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Btrfs: allocate new chunks if the space is not enough for global rsv
[deliverable/linux.git] / fs / btrfs / extent-tree.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/pagemap.h>
20 #include <linux/writeback.h>
21 #include <linux/blkdev.h>
22 #include <linux/sort.h>
23 #include <linux/rcupdate.h>
24 #include <linux/kthread.h>
25 #include <linux/slab.h>
26 #include <linux/ratelimit.h>
27 #include "compat.h"
28 #include "hash.h"
29 #include "ctree.h"
30 #include "disk-io.h"
31 #include "print-tree.h"
32 #include "transaction.h"
33 #include "volumes.h"
34 #include "raid56.h"
35 #include "locking.h"
36 #include "free-space-cache.h"
37 #include "math.h"
38
39 #undef SCRAMBLE_DELAYED_REFS
40
41 /*
42 * control flags for do_chunk_alloc's force field
43 * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
44 * if we really need one.
45 *
46 * CHUNK_ALLOC_LIMITED means to only try and allocate one
47 * if we have very few chunks already allocated. This is
48 * used as part of the clustering code to help make sure
49 * we have a good pool of storage to cluster in, without
50 * filling the FS with empty chunks
51 *
52 * CHUNK_ALLOC_FORCE means it must try to allocate one
53 *
54 */
55 enum {
56 CHUNK_ALLOC_NO_FORCE = 0,
57 CHUNK_ALLOC_LIMITED = 1,
58 CHUNK_ALLOC_FORCE = 2,
59 };
60
61 /*
62 * Control how reservations are dealt with.
63 *
64 * RESERVE_FREE - freeing a reservation.
65 * RESERVE_ALLOC - allocating space and we need to update bytes_may_use for
66 * ENOSPC accounting
67 * RESERVE_ALLOC_NO_ACCOUNT - allocating space and we should not update
68 * bytes_may_use as the ENOSPC accounting is done elsewhere
69 */
70 enum {
71 RESERVE_FREE = 0,
72 RESERVE_ALLOC = 1,
73 RESERVE_ALLOC_NO_ACCOUNT = 2,
74 };
75
76 static int update_block_group(struct btrfs_root *root,
77 u64 bytenr, u64 num_bytes, int alloc);
78 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
79 struct btrfs_root *root,
80 u64 bytenr, u64 num_bytes, u64 parent,
81 u64 root_objectid, u64 owner_objectid,
82 u64 owner_offset, int refs_to_drop,
83 struct btrfs_delayed_extent_op *extra_op);
84 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
85 struct extent_buffer *leaf,
86 struct btrfs_extent_item *ei);
87 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
88 struct btrfs_root *root,
89 u64 parent, u64 root_objectid,
90 u64 flags, u64 owner, u64 offset,
91 struct btrfs_key *ins, int ref_mod);
92 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
93 struct btrfs_root *root,
94 u64 parent, u64 root_objectid,
95 u64 flags, struct btrfs_disk_key *key,
96 int level, struct btrfs_key *ins);
97 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
98 struct btrfs_root *extent_root, u64 flags,
99 int force);
100 static int find_next_key(struct btrfs_path *path, int level,
101 struct btrfs_key *key);
102 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
103 int dump_block_groups);
104 static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
105 u64 num_bytes, int reserve);
106 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
107 u64 num_bytes);
108
109 static noinline int
110 block_group_cache_done(struct btrfs_block_group_cache *cache)
111 {
112 smp_mb();
113 return cache->cached == BTRFS_CACHE_FINISHED;
114 }
115
116 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
117 {
118 return (cache->flags & bits) == bits;
119 }
120
121 static void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
122 {
123 atomic_inc(&cache->count);
124 }
125
126 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
127 {
128 if (atomic_dec_and_test(&cache->count)) {
129 WARN_ON(cache->pinned > 0);
130 WARN_ON(cache->reserved > 0);
131 kfree(cache->free_space_ctl);
132 kfree(cache);
133 }
134 }
135
136 /*
137 * this adds the block group to the fs_info rb tree for the block group
138 * cache
139 */
140 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
141 struct btrfs_block_group_cache *block_group)
142 {
143 struct rb_node **p;
144 struct rb_node *parent = NULL;
145 struct btrfs_block_group_cache *cache;
146
147 spin_lock(&info->block_group_cache_lock);
148 p = &info->block_group_cache_tree.rb_node;
149
150 while (*p) {
151 parent = *p;
152 cache = rb_entry(parent, struct btrfs_block_group_cache,
153 cache_node);
154 if (block_group->key.objectid < cache->key.objectid) {
155 p = &(*p)->rb_left;
156 } else if (block_group->key.objectid > cache->key.objectid) {
157 p = &(*p)->rb_right;
158 } else {
159 spin_unlock(&info->block_group_cache_lock);
160 return -EEXIST;
161 }
162 }
163
164 rb_link_node(&block_group->cache_node, parent, p);
165 rb_insert_color(&block_group->cache_node,
166 &info->block_group_cache_tree);
167
168 if (info->first_logical_byte > block_group->key.objectid)
169 info->first_logical_byte = block_group->key.objectid;
170
171 spin_unlock(&info->block_group_cache_lock);
172
173 return 0;
174 }
175
176 /*
177 * This will return the block group at or after bytenr if contains is 0, else
178 * it will return the block group that contains the bytenr
179 */
180 static struct btrfs_block_group_cache *
181 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
182 int contains)
183 {
184 struct btrfs_block_group_cache *cache, *ret = NULL;
185 struct rb_node *n;
186 u64 end, start;
187
188 spin_lock(&info->block_group_cache_lock);
189 n = info->block_group_cache_tree.rb_node;
190
191 while (n) {
192 cache = rb_entry(n, struct btrfs_block_group_cache,
193 cache_node);
