mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race
[linux/fpc-iii.git] / fs / btrfs / extent-tree.c
blob00481cfe6cfce574875fe9d5dbaffcc8d8acc268
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
18 #include <linux/sched.h>
19 #include <linux/sched/signal.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/sort.h>
24 #include <linux/rcupdate.h>
25 #include <linux/kthread.h>
26 #include <linux/slab.h>
27 #include <linux/ratelimit.h>
28 #include <linux/percpu_counter.h>
29 #include "hash.h"
30 #include "tree-log.h"
31 #include "disk-io.h"
32 #include "print-tree.h"
33 #include "volumes.h"
34 #include "raid56.h"
35 #include "locking.h"
36 #include "free-space-cache.h"
37 #include "free-space-tree.h"
38 #include "math.h"
39 #include "sysfs.h"
40 #include "qgroup.h"
42 #undef SCRAMBLE_DELAYED_REFS
45 * control flags for do_chunk_alloc's force field
46 * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
47 * if we really need one.
49 * CHUNK_ALLOC_LIMITED means to only try and allocate one
50 * if we have very few chunks already allocated. This is
51 * used as part of the clustering code to help make sure
52 * we have a good pool of storage to cluster in, without
53 * filling the FS with empty chunks
55 * CHUNK_ALLOC_FORCE means it must try to allocate one
58 enum {
59 CHUNK_ALLOC_NO_FORCE = 0,
60 CHUNK_ALLOC_LIMITED = 1,
61 CHUNK_ALLOC_FORCE = 2,
64 static int update_block_group(struct btrfs_trans_handle *trans,
65 struct btrfs_fs_info *fs_info, u64 bytenr,
66 u64 num_bytes, int alloc);
67 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
68 struct btrfs_fs_info *fs_info,
69 struct btrfs_delayed_ref_node *node, u64 parent,
70 u64 root_objectid, u64 owner_objectid,
71 u64 owner_offset, int refs_to_drop,
72 struct btrfs_delayed_extent_op *extra_op);
73 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
74 struct extent_buffer *leaf,
75 struct btrfs_extent_item *ei);
76 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
77 struct btrfs_fs_info *fs_info,
78 u64 parent, u64 root_objectid,
79 u64 flags, u64 owner, u64 offset,
80 struct btrfs_key *ins, int ref_mod);
81 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
82 struct btrfs_fs_info *fs_info,
83 u64 parent, u64 root_objectid,
84 u64 flags, struct btrfs_disk_key *key,
85 int level, struct btrfs_key *ins);
86 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
87 struct btrfs_fs_info *fs_info, u64 flags,
88 int force);
89 static int find_next_key(struct btrfs_path *path, int level,
90 struct btrfs_key *key);
91 static void dump_space_info(struct btrfs_fs_info *fs_info,
92 struct btrfs_space_info *info, u64 bytes,
93 int dump_block_groups);
94 static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
95 u64 ram_bytes, u64 num_bytes, int delalloc);
96 static int btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
97 u64 num_bytes, int delalloc);
98 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
99 u64 num_bytes);
100 static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
101 struct btrfs_space_info *space_info,
102 u64 orig_bytes,
103 enum btrfs_reserve_flush_enum flush,
104 bool system_chunk);
105 static void space_info_add_new_bytes(struct btrfs_fs_info *fs_info,
106 struct btrfs_space_info *space_info,
107 u64 num_bytes);
108 static void space_info_add_old_bytes(struct btrfs_fs_info *fs_info,
109 struct btrfs_space_info *space_info,
110 u64 num_bytes);
112 static noinline int
113 block_group_cache_done(struct btrfs_block_group_cache *cache)
115 smp_mb();
116 return cache->cached == BTRFS_CACHE_FINISHED ||
117 cache->cached == BTRFS_CACHE_ERROR;
120 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
122 return (cache->flags & bits) == bits;
125 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
127 atomic_inc(&cache->count);
130 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
132 if (atomic_dec_and_test(&cache->count)) {
133 WARN_ON(cache->pinned > 0);
134 WARN_ON(cache->reserved > 0);
137 * If not empty, someone is still holding mutex of
138 * full_stripe_lock, which can only be released by caller.
139 * And it will definitely cause use-after-free when caller
140 * tries to release full stripe lock.
142 * No better way to resolve, but only to warn.
144 WARN_ON(!RB_EMPTY_ROOT(&cache->full_stripe_locks_root.root));
145 kfree(cache->free_space_ctl);
146 kfree(cache);
151 * this adds the block group to the fs_info rb tree for the block group
152 * cache
154 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
155 struct btrfs_block_group_cache *block_group)
157 struct rb_node **p;
158 struct rb_node *parent = NULL;
159 struct btrfs_block_group_cache *cache;
161 spin_lock(&info->block_group_cache_lock);
162 p = &info->block_group_cache_tree.rb_node;
164 while (*p) {
165 parent = *p;
166 cache = rb_entry(parent, struct btrfs_block_group_cache,
167 cache_node);
168 if (block_group->key.objectid < cache->key.objectid) {
169 p = &(*p)->rb_left;
170 } else if (block_group->key.objectid > cache->key.objectid) {
171 p = &(*p)->rb_right;
172 } else {
173 spin_unlock(&info->block_group_cache_lock);
174 return -EEXIST;
178 rb_link_node(&block_group->cache_node, parent, p);
179 rb_insert_color(&block_group->cache_node,
180 &info->block_group_cache_tree);
182 if (info->first_logical_byte > block_group->key.objectid)
183 info->first_logical_byte = block_group->key.objectid;
185 spin_unlock(&info->block_group_cache_lock);
187 return 0;
191 * This will return the block group at or after bytenr if contains is 0, else
192 * it will return the block group that contains the bytenr
194 static struct btrfs_block_group_cache *
195 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
196 int contains)
198 struct btrfs_block_group_cache *cache, *ret = NULL;
199 struct rb_node *n;
200 u64 end, start;
202 spin_lock(&info->block_group_cache_lock);
203 n = info->block_group_cache_tree.rb_node;
205 while (n) {
206 cache = rb_entry(n, struct btrfs_block_group_cache,
207 cache_node);
208 end = cache->key.objectid + cache->key.offset - 1;
209 start = cache->key.objectid;
211 if (bytenr < start) {
212 if (!contains && (!ret || start < ret->key.objectid))
213 ret = cache;
214 n = n->rb_left;
215 } else if (bytenr > start) {
216 if (contains && bytenr <= end) {
217 ret = cache;
218 break;
220 n = n->rb_right;
221 } else {
222 ret = cache;
223 break;
226 if (ret) {
227 btrfs_get_block_group(ret);
228 if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
229 info->first_logical_byte = ret->key.objectid;
231 spin_unlock(&info->block_group_cache_lock);
233 return ret;
236 static int add_excluded_extent(struct btrfs_fs_info *fs_info,
237 u64 start, u64 num_bytes)
239 u64 end = start + num_bytes - 1;
240 set_extent_bits(&fs_info->freed_extents[0],
241 start, end, EXTENT_UPTODATE);
242 set_extent_bits(&fs_info->freed_extents[1],
243 start, end, EXTENT_UPTODATE);
244 return 0;
247 static void free_excluded_extents(struct btrfs_fs_info *fs_info,
248 struct btrfs_block_group_cache *cache)
250 u64 start, end;
252 start = cache->key.objectid;
253 end = start + cache->key.offset - 1;
255 clear_extent_bits(&fs_info->freed_extents[0],
256 start, end, EXTENT_UPTODATE);
257 clear_extent_bits(&fs_info->freed_extents[1],
258 start, end, EXTENT_UPTODATE);
261 static int exclude_super_stripes(struct btrfs_fs_info *fs_info,
262 struct btrfs_block_group_cache *cache)
264 u64 bytenr;
265 u64 *logical;
266 int stripe_len;
267 int i, nr, ret;
269 if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
270 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
271 cache->bytes_super += stripe_len;
272 ret = add_excluded_extent(fs_info, cache->key.objectid,
273 stripe_len);
274 if (ret)
275 return ret;
278 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
279 bytenr = btrfs_sb_offset(i);
280 ret = btrfs_rmap_block(fs_info, cache->key.objectid,
281 bytenr, 0, &logical, &nr, &stripe_len);
282 if (ret)
283 return ret;
285 while (nr--) {
286 u64 start, len;
288 if (logical[nr] > cache->key.objectid +
289 cache->key.offset)
290 continue;
292 if (logical[nr] + stripe_len <= cache->key.objectid)
293 continue;
295 start = logical[nr];
296 if (start < cache->key.objectid) {
297 start = cache->key.objectid;
298 len = (logical[nr] + stripe_len) - start;
299 } else {
300 len = min_t(u64, stripe_len,
301 cache->key.objectid +
302 cache->key.offset - start);
305 cache->bytes_super += len;
306 ret = add_excluded_extent(fs_info, start, len);
307 if (ret) {
308 kfree(logical);
309 return ret;
313 kfree(logical);
315 return 0;
318 static struct btrfs_caching_control *
319 get_caching_control(struct btrfs_block_group_cache *cache)
321 struct btrfs_caching_control *ctl;
323 spin_lock(&cache->lock);
324 if (!cache->caching_ctl) {
325 spin_unlock(&cache->lock);
326 return NULL;
329 ctl = cache->caching_ctl;
330 refcount_inc(&ctl->count);
331 spin_unlock(&cache->lock);
332 return ctl;
335 static void put_caching_control(struct btrfs_caching_control *ctl)
337 if (refcount_dec_and_test(&ctl->count))
338 kfree(ctl);
341 #ifdef CONFIG_BTRFS_DEBUG
342 static void fragment_free_space(struct btrfs_block_group_cache *block_group)
344 struct btrfs_fs_info *fs_info = block_group->fs_info;
345 u64 start = block_group->key.objectid;
346 u64 len = block_group->key.offset;
347 u64 chunk = block_group->flags & BTRFS_BLOCK_GROUP_METADATA ?
348 fs_info->nodesize : fs_info->sectorsize;
349 u64 step = chunk << 1;
351 while (len > chunk) {
352 btrfs_remove_free_space(block_group, start, chunk);
353 start += step;
354 if (len < step)
355 len = 0;
356 else
357 len -= step;
360 #endif
363 * this is only called by cache_block_group, since we could have freed extents
364 * we need to check the pinned_extents for any extents that can't be used yet
365 * since their free space will be released as soon as the transaction commits.
367 u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
368 struct btrfs_fs_info *info, u64 start, u64 end)
370 u64 extent_start, extent_end, size, total_added = 0;
371 int ret;
373 while (start < end) {
374 ret = find_first_extent_bit(info->pinned_extents, start,
375 &extent_start, &extent_end,
376 EXTENT_DIRTY | EXTENT_UPTODATE,
377 NULL);
378 if (ret)
379 break;
381 if (extent_start <= start) {
382 start = extent_end + 1;
383 } else if (extent_start > start && extent_start < end) {
384 size = extent_start - start;
385 total_added += size;
386 ret = btrfs_add_free_space(block_group, start,
387 size);
388 BUG_ON(ret); /* -ENOMEM or logic error */
389 start = extent_end + 1;
390 } else {
391 break;
395 if (start < end) {
396 size = end - start;
397 total_added += size;
398 ret = btrfs_add_free_space(block_group, start, size);
399 BUG_ON(ret); /* -ENOMEM or logic error */
402 return total_added;
405 static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)
407 struct btrfs_block_group_cache *block_group = caching_ctl->block_group;
408 struct btrfs_fs_info *fs_info = block_group->fs_info;
409 struct btrfs_root *extent_root = fs_info->extent_root;
410 struct btrfs_path *path;
411 struct extent_buffer *leaf;
412 struct btrfs_key key;
413 u64 total_found = 0;
414 u64 last = 0;
415 u32 nritems;
416 int ret;
417 bool wakeup = true;
419 path = btrfs_alloc_path();
420 if (!path)
421 return -ENOMEM;
423 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
425 #ifdef CONFIG_BTRFS_DEBUG
427 * If we're fragmenting we don't want to make anybody think we can
428 * allocate from this block group until we've had a chance to fragment
429 * the free space.
431 if (btrfs_should_fragment_free_space(block_group))
432 wakeup = false;
433 #endif
435 * We don't want to deadlock with somebody trying to allocate a new
436 * extent for the extent root while also trying to search the extent
437 * root to add free space. So we skip locking and search the commit
438 * root, since its read-only
440 path->skip_locking = 1;
441 path->search_commit_root = 1;
442 path->reada = READA_FORWARD;
444 key.objectid = last;
445 key.offset = 0;
446 key.type = BTRFS_EXTENT_ITEM_KEY;
448 next:
449 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
450 if (ret < 0)
451 goto out;
453 leaf = path->nodes[0];
454 nritems = btrfs_header_nritems(leaf);
456 while (1) {
457 if (btrfs_fs_closing(fs_info) > 1) {
458 last = (u64)-1;
459 break;
462 if (path->slots[0] < nritems) {
463 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
464 } else {
465 ret = find_next_key(path, 0, &key);
466 if (ret)
467 break;
469 if (need_resched() ||
470 rwsem_is_contended(&fs_info->commit_root_sem)) {
471 if (wakeup)
472 caching_ctl->progress = last;
473 btrfs_release_path(path);
474 up_read(&fs_info->commit_root_sem);
475 mutex_unlock(&caching_ctl->mutex);
476 cond_resched();
477 mutex_lock(&caching_ctl->mutex);
478 down_read(&fs_info->commit_root_sem);
479 goto next;
482 ret = btrfs_next_leaf(extent_root, path);
483 if (ret < 0)
484 goto out;
485 if (ret)
486 break;
487 leaf = path->nodes[0];
488 nritems = btrfs_header_nritems(leaf);
489 continue;
492 if (key.objectid < last) {
493 key.objectid = last;
494 key.offset = 0;
495 key.type = BTRFS_EXTENT_ITEM_KEY;
497 if (wakeup)
498 caching_ctl->progress = last;
499 btrfs_release_path(path);
500 goto next;
503 if (key.objectid < block_group->key.objectid) {
504 path->slots[0]++;
505 continue;
508 if (key.objectid >= block_group->key.objectid +
509 block_group->key.offset)
510 break;
512 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
513 key.type == BTRFS_METADATA_ITEM_KEY) {
514 total_found += add_new_free_space(block_group,
515 fs_info, last,
516 key.objectid);
517 if (key.type == BTRFS_METADATA_ITEM_KEY)
518 last = key.objectid +
519 fs_info->nodesize;
520 else
521 last = key.objectid + key.offset;
523 if (total_found > CACHING_CTL_WAKE_UP) {
524 total_found = 0;
525 if (wakeup)
526 wake_up(&caching_ctl->wait);
529 path->slots[0]++;
531 ret = 0;
533 total_found += add_new_free_space(block_group, fs_info, last,
534 block_group->key.objectid +
535 block_group->key.offset);
536 caching_ctl->progress = (u64)-1;
538 out:
539 btrfs_free_path(path);
540 return ret;
543 static noinline void caching_thread(struct btrfs_work *work)
545 struct btrfs_block_group_cache *block_group;
546 struct btrfs_fs_info *fs_info;
547 struct btrfs_caching_control *caching_ctl;
548 struct btrfs_root *extent_root;
549 int ret;
551 caching_ctl = container_of(work, struct btrfs_caching_control, work);
552 block_group = caching_ctl->block_group;
553 fs_info = block_group->fs_info;
554 extent_root = fs_info->extent_root;
556 mutex_lock(&caching_ctl->mutex);
557 down_read(&fs_info->commit_root_sem);
559 if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
560 ret = load_free_space_tree(caching_ctl);
561 else
562 ret = load_extent_tree_free(caching_ctl);
564 spin_lock(&block_group->lock);
565 block_group->caching_ctl = NULL;
566 block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED;
567 spin_unlock(&block_group->lock);
569 #ifdef CONFIG_BTRFS_DEBUG
570 if (btrfs_should_fragment_free_space(block_group)) {
571 u64 bytes_used;
573 spin_lock(&block_group->space_info->lock);
574 spin_lock(&block_group->lock);
575 bytes_used = block_group->key.offset -
576 btrfs_block_group_used(&block_group->item);
577 block_group->space_info->bytes_used += bytes_used >> 1;
578 spin_unlock(&block_group->lock);
579 spin_unlock(&block_group->space_info->lock);
580 fragment_free_space(block_group);
582 #endif
584 caching_ctl->progress = (u64)-1;
586 up_read(&fs_info->commit_root_sem);
587 free_excluded_extents(fs_info, block_group);
588 mutex_unlock(&caching_ctl->mutex);
590 wake_up(&caching_ctl->wait);
592 put_caching_control(caching_ctl);
593 btrfs_put_block_group(block_group);
596 static int cache_block_group(struct btrfs_block_group_cache *cache,
597 int load_cache_only)
599 DEFINE_WAIT(wait);
600 struct btrfs_fs_info *fs_info = cache->fs_info;
601 struct btrfs_caching_control *caching_ctl;
602 int ret = 0;
604 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
605 if (!caching_ctl)
606 return -ENOMEM;
608 INIT_LIST_HEAD(&caching_ctl->list);
609 mutex_init(&caching_ctl->mutex);
610 init_waitqueue_head(&caching_ctl->wait);
611 caching_ctl->block_group = cache;
612 caching_ctl->progress = cache->key.objectid;
613 refcount_set(&caching_ctl->count, 1);
614 btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
615 caching_thread, NULL, NULL);
617 spin_lock(&cache->lock);
619 * This should be a rare occasion, but this could happen I think in the
620 * case where one thread starts to load the space cache info, and then
621 * some other thread starts a transaction commit which tries to do an
622 * allocation while the other thread is still loading the space cache
623 * info. The previous loop should have kept us from choosing this block
624 * group, but if we've moved to the state where we will wait on caching
625 * block groups we need to first check if we're doing a fast load here,
626 * so we can wait for it to finish, otherwise we could end up allocating
627 * from a block group who's cache gets evicted for one reason or
628 * another.
630 while (cache->cached == BTRFS_CACHE_FAST) {
631 struct btrfs_caching_control *ctl;
633 ctl = cache->caching_ctl;
634 refcount_inc(&ctl->count);
635 prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
636 spin_unlock(&cache->lock);
638 schedule();
640 finish_wait(&ctl->wait, &wait);
641 put_caching_control(ctl);
642 spin_lock(&cache->lock);
645 if (cache->cached != BTRFS_CACHE_NO) {
646 spin_unlock(&cache->lock);
647 kfree(caching_ctl);
648 return 0;
650 WARN_ON(cache->caching_ctl);
651 cache->caching_ctl = caching_ctl;
652 cache->cached = BTRFS_CACHE_FAST;
653 spin_unlock(&cache->lock);
655 if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) {
656 mutex_lock(&caching_ctl->mutex);
657 ret = load_free_space_cache(fs_info, cache);
659 spin_lock(&cache->lock);
660 if (ret == 1) {
661 cache->caching_ctl = NULL;
662 cache->cached = BTRFS_CACHE_FINISHED;
663 cache->last_byte_to_unpin = (u64)-1;
664 caching_ctl->progress = (u64)-1;
665 } else {
666 if (load_cache_only) {
667 cache->caching_ctl = NULL;
668 cache->cached = BTRFS_CACHE_NO;
669 } else {
670 cache->cached = BTRFS_CACHE_STARTED;
671 cache->has_caching_ctl = 1;
674 spin_unlock(&cache->lock);
675 #ifdef CONFIG_BTRFS_DEBUG
676 if (ret == 1 &&
677 btrfs_should_fragment_free_space(cache)) {
678 u64 bytes_used;
680 spin_lock(&cache->space_info->lock);
681 spin_lock(&cache->lock);
682 bytes_used = cache->key.offset -
683 btrfs_block_group_used(&cache->item);
684 cache->space_info->bytes_used += bytes_used >> 1;
685 spin_unlock(&cache->lock);
686 spin_unlock(&cache->space_info->lock);
687 fragment_free_space(cache);
689 #endif
690 mutex_unlock(&caching_ctl->mutex);
692 wake_up(&caching_ctl->wait);
693 if (ret == 1) {
694 put_caching_control(caching_ctl);
695 free_excluded_extents(fs_info, cache);
696 return 0;
698 } else {
700 * We're either using the free space tree or no caching at all.
701 * Set cached to the appropriate value and wakeup any waiters.
703 spin_lock(&cache->lock);
704 if (load_cache_only) {
705 cache->caching_ctl = NULL;
706 cache->cached = BTRFS_CACHE_NO;
707 } else {
708 cache->cached = BTRFS_CACHE_STARTED;
709 cache->has_caching_ctl = 1;
711 spin_unlock(&cache->lock);
712 wake_up(&caching_ctl->wait);
715 if (load_cache_only) {
716 put_caching_control(caching_ctl);
717 return 0;
720 down_write(&fs_info->commit_root_sem);
721 refcount_inc(&caching_ctl->count);
722 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
723 up_write(&fs_info->commit_root_sem);
725 btrfs_get_block_group(cache);
727 btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
729 return ret;
733 * return the block group that starts at or after bytenr
735 static struct btrfs_block_group_cache *
736 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
738 return block_group_cache_tree_search(info, bytenr, 0);
742 * return the block group that contains the given bytenr
744 struct btrfs_block_group_cache *btrfs_lookup_block_group(
745 struct btrfs_fs_info *info,
746 u64 bytenr)
748 return block_group_cache_tree_search(info, bytenr, 1);
751 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
752 u64 flags)
754 struct list_head *head = &info->space_info;
755 struct btrfs_space_info *found;
757 flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
759 rcu_read_lock();
760 list_for_each_entry_rcu(found, head, list) {
761 if (found->flags & flags) {
762 rcu_read_unlock();
763 return found;
766 rcu_read_unlock();
767 return NULL;
770 static void add_pinned_bytes(struct btrfs_fs_info *fs_info, s64 num_bytes,
771 u64 owner, u64 root_objectid)
773 struct btrfs_space_info *space_info;
774 u64 flags;
776 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
777 if (root_objectid == BTRFS_CHUNK_TREE_OBJECTID)
778 flags = BTRFS_BLOCK_GROUP_SYSTEM;
779 else
780 flags = BTRFS_BLOCK_GROUP_METADATA;
781 } else {
782 flags = BTRFS_BLOCK_GROUP_DATA;
785 space_info = __find_space_info(fs_info, flags);
786 ASSERT(space_info);
787 percpu_counter_add(&space_info->total_bytes_pinned, num_bytes);
791 * after adding space to the filesystem, we need to clear the full flags
792 * on all the space infos.
794 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
796 struct list_head *head = &info->space_info;
797 struct btrfs_space_info *found;
799 rcu_read_lock();
800 list_for_each_entry_rcu(found, head, list)
801 found->full = 0;
802 rcu_read_unlock();
805 /* simple helper to search for an existing data extent at a given offset */
806 int btrfs_lookup_data_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len)
808 int ret;
809 struct btrfs_key key;
810 struct btrfs_path *path;
812 path = btrfs_alloc_path();
813 if (!path)
814 return -ENOMEM;
816 key.objectid = start;
817 key.offset = len;
818 key.type = BTRFS_EXTENT_ITEM_KEY;
819 ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
820 btrfs_free_path(path);
821 return ret;
825 * helper function to lookup reference count and flags of a tree block.
827 * the head node for delayed ref is used to store the sum of all the
828 * reference count modifications queued up in the rbtree. the head
829 * node may also store the extent flags to set. This way you can check
830 * to see what the reference count and extent flags would be if all of
831 * the delayed refs are not processed.
833 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
834 struct btrfs_fs_info *fs_info, u64 bytenr,
835 u64 offset, int metadata, u64 *refs, u64 *flags)
837 struct btrfs_delayed_ref_head *head;
838 struct btrfs_delayed_ref_root *delayed_refs;
839 struct btrfs_path *path;
840 struct btrfs_extent_item *ei;
841 struct extent_buffer *leaf;
842 struct btrfs_key key;
843 u32 item_size;
844 u64 num_refs;
845 u64 extent_flags;
846 int ret;
849 * If we don't have skinny metadata, don't bother doing anything
850 * different
852 if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA)) {
853 offset = fs_info->nodesize;
854 metadata = 0;
857 path = btrfs_alloc_path();
858 if (!path)
859 return -ENOMEM;
861 if (!trans) {
862 path->skip_locking = 1;
863 path->search_commit_root = 1;
866 search_again:
867 key.objectid = bytenr;
868 key.offset = offset;
869 if (metadata)
870 key.type = BTRFS_METADATA_ITEM_KEY;
871 else
872 key.type = BTRFS_EXTENT_ITEM_KEY;
874 ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);
875 if (ret < 0)
876 goto out_free;
878 if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
879 if (path->slots[0]) {
880 path->slots[0]--;
881 btrfs_item_key_to_cpu(path->nodes[0], &key,
882 path->slots[0]);
883 if (key.objectid == bytenr &&
884 key.type == BTRFS_EXTENT_ITEM_KEY &&
885 key.offset == fs_info->nodesize)
886 ret = 0;
890 if (ret == 0) {
891 leaf = path->nodes[0];
892 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
893 if (item_size >= sizeof(*ei)) {
894 ei = btrfs_item_ptr(leaf, path->slots[0],
895 struct btrfs_extent_item);
896 num_refs = btrfs_extent_refs(leaf, ei);
897 extent_flags = btrfs_extent_flags(leaf, ei);
898 } else {
899 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
900 struct btrfs_extent_item_v0 *ei0;
901 BUG_ON(item_size != sizeof(*ei0));
902 ei0 = btrfs_item_ptr(leaf, path->slots[0],
903 struct btrfs_extent_item_v0);
904 num_refs = btrfs_extent_refs_v0(leaf, ei0);
905 /* FIXME: this isn't correct for data */
906 extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
907 #else
908 BUG();
909 #endif
911 BUG_ON(num_refs == 0);
912 } else {
913 num_refs = 0;
914 extent_flags = 0;
915 ret = 0;
918 if (!trans)
919 goto out;
921 delayed_refs = &trans->transaction->delayed_refs;
922 spin_lock(&delayed_refs->lock);
923 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
924 if (head) {
925 if (!mutex_trylock(&head->mutex)) {
926 refcount_inc(&head->node.refs);
927 spin_unlock(&delayed_refs->lock);
929 btrfs_release_path(path);
932 * Mutex was contended, block until it's released and try
933 * again
935 mutex_lock(&head->mutex);
936 mutex_unlock(&head->mutex);
937 btrfs_put_delayed_ref(&head->node);
938 goto search_again;
940 spin_lock(&head->lock);
941 if (head->extent_op && head->extent_op->update_flags)
942 extent_flags |= head->extent_op->flags_to_set;
943 else
944 BUG_ON(num_refs == 0);
946 num_refs += head->node.ref_mod;
947 spin_unlock(&head->lock);
948 mutex_unlock(&head->mutex);
950 spin_unlock(&delayed_refs->lock);
951 out:
952 WARN_ON(num_refs == 0);
953 if (refs)
954 *refs = num_refs;
955 if (flags)
956 *flags = extent_flags;
957 out_free:
958 btrfs_free_path(path);
959 return ret;
963 * Back reference rules. Back refs have three main goals:
965 * 1) differentiate between all holders of references to an extent so that
966 * when a reference is dropped we can make sure it was a valid reference
967 * before freeing the extent.
969 * 2) Provide enough information to quickly find the holders of an extent
970 * if we notice a given block is corrupted or bad.
972 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
973 * maintenance. This is actually the same as #2, but with a slightly
974 * different use case.
976 * There are two kinds of back refs. The implicit back refs is optimized
977 * for pointers in non-shared tree blocks. For a given pointer in a block,
978 * back refs of this kind provide information about the block's owner tree
979 * and the pointer's key. These information allow us to find the block by
980 * b-tree searching. The full back refs is for pointers in tree blocks not
981 * referenced by their owner trees. The location of tree block is recorded
982 * in the back refs. Actually the full back refs is generic, and can be
983 * used in all cases the implicit back refs is used. The major shortcoming
984 * of the full back refs is its overhead. Every time a tree block gets
985 * COWed, we have to update back refs entry for all pointers in it.
987 * For a newly allocated tree block, we use implicit back refs for
988 * pointers in it. This means most tree related operations only involve
989 * implicit back refs. For a tree block created in old transaction, the
990 * only way to drop a reference to it is COW it. So we can detect the
991 * event that tree block loses its owner tree's reference and do the
992 * back refs conversion.
994 * When a tree block is COWed through a tree, there are four cases:
996 * The reference count of the block is one and the tree is the block's
997 * owner tree. Nothing to do in this case.
999 * The reference count of the block is one and the tree is not the
1000 * block's owner tree. In this case, full back refs is used for pointers
1001 * in the block. Remove these full back refs, add implicit back refs for
1002 * every pointers in the new block.
1004 * The reference count of the block is greater than one and the tree is
1005 * the block's owner tree. In this case, implicit back refs is used for
1006 * pointers in the block. Add full back refs for every pointers in the
1007 * block, increase lower level extents' reference counts. The original
1008 * implicit back refs are entailed to the new block.
1010 * The reference count of the block is greater than one and the tree is
1011 * not the block's owner tree. Add implicit back refs for every pointer in
1012 * the new block, increase lower level extents' reference count.
1014 * Back Reference Key composing:
1016 * The key objectid corresponds to the first byte in the extent,
1017 * The key type is used to differentiate between types of back refs.
1018 * There are different meanings of the key offset for different types
1019 * of back refs.
1021 * File extents can be referenced by:
1023 * - multiple snapshots, subvolumes, or different generations in one subvol
1024 * - different files inside a single subvolume
1025 * - different offsets inside a file (bookend extents in file.c)
1027 * The extent ref structure for the implicit back refs has fields for:
1029 * - Objectid of the subvolume root
1030 * - objectid of the file holding the reference
1031 * - original offset in the file
1032 * - how many bookend extents
1034 * The key offset for the implicit back refs is hash of the first
1035 * three fields.
1037 * The extent ref structure for the full back refs has field for:
1039 * - number of pointers in the tree leaf
1041 * The key offset for the implicit back refs is the first byte of
1042 * the tree leaf
1044 * When a file extent is allocated, The implicit back refs is used.
1045 * the fields are filled in:
1047 * (root_key.objectid, inode objectid, offset in file, 1)
1049 * When a file extent is removed file truncation, we find the
1050 * corresponding implicit back refs and check the following fields:
1052 * (btrfs_header_owner(leaf), inode objectid, offset in file)
1054 * Btree extents can be referenced by:
1056 * - Different subvolumes
1058 * Both the implicit back refs and the full back refs for tree blocks
1059 * only consist of key. The key offset for the implicit back refs is
1060 * objectid of block's owner tree. The key offset for the full back refs
1061 * is the first byte of parent block.
1063 * When implicit back refs is used, information about the lowest key and
1064 * level of the tree block are required. These information are stored in
1065 * tree block info structure.
1068 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1069 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
1070 struct btrfs_fs_info *fs_info,
1071 struct btrfs_path *path,
1072 u64 owner, u32 extra_size)
1074 struct btrfs_root *root = fs_info->extent_root;
1075 struct btrfs_extent_item *item;
1076 struct btrfs_extent_item_v0 *ei0;
1077 struct btrfs_extent_ref_v0 *ref0;
1078 struct btrfs_tree_block_info *bi;
1079 struct extent_buffer *leaf;
1080 struct btrfs_key key;
1081 struct btrfs_key found_key;
1082 u32 new_size = sizeof(*item);
1083 u64 refs;
1084 int ret;
1086 leaf = path->nodes[0];
1087 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
1089 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1090 ei0 = btrfs_item_ptr(leaf, path->slots[0],
1091 struct btrfs_extent_item_v0);
1092 refs = btrfs_extent_refs_v0(leaf, ei0);
1094 if (owner == (u64)-1) {
1095 while (1) {
1096 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1097 ret = btrfs_next_leaf(root, path);
1098 if (ret < 0)
1099 return ret;
1100 BUG_ON(ret > 0); /* Corruption */
1101 leaf = path->nodes[0];
1103 btrfs_item_key_to_cpu(leaf, &found_key,
1104 path->slots[0]);
1105 BUG_ON(key.objectid != found_key.objectid);
1106 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
1107 path->slots[0]++;
1108 continue;
1110 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1111 struct btrfs_extent_ref_v0);
1112 owner = btrfs_ref_objectid_v0(leaf, ref0);
1113 break;
1116 btrfs_release_path(path);
1118 if (owner < BTRFS_FIRST_FREE_OBJECTID)
1119 new_size += sizeof(*bi);
1121 new_size -= sizeof(*ei0);
1122 ret = btrfs_search_slot(trans, root, &key, path,
1123 new_size + extra_size, 1);
1124 if (ret < 0)
1125 return ret;
1126 BUG_ON(ret); /* Corruption */
1128 btrfs_extend_item(fs_info, path, new_size);
1130 leaf = path->nodes[0];
1131 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1132 btrfs_set_extent_refs(leaf, item, refs);
1133 /* FIXME: get real generation */
1134 btrfs_set_extent_generation(leaf, item, 0);
1135 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1136 btrfs_set_extent_flags(leaf, item,
1137 BTRFS_EXTENT_FLAG_TREE_BLOCK |
1138 BTRFS_BLOCK_FLAG_FULL_BACKREF);
1139 bi = (struct btrfs_tree_block_info *)(item + 1);
1140 /* FIXME: get first key of the block */
1141 memzero_extent_buffer(leaf, (unsigned long)bi, sizeof(*bi));
1142 btrfs_set_tree_block_level(leaf, bi, (int)owner);
1143 } else {
1144 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
1146 btrfs_mark_buffer_dirty(leaf);
1147 return 0;
1149 #endif
1152 * is_data == BTRFS_REF_TYPE_BLOCK, tree block type is required,
1153 * is_data == BTRFS_REF_TYPE_DATA, data type is requried,
1154 * is_data == BTRFS_REF_TYPE_ANY, either type is OK.
1156 int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
1157 struct btrfs_extent_inline_ref *iref,
1158 enum btrfs_inline_ref_type is_data)
1160 int type = btrfs_extent_inline_ref_type(eb, iref);
1161 u64 offset = btrfs_extent_inline_ref_offset(eb, iref);
1163 if (type == BTRFS_TREE_BLOCK_REF_KEY ||
1164 type == BTRFS_SHARED_BLOCK_REF_KEY ||
1165 type == BTRFS_SHARED_DATA_REF_KEY ||
1166 type == BTRFS_EXTENT_DATA_REF_KEY) {
1167 if (is_data == BTRFS_REF_TYPE_BLOCK) {
1168 if (type == BTRFS_TREE_BLOCK_REF_KEY)
1169 return type;
1170 if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1171 ASSERT(eb->fs_info);
1173 * Every shared one has parent tree block,
1174 * which must be aligned to sector size.
1176 if (offset &&
1177 IS_ALIGNED(offset, eb->fs_info->sectorsize))
1178 return type;
1180 } else if (is_data == BTRFS_REF_TYPE_DATA) {
1181 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1182 return type;
1183 if (type == BTRFS_SHARED_DATA_REF_KEY) {
1184 ASSERT(eb->fs_info);
1186 * Every shared one has parent tree block,
1187 * which must be aligned to sector size.
1189 if (offset &&
1190 IS_ALIGNED(offset, eb->fs_info->sectorsize))
1191 return type;
1193 } else {
1194 ASSERT(is_data == BTRFS_REF_TYPE_ANY);
1195 return type;
1199 btrfs_print_leaf((struct extent_buffer *)eb);
1200 btrfs_err(eb->fs_info,
1201 "eb %llu iref 0x%lx invalid extent inline ref type %d",
1202 eb->start, (unsigned long)iref, type);
1203 WARN_ON(1);
1205 return BTRFS_REF_TYPE_INVALID;
1208 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
1210 u32 high_crc = ~(u32)0;
1211 u32 low_crc = ~(u32)0;
1212 __le64 lenum;
1214 lenum = cpu_to_le64(root_objectid);
1215 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
1216 lenum = cpu_to_le64(owner);
1217 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
1218 lenum = cpu_to_le64(offset);
1219 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
1221 return ((u64)high_crc << 31) ^ (u64)low_crc;
1224 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
1225 struct btrfs_extent_data_ref *ref)
1227 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
1228 btrfs_extent_data_ref_objectid(leaf, ref),
1229 btrfs_extent_data_ref_offset(leaf, ref));
1232 static int match_extent_data_ref(struct extent_buffer *leaf,
1233 struct btrfs_extent_data_ref *ref,
1234 u64 root_objectid, u64 owner, u64 offset)
1236 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
1237 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
1238 btrfs_extent_data_ref_offset(leaf, ref) != offset)
1239 return 0;
1240 return 1;
1243 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
1244 struct btrfs_fs_info *fs_info,
1245 struct btrfs_path *path,
1246 u64 bytenr, u64 parent,
1247 u64 root_objectid,
1248 u64 owner, u64 offset)
1250 struct btrfs_root *root = fs_info->extent_root;
1251 struct btrfs_key key;
1252 struct btrfs_extent_data_ref *ref;
1253 struct extent_buffer *leaf;
1254 u32 nritems;
1255 int ret;
1256 int recow;
1257 int err = -ENOENT;
1259 key.objectid = bytenr;
1260 if (parent) {
1261 key.type = BTRFS_SHARED_DATA_REF_KEY;
1262 key.offset = parent;
1263 } else {
1264 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1265 key.offset = hash_extent_data_ref(root_objectid,
1266 owner, offset);
1268 again:
1269 recow = 0;
1270 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1271 if (ret < 0) {
1272 err = ret;
1273 goto fail;
1276 if (parent) {
1277 if (!ret)
1278 return 0;
1279 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1280 key.type = BTRFS_EXTENT_REF_V0_KEY;
1281 btrfs_release_path(path);
1282 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1283 if (ret < 0) {
1284 err = ret;
1285 goto fail;
1287 if (!ret)
1288 return 0;
1289 #endif
1290 goto fail;
1293 leaf = path->nodes[0];
1294 nritems = btrfs_header_nritems(leaf);
1295 while (1) {
1296 if (path->slots[0] >= nritems) {
1297 ret = btrfs_next_leaf(root, path);
1298 if (ret < 0)
1299 err = ret;
1300 if (ret)
1301 goto fail;
1303 leaf = path->nodes[0];
1304 nritems = btrfs_header_nritems(leaf);
1305 recow = 1;
1308 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1309 if (key.objectid != bytenr ||
1310 key.type != BTRFS_EXTENT_DATA_REF_KEY)
1311 goto fail;
1313 ref = btrfs_item_ptr(leaf, path->slots[0],
1314 struct btrfs_extent_data_ref);
1316 if (match_extent_data_ref(leaf, ref, root_objectid,
1317 owner, offset)) {
1318 if (recow) {
1319 btrfs_release_path(path);
1320 goto again;
1322 err = 0;
1323 break;
1325 path->slots[0]++;
1327 fail:
1328 return err;
1331 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
1332 struct btrfs_fs_info *fs_info,
1333 struct btrfs_path *path,
1334 u64 bytenr, u64 parent,
1335 u64 root_objectid, u64 owner,
1336 u64 offset, int refs_to_add)
1338 struct btrfs_root *root = fs_info->extent_root;
1339 struct btrfs_key key;
1340 struct extent_buffer *leaf;
1341 u32 size;
1342 u32 num_refs;
1343 int ret;
1345 key.objectid = bytenr;
1346 if (parent) {
1347 key.type = BTRFS_SHARED_DATA_REF_KEY;
1348 key.offset = parent;
1349 size = sizeof(struct btrfs_shared_data_ref);
1350 } else {
1351 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1352 key.offset = hash_extent_data_ref(root_objectid,
1353 owner, offset);
1354 size = sizeof(struct btrfs_extent_data_ref);
1357 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
1358 if (ret && ret != -EEXIST)
1359 goto fail;
1361 leaf = path->nodes[0];
1362 if (parent) {
1363 struct btrfs_shared_data_ref *ref;
1364 ref = btrfs_item_ptr(leaf, path->slots[0],
1365 struct btrfs_shared_data_ref);
1366 if (ret == 0) {
1367 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
1368 } else {
1369 num_refs = btrfs_shared_data_ref_count(leaf, ref);
1370 num_refs += refs_to_add;
1371 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
1373 } else {
1374 struct btrfs_extent_data_ref *ref;
1375 while (ret == -EEXIST) {
1376 ref = btrfs_item_ptr(leaf, path->slots[0],
1377 struct btrfs_extent_data_ref);
1378 if (match_extent_data_ref(leaf, ref, root_objectid,
1379 owner, offset))
1380 break;
1381 btrfs_release_path(path);
1382 key.offset++;
1383 ret = btrfs_insert_empty_item(trans, root, path, &key,
1384 size);
1385 if (ret && ret != -EEXIST)
1386 goto fail;
1388 leaf = path->nodes[0];
1390 ref = btrfs_item_ptr(leaf, path->slots[0],
1391 struct btrfs_extent_data_ref);
1392 if (ret == 0) {
1393 btrfs_set_extent_data_ref_root(leaf, ref,
1394 root_objectid);
1395 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
1396 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
1397 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
1398 } else {
1399 num_refs = btrfs_extent_data_ref_count(leaf, ref);
1400 num_refs += refs_to_add;
1401 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
1404 btrfs_mark_buffer_dirty(leaf);
1405 ret = 0;
1406 fail:
1407 btrfs_release_path(path);
1408 return ret;
1411 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
1412 struct btrfs_fs_info *fs_info,
1413 struct btrfs_path *path,
1414 int refs_to_drop, int *last_ref)
1416 struct btrfs_key key;
1417 struct btrfs_extent_data_ref *ref1 = NULL;
1418 struct btrfs_shared_data_ref *ref2 = NULL;
1419 struct extent_buffer *leaf;
1420 u32 num_refs = 0;
1421 int ret = 0;
1423 leaf = path->nodes[0];
1424 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1426 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1427 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1428 struct btrfs_extent_data_ref);
1429 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1430 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1431 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1432 struct btrfs_shared_data_ref);
1433 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1434 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1435 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1436 struct btrfs_extent_ref_v0 *ref0;
1437 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1438 struct btrfs_extent_ref_v0);
1439 num_refs = btrfs_ref_count_v0(leaf, ref0);
1440 #endif
1441 } else {
1442 BUG();
1445 BUG_ON(num_refs < refs_to_drop);
1446 num_refs -= refs_to_drop;
1448 if (num_refs == 0) {
1449 ret = btrfs_del_item(trans, fs_info->extent_root, path);
1450 *last_ref = 1;
1451 } else {
1452 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
1453 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
1454 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
1455 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
1456 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1457 else {
1458 struct btrfs_extent_ref_v0 *ref0;
1459 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1460 struct btrfs_extent_ref_v0);
1461 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
1463 #endif
1464 btrfs_mark_buffer_dirty(leaf);
1466 return ret;
1469 static noinline u32 extent_data_ref_count(struct btrfs_path *path,
1470 struct btrfs_extent_inline_ref *iref)
1472 struct btrfs_key key;
1473 struct extent_buffer *leaf;
1474 struct btrfs_extent_data_ref *ref1;
1475 struct btrfs_shared_data_ref *ref2;
1476 u32 num_refs = 0;
1477 int type;
1479 leaf = path->nodes[0];
1480 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1481 if (iref) {
1483 * If type is invalid, we should have bailed out earlier than
1484 * this call.
