 continue;
3032 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
3033 bytes, cont1_bytes, min_bytes);
3034 if (!ret)
3035 return 0;
3036 }
3037
3038 /*
3039 * The bitmaps list has all the bitmaps that record free space
3040 * starting after offset, so no more search is required.
3041 */
3042 return -ENOSPC;
3043 }
3044
3045 /*
3046 * here we try to find a cluster of blocks in a block group. The goal
3047 * is to find at least bytes+empty_size.
3048 * We might not find them all in one contiguous area.
3049 *
3050 * returns zero and sets up cluster if things worked out, otherwise
3051 * it returns -enospc
3052 */
3053 int btrfs_find_space_cluster(struct btrfs_block_group_cache *block_group,
3054 struct btrfs_free_cluster *cluster,
3055 u64 offset, u64 bytes, u64 empty_size)
3056 {
3057 struct btrfs_fs_info *fs_info = block_group->fs_info;
3058 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3059 struct btrfs_free_space *entry, *tmp;
3060 LIST_HEAD(bitmaps);
3061 u64 min_bytes;
3062 u64 cont1_bytes;
3063 int ret;
3064
3065 /*
3066 * Choose the minimum extent size we'll require for this
3067 * cluster. For SSD_SPREAD, don't allow any fragmentation.
3068 * For metadata, allow allocates with smaller extents. For
3069 * data, keep it dense.
3070 */
3071 if (btrfs_test_opt(fs_info, SSD_SPREAD)) {
3072 cont1_bytes = min_bytes = bytes + empty_size;
3073 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
3074 cont1_bytes = bytes;
3075 min_bytes = fs_info->sectorsize;
3076 } else {
3077 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
3078 min_bytes = fs_info->sectorsize;
3079 }
3080
3081 spin_lock(&ctl->tree_lock);
3082
3083 /*
3084 * If we know we don't have enough space to make a cluster don't even
3085 * bother doing all the work to try and find one.
3086 */
3087 if (ctl->free_space < bytes) {
3088 spin_unlock(&ctl->tree_lock);
3089 return -ENOSPC;
3090 }
3091
3092 spin_lock(&cluster->lock);
3093
3094 /* someone already found a cluster, hooray */
3095 if (cluster->block_group) {
3096 ret = 0;
3097 goto out;
3098 }
3099
3100 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
3101 min_bytes);
3102
3103 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
3104 bytes + empty_size,
3105 cont1_bytes, min_bytes);
3106 if (ret)
3107 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
3108 offset, bytes + empty_size,
3109 cont1_bytes, min_bytes);
3110
3111 /* Clear our temporary list */
3112 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
3113 list_del_init(&entry->list);
3114
3115 if (!ret) {
3116 atomic_inc(&block_group->count);
3117 list_add_tail(&cluster->block_group_list,
3118 &block_group->cluster_list);
3119 cluster->block_group = block_group;
3120 } else {
3121 trace_btrfs_failed_cluster_setup(block_group);
3122 }
3123 out:
3124 spin_unlock(&cluster->lock);
3125 spin_unlock(&ctl->tree_lock);
3126
3127 return ret;
3128 }
3129
3130 /*
3131 * simple code to zero out a cluster
3132 */
3133 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
3134 {
3135 spin_lock_init(&cluster->lock);
3136 spin_lock_init(&cluster->refill_lock);
3137 cluster->root = RB_ROOT;
3138 cluster->max_size = 0;
3139 cluster->fragmented = false;
3140 INIT_LIST_HEAD(&cluster->block_group_list);
3141 cluster->block_group = NULL;
3142 }
3143
3144 static int do_trimming(struct btrfs_block_group_cache *block_group,
3145 u64 *total_trimmed, u64 start, u64 bytes,
3146 u64 reserved_start, u64 reserved_bytes,
3147 struct btrfs_trim_range *trim_entry)
3148 {
3149 struct btrfs_space_info *space_info = block_group->space_info;
3150 struct btrfs_fs_info *fs_info = block_group->fs_info;
3151 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3152 int ret;
3153 int update = 0;
