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1// SPDX-License-Identifier: GPL-2.0
2
3#include "misc.h"
4#include "ctree.h"
5#include "block-group.h"
6#include "space-info.h"
7#include "disk-io.h"
8#include "free-space-cache.h"
9#include "free-space-tree.h"
10#include "disk-io.h"
11#include "volumes.h"
12#include "transaction.h"
13#include "ref-verify.h"
14#include "sysfs.h"
15#include "tree-log.h"
16#include "delalloc-space.h"
17
18/*
19 * Return target flags in extended format or 0 if restripe for this chunk_type
20 * is not in progress
21 *
22 * Should be called with balance_lock held
23 */
24static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
25{
26 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
27 u64 target = 0;
28
29 if (!bctl)
30 return 0;
31
32 if (flags & BTRFS_BLOCK_GROUP_DATA &&
33 bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
34 target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
35 } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
36 bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
37 target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
38 } else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
39 bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
40 target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
41 }
42
43 return target;
44}
45
46/*
47 * @flags: available profiles in extended format (see ctree.h)
48 *
49 * Return reduced profile in chunk format. If profile changing is in progress
50 * (either running or paused) picks the target profile (if it's already
51 * available), otherwise falls back to plain reducing.
52 */
53static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags)
54{
55 u64 num_devices = fs_info->fs_devices->rw_devices;
56 u64 target;
57 u64 raid_type;
58 u64 allowed = 0;
59
60 /*
61 * See if restripe for this chunk_type is in progress, if so try to
62 * reduce to the target profile
63 */
64 spin_lock(&fs_info->balance_lock);
65 target = get_restripe_target(fs_info, flags);
66 if (target) {
67 /* Pick target profile only if it's already available */
68 if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
69 spin_unlock(&fs_info->balance_lock);
70 return extended_to_chunk(target);
71 }
72 }
73 spin_unlock(&fs_info->balance_lock);
74
75 /* First, mask out the RAID levels which aren't possible */
76 for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
77 if (num_devices >= btrfs_raid_array[raid_type].devs_min)
78 allowed |= btrfs_raid_array[raid_type].bg_flag;
79 }
80 allowed &= flags;
81
82 if (allowed & BTRFS_BLOCK_GROUP_RAID6)
83 allowed = BTRFS_BLOCK_GROUP_RAID6;
84 else if (allowed & BTRFS_BLOCK_GROUP_RAID5)
85 allowed = BTRFS_BLOCK_GROUP_RAID5;
86 else if (allowed & BTRFS_BLOCK_GROUP_RAID10)
87 allowed = BTRFS_BLOCK_GROUP_RAID10;
88 else if (allowed & BTRFS_BLOCK_GROUP_RAID1)
89 allowed = BTRFS_BLOCK_GROUP_RAID1;
90 else if (allowed & BTRFS_BLOCK_GROUP_RAID0)
91 allowed = BTRFS_BLOCK_GROUP_RAID0;
92
93 flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
94
95 return extended_to_chunk(flags | allowed);
96}
97
98static u64 get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
99{
100 unsigned seq;
101 u64 flags;
102
103 do {
104 flags = orig_flags;
105 seq = read_seqbegin(&fs_info->profiles_lock);
106
107 if (flags & BTRFS_BLOCK_GROUP_DATA)
108 flags |= fs_info->avail_data_alloc_bits;
109 else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
110 flags |= fs_info->avail_system_alloc_bits;
111 else if (flags & BTRFS_BLOCK_GROUP_METADATA)
112 flags |= fs_info->avail_metadata_alloc_bits;
113 } while (read_seqretry(&fs_info->profiles_lock, seq));
114
115 return btrfs_reduce_alloc_profile(fs_info, flags);
116}
117
118u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
119{
120 return get_alloc_profile(fs_info, orig_flags);
121}
122
123void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
124{
125 atomic_inc(&cache->count);
126}
127
128void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
129{
130 if (atomic_dec_and_test(&cache->count)) {
131 WARN_ON(cache->pinned > 0);
132 WARN_ON(cache->reserved > 0);
133
134 /*
135 * If not empty, someone is still holding mutex of
136 * full_stripe_lock, which can only be released by caller.
137 * And it will definitely cause use-after-free when caller
138 * tries to release full stripe lock.
139 *
140 * No better way to resolve, but only to warn.
141 */
142 WARN_ON(!RB_EMPTY_ROOT(&cache->full_stripe_locks_root.root));
143 kfree(cache->free_space_ctl);
144 kfree(cache);
145 }
146}
147
148/*
149 * This adds the block group to the fs_info rb tree for the block group cache
150 */
151static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
152 struct btrfs_block_group_cache *block_group)
153{
154 struct rb_node **p;
155 struct rb_node *parent = NULL;
156 struct btrfs_block_group_cache *cache;
157
158 spin_lock(&info->block_group_cache_lock);
159 p = &info->block_group_cache_tree.rb_node;
160
161 while (*p) {
162 parent = *p;
163 cache = rb_entry(parent, struct btrfs_block_group_cache,
164 cache_node);
165 if (block_group->key.objectid < cache->key.objectid) {
166 p = &(*p)->rb_left;
167 } else if (block_group->key.objectid > cache->key.objectid) {
168 p = &(*p)->rb_right;
169 } else {
170 spin_unlock(&info->block_group_cache_lock);
171 return -EEXIST;
172 }
173 }
174
175 rb_link_node(&block_group->cache_node, parent, p);
176 rb_insert_color(&block_group->cache_node,
177 &info->block_group_cache_tree);
178
179 if (info->first_logical_byte > block_group->key.objectid)
180 info->first_logical_byte = block_group->key.objectid;
181
182 spin_unlock(&info->block_group_cache_lock);
183
184 return 0;
185}
186
187/*
188 * This will return the block group at or after bytenr if contains is 0, else
189 * it will return the block group that contains the bytenr
190 */
191static struct btrfs_block_group_cache *block_group_cache_tree_search(
192 struct btrfs_fs_info *info, u64 bytenr, int contains)
193{
194 struct btrfs_block_group_cache *cache, *ret = NULL;
195 struct rb_node *n;
196 u64 end, start;
197
198 spin_lock(&info->block_group_cache_lock);
199 n = info->block_group_cache_tree.rb_node;
200
201 while (n) {
202 cache = rb_entry(n, struct btrfs_block_group_cache,
203 cache_node);
204 end = cache->key.objectid + cache->key.offset - 1;
205 start = cache->key.objectid;
206
207 if (bytenr < start) {
208 if (!contains && (!ret || start < ret->key.objectid))
209 ret = cache;
210 n = n->rb_left;
211 } else if (bytenr > start) {
212 if (contains && bytenr <= end) {
213 ret = cache;
214 break;
215 }
216 n = n->rb_right;
217 } else {
218 ret = cache;
219 break;
220 }
221 }
222 if (ret) {
223 btrfs_get_block_group(ret);
224 if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
225 info->first_logical_byte = ret->key.objectid;
226 }
227 spin_unlock(&info->block_group_cache_lock);
228
229 return ret;
230}
231
232/*
233 * Return the block group that starts at or after bytenr
234 */
235struct btrfs_block_group_cache *btrfs_lookup_first_block_group(
236 struct btrfs_fs_info *info, u64 bytenr)
237{
238 return block_group_cache_tree_search(info, bytenr, 0);
239}
240
241/*
242 * Return the block group that contains the given bytenr
243 */
244struct btrfs_block_group_cache *btrfs_lookup_block_group(
245 struct btrfs_fs_info *info, u64 bytenr)
246{
247 return block_group_cache_tree_search(info, bytenr, 1);
248}
249
250struct btrfs_block_group_cache *btrfs_next_block_group(
251 struct btrfs_block_group_cache *cache)
252{
253 struct btrfs_fs_info *fs_info = cache->fs_info;
254 struct rb_node *node;
255
256 spin_lock(&fs_info->block_group_cache_lock);
257
258 /* If our block group was removed, we need a full search. */
259 if (RB_EMPTY_NODE(&cache->cache_node)) {
260 const u64 next_bytenr = cache->key.objectid + cache->key.offset;
261
262 spin_unlock(&fs_info->block_group_cache_lock);
263 btrfs_put_block_group(cache);
264 cache = btrfs_lookup_first_block_group(fs_info, next_bytenr); return cache;
265 }
266 node = rb_next(&cache->cache_node);
267 btrfs_put_block_group(cache);
268 if (node) {
269 cache = rb_entry(node, struct btrfs_block_group_cache,
270 cache_node);
271 btrfs_get_block_group(cache);
272 } else
273 cache = NULL;
274 spin_unlock(&fs_info->block_group_cache_lock);
275 return cache;
276}
277
278bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
279{
280 struct btrfs_block_group_cache *bg;
281 bool ret = true;
282
283 bg = btrfs_lookup_block_group(fs_info, bytenr);
284 if (!bg)
285 return false;
286
287 spin_lock(&bg->lock);
288 if (bg->ro)
289 ret = false;
290 else
291 atomic_inc(&bg->nocow_writers);
292 spin_unlock(&bg->lock);
293
294 /* No put on block group, done by btrfs_dec_nocow_writers */
295 if (!ret)
296 btrfs_put_block_group(bg);
297
298 return ret;
299}
300
301void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
302{
303 struct btrfs_block_group_cache *bg;
304
305 bg = btrfs_lookup_block_group(fs_info, bytenr);
306 ASSERT(bg);
307 if (atomic_dec_and_test(&bg->nocow_writers))
308 wake_up_var(&bg->nocow_writers);
309 /*
310 * Once for our lookup and once for the lookup done by a previous call
311 * to btrfs_inc_nocow_writers()
312 */
313 btrfs_put_block_group(bg);
314 btrfs_put_block_group(bg);
315}
316
317void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg)
318{
319 wait_var_event(&bg->nocow_writers, !atomic_read(&bg->nocow_writers));
320}
321
322void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
323 const u64 start)
324{
325 struct btrfs_block_group_cache *bg;
326
327 bg = btrfs_lookup_block_group(fs_info, start);
328 ASSERT(bg);
329 if (atomic_dec_and_test(&bg->reservations))
330 wake_up_var(&bg->reservations);
331 btrfs_put_block_group(bg);
332}
333
334void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg)
335{
336 struct btrfs_space_info *space_info = bg->space_info;
337
338 ASSERT(bg->ro);
339
340 if (!(bg->flags & BTRFS_BLOCK_GROUP_DATA))
341 return;
342
343 /*
344 * Our block group is read only but before we set it to read only,
345 * some task might have had allocated an extent from it already, but it
346 * has not yet created a respective ordered extent (and added it to a
347 * root's list of ordered extents).
348 * Therefore wait for any task currently allocating extents, since the
349 * block group's reservations counter is incremented while a read lock
350 * on the groups' semaphore is held and decremented after releasing
351 * the read access on that semaphore and creating the ordered extent.
352 */
353 down_write(&space_info->groups_sem);
354 up_write(&space_info->groups_sem);
355
356 wait_var_event(&bg->reservations, !atomic_read(&bg->reservations));
357}
358
359struct btrfs_caching_control *btrfs_get_caching_control(
360 struct btrfs_block_group_cache *cache)
361{
362 struct btrfs_caching_control *ctl;
363
364 spin_lock(&cache->lock);
365 if (!cache->caching_ctl) {
366 spin_unlock(&cache->lock);
367 return NULL;
368 }
369
370 ctl = cache->caching_ctl;
371 refcount_inc(&ctl->count);
372 spin_unlock(&cache->lock);
373 return ctl;
374}
375
376void btrfs_put_caching_control(struct btrfs_caching_control *ctl)
377{
378 if (refcount_dec_and_test(&ctl->count))
379 kfree(ctl);
380}
381
382/*
383 * When we wait for progress in the block group caching, its because our
384 * allocation attempt failed at least once. So, we must sleep and let some
385 * progress happen before we try again.
386 *
387 * This function will sleep at least once waiting for new free space to show
388 * up, and then it will check the block group free space numbers for our min
389 * num_bytes. Another option is to have it go ahead and look in the rbtree for
390 * a free extent of a given size, but this is a good start.
391 *
392 * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
393 * any of the information in this block group.
394 */
395void btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
396 u64 num_bytes)
397{
398 struct btrfs_caching_control *caching_ctl;
399
400 caching_ctl = btrfs_get_caching_control(cache);
401 if (!caching_ctl)
402 return;
403
404 wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache) ||
405 (cache->free_space_ctl->free_space >= num_bytes));
406
407 btrfs_put_caching_control(caching_ctl);
408}
409
410int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
411{
412 struct btrfs_caching_control *caching_ctl;
413 int ret = 0;
414
415 caching_ctl = btrfs_get_caching_control(cache);
416 if (!caching_ctl)
417 return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
418
419 wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache));
420 if (cache->cached == BTRFS_CACHE_ERROR)
421 ret = -EIO;
422 btrfs_put_caching_control(caching_ctl);
423 return ret;
424}
425
426#ifdef CONFIG_BTRFS_DEBUG
427static void fragment_free_space(struct btrfs_block_group_cache *block_group)
428{
429 struct btrfs_fs_info *fs_info = block_group->fs_info;
430 u64 start = block_group->key.objectid;
431 u64 len = block_group->key.offset;
432 u64 chunk = block_group->flags & BTRFS_BLOCK_GROUP_METADATA ?
433 fs_info->nodesize : fs_info->sectorsize;
434 u64 step = chunk << 1;
435
436 while (len > chunk) {
437 btrfs_remove_free_space(block_group, start, chunk);
438 start += step;
439 if (len < step)
440 len = 0;
441 else
442 len -= step;
443 }
444}
445#endif
446
447/*
448 * This is only called by btrfs_cache_block_group, since we could have freed
449 * extents we need to check the pinned_extents for any extents that can't be
450 * used yet since their free space will be released as soon as the transaction
451 * commits.
452 */
453u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
454 u64 start, u64 end)
455{
456 struct btrfs_fs_info *info = block_group->fs_info;
457 u64 extent_start, extent_end, size, total_added = 0;
458 int ret;
459
460 while (start < end) {
461 ret = find_first_extent_bit(info->pinned_extents, start,
462 &extent_start, &extent_end,
463 EXTENT_DIRTY | EXTENT_UPTODATE,
464 NULL);
465 if (ret)
466 break;
467
468 if (extent_start <= start) {
469 start = extent_end + 1;
470 } else if (extent_start > start && extent_start < end) {
471 size = extent_start - start;
472 total_added += size;
473 ret = btrfs_add_free_space(block_group, start,
474 size);
475 BUG_ON(ret); /* -ENOMEM or logic error */
476 start = extent_end + 1;
477 } else {
478 break;
479 }
480 }
481
482 if (start < end) {
483 size = end - start;
484 total_added += size;
485 ret = btrfs_add_free_space(block_group, start, size);
486 BUG_ON(ret); /* -ENOMEM or logic error */
487 }
488
489 return total_added;
490}
491
492static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)
493{
494 struct btrfs_block_group_cache *block_group = caching_ctl->block_group;
495 struct btrfs_fs_info *fs_info = block_group->fs_info;
496 struct btrfs_root *extent_root = fs_info->extent_root;
497 struct btrfs_path *path;
498 struct extent_buffer *leaf;
499 struct btrfs_key key;
500 u64 total_found = 0;
501 u64 last = 0;
502 u32 nritems;
503 int ret;
504 bool wakeup = true;
505
506 path = btrfs_alloc_path();
507 if (!path)
508 return -ENOMEM;
509
510 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
511
512#ifdef CONFIG_BTRFS_DEBUG
513 /*
514 * If we're fragmenting we don't want to make anybody think we can
515 * allocate from this block group until we've had a chance to fragment
516 * the free space.
517 */
518 if (btrfs_should_fragment_free_space(block_group))
519 wakeup = false;
520#endif
521 /*
522 * We don't want to deadlock with somebody trying to allocate a new
523 * extent for the extent root while also trying to search the extent
524 * root to add free space. So we skip locking and search the commit
525 * root, since its read-only
526 */
527 path->skip_locking = 1;
528 path->search_commit_root = 1;
529 path->reada = READA_FORWARD;
530
531 key.objectid = last;
532 key.offset = 0;
533 key.type = BTRFS_EXTENT_ITEM_KEY;
534
535next:
536 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
537 if (ret < 0)
538 goto out;
539
540 leaf = path->nodes[0];
541 nritems = btrfs_header_nritems(leaf);
542
543 while (1) {
544 if (btrfs_fs_closing(fs_info) > 1) {
545 last = (u64)-1;
546 break;
547 }
548
549 if (path->slots[0] < nritems) {
550 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
551 } else {
552 ret = btrfs_find_next_key(extent_root, path, &key, 0, 0);
553 if (ret)
554 break;
555
556 if (need_resched() ||
557 rwsem_is_contended(&fs_info->commit_root_sem)) {
558 if (wakeup)
559 caching_ctl->progress = last;
560 btrfs_release_path(path);
561 up_read(&fs_info->commit_root_sem);
562 mutex_unlock(&caching_ctl->mutex);
563 cond_resched();
564 mutex_lock(&caching_ctl->mutex);
565 down_read(&fs_info->commit_root_sem);
566 goto next;
567 }
568
569 ret = btrfs_next_leaf(extent_root, path);
570 if (ret < 0)
571 goto out;
572 if (ret)
573 break;
574 leaf = path->nodes[0];
575 nritems = btrfs_header_nritems(leaf);
576 continue;
577 }
578
579 if (key.objectid < last) {
580 key.objectid = last;
581 key.offset = 0;
582 key.type = BTRFS_EXTENT_ITEM_KEY;
583
584 if (wakeup)
585 caching_ctl->progress = last;
586 btrfs_release_path(path);
587 goto next;
588 }
589
590 if (key.objectid < block_group->key.objectid) {
591 path->slots[0]++;
592 continue;
593 }
594
595 if (key.objectid >= block_group->key.objectid +
596 block_group->key.offset)
597 break;
598
599 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
600 key.type == BTRFS_METADATA_ITEM_KEY) {
601 total_found += add_new_free_space(block_group, last,
602 key.objectid);
603 if (key.type == BTRFS_METADATA_ITEM_KEY)
604 last = key.objectid +
605 fs_info->nodesize;
606 else
607 last = key.objectid + key.offset;
608
609 if (total_found > CACHING_CTL_WAKE_UP) {
610 total_found = 0;
611 if (wakeup)
612 wake_up(&caching_ctl->wait);
613 }
614 }
615 path->slots[0]++;
616 }
617 ret = 0;
618
619 total_found += add_new_free_space(block_group, last,
620 block_group->key.objectid +
621 block_group->key.offset);
622 caching_ctl->progress = (u64)-1;
623
624out:
625 btrfs_free_path(path);
626 return ret;
627}
628
629static noinline void caching_thread(struct btrfs_work *work)
630{
631 struct btrfs_block_group_cache *block_group;
632 struct btrfs_fs_info *fs_info;
633 struct btrfs_caching_control *caching_ctl;
634 int ret;
635
636 caching_ctl = container_of(work, struct btrfs_caching_control, work);
637 block_group = caching_ctl->block_group;
638 fs_info = block_group->fs_info;
639
640 mutex_lock(&caching_ctl->mutex);
641 down_read(&fs_info->commit_root_sem);
642
643 if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
644 ret = load_free_space_tree(caching_ctl);
645 else
646 ret = load_extent_tree_free(caching_ctl);
647
648 spin_lock(&block_group->lock);
649 block_group->caching_ctl = NULL;
650 block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED;
651 spin_unlock(&block_group->lock);
652
653#ifdef CONFIG_BTRFS_DEBUG
654 if (btrfs_should_fragment_free_space(block_group)) {
655 u64 bytes_used;
656
657 spin_lock(&block_group->space_info->lock);
658 spin_lock(&block_group->lock);
659 bytes_used = block_group->key.offset -
660 btrfs_block_group_used(&block_group->item);
661 block_group->space_info->bytes_used += bytes_used >> 1;
662 spin_unlock(&block_group->lock);
663 spin_unlock(&block_group->space_info->lock);
664 fragment_free_space(block_group);
665 }
666#endif
667
668 caching_ctl->progress = (u64)-1;
669
670 up_read(&fs_info->commit_root_sem);
671 btrfs_free_excluded_extents(block_group);
672 mutex_unlock(&caching_ctl->mutex);
673
674 wake_up(&caching_ctl->wait);
675
676 btrfs_put_caching_control(caching_ctl);
677 btrfs_put_block_group(block_group);
678}
679
680int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
681 int load_cache_only)
682{
683 DEFINE_WAIT(wait);
684 struct btrfs_fs_info *fs_info = cache->fs_info;
685 struct btrfs_caching_control *caching_ctl;
686 int ret = 0;
687
688 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
689 if (!caching_ctl)
690 return -ENOMEM;
691
692 INIT_LIST_HEAD(&caching_ctl->list);
693 mutex_init(&caching_ctl->mutex);
694 init_waitqueue_head(&caching_ctl->wait);
695 caching_ctl->block_group = cache;
696 caching_ctl->progress = cache->key.objectid;
697 refcount_set(&caching_ctl->count, 1);
698 btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
699 caching_thread, NULL, NULL);
700
701 spin_lock(&cache->lock);
702 /*
703 * This should be a rare occasion, but this could happen I think in the
704 * case where one thread starts to load the space cache info, and then
705 * some other thread starts a transaction commit which tries to do an
706 * allocation while the other thread is still loading the space cache
707 * info. The previous loop should have kept us from choosing this block
708 * group, but if we've moved to the state where we will wait on caching
709 * block groups we need to first check if we're doing a fast load here,
710 * so we can wait for it to finish, otherwise we could end up allocating
711 * from a block group who's cache gets evicted for one reason or
712 * another.
713 */
714 while (cache->cached == BTRFS_CACHE_FAST) {
715 struct btrfs_caching_control *ctl;
716
717 ctl = cache->caching_ctl;
718 refcount_inc(&ctl->count);
719 prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
720 spin_unlock(&cache->lock);
721
722 schedule();
723
724 finish_wait(&ctl->wait, &wait);
725 btrfs_put_caching_control(ctl);
726 spin_lock(&cache->lock);
727 }
728
729 if (cache->cached != BTRFS_CACHE_NO) {
730 spin_unlock(&cache->lock);
731 kfree(caching_ctl);
732 return 0;
733 }
734 WARN_ON(cache->caching_ctl);
735 cache->caching_ctl = caching_ctl;
736 cache->cached = BTRFS_CACHE_FAST;
737 spin_unlock(&cache->lock);
738
739 if (btrfs_test_opt(fs_info, SPACE_CACHE)) {
740 mutex_lock(&caching_ctl->mutex);
741 ret = load_free_space_cache(cache);
742
743 spin_lock(&cache->lock);
744 if (ret == 1) {
745 cache->caching_ctl = NULL;
746 cache->cached = BTRFS_CACHE_FINISHED;
747 cache->last_byte_to_unpin = (u64)-1;
748 caching_ctl->progress = (u64)-1;
749 } else {
750 if (load_cache_only) {
751 cache->caching_ctl = NULL;
752 cache->cached = BTRFS_CACHE_NO;
753 } else {
754 cache->cached = BTRFS_CACHE_STARTED;
755 cache->has_caching_ctl = 1;
756 }
757 }
758 spin_unlock(&cache->lock);
759#ifdef CONFIG_BTRFS_DEBUG
760 if (ret == 1 &&
761 btrfs_should_fragment_free_space(cache)) {
762 u64 bytes_used;
763
764 spin_lock(&cache->space_info->lock);
765 spin_lock(&cache->lock);
766 bytes_used = cache->key.offset -
767 btrfs_block_group_used(&cache->item);
768 cache->space_info->bytes_used += bytes_used >> 1;
769 spin_unlock(&cache->lock);
770 spin_unlock(&cache->space_info->lock);
771 fragment_free_space(cache);
772 }
773#endif
774 mutex_unlock(&caching_ctl->mutex);
775
776 wake_up(&caching_ctl->wait);
777 if (ret == 1) {
778 btrfs_put_caching_control(caching_ctl);
779 btrfs_free_excluded_extents(cache);
780 return 0;
781 }
782 } else {
783 /*
784 * We're either using the free space tree or no caching at all.
785 * Set cached to the appropriate value and wakeup any waiters.
786 */
787 spin_lock(&cache->lock);
788 if (load_cache_only) {
789 cache->caching_ctl = NULL;
790 cache->cached = BTRFS_CACHE_NO;
791 } else {
792 cache->cached = BTRFS_CACHE_STARTED;
793 cache->has_caching_ctl = 1;
794 }
795 spin_unlock(&cache->lock);
796 wake_up(&caching_ctl->wait);
797 }
798
799 if (load_cache_only) {
800 btrfs_put_caching_control(caching_ctl);
801 return 0;
802 }
803
804 down_write(&fs_info->commit_root_sem);
805 refcount_inc(&caching_ctl->count);
806 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
807 up_write(&fs_info->commit_root_sem);
808
809 btrfs_get_block_group(cache);
810
811 btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
812
813 return ret;
814}
815
816static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
817{
818 u64 extra_flags = chunk_to_extended(flags) &
819 BTRFS_EXTENDED_PROFILE_MASK;
820
821 write_seqlock(&fs_info->profiles_lock);
822 if (flags & BTRFS_BLOCK_GROUP_DATA)
823 fs_info->avail_data_alloc_bits &= ~extra_flags;
824 if (flags & BTRFS_BLOCK_GROUP_METADATA)
825 fs_info->avail_metadata_alloc_bits &= ~extra_flags;
826 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
827 fs_info->avail_system_alloc_bits &= ~extra_flags;
828 write_sequnlock(&fs_info->profiles_lock);
829}
830
831/*
832 * Clear incompat bits for the following feature(s):
833 *
834 * - RAID56 - in case there's neither RAID5 nor RAID6 profile block group
835 * in the whole filesystem
836 */
837static void clear_incompat_bg_bits(struct btrfs_fs_info *fs_info, u64 flags)
838{
839 if (flags & BTRFS_BLOCK_GROUP_RAID56_MASK) {
840 struct list_head *head = &fs_info->space_info;
841 struct btrfs_space_info *sinfo;
842
843 list_for_each_entry_rcu(sinfo, head, list) {
844 bool found = false;
845
846 down_read(&sinfo->groups_sem);
847 if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID5]))
848 found = true;
849 if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID6]))
850 found = true;
851 up_read(&sinfo->groups_sem);
852
853 if (found)
854 return;
855 }
856 btrfs_clear_fs_incompat(fs_info, RAID56);
857 }
858}
859
860int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
861 u64 group_start, struct extent_map *em)
862{
863 struct btrfs_fs_info *fs_info = trans->fs_info;
864 struct btrfs_root *root = fs_info->extent_root;
865 struct btrfs_path *path;
866 struct btrfs_block_group_cache *block_group;
867 struct btrfs_free_cluster *cluster;
868 struct btrfs_root *tree_root = fs_info->tree_root;
869 struct btrfs_key key;
870 struct inode *inode;
871 struct kobject *kobj = NULL;
872 int ret;
873 int index;
874 int factor;
875 struct btrfs_caching_control *caching_ctl = NULL;
876 bool remove_em;
877 bool remove_rsv = false;
878
879 block_group = btrfs_lookup_block_group(fs_info, group_start);
880 BUG_ON(!block_group);
881 BUG_ON(!block_group->ro);
882
883 trace_btrfs_remove_block_group(block_group);
884 /*
885 * Free the reserved super bytes from this block group before
886 * remove it.
887 */
888 btrfs_free_excluded_extents(block_group);
889 btrfs_free_ref_tree_range(fs_info, block_group->key.objectid,
890 block_group->key.offset);
891
892 memcpy(&key, &block_group->key, sizeof(key));
893 index = btrfs_bg_flags_to_raid_index(block_group->flags);
894 factor = btrfs_bg_type_to_factor(block_group->flags);
895
896 /* make sure this block group isn't part of an allocation cluster */
897 cluster = &fs_info->data_alloc_cluster;
898 spin_lock(&cluster->refill_lock);
899 btrfs_return_cluster_to_free_space(block_group, cluster);
900 spin_unlock(&cluster->refill_lock);
901
902 /*
903 * make sure this block group isn't part of a metadata
904 * allocation cluster
905 */
906 cluster = &fs_info->meta_alloc_cluster;
907 spin_lock(&cluster->refill_lock);
908 btrfs_return_cluster_to_free_space(block_group, cluster);
909 spin_unlock(&cluster->refill_lock);
910
911 path = btrfs_alloc_path();
912 if (!path) {
913 ret = -ENOMEM;
914 goto out;
915 }
916
917 /*
918 * get the inode first so any iput calls done for the io_list
919 * aren't the final iput (no unlinks allowed now)
920 */
921 inode = lookup_free_space_inode(block_group, path);
922
923 mutex_lock(&trans->transaction->cache_write_mutex);
924 /*
925 * Make sure our free space cache IO is done before removing the
926 * free space inode
927 */
928 spin_lock(&trans->transaction->dirty_bgs_lock);
929 if (!list_empty(&block_group->io_list)) {
930 list_del_init(&block_group->io_list);
931
932 WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
933
934 spin_unlock(&trans->transaction->dirty_bgs_lock);
935 btrfs_wait_cache_io(trans, block_group, path);
936 btrfs_put_block_group(block_group);
937 spin_lock(&trans->transaction->dirty_bgs_lock);
938 }
939
940 if (!list_empty(&block_group->dirty_list)) {
941 list_del_init(&block_group->dirty_list);
942 remove_rsv = true;
943 btrfs_put_block_group(block_group);
944 }
945 spin_unlock(&trans->transaction->dirty_bgs_lock);
946 mutex_unlock(&trans->transaction->cache_write_mutex);
947
948 if (!IS_ERR(inode)) {
949 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
950 if (ret) {
951 btrfs_add_delayed_iput(inode);
952 goto out;
953 }
954 clear_nlink(inode);
955 /* One for the block groups ref */
956 spin_lock(&block_group->lock);
957 if (block_group->iref) {
958 block_group->iref = 0;
959 block_group->inode = NULL;
960 spin_unlock(&block_group->lock);
961 iput(inode);
962 } else {
963 spin_unlock(&block_group->lock);
964 }
965 /* One for our lookup ref */
966 btrfs_add_delayed_iput(inode);
967 }
968
969 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
970 key.offset = block_group->key.objectid;
971 key.type = 0;
972
973 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
974 if (ret < 0)
975 goto out;
976 if (ret > 0)
977 btrfs_release_path(path);
978 if (ret == 0) {
979 ret = btrfs_del_item(trans, tree_root, path);
980 if (ret)
981 goto out;
982 btrfs_release_path(path);
983 }
984
985 spin_lock(&fs_info->block_group_cache_lock);
986 rb_erase(&block_group->cache_node,
987 &fs_info->block_group_cache_tree);
988 RB_CLEAR_NODE(&block_group->cache_node);
989
990 if (fs_info->first_logical_byte == block_group->key.objectid)
991 fs_info->first_logical_byte = (u64)-1;
992 spin_unlock(&fs_info->block_group_cache_lock);
993
994 down_write(&block_group->space_info->groups_sem);
995 /*
996 * we must use list_del_init so people can check to see if they
997 * are still on the list after taking the semaphore
998 */
999 list_del_init(&block_group->list);
1000 if (list_empty(&block_group->space_info->block_groups[index])) {
1001 kobj = block_group->space_info->block_group_kobjs[index];
1002 block_group->space_info->block_group_kobjs[index] = NULL;
1003 clear_avail_alloc_bits(fs_info, block_group->flags);
1004 }
1005 up_write(&block_group->space_info->groups_sem);
1006 clear_incompat_bg_bits(fs_info, block_group->flags);
1007 if (kobj) {
1008 kobject_del(kobj);
1009 kobject_put(kobj);
1010 }
1011
1012 if (block_group->has_caching_ctl)
1013 caching_ctl = btrfs_get_caching_control(block_group);
1014 if (block_group->cached == BTRFS_CACHE_STARTED)
1015 btrfs_wait_block_group_cache_done(block_group);
1016 if (block_group->has_caching_ctl) {
1017 down_write(&fs_info->commit_root_sem);
1018 if (!caching_ctl) {
1019 struct btrfs_caching_control *ctl;
1020
1021 list_for_each_entry(ctl,
1022 &fs_info->caching_block_groups, list)
1023 if (ctl->block_group == block_group) {
1024 caching_ctl = ctl;
1025 refcount_inc(&caching_ctl->count);
1026 break;
1027 }
1028 }
1029 if (caching_ctl)
1030 list_del_init(&caching_ctl->list);
1031 up_write(&fs_info->commit_root_sem);
1032 if (caching_ctl) {
1033 /* Once for the caching bgs list and once for us. */
1034 btrfs_put_caching_control(caching_ctl);
1035 btrfs_put_caching_control(caching_ctl);
1036 }
1037 }
1038
1039 spin_lock(&trans->transaction->dirty_bgs_lock);
1040 WARN_ON(!list_empty(&block_group->dirty_list));
1041 WARN_ON(!list_empty(&block_group->io_list));
1042 spin_unlock(&trans->transaction->dirty_bgs_lock);
1043
1044 btrfs_remove_free_space_cache(block_group);
1045
1046 spin_lock(&block_group->space_info->lock);
1047 list_del_init(&block_group->ro_list);
1048
1049 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
1050 WARN_ON(block_group->space_info->total_bytes
1051 < block_group->key.offset);
1052 WARN_ON(block_group->space_info->bytes_readonly
1053 < block_group->key.offset);
1054 WARN_ON(block_group->space_info->disk_total
1055 < block_group->key.offset * factor);
1056 }
1057 block_group->space_info->total_bytes -= block_group->key.offset;
1058 block_group->space_info->bytes_readonly -= block_group->key.offset;
1059 block_group->space_info->disk_total -= block_group->key.offset * factor;
1060
1061 spin_unlock(&block_group->space_info->lock);
1062
1063 memcpy(&key, &block_group->key, sizeof(key));
1064
1065 mutex_lock(&fs_info->chunk_mutex);
1066 spin_lock(&block_group->lock);
1067 block_group->removed = 1;
1068 /*
1069 * At this point trimming can't start on this block group, because we
1070 * removed the block group from the tree fs_info->block_group_cache_tree
1071 * so no one can't find it anymore and even if someone already got this
1072 * block group before we removed it from the rbtree, they have already
1073 * incremented block_group->trimming - if they didn't, they won't find
1074 * any free space entries because we already removed them all when we
1075 * called btrfs_remove_free_space_cache().
1076 *
1077 * And we must not remove the extent map from the fs_info->mapping_tree
1078 * to prevent the same logical address range and physical device space
1079 * ranges from being reused for a new block group. This is because our
1080 * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
1081 * completely transactionless, so while it is trimming a range the
1082 * currently running transaction might finish and a new one start,
1083 * allowing for new block groups to be created that can reuse the same
1084 * physical device locations unless we take this special care.