1486 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA);
1487 ASSERT(type != BTRFS_REF_TYPE_INVALID);
1488 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1489 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
1490 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1491 } else {
1492 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
1493 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1495 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1496 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1497 struct btrfs_extent_data_ref);
1498 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1499 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1500 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1501 struct btrfs_shared_data_ref);
1502 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1503 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1504 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1505 struct btrfs_extent_ref_v0 *ref0;
1506 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1507 struct btrfs_extent_ref_v0);
1508 num_refs = btrfs_ref_count_v0(leaf, ref0);
1509 #endif
1510 } else {
1511 WARN_ON(1);
1513 return num_refs;
1516 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
1517 struct btrfs_fs_info *fs_info,
1518 struct btrfs_path *path,
1519 u64 bytenr, u64 parent,
1520 u64 root_objectid)
1522 struct btrfs_root *root = fs_info->extent_root;
1523 struct btrfs_key key;
1524 int ret;
1526 key.objectid = bytenr;
1527 if (parent) {
1528 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1529 key.offset = parent;
1530 } else {
1531 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1532 key.offset = root_objectid;
1535 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1536 if (ret > 0)
1537 ret = -ENOENT;
1538 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1539 if (ret == -ENOENT && parent) {
1540 btrfs_release_path(path);
1541 key.type = BTRFS_EXTENT_REF_V0_KEY;
1542 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1543 if (ret > 0)
1544 ret = -ENOENT;
1546 #endif
1547 return ret;
1550 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
1551 struct btrfs_fs_info *fs_info,
1552 struct btrfs_path *path,
1553 u64 bytenr, u64 parent,
1554 u64 root_objectid)
1556 struct btrfs_key key;
1557 int ret;
1559 key.objectid = bytenr;
1560 if (parent) {
1561 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1562 key.offset = parent;
1563 } else {
1564 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1565 key.offset = root_objectid;
1568 ret = btrfs_insert_empty_item(trans, fs_info->extent_root,
1569 path, &key, 0);
1570 btrfs_release_path(path);
1571 return ret;
1574 static inline int extent_ref_type(u64 parent, u64 owner)
1576 int type;
1577 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1578 if (parent > 0)
1579 type = BTRFS_SHARED_BLOCK_REF_KEY;
1580 else
1581 type = BTRFS_TREE_BLOCK_REF_KEY;
1582 } else {
1583 if (parent > 0)
1584 type = BTRFS_SHARED_DATA_REF_KEY;
1585 else
1586 type = BTRFS_EXTENT_DATA_REF_KEY;
1588 return type;
1591 static int find_next_key(struct btrfs_path *path, int level,
1592 struct btrfs_key *key)
1595 for (; level < BTRFS_MAX_LEVEL; level++) {
1596 if (!path->nodes[level])
1597 break;
1598 if (path->slots[level] + 1 >=
1599 btrfs_header_nritems(path->nodes[level]))
1600 continue;
1601 if (level == 0)
1602 btrfs_item_key_to_cpu(path->nodes[level], key,
1603 path->slots[level] + 1);
1604 else
1605 btrfs_node_key_to_cpu(path->nodes[level], key,
1606 path->slots[level] + 1);
1607 return 0;
1609 return 1;
1613 * look for inline back ref. if back ref is found, *ref_ret is set
1614 * to the address of inline back ref, and 0 is returned.
1616 * if back ref isn't found, *ref_ret is set to the address where it
1617 * should be inserted, and -ENOENT is returned.
1619 * if insert is true and there are too many inline back refs, the path
1620 * points to the extent item, and -EAGAIN is returned.
1622 * NOTE: inline back refs are ordered in the same way that back ref
1623 * items in the tree are ordered.
1625 static noinline_for_stack
1626 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1627 struct btrfs_fs_info *fs_info,
1628 struct btrfs_path *path,
1629 struct btrfs_extent_inline_ref **ref_ret,
1630 u64 bytenr, u64 num_bytes,
1631 u64 parent, u64 root_objectid,
1632 u64 owner, u64 offset, int insert)
1634 struct btrfs_root *root = fs_info->extent_root;
1635 struct btrfs_key key;
1636 struct extent_buffer *leaf;
1637 struct btrfs_extent_item *ei;
1638 struct btrfs_extent_inline_ref *iref;
1639 u64 flags;
1640 u64 item_size;
1641 unsigned long ptr;
1642 unsigned long end;
1643 int extra_size;
1644 int type;
1645 int want;
1646 int ret;
1647 int err = 0;
1648 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
1649 int needed;
1651 key.objectid = bytenr;
1652 key.type = BTRFS_EXTENT_ITEM_KEY;
1653 key.offset = num_bytes;
1655 want = extent_ref_type(parent, owner);
1656 if (insert) {
1657 extra_size = btrfs_extent_inline_ref_size(want);
1658 path->keep_locks = 1;
1659 } else
1660 extra_size = -1;
1663 * Owner is our parent level, so we can just add one to get the level
1664 * for the block we are interested in.
1666 if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) {
1667 key.type = BTRFS_METADATA_ITEM_KEY;
1668 key.offset = owner;
1671 again:
1672 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1673 if (ret < 0) {
1674 err = ret;
1675 goto out;
1679 * We may be a newly converted file system which still has the old fat
1680 * extent entries for metadata, so try and see if we have one of those.
1682 if (ret > 0 && skinny_metadata) {
1683 skinny_metadata = false;
1684 if (path->slots[0]) {
1685 path->slots[0]--;
1686 btrfs_item_key_to_cpu(path->nodes[0], &key,
1687 path->slots[0]);
1688 if (key.objectid == bytenr &&
1689 key.type == BTRFS_EXTENT_ITEM_KEY &&
1690 key.offset == num_bytes)
1691 ret = 0;
1693 if (ret) {
1694 key.objectid = bytenr;
1695 key.type = BTRFS_EXTENT_ITEM_KEY;
1696 key.offset = num_bytes;
1697 btrfs_release_path(path);
1698 goto again;
1702 if (ret && !insert) {
1703 err = -ENOENT;
1704 goto out;
1705 } else if (WARN_ON(ret)) {
1706 err = -EIO;
1707 goto out;
1710 leaf = path->nodes[0];
1711 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1712 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1713 if (item_size < sizeof(*ei)) {
1714 if (!insert) {
1715 err = -ENOENT;
1716 goto out;
1718 ret = convert_extent_item_v0(trans, fs_info, path, owner,
1719 extra_size);
1720 if (ret < 0) {
1721 err = ret;
1722 goto out;
1724 leaf = path->nodes[0];
1725 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1727 #endif
1728 BUG_ON(item_size < sizeof(*ei));
1730 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1731 flags = btrfs_extent_flags(leaf, ei);
1733 ptr = (unsigned long)(ei + 1);
1734 end = (unsigned long)ei + item_size;
1736 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
1737 ptr += sizeof(struct btrfs_tree_block_info);
1738 BUG_ON(ptr > end);
1741 if (owner >= BTRFS_FIRST_FREE_OBJECTID)
1742 needed = BTRFS_REF_TYPE_DATA;
1743 else
1744 needed = BTRFS_REF_TYPE_BLOCK;
1746 err = -ENOENT;
1747 while (1) {
1748 if (ptr >= end) {
1749 WARN_ON(ptr > end);
1750 break;
1752 iref = (struct btrfs_extent_inline_ref *)ptr;
1753 type = btrfs_get_extent_inline_ref_type(leaf, iref, needed);
1754 if (type == BTRFS_REF_TYPE_INVALID) {
1755 err = -EINVAL;
1756 goto out;
1759 if (want < type)
1760 break;
1761 if (want > type) {
1762 ptr += btrfs_extent_inline_ref_size(type);
1763 continue;
1766 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1767 struct btrfs_extent_data_ref *dref;
1768 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1769 if (match_extent_data_ref(leaf, dref, root_objectid,
1770 owner, offset)) {
1771 err = 0;
1772 break;
1774 if (hash_extent_data_ref_item(leaf, dref) <
1775 hash_extent_data_ref(root_objectid, owner, offset))
1776 break;
1777 } else {
1778 u64 ref_offset;
1779 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1780 if (parent > 0) {
1781 if (parent == ref_offset) {
1782 err = 0;
1783 break;
1785 if (ref_offset < parent)
1786 break;
1787 } else {
1788 if (root_objectid == ref_offset) {
1789 err = 0;
1790 break;
1792 if (ref_offset < root_objectid)
1793 break;
1796 ptr += btrfs_extent_inline_ref_size(type);
1798 if (err == -ENOENT && insert) {
1799 if (item_size + extra_size >=
1800 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1801 err = -EAGAIN;
1802 goto out;
1805 * To add new inline back ref, we have to make sure
1806 * there is no corresponding back ref item.
1807 * For simplicity, we just do not add new inline back
1808 * ref if there is any kind of item for this block
1810 if (find_next_key(path, 0, &key) == 0 &&
1811 key.objectid == bytenr &&
1812 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1813 err = -EAGAIN;
1814 goto out;
1817 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1818 out:
1819 if (insert) {
1820 path->keep_locks = 0;
1821 btrfs_unlock_up_safe(path, 1);
1823 return err;
1827 * helper to add new inline back ref
1829 static noinline_for_stack
1830 void setup_inline_extent_backref(struct btrfs_fs_info *fs_info,
1831 struct btrfs_path *path,
1832 struct btrfs_extent_inline_ref *iref,
1833 u64 parent, u64 root_objectid,
1834 u64 owner, u64 offset, int refs_to_add,
1835 struct btrfs_delayed_extent_op *extent_op)
1837 struct extent_buffer *leaf;
1838 struct btrfs_extent_item *ei;
1839 unsigned long ptr;
1840 unsigned long end;
1841 unsigned long item_offset;
1842 u64 refs;
1843 int size;
1844 int type;
1846 leaf = path->nodes[0];
1847 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1848 item_offset = (unsigned long)iref - (unsigned long)ei;
1850 type = extent_ref_type(parent, owner);
1851 size = btrfs_extent_inline_ref_size(type);
1853 btrfs_extend_item(fs_info, path, size);
1855 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1856 refs = btrfs_extent_refs(leaf, ei);
1857 refs += refs_to_add;
1858 btrfs_set_extent_refs(leaf, ei, refs);
1859 if (extent_op)
1860 __run_delayed_extent_op(extent_op, leaf, ei);
1862 ptr = (unsigned long)ei + item_offset;
1863 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1864 if (ptr < end - size)
1865 memmove_extent_buffer(leaf, ptr + size, ptr,
1866 end - size - ptr);
1868 iref = (struct btrfs_extent_inline_ref *)ptr;
1869 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1870 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1871 struct btrfs_extent_data_ref *dref;
1872 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1873 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1874 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1875 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1876 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1877 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1878 struct btrfs_shared_data_ref *sref;
1879 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1880 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1881 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1882 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1883 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1884 } else {
1885 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1887 btrfs_mark_buffer_dirty(leaf);
1890 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1891 struct btrfs_fs_info *fs_info,
1892 struct btrfs_path *path,
1893 struct btrfs_extent_inline_ref **ref_ret,
1894 u64 bytenr, u64 num_bytes, u64 parent,
1895 u64 root_objectid, u64 owner, u64 offset)
1897 int ret;
1899 ret = lookup_inline_extent_backref(trans, fs_info, path, ref_ret,
1900 bytenr, num_bytes, parent,
1901 root_objectid, owner, offset, 0);
1902 if (ret != -ENOENT)
1903 return ret;
1905 btrfs_release_path(path);
1906 *ref_ret = NULL;
1908 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1909 ret = lookup_tree_block_ref(trans, fs_info, path, bytenr,
1910 parent, root_objectid);
1911 } else {
1912 ret = lookup_extent_data_ref(trans, fs_info, path, bytenr,
1913 parent, root_objectid, owner,
1914 offset);
1916 return ret;
1920 * helper to update/remove inline back ref
1922 static noinline_for_stack
1923 void update_inline_extent_backref(struct btrfs_fs_info *fs_info,
1924 struct btrfs_path *path,
1925 struct btrfs_extent_inline_ref *iref,
1926 int refs_to_mod,
1927 struct btrfs_delayed_extent_op *extent_op,
1928 int *last_ref)
1930 struct extent_buffer *leaf;
1931 struct btrfs_extent_item *ei;
1932 struct btrfs_extent_data_ref *dref = NULL;
1933 struct btrfs_shared_data_ref *sref = NULL;
1934 unsigned long ptr;
1935 unsigned long end;
1936 u32 item_size;
1937 int size;
1938 int type;
1939 u64 refs;
1941 leaf = path->nodes[0];
1942 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1943 refs = btrfs_extent_refs(leaf, ei);
1944 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1945 refs += refs_to_mod;
1946 btrfs_set_extent_refs(leaf, ei, refs);
1947 if (extent_op)
1948 __run_delayed_extent_op(extent_op, leaf, ei);
1951 * If type is invalid, we should have bailed out after
1952 * lookup_inline_extent_backref().
1954 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_ANY);
1955 ASSERT(type != BTRFS_REF_TYPE_INVALID);
1957 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1958 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1959 refs = btrfs_extent_data_ref_count(leaf, dref);
1960 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1961 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1962 refs = btrfs_shared_data_ref_count(leaf, sref);
1963 } else {
1964 refs = 1;
1965 BUG_ON(refs_to_mod != -1);
1968 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1969 refs += refs_to_mod;
1971 if (refs > 0) {
1972 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1973 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1974 else
1975 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1976 } else {
1977 *last_ref = 1;
1978 size = btrfs_extent_inline_ref_size(type);
1979 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1980 ptr = (unsigned long)iref;
1981 end = (unsigned long)ei + item_size;
1982 if (ptr + size < end)
1983 memmove_extent_buffer(leaf, ptr, ptr + size,
1984 end - ptr - size);
1985 item_size -= size;
1986 btrfs_truncate_item(fs_info, path, item_size, 1);
1988 btrfs_mark_buffer_dirty(leaf);
1991 static noinline_for_stack
1992 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1993 struct btrfs_fs_info *fs_info,
1994 struct btrfs_path *path,
1995 u64 bytenr, u64 num_bytes, u64 parent,
1996 u64 root_objectid, u64 owner,
1997 u64 offset, int refs_to_add,
1998 struct btrfs_delayed_extent_op *extent_op)
2000 struct btrfs_extent_inline_ref *iref;
2001 int ret;
2003 ret = lookup_inline_extent_backref(trans, fs_info, path, &iref,
2004 bytenr, num_bytes, parent,
2005 root_objectid, owner, offset, 1);
2006 if (ret == 0) {
2007 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
2008 update_inline_extent_backref(fs_info, path, iref,
2009 refs_to_add, extent_op, NULL);
2010 } else if (ret == -ENOENT) {
2011 setup_inline_extent_backref(fs_info, path, iref, parent,
2012 root_objectid, owner, offset,
2013 refs_to_add, extent_op);
2014 ret = 0;
2016 return ret;
2019 static int insert_extent_backref(struct btrfs_trans_handle *trans,
2020 struct btrfs_fs_info *fs_info,
2021 struct btrfs_path *path,
2022 u64 bytenr, u64 parent, u64 root_objectid,
2023 u64 owner, u64 offset, int refs_to_add)
2025 int ret;
2026 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
2027 BUG_ON(refs_to_add != 1);
2028 ret = insert_tree_block_ref(trans, fs_info, path, bytenr,
2029 parent, root_objectid);
2030 } else {
2031 ret = insert_extent_data_ref(trans, fs_info, path, bytenr,
2032 parent, root_objectid,
2033 owner, offset, refs_to_add);
2035 return ret;
2038 static int remove_extent_backref(struct btrfs_trans_handle *trans,
2039 struct btrfs_fs_info *fs_info,
2040 struct btrfs_path *path,
2041 struct btrfs_extent_inline_ref *iref,
2042 int refs_to_drop, int is_data, int *last_ref)
2044 int ret = 0;
2046 BUG_ON(!is_data && refs_to_drop != 1);
2047 if (iref) {
2048 update_inline_extent_backref(fs_info, path, iref,
2049 -refs_to_drop, NULL, last_ref);
2050 } else if (is_data) {
2051 ret = remove_extent_data_ref(trans, fs_info, path, refs_to_drop,
2052 last_ref);
2053 } else {
2054 *last_ref = 1;
2055 ret = btrfs_del_item(trans, fs_info->extent_root, path);
2057 return ret;
2060 #define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
2061 static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len,
2062 u64 *discarded_bytes)
2064 int j, ret = 0;
2065 u64 bytes_left, end;
2066 u64 aligned_start = ALIGN(start, 1 << 9);
2068 if (WARN_ON(start != aligned_start)) {
2069 len -= aligned_start - start;
2070 len = round_down(len, 1 << 9);
2071 start = aligned_start;
2074 *discarded_bytes = 0;
2076 if (!len)
2077 return 0;
2079 end = start + len;
2080 bytes_left = len;
2082 /* Skip any superblocks on this device. */
2083 for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) {
2084 u64 sb_start = btrfs_sb_offset(j);
2085 u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE;
2086 u64 size = sb_start - start;
2088 if (!in_range(sb_start, start, bytes_left) &&
2089 !in_range(sb_end, start, bytes_left) &&
2090 !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE))
2091 continue;
2094 * Superblock spans beginning of range. Adjust start and
2095 * try again.
2097 if (sb_start <= start) {
2098 start += sb_end - start;
2099 if (start > end) {
2100 bytes_left = 0;
2101 break;
2103 bytes_left = end - start;
2104 continue;
2107 if (size) {
2108 ret = blkdev_issue_discard(bdev, start >> 9, size >> 9,
2109 GFP_NOFS, 0);
2110 if (!ret)
2111 *discarded_bytes += size;
2112 else if (ret != -EOPNOTSUPP)
2113 return ret;
2116 start = sb_end;
2117 if (start > end) {
2118 bytes_left = 0;
2119 break;
2121 bytes_left = end - start;
2124 if (bytes_left) {
2125 ret = blkdev_issue_discard(bdev, start >> 9, bytes_left >> 9,
2126 GFP_NOFS, 0);
2127 if (!ret)
2128 *discarded_bytes += bytes_left;
2130 return ret;
2133 int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
2134 u64 num_bytes, u64 *actual_bytes)
2136 int ret;
2137 u64 discarded_bytes = 0;
2138 struct btrfs_bio *bbio = NULL;
2142 * Avoid races with device replace and make sure our bbio has devices
2143 * associated to its stripes that don't go away while we are discarding.
2145 btrfs_bio_counter_inc_blocked(fs_info);
2146 /* Tell the block device(s) that the sectors can be discarded */
2147 ret = btrfs_map_block(fs_info, BTRFS_MAP_DISCARD, bytenr, &num_bytes,
2148 &bbio, 0);
2149 /* Error condition is -ENOMEM */
2150 if (!ret) {
2151 struct btrfs_bio_stripe *stripe = bbio->stripes;
2152 int i;
2155 for (i = 0; i < bbio->num_stripes; i++, stripe++) {
2156 u64 bytes;
2157 if (!stripe->dev->can_discard)
2158 continue;
2160 ret = btrfs_issue_discard(stripe->dev->bdev,
2161 stripe->physical,
2162 stripe->length,
2163 &bytes);
2164 if (!ret)
2165 discarded_bytes += bytes;
2166 else if (ret != -EOPNOTSUPP)
2167 break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */
2170 * Just in case we get back EOPNOTSUPP for some reason,
2171 * just ignore the return value so we don't screw up
2172 * people calling discard_extent.
2174 ret = 0;
2176 btrfs_put_bbio(bbio);
2178 btrfs_bio_counter_dec(fs_info);
2180 if (actual_bytes)
2181 *actual_bytes = discarded_bytes;
2184 if (ret == -EOPNOTSUPP)
2185 ret = 0;
2186 return ret;
2189 /* Can return -ENOMEM */
2190 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
2191 struct btrfs_fs_info *fs_info,
2192 u64 bytenr, u64 num_bytes, u64 parent,
2193 u64 root_objectid, u64 owner, u64 offset)
2195 int old_ref_mod, new_ref_mod;
2196 int ret;
2198 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
2199 root_objectid == BTRFS_TREE_LOG_OBJECTID);
2201 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
2202 ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
2203 num_bytes, parent,
2204 root_objectid, (int)owner,
2205 BTRFS_ADD_DELAYED_REF, NULL,
2206 &old_ref_mod, &new_ref_mod);
2207 } else {
2208 ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
2209 num_bytes, parent,
2210 root_objectid, owner, offset,
2211 0, BTRFS_ADD_DELAYED_REF,
2212 &old_ref_mod, &new_ref_mod);
2215 if (ret == 0 && old_ref_mod < 0 && new_ref_mod >= 0)
2216 add_pinned_bytes(fs_info, -num_bytes, owner, root_objectid);
2218 return ret;
2221 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
2222 struct btrfs_fs_info *fs_info,
2223 struct btrfs_delayed_ref_node *node,
2224 u64 parent, u64 root_objectid,
2225 u64 owner, u64 offset, int refs_to_add,
2226 struct btrfs_delayed_extent_op *extent_op)
2228 struct btrfs_path *path;
2229 struct extent_buffer *leaf;
2230 struct btrfs_extent_item *item;
2231 struct btrfs_key key;
2232 u64 bytenr = node->bytenr;
2233 u64 num_bytes = node->num_bytes;
2234 u64 refs;
2235 int ret;
2237 path = btrfs_alloc_path();
2238 if (!path)
2239 return -ENOMEM;
2241 path->reada = READA_FORWARD;
2242 path->leave_spinning = 1;
2243 /* this will setup the path even if it fails to insert the back ref */
2244 ret = insert_inline_extent_backref(trans, fs_info, path, bytenr,
2245 num_bytes, parent, root_objectid,
2246 owner, offset,
2247 refs_to_add, extent_op);
2248 if ((ret < 0 && ret != -EAGAIN) || !ret)
2249 goto out;
2252 * Ok we had -EAGAIN which means we didn't have space to insert and
2253 * inline extent ref, so just update the reference count and add a
2254 * normal backref.
2256 leaf = path->nodes[0];
2257 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2258 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2259 refs = btrfs_extent_refs(leaf, item);
2260 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
2261 if (extent_op)
2262 __run_delayed_extent_op(extent_op, leaf, item);
2264 btrfs_mark_buffer_dirty(leaf);
2265 btrfs_release_path(path);
2267 path->reada = READA_FORWARD;
2268 path->leave_spinning = 1;
2269 /* now insert the actual backref */
2270 ret = insert_extent_backref(trans, fs_info, path, bytenr, parent,
2271 root_objectid, owner, offset, refs_to_add);
2272 if (ret)
2273 btrfs_abort_transaction(trans, ret);
2274 out:
2275 btrfs_free_path(path);
2276 return ret;
2279 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
2280 struct btrfs_fs_info *fs_info,
2281 struct btrfs_delayed_ref_node *node,
2282 struct btrfs_delayed_extent_op *extent_op,
2283 int insert_reserved)
2285 int ret = 0;
2286 struct btrfs_delayed_data_ref *ref;
2287 struct btrfs_key ins;
2288 u64 parent = 0;
2289 u64 ref_root = 0;
2290 u64 flags = 0;
2292 ins.objectid = node->bytenr;
2293 ins.offset = node->num_bytes;
2294 ins.type = BTRFS_EXTENT_ITEM_KEY;
2296 ref = btrfs_delayed_node_to_data_ref(node);
2297 trace_run_delayed_data_ref(fs_info, node, ref, node->action);
2299 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
2300 parent = ref->parent;
2301 ref_root = ref->root;
2303 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2304 if (extent_op)
2305 flags |= extent_op->flags_to_set;
2306 ret = alloc_reserved_file_extent(trans, fs_info,
2307 parent, ref_root, flags,
2308 ref->objectid, ref->offset,
2309 &ins, node->ref_mod);
2310 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2311 ret = __btrfs_inc_extent_ref(trans, fs_info, node, parent,
2312 ref_root, ref->objectid,
2313 ref->offset, node->ref_mod,
2314 extent_op);
2315 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2316 ret = __btrfs_free_extent(trans, fs_info, node, parent,
2317 ref_root, ref->objectid,
2318 ref->offset, node->ref_mod,
2319 extent_op);
2320 } else {
2321 BUG();
2323 return ret;
2326 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
2327 struct extent_buffer *leaf,
2328 struct btrfs_extent_item *ei)
2330 u64 flags = btrfs_extent_flags(leaf, ei);
2331 if (extent_op->update_flags) {
2332 flags |= extent_op->flags_to_set;
2333 btrfs_set_extent_flags(leaf, ei, flags);
2336 if (extent_op->update_key) {
2337 struct btrfs_tree_block_info *bi;
2338 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
2339 bi = (struct btrfs_tree_block_info *)(ei + 1);
2340 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
2344 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
2345 struct btrfs_fs_info *fs_info,
2346 struct btrfs_delayed_ref_node *node,
2347 struct btrfs_delayed_extent_op *extent_op)
2349 struct btrfs_key key;
2350 struct btrfs_path *path;
2351 struct btrfs_extent_item *ei;
2352 struct extent_buffer *leaf;
2353 u32 item_size;
2354 int ret;
2355 int err = 0;
2356 int metadata = !extent_op->is_data;
2358 if (trans->aborted)
2359 return 0;
2361 if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2362 metadata = 0;
2364 path = btrfs_alloc_path();
2365 if (!path)
2366 return -ENOMEM;
2368 key.objectid = node->bytenr;
2370 if (metadata) {
2371 key.type = BTRFS_METADATA_ITEM_KEY;
2372 key.offset = extent_op->level;
2373 } else {
2374 key.type = BTRFS_EXTENT_ITEM_KEY;
2375 key.offset = node->num_bytes;
2378 again:
2379 path->reada = READA_FORWARD;
2380 path->leave_spinning = 1;
2381 ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 1);
2382 if (ret < 0) {
2383 err = ret;
2384 goto out;
2386 if (ret > 0) {
2387 if (metadata) {
2388 if (path->slots[0] > 0) {
2389 path->slots[0]--;
2390 btrfs_item_key_to_cpu(path->nodes[0], &key,
2391 path->slots[0]);
2392 if (key.objectid == node->bytenr &&
2393 key.type == BTRFS_EXTENT_ITEM_KEY &&
2394 key.offset == node->num_bytes)
2395 ret = 0;
2397 if (ret > 0) {
2398 btrfs_release_path(path);
2399 metadata = 0;
2401 key.objectid = node->bytenr;
2402 key.offset = node->num_bytes;
2403 key.type = BTRFS_EXTENT_ITEM_KEY;
2404 goto again;
2406 } else {
2407 err = -EIO;
2408 goto out;
2412 leaf = path->nodes[0];
2413 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2414 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2415 if (item_size < sizeof(*ei)) {
2416 ret = convert_extent_item_v0(trans, fs_info, path, (u64)-1, 0);
2417 if (ret < 0) {
2418 err = ret;
2419 goto out;
2421 leaf = path->nodes[0];
2422 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2424 #endif
2425 BUG_ON(item_size < sizeof(*ei));
2426 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2427 __run_delayed_extent_op(extent_op, leaf, ei);
2429 btrfs_mark_buffer_dirty(leaf);
2430 out:
2431 btrfs_free_path(path);
2432 return err;
2435 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
2436 struct btrfs_fs_info *fs_info,
2437 struct btrfs_delayed_ref_node *node,
2438 struct btrfs_delayed_extent_op *extent_op,
2439 int insert_reserved)
2441 int ret = 0;
2442 struct btrfs_delayed_tree_ref *ref;
2443 struct btrfs_key ins;
2444 u64 parent = 0;
2445 u64 ref_root = 0;
2446 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
2448 ref = btrfs_delayed_node_to_tree_ref(node);
2449 trace_run_delayed_tree_ref(fs_info, node, ref, node->action);
2451 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2452 parent = ref->parent;
2453 ref_root = ref->root;
2455 ins.objectid = node->bytenr;
2456 if (skinny_metadata) {
2457 ins.offset = ref->level;
2458 ins.type = BTRFS_METADATA_ITEM_KEY;
2459 } else {
2460 ins.offset = node->num_bytes;
2461 ins.type = BTRFS_EXTENT_ITEM_KEY;
2464 if (node->ref_mod != 1) {
2465 btrfs_err(fs_info,
2466 "btree block(%llu) has %d references rather than 1: action %d ref_root %llu parent %llu",
2467 node->bytenr, node->ref_mod, node->action, ref_root,
2468 parent);
2469 return -EIO;
2471 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2472 BUG_ON(!extent_op || !extent_op->update_flags);
2473 ret = alloc_reserved_tree_block(trans, fs_info,
2474 parent, ref_root,
2475 extent_op->flags_to_set,
2476 &extent_op->key,
2477 ref->level, &ins);
2478 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2479 ret = __btrfs_inc_extent_ref(trans, fs_info, node,
2480 parent, ref_root,
2481 ref->level, 0, 1,
2482 extent_op);
2483 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2484 ret = __btrfs_free_extent(trans, fs_info, node,
2485 parent, ref_root,
2486 ref->level, 0, 1, extent_op);
2487 } else {
2488 BUG();
2490 return ret;
2493 /* helper function to actually process a single delayed ref entry */
2494 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
2495 struct btrfs_fs_info *fs_info,
2496 struct btrfs_delayed_ref_node *node,
2497 struct btrfs_delayed_extent_op *extent_op,
2498 int insert_reserved)
2500 int ret = 0;
2502 if (trans->aborted) {
2503 if (insert_reserved)
2504 btrfs_pin_extent(fs_info, node->bytenr,
2505 node->num_bytes, 1);
2506 return 0;
2509 if (btrfs_delayed_ref_is_head(node)) {
2510 struct btrfs_delayed_ref_head *head;
2512 * we've hit the end of the chain and we were supposed
2513 * to insert this extent into the tree. But, it got
2514 * deleted before we ever needed to insert it, so all
2515 * we have to do is clean up the accounting
2517 BUG_ON(extent_op);
2518 head = btrfs_delayed_node_to_head(node);
2519 trace_run_delayed_ref_head(fs_info, node, head, node->action);
2521 if (head->total_ref_mod < 0) {
2522 struct btrfs_block_group_cache *cache;
2524 cache = btrfs_lookup_block_group(fs_info, node->bytenr);
2525 ASSERT(cache);
2526 percpu_counter_add(&cache->space_info->total_bytes_pinned,
2527 -node->num_bytes);
2528 btrfs_put_block_group(cache);
2531 if (insert_reserved) {
2532 btrfs_pin_extent(fs_info, node->bytenr,
2533 node->num_bytes, 1);
2534 if (head->is_data) {
2535 ret = btrfs_del_csums(trans, fs_info,
2536 node->bytenr,
2537 node->num_bytes);
2541 /* Also free its reserved qgroup space */
2542 btrfs_qgroup_free_delayed_ref(fs_info, head->qgroup_ref_root,
2543 head->qgroup_reserved);
2544 return ret;
2547 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
2548 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2549 ret = run_delayed_tree_ref(trans, fs_info, node, extent_op,
2550 insert_reserved);
2551 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
2552 node->type == BTRFS_SHARED_DATA_REF_KEY)
2553 ret = run_delayed_data_ref(trans, fs_info, node, extent_op,
2554 insert_reserved);
2555 else
2556 BUG();
2557 return ret;
2560 static inline struct btrfs_delayed_ref_node *
2561 select_delayed_ref(struct btrfs_delayed_ref_head *head)
2563 struct btrfs_delayed_ref_node *ref;
2565 if (list_empty(&head->ref_list))
2566 return NULL;
2569 * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first.
2570 * This is to prevent a ref count from going down to zero, which deletes
2571 * the extent item from the extent tree, when there still are references
2572 * to add, which would fail because they would not find the extent item.
2574 if (!list_empty(&head->ref_add_list))
2575 return list_first_entry(&head->ref_add_list,
2576 struct btrfs_delayed_ref_node, add_list);
2578 ref = list_first_entry(&head->ref_list, struct btrfs_delayed_ref_node,
2579 list);
2580 ASSERT(list_empty(&ref->add_list));
2581 return ref;
2585 * Returns 0 on success or if called with an already aborted transaction.
2586 * Returns -ENOMEM or -EIO on failure and will abort the transaction.
2588 static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2589 struct btrfs_fs_info *fs_info,
2590 unsigned long nr)
2592 struct btrfs_delayed_ref_root *delayed_refs;
2593 struct btrfs_delayed_ref_node *ref;
2594 struct btrfs_delayed_ref_head *locked_ref = NULL;
2595 struct btrfs_delayed_extent_op *extent_op;
2596 ktime_t start = ktime_get();
2597 int ret;
2598 unsigned long count = 0;
2599 unsigned long actual_count = 0;
2600 int must_insert_reserved = 0;
2602 delayed_refs = &trans->transaction->delayed_refs;
2603 while (1) {
2604 if (!locked_ref) {
2605 if (count >= nr)
2606 break;
2608 spin_lock(&delayed_refs->lock);
2609 locked_ref = btrfs_select_ref_head(trans);
2610 if (!locked_ref) {
2611 spin_unlock(&delayed_refs->lock);
2612 break;
2615 /* grab the lock that says we are going to process
2616 * all the refs for this head */
2617 ret = btrfs_delayed_ref_lock(trans, locked_ref);
2618 spin_unlock(&delayed_refs->lock);
2620 * we may have dropped the spin lock to get the head
2621 * mutex lock, and that might have given someone else
2622 * time to free the head. If that's true, it has been
2623 * removed from our list and we can move on.
2625 if (ret == -EAGAIN) {
2626 locked_ref = NULL;
2627 count++;
2628 continue;
2633 * We need to try and merge add/drops of the same ref since we
2634 * can run into issues with relocate dropping the implicit ref
2635 * and then it being added back again before the drop can
2636 * finish. If we merged anything we need to re-loop so we can
2637 * get a good ref.
2638 * Or we can get node references of the same type that weren't
2639 * merged when created due to bumps in the tree mod seq, and
2640 * we need to merge them to prevent adding an inline extent
2641 * backref before dropping it (triggering a BUG_ON at
2642 * insert_inline_extent_backref()).
2644 spin_lock(&locked_ref->lock);
2645 btrfs_merge_delayed_refs(trans, fs_info, delayed_refs,
2646 locked_ref);
2649 * locked_ref is the head node, so we have to go one
2650 * node back for any delayed ref updates
2652 ref = select_delayed_ref(locked_ref);
2654 if (ref && ref->seq &&
2655 btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) {
2656 spin_unlock(&locked_ref->lock);
2657 spin_lock(&delayed_refs->lock);
2658 locked_ref->processing = 0;
2659 delayed_refs->num_heads_ready++;
2660 spin_unlock(&delayed_refs->lock);
2661 btrfs_delayed_ref_unlock(locked_ref);
2662 locked_ref = NULL;
2663 cond_resched();
2664 count++;
2665 continue;
2669 * record the must insert reserved flag before we
2670 * drop the spin lock.
2672 must_insert_reserved = locked_ref->must_insert_reserved;
2673 locked_ref->must_insert_reserved = 0;
2675 extent_op = locked_ref->extent_op;
2676 locked_ref->extent_op = NULL;
2678 if (!ref) {
2681 /* All delayed refs have been processed, Go ahead
2682 * and send the head node to run_one_delayed_ref,
2683 * so that any accounting fixes can happen
2685 ref = &locked_ref->node;
2687 if (extent_op && must_insert_reserved) {
2688 btrfs_free_delayed_extent_op(extent_op);
2689 extent_op = NULL;
2692 if (extent_op) {
2693 spin_unlock(&locked_ref->lock);
2694 ret = run_delayed_extent_op(trans, fs_info,
2695 ref, extent_op);
2696 btrfs_free_delayed_extent_op(extent_op);
2698 if (ret) {
2700 * Need to reset must_insert_reserved if
2701 * there was an error so the abort stuff
2702 * can cleanup the reserved space
2703 * properly.
2705 if (must_insert_reserved)
2706 locked_ref->must_insert_reserved = 1;
2707 spin_lock(&delayed_refs->lock);
2708 locked_ref->processing = 0;
2709 delayed_refs->num_heads_ready++;
2710 spin_unlock(&delayed_refs->lock);
2711 btrfs_debug(fs_info,
2712 "run_delayed_extent_op returned %d",
2713 ret);
2714 btrfs_delayed_ref_unlock(locked_ref);
2715 return ret;
2717 continue;
2721 * Need to drop our head ref lock and re-acquire the
2722 * delayed ref lock and then re-check to make sure
2723 * nobody got added.
2725 spin_unlock(&locked_ref->lock);
2726 spin_lock(&delayed_refs->lock);
2727 spin_lock(&locked_ref->lock);
2728 if (!list_empty(&locked_ref->ref_list) ||
2729 locked_ref->extent_op) {
2730 spin_unlock(&locked_ref->lock);
2731 spin_unlock(&delayed_refs->lock);
2732 continue;
2734 ref->in_tree = 0;
2735 delayed_refs->num_heads--;
2736 rb_erase(&locked_ref->href_node,
2737 &delayed_refs->href_root);
2738 spin_unlock(&delayed_refs->lock);
2739 } else {
2740 actual_count++;
2741 ref->in_tree = 0;
2742 list_del(&ref->list);
2743 if (!list_empty(&ref->add_list))
2744 list_del(&ref->add_list);
2746 atomic_dec(&delayed_refs->num_entries);
2748 if (!btrfs_delayed_ref_is_head(ref)) {
2750 * when we play the delayed ref, also correct the
2751 * ref_mod on head
2753 switch (ref->action) {
2754 case BTRFS_ADD_DELAYED_REF:
2755 case BTRFS_ADD_DELAYED_EXTENT:
2756 locked_ref->node.ref_mod -= ref->ref_mod;
2757 break;
2758 case BTRFS_DROP_DELAYED_REF:
2759 locked_ref->node.ref_mod += ref->ref_mod;
2760 break;
2761 default:
2762 WARN_ON(1);
2765 spin_unlock(&locked_ref->lock);
2767 ret = run_one_delayed_ref(trans, fs_info, ref, extent_op,
2768 must_insert_reserved);
2770 btrfs_free_delayed_extent_op(extent_op);
2771 if (ret) {
2772 spin_lock(&delayed_refs->lock);
2773 locked_ref->processing = 0;
2774 delayed_refs->num_heads_ready++;
2775 spin_unlock(&delayed_refs->lock);
2776 btrfs_delayed_ref_unlock(locked_ref);
2777 btrfs_put_delayed_ref(ref);
2778 btrfs_debug(fs_info, "run_one_delayed_ref returned %d",
2779 ret);
2780 return ret;
2784 * If this node is a head, that means all the refs in this head
2785 * have been dealt with, and we will pick the next head to deal
2786 * with, so we must unlock the head and drop it from the cluster
2787 * list before we release it.
2789 if (btrfs_delayed_ref_is_head(ref)) {
2790 if (locked_ref->is_data &&
2791 locked_ref->total_ref_mod < 0) {
2792 spin_lock(&delayed_refs->lock);
2793 delayed_refs->pending_csums -= ref->num_bytes;
2794 spin_unlock(&delayed_refs->lock);
2796 btrfs_delayed_ref_unlock(locked_ref);
2797 locked_ref = NULL;
2799 btrfs_put_delayed_ref(ref);
2800 count++;
2801 cond_resched();
2805 * We don't want to include ref heads since we can have empty ref heads
2806 * and those will drastically skew our runtime down since we just do
2807 * accounting, no actual extent tree updates.
2809 if (actual_count > 0) {
2810 u64 runtime = ktime_to_ns(ktime_sub(ktime_get(), start));
2811 u64 avg;
2814 * We weigh the current average higher than our current runtime
2815 * to avoid large swings in the average.
2817 spin_lock(&delayed_refs->lock);
2818 avg = fs_info->avg_delayed_ref_runtime * 3 + runtime;
2819 fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */
2820 spin_unlock(&delayed_refs->lock);
2822 return 0;
2825 #ifdef SCRAMBLE_DELAYED_REFS
2827 * Normally delayed refs get processed in ascending bytenr order. This
2828 * correlates in most cases to the order added. To expose dependencies on this
2829 * order, we start to process the tree in the middle instead of the beginning
2831 static u64 find_middle(struct rb_root *root)
2833 struct rb_node *n = root->rb_node;
2834 struct btrfs_delayed_ref_node *entry;
2835 int alt = 1;
2836 u64 middle;
2837 u64 first = 0, last = 0;
2839 n = rb_first(root);
2840 if (n) {
2841 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2842 first = entry->bytenr;
2844 n = rb_last(root);
2845 if (n) {
2846 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2847 last = entry->bytenr;
2849 n = root->rb_node;
2851 while (n) {
2852 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2853 WARN_ON(!entry->in_tree);
2855 middle = entry->bytenr;
2857 if (alt)
2858 n = n->rb_left;
2859 else
2860 n = n->rb_right;
2862 alt = 1 - alt;
2864 return middle;
2866 #endif
2868 static inline u64 heads_to_leaves(struct btrfs_fs_info *fs_info, u64 heads)
2870 u64 num_bytes;
2872 num_bytes = heads * (sizeof(struct btrfs_extent_item) +
2873 sizeof(struct btrfs_extent_inline_ref));
2874 if (!btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2875 num_bytes += heads * sizeof(struct btrfs_tree_block_info);
2878 * We don't ever fill up leaves all the way so multiply by 2 just to be
2879 * closer to what we're really going to want to use.
2881 return div_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(fs_info));
2885 * Takes the number of bytes to be csumm'ed and figures out how many leaves it
2886 * would require to store the csums for that many bytes.
2888 u64 btrfs_csum_bytes_to_leaves(struct btrfs_fs_info *fs_info, u64 csum_bytes)
2890 u64 csum_size;
2891 u64 num_csums_per_leaf;
2892 u64 num_csums;
2894 csum_size = BTRFS_MAX_ITEM_SIZE(fs_info);
2895 num_csums_per_leaf = div64_u64(csum_size,
2896 (u64)btrfs_super_csum_size(fs_info->super_copy));
2897 num_csums = div64_u64(csum_bytes, fs_info->sectorsize);
2898 num_csums += num_csums_per_leaf - 1;
2899 num_csums = div64_u64(num_csums, num_csums_per_leaf);
2900 return num_csums;
2903 int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
2904 struct btrfs_fs_info *fs_info)
2906 struct btrfs_block_rsv *global_rsv;
2907 u64 num_heads = trans->transaction->delayed_refs.num_heads_ready;
2908 u64 csum_bytes = trans->transaction->delayed_refs.pending_csums;
2909 u64 num_dirty_bgs = trans->transaction->num_dirty_bgs;
2910 u64 num_bytes, num_dirty_bgs_bytes;
2911 int ret = 0;
2913 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
2914 num_heads = heads_to_leaves(fs_info, num_heads);
2915 if (num_heads > 1)
2916 num_bytes += (num_heads - 1) * fs_info->nodesize;
2917 num_bytes <<= 1;
2918 num_bytes += btrfs_csum_bytes_to_leaves(fs_info, csum_bytes) *
2919 fs_info->nodesize;
2920 num_dirty_bgs_bytes = btrfs_calc_trans_metadata_size(fs_info,
2921 num_dirty_bgs);
2922 global_rsv = &fs_info->global_block_rsv;
2925 * If we can't allocate any more chunks lets make sure we have _lots_ of
2926 * wiggle room since running delayed refs can create more delayed refs.