3154 u64 trimmed = 0;
3155
3156 spin_lock(&space_info->lock);
3157 spin_lock(&block_group->lock);
3158 if (!block_group->ro) {
3159 block_group->reserved += reserved_bytes;
3160 space_info->bytes_reserved += reserved_bytes;
3161 update = 1;
3162 }
3163 spin_unlock(&block_group->lock);
3164 spin_unlock(&space_info->lock);
3165
3166 ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
3167 if (!ret)
3168 *total_trimmed += trimmed;
3169
3170 mutex_lock(&ctl->cache_writeout_mutex);
3171 btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
3172 list_del(&trim_entry->list);
3173 mutex_unlock(&ctl->cache_writeout_mutex);
3174
3175 if (update) {
3176 spin_lock(&space_info->lock);
3177 spin_lock(&block_group->lock);
3178 if (block_group->ro)
3179 space_info->bytes_readonly += reserved_bytes;
3180 block_group->reserved -= reserved_bytes;
3181 space_info->bytes_reserved -= reserved_bytes;
3182 spin_unlock(&block_group->lock);
3183 spin_unlock(&space_info->lock);
3184 }
3185
3186 return ret;
3187 }
3188
3189 static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
3190 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3191 {
3192 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3193 struct btrfs_free_space *entry;
3194 struct rb_node *node;
3195 int ret = 0;
3196 u64 extent_start;
3197 u64 extent_bytes;
3198 u64 bytes;
3199
3200 while (start < end) {
3201 struct btrfs_trim_range trim_entry;
3202
3203 mutex_lock(&ctl->cache_writeout_mutex);
3204 spin_lock(&ctl->tree_lock);
3205
3206 if (ctl->free_space < minlen) {
3207 spin_unlock(&ctl->tree_lock);
3208 mutex_unlock(&ctl->cache_writeout_mutex);
3209 break;
3210 }
3211
3212 entry = tree_search_offset(ctl, start, 0, 1);
3213 if (!entry) {
3214 spin_unlock(&ctl->tree_lock);
3215 mutex_unlock(&ctl->cache_writeout_mutex);
3216 break;
3217 }
3218
3219 /* skip bitmaps */
3220 while (entry->bitmap) {
3221 node = rb_next(&entry->offset_index);
3222 if (!node) {
3223 spin_unlock(&ctl->tree_lock);
3224 mutex_unlock(&ctl->cache_writeout_mutex);
3225 goto out;
3226 }
3227 entry = rb_entry(node, struct btrfs_free_space,
3228 offset_index);
3229 }
3230
3231 if (entry->offset >= end) {
3232 spin_unlock(&ctl->tree_lock);
3233 mutex_unlock(&ctl->cache_writeout_mutex);
3234 break;
3235 }
3236
3237 extent_start = entry->offset;
3238 extent_bytes = entry->bytes;
3239 start = max(start, extent_start);
3240 bytes = min(extent_start + extent_bytes, end) - start;
3241 if (bytes < minlen) {
3242 spin_unlock(&ctl->tree_lock);
3243 mutex_unlock(&ctl->cache_writeout_mutex);
3244 goto next;
3245 }
3246
3247 unlink_free_space(ctl, entry);
3248 kmem_cache_free(btrfs_free_space_cachep, entry);
3249
3250 spin_unlock(&ctl->tree_lock);
3251 trim_entry.start = extent_start;
3252 trim_entry.bytes = extent_bytes;
3253 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3254 mutex_unlock(&ctl->cache_writeout_mutex);
3255
3256 ret = do_trimming(block_group, total_trimmed, start, bytes,
3257 extent_start, extent_bytes, &trim_entry);
3258 if (ret)
3259 break;
3260 next:
3261 start += bytes;
3262
3263 if (fatal_signal_pending(current)) {
3264 ret = -ERESTARTSYS;
3265 break;
3266 }
3267
3268 cond_resched();
3269 }
3270 out:
3271 return ret;
3272 }
3273
3274 static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
3275 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3276 {
3277 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3278 struct btrfs_free_space *entry;
3279 int ret = 0;
3280 int ret2;
3281 u64 bytes;
3282 u64 offset = offset_to_bitmap(ctl, start);
3283
3284 while (offset < end) {
3285 bool next_bitmap = false;
3286 struct btrfs_trim_range trim_entry;
3287
3288 mutex_lock(&ctl->cache_writeout_mutex);
3289 spin_lock(&ctl->tree_lock);