194 end = cache->key.objectid + cache->key.offset - 1;
195 start = cache->key.objectid;
196
197 if (bytenr < start) {
198 if (!contains && (!ret || start < ret->key.objectid))
199 ret = cache;
200 n = n->rb_left;
201 } else if (bytenr > start) {
202 if (contains && bytenr <= end) {
203 ret = cache;
204 break;
205 }
206 n = n->rb_right;
207 } else {
208 ret = cache;
209 break;
210 }
211 }
212 if (ret) {
213 btrfs_get_block_group(ret);
214 if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
215 info->first_logical_byte = ret->key.objectid;
216 }
217 spin_unlock(&info->block_group_cache_lock);
218
219 return ret;
220 }
221
222 static int add_excluded_extent(struct btrfs_root *root,
223 u64 start, u64 num_bytes)
224 {
225 u64 end = start + num_bytes - 1;
226 set_extent_bits(&root->fs_info->freed_extents[0],
227 start, end, EXTENT_UPTODATE, GFP_NOFS);
228 set_extent_bits(&root->fs_info->freed_extents[1],
229 start, end, EXTENT_UPTODATE, GFP_NOFS);
230 return 0;
231 }
232
233 static void free_excluded_extents(struct btrfs_root *root,
234 struct btrfs_block_group_cache *cache)
235 {
236 u64 start, end;
237
238 start = cache->key.objectid;
239 end = start + cache->key.offset - 1;
240
241 clear_extent_bits(&root->fs_info->freed_extents[0],
242 start, end, EXTENT_UPTODATE, GFP_NOFS);
243 clear_extent_bits(&root->fs_info->freed_extents[1],
244 start, end, EXTENT_UPTODATE, GFP_NOFS);
245 }
246
247 static int exclude_super_stripes(struct btrfs_root *root,
248 struct btrfs_block_group_cache *cache)
249 {
250 u64 bytenr;
251 u64 *logical;
252 int stripe_len;
253 int i, nr, ret;
254
255 if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
256 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
257 cache->bytes_super += stripe_len;
258 ret = add_excluded_extent(root, cache->key.objectid,
259 stripe_len);
260 if (ret)
261 return ret;
262 }
263
264 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
265 bytenr = btrfs_sb_offset(i);
266 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
267 cache->key.objectid, bytenr,
268 0, &logical, &nr, &stripe_len);
269 if (ret)
270 return ret;
271
272 while (nr--) {
273 u64 start, len;
274
275 if (logical[nr] > cache->key.objectid +
276 cache->key.offset)
277 continue;
278
279 if (logical[nr] + stripe_len <= cache->key.objectid)
280 continue;
281
282 start = logical[nr];
283 if (start < cache->key.objectid) {
284 start = cache->key.objectid;
285 len = (logical[nr] + stripe_len) - start;
286 } else {
287 len = min_t(u64, stripe_len,
288 cache->key.objectid +
289 cache->key.offset - start);
290 }
291
292 cache->bytes_super += len;
293 ret = add_excluded_extent(root, start, len);
294 if (ret) {
295 kfree(logical);
296 return ret;
297 }
298 }
299
300 kfree(logical);
301 }
302 return 0;
303 }
304
305 static struct btrfs_caching_control *
306 get_caching_control(struct btrfs_block_group_cache *cache)
307 {
308 struct btrfs_caching_control *ctl;
309
310 spin_lock(&cache->lock);
311 if (cache->cached != BTRFS_CACHE_STARTED) {
312 spin_unlock(&cache->lock);
313 return NULL;
314 }
315
316 /* We're loading it the fast way, so we don't have a caching_ctl. */
317 if (!cache->caching_ctl) {
318 spin_unlock(&cache->lock);
319 return NULL;
320 }
321
322 ctl = cache->caching_ctl;
323 atomic_inc(&ctl->count);
324 spin_unlock(&cache->lock);
325 return ctl;
326 }
327
328 static void put_caching_control(struct btrfs_caching_control *ctl)
329 {
330 if (atomic_dec_and_test(&ctl->count))
331 kfree(ctl);
332 }
333
334 /*
335 * this is only called by cache_block_group, since we could have freed extents
336 * we need to check the pinned_extents for any extents that can't be used yet
337 * since their free space will be released as soon as the transaction commits.
338 */
339 static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
340 struct btrfs_fs_info *info, u64 start, u64 end)
341 {
342 u64 extent_start, extent_end, size, total_added = 0;
343 int ret;
344
345 while (start < end) {
346 ret = find_first_extent_bit(info->pinned_extents, start,
347 &extent_start, &extent_end,
348 EXTENT_DIRTY | EXTENT_UPTODATE,
349 NULL);
350 if (ret)
351 break;
352
353 if (extent_start <= start) {
354 start = extent_end + 1;
355 } else if (extent_start > start && extent_start < end) {
356 size = extent_start - start;
357 total_added += size;
358 ret = btrfs_add_free_space(block_group, start,
359 size);
360 BUG_ON(ret); /* -ENOMEM or logic error */
361 start = extent_end + 1;
362 } else {
363 break;
364 }
365 }
366
367 if (start < end) {
368 size = end - start;
369 total_added += size;
370 ret = btrfs_add_free_space(block_group, start, size);
371 BUG_ON(ret); /* -ENOMEM or logic error */
372 }
373
374 return total_added;
375 }
376
377 static noinline void caching_thread(struct btrfs_work *work)
378 {
379 struct btrfs_block_group_cache *block_group;
380 struct btrfs_fs_info *fs_info;
381 struct btrfs_caching_control *caching_ctl;
382 struct btrfs_root *extent_root;
383 struct btrfs_path *path;
384 struct extent_buffer *leaf;
385 struct btrfs_key key;
386 u64 total_found = 0;
387 u64 last = 0;
388 u32 nritems;
389 int ret = 0;
390
391 caching_ctl = container_of(work, struct btrfs_caching_control, work);
392 block_group = caching_ctl->block_group;
393 fs_info = block_group->fs_info;
394 extent_root = fs_info->extent_root;
395
396 path = btrfs_alloc_path();
397 if (!path)
398 goto out;
399
400 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
401
402 /*
403 * We don't want to deadlock with somebody trying to allocate a new