2928 if (global_rsv->space_info->full) {
2929 num_dirty_bgs_bytes <<= 1;
2930 num_bytes <<= 1;
2933 spin_lock(&global_rsv->lock);
2934 if (global_rsv->reserved <= num_bytes + num_dirty_bgs_bytes)
2935 ret = 1;
2936 spin_unlock(&global_rsv->lock);
2937 return ret;
2940 int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans,
2941 struct btrfs_fs_info *fs_info)
2943 u64 num_entries =
2944 atomic_read(&trans->transaction->delayed_refs.num_entries);
2945 u64 avg_runtime;
2946 u64 val;
2948 smp_mb();
2949 avg_runtime = fs_info->avg_delayed_ref_runtime;
2950 val = num_entries * avg_runtime;
2951 if (val >= NSEC_PER_SEC)
2952 return 1;
2953 if (val >= NSEC_PER_SEC / 2)
2954 return 2;
2956 return btrfs_check_space_for_delayed_refs(trans, fs_info);
2959 struct async_delayed_refs {
2960 struct btrfs_root *root;
2961 u64 transid;
2962 int count;
2963 int error;
2964 int sync;
2965 struct completion wait;
2966 struct btrfs_work work;
2969 static inline struct async_delayed_refs *
2970 to_async_delayed_refs(struct btrfs_work *work)
2972 return container_of(work, struct async_delayed_refs, work);
2975 static void delayed_ref_async_start(struct btrfs_work *work)
2977 struct async_delayed_refs *async = to_async_delayed_refs(work);
2978 struct btrfs_trans_handle *trans;
2979 struct btrfs_fs_info *fs_info = async->root->fs_info;
2980 int ret;
2982 /* if the commit is already started, we don't need to wait here */
2983 if (btrfs_transaction_blocked(fs_info))
2984 goto done;
2986 trans = btrfs_join_transaction(async->root);
2987 if (IS_ERR(trans)) {
2988 async->error = PTR_ERR(trans);
2989 goto done;
2993 * trans->sync means that when we call end_transaction, we won't
2994 * wait on delayed refs
2996 trans->sync = true;
2998 /* Don't bother flushing if we got into a different transaction */
2999 if (trans->transid > async->transid)
3000 goto end;
3002 ret = btrfs_run_delayed_refs(trans, fs_info, async->count);
3003 if (ret)
3004 async->error = ret;
3005 end:
3006 ret = btrfs_end_transaction(trans);
3007 if (ret && !async->error)
3008 async->error = ret;
3009 done:
3010 if (async->sync)
3011 complete(&async->wait);
3012 else
3013 kfree(async);
3016 int btrfs_async_run_delayed_refs(struct btrfs_fs_info *fs_info,
3017 unsigned long count, u64 transid, int wait)
3019 struct async_delayed_refs *async;
3020 int ret;
3022 async = kmalloc(sizeof(*async), GFP_NOFS);
3023 if (!async)
3024 return -ENOMEM;
3026 async->root = fs_info->tree_root;
3027 async->count = count;
3028 async->error = 0;
3029 async->transid = transid;
3030 if (wait)
3031 async->sync = 1;
3032 else
3033 async->sync = 0;
3034 init_completion(&async->wait);
3036 btrfs_init_work(&async->work, btrfs_extent_refs_helper,
3037 delayed_ref_async_start, NULL, NULL);
3039 btrfs_queue_work(fs_info->extent_workers, &async->work);
3041 if (wait) {
3042 wait_for_completion(&async->wait);
3043 ret = async->error;
3044 kfree(async);
3045 return ret;
3047 return 0;
3051 * this starts processing the delayed reference count updates and
3052 * extent insertions we have queued up so far. count can be
3053 * 0, which means to process everything in the tree at the start
3054 * of the run (but not newly added entries), or it can be some target
3055 * number you'd like to process.
3057 * Returns 0 on success or if called with an aborted transaction
3058 * Returns <0 on error and aborts the transaction
3060 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
3061 struct btrfs_fs_info *fs_info, unsigned long count)
3063 struct rb_node *node;
3064 struct btrfs_delayed_ref_root *delayed_refs;
3065 struct btrfs_delayed_ref_head *head;
3066 int ret;
3067 int run_all = count == (unsigned long)-1;
3068 bool can_flush_pending_bgs = trans->can_flush_pending_bgs;
3070 /* We'll clean this up in btrfs_cleanup_transaction */
3071 if (trans->aborted)
3072 return 0;
3074 if (test_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags))
3075 return 0;
3077 delayed_refs = &trans->transaction->delayed_refs;
3078 if (count == 0)
3079 count = atomic_read(&delayed_refs->num_entries) * 2;
3081 again:
3082 #ifdef SCRAMBLE_DELAYED_REFS
3083 delayed_refs->run_delayed_start = find_middle(&delayed_refs->root);
3084 #endif
3085 trans->can_flush_pending_bgs = false;
3086 ret = __btrfs_run_delayed_refs(trans, fs_info, count);
3087 if (ret < 0) {
3088 btrfs_abort_transaction(trans, ret);
3089 return ret;
3092 if (run_all) {
3093 if (!list_empty(&trans->new_bgs))
3094 btrfs_create_pending_block_groups(trans, fs_info);
3096 spin_lock(&delayed_refs->lock);
3097 node = rb_first(&delayed_refs->href_root);
3098 if (!node) {
3099 spin_unlock(&delayed_refs->lock);
3100 goto out;
3103 while (node) {
3104 head = rb_entry(node, struct btrfs_delayed_ref_head,
3105 href_node);
3106 if (btrfs_delayed_ref_is_head(&head->node)) {
3107 struct btrfs_delayed_ref_node *ref;
3109 ref = &head->node;
3110 refcount_inc(&ref->refs);
3112 spin_unlock(&delayed_refs->lock);
3114 * Mutex was contended, block until it's
3115 * released and try again
3117 mutex_lock(&head->mutex);
3118 mutex_unlock(&head->mutex);
3120 btrfs_put_delayed_ref(ref);
3121 cond_resched();
3122 goto again;
3123 } else {
3124 WARN_ON(1);
3126 node = rb_next(node);
3128 spin_unlock(&delayed_refs->lock);
3129 cond_resched();
3130 goto again;
3132 out:
3133 trans->can_flush_pending_bgs = can_flush_pending_bgs;
3134 return 0;
3137 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
3138 struct btrfs_fs_info *fs_info,
3139 u64 bytenr, u64 num_bytes, u64 flags,
3140 int level, int is_data)
3142 struct btrfs_delayed_extent_op *extent_op;
3143 int ret;
3145 extent_op = btrfs_alloc_delayed_extent_op();
3146 if (!extent_op)
3147 return -ENOMEM;
3149 extent_op->flags_to_set = flags;
3150 extent_op->update_flags = true;
3151 extent_op->update_key = false;
3152 extent_op->is_data = is_data ? true : false;
3153 extent_op->level = level;
3155 ret = btrfs_add_delayed_extent_op(fs_info, trans, bytenr,
3156 num_bytes, extent_op);
3157 if (ret)
3158 btrfs_free_delayed_extent_op(extent_op);
3159 return ret;
3162 static noinline int check_delayed_ref(struct btrfs_root *root,
3163 struct btrfs_path *path,
3164 u64 objectid, u64 offset, u64 bytenr)
3166 struct btrfs_delayed_ref_head *head;
3167 struct btrfs_delayed_ref_node *ref;
3168 struct btrfs_delayed_data_ref *data_ref;
3169 struct btrfs_delayed_ref_root *delayed_refs;
3170 struct btrfs_transaction *cur_trans;
3171 int ret = 0;
3173 spin_lock(&root->fs_info->trans_lock);
3174 cur_trans = root->fs_info->running_transaction;
3175 if (cur_trans)
3176 refcount_inc(&cur_trans->use_count);
3177 spin_unlock(&root->fs_info->trans_lock);
3178 if (!cur_trans)
3179 return 0;
3181 delayed_refs = &cur_trans->delayed_refs;
3182 spin_lock(&delayed_refs->lock);
3183 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
3184 if (!head) {
3185 spin_unlock(&delayed_refs->lock);
3186 btrfs_put_transaction(cur_trans);
3187 return 0;
3190 if (!mutex_trylock(&head->mutex)) {
3191 refcount_inc(&head->node.refs);
3192 spin_unlock(&delayed_refs->lock);
3194 btrfs_release_path(path);
3197 * Mutex was contended, block until it's released and let
3198 * caller try again
3200 mutex_lock(&head->mutex);
3201 mutex_unlock(&head->mutex);
3202 btrfs_put_delayed_ref(&head->node);
3203 btrfs_put_transaction(cur_trans);
3204 return -EAGAIN;
3206 spin_unlock(&delayed_refs->lock);
3208 spin_lock(&head->lock);
3209 list_for_each_entry(ref, &head->ref_list, list) {
3210 /* If it's a shared ref we know a cross reference exists */
3211 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) {
3212 ret = 1;
3213 break;
3216 data_ref = btrfs_delayed_node_to_data_ref(ref);
3219 * If our ref doesn't match the one we're currently looking at
3220 * then we have a cross reference.
3222 if (data_ref->root != root->root_key.objectid ||
3223 data_ref->objectid != objectid ||
3224 data_ref->offset != offset) {
3225 ret = 1;
3226 break;
3229 spin_unlock(&head->lock);
3230 mutex_unlock(&head->mutex);
3231 btrfs_put_transaction(cur_trans);
3232 return ret;
3235 static noinline int check_committed_ref(struct btrfs_root *root,
3236 struct btrfs_path *path,
3237 u64 objectid, u64 offset, u64 bytenr)
3239 struct btrfs_fs_info *fs_info = root->fs_info;
3240 struct btrfs_root *extent_root = fs_info->extent_root;
3241 struct extent_buffer *leaf;
3242 struct btrfs_extent_data_ref *ref;
3243 struct btrfs_extent_inline_ref *iref;
3244 struct btrfs_extent_item *ei;
3245 struct btrfs_key key;
3246 u32 item_size;
3247 int type;
3248 int ret;
3250 key.objectid = bytenr;
3251 key.offset = (u64)-1;
3252 key.type = BTRFS_EXTENT_ITEM_KEY;
3254 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
3255 if (ret < 0)
3256 goto out;
3257 BUG_ON(ret == 0); /* Corruption */
3259 ret = -ENOENT;
3260 if (path->slots[0] == 0)
3261 goto out;
3263 path->slots[0]--;
3264 leaf = path->nodes[0];
3265 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3267 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
3268 goto out;
3270 ret = 1;
3271 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
3272 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3273 if (item_size < sizeof(*ei)) {
3274 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3275 goto out;
3277 #endif
3278 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
3280 if (item_size != sizeof(*ei) +
3281 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
3282 goto out;
3284 if (btrfs_extent_generation(leaf, ei) <=
3285 btrfs_root_last_snapshot(&root->root_item))
3286 goto out;
3288 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
3290 type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA);
3291 if (type != BTRFS_EXTENT_DATA_REF_KEY)
3292 goto out;
3294 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
3295 if (btrfs_extent_refs(leaf, ei) !=
3296 btrfs_extent_data_ref_count(leaf, ref) ||
3297 btrfs_extent_data_ref_root(leaf, ref) !=
3298 root->root_key.objectid ||
3299 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
3300 btrfs_extent_data_ref_offset(leaf, ref) != offset)
3301 goto out;
3303 ret = 0;
3304 out:
3305 return ret;
3308 int btrfs_cross_ref_exist(struct btrfs_root *root, u64 objectid, u64 offset,
3309 u64 bytenr)
3311 struct btrfs_path *path;
3312 int ret;
3313 int ret2;
3315 path = btrfs_alloc_path();
3316 if (!path)
3317 return -ENOENT;
3319 do {
3320 ret = check_committed_ref(root, path, objectid,
3321 offset, bytenr);
3322 if (ret && ret != -ENOENT)
3323 goto out;
3325 ret2 = check_delayed_ref(root, path, objectid,
3326 offset, bytenr);
3327 } while (ret2 == -EAGAIN);
3329 if (ret2 && ret2 != -ENOENT) {
3330 ret = ret2;
3331 goto out;
3334 if (ret != -ENOENT || ret2 != -ENOENT)
3335 ret = 0;
3336 out:
3337 btrfs_free_path(path);
3338 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
3339 WARN_ON(ret > 0);
3340 return ret;
3343 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
3344 struct btrfs_root *root,
3345 struct extent_buffer *buf,
3346 int full_backref, int inc)
3348 struct btrfs_fs_info *fs_info = root->fs_info;
3349 u64 bytenr;
3350 u64 num_bytes;
3351 u64 parent;
3352 u64 ref_root;
3353 u32 nritems;
3354 struct btrfs_key key;
3355 struct btrfs_file_extent_item *fi;
3356 int i;
3357 int level;
3358 int ret = 0;
3359 int (*process_func)(struct btrfs_trans_handle *,
3360 struct btrfs_fs_info *,
3361 u64, u64, u64, u64, u64, u64);
3364 if (btrfs_is_testing(fs_info))
3365 return 0;
3367 ref_root = btrfs_header_owner(buf);
3368 nritems = btrfs_header_nritems(buf);
3369 level = btrfs_header_level(buf);
3371 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state) && level == 0)
3372 return 0;
3374 if (inc)
3375 process_func = btrfs_inc_extent_ref;
3376 else
3377 process_func = btrfs_free_extent;
3379 if (full_backref)
3380 parent = buf->start;
3381 else
3382 parent = 0;
3384 for (i = 0; i < nritems; i++) {
3385 if (level == 0) {
3386 btrfs_item_key_to_cpu(buf, &key, i);
3387 if (key.type != BTRFS_EXTENT_DATA_KEY)
3388 continue;
3389 fi = btrfs_item_ptr(buf, i,
3390 struct btrfs_file_extent_item);
3391 if (btrfs_file_extent_type(buf, fi) ==
3392 BTRFS_FILE_EXTENT_INLINE)
3393 continue;
3394 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
3395 if (bytenr == 0)
3396 continue;
3398 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
3399 key.offset -= btrfs_file_extent_offset(buf, fi);
3400 ret = process_func(trans, fs_info, bytenr, num_bytes,
3401 parent, ref_root, key.objectid,
3402 key.offset);
3403 if (ret)
3404 goto fail;
3405 } else {
3406 bytenr = btrfs_node_blockptr(buf, i);
3407 num_bytes = fs_info->nodesize;
3408 ret = process_func(trans, fs_info, bytenr, num_bytes,
3409 parent, ref_root, level - 1, 0);
3410 if (ret)
3411 goto fail;
3414 return 0;
3415 fail:
3416 return ret;
3419 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3420 struct extent_buffer *buf, int full_backref)
3422 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
3425 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3426 struct extent_buffer *buf, int full_backref)
3428 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
3431 static int write_one_cache_group(struct btrfs_trans_handle *trans,
3432 struct btrfs_fs_info *fs_info,
3433 struct btrfs_path *path,
3434 struct btrfs_block_group_cache *cache)
3436 int ret;
3437 struct btrfs_root *extent_root = fs_info->extent_root;
3438 unsigned long bi;
3439 struct extent_buffer *leaf;
3441 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
3442 if (ret) {
3443 if (ret > 0)
3444 ret = -ENOENT;
3445 goto fail;
3448 leaf = path->nodes[0];
3449 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
3450 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
3451 btrfs_mark_buffer_dirty(leaf);
3452 fail:
3453 btrfs_release_path(path);
3454 return ret;
3458 static struct btrfs_block_group_cache *
3459 next_block_group(struct btrfs_fs_info *fs_info,
3460 struct btrfs_block_group_cache *cache)
3462 struct rb_node *node;
3464 spin_lock(&fs_info->block_group_cache_lock);
3466 /* If our block group was removed, we need a full search. */
3467 if (RB_EMPTY_NODE(&cache->cache_node)) {
3468 const u64 next_bytenr = cache->key.objectid + cache->key.offset;
3470 spin_unlock(&fs_info->block_group_cache_lock);
3471 btrfs_put_block_group(cache);
3472 cache = btrfs_lookup_first_block_group(fs_info, next_bytenr); return cache;
3474 node = rb_next(&cache->cache_node);
3475 btrfs_put_block_group(cache);
3476 if (node) {
3477 cache = rb_entry(node, struct btrfs_block_group_cache,
3478 cache_node);
3479 btrfs_get_block_group(cache);
3480 } else
3481 cache = NULL;
3482 spin_unlock(&fs_info->block_group_cache_lock);
3483 return cache;
3486 static int cache_save_setup(struct btrfs_block_group_cache *block_group,
3487 struct btrfs_trans_handle *trans,
3488 struct btrfs_path *path)
3490 struct btrfs_fs_info *fs_info = block_group->fs_info;
3491 struct btrfs_root *root = fs_info->tree_root;
3492 struct inode *inode = NULL;
3493 struct extent_changeset *data_reserved = NULL;
3494 u64 alloc_hint = 0;
3495 int dcs = BTRFS_DC_ERROR;
3496 u64 num_pages = 0;
3497 int retries = 0;
3498 int ret = 0;
3501 * If this block group is smaller than 100 megs don't bother caching the
3502 * block group.
3504 if (block_group->key.offset < (100 * SZ_1M)) {
3505 spin_lock(&block_group->lock);
3506 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
3507 spin_unlock(&block_group->lock);
3508 return 0;
3511 if (trans->aborted)
3512 return 0;
3513 again:
3514 inode = lookup_free_space_inode(fs_info, block_group, path);
3515 if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
3516 ret = PTR_ERR(inode);
3517 btrfs_release_path(path);
3518 goto out;
3521 if (IS_ERR(inode)) {
3522 BUG_ON(retries);
3523 retries++;
3525 if (block_group->ro)
3526 goto out_free;
3528 ret = create_free_space_inode(fs_info, trans, block_group,
3529 path);
3530 if (ret)
3531 goto out_free;
3532 goto again;
3536 * We want to set the generation to 0, that way if anything goes wrong
3537 * from here on out we know not to trust this cache when we load up next
3538 * time.
3540 BTRFS_I(inode)->generation = 0;
3541 ret = btrfs_update_inode(trans, root, inode);
3542 if (ret) {
3544 * So theoretically we could recover from this, simply set the
3545 * super cache generation to 0 so we know to invalidate the
3546 * cache, but then we'd have to keep track of the block groups
3547 * that fail this way so we know we _have_ to reset this cache
3548 * before the next commit or risk reading stale cache. So to
3549 * limit our exposure to horrible edge cases lets just abort the
3550 * transaction, this only happens in really bad situations
3551 * anyway.
3553 btrfs_abort_transaction(trans, ret);
3554 goto out_put;
3556 WARN_ON(ret);
3558 /* We've already setup this transaction, go ahead and exit */
3559 if (block_group->cache_generation == trans->transid &&
3560 i_size_read(inode)) {
3561 dcs = BTRFS_DC_SETUP;
3562 goto out_put;
3565 if (i_size_read(inode) > 0) {
3566 ret = btrfs_check_trunc_cache_free_space(fs_info,
3567 &fs_info->global_block_rsv);
3568 if (ret)
3569 goto out_put;
3571 ret = btrfs_truncate_free_space_cache(trans, NULL, inode);
3572 if (ret)
3573 goto out_put;
3576 spin_lock(&block_group->lock);
3577 if (block_group->cached != BTRFS_CACHE_FINISHED ||
3578 !btrfs_test_opt(fs_info, SPACE_CACHE)) {
3580 * don't bother trying to write stuff out _if_
3581 * a) we're not cached,
3582 * b) we're with nospace_cache mount option,
3583 * c) we're with v2 space_cache (FREE_SPACE_TREE).
3585 dcs = BTRFS_DC_WRITTEN;
3586 spin_unlock(&block_group->lock);
3587 goto out_put;
3589 spin_unlock(&block_group->lock);
3592 * We hit an ENOSPC when setting up the cache in this transaction, just
3593 * skip doing the setup, we've already cleared the cache so we're safe.
3595 if (test_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags)) {
3596 ret = -ENOSPC;
3597 goto out_put;
3601 * Try to preallocate enough space based on how big the block group is.
3602 * Keep in mind this has to include any pinned space which could end up
3603 * taking up quite a bit since it's not folded into the other space
3604 * cache.
3606 num_pages = div_u64(block_group->key.offset, SZ_256M);
3607 if (!num_pages)
3608 num_pages = 1;
3610 num_pages *= 16;
3611 num_pages *= PAGE_SIZE;
3613 ret = btrfs_check_data_free_space(inode, &data_reserved, 0, num_pages);
3614 if (ret)
3615 goto out_put;
3617 ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
3618 num_pages, num_pages,
3619 &alloc_hint);
3621 * Our cache requires contiguous chunks so that we don't modify a bunch
3622 * of metadata or split extents when writing the cache out, which means
3623 * we can enospc if we are heavily fragmented in addition to just normal
3624 * out of space conditions. So if we hit this just skip setting up any
3625 * other block groups for this transaction, maybe we'll unpin enough
3626 * space the next time around.
3628 if (!ret)
3629 dcs = BTRFS_DC_SETUP;
3630 else if (ret == -ENOSPC)
3631 set_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags);
3633 out_put:
3634 iput(inode);
3635 out_free:
3636 btrfs_release_path(path);
3637 out:
3638 spin_lock(&block_group->lock);
3639 if (!ret && dcs == BTRFS_DC_SETUP)
3640 block_group->cache_generation = trans->transid;
3641 block_group->disk_cache_state = dcs;
3642 spin_unlock(&block_group->lock);
3644 extent_changeset_free(data_reserved);
3645 return ret;
3648 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
3649 struct btrfs_fs_info *fs_info)
3651 struct btrfs_block_group_cache *cache, *tmp;
3652 struct btrfs_transaction *cur_trans = trans->transaction;
3653 struct btrfs_path *path;
3655 if (list_empty(&cur_trans->dirty_bgs) ||
3656 !btrfs_test_opt(fs_info, SPACE_CACHE))
3657 return 0;
3659 path = btrfs_alloc_path();
3660 if (!path)
3661 return -ENOMEM;
3663 /* Could add new block groups, use _safe just in case */
3664 list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
3665 dirty_list) {
3666 if (cache->disk_cache_state == BTRFS_DC_CLEAR)
3667 cache_save_setup(cache, trans, path);
3670 btrfs_free_path(path);
3671 return 0;
3675 * transaction commit does final block group cache writeback during a
3676 * critical section where nothing is allowed to change the FS. This is
3677 * required in order for the cache to actually match the block group,
3678 * but can introduce a lot of latency into the commit.
3680 * So, btrfs_start_dirty_block_groups is here to kick off block group
3681 * cache IO. There's a chance we'll have to redo some of it if the
3682 * block group changes again during the commit, but it greatly reduces
3683 * the commit latency by getting rid of the easy block groups while
3684 * we're still allowing others to join the commit.
3686 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans,
3687 struct btrfs_fs_info *fs_info)
3689 struct btrfs_block_group_cache *cache;
3690 struct btrfs_transaction *cur_trans = trans->transaction;
3691 int ret = 0;
3692 int should_put;
3693 struct btrfs_path *path = NULL;
3694 LIST_HEAD(dirty);
3695 struct list_head *io = &cur_trans->io_bgs;
3696 int num_started = 0;
3697 int loops = 0;
3699 spin_lock(&cur_trans->dirty_bgs_lock);
3700 if (list_empty(&cur_trans->dirty_bgs)) {
3701 spin_unlock(&cur_trans->dirty_bgs_lock);
3702 return 0;
3704 list_splice_init(&cur_trans->dirty_bgs, &dirty);
3705 spin_unlock(&cur_trans->dirty_bgs_lock);
3707 again:
3709 * make sure all the block groups on our dirty list actually
3710 * exist
3712 btrfs_create_pending_block_groups(trans, fs_info);
3714 if (!path) {
3715 path = btrfs_alloc_path();
3716 if (!path)
3717 return -ENOMEM;
3721 * cache_write_mutex is here only to save us from balance or automatic
3722 * removal of empty block groups deleting this block group while we are
3723 * writing out the cache
3725 mutex_lock(&trans->transaction->cache_write_mutex);
3726 while (!list_empty(&dirty)) {
3727 cache = list_first_entry(&dirty,
3728 struct btrfs_block_group_cache,
3729 dirty_list);
3731 * this can happen if something re-dirties a block
3732 * group that is already under IO. Just wait for it to
3733 * finish and then do it all again
3735 if (!list_empty(&cache->io_list)) {
3736 list_del_init(&cache->io_list);
3737 btrfs_wait_cache_io(trans, cache, path);
3738 btrfs_put_block_group(cache);
3743 * btrfs_wait_cache_io uses the cache->dirty_list to decide
3744 * if it should update the cache_state. Don't delete
3745 * until after we wait.
3747 * Since we're not running in the commit critical section
3748 * we need the dirty_bgs_lock to protect from update_block_group
3750 spin_lock(&cur_trans->dirty_bgs_lock);
3751 list_del_init(&cache->dirty_list);
3752 spin_unlock(&cur_trans->dirty_bgs_lock);
3754 should_put = 1;
3756 cache_save_setup(cache, trans, path);
3758 if (cache->disk_cache_state == BTRFS_DC_SETUP) {
3759 cache->io_ctl.inode = NULL;
3760 ret = btrfs_write_out_cache(fs_info, trans,
3761 cache, path);
3762 if (ret == 0 && cache->io_ctl.inode) {
3763 num_started++;
3764 should_put = 0;
3767 * the cache_write_mutex is protecting
3768 * the io_list
3770 list_add_tail(&cache->io_list, io);
3771 } else {
3773 * if we failed to write the cache, the
3774 * generation will be bad and life goes on
3776 ret = 0;
3779 if (!ret) {
3780 ret = write_one_cache_group(trans, fs_info,
3781 path, cache);
3783 * Our block group might still be attached to the list
3784 * of new block groups in the transaction handle of some
3785 * other task (struct btrfs_trans_handle->new_bgs). This
3786 * means its block group item isn't yet in the extent
3787 * tree. If this happens ignore the error, as we will
3788 * try again later in the critical section of the
3789 * transaction commit.
3791 if (ret == -ENOENT) {
3792 ret = 0;
3793 spin_lock(&cur_trans->dirty_bgs_lock);
3794 if (list_empty(&cache->dirty_list)) {
3795 list_add_tail(&cache->dirty_list,
3796 &cur_trans->dirty_bgs);
3797 btrfs_get_block_group(cache);
3799 spin_unlock(&cur_trans->dirty_bgs_lock);
3800 } else if (ret) {
3801 btrfs_abort_transaction(trans, ret);
3805 /* if its not on the io list, we need to put the block group */
3806 if (should_put)
3807 btrfs_put_block_group(cache);
3809 if (ret)
3810 break;
3813 * Avoid blocking other tasks for too long. It might even save
3814 * us from writing caches for block groups that are going to be
3815 * removed.
3817 mutex_unlock(&trans->transaction->cache_write_mutex);
3818 mutex_lock(&trans->transaction->cache_write_mutex);
3820 mutex_unlock(&trans->transaction->cache_write_mutex);
3823 * go through delayed refs for all the stuff we've just kicked off
3824 * and then loop back (just once)
3826 ret = btrfs_run_delayed_refs(trans, fs_info, 0);
3827 if (!ret && loops == 0) {
3828 loops++;
3829 spin_lock(&cur_trans->dirty_bgs_lock);
3830 list_splice_init(&cur_trans->dirty_bgs, &dirty);
3832 * dirty_bgs_lock protects us from concurrent block group
3833 * deletes too (not just cache_write_mutex).
3835 if (!list_empty(&dirty)) {
3836 spin_unlock(&cur_trans->dirty_bgs_lock);
3837 goto again;
3839 spin_unlock(&cur_trans->dirty_bgs_lock);
3840 } else if (ret < 0) {
3841 btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
3844 btrfs_free_path(path);
3845 return ret;
3848 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
3849 struct btrfs_fs_info *fs_info)
3851 struct btrfs_block_group_cache *cache;
3852 struct btrfs_transaction *cur_trans = trans->transaction;
3853 int ret = 0;
3854 int should_put;
3855 struct btrfs_path *path;
3856 struct list_head *io = &cur_trans->io_bgs;
3857 int num_started = 0;
3859 path = btrfs_alloc_path();
3860 if (!path)
3861 return -ENOMEM;
3864 * Even though we are in the critical section of the transaction commit,
3865 * we can still have concurrent tasks adding elements to this
3866 * transaction's list of dirty block groups. These tasks correspond to
3867 * endio free space workers started when writeback finishes for a
3868 * space cache, which run inode.c:btrfs_finish_ordered_io(), and can
3869 * allocate new block groups as a result of COWing nodes of the root
3870 * tree when updating the free space inode. The writeback for the space
3871 * caches is triggered by an earlier call to
3872 * btrfs_start_dirty_block_groups() and iterations of the following
3873 * loop.
3874 * Also we want to do the cache_save_setup first and then run the
3875 * delayed refs to make sure we have the best chance at doing this all
3876 * in one shot.
3878 spin_lock(&cur_trans->dirty_bgs_lock);
3879 while (!list_empty(&cur_trans->dirty_bgs)) {
3880 cache = list_first_entry(&cur_trans->dirty_bgs,
3881 struct btrfs_block_group_cache,
3882 dirty_list);
3885 * this can happen if cache_save_setup re-dirties a block
3886 * group that is already under IO. Just wait for it to
3887 * finish and then do it all again
3889 if (!list_empty(&cache->io_list)) {
3890 spin_unlock(&cur_trans->dirty_bgs_lock);
3891 list_del_init(&cache->io_list);
3892 btrfs_wait_cache_io(trans, cache, path);
3893 btrfs_put_block_group(cache);
3894 spin_lock(&cur_trans->dirty_bgs_lock);
3898 * don't remove from the dirty list until after we've waited
3899 * on any pending IO
3901 list_del_init(&cache->dirty_list);
3902 spin_unlock(&cur_trans->dirty_bgs_lock);
3903 should_put = 1;
3905 cache_save_setup(cache, trans, path);
3907 if (!ret)
3908 ret = btrfs_run_delayed_refs(trans, fs_info,
3909 (unsigned long) -1);
3911 if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
3912 cache->io_ctl.inode = NULL;
3913 ret = btrfs_write_out_cache(fs_info, trans,
3914 cache, path);
3915 if (ret == 0 && cache->io_ctl.inode) {
3916 num_started++;
3917 should_put = 0;
3918 list_add_tail(&cache->io_list, io);
3919 } else {
3921 * if we failed to write the cache, the
3922 * generation will be bad and life goes on
3924 ret = 0;
3927 if (!ret) {
3928 ret = write_one_cache_group(trans, fs_info,
3929 path, cache);
3931 * One of the free space endio workers might have
3932 * created a new block group while updating a free space
3933 * cache's inode (at inode.c:btrfs_finish_ordered_io())
3934 * and hasn't released its transaction handle yet, in
3935 * which case the new block group is still attached to
3936 * its transaction handle and its creation has not
3937 * finished yet (no block group item in the extent tree
3938 * yet, etc). If this is the case, wait for all free
3939 * space endio workers to finish and retry. This is a
3940 * a very rare case so no need for a more efficient and
3941 * complex approach.
3943 if (ret == -ENOENT) {
3944 wait_event(cur_trans->writer_wait,
3945 atomic_read(&cur_trans->num_writers) == 1);
3946 ret = write_one_cache_group(trans, fs_info,
3947 path, cache);
3949 if (ret)
3950 btrfs_abort_transaction(trans, ret);
3953 /* if its not on the io list, we need to put the block group */
3954 if (should_put)
3955 btrfs_put_block_group(cache);
3956 spin_lock(&cur_trans->dirty_bgs_lock);
3958 spin_unlock(&cur_trans->dirty_bgs_lock);
3960 while (!list_empty(io)) {
3961 cache = list_first_entry(io, struct btrfs_block_group_cache,
3962 io_list);
3963 list_del_init(&cache->io_list);
3964 btrfs_wait_cache_io(trans, cache, path);
3965 btrfs_put_block_group(cache);
3968 btrfs_free_path(path);
3969 return ret;
3972 int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
3974 struct btrfs_block_group_cache *block_group;
3975 int readonly = 0;
3977 block_group = btrfs_lookup_block_group(fs_info, bytenr);
3978 if (!block_group || block_group->ro)
3979 readonly = 1;
3980 if (block_group)
3981 btrfs_put_block_group(block_group);
3982 return readonly;
3985 bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
3987 struct btrfs_block_group_cache *bg;
3988 bool ret = true;
3990 bg = btrfs_lookup_block_group(fs_info, bytenr);
3991 if (!bg)
3992 return false;
3994 spin_lock(&bg->lock);
3995 if (bg->ro)
3996 ret = false;
3997 else
3998 atomic_inc(&bg->nocow_writers);
3999 spin_unlock(&bg->lock);
4001 /* no put on block group, done by btrfs_dec_nocow_writers */
4002 if (!ret)
4003 btrfs_put_block_group(bg);
4005 return ret;
4009 void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
4011 struct btrfs_block_group_cache *bg;
4013 bg = btrfs_lookup_block_group(fs_info, bytenr);
4014 ASSERT(bg);
4015 if (atomic_dec_and_test(&bg->nocow_writers))
4016 wake_up_atomic_t(&bg->nocow_writers);
4018 * Once for our lookup and once for the lookup done by a previous call
4019 * to btrfs_inc_nocow_writers()
4021 btrfs_put_block_group(bg);
4022 btrfs_put_block_group(bg);
4025 static int btrfs_wait_nocow_writers_atomic_t(atomic_t *a)
4027 schedule();
4028 return 0;
4031 void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg)
4033 wait_on_atomic_t(&bg->nocow_writers,
4034 btrfs_wait_nocow_writers_atomic_t,
4035 TASK_UNINTERRUPTIBLE);
4038 static const char *alloc_name(u64 flags)
4040 switch (flags) {
4041 case BTRFS_BLOCK_GROUP_METADATA|BTRFS_BLOCK_GROUP_DATA:
4042 return "mixed";
4043 case BTRFS_BLOCK_GROUP_METADATA:
4044 return "metadata";
4045 case BTRFS_BLOCK_GROUP_DATA:
4046 return "data";
4047 case BTRFS_BLOCK_GROUP_SYSTEM:
4048 return "system";
4049 default:
4050 WARN_ON(1);
4051 return "invalid-combination";
4055 static int create_space_info(struct btrfs_fs_info *info, u64 flags,
4056 struct btrfs_space_info **new)
4059 struct btrfs_space_info *space_info;
4060 int i;
4061 int ret;
4063 space_info = kzalloc(sizeof(*space_info), GFP_NOFS);
4064 if (!space_info)
4065 return -ENOMEM;
4067 ret = percpu_counter_init(&space_info->total_bytes_pinned, 0,
4068 GFP_KERNEL);
4069 if (ret) {
4070 kfree(space_info);
4071 return ret;
4074 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
4075 INIT_LIST_HEAD(&space_info->block_groups[i]);
4076 init_rwsem(&space_info->groups_sem);
4077 spin_lock_init(&space_info->lock);
4078 space_info->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
4079 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
4080 init_waitqueue_head(&space_info->wait);
4081 INIT_LIST_HEAD(&space_info->ro_bgs);
4082 INIT_LIST_HEAD(&space_info->tickets);
4083 INIT_LIST_HEAD(&space_info->priority_tickets);
4085 ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
4086 info->space_info_kobj, "%s",
4087 alloc_name(space_info->flags));
4088 if (ret) {
4089 kobject_put(&space_info->kobj);
4090 return ret;
4093 *new = space_info;
4094 list_add_rcu(&space_info->list, &info->space_info);
4095 if (flags & BTRFS_BLOCK_GROUP_DATA)
4096 info->data_sinfo = space_info;
4098 return ret;
4101 static void update_space_info(struct btrfs_fs_info *info, u64 flags,
4102 u64 total_bytes, u64 bytes_used,
4103 u64 bytes_readonly,
4104 struct btrfs_space_info **space_info)
4106 struct btrfs_space_info *found;
4107 int factor;
4109 if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
4110 BTRFS_BLOCK_GROUP_RAID10))
4111 factor = 2;
4112 else
4113 factor = 1;
4115 found = __find_space_info(info, flags);
4116 ASSERT(found);
4117 spin_lock(&found->lock);
4118 found->total_bytes += total_bytes;
4119 found->disk_total += total_bytes * factor;
4120 found->bytes_used += bytes_used;
4121 found->disk_used += bytes_used * factor;
4122 found->bytes_readonly += bytes_readonly;
4123 if (total_bytes > 0)
4124 found->full = 0;
4125 space_info_add_new_bytes(info, found, total_bytes -
4126 bytes_used - bytes_readonly);
4127 spin_unlock(&found->lock);
4128 *space_info = found;
4131 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
4133 u64 extra_flags = chunk_to_extended(flags) &
4134 BTRFS_EXTENDED_PROFILE_MASK;
4136 write_seqlock(&fs_info->profiles_lock);
4137 if (flags & BTRFS_BLOCK_GROUP_DATA)
4138 fs_info->avail_data_alloc_bits |= extra_flags;
4139 if (flags & BTRFS_BLOCK_GROUP_METADATA)
4140 fs_info->avail_metadata_alloc_bits |= extra_flags;
4141 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
4142 fs_info->avail_system_alloc_bits |= extra_flags;
4143 write_sequnlock(&fs_info->profiles_lock);
4147 * returns target flags in extended format or 0 if restripe for this
4148 * chunk_type is not in progress
4150 * should be called with either volume_mutex or balance_lock held
4152 static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
4154 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4155 u64 target = 0;
4157 if (!bctl)
4158 return 0;
4160 if (flags & BTRFS_BLOCK_GROUP_DATA &&
4161 bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
4162 target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
4163 } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
4164 bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
4165 target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
4166 } else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
4167 bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
4168 target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
4171 return target;
4175 * @flags: available profiles in extended format (see ctree.h)
4177 * Returns reduced profile in chunk format. If profile changing is in
4178 * progress (either running or paused) picks the target profile (if it's
4179 * already available), otherwise falls back to plain reducing.
4181 static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags)
4183 u64 num_devices = fs_info->fs_devices->rw_devices;
4184 u64 target;
4185 u64 raid_type;
4186 u64 allowed = 0;
4189 * see if restripe for this chunk_type is in progress, if so
4190 * try to reduce to the target profile
4192 spin_lock(&fs_info->balance_lock);
4193 target = get_restripe_target(fs_info, flags);
4194 if (target) {
4195 /* pick target profile only if it's already available */
4196 if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
4197 spin_unlock(&fs_info->balance_lock);
4198 return extended_to_chunk(target);
4201 spin_unlock(&fs_info->balance_lock);
4203 /* First, mask out the RAID levels which aren't possible */
4204 for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
4205 if (num_devices >= btrfs_raid_array[raid_type].devs_min)
4206 allowed |= btrfs_raid_group[raid_type];
4208 allowed &= flags;
4210 if (allowed & BTRFS_BLOCK_GROUP_RAID6)
4211 allowed = BTRFS_BLOCK_GROUP_RAID6;
4212 else if (allowed & BTRFS_BLOCK_GROUP_RAID5)
4213 allowed = BTRFS_BLOCK_GROUP_RAID5;
4214 else if (allowed & BTRFS_BLOCK_GROUP_RAID10)
4215 allowed = BTRFS_BLOCK_GROUP_RAID10;
4216 else if (allowed & BTRFS_BLOCK_GROUP_RAID1)
4217 allowed = BTRFS_BLOCK_GROUP_RAID1;
4218 else if (allowed & BTRFS_BLOCK_GROUP_RAID0)
4219 allowed = BTRFS_BLOCK_GROUP_RAID0;
4221 flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
4223 return extended_to_chunk(flags | allowed);
4226 static u64 get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
4228 unsigned seq;
4229 u64 flags;
4231 do {
4232 flags = orig_flags;
4233 seq = read_seqbegin(&fs_info->profiles_lock);
4235 if (flags & BTRFS_BLOCK_GROUP_DATA)
4236 flags |= fs_info->avail_data_alloc_bits;
4237 else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
4238 flags |= fs_info->avail_system_alloc_bits;
4239 else if (flags & BTRFS_BLOCK_GROUP_METADATA)
4240 flags |= fs_info->avail_metadata_alloc_bits;
4241 } while (read_seqretry(&fs_info->profiles_lock, seq));
4243 return btrfs_reduce_alloc_profile(fs_info, flags);
4246 static u64 get_alloc_profile_by_root(struct btrfs_root *root, int data)
4248 struct btrfs_fs_info *fs_info = root->fs_info;
4249 u64 flags;
4250 u64 ret;
4252 if (data)
4253 flags = BTRFS_BLOCK_GROUP_DATA;
4254 else if (root == fs_info->chunk_root)
4255 flags = BTRFS_BLOCK_GROUP_SYSTEM;
4256 else
4257 flags = BTRFS_BLOCK_GROUP_METADATA;
4259 ret = get_alloc_profile(fs_info, flags);
4260 return ret;
4263 u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
4265 return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
4268 u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
4270 return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
4273 u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
4275 return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
4278 static u64 btrfs_space_info_used(struct btrfs_space_info *s_info,
4279 bool may_use_included)
4281 ASSERT(s_info);
4282 return s_info->bytes_used + s_info->bytes_reserved +
4283 s_info->bytes_pinned + s_info->bytes_readonly +
4284 (may_use_included ? s_info->bytes_may_use : 0);
4287 int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes)
4289 struct btrfs_root *root = inode->root;
4290 struct btrfs_fs_info *fs_info = root->fs_info;
4291 struct btrfs_space_info *data_sinfo = fs_info->data_sinfo;
4292 u64 used;
4293 int ret = 0;
4294 int need_commit = 2;
4295 int have_pinned_space;
4297 /* make sure bytes are sectorsize aligned */
4298 bytes = ALIGN(bytes, fs_info->sectorsize);
4300 if (btrfs_is_free_space_inode(inode)) {
4301 need_commit = 0;
4302 ASSERT(current->journal_info);
4305 again:
4306 /* make sure we have enough space to handle the data first */
4307 spin_lock(&data_sinfo->lock);
4308 used = btrfs_space_info_used(data_sinfo, true);
4310 if (used + bytes > data_sinfo->total_bytes) {
4311 struct btrfs_trans_handle *trans;
4314 * if we don't have enough free bytes in this space then we need
4315 * to alloc a new chunk.
4317 if (!data_sinfo->full) {
4318 u64 alloc_target;
4320 data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
4321 spin_unlock(&data_sinfo->lock);
4323 alloc_target = btrfs_data_alloc_profile(fs_info);
4325 * It is ugly that we don't call nolock join
4326 * transaction for the free space inode case here.
4327 * But it is safe because we only do the data space
4328 * reservation for the free space cache in the
4329 * transaction context, the common join transaction
4330 * just increase the counter of the current transaction
4331 * handler, doesn't try to acquire the trans_lock of
4332 * the fs.
4334 trans = btrfs_join_transaction(root);
4335 if (IS_ERR(trans))
4336 return PTR_ERR(trans);
4338 ret = do_chunk_alloc(trans, fs_info, alloc_target,
4339 CHUNK_ALLOC_NO_FORCE);
4340 btrfs_end_transaction(trans);
4341 if (ret < 0) {
4342 if (ret != -ENOSPC)
4343 return ret;
4344 else {
4345 have_pinned_space = 1;
4346 goto commit_trans;
4350 goto again;
4354 * If we don't have enough pinned space to deal with this
4355 * allocation, and no removed chunk in current transaction,
4356 * don't bother committing the transaction.
4358 have_pinned_space = percpu_counter_compare(
4359 &data_sinfo->total_bytes_pinned,
4360 used + bytes - data_sinfo->total_bytes);
4361 spin_unlock(&data_sinfo->lock);
4363 /* commit the current transaction and try again */
4364 commit_trans:
4365 if (need_commit &&
4366 !atomic_read(&fs_info->open_ioctl_trans)) {
4367 need_commit--;
4369 if (need_commit > 0) {
4370 btrfs_start_delalloc_roots(fs_info, 0, -1);
4371 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0,
4372 (u64)-1);
4375 trans = btrfs_join_transaction(root);
4376 if (IS_ERR(trans))
4377 return PTR_ERR(trans);
4378 if (have_pinned_space >= 0 ||
4379 test_bit(BTRFS_TRANS_HAVE_FREE_BGS,
4380 &trans->transaction->flags) ||
4381 need_commit > 0) {
4382 ret = btrfs_commit_transaction(trans);
4383 if (ret)
4384 return ret;
4386 * The cleaner kthread might still be doing iput
4387 * operations. Wait for it to finish so that
4388 * more space is released.
4390 mutex_lock(&fs_info->cleaner_delayed_iput_mutex);
4391 mutex_unlock(&fs_info->cleaner_delayed_iput_mutex);
4392 goto again;
4393 } else {
4394 btrfs_end_transaction(trans);
4398 trace_btrfs_space_reservation(fs_info,
4399 "space_info:enospc",
4400 data_sinfo->flags, bytes, 1);
4401 return -ENOSPC;
4403 data_sinfo->bytes_may_use += bytes;
4404 trace_btrfs_space_reservation(fs_info, "space_info",
4405 data_sinfo->flags, bytes, 1);
4406 spin_unlock(&data_sinfo->lock);
4408 return 0;
4411 int btrfs_check_data_free_space(struct inode *inode,
4412 struct extent_changeset **reserved, u64 start, u64 len)
4414 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4415 int ret;
4417 /* align the range */
4418 len = round_up(start + len, fs_info->sectorsize) -
4419 round_down(start, fs_info->sectorsize);
4420 start = round_down(start, fs_info->sectorsize);
4422 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode), len);
4423 if (ret < 0)
4424 return ret;
4426 /* Use new btrfs_qgroup_reserve_data to reserve precious data space. */
4427 ret = btrfs_qgroup_reserve_data(inode, reserved, start, len);
4428 if (ret < 0)
4429 btrfs_free_reserved_data_space_noquota(inode, start, len);
4430 else
4431 ret = 0;
4432 return ret;
4436 * Called if we need to clear a data reservation for this inode
4437 * Normally in a error case.