3290
3291 if (ctl->free_space < minlen) {
3292 spin_unlock(&ctl->tree_lock);
3293 mutex_unlock(&ctl->cache_writeout_mutex);
3294 break;
3295 }
3296
3297 entry = tree_search_offset(ctl, offset, 1, 0);
3298 if (!entry) {
3299 spin_unlock(&ctl->tree_lock);
3300 mutex_unlock(&ctl->cache_writeout_mutex);
3301 next_bitmap = true;
3302 goto next;
3303 }
3304
3305 bytes = minlen;
3306 ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
3307 if (ret2 || start >= end) {
3308 spin_unlock(&ctl->tree_lock);
3309 mutex_unlock(&ctl->cache_writeout_mutex);
3310 next_bitmap = true;
3311 goto next;
3312 }
3313
3314 bytes = min(bytes, end - start);
3315 if (bytes < minlen) {
3316 spin_unlock(&ctl->tree_lock);
3317 mutex_unlock(&ctl->cache_writeout_mutex);
3318 goto next;
3319 }
3320
3321 bitmap_clear_bits(ctl, entry, start, bytes);
3322 if (entry->bytes == 0)
3323 free_bitmap(ctl, entry);
3324
3325 spin_unlock(&ctl->tree_lock);
3326 trim_entry.start = start;
3327 trim_entry.bytes = bytes;
3328 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3329 mutex_unlock(&ctl->cache_writeout_mutex);
3330
3331 ret = do_trimming(block_group, total_trimmed, start, bytes,
3332 start, bytes, &trim_entry);
3333 if (ret)
3334 break;
3335 next:
3336 if (next_bitmap) {
3337 offset += BITS_PER_BITMAP * ctl->unit;
3338 } else {
3339 start += bytes;
3340 if (start >= offset + BITS_PER_BITMAP * ctl->unit)
3341 offset += BITS_PER_BITMAP * ctl->unit;
3342 }
3343
3344 if (fatal_signal_pending(current)) {
3345 ret = -ERESTARTSYS;
3346 break;
3347 }
3348
3349 cond_resched();
3350 }
3351
3352 return ret;
3353 }
3354
3355 void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache)
3356 {
3357 atomic_inc(&cache->trimming);
3358 }
3359
3360 void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *block_group)
3361 {
3362 struct btrfs_fs_info *fs_info = block_group->fs_info;
3363 struct extent_map_tree *em_tree;
3364 struct extent_map *em;
3365 bool cleanup;
3366
3367 spin_lock(&block_group->lock);
3368 cleanup = (atomic_dec_and_test(&block_group->trimming) &&
3369 block_group->removed);
3370 spin_unlock(&block_group->lock);
3371
3372 if (cleanup) {
3373 mutex_lock(&fs_info->chunk_mutex);
3374 em_tree = &fs_info->mapping_tree;
3375 write_lock(&em_tree->lock);
3376 em = lookup_extent_mapping(em_tree, block_group->key.objectid,
3377 1);
3378 BUG_ON(!em); /* logic error, can't happen */
3379 remove_extent_mapping(em_tree, em);
3380 write_unlock(&em_tree->lock);
3381 mutex_unlock(&fs_info->chunk_mutex);
3382
3383 /* once for us and once for the tree */
3384 free_extent_map(em);
3385 free_extent_map(em);
3386
3387 /*
3388 * We've left one free space entry and other tasks trimming
3389 * this block group have left 1 entry each one. Free them.
3390 */
3391 __btrfs_remove_free_space_cache(block_group->free_space_ctl);
3392 }
3393 }
3394
3395 int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
3396 u64 *trimmed, u64 start, u64 end, u64 minlen)
3397 {
3398 int ret;
3399
3400 *trimmed = 0;
3401
3402 spin_lock(&block_group->lock);
3403 if (block_group->removed) {
3404 spin_unlock(&block_group->lock);
3405 return 0;
3406 }
3407 btrfs_get_block_group_trimming(block_group);
3408 spin_unlock(&block_group->lock);
3409
3410 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
3411 if (ret)
3412 goto out;
3413
3414 ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
3415 out:
3416 btrfs_put_block_group_trimming(block_group);
3417 return ret;
3418 }
3419
3420 /*
3421 * Find the left-most item in the cache tree, and then return the
3422 * smallest inode number in the item.
3423 *
3424 * Note: the returned inode number may not be the smallest one in
3425 * the tree, if the left-most item is a bitmap.