404 * extent for the extent root while also trying to search the extent
405 * root to add free space. So we skip locking and search the commit
406 * root, since its read-only
407 */
408 path->skip_locking = 1;
409 path->search_commit_root = 1;
410 path->reada = 1;
411
412 key.objectid = last;
413 key.offset = 0;
414 key.type = BTRFS_EXTENT_ITEM_KEY;
415 again:
416 mutex_lock(&caching_ctl->mutex);
417 /* need to make sure the commit_root doesn't disappear */
418 down_read(&fs_info->extent_commit_sem);
419
420 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
421 if (ret < 0)
422 goto err;
423
424 leaf = path->nodes[0];
425 nritems = btrfs_header_nritems(leaf);
426
427 while (1) {
428 if (btrfs_fs_closing(fs_info) > 1) {
429 last = (u64)-1;
430 break;
431 }
432
433 if (path->slots[0] < nritems) {
434 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
435 } else {
436 ret = find_next_key(path, 0, &key);
437 if (ret)
438 break;
439
440 if (need_resched()) {
441 caching_ctl->progress = last;
442 btrfs_release_path(path);
443 up_read(&fs_info->extent_commit_sem);
444 mutex_unlock(&caching_ctl->mutex);
445 cond_resched();
446 goto again;
447 }
448
449 ret = btrfs_next_leaf(extent_root, path);
450 if (ret < 0)
451 goto err;
452 if (ret)
453 break;
454 leaf = path->nodes[0];
455 nritems = btrfs_header_nritems(leaf);
456 continue;
457 }
458
459 if (key.objectid < block_group->key.objectid) {
460 path->slots[0]++;
461 continue;
462 }
463
464 if (key.objectid >= block_group->key.objectid +
465 block_group->key.offset)
466 break;
467
468 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
469 key.type == BTRFS_METADATA_ITEM_KEY) {
470 total_found += add_new_free_space(block_group,
471 fs_info, last,
472 key.objectid);
473 if (key.type == BTRFS_METADATA_ITEM_KEY)
474 last = key.objectid +
475 fs_info->tree_root->leafsize;
476 else
477 last = key.objectid + key.offset;
478
479 if (total_found > (1024 * 1024 * 2)) {
480 total_found = 0;
481 wake_up(&caching_ctl->wait);
482 }
483 }
484 path->slots[0]++;
485 }
486 ret = 0;
487
488 total_found += add_new_free_space(block_group, fs_info, last,
489 block_group->key.objectid +
490 block_group->key.offset);
491 caching_ctl->progress = (u64)-1;
492
493 spin_lock(&block_group->lock);
494 block_group->caching_ctl = NULL;
495 block_group->cached = BTRFS_CACHE_FINISHED;
496 spin_unlock(&block_group->lock);
497
498 err:
499 btrfs_free_path(path);
500 up_read(&fs_info->extent_commit_sem);
501
502 free_excluded_extents(extent_root, block_group);
503
504 mutex_unlock(&caching_ctl->mutex);
505 out:
506 wake_up(&caching_ctl->wait);
507
508 put_caching_control(caching_ctl);
509 btrfs_put_block_group(block_group);
510 }
511
512 static int cache_block_group(struct btrfs_block_group_cache *cache,
513 int load_cache_only)
514 {
515 DEFINE_WAIT(wait);
516 struct btrfs_fs_info *fs_info = cache->fs_info;
517 struct btrfs_caching_control *caching_ctl;
518 int ret = 0;
519
520 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
521 if (!caching_ctl)
522 return -ENOMEM;
523
524 INIT_LIST_HEAD(&caching_ctl->list);
525 mutex_init(&caching_ctl->mutex);
526 init_waitqueue_head(&caching_ctl->wait);
527 caching_ctl->block_group = cache;
528 caching_ctl->progress = cache->key.objectid;
529 atomic_set(&caching_ctl->count, 1);
530 caching_ctl->work.func = caching_thread;
531
532 spin_lock(&cache->lock);
533 /*
534 * This should be a rare occasion, but this could happen I think in the
535 * case where one thread starts to load the space cache info, and then
536 * some other thread starts a transaction commit which tries to do an
537 * allocation while the other thread is still loading the space cache
538 * info. The previous loop should have kept us from choosing this block
539 * group, but if we've moved to the state where we will wait on caching
540 * block groups we need to first check if we're doing a fast load here,
541 * so we can wait for it to finish, otherwise we could end up allocating
542 * from a block group who's cache gets evicted for one reason or
543 * another.
544 */
545 while (cache->cached == BTRFS_CACHE_FAST) {
546 struct btrfs_caching_control *ctl;
547
548 ctl = cache->caching_ctl;
549 atomic_inc(&ctl->count);
550 prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
551 spin_unlock(&cache->lock);
552
553 schedule();
554
555 finish_wait(&ctl->wait, &wait);
556 put_caching_control(ctl);
557 spin_lock(&cache->lock);
558 }
559
560 if (cache->cached != BTRFS_CACHE_NO) {
561 spin_unlock(&cache->lock);
562 kfree(caching_ctl);
563 return 0;
564 }
565 WARN_ON(cache->caching_ctl);
566 cache->caching_ctl = caching_ctl;
567 cache->cached = BTRFS_CACHE_FAST;
568 spin_unlock(&cache->lock);
569
570 if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) {
571 ret = load_free_space_cache(fs_info, cache);
572
573 spin_lock(&cache->lock);
574 if (ret == 1) {
575 cache->caching_ctl = NULL;
576 cache->cached = BTRFS_CACHE_FINISHED;
577 cache->last_byte_to_unpin = (u64)-1;
578 } else {
579 if (load_cache_only) {
580 cache->caching_ctl = NULL;
581 cache->cached = BTRFS_CACHE_NO;
582 } else {
583 cache->cached = BTRFS_CACHE_STARTED;
584 }
585 }
586 spin_unlock(&cache->lock);
587 wake_up(&caching_ctl->wait);
588 if (ret == 1) {
589 put_caching_control(caching_ctl);
590 free_excluded_extents(fs_info->extent_root, cache);
591 return 0;
592 }
593 } else {
594 /*
595 * We are not going to do the fast caching, set cached to the
596 * appropriate value and wakeup any waiters.