1085 *
1086 * There may also be an implicit trim operation if the file system
1087 * is mounted with -odiscard. The same protections must remain
1088 * in place until the extents have been discarded completely when
1089 * the transaction commit has completed.
1090 */
1091 remove_em = (atomic_read(&block_group->trimming) == 0);
1092 spin_unlock(&block_group->lock);
1093
1094 mutex_unlock(&fs_info->chunk_mutex);
1095
1096 ret = remove_block_group_free_space(trans, block_group);
1097 if (ret)
1098 goto out;
1099
1100 btrfs_put_block_group(block_group);
1101 btrfs_put_block_group(block_group);
1102
1103 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1104 if (ret > 0)
1105 ret = -EIO;
1106 if (ret < 0)
1107 goto out;
1108
1109 ret = btrfs_del_item(trans, root, path);
1110 if (ret)
1111 goto out;
1112
1113 if (remove_em) {
1114 struct extent_map_tree *em_tree;
1115
1116 em_tree = &fs_info->mapping_tree;
1117 write_lock(&em_tree->lock);
1118 remove_extent_mapping(em_tree, em);
1119 write_unlock(&em_tree->lock);
1120 /* once for the tree */
1121 free_extent_map(em);
1122 }
1123out:
1124 if (remove_rsv)
1125 btrfs_delayed_refs_rsv_release(fs_info, 1);
1126 btrfs_free_path(path);
1127 return ret;
1128}
1129
1130struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
1131 struct btrfs_fs_info *fs_info, const u64 chunk_offset)
1132{
1133 struct extent_map_tree *em_tree = &fs_info->mapping_tree;
1134 struct extent_map *em;
1135 struct map_lookup *map;
1136 unsigned int num_items;
1137
1138 read_lock(&em_tree->lock);
1139 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1140 read_unlock(&em_tree->lock);
1141 ASSERT(em && em->start == chunk_offset);
1142
1143 /*
1144 * We need to reserve 3 + N units from the metadata space info in order
1145 * to remove a block group (done at btrfs_remove_chunk() and at
1146 * btrfs_remove_block_group()), which are used for:
1147 *
1148 * 1 unit for adding the free space inode's orphan (located in the tree
1149 * of tree roots).
1150 * 1 unit for deleting the block group item (located in the extent
1151 * tree).
1152 * 1 unit for deleting the free space item (located in tree of tree
1153 * roots).
1154 * N units for deleting N device extent items corresponding to each
1155 * stripe (located in the device tree).
1156 *
1157 * In order to remove a block group we also need to reserve units in the
1158 * system space info in order to update the chunk tree (update one or
1159 * more device items and remove one chunk item), but this is done at
1160 * btrfs_remove_chunk() through a call to check_system_chunk().
1161 */
1162 map = em->map_lookup;
1163 num_items = 3 + map->num_stripes;
1164 free_extent_map(em);
1165
1166 return btrfs_start_transaction_fallback_global_rsv(fs_info->extent_root,
1167 num_items, 1);
1168}
1169
1170/*
1171 * Mark block group @cache read-only, so later write won't happen to block
1172 * group @cache.
1173 *
1174 * If @force is not set, this function will only mark the block group readonly
1175 * if we have enough free space (1M) in other metadata/system block groups.
1176 * If @force is not set, this function will mark the block group readonly
1177 * without checking free space.
1178 *
1179 * NOTE: This function doesn't care if other block groups can contain all the
1180 * data in this block group. That check should be done by relocation routine,
1181 * not this function.
1182 */
1183static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
1184{
1185 struct btrfs_space_info *sinfo = cache->space_info;
1186 u64 num_bytes;
1187 u64 sinfo_used;
1188 u64 min_allocable_bytes;
1189 int ret = -ENOSPC;
1190
1191 /*
1192 * We need some metadata space and system metadata space for
1193 * allocating chunks in some corner cases until we force to set
1194 * it to be readonly.
1195 */
1196 if ((sinfo->flags &
1197 (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
1198 !force)
1199 min_allocable_bytes = SZ_1M;
1200 else
1201 min_allocable_bytes = 0;
1202
1203 spin_lock(&sinfo->lock);
1204 spin_lock(&cache->lock);
1205
1206 if (cache->ro) {
1207 cache->ro++;
1208 ret = 0;
1209 goto out;
1210 }
1211
1212 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
1213 cache->bytes_super - btrfs_block_group_used(&cache->item);
1214 sinfo_used = btrfs_space_info_used(sinfo, true);
1215
1216 /*
1217 * sinfo_used + num_bytes should always <= sinfo->total_bytes.
1218 *
1219 * Here we make sure if we mark this bg RO, we still have enough
1220 * free space as buffer (if min_allocable_bytes is not 0).
1221 */
1222 if (sinfo_used + num_bytes + min_allocable_bytes <=
1223 sinfo->total_bytes) {
1224 sinfo->bytes_readonly += num_bytes;
1225 cache->ro++;
1226 list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
1227 ret = 0;
1228 }
1229out:
1230 spin_unlock(&cache->lock);
1231 spin_unlock(&sinfo->lock);
1232 if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) {
1233 btrfs_info(cache->fs_info,
1234 "unable to make block group %llu ro",
1235 cache->key.objectid);
1236 btrfs_info(cache->fs_info,
1237 "sinfo_used=%llu bg_num_bytes=%llu min_allocable=%llu",
1238 sinfo_used, num_bytes, min_allocable_bytes);
1239 btrfs_dump_space_info(cache->fs_info, cache->space_info, 0, 0);
1240 }
1241 return ret;
1242}
1243
1244/*
1245 * Process the unused_bgs list and remove any that don't have any allocated
1246 * space inside of them.
1247 */
1248void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
1249{
1250 struct btrfs_block_group_cache *block_group;
1251 struct btrfs_space_info *space_info;
1252 struct btrfs_trans_handle *trans;
1253 int ret = 0;
1254
1255 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1256 return;
1257
1258 spin_lock(&fs_info->unused_bgs_lock);
1259 while (!list_empty(&fs_info->unused_bgs)) {
1260 u64 start, end;
1261 int trimming;
1262
1263 block_group = list_first_entry(&fs_info->unused_bgs,
1264 struct btrfs_block_group_cache,
1265 bg_list);
1266 list_del_init(&block_group->bg_list);
1267
1268 space_info = block_group->space_info;
1269
1270 if (ret || btrfs_mixed_space_info(space_info)) {
1271 btrfs_put_block_group(block_group);
1272 continue;
1273 }
1274 spin_unlock(&fs_info->unused_bgs_lock);
1275
1276 mutex_lock(&fs_info->delete_unused_bgs_mutex);
1277
1278 /* Don't want to race with allocators so take the groups_sem */
1279 down_write(&space_info->groups_sem);
1280 spin_lock(&block_group->lock);
1281 if (block_group->reserved || block_group->pinned ||
1282 btrfs_block_group_used(&block_group->item) ||
1283 block_group->ro ||
1284 list_is_singular(&block_group->list)) {
1285 /*
1286 * We want to bail if we made new allocations or have
1287 * outstanding allocations in this block group. We do
1288 * the ro check in case balance is currently acting on
1289 * this block group.
1290 */
1291 trace_btrfs_skip_unused_block_group(block_group);
1292 spin_unlock(&block_group->lock);
1293 up_write(&space_info->groups_sem);
1294 goto next;
1295 }
1296 spin_unlock(&block_group->lock);
1297
1298 /* We don't want to force the issue, only flip if it's ok. */
1299 ret = inc_block_group_ro(block_group, 0);
1300 up_write(&space_info->groups_sem);
1301 if (ret < 0) {
1302 ret = 0;
1303 goto next;
1304 }
1305
1306 /*
1307 * Want to do this before we do anything else so we can recover
1308 * properly if we fail to join the transaction.
1309 */
1310 trans = btrfs_start_trans_remove_block_group(fs_info,
1311 block_group->key.objectid);
1312 if (IS_ERR(trans)) {
1313 btrfs_dec_block_group_ro(block_group);
1314 ret = PTR_ERR(trans);
1315 goto next;
1316 }
1317
1318 /*
1319 * We could have pending pinned extents for this block group,
1320 * just delete them, we don't care about them anymore.
1321 */
1322 start = block_group->key.objectid;
1323 end = start + block_group->key.offset - 1;
1324 /*
1325 * Hold the unused_bg_unpin_mutex lock to avoid racing with
1326 * btrfs_finish_extent_commit(). If we are at transaction N,
1327 * another task might be running finish_extent_commit() for the
1328 * previous transaction N - 1, and have seen a range belonging
1329 * to the block group in freed_extents[] before we were able to
1330 * clear the whole block group range from freed_extents[]. This
1331 * means that task can lookup for the block group after we
1332 * unpinned it from freed_extents[] and removed it, leading to
1333 * a BUG_ON() at btrfs_unpin_extent_range().
1334 */
1335 mutex_lock(&fs_info->unused_bg_unpin_mutex);
1336 ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
1337 EXTENT_DIRTY);
1338 if (ret) {
1339 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
1340 btrfs_dec_block_group_ro(block_group);
1341 goto end_trans;
1342 }
1343 ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
1344 EXTENT_DIRTY);
1345 if (ret) {
1346 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
1347 btrfs_dec_block_group_ro(block_group);
1348 goto end_trans;
1349 }
1350 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
1351
1352 /* Reset pinned so btrfs_put_block_group doesn't complain */
1353 spin_lock(&space_info->lock);
1354 spin_lock(&block_group->lock);
1355
1356 btrfs_space_info_update_bytes_pinned(fs_info, space_info,
1357 -block_group->pinned);
1358 space_info->bytes_readonly += block_group->pinned;
1359 percpu_counter_add_batch(&space_info->total_bytes_pinned,
1360 -block_group->pinned,
1361 BTRFS_TOTAL_BYTES_PINNED_BATCH);
1362 block_group->pinned = 0;
1363
1364 spin_unlock(&block_group->lock);
1365 spin_unlock(&space_info->lock);
1366
1367 /* DISCARD can flip during remount */
1368 trimming = btrfs_test_opt(fs_info, DISCARD);
1369
1370 /* Implicit trim during transaction commit. */
1371 if (trimming)
1372 btrfs_get_block_group_trimming(block_group);
1373
1374 /*
1375 * Btrfs_remove_chunk will abort the transaction if things go
1376 * horribly wrong.
1377 */
1378 ret = btrfs_remove_chunk(trans, block_group->key.objectid);
1379
1380 if (ret) {
1381 if (trimming)
1382 btrfs_put_block_group_trimming(block_group);
1383 goto end_trans;
1384 }
1385
1386 /*
1387 * If we're not mounted with -odiscard, we can just forget
1388 * about this block group. Otherwise we'll need to wait
1389 * until transaction commit to do the actual discard.
1390 */
1391 if (trimming) {
1392 spin_lock(&fs_info->unused_bgs_lock);
1393 /*
1394 * A concurrent scrub might have added us to the list
1395 * fs_info->unused_bgs, so use a list_move operation
1396 * to add the block group to the deleted_bgs list.
1397 */
1398 list_move(&block_group->bg_list,
1399 &trans->transaction->deleted_bgs);
1400 spin_unlock(&fs_info->unused_bgs_lock);
1401 btrfs_get_block_group(block_group);
1402 }
1403end_trans:
1404 btrfs_end_transaction(trans);
1405next:
1406 mutex_unlock(&fs_info->delete_unused_bgs_mutex);
1407 btrfs_put_block_group(block_group);
1408 spin_lock(&fs_info->unused_bgs_lock);
1409 }
1410 spin_unlock(&fs_info->unused_bgs_lock);
1411}
1412
1413void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg)
1414{
1415 struct btrfs_fs_info *fs_info = bg->fs_info;
1416
1417 spin_lock(&fs_info->unused_bgs_lock);
1418 if (list_empty(&bg->bg_list)) {
1419 btrfs_get_block_group(bg);
1420 trace_btrfs_add_unused_block_group(bg);
1421 list_add_tail(&bg->bg_list, &fs_info->unused_bgs);
1422 }
1423 spin_unlock(&fs_info->unused_bgs_lock);
1424}
1425
1426static int find_first_block_group(struct btrfs_fs_info *fs_info,
1427 struct btrfs_path *path,
1428 struct btrfs_key *key)
1429{
1430 struct btrfs_root *root = fs_info->extent_root;
1431 int ret = 0;
1432 struct btrfs_key found_key;
1433 struct extent_buffer *leaf;
1434 struct btrfs_block_group_item bg;
1435 u64 flags;
1436 int slot;
1437
1438 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
1439 if (ret < 0)
1440 goto out;
1441
1442 while (1) {
1443 slot = path->slots[0];
1444 leaf = path->nodes[0];
1445 if (slot >= btrfs_header_nritems(leaf)) {
1446 ret = btrfs_next_leaf(root, path);
1447 if (ret == 0)
1448 continue;
1449 if (ret < 0)
1450 goto out;
1451 break;
1452 }
1453 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1454
1455 if (found_key.objectid >= key->objectid &&
1456 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
1457 struct extent_map_tree *em_tree;
1458 struct extent_map *em;
1459
1460 em_tree = &root->fs_info->mapping_tree;
1461 read_lock(&em_tree->lock);
1462 em = lookup_extent_mapping(em_tree, found_key.objectid,
1463 found_key.offset);
1464 read_unlock(&em_tree->lock);
1465 if (!em) {
1466 btrfs_err(fs_info,
1467 "logical %llu len %llu found bg but no related chunk",
1468 found_key.objectid, found_key.offset);
1469 ret = -ENOENT;
1470 } else if (em->start != found_key.objectid ||
1471 em->len != found_key.offset) {
1472 btrfs_err(fs_info,
1473 "block group %llu len %llu mismatch with chunk %llu len %llu",
1474 found_key.objectid, found_key.offset,
1475 em->start, em->len);
1476 ret = -EUCLEAN;
1477 } else {
1478 read_extent_buffer(leaf, &bg,
1479 btrfs_item_ptr_offset(leaf, slot),
1480 sizeof(bg));
1481 flags = btrfs_block_group_flags(&bg) &
1482 BTRFS_BLOCK_GROUP_TYPE_MASK;
1483
1484 if (flags != (em->map_lookup->type &
1485 BTRFS_BLOCK_GROUP_TYPE_MASK)) {
1486 btrfs_err(fs_info,
1487"block group %llu len %llu type flags 0x%llx mismatch with chunk type flags 0x%llx",
1488 found_key.objectid,
1489 found_key.offset, flags,
1490 (BTRFS_BLOCK_GROUP_TYPE_MASK &
1491 em->map_lookup->type));
1492 ret = -EUCLEAN;
1493 } else {
1494 ret = 0;
1495 }
1496 }
1497 free_extent_map(em);
1498 goto out;
1499 }
1500 path->slots[0]++;
1501 }
1502out:
1503 return ret;
1504}
1505
1506static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1507{
1508 u64 extra_flags = chunk_to_extended(flags) &
1509 BTRFS_EXTENDED_PROFILE_MASK;
1510
1511 write_seqlock(&fs_info->profiles_lock);
1512 if (flags & BTRFS_BLOCK_GROUP_DATA)
1513 fs_info->avail_data_alloc_bits |= extra_flags;
1514 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1515 fs_info->avail_metadata_alloc_bits |= extra_flags;
1516 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1517 fs_info->avail_system_alloc_bits |= extra_flags;
1518 write_sequnlock(&fs_info->profiles_lock);
1519}
1520
1521static int exclude_super_stripes(struct btrfs_block_group_cache *cache)
1522{
1523 struct btrfs_fs_info *fs_info = cache->fs_info;
1524 u64 bytenr;
1525 u64 *logical;
1526 int stripe_len;
1527 int i, nr, ret;
1528
1529 if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
1530 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
1531 cache->bytes_super += stripe_len;
1532 ret = btrfs_add_excluded_extent(fs_info, cache->key.objectid,
1533 stripe_len);
1534 if (ret)
1535 return ret;
1536 }
1537
1538 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1539 bytenr = btrfs_sb_offset(i);
1540 ret = btrfs_rmap_block(fs_info, cache->key.objectid,
1541 bytenr, &logical, &nr, &stripe_len);
1542 if (ret)
1543 return ret;
1544
1545 while (nr--) {
1546 u64 start, len;
1547
1548 if (logical[nr] > cache->key.objectid +
1549 cache->key.offset)
1550 continue;
1551
1552 if (logical[nr] + stripe_len <= cache->key.objectid)
1553 continue;
1554
1555 start = logical[nr];
1556 if (start < cache->key.objectid) {
1557 start = cache->key.objectid;
1558 len = (logical[nr] + stripe_len) - start;
1559 } else {
1560 len = min_t(u64, stripe_len,
1561 cache->key.objectid +
1562 cache->key.offset - start);
1563 }
1564
1565 cache->bytes_super += len;
1566 ret = btrfs_add_excluded_extent(fs_info, start, len);
1567 if (ret) {
1568 kfree(logical);
1569 return ret;
1570 }
1571 }
1572
1573 kfree(logical);
1574 }
1575 return 0;
1576}
1577
1578static void link_block_group(struct btrfs_block_group_cache *cache)
1579{
1580 struct btrfs_space_info *space_info = cache->space_info;
1581 int index = btrfs_bg_flags_to_raid_index(cache->flags);
1582 bool first = false;
1583
1584 down_write(&space_info->groups_sem);
1585 if (list_empty(&space_info->block_groups[index]))
1586 first = true;
1587 list_add_tail(&cache->list, &space_info->block_groups[index]);
1588 up_write(&space_info->groups_sem);
1589
1590 if (first)
1591 btrfs_sysfs_add_block_group_type(cache);
1592}
1593
1594static struct btrfs_block_group_cache *btrfs_create_block_group_cache(
1595 struct btrfs_fs_info *fs_info, u64 start, u64 size)
1596{
1597 struct btrfs_block_group_cache *cache;
1598
1599 cache = kzalloc(sizeof(*cache), GFP_NOFS);
1600 if (!cache)
1601 return NULL;
1602
1603 cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
1604 GFP_NOFS);
1605 if (!cache->free_space_ctl) {
1606 kfree(cache);
1607 return NULL;
1608 }
1609
1610 cache->key.objectid = start;
1611 cache->key.offset = size;
1612 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
1613
1614 cache->fs_info = fs_info;
1615 cache->full_stripe_len = btrfs_full_stripe_len(fs_info, start);
1616 set_free_space_tree_thresholds(cache);
1617
1618 atomic_set(&cache->count, 1);
1619 spin_lock_init(&cache->lock);
1620 init_rwsem(&cache->data_rwsem);
1621 INIT_LIST_HEAD(&cache->list);
1622 INIT_LIST_HEAD(&cache->cluster_list);
1623 INIT_LIST_HEAD(&cache->bg_list);
1624 INIT_LIST_HEAD(&cache->ro_list);
1625 INIT_LIST_HEAD(&cache->dirty_list);
1626 INIT_LIST_HEAD(&cache->io_list);
1627 btrfs_init_free_space_ctl(cache);
1628 atomic_set(&cache->trimming, 0);
1629 mutex_init(&cache->free_space_lock);
1630 btrfs_init_full_stripe_locks_tree(&cache->full_stripe_locks_root);
1631
1632 return cache;
1633}
1634
1635/*
1636 * Iterate all chunks and verify that each of them has the corresponding block
1637 * group
1638 */
1639static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info)
1640{
1641 struct extent_map_tree *map_tree = &fs_info->mapping_tree;
1642 struct extent_map *em;
1643 struct btrfs_block_group_cache *bg;
1644 u64 start = 0;
1645 int ret = 0;
1646
1647 while (1) {
1648 read_lock(&map_tree->lock);
1649 /*
1650 * lookup_extent_mapping will return the first extent map
1651 * intersecting the range, so setting @len to 1 is enough to
1652 * get the first chunk.
1653 */
1654 em = lookup_extent_mapping(map_tree, start, 1);
1655 read_unlock(&map_tree->lock);
1656 if (!em)
1657 break;
1658
1659 bg = btrfs_lookup_block_group(fs_info, em->start);
1660 if (!bg) {
1661 btrfs_err(fs_info,
1662 "chunk start=%llu len=%llu doesn't have corresponding block group",
1663 em->start, em->len);
1664 ret = -EUCLEAN;
1665 free_extent_map(em);
1666 break;
1667 }
1668 if (bg->key.objectid != em->start ||
1669 bg->key.offset != em->len ||
1670 (bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK) !=
1671 (em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) {
1672 btrfs_err(fs_info,
1673"chunk start=%llu len=%llu flags=0x%llx doesn't match block group start=%llu len=%llu flags=0x%llx",
1674 em->start, em->len,
1675 em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK,
1676 bg->key.objectid, bg->key.offset,
1677 bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK);
1678 ret = -EUCLEAN;
1679 free_extent_map(em);
1680 btrfs_put_block_group(bg);
1681 break;
1682 }
1683 start = em->start + em->len;
1684 free_extent_map(em);
1685 btrfs_put_block_group(bg);
1686 }
1687 return ret;
1688}
1689
1690int btrfs_read_block_groups(struct btrfs_fs_info *info)
1691{
1692 struct btrfs_path *path;
1693 int ret;
1694 struct btrfs_block_group_cache *cache;
1695 struct btrfs_space_info *space_info;
1696 struct btrfs_key key;
1697 struct btrfs_key found_key;
1698 struct extent_buffer *leaf;
1699 int need_clear = 0;
1700 u64 cache_gen;
1701 u64 feature;
1702 int mixed;
1703
1704 feature = btrfs_super_incompat_flags(info->super_copy);
1705 mixed = !!(feature & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS);
1706
1707 key.objectid = 0;
1708 key.offset = 0;
1709 key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
1710 path = btrfs_alloc_path();
1711 if (!path)
1712 return -ENOMEM;
1713 path->reada = READA_FORWARD;
1714
1715 cache_gen = btrfs_super_cache_generation(info->super_copy);
1716 if (btrfs_test_opt(info, SPACE_CACHE) &&
1717 btrfs_super_generation(info->super_copy) != cache_gen)
1718 need_clear = 1;
1719 if (btrfs_test_opt(info, CLEAR_CACHE))
1720 need_clear = 1;
1721
1722 while (1) {
1723 ret = find_first_block_group(info, path, &key);
1724 if (ret > 0)
1725 break;
1726 if (ret != 0)
1727 goto error;
1728
1729 leaf = path->nodes[0];
1730 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1731
1732 cache = btrfs_create_block_group_cache(info, found_key.objectid,
1733 found_key.offset);
1734 if (!cache) {
1735 ret = -ENOMEM;
1736 goto error;
1737 }
1738
1739 if (need_clear) {
1740 /*
1741 * When we mount with old space cache, we need to
1742 * set BTRFS_DC_CLEAR and set dirty flag.
1743 *
1744 * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
1745 * truncate the old free space cache inode and
1746 * setup a new one.
1747 * b) Setting 'dirty flag' makes sure that we flush
1748 * the new space cache info onto disk.
1749 */
1750 if (btrfs_test_opt(info, SPACE_CACHE))
1751 cache->disk_cache_state = BTRFS_DC_CLEAR;
1752 }
1753
1754 read_extent_buffer(leaf, &cache->item,
1755 btrfs_item_ptr_offset(leaf, path->slots[0]),
1756 sizeof(cache->item));
1757 cache->flags = btrfs_block_group_flags(&cache->item);
1758 if (!mixed &&
1759 ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
1760 (cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
1761 btrfs_err(info,
1762"bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups",
1763 cache->key.objectid);
1764 btrfs_put_block_group(cache);
1765 ret = -EINVAL;
1766 goto error;
1767 }
1768
1769 key.objectid = found_key.objectid + found_key.offset;
1770 btrfs_release_path(path);
1771
1772 /*
1773 * We need to exclude the super stripes now so that the space
1774 * info has super bytes accounted for, otherwise we'll think
1775 * we have more space than we actually do.
1776 */
1777 ret = exclude_super_stripes(cache);
1778 if (ret) {
1779 /*
1780 * We may have excluded something, so call this just in
1781 * case.
1782 */
1783 btrfs_free_excluded_extents(cache);
1784 btrfs_put_block_group(cache);
1785 goto error;
1786 }
1787
1788 /*
1789 * Check for two cases, either we are full, and therefore
1790 * don't need to bother with the caching work since we won't
1791 * find any space, or we are empty, and we can just add all
1792 * the space in and be done with it. This saves us _a_lot_ of
1793 * time, particularly in the full case.
1794 */
1795 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
1796 cache->last_byte_to_unpin = (u64)-1;
1797 cache->cached = BTRFS_CACHE_FINISHED;
1798 btrfs_free_excluded_extents(cache);
1799 } else if (btrfs_block_group_used(&cache->item) == 0) {
1800 cache->last_byte_to_unpin = (u64)-1;
1801 cache->cached = BTRFS_CACHE_FINISHED;
1802 add_new_free_space(cache, found_key.objectid,
1803 found_key.objectid +
1804 found_key.offset);
1805 btrfs_free_excluded_extents(cache);
1806 }
1807
1808 ret = btrfs_add_block_group_cache(info, cache);
1809 if (ret) {
1810 btrfs_remove_free_space_cache(cache);
1811 btrfs_put_block_group(cache);
1812 goto error;
1813 }
1814
1815 trace_btrfs_add_block_group(info, cache, 0);
1816 btrfs_update_space_info(info, cache->flags, found_key.offset,
1817 btrfs_block_group_used(&cache->item),
1818 cache->bytes_super, &space_info);
1819
1820 cache->space_info = space_info;
1821
1822 link_block_group(cache);
1823
1824 set_avail_alloc_bits(info, cache->flags);
1825 if (btrfs_chunk_readonly(info, cache->key.objectid)) {
1826 inc_block_group_ro(cache, 1);
1827 } else if (btrfs_block_group_used(&cache->item) == 0) {
1828 ASSERT(list_empty(&cache->bg_list));
1829 btrfs_mark_bg_unused(cache);
1830 }
1831 }
1832
1833 list_for_each_entry_rcu(space_info, &info->space_info, list) {
1834 if (!(btrfs_get_alloc_profile(info, space_info->flags) &
1835 (BTRFS_BLOCK_GROUP_RAID10 |
1836 BTRFS_BLOCK_GROUP_RAID1_MASK |
1837 BTRFS_BLOCK_GROUP_RAID56_MASK |
1838 BTRFS_BLOCK_GROUP_DUP)))
1839 continue;
1840 /*
1841 * Avoid allocating from un-mirrored block group if there are
1842 * mirrored block groups.
1843 */
1844 list_for_each_entry(cache,
1845 &space_info->block_groups[BTRFS_RAID_RAID0],
1846 list)
1847 inc_block_group_ro(cache, 1);
1848 list_for_each_entry(cache,
1849 &space_info->block_groups[BTRFS_RAID_SINGLE],
1850 list)
1851 inc_block_group_ro(cache, 1);
1852 }
1853
1854 btrfs_init_global_block_rsv(info);
1855 ret = check_chunk_block_group_mappings(info);
1856error:
1857 btrfs_free_path(path);
1858 return ret;
1859}
1860
1861void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans)
1862{
1863 struct btrfs_fs_info *fs_info = trans->fs_info;
1864 struct btrfs_block_group_cache *block_group;
1865 struct btrfs_root *extent_root = fs_info->extent_root;
1866 struct btrfs_block_group_item item;
1867 struct btrfs_key key;
1868 int ret = 0;
1869
1870 if (!trans->can_flush_pending_bgs)
1871 return;
1872
1873 while (!list_empty(&trans->new_bgs)) {
1874 block_group = list_first_entry(&trans->new_bgs,
1875 struct btrfs_block_group_cache,
1876 bg_list);
1877 if (ret)
1878 goto next;
1879
1880 spin_lock(&block_group->lock);
1881 memcpy(&item, &block_group->item, sizeof(item));
1882 memcpy(&key, &block_group->key, sizeof(key));
1883 spin_unlock(&block_group->lock);
1884
1885 ret = btrfs_insert_item(trans, extent_root, &key, &item,
1886 sizeof(item));
1887 if (ret)
1888 btrfs_abort_transaction(trans, ret);
1889 ret = btrfs_finish_chunk_alloc(trans, key.objectid, key.offset);
1890 if (ret)
1891 btrfs_abort_transaction(trans, ret);
1892 add_block_group_free_space(trans, block_group);
1893 /* Already aborted the transaction if it failed. */
1894next:
1895 btrfs_delayed_refs_rsv_release(fs_info, 1);
1896 list_del_init(&block_group->bg_list);
1897 }
1898 btrfs_trans_release_chunk_metadata(trans);
1899}
1900
1901int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
1902 u64 type, u64 chunk_offset, u64 size)
1903{
1904 struct btrfs_fs_info *fs_info = trans->fs_info;
1905 struct btrfs_block_group_cache *cache;
1906 int ret;
1907
1908 btrfs_set_log_full_commit(trans);
1909
1910 cache = btrfs_create_block_group_cache(fs_info, chunk_offset, size);
1911 if (!cache)
1912 return -ENOMEM;
1913
1914 btrfs_set_block_group_used(&cache->item, bytes_used);
1915 btrfs_set_block_group_chunk_objectid(&cache->item,
1916 BTRFS_FIRST_CHUNK_TREE_OBJECTID);
1917 btrfs_set_block_group_flags(&cache->item, type);
1918
1919 cache->flags = type;
1920 cache->last_byte_to_unpin = (u64)-1;
1921 cache->cached = BTRFS_CACHE_FINISHED;
1922 cache->needs_free_space = 1;
1923 ret = exclude_super_stripes(cache);
1924 if (ret) {
1925 /* We may have excluded something, so call this just in case */
1926 btrfs_free_excluded_extents(cache);
1927 btrfs_put_block_group(cache);
1928 return ret;
1929 }
1930
1931 add_new_free_space(cache, chunk_offset, chunk_offset + size);
1932
1933 btrfs_free_excluded_extents(cache);
1934
1935#ifdef CONFIG_BTRFS_DEBUG
1936 if (btrfs_should_fragment_free_space(cache)) {
1937 u64 new_bytes_used = size - bytes_used;
1938
1939 bytes_used += new_bytes_used >> 1;
1940 fragment_free_space(cache);
1941 }
1942#endif
1943 /*
1944 * Ensure the corresponding space_info object is created and
1945 * assigned to our block group. We want our bg to be added to the rbtree
1946 * with its ->space_info set.
1947 */
1948 cache->space_info = btrfs_find_space_info(fs_info, cache->flags);
1949 ASSERT(cache->space_info);
1950
1951 ret = btrfs_add_block_group_cache(fs_info, cache);
1952 if (ret) {
1953 btrfs_remove_free_space_cache(cache);
1954 btrfs_put_block_group(cache);
1955 return ret;
1956 }
1957
1958 /*
1959 * Now that our block group has its ->space_info set and is inserted in
1960 * the rbtree, update the space info's counters.
1961 */
1962 trace_btrfs_add_block_group(fs_info, cache, 1);
1963 btrfs_update_space_info(fs_info, cache->flags, size, bytes_used,
1964 cache->bytes_super, &cache->space_info);
1965 btrfs_update_global_block_rsv(fs_info);
1966
1967 link_block_group(cache);
1968
1969 list_add_tail(&cache->bg_list, &trans->new_bgs);
1970 trans->delayed_ref_updates++;
1971 btrfs_update_delayed_refs_rsv(trans);
1972
1973 set_avail_alloc_bits(fs_info, type);
1974 return 0;
1975}
1976
1977static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags)
1978{
1979 u64 num_devices;
1980 u64 stripped;
1981
1982 /*
1983 * if restripe for this chunk_type is on pick target profile and
1984 * return, otherwise do the usual balance
1985 */
1986 stripped = get_restripe_target(fs_info, flags);
1987 if (stripped)
1988 return extended_to_chunk(stripped);
1989
1990 num_devices = fs_info->fs_devices->rw_devices;
1991
1992 stripped = BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID56_MASK |
1993 BTRFS_BLOCK_GROUP_RAID1_MASK | BTRFS_BLOCK_GROUP_RAID10;
1994
1995 if (num_devices == 1) {
1996 stripped |= BTRFS_BLOCK_GROUP_DUP;
1997 stripped = flags & ~stripped;
1998
1999 /* turn raid0 into single device chunks */
2000 if (flags & BTRFS_BLOCK_GROUP_RAID0)
2001 return stripped;
2002
2003 /* turn mirroring into duplication */
2004 if (flags & (BTRFS_BLOCK_GROUP_RAID1_MASK |
2005 BTRFS_BLOCK_GROUP_RAID10))
2006 return stripped | BTRFS_BLOCK_GROUP_DUP;
2007 } else {
2008 /* they already had raid on here, just return */
2009 if (flags & stripped)
2010 return flags;
2011
2012 stripped |= BTRFS_BLOCK_GROUP_DUP;
2013 stripped = flags & ~stripped;
2014
2015 /* switch duplicated blocks with raid1 */
2016 if (flags & BTRFS_BLOCK_GROUP_DUP)
2017 return stripped | BTRFS_BLOCK_GROUP_RAID1;
2018
2019 /* this is drive concat, leave it alone */
2020 }
2021
2022 return flags;
2023}
2024
2025int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache)
2026
2027{
2028 struct btrfs_fs_info *fs_info = cache->fs_info;
2029 struct btrfs_trans_handle *trans;
2030 u64 alloc_flags;
2031 int ret;
2032
2033again:
2034 trans = btrfs_join_transaction(fs_info->extent_root);
2035 if (IS_ERR(trans))
2036 return PTR_ERR(trans);
2037
2038 /*
2039 * we're not allowed to set block groups readonly after the dirty
2040 * block groups cache has started writing. If it already started,
2041 * back off and let this transaction commit
2042 */
2043 mutex_lock(&fs_info->ro_block_group_mutex);
2044 if (test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &trans->transaction->flags)) {
2045 u64 transid = trans->transid;
2046
2047 mutex_unlock(&fs_info->ro_block_group_mutex);
2048 btrfs_end_transaction(trans);
2049
2050 ret = btrfs_wait_for_commit(fs_info, transid);
2051 if (ret)
2052 return ret;
2053 goto again;
2054 }
2055
2056 /*
2057 * if we are changing raid levels, try to allocate a corresponding
2058 * block group with the new raid level.