3426 */
3427 u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
3428 {
3429 struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
3430 struct btrfs_free_space *entry = NULL;
3431 u64 ino = 0;
3432
3433 spin_lock(&ctl->tree_lock);
3434
3435 if (RB_EMPTY_ROOT(&ctl->free_space_offset))
3436 goto out;
3437
3438 entry = rb_entry(rb_first(&ctl->free_space_offset),
3439 struct btrfs_free_space, offset_index);
3440
3441 if (!entry->bitmap) {
3442 ino = entry->offset;
3443
3444 unlink_free_space(ctl, entry);
3445 entry->offset++;
3446 entry->bytes--;
3447 if (!entry->bytes)
3448 kmem_cache_free(btrfs_free_space_cachep, entry);
3449 else
3450 link_free_space(ctl, entry);
3451 } else {
3452 u64 offset = 0;
3453 u64 count = 1;
3454 int ret;
3455
3456 ret = search_bitmap(ctl, entry, &offset, &count, true);
3457 /* Logic error; Should be empty if it can't find anything */
3458 ASSERT(!ret);
3459
3460 ino = offset;
3461 bitmap_clear_bits(ctl, entry, offset, 1);
3462 if (entry->bytes == 0)
3463 free_bitmap(ctl, entry);
3464 }
3465 out:
3466 spin_unlock(&ctl->tree_lock);
3467
3468 return ino;
3469 }
3470
3471 struct inode *lookup_free_ino_inode(struct btrfs_root *root,
3472 struct btrfs_path *path)
3473 {
3474 struct inode *inode = NULL;
3475
3476 spin_lock(&root->ino_cache_lock);
3477 if (root->ino_cache_inode)
3478 inode = igrab(root->ino_cache_inode);
3479 spin_unlock(&root->ino_cache_lock);
3480 if (inode)
3481 return inode;
3482
3483 inode = __lookup_free_space_inode(root, path, 0);
3484 if (IS_ERR(inode))
3485 return inode;
3486
3487 spin_lock(&root->ino_cache_lock);
3488 if (!btrfs_fs_closing(root->fs_info))
3489 root->ino_cache_inode = igrab(inode);
3490 spin_unlock(&root->ino_cache_lock);
3491
3492 return inode;
3493 }
3494
3495 int create_free_ino_inode(struct btrfs_root *root,
3496 struct btrfs_trans_handle *trans,
3497 struct btrfs_path *path)
3498 {
3499 return __create_free_space_inode(root, trans, path,
3500 BTRFS_FREE_INO_OBJECTID, 0);
3501 }
3502
3503 int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3504 {
3505 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3506 struct btrfs_path *path;
3507 struct inode *inode;
3508 int ret = 0;
3509 u64 root_gen = btrfs_root_generation(&root->root_item);
3510
3511 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3512 return 0;
3513
3514 /*
3515 * If we're unmounting then just return, since this does a search on the
3516 * normal root and not the commit root and we could deadlock.
3517 */
3518 if (btrfs_fs_closing(fs_info))
3519 return 0;
3520
3521 path = btrfs_alloc_path();
3522 if (!path)
3523 return 0;
3524
3525 inode = lookup_free_ino_inode(root, path);
3526 if (IS_ERR(inode))
3527 goto out;
3528
3529 if (root_gen != BTRFS_I(inode)->generation)
3530 goto out_put;
3531
3532 ret = __load_free_space_cache(root, inode, ctl, path, 0);
3533
3534 if (ret < 0)
3535 btrfs_err(fs_info,
3536 "failed to load free ino cache for root %llu",
3537 root->root_key.objectid);
3538 out_put:
3539 iput(inode);
3540 out:
3541 btrfs_free_path(path);
3542 return ret;
3543 }
3544
3545 int btrfs_write_out_ino_cache(struct btrfs_root *root,
3546 struct btrfs_trans_handle *trans,
3547 struct btrfs_path *path,
3548 struct inode *inode)
3549 {
3550 struct btrfs_fs_info *fs_info = root->fs_info;
3551 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3552 int ret;
3553 struct btrfs_io_ctl io_ctl;
3554 bool release_metadata = true;
3555
3556 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3557 return 0;
3558
3559 memset(&io_ctl, 0, sizeof(io_ctl));
3560 ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl, trans);
3561 if (!ret) {
3562 /*
3563 * At this point writepages() didn't error out, so our metadata
3564 * reservation is released when the writeback finishes, at
3565 * inode.c:btrfs_finish_ordered_io(), regardless of it finishing
3566 * with or without an error.
3567 */
3568 release_metadata = false;
3569 ret = btrfs_wait_cache_io_root(root, trans, &io_ctl, path);
3570 }
3571
3572 if (ret) {
3573 if (release_metadata)
3574 btrfs_delalloc_release_metadata(BTRFS_I(inode),
3575 inode->i_size, true);
3576 #ifdef DEBUG
3577 btrfs_err(fs_info,
3578 "failed to write free ino cache for root %llu",
3579 root->root_key.objectid);
3580 #endif
3581 }
3582
3583 return ret;
3584 }
3585
3586 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3587 /*
3588 * Use this if you need to make a bitmap or extent entry specifically, it
3589 * doesn't do any of the merging that add_free_space does, this acts a lot like
3590 * how the free space cache loading stuff works, so you can get really weird
3591 * configurations.