597 */
598 spin_lock(&cache->lock);
599 if (load_cache_only) {
600 cache->caching_ctl = NULL;
601 cache->cached = BTRFS_CACHE_NO;
602 } else {
603 cache->cached = BTRFS_CACHE_STARTED;
604 }
605 spin_unlock(&cache->lock);
606 wake_up(&caching_ctl->wait);
607 }
608
609 if (load_cache_only) {
610 put_caching_control(caching_ctl);
611 return 0;
612 }
613
614 down_write(&fs_info->extent_commit_sem);
615 atomic_inc(&caching_ctl->count);
616 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
617 up_write(&fs_info->extent_commit_sem);
618
619 btrfs_get_block_group(cache);
620
621 btrfs_queue_worker(&fs_info->caching_workers, &caching_ctl->work);
622
623 return ret;
624 }
625
626 /*
627 * return the block group that starts at or after bytenr
628 */
629 static struct btrfs_block_group_cache *
630 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
631 {
632 struct btrfs_block_group_cache *cache;
633
634 cache = block_group_cache_tree_search(info, bytenr, 0);
635
636 return cache;
637 }
638
639 /*
640 * return the block group that contains the given bytenr
641 */
642 struct btrfs_block_group_cache *btrfs_lookup_block_group(
643 struct btrfs_fs_info *info,
644 u64 bytenr)
645 {
646 struct btrfs_block_group_cache *cache;
647
648 cache = block_group_cache_tree_search(info, bytenr, 1);
649
650 return cache;
651 }
652
653 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
654 u64 flags)
655 {
656 struct list_head *head = &info->space_info;
657 struct btrfs_space_info *found;
658
659 flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
660
661 rcu_read_lock();
662 list_for_each_entry_rcu(found, head, list) {
663 if (found->flags & flags) {
664 rcu_read_unlock();
665 return found;
666 }
667 }
668 rcu_read_unlock();
669 return NULL;
670 }
671
672 /*
673 * after adding space to the filesystem, we need to clear the full flags
674 * on all the space infos.
675 */
676 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
677 {
678 struct list_head *head = &info->space_info;
679 struct btrfs_space_info *found;
680
681 rcu_read_lock();
682 list_for_each_entry_rcu(found, head, list)
683 found->full = 0;
684 rcu_read_unlock();
685 }
686
687 u64 btrfs_find_block_group(struct btrfs_root *root,
688 u64 search_start, u64 search_hint, int owner)
689 {
690 struct btrfs_block_group_cache *cache;
691 u64 used;
692 u64 last = max(search_hint, search_start);
693 u64 group_start = 0;
694 int full_search = 0;
695 int factor = 9;
696 int wrapped = 0;
697 again:
698 while (1) {
699 cache = btrfs_lookup_first_block_group(root->fs_info, last);
700 if (!cache)
701 break;
702
703 spin_lock(&cache->lock);
704 last = cache->key.objectid + cache->key.offset;
705 used = btrfs_block_group_used(&cache->item);
706
707 if ((full_search || !cache->ro) &&
708 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
709 if (used + cache->pinned + cache->reserved <
710 div_factor(cache->key.offset, factor)) {
711 group_start = cache->key.objectid;
712 spin_unlock(&cache->lock);
713 btrfs_put_block_group(cache);
714 goto found;
715 }
716 }
717 spin_unlock(&cache->lock);
718 btrfs_put_block_group(cache);
719 cond_resched();
720 }
721 if (!wrapped) {
722 last = search_start;
723 wrapped = 1;
724 goto again;
725 }
726 if (!full_search && factor < 10) {
727 last = search_start;
728 full_search = 1;
729 factor = 10;
730 goto again;
731 }
732 found:
733 return group_start;
734 }
735
736 /* simple helper to search for an existing extent at a given offset */
737 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
738 {
739 int ret;
740 struct btrfs_key key;
741 struct btrfs_path *path;
742
743 path = btrfs_alloc_path();
744 if (!path)
745 return -ENOMEM;
746
747 key.objectid = start;
748 key.offset = len;
749 key.type = BTRFS_EXTENT_ITEM_KEY;
750 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
751 0, 0);
752 if (ret > 0) {
753 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
754 if (key.objectid == start &&
755 key.type == BTRFS_METADATA_ITEM_KEY)
756 ret = 0;
757 }
758 btrfs_free_path(path);
759 return ret;
760 }
761
762 /*
763 * helper function to lookup reference count and flags of a tree block.
764 *
765 * the head node for delayed ref is used to store the sum of all the
766 * reference count modifications queued up in the rbtree. the head
767 * node may also store the extent flags to set. This way you can check
768 * to see what the reference count and extent flags would be if all of
769 * the delayed refs are not processed.