4439 * This one will *NOT* use accurate qgroup reserved space API, just for case
4440 * which we can't sleep and is sure it won't affect qgroup reserved space.
4441 * Like clear_bit_hook().
4443 void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start,
4444 u64 len)
4446 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4447 struct btrfs_space_info *data_sinfo;
4449 /* Make sure the range is aligned to sectorsize */
4450 len = round_up(start + len, fs_info->sectorsize) -
4451 round_down(start, fs_info->sectorsize);
4452 start = round_down(start, fs_info->sectorsize);
4454 data_sinfo = fs_info->data_sinfo;
4455 spin_lock(&data_sinfo->lock);
4456 if (WARN_ON(data_sinfo->bytes_may_use < len))
4457 data_sinfo->bytes_may_use = 0;
4458 else
4459 data_sinfo->bytes_may_use -= len;
4460 trace_btrfs_space_reservation(fs_info, "space_info",
4461 data_sinfo->flags, len, 0);
4462 spin_unlock(&data_sinfo->lock);
4466 * Called if we need to clear a data reservation for this inode
4467 * Normally in a error case.
4469 * This one will handle the per-inode data rsv map for accurate reserved
4470 * space framework.
4472 void btrfs_free_reserved_data_space(struct inode *inode,
4473 struct extent_changeset *reserved, u64 start, u64 len)
4475 struct btrfs_root *root = BTRFS_I(inode)->root;
4477 /* Make sure the range is aligned to sectorsize */
4478 len = round_up(start + len, root->fs_info->sectorsize) -
4479 round_down(start, root->fs_info->sectorsize);
4480 start = round_down(start, root->fs_info->sectorsize);
4482 btrfs_free_reserved_data_space_noquota(inode, start, len);
4483 btrfs_qgroup_free_data(inode, reserved, start, len);
4486 static void force_metadata_allocation(struct btrfs_fs_info *info)
4488 struct list_head *head = &info->space_info;
4489 struct btrfs_space_info *found;
4491 rcu_read_lock();
4492 list_for_each_entry_rcu(found, head, list) {
4493 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
4494 found->force_alloc = CHUNK_ALLOC_FORCE;
4496 rcu_read_unlock();
4499 static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
4501 return (global->size << 1);
4504 static int should_alloc_chunk(struct btrfs_fs_info *fs_info,
4505 struct btrfs_space_info *sinfo, int force)
4507 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
4508 u64 bytes_used = btrfs_space_info_used(sinfo, false);
4509 u64 thresh;
4511 if (force == CHUNK_ALLOC_FORCE)
4512 return 1;
4515 * We need to take into account the global rsv because for all intents
4516 * and purposes it's used space. Don't worry about locking the
4517 * global_rsv, it doesn't change except when the transaction commits.
4519 if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA)
4520 bytes_used += calc_global_rsv_need_space(global_rsv);
4523 * in limited mode, we want to have some free space up to
4524 * about 1% of the FS size.
4526 if (force == CHUNK_ALLOC_LIMITED) {
4527 thresh = btrfs_super_total_bytes(fs_info->super_copy);
4528 thresh = max_t(u64, SZ_64M, div_factor_fine(thresh, 1));
4530 if (sinfo->total_bytes - bytes_used < thresh)
4531 return 1;
4534 if (bytes_used + SZ_2M < div_factor(sinfo->total_bytes, 8))
4535 return 0;
4536 return 1;
4539 static u64 get_profile_num_devs(struct btrfs_fs_info *fs_info, u64 type)
4541 u64 num_dev;
4543 if (type & (BTRFS_BLOCK_GROUP_RAID10 |
4544 BTRFS_BLOCK_GROUP_RAID0 |
4545 BTRFS_BLOCK_GROUP_RAID5 |
4546 BTRFS_BLOCK_GROUP_RAID6))
4547 num_dev = fs_info->fs_devices->rw_devices;
4548 else if (type & BTRFS_BLOCK_GROUP_RAID1)
4549 num_dev = 2;
4550 else
4551 num_dev = 1; /* DUP or single */
4553 return num_dev;
4557 * If @is_allocation is true, reserve space in the system space info necessary
4558 * for allocating a chunk, otherwise if it's false, reserve space necessary for
4559 * removing a chunk.
4561 void check_system_chunk(struct btrfs_trans_handle *trans,
4562 struct btrfs_fs_info *fs_info, u64 type)
4564 struct btrfs_space_info *info;
4565 u64 left;
4566 u64 thresh;
4567 int ret = 0;
4568 u64 num_devs;
4571 * Needed because we can end up allocating a system chunk and for an
4572 * atomic and race free space reservation in the chunk block reserve.
4574 ASSERT(mutex_is_locked(&fs_info->chunk_mutex));
4576 info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
4577 spin_lock(&info->lock);
4578 left = info->total_bytes - btrfs_space_info_used(info, true);
4579 spin_unlock(&info->lock);
4581 num_devs = get_profile_num_devs(fs_info, type);
4583 /* num_devs device items to update and 1 chunk item to add or remove */
4584 thresh = btrfs_calc_trunc_metadata_size(fs_info, num_devs) +
4585 btrfs_calc_trans_metadata_size(fs_info, 1);
4587 if (left < thresh && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
4588 btrfs_info(fs_info, "left=%llu, need=%llu, flags=%llu",
4589 left, thresh, type);
4590 dump_space_info(fs_info, info, 0, 0);
4593 if (left < thresh) {
4594 u64 flags = btrfs_system_alloc_profile(fs_info);
4597 * Ignore failure to create system chunk. We might end up not
4598 * needing it, as we might not need to COW all nodes/leafs from
4599 * the paths we visit in the chunk tree (they were already COWed
4600 * or created in the current transaction for example).
4602 ret = btrfs_alloc_chunk(trans, fs_info, flags);
4605 if (!ret) {
4606 ret = btrfs_block_rsv_add(fs_info->chunk_root,
4607 &fs_info->chunk_block_rsv,
4608 thresh, BTRFS_RESERVE_NO_FLUSH);
4609 if (!ret)
4610 trans->chunk_bytes_reserved += thresh;
4615 * If force is CHUNK_ALLOC_FORCE:
4616 * - return 1 if it successfully allocates a chunk,
4617 * - return errors including -ENOSPC otherwise.
4618 * If force is NOT CHUNK_ALLOC_FORCE:
4619 * - return 0 if it doesn't need to allocate a new chunk,
4620 * - return 1 if it successfully allocates a chunk,
4621 * - return errors including -ENOSPC otherwise.
4623 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
4624 struct btrfs_fs_info *fs_info, u64 flags, int force)
4626 struct btrfs_space_info *space_info;
4627 int wait_for_alloc = 0;
4628 int ret = 0;
4630 /* Don't re-enter if we're already allocating a chunk */
4631 if (trans->allocating_chunk)
4632 return -ENOSPC;
4634 space_info = __find_space_info(fs_info, flags);
4635 if (!space_info) {
4636 ret = create_space_info(fs_info, flags, &space_info);
4637 if (ret)
4638 return ret;
4641 again:
4642 spin_lock(&space_info->lock);
4643 if (force < space_info->force_alloc)
4644 force = space_info->force_alloc;
4645 if (space_info->full) {
4646 if (should_alloc_chunk(fs_info, space_info, force))
4647 ret = -ENOSPC;
4648 else
4649 ret = 0;
4650 spin_unlock(&space_info->lock);
4651 return ret;
4654 if (!should_alloc_chunk(fs_info, space_info, force)) {
4655 spin_unlock(&space_info->lock);
4656 return 0;
4657 } else if (space_info->chunk_alloc) {
4658 wait_for_alloc = 1;
4659 } else {
4660 space_info->chunk_alloc = 1;
4663 spin_unlock(&space_info->lock);
4665 mutex_lock(&fs_info->chunk_mutex);
4668 * The chunk_mutex is held throughout the entirety of a chunk
4669 * allocation, so once we've acquired the chunk_mutex we know that the
4670 * other guy is done and we need to recheck and see if we should
4671 * allocate.
4673 if (wait_for_alloc) {
4674 mutex_unlock(&fs_info->chunk_mutex);
4675 wait_for_alloc = 0;
4676 cond_resched();
4677 goto again;
4680 trans->allocating_chunk = true;
4683 * If we have mixed data/metadata chunks we want to make sure we keep
4684 * allocating mixed chunks instead of individual chunks.
4686 if (btrfs_mixed_space_info(space_info))
4687 flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
4690 * if we're doing a data chunk, go ahead and make sure that
4691 * we keep a reasonable number of metadata chunks allocated in the
4692 * FS as well.
4694 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
4695 fs_info->data_chunk_allocations++;
4696 if (!(fs_info->data_chunk_allocations %
4697 fs_info->metadata_ratio))
4698 force_metadata_allocation(fs_info);
4702 * Check if we have enough space in SYSTEM chunk because we may need
4703 * to update devices.
4705 check_system_chunk(trans, fs_info, flags);
4707 ret = btrfs_alloc_chunk(trans, fs_info, flags);
4708 trans->allocating_chunk = false;
4710 spin_lock(&space_info->lock);
4711 if (ret < 0 && ret != -ENOSPC)
4712 goto out;
4713 if (ret)
4714 space_info->full = 1;
4715 else
4716 ret = 1;
4718 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
4719 out:
4720 space_info->chunk_alloc = 0;
4721 spin_unlock(&space_info->lock);
4722 mutex_unlock(&fs_info->chunk_mutex);
4724 * When we allocate a new chunk we reserve space in the chunk block
4725 * reserve to make sure we can COW nodes/leafs in the chunk tree or
4726 * add new nodes/leafs to it if we end up needing to do it when
4727 * inserting the chunk item and updating device items as part of the
4728 * second phase of chunk allocation, performed by
4729 * btrfs_finish_chunk_alloc(). So make sure we don't accumulate a
4730 * large number of new block groups to create in our transaction
4731 * handle's new_bgs list to avoid exhausting the chunk block reserve
4732 * in extreme cases - like having a single transaction create many new
4733 * block groups when starting to write out the free space caches of all
4734 * the block groups that were made dirty during the lifetime of the
4735 * transaction.
4737 if (trans->can_flush_pending_bgs &&
4738 trans->chunk_bytes_reserved >= (u64)SZ_2M) {
4739 btrfs_create_pending_block_groups(trans, fs_info);
4740 btrfs_trans_release_chunk_metadata(trans);
4742 return ret;
4745 static int can_overcommit(struct btrfs_fs_info *fs_info,
4746 struct btrfs_space_info *space_info, u64 bytes,
4747 enum btrfs_reserve_flush_enum flush,
4748 bool system_chunk)
4750 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
4751 u64 profile;
4752 u64 space_size;
4753 u64 avail;
4754 u64 used;
4756 /* Don't overcommit when in mixed mode. */
4757 if (space_info->flags & BTRFS_BLOCK_GROUP_DATA)
4758 return 0;
4760 if (system_chunk)
4761 profile = btrfs_system_alloc_profile(fs_info);
4762 else
4763 profile = btrfs_metadata_alloc_profile(fs_info);
4765 used = btrfs_space_info_used(space_info, false);
4768 * We only want to allow over committing if we have lots of actual space
4769 * free, but if we don't have enough space to handle the global reserve
4770 * space then we could end up having a real enospc problem when trying
4771 * to allocate a chunk or some other such important allocation.
4773 spin_lock(&global_rsv->lock);
4774 space_size = calc_global_rsv_need_space(global_rsv);
4775 spin_unlock(&global_rsv->lock);
4776 if (used + space_size >= space_info->total_bytes)
4777 return 0;
4779 used += space_info->bytes_may_use;
4781 avail = atomic64_read(&fs_info->free_chunk_space);
4784 * If we have dup, raid1 or raid10 then only half of the free
4785 * space is actually useable. For raid56, the space info used
4786 * doesn't include the parity drive, so we don't have to
4787 * change the math
4789 if (profile & (BTRFS_BLOCK_GROUP_DUP |
4790 BTRFS_BLOCK_GROUP_RAID1 |
4791 BTRFS_BLOCK_GROUP_RAID10))
4792 avail >>= 1;
4795 * If we aren't flushing all things, let us overcommit up to
4796 * 1/2th of the space. If we can flush, don't let us overcommit
4797 * too much, let it overcommit up to 1/8 of the space.
4799 if (flush == BTRFS_RESERVE_FLUSH_ALL)
4800 avail >>= 3;
4801 else
4802 avail >>= 1;
4804 if (used + bytes < space_info->total_bytes + avail)
4805 return 1;
4806 return 0;
4809 static void btrfs_writeback_inodes_sb_nr(struct btrfs_fs_info *fs_info,
4810 unsigned long nr_pages, int nr_items)
4812 struct super_block *sb = fs_info->sb;
4814 if (down_read_trylock(&sb->s_umount)) {
4815 writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE);
4816 up_read(&sb->s_umount);
4817 } else {
4819 * We needn't worry the filesystem going from r/w to r/o though
4820 * we don't acquire ->s_umount mutex, because the filesystem
4821 * should guarantee the delalloc inodes list be empty after
4822 * the filesystem is readonly(all dirty pages are written to
4823 * the disk).
4825 btrfs_start_delalloc_roots(fs_info, 0, nr_items);
4826 if (!current->journal_info)
4827 btrfs_wait_ordered_roots(fs_info, nr_items, 0, (u64)-1);
4831 static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
4832 u64 to_reclaim)
4834 u64 bytes;
4835 u64 nr;
4837 bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
4838 nr = div64_u64(to_reclaim, bytes);
4839 if (!nr)
4840 nr = 1;
4841 return nr;
4844 #define EXTENT_SIZE_PER_ITEM SZ_256K
4847 * shrink metadata reservation for delalloc
4849 static void shrink_delalloc(struct btrfs_fs_info *fs_info, u64 to_reclaim,
4850 u64 orig, bool wait_ordered)
4852 struct btrfs_block_rsv *block_rsv;
4853 struct btrfs_space_info *space_info;
4854 struct btrfs_trans_handle *trans;
4855 u64 delalloc_bytes;
4856 u64 max_reclaim;
4857 u64 items;
4858 long time_left;
4859 unsigned long nr_pages;
4860 int loops;
4861 enum btrfs_reserve_flush_enum flush;
4863 /* Calc the number of the pages we need flush for space reservation */
4864 items = calc_reclaim_items_nr(fs_info, to_reclaim);
4865 to_reclaim = items * EXTENT_SIZE_PER_ITEM;
4867 trans = (struct btrfs_trans_handle *)current->journal_info;
4868 block_rsv = &fs_info->delalloc_block_rsv;
4869 space_info = block_rsv->space_info;
4871 delalloc_bytes = percpu_counter_sum_positive(
4872 &fs_info->delalloc_bytes);
4873 if (delalloc_bytes == 0) {
4874 if (trans)
4875 return;
4876 if (wait_ordered)
4877 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
4878 return;
4881 loops = 0;
4882 while (delalloc_bytes && loops < 3) {
4883 max_reclaim = min(delalloc_bytes, to_reclaim);
4884 nr_pages = max_reclaim >> PAGE_SHIFT;
4885 btrfs_writeback_inodes_sb_nr(fs_info, nr_pages, items);
4887 * We need to wait for the async pages to actually start before
4888 * we do anything.
4890 max_reclaim = atomic_read(&fs_info->async_delalloc_pages);
4891 if (!max_reclaim)
4892 goto skip_async;
4894 if (max_reclaim <= nr_pages)
4895 max_reclaim = 0;
4896 else
4897 max_reclaim -= nr_pages;
4899 wait_event(fs_info->async_submit_wait,
4900 atomic_read(&fs_info->async_delalloc_pages) <=
4901 (int)max_reclaim);
4902 skip_async:
4903 if (!trans)
4904 flush = BTRFS_RESERVE_FLUSH_ALL;
4905 else
4906 flush = BTRFS_RESERVE_NO_FLUSH;
4907 spin_lock(&space_info->lock);
4908 if (list_empty(&space_info->tickets) &&
4909 list_empty(&space_info->priority_tickets)) {
4910 spin_unlock(&space_info->lock);
4911 break;
4913 spin_unlock(&space_info->lock);
4915 loops++;
4916 if (wait_ordered && !trans) {
4917 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
4918 } else {
4919 time_left = schedule_timeout_killable(1);
4920 if (time_left)
4921 break;
4923 delalloc_bytes = percpu_counter_sum_positive(
4924 &fs_info->delalloc_bytes);
4928 struct reserve_ticket {
4929 u64 bytes;
4930 int error;
4931 struct list_head list;
4932 wait_queue_head_t wait;
4936 * maybe_commit_transaction - possibly commit the transaction if its ok to
4937 * @root - the root we're allocating for
4938 * @bytes - the number of bytes we want to reserve
4939 * @force - force the commit
4941 * This will check to make sure that committing the transaction will actually
4942 * get us somewhere and then commit the transaction if it does. Otherwise it
4943 * will return -ENOSPC.
4945 static int may_commit_transaction(struct btrfs_fs_info *fs_info,
4946 struct btrfs_space_info *space_info)
4948 struct reserve_ticket *ticket = NULL;
4949 struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_block_rsv;
4950 struct btrfs_trans_handle *trans;
4951 u64 bytes;
4953 trans = (struct btrfs_trans_handle *)current->journal_info;
4954 if (trans)
4955 return -EAGAIN;
4957 spin_lock(&space_info->lock);
4958 if (!list_empty(&space_info->priority_tickets))
4959 ticket = list_first_entry(&space_info->priority_tickets,
4960 struct reserve_ticket, list);
4961 else if (!list_empty(&space_info->tickets))
4962 ticket = list_first_entry(&space_info->tickets,
4963 struct reserve_ticket, list);
4964 bytes = (ticket) ? ticket->bytes : 0;
4965 spin_unlock(&space_info->lock);
4967 if (!bytes)
4968 return 0;
4970 /* See if there is enough pinned space to make this reservation */
4971 if (percpu_counter_compare(&space_info->total_bytes_pinned,
4972 bytes) >= 0)
4973 goto commit;
4976 * See if there is some space in the delayed insertion reservation for
4977 * this reservation.
4979 if (space_info != delayed_rsv->space_info)
4980 return -ENOSPC;
4982 spin_lock(&delayed_rsv->lock);
4983 if (delayed_rsv->size > bytes)
4984 bytes = 0;
4985 else
4986 bytes -= delayed_rsv->size;
4987 if (percpu_counter_compare(&space_info->total_bytes_pinned,
4988 bytes) < 0) {
4989 spin_unlock(&delayed_rsv->lock);
4990 return -ENOSPC;
4992 spin_unlock(&delayed_rsv->lock);
4994 commit:
4995 trans = btrfs_join_transaction(fs_info->extent_root);
4996 if (IS_ERR(trans))
4997 return -ENOSPC;
4999 return btrfs_commit_transaction(trans);
5003 * Try to flush some data based on policy set by @state. This is only advisory
5004 * and may fail for various reasons. The caller is supposed to examine the
5005 * state of @space_info to detect the outcome.
5007 static void flush_space(struct btrfs_fs_info *fs_info,
5008 struct btrfs_space_info *space_info, u64 num_bytes,
5009 int state)
5011 struct btrfs_root *root = fs_info->extent_root;
5012 struct btrfs_trans_handle *trans;
5013 int nr;
5014 int ret = 0;
5016 switch (state) {
5017 case FLUSH_DELAYED_ITEMS_NR:
5018 case FLUSH_DELAYED_ITEMS:
5019 if (state == FLUSH_DELAYED_ITEMS_NR)
5020 nr = calc_reclaim_items_nr(fs_info, num_bytes) * 2;
5021 else
5022 nr = -1;
5024 trans = btrfs_join_transaction(root);
5025 if (IS_ERR(trans)) {
5026 ret = PTR_ERR(trans);
5027 break;
5029 ret = btrfs_run_delayed_items_nr(trans, fs_info, nr);
5030 btrfs_end_transaction(trans);
5031 break;
5032 case FLUSH_DELALLOC:
5033 case FLUSH_DELALLOC_WAIT:
5034 shrink_delalloc(fs_info, num_bytes * 2, num_bytes,
5035 state == FLUSH_DELALLOC_WAIT);
5036 break;
5037 case ALLOC_CHUNK:
5038 trans = btrfs_join_transaction(root);
5039 if (IS_ERR(trans)) {
5040 ret = PTR_ERR(trans);
5041 break;
5043 ret = do_chunk_alloc(trans, fs_info,
5044 btrfs_metadata_alloc_profile(fs_info),
5045 CHUNK_ALLOC_NO_FORCE);
5046 btrfs_end_transaction(trans);
5047 if (ret > 0 || ret == -ENOSPC)
5048 ret = 0;
5049 break;
5050 case COMMIT_TRANS:
5051 ret = may_commit_transaction(fs_info, space_info);
5052 break;
5053 default:
5054 ret = -ENOSPC;
5055 break;
5058 trace_btrfs_flush_space(fs_info, space_info->flags, num_bytes, state,
5059 ret);
5060 return;
5063 static inline u64
5064 btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info,
5065 struct btrfs_space_info *space_info,
5066 bool system_chunk)
5068 struct reserve_ticket *ticket;
5069 u64 used;
5070 u64 expected;
5071 u64 to_reclaim = 0;
5073 list_for_each_entry(ticket, &space_info->tickets, list)
5074 to_reclaim += ticket->bytes;
5075 list_for_each_entry(ticket, &space_info->priority_tickets, list)
5076 to_reclaim += ticket->bytes;
5077 if (to_reclaim)
5078 return to_reclaim;
5080 to_reclaim = min_t(u64, num_online_cpus() * SZ_1M, SZ_16M);
5081 if (can_overcommit(fs_info, space_info, to_reclaim,
5082 BTRFS_RESERVE_FLUSH_ALL, system_chunk))
5083 return 0;
5085 used = btrfs_space_info_used(space_info, true);
5087 if (can_overcommit(fs_info, space_info, SZ_1M,
5088 BTRFS_RESERVE_FLUSH_ALL, system_chunk))
5089 expected = div_factor_fine(space_info->total_bytes, 95);
5090 else
5091 expected = div_factor_fine(space_info->total_bytes, 90);
5093 if (used > expected)
5094 to_reclaim = used - expected;
5095 else
5096 to_reclaim = 0;
5097 to_reclaim = min(to_reclaim, space_info->bytes_may_use +
5098 space_info->bytes_reserved);
5099 return to_reclaim;
5102 static inline int need_do_async_reclaim(struct btrfs_fs_info *fs_info,
5103 struct btrfs_space_info *space_info,
5104 u64 used, bool system_chunk)
5106 u64 thresh = div_factor_fine(space_info->total_bytes, 98);
5108 /* If we're just plain full then async reclaim just slows us down. */
5109 if ((space_info->bytes_used + space_info->bytes_reserved) >= thresh)
5110 return 0;
5112 if (!btrfs_calc_reclaim_metadata_size(fs_info, space_info,
5113 system_chunk))
5114 return 0;
5116 return (used >= thresh && !btrfs_fs_closing(fs_info) &&
5117 !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
5120 static void wake_all_tickets(struct list_head *head)
5122 struct reserve_ticket *ticket;
5124 while (!list_empty(head)) {
5125 ticket = list_first_entry(head, struct reserve_ticket, list);
5126 list_del_init(&ticket->list);
5127 ticket->error = -ENOSPC;
5128 wake_up(&ticket->wait);
5133 * This is for normal flushers, we can wait all goddamned day if we want to. We
5134 * will loop and continuously try to flush as long as we are making progress.
5135 * We count progress as clearing off tickets each time we have to loop.
5137 static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
5139 struct btrfs_fs_info *fs_info;
5140 struct btrfs_space_info *space_info;
5141 u64 to_reclaim;
5142 int flush_state;
5143 int commit_cycles = 0;
5144 u64 last_tickets_id;
5146 fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
5147 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
5149 spin_lock(&space_info->lock);
5150 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info,
5151 false);
5152 if (!to_reclaim) {
5153 space_info->flush = 0;
5154 spin_unlock(&space_info->lock);
5155 return;
5157 last_tickets_id = space_info->tickets_id;
5158 spin_unlock(&space_info->lock);
5160 flush_state = FLUSH_DELAYED_ITEMS_NR;
5161 do {
5162 flush_space(fs_info, space_info, to_reclaim, flush_state);
5163 spin_lock(&space_info->lock);
5164 if (list_empty(&space_info->tickets)) {
5165 space_info->flush = 0;
5166 spin_unlock(&space_info->lock);
5167 return;
5169 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info,
5170 space_info,
5171 false);
5172 if (last_tickets_id == space_info->tickets_id) {
5173 flush_state++;
5174 } else {
5175 last_tickets_id = space_info->tickets_id;
5176 flush_state = FLUSH_DELAYED_ITEMS_NR;
5177 if (commit_cycles)
5178 commit_cycles--;
5181 if (flush_state > COMMIT_TRANS) {
5182 commit_cycles++;
5183 if (commit_cycles > 2) {
5184 wake_all_tickets(&space_info->tickets);
5185 space_info->flush = 0;
5186 } else {
5187 flush_state = FLUSH_DELAYED_ITEMS_NR;
5190 spin_unlock(&space_info->lock);
5191 } while (flush_state <= COMMIT_TRANS);
5194 void btrfs_init_async_reclaim_work(struct work_struct *work)
5196 INIT_WORK(work, btrfs_async_reclaim_metadata_space);
5199 static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
5200 struct btrfs_space_info *space_info,
5201 struct reserve_ticket *ticket)
5203 u64 to_reclaim;
5204 int flush_state = FLUSH_DELAYED_ITEMS_NR;
5206 spin_lock(&space_info->lock);
5207 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info,
5208 false);
5209 if (!to_reclaim) {
5210 spin_unlock(&space_info->lock);
5211 return;
5213 spin_unlock(&space_info->lock);
5215 do {
5216 flush_space(fs_info, space_info, to_reclaim, flush_state);
5217 flush_state++;
5218 spin_lock(&space_info->lock);
5219 if (ticket->bytes == 0) {
5220 spin_unlock(&space_info->lock);
5221 return;
5223 spin_unlock(&space_info->lock);
5226 * Priority flushers can't wait on delalloc without
5227 * deadlocking.
5229 if (flush_state == FLUSH_DELALLOC ||
5230 flush_state == FLUSH_DELALLOC_WAIT)
5231 flush_state = ALLOC_CHUNK;
5232 } while (flush_state < COMMIT_TRANS);
5235 static int wait_reserve_ticket(struct btrfs_fs_info *fs_info,
5236 struct btrfs_space_info *space_info,
5237 struct reserve_ticket *ticket, u64 orig_bytes)
5240 DEFINE_WAIT(wait);
5241 int ret = 0;
5243 spin_lock(&space_info->lock);
5244 while (ticket->bytes > 0 && ticket->error == 0) {
5245 ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE);
5246 if (ret) {
5247 ret = -EINTR;
5248 break;
5250 spin_unlock(&space_info->lock);
5252 schedule();
5254 finish_wait(&ticket->wait, &wait);
5255 spin_lock(&space_info->lock);
5257 if (!ret)
5258 ret = ticket->error;
5259 if (!list_empty(&ticket->list))
5260 list_del_init(&ticket->list);
5261 if (ticket->bytes && ticket->bytes < orig_bytes) {
5262 u64 num_bytes = orig_bytes - ticket->bytes;
5263 space_info->bytes_may_use -= num_bytes;
5264 trace_btrfs_space_reservation(fs_info, "space_info",
5265 space_info->flags, num_bytes, 0);
5267 spin_unlock(&space_info->lock);
5269 return ret;
5273 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
5274 * @root - the root we're allocating for
5275 * @space_info - the space info we want to allocate from
5276 * @orig_bytes - the number of bytes we want
5277 * @flush - whether or not we can flush to make our reservation
5279 * This will reserve orig_bytes number of bytes from the space info associated
5280 * with the block_rsv. If there is not enough space it will make an attempt to
5281 * flush out space to make room. It will do this by flushing delalloc if
5282 * possible or committing the transaction. If flush is 0 then no attempts to
5283 * regain reservations will be made and this will fail if there is not enough
5284 * space already.
5286 static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
5287 struct btrfs_space_info *space_info,
5288 u64 orig_bytes,
5289 enum btrfs_reserve_flush_enum flush,
5290 bool system_chunk)
5292 struct reserve_ticket ticket;
5293 u64 used;
5294 int ret = 0;
5296 ASSERT(orig_bytes);
5297 ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL);
5299 spin_lock(&space_info->lock);
5300 ret = -ENOSPC;
5301 used = btrfs_space_info_used(space_info, true);
5304 * If we have enough space then hooray, make our reservation and carry
5305 * on. If not see if we can overcommit, and if we can, hooray carry on.
5306 * If not things get more complicated.
5308 if (used + orig_bytes <= space_info->total_bytes) {
5309 space_info->bytes_may_use += orig_bytes;
5310 trace_btrfs_space_reservation(fs_info, "space_info",
5311 space_info->flags, orig_bytes, 1);
5312 ret = 0;
5313 } else if (can_overcommit(fs_info, space_info, orig_bytes, flush,
5314 system_chunk)) {
5315 space_info->bytes_may_use += orig_bytes;
5316 trace_btrfs_space_reservation(fs_info, "space_info",
5317 space_info->flags, orig_bytes, 1);
5318 ret = 0;
5322 * If we couldn't make a reservation then setup our reservation ticket
5323 * and kick the async worker if it's not already running.
5325 * If we are a priority flusher then we just need to add our ticket to
5326 * the list and we will do our own flushing further down.
5328 if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
5329 ticket.bytes = orig_bytes;
5330 ticket.error = 0;
5331 init_waitqueue_head(&ticket.wait);
5332 if (flush == BTRFS_RESERVE_FLUSH_ALL) {
5333 list_add_tail(&ticket.list, &space_info->tickets);
5334 if (!space_info->flush) {
5335 space_info->flush = 1;
5336 trace_btrfs_trigger_flush(fs_info,
5337 space_info->flags,
5338 orig_bytes, flush,
5339 "enospc");
5340 queue_work(system_unbound_wq,
5341 &fs_info->async_reclaim_work);
5343 } else {
5344 list_add_tail(&ticket.list,
5345 &space_info->priority_tickets);
5347 } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
5348 used += orig_bytes;
5350 * We will do the space reservation dance during log replay,
5351 * which means we won't have fs_info->fs_root set, so don't do
5352 * the async reclaim as we will panic.
5354 if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags) &&
5355 need_do_async_reclaim(fs_info, space_info,
5356 used, system_chunk) &&
5357 !work_busy(&fs_info->async_reclaim_work)) {
5358 trace_btrfs_trigger_flush(fs_info, space_info->flags,
5359 orig_bytes, flush, "preempt");
5360 queue_work(system_unbound_wq,
5361 &fs_info->async_reclaim_work);
5364 spin_unlock(&space_info->lock);
5365 if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
5366 return ret;
5368 if (flush == BTRFS_RESERVE_FLUSH_ALL)
5369 return wait_reserve_ticket(fs_info, space_info, &ticket,
5370 orig_bytes);
5372 ret = 0;
5373 priority_reclaim_metadata_space(fs_info, space_info, &ticket);
5374 spin_lock(&space_info->lock);
5375 if (ticket.bytes) {
5376 if (ticket.bytes < orig_bytes) {
5377 u64 num_bytes = orig_bytes - ticket.bytes;
5378 space_info->bytes_may_use -= num_bytes;
5379 trace_btrfs_space_reservation(fs_info, "space_info",
5380 space_info->flags,
5381 num_bytes, 0);
5384 list_del_init(&ticket.list);
5385 ret = -ENOSPC;
5387 spin_unlock(&space_info->lock);
5388 ASSERT(list_empty(&ticket.list));
5389 return ret;
5393 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
5394 * @root - the root we're allocating for
5395 * @block_rsv - the block_rsv we're allocating for
5396 * @orig_bytes - the number of bytes we want
5397 * @flush - whether or not we can flush to make our reservation
5399 * This will reserve orgi_bytes number of bytes from the space info associated
5400 * with the block_rsv. If there is not enough space it will make an attempt to
5401 * flush out space to make room. It will do this by flushing delalloc if
5402 * possible or committing the transaction. If flush is 0 then no attempts to
5403 * regain reservations will be made and this will fail if there is not enough
5404 * space already.
5406 static int reserve_metadata_bytes(struct btrfs_root *root,
5407 struct btrfs_block_rsv *block_rsv,
5408 u64 orig_bytes,
5409 enum btrfs_reserve_flush_enum flush)
5411 struct btrfs_fs_info *fs_info = root->fs_info;
5412 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5413 int ret;
5414 bool system_chunk = (root == fs_info->chunk_root);
5416 ret = __reserve_metadata_bytes(fs_info, block_rsv->space_info,
5417 orig_bytes, flush, system_chunk);
5418 if (ret == -ENOSPC &&
5419 unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
5420 if (block_rsv != global_rsv &&
5421 !block_rsv_use_bytes(global_rsv, orig_bytes))
5422 ret = 0;
5424 if (ret == -ENOSPC)
5425 trace_btrfs_space_reservation(fs_info, "space_info:enospc",
5426 block_rsv->space_info->flags,
5427 orig_bytes, 1);
5428 return ret;
5431 static struct btrfs_block_rsv *get_block_rsv(
5432 const struct btrfs_trans_handle *trans,
5433 const struct btrfs_root *root)
5435 struct btrfs_fs_info *fs_info = root->fs_info;
5436 struct btrfs_block_rsv *block_rsv = NULL;
5438 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
5439 (root == fs_info->csum_root && trans->adding_csums) ||
5440 (root == fs_info->uuid_root))
5441 block_rsv = trans->block_rsv;
5443 if (!block_rsv)
5444 block_rsv = root->block_rsv;
5446 if (!block_rsv)
5447 block_rsv = &fs_info->empty_block_rsv;
5449 return block_rsv;
5452 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
5453 u64 num_bytes)
5455 int ret = -ENOSPC;
5456 spin_lock(&block_rsv->lock);
5457 if (block_rsv->reserved >= num_bytes) {
5458 block_rsv->reserved -= num_bytes;
5459 if (block_rsv->reserved < block_rsv->size)
5460 block_rsv->full = 0;
5461 ret = 0;
5463 spin_unlock(&block_rsv->lock);
5464 return ret;
5467 static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
5468 u64 num_bytes, int update_size)
5470 spin_lock(&block_rsv->lock);
5471 block_rsv->reserved += num_bytes;
5472 if (update_size)
5473 block_rsv->size += num_bytes;
5474 else if (block_rsv->reserved >= block_rsv->size)
5475 block_rsv->full = 1;
5476 spin_unlock(&block_rsv->lock);
5479 int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
5480 struct btrfs_block_rsv *dest, u64 num_bytes,
5481 int min_factor)
5483 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5484 u64 min_bytes;
5486 if (global_rsv->space_info != dest->space_info)
5487 return -ENOSPC;
5489 spin_lock(&global_rsv->lock);
5490 min_bytes = div_factor(global_rsv->size, min_factor);
5491 if (global_rsv->reserved < min_bytes + num_bytes) {
5492 spin_unlock(&global_rsv->lock);
5493 return -ENOSPC;
5495 global_rsv->reserved -= num_bytes;
5496 if (global_rsv->reserved < global_rsv->size)
5497 global_rsv->full = 0;
5498 spin_unlock(&global_rsv->lock);
5500 block_rsv_add_bytes(dest, num_bytes, 1);
5501 return 0;
5505 * This is for space we already have accounted in space_info->bytes_may_use, so
5506 * basically when we're returning space from block_rsv's.
5508 static void space_info_add_old_bytes(struct btrfs_fs_info *fs_info,
5509 struct btrfs_space_info *space_info,
5510 u64 num_bytes)
5512 struct reserve_ticket *ticket;
5513 struct list_head *head;
5514 u64 used;
5515 enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH;
5516 bool check_overcommit = false;
5518 spin_lock(&space_info->lock);
5519 head = &space_info->priority_tickets;
5522 * If we are over our limit then we need to check and see if we can
5523 * overcommit, and if we can't then we just need to free up our space
5524 * and not satisfy any requests.
5526 used = btrfs_space_info_used(space_info, true);
5527 if (used - num_bytes >= space_info->total_bytes)
5528 check_overcommit = true;
5529 again:
5530 while (!list_empty(head) && num_bytes) {
5531 ticket = list_first_entry(head, struct reserve_ticket,
5532 list);
5534 * We use 0 bytes because this space is already reserved, so
5535 * adding the ticket space would be a double count.
5537 if (check_overcommit &&
5538 !can_overcommit(fs_info, space_info, 0, flush, false))
5539 break;
5540 if (num_bytes >= ticket->bytes) {
5541 list_del_init(&ticket->list);
5542 num_bytes -= ticket->bytes;
5543 ticket->bytes = 0;
5544 space_info->tickets_id++;
5545 wake_up(&ticket->wait);
5546 } else {
5547 ticket->bytes -= num_bytes;
5548 num_bytes = 0;
5552 if (num_bytes && head == &space_info->priority_tickets) {
5553 head = &space_info->tickets;
5554 flush = BTRFS_RESERVE_FLUSH_ALL;
5555 goto again;
5557 space_info->bytes_may_use -= num_bytes;
5558 trace_btrfs_space_reservation(fs_info, "space_info",
5559 space_info->flags, num_bytes, 0);
5560 spin_unlock(&space_info->lock);
5564 * This is for newly allocated space that isn't accounted in
5565 * space_info->bytes_may_use yet. So if we allocate a chunk or unpin an extent
5566 * we use this helper.
5568 static void space_info_add_new_bytes(struct btrfs_fs_info *fs_info,
5569 struct btrfs_space_info *space_info,
5570 u64 num_bytes)
5572 struct reserve_ticket *ticket;
5573 struct list_head *head = &space_info->priority_tickets;
5575 again:
5576 while (!list_empty(head) && num_bytes) {
5577 ticket = list_first_entry(head, struct reserve_ticket,
5578 list);
5579 if (num_bytes >= ticket->bytes) {
5580 trace_btrfs_space_reservation(fs_info, "space_info",
5581 space_info->flags,
5582 ticket->bytes, 1);
5583 list_del_init(&ticket->list);
5584 num_bytes -= ticket->bytes;
5585 space_info->bytes_may_use += ticket->bytes;
5586 ticket->bytes = 0;
5587 space_info->tickets_id++;
5588 wake_up(&ticket->wait);
5589 } else {
5590 trace_btrfs_space_reservation(fs_info, "space_info",
5591 space_info->flags,
5592 num_bytes, 1);
5593 space_info->bytes_may_use += num_bytes;
5594 ticket->bytes -= num_bytes;
5595 num_bytes = 0;
5599 if (num_bytes && head == &space_info->priority_tickets) {
5600 head = &space_info->tickets;
5601 goto again;
5605 static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
5606 struct btrfs_block_rsv *block_rsv,
5607 struct btrfs_block_rsv *dest, u64 num_bytes)
5609 struct btrfs_space_info *space_info = block_rsv->space_info;
5611 spin_lock(&block_rsv->lock);
5612 if (num_bytes == (u64)-1)
5613 num_bytes = block_rsv->size;
5614 block_rsv->size -= num_bytes;
5615 if (block_rsv->reserved >= block_rsv->size) {
5616 num_bytes = block_rsv->reserved - block_rsv->size;
5617 block_rsv->reserved = block_rsv->size;
5618 block_rsv->full = 1;
5619 } else {
5620 num_bytes = 0;
5622 spin_unlock(&block_rsv->lock);
5624 if (num_bytes > 0) {
5625 if (dest) {
5626 spin_lock(&dest->lock);
5627 if (!dest->full) {
5628 u64 bytes_to_add;
5630 bytes_to_add = dest->size - dest->reserved;
5631 bytes_to_add = min(num_bytes, bytes_to_add);
5632 dest->reserved += bytes_to_add;
5633 if (dest->reserved >= dest->size)
5634 dest->full = 1;
5635 num_bytes -= bytes_to_add;
5637 spin_unlock(&dest->lock);
5639 if (num_bytes)
5640 space_info_add_old_bytes(fs_info, space_info,
5641 num_bytes);
5645 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src,
5646 struct btrfs_block_rsv *dst, u64 num_bytes,
5647 int update_size)
5649 int ret;
5651 ret = block_rsv_use_bytes(src, num_bytes);
5652 if (ret)
5653 return ret;
5655 block_rsv_add_bytes(dst, num_bytes, update_size);
5656 return 0;
5659 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
5661 memset(rsv, 0, sizeof(*rsv));
5662 spin_lock_init(&rsv->lock);
5663 rsv->type = type;
5666 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
5667 unsigned short type)
5669 struct btrfs_block_rsv *block_rsv;
5671 block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
5672 if (!block_rsv)
5673 return NULL;
5675 btrfs_init_block_rsv(block_rsv, type);
5676 block_rsv->space_info = __find_space_info(fs_info,
5677 BTRFS_BLOCK_GROUP_METADATA);
5678 return block_rsv;
5681 void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
5682 struct btrfs_block_rsv *rsv)
5684 if (!rsv)
5685 return;
5686 btrfs_block_rsv_release(fs_info, rsv, (u64)-1);
5687 kfree(rsv);
5690 void __btrfs_free_block_rsv(struct btrfs_block_rsv *rsv)
5692 kfree(rsv);
5695 int btrfs_block_rsv_add(struct btrfs_root *root,
5696 struct btrfs_block_rsv *block_rsv, u64 num_bytes,
5697 enum btrfs_reserve_flush_enum flush)
5699 int ret;
5701 if (num_bytes == 0)
5702 return 0;
5704 ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
5705 if (!ret) {
5706 block_rsv_add_bytes(block_rsv, num_bytes, 1);
5707 return 0;
5710 return ret;
5713 int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_factor)
5715 u64 num_bytes = 0;
5716 int ret = -ENOSPC;
5718 if (!block_rsv)
5719 return 0;
5721 spin_lock(&block_rsv->lock);
5722 num_bytes = div_factor(block_rsv->size, min_factor);
5723 if (block_rsv->reserved >= num_bytes)
5724 ret = 0;
5725 spin_unlock(&block_rsv->lock);
5727 return ret;
5730 int btrfs_block_rsv_refill(struct btrfs_root *root,
5731 struct btrfs_block_rsv *block_rsv, u64 min_reserved,
5732 enum btrfs_reserve_flush_enum flush)
5734 u64 num_bytes = 0;
5735 int ret = -ENOSPC;
5737 if (!block_rsv)
5738 return 0;
5740 spin_lock(&block_rsv->lock);
5741 num_bytes = min_reserved;
5742 if (block_rsv->reserved >= num_bytes)
5743 ret = 0;
5744 else
5745 num_bytes -= block_rsv->reserved;
5746 spin_unlock(&block_rsv->lock);
5748 if (!ret)
5749 return 0;
5751 ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
5752 if (!ret) {
5753 block_rsv_add_bytes(block_rsv, num_bytes, 0);
5754 return 0;
5757 return ret;
5760 void btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
5761 struct btrfs_block_rsv *block_rsv,
5762 u64 num_bytes)
5764 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5766 if (global_rsv == block_rsv ||
5767 block_rsv->space_info != global_rsv->space_info)
5768 global_rsv = NULL;
5769 block_rsv_release_bytes(fs_info, block_rsv, global_rsv, num_bytes);
5772 static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
5774 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
5775 struct btrfs_space_info *sinfo = block_rsv->space_info;
5776 u64 num_bytes;
5779 * The global block rsv is based on the size of the extent tree, the
5780 * checksum tree and the root tree. If the fs is empty we want to set
5781 * it to a minimal amount for safety.