2059 */
2060 alloc_flags = update_block_group_flags(fs_info, cache->flags);
2061 if (alloc_flags != cache->flags) {
2062 ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
2063 /*
2064 * ENOSPC is allowed here, we may have enough space
2065 * already allocated at the new raid level to
2066 * carry on
2067 */
2068 if (ret == -ENOSPC)
2069 ret = 0;
2070 if (ret < 0)
2071 goto out;
2072 }
2073
2074 ret = inc_block_group_ro(cache, 0);
2075 if (!ret)
2076 goto out;
2077 alloc_flags = btrfs_get_alloc_profile(fs_info, cache->space_info->flags);
2078 ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
2079 if (ret < 0)
2080 goto out;
2081 ret = inc_block_group_ro(cache, 0);
2082out:
2083 if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
2084 alloc_flags = update_block_group_flags(fs_info, cache->flags);
2085 mutex_lock(&fs_info->chunk_mutex);
2086 check_system_chunk(trans, alloc_flags);
2087 mutex_unlock(&fs_info->chunk_mutex);
2088 }
2089 mutex_unlock(&fs_info->ro_block_group_mutex);
2090
2091 btrfs_end_transaction(trans);
2092 return ret;
2093}
2094
2095void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache)
2096{
2097 struct btrfs_space_info *sinfo = cache->space_info;
2098 u64 num_bytes;
2099
2100 BUG_ON(!cache->ro);
2101
2102 spin_lock(&sinfo->lock);
2103 spin_lock(&cache->lock);
2104 if (!--cache->ro) {
2105 num_bytes = cache->key.offset - cache->reserved -
2106 cache->pinned - cache->bytes_super -
2107 btrfs_block_group_used(&cache->item);
2108 sinfo->bytes_readonly -= num_bytes;
2109 list_del_init(&cache->ro_list);
2110 }
2111 spin_unlock(&cache->lock);
2112 spin_unlock(&sinfo->lock);
2113}
2114
2115static int write_one_cache_group(struct btrfs_trans_handle *trans,
2116 struct btrfs_path *path,
2117 struct btrfs_block_group_cache *cache)
2118{
2119 struct btrfs_fs_info *fs_info = trans->fs_info;
2120 int ret;
2121 struct btrfs_root *extent_root = fs_info->extent_root;
2122 unsigned long bi;
2123 struct extent_buffer *leaf;
2124
2125 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
2126 if (ret) {
2127 if (ret > 0)
2128 ret = -ENOENT;
2129 goto fail;
2130 }
2131
2132 leaf = path->nodes[0];
2133 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
2134 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
2135 btrfs_mark_buffer_dirty(leaf);
2136fail:
2137 btrfs_release_path(path);
2138 return ret;
2139
2140}
2141
2142static int cache_save_setup(struct btrfs_block_group_cache *block_group,
2143 struct btrfs_trans_handle *trans,
2144 struct btrfs_path *path)
2145{
2146 struct btrfs_fs_info *fs_info = block_group->fs_info;
2147 struct btrfs_root *root = fs_info->tree_root;
2148 struct inode *inode = NULL;
2149 struct extent_changeset *data_reserved = NULL;
2150 u64 alloc_hint = 0;
2151 int dcs = BTRFS_DC_ERROR;
2152 u64 num_pages = 0;
2153 int retries = 0;
2154 int ret = 0;
2155
2156 /*
2157 * If this block group is smaller than 100 megs don't bother caching the
2158 * block group.
2159 */
2160 if (block_group->key.offset < (100 * SZ_1M)) {
2161 spin_lock(&block_group->lock);
2162 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
2163 spin_unlock(&block_group->lock);
2164 return 0;
2165 }
2166
2167 if (trans->aborted)
2168 return 0;
2169again:
2170 inode = lookup_free_space_inode(block_group, path);
2171 if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
2172 ret = PTR_ERR(inode);
2173 btrfs_release_path(path);
2174 goto out;
2175 }
2176
2177 if (IS_ERR(inode)) {
2178 BUG_ON(retries);
2179 retries++;
2180
2181 if (block_group->ro)
2182 goto out_free;
2183
2184 ret = create_free_space_inode(trans, block_group, path);
2185 if (ret)
2186 goto out_free;
2187 goto again;
2188 }
2189
2190 /*
2191 * We want to set the generation to 0, that way if anything goes wrong
2192 * from here on out we know not to trust this cache when we load up next
2193 * time.
2194 */
2195 BTRFS_I(inode)->generation = 0;
2196 ret = btrfs_update_inode(trans, root, inode);
2197 if (ret) {
2198 /*
2199 * So theoretically we could recover from this, simply set the
2200 * super cache generation to 0 so we know to invalidate the
2201 * cache, but then we'd have to keep track of the block groups
2202 * that fail this way so we know we _have_ to reset this cache
2203 * before the next commit or risk reading stale cache. So to
2204 * limit our exposure to horrible edge cases lets just abort the
2205 * transaction, this only happens in really bad situations
2206 * anyway.
2207 */
2208 btrfs_abort_transaction(trans, ret);
2209 goto out_put;
2210 }
2211 WARN_ON(ret);
2212
2213 /* We've already setup this transaction, go ahead and exit */
2214 if (block_group->cache_generation == trans->transid &&
2215 i_size_read(inode)) {
2216 dcs = BTRFS_DC_SETUP;
2217 goto out_put;
2218 }
2219
2220 if (i_size_read(inode) > 0) {
2221 ret = btrfs_check_trunc_cache_free_space(fs_info,
2222 &fs_info->global_block_rsv);
2223 if (ret)
2224 goto out_put;
2225
2226 ret = btrfs_truncate_free_space_cache(trans, NULL, inode);
2227 if (ret)
2228 goto out_put;
2229 }
2230
2231 spin_lock(&block_group->lock);
2232 if (block_group->cached != BTRFS_CACHE_FINISHED ||
2233 !btrfs_test_opt(fs_info, SPACE_CACHE)) {
2234 /*
2235 * don't bother trying to write stuff out _if_
2236 * a) we're not cached,
2237 * b) we're with nospace_cache mount option,
2238 * c) we're with v2 space_cache (FREE_SPACE_TREE).
2239 */
2240 dcs = BTRFS_DC_WRITTEN;
2241 spin_unlock(&block_group->lock);
2242 goto out_put;
2243 }
2244 spin_unlock(&block_group->lock);
2245
2246 /*
2247 * We hit an ENOSPC when setting up the cache in this transaction, just
2248 * skip doing the setup, we've already cleared the cache so we're safe.
2249 */
2250 if (test_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags)) {
2251 ret = -ENOSPC;
2252 goto out_put;
2253 }
2254
2255 /*
2256 * Try to preallocate enough space based on how big the block group is.
2257 * Keep in mind this has to include any pinned space which could end up
2258 * taking up quite a bit since it's not folded into the other space
2259 * cache.
2260 */
2261 num_pages = div_u64(block_group->key.offset, SZ_256M);
2262 if (!num_pages)
2263 num_pages = 1;
2264
2265 num_pages *= 16;
2266 num_pages *= PAGE_SIZE;
2267
2268 ret = btrfs_check_data_free_space(inode, &data_reserved, 0, num_pages);
2269 if (ret)
2270 goto out_put;
2271
2272 ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
2273 num_pages, num_pages,
2274 &alloc_hint);
2275 /*
2276 * Our cache requires contiguous chunks so that we don't modify a bunch
2277 * of metadata or split extents when writing the cache out, which means
2278 * we can enospc if we are heavily fragmented in addition to just normal
2279 * out of space conditions. So if we hit this just skip setting up any
2280 * other block groups for this transaction, maybe we'll unpin enough
2281 * space the next time around.
2282 */
2283 if (!ret)
2284 dcs = BTRFS_DC_SETUP;
2285 else if (ret == -ENOSPC)
2286 set_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags);
2287
2288out_put:
2289 iput(inode);
2290out_free:
2291 btrfs_release_path(path);
2292out:
2293 spin_lock(&block_group->lock);
2294 if (!ret && dcs == BTRFS_DC_SETUP)
2295 block_group->cache_generation = trans->transid;
2296 block_group->disk_cache_state = dcs;
2297 spin_unlock(&block_group->lock);
2298
2299 extent_changeset_free(data_reserved);
2300 return ret;
2301}
2302
2303int btrfs_setup_space_cache(struct btrfs_trans_handle *trans)
2304{
2305 struct btrfs_fs_info *fs_info = trans->fs_info;
2306 struct btrfs_block_group_cache *cache, *tmp;
2307 struct btrfs_transaction *cur_trans = trans->transaction;
2308 struct btrfs_path *path;
2309
2310 if (list_empty(&cur_trans->dirty_bgs) ||
2311 !btrfs_test_opt(fs_info, SPACE_CACHE))
2312 return 0;
2313
2314 path = btrfs_alloc_path();
2315 if (!path)
2316 return -ENOMEM;
2317
2318 /* Could add new block groups, use _safe just in case */
2319 list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
2320 dirty_list) {
2321 if (cache->disk_cache_state == BTRFS_DC_CLEAR)
2322 cache_save_setup(cache, trans, path);
2323 }
2324
2325 btrfs_free_path(path);
2326 return 0;
2327}
2328
2329/*
2330 * Transaction commit does final block group cache writeback during a critical
2331 * section where nothing is allowed to change the FS. This is required in
2332 * order for the cache to actually match the block group, but can introduce a
2333 * lot of latency into the commit.
2334 *
2335 * So, btrfs_start_dirty_block_groups is here to kick off block group cache IO.
2336 * There's a chance we'll have to redo some of it if the block group changes
2337 * again during the commit, but it greatly reduces the commit latency by
2338 * getting rid of the easy block groups while we're still allowing others to
2339 * join the commit.
2340 */
2341int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans)
2342{
2343 struct btrfs_fs_info *fs_info = trans->fs_info;
2344 struct btrfs_block_group_cache *cache;
2345 struct btrfs_transaction *cur_trans = trans->transaction;
2346 int ret = 0;
2347 int should_put;
2348 struct btrfs_path *path = NULL;
2349 LIST_HEAD(dirty);
2350 struct list_head *io = &cur_trans->io_bgs;
2351 int num_started = 0;
2352 int loops = 0;
2353
2354 spin_lock(&cur_trans->dirty_bgs_lock);
2355 if (list_empty(&cur_trans->dirty_bgs)) {
2356 spin_unlock(&cur_trans->dirty_bgs_lock);
2357 return 0;
2358 }
2359 list_splice_init(&cur_trans->dirty_bgs, &dirty);
2360 spin_unlock(&cur_trans->dirty_bgs_lock);
2361
2362again:
2363 /* Make sure all the block groups on our dirty list actually exist */
2364 btrfs_create_pending_block_groups(trans);
2365
2366 if (!path) {
2367 path = btrfs_alloc_path();
2368 if (!path)
2369 return -ENOMEM;
2370 }
2371
2372 /*
2373 * cache_write_mutex is here only to save us from balance or automatic
2374 * removal of empty block groups deleting this block group while we are
2375 * writing out the cache
2376 */
2377 mutex_lock(&trans->transaction->cache_write_mutex);
2378 while (!list_empty(&dirty)) {
2379 bool drop_reserve = true;
2380
2381 cache = list_first_entry(&dirty,
2382 struct btrfs_block_group_cache,
2383 dirty_list);
2384 /*
2385 * This can happen if something re-dirties a block group that
2386 * is already under IO. Just wait for it to finish and then do
2387 * it all again
2388 */
2389 if (!list_empty(&cache->io_list)) {
2390 list_del_init(&cache->io_list);
2391 btrfs_wait_cache_io(trans, cache, path);
2392 btrfs_put_block_group(cache);
2393 }
2394
2395
2396 /*
2397 * btrfs_wait_cache_io uses the cache->dirty_list to decide if
2398 * it should update the cache_state. Don't delete until after
2399 * we wait.
2400 *
2401 * Since we're not running in the commit critical section
2402 * we need the dirty_bgs_lock to protect from update_block_group
2403 */
2404 spin_lock(&cur_trans->dirty_bgs_lock);
2405 list_del_init(&cache->dirty_list);
2406 spin_unlock(&cur_trans->dirty_bgs_lock);
2407
2408 should_put = 1;
2409
2410 cache_save_setup(cache, trans, path);
2411
2412 if (cache->disk_cache_state == BTRFS_DC_SETUP) {
2413 cache->io_ctl.inode = NULL;
2414 ret = btrfs_write_out_cache(trans, cache, path);
2415 if (ret == 0 && cache->io_ctl.inode) {
2416 num_started++;
2417 should_put = 0;
2418
2419 /*
2420 * The cache_write_mutex is protecting the
2421 * io_list, also refer to the definition of
2422 * btrfs_transaction::io_bgs for more details
2423 */
2424 list_add_tail(&cache->io_list, io);
2425 } else {
2426 /*
2427 * If we failed to write the cache, the
2428 * generation will be bad and life goes on
2429 */
2430 ret = 0;
2431 }
2432 }
2433 if (!ret) {
2434 ret = write_one_cache_group(trans, path, cache);
2435 /*
2436 * Our block group might still be attached to the list
2437 * of new block groups in the transaction handle of some
2438 * other task (struct btrfs_trans_handle->new_bgs). This
2439 * means its block group item isn't yet in the extent
2440 * tree. If this happens ignore the error, as we will
2441 * try again later in the critical section of the
2442 * transaction commit.
2443 */
2444 if (ret == -ENOENT) {
2445 ret = 0;
2446 spin_lock(&cur_trans->dirty_bgs_lock);
2447 if (list_empty(&cache->dirty_list)) {
2448 list_add_tail(&cache->dirty_list,
2449 &cur_trans->dirty_bgs);
2450 btrfs_get_block_group(cache);
2451 drop_reserve = false;
2452 }
2453 spin_unlock(&cur_trans->dirty_bgs_lock);
2454 } else if (ret) {
2455 btrfs_abort_transaction(trans, ret);
2456 }
2457 }
2458
2459 /* If it's not on the io list, we need to put the block group */
2460 if (should_put)
2461 btrfs_put_block_group(cache);
2462 if (drop_reserve)
2463 btrfs_delayed_refs_rsv_release(fs_info, 1);
2464
2465 if (ret)
2466 break;
2467
2468 /*
2469 * Avoid blocking other tasks for too long. It might even save
2470 * us from writing caches for block groups that are going to be
2471 * removed.
2472 */
2473 mutex_unlock(&trans->transaction->cache_write_mutex);
2474 mutex_lock(&trans->transaction->cache_write_mutex);
2475 }
2476 mutex_unlock(&trans->transaction->cache_write_mutex);
2477
2478 /*
2479 * Go through delayed refs for all the stuff we've just kicked off
2480 * and then loop back (just once)
2481 */
2482 ret = btrfs_run_delayed_refs(trans, 0);
2483 if (!ret && loops == 0) {
2484 loops++;
2485 spin_lock(&cur_trans->dirty_bgs_lock);
2486 list_splice_init(&cur_trans->dirty_bgs, &dirty);
2487 /*
2488 * dirty_bgs_lock protects us from concurrent block group
2489 * deletes too (not just cache_write_mutex).
2490 */
2491 if (!list_empty(&dirty)) {
2492 spin_unlock(&cur_trans->dirty_bgs_lock);
2493 goto again;
2494 }
2495 spin_unlock(&cur_trans->dirty_bgs_lock);
2496 } else if (ret < 0) {
2497 btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
2498 }
2499
2500 btrfs_free_path(path);
2501 return ret;
2502}
2503
2504int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans)
2505{
2506 struct btrfs_fs_info *fs_info = trans->fs_info;
2507 struct btrfs_block_group_cache *cache;
2508 struct btrfs_transaction *cur_trans = trans->transaction;
2509 int ret = 0;
2510 int should_put;
2511 struct btrfs_path *path;
2512 struct list_head *io = &cur_trans->io_bgs;
2513 int num_started = 0;
2514
2515 path = btrfs_alloc_path();
2516 if (!path)
2517 return -ENOMEM;
2518
2519 /*
2520 * Even though we are in the critical section of the transaction commit,
2521 * we can still have concurrent tasks adding elements to this
2522 * transaction's list of dirty block groups. These tasks correspond to
2523 * endio free space workers started when writeback finishes for a
2524 * space cache, which run inode.c:btrfs_finish_ordered_io(), and can
2525 * allocate new block groups as a result of COWing nodes of the root
2526 * tree when updating the free space inode. The writeback for the space
2527 * caches is triggered by an earlier call to
2528 * btrfs_start_dirty_block_groups() and iterations of the following
2529 * loop.
2530 * Also we want to do the cache_save_setup first and then run the
2531 * delayed refs to make sure we have the best chance at doing this all
2532 * in one shot.
2533 */
2534 spin_lock(&cur_trans->dirty_bgs_lock);
2535 while (!list_empty(&cur_trans->dirty_bgs)) {
2536 cache = list_first_entry(&cur_trans->dirty_bgs,
2537 struct btrfs_block_group_cache,
2538 dirty_list);
2539
2540 /*
2541 * This can happen if cache_save_setup re-dirties a block group
2542 * that is already under IO. Just wait for it to finish and
2543 * then do it all again
2544 */
2545 if (!list_empty(&cache->io_list)) {
2546 spin_unlock(&cur_trans->dirty_bgs_lock);
2547 list_del_init(&cache->io_list);
2548 btrfs_wait_cache_io(trans, cache, path);
2549 btrfs_put_block_group(cache);
2550 spin_lock(&cur_trans->dirty_bgs_lock);
2551 }
2552
2553 /*
2554 * Don't remove from the dirty list until after we've waited on
2555 * any pending IO
2556 */
2557 list_del_init(&cache->dirty_list);
2558 spin_unlock(&cur_trans->dirty_bgs_lock);
2559 should_put = 1;
2560
2561 cache_save_setup(cache, trans, path);
2562
2563 if (!ret)
2564 ret = btrfs_run_delayed_refs(trans,
2565 (unsigned long) -1);
2566
2567 if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
2568 cache->io_ctl.inode = NULL;
2569 ret = btrfs_write_out_cache(trans, cache, path);
2570 if (ret == 0 && cache->io_ctl.inode) {
2571 num_started++;
2572 should_put = 0;
2573 list_add_tail(&cache->io_list, io);
2574 } else {
2575 /*
2576 * If we failed to write the cache, the
2577 * generation will be bad and life goes on
2578 */
2579 ret = 0;
2580 }
2581 }
2582 if (!ret) {
2583 ret = write_one_cache_group(trans, path, cache);
2584 /*
2585 * One of the free space endio workers might have
2586 * created a new block group while updating a free space
2587 * cache's inode (at inode.c:btrfs_finish_ordered_io())
2588 * and hasn't released its transaction handle yet, in
2589 * which case the new block group is still attached to
2590 * its transaction handle and its creation has not
2591 * finished yet (no block group item in the extent tree
2592 * yet, etc). If this is the case, wait for all free
2593 * space endio workers to finish and retry. This is a
2594 * a very rare case so no need for a more efficient and
2595 * complex approach.
2596 */
2597 if (ret == -ENOENT) {
2598 wait_event(cur_trans->writer_wait,
2599 atomic_read(&cur_trans->num_writers) == 1);
2600 ret = write_one_cache_group(trans, path, cache);
2601 }
2602 if (ret)
2603 btrfs_abort_transaction(trans, ret);
2604 }
2605
2606 /* If its not on the io list, we need to put the block group */
2607 if (should_put)
2608 btrfs_put_block_group(cache);
2609 btrfs_delayed_refs_rsv_release(fs_info, 1);
2610 spin_lock(&cur_trans->dirty_bgs_lock);
2611 }
2612 spin_unlock(&cur_trans->dirty_bgs_lock);
2613
2614 /*
2615 * Refer to the definition of io_bgs member for details why it's safe
2616 * to use it without any locking
2617 */
2618 while (!list_empty(io)) {
2619 cache = list_first_entry(io, struct btrfs_block_group_cache,
2620 io_list);
2621 list_del_init(&cache->io_list);
2622 btrfs_wait_cache_io(trans, cache, path);
2623 btrfs_put_block_group(cache);
2624 }
2625
2626 btrfs_free_path(path);
2627 return ret;
2628}
2629
2630int btrfs_update_block_group(struct btrfs_trans_handle *trans,
2631 u64 bytenr, u64 num_bytes, int alloc)
2632{
2633 struct btrfs_fs_info *info = trans->fs_info;
2634 struct btrfs_block_group_cache *cache = NULL;
2635 u64 total = num_bytes;
2636 u64 old_val;
2637 u64 byte_in_group;
2638 int factor;
2639 int ret = 0;
2640
2641 /* Block accounting for super block */
2642 spin_lock(&info->delalloc_root_lock);
2643 old_val = btrfs_super_bytes_used(info->super_copy);
2644 if (alloc)
2645 old_val += num_bytes;
2646 else
2647 old_val -= num_bytes;
2648 btrfs_set_super_bytes_used(info->super_copy, old_val);
2649 spin_unlock(&info->delalloc_root_lock);
2650
2651 while (total) {
2652 cache = btrfs_lookup_block_group(info, bytenr);
2653 if (!cache) {
2654 ret = -ENOENT;
2655 break;
2656 }
2657 factor = btrfs_bg_type_to_factor(cache->flags);
2658
2659 /*
2660 * If this block group has free space cache written out, we
2661 * need to make sure to load it if we are removing space. This
2662 * is because we need the unpinning stage to actually add the
2663 * space back to the block group, otherwise we will leak space.
2664 */
2665 if (!alloc && cache->cached == BTRFS_CACHE_NO)
2666 btrfs_cache_block_group(cache, 1);
2667
2668 byte_in_group = bytenr - cache->key.objectid;
2669 WARN_ON(byte_in_group > cache->key.offset);
2670
2671 spin_lock(&cache->space_info->lock);
2672 spin_lock(&cache->lock);
2673
2674 if (btrfs_test_opt(info, SPACE_CACHE) &&
2675 cache->disk_cache_state < BTRFS_DC_CLEAR)
2676 cache->disk_cache_state = BTRFS_DC_CLEAR;
2677
2678 old_val = btrfs_block_group_used(&cache->item);
2679 num_bytes = min(total, cache->key.offset - byte_in_group);
2680 if (alloc) {
2681 old_val += num_bytes;
2682 btrfs_set_block_group_used(&cache->item, old_val);
2683 cache->reserved -= num_bytes;
2684 cache->space_info->bytes_reserved -= num_bytes;
2685 cache->space_info->bytes_used += num_bytes;
2686 cache->space_info->disk_used += num_bytes * factor;
2687 spin_unlock(&cache->lock);
2688 spin_unlock(&cache->space_info->lock);
2689 } else {
2690 old_val -= num_bytes;
2691 btrfs_set_block_group_used(&cache->item, old_val);
2692 cache->pinned += num_bytes;
2693 btrfs_space_info_update_bytes_pinned(info,
2694 cache->space_info, num_bytes);
2695 cache->space_info->bytes_used -= num_bytes;
2696 cache->space_info->disk_used -= num_bytes * factor;
2697 spin_unlock(&cache->lock);
2698 spin_unlock(&cache->space_info->lock);
2699
2700 percpu_counter_add_batch(
2701 &cache->space_info->total_bytes_pinned,
2702 num_bytes,
2703 BTRFS_TOTAL_BYTES_PINNED_BATCH);
2704 set_extent_dirty(info->pinned_extents,
2705 bytenr, bytenr + num_bytes - 1,
2706 GFP_NOFS | __GFP_NOFAIL);
2707 }
2708
2709 spin_lock(&trans->transaction->dirty_bgs_lock);
2710 if (list_empty(&cache->dirty_list)) {
2711 list_add_tail(&cache->dirty_list,
2712 &trans->transaction->dirty_bgs);
2713 trans->delayed_ref_updates++;
2714 btrfs_get_block_group(cache);
2715 }
2716 spin_unlock(&trans->transaction->dirty_bgs_lock);
2717
2718 /*
2719 * No longer have used bytes in this block group, queue it for
2720 * deletion. We do this after adding the block group to the
2721 * dirty list to avoid races between cleaner kthread and space
2722 * cache writeout.
2723 */
2724 if (!alloc && old_val == 0)
2725 btrfs_mark_bg_unused(cache);
2726
2727 btrfs_put_block_group(cache);
2728 total -= num_bytes;
2729 bytenr += num_bytes;
2730 }
2731
2732 /* Modified block groups are accounted for in the delayed_refs_rsv. */
2733 btrfs_update_delayed_refs_rsv(trans);
2734 return ret;
2735}
2736
2737/**
2738 * btrfs_add_reserved_bytes - update the block_group and space info counters
2739 * @cache: The cache we are manipulating
2740 * @ram_bytes: The number of bytes of file content, and will be same to
2741 * @num_bytes except for the compress path.
2742 * @num_bytes: The number of bytes in question
2743 * @delalloc: The blocks are allocated for the delalloc write
2744 *
2745 * This is called by the allocator when it reserves space. If this is a
2746 * reservation and the block group has become read only we cannot make the
2747 * reservation and return -EAGAIN, otherwise this function always succeeds.
2748 */
2749int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
2750 u64 ram_bytes, u64 num_bytes, int delalloc)
2751{
2752 struct btrfs_space_info *space_info = cache->space_info;
2753 int ret = 0;
2754
2755 spin_lock(&space_info->lock);
2756 spin_lock(&cache->lock);
2757 if (cache->ro) {
2758 ret = -EAGAIN;
2759 } else {
2760 cache->reserved += num_bytes;
2761 space_info->bytes_reserved += num_bytes;
2762 trace_btrfs_space_reservation(cache->fs_info, "space_info",
2763 space_info->flags, num_bytes, 1);
2764 btrfs_space_info_update_bytes_may_use(cache->fs_info,
2765 space_info, -ram_bytes);
2766 if (delalloc)
2767 cache->delalloc_bytes += num_bytes;
2768 }
2769 spin_unlock(&cache->lock);
2770 spin_unlock(&space_info->lock);
2771 return ret;
2772}
2773
2774/**
2775 * btrfs_free_reserved_bytes - update the block_group and space info counters
2776 * @cache: The cache we are manipulating
2777 * @num_bytes: The number of bytes in question
2778 * @delalloc: The blocks are allocated for the delalloc write
2779 *
2780 * This is called by somebody who is freeing space that was never actually used
2781 * on disk. For example if you reserve some space for a new leaf in transaction
2782 * A and before transaction A commits you free that leaf, you call this with
2783 * reserve set to 0 in order to clear the reservation.
2784 */
2785void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
2786 u64 num_bytes, int delalloc)
2787{
2788 struct btrfs_space_info *space_info = cache->space_info;
2789
2790 spin_lock(&space_info->lock);
2791 spin_lock(&cache->lock);
2792 if (cache->ro)
2793 space_info->bytes_readonly += num_bytes;
2794 cache->reserved -= num_bytes;
2795 space_info->bytes_reserved -= num_bytes;
2796 space_info->max_extent_size = 0;
2797
2798 if (delalloc)
2799 cache->delalloc_bytes -= num_bytes;
2800 spin_unlock(&cache->lock);
2801 spin_unlock(&space_info->lock);
2802}
2803
2804static void force_metadata_allocation(struct btrfs_fs_info *info)
2805{
2806 struct list_head *head = &info->space_info;
2807 struct btrfs_space_info *found;
2808
2809 rcu_read_lock();
2810 list_for_each_entry_rcu(found, head, list) {
2811 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
2812 found->force_alloc = CHUNK_ALLOC_FORCE;
2813 }
2814 rcu_read_unlock();
2815}
2816
2817static int should_alloc_chunk(struct btrfs_fs_info *fs_info,
2818 struct btrfs_space_info *sinfo, int force)
2819{
2820 u64 bytes_used = btrfs_space_info_used(sinfo, false);
2821 u64 thresh;
2822
2823 if (force == CHUNK_ALLOC_FORCE)
2824 return 1;
2825
2826 /*
2827 * in limited mode, we want to have some free space up to
2828 * about 1% of the FS size.
2829 */
2830 if (force == CHUNK_ALLOC_LIMITED) {
2831 thresh = btrfs_super_total_bytes(fs_info->super_copy);
2832 thresh = max_t(u64, SZ_64M, div_factor_fine(thresh, 1));
2833
2834 if (sinfo->total_bytes - bytes_used < thresh)
2835 return 1;
2836 }
2837
2838 if (bytes_used + SZ_2M < div_factor(sinfo->total_bytes, 8))
2839 return 0;
2840 return 1;
2841}
2842
2843int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type)
2844{
2845 u64 alloc_flags = btrfs_get_alloc_profile(trans->fs_info, type);
2846
2847 return btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
2848}
2849
2850/*
2851 * If force is CHUNK_ALLOC_FORCE:
2852 * - return 1 if it successfully allocates a chunk,
2853 * - return errors including -ENOSPC otherwise.
2854 * If force is NOT CHUNK_ALLOC_FORCE:
2855 * - return 0 if it doesn't need to allocate a new chunk,
2856 * - return 1 if it successfully allocates a chunk,
2857 * - return errors including -ENOSPC otherwise.
2858 */
2859int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
2860 enum btrfs_chunk_alloc_enum force)
2861{
2862 struct btrfs_fs_info *fs_info = trans->fs_info;
2863 struct btrfs_space_info *space_info;
2864 bool wait_for_alloc = false;
2865 bool should_alloc = false;
2866 int ret = 0;
2867
2868 /* Don't re-enter if we're already allocating a chunk */
2869 if (trans->allocating_chunk)
2870 return -ENOSPC;
2871
2872 space_info = btrfs_find_space_info(fs_info, flags);
2873 ASSERT(space_info);
2874
2875 do {
2876 spin_lock(&space_info->lock);
2877 if (force < space_info->force_alloc)
2878 force = space_info->force_alloc;
2879 should_alloc = should_alloc_chunk(fs_info, space_info, force);
2880 if (space_info->full) {
2881 /* No more free physical space */
2882 if (should_alloc)
2883 ret = -ENOSPC;
2884 else
2885 ret = 0;
2886 spin_unlock(&space_info->lock);
2887 return ret;
2888 } else if (!should_alloc) {
2889 spin_unlock(&space_info->lock);
2890 return 0;
2891 } else if (space_info->chunk_alloc) {
2892 /*
2893 * Someone is already allocating, so we need to block
2894 * until this someone is finished and then loop to
2895 * recheck if we should continue with our allocation
2896 * attempt.
2897 */
2898 wait_for_alloc = true;
2899 spin_unlock(&space_info->lock);
2900 mutex_lock(&fs_info->chunk_mutex);
2901 mutex_unlock(&fs_info->chunk_mutex);
2902 } else {
2903 /* Proceed with allocation */
2904 space_info->chunk_alloc = 1;
2905 wait_for_alloc = false;
2906 spin_unlock(&space_info->lock);
2907 }
2908
2909 cond_resched();
2910 } while (wait_for_alloc);
2911
2912 mutex_lock(&fs_info->chunk_mutex);
2913 trans->allocating_chunk = true;
2914
2915 /*
2916 * If we have mixed data/metadata chunks we want to make sure we keep
2917 * allocating mixed chunks instead of individual chunks.
2918 */
2919 if (btrfs_mixed_space_info(space_info))
2920 flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
2921
2922 /*
2923 * if we're doing a data chunk, go ahead and make sure that
2924 * we keep a reasonable number of metadata chunks allocated in the
2925 * FS as well.
2926 */
2927 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
2928 fs_info->data_chunk_allocations++;
2929 if (!(fs_info->data_chunk_allocations %
2930 fs_info->metadata_ratio))
2931 force_metadata_allocation(fs_info);
2932 }
2933
2934 /*
2935 * Check if we have enough space in SYSTEM chunk because we may need
2936 * to update devices.
2937 */
2938 check_system_chunk(trans, flags);
2939
2940 ret = btrfs_alloc_chunk(trans, flags);
2941 trans->allocating_chunk = false;
2942
2943 spin_lock(&space_info->lock);
2944 if (ret < 0) {
2945 if (ret == -ENOSPC)
2946 space_info->full = 1;
2947 else
2948 goto out;
2949 } else {
2950 ret = 1;
2951 space_info->max_extent_size = 0;
2952 }
2953
2954 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
2955out:
2956 space_info->chunk_alloc = 0;
2957 spin_unlock(&space_info->lock);
2958 mutex_unlock(&fs_info->chunk_mutex);
2959 /*
2960 * When we allocate a new chunk we reserve space in the chunk block
2961 * reserve to make sure we can COW nodes/leafs in the chunk tree or
2962 * add new nodes/leafs to it if we end up needing to do it when
2963 * inserting the chunk item and updating device items as part of the
2964 * second phase of chunk allocation, performed by
2965 * btrfs_finish_chunk_alloc(). So make sure we don't accumulate a
2966 * large number of new block groups to create in our transaction
2967 * handle's new_bgs list to avoid exhausting the chunk block reserve
2968 * in extreme cases - like having a single transaction create many new
2969 * block groups when starting to write out the free space caches of all
2970 * the block groups that were made dirty during the lifetime of the
2971 * transaction.
2972 */
2973 if (trans->chunk_bytes_reserved >= (u64)SZ_2M)
2974 btrfs_create_pending_block_groups(trans);
2975
2976 return ret;
2977}
2978
2979static u64 get_profile_num_devs(struct btrfs_fs_info *fs_info, u64 type)
2980{
2981 u64 num_dev;
2982
2983 num_dev = btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)].devs_max;
2984 if (!num_dev)
2985 num_dev = fs_info->fs_devices->rw_devices;
2986
2987 return num_dev;
2988}
2989
2990/*
2991 * If @is_allocation is true, reserve space in the system space info necessary
2992 * for allocating a chunk, otherwise if it's false, reserve space necessary for
2993 * removing a chunk.
2994 */
2995void check_system_chunk(struct btrfs_trans_handle *trans, u64 type)
2996{
2997 struct btrfs_fs_info *fs_info = trans->fs_info;
2998 struct btrfs_space_info *info;
2999 u64 left;
3000 u64 thresh;
3001 int ret = 0;
3002 u64 num_devs;
3003
3004 /*
3005 * Needed because we can end up allocating a system chunk and for an
3006 * atomic and race free space reservation in the chunk block reserve.
3007 */
3008 lockdep_assert_held(&fs_info->chunk_mutex);
3009
3010 info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
3011 spin_lock(&info->lock);
3012 left = info->total_bytes - btrfs_space_info_used(info, true);
3013 spin_unlock(&info->lock);
3014
3015 num_devs = get_profile_num_devs(fs_info, type);
3016
3017 /* num_devs device items to update and 1 chunk item to add or remove */
3018 thresh = btrfs_calc_metadata_size(fs_info, num_devs) +
3019 btrfs_calc_insert_metadata_size(fs_info, 1);
3020
3021 if (left < thresh && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
3022 btrfs_info(fs_info, "left=%llu, need=%llu, flags=%llu",
3023 left, thresh, type);
3024 btrfs_dump_space_info(fs_info, info, 0, 0);
3025 }
3026
3027 if (left < thresh) {
3028 u64 flags = btrfs_system_alloc_profile(fs_info);
3029
3030 /*
3031 * Ignore failure to create system chunk. We might end up not
3032 * needing it, as we might not need to COW all nodes/leafs from
3033 * the paths we visit in the chunk tree (they were already COWed
3034 * or created in the current transaction for example).