770 */
771 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
772 struct btrfs_root *root, u64 bytenr,
773 u64 offset, int metadata, u64 *refs, u64 *flags)
774 {
775 struct btrfs_delayed_ref_head *head;
776 struct btrfs_delayed_ref_root *delayed_refs;
777 struct btrfs_path *path;
778 struct btrfs_extent_item *ei;
779 struct extent_buffer *leaf;
780 struct btrfs_key key;
781 u32 item_size;
782 u64 num_refs;
783 u64 extent_flags;
784 int ret;
785
786 /*
787 * If we don't have skinny metadata, don't bother doing anything
788 * different
789 */
790 if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) {
791 offset = root->leafsize;
792 metadata = 0;
793 }
794
795 path = btrfs_alloc_path();
796 if (!path)
797 return -ENOMEM;
798
799 if (metadata) {
800 key.objectid = bytenr;
801 key.type = BTRFS_METADATA_ITEM_KEY;
802 key.offset = offset;
803 } else {
804 key.objectid = bytenr;
805 key.type = BTRFS_EXTENT_ITEM_KEY;
806 key.offset = offset;
807 }
808
809 if (!trans) {
810 path->skip_locking = 1;
811 path->search_commit_root = 1;
812 }
813 again:
814 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
815 &key, path, 0, 0);
816 if (ret < 0)
817 goto out_free;
818
819 if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
820 key.type = BTRFS_EXTENT_ITEM_KEY;
821 key.offset = root->leafsize;
822 btrfs_release_path(path);
823 goto again;
824 }
825
826 if (ret == 0) {
827 leaf = path->nodes[0];
828 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
829 if (item_size >= sizeof(*ei)) {
830 ei = btrfs_item_ptr(leaf, path->slots[0],
831 struct btrfs_extent_item);
832 num_refs = btrfs_extent_refs(leaf, ei);
833 extent_flags = btrfs_extent_flags(leaf, ei);
834 } else {
835 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
836 struct btrfs_extent_item_v0 *ei0;
837 BUG_ON(item_size != sizeof(*ei0));
838 ei0 = btrfs_item_ptr(leaf, path->slots[0],
839 struct btrfs_extent_item_v0);
840 num_refs = btrfs_extent_refs_v0(leaf, ei0);
841 /* FIXME: this isn't correct for data */
842 extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
843 #else
844 BUG();
845 #endif
846 }
847 BUG_ON(num_refs == 0);
848 } else {
849 num_refs = 0;
850 extent_flags = 0;
851 ret = 0;
852 }
853
854 if (!trans)
855 goto out;
856
857 delayed_refs = &trans->transaction->delayed_refs;
858 spin_lock(&delayed_refs->lock);
859 head = btrfs_find_delayed_ref_head(trans, bytenr);
860 if (head) {
861 if (!mutex_trylock(&head->mutex)) {
862 atomic_inc(&head->node.refs);
863 spin_unlock(&delayed_refs->lock);
864
865 btrfs_release_path(path);
866
867 /*
868 * Mutex was contended, block until it's released and try
869 * again
870 */
871 mutex_lock(&head->mutex);
872 mutex_unlock(&head->mutex);
873 btrfs_put_delayed_ref(&head->node);
874 goto again;
875 }
876 if (head->extent_op && head->extent_op->update_flags)
877 extent_flags |= head->extent_op->flags_to_set;
878 else
879 BUG_ON(num_refs == 0);
880
881 num_refs += head->node.ref_mod;
882 mutex_unlock(&head->mutex);
883 }
884 spin_unlock(&delayed_refs->lock);
885 out:
886 WARN_ON(num_refs == 0);
887 if (refs)
888 *refs = num_refs;
889 if (flags)
890 *flags = extent_flags;
891 out_free:
892 btrfs_free_path(path);
893 return ret;
894 }
895
896 /*
897 * Back reference rules. Back refs have three main goals:
898 *
899 * 1) differentiate between all holders of references to an extent so that
900 * when a reference is dropped we can make sure it was a valid reference
901 * before freeing the extent.
902 *
903 * 2) Provide enough information to quickly find the holders of an extent
904 * if we notice a given block is corrupted or bad.
905 *
906 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
907 * maintenance. This is actually the same as #2, but with a slightly
908 * different use case.
909 *
910 * There are two kinds of back refs. The implicit back refs is optimized
911 * for pointers in non-shared tree blocks. For a given pointer in a block,
912 * back refs of this kind provide information about the block's owner tree
913 * and the pointer's key. These information allow us to find the block by
914 * b-tree searching. The full back refs is for pointers in tree blocks not
915 * referenced by their owner trees. The location of tree block is recorded
916 * in the back refs. Actually the full back refs is generic, and can be
917 * used in all cases the implicit back refs is used. The major shortcoming
918 * of the full back refs is its overhead. Every time a tree block gets
919 * COWed, we have to update back refs entry for all pointers in it.
920 *
921 * For a newly allocated tree block, we use implicit back refs for
922 * pointers in it. This means most tree related operations only involve
923 * implicit back refs. For a tree block created in old transaction, the
924 * only way to drop a reference to it is COW it. So we can detect the
925 * event that tree block loses its owner tree's reference and do the
926 * back refs conversion.
927 *
928 * When a tree block is COW'd through a tree, there are four cases:
929 *
930 * The reference count of the block is one and the tree is the block's
931 * owner tree. Nothing to do in this case.
932 *
933 * The reference count of the block is one and the tree is not the
934 * block's owner tree. In this case, full back refs is used for pointers
935 * in the block. Remove these full back refs, add implicit back refs for
936 * every pointers in the new block.
937 *
938 * The reference count of the block is greater than one and the tree is
939 * the block's owner tree. In this case, implicit back refs is used for
940 * pointers in the block. Add full back refs for every pointers in the
941 * block, increase lower level extents' reference counts. The original
942 * implicit back refs are entailed to the new block.
943 *
944 * The reference count of the block is greater than one and the tree is
945 * not the block's owner tree. Add implicit back refs for every pointer in
946 * the new block, increase lower level extents' reference count.
947 *
948 * Back Reference Key composing:
949 *
950 * The key objectid corresponds to the first byte in the extent,
951 * The key type is used to differentiate between types of back refs.
952 * There are different meanings of the key offset for different types
953 * of back refs.
954 *
955 * File extents can be referenced by:
956 *
957 * - multiple snapshots, subvolumes, or different generations in one subvol
958 * - different files inside a single subvolume
959 * - different offsets inside a file (bookend extents in file.c)
960 *
961 * The extent ref structure for the implicit back refs has fields for:
962 *
963 * - Objectid of the subvolume root
964 * - objectid of the file holding the reference
965 * - original offset in the file
966 * - how many bookend extents
967 *
968 * The key offset for the implicit back refs is hash of the first
969 * three fields.
970 *
971 * The extent ref structure for the full back refs has field for:
972 *
973 * - number of pointers in the tree leaf
974 *
975 * The key offset for the implicit back refs is the first byte of
976 * the tree leaf
977 *
978 * When a file extent is allocated, The implicit back refs is used.
979 * the fields are filled in:
980 *
981 * (root_key.objectid, inode objectid, offset in file, 1)
982 *
983 * When a file extent is removed file truncation, we find the
984 * corresponding implicit back refs and check the following fields:
985 *
986 * (btrfs_header_owner(leaf), inode objectid, offset in file)
987 *
988 * Btree extents can be referenced by:
989 *
990 * - Different subvolumes
991 *
992 * Both the implicit back refs and the full back refs for tree blocks
993 * only consist of key. The key offset for the implicit back refs is
994 * objectid of block's owner tree. The key offset for the full back refs
995 * is the first byte of parent block.
996 *
997 * When implicit back refs is used, information about the lowest key and
998 * level of the tree block are required. These information are stored in
999 * tree block info structure.