5783 num_bytes = btrfs_root_used(&fs_info->extent_root->root_item) +
5784 btrfs_root_used(&fs_info->csum_root->root_item) +
5785 btrfs_root_used(&fs_info->tree_root->root_item);
5786 num_bytes = max_t(u64, num_bytes, SZ_16M);
5788 spin_lock(&sinfo->lock);
5789 spin_lock(&block_rsv->lock);
5791 block_rsv->size = min_t(u64, num_bytes, SZ_512M);
5793 if (block_rsv->reserved < block_rsv->size) {
5794 num_bytes = btrfs_space_info_used(sinfo, true);
5795 if (sinfo->total_bytes > num_bytes) {
5796 num_bytes = sinfo->total_bytes - num_bytes;
5797 num_bytes = min(num_bytes,
5798 block_rsv->size - block_rsv->reserved);
5799 block_rsv->reserved += num_bytes;
5800 sinfo->bytes_may_use += num_bytes;
5801 trace_btrfs_space_reservation(fs_info, "space_info",
5802 sinfo->flags, num_bytes,
5805 } else if (block_rsv->reserved > block_rsv->size) {
5806 num_bytes = block_rsv->reserved - block_rsv->size;
5807 sinfo->bytes_may_use -= num_bytes;
5808 trace_btrfs_space_reservation(fs_info, "space_info",
5809 sinfo->flags, num_bytes, 0);
5810 block_rsv->reserved = block_rsv->size;
5813 if (block_rsv->reserved == block_rsv->size)
5814 block_rsv->full = 1;
5815 else
5816 block_rsv->full = 0;
5818 spin_unlock(&block_rsv->lock);
5819 spin_unlock(&sinfo->lock);
5822 static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
5824 struct btrfs_space_info *space_info;
5826 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
5827 fs_info->chunk_block_rsv.space_info = space_info;
5829 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
5830 fs_info->global_block_rsv.space_info = space_info;
5831 fs_info->delalloc_block_rsv.space_info = space_info;
5832 fs_info->trans_block_rsv.space_info = space_info;
5833 fs_info->empty_block_rsv.space_info = space_info;
5834 fs_info->delayed_block_rsv.space_info = space_info;
5836 fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
5837 fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
5838 fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
5839 fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
5840 if (fs_info->quota_root)
5841 fs_info->quota_root->block_rsv = &fs_info->global_block_rsv;
5842 fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
5844 update_global_block_rsv(fs_info);
5847 static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
5849 block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL,
5850 (u64)-1);
5851 WARN_ON(fs_info->delalloc_block_rsv.size > 0);
5852 WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
5853 WARN_ON(fs_info->trans_block_rsv.size > 0);
5854 WARN_ON(fs_info->trans_block_rsv.reserved > 0);
5855 WARN_ON(fs_info->chunk_block_rsv.size > 0);
5856 WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
5857 WARN_ON(fs_info->delayed_block_rsv.size > 0);
5858 WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
5861 void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
5862 struct btrfs_fs_info *fs_info)
5864 if (!trans->block_rsv)
5865 return;
5867 if (!trans->bytes_reserved)
5868 return;
5870 trace_btrfs_space_reservation(fs_info, "transaction",
5871 trans->transid, trans->bytes_reserved, 0);
5872 btrfs_block_rsv_release(fs_info, trans->block_rsv,
5873 trans->bytes_reserved);
5874 trans->bytes_reserved = 0;
5878 * To be called after all the new block groups attached to the transaction
5879 * handle have been created (btrfs_create_pending_block_groups()).
5881 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans)
5883 struct btrfs_fs_info *fs_info = trans->fs_info;
5885 if (!trans->chunk_bytes_reserved)
5886 return;
5888 WARN_ON_ONCE(!list_empty(&trans->new_bgs));
5890 block_rsv_release_bytes(fs_info, &fs_info->chunk_block_rsv, NULL,
5891 trans->chunk_bytes_reserved);
5892 trans->chunk_bytes_reserved = 0;
5895 /* Can only return 0 or -ENOSPC */
5896 int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
5897 struct btrfs_inode *inode)
5899 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
5900 struct btrfs_root *root = inode->root;
5902 * We always use trans->block_rsv here as we will have reserved space
5903 * for our orphan when starting the transaction, using get_block_rsv()
5904 * here will sometimes make us choose the wrong block rsv as we could be
5905 * doing a reloc inode for a non refcounted root.
5907 struct btrfs_block_rsv *src_rsv = trans->block_rsv;
5908 struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
5911 * We need to hold space in order to delete our orphan item once we've
5912 * added it, so this takes the reservation so we can release it later
5913 * when we are truly done with the orphan item.
5915 u64 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
5917 trace_btrfs_space_reservation(fs_info, "orphan", btrfs_ino(inode),
5918 num_bytes, 1);
5919 return btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, 1);
5922 void btrfs_orphan_release_metadata(struct btrfs_inode *inode)
5924 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
5925 struct btrfs_root *root = inode->root;
5926 u64 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
5928 trace_btrfs_space_reservation(fs_info, "orphan", btrfs_ino(inode),
5929 num_bytes, 0);
5930 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv, num_bytes);
5934 * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
5935 * root: the root of the parent directory
5936 * rsv: block reservation
5937 * items: the number of items that we need do reservation
5938 * qgroup_reserved: used to return the reserved size in qgroup
5940 * This function is used to reserve the space for snapshot/subvolume
5941 * creation and deletion. Those operations are different with the
5942 * common file/directory operations, they change two fs/file trees
5943 * and root tree, the number of items that the qgroup reserves is
5944 * different with the free space reservation. So we can not use
5945 * the space reservation mechanism in start_transaction().
5947 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
5948 struct btrfs_block_rsv *rsv,
5949 int items,
5950 u64 *qgroup_reserved,
5951 bool use_global_rsv)
5953 u64 num_bytes;
5954 int ret;
5955 struct btrfs_fs_info *fs_info = root->fs_info;
5956 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5958 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
5959 /* One for parent inode, two for dir entries */
5960 num_bytes = 3 * fs_info->nodesize;
5961 ret = btrfs_qgroup_reserve_meta(root, num_bytes, true);
5962 if (ret)
5963 return ret;
5964 } else {
5965 num_bytes = 0;
5968 *qgroup_reserved = num_bytes;
5970 num_bytes = btrfs_calc_trans_metadata_size(fs_info, items);
5971 rsv->space_info = __find_space_info(fs_info,
5972 BTRFS_BLOCK_GROUP_METADATA);
5973 ret = btrfs_block_rsv_add(root, rsv, num_bytes,
5974 BTRFS_RESERVE_FLUSH_ALL);
5976 if (ret == -ENOSPC && use_global_rsv)
5977 ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes, 1);
5979 if (ret && *qgroup_reserved)
5980 btrfs_qgroup_free_meta(root, *qgroup_reserved);
5982 return ret;
5985 void btrfs_subvolume_release_metadata(struct btrfs_fs_info *fs_info,
5986 struct btrfs_block_rsv *rsv)
5988 btrfs_block_rsv_release(fs_info, rsv, (u64)-1);
5992 * drop_outstanding_extent - drop an outstanding extent
5993 * @inode: the inode we're dropping the extent for
5994 * @num_bytes: the number of bytes we're releasing.
5996 * This is called when we are freeing up an outstanding extent, either called
5997 * after an error or after an extent is written. This will return the number of
5998 * reserved extents that need to be freed. This must be called with
5999 * BTRFS_I(inode)->lock held.
6001 static unsigned drop_outstanding_extent(struct btrfs_inode *inode,
6002 u64 num_bytes)
6004 unsigned drop_inode_space = 0;
6005 unsigned dropped_extents = 0;
6006 unsigned num_extents;
6008 num_extents = count_max_extents(num_bytes);
6009 ASSERT(num_extents);
6010 ASSERT(inode->outstanding_extents >= num_extents);
6011 inode->outstanding_extents -= num_extents;
6013 if (inode->outstanding_extents == 0 &&
6014 test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
6015 &inode->runtime_flags))
6016 drop_inode_space = 1;
6019 * If we have more or the same amount of outstanding extents than we have
6020 * reserved then we need to leave the reserved extents count alone.
6022 if (inode->outstanding_extents >= inode->reserved_extents)
6023 return drop_inode_space;
6025 dropped_extents = inode->reserved_extents - inode->outstanding_extents;
6026 inode->reserved_extents -= dropped_extents;
6027 return dropped_extents + drop_inode_space;
6031 * calc_csum_metadata_size - return the amount of metadata space that must be
6032 * reserved/freed for the given bytes.
6033 * @inode: the inode we're manipulating
6034 * @num_bytes: the number of bytes in question
6035 * @reserve: 1 if we are reserving space, 0 if we are freeing space
6037 * This adjusts the number of csum_bytes in the inode and then returns the
6038 * correct amount of metadata that must either be reserved or freed. We
6039 * calculate how many checksums we can fit into one leaf and then divide the
6040 * number of bytes that will need to be checksumed by this value to figure out
6041 * how many checksums will be required. If we are adding bytes then the number
6042 * may go up and we will return the number of additional bytes that must be
6043 * reserved. If it is going down we will return the number of bytes that must
6044 * be freed.
6046 * This must be called with BTRFS_I(inode)->lock held.
6048 static u64 calc_csum_metadata_size(struct btrfs_inode *inode, u64 num_bytes,
6049 int reserve)
6051 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6052 u64 old_csums, num_csums;
6054 if (inode->flags & BTRFS_INODE_NODATASUM && inode->csum_bytes == 0)
6055 return 0;
6057 old_csums = btrfs_csum_bytes_to_leaves(fs_info, inode->csum_bytes);
6058 if (reserve)
6059 inode->csum_bytes += num_bytes;
6060 else
6061 inode->csum_bytes -= num_bytes;
6062 num_csums = btrfs_csum_bytes_to_leaves(fs_info, inode->csum_bytes);
6064 /* No change, no need to reserve more */
6065 if (old_csums == num_csums)
6066 return 0;
6068 if (reserve)
6069 return btrfs_calc_trans_metadata_size(fs_info,
6070 num_csums - old_csums);
6072 return btrfs_calc_trans_metadata_size(fs_info, old_csums - num_csums);
6075 int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
6077 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6078 struct btrfs_root *root = inode->root;
6079 struct btrfs_block_rsv *block_rsv = &fs_info->delalloc_block_rsv;
6080 u64 to_reserve = 0;
6081 u64 csum_bytes;
6082 unsigned nr_extents;
6083 enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL;
6084 int ret = 0;
6085 bool delalloc_lock = true;
6086 u64 to_free = 0;
6087 unsigned dropped;
6088 bool release_extra = false;
6090 /* If we are a free space inode we need to not flush since we will be in
6091 * the middle of a transaction commit. We also don't need the delalloc
6092 * mutex since we won't race with anybody. We need this mostly to make
6093 * lockdep shut its filthy mouth.
6095 * If we have a transaction open (can happen if we call truncate_block
6096 * from truncate), then we need FLUSH_LIMIT so we don't deadlock.
6098 if (btrfs_is_free_space_inode(inode)) {
6099 flush = BTRFS_RESERVE_NO_FLUSH;
6100 delalloc_lock = false;
6101 } else if (current->journal_info) {
6102 flush = BTRFS_RESERVE_FLUSH_LIMIT;
6105 if (flush != BTRFS_RESERVE_NO_FLUSH &&
6106 btrfs_transaction_in_commit(fs_info))
6107 schedule_timeout(1);
6109 if (delalloc_lock)
6110 mutex_lock(&inode->delalloc_mutex);
6112 num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
6114 spin_lock(&inode->lock);
6115 nr_extents = count_max_extents(num_bytes);
6116 inode->outstanding_extents += nr_extents;
6118 nr_extents = 0;
6119 if (inode->outstanding_extents > inode->reserved_extents)
6120 nr_extents += inode->outstanding_extents -
6121 inode->reserved_extents;
6123 /* We always want to reserve a slot for updating the inode. */
6124 to_reserve = btrfs_calc_trans_metadata_size(fs_info, nr_extents + 1);
6125 to_reserve += calc_csum_metadata_size(inode, num_bytes, 1);
6126 csum_bytes = inode->csum_bytes;
6127 spin_unlock(&inode->lock);
6129 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
6130 ret = btrfs_qgroup_reserve_meta(root,
6131 nr_extents * fs_info->nodesize, true);
6132 if (ret)
6133 goto out_fail;
6136 ret = btrfs_block_rsv_add(root, block_rsv, to_reserve, flush);
6137 if (unlikely(ret)) {
6138 btrfs_qgroup_free_meta(root,
6139 nr_extents * fs_info->nodesize);
6140 goto out_fail;
6143 spin_lock(&inode->lock);
6144 if (test_and_set_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
6145 &inode->runtime_flags)) {
6146 to_reserve -= btrfs_calc_trans_metadata_size(fs_info, 1);
6147 release_extra = true;
6149 inode->reserved_extents += nr_extents;
6150 spin_unlock(&inode->lock);
6152 if (delalloc_lock)
6153 mutex_unlock(&inode->delalloc_mutex);
6155 if (to_reserve)
6156 trace_btrfs_space_reservation(fs_info, "delalloc",
6157 btrfs_ino(inode), to_reserve, 1);
6158 if (release_extra)
6159 btrfs_block_rsv_release(fs_info, block_rsv,
6160 btrfs_calc_trans_metadata_size(fs_info, 1));
6161 return 0;
6163 out_fail:
6164 spin_lock(&inode->lock);
6165 dropped = drop_outstanding_extent(inode, num_bytes);
6167 * If the inodes csum_bytes is the same as the original
6168 * csum_bytes then we know we haven't raced with any free()ers
6169 * so we can just reduce our inodes csum bytes and carry on.
6171 if (inode->csum_bytes == csum_bytes) {
6172 calc_csum_metadata_size(inode, num_bytes, 0);
6173 } else {
6174 u64 orig_csum_bytes = inode->csum_bytes;
6175 u64 bytes;
6178 * This is tricky, but first we need to figure out how much we
6179 * freed from any free-ers that occurred during this
6180 * reservation, so we reset ->csum_bytes to the csum_bytes
6181 * before we dropped our lock, and then call the free for the
6182 * number of bytes that were freed while we were trying our
6183 * reservation.
6185 bytes = csum_bytes - inode->csum_bytes;
6186 inode->csum_bytes = csum_bytes;
6187 to_free = calc_csum_metadata_size(inode, bytes, 0);
6191 * Now we need to see how much we would have freed had we not
6192 * been making this reservation and our ->csum_bytes were not
6193 * artificially inflated.
6195 inode->csum_bytes = csum_bytes - num_bytes;
6196 bytes = csum_bytes - orig_csum_bytes;
6197 bytes = calc_csum_metadata_size(inode, bytes, 0);
6200 * Now reset ->csum_bytes to what it should be. If bytes is
6201 * more than to_free then we would have freed more space had we
6202 * not had an artificially high ->csum_bytes, so we need to free
6203 * the remainder. If bytes is the same or less then we don't
6204 * need to do anything, the other free-ers did the correct
6205 * thing.
6207 inode->csum_bytes = orig_csum_bytes - num_bytes;
6208 if (bytes > to_free)
6209 to_free = bytes - to_free;
6210 else
6211 to_free = 0;
6213 spin_unlock(&inode->lock);
6214 if (dropped)
6215 to_free += btrfs_calc_trans_metadata_size(fs_info, dropped);
6217 if (to_free) {
6218 btrfs_block_rsv_release(fs_info, block_rsv, to_free);
6219 trace_btrfs_space_reservation(fs_info, "delalloc",
6220 btrfs_ino(inode), to_free, 0);
6222 if (delalloc_lock)
6223 mutex_unlock(&inode->delalloc_mutex);
6224 return ret;
6228 * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
6229 * @inode: the inode to release the reservation for
6230 * @num_bytes: the number of bytes we're releasing
6232 * This will release the metadata reservation for an inode. This can be called
6233 * once we complete IO for a given set of bytes to release their metadata
6234 * reservations.
6236 void btrfs_delalloc_release_metadata(struct btrfs_inode *inode, u64 num_bytes)
6238 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6239 u64 to_free = 0;
6240 unsigned dropped;
6242 num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
6243 spin_lock(&inode->lock);
6244 dropped = drop_outstanding_extent(inode, num_bytes);
6246 if (num_bytes)
6247 to_free = calc_csum_metadata_size(inode, num_bytes, 0);
6248 spin_unlock(&inode->lock);
6249 if (dropped > 0)
6250 to_free += btrfs_calc_trans_metadata_size(fs_info, dropped);
6252 if (btrfs_is_testing(fs_info))
6253 return;
6255 trace_btrfs_space_reservation(fs_info, "delalloc", btrfs_ino(inode),
6256 to_free, 0);
6258 btrfs_block_rsv_release(fs_info, &fs_info->delalloc_block_rsv, to_free);
6262 * btrfs_delalloc_reserve_space - reserve data and metadata space for
6263 * delalloc
6264 * @inode: inode we're writing to
6265 * @start: start range we are writing to
6266 * @len: how long the range we are writing to
6267 * @reserved: mandatory parameter, record actually reserved qgroup ranges of
6268 * current reservation.
6270 * This will do the following things
6272 * o reserve space in data space info for num bytes
6273 * and reserve precious corresponding qgroup space
6274 * (Done in check_data_free_space)
6276 * o reserve space for metadata space, based on the number of outstanding
6277 * extents and how much csums will be needed
6278 * also reserve metadata space in a per root over-reserve method.
6279 * o add to the inodes->delalloc_bytes
6280 * o add it to the fs_info's delalloc inodes list.
6281 * (Above 3 all done in delalloc_reserve_metadata)
6283 * Return 0 for success
6284 * Return <0 for error(-ENOSPC or -EQUOT)
6286 int btrfs_delalloc_reserve_space(struct inode *inode,
6287 struct extent_changeset **reserved, u64 start, u64 len)
6289 int ret;
6291 ret = btrfs_check_data_free_space(inode, reserved, start, len);
6292 if (ret < 0)
6293 return ret;
6294 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len);
6295 if (ret < 0)
6296 btrfs_free_reserved_data_space(inode, *reserved, start, len);
6297 return ret;
6301 * btrfs_delalloc_release_space - release data and metadata space for delalloc
6302 * @inode: inode we're releasing space for
6303 * @start: start position of the space already reserved
6304 * @len: the len of the space already reserved
6306 * This must be matched with a call to btrfs_delalloc_reserve_space. This is
6307 * called in the case that we don't need the metadata AND data reservations
6308 * anymore. So if there is an error or we insert an inline extent.
6310 * This function will release the metadata space that was not used and will
6311 * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
6312 * list if there are no delalloc bytes left.
6313 * Also it will handle the qgroup reserved space.
6315 void btrfs_delalloc_release_space(struct inode *inode,
6316 struct extent_changeset *reserved, u64 start, u64 len)
6318 btrfs_delalloc_release_metadata(BTRFS_I(inode), len);
6319 btrfs_free_reserved_data_space(inode, reserved, start, len);
6322 static int update_block_group(struct btrfs_trans_handle *trans,
6323 struct btrfs_fs_info *info, u64 bytenr,
6324 u64 num_bytes, int alloc)
6326 struct btrfs_block_group_cache *cache = NULL;
6327 u64 total = num_bytes;
6328 u64 old_val;
6329 u64 byte_in_group;
6330 int factor;
6332 /* block accounting for super block */
6333 spin_lock(&info->delalloc_root_lock);
6334 old_val = btrfs_super_bytes_used(info->super_copy);
6335 if (alloc)
6336 old_val += num_bytes;
6337 else
6338 old_val -= num_bytes;
6339 btrfs_set_super_bytes_used(info->super_copy, old_val);
6340 spin_unlock(&info->delalloc_root_lock);
6342 while (total) {
6343 cache = btrfs_lookup_block_group(info, bytenr);
6344 if (!cache)
6345 return -ENOENT;
6346 if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
6347 BTRFS_BLOCK_GROUP_RAID1 |
6348 BTRFS_BLOCK_GROUP_RAID10))
6349 factor = 2;
6350 else
6351 factor = 1;
6353 * If this block group has free space cache written out, we
6354 * need to make sure to load it if we are removing space. This
6355 * is because we need the unpinning stage to actually add the
6356 * space back to the block group, otherwise we will leak space.
6358 if (!alloc && cache->cached == BTRFS_CACHE_NO)
6359 cache_block_group(cache, 1);
6361 byte_in_group = bytenr - cache->key.objectid;
6362 WARN_ON(byte_in_group > cache->key.offset);
6364 spin_lock(&cache->space_info->lock);
6365 spin_lock(&cache->lock);
6367 if (btrfs_test_opt(info, SPACE_CACHE) &&
6368 cache->disk_cache_state < BTRFS_DC_CLEAR)
6369 cache->disk_cache_state = BTRFS_DC_CLEAR;
6371 old_val = btrfs_block_group_used(&cache->item);
6372 num_bytes = min(total, cache->key.offset - byte_in_group);
6373 if (alloc) {
6374 old_val += num_bytes;
6375 btrfs_set_block_group_used(&cache->item, old_val);
6376 cache->reserved -= num_bytes;
6377 cache->space_info->bytes_reserved -= num_bytes;
6378 cache->space_info->bytes_used += num_bytes;
6379 cache->space_info->disk_used += num_bytes * factor;
6380 spin_unlock(&cache->lock);
6381 spin_unlock(&cache->space_info->lock);
6382 } else {
6383 old_val -= num_bytes;
6384 btrfs_set_block_group_used(&cache->item, old_val);
6385 cache->pinned += num_bytes;
6386 cache->space_info->bytes_pinned += num_bytes;
6387 cache->space_info->bytes_used -= num_bytes;
6388 cache->space_info->disk_used -= num_bytes * factor;
6389 spin_unlock(&cache->lock);
6390 spin_unlock(&cache->space_info->lock);
6392 trace_btrfs_space_reservation(info, "pinned",
6393 cache->space_info->flags,
6394 num_bytes, 1);
6395 percpu_counter_add(&cache->space_info->total_bytes_pinned,
6396 num_bytes);
6397 set_extent_dirty(info->pinned_extents,
6398 bytenr, bytenr + num_bytes - 1,
6399 GFP_NOFS | __GFP_NOFAIL);
6402 spin_lock(&trans->transaction->dirty_bgs_lock);
6403 if (list_empty(&cache->dirty_list)) {
6404 list_add_tail(&cache->dirty_list,
6405 &trans->transaction->dirty_bgs);
6406 trans->transaction->num_dirty_bgs++;
6407 btrfs_get_block_group(cache);
6409 spin_unlock(&trans->transaction->dirty_bgs_lock);
6412 * No longer have used bytes in this block group, queue it for
6413 * deletion. We do this after adding the block group to the
6414 * dirty list to avoid races between cleaner kthread and space
6415 * cache writeout.
6417 if (!alloc && old_val == 0) {
6418 spin_lock(&info->unused_bgs_lock);
6419 if (list_empty(&cache->bg_list)) {
6420 btrfs_get_block_group(cache);
6421 list_add_tail(&cache->bg_list,
6422 &info->unused_bgs);
6424 spin_unlock(&info->unused_bgs_lock);
6427 btrfs_put_block_group(cache);
6428 total -= num_bytes;
6429 bytenr += num_bytes;
6431 return 0;
6434 static u64 first_logical_byte(struct btrfs_fs_info *fs_info, u64 search_start)
6436 struct btrfs_block_group_cache *cache;
6437 u64 bytenr;
6439 spin_lock(&fs_info->block_group_cache_lock);
6440 bytenr = fs_info->first_logical_byte;
6441 spin_unlock(&fs_info->block_group_cache_lock);
6443 if (bytenr < (u64)-1)
6444 return bytenr;
6446 cache = btrfs_lookup_first_block_group(fs_info, search_start);
6447 if (!cache)
6448 return 0;
6450 bytenr = cache->key.objectid;
6451 btrfs_put_block_group(cache);
6453 return bytenr;
6456 static int pin_down_extent(struct btrfs_fs_info *fs_info,
6457 struct btrfs_block_group_cache *cache,
6458 u64 bytenr, u64 num_bytes, int reserved)
6460 spin_lock(&cache->space_info->lock);
6461 spin_lock(&cache->lock);
6462 cache->pinned += num_bytes;
6463 cache->space_info->bytes_pinned += num_bytes;
6464 if (reserved) {
6465 cache->reserved -= num_bytes;
6466 cache->space_info->bytes_reserved -= num_bytes;
6468 spin_unlock(&cache->lock);
6469 spin_unlock(&cache->space_info->lock);
6471 trace_btrfs_space_reservation(fs_info, "pinned",
6472 cache->space_info->flags, num_bytes, 1);
6473 percpu_counter_add(&cache->space_info->total_bytes_pinned, num_bytes);
6474 set_extent_dirty(fs_info->pinned_extents, bytenr,
6475 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
6476 return 0;
6480 * this function must be called within transaction
6482 int btrfs_pin_extent(struct btrfs_fs_info *fs_info,
6483 u64 bytenr, u64 num_bytes, int reserved)
6485 struct btrfs_block_group_cache *cache;
6487 cache = btrfs_lookup_block_group(fs_info, bytenr);
6488 BUG_ON(!cache); /* Logic error */
6490 pin_down_extent(fs_info, cache, bytenr, num_bytes, reserved);
6492 btrfs_put_block_group(cache);
6493 return 0;
6497 * this function must be called within transaction
6499 int btrfs_pin_extent_for_log_replay(struct btrfs_fs_info *fs_info,
6500 u64 bytenr, u64 num_bytes)
6502 struct btrfs_block_group_cache *cache;
6503 int ret;
6505 cache = btrfs_lookup_block_group(fs_info, bytenr);
6506 if (!cache)
6507 return -EINVAL;
6510 * pull in the free space cache (if any) so that our pin
6511 * removes the free space from the cache. We have load_only set
6512 * to one because the slow code to read in the free extents does check
6513 * the pinned extents.
6515 cache_block_group(cache, 1);
6517 pin_down_extent(fs_info, cache, bytenr, num_bytes, 0);
6519 /* remove us from the free space cache (if we're there at all) */
6520 ret = btrfs_remove_free_space(cache, bytenr, num_bytes);
6521 btrfs_put_block_group(cache);
6522 return ret;
6525 static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
6526 u64 start, u64 num_bytes)
6528 int ret;
6529 struct btrfs_block_group_cache *block_group;
6530 struct btrfs_caching_control *caching_ctl;
6532 block_group = btrfs_lookup_block_group(fs_info, start);
6533 if (!block_group)
6534 return -EINVAL;
6536 cache_block_group(block_group, 0);
6537 caching_ctl = get_caching_control(block_group);
6539 if (!caching_ctl) {
6540 /* Logic error */
6541 BUG_ON(!block_group_cache_done(block_group));
6542 ret = btrfs_remove_free_space(block_group, start, num_bytes);
6543 } else {
6544 mutex_lock(&caching_ctl->mutex);
6546 if (start >= caching_ctl->progress) {
6547 ret = add_excluded_extent(fs_info, start, num_bytes);
6548 } else if (start + num_bytes <= caching_ctl->progress) {
6549 ret = btrfs_remove_free_space(block_group,
6550 start, num_bytes);
6551 } else {
6552 num_bytes = caching_ctl->progress - start;
6553 ret = btrfs_remove_free_space(block_group,
6554 start, num_bytes);
6555 if (ret)
6556 goto out_lock;
6558 num_bytes = (start + num_bytes) -
6559 caching_ctl->progress;
6560 start = caching_ctl->progress;
6561 ret = add_excluded_extent(fs_info, start, num_bytes);
6563 out_lock:
6564 mutex_unlock(&caching_ctl->mutex);
6565 put_caching_control(caching_ctl);
6567 btrfs_put_block_group(block_group);
6568 return ret;
6571 int btrfs_exclude_logged_extents(struct btrfs_fs_info *fs_info,
6572 struct extent_buffer *eb)
6574 struct btrfs_file_extent_item *item;
6575 struct btrfs_key key;
6576 int found_type;
6577 int i;
6579 if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS))
6580 return 0;
6582 for (i = 0; i < btrfs_header_nritems(eb); i++) {
6583 btrfs_item_key_to_cpu(eb, &key, i);
6584 if (key.type != BTRFS_EXTENT_DATA_KEY)
6585 continue;
6586 item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
6587 found_type = btrfs_file_extent_type(eb, item);
6588 if (found_type == BTRFS_FILE_EXTENT_INLINE)
6589 continue;
6590 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
6591 continue;
6592 key.objectid = btrfs_file_extent_disk_bytenr(eb, item);
6593 key.offset = btrfs_file_extent_disk_num_bytes(eb, item);
6594 __exclude_logged_extent(fs_info, key.objectid, key.offset);
6597 return 0;
6600 static void
6601 btrfs_inc_block_group_reservations(struct btrfs_block_group_cache *bg)
6603 atomic_inc(&bg->reservations);
6606 void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
6607 const u64 start)
6609 struct btrfs_block_group_cache *bg;
6611 bg = btrfs_lookup_block_group(fs_info, start);
6612 ASSERT(bg);
6613 if (atomic_dec_and_test(&bg->reservations))
6614 wake_up_atomic_t(&bg->reservations);
6615 btrfs_put_block_group(bg);
6618 static int btrfs_wait_bg_reservations_atomic_t(atomic_t *a)
6620 schedule();
6621 return 0;
6624 void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg)
6626 struct btrfs_space_info *space_info = bg->space_info;
6628 ASSERT(bg->ro);
6630 if (!(bg->flags & BTRFS_BLOCK_GROUP_DATA))
6631 return;
6634 * Our block group is read only but before we set it to read only,
6635 * some task might have had allocated an extent from it already, but it
6636 * has not yet created a respective ordered extent (and added it to a
6637 * root's list of ordered extents).
6638 * Therefore wait for any task currently allocating extents, since the
6639 * block group's reservations counter is incremented while a read lock
6640 * on the groups' semaphore is held and decremented after releasing
6641 * the read access on that semaphore and creating the ordered extent.
6643 down_write(&space_info->groups_sem);
6644 up_write(&space_info->groups_sem);
6646 wait_on_atomic_t(&bg->reservations,
6647 btrfs_wait_bg_reservations_atomic_t,
6648 TASK_UNINTERRUPTIBLE);
6652 * btrfs_add_reserved_bytes - update the block_group and space info counters
6653 * @cache: The cache we are manipulating
6654 * @ram_bytes: The number of bytes of file content, and will be same to
6655 * @num_bytes except for the compress path.
6656 * @num_bytes: The number of bytes in question
6657 * @delalloc: The blocks are allocated for the delalloc write
6659 * This is called by the allocator when it reserves space. If this is a
6660 * reservation and the block group has become read only we cannot make the
6661 * reservation and return -EAGAIN, otherwise this function always succeeds.
6663 static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
6664 u64 ram_bytes, u64 num_bytes, int delalloc)
6666 struct btrfs_space_info *space_info = cache->space_info;
6667 int ret = 0;
6669 spin_lock(&space_info->lock);
6670 spin_lock(&cache->lock);
6671 if (cache->ro) {
6672 ret = -EAGAIN;
6673 } else {
6674 cache->reserved += num_bytes;
6675 space_info->bytes_reserved += num_bytes;
6677 trace_btrfs_space_reservation(cache->fs_info,
6678 "space_info", space_info->flags,
6679 ram_bytes, 0);
6680 space_info->bytes_may_use -= ram_bytes;
6681 if (delalloc)
6682 cache->delalloc_bytes += num_bytes;
6684 spin_unlock(&cache->lock);
6685 spin_unlock(&space_info->lock);
6686 return ret;
6690 * btrfs_free_reserved_bytes - update the block_group and space info counters
6691 * @cache: The cache we are manipulating
6692 * @num_bytes: The number of bytes in question
6693 * @delalloc: The blocks are allocated for the delalloc write
6695 * This is called by somebody who is freeing space that was never actually used
6696 * on disk. For example if you reserve some space for a new leaf in transaction
6697 * A and before transaction A commits you free that leaf, you call this with
6698 * reserve set to 0 in order to clear the reservation.
6701 static int btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
6702 u64 num_bytes, int delalloc)
6704 struct btrfs_space_info *space_info = cache->space_info;
6705 int ret = 0;
6707 spin_lock(&space_info->lock);
6708 spin_lock(&cache->lock);
6709 if (cache->ro)
6710 space_info->bytes_readonly += num_bytes;
6711 cache->reserved -= num_bytes;
6712 space_info->bytes_reserved -= num_bytes;
6714 if (delalloc)
6715 cache->delalloc_bytes -= num_bytes;
6716 spin_unlock(&cache->lock);
6717 spin_unlock(&space_info->lock);
6718 return ret;
6720 void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info)
6722 struct btrfs_caching_control *next;
6723 struct btrfs_caching_control *caching_ctl;
6724 struct btrfs_block_group_cache *cache;
6726 down_write(&fs_info->commit_root_sem);
6728 list_for_each_entry_safe(caching_ctl, next,
6729 &fs_info->caching_block_groups, list) {
6730 cache = caching_ctl->block_group;
6731 if (block_group_cache_done(cache)) {
6732 cache->last_byte_to_unpin = (u64)-1;
6733 list_del_init(&caching_ctl->list);
6734 put_caching_control(caching_ctl);
6735 } else {
6736 cache->last_byte_to_unpin = caching_ctl->progress;
6740 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
6741 fs_info->pinned_extents = &fs_info->freed_extents[1];
6742 else
6743 fs_info->pinned_extents = &fs_info->freed_extents[0];
6745 up_write(&fs_info->commit_root_sem);
6747 update_global_block_rsv(fs_info);
6751 * Returns the free cluster for the given space info and sets empty_cluster to
6752 * what it should be based on the mount options.
6754 static struct btrfs_free_cluster *
6755 fetch_cluster_info(struct btrfs_fs_info *fs_info,
6756 struct btrfs_space_info *space_info, u64 *empty_cluster)
6758 struct btrfs_free_cluster *ret = NULL;
6760 *empty_cluster = 0;
6761 if (btrfs_mixed_space_info(space_info))
6762 return ret;
6764 if (space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
6765 ret = &fs_info->meta_alloc_cluster;
6766 if (btrfs_test_opt(fs_info, SSD))
6767 *empty_cluster = SZ_2M;
6768 else
6769 *empty_cluster = SZ_64K;
6770 } else if ((space_info->flags & BTRFS_BLOCK_GROUP_DATA) &&
6771 btrfs_test_opt(fs_info, SSD_SPREAD)) {
6772 *empty_cluster = SZ_2M;
6773 ret = &fs_info->data_alloc_cluster;
6776 return ret;
6779 static int unpin_extent_range(struct btrfs_fs_info *fs_info,
6780 u64 start, u64 end,
6781 const bool return_free_space)
6783 struct btrfs_block_group_cache *cache = NULL;
6784 struct btrfs_space_info *space_info;
6785 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
6786 struct btrfs_free_cluster *cluster = NULL;
6787 u64 len;
6788 u64 total_unpinned = 0;
6789 u64 empty_cluster = 0;
6790 bool readonly;
6792 while (start <= end) {
6793 readonly = false;
6794 if (!cache ||
6795 start >= cache->key.objectid + cache->key.offset) {
6796 if (cache)
6797 btrfs_put_block_group(cache);
6798 total_unpinned = 0;
6799 cache = btrfs_lookup_block_group(fs_info, start);
6800 BUG_ON(!cache); /* Logic error */
6802 cluster = fetch_cluster_info(fs_info,
6803 cache->space_info,
6804 &empty_cluster);
6805 empty_cluster <<= 1;
6808 len = cache->key.objectid + cache->key.offset - start;
6809 len = min(len, end + 1 - start);
6811 if (start < cache->last_byte_to_unpin) {
6812 len = min(len, cache->last_byte_to_unpin - start);
6813 if (return_free_space)
6814 btrfs_add_free_space(cache, start, len);
6817 start += len;
6818 total_unpinned += len;
6819 space_info = cache->space_info;
6822 * If this space cluster has been marked as fragmented and we've
6823 * unpinned enough in this block group to potentially allow a
6824 * cluster to be created inside of it go ahead and clear the
6825 * fragmented check.
6827 if (cluster && cluster->fragmented &&
6828 total_unpinned > empty_cluster) {
6829 spin_lock(&cluster->lock);
6830 cluster->fragmented = 0;
6831 spin_unlock(&cluster->lock);
6834 spin_lock(&space_info->lock);
6835 spin_lock(&cache->lock);
6836 cache->pinned -= len;
6837 space_info->bytes_pinned -= len;
6839 trace_btrfs_space_reservation(fs_info, "pinned",
6840 space_info->flags, len, 0);
6841 space_info->max_extent_size = 0;
6842 percpu_counter_add(&space_info->total_bytes_pinned, -len);
6843 if (cache->ro) {
6844 space_info->bytes_readonly += len;
6845 readonly = true;
6847 spin_unlock(&cache->lock);
6848 if (!readonly && return_free_space &&
6849 global_rsv->space_info == space_info) {
6850 u64 to_add = len;
6852 spin_lock(&global_rsv->lock);
6853 if (!global_rsv->full) {
6854 to_add = min(len, global_rsv->size -
6855 global_rsv->reserved);
6856 global_rsv->reserved += to_add;
6857 space_info->bytes_may_use += to_add;
6858 if (global_rsv->reserved >= global_rsv->size)
6859 global_rsv->full = 1;
6860 trace_btrfs_space_reservation(fs_info,
6861 "space_info",
6862 space_info->flags,
6863 to_add, 1);
6864 len -= to_add;
6866 spin_unlock(&global_rsv->lock);
6867 /* Add to any tickets we may have */
6868 if (len)
6869 space_info_add_new_bytes(fs_info, space_info,
6870 len);
6872 spin_unlock(&space_info->lock);
6875 if (cache)
6876 btrfs_put_block_group(cache);
6877 return 0;
6880 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
6881 struct btrfs_fs_info *fs_info)
6883 struct btrfs_block_group_cache *block_group, *tmp;
6884 struct list_head *deleted_bgs;
6885 struct extent_io_tree *unpin;
6886 u64 start;
6887 u64 end;
6888 int ret;
6890 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
6891 unpin = &fs_info->freed_extents[1];
6892 else
6893 unpin = &fs_info->freed_extents[0];
6895 while (!trans->aborted) {
6896 mutex_lock(&fs_info->unused_bg_unpin_mutex);
6897 ret = find_first_extent_bit(unpin, 0, &start, &end,
6898 EXTENT_DIRTY, NULL);
6899 if (ret) {
6900 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
6901 break;
6904 if (btrfs_test_opt(fs_info, DISCARD))
6905 ret = btrfs_discard_extent(fs_info, start,
6906 end + 1 - start, NULL);
6908 clear_extent_dirty(unpin, start, end);
6909 unpin_extent_range(fs_info, start, end, true);
6910 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
6911 cond_resched();
6915 * Transaction is finished. We don't need the lock anymore. We
6916 * do need to clean up the block groups in case of a transaction
6917 * abort.
6919 deleted_bgs = &trans->transaction->deleted_bgs;
6920 list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) {
6921 u64 trimmed = 0;
6923 ret = -EROFS;
6924 if (!trans->aborted)
6925 ret = btrfs_discard_extent(fs_info,
6926 block_group->key.objectid,
6927 block_group->key.offset,
6928 &trimmed);
6930 list_del_init(&block_group->bg_list);
6931 btrfs_put_block_group_trimming(block_group);
6932 btrfs_put_block_group(block_group);
6934 if (ret) {
6935 const char *errstr = btrfs_decode_error(ret);
6936 btrfs_warn(fs_info,
6937 "discard failed while removing blockgroup: errno=%d %s",
6938 ret, errstr);
6942 return 0;
6945 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
6946 struct btrfs_fs_info *info,
6947 struct btrfs_delayed_ref_node *node, u64 parent,
6948 u64 root_objectid, u64 owner_objectid,
6949 u64 owner_offset, int refs_to_drop,
6950 struct btrfs_delayed_extent_op *extent_op)
6952 struct btrfs_key key;
6953 struct btrfs_path *path;
6954 struct btrfs_root *extent_root = info->extent_root;
6955 struct extent_buffer *leaf;
6956 struct btrfs_extent_item *ei;
6957 struct btrfs_extent_inline_ref *iref;
6958 int ret;
6959 int is_data;
6960 int extent_slot = 0;
6961 int found_extent = 0;
6962 int num_to_del = 1;
6963 u32 item_size;
6964 u64 refs;
6965 u64 bytenr = node->bytenr;
6966 u64 num_bytes = node->num_bytes;
6967 int last_ref = 0;
6968 bool skinny_metadata = btrfs_fs_incompat(info, SKINNY_METADATA);
6970 path = btrfs_alloc_path();
6971 if (!path)
6972 return -ENOMEM;
6974 path->reada = READA_FORWARD;
6975 path->leave_spinning = 1;
6977 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
6978 BUG_ON(!is_data && refs_to_drop != 1);
6980 if (is_data)
6981 skinny_metadata = 0;
6983 ret = lookup_extent_backref(trans, info, path, &iref,
6984 bytenr, num_bytes, parent,
6985 root_objectid, owner_objectid,
6986 owner_offset);
6987 if (ret == 0) {
6988 extent_slot = path->slots[0];
6989 while (extent_slot >= 0) {
6990 btrfs_item_key_to_cpu(path->nodes[0], &key,
6991 extent_slot);
6992 if (key.objectid != bytenr)
6993 break;
6994 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
6995 key.offset == num_bytes) {
6996 found_extent = 1;
6997 break;
6999 if (key.type == BTRFS_METADATA_ITEM_KEY &&
7000 key.offset == owner_objectid) {
7001 found_extent = 1;
7002 break;
7004 if (path->slots[0] - extent_slot > 5)
7005 break;
7006 extent_slot--;
7008 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
7009 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
7010 if (found_extent && item_size < sizeof(*ei))
7011 found_extent = 0;
7012 #endif
7013 if (!found_extent) {
7014 BUG_ON(iref);
7015 ret = remove_extent_backref(trans, info, path, NULL,
7016 refs_to_drop,
7017 is_data, &last_ref);
7018 if (ret) {
7019 btrfs_abort_transaction(trans, ret);
7020 goto out;
7022 btrfs_release_path(path);
7023 path->leave_spinning = 1;
7025 key.objectid = bytenr;
7026 key.type = BTRFS_EXTENT_ITEM_KEY;
7027 key.offset = num_bytes;
7029 if (!is_data && skinny_metadata) {
7030 key.type = BTRFS_METADATA_ITEM_KEY;
7031 key.offset = owner_objectid;
7034 ret = btrfs_search_slot(trans, extent_root,
7035 &key, path, -1, 1);
7036 if (ret > 0 && skinny_metadata && path->slots[0]) {
7038 * Couldn't find our skinny metadata item,
7039 * see if we have ye olde extent item.