3035 */
3036 ret = btrfs_alloc_chunk(trans, flags);
3037 }
3038
3039 if (!ret) {
3040 ret = btrfs_block_rsv_add(fs_info->chunk_root,
3041 &fs_info->chunk_block_rsv,
3042 thresh, BTRFS_RESERVE_NO_FLUSH);
3043 if (!ret)
3044 trans->chunk_bytes_reserved += thresh;
3045 }
3046}
3047
3048void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
3049{
3050 struct btrfs_block_group_cache *block_group;
3051 u64 last = 0;
3052
3053 while (1) {
3054 struct inode *inode;
3055
3056 block_group = btrfs_lookup_first_block_group(info, last);
3057 while (block_group) {
3058 btrfs_wait_block_group_cache_done(block_group);
3059 spin_lock(&block_group->lock);
3060 if (block_group->iref)
3061 break;
3062 spin_unlock(&block_group->lock);
3063 block_group = btrfs_next_block_group(block_group);
3064 }
3065 if (!block_group) {
3066 if (last == 0)
3067 break;
3068 last = 0;
3069 continue;
3070 }
3071
3072 inode = block_group->inode;
3073 block_group->iref = 0;
3074 block_group->inode = NULL;
3075 spin_unlock(&block_group->lock);
3076 ASSERT(block_group->io_ctl.inode == NULL);
3077 iput(inode);
3078 last = block_group->key.objectid + block_group->key.offset;
3079 btrfs_put_block_group(block_group);
3080 }
3081}
3082
3083/*
3084 * Must be called only after stopping all workers, since we could have block
3085 * group caching kthreads running, and therefore they could race with us if we
3086 * freed the block groups before stopping them.
3087 */
3088int btrfs_free_block_groups(struct btrfs_fs_info *info)
3089{
3090 struct btrfs_block_group_cache *block_group;
3091 struct btrfs_space_info *space_info;
3092 struct btrfs_caching_control *caching_ctl;
3093 struct rb_node *n;
3094
3095 down_write(&info->commit_root_sem);
3096 while (!list_empty(&info->caching_block_groups)) {
3097 caching_ctl = list_entry(info->caching_block_groups.next,
3098 struct btrfs_caching_control, list);
3099 list_del(&caching_ctl->list);
3100 btrfs_put_caching_control(caching_ctl);
3101 }
3102 up_write(&info->commit_root_sem);
3103
3104 spin_lock(&info->unused_bgs_lock);
3105 while (!list_empty(&info->unused_bgs)) {
3106 block_group = list_first_entry(&info->unused_bgs,
3107 struct btrfs_block_group_cache,
3108 bg_list);
3109 list_del_init(&block_group->bg_list);
3110 btrfs_put_block_group(block_group);
3111 }
3112 spin_unlock(&info->unused_bgs_lock);
3113
3114 spin_lock(&info->block_group_cache_lock);
3115 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
3116 block_group = rb_entry(n, struct btrfs_block_group_cache,
3117 cache_node);
3118 rb_erase(&block_group->cache_node,
3119 &info->block_group_cache_tree);
3120 RB_CLEAR_NODE(&block_group->cache_node);
3121 spin_unlock(&info->block_group_cache_lock);
3122
3123 down_write(&block_group->space_info->groups_sem);
3124 list_del(&block_group->list);
3125 up_write(&block_group->space_info->groups_sem);
3126
3127 /*
3128 * We haven't cached this block group, which means we could
3129 * possibly have excluded extents on this block group.
3130 */
3131 if (block_group->cached == BTRFS_CACHE_NO ||
3132 block_group->cached == BTRFS_CACHE_ERROR)
3133 btrfs_free_excluded_extents(block_group);
3134
3135 btrfs_remove_free_space_cache(block_group);
3136 ASSERT(block_group->cached != BTRFS_CACHE_STARTED);
3137 ASSERT(list_empty(&block_group->dirty_list));
3138 ASSERT(list_empty(&block_group->io_list));
3139 ASSERT(list_empty(&block_group->bg_list));
3140 ASSERT(atomic_read(&block_group->count) == 1);
3141 btrfs_put_block_group(block_group);
3142
3143 spin_lock(&info->block_group_cache_lock);
3144 }
3145 spin_unlock(&info->block_group_cache_lock);
3146
3147 /*
3148 * Now that all the block groups are freed, go through and free all the
3149 * space_info structs. This is only called during the final stages of
3150 * unmount, and so we know nobody is using them. We call
3151 * synchronize_rcu() once before we start, just to be on the safe side.
3152 */
3153 synchronize_rcu();
3154
3155 btrfs_release_global_block_rsv(info);
3156
3157 while (!list_empty(&info->space_info)) {
3158 space_info = list_entry(info->space_info.next,
3159 struct btrfs_space_info,
3160 list);
3161
3162 /*
3163 * Do not hide this behind enospc_debug, this is actually
3164 * important and indicates a real bug if this happens.
3165 */
3166 if (WARN_ON(space_info->bytes_pinned > 0 ||
3167 space_info->bytes_reserved > 0 ||
3168 space_info->bytes_may_use > 0))
3169 btrfs_dump_space_info(info, space_info, 0, 0);
3170 list_del(&space_info->list);
3171 btrfs_sysfs_remove_space_info(space_info);
3172 }
3173 return 0;
3174}
1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/sizes.h>
4#include <linux/list_sort.h>
5#include "misc.h"
6#include "ctree.h"
7#include "block-group.h"
8#include "space-info.h"
9#include "disk-io.h"
10#include "free-space-cache.h"
11#include "free-space-tree.h"
12#include "volumes.h"
13#include "transaction.h"
14#include "ref-verify.h"
15#include "sysfs.h"
16#include "tree-log.h"
17#include "delalloc-space.h"
18#include "discard.h"
19#include "raid56.h"
20#include "zoned.h"
21#include "fs.h"
22#include "accessors.h"
23#include "extent-tree.h"
24
25#ifdef CONFIG_BTRFS_DEBUG
26int btrfs_should_fragment_free_space(struct btrfs_block_group *block_group)
27{
28 struct btrfs_fs_info *fs_info = block_group->fs_info;
29
30 return (btrfs_test_opt(fs_info, FRAGMENT_METADATA) &&
31 block_group->flags & BTRFS_BLOCK_GROUP_METADATA) ||
32 (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
33 block_group->flags & BTRFS_BLOCK_GROUP_DATA);
34}
35#endif
36
37/*
38 * Return target flags in extended format or 0 if restripe for this chunk_type
39 * is not in progress
40 *
41 * Should be called with balance_lock held
42 */
43static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
44{
45 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
46 u64 target = 0;
47
48 if (!bctl)
49 return 0;
50
51 if (flags & BTRFS_BLOCK_GROUP_DATA &&
52 bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
53 target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
54 } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
55 bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
56 target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
57 } else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
58 bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
59 target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
60 }
61
62 return target;
63}
64
65/*
66 * @flags: available profiles in extended format (see ctree.h)
67 *
68 * Return reduced profile in chunk format. If profile changing is in progress
69 * (either running or paused) picks the target profile (if it's already
70 * available), otherwise falls back to plain reducing.
71 */
72static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags)
73{
74 u64 num_devices = fs_info->fs_devices->rw_devices;
75 u64 target;
76 u64 raid_type;
77 u64 allowed = 0;
78
79 /*
80 * See if restripe for this chunk_type is in progress, if so try to
81 * reduce to the target profile
82 */
83 spin_lock(&fs_info->balance_lock);
84 target = get_restripe_target(fs_info, flags);
85 if (target) {
86 spin_unlock(&fs_info->balance_lock);
87 return extended_to_chunk(target);
88 }
89 spin_unlock(&fs_info->balance_lock);
90
91 /* First, mask out the RAID levels which aren't possible */
92 for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
93 if (num_devices >= btrfs_raid_array[raid_type].devs_min)
94 allowed |= btrfs_raid_array[raid_type].bg_flag;
95 }
96 allowed &= flags;
97
98 /* Select the highest-redundancy RAID level. */
99 if (allowed & BTRFS_BLOCK_GROUP_RAID1C4)
100 allowed = BTRFS_BLOCK_GROUP_RAID1C4;
101 else if (allowed & BTRFS_BLOCK_GROUP_RAID6)
102 allowed = BTRFS_BLOCK_GROUP_RAID6;
103 else if (allowed & BTRFS_BLOCK_GROUP_RAID1C3)
104 allowed = BTRFS_BLOCK_GROUP_RAID1C3;
105 else if (allowed & BTRFS_BLOCK_GROUP_RAID5)
106 allowed = BTRFS_BLOCK_GROUP_RAID5;
107 else if (allowed & BTRFS_BLOCK_GROUP_RAID10)
108 allowed = BTRFS_BLOCK_GROUP_RAID10;
109 else if (allowed & BTRFS_BLOCK_GROUP_RAID1)
110 allowed = BTRFS_BLOCK_GROUP_RAID1;
111 else if (allowed & BTRFS_BLOCK_GROUP_DUP)
112 allowed = BTRFS_BLOCK_GROUP_DUP;
113 else if (allowed & BTRFS_BLOCK_GROUP_RAID0)
114 allowed = BTRFS_BLOCK_GROUP_RAID0;
115
116 flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
117
118 return extended_to_chunk(flags | allowed);
119}
120
121u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
122{
123 unsigned seq;
124 u64 flags;
125
126 do {
127 flags = orig_flags;
128 seq = read_seqbegin(&fs_info->profiles_lock);
129
130 if (flags & BTRFS_BLOCK_GROUP_DATA)
131 flags |= fs_info->avail_data_alloc_bits;
132 else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
133 flags |= fs_info->avail_system_alloc_bits;
134 else if (flags & BTRFS_BLOCK_GROUP_METADATA)
135 flags |= fs_info->avail_metadata_alloc_bits;
136 } while (read_seqretry(&fs_info->profiles_lock, seq));
137
138 return btrfs_reduce_alloc_profile(fs_info, flags);
139}
140
141void btrfs_get_block_group(struct btrfs_block_group *cache)
142{
143 refcount_inc(&cache->refs);
144}
145
146void btrfs_put_block_group(struct btrfs_block_group *cache)
147{
148 if (refcount_dec_and_test(&cache->refs)) {
149 WARN_ON(cache->pinned > 0);
150 /*
151 * If there was a failure to cleanup a log tree, very likely due
152 * to an IO failure on a writeback attempt of one or more of its
153 * extent buffers, we could not do proper (and cheap) unaccounting
154 * of their reserved space, so don't warn on reserved > 0 in that
155 * case.
156 */
157 if (!(cache->flags & BTRFS_BLOCK_GROUP_METADATA) ||
158 !BTRFS_FS_LOG_CLEANUP_ERROR(cache->fs_info))
159 WARN_ON(cache->reserved > 0);
160
161 /*
162 * A block_group shouldn't be on the discard_list anymore.
163 * Remove the block_group from the discard_list to prevent us
164 * from causing a panic due to NULL pointer dereference.
165 */
166 if (WARN_ON(!list_empty(&cache->discard_list)))
167 btrfs_discard_cancel_work(&cache->fs_info->discard_ctl,
168 cache);
169
170 kfree(cache->free_space_ctl);
171 btrfs_free_chunk_map(cache->physical_map);
172 kfree(cache);
173 }
174}
175
176/*
177 * This adds the block group to the fs_info rb tree for the block group cache
178 */
179static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
180 struct btrfs_block_group *block_group)
181{
182 struct rb_node **p;
183 struct rb_node *parent = NULL;
184 struct btrfs_block_group *cache;
185 bool leftmost = true;
186
187 ASSERT(block_group->length != 0);
188
189 write_lock(&info->block_group_cache_lock);
190 p = &info->block_group_cache_tree.rb_root.rb_node;
191
192 while (*p) {
193 parent = *p;
194 cache = rb_entry(parent, struct btrfs_block_group, cache_node);
195 if (block_group->start < cache->start) {
196 p = &(*p)->rb_left;
197 } else if (block_group->start > cache->start) {
198 p = &(*p)->rb_right;
199 leftmost = false;
200 } else {
201 write_unlock(&info->block_group_cache_lock);
202 return -EEXIST;
203 }
204 }
205
206 rb_link_node(&block_group->cache_node, parent, p);
207 rb_insert_color_cached(&block_group->cache_node,
208 &info->block_group_cache_tree, leftmost);
209
210 write_unlock(&info->block_group_cache_lock);
211
212 return 0;
213}
214
215/*
216 * This will return the block group at or after bytenr if contains is 0, else
217 * it will return the block group that contains the bytenr
218 */
219static struct btrfs_block_group *block_group_cache_tree_search(
220 struct btrfs_fs_info *info, u64 bytenr, int contains)
221{
222 struct btrfs_block_group *cache, *ret = NULL;
223 struct rb_node *n;
224 u64 end, start;
225
226 read_lock(&info->block_group_cache_lock);
227 n = info->block_group_cache_tree.rb_root.rb_node;
228
229 while (n) {
230 cache = rb_entry(n, struct btrfs_block_group, cache_node);
231 end = cache->start + cache->length - 1;
232 start = cache->start;
233
234 if (bytenr < start) {
235 if (!contains && (!ret || start < ret->start))
236 ret = cache;
237 n = n->rb_left;
238 } else if (bytenr > start) {
239 if (contains && bytenr <= end) {
240 ret = cache;
241 break;
242 }
243 n = n->rb_right;
244 } else {
245 ret = cache;
246 break;
247 }
248 }
249 if (ret)
250 btrfs_get_block_group(ret);
251 read_unlock(&info->block_group_cache_lock);
252
253 return ret;
254}
255
256/*
257 * Return the block group that starts at or after bytenr
258 */
259struct btrfs_block_group *btrfs_lookup_first_block_group(
260 struct btrfs_fs_info *info, u64 bytenr)
261{
262 return block_group_cache_tree_search(info, bytenr, 0);
263}
264
265/*
266 * Return the block group that contains the given bytenr
267 */
268struct btrfs_block_group *btrfs_lookup_block_group(
269 struct btrfs_fs_info *info, u64 bytenr)
270{
271 return block_group_cache_tree_search(info, bytenr, 1);
272}
273
274struct btrfs_block_group *btrfs_next_block_group(
275 struct btrfs_block_group *cache)
276{
277 struct btrfs_fs_info *fs_info = cache->fs_info;
278 struct rb_node *node;
279
280 read_lock(&fs_info->block_group_cache_lock);
281
282 /* If our block group was removed, we need a full search. */
283 if (RB_EMPTY_NODE(&cache->cache_node)) {
284 const u64 next_bytenr = cache->start + cache->length;
285
286 read_unlock(&fs_info->block_group_cache_lock);
287 btrfs_put_block_group(cache);
288 return btrfs_lookup_first_block_group(fs_info, next_bytenr);
289 }
290 node = rb_next(&cache->cache_node);
291 btrfs_put_block_group(cache);
292 if (node) {
293 cache = rb_entry(node, struct btrfs_block_group, cache_node);
294 btrfs_get_block_group(cache);
295 } else
296 cache = NULL;
297 read_unlock(&fs_info->block_group_cache_lock);
298 return cache;
299}
300
301/*
302 * Check if we can do a NOCOW write for a given extent.
303 *
304 * @fs_info: The filesystem information object.
305 * @bytenr: Logical start address of the extent.
306 *
307 * Check if we can do a NOCOW write for the given extent, and increments the
308 * number of NOCOW writers in the block group that contains the extent, as long
309 * as the block group exists and it's currently not in read-only mode.
310 *
311 * Returns: A non-NULL block group pointer if we can do a NOCOW write, the caller
312 * is responsible for calling btrfs_dec_nocow_writers() later.
313 *
314 * Or NULL if we can not do a NOCOW write
315 */
316struct btrfs_block_group *btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info,
317 u64 bytenr)
318{
319 struct btrfs_block_group *bg;
320 bool can_nocow = true;
321
322 bg = btrfs_lookup_block_group(fs_info, bytenr);
323 if (!bg)
324 return NULL;
325
326 spin_lock(&bg->lock);
327 if (bg->ro)
328 can_nocow = false;
329 else
330 atomic_inc(&bg->nocow_writers);
331 spin_unlock(&bg->lock);
332
333 if (!can_nocow) {
334 btrfs_put_block_group(bg);
335 return NULL;
336 }
337
338 /* No put on block group, done by btrfs_dec_nocow_writers(). */
339 return bg;
340}
341
342/*
343 * Decrement the number of NOCOW writers in a block group.
344 *
345 * This is meant to be called after a previous call to btrfs_inc_nocow_writers(),
346 * and on the block group returned by that call. Typically this is called after
347 * creating an ordered extent for a NOCOW write, to prevent races with scrub and
348 * relocation.
349 *
350 * After this call, the caller should not use the block group anymore. It it wants
351 * to use it, then it should get a reference on it before calling this function.
352 */
353void btrfs_dec_nocow_writers(struct btrfs_block_group *bg)
354{
355 if (atomic_dec_and_test(&bg->nocow_writers))
356 wake_up_var(&bg->nocow_writers);
357
358 /* For the lookup done by a previous call to btrfs_inc_nocow_writers(). */
359 btrfs_put_block_group(bg);
360}
361
362void btrfs_wait_nocow_writers(struct btrfs_block_group *bg)
363{
364 wait_var_event(&bg->nocow_writers, !atomic_read(&bg->nocow_writers));
365}
366
367void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
368 const u64 start)
369{
370 struct btrfs_block_group *bg;
371
372 bg = btrfs_lookup_block_group(fs_info, start);
373 ASSERT(bg);
374 if (atomic_dec_and_test(&bg->reservations))
375 wake_up_var(&bg->reservations);
376 btrfs_put_block_group(bg);
377}
378
379void btrfs_wait_block_group_reservations(struct btrfs_block_group *bg)
380{
381 struct btrfs_space_info *space_info = bg->space_info;
382
383 ASSERT(bg->ro);
384
385 if (!(bg->flags & BTRFS_BLOCK_GROUP_DATA))
386 return;
387
388 /*
389 * Our block group is read only but before we set it to read only,
390 * some task might have had allocated an extent from it already, but it
391 * has not yet created a respective ordered extent (and added it to a
392 * root's list of ordered extents).
393 * Therefore wait for any task currently allocating extents, since the
394 * block group's reservations counter is incremented while a read lock
395 * on the groups' semaphore is held and decremented after releasing
396 * the read access on that semaphore and creating the ordered extent.
397 */
398 down_write(&space_info->groups_sem);
399 up_write(&space_info->groups_sem);
400
401 wait_var_event(&bg->reservations, !atomic_read(&bg->reservations));
402}
403
404struct btrfs_caching_control *btrfs_get_caching_control(
405 struct btrfs_block_group *cache)
406{
407 struct btrfs_caching_control *ctl;
408
409 spin_lock(&cache->lock);
410 if (!cache->caching_ctl) {
411 spin_unlock(&cache->lock);
412 return NULL;
413 }
414
415 ctl = cache->caching_ctl;
416 refcount_inc(&ctl->count);
417 spin_unlock(&cache->lock);
418 return ctl;
419}
420
421static void btrfs_put_caching_control(struct btrfs_caching_control *ctl)
422{
423 if (refcount_dec_and_test(&ctl->count))
424 kfree(ctl);
425}
426
427/*
428 * When we wait for progress in the block group caching, its because our
429 * allocation attempt failed at least once. So, we must sleep and let some
430 * progress happen before we try again.
431 *
432 * This function will sleep at least once waiting for new free space to show
433 * up, and then it will check the block group free space numbers for our min
434 * num_bytes. Another option is to have it go ahead and look in the rbtree for
435 * a free extent of a given size, but this is a good start.
436 *
437 * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
438 * any of the information in this block group.
439 */
440void btrfs_wait_block_group_cache_progress(struct btrfs_block_group *cache,
441 u64 num_bytes)
442{
443 struct btrfs_caching_control *caching_ctl;
444 int progress;
445
446 caching_ctl = btrfs_get_caching_control(cache);
447 if (!caching_ctl)
448 return;
449
450 /*
451 * We've already failed to allocate from this block group, so even if
452 * there's enough space in the block group it isn't contiguous enough to
453 * allow for an allocation, so wait for at least the next wakeup tick,
454 * or for the thing to be done.
455 */
456 progress = atomic_read(&caching_ctl->progress);
457
458 wait_event(caching_ctl->wait, btrfs_block_group_done(cache) ||
459 (progress != atomic_read(&caching_ctl->progress) &&
460 (cache->free_space_ctl->free_space >= num_bytes)));
461
462 btrfs_put_caching_control(caching_ctl);
463}
464
465static int btrfs_caching_ctl_wait_done(struct btrfs_block_group *cache,
466 struct btrfs_caching_control *caching_ctl)
467{
468 wait_event(caching_ctl->wait, btrfs_block_group_done(cache));
469 return cache->cached == BTRFS_CACHE_ERROR ? -EIO : 0;
470}
471
472static int btrfs_wait_block_group_cache_done(struct btrfs_block_group *cache)
473{
474 struct btrfs_caching_control *caching_ctl;
475 int ret;
476
477 caching_ctl = btrfs_get_caching_control(cache);
478 if (!caching_ctl)
479 return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
480 ret = btrfs_caching_ctl_wait_done(cache, caching_ctl);
481 btrfs_put_caching_control(caching_ctl);
482 return ret;
483}
484
485#ifdef CONFIG_BTRFS_DEBUG
486static void fragment_free_space(struct btrfs_block_group *block_group)
487{
488 struct btrfs_fs_info *fs_info = block_group->fs_info;
489 u64 start = block_group->start;
490 u64 len = block_group->length;
491 u64 chunk = block_group->flags & BTRFS_BLOCK_GROUP_METADATA ?
492 fs_info->nodesize : fs_info->sectorsize;
493 u64 step = chunk << 1;
494
495 while (len > chunk) {
496 btrfs_remove_free_space(block_group, start, chunk);
497 start += step;
498 if (len < step)
499 len = 0;
500 else
501 len -= step;
502 }
503}
504#endif
505
506/*
507 * Add a free space range to the in memory free space cache of a block group.
508 * This checks if the range contains super block locations and any such
509 * locations are not added to the free space cache.
510 *
511 * @block_group: The target block group.
512 * @start: Start offset of the range.
513 * @end: End offset of the range (exclusive).
514 * @total_added_ret: Optional pointer to return the total amount of space
515 * added to the block group's free space cache.
516 *
517 * Returns 0 on success or < 0 on error.
518 */
519int btrfs_add_new_free_space(struct btrfs_block_group *block_group, u64 start,
520 u64 end, u64 *total_added_ret)
521{
522 struct btrfs_fs_info *info = block_group->fs_info;
523 u64 extent_start, extent_end, size;
524 int ret;
525
526 if (total_added_ret)
527 *total_added_ret = 0;
528
529 while (start < end) {
530 if (!find_first_extent_bit(&info->excluded_extents, start,
531 &extent_start, &extent_end,
532 EXTENT_DIRTY | EXTENT_UPTODATE,
533 NULL))
534 break;
535
536 if (extent_start <= start) {
537 start = extent_end + 1;
538 } else if (extent_start > start && extent_start < end) {
539 size = extent_start - start;
540 ret = btrfs_add_free_space_async_trimmed(block_group,
541 start, size);
542 if (ret)
543 return ret;
544 if (total_added_ret)
545 *total_added_ret += size;
546 start = extent_end + 1;
547 } else {
548 break;
549 }
550 }
551
552 if (start < end) {
553 size = end - start;
554 ret = btrfs_add_free_space_async_trimmed(block_group, start,
555 size);
556 if (ret)
557 return ret;
558 if (total_added_ret)
559 *total_added_ret += size;
560 }
561
562 return 0;
563}
564
565/*
566 * Get an arbitrary extent item index / max_index through the block group
567 *
568 * @block_group the block group to sample from
569 * @index: the integral step through the block group to grab from
570 * @max_index: the granularity of the sampling
571 * @key: return value parameter for the item we find
572 *
573 * Pre-conditions on indices:
574 * 0 <= index <= max_index
575 * 0 < max_index
576 *
577 * Returns: 0 on success, 1 if the search didn't yield a useful item, negative
578 * error code on error.
579 */
580static int sample_block_group_extent_item(struct btrfs_caching_control *caching_ctl,
581 struct btrfs_block_group *block_group,
582 int index, int max_index,
583 struct btrfs_key *found_key)
584{
585 struct btrfs_fs_info *fs_info = block_group->fs_info;
586 struct btrfs_root *extent_root;
587 u64 search_offset;
588 u64 search_end = block_group->start + block_group->length;
589 struct btrfs_path *path;
590 struct btrfs_key search_key;
591 int ret = 0;
592
593 ASSERT(index >= 0);
594 ASSERT(index <= max_index);
595 ASSERT(max_index > 0);
596 lockdep_assert_held(&caching_ctl->mutex);
597 lockdep_assert_held_read(&fs_info->commit_root_sem);
598
599 path = btrfs_alloc_path();
600 if (!path)
601 return -ENOMEM;
602
603 extent_root = btrfs_extent_root(fs_info, max_t(u64, block_group->start,
604 BTRFS_SUPER_INFO_OFFSET));
605
606 path->skip_locking = 1;
607 path->search_commit_root = 1;
608 path->reada = READA_FORWARD;
609
610 search_offset = index * div_u64(block_group->length, max_index);
611 search_key.objectid = block_group->start + search_offset;
612 search_key.type = BTRFS_EXTENT_ITEM_KEY;
613 search_key.offset = 0;
614
615 btrfs_for_each_slot(extent_root, &search_key, found_key, path, ret) {
616 /* Success; sampled an extent item in the block group */
617 if (found_key->type == BTRFS_EXTENT_ITEM_KEY &&
618 found_key->objectid >= block_group->start &&
619 found_key->objectid + found_key->offset <= search_end)
620 break;
621
622 /* We can't possibly find a valid extent item anymore */
623 if (found_key->objectid >= search_end) {
624 ret = 1;
625 break;
626 }
627 }
628
629 lockdep_assert_held(&caching_ctl->mutex);
630 lockdep_assert_held_read(&fs_info->commit_root_sem);
631 btrfs_free_path(path);
632 return ret;
633}
634
635/*
636 * Best effort attempt to compute a block group's size class while caching it.
637 *
638 * @block_group: the block group we are caching
639 *
640 * We cannot infer the size class while adding free space extents, because that
641 * logic doesn't care about contiguous file extents (it doesn't differentiate
642 * between a 100M extent and 100 contiguous 1M extents). So we need to read the
643 * file extent items. Reading all of them is quite wasteful, because usually
644 * only a handful are enough to give a good answer. Therefore, we just grab 5 of
645 * them at even steps through the block group and pick the smallest size class
646 * we see. Since size class is best effort, and not guaranteed in general,
647 * inaccuracy is acceptable.
648 *
649 * To be more explicit about why this algorithm makes sense:
650 *
651 * If we are caching in a block group from disk, then there are three major cases
652 * to consider:
653 * 1. the block group is well behaved and all extents in it are the same size
654 * class.
655 * 2. the block group is mostly one size class with rare exceptions for last
656 * ditch allocations
657 * 3. the block group was populated before size classes and can have a totally
658 * arbitrary mix of size classes.
659 *
660 * In case 1, looking at any extent in the block group will yield the correct
661 * result. For the mixed cases, taking the minimum size class seems like a good
662 * approximation, since gaps from frees will be usable to the size class. For
663 * 2., a small handful of file extents is likely to yield the right answer. For
664 * 3, we can either read every file extent, or admit that this is best effort
665 * anyway and try to stay fast.
666 *
667 * Returns: 0 on success, negative error code on error.
668 */
669static int load_block_group_size_class(struct btrfs_caching_control *caching_ctl,
670 struct btrfs_block_group *block_group)
671{
672 struct btrfs_fs_info *fs_info = block_group->fs_info;
673 struct btrfs_key key;
674 int i;
675 u64 min_size = block_group->length;
676 enum btrfs_block_group_size_class size_class = BTRFS_BG_SZ_NONE;
677 int ret;
678
679 if (!btrfs_block_group_should_use_size_class(block_group))
680 return 0;
681
682 lockdep_assert_held(&caching_ctl->mutex);
683 lockdep_assert_held_read(&fs_info->commit_root_sem);
684 for (i = 0; i < 5; ++i) {
685 ret = sample_block_group_extent_item(caching_ctl, block_group, i, 5, &key);
686 if (ret < 0)
687 goto out;
688 if (ret > 0)
689 continue;
690 min_size = min_t(u64, min_size, key.offset);
691 size_class = btrfs_calc_block_group_size_class(min_size);
692 }
693 if (size_class != BTRFS_BG_SZ_NONE) {
694 spin_lock(&block_group->lock);
695 block_group->size_class = size_class;
696 spin_unlock(&block_group->lock);
697 }
698out:
699 return ret;
700}
701
702static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)
703{
704 struct btrfs_block_group *block_group = caching_ctl->block_group;
705 struct btrfs_fs_info *fs_info = block_group->fs_info;
706 struct btrfs_root *extent_root;
707 struct btrfs_path *path;
708 struct extent_buffer *leaf;
709 struct btrfs_key key;
710 u64 total_found = 0;
711 u64 last = 0;
712 u32 nritems;
713 int ret;
714 bool wakeup = true;
715
716 path = btrfs_alloc_path();
717 if (!path)
718 return -ENOMEM;
719
720 last = max_t(u64, block_group->start, BTRFS_SUPER_INFO_OFFSET);
721 extent_root = btrfs_extent_root(fs_info, last);
722
723#ifdef CONFIG_BTRFS_DEBUG
724 /*
725 * If we're fragmenting we don't want to make anybody think we can
726 * allocate from this block group until we've had a chance to fragment
727 * the free space.
728 */
729 if (btrfs_should_fragment_free_space(block_group))
730 wakeup = false;
731#endif
732 /*
733 * We don't want to deadlock with somebody trying to allocate a new
734 * extent for the extent root while also trying to search the extent
735 * root to add free space. So we skip locking and search the commit
736 * root, since its read-only
737 */
738 path->skip_locking = 1;
739 path->search_commit_root = 1;
740 path->reada = READA_FORWARD;
741
742 key.objectid = last;
743 key.offset = 0;
744 key.type = BTRFS_EXTENT_ITEM_KEY;
745
746next:
747 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
748 if (ret < 0)
749 goto out;
750
751 leaf = path->nodes[0];
752 nritems = btrfs_header_nritems(leaf);
753
754 while (1) {
755 if (btrfs_fs_closing(fs_info) > 1) {
756 last = (u64)-1;
757 break;
758 }
759
760 if (path->slots[0] < nritems) {
761 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
762 } else {
763 ret = btrfs_find_next_key(extent_root, path, &key, 0, 0);
764 if (ret)
765 break;
766
767 if (need_resched() ||
768 rwsem_is_contended(&fs_info->commit_root_sem)) {
769 btrfs_release_path(path);
770 up_read(&fs_info->commit_root_sem);
771 mutex_unlock(&caching_ctl->mutex);
772 cond_resched();
773 mutex_lock(&caching_ctl->mutex);
774 down_read(&fs_info->commit_root_sem);
775 goto next;
776 }
777
778 ret = btrfs_next_leaf(extent_root, path);
779 if (ret < 0)
780 goto out;
781 if (ret)
782 break;
783 leaf = path->nodes[0];
784 nritems = btrfs_header_nritems(leaf);
785 continue;
786 }
787
788 if (key.objectid < last) {
789 key.objectid = last;
790 key.offset = 0;
791 key.type = BTRFS_EXTENT_ITEM_KEY;
792 btrfs_release_path(path);
793 goto next;
794 }
795
796 if (key.objectid < block_group->start) {
797 path->slots[0]++;
798 continue;
799 }
800
801 if (key.objectid >= block_group->start + block_group->length)
802 break;
803
804 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
805 key.type == BTRFS_METADATA_ITEM_KEY) {
806 u64 space_added;
807
808 ret = btrfs_add_new_free_space(block_group, last,
809 key.objectid, &space_added);
810 if (ret)
811 goto out;
812 total_found += space_added;
813 if (key.type == BTRFS_METADATA_ITEM_KEY)
814 last = key.objectid +
815 fs_info->nodesize;
816 else
817 last = key.objectid + key.offset;
818
819 if (total_found > CACHING_CTL_WAKE_UP) {
820 total_found = 0;
821 if (wakeup) {
822 atomic_inc(&caching_ctl->progress);
823 wake_up(&caching_ctl->wait);
824 }
825 }
826 }
827 path->slots[0]++;
828 }
829
830 ret = btrfs_add_new_free_space(block_group, last,
831 block_group->start + block_group->length,
832 NULL);
833out:
834 btrfs_free_path(path);
835 return ret;
836}
837
838static inline void btrfs_free_excluded_extents(const struct btrfs_block_group *bg)
839{
840 clear_extent_bits(&bg->fs_info->excluded_extents, bg->start,
841 bg->start + bg->length - 1, EXTENT_UPTODATE);
842}
843
844static noinline void caching_thread(struct btrfs_work *work)
845{
846 struct btrfs_block_group *block_group;
847 struct btrfs_fs_info *fs_info;
848 struct btrfs_caching_control *caching_ctl;
849 int ret;
850
851 caching_ctl = container_of(work, struct btrfs_caching_control, work);
852 block_group = caching_ctl->block_group;
853 fs_info = block_group->fs_info;
854
855 mutex_lock(&caching_ctl->mutex);
856 down_read(&fs_info->commit_root_sem);
857
858 load_block_group_size_class(caching_ctl, block_group);
859 if (btrfs_test_opt(fs_info, SPACE_CACHE)) {
860 ret = load_free_space_cache(block_group);
861 if (ret == 1) {
862 ret = 0;
863 goto done;
864 }
865
866 /*
867 * We failed to load the space cache, set ourselves to
868 * CACHE_STARTED and carry on.
869 */
870 spin_lock(&block_group->lock);
871 block_group->cached = BTRFS_CACHE_STARTED;
872 spin_unlock(&block_group->lock);
873 wake_up(&caching_ctl->wait);
874 }
875
876 /*
877 * If we are in the transaction that populated the free space tree we
878 * can't actually cache from the free space tree as our commit root and
879 * real root are the same, so we could change the contents of the blocks
880 * while caching. Instead do the slow caching in this case, and after
881 * the transaction has committed we will be safe.