1000 */
1001
1002 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1003 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
1004 struct btrfs_root *root,
1005 struct btrfs_path *path,
1006 u64 owner, u32 extra_size)
1007 {
1008 struct btrfs_extent_item *item;
1009 struct btrfs_extent_item_v0 *ei0;
1010 struct btrfs_extent_ref_v0 *ref0;
1011 struct btrfs_tree_block_info *bi;
1012 struct extent_buffer *leaf;
1013 struct btrfs_key key;
1014 struct btrfs_key found_key;
1015 u32 new_size = sizeof(*item);
1016 u64 refs;
1017 int ret;
1018
1019 leaf = path->nodes[0];
1020 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
1021
1022 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1023 ei0 = btrfs_item_ptr(leaf, path->slots[0],
1024 struct btrfs_extent_item_v0);
1025 refs = btrfs_extent_refs_v0(leaf, ei0);
1026
1027 if (owner == (u64)-1) {
1028 while (1) {
1029 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1030 ret = btrfs_next_leaf(root, path);
1031 if (ret < 0)
1032 return ret;
1033 BUG_ON(ret > 0); /* Corruption */
1034 leaf = path->nodes[0];
1035 }
1036 btrfs_item_key_to_cpu(leaf, &found_key,
1037 path->slots[0]);
1038 BUG_ON(key.objectid != found_key.objectid);
1039 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
1040 path->slots[0]++;
1041 continue;
1042 }
1043 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1044 struct btrfs_extent_ref_v0);
1045 owner = btrfs_ref_objectid_v0(leaf, ref0);
1046 break;
1047 }
1048 }
1049 btrfs_release_path(path);
1050
1051 if (owner < BTRFS_FIRST_FREE_OBJECTID)
1052 new_size += sizeof(*bi);
1053
1054 new_size -= sizeof(*ei0);
1055 ret = btrfs_search_slot(trans, root, &key, path,
1056 new_size + extra_size, 1);
1057 if (ret < 0)
1058 return ret;
1059 BUG_ON(ret); /* Corruption */
1060
1061 btrfs_extend_item(root, path, new_size);
1062
1063 leaf = path->nodes[0];
1064 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1065 btrfs_set_extent_refs(leaf, item, refs);
1066 /* FIXME: get real generation */
1067 btrfs_set_extent_generation(leaf, item, 0);
1068 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1069 btrfs_set_extent_flags(leaf, item,
1070 BTRFS_EXTENT_FLAG_TREE_BLOCK |
1071 BTRFS_BLOCK_FLAG_FULL_BACKREF);
1072 bi = (struct btrfs_tree_block_info *)(item + 1);
1073 /* FIXME: get first key of the block */
1074 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
1075 btrfs_set_tree_block_level(leaf, bi, (int)owner);
1076 } else {
1077 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
1078 }
1079 btrfs_mark_buffer_dirty(leaf);
1080 return 0;
1081 }
1082 #endif
1083
1084 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
1085 {
1086 u32 high_crc = ~(u32)0;
1087 u32 low_crc = ~(u32)0;
1088 __le64 lenum;
1089
1090 lenum = cpu_to_le64(root_objectid);
1091 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
1092 lenum = cpu_to_le64(owner);
1093 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
1094 lenum = cpu_to_le64(offset);
1095 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
1096
1097 return ((u64)high_crc << 31) ^ (u64)low_crc;
1098 }
1099
1100 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
1101 struct btrfs_extent_data_ref *ref)
1102 {
1103 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
1104 btrfs_extent_data_ref_objectid(leaf, ref),
1105 btrfs_extent_data_ref_offset(leaf, ref));
1106 }
1107
1108 static int match_extent_data_ref(struct extent_buffer *leaf,
1109 struct btrfs_extent_data_ref *ref,
1110 u64 root_objectid, u64 owner, u64 offset)
1111 {
1112 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
1113 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
1114 btrfs_extent_data_ref_offset(leaf, ref) != offset)
1115 return 0;
1116 return 1;
1117 }
1118
1119 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
1120 struct btrfs_root *root,
1121 struct btrfs_path *path,
1122 u64 bytenr, u64 parent,
1123 u64 root_objectid,
1124 u64 owner, u64 offset)
1125 {
1126 struct btrfs_key key;
1127 struct btrfs_extent_data_ref *ref;
1128 struct extent_buffer *leaf;
1129 u32 nritems;
1130 int ret;
1131 int recow;
1132 int err = -ENOENT;
1133
1134 key.objectid = bytenr;
1135 if (parent) {
1136 key.type = BTRFS_SHARED_DATA_REF_KEY;
1137 key.offset = parent;
1138 } else {
1139 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1140 key.offset = hash_extent_data_ref(root_objectid,
1141 owner, offset);
1142 }
1143 again:
1144 recow = 0;
1145 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1146 if (ret < 0) {
1147 err = ret;
1148 goto fail;
1149 }
1150
1151 if (parent) {
1152 if (!ret)
1153 return 0;
1154 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1155 key.type = BTRFS_EXTENT_REF_V0_KEY;
1156 btrfs_release_path(path);
1157 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1158 if (ret < 0) {
1159 err = ret;
1160 goto fail;
1161 }
1162 if (!ret)
1163 return 0;
1164 #endif
1165 goto fail;
1166 }
1167
1168 leaf = path->nodes[0];
1169 nritems = btrfs_header_nritems(leaf);
1170 while (1) {
1171 if (path->slots[0] >= nritems) {
1172 ret = btrfs_next_leaf(root, path);
1173 if (ret < 0)
1174 err = ret;
1175 if (ret)
1176 goto fail;
1177
1178 leaf = path->nodes[0];
1179 nritems = btrfs_header_nritems(leaf);
1180 recow = 1;
1181 }
1182
1183 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1184 if (key.objectid != bytenr ||
1185 key.type != BTRFS_EXTENT_DATA_REF_KEY)
1186 goto fail;
1187
1188 ref = btrfs_item_ptr(leaf, path->slots[0],
1189 struct btrfs_extent_data_ref);
1190
1191 if (match_extent_data_ref(leaf, ref, root_objectid,
1192 owner, offset)) {
1193 if (recow) {
1194 btrfs_release_path(path);
1195 goto again;
1196 }
1197 err = 0;
1198 break;
1199 }
1200 path->slots[0]++;
1201 }
1202 fail:
1203 return err;
1204 }
1205
1206 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
1207 struct btrfs_root *root,
1208 struct btrfs_path *path,
1209 u64 bytenr, u64 parent,
1210 u64 root_objectid, u64 owner,