7041 path->slots[0]--;
7042 btrfs_item_key_to_cpu(path->nodes[0], &key,
7043 path->slots[0]);
7044 if (key.objectid == bytenr &&
7045 key.type == BTRFS_EXTENT_ITEM_KEY &&
7046 key.offset == num_bytes)
7047 ret = 0;
7050 if (ret > 0 && skinny_metadata) {
7051 skinny_metadata = false;
7052 key.objectid = bytenr;
7053 key.type = BTRFS_EXTENT_ITEM_KEY;
7054 key.offset = num_bytes;
7055 btrfs_release_path(path);
7056 ret = btrfs_search_slot(trans, extent_root,
7057 &key, path, -1, 1);
7060 if (ret) {
7061 btrfs_err(info,
7062 "umm, got %d back from search, was looking for %llu",
7063 ret, bytenr);
7064 if (ret > 0)
7065 btrfs_print_leaf(path->nodes[0]);
7067 if (ret < 0) {
7068 btrfs_abort_transaction(trans, ret);
7069 goto out;
7071 extent_slot = path->slots[0];
7073 } else if (WARN_ON(ret == -ENOENT)) {
7074 btrfs_print_leaf(path->nodes[0]);
7075 btrfs_err(info,
7076 "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu",
7077 bytenr, parent, root_objectid, owner_objectid,
7078 owner_offset);
7079 btrfs_abort_transaction(trans, ret);
7080 goto out;
7081 } else {
7082 btrfs_abort_transaction(trans, ret);
7083 goto out;
7086 leaf = path->nodes[0];
7087 item_size = btrfs_item_size_nr(leaf, extent_slot);
7088 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
7089 if (item_size < sizeof(*ei)) {
7090 BUG_ON(found_extent || extent_slot != path->slots[0]);
7091 ret = convert_extent_item_v0(trans, info, path, owner_objectid,
7093 if (ret < 0) {
7094 btrfs_abort_transaction(trans, ret);
7095 goto out;
7098 btrfs_release_path(path);
7099 path->leave_spinning = 1;
7101 key.objectid = bytenr;
7102 key.type = BTRFS_EXTENT_ITEM_KEY;
7103 key.offset = num_bytes;
7105 ret = btrfs_search_slot(trans, extent_root, &key, path,
7106 -1, 1);
7107 if (ret) {
7108 btrfs_err(info,
7109 "umm, got %d back from search, was looking for %llu",
7110 ret, bytenr);
7111 btrfs_print_leaf(path->nodes[0]);
7113 if (ret < 0) {
7114 btrfs_abort_transaction(trans, ret);
7115 goto out;
7118 extent_slot = path->slots[0];
7119 leaf = path->nodes[0];
7120 item_size = btrfs_item_size_nr(leaf, extent_slot);
7122 #endif
7123 BUG_ON(item_size < sizeof(*ei));
7124 ei = btrfs_item_ptr(leaf, extent_slot,
7125 struct btrfs_extent_item);
7126 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
7127 key.type == BTRFS_EXTENT_ITEM_KEY) {
7128 struct btrfs_tree_block_info *bi;
7129 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
7130 bi = (struct btrfs_tree_block_info *)(ei + 1);
7131 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
7134 refs = btrfs_extent_refs(leaf, ei);
7135 if (refs < refs_to_drop) {
7136 btrfs_err(info,
7137 "trying to drop %d refs but we only have %Lu for bytenr %Lu",
7138 refs_to_drop, refs, bytenr);
7139 ret = -EINVAL;
7140 btrfs_abort_transaction(trans, ret);
7141 goto out;
7143 refs -= refs_to_drop;
7145 if (refs > 0) {
7146 if (extent_op)
7147 __run_delayed_extent_op(extent_op, leaf, ei);
7149 * In the case of inline back ref, reference count will
7150 * be updated by remove_extent_backref
7152 if (iref) {
7153 BUG_ON(!found_extent);
7154 } else {
7155 btrfs_set_extent_refs(leaf, ei, refs);
7156 btrfs_mark_buffer_dirty(leaf);
7158 if (found_extent) {
7159 ret = remove_extent_backref(trans, info, path,
7160 iref, refs_to_drop,
7161 is_data, &last_ref);
7162 if (ret) {
7163 btrfs_abort_transaction(trans, ret);
7164 goto out;
7167 } else {
7168 if (found_extent) {
7169 BUG_ON(is_data && refs_to_drop !=
7170 extent_data_ref_count(path, iref));
7171 if (iref) {
7172 BUG_ON(path->slots[0] != extent_slot);
7173 } else {
7174 BUG_ON(path->slots[0] != extent_slot + 1);
7175 path->slots[0] = extent_slot;
7176 num_to_del = 2;
7180 last_ref = 1;
7181 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
7182 num_to_del);
7183 if (ret) {
7184 btrfs_abort_transaction(trans, ret);
7185 goto out;
7187 btrfs_release_path(path);
7189 if (is_data) {
7190 ret = btrfs_del_csums(trans, info, bytenr, num_bytes);
7191 if (ret) {
7192 btrfs_abort_transaction(trans, ret);
7193 goto out;
7197 ret = add_to_free_space_tree(trans, info, bytenr, num_bytes);
7198 if (ret) {
7199 btrfs_abort_transaction(trans, ret);
7200 goto out;
7203 ret = update_block_group(trans, info, bytenr, num_bytes, 0);
7204 if (ret) {
7205 btrfs_abort_transaction(trans, ret);
7206 goto out;
7209 btrfs_release_path(path);
7211 out:
7212 btrfs_free_path(path);
7213 return ret;
7217 * when we free an block, it is possible (and likely) that we free the last
7218 * delayed ref for that extent as well. This searches the delayed ref tree for
7219 * a given extent, and if there are no other delayed refs to be processed, it
7220 * removes it from the tree.
7222 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
7223 u64 bytenr)
7225 struct btrfs_delayed_ref_head *head;
7226 struct btrfs_delayed_ref_root *delayed_refs;
7227 int ret = 0;
7229 delayed_refs = &trans->transaction->delayed_refs;
7230 spin_lock(&delayed_refs->lock);
7231 head = btrfs_find_delayed_ref_head(delayed_refs, bytenr);
7232 if (!head)
7233 goto out_delayed_unlock;
7235 spin_lock(&head->lock);
7236 if (!list_empty(&head->ref_list))
7237 goto out;
7239 if (head->extent_op) {
7240 if (!head->must_insert_reserved)
7241 goto out;
7242 btrfs_free_delayed_extent_op(head->extent_op);
7243 head->extent_op = NULL;
7247 * waiting for the lock here would deadlock. If someone else has it
7248 * locked they are already in the process of dropping it anyway
7250 if (!mutex_trylock(&head->mutex))
7251 goto out;
7254 * at this point we have a head with no other entries. Go
7255 * ahead and process it.
7257 head->node.in_tree = 0;
7258 rb_erase(&head->href_node, &delayed_refs->href_root);
7260 atomic_dec(&delayed_refs->num_entries);
7263 * we don't take a ref on the node because we're removing it from the
7264 * tree, so we just steal the ref the tree was holding.
7266 delayed_refs->num_heads--;
7267 if (head->processing == 0)
7268 delayed_refs->num_heads_ready--;
7269 head->processing = 0;
7270 spin_unlock(&head->lock);
7271 spin_unlock(&delayed_refs->lock);
7273 BUG_ON(head->extent_op);
7274 if (head->must_insert_reserved)
7275 ret = 1;
7277 mutex_unlock(&head->mutex);
7278 btrfs_put_delayed_ref(&head->node);
7279 return ret;
7280 out:
7281 spin_unlock(&head->lock);
7283 out_delayed_unlock:
7284 spin_unlock(&delayed_refs->lock);
7285 return 0;
7288 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
7289 struct btrfs_root *root,
7290 struct extent_buffer *buf,
7291 u64 parent, int last_ref)
7293 struct btrfs_fs_info *fs_info = root->fs_info;
7294 int pin = 1;
7295 int ret;
7297 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
7298 int old_ref_mod, new_ref_mod;
7300 ret = btrfs_add_delayed_tree_ref(fs_info, trans, buf->start,
7301 buf->len, parent,
7302 root->root_key.objectid,
7303 btrfs_header_level(buf),
7304 BTRFS_DROP_DELAYED_REF, NULL,
7305 &old_ref_mod, &new_ref_mod);
7306 BUG_ON(ret); /* -ENOMEM */
7307 pin = old_ref_mod >= 0 && new_ref_mod < 0;
7310 if (last_ref && btrfs_header_generation(buf) == trans->transid) {
7311 struct btrfs_block_group_cache *cache;
7313 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
7314 ret = check_ref_cleanup(trans, buf->start);
7315 if (!ret)
7316 goto out;
7319 pin = 0;
7320 cache = btrfs_lookup_block_group(fs_info, buf->start);
7322 if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
7323 pin_down_extent(fs_info, cache, buf->start,
7324 buf->len, 1);
7325 btrfs_put_block_group(cache);
7326 goto out;
7329 WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
7331 btrfs_add_free_space(cache, buf->start, buf->len);
7332 btrfs_free_reserved_bytes(cache, buf->len, 0);
7333 btrfs_put_block_group(cache);
7334 trace_btrfs_reserved_extent_free(fs_info, buf->start, buf->len);
7336 out:
7337 if (pin)
7338 add_pinned_bytes(fs_info, buf->len, btrfs_header_level(buf),
7339 root->root_key.objectid);
7341 if (last_ref) {
7343 * Deleting the buffer, clear the corrupt flag since it doesn't
7344 * matter anymore.
7346 clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
7350 /* Can return -ENOMEM */
7351 int btrfs_free_extent(struct btrfs_trans_handle *trans,
7352 struct btrfs_fs_info *fs_info,
7353 u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
7354 u64 owner, u64 offset)
7356 int old_ref_mod, new_ref_mod;
7357 int ret;
7359 if (btrfs_is_testing(fs_info))
7360 return 0;
7364 * tree log blocks never actually go into the extent allocation
7365 * tree, just update pinning info and exit early.
7367 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
7368 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
7369 /* unlocks the pinned mutex */
7370 btrfs_pin_extent(fs_info, bytenr, num_bytes, 1);
7371 old_ref_mod = new_ref_mod = 0;
7372 ret = 0;
7373 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
7374 ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
7375 num_bytes, parent,
7376 root_objectid, (int)owner,
7377 BTRFS_DROP_DELAYED_REF, NULL,
7378 &old_ref_mod, &new_ref_mod);
7379 } else {
7380 ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
7381 num_bytes, parent,
7382 root_objectid, owner, offset,
7383 0, BTRFS_DROP_DELAYED_REF,
7384 &old_ref_mod, &new_ref_mod);
7387 if (ret == 0 && old_ref_mod >= 0 && new_ref_mod < 0)
7388 add_pinned_bytes(fs_info, num_bytes, owner, root_objectid);
7390 return ret;
7394 * when we wait for progress in the block group caching, its because
7395 * our allocation attempt failed at least once. So, we must sleep
7396 * and let some progress happen before we try again.
7398 * This function will sleep at least once waiting for new free space to
7399 * show up, and then it will check the block group free space numbers
7400 * for our min num_bytes. Another option is to have it go ahead
7401 * and look in the rbtree for a free extent of a given size, but this
7402 * is a good start.
7404 * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
7405 * any of the information in this block group.
7407 static noinline void
7408 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
7409 u64 num_bytes)
7411 struct btrfs_caching_control *caching_ctl;
7413 caching_ctl = get_caching_control(cache);
7414 if (!caching_ctl)
7415 return;
7417 wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
7418 (cache->free_space_ctl->free_space >= num_bytes));
7420 put_caching_control(caching_ctl);
7423 static noinline int
7424 wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
7426 struct btrfs_caching_control *caching_ctl;
7427 int ret = 0;
7429 caching_ctl = get_caching_control(cache);
7430 if (!caching_ctl)
7431 return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
7433 wait_event(caching_ctl->wait, block_group_cache_done(cache));
7434 if (cache->cached == BTRFS_CACHE_ERROR)
7435 ret = -EIO;
7436 put_caching_control(caching_ctl);
7437 return ret;
7440 int __get_raid_index(u64 flags)
7442 if (flags & BTRFS_BLOCK_GROUP_RAID10)
7443 return BTRFS_RAID_RAID10;
7444 else if (flags & BTRFS_BLOCK_GROUP_RAID1)
7445 return BTRFS_RAID_RAID1;
7446 else if (flags & BTRFS_BLOCK_GROUP_DUP)
7447 return BTRFS_RAID_DUP;
7448 else if (flags & BTRFS_BLOCK_GROUP_RAID0)
7449 return BTRFS_RAID_RAID0;
7450 else if (flags & BTRFS_BLOCK_GROUP_RAID5)
7451 return BTRFS_RAID_RAID5;
7452 else if (flags & BTRFS_BLOCK_GROUP_RAID6)
7453 return BTRFS_RAID_RAID6;
7455 return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
7458 int get_block_group_index(struct btrfs_block_group_cache *cache)
7460 return __get_raid_index(cache->flags);
7463 static const char *btrfs_raid_type_names[BTRFS_NR_RAID_TYPES] = {
7464 [BTRFS_RAID_RAID10] = "raid10",
7465 [BTRFS_RAID_RAID1] = "raid1",
7466 [BTRFS_RAID_DUP] = "dup",
7467 [BTRFS_RAID_RAID0] = "raid0",
7468 [BTRFS_RAID_SINGLE] = "single",
7469 [BTRFS_RAID_RAID5] = "raid5",
7470 [BTRFS_RAID_RAID6] = "raid6",
7473 static const char *get_raid_name(enum btrfs_raid_types type)
7475 if (type >= BTRFS_NR_RAID_TYPES)
7476 return NULL;
7478 return btrfs_raid_type_names[type];
7481 enum btrfs_loop_type {
7482 LOOP_CACHING_NOWAIT = 0,
7483 LOOP_CACHING_WAIT = 1,
7484 LOOP_ALLOC_CHUNK = 2,
7485 LOOP_NO_EMPTY_SIZE = 3,
7488 static inline void
7489 btrfs_lock_block_group(struct btrfs_block_group_cache *cache,
7490 int delalloc)
7492 if (delalloc)
7493 down_read(&cache->data_rwsem);
7496 static inline void
7497 btrfs_grab_block_group(struct btrfs_block_group_cache *cache,
7498 int delalloc)
7500 btrfs_get_block_group(cache);
7501 if (delalloc)
7502 down_read(&cache->data_rwsem);
7505 static struct btrfs_block_group_cache *
7506 btrfs_lock_cluster(struct btrfs_block_group_cache *block_group,
7507 struct btrfs_free_cluster *cluster,
7508 int delalloc)
7510 struct btrfs_block_group_cache *used_bg = NULL;
7512 spin_lock(&cluster->refill_lock);
7513 while (1) {
7514 used_bg = cluster->block_group;
7515 if (!used_bg)
7516 return NULL;
7518 if (used_bg == block_group)
7519 return used_bg;
7521 btrfs_get_block_group(used_bg);
7523 if (!delalloc)
7524 return used_bg;
7526 if (down_read_trylock(&used_bg->data_rwsem))
7527 return used_bg;
7529 spin_unlock(&cluster->refill_lock);
7531 /* We should only have one-level nested. */
7532 down_read_nested(&used_bg->data_rwsem, SINGLE_DEPTH_NESTING);
7534 spin_lock(&cluster->refill_lock);
7535 if (used_bg == cluster->block_group)
7536 return used_bg;
7538 up_read(&used_bg->data_rwsem);
7539 btrfs_put_block_group(used_bg);
7543 static inline void
7544 btrfs_release_block_group(struct btrfs_block_group_cache *cache,
7545 int delalloc)
7547 if (delalloc)
7548 up_read(&cache->data_rwsem);
7549 btrfs_put_block_group(cache);
7553 * walks the btree of allocated extents and find a hole of a given size.
7554 * The key ins is changed to record the hole:
7555 * ins->objectid == start position
7556 * ins->flags = BTRFS_EXTENT_ITEM_KEY
7557 * ins->offset == the size of the hole.
7558 * Any available blocks before search_start are skipped.
7560 * If there is no suitable free space, we will record the max size of
7561 * the free space extent currently.
7563 static noinline int find_free_extent(struct btrfs_fs_info *fs_info,
7564 u64 ram_bytes, u64 num_bytes, u64 empty_size,
7565 u64 hint_byte, struct btrfs_key *ins,
7566 u64 flags, int delalloc)
7568 int ret = 0;
7569 struct btrfs_root *root = fs_info->extent_root;
7570 struct btrfs_free_cluster *last_ptr = NULL;
7571 struct btrfs_block_group_cache *block_group = NULL;
7572 u64 search_start = 0;
7573 u64 max_extent_size = 0;
7574 u64 max_free_space = 0;
7575 u64 empty_cluster = 0;
7576 struct btrfs_space_info *space_info;
7577 int loop = 0;
7578 int index = __get_raid_index(flags);
7579 bool failed_cluster_refill = false;
7580 bool failed_alloc = false;
7581 bool use_cluster = true;
7582 bool have_caching_bg = false;
7583 bool orig_have_caching_bg = false;
7584 bool full_search = false;
7586 WARN_ON(num_bytes < fs_info->sectorsize);
7587 ins->type = BTRFS_EXTENT_ITEM_KEY;
7588 ins->objectid = 0;
7589 ins->offset = 0;
7591 trace_find_free_extent(fs_info, num_bytes, empty_size, flags);
7593 space_info = __find_space_info(fs_info, flags);
7594 if (!space_info) {
7595 btrfs_err(fs_info, "No space info for %llu", flags);
7596 return -ENOSPC;
7600 * If our free space is heavily fragmented we may not be able to make
7601 * big contiguous allocations, so instead of doing the expensive search
7602 * for free space, simply return ENOSPC with our max_extent_size so we
7603 * can go ahead and search for a more manageable chunk.
7605 * If our max_extent_size is large enough for our allocation simply
7606 * disable clustering since we will likely not be able to find enough
7607 * space to create a cluster and induce latency trying.
7609 if (unlikely(space_info->max_extent_size)) {
7610 spin_lock(&space_info->lock);
7611 if (space_info->max_extent_size &&
7612 num_bytes > space_info->max_extent_size) {
7613 ins->offset = space_info->max_extent_size;
7614 spin_unlock(&space_info->lock);
7615 return -ENOSPC;
7616 } else if (space_info->max_extent_size) {
7617 use_cluster = false;
7619 spin_unlock(&space_info->lock);
7622 last_ptr = fetch_cluster_info(fs_info, space_info, &empty_cluster);
7623 if (last_ptr) {
7624 spin_lock(&last_ptr->lock);
7625 if (last_ptr->block_group)
7626 hint_byte = last_ptr->window_start;
7627 if (last_ptr->fragmented) {
7629 * We still set window_start so we can keep track of the
7630 * last place we found an allocation to try and save
7631 * some time.
7633 hint_byte = last_ptr->window_start;
7634 use_cluster = false;
7636 spin_unlock(&last_ptr->lock);
7639 search_start = max(search_start, first_logical_byte(fs_info, 0));
7640 search_start = max(search_start, hint_byte);
7641 if (search_start == hint_byte) {
7642 block_group = btrfs_lookup_block_group(fs_info, search_start);
7644 * we don't want to use the block group if it doesn't match our
7645 * allocation bits, or if its not cached.
7647 * However if we are re-searching with an ideal block group
7648 * picked out then we don't care that the block group is cached.
7650 if (block_group && block_group_bits(block_group, flags) &&
7651 block_group->cached != BTRFS_CACHE_NO) {
7652 down_read(&space_info->groups_sem);
7653 if (list_empty(&block_group->list) ||
7654 block_group->ro) {
7656 * someone is removing this block group,
7657 * we can't jump into the have_block_group
7658 * target because our list pointers are not
7659 * valid
7661 btrfs_put_block_group(block_group);
7662 up_read(&space_info->groups_sem);
7663 } else {
7664 index = get_block_group_index(block_group);
7665 btrfs_lock_block_group(block_group, delalloc);
7666 goto have_block_group;
7668 } else if (block_group) {
7669 btrfs_put_block_group(block_group);
7672 search:
7673 have_caching_bg = false;
7674 if (index == 0 || index == __get_raid_index(flags))
7675 full_search = true;
7676 down_read(&space_info->groups_sem);
7677 list_for_each_entry(block_group, &space_info->block_groups[index],
7678 list) {
7679 u64 offset;
7680 int cached;
7682 /* If the block group is read-only, we can skip it entirely. */
7683 if (unlikely(block_group->ro))
7684 continue;
7686 btrfs_grab_block_group(block_group, delalloc);
7687 search_start = block_group->key.objectid;
7690 * this can happen if we end up cycling through all the
7691 * raid types, but we want to make sure we only allocate
7692 * for the proper type.
7694 if (!block_group_bits(block_group, flags)) {
7695 u64 extra = BTRFS_BLOCK_GROUP_DUP |
7696 BTRFS_BLOCK_GROUP_RAID1 |
7697 BTRFS_BLOCK_GROUP_RAID5 |
7698 BTRFS_BLOCK_GROUP_RAID6 |
7699 BTRFS_BLOCK_GROUP_RAID10;
7702 * if they asked for extra copies and this block group
7703 * doesn't provide them, bail. This does allow us to
7704 * fill raid0 from raid1.
7706 if ((flags & extra) && !(block_group->flags & extra))
7707 goto loop;
7710 * This block group has different flags than we want.
7711 * It's possible that we have MIXED_GROUP flag but no
7712 * block group is mixed. Just skip such block group.
7714 btrfs_release_block_group(block_group, delalloc);
7715 continue;
7718 have_block_group:
7719 cached = block_group_cache_done(block_group);
7720 if (unlikely(!cached)) {
7721 have_caching_bg = true;
7722 ret = cache_block_group(block_group, 0);
7723 BUG_ON(ret < 0);
7724 ret = 0;
7727 if (unlikely(block_group->cached == BTRFS_CACHE_ERROR))
7728 goto loop;
7731 * Ok we want to try and use the cluster allocator, so
7732 * lets look there
7734 if (last_ptr && use_cluster) {
7735 struct btrfs_block_group_cache *used_block_group;
7736 unsigned long aligned_cluster;
7738 * the refill lock keeps out other
7739 * people trying to start a new cluster
7741 used_block_group = btrfs_lock_cluster(block_group,
7742 last_ptr,
7743 delalloc);
7744 if (!used_block_group)
7745 goto refill_cluster;
7747 if (used_block_group != block_group &&
7748 (used_block_group->ro ||
7749 !block_group_bits(used_block_group, flags)))
7750 goto release_cluster;
7752 offset = btrfs_alloc_from_cluster(used_block_group,
7753 last_ptr,
7754 num_bytes,
7755 used_block_group->key.objectid,
7756 &max_extent_size);
7757 if (offset) {
7758 /* we have a block, we're done */
7759 spin_unlock(&last_ptr->refill_lock);
7760 trace_btrfs_reserve_extent_cluster(fs_info,
7761 used_block_group,
7762 search_start, num_bytes);
7763 if (used_block_group != block_group) {
7764 btrfs_release_block_group(block_group,
7765 delalloc);
7766 block_group = used_block_group;
7768 goto checks;
7771 WARN_ON(last_ptr->block_group != used_block_group);
7772 release_cluster:
7773 /* If we are on LOOP_NO_EMPTY_SIZE, we can't
7774 * set up a new clusters, so lets just skip it
7775 * and let the allocator find whatever block
7776 * it can find. If we reach this point, we
7777 * will have tried the cluster allocator
7778 * plenty of times and not have found
7779 * anything, so we are likely way too
7780 * fragmented for the clustering stuff to find
7781 * anything.
7783 * However, if the cluster is taken from the
7784 * current block group, release the cluster
7785 * first, so that we stand a better chance of
7786 * succeeding in the unclustered
7787 * allocation. */
7788 if (loop >= LOOP_NO_EMPTY_SIZE &&
7789 used_block_group != block_group) {
7790 spin_unlock(&last_ptr->refill_lock);
7791 btrfs_release_block_group(used_block_group,
7792 delalloc);
7793 goto unclustered_alloc;
7797 * this cluster didn't work out, free it and
7798 * start over
7800 btrfs_return_cluster_to_free_space(NULL, last_ptr);
7802 if (used_block_group != block_group)
7803 btrfs_release_block_group(used_block_group,
7804 delalloc);
7805 refill_cluster:
7806 if (loop >= LOOP_NO_EMPTY_SIZE) {
7807 spin_unlock(&last_ptr->refill_lock);
7808 goto unclustered_alloc;
7811 aligned_cluster = max_t(unsigned long,
7812 empty_cluster + empty_size,
7813 block_group->full_stripe_len);
7815 /* allocate a cluster in this block group */
7816 ret = btrfs_find_space_cluster(fs_info, block_group,
7817 last_ptr, search_start,
7818 num_bytes,
7819 aligned_cluster);
7820 if (ret == 0) {
7822 * now pull our allocation out of this
7823 * cluster
7825 offset = btrfs_alloc_from_cluster(block_group,
7826 last_ptr,
7827 num_bytes,
7828 search_start,
7829 &max_extent_size);
7830 if (offset) {
7831 /* we found one, proceed */
7832 spin_unlock(&last_ptr->refill_lock);
7833 trace_btrfs_reserve_extent_cluster(fs_info,
7834 block_group, search_start,
7835 num_bytes);
7836 goto checks;
7838 } else if (!cached && loop > LOOP_CACHING_NOWAIT
7839 && !failed_cluster_refill) {
7840 spin_unlock(&last_ptr->refill_lock);
7842 failed_cluster_refill = true;
7843 wait_block_group_cache_progress(block_group,
7844 num_bytes + empty_cluster + empty_size);
7845 goto have_block_group;
7849 * at this point we either didn't find a cluster
7850 * or we weren't able to allocate a block from our
7851 * cluster. Free the cluster we've been trying
7852 * to use, and go to the next block group
7854 btrfs_return_cluster_to_free_space(NULL, last_ptr);
7855 spin_unlock(&last_ptr->refill_lock);
7856 goto loop;
7859 unclustered_alloc:
7861 * We are doing an unclustered alloc, set the fragmented flag so
7862 * we don't bother trying to setup a cluster again until we get
7863 * more space.
7865 if (unlikely(last_ptr)) {
7866 spin_lock(&last_ptr->lock);
7867 last_ptr->fragmented = 1;
7868 spin_unlock(&last_ptr->lock);
7870 if (cached) {
7871 struct btrfs_free_space_ctl *ctl =
7872 block_group->free_space_ctl;
7874 spin_lock(&ctl->tree_lock);
7875 if (ctl->free_space <
7876 num_bytes + empty_cluster + empty_size) {
7877 max_free_space = max(max_free_space,
7878 ctl->free_space);
7879 spin_unlock(&ctl->tree_lock);
7880 goto loop;
7882 spin_unlock(&ctl->tree_lock);
7885 offset = btrfs_find_space_for_alloc(block_group, search_start,
7886 num_bytes, empty_size,
7887 &max_extent_size);
7889 * If we didn't find a chunk, and we haven't failed on this
7890 * block group before, and this block group is in the middle of
7891 * caching and we are ok with waiting, then go ahead and wait
7892 * for progress to be made, and set failed_alloc to true.
7894 * If failed_alloc is true then we've already waited on this
7895 * block group once and should move on to the next block group.
7897 if (!offset && !failed_alloc && !cached &&
7898 loop > LOOP_CACHING_NOWAIT) {
7899 wait_block_group_cache_progress(block_group,
7900 num_bytes + empty_size);
7901 failed_alloc = true;
7902 goto have_block_group;
7903 } else if (!offset) {
7904 goto loop;
7906 checks:
7907 search_start = ALIGN(offset, fs_info->stripesize);
7909 /* move on to the next group */
7910 if (search_start + num_bytes >
7911 block_group->key.objectid + block_group->key.offset) {
7912 btrfs_add_free_space(block_group, offset, num_bytes);
7913 goto loop;
7916 if (offset < search_start)
7917 btrfs_add_free_space(block_group, offset,
7918 search_start - offset);
7919 BUG_ON(offset > search_start);
7921 ret = btrfs_add_reserved_bytes(block_group, ram_bytes,
7922 num_bytes, delalloc);
7923 if (ret == -EAGAIN) {
7924 btrfs_add_free_space(block_group, offset, num_bytes);
7925 goto loop;
7927 btrfs_inc_block_group_reservations(block_group);
7929 /* we are all good, lets return */
7930 ins->objectid = search_start;
7931 ins->offset = num_bytes;
7933 trace_btrfs_reserve_extent(fs_info, block_group,
7934 search_start, num_bytes);
7935 btrfs_release_block_group(block_group, delalloc);
7936 break;
7937 loop:
7938 failed_cluster_refill = false;
7939 failed_alloc = false;
7940 BUG_ON(index != get_block_group_index(block_group));
7941 btrfs_release_block_group(block_group, delalloc);
7942 cond_resched();
7944 up_read(&space_info->groups_sem);
7946 if ((loop == LOOP_CACHING_NOWAIT) && have_caching_bg
7947 && !orig_have_caching_bg)
7948 orig_have_caching_bg = true;
7950 if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg)
7951 goto search;
7953 if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
7954 goto search;
7957 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
7958 * caching kthreads as we move along
7959 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
7960 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
7961 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
7962 * again
7964 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) {
7965 index = 0;
7966 if (loop == LOOP_CACHING_NOWAIT) {
7968 * We want to skip the LOOP_CACHING_WAIT step if we
7969 * don't have any uncached bgs and we've already done a
7970 * full search through.
7972 if (orig_have_caching_bg || !full_search)
7973 loop = LOOP_CACHING_WAIT;
7974 else
7975 loop = LOOP_ALLOC_CHUNK;
7976 } else {
7977 loop++;
7980 if (loop == LOOP_ALLOC_CHUNK) {
7981 struct btrfs_trans_handle *trans;
7982 int exist = 0;
7984 trans = current->journal_info;
7985 if (trans)
7986 exist = 1;
7987 else
7988 trans = btrfs_join_transaction(root);
7990 if (IS_ERR(trans)) {
7991 ret = PTR_ERR(trans);
7992 goto out;
7995 ret = do_chunk_alloc(trans, fs_info, flags,
7996 CHUNK_ALLOC_FORCE);
7999 * If we can't allocate a new chunk we've already looped
8000 * through at least once, move on to the NO_EMPTY_SIZE
8001 * case.
8003 if (ret == -ENOSPC)
8004 loop = LOOP_NO_EMPTY_SIZE;
8007 * Do not bail out on ENOSPC since we
8008 * can do more things.
8010 if (ret < 0 && ret != -ENOSPC)
8011 btrfs_abort_transaction(trans, ret);
8012 else
8013 ret = 0;
8014 if (!exist)
8015 btrfs_end_transaction(trans);
8016 if (ret)
8017 goto out;
8020 if (loop == LOOP_NO_EMPTY_SIZE) {
8022 * Don't loop again if we already have no empty_size and
8023 * no empty_cluster.
8025 if (empty_size == 0 &&
8026 empty_cluster == 0) {
8027 ret = -ENOSPC;
8028 goto out;
8030 empty_size = 0;
8031 empty_cluster = 0;
8034 goto search;
8035 } else if (!ins->objectid) {
8036 ret = -ENOSPC;
8037 } else if (ins->objectid) {
8038 if (!use_cluster && last_ptr) {
8039 spin_lock(&last_ptr->lock);
8040 last_ptr->window_start = ins->objectid;
8041 spin_unlock(&last_ptr->lock);
8043 ret = 0;
8045 out:
8046 if (ret == -ENOSPC) {
8047 if (!max_extent_size)
8048 max_extent_size = max_free_space;
8049 spin_lock(&space_info->lock);
8050 space_info->max_extent_size = max_extent_size;
8051 spin_unlock(&space_info->lock);
8052 ins->offset = max_extent_size;
8054 return ret;
8057 static void dump_space_info(struct btrfs_fs_info *fs_info,
8058 struct btrfs_space_info *info, u64 bytes,
8059 int dump_block_groups)
8061 struct btrfs_block_group_cache *cache;
8062 int index = 0;
8064 spin_lock(&info->lock);
8065 btrfs_info(fs_info, "space_info %llu has %llu free, is %sfull",
8066 info->flags,
8067 info->total_bytes - btrfs_space_info_used(info, true),
8068 info->full ? "" : "not ");
8069 btrfs_info(fs_info,
8070 "space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu",
8071 info->total_bytes, info->bytes_used, info->bytes_pinned,
8072 info->bytes_reserved, info->bytes_may_use,
8073 info->bytes_readonly);
8074 spin_unlock(&info->lock);
8076 if (!dump_block_groups)
8077 return;
8079 down_read(&info->groups_sem);
8080 again:
8081 list_for_each_entry(cache, &info->block_groups[index], list) {
8082 spin_lock(&cache->lock);
8083 btrfs_info(fs_info,
8084 "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s",
8085 cache->key.objectid, cache->key.offset,
8086 btrfs_block_group_used(&cache->item), cache->pinned,
8087 cache->reserved, cache->ro ? "[readonly]" : "");
8088 btrfs_dump_free_space(cache, bytes);
8089 spin_unlock(&cache->lock);
8091 if (++index < BTRFS_NR_RAID_TYPES)
8092 goto again;
8093 up_read(&info->groups_sem);
8096 int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes,
8097 u64 num_bytes, u64 min_alloc_size,
8098 u64 empty_size, u64 hint_byte,
8099 struct btrfs_key *ins, int is_data, int delalloc)
8101 struct btrfs_fs_info *fs_info = root->fs_info;
8102 bool final_tried = num_bytes == min_alloc_size;
8103 u64 flags;
8104 int ret;
8106 flags = get_alloc_profile_by_root(root, is_data);
8107 again:
8108 WARN_ON(num_bytes < fs_info->sectorsize);
8109 ret = find_free_extent(fs_info, ram_bytes, num_bytes, empty_size,
8110 hint_byte, ins, flags, delalloc);
8111 if (!ret && !is_data) {
8112 btrfs_dec_block_group_reservations(fs_info, ins->objectid);
8113 } else if (ret == -ENOSPC) {
8114 if (!final_tried && ins->offset) {
8115 num_bytes = min(num_bytes >> 1, ins->offset);
8116 num_bytes = round_down(num_bytes,
8117 fs_info->sectorsize);
8118 num_bytes = max(num_bytes, min_alloc_size);
8119 ram_bytes = num_bytes;
8120 if (num_bytes == min_alloc_size)
8121 final_tried = true;
8122 goto again;
8123 } else if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
8124 struct btrfs_space_info *sinfo;
8126 sinfo = __find_space_info(fs_info, flags);
8127 btrfs_err(fs_info,
8128 "allocation failed flags %llu, wanted %llu",
8129 flags, num_bytes);
8130 if (sinfo)
8131 dump_space_info(fs_info, sinfo, num_bytes, 1);
8135 return ret;
8138 static int __btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info,
8139 u64 start, u64 len,
8140 int pin, int delalloc)
8142 struct btrfs_block_group_cache *cache;
8143 int ret = 0;
8145 cache = btrfs_lookup_block_group(fs_info, start);
8146 if (!cache) {
8147 btrfs_err(fs_info, "Unable to find block group for %llu",
8148 start);
8149 return -ENOSPC;
8152 if (pin)
8153 pin_down_extent(fs_info, cache, start, len, 1);
8154 else {
8155 if (btrfs_test_opt(fs_info, DISCARD))
8156 ret = btrfs_discard_extent(fs_info, start, len, NULL);
8157 btrfs_add_free_space(cache, start, len);
8158 btrfs_free_reserved_bytes(cache, len, delalloc);
8159 trace_btrfs_reserved_extent_free(fs_info, start, len);
8162 btrfs_put_block_group(cache);
8163 return ret;
8166 int btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info,
8167 u64 start, u64 len, int delalloc)
8169 return __btrfs_free_reserved_extent(fs_info, start, len, 0, delalloc);
8172 int btrfs_free_and_pin_reserved_extent(struct btrfs_fs_info *fs_info,
8173 u64 start, u64 len)
8175 return __btrfs_free_reserved_extent(fs_info, start, len, 1, 0);
8178 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
8179 struct btrfs_fs_info *fs_info,
8180 u64 parent, u64 root_objectid,
8181 u64 flags, u64 owner, u64 offset,
8182 struct btrfs_key *ins, int ref_mod)
8184 int ret;
8185 struct btrfs_extent_item *extent_item;
8186 struct btrfs_extent_inline_ref *iref;
8187 struct btrfs_path *path;
8188 struct extent_buffer *leaf;
8189 int type;
8190 u32 size;
8192 if (parent > 0)
8193 type = BTRFS_SHARED_DATA_REF_KEY;
8194 else
8195 type = BTRFS_EXTENT_DATA_REF_KEY;
8197 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
8199 path = btrfs_alloc_path();
8200 if (!path)
8201 return -ENOMEM;
8203 path->leave_spinning = 1;
8204 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
8205 ins, size);
8206 if (ret) {
8207 btrfs_free_path(path);
8208 return ret;
8211 leaf = path->nodes[0];
8212 extent_item = btrfs_item_ptr(leaf, path->slots[0],
8213 struct btrfs_extent_item);
8214 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
8215 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
8216 btrfs_set_extent_flags(leaf, extent_item,
8217 flags | BTRFS_EXTENT_FLAG_DATA);
8219 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
8220 btrfs_set_extent_inline_ref_type(leaf, iref, type);
8221 if (parent > 0) {
8222 struct btrfs_shared_data_ref *ref;
8223 ref = (struct btrfs_shared_data_ref *)(iref + 1);
8224 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
8225 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
8226 } else {
8227 struct btrfs_extent_data_ref *ref;
8228 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
8229 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
8230 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
8231 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
8232 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
8235 btrfs_mark_buffer_dirty(path->nodes[0]);
8236 btrfs_free_path(path);
8238 ret = remove_from_free_space_tree(trans, fs_info, ins->objectid,
8239 ins->offset);
8240 if (ret)
8241 return ret;
8243 ret = update_block_group(trans, fs_info, ins->objectid, ins->offset, 1);
8244 if (ret) { /* -ENOENT, logic error */
8245 btrfs_err(fs_info, "update block group failed for %llu %llu",
8246 ins->objectid, ins->offset);
8247 BUG();
8249 trace_btrfs_reserved_extent_alloc(fs_info, ins->objectid, ins->offset);
8250 return ret;
8253 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
8254 struct btrfs_fs_info *fs_info,
8255 u64 parent, u64 root_objectid,
8256 u64 flags, struct btrfs_disk_key *key,
8257 int level, struct btrfs_key *ins)
8259 int ret;
8260 struct btrfs_extent_item *extent_item;
8261 struct btrfs_tree_block_info *block_info;
8262 struct btrfs_extent_inline_ref *iref;
8263 struct btrfs_path *path;
8264 struct extent_buffer *leaf;
8265 u32 size = sizeof(*extent_item) + sizeof(*iref);
8266 u64 num_bytes = ins->offset;
8267 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
8269 if (!skinny_metadata)
8270 size += sizeof(*block_info);
8272 path = btrfs_alloc_path();
8273 if (!path) {
8274 btrfs_free_and_pin_reserved_extent(fs_info, ins->objectid,
8275 fs_info->nodesize);
8276 return -ENOMEM;
8279 path->leave_spinning = 1;
8280 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
8281 ins, size);
8282 if (ret) {
8283 btrfs_free_path(path);
8284 btrfs_free_and_pin_reserved_extent(fs_info, ins->objectid,
8285 fs_info->nodesize);
8286 return ret;
8289 leaf = path->nodes[0];
8290 extent_item = btrfs_item_ptr(leaf, path->slots[0],
8291 struct btrfs_extent_item);
8292 btrfs_set_extent_refs(leaf, extent_item, 1);
8293 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
8294 btrfs_set_extent_flags(leaf, extent_item,
8295 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
8297 if (skinny_metadata) {
8298 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
8299 num_bytes = fs_info->nodesize;
8300 } else {
8301 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
8302 btrfs_set_tree_block_key(leaf, block_info, key);
8303 btrfs_set_tree_block_level(leaf, block_info, level);
8304 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
8307 if (parent > 0) {
8308 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
8309 btrfs_set_extent_inline_ref_type(leaf, iref,
8310 BTRFS_SHARED_BLOCK_REF_KEY);
8311 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
8312 } else {
8313 btrfs_set_extent_inline_ref_type(leaf, iref,
8314 BTRFS_TREE_BLOCK_REF_KEY);
8315 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
8318 btrfs_mark_buffer_dirty(leaf);
8319 btrfs_free_path(path);
8321 ret = remove_from_free_space_tree(trans, fs_info, ins->objectid,
8322 num_bytes);
8323 if (ret)
8324 return ret;
8326 ret = update_block_group(trans, fs_info, ins->objectid,
8327 fs_info->nodesize, 1);
8328 if (ret) { /* -ENOENT, logic error */
8329 btrfs_err(fs_info, "update block group failed for %llu %llu",
8330 ins->objectid, ins->offset);
8331 BUG();
8334 trace_btrfs_reserved_extent_alloc(fs_info, ins->objectid,
8335 fs_info->nodesize);
8336 return ret;
8339 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
8340 u64 root_objectid, u64 owner,
8341 u64 offset, u64 ram_bytes,
8342 struct btrfs_key *ins)
8344 struct btrfs_fs_info *fs_info = trans->fs_info;
8345 int ret;
8347 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
8349 ret = btrfs_add_delayed_data_ref(fs_info, trans, ins->objectid,
8350 ins->offset, 0, root_objectid, owner,
8351 offset, ram_bytes,
8352 BTRFS_ADD_DELAYED_EXTENT, NULL, NULL);
8353 return ret;
8357 * this is used by the tree logging recovery code. It records that
8358 * an extent has been allocated and makes sure to clear the free
8359 * space cache bits as well
8361 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
8362 struct btrfs_fs_info *fs_info,
8363 u64 root_objectid, u64 owner, u64 offset,
8364 struct btrfs_key *ins)
8366 int ret;
8367 struct btrfs_block_group_cache *block_group;
8368 struct btrfs_space_info *space_info;
8371 * Mixed block groups will exclude before processing the log so we only
8372 * need to do the exclude dance if this fs isn't mixed.
8374 if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
8375 ret = __exclude_logged_extent(fs_info, ins->objectid,
8376 ins->offset);
8377 if (ret)
8378 return ret;
8381 block_group = btrfs_lookup_block_group(fs_info, ins->objectid);
8382 if (!block_group)
8383 return -EINVAL;
8385 space_info = block_group->space_info;
8386 spin_lock(&space_info->lock);
8387 spin_lock(&block_group->lock);
8388 space_info->bytes_reserved += ins->offset;
8389 block_group->reserved += ins->offset;
8390 spin_unlock(&block_group->lock);
8391 spin_unlock(&space_info->lock);
8393 ret = alloc_reserved_file_extent(trans, fs_info, 0, root_objectid,
8394 0, owner, offset, ins, 1);
8395 btrfs_put_block_group(block_group);
8396 return ret;
8399 static struct extent_buffer *
8400 btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
8401 u64 bytenr, int level)
8403 struct btrfs_fs_info *fs_info = root->fs_info;
8404 struct extent_buffer *buf;
8406 buf = btrfs_find_create_tree_block(fs_info, bytenr);
8407 if (IS_ERR(buf))
8408 return buf;
8411 * Extra safety check in case the extent tree is corrupted and extent
8412 * allocator chooses to use a tree block which is already used and
8413 * locked.
8415 if (buf->lock_owner == current->pid) {
8416 btrfs_err_rl(fs_info,
8417 "tree block %llu owner %llu already locked by pid=%d, extent tree corruption detected",
8418 buf->start, btrfs_header_owner(buf), current->pid);
8419 free_extent_buffer(buf);
8420 return ERR_PTR(-EUCLEAN);
8423 btrfs_set_header_generation(buf, trans->transid);
8424 btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
8425 btrfs_tree_lock(buf);
8426 clean_tree_block(fs_info, buf);
8427 clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
8429 btrfs_set_lock_blocking(buf);
8430 set_extent_buffer_uptodate(buf);
8432 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
8433 buf->log_index = root->log_transid % 2;
8435 * we allow two log transactions at a time, use different
8436 * EXENT bit to differentiate dirty pages.