882 */
883 if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
884 !(test_bit(BTRFS_FS_FREE_SPACE_TREE_UNTRUSTED, &fs_info->flags)))
885 ret = load_free_space_tree(caching_ctl);
886 else
887 ret = load_extent_tree_free(caching_ctl);
888done:
889 spin_lock(&block_group->lock);
890 block_group->caching_ctl = NULL;
891 block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED;
892 spin_unlock(&block_group->lock);
893
894#ifdef CONFIG_BTRFS_DEBUG
895 if (btrfs_should_fragment_free_space(block_group)) {
896 u64 bytes_used;
897
898 spin_lock(&block_group->space_info->lock);
899 spin_lock(&block_group->lock);
900 bytes_used = block_group->length - block_group->used;
901 block_group->space_info->bytes_used += bytes_used >> 1;
902 spin_unlock(&block_group->lock);
903 spin_unlock(&block_group->space_info->lock);
904 fragment_free_space(block_group);
905 }
906#endif
907
908 up_read(&fs_info->commit_root_sem);
909 btrfs_free_excluded_extents(block_group);
910 mutex_unlock(&caching_ctl->mutex);
911
912 wake_up(&caching_ctl->wait);
913
914 btrfs_put_caching_control(caching_ctl);
915 btrfs_put_block_group(block_group);
916}
917
918int btrfs_cache_block_group(struct btrfs_block_group *cache, bool wait)
919{
920 struct btrfs_fs_info *fs_info = cache->fs_info;
921 struct btrfs_caching_control *caching_ctl = NULL;
922 int ret = 0;
923
924 /* Allocator for zoned filesystems does not use the cache at all */
925 if (btrfs_is_zoned(fs_info))
926 return 0;
927
928 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
929 if (!caching_ctl)
930 return -ENOMEM;
931
932 INIT_LIST_HEAD(&caching_ctl->list);
933 mutex_init(&caching_ctl->mutex);
934 init_waitqueue_head(&caching_ctl->wait);
935 caching_ctl->block_group = cache;
936 refcount_set(&caching_ctl->count, 2);
937 atomic_set(&caching_ctl->progress, 0);
938 btrfs_init_work(&caching_ctl->work, caching_thread, NULL);
939
940 spin_lock(&cache->lock);
941 if (cache->cached != BTRFS_CACHE_NO) {
942 kfree(caching_ctl);
943
944 caching_ctl = cache->caching_ctl;
945 if (caching_ctl)
946 refcount_inc(&caching_ctl->count);
947 spin_unlock(&cache->lock);
948 goto out;
949 }
950 WARN_ON(cache->caching_ctl);
951 cache->caching_ctl = caching_ctl;
952 cache->cached = BTRFS_CACHE_STARTED;
953 spin_unlock(&cache->lock);
954
955 write_lock(&fs_info->block_group_cache_lock);
956 refcount_inc(&caching_ctl->count);
957 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
958 write_unlock(&fs_info->block_group_cache_lock);
959
960 btrfs_get_block_group(cache);
961
962 btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
963out:
964 if (wait && caching_ctl)
965 ret = btrfs_caching_ctl_wait_done(cache, caching_ctl);
966 if (caching_ctl)
967 btrfs_put_caching_control(caching_ctl);
968
969 return ret;
970}
971
972static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
973{
974 u64 extra_flags = chunk_to_extended(flags) &
975 BTRFS_EXTENDED_PROFILE_MASK;
976
977 write_seqlock(&fs_info->profiles_lock);
978 if (flags & BTRFS_BLOCK_GROUP_DATA)
979 fs_info->avail_data_alloc_bits &= ~extra_flags;
980 if (flags & BTRFS_BLOCK_GROUP_METADATA)
981 fs_info->avail_metadata_alloc_bits &= ~extra_flags;
982 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
983 fs_info->avail_system_alloc_bits &= ~extra_flags;
984 write_sequnlock(&fs_info->profiles_lock);
985}
986
987/*
988 * Clear incompat bits for the following feature(s):
989 *
990 * - RAID56 - in case there's neither RAID5 nor RAID6 profile block group
991 * in the whole filesystem
992 *
993 * - RAID1C34 - same as above for RAID1C3 and RAID1C4 block groups
994 */
995static void clear_incompat_bg_bits(struct btrfs_fs_info *fs_info, u64 flags)
996{
997 bool found_raid56 = false;
998 bool found_raid1c34 = false;
999
1000 if ((flags & BTRFS_BLOCK_GROUP_RAID56_MASK) ||
1001 (flags & BTRFS_BLOCK_GROUP_RAID1C3) ||
1002 (flags & BTRFS_BLOCK_GROUP_RAID1C4)) {
1003 struct list_head *head = &fs_info->space_info;
1004 struct btrfs_space_info *sinfo;
1005
1006 list_for_each_entry_rcu(sinfo, head, list) {
1007 down_read(&sinfo->groups_sem);
1008 if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID5]))
1009 found_raid56 = true;
1010 if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID6]))
1011 found_raid56 = true;
1012 if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID1C3]))
1013 found_raid1c34 = true;
1014 if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID1C4]))
1015 found_raid1c34 = true;
1016 up_read(&sinfo->groups_sem);
1017 }
1018 if (!found_raid56)
1019 btrfs_clear_fs_incompat(fs_info, RAID56);
1020 if (!found_raid1c34)
1021 btrfs_clear_fs_incompat(fs_info, RAID1C34);
1022 }
1023}
1024
1025static int remove_block_group_item(struct btrfs_trans_handle *trans,
1026 struct btrfs_path *path,
1027 struct btrfs_block_group *block_group)
1028{
1029 struct btrfs_fs_info *fs_info = trans->fs_info;
1030 struct btrfs_root *root;
1031 struct btrfs_key key;
1032 int ret;
1033
1034 root = btrfs_block_group_root(fs_info);
1035 key.objectid = block_group->start;
1036 key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
1037 key.offset = block_group->length;
1038
1039 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1040 if (ret > 0)
1041 ret = -ENOENT;
1042 if (ret < 0)
1043 return ret;
1044
1045 ret = btrfs_del_item(trans, root, path);
1046 return ret;
1047}
1048
1049int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
1050 struct btrfs_chunk_map *map)
1051{
1052 struct btrfs_fs_info *fs_info = trans->fs_info;
1053 struct btrfs_path *path;
1054 struct btrfs_block_group *block_group;
1055 struct btrfs_free_cluster *cluster;
1056 struct inode *inode;
1057 struct kobject *kobj = NULL;
1058 int ret;
1059 int index;
1060 int factor;
1061 struct btrfs_caching_control *caching_ctl = NULL;
1062 bool remove_map;
1063 bool remove_rsv = false;
1064
1065 block_group = btrfs_lookup_block_group(fs_info, map->start);
1066 if (!block_group)
1067 return -ENOENT;
1068
1069 BUG_ON(!block_group->ro);
1070
1071 trace_btrfs_remove_block_group(block_group);
1072 /*
1073 * Free the reserved super bytes from this block group before
1074 * remove it.
1075 */
1076 btrfs_free_excluded_extents(block_group);
1077 btrfs_free_ref_tree_range(fs_info, block_group->start,
1078 block_group->length);
1079
1080 index = btrfs_bg_flags_to_raid_index(block_group->flags);
1081 factor = btrfs_bg_type_to_factor(block_group->flags);
1082
1083 /* make sure this block group isn't part of an allocation cluster */
1084 cluster = &fs_info->data_alloc_cluster;
1085 spin_lock(&cluster->refill_lock);
1086 btrfs_return_cluster_to_free_space(block_group, cluster);
1087 spin_unlock(&cluster->refill_lock);
1088
1089 /*
1090 * make sure this block group isn't part of a metadata
1091 * allocation cluster
1092 */
1093 cluster = &fs_info->meta_alloc_cluster;
1094 spin_lock(&cluster->refill_lock);
1095 btrfs_return_cluster_to_free_space(block_group, cluster);
1096 spin_unlock(&cluster->refill_lock);
1097
1098 btrfs_clear_treelog_bg(block_group);
1099 btrfs_clear_data_reloc_bg(block_group);
1100
1101 path = btrfs_alloc_path();
1102 if (!path) {
1103 ret = -ENOMEM;
1104 goto out;
1105 }
1106
1107 /*
1108 * get the inode first so any iput calls done for the io_list
1109 * aren't the final iput (no unlinks allowed now)
1110 */
1111 inode = lookup_free_space_inode(block_group, path);
1112
1113 mutex_lock(&trans->transaction->cache_write_mutex);
1114 /*
1115 * Make sure our free space cache IO is done before removing the
1116 * free space inode
1117 */
1118 spin_lock(&trans->transaction->dirty_bgs_lock);
1119 if (!list_empty(&block_group->io_list)) {
1120 list_del_init(&block_group->io_list);
1121
1122 WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
1123
1124 spin_unlock(&trans->transaction->dirty_bgs_lock);
1125 btrfs_wait_cache_io(trans, block_group, path);
1126 btrfs_put_block_group(block_group);
1127 spin_lock(&trans->transaction->dirty_bgs_lock);
1128 }
1129
1130 if (!list_empty(&block_group->dirty_list)) {
1131 list_del_init(&block_group->dirty_list);
1132 remove_rsv = true;
1133 btrfs_put_block_group(block_group);
1134 }
1135 spin_unlock(&trans->transaction->dirty_bgs_lock);
1136 mutex_unlock(&trans->transaction->cache_write_mutex);
1137
1138 ret = btrfs_remove_free_space_inode(trans, inode, block_group);
1139 if (ret)
1140 goto out;
1141
1142 write_lock(&fs_info->block_group_cache_lock);
1143 rb_erase_cached(&block_group->cache_node,
1144 &fs_info->block_group_cache_tree);
1145 RB_CLEAR_NODE(&block_group->cache_node);
1146
1147 /* Once for the block groups rbtree */
1148 btrfs_put_block_group(block_group);
1149
1150 write_unlock(&fs_info->block_group_cache_lock);
1151
1152 down_write(&block_group->space_info->groups_sem);
1153 /*
1154 * we must use list_del_init so people can check to see if they
1155 * are still on the list after taking the semaphore
1156 */
1157 list_del_init(&block_group->list);
1158 if (list_empty(&block_group->space_info->block_groups[index])) {
1159 kobj = block_group->space_info->block_group_kobjs[index];
1160 block_group->space_info->block_group_kobjs[index] = NULL;
1161 clear_avail_alloc_bits(fs_info, block_group->flags);
1162 }
1163 up_write(&block_group->space_info->groups_sem);
1164 clear_incompat_bg_bits(fs_info, block_group->flags);
1165 if (kobj) {
1166 kobject_del(kobj);
1167 kobject_put(kobj);
1168 }
1169
1170 if (block_group->cached == BTRFS_CACHE_STARTED)
1171 btrfs_wait_block_group_cache_done(block_group);
1172
1173 write_lock(&fs_info->block_group_cache_lock);
1174 caching_ctl = btrfs_get_caching_control(block_group);
1175 if (!caching_ctl) {
1176 struct btrfs_caching_control *ctl;
1177
1178 list_for_each_entry(ctl, &fs_info->caching_block_groups, list) {
1179 if (ctl->block_group == block_group) {
1180 caching_ctl = ctl;
1181 refcount_inc(&caching_ctl->count);
1182 break;
1183 }
1184 }
1185 }
1186 if (caching_ctl)
1187 list_del_init(&caching_ctl->list);
1188 write_unlock(&fs_info->block_group_cache_lock);
1189
1190 if (caching_ctl) {
1191 /* Once for the caching bgs list and once for us. */
1192 btrfs_put_caching_control(caching_ctl);
1193 btrfs_put_caching_control(caching_ctl);
1194 }
1195
1196 spin_lock(&trans->transaction->dirty_bgs_lock);
1197 WARN_ON(!list_empty(&block_group->dirty_list));
1198 WARN_ON(!list_empty(&block_group->io_list));
1199 spin_unlock(&trans->transaction->dirty_bgs_lock);
1200
1201 btrfs_remove_free_space_cache(block_group);
1202
1203 spin_lock(&block_group->space_info->lock);
1204 list_del_init(&block_group->ro_list);
1205
1206 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
1207 WARN_ON(block_group->space_info->total_bytes
1208 < block_group->length);
1209 WARN_ON(block_group->space_info->bytes_readonly
1210 < block_group->length - block_group->zone_unusable);
1211 WARN_ON(block_group->space_info->bytes_zone_unusable
1212 < block_group->zone_unusable);
1213 WARN_ON(block_group->space_info->disk_total
1214 < block_group->length * factor);
1215 }
1216 block_group->space_info->total_bytes -= block_group->length;
1217 block_group->space_info->bytes_readonly -=
1218 (block_group->length - block_group->zone_unusable);
1219 block_group->space_info->bytes_zone_unusable -=
1220 block_group->zone_unusable;
1221 block_group->space_info->disk_total -= block_group->length * factor;
1222
1223 spin_unlock(&block_group->space_info->lock);
1224
1225 /*
1226 * Remove the free space for the block group from the free space tree
1227 * and the block group's item from the extent tree before marking the
1228 * block group as removed. This is to prevent races with tasks that
1229 * freeze and unfreeze a block group, this task and another task
1230 * allocating a new block group - the unfreeze task ends up removing
1231 * the block group's extent map before the task calling this function
1232 * deletes the block group item from the extent tree, allowing for
1233 * another task to attempt to create another block group with the same
1234 * item key (and failing with -EEXIST and a transaction abort).
1235 */
1236 ret = remove_block_group_free_space(trans, block_group);
1237 if (ret)
1238 goto out;
1239
1240 ret = remove_block_group_item(trans, path, block_group);
1241 if (ret < 0)
1242 goto out;
1243
1244 spin_lock(&block_group->lock);
1245 set_bit(BLOCK_GROUP_FLAG_REMOVED, &block_group->runtime_flags);
1246
1247 /*
1248 * At this point trimming or scrub can't start on this block group,
1249 * because we removed the block group from the rbtree
1250 * fs_info->block_group_cache_tree so no one can't find it anymore and
1251 * even if someone already got this block group before we removed it
1252 * from the rbtree, they have already incremented block_group->frozen -
1253 * if they didn't, for the trimming case they won't find any free space
1254 * entries because we already removed them all when we called
1255 * btrfs_remove_free_space_cache().
1256 *
1257 * And we must not remove the chunk map from the fs_info->mapping_tree
1258 * to prevent the same logical address range and physical device space
1259 * ranges from being reused for a new block group. This is needed to
1260 * avoid races with trimming and scrub.
1261 *
1262 * An fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
1263 * completely transactionless, so while it is trimming a range the
1264 * currently running transaction might finish and a new one start,
1265 * allowing for new block groups to be created that can reuse the same
1266 * physical device locations unless we take this special care.
1267 *
1268 * There may also be an implicit trim operation if the file system
1269 * is mounted with -odiscard. The same protections must remain
1270 * in place until the extents have been discarded completely when
1271 * the transaction commit has completed.
1272 */
1273 remove_map = (atomic_read(&block_group->frozen) == 0);
1274 spin_unlock(&block_group->lock);
1275
1276 if (remove_map)
1277 btrfs_remove_chunk_map(fs_info, map);
1278
1279out:
1280 /* Once for the lookup reference */
1281 btrfs_put_block_group(block_group);
1282 if (remove_rsv)
1283 btrfs_dec_delayed_refs_rsv_bg_updates(fs_info);
1284 btrfs_free_path(path);
1285 return ret;
1286}
1287
1288struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
1289 struct btrfs_fs_info *fs_info, const u64 chunk_offset)
1290{
1291 struct btrfs_root *root = btrfs_block_group_root(fs_info);
1292 struct btrfs_chunk_map *map;
1293 unsigned int num_items;
1294
1295 map = btrfs_find_chunk_map(fs_info, chunk_offset, 1);
1296 ASSERT(map != NULL);
1297 ASSERT(map->start == chunk_offset);
1298
1299 /*
1300 * We need to reserve 3 + N units from the metadata space info in order
1301 * to remove a block group (done at btrfs_remove_chunk() and at
1302 * btrfs_remove_block_group()), which are used for:
1303 *
1304 * 1 unit for adding the free space inode's orphan (located in the tree
1305 * of tree roots).
1306 * 1 unit for deleting the block group item (located in the extent
1307 * tree).
1308 * 1 unit for deleting the free space item (located in tree of tree
1309 * roots).
1310 * N units for deleting N device extent items corresponding to each
1311 * stripe (located in the device tree).
1312 *
1313 * In order to remove a block group we also need to reserve units in the
1314 * system space info in order to update the chunk tree (update one or
1315 * more device items and remove one chunk item), but this is done at
1316 * btrfs_remove_chunk() through a call to check_system_chunk().
1317 */
1318 num_items = 3 + map->num_stripes;
1319 btrfs_free_chunk_map(map);
1320
1321 return btrfs_start_transaction_fallback_global_rsv(root, num_items);
1322}
1323
1324/*
1325 * Mark block group @cache read-only, so later write won't happen to block
1326 * group @cache.
1327 *
1328 * If @force is not set, this function will only mark the block group readonly
1329 * if we have enough free space (1M) in other metadata/system block groups.
1330 * If @force is not set, this function will mark the block group readonly
1331 * without checking free space.
1332 *
1333 * NOTE: This function doesn't care if other block groups can contain all the
1334 * data in this block group. That check should be done by relocation routine,
1335 * not this function.
1336 */
1337static int inc_block_group_ro(struct btrfs_block_group *cache, int force)
1338{
1339 struct btrfs_space_info *sinfo = cache->space_info;
1340 u64 num_bytes;
1341 int ret = -ENOSPC;
1342
1343 spin_lock(&sinfo->lock);
1344 spin_lock(&cache->lock);
1345
1346 if (cache->swap_extents) {
1347 ret = -ETXTBSY;
1348 goto out;
1349 }
1350
1351 if (cache->ro) {
1352 cache->ro++;
1353 ret = 0;
1354 goto out;
1355 }
1356
1357 num_bytes = cache->length - cache->reserved - cache->pinned -
1358 cache->bytes_super - cache->zone_unusable - cache->used;
1359
1360 /*
1361 * Data never overcommits, even in mixed mode, so do just the straight
1362 * check of left over space in how much we have allocated.
1363 */
1364 if (force) {
1365 ret = 0;
1366 } else if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA) {
1367 u64 sinfo_used = btrfs_space_info_used(sinfo, true);
1368
1369 /*
1370 * Here we make sure if we mark this bg RO, we still have enough
1371 * free space as buffer.
1372 */
1373 if (sinfo_used + num_bytes <= sinfo->total_bytes)
1374 ret = 0;
1375 } else {
1376 /*
1377 * We overcommit metadata, so we need to do the
1378 * btrfs_can_overcommit check here, and we need to pass in
1379 * BTRFS_RESERVE_NO_FLUSH to give ourselves the most amount of
1380 * leeway to allow us to mark this block group as read only.
1381 */
1382 if (btrfs_can_overcommit(cache->fs_info, sinfo, num_bytes,
1383 BTRFS_RESERVE_NO_FLUSH))
1384 ret = 0;
1385 }
1386
1387 if (!ret) {
1388 sinfo->bytes_readonly += num_bytes;
1389 if (btrfs_is_zoned(cache->fs_info)) {
1390 /* Migrate zone_unusable bytes to readonly */
1391 sinfo->bytes_readonly += cache->zone_unusable;
1392 sinfo->bytes_zone_unusable -= cache->zone_unusable;
1393 cache->zone_unusable = 0;
1394 }
1395 cache->ro++;
1396 list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
1397 }
1398out:
1399 spin_unlock(&cache->lock);
1400 spin_unlock(&sinfo->lock);
1401 if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) {
1402 btrfs_info(cache->fs_info,
1403 "unable to make block group %llu ro", cache->start);
1404 btrfs_dump_space_info(cache->fs_info, cache->space_info, 0, 0);
1405 }
1406 return ret;
1407}
1408
1409static bool clean_pinned_extents(struct btrfs_trans_handle *trans,
1410 struct btrfs_block_group *bg)
1411{
1412 struct btrfs_fs_info *fs_info = bg->fs_info;
1413 struct btrfs_transaction *prev_trans = NULL;
1414 const u64 start = bg->start;
1415 const u64 end = start + bg->length - 1;
1416 int ret;
1417
1418 spin_lock(&fs_info->trans_lock);
1419 if (trans->transaction->list.prev != &fs_info->trans_list) {
1420 prev_trans = list_last_entry(&trans->transaction->list,
1421 struct btrfs_transaction, list);
1422 refcount_inc(&prev_trans->use_count);
1423 }
1424 spin_unlock(&fs_info->trans_lock);
1425
1426 /*
1427 * Hold the unused_bg_unpin_mutex lock to avoid racing with
1428 * btrfs_finish_extent_commit(). If we are at transaction N, another
1429 * task might be running finish_extent_commit() for the previous
1430 * transaction N - 1, and have seen a range belonging to the block
1431 * group in pinned_extents before we were able to clear the whole block
1432 * group range from pinned_extents. This means that task can lookup for
1433 * the block group after we unpinned it from pinned_extents and removed
1434 * it, leading to an error at unpin_extent_range().
1435 */
1436 mutex_lock(&fs_info->unused_bg_unpin_mutex);
1437 if (prev_trans) {
1438 ret = clear_extent_bits(&prev_trans->pinned_extents, start, end,
1439 EXTENT_DIRTY);
1440 if (ret)
1441 goto out;
1442 }
1443
1444 ret = clear_extent_bits(&trans->transaction->pinned_extents, start, end,
1445 EXTENT_DIRTY);
1446out:
1447 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
1448 if (prev_trans)
1449 btrfs_put_transaction(prev_trans);
1450
1451 return ret == 0;
1452}
1453
1454/*
1455 * Process the unused_bgs list and remove any that don't have any allocated
1456 * space inside of them.
1457 */
1458void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
1459{
1460 LIST_HEAD(retry_list);
1461 struct btrfs_block_group *block_group;
1462 struct btrfs_space_info *space_info;
1463 struct btrfs_trans_handle *trans;
1464 const bool async_trim_enabled = btrfs_test_opt(fs_info, DISCARD_ASYNC);
1465 int ret = 0;
1466
1467 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1468 return;
1469
1470 if (btrfs_fs_closing(fs_info))
1471 return;
1472
1473 /*
1474 * Long running balances can keep us blocked here for eternity, so
1475 * simply skip deletion if we're unable to get the mutex.
1476 */
1477 if (!mutex_trylock(&fs_info->reclaim_bgs_lock))
1478 return;
1479
1480 spin_lock(&fs_info->unused_bgs_lock);
1481 while (!list_empty(&fs_info->unused_bgs)) {
1482 u64 used;
1483 int trimming;
1484
1485 block_group = list_first_entry(&fs_info->unused_bgs,
1486 struct btrfs_block_group,
1487 bg_list);
1488 list_del_init(&block_group->bg_list);
1489
1490 space_info = block_group->space_info;
1491
1492 if (ret || btrfs_mixed_space_info(space_info)) {
1493 btrfs_put_block_group(block_group);
1494 continue;
1495 }
1496 spin_unlock(&fs_info->unused_bgs_lock);
1497
1498 btrfs_discard_cancel_work(&fs_info->discard_ctl, block_group);
1499
1500 /* Don't want to race with allocators so take the groups_sem */
1501 down_write(&space_info->groups_sem);
1502
1503 /*
1504 * Async discard moves the final block group discard to be prior
1505 * to the unused_bgs code path. Therefore, if it's not fully
1506 * trimmed, punt it back to the async discard lists.
1507 */
1508 if (btrfs_test_opt(fs_info, DISCARD_ASYNC) &&
1509 !btrfs_is_free_space_trimmed(block_group)) {
1510 trace_btrfs_skip_unused_block_group(block_group);
1511 up_write(&space_info->groups_sem);
1512 /* Requeue if we failed because of async discard */
1513 btrfs_discard_queue_work(&fs_info->discard_ctl,
1514 block_group);
1515 goto next;
1516 }
1517
1518 spin_lock(&space_info->lock);
1519 spin_lock(&block_group->lock);
1520 if (btrfs_is_block_group_used(block_group) || block_group->ro ||
1521 list_is_singular(&block_group->list)) {
1522 /*
1523 * We want to bail if we made new allocations or have
1524 * outstanding allocations in this block group. We do
1525 * the ro check in case balance is currently acting on
1526 * this block group.
1527 *
1528 * Also bail out if this is the only block group for its
1529 * type, because otherwise we would lose profile
1530 * information from fs_info->avail_*_alloc_bits and the
1531 * next block group of this type would be created with a
1532 * "single" profile (even if we're in a raid fs) because
1533 * fs_info->avail_*_alloc_bits would be 0.
1534 */
1535 trace_btrfs_skip_unused_block_group(block_group);
1536 spin_unlock(&block_group->lock);
1537 spin_unlock(&space_info->lock);
1538 up_write(&space_info->groups_sem);
1539 goto next;
1540 }
1541
1542 /*
1543 * The block group may be unused but there may be space reserved
1544 * accounting with the existence of that block group, that is,
1545 * space_info->bytes_may_use was incremented by a task but no
1546 * space was yet allocated from the block group by the task.
1547 * That space may or may not be allocated, as we are generally
1548 * pessimistic about space reservation for metadata as well as
1549 * for data when using compression (as we reserve space based on
1550 * the worst case, when data can't be compressed, and before
1551 * actually attempting compression, before starting writeback).
1552 *
1553 * So check if the total space of the space_info minus the size
1554 * of this block group is less than the used space of the
1555 * space_info - if that's the case, then it means we have tasks
1556 * that might be relying on the block group in order to allocate
1557 * extents, and add back the block group to the unused list when
1558 * we finish, so that we retry later in case no tasks ended up
1559 * needing to allocate extents from the block group.
1560 */
1561 used = btrfs_space_info_used(space_info, true);
1562 if (space_info->total_bytes - block_group->length < used &&
1563 block_group->zone_unusable < block_group->length) {
1564 /*
1565 * Add a reference for the list, compensate for the ref
1566 * drop under the "next" label for the
1567 * fs_info->unused_bgs list.
1568 */
1569 btrfs_get_block_group(block_group);
1570 list_add_tail(&block_group->bg_list, &retry_list);
1571
1572 trace_btrfs_skip_unused_block_group(block_group);
1573 spin_unlock(&block_group->lock);
1574 spin_unlock(&space_info->lock);
1575 up_write(&space_info->groups_sem);
1576 goto next;
1577 }
1578
1579 spin_unlock(&block_group->lock);
1580 spin_unlock(&space_info->lock);
1581
1582 /* We don't want to force the issue, only flip if it's ok. */
1583 ret = inc_block_group_ro(block_group, 0);
1584 up_write(&space_info->groups_sem);
1585 if (ret < 0) {
1586 ret = 0;
1587 goto next;
1588 }
1589
1590 ret = btrfs_zone_finish(block_group);
1591 if (ret < 0) {
1592 btrfs_dec_block_group_ro(block_group);
1593 if (ret == -EAGAIN)
1594 ret = 0;
1595 goto next;
1596 }
1597
1598 /*
1599 * Want to do this before we do anything else so we can recover
1600 * properly if we fail to join the transaction.
1601 */
1602 trans = btrfs_start_trans_remove_block_group(fs_info,
1603 block_group->start);
1604 if (IS_ERR(trans)) {
1605 btrfs_dec_block_group_ro(block_group);
1606 ret = PTR_ERR(trans);
1607 goto next;
1608 }
1609
1610 /*
1611 * We could have pending pinned extents for this block group,
1612 * just delete them, we don't care about them anymore.
1613 */
1614 if (!clean_pinned_extents(trans, block_group)) {
1615 btrfs_dec_block_group_ro(block_group);
1616 goto end_trans;
1617 }
1618
1619 /*
1620 * At this point, the block_group is read only and should fail
1621 * new allocations. However, btrfs_finish_extent_commit() can
1622 * cause this block_group to be placed back on the discard
1623 * lists because now the block_group isn't fully discarded.
1624 * Bail here and try again later after discarding everything.
1625 */
1626 spin_lock(&fs_info->discard_ctl.lock);
1627 if (!list_empty(&block_group->discard_list)) {
1628 spin_unlock(&fs_info->discard_ctl.lock);
1629 btrfs_dec_block_group_ro(block_group);
1630 btrfs_discard_queue_work(&fs_info->discard_ctl,
1631 block_group);
1632 goto end_trans;
1633 }
1634 spin_unlock(&fs_info->discard_ctl.lock);
1635
1636 /* Reset pinned so btrfs_put_block_group doesn't complain */
1637 spin_lock(&space_info->lock);
1638 spin_lock(&block_group->lock);
1639
1640 btrfs_space_info_update_bytes_pinned(fs_info, space_info,
1641 -block_group->pinned);
1642 space_info->bytes_readonly += block_group->pinned;
1643 block_group->pinned = 0;
1644
1645 spin_unlock(&block_group->lock);
1646 spin_unlock(&space_info->lock);
1647
1648 /*
1649 * The normal path here is an unused block group is passed here,
1650 * then trimming is handled in the transaction commit path.
1651 * Async discard interposes before this to do the trimming
1652 * before coming down the unused block group path as trimming
1653 * will no longer be done later in the transaction commit path.
1654 */
1655 if (!async_trim_enabled && btrfs_test_opt(fs_info, DISCARD_ASYNC))
1656 goto flip_async;
1657
1658 /*
1659 * DISCARD can flip during remount. On zoned filesystems, we
1660 * need to reset sequential-required zones.
1661 */
1662 trimming = btrfs_test_opt(fs_info, DISCARD_SYNC) ||
1663 btrfs_is_zoned(fs_info);
1664
1665 /* Implicit trim during transaction commit. */
1666 if (trimming)
1667 btrfs_freeze_block_group(block_group);
1668
1669 /*
1670 * Btrfs_remove_chunk will abort the transaction if things go
1671 * horribly wrong.
1672 */
1673 ret = btrfs_remove_chunk(trans, block_group->start);
1674
1675 if (ret) {
1676 if (trimming)
1677 btrfs_unfreeze_block_group(block_group);
1678 goto end_trans;
1679 }
1680
1681 /*
1682 * If we're not mounted with -odiscard, we can just forget
1683 * about this block group. Otherwise we'll need to wait
1684 * until transaction commit to do the actual discard.
1685 */
1686 if (trimming) {
1687 spin_lock(&fs_info->unused_bgs_lock);
1688 /*
1689 * A concurrent scrub might have added us to the list
1690 * fs_info->unused_bgs, so use a list_move operation
1691 * to add the block group to the deleted_bgs list.
1692 */
1693 list_move(&block_group->bg_list,
1694 &trans->transaction->deleted_bgs);
1695 spin_unlock(&fs_info->unused_bgs_lock);
1696 btrfs_get_block_group(block_group);
1697 }
1698end_trans:
1699 btrfs_end_transaction(trans);
1700next:
1701 btrfs_put_block_group(block_group);
1702 spin_lock(&fs_info->unused_bgs_lock);
1703 }
1704 list_splice_tail(&retry_list, &fs_info->unused_bgs);
1705 spin_unlock(&fs_info->unused_bgs_lock);
1706 mutex_unlock(&fs_info->reclaim_bgs_lock);
1707 return;
1708
1709flip_async:
1710 btrfs_end_transaction(trans);
1711 spin_lock(&fs_info->unused_bgs_lock);
1712 list_splice_tail(&retry_list, &fs_info->unused_bgs);
1713 spin_unlock(&fs_info->unused_bgs_lock);
1714 mutex_unlock(&fs_info->reclaim_bgs_lock);
1715 btrfs_put_block_group(block_group);
1716 btrfs_discard_punt_unused_bgs_list(fs_info);
1717}
1718
1719void btrfs_mark_bg_unused(struct btrfs_block_group *bg)
1720{
1721 struct btrfs_fs_info *fs_info = bg->fs_info;
1722
1723 spin_lock(&fs_info->unused_bgs_lock);
1724 if (list_empty(&bg->bg_list)) {
1725 btrfs_get_block_group(bg);
1726 trace_btrfs_add_unused_block_group(bg);
1727 list_add_tail(&bg->bg_list, &fs_info->unused_bgs);
1728 } else if (!test_bit(BLOCK_GROUP_FLAG_NEW, &bg->runtime_flags)) {
1729 /* Pull out the block group from the reclaim_bgs list. */
1730 trace_btrfs_add_unused_block_group(bg);
1731 list_move_tail(&bg->bg_list, &fs_info->unused_bgs);
1732 }
1733 spin_unlock(&fs_info->unused_bgs_lock);
1734}
1735
1736/*
1737 * We want block groups with a low number of used bytes to be in the beginning
1738 * of the list, so they will get reclaimed first.
1739 */
1740static int reclaim_bgs_cmp(void *unused, const struct list_head *a,
1741 const struct list_head *b)
1742{
1743 const struct btrfs_block_group *bg1, *bg2;
1744
1745 bg1 = list_entry(a, struct btrfs_block_group, bg_list);
1746 bg2 = list_entry(b, struct btrfs_block_group, bg_list);
1747
1748 return bg1->used > bg2->used;
1749}
1750
1751static inline bool btrfs_should_reclaim(struct btrfs_fs_info *fs_info)
1752{
1753 if (btrfs_is_zoned(fs_info))
1754 return btrfs_zoned_should_reclaim(fs_info);
1755 return true;
1756}
1757
1758static bool should_reclaim_block_group(struct btrfs_block_group *bg, u64 bytes_freed)
1759{
1760 const struct btrfs_space_info *space_info = bg->space_info;
1761 const int reclaim_thresh = READ_ONCE(space_info->bg_reclaim_threshold);
1762 const u64 new_val = bg->used;
1763 const u64 old_val = new_val + bytes_freed;
1764 u64 thresh;
1765
1766 if (reclaim_thresh == 0)
1767 return false;
1768
1769 thresh = mult_perc(bg->length, reclaim_thresh);
1770
1771 /*
1772 * If we were below the threshold before don't reclaim, we are likely a
1773 * brand new block group and we don't want to relocate new block groups.
1774 */
1775 if (old_val < thresh)
1776 return false;
1777 if (new_val >= thresh)
1778 return false;
1779 return true;
1780}
1781
1782void btrfs_reclaim_bgs_work(struct work_struct *work)
1783{
1784 struct btrfs_fs_info *fs_info =
1785 container_of(work, struct btrfs_fs_info, reclaim_bgs_work);
1786 struct btrfs_block_group *bg;
1787 struct btrfs_space_info *space_info;
1788
1789 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
1790 return;
1791
1792 if (btrfs_fs_closing(fs_info))
1793 return;
1794
1795 if (!btrfs_should_reclaim(fs_info))
1796 return;
1797
1798 sb_start_write(fs_info->sb);
1799
1800 if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
1801 sb_end_write(fs_info->sb);
1802 return;
1803 }
1804
1805 /*
1806 * Long running balances can keep us blocked here for eternity, so
1807 * simply skip reclaim if we're unable to get the mutex.
1808 */
1809 if (!mutex_trylock(&fs_info->reclaim_bgs_lock)) {
1810 btrfs_exclop_finish(fs_info);
1811 sb_end_write(fs_info->sb);
1812 return;
1813 }
1814
1815 spin_lock(&fs_info->unused_bgs_lock);
1816 /*
1817 * Sort happens under lock because we can't simply splice it and sort.
1818 * The block groups might still be in use and reachable via bg_list,
1819 * and their presence in the reclaim_bgs list must be preserved.