1211 u64 offset, int refs_to_add)
1212 {
1213 struct btrfs_key key;
1214 struct extent_buffer *leaf;
1215 u32 size;
1216 u32 num_refs;
1217 int ret;
1218
1219 key.objectid = bytenr;
1220 if (parent) {
1221 key.type = BTRFS_SHARED_DATA_REF_KEY;
1222 key.offset = parent;
1223 size = sizeof(struct btrfs_shared_data_ref);
1224 } else {
1225 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1226 key.offset = hash_extent_data_ref(root_objectid,
1227 owner, offset);
1228 size = sizeof(struct btrfs_extent_data_ref);
1229 }
1230
1231 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
1232 if (ret && ret != -EEXIST)
1233 goto fail;
1234
1235 leaf = path->nodes[0];
1236 if (parent) {
1237 struct btrfs_shared_data_ref *ref;
1238 ref = btrfs_item_ptr(leaf, path->slots[0],
1239 struct btrfs_shared_data_ref);
1240 if (ret == 0) {
1241 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
1242 } else {
1243 num_refs = btrfs_shared_data_ref_count(leaf, ref);
1244 num_refs += refs_to_add;
1245 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
1246 }
1247 } else {
1248 struct btrfs_extent_data_ref *ref;
1249 while (ret == -EEXIST) {
1250 ref = btrfs_item_ptr(leaf, path->slots[0],
1251 struct btrfs_extent_data_ref);
1252 if (match_extent_data_ref(leaf, ref, root_objectid,
1253 owner, offset))
1254 break;
1255 btrfs_release_path(path);
1256 key.offset++;
1257 ret = btrfs_insert_empty_item(trans, root, path, &key,
1258 size);
1259 if (ret && ret != -EEXIST)
1260 goto fail;
1261
1262 leaf = path->nodes[0];
1263 }
1264 ref = btrfs_item_ptr(leaf, path->slots[0],
1265 struct btrfs_extent_data_ref);
1266 if (ret == 0) {
1267 btrfs_set_extent_data_ref_root(leaf, ref,
1268 root_objectid);
1269 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
1270 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
1271 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
1272 } else {
1273 num_refs = btrfs_extent_data_ref_count(leaf, ref);
1274 num_refs += refs_to_add;
1275 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
1276 }
1277 }
1278 btrfs_mark_buffer_dirty(leaf);
1279 ret = 0;
1280 fail:
1281 btrfs_release_path(path);
1282 return ret;
1283 }
1284
1285 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
1286 struct btrfs_root *root,
1287 struct btrfs_path *path,
1288 int refs_to_drop)
1289 {
1290 struct btrfs_key key;
1291 struct btrfs_extent_data_ref *ref1 = NULL;
1292 struct btrfs_shared_data_ref *ref2 = NULL;
1293 struct extent_buffer *leaf;
1294 u32 num_refs = 0;
1295 int ret = 0;
1296
1297 leaf = path->nodes[0];
1298 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1299
1300 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1301 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1302 struct btrfs_extent_data_ref);
1303 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1304 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1305 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1306 struct btrfs_shared_data_ref);
1307 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1308 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1309 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1310 struct btrfs_extent_ref_v0 *ref0;
1311 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1312 struct btrfs_extent_ref_v0);
1313 num_refs = btrfs_ref_count_v0(leaf, ref0);
1314 #endif
1315 } else {
1316 BUG();
1317 }
1318
1319 BUG_ON(num_refs < refs_to_drop);
1320 num_refs -= refs_to_drop;
1321
1322 if (num_refs == 0) {
1323 ret = btrfs_del_item(trans, root, path);
1324 } else {
1325 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
1326 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
1327 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
1328 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
1329 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1330 else {
1331 struct btrfs_extent_ref_v0 *ref0;
1332 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1333 struct btrfs_extent_ref_v0);
1334 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
1335 }
1336 #endif
1337 btrfs_mark_buffer_dirty(leaf);
1338 }
1339 return ret;
1340 }
1341
1342 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
1343 struct btrfs_path *path,
1344 struct btrfs_extent_inline_ref *iref)
1345 {
1346 struct btrfs_key key;
1347 struct extent_buffer *leaf;
1348 struct btrfs_extent_data_ref *ref1;
1349 struct btrfs_shared_data_ref *ref2;
1350 u32 num_refs = 0;
1351
1352 leaf = path->nodes[0];
1353 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1354 if (iref) {
1355 if (btrfs_extent_inline_ref_type(leaf, iref) ==
1356 BTRFS_EXTENT_DATA_REF_KEY) {
1357 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
1358 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1359 } else {
1360 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
1361 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1362 }
1363 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1364 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1365 struct btrfs_extent_data_ref);
1366 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1367 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1368 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1369 struct btrfs_shared_data_ref);
1370 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1371 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1372 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1373 struct btrfs_extent_ref_v0 *ref0;
1374 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1375 struct btrfs_extent_ref_v0);
1376 num_refs = btrfs_ref_count_v0(leaf, ref0);
1377 #endif
1378 } else {
1379 WARN_ON(1);
1380 }
1381 return num_refs;
1382 }
1383
1384 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
1385 struct btrfs_root *root,
1386 struct btrfs_path *path,
1387 u64 bytenr, u64 parent,
1388 u64 root_objectid)
1389 {
1390 struct btrfs_key key;
1391 int ret;
1392
1393 key.objectid = bytenr;
1394 if (parent) {