8438 if (buf->log_index == 0)
8439 set_extent_dirty(&root->dirty_log_pages, buf->start,
8440 buf->start + buf->len - 1, GFP_NOFS);
8441 else
8442 set_extent_new(&root->dirty_log_pages, buf->start,
8443 buf->start + buf->len - 1);
8444 } else {
8445 buf->log_index = -1;
8446 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
8447 buf->start + buf->len - 1, GFP_NOFS);
8449 trans->dirty = true;
8450 /* this returns a buffer locked for blocking */
8451 return buf;
8454 static struct btrfs_block_rsv *
8455 use_block_rsv(struct btrfs_trans_handle *trans,
8456 struct btrfs_root *root, u32 blocksize)
8458 struct btrfs_fs_info *fs_info = root->fs_info;
8459 struct btrfs_block_rsv *block_rsv;
8460 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
8461 int ret;
8462 bool global_updated = false;
8464 block_rsv = get_block_rsv(trans, root);
8466 if (unlikely(block_rsv->size == 0))
8467 goto try_reserve;
8468 again:
8469 ret = block_rsv_use_bytes(block_rsv, blocksize);
8470 if (!ret)
8471 return block_rsv;
8473 if (block_rsv->failfast)
8474 return ERR_PTR(ret);
8476 if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
8477 global_updated = true;
8478 update_global_block_rsv(fs_info);
8479 goto again;
8482 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
8483 static DEFINE_RATELIMIT_STATE(_rs,
8484 DEFAULT_RATELIMIT_INTERVAL * 10,
8485 /*DEFAULT_RATELIMIT_BURST*/ 1);
8486 if (__ratelimit(&_rs))
8487 WARN(1, KERN_DEBUG
8488 "BTRFS: block rsv returned %d\n", ret);
8490 try_reserve:
8491 ret = reserve_metadata_bytes(root, block_rsv, blocksize,
8492 BTRFS_RESERVE_NO_FLUSH);
8493 if (!ret)
8494 return block_rsv;
8496 * If we couldn't reserve metadata bytes try and use some from
8497 * the global reserve if its space type is the same as the global
8498 * reservation.
8500 if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
8501 block_rsv->space_info == global_rsv->space_info) {
8502 ret = block_rsv_use_bytes(global_rsv, blocksize);
8503 if (!ret)
8504 return global_rsv;
8506 return ERR_PTR(ret);
8509 static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
8510 struct btrfs_block_rsv *block_rsv, u32 blocksize)
8512 block_rsv_add_bytes(block_rsv, blocksize, 0);
8513 block_rsv_release_bytes(fs_info, block_rsv, NULL, 0);
8517 * finds a free extent and does all the dirty work required for allocation
8518 * returns the tree buffer or an ERR_PTR on error.
8520 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
8521 struct btrfs_root *root,
8522 u64 parent, u64 root_objectid,
8523 const struct btrfs_disk_key *key,
8524 int level, u64 hint,
8525 u64 empty_size)
8527 struct btrfs_fs_info *fs_info = root->fs_info;
8528 struct btrfs_key ins;
8529 struct btrfs_block_rsv *block_rsv;
8530 struct extent_buffer *buf;
8531 struct btrfs_delayed_extent_op *extent_op;
8532 u64 flags = 0;
8533 int ret;
8534 u32 blocksize = fs_info->nodesize;
8535 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
8537 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
8538 if (btrfs_is_testing(fs_info)) {
8539 buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr,
8540 level);
8541 if (!IS_ERR(buf))
8542 root->alloc_bytenr += blocksize;
8543 return buf;
8545 #endif
8547 block_rsv = use_block_rsv(trans, root, blocksize);
8548 if (IS_ERR(block_rsv))
8549 return ERR_CAST(block_rsv);
8551 ret = btrfs_reserve_extent(root, blocksize, blocksize, blocksize,
8552 empty_size, hint, &ins, 0, 0);
8553 if (ret)
8554 goto out_unuse;
8556 buf = btrfs_init_new_buffer(trans, root, ins.objectid, level);
8557 if (IS_ERR(buf)) {
8558 ret = PTR_ERR(buf);
8559 goto out_free_reserved;
8562 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
8563 if (parent == 0)
8564 parent = ins.objectid;
8565 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
8566 } else
8567 BUG_ON(parent > 0);
8569 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
8570 extent_op = btrfs_alloc_delayed_extent_op();
8571 if (!extent_op) {
8572 ret = -ENOMEM;
8573 goto out_free_buf;
8575 if (key)
8576 memcpy(&extent_op->key, key, sizeof(extent_op->key));
8577 else
8578 memset(&extent_op->key, 0, sizeof(extent_op->key));
8579 extent_op->flags_to_set = flags;
8580 extent_op->update_key = skinny_metadata ? false : true;
8581 extent_op->update_flags = true;
8582 extent_op->is_data = false;
8583 extent_op->level = level;
8585 ret = btrfs_add_delayed_tree_ref(fs_info, trans, ins.objectid,
8586 ins.offset, parent,
8587 root_objectid, level,
8588 BTRFS_ADD_DELAYED_EXTENT,
8589 extent_op, NULL, NULL);
8590 if (ret)
8591 goto out_free_delayed;
8593 return buf;
8595 out_free_delayed:
8596 btrfs_free_delayed_extent_op(extent_op);
8597 out_free_buf:
8598 free_extent_buffer(buf);
8599 out_free_reserved:
8600 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 0);
8601 out_unuse:
8602 unuse_block_rsv(fs_info, block_rsv, blocksize);
8603 return ERR_PTR(ret);
8606 struct walk_control {
8607 u64 refs[BTRFS_MAX_LEVEL];
8608 u64 flags[BTRFS_MAX_LEVEL];
8609 struct btrfs_key update_progress;
8610 int stage;
8611 int level;
8612 int shared_level;
8613 int update_ref;
8614 int keep_locks;
8615 int reada_slot;
8616 int reada_count;
8617 int for_reloc;
8620 #define DROP_REFERENCE 1
8621 #define UPDATE_BACKREF 2
8623 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
8624 struct btrfs_root *root,
8625 struct walk_control *wc,
8626 struct btrfs_path *path)
8628 struct btrfs_fs_info *fs_info = root->fs_info;
8629 u64 bytenr;
8630 u64 generation;
8631 u64 refs;
8632 u64 flags;
8633 u32 nritems;
8634 struct btrfs_key key;
8635 struct extent_buffer *eb;
8636 int ret;
8637 int slot;
8638 int nread = 0;
8640 if (path->slots[wc->level] < wc->reada_slot) {
8641 wc->reada_count = wc->reada_count * 2 / 3;
8642 wc->reada_count = max(wc->reada_count, 2);
8643 } else {
8644 wc->reada_count = wc->reada_count * 3 / 2;
8645 wc->reada_count = min_t(int, wc->reada_count,
8646 BTRFS_NODEPTRS_PER_BLOCK(fs_info));
8649 eb = path->nodes[wc->level];
8650 nritems = btrfs_header_nritems(eb);
8652 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
8653 if (nread >= wc->reada_count)
8654 break;
8656 cond_resched();
8657 bytenr = btrfs_node_blockptr(eb, slot);
8658 generation = btrfs_node_ptr_generation(eb, slot);
8660 if (slot == path->slots[wc->level])
8661 goto reada;
8663 if (wc->stage == UPDATE_BACKREF &&
8664 generation <= root->root_key.offset)
8665 continue;
8667 /* We don't lock the tree block, it's OK to be racy here */
8668 ret = btrfs_lookup_extent_info(trans, fs_info, bytenr,
8669 wc->level - 1, 1, &refs,
8670 &flags);
8671 /* We don't care about errors in readahead. */
8672 if (ret < 0)
8673 continue;
8674 BUG_ON(refs == 0);
8676 if (wc->stage == DROP_REFERENCE) {
8677 if (refs == 1)
8678 goto reada;
8680 if (wc->level == 1 &&
8681 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8682 continue;
8683 if (!wc->update_ref ||
8684 generation <= root->root_key.offset)
8685 continue;
8686 btrfs_node_key_to_cpu(eb, &key, slot);
8687 ret = btrfs_comp_cpu_keys(&key,
8688 &wc->update_progress);
8689 if (ret < 0)
8690 continue;
8691 } else {
8692 if (wc->level == 1 &&
8693 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8694 continue;
8696 reada:
8697 readahead_tree_block(fs_info, bytenr);
8698 nread++;
8700 wc->reada_slot = slot;
8704 * helper to process tree block while walking down the tree.
8706 * when wc->stage == UPDATE_BACKREF, this function updates
8707 * back refs for pointers in the block.
8709 * NOTE: return value 1 means we should stop walking down.
8711 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
8712 struct btrfs_root *root,
8713 struct btrfs_path *path,
8714 struct walk_control *wc, int lookup_info)
8716 struct btrfs_fs_info *fs_info = root->fs_info;
8717 int level = wc->level;
8718 struct extent_buffer *eb = path->nodes[level];
8719 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
8720 int ret;
8722 if (wc->stage == UPDATE_BACKREF &&
8723 btrfs_header_owner(eb) != root->root_key.objectid)
8724 return 1;
8727 * when reference count of tree block is 1, it won't increase
8728 * again. once full backref flag is set, we never clear it.
8730 if (lookup_info &&
8731 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
8732 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
8733 BUG_ON(!path->locks[level]);
8734 ret = btrfs_lookup_extent_info(trans, fs_info,
8735 eb->start, level, 1,
8736 &wc->refs[level],
8737 &wc->flags[level]);
8738 BUG_ON(ret == -ENOMEM);
8739 if (ret)
8740 return ret;
8741 BUG_ON(wc->refs[level] == 0);
8744 if (wc->stage == DROP_REFERENCE) {
8745 if (wc->refs[level] > 1)
8746 return 1;
8748 if (path->locks[level] && !wc->keep_locks) {
8749 btrfs_tree_unlock_rw(eb, path->locks[level]);
8750 path->locks[level] = 0;
8752 return 0;
8755 /* wc->stage == UPDATE_BACKREF */
8756 if (!(wc->flags[level] & flag)) {
8757 BUG_ON(!path->locks[level]);
8758 ret = btrfs_inc_ref(trans, root, eb, 1);
8759 BUG_ON(ret); /* -ENOMEM */
8760 ret = btrfs_dec_ref(trans, root, eb, 0);
8761 BUG_ON(ret); /* -ENOMEM */
8762 ret = btrfs_set_disk_extent_flags(trans, fs_info, eb->start,
8763 eb->len, flag,
8764 btrfs_header_level(eb), 0);
8765 BUG_ON(ret); /* -ENOMEM */
8766 wc->flags[level] |= flag;
8770 * the block is shared by multiple trees, so it's not good to
8771 * keep the tree lock
8773 if (path->locks[level] && level > 0) {
8774 btrfs_tree_unlock_rw(eb, path->locks[level]);
8775 path->locks[level] = 0;
8777 return 0;
8781 * helper to process tree block pointer.
8783 * when wc->stage == DROP_REFERENCE, this function checks
8784 * reference count of the block pointed to. if the block
8785 * is shared and we need update back refs for the subtree
8786 * rooted at the block, this function changes wc->stage to
8787 * UPDATE_BACKREF. if the block is shared and there is no
8788 * need to update back, this function drops the reference
8789 * to the block.
8791 * NOTE: return value 1 means we should stop walking down.
8793 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
8794 struct btrfs_root *root,
8795 struct btrfs_path *path,
8796 struct walk_control *wc, int *lookup_info)
8798 struct btrfs_fs_info *fs_info = root->fs_info;
8799 u64 bytenr;
8800 u64 generation;
8801 u64 parent;
8802 u32 blocksize;
8803 struct btrfs_key key;
8804 struct extent_buffer *next;
8805 int level = wc->level;
8806 int reada = 0;
8807 int ret = 0;
8808 bool need_account = false;
8810 generation = btrfs_node_ptr_generation(path->nodes[level],
8811 path->slots[level]);
8813 * if the lower level block was created before the snapshot
8814 * was created, we know there is no need to update back refs
8815 * for the subtree
8817 if (wc->stage == UPDATE_BACKREF &&
8818 generation <= root->root_key.offset) {
8819 *lookup_info = 1;
8820 return 1;
8823 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
8824 blocksize = fs_info->nodesize;
8826 next = find_extent_buffer(fs_info, bytenr);
8827 if (!next) {
8828 next = btrfs_find_create_tree_block(fs_info, bytenr);
8829 if (IS_ERR(next))
8830 return PTR_ERR(next);
8832 btrfs_set_buffer_lockdep_class(root->root_key.objectid, next,
8833 level - 1);
8834 reada = 1;
8836 btrfs_tree_lock(next);
8837 btrfs_set_lock_blocking(next);
8839 ret = btrfs_lookup_extent_info(trans, fs_info, bytenr, level - 1, 1,
8840 &wc->refs[level - 1],
8841 &wc->flags[level - 1]);
8842 if (ret < 0)
8843 goto out_unlock;
8845 if (unlikely(wc->refs[level - 1] == 0)) {
8846 btrfs_err(fs_info, "Missing references.");
8847 ret = -EIO;
8848 goto out_unlock;
8850 *lookup_info = 0;
8852 if (wc->stage == DROP_REFERENCE) {
8853 if (wc->refs[level - 1] > 1) {
8854 need_account = true;
8855 if (level == 1 &&
8856 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8857 goto skip;
8859 if (!wc->update_ref ||
8860 generation <= root->root_key.offset)
8861 goto skip;
8863 btrfs_node_key_to_cpu(path->nodes[level], &key,
8864 path->slots[level]);
8865 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
8866 if (ret < 0)
8867 goto skip;
8869 wc->stage = UPDATE_BACKREF;
8870 wc->shared_level = level - 1;
8872 } else {
8873 if (level == 1 &&
8874 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8875 goto skip;
8878 if (!btrfs_buffer_uptodate(next, generation, 0)) {
8879 btrfs_tree_unlock(next);
8880 free_extent_buffer(next);
8881 next = NULL;
8882 *lookup_info = 1;
8885 if (!next) {
8886 if (reada && level == 1)
8887 reada_walk_down(trans, root, wc, path);
8888 next = read_tree_block(fs_info, bytenr, generation);
8889 if (IS_ERR(next)) {
8890 return PTR_ERR(next);
8891 } else if (!extent_buffer_uptodate(next)) {
8892 free_extent_buffer(next);
8893 return -EIO;
8895 btrfs_tree_lock(next);
8896 btrfs_set_lock_blocking(next);
8899 level--;
8900 ASSERT(level == btrfs_header_level(next));
8901 if (level != btrfs_header_level(next)) {
8902 btrfs_err(root->fs_info, "mismatched level");
8903 ret = -EIO;
8904 goto out_unlock;
8906 path->nodes[level] = next;
8907 path->slots[level] = 0;
8908 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
8909 wc->level = level;
8910 if (wc->level == 1)
8911 wc->reada_slot = 0;
8912 return 0;
8913 skip:
8914 wc->refs[level - 1] = 0;
8915 wc->flags[level - 1] = 0;
8916 if (wc->stage == DROP_REFERENCE) {
8917 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
8918 parent = path->nodes[level]->start;
8919 } else {
8920 ASSERT(root->root_key.objectid ==
8921 btrfs_header_owner(path->nodes[level]));
8922 if (root->root_key.objectid !=
8923 btrfs_header_owner(path->nodes[level])) {
8924 btrfs_err(root->fs_info,
8925 "mismatched block owner");
8926 ret = -EIO;
8927 goto out_unlock;
8929 parent = 0;
8932 if (need_account) {
8933 ret = btrfs_qgroup_trace_subtree(trans, root, next,
8934 generation, level - 1);
8935 if (ret) {
8936 btrfs_err_rl(fs_info,
8937 "Error %d accounting shared subtree. Quota is out of sync, rescan required.",
8938 ret);
8941 ret = btrfs_free_extent(trans, fs_info, bytenr, blocksize,
8942 parent, root->root_key.objectid,
8943 level - 1, 0);
8944 if (ret)
8945 goto out_unlock;
8948 *lookup_info = 1;
8949 ret = 1;
8951 out_unlock:
8952 btrfs_tree_unlock(next);
8953 free_extent_buffer(next);
8955 return ret;
8959 * helper to process tree block while walking up the tree.
8961 * when wc->stage == DROP_REFERENCE, this function drops
8962 * reference count on the block.
8964 * when wc->stage == UPDATE_BACKREF, this function changes
8965 * wc->stage back to DROP_REFERENCE if we changed wc->stage
8966 * to UPDATE_BACKREF previously while processing the block.
8968 * NOTE: return value 1 means we should stop walking up.
8970 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
8971 struct btrfs_root *root,
8972 struct btrfs_path *path,
8973 struct walk_control *wc)
8975 struct btrfs_fs_info *fs_info = root->fs_info;
8976 int ret;
8977 int level = wc->level;
8978 struct extent_buffer *eb = path->nodes[level];
8979 u64 parent = 0;
8981 if (wc->stage == UPDATE_BACKREF) {
8982 BUG_ON(wc->shared_level < level);
8983 if (level < wc->shared_level)
8984 goto out;
8986 ret = find_next_key(path, level + 1, &wc->update_progress);
8987 if (ret > 0)
8988 wc->update_ref = 0;
8990 wc->stage = DROP_REFERENCE;
8991 wc->shared_level = -1;
8992 path->slots[level] = 0;
8995 * check reference count again if the block isn't locked.
8996 * we should start walking down the tree again if reference
8997 * count is one.
8999 if (!path->locks[level]) {
9000 BUG_ON(level == 0);
9001 btrfs_tree_lock(eb);
9002 btrfs_set_lock_blocking(eb);
9003 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
9005 ret = btrfs_lookup_extent_info(trans, fs_info,
9006 eb->start, level, 1,
9007 &wc->refs[level],
9008 &wc->flags[level]);
9009 if (ret < 0) {
9010 btrfs_tree_unlock_rw(eb, path->locks[level]);
9011 path->locks[level] = 0;
9012 return ret;
9014 BUG_ON(wc->refs[level] == 0);
9015 if (wc->refs[level] == 1) {
9016 btrfs_tree_unlock_rw(eb, path->locks[level]);
9017 path->locks[level] = 0;
9018 return 1;
9023 /* wc->stage == DROP_REFERENCE */
9024 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
9026 if (wc->refs[level] == 1) {
9027 if (level == 0) {
9028 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
9029 ret = btrfs_dec_ref(trans, root, eb, 1);
9030 else
9031 ret = btrfs_dec_ref(trans, root, eb, 0);
9032 BUG_ON(ret); /* -ENOMEM */
9033 ret = btrfs_qgroup_trace_leaf_items(trans, fs_info, eb);
9034 if (ret) {
9035 btrfs_err_rl(fs_info,
9036 "error %d accounting leaf items. Quota is out of sync, rescan required.",
9037 ret);
9040 /* make block locked assertion in clean_tree_block happy */
9041 if (!path->locks[level] &&
9042 btrfs_header_generation(eb) == trans->transid) {
9043 btrfs_tree_lock(eb);
9044 btrfs_set_lock_blocking(eb);
9045 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
9047 clean_tree_block(fs_info, eb);
9050 if (eb == root->node) {
9051 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
9052 parent = eb->start;
9053 else if (root->root_key.objectid != btrfs_header_owner(eb))
9054 goto owner_mismatch;
9055 } else {
9056 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
9057 parent = path->nodes[level + 1]->start;
9058 else if (root->root_key.objectid !=
9059 btrfs_header_owner(path->nodes[level + 1]))
9060 goto owner_mismatch;
9063 btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
9064 out:
9065 wc->refs[level] = 0;
9066 wc->flags[level] = 0;
9067 return 0;
9069 owner_mismatch:
9070 btrfs_err_rl(fs_info, "unexpected tree owner, have %llu expect %llu",
9071 btrfs_header_owner(eb), root->root_key.objectid);
9072 return -EUCLEAN;
9075 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
9076 struct btrfs_root *root,
9077 struct btrfs_path *path,
9078 struct walk_control *wc)
9080 int level = wc->level;
9081 int lookup_info = 1;
9082 int ret;
9084 while (level >= 0) {
9085 ret = walk_down_proc(trans, root, path, wc, lookup_info);
9086 if (ret > 0)
9087 break;
9089 if (level == 0)
9090 break;
9092 if (path->slots[level] >=
9093 btrfs_header_nritems(path->nodes[level]))
9094 break;
9096 ret = do_walk_down(trans, root, path, wc, &lookup_info);
9097 if (ret > 0) {
9098 path->slots[level]++;
9099 continue;
9100 } else if (ret < 0)
9101 return ret;
9102 level = wc->level;
9104 return 0;
9107 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
9108 struct btrfs_root *root,
9109 struct btrfs_path *path,
9110 struct walk_control *wc, int max_level)
9112 int level = wc->level;
9113 int ret;
9115 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
9116 while (level < max_level && path->nodes[level]) {
9117 wc->level = level;
9118 if (path->slots[level] + 1 <
9119 btrfs_header_nritems(path->nodes[level])) {
9120 path->slots[level]++;
9121 return 0;
9122 } else {
9123 ret = walk_up_proc(trans, root, path, wc);
9124 if (ret > 0)
9125 return 0;
9126 if (ret < 0)
9127 return ret;
9129 if (path->locks[level]) {
9130 btrfs_tree_unlock_rw(path->nodes[level],
9131 path->locks[level]);
9132 path->locks[level] = 0;
9134 free_extent_buffer(path->nodes[level]);
9135 path->nodes[level] = NULL;
9136 level++;
9139 return 1;
9143 * drop a subvolume tree.
9145 * this function traverses the tree freeing any blocks that only
9146 * referenced by the tree.
9148 * when a shared tree block is found. this function decreases its
9149 * reference count by one. if update_ref is true, this function
9150 * also make sure backrefs for the shared block and all lower level
9151 * blocks are properly updated.
9153 * If called with for_reloc == 0, may exit early with -EAGAIN
9155 int btrfs_drop_snapshot(struct btrfs_root *root,
9156 struct btrfs_block_rsv *block_rsv, int update_ref,
9157 int for_reloc)
9159 struct btrfs_fs_info *fs_info = root->fs_info;
9160 struct btrfs_path *path;
9161 struct btrfs_trans_handle *trans;
9162 struct btrfs_root *tree_root = fs_info->tree_root;
9163 struct btrfs_root_item *root_item = &root->root_item;
9164 struct walk_control *wc;
9165 struct btrfs_key key;
9166 int err = 0;
9167 int ret;
9168 int level;
9169 bool root_dropped = false;
9171 btrfs_debug(fs_info, "Drop subvolume %llu", root->objectid);
9173 path = btrfs_alloc_path();
9174 if (!path) {
9175 err = -ENOMEM;
9176 goto out;
9179 wc = kzalloc(sizeof(*wc), GFP_NOFS);
9180 if (!wc) {
9181 btrfs_free_path(path);
9182 err = -ENOMEM;
9183 goto out;
9186 trans = btrfs_start_transaction(tree_root, 0);
9187 if (IS_ERR(trans)) {
9188 err = PTR_ERR(trans);
9189 goto out_free;
9192 if (block_rsv)
9193 trans->block_rsv = block_rsv;
9195 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
9196 level = btrfs_header_level(root->node);
9197 path->nodes[level] = btrfs_lock_root_node(root);
9198 btrfs_set_lock_blocking(path->nodes[level]);
9199 path->slots[level] = 0;
9200 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
9201 memset(&wc->update_progress, 0,
9202 sizeof(wc->update_progress));
9203 } else {
9204 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
9205 memcpy(&wc->update_progress, &key,
9206 sizeof(wc->update_progress));
9208 level = root_item->drop_level;
9209 BUG_ON(level == 0);
9210 path->lowest_level = level;
9211 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
9212 path->lowest_level = 0;
9213 if (ret < 0) {
9214 err = ret;
9215 goto out_end_trans;
9217 WARN_ON(ret > 0);
9220 * unlock our path, this is safe because only this
9221 * function is allowed to delete this snapshot
9223 btrfs_unlock_up_safe(path, 0);
9225 level = btrfs_header_level(root->node);
9226 while (1) {
9227 btrfs_tree_lock(path->nodes[level]);
9228 btrfs_set_lock_blocking(path->nodes[level]);
9229 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
9231 ret = btrfs_lookup_extent_info(trans, fs_info,
9232 path->nodes[level]->start,
9233 level, 1, &wc->refs[level],
9234 &wc->flags[level]);
9235 if (ret < 0) {
9236 err = ret;
9237 goto out_end_trans;
9239 BUG_ON(wc->refs[level] == 0);
9241 if (level == root_item->drop_level)
9242 break;
9244 btrfs_tree_unlock(path->nodes[level]);
9245 path->locks[level] = 0;
9246 WARN_ON(wc->refs[level] != 1);
9247 level--;
9251 wc->level = level;
9252 wc->shared_level = -1;
9253 wc->stage = DROP_REFERENCE;
9254 wc->update_ref = update_ref;
9255 wc->keep_locks = 0;
9256 wc->for_reloc = for_reloc;
9257 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info);
9259 while (1) {
9261 ret = walk_down_tree(trans, root, path, wc);
9262 if (ret < 0) {
9263 err = ret;
9264 break;
9267 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
9268 if (ret < 0) {
9269 err = ret;
9270 break;
9273 if (ret > 0) {
9274 BUG_ON(wc->stage != DROP_REFERENCE);
9275 break;
9278 if (wc->stage == DROP_REFERENCE) {
9279 level = wc->level;
9280 btrfs_node_key(path->nodes[level],
9281 &root_item->drop_progress,
9282 path->slots[level]);
9283 root_item->drop_level = level;
9286 BUG_ON(wc->level == 0);
9287 if (btrfs_should_end_transaction(trans) ||
9288 (!for_reloc && btrfs_need_cleaner_sleep(fs_info))) {
9289 ret = btrfs_update_root(trans, tree_root,
9290 &root->root_key,
9291 root_item);
9292 if (ret) {
9293 btrfs_abort_transaction(trans, ret);
9294 err = ret;
9295 goto out_end_trans;
9298 btrfs_end_transaction_throttle(trans);
9299 if (!for_reloc && btrfs_need_cleaner_sleep(fs_info)) {
9300 btrfs_debug(fs_info,
9301 "drop snapshot early exit");
9302 err = -EAGAIN;
9303 goto out_free;
9306 trans = btrfs_start_transaction(tree_root, 0);
9307 if (IS_ERR(trans)) {
9308 err = PTR_ERR(trans);
9309 goto out_free;
9311 if (block_rsv)
9312 trans->block_rsv = block_rsv;
9315 btrfs_release_path(path);
9316 if (err)
9317 goto out_end_trans;
9319 ret = btrfs_del_root(trans, fs_info, &root->root_key);
9320 if (ret) {
9321 btrfs_abort_transaction(trans, ret);
9322 err = ret;
9323 goto out_end_trans;
9326 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
9327 ret = btrfs_find_root(tree_root, &root->root_key, path,
9328 NULL, NULL);
9329 if (ret < 0) {
9330 btrfs_abort_transaction(trans, ret);
9331 err = ret;
9332 goto out_end_trans;
9333 } else if (ret > 0) {
9334 /* if we fail to delete the orphan item this time
9335 * around, it'll get picked up the next time.
9337 * The most common failure here is just -ENOENT.
9339 btrfs_del_orphan_item(trans, tree_root,
9340 root->root_key.objectid);
9344 if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state)) {
9345 btrfs_add_dropped_root(trans, root);
9346 } else {
9347 free_extent_buffer(root->node);
9348 free_extent_buffer(root->commit_root);
9349 btrfs_put_fs_root(root);
9351 root_dropped = true;
9352 out_end_trans:
9353 btrfs_end_transaction_throttle(trans);
9354 out_free:
9355 kfree(wc);
9356 btrfs_free_path(path);
9357 out:
9359 * So if we need to stop dropping the snapshot for whatever reason we
9360 * need to make sure to add it back to the dead root list so that we
9361 * keep trying to do the work later. This also cleans up roots if we
9362 * don't have it in the radix (like when we recover after a power fail
9363 * or unmount) so we don't leak memory.
9365 if (!for_reloc && root_dropped == false)
9366 btrfs_add_dead_root(root);
9367 return err;
9371 * drop subtree rooted at tree block 'node'.
9373 * NOTE: this function will unlock and release tree block 'node'
9374 * only used by relocation code
9376 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
9377 struct btrfs_root *root,
9378 struct extent_buffer *node,
9379 struct extent_buffer *parent)
9381 struct btrfs_fs_info *fs_info = root->fs_info;
9382 struct btrfs_path *path;
9383 struct walk_control *wc;
9384 int level;
9385 int parent_level;
9386 int ret = 0;
9387 int wret;
9389 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
9391 path = btrfs_alloc_path();
9392 if (!path)
9393 return -ENOMEM;
9395 wc = kzalloc(sizeof(*wc), GFP_NOFS);
9396 if (!wc) {
9397 btrfs_free_path(path);
9398 return -ENOMEM;
9401 btrfs_assert_tree_locked(parent);
9402 parent_level = btrfs_header_level(parent);
9403 extent_buffer_get(parent);
9404 path->nodes[parent_level] = parent;
9405 path->slots[parent_level] = btrfs_header_nritems(parent);
9407 btrfs_assert_tree_locked(node);
9408 level = btrfs_header_level(node);
9409 path->nodes[level] = node;
9410 path->slots[level] = 0;
9411 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
9413 wc->refs[parent_level] = 1;
9414 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
9415 wc->level = level;
9416 wc->shared_level = -1;
9417 wc->stage = DROP_REFERENCE;
9418 wc->update_ref = 0;
9419 wc->keep_locks = 1;
9420 wc->for_reloc = 1;
9421 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info);
9423 while (1) {
9424 wret = walk_down_tree(trans, root, path, wc);
9425 if (wret < 0) {
9426 ret = wret;
9427 break;
9430 wret = walk_up_tree(trans, root, path, wc, parent_level);
9431 if (wret < 0)
9432 ret = wret;
9433 if (wret != 0)
9434 break;
9437 kfree(wc);
9438 btrfs_free_path(path);
9439 return ret;
9442 static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags)
9444 u64 num_devices;
9445 u64 stripped;
9448 * if restripe for this chunk_type is on pick target profile and
9449 * return, otherwise do the usual balance
9451 stripped = get_restripe_target(fs_info, flags);
9452 if (stripped)
9453 return extended_to_chunk(stripped);
9455 num_devices = fs_info->fs_devices->rw_devices;
9457 stripped = BTRFS_BLOCK_GROUP_RAID0 |
9458 BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
9459 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
9461 if (num_devices == 1) {
9462 stripped |= BTRFS_BLOCK_GROUP_DUP;
9463 stripped = flags & ~stripped;
9465 /* turn raid0 into single device chunks */
9466 if (flags & BTRFS_BLOCK_GROUP_RAID0)
9467 return stripped;
9469 /* turn mirroring into duplication */
9470 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
9471 BTRFS_BLOCK_GROUP_RAID10))
9472 return stripped | BTRFS_BLOCK_GROUP_DUP;
9473 } else {
9474 /* they already had raid on here, just return */
9475 if (flags & stripped)
9476 return flags;
9478 stripped |= BTRFS_BLOCK_GROUP_DUP;
9479 stripped = flags & ~stripped;
9481 /* switch duplicated blocks with raid1 */
9482 if (flags & BTRFS_BLOCK_GROUP_DUP)
9483 return stripped | BTRFS_BLOCK_GROUP_RAID1;
9485 /* this is drive concat, leave it alone */
9488 return flags;
9491 static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
9493 struct btrfs_space_info *sinfo = cache->space_info;
9494 u64 num_bytes;
9495 u64 min_allocable_bytes;
9496 int ret = -ENOSPC;
9499 * We need some metadata space and system metadata space for
9500 * allocating chunks in some corner cases until we force to set
9501 * it to be readonly.
9503 if ((sinfo->flags &
9504 (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
9505 !force)
9506 min_allocable_bytes = SZ_1M;
9507 else
9508 min_allocable_bytes = 0;
9510 spin_lock(&sinfo->lock);
9511 spin_lock(&cache->lock);
9513 if (cache->ro) {
9514 cache->ro++;
9515 ret = 0;
9516 goto out;
9519 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
9520 cache->bytes_super - btrfs_block_group_used(&cache->item);
9522 if (btrfs_space_info_used(sinfo, true) + num_bytes +
9523 min_allocable_bytes <= sinfo->total_bytes) {
9524 sinfo->bytes_readonly += num_bytes;
9525 cache->ro++;
9526 list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
9527 ret = 0;
9529 out:
9530 spin_unlock(&cache->lock);
9531 spin_unlock(&sinfo->lock);
9532 return ret;
9535 int btrfs_inc_block_group_ro(struct btrfs_fs_info *fs_info,
9536 struct btrfs_block_group_cache *cache)
9539 struct btrfs_trans_handle *trans;
9540 u64 alloc_flags;
9541 int ret;
9543 again:
9544 trans = btrfs_join_transaction(fs_info->extent_root);
9545 if (IS_ERR(trans))
9546 return PTR_ERR(trans);
9549 * we're not allowed to set block groups readonly after the dirty
9550 * block groups cache has started writing. If it already started,
9551 * back off and let this transaction commit
9553 mutex_lock(&fs_info->ro_block_group_mutex);
9554 if (test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &trans->transaction->flags)) {
9555 u64 transid = trans->transid;
9557 mutex_unlock(&fs_info->ro_block_group_mutex);
9558 btrfs_end_transaction(trans);
9560 ret = btrfs_wait_for_commit(fs_info, transid);
9561 if (ret)
9562 return ret;
9563 goto again;
9567 * if we are changing raid levels, try to allocate a corresponding
9568 * block group with the new raid level.
9570 alloc_flags = update_block_group_flags(fs_info, cache->flags);
9571 if (alloc_flags != cache->flags) {
9572 ret = do_chunk_alloc(trans, fs_info, alloc_flags,
9573 CHUNK_ALLOC_FORCE);
9575 * ENOSPC is allowed here, we may have enough space
9576 * already allocated at the new raid level to
9577 * carry on
9579 if (ret == -ENOSPC)
9580 ret = 0;
9581 if (ret < 0)
9582 goto out;
9585 ret = inc_block_group_ro(cache, 0);
9586 if (!ret)
9587 goto out;
9588 alloc_flags = get_alloc_profile(fs_info, cache->space_info->flags);
9589 ret = do_chunk_alloc(trans, fs_info, alloc_flags,
9590 CHUNK_ALLOC_FORCE);
9591 if (ret < 0)
9592 goto out;
9593 ret = inc_block_group_ro(cache, 0);
9594 out:
9595 if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
9596 alloc_flags = update_block_group_flags(fs_info, cache->flags);
9597 mutex_lock(&fs_info->chunk_mutex);
9598 check_system_chunk(trans, fs_info, alloc_flags);
9599 mutex_unlock(&fs_info->chunk_mutex);
9601 mutex_unlock(&fs_info->ro_block_group_mutex);
9603 btrfs_end_transaction(trans);
9604 return ret;
9607 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
9608 struct btrfs_fs_info *fs_info, u64 type)
9610 u64 alloc_flags = get_alloc_profile(fs_info, type);
9612 return do_chunk_alloc(trans, fs_info, alloc_flags, CHUNK_ALLOC_FORCE);
9616 * helper to account the unused space of all the readonly block group in the
9617 * space_info. takes mirrors into account.
9619 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
9621 struct btrfs_block_group_cache *block_group;
9622 u64 free_bytes = 0;
9623 int factor;
9625 /* It's df, we don't care if it's racy */
9626 if (list_empty(&sinfo->ro_bgs))
9627 return 0;
9629 spin_lock(&sinfo->lock);
9630 list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) {
9631 spin_lock(&block_group->lock);
9633 if (!block_group->ro) {
9634 spin_unlock(&block_group->lock);
9635 continue;
9638 if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
9639 BTRFS_BLOCK_GROUP_RAID10 |
9640 BTRFS_BLOCK_GROUP_DUP))
9641 factor = 2;
9642 else
9643 factor = 1;
9645 free_bytes += (block_group->key.offset -
9646 btrfs_block_group_used(&block_group->item)) *
9647 factor;
9649 spin_unlock(&block_group->lock);
9651 spin_unlock(&sinfo->lock);
9653 return free_bytes;
9656 void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache)
9658 struct btrfs_space_info *sinfo = cache->space_info;
9659 u64 num_bytes;
9661 BUG_ON(!cache->ro);
9663 spin_lock(&sinfo->lock);
9664 spin_lock(&cache->lock);
9665 if (!--cache->ro) {
9666 num_bytes = cache->key.offset - cache->reserved -
9667 cache->pinned - cache->bytes_super -
9668 btrfs_block_group_used(&cache->item);
9669 sinfo->bytes_readonly -= num_bytes;
9670 list_del_init(&cache->ro_list);
9672 spin_unlock(&cache->lock);
9673 spin_unlock(&sinfo->lock);
9677 * checks to see if its even possible to relocate this block group.
9679 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
9680 * ok to go ahead and try.
9682 int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr)
9684 struct btrfs_root *root = fs_info->extent_root;
9685 struct btrfs_block_group_cache *block_group;
9686 struct btrfs_space_info *space_info;
9687 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
9688 struct btrfs_device *device;
9689 struct btrfs_trans_handle *trans;
9690 u64 min_free;
9691 u64 dev_min = 1;
9692 u64 dev_nr = 0;
9693 u64 target;
9694 int debug;
9695 int index;
9696 int full = 0;
9697 int ret = 0;
9699 debug = btrfs_test_opt(fs_info, ENOSPC_DEBUG);
9701 block_group = btrfs_lookup_block_group(fs_info, bytenr);
9703 /* odd, couldn't find the block group, leave it alone */
9704 if (!block_group) {
9705 if (debug)
9706 btrfs_warn(fs_info,
9707 "can't find block group for bytenr %llu",
9708 bytenr);
9709 return -1;
9712 min_free = btrfs_block_group_used(&block_group->item);
9714 /* no bytes used, we're good */
9715 if (!min_free)
9716 goto out;
9718 space_info = block_group->space_info;
9719 spin_lock(&space_info->lock);
9721 full = space_info->full;
9724 * if this is the last block group we have in this space, we can't
9725 * relocate it unless we're able to allocate a new chunk below.
9727 * Otherwise, we need to make sure we have room in the space to handle
9728 * all of the extents from this block group. If we can, we're good
9730 if ((space_info->total_bytes != block_group->key.offset) &&
9731 (btrfs_space_info_used(space_info, false) + min_free <
9732 space_info->total_bytes)) {
9733 spin_unlock(&space_info->lock);
9734 goto out;
9736 spin_unlock(&space_info->lock);
9739 * ok we don't have enough space, but maybe we have free space on our
9740 * devices to allocate new chunks for relocation, so loop through our
9741 * alloc devices and guess if we have enough space. if this block
9742 * group is going to be restriped, run checks against the target
9743 * profile instead of the current one.
9745 ret = -1;
9748 * index:
9749 * 0: raid10
9750 * 1: raid1
9751 * 2: dup
9752 * 3: raid0
9753 * 4: single
9755 target = get_restripe_target(fs_info, block_group->flags);
9756 if (target) {
9757 index = __get_raid_index(extended_to_chunk(target));
9758 } else {
9760 * this is just a balance, so if we were marked as full
9761 * we know there is no space for a new chunk
9763 if (full) {
9764 if (debug)
9765 btrfs_warn(fs_info,
9766 "no space to alloc new chunk for block group %llu",
9767 block_group->key.objectid);
9768 goto out;
9771 index = get_block_group_index(block_group);
9774 if (index == BTRFS_RAID_RAID10) {
9775 dev_min = 4;
9776 /* Divide by 2 */
9777 min_free >>= 1;
9778 } else if (index == BTRFS_RAID_RAID1) {
9779 dev_min = 2;
9780 } else if (index == BTRFS_RAID_DUP) {
9781 /* Multiply by 2 */
9782 min_free <<= 1;
9783 } else if (index == BTRFS_RAID_RAID0) {
9784 dev_min = fs_devices->rw_devices;
9785 min_free = div64_u64(min_free, dev_min);
9788 /* We need to do this so that we can look at pending chunks */
9789 trans = btrfs_join_transaction(root);
9790 if (IS_ERR(trans)) {
9791 ret = PTR_ERR(trans);
9792 goto out;
9795 mutex_lock(&fs_info->chunk_mutex);
9796 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
9797 u64 dev_offset;
9800 * check to make sure we can actually find a chunk with enough
9801 * space to fit our block group in.
9803 if (device->total_bytes > device->bytes_used + min_free &&
9804 !device->is_tgtdev_for_dev_replace) {
9805 ret = find_free_dev_extent(trans, device, min_free,
9806 &dev_offset, NULL);
9807 if (!ret)
9808 dev_nr++;
9810 if (dev_nr >= dev_min)
9811 break;
9813 ret = -1;
9816 if (debug && ret == -1)
9817 btrfs_warn(fs_info,
9818 "no space to allocate a new chunk for block group %llu",
9819 block_group->key.objectid);
9820 mutex_unlock(&fs_info->chunk_mutex);
9821 btrfs_end_transaction(trans);
9822 out:
9823 btrfs_put_block_group(block_group);
9824 return ret;
9827 static int find_first_block_group(struct btrfs_fs_info *fs_info,
9828 struct btrfs_path *path,
9829 struct btrfs_key *key)
9831 struct btrfs_root *root = fs_info->extent_root;
9832 int ret = 0;
9833 struct btrfs_key found_key;
9834 struct extent_buffer *leaf;
9835 struct btrfs_block_group_item bg;
9836 u64 flags;
9837 int slot;
9839 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
9840 if (ret < 0)
9841 goto out;
9843 while (1) {
9844 slot = path->slots[0];
9845 leaf = path->nodes[0];
9846 if (slot >= btrfs_header_nritems(leaf)) {
9847 ret = btrfs_next_leaf(root, path);
9848 if (ret == 0)
9849 continue;
9850 if (ret < 0)
9851 goto out;
9852 break;
9854 btrfs_item_key_to_cpu(leaf, &found_key, slot);
9856 if (found_key.objectid >= key->objectid &&
9857 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
9858 struct extent_map_tree *em_tree;
9859 struct extent_map *em;
9861 em_tree = &root->fs_info->mapping_tree.map_tree;
9862 read_lock(&em_tree->lock);
9863 em = lookup_extent_mapping(em_tree, found_key.objectid,
9864 found_key.offset);
9865 read_unlock(&em_tree->lock);
9866 if (!em) {
9867 btrfs_err(fs_info,
9868 "logical %llu len %llu found bg but no related chunk",
9869 found_key.objectid, found_key.offset);
9870 ret = -ENOENT;
9871 } else if (em->start != found_key.objectid ||
9872 em->len != found_key.offset) {
9873 btrfs_err(fs_info,
9874 "block group %llu len %llu mismatch with chunk %llu len %llu",
9875 found_key.objectid, found_key.offset,
9876 em->start, em->len);
9877 ret = -EUCLEAN;
9878 } else {
9879 read_extent_buffer(leaf, &bg,
9880 btrfs_item_ptr_offset(leaf, slot),
9881 sizeof(bg));
9882 flags = btrfs_block_group_flags(&bg) &
9883 BTRFS_BLOCK_GROUP_TYPE_MASK;
9885 if (flags != (em->map_lookup->type &
9886 BTRFS_BLOCK_GROUP_TYPE_MASK)) {
9887 btrfs_err(fs_info,
9888 "block group %llu len %llu type flags 0x%llx mismatch with chunk type flags 0x%llx",
9889 found_key.objectid,
9890 found_key.offset, flags,
9891 (BTRFS_BLOCK_GROUP_TYPE_MASK &
9892 em->map_lookup->type));
9893 ret = -EUCLEAN;
9894 } else {
9895 ret = 0;
9898 free_extent_map(em);
9899 goto out;
9901 path->slots[0]++;
9903 out:
9904 return ret;
9907 void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
9909 struct btrfs_block_group_cache *block_group;
9910 u64 last = 0;
9912 while (1) {
9913 struct inode *inode;
9915 block_group = btrfs_lookup_first_block_group(info, last);
9916 while (block_group) {
9917 wait_block_group_cache_done(block_group);
9918 spin_lock(&block_group->lock);
9919 if (block_group->iref)
9920 break;
9921 spin_unlock(&block_group->lock);
9922 block_group = next_block_group(info, block_group);
9924 if (!block_group) {
9925 if (last == 0)
9926 break;
9927 last = 0;
9928 continue;
9931 inode = block_group->inode;
9932 block_group->iref = 0;
9933 block_group->inode = NULL;
9934 spin_unlock(&block_group->lock);
9935 ASSERT(block_group->io_ctl.inode == NULL);
9936 iput(inode);
9937 last = block_group->key.objectid + block_group->key.offset;
9938 btrfs_put_block_group(block_group);
9943 * Must be called only after stopping all workers, since we could have block
9944 * group caching kthreads running, and therefore they could race with us if we
9945 * freed the block groups before stopping them.