1820 */
1821 list_sort(NULL, &fs_info->reclaim_bgs, reclaim_bgs_cmp);
1822 while (!list_empty(&fs_info->reclaim_bgs)) {
1823 u64 zone_unusable;
1824 int ret = 0;
1825
1826 bg = list_first_entry(&fs_info->reclaim_bgs,
1827 struct btrfs_block_group,
1828 bg_list);
1829 list_del_init(&bg->bg_list);
1830
1831 space_info = bg->space_info;
1832 spin_unlock(&fs_info->unused_bgs_lock);
1833
1834 /* Don't race with allocators so take the groups_sem */
1835 down_write(&space_info->groups_sem);
1836
1837 spin_lock(&bg->lock);
1838 if (bg->reserved || bg->pinned || bg->ro) {
1839 /*
1840 * We want to bail if we made new allocations or have
1841 * outstanding allocations in this block group. We do
1842 * the ro check in case balance is currently acting on
1843 * this block group.
1844 */
1845 spin_unlock(&bg->lock);
1846 up_write(&space_info->groups_sem);
1847 goto next;
1848 }
1849 if (bg->used == 0) {
1850 /*
1851 * It is possible that we trigger relocation on a block
1852 * group as its extents are deleted and it first goes
1853 * below the threshold, then shortly after goes empty.
1854 *
1855 * In this case, relocating it does delete it, but has
1856 * some overhead in relocation specific metadata, looking
1857 * for the non-existent extents and running some extra
1858 * transactions, which we can avoid by using one of the
1859 * other mechanisms for dealing with empty block groups.
1860 */
1861 if (!btrfs_test_opt(fs_info, DISCARD_ASYNC))
1862 btrfs_mark_bg_unused(bg);
1863 spin_unlock(&bg->lock);
1864 up_write(&space_info->groups_sem);
1865 goto next;
1866
1867 }
1868 /*
1869 * The block group might no longer meet the reclaim condition by
1870 * the time we get around to reclaiming it, so to avoid
1871 * reclaiming overly full block_groups, skip reclaiming them.
1872 *
1873 * Since the decision making process also depends on the amount
1874 * being freed, pass in a fake giant value to skip that extra
1875 * check, which is more meaningful when adding to the list in
1876 * the first place.
1877 */
1878 if (!should_reclaim_block_group(bg, bg->length)) {
1879 spin_unlock(&bg->lock);
1880 up_write(&space_info->groups_sem);
1881 goto next;
1882 }
1883 spin_unlock(&bg->lock);
1884
1885 /*
1886 * Get out fast, in case we're read-only or unmounting the
1887 * filesystem. It is OK to drop block groups from the list even
1888 * for the read-only case. As we did sb_start_write(),
1889 * "mount -o remount,ro" won't happen and read-only filesystem
1890 * means it is forced read-only due to a fatal error. So, it
1891 * never gets back to read-write to let us reclaim again.
1892 */
1893 if (btrfs_need_cleaner_sleep(fs_info)) {
1894 up_write(&space_info->groups_sem);
1895 goto next;
1896 }
1897
1898 /*
1899 * Cache the zone_unusable value before turning the block group
1900 * to read only. As soon as the blog group is read only it's
1901 * zone_unusable value gets moved to the block group's read-only
1902 * bytes and isn't available for calculations anymore.
1903 */
1904 zone_unusable = bg->zone_unusable;
1905 ret = inc_block_group_ro(bg, 0);
1906 up_write(&space_info->groups_sem);
1907 if (ret < 0)
1908 goto next;
1909
1910 btrfs_info(fs_info,
1911 "reclaiming chunk %llu with %llu%% used %llu%% unusable",
1912 bg->start,
1913 div64_u64(bg->used * 100, bg->length),
1914 div64_u64(zone_unusable * 100, bg->length));
1915 trace_btrfs_reclaim_block_group(bg);
1916 ret = btrfs_relocate_chunk(fs_info, bg->start);
1917 if (ret) {
1918 btrfs_dec_block_group_ro(bg);
1919 btrfs_err(fs_info, "error relocating chunk %llu",
1920 bg->start);
1921 }
1922
1923next:
1924 if (ret)
1925 btrfs_mark_bg_to_reclaim(bg);
1926 btrfs_put_block_group(bg);
1927
1928 mutex_unlock(&fs_info->reclaim_bgs_lock);
1929 /*
1930 * Reclaiming all the block groups in the list can take really
1931 * long. Prioritize cleaning up unused block groups.
1932 */
1933 btrfs_delete_unused_bgs(fs_info);
1934 /*
1935 * If we are interrupted by a balance, we can just bail out. The
1936 * cleaner thread restart again if necessary.
1937 */
1938 if (!mutex_trylock(&fs_info->reclaim_bgs_lock))
1939 goto end;
1940 spin_lock(&fs_info->unused_bgs_lock);
1941 }
1942 spin_unlock(&fs_info->unused_bgs_lock);
1943 mutex_unlock(&fs_info->reclaim_bgs_lock);
1944end:
1945 btrfs_exclop_finish(fs_info);
1946 sb_end_write(fs_info->sb);
1947}
1948
1949void btrfs_reclaim_bgs(struct btrfs_fs_info *fs_info)
1950{
1951 spin_lock(&fs_info->unused_bgs_lock);
1952 if (!list_empty(&fs_info->reclaim_bgs))
1953 queue_work(system_unbound_wq, &fs_info->reclaim_bgs_work);
1954 spin_unlock(&fs_info->unused_bgs_lock);
1955}
1956
1957void btrfs_mark_bg_to_reclaim(struct btrfs_block_group *bg)
1958{
1959 struct btrfs_fs_info *fs_info = bg->fs_info;
1960
1961 spin_lock(&fs_info->unused_bgs_lock);
1962 if (list_empty(&bg->bg_list)) {
1963 btrfs_get_block_group(bg);
1964 trace_btrfs_add_reclaim_block_group(bg);
1965 list_add_tail(&bg->bg_list, &fs_info->reclaim_bgs);
1966 }
1967 spin_unlock(&fs_info->unused_bgs_lock);
1968}
1969
1970static int read_bg_from_eb(struct btrfs_fs_info *fs_info, struct btrfs_key *key,
1971 struct btrfs_path *path)
1972{
1973 struct btrfs_chunk_map *map;
1974 struct btrfs_block_group_item bg;
1975 struct extent_buffer *leaf;
1976 int slot;
1977 u64 flags;
1978 int ret = 0;
1979
1980 slot = path->slots[0];
1981 leaf = path->nodes[0];
1982
1983 map = btrfs_find_chunk_map(fs_info, key->objectid, key->offset);
1984 if (!map) {
1985 btrfs_err(fs_info,
1986 "logical %llu len %llu found bg but no related chunk",
1987 key->objectid, key->offset);
1988 return -ENOENT;
1989 }
1990
1991 if (map->start != key->objectid || map->chunk_len != key->offset) {
1992 btrfs_err(fs_info,
1993 "block group %llu len %llu mismatch with chunk %llu len %llu",
1994 key->objectid, key->offset, map->start, map->chunk_len);
1995 ret = -EUCLEAN;
1996 goto out_free_map;
1997 }
1998
1999 read_extent_buffer(leaf, &bg, btrfs_item_ptr_offset(leaf, slot),
2000 sizeof(bg));
2001 flags = btrfs_stack_block_group_flags(&bg) &
2002 BTRFS_BLOCK_GROUP_TYPE_MASK;
2003
2004 if (flags != (map->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) {
2005 btrfs_err(fs_info,
2006"block group %llu len %llu type flags 0x%llx mismatch with chunk type flags 0x%llx",
2007 key->objectid, key->offset, flags,
2008 (BTRFS_BLOCK_GROUP_TYPE_MASK & map->type));
2009 ret = -EUCLEAN;
2010 }
2011
2012out_free_map:
2013 btrfs_free_chunk_map(map);
2014 return ret;
2015}
2016
2017static int find_first_block_group(struct btrfs_fs_info *fs_info,
2018 struct btrfs_path *path,
2019 struct btrfs_key *key)
2020{
2021 struct btrfs_root *root = btrfs_block_group_root(fs_info);
2022 int ret;
2023 struct btrfs_key found_key;
2024
2025 btrfs_for_each_slot(root, key, &found_key, path, ret) {
2026 if (found_key.objectid >= key->objectid &&
2027 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
2028 return read_bg_from_eb(fs_info, &found_key, path);
2029 }
2030 }
2031 return ret;
2032}
2033
2034static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
2035{
2036 u64 extra_flags = chunk_to_extended(flags) &
2037 BTRFS_EXTENDED_PROFILE_MASK;
2038
2039 write_seqlock(&fs_info->profiles_lock);
2040 if (flags & BTRFS_BLOCK_GROUP_DATA)
2041 fs_info->avail_data_alloc_bits |= extra_flags;
2042 if (flags & BTRFS_BLOCK_GROUP_METADATA)
2043 fs_info->avail_metadata_alloc_bits |= extra_flags;
2044 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
2045 fs_info->avail_system_alloc_bits |= extra_flags;
2046 write_sequnlock(&fs_info->profiles_lock);
2047}
2048
2049/*
2050 * Map a physical disk address to a list of logical addresses.
2051 *
2052 * @fs_info: the filesystem
2053 * @chunk_start: logical address of block group
2054 * @physical: physical address to map to logical addresses
2055 * @logical: return array of logical addresses which map to @physical
2056 * @naddrs: length of @logical
2057 * @stripe_len: size of IO stripe for the given block group
2058 *
2059 * Maps a particular @physical disk address to a list of @logical addresses.
2060 * Used primarily to exclude those portions of a block group that contain super
2061 * block copies.
2062 */
2063int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
2064 u64 physical, u64 **logical, int *naddrs, int *stripe_len)
2065{
2066 struct btrfs_chunk_map *map;
2067 u64 *buf;
2068 u64 bytenr;
2069 u64 data_stripe_length;
2070 u64 io_stripe_size;
2071 int i, nr = 0;
2072 int ret = 0;
2073
2074 map = btrfs_get_chunk_map(fs_info, chunk_start, 1);
2075 if (IS_ERR(map))
2076 return -EIO;
2077
2078 data_stripe_length = map->stripe_size;
2079 io_stripe_size = BTRFS_STRIPE_LEN;
2080 chunk_start = map->start;
2081
2082 /* For RAID5/6 adjust to a full IO stripe length */
2083 if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
2084 io_stripe_size = btrfs_stripe_nr_to_offset(nr_data_stripes(map));
2085
2086 buf = kcalloc(map->num_stripes, sizeof(u64), GFP_NOFS);
2087 if (!buf) {
2088 ret = -ENOMEM;
2089 goto out;
2090 }
2091
2092 for (i = 0; i < map->num_stripes; i++) {
2093 bool already_inserted = false;
2094 u32 stripe_nr;
2095 u32 offset;
2096 int j;
2097
2098 if (!in_range(physical, map->stripes[i].physical,
2099 data_stripe_length))
2100 continue;
2101
2102 stripe_nr = (physical - map->stripes[i].physical) >>
2103 BTRFS_STRIPE_LEN_SHIFT;
2104 offset = (physical - map->stripes[i].physical) &
2105 BTRFS_STRIPE_LEN_MASK;
2106
2107 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2108 BTRFS_BLOCK_GROUP_RAID10))
2109 stripe_nr = div_u64(stripe_nr * map->num_stripes + i,
2110 map->sub_stripes);
2111 /*
2112 * The remaining case would be for RAID56, multiply by
2113 * nr_data_stripes(). Alternatively, just use rmap_len below
2114 * instead of map->stripe_len
2115 */
2116 bytenr = chunk_start + stripe_nr * io_stripe_size + offset;
2117
2118 /* Ensure we don't add duplicate addresses */
2119 for (j = 0; j < nr; j++) {
2120 if (buf[j] == bytenr) {
2121 already_inserted = true;
2122 break;
2123 }
2124 }
2125
2126 if (!already_inserted)
2127 buf[nr++] = bytenr;
2128 }
2129
2130 *logical = buf;
2131 *naddrs = nr;
2132 *stripe_len = io_stripe_size;
2133out:
2134 btrfs_free_chunk_map(map);
2135 return ret;
2136}
2137
2138static int exclude_super_stripes(struct btrfs_block_group *cache)
2139{
2140 struct btrfs_fs_info *fs_info = cache->fs_info;
2141 const bool zoned = btrfs_is_zoned(fs_info);
2142 u64 bytenr;
2143 u64 *logical;
2144 int stripe_len;
2145 int i, nr, ret;
2146
2147 if (cache->start < BTRFS_SUPER_INFO_OFFSET) {
2148 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->start;
2149 cache->bytes_super += stripe_len;
2150 ret = set_extent_bit(&fs_info->excluded_extents, cache->start,
2151 cache->start + stripe_len - 1,
2152 EXTENT_UPTODATE, NULL);
2153 if (ret)
2154 return ret;
2155 }
2156
2157 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
2158 bytenr = btrfs_sb_offset(i);
2159 ret = btrfs_rmap_block(fs_info, cache->start,
2160 bytenr, &logical, &nr, &stripe_len);
2161 if (ret)
2162 return ret;
2163
2164 /* Shouldn't have super stripes in sequential zones */
2165 if (zoned && nr) {
2166 kfree(logical);
2167 btrfs_err(fs_info,
2168 "zoned: block group %llu must not contain super block",
2169 cache->start);
2170 return -EUCLEAN;
2171 }
2172
2173 while (nr--) {
2174 u64 len = min_t(u64, stripe_len,
2175 cache->start + cache->length - logical[nr]);
2176
2177 cache->bytes_super += len;
2178 ret = set_extent_bit(&fs_info->excluded_extents, logical[nr],
2179 logical[nr] + len - 1,
2180 EXTENT_UPTODATE, NULL);
2181 if (ret) {
2182 kfree(logical);
2183 return ret;
2184 }
2185 }
2186
2187 kfree(logical);
2188 }
2189 return 0;
2190}
2191
2192static struct btrfs_block_group *btrfs_create_block_group_cache(
2193 struct btrfs_fs_info *fs_info, u64 start)
2194{
2195 struct btrfs_block_group *cache;
2196
2197 cache = kzalloc(sizeof(*cache), GFP_NOFS);
2198 if (!cache)
2199 return NULL;
2200
2201 cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
2202 GFP_NOFS);
2203 if (!cache->free_space_ctl) {
2204 kfree(cache);
2205 return NULL;
2206 }
2207
2208 cache->start = start;
2209
2210 cache->fs_info = fs_info;
2211 cache->full_stripe_len = btrfs_full_stripe_len(fs_info, start);
2212
2213 cache->discard_index = BTRFS_DISCARD_INDEX_UNUSED;
2214
2215 refcount_set(&cache->refs, 1);
2216 spin_lock_init(&cache->lock);
2217 init_rwsem(&cache->data_rwsem);
2218 INIT_LIST_HEAD(&cache->list);
2219 INIT_LIST_HEAD(&cache->cluster_list);
2220 INIT_LIST_HEAD(&cache->bg_list);
2221 INIT_LIST_HEAD(&cache->ro_list);
2222 INIT_LIST_HEAD(&cache->discard_list);
2223 INIT_LIST_HEAD(&cache->dirty_list);
2224 INIT_LIST_HEAD(&cache->io_list);
2225 INIT_LIST_HEAD(&cache->active_bg_list);
2226 btrfs_init_free_space_ctl(cache, cache->free_space_ctl);
2227 atomic_set(&cache->frozen, 0);
2228 mutex_init(&cache->free_space_lock);
2229
2230 return cache;
2231}
2232
2233/*
2234 * Iterate all chunks and verify that each of them has the corresponding block
2235 * group
2236 */
2237static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info)
2238{
2239 u64 start = 0;
2240 int ret = 0;
2241
2242 while (1) {
2243 struct btrfs_chunk_map *map;
2244 struct btrfs_block_group *bg;
2245
2246 /*
2247 * btrfs_find_chunk_map() will return the first chunk map
2248 * intersecting the range, so setting @length to 1 is enough to
2249 * get the first chunk.
2250 */
2251 map = btrfs_find_chunk_map(fs_info, start, 1);
2252 if (!map)
2253 break;
2254
2255 bg = btrfs_lookup_block_group(fs_info, map->start);
2256 if (!bg) {
2257 btrfs_err(fs_info,
2258 "chunk start=%llu len=%llu doesn't have corresponding block group",
2259 map->start, map->chunk_len);
2260 ret = -EUCLEAN;
2261 btrfs_free_chunk_map(map);
2262 break;
2263 }
2264 if (bg->start != map->start || bg->length != map->chunk_len ||
2265 (bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK) !=
2266 (map->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) {
2267 btrfs_err(fs_info,
2268"chunk start=%llu len=%llu flags=0x%llx doesn't match block group start=%llu len=%llu flags=0x%llx",
2269 map->start, map->chunk_len,
2270 map->type & BTRFS_BLOCK_GROUP_TYPE_MASK,
2271 bg->start, bg->length,
2272 bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK);
2273 ret = -EUCLEAN;
2274 btrfs_free_chunk_map(map);
2275 btrfs_put_block_group(bg);
2276 break;
2277 }
2278 start = map->start + map->chunk_len;
2279 btrfs_free_chunk_map(map);
2280 btrfs_put_block_group(bg);
2281 }
2282 return ret;
2283}
2284
2285static int read_one_block_group(struct btrfs_fs_info *info,
2286 struct btrfs_block_group_item *bgi,
2287 const struct btrfs_key *key,
2288 int need_clear)
2289{
2290 struct btrfs_block_group *cache;
2291 const bool mixed = btrfs_fs_incompat(info, MIXED_GROUPS);
2292 int ret;
2293
2294 ASSERT(key->type == BTRFS_BLOCK_GROUP_ITEM_KEY);
2295
2296 cache = btrfs_create_block_group_cache(info, key->objectid);
2297 if (!cache)
2298 return -ENOMEM;
2299
2300 cache->length = key->offset;
2301 cache->used = btrfs_stack_block_group_used(bgi);
2302 cache->commit_used = cache->used;
2303 cache->flags = btrfs_stack_block_group_flags(bgi);
2304 cache->global_root_id = btrfs_stack_block_group_chunk_objectid(bgi);
2305
2306 set_free_space_tree_thresholds(cache);
2307
2308 if (need_clear) {
2309 /*
2310 * When we mount with old space cache, we need to
2311 * set BTRFS_DC_CLEAR and set dirty flag.
2312 *
2313 * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
2314 * truncate the old free space cache inode and
2315 * setup a new one.
2316 * b) Setting 'dirty flag' makes sure that we flush
2317 * the new space cache info onto disk.
2318 */
2319 if (btrfs_test_opt(info, SPACE_CACHE))
2320 cache->disk_cache_state = BTRFS_DC_CLEAR;
2321 }
2322 if (!mixed && ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
2323 (cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
2324 btrfs_err(info,
2325"bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups",
2326 cache->start);
2327 ret = -EINVAL;
2328 goto error;
2329 }
2330
2331 ret = btrfs_load_block_group_zone_info(cache, false);
2332 if (ret) {
2333 btrfs_err(info, "zoned: failed to load zone info of bg %llu",
2334 cache->start);
2335 goto error;
2336 }
2337
2338 /*
2339 * We need to exclude the super stripes now so that the space info has
2340 * super bytes accounted for, otherwise we'll think we have more space
2341 * than we actually do.
2342 */
2343 ret = exclude_super_stripes(cache);
2344 if (ret) {
2345 /* We may have excluded something, so call this just in case. */
2346 btrfs_free_excluded_extents(cache);
2347 goto error;
2348 }
2349
2350 /*
2351 * For zoned filesystem, space after the allocation offset is the only
2352 * free space for a block group. So, we don't need any caching work.
2353 * btrfs_calc_zone_unusable() will set the amount of free space and
2354 * zone_unusable space.
2355 *
2356 * For regular filesystem, check for two cases, either we are full, and
2357 * therefore don't need to bother with the caching work since we won't
2358 * find any space, or we are empty, and we can just add all the space
2359 * in and be done with it. This saves us _a_lot_ of time, particularly
2360 * in the full case.
2361 */
2362 if (btrfs_is_zoned(info)) {
2363 btrfs_calc_zone_unusable(cache);
2364 /* Should not have any excluded extents. Just in case, though. */
2365 btrfs_free_excluded_extents(cache);
2366 } else if (cache->length == cache->used) {
2367 cache->cached = BTRFS_CACHE_FINISHED;
2368 btrfs_free_excluded_extents(cache);
2369 } else if (cache->used == 0) {
2370 cache->cached = BTRFS_CACHE_FINISHED;
2371 ret = btrfs_add_new_free_space(cache, cache->start,
2372 cache->start + cache->length, NULL);
2373 btrfs_free_excluded_extents(cache);
2374 if (ret)
2375 goto error;
2376 }
2377
2378 ret = btrfs_add_block_group_cache(info, cache);
2379 if (ret) {
2380 btrfs_remove_free_space_cache(cache);
2381 goto error;
2382 }
2383 trace_btrfs_add_block_group(info, cache, 0);
2384 btrfs_add_bg_to_space_info(info, cache);
2385
2386 set_avail_alloc_bits(info, cache->flags);
2387 if (btrfs_chunk_writeable(info, cache->start)) {
2388 if (cache->used == 0) {
2389 ASSERT(list_empty(&cache->bg_list));
2390 if (btrfs_test_opt(info, DISCARD_ASYNC))
2391 btrfs_discard_queue_work(&info->discard_ctl, cache);
2392 else
2393 btrfs_mark_bg_unused(cache);
2394 }
2395 } else {
2396 inc_block_group_ro(cache, 1);
2397 }
2398
2399 return 0;
2400error:
2401 btrfs_put_block_group(cache);
2402 return ret;
2403}
2404
2405static int fill_dummy_bgs(struct btrfs_fs_info *fs_info)
2406{
2407 struct rb_node *node;
2408 int ret = 0;
2409
2410 for (node = rb_first_cached(&fs_info->mapping_tree); node; node = rb_next(node)) {
2411 struct btrfs_chunk_map *map;
2412 struct btrfs_block_group *bg;
2413
2414 map = rb_entry(node, struct btrfs_chunk_map, rb_node);
2415 bg = btrfs_create_block_group_cache(fs_info, map->start);
2416 if (!bg) {
2417 ret = -ENOMEM;
2418 break;
2419 }
2420
2421 /* Fill dummy cache as FULL */
2422 bg->length = map->chunk_len;
2423 bg->flags = map->type;
2424 bg->cached = BTRFS_CACHE_FINISHED;
2425 bg->used = map->chunk_len;
2426 bg->flags = map->type;
2427 ret = btrfs_add_block_group_cache(fs_info, bg);
2428 /*
2429 * We may have some valid block group cache added already, in
2430 * that case we skip to the next one.
2431 */
2432 if (ret == -EEXIST) {
2433 ret = 0;
2434 btrfs_put_block_group(bg);
2435 continue;
2436 }
2437
2438 if (ret) {
2439 btrfs_remove_free_space_cache(bg);
2440 btrfs_put_block_group(bg);
2441 break;
2442 }
2443
2444 btrfs_add_bg_to_space_info(fs_info, bg);
2445
2446 set_avail_alloc_bits(fs_info, bg->flags);
2447 }
2448 if (!ret)
2449 btrfs_init_global_block_rsv(fs_info);
2450 return ret;
2451}
2452
2453int btrfs_read_block_groups(struct btrfs_fs_info *info)
2454{
2455 struct btrfs_root *root = btrfs_block_group_root(info);
2456 struct btrfs_path *path;
2457 int ret;
2458 struct btrfs_block_group *cache;
2459 struct btrfs_space_info *space_info;
2460 struct btrfs_key key;
2461 int need_clear = 0;
2462 u64 cache_gen;
2463
2464 /*
2465 * Either no extent root (with ibadroots rescue option) or we have
2466 * unsupported RO options. The fs can never be mounted read-write, so no
2467 * need to waste time searching block group items.
2468 *
2469 * This also allows new extent tree related changes to be RO compat,
2470 * no need for a full incompat flag.
2471 */
2472 if (!root || (btrfs_super_compat_ro_flags(info->super_copy) &
2473 ~BTRFS_FEATURE_COMPAT_RO_SUPP))
2474 return fill_dummy_bgs(info);
2475
2476 key.objectid = 0;
2477 key.offset = 0;
2478 key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
2479 path = btrfs_alloc_path();
2480 if (!path)
2481 return -ENOMEM;
2482
2483 cache_gen = btrfs_super_cache_generation(info->super_copy);
2484 if (btrfs_test_opt(info, SPACE_CACHE) &&
2485 btrfs_super_generation(info->super_copy) != cache_gen)
2486 need_clear = 1;
2487 if (btrfs_test_opt(info, CLEAR_CACHE))
2488 need_clear = 1;
2489
2490 while (1) {
2491 struct btrfs_block_group_item bgi;
2492 struct extent_buffer *leaf;
2493 int slot;
2494
2495 ret = find_first_block_group(info, path, &key);
2496 if (ret > 0)
2497 break;
2498 if (ret != 0)
2499 goto error;
2500
2501 leaf = path->nodes[0];
2502 slot = path->slots[0];
2503
2504 read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot),
2505 sizeof(bgi));
2506
2507 btrfs_item_key_to_cpu(leaf, &key, slot);
2508 btrfs_release_path(path);
2509 ret = read_one_block_group(info, &bgi, &key, need_clear);
2510 if (ret < 0)
2511 goto error;
2512 key.objectid += key.offset;
2513 key.offset = 0;
2514 }
2515 btrfs_release_path(path);
2516
2517 list_for_each_entry(space_info, &info->space_info, list) {
2518 int i;
2519
2520 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2521 if (list_empty(&space_info->block_groups[i]))
2522 continue;
2523 cache = list_first_entry(&space_info->block_groups[i],
2524 struct btrfs_block_group,
2525 list);
2526 btrfs_sysfs_add_block_group_type(cache);
2527 }
2528
2529 if (!(btrfs_get_alloc_profile(info, space_info->flags) &
2530 (BTRFS_BLOCK_GROUP_RAID10 |
2531 BTRFS_BLOCK_GROUP_RAID1_MASK |
2532 BTRFS_BLOCK_GROUP_RAID56_MASK |
2533 BTRFS_BLOCK_GROUP_DUP)))
2534 continue;
2535 /*
2536 * Avoid allocating from un-mirrored block group if there are
2537 * mirrored block groups.
2538 */
2539 list_for_each_entry(cache,
2540 &space_info->block_groups[BTRFS_RAID_RAID0],
2541 list)
2542 inc_block_group_ro(cache, 1);
2543 list_for_each_entry(cache,
2544 &space_info->block_groups[BTRFS_RAID_SINGLE],
2545 list)
2546 inc_block_group_ro(cache, 1);
2547 }
2548
2549 btrfs_init_global_block_rsv(info);
2550 ret = check_chunk_block_group_mappings(info);
2551error:
2552 btrfs_free_path(path);
2553 /*
2554 * We've hit some error while reading the extent tree, and have
2555 * rescue=ibadroots mount option.
2556 * Try to fill the tree using dummy block groups so that the user can
2557 * continue to mount and grab their data.
2558 */
2559 if (ret && btrfs_test_opt(info, IGNOREBADROOTS))
2560 ret = fill_dummy_bgs(info);
2561 return ret;
2562}
2563
2564/*
2565 * This function, insert_block_group_item(), belongs to the phase 2 of chunk
2566 * allocation.
2567 *
2568 * See the comment at btrfs_chunk_alloc() for details about the chunk allocation
2569 * phases.
2570 */
2571static int insert_block_group_item(struct btrfs_trans_handle *trans,
2572 struct btrfs_block_group *block_group)
2573{
2574 struct btrfs_fs_info *fs_info = trans->fs_info;
2575 struct btrfs_block_group_item bgi;
2576 struct btrfs_root *root = btrfs_block_group_root(fs_info);
2577 struct btrfs_key key;
2578 u64 old_commit_used;
2579 int ret;
2580
2581 spin_lock(&block_group->lock);
2582 btrfs_set_stack_block_group_used(&bgi, block_group->used);
2583 btrfs_set_stack_block_group_chunk_objectid(&bgi,
2584 block_group->global_root_id);
2585 btrfs_set_stack_block_group_flags(&bgi, block_group->flags);
2586 old_commit_used = block_group->commit_used;
2587 block_group->commit_used = block_group->used;
2588 key.objectid = block_group->start;
2589 key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
2590 key.offset = block_group->length;
2591 spin_unlock(&block_group->lock);
2592
2593 ret = btrfs_insert_item(trans, root, &key, &bgi, sizeof(bgi));
2594 if (ret < 0) {
2595 spin_lock(&block_group->lock);
2596 block_group->commit_used = old_commit_used;
2597 spin_unlock(&block_group->lock);
2598 }
2599
2600 return ret;
2601}
2602
2603static int insert_dev_extent(struct btrfs_trans_handle *trans,
2604 struct btrfs_device *device, u64 chunk_offset,
2605 u64 start, u64 num_bytes)
2606{
2607 struct btrfs_fs_info *fs_info = device->fs_info;
2608 struct btrfs_root *root = fs_info->dev_root;
2609 struct btrfs_path *path;
2610 struct btrfs_dev_extent *extent;
2611 struct extent_buffer *leaf;
2612 struct btrfs_key key;
2613 int ret;
2614
2615 WARN_ON(!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state));
2616 WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
2617 path = btrfs_alloc_path();
2618 if (!path)
2619 return -ENOMEM;
2620
2621 key.objectid = device->devid;
2622 key.type = BTRFS_DEV_EXTENT_KEY;
2623 key.offset = start;
2624 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*extent));
2625 if (ret)
2626 goto out;
2627
2628 leaf = path->nodes[0];
2629 extent = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_extent);
2630 btrfs_set_dev_extent_chunk_tree(leaf, extent, BTRFS_CHUNK_TREE_OBJECTID);
2631 btrfs_set_dev_extent_chunk_objectid(leaf, extent,
2632 BTRFS_FIRST_CHUNK_TREE_OBJECTID);
2633 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
2634
2635 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
2636 btrfs_mark_buffer_dirty(trans, leaf);
2637out:
2638 btrfs_free_path(path);
2639 return ret;
2640}
2641
2642/*
2643 * This function belongs to phase 2.
2644 *
2645 * See the comment at btrfs_chunk_alloc() for details about the chunk allocation
2646 * phases.
2647 */
2648static int insert_dev_extents(struct btrfs_trans_handle *trans,
2649 u64 chunk_offset, u64 chunk_size)
2650{
2651 struct btrfs_fs_info *fs_info = trans->fs_info;
2652 struct btrfs_device *device;
2653 struct btrfs_chunk_map *map;
2654 u64 dev_offset;
2655 int i;
2656 int ret = 0;
2657
2658 map = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size);
2659 if (IS_ERR(map))
2660 return PTR_ERR(map);
2661
2662 /*
2663 * Take the device list mutex to prevent races with the final phase of
2664 * a device replace operation that replaces the device object associated
2665 * with the map's stripes, because the device object's id can change
2666 * at any time during that final phase of the device replace operation
2667 * (dev-replace.c:btrfs_dev_replace_finishing()), so we could grab the
2668 * replaced device and then see it with an ID of BTRFS_DEV_REPLACE_DEVID,
2669 * resulting in persisting a device extent item with such ID.
2670 */
2671 mutex_lock(&fs_info->fs_devices->device_list_mutex);
2672 for (i = 0; i < map->num_stripes; i++) {
2673 device = map->stripes[i].dev;
2674 dev_offset = map->stripes[i].physical;
2675
2676 ret = insert_dev_extent(trans, device, chunk_offset, dev_offset,
2677 map->stripe_size);
2678 if (ret)
2679 break;
2680 }
2681 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2682
2683 btrfs_free_chunk_map(map);
2684 return ret;
2685}
2686
2687/*
2688 * This function, btrfs_create_pending_block_groups(), belongs to the phase 2 of
2689 * chunk allocation.
2690 *
2691 * See the comment at btrfs_chunk_alloc() for details about the chunk allocation
2692 * phases.
2693 */
2694void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans)
2695{
2696 struct btrfs_fs_info *fs_info = trans->fs_info;
2697 struct btrfs_block_group *block_group;
2698 int ret = 0;
2699
2700 while (!list_empty(&trans->new_bgs)) {
2701 int index;
2702
2703 block_group = list_first_entry(&trans->new_bgs,
2704 struct btrfs_block_group,
2705 bg_list);
2706 if (ret)
2707 goto next;
2708
2709 index = btrfs_bg_flags_to_raid_index(block_group->flags);
2710
2711 ret = insert_block_group_item(trans, block_group);
2712 if (ret)
2713 btrfs_abort_transaction(trans, ret);
2714 if (!test_bit(BLOCK_GROUP_FLAG_CHUNK_ITEM_INSERTED,
2715 &block_group->runtime_flags)) {
2716 mutex_lock(&fs_info->chunk_mutex);
2717 ret = btrfs_chunk_alloc_add_chunk_item(trans, block_group);
2718 mutex_unlock(&fs_info->chunk_mutex);
2719 if (ret)
2720 btrfs_abort_transaction(trans, ret);
2721 }
2722 ret = insert_dev_extents(trans, block_group->start,
2723 block_group->length);
2724 if (ret)
2725 btrfs_abort_transaction(trans, ret);
2726 add_block_group_free_space(trans, block_group);
2727
2728 /*
2729 * If we restriped during balance, we may have added a new raid
2730 * type, so now add the sysfs entries when it is safe to do so.
2731 * We don't have to worry about locking here as it's handled in
2732 * btrfs_sysfs_add_block_group_type.
2733 */
2734 if (block_group->space_info->block_group_kobjs[index] == NULL)
2735 btrfs_sysfs_add_block_group_type(block_group);
2736
2737 /* Already aborted the transaction if it failed. */
2738next:
2739 btrfs_dec_delayed_refs_rsv_bg_inserts(fs_info);
2740 list_del_init(&block_group->bg_list);
2741 clear_bit(BLOCK_GROUP_FLAG_NEW, &block_group->runtime_flags);
2742
2743 /*
2744 * If the block group is still unused, add it to the list of
2745 * unused block groups. The block group may have been created in
2746 * order to satisfy a space reservation, in which case the
2747 * extent allocation only happens later. But often we don't
2748 * actually need to allocate space that we previously reserved,
2749 * so the block group may become unused for a long time. For
2750 * example for metadata we generally reserve space for a worst
2751 * possible scenario, but then don't end up allocating all that
2752 * space or none at all (due to no need to COW, extent buffers
2753 * were already COWed in the current transaction and still
2754 * unwritten, tree heights lower than the maximum possible
2755 * height, etc). For data we generally reserve the axact amount
2756 * of space we are going to allocate later, the exception is
2757 * when using compression, as we must reserve space based on the
2758 * uncompressed data size, because the compression is only done
2759 * when writeback triggered and we don't know how much space we
2760 * are actually going to need, so we reserve the uncompressed
2761 * size because the data may be uncompressible in the worst case.