3592 */
3593 int test_add_free_space_entry(struct btrfs_block_group_cache *cache,
3594 u64 offset, u64 bytes, bool bitmap)
3595 {
3596 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3597 struct btrfs_free_space *info = NULL, *bitmap_info;
3598 void *map = NULL;
3599 u64 bytes_added;
3600 int ret;
3601
3602 again:
3603 if (!info) {
3604 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
3605 if (!info)
3606 return -ENOMEM;
3607 }
3608
3609 if (!bitmap) {
3610 spin_lock(&ctl->tree_lock);
3611 info->offset = offset;
3612 info->bytes = bytes;
3613 info->max_extent_size = 0;
3614 ret = link_free_space(ctl, info);
3615 spin_unlock(&ctl->tree_lock);
3616 if (ret)
3617 kmem_cache_free(btrfs_free_space_cachep, info);
3618 return ret;
3619 }
3620
3621 if (!map) {
3622 map = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep, GFP_NOFS);
3623 if (!map) {
3624 kmem_cache_free(btrfs_free_space_cachep, info);
3625 return -ENOMEM;
3626 }
3627 }
3628
3629 spin_lock(&ctl->tree_lock);
3630 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3631 1, 0);
3632 if (!bitmap_info) {
3633 info->bitmap = map;
3634 map = NULL;
3635 add_new_bitmap(ctl, info, offset);
3636 bitmap_info = info;
3637 info = NULL;
3638 }
3639
3640 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
3641
3642 bytes -= bytes_added;
3643 offset += bytes_added;
3644 spin_unlock(&ctl->tree_lock);
3645
3646 if (bytes)
3647 goto again;
3648
3649 if (info)
3650 kmem_cache_free(btrfs_free_space_cachep, info);
3651 if (map)
3652 kmem_cache_free(btrfs_free_space_bitmap_cachep, map);
3653 return 0;
3654 }
3655
3656 /*
3657 * Checks to see if the given range is in the free space cache. This is really
3658 * just used to check the absence of space, so if there is free space in the
3659 * range at all we will return 1.
3660 */
3661 int test_check_exists(struct btrfs_block_group_cache *cache,
3662 u64 offset, u64 bytes)
3663 {
3664 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3665 struct btrfs_free_space *info;
3666 int ret = 0;
3667
3668 spin_lock(&ctl->tree_lock);
3669 info = tree_search_offset(ctl, offset, 0, 0);
3670 if (!info) {
3671 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3672 1, 0);
3673 if (!info)
3674 goto out;
3675 }
3676
3677 have_info:
3678 if (info->bitmap) {
3679 u64 bit_off, bit_bytes;
3680 struct rb_node *n;
3681 struct btrfs_free_space *tmp;
3682
3683 bit_off = offset;
3684 bit_bytes = ctl->unit;
3685 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
3686 if (!ret) {
3687 if (bit_off == offset) {
3688 ret = 1;
3689 goto out;
3690 } else if (bit_off > offset &&
3691 offset + bytes > bit_off) {
3692 ret = 1;
3693 goto out;
3694 }
3695 }
3696
3697 n = rb_prev(&info->offset_index);
3698 while (n) {
3699 tmp = rb_entry(n, struct btrfs_free_space,
3700 offset_index);
3701 if (tmp->offset + tmp->bytes < offset)
3702 break;
3703 if (offset + bytes < tmp->offset) {
3704 n = rb_prev(&tmp->offset_index);
3705 continue;
3706 }
3707 info = tmp;
3708 goto have_info;
3709 }
3710
3711 n = rb_next(&info->offset_index);
3712 while (n) {
3713 tmp = rb_entry(n, struct btrfs_free_space,
3714 offset_index);
3715 if (offset + bytes < tmp->offset)
3716 break;
3717 if (tmp->offset + tmp->bytes < offset) {
3718 n = rb_next(&tmp->offset_index);
3719 continue;
3720 }
3721 info = tmp;
3722 goto have_info;
3723 }
3724
3725 ret = 0;
3726 goto out;
3727 }
3728
3729 if (info->offset == offset) {
3730 ret = 1;
3731 goto out;
3732 }
3733
3734 if (offset > info->offset && offset < info->offset + info->bytes)
3735 ret = 1;
3736 out:
3737 spin_unlock(&ctl->tree_lock);
3738 return ret;
3739 }
3740 #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
Linux with added FPC-III support