9947 int btrfs_free_block_groups(struct btrfs_fs_info *info)
9949 struct btrfs_block_group_cache *block_group;
9950 struct btrfs_space_info *space_info;
9951 struct btrfs_caching_control *caching_ctl;
9952 struct rb_node *n;
9954 down_write(&info->commit_root_sem);
9955 while (!list_empty(&info->caching_block_groups)) {
9956 caching_ctl = list_entry(info->caching_block_groups.next,
9957 struct btrfs_caching_control, list);
9958 list_del(&caching_ctl->list);
9959 put_caching_control(caching_ctl);
9961 up_write(&info->commit_root_sem);
9963 spin_lock(&info->unused_bgs_lock);
9964 while (!list_empty(&info->unused_bgs)) {
9965 block_group = list_first_entry(&info->unused_bgs,
9966 struct btrfs_block_group_cache,
9967 bg_list);
9968 list_del_init(&block_group->bg_list);
9969 btrfs_put_block_group(block_group);
9971 spin_unlock(&info->unused_bgs_lock);
9973 spin_lock(&info->block_group_cache_lock);
9974 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
9975 block_group = rb_entry(n, struct btrfs_block_group_cache,
9976 cache_node);
9977 rb_erase(&block_group->cache_node,
9978 &info->block_group_cache_tree);
9979 RB_CLEAR_NODE(&block_group->cache_node);
9980 spin_unlock(&info->block_group_cache_lock);
9982 down_write(&block_group->space_info->groups_sem);
9983 list_del(&block_group->list);
9984 up_write(&block_group->space_info->groups_sem);
9987 * We haven't cached this block group, which means we could
9988 * possibly have excluded extents on this block group.
9990 if (block_group->cached == BTRFS_CACHE_NO ||
9991 block_group->cached == BTRFS_CACHE_ERROR)
9992 free_excluded_extents(info, block_group);
9994 btrfs_remove_free_space_cache(block_group);
9995 ASSERT(block_group->cached != BTRFS_CACHE_STARTED);
9996 ASSERT(list_empty(&block_group->dirty_list));
9997 ASSERT(list_empty(&block_group->io_list));
9998 ASSERT(list_empty(&block_group->bg_list));
9999 ASSERT(atomic_read(&block_group->count) == 1);
10000 btrfs_put_block_group(block_group);
10002 spin_lock(&info->block_group_cache_lock);
10004 spin_unlock(&info->block_group_cache_lock);
10006 /* now that all the block groups are freed, go through and
10007 * free all the space_info structs. This is only called during
10008 * the final stages of unmount, and so we know nobody is
10009 * using them. We call synchronize_rcu() once before we start,
10010 * just to be on the safe side.
10012 synchronize_rcu();
10014 release_global_block_rsv(info);
10016 while (!list_empty(&info->space_info)) {
10017 int i;
10019 space_info = list_entry(info->space_info.next,
10020 struct btrfs_space_info,
10021 list);
10024 * Do not hide this behind enospc_debug, this is actually
10025 * important and indicates a real bug if this happens.
10027 if (WARN_ON(space_info->bytes_pinned > 0 ||
10028 space_info->bytes_reserved > 0 ||
10029 space_info->bytes_may_use > 0))
10030 dump_space_info(info, space_info, 0, 0);
10031 list_del(&space_info->list);
10032 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
10033 struct kobject *kobj;
10034 kobj = space_info->block_group_kobjs[i];
10035 space_info->block_group_kobjs[i] = NULL;
10036 if (kobj) {
10037 kobject_del(kobj);
10038 kobject_put(kobj);
10041 kobject_del(&space_info->kobj);
10042 kobject_put(&space_info->kobj);
10044 return 0;
10047 static void __link_block_group(struct btrfs_space_info *space_info,
10048 struct btrfs_block_group_cache *cache)
10050 int index = get_block_group_index(cache);
10051 bool first = false;
10053 down_write(&space_info->groups_sem);
10054 if (list_empty(&space_info->block_groups[index]))
10055 first = true;
10056 list_add_tail(&cache->list, &space_info->block_groups[index]);
10057 up_write(&space_info->groups_sem);
10059 if (first) {
10060 struct raid_kobject *rkobj;
10061 int ret;
10063 rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
10064 if (!rkobj)
10065 goto out_err;
10066 rkobj->raid_type = index;
10067 kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
10068 ret = kobject_add(&rkobj->kobj, &space_info->kobj,
10069 "%s", get_raid_name(index));
10070 if (ret) {
10071 kobject_put(&rkobj->kobj);
10072 goto out_err;
10074 space_info->block_group_kobjs[index] = &rkobj->kobj;
10077 return;
10078 out_err:
10079 btrfs_warn(cache->fs_info,
10080 "failed to add kobject for block cache, ignoring");
10083 static struct btrfs_block_group_cache *
10084 btrfs_create_block_group_cache(struct btrfs_fs_info *fs_info,
10085 u64 start, u64 size)
10087 struct btrfs_block_group_cache *cache;
10089 cache = kzalloc(sizeof(*cache), GFP_NOFS);
10090 if (!cache)
10091 return NULL;
10093 cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
10094 GFP_NOFS);
10095 if (!cache->free_space_ctl) {
10096 kfree(cache);
10097 return NULL;
10100 cache->key.objectid = start;
10101 cache->key.offset = size;
10102 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
10104 cache->fs_info = fs_info;
10105 cache->full_stripe_len = btrfs_full_stripe_len(fs_info, start);
10106 set_free_space_tree_thresholds(cache);
10108 atomic_set(&cache->count, 1);
10109 spin_lock_init(&cache->lock);
10110 init_rwsem(&cache->data_rwsem);
10111 INIT_LIST_HEAD(&cache->list);
10112 INIT_LIST_HEAD(&cache->cluster_list);
10113 INIT_LIST_HEAD(&cache->bg_list);
10114 INIT_LIST_HEAD(&cache->ro_list);
10115 INIT_LIST_HEAD(&cache->dirty_list);
10116 INIT_LIST_HEAD(&cache->io_list);
10117 btrfs_init_free_space_ctl(cache);
10118 atomic_set(&cache->trimming, 0);
10119 mutex_init(&cache->free_space_lock);
10120 btrfs_init_full_stripe_locks_tree(&cache->full_stripe_locks_root);
10122 return cache;
10127 * Iterate all chunks and verify that each of them has the corresponding block
10128 * group
10130 static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info)
10132 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
10133 struct extent_map *em;
10134 struct btrfs_block_group_cache *bg;
10135 u64 start = 0;
10136 int ret = 0;
10138 while (1) {
10139 read_lock(&map_tree->map_tree.lock);
10141 * lookup_extent_mapping will return the first extent map
10142 * intersecting the range, so setting @len to 1 is enough to
10143 * get the first chunk.
10145 em = lookup_extent_mapping(&map_tree->map_tree, start, 1);
10146 read_unlock(&map_tree->map_tree.lock);
10147 if (!em)
10148 break;
10150 bg = btrfs_lookup_block_group(fs_info, em->start);
10151 if (!bg) {
10152 btrfs_err(fs_info,
10153 "chunk start=%llu len=%llu doesn't have corresponding block group",
10154 em->start, em->len);
10155 ret = -EUCLEAN;
10156 free_extent_map(em);
10157 break;
10159 if (bg->key.objectid != em->start ||
10160 bg->key.offset != em->len ||
10161 (bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK) !=
10162 (em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) {
10163 btrfs_err(fs_info,
10164 "chunk start=%llu len=%llu flags=0x%llx doesn't match block group start=%llu len=%llu flags=0x%llx",
10165 em->start, em->len,
10166 em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK,
10167 bg->key.objectid, bg->key.offset,
10168 bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK);
10169 ret = -EUCLEAN;
10170 free_extent_map(em);
10171 btrfs_put_block_group(bg);
10172 break;
10174 start = em->start + em->len;
10175 free_extent_map(em);
10176 btrfs_put_block_group(bg);
10178 return ret;
10181 int btrfs_read_block_groups(struct btrfs_fs_info *info)
10183 struct btrfs_path *path;
10184 int ret;
10185 struct btrfs_block_group_cache *cache;
10186 struct btrfs_space_info *space_info;
10187 struct btrfs_key key;
10188 struct btrfs_key found_key;
10189 struct extent_buffer *leaf;
10190 int need_clear = 0;
10191 u64 cache_gen;
10192 u64 feature;
10193 int mixed;
10195 feature = btrfs_super_incompat_flags(info->super_copy);
10196 mixed = !!(feature & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS);
10198 key.objectid = 0;
10199 key.offset = 0;
10200 key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
10201 path = btrfs_alloc_path();
10202 if (!path)
10203 return -ENOMEM;
10204 path->reada = READA_FORWARD;
10206 cache_gen = btrfs_super_cache_generation(info->super_copy);
10207 if (btrfs_test_opt(info, SPACE_CACHE) &&
10208 btrfs_super_generation(info->super_copy) != cache_gen)
10209 need_clear = 1;
10210 if (btrfs_test_opt(info, CLEAR_CACHE))
10211 need_clear = 1;
10213 while (1) {
10214 ret = find_first_block_group(info, path, &key);
10215 if (ret > 0)
10216 break;
10217 if (ret != 0)
10218 goto error;
10220 leaf = path->nodes[0];
10221 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
10223 cache = btrfs_create_block_group_cache(info, found_key.objectid,
10224 found_key.offset);
10225 if (!cache) {
10226 ret = -ENOMEM;
10227 goto error;
10230 if (need_clear) {
10232 * When we mount with old space cache, we need to
10233 * set BTRFS_DC_CLEAR and set dirty flag.
10235 * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
10236 * truncate the old free space cache inode and
10237 * setup a new one.
10238 * b) Setting 'dirty flag' makes sure that we flush
10239 * the new space cache info onto disk.
10241 if (btrfs_test_opt(info, SPACE_CACHE))
10242 cache->disk_cache_state = BTRFS_DC_CLEAR;
10245 read_extent_buffer(leaf, &cache->item,
10246 btrfs_item_ptr_offset(leaf, path->slots[0]),
10247 sizeof(cache->item));
10248 cache->flags = btrfs_block_group_flags(&cache->item);
10249 if (!mixed &&
10250 ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
10251 (cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
10252 btrfs_err(info,
10253 "bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups",
10254 cache->key.objectid);
10255 btrfs_put_block_group(cache);
10256 ret = -EINVAL;
10257 goto error;
10260 key.objectid = found_key.objectid + found_key.offset;
10261 btrfs_release_path(path);
10264 * We need to exclude the super stripes now so that the space
10265 * info has super bytes accounted for, otherwise we'll think
10266 * we have more space than we actually do.
10268 ret = exclude_super_stripes(info, cache);
10269 if (ret) {
10271 * We may have excluded something, so call this just in
10272 * case.
10274 free_excluded_extents(info, cache);
10275 btrfs_put_block_group(cache);
10276 goto error;
10280 * check for two cases, either we are full, and therefore
10281 * don't need to bother with the caching work since we won't
10282 * find any space, or we are empty, and we can just add all
10283 * the space in and be done with it. This saves us _alot_ of
10284 * time, particularly in the full case.
10286 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
10287 cache->last_byte_to_unpin = (u64)-1;
10288 cache->cached = BTRFS_CACHE_FINISHED;
10289 free_excluded_extents(info, cache);
10290 } else if (btrfs_block_group_used(&cache->item) == 0) {
10291 cache->last_byte_to_unpin = (u64)-1;
10292 cache->cached = BTRFS_CACHE_FINISHED;
10293 add_new_free_space(cache, info,
10294 found_key.objectid,
10295 found_key.objectid +
10296 found_key.offset);
10297 free_excluded_extents(info, cache);
10300 ret = btrfs_add_block_group_cache(info, cache);
10301 if (ret) {
10302 btrfs_remove_free_space_cache(cache);
10303 btrfs_put_block_group(cache);
10304 goto error;
10307 trace_btrfs_add_block_group(info, cache, 0);
10308 update_space_info(info, cache->flags, found_key.offset,
10309 btrfs_block_group_used(&cache->item),
10310 cache->bytes_super, &space_info);
10312 cache->space_info = space_info;
10314 __link_block_group(space_info, cache);
10316 set_avail_alloc_bits(info, cache->flags);
10317 if (btrfs_chunk_readonly(info, cache->key.objectid)) {
10318 inc_block_group_ro(cache, 1);
10319 } else if (btrfs_block_group_used(&cache->item) == 0) {
10320 spin_lock(&info->unused_bgs_lock);
10321 /* Should always be true but just in case. */
10322 if (list_empty(&cache->bg_list)) {
10323 btrfs_get_block_group(cache);
10324 list_add_tail(&cache->bg_list,
10325 &info->unused_bgs);
10327 spin_unlock(&info->unused_bgs_lock);
10331 list_for_each_entry_rcu(space_info, &info->space_info, list) {
10332 if (!(get_alloc_profile(info, space_info->flags) &
10333 (BTRFS_BLOCK_GROUP_RAID10 |
10334 BTRFS_BLOCK_GROUP_RAID1 |
10335 BTRFS_BLOCK_GROUP_RAID5 |
10336 BTRFS_BLOCK_GROUP_RAID6 |
10337 BTRFS_BLOCK_GROUP_DUP)))
10338 continue;
10340 * avoid allocating from un-mirrored block group if there are
10341 * mirrored block groups.
10343 list_for_each_entry(cache,
10344 &space_info->block_groups[BTRFS_RAID_RAID0],
10345 list)
10346 inc_block_group_ro(cache, 1);
10347 list_for_each_entry(cache,
10348 &space_info->block_groups[BTRFS_RAID_SINGLE],
10349 list)
10350 inc_block_group_ro(cache, 1);
10353 init_global_block_rsv(info);
10354 ret = check_chunk_block_group_mappings(info);
10355 error:
10356 btrfs_free_path(path);
10357 return ret;
10360 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
10361 struct btrfs_fs_info *fs_info)
10363 struct btrfs_block_group_cache *block_group;
10364 struct btrfs_root *extent_root = fs_info->extent_root;
10365 struct btrfs_block_group_item item;
10366 struct btrfs_key key;
10367 int ret = 0;
10368 bool can_flush_pending_bgs = trans->can_flush_pending_bgs;
10370 trans->can_flush_pending_bgs = false;
10371 while (!list_empty(&trans->new_bgs)) {
10372 block_group = list_first_entry(&trans->new_bgs,
10373 struct btrfs_block_group_cache,
10374 bg_list);
10375 if (ret)
10376 goto next;
10378 spin_lock(&block_group->lock);
10379 memcpy(&item, &block_group->item, sizeof(item));
10380 memcpy(&key, &block_group->key, sizeof(key));
10381 spin_unlock(&block_group->lock);
10383 ret = btrfs_insert_item(trans, extent_root, &key, &item,
10384 sizeof(item));
10385 if (ret)
10386 btrfs_abort_transaction(trans, ret);
10387 ret = btrfs_finish_chunk_alloc(trans, fs_info, key.objectid,
10388 key.offset);
10389 if (ret)
10390 btrfs_abort_transaction(trans, ret);
10391 add_block_group_free_space(trans, fs_info, block_group);
10392 /* already aborted the transaction if it failed. */
10393 next:
10394 list_del_init(&block_group->bg_list);
10396 trans->can_flush_pending_bgs = can_flush_pending_bgs;
10399 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
10400 struct btrfs_fs_info *fs_info, u64 bytes_used,
10401 u64 type, u64 chunk_offset, u64 size)
10403 struct btrfs_block_group_cache *cache;
10404 int ret;
10406 btrfs_set_log_full_commit(fs_info, trans);
10408 cache = btrfs_create_block_group_cache(fs_info, chunk_offset, size);
10409 if (!cache)
10410 return -ENOMEM;
10412 btrfs_set_block_group_used(&cache->item, bytes_used);
10413 btrfs_set_block_group_chunk_objectid(&cache->item,
10414 BTRFS_FIRST_CHUNK_TREE_OBJECTID);
10415 btrfs_set_block_group_flags(&cache->item, type);
10417 cache->flags = type;
10418 cache->last_byte_to_unpin = (u64)-1;
10419 cache->cached = BTRFS_CACHE_FINISHED;
10420 cache->needs_free_space = 1;
10421 ret = exclude_super_stripes(fs_info, cache);
10422 if (ret) {
10424 * We may have excluded something, so call this just in
10425 * case.
10427 free_excluded_extents(fs_info, cache);
10428 btrfs_put_block_group(cache);
10429 return ret;
10432 add_new_free_space(cache, fs_info, chunk_offset, chunk_offset + size);
10434 free_excluded_extents(fs_info, cache);
10436 #ifdef CONFIG_BTRFS_DEBUG
10437 if (btrfs_should_fragment_free_space(cache)) {
10438 u64 new_bytes_used = size - bytes_used;
10440 bytes_used += new_bytes_used >> 1;
10441 fragment_free_space(cache);
10443 #endif
10445 * Ensure the corresponding space_info object is created and
10446 * assigned to our block group. We want our bg to be added to the rbtree
10447 * with its ->space_info set.
10449 cache->space_info = __find_space_info(fs_info, cache->flags);
10450 if (!cache->space_info) {
10451 ret = create_space_info(fs_info, cache->flags,
10452 &cache->space_info);
10453 if (ret) {
10454 btrfs_remove_free_space_cache(cache);
10455 btrfs_put_block_group(cache);
10456 return ret;
10460 ret = btrfs_add_block_group_cache(fs_info, cache);
10461 if (ret) {
10462 btrfs_remove_free_space_cache(cache);
10463 btrfs_put_block_group(cache);
10464 return ret;
10468 * Now that our block group has its ->space_info set and is inserted in
10469 * the rbtree, update the space info's counters.
10471 trace_btrfs_add_block_group(fs_info, cache, 1);
10472 update_space_info(fs_info, cache->flags, size, bytes_used,
10473 cache->bytes_super, &cache->space_info);
10474 update_global_block_rsv(fs_info);
10476 __link_block_group(cache->space_info, cache);
10478 list_add_tail(&cache->bg_list, &trans->new_bgs);
10480 set_avail_alloc_bits(fs_info, type);
10481 return 0;
10484 static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
10486 u64 extra_flags = chunk_to_extended(flags) &
10487 BTRFS_EXTENDED_PROFILE_MASK;
10489 write_seqlock(&fs_info->profiles_lock);
10490 if (flags & BTRFS_BLOCK_GROUP_DATA)
10491 fs_info->avail_data_alloc_bits &= ~extra_flags;
10492 if (flags & BTRFS_BLOCK_GROUP_METADATA)
10493 fs_info->avail_metadata_alloc_bits &= ~extra_flags;
10494 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
10495 fs_info->avail_system_alloc_bits &= ~extra_flags;
10496 write_sequnlock(&fs_info->profiles_lock);
10499 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
10500 struct btrfs_fs_info *fs_info, u64 group_start,
10501 struct extent_map *em)
10503 struct btrfs_root *root = fs_info->extent_root;
10504 struct btrfs_path *path;
10505 struct btrfs_block_group_cache *block_group;
10506 struct btrfs_free_cluster *cluster;
10507 struct btrfs_root *tree_root = fs_info->tree_root;
10508 struct btrfs_key key;
10509 struct inode *inode;
10510 struct kobject *kobj = NULL;
10511 int ret;
10512 int index;
10513 int factor;
10514 struct btrfs_caching_control *caching_ctl = NULL;
10515 bool remove_em;
10517 block_group = btrfs_lookup_block_group(fs_info, group_start);
10518 BUG_ON(!block_group);
10519 BUG_ON(!block_group->ro);
10522 * Free the reserved super bytes from this block group before
10523 * remove it.
10525 free_excluded_extents(fs_info, block_group);
10527 memcpy(&key, &block_group->key, sizeof(key));
10528 index = get_block_group_index(block_group);
10529 if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
10530 BTRFS_BLOCK_GROUP_RAID1 |
10531 BTRFS_BLOCK_GROUP_RAID10))
10532 factor = 2;
10533 else
10534 factor = 1;
10536 /* make sure this block group isn't part of an allocation cluster */
10537 cluster = &fs_info->data_alloc_cluster;
10538 spin_lock(&cluster->refill_lock);
10539 btrfs_return_cluster_to_free_space(block_group, cluster);
10540 spin_unlock(&cluster->refill_lock);
10543 * make sure this block group isn't part of a metadata
10544 * allocation cluster
10546 cluster = &fs_info->meta_alloc_cluster;
10547 spin_lock(&cluster->refill_lock);
10548 btrfs_return_cluster_to_free_space(block_group, cluster);
10549 spin_unlock(&cluster->refill_lock);
10551 path = btrfs_alloc_path();
10552 if (!path) {
10553 ret = -ENOMEM;
10554 goto out;
10558 * get the inode first so any iput calls done for the io_list
10559 * aren't the final iput (no unlinks allowed now)
10561 inode = lookup_free_space_inode(fs_info, block_group, path);
10563 mutex_lock(&trans->transaction->cache_write_mutex);
10565 * make sure our free spache cache IO is done before remove the
10566 * free space inode
10568 spin_lock(&trans->transaction->dirty_bgs_lock);
10569 if (!list_empty(&block_group->io_list)) {
10570 list_del_init(&block_group->io_list);
10572 WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
10574 spin_unlock(&trans->transaction->dirty_bgs_lock);
10575 btrfs_wait_cache_io(trans, block_group, path);
10576 btrfs_put_block_group(block_group);
10577 spin_lock(&trans->transaction->dirty_bgs_lock);
10580 if (!list_empty(&block_group->dirty_list)) {
10581 list_del_init(&block_group->dirty_list);
10582 btrfs_put_block_group(block_group);
10584 spin_unlock(&trans->transaction->dirty_bgs_lock);
10585 mutex_unlock(&trans->transaction->cache_write_mutex);
10587 if (!IS_ERR(inode)) {
10588 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
10589 if (ret) {
10590 btrfs_add_delayed_iput(inode);
10591 goto out;
10593 clear_nlink(inode);
10594 /* One for the block groups ref */
10595 spin_lock(&block_group->lock);
10596 if (block_group->iref) {
10597 block_group->iref = 0;
10598 block_group->inode = NULL;
10599 spin_unlock(&block_group->lock);
10600 iput(inode);
10601 } else {
10602 spin_unlock(&block_group->lock);
10604 /* One for our lookup ref */
10605 btrfs_add_delayed_iput(inode);
10608 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
10609 key.offset = block_group->key.objectid;
10610 key.type = 0;
10612 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
10613 if (ret < 0)
10614 goto out;
10615 if (ret > 0)
10616 btrfs_release_path(path);
10617 if (ret == 0) {
10618 ret = btrfs_del_item(trans, tree_root, path);
10619 if (ret)
10620 goto out;
10621 btrfs_release_path(path);
10624 spin_lock(&fs_info->block_group_cache_lock);
10625 rb_erase(&block_group->cache_node,
10626 &fs_info->block_group_cache_tree);
10627 RB_CLEAR_NODE(&block_group->cache_node);
10629 /* Once for the block groups rbtree */
10630 btrfs_put_block_group(block_group);
10632 if (fs_info->first_logical_byte == block_group->key.objectid)
10633 fs_info->first_logical_byte = (u64)-1;
10634 spin_unlock(&fs_info->block_group_cache_lock);
10636 down_write(&block_group->space_info->groups_sem);
10638 * we must use list_del_init so people can check to see if they
10639 * are still on the list after taking the semaphore
10641 list_del_init(&block_group->list);
10642 if (list_empty(&block_group->space_info->block_groups[index])) {
10643 kobj = block_group->space_info->block_group_kobjs[index];
10644 block_group->space_info->block_group_kobjs[index] = NULL;
10645 clear_avail_alloc_bits(fs_info, block_group->flags);
10647 up_write(&block_group->space_info->groups_sem);
10648 if (kobj) {
10649 kobject_del(kobj);
10650 kobject_put(kobj);
10653 if (block_group->has_caching_ctl)
10654 caching_ctl = get_caching_control(block_group);
10655 if (block_group->cached == BTRFS_CACHE_STARTED)
10656 wait_block_group_cache_done(block_group);
10657 if (block_group->has_caching_ctl) {
10658 down_write(&fs_info->commit_root_sem);
10659 if (!caching_ctl) {
10660 struct btrfs_caching_control *ctl;
10662 list_for_each_entry(ctl,
10663 &fs_info->caching_block_groups, list)
10664 if (ctl->block_group == block_group) {
10665 caching_ctl = ctl;
10666 refcount_inc(&caching_ctl->count);
10667 break;
10670 if (caching_ctl)
10671 list_del_init(&caching_ctl->list);
10672 up_write(&fs_info->commit_root_sem);
10673 if (caching_ctl) {
10674 /* Once for the caching bgs list and once for us. */
10675 put_caching_control(caching_ctl);
10676 put_caching_control(caching_ctl);
10680 spin_lock(&trans->transaction->dirty_bgs_lock);
10681 if (!list_empty(&block_group->dirty_list)) {
10682 WARN_ON(1);
10684 if (!list_empty(&block_group->io_list)) {
10685 WARN_ON(1);
10687 spin_unlock(&trans->transaction->dirty_bgs_lock);
10688 btrfs_remove_free_space_cache(block_group);
10690 spin_lock(&block_group->space_info->lock);
10691 list_del_init(&block_group->ro_list);
10693 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
10694 WARN_ON(block_group->space_info->total_bytes
10695 < block_group->key.offset);
10696 WARN_ON(block_group->space_info->bytes_readonly
10697 < block_group->key.offset);
10698 WARN_ON(block_group->space_info->disk_total
10699 < block_group->key.offset * factor);
10701 block_group->space_info->total_bytes -= block_group->key.offset;
10702 block_group->space_info->bytes_readonly -= block_group->key.offset;
10703 block_group->space_info->disk_total -= block_group->key.offset * factor;
10705 spin_unlock(&block_group->space_info->lock);
10707 memcpy(&key, &block_group->key, sizeof(key));
10709 mutex_lock(&fs_info->chunk_mutex);
10710 if (!list_empty(&em->list)) {
10711 /* We're in the transaction->pending_chunks list. */
10712 free_extent_map(em);
10714 spin_lock(&block_group->lock);
10715 block_group->removed = 1;
10717 * At this point trimming can't start on this block group, because we
10718 * removed the block group from the tree fs_info->block_group_cache_tree
10719 * so no one can't find it anymore and even if someone already got this
10720 * block group before we removed it from the rbtree, they have already
10721 * incremented block_group->trimming - if they didn't, they won't find
10722 * any free space entries because we already removed them all when we
10723 * called btrfs_remove_free_space_cache().
10725 * And we must not remove the extent map from the fs_info->mapping_tree
10726 * to prevent the same logical address range and physical device space
10727 * ranges from being reused for a new block group. This is because our
10728 * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
10729 * completely transactionless, so while it is trimming a range the
10730 * currently running transaction might finish and a new one start,
10731 * allowing for new block groups to be created that can reuse the same
10732 * physical device locations unless we take this special care.
10734 * There may also be an implicit trim operation if the file system
10735 * is mounted with -odiscard. The same protections must remain
10736 * in place until the extents have been discarded completely when
10737 * the transaction commit has completed.
10739 remove_em = (atomic_read(&block_group->trimming) == 0);
10741 * Make sure a trimmer task always sees the em in the pinned_chunks list
10742 * if it sees block_group->removed == 1 (needs to lock block_group->lock
10743 * before checking block_group->removed).
10745 if (!remove_em) {
10747 * Our em might be in trans->transaction->pending_chunks which
10748 * is protected by fs_info->chunk_mutex ([lock|unlock]_chunks),
10749 * and so is the fs_info->pinned_chunks list.
10751 * So at this point we must be holding the chunk_mutex to avoid
10752 * any races with chunk allocation (more specifically at
10753 * volumes.c:contains_pending_extent()), to ensure it always
10754 * sees the em, either in the pending_chunks list or in the
10755 * pinned_chunks list.
10757 list_move_tail(&em->list, &fs_info->pinned_chunks);
10759 spin_unlock(&block_group->lock);
10761 if (remove_em) {
10762 struct extent_map_tree *em_tree;
10764 em_tree = &fs_info->mapping_tree.map_tree;
10765 write_lock(&em_tree->lock);
10767 * The em might be in the pending_chunks list, so make sure the
10768 * chunk mutex is locked, since remove_extent_mapping() will
10769 * delete us from that list.
10771 remove_extent_mapping(em_tree, em);
10772 write_unlock(&em_tree->lock);
10773 /* once for the tree */
10774 free_extent_map(em);
10777 mutex_unlock(&fs_info->chunk_mutex);
10779 ret = remove_block_group_free_space(trans, fs_info, block_group);
10780 if (ret)
10781 goto out;
10783 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
10784 if (ret > 0)
10785 ret = -EIO;
10786 if (ret < 0)
10787 goto out;
10789 ret = btrfs_del_item(trans, root, path);
10791 out:
10792 /* Once for the lookup reference */
10793 btrfs_put_block_group(block_group);
10794 btrfs_free_path(path);
10795 return ret;
10798 struct btrfs_trans_handle *
10799 btrfs_start_trans_remove_block_group(struct btrfs_fs_info *fs_info,
10800 const u64 chunk_offset)
10802 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
10803 struct extent_map *em;
10804 struct map_lookup *map;
10805 unsigned int num_items;
10807 read_lock(&em_tree->lock);
10808 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
10809 read_unlock(&em_tree->lock);
10810 ASSERT(em && em->start == chunk_offset);
10813 * We need to reserve 3 + N units from the metadata space info in order
10814 * to remove a block group (done at btrfs_remove_chunk() and at
10815 * btrfs_remove_block_group()), which are used for:
10817 * 1 unit for adding the free space inode's orphan (located in the tree
10818 * of tree roots).
10819 * 1 unit for deleting the block group item (located in the extent
10820 * tree).
10821 * 1 unit for deleting the free space item (located in tree of tree
10822 * roots).
10823 * N units for deleting N device extent items corresponding to each
10824 * stripe (located in the device tree).
10826 * In order to remove a block group we also need to reserve units in the
10827 * system space info in order to update the chunk tree (update one or
10828 * more device items and remove one chunk item), but this is done at
10829 * btrfs_remove_chunk() through a call to check_system_chunk().
10831 map = em->map_lookup;
10832 num_items = 3 + map->num_stripes;
10833 free_extent_map(em);
10835 return btrfs_start_transaction_fallback_global_rsv(fs_info->extent_root,
10836 num_items, 1);
10840 * Process the unused_bgs list and remove any that don't have any allocated
10841 * space inside of them.
10843 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
10845 struct btrfs_block_group_cache *block_group;
10846 struct btrfs_space_info *space_info;
10847 struct btrfs_trans_handle *trans;
10848 int ret = 0;
10850 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
10851 return;
10853 spin_lock(&fs_info->unused_bgs_lock);
10854 while (!list_empty(&fs_info->unused_bgs)) {
10855 u64 start, end;
10856 int trimming;
10858 block_group = list_first_entry(&fs_info->unused_bgs,
10859 struct btrfs_block_group_cache,
10860 bg_list);
10861 list_del_init(&block_group->bg_list);
10863 space_info = block_group->space_info;
10865 if (ret || btrfs_mixed_space_info(space_info)) {
10866 btrfs_put_block_group(block_group);
10867 continue;
10869 spin_unlock(&fs_info->unused_bgs_lock);
10871 mutex_lock(&fs_info->delete_unused_bgs_mutex);
10873 /* Don't want to race with allocators so take the groups_sem */
10874 down_write(&space_info->groups_sem);
10875 spin_lock(&block_group->lock);
10876 if (block_group->reserved || block_group->pinned ||
10877 btrfs_block_group_used(&block_group->item) ||
10878 block_group->ro ||
10879 list_is_singular(&block_group->list)) {
10881 * We want to bail if we made new allocations or have
10882 * outstanding allocations in this block group. We do
10883 * the ro check in case balance is currently acting on
10884 * this block group.
10886 spin_unlock(&block_group->lock);
10887 up_write(&space_info->groups_sem);
10888 goto next;
10890 spin_unlock(&block_group->lock);
10892 /* We don't want to force the issue, only flip if it's ok. */
10893 ret = inc_block_group_ro(block_group, 0);
10894 up_write(&space_info->groups_sem);
10895 if (ret < 0) {
10896 ret = 0;
10897 goto next;
10901 * Want to do this before we do anything else so we can recover
10902 * properly if we fail to join the transaction.
10904 trans = btrfs_start_trans_remove_block_group(fs_info,
10905 block_group->key.objectid);
10906 if (IS_ERR(trans)) {
10907 btrfs_dec_block_group_ro(block_group);
10908 ret = PTR_ERR(trans);
10909 goto next;
10913 * We could have pending pinned extents for this block group,
10914 * just delete them, we don't care about them anymore.
10916 start = block_group->key.objectid;
10917 end = start + block_group->key.offset - 1;
10919 * Hold the unused_bg_unpin_mutex lock to avoid racing with
10920 * btrfs_finish_extent_commit(). If we are at transaction N,
10921 * another task might be running finish_extent_commit() for the
10922 * previous transaction N - 1, and have seen a range belonging
10923 * to the block group in freed_extents[] before we were able to
10924 * clear the whole block group range from freed_extents[]. This
10925 * means that task can lookup for the block group after we
10926 * unpinned it from freed_extents[] and removed it, leading to
10927 * a BUG_ON() at btrfs_unpin_extent_range().
10929 mutex_lock(&fs_info->unused_bg_unpin_mutex);
10930 ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
10931 EXTENT_DIRTY);
10932 if (ret) {
10933 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
10934 btrfs_dec_block_group_ro(block_group);
10935 goto end_trans;
10937 ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
10938 EXTENT_DIRTY);
10939 if (ret) {
10940 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
10941 btrfs_dec_block_group_ro(block_group);
10942 goto end_trans;
10944 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
10946 /* Reset pinned so btrfs_put_block_group doesn't complain */
10947 spin_lock(&space_info->lock);
10948 spin_lock(&block_group->lock);
10950 space_info->bytes_pinned -= block_group->pinned;
10951 space_info->bytes_readonly += block_group->pinned;
10952 percpu_counter_add(&space_info->total_bytes_pinned,
10953 -block_group->pinned);
10954 block_group->pinned = 0;
10956 spin_unlock(&block_group->lock);
10957 spin_unlock(&space_info->lock);
10959 /* DISCARD can flip during remount */
10960 trimming = btrfs_test_opt(fs_info, DISCARD);
10962 /* Implicit trim during transaction commit. */
10963 if (trimming)
10964 btrfs_get_block_group_trimming(block_group);
10967 * Btrfs_remove_chunk will abort the transaction if things go
10968 * horribly wrong.
10970 ret = btrfs_remove_chunk(trans, fs_info,
10971 block_group->key.objectid);
10973 if (ret) {
10974 if (trimming)
10975 btrfs_put_block_group_trimming(block_group);
10976 goto end_trans;
10980 * If we're not mounted with -odiscard, we can just forget
10981 * about this block group. Otherwise we'll need to wait
10982 * until transaction commit to do the actual discard.
10984 if (trimming) {
10985 spin_lock(&fs_info->unused_bgs_lock);
10987 * A concurrent scrub might have added us to the list
10988 * fs_info->unused_bgs, so use a list_move operation
10989 * to add the block group to the deleted_bgs list.
10991 list_move(&block_group->bg_list,
10992 &trans->transaction->deleted_bgs);
10993 spin_unlock(&fs_info->unused_bgs_lock);
10994 btrfs_get_block_group(block_group);
10996 end_trans:
10997 btrfs_end_transaction(trans);
10998 next:
10999 mutex_unlock(&fs_info->delete_unused_bgs_mutex);
11000 btrfs_put_block_group(block_group);
11001 spin_lock(&fs_info->unused_bgs_lock);
11003 spin_unlock(&fs_info->unused_bgs_lock);
11006 int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
11008 struct btrfs_space_info *space_info;
11009 struct btrfs_super_block *disk_super;
11010 u64 features;
11011 u64 flags;
11012 int mixed = 0;
11013 int ret;
11015 disk_super = fs_info->super_copy;
11016 if (!btrfs_super_root(disk_super))
11017 return -EINVAL;
11019 features = btrfs_super_incompat_flags(disk_super);
11020 if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
11021 mixed = 1;
11023 flags = BTRFS_BLOCK_GROUP_SYSTEM;
11024 ret = create_space_info(fs_info, flags, &space_info);
11025 if (ret)
11026 goto out;
11028 if (mixed) {
11029 flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
11030 ret = create_space_info(fs_info, flags, &space_info);
11031 } else {
11032 flags = BTRFS_BLOCK_GROUP_METADATA;
11033 ret = create_space_info(fs_info, flags, &space_info);
11034 if (ret)
11035 goto out;
11037 flags = BTRFS_BLOCK_GROUP_DATA;
11038 ret = create_space_info(fs_info, flags, &space_info);
11040 out:
11041 return ret;
11044 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
11045 u64 start, u64 end)
11047 return unpin_extent_range(fs_info, start, end, false);
11051 * It used to be that old block groups would be left around forever.
11052 * Iterating over them would be enough to trim unused space. Since we
11053 * now automatically remove them, we also need to iterate over unallocated
11054 * space.
11056 * We don't want a transaction for this since the discard may take a
11057 * substantial amount of time. We don't require that a transaction be
11058 * running, but we do need to take a running transaction into account
11059 * to ensure that we're not discarding chunks that were released in
11060 * the current transaction.
11062 * Holding the chunks lock will prevent other threads from allocating
11063 * or releasing chunks, but it won't prevent a running transaction
11064 * from committing and releasing the memory that the pending chunks
11065 * list head uses. For that, we need to take a reference to the
11066 * transaction.
11068 static int btrfs_trim_free_extents(struct btrfs_device *device,
11069 u64 minlen, u64 *trimmed)
11071 u64 start = 0, len = 0;
11072 int ret;
11074 *trimmed = 0;
11076 /* Discard not supported = nothing to do. */
11077 if (!blk_queue_discard(bdev_get_queue(device->bdev)))
11078 return 0;
11080 /* Not writeable = nothing to do. */
11081 if (!device->writeable)
11082 return 0;
11084 /* No free space = nothing to do. */
11085 if (device->total_bytes <= device->bytes_used)
11086 return 0;
11088 ret = 0;
11090 while (1) {
11091 struct btrfs_fs_info *fs_info = device->fs_info;
11092 struct btrfs_transaction *trans;
11093 u64 bytes;
11095 ret = mutex_lock_interruptible(&fs_info->chunk_mutex);
11096 if (ret)
11097 return ret;
11099 down_read(&fs_info->commit_root_sem);
11101 spin_lock(&fs_info->trans_lock);
11102 trans = fs_info->running_transaction;
11103 if (trans)
11104 refcount_inc(&trans->use_count);
11105 spin_unlock(&fs_info->trans_lock);
11107 ret = find_free_dev_extent_start(trans, device, minlen, start,
11108 &start, &len);
11109 if (trans)
11110 btrfs_put_transaction(trans);
11112 if (ret) {
11113 up_read(&fs_info->commit_root_sem);
11114 mutex_unlock(&fs_info->chunk_mutex);
11115 if (ret == -ENOSPC)
11116 ret = 0;
11117 break;
11120 ret = btrfs_issue_discard(device->bdev, start, len, &bytes);
11121 up_read(&fs_info->commit_root_sem);
11122 mutex_unlock(&fs_info->chunk_mutex);
11124 if (ret)
11125 break;
11127 start += len;
11128 *trimmed += bytes;
11130 if (fatal_signal_pending(current)) {
11131 ret = -ERESTARTSYS;
11132 break;
11135 cond_resched();
11138 return ret;
11142 * Trim the whole filesystem by:
11143 * 1) trimming the free space in each block group
11144 * 2) trimming the unallocated space on each device
11146 * This will also continue trimming even if a block group or device encounters
11147 * an error. The return value will be the last error, or 0 if nothing bad
11148 * happens.
11150 int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
11152 struct btrfs_block_group_cache *cache = NULL;
11153 struct btrfs_device *device;
11154 struct list_head *devices;
11155 u64 group_trimmed;
11156 u64 start;
11157 u64 end;
11158 u64 trimmed = 0;
11159 u64 bg_failed = 0;
11160 u64 dev_failed = 0;
11161 int bg_ret = 0;
11162 int dev_ret = 0;
11163 int ret = 0;
11165 cache = btrfs_lookup_first_block_group(fs_info, range->start);
11166 for (; cache; cache = next_block_group(fs_info, cache)) {
11167 if (cache->key.objectid >= (range->start + range->len)) {
11168 btrfs_put_block_group(cache);
11169 break;
11172 start = max(range->start, cache->key.objectid);
11173 end = min(range->start + range->len,
11174 cache->key.objectid + cache->key.offset);
11176 if (end - start >= range->minlen) {
11177 if (!block_group_cache_done(cache)) {
11178 ret = cache_block_group(cache, 0);
11179 if (ret) {
11180 bg_failed++;
11181 bg_ret = ret;
11182 continue;
11184 ret = wait_block_group_cache_done(cache);
11185 if (ret) {
11186 bg_failed++;
11187 bg_ret = ret;
11188 continue;
11191 ret = btrfs_trim_block_group(cache,
11192 &group_trimmed,
11193 start,
11194 end,
11195 range->minlen);
11197 trimmed += group_trimmed;
11198 if (ret) {
11199 bg_failed++;
11200 bg_ret = ret;
11201 continue;
11206 if (bg_failed)
11207 btrfs_warn(fs_info,
11208 "failed to trim %llu block group(s), last error %d",
11209 bg_failed, bg_ret);
11210 mutex_lock(&fs_info->fs_devices->device_list_mutex);
11211 devices = &fs_info->fs_devices->devices;
11212 list_for_each_entry(device, devices, dev_list) {
11213 ret = btrfs_trim_free_extents(device, range->minlen,
11214 &group_trimmed);
11215 if (ret) {
11216 dev_failed++;
11217 dev_ret = ret;
11218 break;
11221 trimmed += group_trimmed;
11223 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
11225 if (dev_failed)
11226 btrfs_warn(fs_info,
11227 "failed to trim %llu device(s), last error %d",
11228 dev_failed, dev_ret);
11229 range->len = trimmed;
11230 if (bg_ret)
11231 return bg_ret;
11232 return dev_ret;
11236 * btrfs_{start,end}_write_no_snapshotting() are similar to
11237 * mnt_{want,drop}_write(), they are used to prevent some tasks from writing
11238 * data into the page cache through nocow before the subvolume is snapshoted,
11239 * but flush the data into disk after the snapshot creation, or to prevent
11240 * operations while snapshotting is ongoing and that cause the snapshot to be
11241 * inconsistent (writes followed by expanding truncates for example).
11243 void btrfs_end_write_no_snapshotting(struct btrfs_root *root)
11245 percpu_counter_dec(&root->subv_writers->counter);
11247 * Make sure counter is updated before we wake up waiters.
11249 smp_mb();
11250 if (waitqueue_active(&root->subv_writers->wait))
11251 wake_up(&root->subv_writers->wait);
11254 int btrfs_start_write_no_snapshotting(struct btrfs_root *root)
11256 if (atomic_read(&root->will_be_snapshotted))
11257 return 0;
11259 percpu_counter_inc(&root->subv_writers->counter);
11261 * Make sure counter is updated before we check for snapshot creation.
11263 smp_mb();
11264 if (atomic_read(&root->will_be_snapshotted)) {
11265 btrfs_end_write_no_snapshotting(root);
11266 return 0;
11268 return 1;
11271 static int wait_snapshotting_atomic_t(atomic_t *a)
11273 schedule();
11274 return 0;
11277 void btrfs_wait_for_snapshot_creation(struct btrfs_root *root)
11279 while (true) {
11280 int ret;
11282 ret = btrfs_start_write_no_snapshotting(root);
11283 if (ret)
11284 break;
11285 wait_on_atomic_t(&root->will_be_snapshotted,
11286 wait_snapshotting_atomic_t,
11287 TASK_UNINTERRUPTIBLE);