2762 */
2763 if (ret == 0) {
2764 bool used;
2765
2766 spin_lock(&block_group->lock);
2767 used = btrfs_is_block_group_used(block_group);
2768 spin_unlock(&block_group->lock);
2769
2770 if (!used)
2771 btrfs_mark_bg_unused(block_group);
2772 }
2773 }
2774 btrfs_trans_release_chunk_metadata(trans);
2775}
2776
2777/*
2778 * For extent tree v2 we use the block_group_item->chunk_offset to point at our
2779 * global root id. For v1 it's always set to BTRFS_FIRST_CHUNK_TREE_OBJECTID.
2780 */
2781static u64 calculate_global_root_id(struct btrfs_fs_info *fs_info, u64 offset)
2782{
2783 u64 div = SZ_1G;
2784 u64 index;
2785
2786 if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
2787 return BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2788
2789 /* If we have a smaller fs index based on 128MiB. */
2790 if (btrfs_super_total_bytes(fs_info->super_copy) <= (SZ_1G * 10ULL))
2791 div = SZ_128M;
2792
2793 offset = div64_u64(offset, div);
2794 div64_u64_rem(offset, fs_info->nr_global_roots, &index);
2795 return index;
2796}
2797
2798struct btrfs_block_group *btrfs_make_block_group(struct btrfs_trans_handle *trans,
2799 u64 type,
2800 u64 chunk_offset, u64 size)
2801{
2802 struct btrfs_fs_info *fs_info = trans->fs_info;
2803 struct btrfs_block_group *cache;
2804 int ret;
2805
2806 btrfs_set_log_full_commit(trans);
2807
2808 cache = btrfs_create_block_group_cache(fs_info, chunk_offset);
2809 if (!cache)
2810 return ERR_PTR(-ENOMEM);
2811
2812 /*
2813 * Mark it as new before adding it to the rbtree of block groups or any
2814 * list, so that no other task finds it and calls btrfs_mark_bg_unused()
2815 * before the new flag is set.
2816 */
2817 set_bit(BLOCK_GROUP_FLAG_NEW, &cache->runtime_flags);
2818
2819 cache->length = size;
2820 set_free_space_tree_thresholds(cache);
2821 cache->flags = type;
2822 cache->cached = BTRFS_CACHE_FINISHED;
2823 cache->global_root_id = calculate_global_root_id(fs_info, cache->start);
2824
2825 if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
2826 set_bit(BLOCK_GROUP_FLAG_NEEDS_FREE_SPACE, &cache->runtime_flags);
2827
2828 ret = btrfs_load_block_group_zone_info(cache, true);
2829 if (ret) {
2830 btrfs_put_block_group(cache);
2831 return ERR_PTR(ret);
2832 }
2833
2834 ret = exclude_super_stripes(cache);
2835 if (ret) {
2836 /* We may have excluded something, so call this just in case */
2837 btrfs_free_excluded_extents(cache);
2838 btrfs_put_block_group(cache);
2839 return ERR_PTR(ret);
2840 }
2841
2842 ret = btrfs_add_new_free_space(cache, chunk_offset, chunk_offset + size, NULL);
2843 btrfs_free_excluded_extents(cache);
2844 if (ret) {
2845 btrfs_put_block_group(cache);
2846 return ERR_PTR(ret);
2847 }
2848
2849 /*
2850 * Ensure the corresponding space_info object is created and
2851 * assigned to our block group. We want our bg to be added to the rbtree
2852 * with its ->space_info set.
2853 */
2854 cache->space_info = btrfs_find_space_info(fs_info, cache->flags);
2855 ASSERT(cache->space_info);
2856
2857 ret = btrfs_add_block_group_cache(fs_info, cache);
2858 if (ret) {
2859 btrfs_remove_free_space_cache(cache);
2860 btrfs_put_block_group(cache);
2861 return ERR_PTR(ret);
2862 }
2863
2864 /*
2865 * Now that our block group has its ->space_info set and is inserted in
2866 * the rbtree, update the space info's counters.
2867 */
2868 trace_btrfs_add_block_group(fs_info, cache, 1);
2869 btrfs_add_bg_to_space_info(fs_info, cache);
2870 btrfs_update_global_block_rsv(fs_info);
2871
2872#ifdef CONFIG_BTRFS_DEBUG
2873 if (btrfs_should_fragment_free_space(cache)) {
2874 cache->space_info->bytes_used += size >> 1;
2875 fragment_free_space(cache);
2876 }
2877#endif
2878
2879 list_add_tail(&cache->bg_list, &trans->new_bgs);
2880 btrfs_inc_delayed_refs_rsv_bg_inserts(fs_info);
2881
2882 set_avail_alloc_bits(fs_info, type);
2883 return cache;
2884}
2885
2886/*
2887 * Mark one block group RO, can be called several times for the same block
2888 * group.
2889 *
2890 * @cache: the destination block group
2891 * @do_chunk_alloc: whether need to do chunk pre-allocation, this is to
2892 * ensure we still have some free space after marking this
2893 * block group RO.
2894 */
2895int btrfs_inc_block_group_ro(struct btrfs_block_group *cache,
2896 bool do_chunk_alloc)
2897{
2898 struct btrfs_fs_info *fs_info = cache->fs_info;
2899 struct btrfs_trans_handle *trans;
2900 struct btrfs_root *root = btrfs_block_group_root(fs_info);
2901 u64 alloc_flags;
2902 int ret;
2903 bool dirty_bg_running;
2904
2905 /*
2906 * This can only happen when we are doing read-only scrub on read-only
2907 * mount.
2908 * In that case we should not start a new transaction on read-only fs.
2909 * Thus here we skip all chunk allocations.
2910 */
2911 if (sb_rdonly(fs_info->sb)) {
2912 mutex_lock(&fs_info->ro_block_group_mutex);
2913 ret = inc_block_group_ro(cache, 0);
2914 mutex_unlock(&fs_info->ro_block_group_mutex);
2915 return ret;
2916 }
2917
2918 do {
2919 trans = btrfs_join_transaction(root);
2920 if (IS_ERR(trans))
2921 return PTR_ERR(trans);
2922
2923 dirty_bg_running = false;
2924
2925 /*
2926 * We're not allowed to set block groups readonly after the dirty
2927 * block group cache has started writing. If it already started,
2928 * back off and let this transaction commit.
2929 */
2930 mutex_lock(&fs_info->ro_block_group_mutex);
2931 if (test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &trans->transaction->flags)) {
2932 u64 transid = trans->transid;
2933
2934 mutex_unlock(&fs_info->ro_block_group_mutex);
2935 btrfs_end_transaction(trans);
2936
2937 ret = btrfs_wait_for_commit(fs_info, transid);
2938 if (ret)
2939 return ret;
2940 dirty_bg_running = true;
2941 }
2942 } while (dirty_bg_running);
2943
2944 if (do_chunk_alloc) {
2945 /*
2946 * If we are changing raid levels, try to allocate a
2947 * corresponding block group with the new raid level.
2948 */
2949 alloc_flags = btrfs_get_alloc_profile(fs_info, cache->flags);
2950 if (alloc_flags != cache->flags) {
2951 ret = btrfs_chunk_alloc(trans, alloc_flags,
2952 CHUNK_ALLOC_FORCE);
2953 /*
2954 * ENOSPC is allowed here, we may have enough space
2955 * already allocated at the new raid level to carry on
2956 */
2957 if (ret == -ENOSPC)
2958 ret = 0;
2959 if (ret < 0)
2960 goto out;
2961 }
2962 }
2963
2964 ret = inc_block_group_ro(cache, 0);
2965 if (!ret)
2966 goto out;
2967 if (ret == -ETXTBSY)
2968 goto unlock_out;
2969
2970 /*
2971 * Skip chunk allocation if the bg is SYSTEM, this is to avoid system
2972 * chunk allocation storm to exhaust the system chunk array. Otherwise
2973 * we still want to try our best to mark the block group read-only.
2974 */
2975 if (!do_chunk_alloc && ret == -ENOSPC &&
2976 (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM))
2977 goto unlock_out;
2978
2979 alloc_flags = btrfs_get_alloc_profile(fs_info, cache->space_info->flags);
2980 ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
2981 if (ret < 0)
2982 goto out;
2983 /*
2984 * We have allocated a new chunk. We also need to activate that chunk to
2985 * grant metadata tickets for zoned filesystem.
2986 */
2987 ret = btrfs_zoned_activate_one_bg(fs_info, cache->space_info, true);
2988 if (ret < 0)
2989 goto out;
2990
2991 ret = inc_block_group_ro(cache, 0);
2992 if (ret == -ETXTBSY)
2993 goto unlock_out;
2994out:
2995 if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
2996 alloc_flags = btrfs_get_alloc_profile(fs_info, cache->flags);
2997 mutex_lock(&fs_info->chunk_mutex);
2998 check_system_chunk(trans, alloc_flags);
2999 mutex_unlock(&fs_info->chunk_mutex);
3000 }
3001unlock_out:
3002 mutex_unlock(&fs_info->ro_block_group_mutex);
3003
3004 btrfs_end_transaction(trans);
3005 return ret;
3006}
3007
3008void btrfs_dec_block_group_ro(struct btrfs_block_group *cache)
3009{
3010 struct btrfs_space_info *sinfo = cache->space_info;
3011 u64 num_bytes;
3012
3013 BUG_ON(!cache->ro);
3014
3015 spin_lock(&sinfo->lock);
3016 spin_lock(&cache->lock);
3017 if (!--cache->ro) {
3018 if (btrfs_is_zoned(cache->fs_info)) {
3019 /* Migrate zone_unusable bytes back */
3020 cache->zone_unusable =
3021 (cache->alloc_offset - cache->used) +
3022 (cache->length - cache->zone_capacity);
3023 sinfo->bytes_zone_unusable += cache->zone_unusable;
3024 sinfo->bytes_readonly -= cache->zone_unusable;
3025 }
3026 num_bytes = cache->length - cache->reserved -
3027 cache->pinned - cache->bytes_super -
3028 cache->zone_unusable - cache->used;
3029 sinfo->bytes_readonly -= num_bytes;
3030 list_del_init(&cache->ro_list);
3031 }
3032 spin_unlock(&cache->lock);
3033 spin_unlock(&sinfo->lock);
3034}
3035
3036static int update_block_group_item(struct btrfs_trans_handle *trans,
3037 struct btrfs_path *path,
3038 struct btrfs_block_group *cache)
3039{
3040 struct btrfs_fs_info *fs_info = trans->fs_info;
3041 int ret;
3042 struct btrfs_root *root = btrfs_block_group_root(fs_info);
3043 unsigned long bi;
3044 struct extent_buffer *leaf;
3045 struct btrfs_block_group_item bgi;
3046 struct btrfs_key key;
3047 u64 old_commit_used;
3048 u64 used;
3049
3050 /*
3051 * Block group items update can be triggered out of commit transaction
3052 * critical section, thus we need a consistent view of used bytes.
3053 * We cannot use cache->used directly outside of the spin lock, as it
3054 * may be changed.
3055 */
3056 spin_lock(&cache->lock);
3057 old_commit_used = cache->commit_used;
3058 used = cache->used;
3059 /* No change in used bytes, can safely skip it. */
3060 if (cache->commit_used == used) {
3061 spin_unlock(&cache->lock);
3062 return 0;
3063 }
3064 cache->commit_used = used;
3065 spin_unlock(&cache->lock);
3066
3067 key.objectid = cache->start;
3068 key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
3069 key.offset = cache->length;
3070
3071 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
3072 if (ret) {
3073 if (ret > 0)
3074 ret = -ENOENT;
3075 goto fail;
3076 }
3077
3078 leaf = path->nodes[0];
3079 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
3080 btrfs_set_stack_block_group_used(&bgi, used);
3081 btrfs_set_stack_block_group_chunk_objectid(&bgi,
3082 cache->global_root_id);
3083 btrfs_set_stack_block_group_flags(&bgi, cache->flags);
3084 write_extent_buffer(leaf, &bgi, bi, sizeof(bgi));
3085 btrfs_mark_buffer_dirty(trans, leaf);
3086fail:
3087 btrfs_release_path(path);
3088 /*
3089 * We didn't update the block group item, need to revert commit_used
3090 * unless the block group item didn't exist yet - this is to prevent a
3091 * race with a concurrent insertion of the block group item, with
3092 * insert_block_group_item(), that happened just after we attempted to
3093 * update. In that case we would reset commit_used to 0 just after the
3094 * insertion set it to a value greater than 0 - if the block group later
3095 * becomes with 0 used bytes, we would incorrectly skip its update.
3096 */
3097 if (ret < 0 && ret != -ENOENT) {
3098 spin_lock(&cache->lock);
3099 cache->commit_used = old_commit_used;
3100 spin_unlock(&cache->lock);
3101 }
3102 return ret;
3103
3104}
3105
3106static int cache_save_setup(struct btrfs_block_group *block_group,
3107 struct btrfs_trans_handle *trans,
3108 struct btrfs_path *path)
3109{
3110 struct btrfs_fs_info *fs_info = block_group->fs_info;
3111 struct inode *inode = NULL;
3112 struct extent_changeset *data_reserved = NULL;
3113 u64 alloc_hint = 0;
3114 int dcs = BTRFS_DC_ERROR;
3115 u64 cache_size = 0;
3116 int retries = 0;
3117 int ret = 0;
3118
3119 if (!btrfs_test_opt(fs_info, SPACE_CACHE))
3120 return 0;
3121
3122 /*
3123 * If this block group is smaller than 100 megs don't bother caching the
3124 * block group.
3125 */
3126 if (block_group->length < (100 * SZ_1M)) {
3127 spin_lock(&block_group->lock);
3128 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
3129 spin_unlock(&block_group->lock);
3130 return 0;
3131 }
3132
3133 if (TRANS_ABORTED(trans))
3134 return 0;
3135again:
3136 inode = lookup_free_space_inode(block_group, path);
3137 if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
3138 ret = PTR_ERR(inode);
3139 btrfs_release_path(path);
3140 goto out;
3141 }
3142
3143 if (IS_ERR(inode)) {
3144 BUG_ON(retries);
3145 retries++;
3146
3147 if (block_group->ro)
3148 goto out_free;
3149
3150 ret = create_free_space_inode(trans, block_group, path);
3151 if (ret)
3152 goto out_free;
3153 goto again;
3154 }
3155
3156 /*
3157 * We want to set the generation to 0, that way if anything goes wrong
3158 * from here on out we know not to trust this cache when we load up next
3159 * time.
3160 */
3161 BTRFS_I(inode)->generation = 0;
3162 ret = btrfs_update_inode(trans, BTRFS_I(inode));
3163 if (ret) {
3164 /*
3165 * So theoretically we could recover from this, simply set the
3166 * super cache generation to 0 so we know to invalidate the
3167 * cache, but then we'd have to keep track of the block groups
3168 * that fail this way so we know we _have_ to reset this cache
3169 * before the next commit or risk reading stale cache. So to
3170 * limit our exposure to horrible edge cases lets just abort the
3171 * transaction, this only happens in really bad situations
3172 * anyway.
3173 */
3174 btrfs_abort_transaction(trans, ret);
3175 goto out_put;
3176 }
3177 WARN_ON(ret);
3178
3179 /* We've already setup this transaction, go ahead and exit */
3180 if (block_group->cache_generation == trans->transid &&
3181 i_size_read(inode)) {
3182 dcs = BTRFS_DC_SETUP;
3183 goto out_put;
3184 }
3185
3186 if (i_size_read(inode) > 0) {
3187 ret = btrfs_check_trunc_cache_free_space(fs_info,
3188 &fs_info->global_block_rsv);
3189 if (ret)
3190 goto out_put;
3191
3192 ret = btrfs_truncate_free_space_cache(trans, NULL, inode);
3193 if (ret)
3194 goto out_put;
3195 }
3196
3197 spin_lock(&block_group->lock);
3198 if (block_group->cached != BTRFS_CACHE_FINISHED ||
3199 !btrfs_test_opt(fs_info, SPACE_CACHE)) {
3200 /*
3201 * don't bother trying to write stuff out _if_
3202 * a) we're not cached,
3203 * b) we're with nospace_cache mount option,
3204 * c) we're with v2 space_cache (FREE_SPACE_TREE).
3205 */
3206 dcs = BTRFS_DC_WRITTEN;
3207 spin_unlock(&block_group->lock);
3208 goto out_put;
3209 }
3210 spin_unlock(&block_group->lock);
3211
3212 /*
3213 * We hit an ENOSPC when setting up the cache in this transaction, just
3214 * skip doing the setup, we've already cleared the cache so we're safe.
3215 */
3216 if (test_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags)) {
3217 ret = -ENOSPC;
3218 goto out_put;
3219 }
3220
3221 /*
3222 * Try to preallocate enough space based on how big the block group is.
3223 * Keep in mind this has to include any pinned space which could end up
3224 * taking up quite a bit since it's not folded into the other space
3225 * cache.
3226 */
3227 cache_size = div_u64(block_group->length, SZ_256M);
3228 if (!cache_size)
3229 cache_size = 1;
3230
3231 cache_size *= 16;
3232 cache_size *= fs_info->sectorsize;
3233
3234 ret = btrfs_check_data_free_space(BTRFS_I(inode), &data_reserved, 0,
3235 cache_size, false);
3236 if (ret)
3237 goto out_put;
3238
3239 ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, cache_size,
3240 cache_size, cache_size,
3241 &alloc_hint);
3242 /*
3243 * Our cache requires contiguous chunks so that we don't modify a bunch
3244 * of metadata or split extents when writing the cache out, which means
3245 * we can enospc if we are heavily fragmented in addition to just normal
3246 * out of space conditions. So if we hit this just skip setting up any
3247 * other block groups for this transaction, maybe we'll unpin enough
3248 * space the next time around.
3249 */
3250 if (!ret)
3251 dcs = BTRFS_DC_SETUP;
3252 else if (ret == -ENOSPC)
3253 set_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags);
3254
3255out_put:
3256 iput(inode);
3257out_free:
3258 btrfs_release_path(path);
3259out:
3260 spin_lock(&block_group->lock);
3261 if (!ret && dcs == BTRFS_DC_SETUP)
3262 block_group->cache_generation = trans->transid;
3263 block_group->disk_cache_state = dcs;
3264 spin_unlock(&block_group->lock);
3265
3266 extent_changeset_free(data_reserved);
3267 return ret;
3268}
3269
3270int btrfs_setup_space_cache(struct btrfs_trans_handle *trans)
3271{
3272 struct btrfs_fs_info *fs_info = trans->fs_info;
3273 struct btrfs_block_group *cache, *tmp;
3274 struct btrfs_transaction *cur_trans = trans->transaction;
3275 struct btrfs_path *path;
3276
3277 if (list_empty(&cur_trans->dirty_bgs) ||
3278 !btrfs_test_opt(fs_info, SPACE_CACHE))
3279 return 0;
3280
3281 path = btrfs_alloc_path();
3282 if (!path)
3283 return -ENOMEM;
3284
3285 /* Could add new block groups, use _safe just in case */
3286 list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
3287 dirty_list) {
3288 if (cache->disk_cache_state == BTRFS_DC_CLEAR)
3289 cache_save_setup(cache, trans, path);
3290 }
3291
3292 btrfs_free_path(path);
3293 return 0;
3294}
3295
3296/*
3297 * Transaction commit does final block group cache writeback during a critical
3298 * section where nothing is allowed to change the FS. This is required in
3299 * order for the cache to actually match the block group, but can introduce a
3300 * lot of latency into the commit.
3301 *
3302 * So, btrfs_start_dirty_block_groups is here to kick off block group cache IO.
3303 * There's a chance we'll have to redo some of it if the block group changes
3304 * again during the commit, but it greatly reduces the commit latency by
3305 * getting rid of the easy block groups while we're still allowing others to
3306 * join the commit.
3307 */
3308int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans)
3309{
3310 struct btrfs_fs_info *fs_info = trans->fs_info;
3311 struct btrfs_block_group *cache;
3312 struct btrfs_transaction *cur_trans = trans->transaction;
3313 int ret = 0;
3314 int should_put;
3315 struct btrfs_path *path = NULL;
3316 LIST_HEAD(dirty);
3317 struct list_head *io = &cur_trans->io_bgs;
3318 int loops = 0;
3319
3320 spin_lock(&cur_trans->dirty_bgs_lock);
3321 if (list_empty(&cur_trans->dirty_bgs)) {
3322 spin_unlock(&cur_trans->dirty_bgs_lock);
3323 return 0;
3324 }
3325 list_splice_init(&cur_trans->dirty_bgs, &dirty);
3326 spin_unlock(&cur_trans->dirty_bgs_lock);
3327
3328again:
3329 /* Make sure all the block groups on our dirty list actually exist */
3330 btrfs_create_pending_block_groups(trans);
3331
3332 if (!path) {
3333 path = btrfs_alloc_path();
3334 if (!path) {
3335 ret = -ENOMEM;
3336 goto out;
3337 }
3338 }
3339
3340 /*
3341 * cache_write_mutex is here only to save us from balance or automatic
3342 * removal of empty block groups deleting this block group while we are
3343 * writing out the cache
3344 */
3345 mutex_lock(&trans->transaction->cache_write_mutex);
3346 while (!list_empty(&dirty)) {
3347 bool drop_reserve = true;
3348
3349 cache = list_first_entry(&dirty, struct btrfs_block_group,
3350 dirty_list);
3351 /*
3352 * This can happen if something re-dirties a block group that
3353 * is already under IO. Just wait for it to finish and then do
3354 * it all again
3355 */
3356 if (!list_empty(&cache->io_list)) {
3357 list_del_init(&cache->io_list);
3358 btrfs_wait_cache_io(trans, cache, path);
3359 btrfs_put_block_group(cache);
3360 }
3361
3362
3363 /*
3364 * btrfs_wait_cache_io uses the cache->dirty_list to decide if
3365 * it should update the cache_state. Don't delete until after
3366 * we wait.
3367 *
3368 * Since we're not running in the commit critical section
3369 * we need the dirty_bgs_lock to protect from update_block_group
3370 */
3371 spin_lock(&cur_trans->dirty_bgs_lock);
3372 list_del_init(&cache->dirty_list);
3373 spin_unlock(&cur_trans->dirty_bgs_lock);
3374
3375 should_put = 1;
3376
3377 cache_save_setup(cache, trans, path);
3378
3379 if (cache->disk_cache_state == BTRFS_DC_SETUP) {
3380 cache->io_ctl.inode = NULL;
3381 ret = btrfs_write_out_cache(trans, cache, path);
3382 if (ret == 0 && cache->io_ctl.inode) {
3383 should_put = 0;
3384
3385 /*
3386 * The cache_write_mutex is protecting the
3387 * io_list, also refer to the definition of
3388 * btrfs_transaction::io_bgs for more details
3389 */
3390 list_add_tail(&cache->io_list, io);
3391 } else {
3392 /*
3393 * If we failed to write the cache, the
3394 * generation will be bad and life goes on
3395 */
3396 ret = 0;
3397 }
3398 }
3399 if (!ret) {
3400 ret = update_block_group_item(trans, path, cache);
3401 /*
3402 * Our block group might still be attached to the list
3403 * of new block groups in the transaction handle of some
3404 * other task (struct btrfs_trans_handle->new_bgs). This
3405 * means its block group item isn't yet in the extent
3406 * tree. If this happens ignore the error, as we will
3407 * try again later in the critical section of the
3408 * transaction commit.
3409 */
3410 if (ret == -ENOENT) {
3411 ret = 0;
3412 spin_lock(&cur_trans->dirty_bgs_lock);
3413 if (list_empty(&cache->dirty_list)) {
3414 list_add_tail(&cache->dirty_list,
3415 &cur_trans->dirty_bgs);
3416 btrfs_get_block_group(cache);
3417 drop_reserve = false;
3418 }
3419 spin_unlock(&cur_trans->dirty_bgs_lock);
3420 } else if (ret) {
3421 btrfs_abort_transaction(trans, ret);
3422 }
3423 }
3424
3425 /* If it's not on the io list, we need to put the block group */
3426 if (should_put)
3427 btrfs_put_block_group(cache);
3428 if (drop_reserve)
3429 btrfs_dec_delayed_refs_rsv_bg_updates(fs_info);
3430 /*
3431 * Avoid blocking other tasks for too long. It might even save
3432 * us from writing caches for block groups that are going to be
3433 * removed.
3434 */
3435 mutex_unlock(&trans->transaction->cache_write_mutex);
3436 if (ret)
3437 goto out;
3438 mutex_lock(&trans->transaction->cache_write_mutex);
3439 }
3440 mutex_unlock(&trans->transaction->cache_write_mutex);
3441
3442 /*
3443 * Go through delayed refs for all the stuff we've just kicked off
3444 * and then loop back (just once)
3445 */
3446 if (!ret)
3447 ret = btrfs_run_delayed_refs(trans, 0);
3448 if (!ret && loops == 0) {
3449 loops++;
3450 spin_lock(&cur_trans->dirty_bgs_lock);
3451 list_splice_init(&cur_trans->dirty_bgs, &dirty);
3452 /*
3453 * dirty_bgs_lock protects us from concurrent block group
3454 * deletes too (not just cache_write_mutex).
3455 */
3456 if (!list_empty(&dirty)) {
3457 spin_unlock(&cur_trans->dirty_bgs_lock);
3458 goto again;
3459 }
3460 spin_unlock(&cur_trans->dirty_bgs_lock);
3461 }
3462out:
3463 if (ret < 0) {
3464 spin_lock(&cur_trans->dirty_bgs_lock);
3465 list_splice_init(&dirty, &cur_trans->dirty_bgs);
3466 spin_unlock(&cur_trans->dirty_bgs_lock);
3467 btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
3468 }
3469
3470 btrfs_free_path(path);
3471 return ret;
3472}
3473
3474int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans)
3475{
3476 struct btrfs_fs_info *fs_info = trans->fs_info;
3477 struct btrfs_block_group *cache;
3478 struct btrfs_transaction *cur_trans = trans->transaction;
3479 int ret = 0;
3480 int should_put;
3481 struct btrfs_path *path;
3482 struct list_head *io = &cur_trans->io_bgs;
3483
3484 path = btrfs_alloc_path();
3485 if (!path)
3486 return -ENOMEM;
3487
3488 /*
3489 * Even though we are in the critical section of the transaction commit,
3490 * we can still have concurrent tasks adding elements to this
3491 * transaction's list of dirty block groups. These tasks correspond to
3492 * endio free space workers started when writeback finishes for a
3493 * space cache, which run inode.c:btrfs_finish_ordered_io(), and can
3494 * allocate new block groups as a result of COWing nodes of the root
3495 * tree when updating the free space inode. The writeback for the space
3496 * caches is triggered by an earlier call to
3497 * btrfs_start_dirty_block_groups() and iterations of the following
3498 * loop.
3499 * Also we want to do the cache_save_setup first and then run the
3500 * delayed refs to make sure we have the best chance at doing this all
3501 * in one shot.
3502 */
3503 spin_lock(&cur_trans->dirty_bgs_lock);
3504 while (!list_empty(&cur_trans->dirty_bgs)) {
3505 cache = list_first_entry(&cur_trans->dirty_bgs,
3506 struct btrfs_block_group,
3507 dirty_list);
3508
3509 /*
3510 * This can happen if cache_save_setup re-dirties a block group
3511 * that is already under IO. Just wait for it to finish and
3512 * then do it all again
3513 */
3514 if (!list_empty(&cache->io_list)) {
3515 spin_unlock(&cur_trans->dirty_bgs_lock);
3516 list_del_init(&cache->io_list);
3517 btrfs_wait_cache_io(trans, cache, path);
3518 btrfs_put_block_group(cache);
3519 spin_lock(&cur_trans->dirty_bgs_lock);
3520 }
3521
3522 /*
3523 * Don't remove from the dirty list until after we've waited on
3524 * any pending IO
3525 */
3526 list_del_init(&cache->dirty_list);
3527 spin_unlock(&cur_trans->dirty_bgs_lock);
3528 should_put = 1;
3529
3530 cache_save_setup(cache, trans, path);
3531
3532 if (!ret)
3533 ret = btrfs_run_delayed_refs(trans, U64_MAX);
3534
3535 if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
3536 cache->io_ctl.inode = NULL;
3537 ret = btrfs_write_out_cache(trans, cache, path);
3538 if (ret == 0 && cache->io_ctl.inode) {
3539 should_put = 0;
3540 list_add_tail(&cache->io_list, io);
3541 } else {
3542 /*
3543 * If we failed to write the cache, the
3544 * generation will be bad and life goes on
3545 */
3546 ret = 0;
3547 }
3548 }
3549 if (!ret) {
3550 ret = update_block_group_item(trans, path, cache);
3551 /*
3552 * One of the free space endio workers might have
3553 * created a new block group while updating a free space
3554 * cache's inode (at inode.c:btrfs_finish_ordered_io())
3555 * and hasn't released its transaction handle yet, in
3556 * which case the new block group is still attached to
3557 * its transaction handle and its creation has not
3558 * finished yet (no block group item in the extent tree
3559 * yet, etc). If this is the case, wait for all free
3560 * space endio workers to finish and retry. This is a
3561 * very rare case so no need for a more efficient and
3562 * complex approach.
3563 */
3564 if (ret == -ENOENT) {
3565 wait_event(cur_trans->writer_wait,
3566 atomic_read(&cur_trans->num_writers) == 1);
3567 ret = update_block_group_item(trans, path, cache);
3568 }
3569 if (ret)
3570 btrfs_abort_transaction(trans, ret);
3571 }
3572
3573 /* If its not on the io list, we need to put the block group */
3574 if (should_put)
3575 btrfs_put_block_group(cache);
3576 btrfs_dec_delayed_refs_rsv_bg_updates(fs_info);
3577 spin_lock(&cur_trans->dirty_bgs_lock);
3578 }
3579 spin_unlock(&cur_trans->dirty_bgs_lock);
3580
3581 /*
3582 * Refer to the definition of io_bgs member for details why it's safe
3583 * to use it without any locking
3584 */
3585 while (!list_empty(io)) {
3586 cache = list_first_entry(io, struct btrfs_block_group,
3587 io_list);
3588 list_del_init(&cache->io_list);
3589 btrfs_wait_cache_io(trans, cache, path);
3590 btrfs_put_block_group(cache);
3591 }
3592
3593 btrfs_free_path(path);
3594 return ret;
3595}
3596
3597int btrfs_update_block_group(struct btrfs_trans_handle *trans,
3598 u64 bytenr, u64 num_bytes, bool alloc)
3599{
3600 struct btrfs_fs_info *info = trans->fs_info;
3601 struct btrfs_space_info *space_info;
3602 struct btrfs_block_group *cache;
3603 u64 old_val;
3604 bool reclaim = false;
3605 bool bg_already_dirty = true;
3606 int factor;
3607
3608 /* Block accounting for super block */
3609 spin_lock(&info->delalloc_root_lock);
3610 old_val = btrfs_super_bytes_used(info->super_copy);
3611 if (alloc)
3612 old_val += num_bytes;
3613 else
3614 old_val -= num_bytes;
3615 btrfs_set_super_bytes_used(info->super_copy, old_val);
3616 spin_unlock(&info->delalloc_root_lock);
3617
3618 cache = btrfs_lookup_block_group(info, bytenr);
3619 if (!cache)
3620 return -ENOENT;
3621
3622 /* An extent can not span multiple block groups. */
3623 ASSERT(bytenr + num_bytes <= cache->start + cache->length);
3624
3625 space_info = cache->space_info;
3626 factor = btrfs_bg_type_to_factor(cache->flags);
3627
3628 /*
3629 * If this block group has free space cache written out, we need to make
3630 * sure to load it if we are removing space. This is because we need
3631 * the unpinning stage to actually add the space back to the block group,
3632 * otherwise we will leak space.
3633 */
3634 if (!alloc && !btrfs_block_group_done(cache))
3635 btrfs_cache_block_group(cache, true);
3636
3637 spin_lock(&space_info->lock);
3638 spin_lock(&cache->lock);
3639
3640 if (btrfs_test_opt(info, SPACE_CACHE) &&
3641 cache->disk_cache_state < BTRFS_DC_CLEAR)
3642 cache->disk_cache_state = BTRFS_DC_CLEAR;
3643
3644 old_val = cache->used;
3645 if (alloc) {
3646 old_val += num_bytes;
3647 cache->used = old_val;
3648 cache->reserved -= num_bytes;
3649 space_info->bytes_reserved -= num_bytes;
3650 space_info->bytes_used += num_bytes;
3651 space_info->disk_used += num_bytes * factor;
3652 spin_unlock(&cache->lock);
3653 spin_unlock(&space_info->lock);
3654 } else {
3655 old_val -= num_bytes;
3656 cache->used = old_val;
3657 cache->pinned += num_bytes;
3658 btrfs_space_info_update_bytes_pinned(info, space_info, num_bytes);
3659 space_info->bytes_used -= num_bytes;
3660 space_info->disk_used -= num_bytes * factor;
3661
3662 reclaim = should_reclaim_block_group(cache, num_bytes);
3663
3664 spin_unlock(&cache->lock);
3665 spin_unlock(&space_info->lock);
3666
3667 set_extent_bit(&trans->transaction->pinned_extents, bytenr,
3668 bytenr + num_bytes - 1, EXTENT_DIRTY, NULL);
3669 }
3670
3671 spin_lock(&trans->transaction->dirty_bgs_lock);
3672 if (list_empty(&cache->dirty_list)) {
3673 list_add_tail(&cache->dirty_list, &trans->transaction->dirty_bgs);
3674 bg_already_dirty = false;
3675 btrfs_get_block_group(cache);
3676 }
3677 spin_unlock(&trans->transaction->dirty_bgs_lock);
3678
3679 /*
3680 * No longer have used bytes in this block group, queue it for deletion.
3681 * We do this after adding the block group to the dirty list to avoid
3682 * races between cleaner kthread and space cache writeout.
3683 */
3684 if (!alloc && old_val == 0) {
3685 if (!btrfs_test_opt(info, DISCARD_ASYNC))
3686 btrfs_mark_bg_unused(cache);
3687 } else if (!alloc && reclaim) {
3688 btrfs_mark_bg_to_reclaim(cache);
3689 }
3690
3691 btrfs_put_block_group(cache);
3692
3693 /* Modified block groups are accounted for in the delayed_refs_rsv. */
3694 if (!bg_already_dirty)
3695 btrfs_inc_delayed_refs_rsv_bg_updates(info);
3696
3697 return 0;
3698}
3699
3700/*
3701 * Update the block_group and space info counters.
3702 *
3703 * @cache: The cache we are manipulating
3704 * @ram_bytes: The number of bytes of file content, and will be same to
3705 * @num_bytes except for the compress path.
3706 * @num_bytes: The number of bytes in question
3707 * @delalloc: The blocks are allocated for the delalloc write
3708 *
3709 * This is called by the allocator when it reserves space. If this is a
3710 * reservation and the block group has become read only we cannot make the
3711 * reservation and return -EAGAIN, otherwise this function always succeeds.
3712 */
3713int btrfs_add_reserved_bytes(struct btrfs_block_group *cache,
3714 u64 ram_bytes, u64 num_bytes, int delalloc,
3715 bool force_wrong_size_class)
3716{
3717 struct btrfs_space_info *space_info = cache->space_info;
3718 enum btrfs_block_group_size_class size_class;
3719 int ret = 0;
3720
3721 spin_lock(&space_info->lock);
3722 spin_lock(&cache->lock);
3723 if (cache->ro) {
3724 ret = -EAGAIN;
3725 goto out;
3726 }
3727
3728 if (btrfs_block_group_should_use_size_class(cache)) {
3729 size_class = btrfs_calc_block_group_size_class(num_bytes);
3730 ret = btrfs_use_block_group_size_class(cache, size_class, force_wrong_size_class);
3731 if (ret)
3732 goto out;
3733 }
3734 cache->reserved += num_bytes;
3735 space_info->bytes_reserved += num_bytes;
3736 trace_btrfs_space_reservation(cache->fs_info, "space_info",
3737 space_info->flags, num_bytes, 1);
3738 btrfs_space_info_update_bytes_may_use(cache->fs_info,
3739 space_info, -ram_bytes);
3740 if (delalloc)
3741 cache->delalloc_bytes += num_bytes;
3742
3743 /*
3744 * Compression can use less space than we reserved, so wake tickets if
3745 * that happens.
3746 */
3747 if (num_bytes < ram_bytes)
3748 btrfs_try_granting_tickets(cache->fs_info, space_info);
3749out:
3750 spin_unlock(&cache->lock);
3751 spin_unlock(&space_info->lock);
3752 return ret;
3753}
3754
3755/*
3756 * Update the block_group and space info counters.
3757 *
3758 * @cache: The cache we are manipulating
3759 * @num_bytes: The number of bytes in question
3760 * @delalloc: The blocks are allocated for the delalloc write
3761 *
3762 * This is called by somebody who is freeing space that was never actually used
3763 * on disk. For example if you reserve some space for a new leaf in transaction
3764 * A and before transaction A commits you free that leaf, you call this with
3765 * reserve set to 0 in order to clear the reservation.
3766 */
3767void btrfs_free_reserved_bytes(struct btrfs_block_group *cache,
3768 u64 num_bytes, int delalloc)
3769{
3770 struct btrfs_space_info *space_info = cache->space_info;
3771
3772 spin_lock(&space_info->lock);
3773 spin_lock(&cache->lock);
3774 if (cache->ro)
3775 space_info->bytes_readonly += num_bytes;
3776 cache->reserved -= num_bytes;
3777 space_info->bytes_reserved -= num_bytes;
3778 space_info->max_extent_size = 0;
3779
3780 if (delalloc)
3781 cache->delalloc_bytes -= num_bytes;
3782 spin_unlock(&cache->lock);
3783
3784 btrfs_try_granting_tickets(cache->fs_info, space_info);
3785 spin_unlock(&space_info->lock);
3786}
3787
3788static void force_metadata_allocation(struct btrfs_fs_info *info)
3789{
3790 struct list_head *head = &info->space_info;
3791 struct btrfs_space_info *found;
3792
3793 list_for_each_entry(found, head, list) {
3794 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
3795 found->force_alloc = CHUNK_ALLOC_FORCE;
3796 }
3797}
3798
3799static int should_alloc_chunk(struct btrfs_fs_info *fs_info,
3800 struct btrfs_space_info *sinfo, int force)
3801{
3802 u64 bytes_used = btrfs_space_info_used(sinfo, false);
3803 u64 thresh;
3804
3805 if (force == CHUNK_ALLOC_FORCE)
3806 return 1;
3807
3808 /*
3809 * in limited mode, we want to have some free space up to
3810 * about 1% of the FS size.
3811 */
3812 if (force == CHUNK_ALLOC_LIMITED) {
3813 thresh = btrfs_super_total_bytes(fs_info->super_copy);
3814 thresh = max_t(u64, SZ_64M, mult_perc(thresh, 1));
3815
3816 if (sinfo->total_bytes - bytes_used < thresh)
3817 return 1;
3818 }
3819
3820 if (bytes_used + SZ_2M < mult_perc(sinfo->total_bytes, 80))
3821 return 0;
3822 return 1;
3823}
3824
3825int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type)
3826{
3827 u64 alloc_flags = btrfs_get_alloc_profile(trans->fs_info, type);
3828
3829 return btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE);
3830}
3831
3832static struct btrfs_block_group *do_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags)
3833{
3834 struct btrfs_block_group *bg;
3835 int ret;
3836
3837 /*
3838 * Check if we have enough space in the system space info because we
3839 * will need to update device items in the chunk btree and insert a new
3840 * chunk item in the chunk btree as well. This will allocate a new
3841 * system block group if needed.
3842 */
3843 check_system_chunk(trans, flags);
3844
3845 bg = btrfs_create_chunk(trans, flags);
3846 if (IS_ERR(bg)) {
3847 ret = PTR_ERR(bg);
3848 goto out;
3849 }
3850
3851 ret = btrfs_chunk_alloc_add_chunk_item(trans, bg);
3852 /*
3853 * Normally we are not expected to fail with -ENOSPC here, since we have
3854 * previously reserved space in the system space_info and allocated one
3855 * new system chunk if necessary. However there are three exceptions:
3856 *
3857 * 1) We may have enough free space in the system space_info but all the
3858 * existing system block groups have a profile which can not be used
3859 * for extent allocation.
3860 *
3861 * This happens when mounting in degraded mode. For example we have a
3862 * RAID1 filesystem with 2 devices, lose one device and mount the fs
3863 * using the other device in degraded mode. If we then allocate a chunk,
3864 * we may have enough free space in the existing system space_info, but
3865 * none of the block groups can be used for extent allocation since they
3866 * have a RAID1 profile, and because we are in degraded mode with a
3867 * single device, we are forced to allocate a new system chunk with a
3868 * SINGLE profile. Making check_system_chunk() iterate over all system
3869 * block groups and check if they have a usable profile and enough space
3870 * can be slow on very large filesystems, so we tolerate the -ENOSPC and
3871 * try again after forcing allocation of a new system chunk. Like this
3872 * we avoid paying the cost of that search in normal circumstances, when
3873 * we were not mounted in degraded mode;
3874 *
3875 * 2) We had enough free space info the system space_info, and one suitable
3876 * block group to allocate from when we called check_system_chunk()
3877 * above. However right after we called it, the only system block group
3878 * with enough free space got turned into RO mode by a running scrub,
3879 * and in this case we have to allocate a new one and retry. We only
3880 * need do this allocate and retry once, since we have a transaction
3881 * handle and scrub uses the commit root to search for block groups;
3882 *
3883 * 3) We had one system block group with enough free space when we called
3884 * check_system_chunk(), but after that, right before we tried to
3885 * allocate the last extent buffer we needed, a discard operation came
3886 * in and it temporarily removed the last free space entry from the
3887 * block group (discard removes a free space entry, discards it, and
3888 * then adds back the entry to the block group cache).
3889 */
3890 if (ret == -ENOSPC) {
3891 const u64 sys_flags = btrfs_system_alloc_profile(trans->fs_info);
3892 struct btrfs_block_group *sys_bg;
3893
3894 sys_bg = btrfs_create_chunk(trans, sys_flags);
3895 if (IS_ERR(sys_bg)) {
3896 ret = PTR_ERR(sys_bg);
3897 btrfs_abort_transaction(trans, ret);
3898 goto out;
3899 }
3900
3901 ret = btrfs_chunk_alloc_add_chunk_item(trans, sys_bg);
3902 if (ret) {
3903 btrfs_abort_transaction(trans, ret);
3904 goto out;
3905 }
3906
3907 ret = btrfs_chunk_alloc_add_chunk_item(trans, bg);
3908 if (ret) {
3909 btrfs_abort_transaction(trans, ret);
3910 goto out;
3911 }
3912 } else if (ret) {
3913 btrfs_abort_transaction(trans, ret);
3914 goto out;
3915 }
3916out:
3917 btrfs_trans_release_chunk_metadata(trans);
3918
3919 if (ret)
3920 return ERR_PTR(ret);
3921
3922 btrfs_get_block_group(bg);
3923 return bg;
3924}
3925
3926/*
3927 * Chunk allocation is done in 2 phases:
3928 *
3929 * 1) Phase 1 - through btrfs_chunk_alloc() we allocate device extents for
3930 * the chunk, the chunk mapping, create its block group and add the items
3931 * that belong in the chunk btree to it - more specifically, we need to
3932 * update device items in the chunk btree and add a new chunk item to it.
3933 *
3934 * 2) Phase 2 - through btrfs_create_pending_block_groups(), we add the block
3935 * group item to the extent btree and the device extent items to the devices
3936 * btree.
3937 *
3938 * This is done to prevent deadlocks. For example when COWing a node from the
3939 * extent btree we are holding a write lock on the node's parent and if we
3940 * trigger chunk allocation and attempted to insert the new block group item
3941 * in the extent btree right way, we could deadlock because the path for the
3942 * insertion can include that parent node. At first glance it seems impossible
3943 * to trigger chunk allocation after starting a transaction since tasks should
3944 * reserve enough transaction units (metadata space), however while that is true
3945 * most of the time, chunk allocation may still be triggered for several reasons:
3946 *
3947 * 1) When reserving metadata, we check if there is enough free space in the
3948 * metadata space_info and therefore don't trigger allocation of a new chunk.
3949 * However later when the task actually tries to COW an extent buffer from
3950 * the extent btree or from the device btree for example, it is forced to
3951 * allocate a new block group (chunk) because the only one that had enough
3952 * free space was just turned to RO mode by a running scrub for example (or
3953 * device replace, block group reclaim thread, etc), so we can not use it
3954 * for allocating an extent and end up being forced to allocate a new one;
3955 *
3956 * 2) Because we only check that the metadata space_info has enough free bytes,
3957 * we end up not allocating a new metadata chunk in that case. However if
3958 * the filesystem was mounted in degraded mode, none of the existing block
3959 * groups might be suitable for extent allocation due to their incompatible
3960 * profile (for e.g. mounting a 2 devices filesystem, where all block groups
3961 * use a RAID1 profile, in degraded mode using a single device). In this case
3962 * when the task attempts to COW some extent buffer of the extent btree for
3963 * example, it will trigger allocation of a new metadata block group with a
3964 * suitable profile (SINGLE profile in the example of the degraded mount of
3965 * the RAID1 filesystem);
3966 *
3967 * 3) The task has reserved enough transaction units / metadata space, but when
3968 * it attempts to COW an extent buffer from the extent or device btree for
3969 * example, it does not find any free extent in any metadata block group,
3970 * therefore forced to try to allocate a new metadata block group.
3971 * This is because some other task allocated all available extents in the
3972 * meanwhile - this typically happens with tasks that don't reserve space
3973 * properly, either intentionally or as a bug. One example where this is
3974 * done intentionally is fsync, as it does not reserve any transaction units
3975 * and ends up allocating a variable number of metadata extents for log
3976 * tree extent buffers;
3977 *
3978 * 4) The task has reserved enough transaction units / metadata space, but right
3979 * before it tries to allocate the last extent buffer it needs, a discard
3980 * operation comes in and, temporarily, removes the last free space entry from
3981 * the only metadata block group that had free space (discard starts by
3982 * removing a free space entry from a block group, then does the discard
3983 * operation and, once it's done, it adds back the free space entry to the
3984 * block group).
3985 *
3986 * We also need this 2 phases setup when adding a device to a filesystem with
3987 * a seed device - we must create new metadata and system chunks without adding
3988 * any of the block group items to the chunk, extent and device btrees. If we
3989 * did not do it this way, we would get ENOSPC when attempting to update those
3990 * btrees, since all the chunks from the seed device are read-only.
3991 *
3992 * Phase 1 does the updates and insertions to the chunk btree because if we had
3993 * it done in phase 2 and have a thundering herd of tasks allocating chunks in
3994 * parallel, we risk having too many system chunks allocated by many tasks if
3995 * many tasks reach phase 1 without the previous ones completing phase 2. In the
3996 * extreme case this leads to exhaustion of the system chunk array in the
3997 * superblock. This is easier to trigger if using a btree node/leaf size of 64K
3998 * and with RAID filesystems (so we have more device items in the chunk btree).
3999 * This has happened before and commit eafa4fd0ad0607 ("btrfs: fix exhaustion of
4000 * the system chunk array due to concurrent allocations") provides more details.
4001 *
4002 * Allocation of system chunks does not happen through this function. A task that
4003 * needs to update the chunk btree (the only btree that uses system chunks), must
4004 * preallocate chunk space by calling either check_system_chunk() or
4005 * btrfs_reserve_chunk_metadata() - the former is used when allocating a data or
4006 * metadata chunk or when removing a chunk, while the later is used before doing
4007 * a modification to the chunk btree - use cases for the later are adding,
4008 * removing and resizing a device as well as relocation of a system chunk.
4009 * See the comment below for more details.
4010 *
4011 * The reservation of system space, done through check_system_chunk(), as well
4012 * as all the updates and insertions into the chunk btree must be done while
4013 * holding fs_info->chunk_mutex. This is important to guarantee that while COWing
4014 * an extent buffer from the chunks btree we never trigger allocation of a new
4015 * system chunk, which would result in a deadlock (trying to lock twice an
4016 * extent buffer of the chunk btree, first time before triggering the chunk
4017 * allocation and the second time during chunk allocation while attempting to
4018 * update the chunks btree). The system chunk array is also updated while holding
4019 * that mutex. The same logic applies to removing chunks - we must reserve system
4020 * space, update the chunk btree and the system chunk array in the superblock
4021 * while holding fs_info->chunk_mutex.
4022 *
4023 * This function, btrfs_chunk_alloc(), belongs to phase 1.
4024 *
4025 * If @force is CHUNK_ALLOC_FORCE:
4026 * - return 1 if it successfully allocates a chunk,
4027 * - return errors including -ENOSPC otherwise.
4028 * If @force is NOT CHUNK_ALLOC_FORCE:
4029 * - return 0 if it doesn't need to allocate a new chunk,
4030 * - return 1 if it successfully allocates a chunk,
4031 * - return errors including -ENOSPC otherwise.
4032 */
4033int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
4034 enum btrfs_chunk_alloc_enum force)
4035{
4036 struct btrfs_fs_info *fs_info = trans->fs_info;
4037 struct btrfs_space_info *space_info;
4038 struct btrfs_block_group *ret_bg;
4039 bool wait_for_alloc = false;
4040 bool should_alloc = false;
4041 bool from_extent_allocation = false;
4042 int ret = 0;
4043
4044 if (force == CHUNK_ALLOC_FORCE_FOR_EXTENT) {
4045 from_extent_allocation = true;
4046 force = CHUNK_ALLOC_FORCE;
4047 }
4048
4049 /* Don't re-enter if we're already allocating a chunk */
4050 if (trans->allocating_chunk)
4051 return -ENOSPC;
4052 /*
4053 * Allocation of system chunks can not happen through this path, as we
4054 * could end up in a deadlock if we are allocating a data or metadata
4055 * chunk and there is another task modifying the chunk btree.
4056 *
4057 * This is because while we are holding the chunk mutex, we will attempt
4058 * to add the new chunk item to the chunk btree or update an existing
4059 * device item in the chunk btree, while the other task that is modifying
4060 * the chunk btree is attempting to COW an extent buffer while holding a
4061 * lock on it and on its parent - if the COW operation triggers a system
4062 * chunk allocation, then we can deadlock because we are holding the
4063 * chunk mutex and we may need to access that extent buffer or its parent
4064 * in order to add the chunk item or update a device item.
4065 *
4066 * Tasks that want to modify the chunk tree should reserve system space
4067 * before updating the chunk btree, by calling either
4068 * btrfs_reserve_chunk_metadata() or check_system_chunk().
4069 * It's possible that after a task reserves the space, it still ends up
4070 * here - this happens in the cases described above at do_chunk_alloc().
4071 * The task will have to either retry or fail.
4072 */
4073 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
4074 return -ENOSPC;
4075
4076 space_info = btrfs_find_space_info(fs_info, flags);
4077 ASSERT(space_info);
4078
4079 do {
4080 spin_lock(&space_info->lock);
4081 if (force < space_info->force_alloc)
4082 force = space_info->force_alloc;
4083 should_alloc = should_alloc_chunk(fs_info, space_info, force);
4084 if (space_info->full) {
4085 /* No more free physical space */
4086 if (should_alloc)
4087 ret = -ENOSPC;
4088 else
4089 ret = 0;
4090 spin_unlock(&space_info->lock);
4091 return ret;
4092 } else if (!should_alloc) {
4093 spin_unlock(&space_info->lock);
4094 return 0;
4095 } else if (space_info->chunk_alloc) {
4096 /*
4097 * Someone is already allocating, so we need to block
4098 * until this someone is finished and then loop to
4099 * recheck if we should continue with our allocation
4100 * attempt.
4101 */
4102 wait_for_alloc = true;
4103 force = CHUNK_ALLOC_NO_FORCE;
4104 spin_unlock(&space_info->lock);
4105 mutex_lock(&fs_info->chunk_mutex);
4106 mutex_unlock(&fs_info->chunk_mutex);
4107 } else {
4108 /* Proceed with allocation */
4109 space_info->chunk_alloc = 1;
4110 wait_for_alloc = false;
4111 spin_unlock(&space_info->lock);
4112 }
4113
4114 cond_resched();
4115 } while (wait_for_alloc);
4116
4117 mutex_lock(&fs_info->chunk_mutex);
4118 trans->allocating_chunk = true;
4119
4120 /*
4121 * If we have mixed data/metadata chunks we want to make sure we keep
4122 * allocating mixed chunks instead of individual chunks.
4123 */
4124 if (btrfs_mixed_space_info(space_info))
4125 flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
4126
4127 /*
4128 * if we're doing a data chunk, go ahead and make sure that
4129 * we keep a reasonable number of metadata chunks allocated in the
4130 * FS as well.
4131 */
4132 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
4133 fs_info->data_chunk_allocations++;
4134 if (!(fs_info->data_chunk_allocations %
4135 fs_info->metadata_ratio))
4136 force_metadata_allocation(fs_info);
4137 }
4138
4139 ret_bg = do_chunk_alloc(trans, flags);
4140 trans->allocating_chunk = false;
4141
4142 if (IS_ERR(ret_bg)) {
4143 ret = PTR_ERR(ret_bg);
4144 } else if (from_extent_allocation && (flags & BTRFS_BLOCK_GROUP_DATA)) {
4145 /*
4146 * New block group is likely to be used soon. Try to activate
4147 * it now. Failure is OK for now.
4148 */
4149 btrfs_zone_activate(ret_bg);
4150 }
4151
4152 if (!ret)
4153 btrfs_put_block_group(ret_bg);
4154
4155 spin_lock(&space_info->lock);
4156 if (ret < 0) {
4157 if (ret == -ENOSPC)
4158 space_info->full = 1;
4159 else
4160 goto out;
4161 } else {
4162 ret = 1;
4163 space_info->max_extent_size = 0;
4164 }
4165
4166 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
4167out:
4168 space_info->chunk_alloc = 0;
4169 spin_unlock(&space_info->lock);
4170 mutex_unlock(&fs_info->chunk_mutex);
4171
4172 return ret;
4173}
4174
4175static u64 get_profile_num_devs(struct btrfs_fs_info *fs_info, u64 type)
4176{
4177 u64 num_dev;
4178
4179 num_dev = btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)].devs_max;
4180 if (!num_dev)
4181 num_dev = fs_info->fs_devices->rw_devices;
4182
4183 return num_dev;
4184}
4185
4186static void reserve_chunk_space(struct btrfs_trans_handle *trans,
4187 u64 bytes,
4188 u64 type)
4189{
4190 struct btrfs_fs_info *fs_info = trans->fs_info;
4191 struct btrfs_space_info *info;
4192 u64 left;
4193 int ret = 0;
4194
4195 /*
4196 * Needed because we can end up allocating a system chunk and for an
4197 * atomic and race free space reservation in the chunk block reserve.
4198 */
4199 lockdep_assert_held(&fs_info->chunk_mutex);
4200
4201 info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
4202 spin_lock(&info->lock);
4203 left = info->total_bytes - btrfs_space_info_used(info, true);
4204 spin_unlock(&info->lock);
4205
4206 if (left < bytes && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
4207 btrfs_info(fs_info, "left=%llu, need=%llu, flags=%llu",
4208 left, bytes, type);
4209 btrfs_dump_space_info(fs_info, info, 0, 0);
4210 }
4211
4212 if (left < bytes) {
4213 u64 flags = btrfs_system_alloc_profile(fs_info);
4214 struct btrfs_block_group *bg;
4215
4216 /*
4217 * Ignore failure to create system chunk. We might end up not
4218 * needing it, as we might not need to COW all nodes/leafs from
4219 * the paths we visit in the chunk tree (they were already COWed
4220 * or created in the current transaction for example).
4221 */
4222 bg = btrfs_create_chunk(trans, flags);
4223 if (IS_ERR(bg)) {
4224 ret = PTR_ERR(bg);
4225 } else {
4226 /*
4227 * We have a new chunk. We also need to activate it for
4228 * zoned filesystem.
4229 */
4230 ret = btrfs_zoned_activate_one_bg(fs_info, info, true);
4231 if (ret < 0)
4232 return;
4233
4234 /*
4235 * If we fail to add the chunk item here, we end up
4236 * trying again at phase 2 of chunk allocation, at
4237 * btrfs_create_pending_block_groups(). So ignore
4238 * any error here. An ENOSPC here could happen, due to
4239 * the cases described at do_chunk_alloc() - the system
4240 * block group we just created was just turned into RO
4241 * mode by a scrub for example, or a running discard
4242 * temporarily removed its free space entries, etc.
4243 */
4244 btrfs_chunk_alloc_add_chunk_item(trans, bg);
4245 }
4246 }
4247
4248 if (!ret) {
4249 ret = btrfs_block_rsv_add(fs_info,
4250 &fs_info->chunk_block_rsv,
4251 bytes, BTRFS_RESERVE_NO_FLUSH);
4252 if (!ret)
4253 trans->chunk_bytes_reserved += bytes;
4254 }
4255}
4256
4257/*
4258 * Reserve space in the system space for allocating or removing a chunk.
4259 * The caller must be holding fs_info->chunk_mutex.
4260 */
4261void check_system_chunk(struct btrfs_trans_handle *trans, u64 type)
4262{
4263 struct btrfs_fs_info *fs_info = trans->fs_info;
4264 const u64 num_devs = get_profile_num_devs(fs_info, type);
4265 u64 bytes;
4266
4267 /* num_devs device items to update and 1 chunk item to add or remove. */
4268 bytes = btrfs_calc_metadata_size(fs_info, num_devs) +
4269 btrfs_calc_insert_metadata_size(fs_info, 1);
4270
4271 reserve_chunk_space(trans, bytes, type);
4272}
4273
4274/*
4275 * Reserve space in the system space, if needed, for doing a modification to the
4276 * chunk btree.
4277 *
4278 * @trans: A transaction handle.
4279 * @is_item_insertion: Indicate if the modification is for inserting a new item
4280 * in the chunk btree or if it's for the deletion or update
4281 * of an existing item.
4282 *
4283 * This is used in a context where we need to update the chunk btree outside
4284 * block group allocation and removal, to avoid a deadlock with a concurrent
4285 * task that is allocating a metadata or data block group and therefore needs to
4286 * update the chunk btree while holding the chunk mutex. After the update to the
4287 * chunk btree is done, btrfs_trans_release_chunk_metadata() should be called.
4288 *
4289 */
4290void btrfs_reserve_chunk_metadata(struct btrfs_trans_handle *trans,
4291 bool is_item_insertion)
4292{
4293 struct btrfs_fs_info *fs_info = trans->fs_info;
4294 u64 bytes;
4295
4296 if (is_item_insertion)
4297 bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
4298 else
4299 bytes = btrfs_calc_metadata_size(fs_info, 1);
4300
4301 mutex_lock(&fs_info->chunk_mutex);
4302 reserve_chunk_space(trans, bytes, BTRFS_BLOCK_GROUP_SYSTEM);
4303 mutex_unlock(&fs_info->chunk_mutex);
4304}
4305
4306void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
4307{
4308 struct btrfs_block_group *block_group;
4309
4310 block_group = btrfs_lookup_first_block_group(info, 0);
4311 while (block_group) {
4312 btrfs_wait_block_group_cache_done(block_group);
4313 spin_lock(&block_group->lock);
4314 if (test_and_clear_bit(BLOCK_GROUP_FLAG_IREF,
4315 &block_group->runtime_flags)) {
4316 struct inode *inode = block_group->inode;
4317
4318 block_group->inode = NULL;
4319 spin_unlock(&block_group->lock);
4320
4321 ASSERT(block_group->io_ctl.inode == NULL);
4322 iput(inode);
4323 } else {
4324 spin_unlock(&block_group->lock);
4325 }
4326 block_group = btrfs_next_block_group(block_group);
4327 }
4328}
4329
4330/*
4331 * Must be called only after stopping all workers, since we could have block
4332 * group caching kthreads running, and therefore they could race with us if we
4333 * freed the block groups before stopping them.
4334 */
4335int btrfs_free_block_groups(struct btrfs_fs_info *info)
4336{
4337 struct btrfs_block_group *block_group;
4338 struct btrfs_space_info *space_info;
4339 struct btrfs_caching_control *caching_ctl;
4340 struct rb_node *n;
4341
4342 if (btrfs_is_zoned(info)) {
4343 if (info->active_meta_bg) {
4344 btrfs_put_block_group(info->active_meta_bg);
4345 info->active_meta_bg = NULL;
4346 }
4347 if (info->active_system_bg) {
4348 btrfs_put_block_group(info->active_system_bg);
4349 info->active_system_bg = NULL;
4350 }
4351 }
4352
4353 write_lock(&info->block_group_cache_lock);
4354 while (!list_empty(&info->caching_block_groups)) {
4355 caching_ctl = list_entry(info->caching_block_groups.next,
4356 struct btrfs_caching_control, list);
4357 list_del(&caching_ctl->list);
4358 btrfs_put_caching_control(caching_ctl);
4359 }
4360 write_unlock(&info->block_group_cache_lock);
4361
4362 spin_lock(&info->unused_bgs_lock);
4363 while (!list_empty(&info->unused_bgs)) {
4364 block_group = list_first_entry(&info->unused_bgs,
4365 struct btrfs_block_group,
4366 bg_list);
4367 list_del_init(&block_group->bg_list);
4368 btrfs_put_block_group(block_group);
4369 }
4370
4371 while (!list_empty(&info->reclaim_bgs)) {
4372 block_group = list_first_entry(&info->reclaim_bgs,
4373 struct btrfs_block_group,
4374 bg_list);
4375 list_del_init(&block_group->bg_list);
4376 btrfs_put_block_group(block_group);
4377 }
4378 spin_unlock(&info->unused_bgs_lock);
4379
4380 spin_lock(&info->zone_active_bgs_lock);
4381 while (!list_empty(&info->zone_active_bgs)) {
4382 block_group = list_first_entry(&info->zone_active_bgs,
4383 struct btrfs_block_group,
4384 active_bg_list);
4385 list_del_init(&block_group->active_bg_list);
4386 btrfs_put_block_group(block_group);
4387 }
4388 spin_unlock(&info->zone_active_bgs_lock);
4389
4390 write_lock(&info->block_group_cache_lock);
4391 while ((n = rb_last(&info->block_group_cache_tree.rb_root)) != NULL) {
4392 block_group = rb_entry(n, struct btrfs_block_group,
4393 cache_node);
4394 rb_erase_cached(&block_group->cache_node,
4395 &info->block_group_cache_tree);
4396 RB_CLEAR_NODE(&block_group->cache_node);
4397 write_unlock(&info->block_group_cache_lock);
4398
4399 down_write(&block_group->space_info->groups_sem);
4400 list_del(&block_group->list);
4401 up_write(&block_group->space_info->groups_sem);
4402
4403 /*
4404 * We haven't cached this block group, which means we could
4405 * possibly have excluded extents on this block group.
4406 */
4407 if (block_group->cached == BTRFS_CACHE_NO ||
4408 block_group->cached == BTRFS_CACHE_ERROR)
4409 btrfs_free_excluded_extents(block_group);
4410
4411 btrfs_remove_free_space_cache(block_group);
4412 ASSERT(block_group->cached != BTRFS_CACHE_STARTED);
4413 ASSERT(list_empty(&block_group->dirty_list));
4414 ASSERT(list_empty(&block_group->io_list));
4415 ASSERT(list_empty(&block_group->bg_list));
4416 ASSERT(refcount_read(&block_group->refs) == 1);
4417 ASSERT(block_group->swap_extents == 0);
4418 btrfs_put_block_group(block_group);
4419
4420 write_lock(&info->block_group_cache_lock);
4421 }
4422 write_unlock(&info->block_group_cache_lock);
4423
4424 btrfs_release_global_block_rsv(info);
4425
4426 while (!list_empty(&info->space_info)) {
4427 space_info = list_entry(info->space_info.next,
4428 struct btrfs_space_info,
4429 list);
4430
4431 /*
4432 * Do not hide this behind enospc_debug, this is actually
4433 * important and indicates a real bug if this happens.
4434 */
4435 if (WARN_ON(space_info->bytes_pinned > 0 ||
4436 space_info->bytes_may_use > 0))
4437 btrfs_dump_space_info(info, space_info, 0, 0);
4438
4439 /*
4440 * If there was a failure to cleanup a log tree, very likely due
4441 * to an IO failure on a writeback attempt of one or more of its
4442 * extent buffers, we could not do proper (and cheap) unaccounting
4443 * of their reserved space, so don't warn on bytes_reserved > 0 in
4444 * that case.
4445 */
4446 if (!(space_info->flags & BTRFS_BLOCK_GROUP_METADATA) ||
4447 !BTRFS_FS_LOG_CLEANUP_ERROR(info)) {
4448 if (WARN_ON(space_info->bytes_reserved > 0))
4449 btrfs_dump_space_info(info, space_info, 0, 0);
4450 }
4451
4452 WARN_ON(space_info->reclaim_size > 0);
4453 list_del(&space_info->list);
4454 btrfs_sysfs_remove_space_info(space_info);
4455 }
4456 return 0;
4457}
4458
4459void btrfs_freeze_block_group(struct btrfs_block_group *cache)
4460{
4461 atomic_inc(&cache->frozen);
4462}
4463
4464void btrfs_unfreeze_block_group(struct btrfs_block_group *block_group)
4465{
4466 struct btrfs_fs_info *fs_info = block_group->fs_info;
4467 bool cleanup;
4468
4469 spin_lock(&block_group->lock);
4470 cleanup = (atomic_dec_and_test(&block_group->frozen) &&
4471 test_bit(BLOCK_GROUP_FLAG_REMOVED, &block_group->runtime_flags));
4472 spin_unlock(&block_group->lock);
4473
4474 if (cleanup) {
4475 struct btrfs_chunk_map *map;
4476
4477 map = btrfs_find_chunk_map(fs_info, block_group->start, 1);
4478 /* Logic error, can't happen. */
4479 ASSERT(map);
4480
4481 btrfs_remove_chunk_map(fs_info, map);
4482
4483 /* Once for our lookup reference. */
4484 btrfs_free_chunk_map(map);
4485
4486 /*
4487 * We may have left one free space entry and other possible
4488 * tasks trimming this block group have left 1 entry each one.
4489 * Free them if any.
4490 */
4491 btrfs_remove_free_space_cache(block_group);
4492 }
4493}
4494
4495bool btrfs_inc_block_group_swap_extents(struct btrfs_block_group *bg)
4496{
4497 bool ret = true;
4498
4499 spin_lock(&bg->lock);
4500 if (bg->ro)
4501 ret = false;
4502 else
4503 bg->swap_extents++;
4504 spin_unlock(&bg->lock);
4505
4506 return ret;
4507}
4508
4509void btrfs_dec_block_group_swap_extents(struct btrfs_block_group *bg, int amount)
4510{
4511 spin_lock(&bg->lock);
4512 ASSERT(!bg->ro);
4513 ASSERT(bg->swap_extents >= amount);
4514 bg->swap_extents -= amount;
4515 spin_unlock(&bg->lock);
4516}
4517
4518enum btrfs_block_group_size_class btrfs_calc_block_group_size_class(u64 size)
4519{
4520 if (size <= SZ_128K)
4521 return BTRFS_BG_SZ_SMALL;
4522 if (size <= SZ_8M)
4523 return BTRFS_BG_SZ_MEDIUM;
4524 return BTRFS_BG_SZ_LARGE;
4525}
4526
4527/*
4528 * Handle a block group allocating an extent in a size class
4529 *
4530 * @bg: The block group we allocated in.
4531 * @size_class: The size class of the allocation.
4532 * @force_wrong_size_class: Whether we are desperate enough to allow
4533 * mismatched size classes.
4534 *
4535 * Returns: 0 if the size class was valid for this block_group, -EAGAIN in the
4536 * case of a race that leads to the wrong size class without
4537 * force_wrong_size_class set.
4538 *
4539 * find_free_extent will skip block groups with a mismatched size class until
4540 * it really needs to avoid ENOSPC. In that case it will set
4541 * force_wrong_size_class. However, if a block group is newly allocated and
4542 * doesn't yet have a size class, then it is possible for two allocations of
4543 * different sizes to race and both try to use it. The loser is caught here and
4544 * has to retry.
4545 */
4546int btrfs_use_block_group_size_class(struct btrfs_block_group *bg,
4547 enum btrfs_block_group_size_class size_class,
4548 bool force_wrong_size_class)
4549{
4550 ASSERT(size_class != BTRFS_BG_SZ_NONE);
4551
4552 /* The new allocation is in the right size class, do nothing */
4553 if (bg->size_class == size_class)
4554 return 0;
4555 /*
4556 * The new allocation is in a mismatched size class.
4557 * This means one of two things:
4558 *
4559 * 1. Two tasks in find_free_extent for different size_classes raced
4560 * and hit the same empty block_group. Make the loser try again.
4561 * 2. A call to find_free_extent got desperate enough to set
4562 * 'force_wrong_slab'. Don't change the size_class, but allow the
4563 * allocation.
4564 */
4565 if (bg->size_class != BTRFS_BG_SZ_NONE) {
4566 if (force_wrong_size_class)
4567 return 0;
4568 return -EAGAIN;
4569 }
4570 /*
4571 * The happy new block group case: the new allocation is the first
4572 * one in the block_group so we set size_class.
4573 */
4574 bg->size_class = size_class;
4575
4576 return 0;
4577}
4578
4579bool btrfs_block_group_should_use_size_class(struct btrfs_block_group *bg)
4580{
4581 if (btrfs_is_zoned(bg->fs_info))
4582 return false;
4583 if (!btrfs_is_block_group_data_only(bg))
4584 return false;
4585 return true;
4586}