1395 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1396 key.offset = parent;
1397 } else {
1398 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1399 key.offset = root_objectid;
1400 }
1401
1402 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1403 if (ret > 0)
1404 ret = -ENOENT;
1405 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1406 if (ret == -ENOENT && parent) {
1407 btrfs_release_path(path);
1408 key.type = BTRFS_EXTENT_REF_V0_KEY;
1409 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1410 if (ret > 0)
1411 ret = -ENOENT;
1412 }
1413 #endif
1414 return ret;
1415 }
1416
1417 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
1418 struct btrfs_root *root,
1419 struct btrfs_path *path,
1420 u64 bytenr, u64 parent,
1421 u64 root_objectid)
1422 {
1423 struct btrfs_key key;
1424 int ret;
1425
1426 key.objectid = bytenr;
1427 if (parent) {
1428 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1429 key.offset = parent;
1430 } else {
1431 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1432 key.offset = root_objectid;
1433 }
1434
1435 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1436 btrfs_release_path(path);
1437 return ret;
1438 }
1439
1440 static inline int extent_ref_type(u64 parent, u64 owner)
1441 {
1442 int type;
1443 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1444 if (parent > 0)
1445 type = BTRFS_SHARED_BLOCK_REF_KEY;
1446 else
1447 type = BTRFS_TREE_BLOCK_REF_KEY;
1448 } else {
1449 if (parent > 0)
1450 type = BTRFS_SHARED_DATA_REF_KEY;
1451 else
1452 type = BTRFS_EXTENT_DATA_REF_KEY;
1453 }
1454 return type;
1455 }
1456
1457 static int find_next_key(struct btrfs_path *path, int level,
1458 struct btrfs_key *key)
1459
1460 {
1461 for (; level < BTRFS_MAX_LEVEL; level++) {
1462 if (!path->nodes[level])
1463 break;
1464 if (path->slots[level] + 1 >=
1465 btrfs_header_nritems(path->nodes[level]))
1466 continue;
1467 if (level == 0)
1468 btrfs_item_key_to_cpu(path->nodes[level], key,
1469 path->slots[level] + 1);
1470 else
1471 btrfs_node_key_to_cpu(path->nodes[level], key,
1472 path->slots[level] + 1);
1473 return 0;
1474 }
1475 return 1;
1476 }
1477
1478 /*
1479 * look for inline back ref. if back ref is found, *ref_ret is set
1480 * to the address of inline back ref, and 0 is returned.
1481 *
1482 * if back ref isn't found, *ref_ret is set to the address where it
1483 * should be inserted, and -ENOENT is returned.
1484 *
1485 * if insert is true and there are too many inline back refs, the path
1486 * points to the extent item, and -EAGAIN is returned.
1487 *
1488 * NOTE: inline back refs are ordered in the same way that back ref
1489 * items in the tree are ordered.
1490 */
1491 static noinline_for_stack
1492 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1493 struct btrfs_root *root,
1494 struct btrfs_path *path,
1495 struct btrfs_extent_inline_ref **ref_ret,
1496 u64 bytenr, u64 num_bytes,
1497 u64 parent, u64 root_objectid,
1498 u64 owner, u64 offset, int insert)
1499 {
1500 struct btrfs_key key;
1501 struct extent_buffer *leaf;
1502 struct btrfs_extent_item *ei;
1503 struct btrfs_extent_inline_ref *iref;
1504 u64 flags;
1505 u64 item_size;
1506 unsigned long ptr;
1507 unsigned long end;
1508 int extra_size;
1509 int type;
1510 int want;
1511 int ret;
1512 int err = 0;
1513 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
1514 SKINNY_METADATA);
1515
1516 key.objectid = bytenr;
1517 key.type = BTRFS_EXTENT_ITEM_KEY;
1518 key.offset = num_bytes;
1519
1520 want = extent_ref_type(parent, owner);
1521 if (insert) {
1522 extra_size = btrfs_extent_inline_ref_size(want);
1523 path->keep_locks = 1;
1524 } else
1525 extra_size = -1;
1526
1527 /*
1528 * Owner is our parent level, so we can just add one to get the level
1529 * for the block we are interested in.
1530 */
1531 if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) {
1532 key.type = BTRFS_METADATA_ITEM_KEY;
1533 key.offset = owner;
1534 }
1535
1536 again:
1537 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1538 if (ret < 0) {
1539 err = ret;
1540 goto out;
1541 }
1542
1543 /*
1544 * We may be a newly converted file system which still has the old fat
1545 * extent entries for metadata, so try and see if we have one of those.
1546 */
1547 if (ret > 0 && skinny_metadata) {
1548 skinny_metadata = false;
1549 if (path->slots[0]) {
1550 path->slots[0]--;
1551 btrfs_item_key_to_cpu(path->nodes[0], &key,
1552 path->slots[0]);
1553 if (key.objectid == bytenr &&
1554 key.type == BTRFS_EXTENT_ITEM_KEY &&
1555 key.offset == num_bytes)
1556 ret = 0;
1557 }
1558 if (ret) {
1559 key.type = BTRFS_EXTENT_ITEM_KEY;
1560 key.offset = num_bytes;
1561 btrfs_release_path(path);
1562 goto again;
1563 }
1564 }
1565
1566 if (ret && !insert) {
1567 err = -ENOENT;
1568 goto out;
1569 } else if (ret) {
1570 err = -EIO;
1571 WARN_ON(1);
1572 goto out;
1573 }
1574
1575 leaf = path->nodes[0];
1576 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1577 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1578 if (item_size < sizeof(*ei)) {
1579 if (!insert) {
1580 err = -ENOENT;
1581 goto out;
1582 }
1583 ret = convert_extent_item_v0(trans, root, path, owner,
1584 extra_size);
1585 if (ret < 0) {
1586 err = ret;
1587 goto out;
1588 }
1589 leaf = path->nodes[0];
1590 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1591 }
1592 #endif
1593 BUG_ON(item_size < sizeof(*ei));
1594
1595 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1596 flags = btrfs_extent_flags(leaf, ei);
1597
1598 ptr = (unsigned long)(ei + 1);
1599 end = (unsigned long)ei + item_size;
1600
1601 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
1602 ptr += sizeof(struct btrfs_tree_block_info);
1603 BUG_ON(ptr > end);
1604 }
1605
1606 err = -ENOENT;
1607 while (1) {
1608 if (ptr >= end) {
1609 WARN_ON(ptr > end);
1610 break;
1611 }
1612 iref = (struct btrfs_extent_inline_ref *)ptr;
1613 type = btrfs_extent_inline_ref_type(leaf, iref);
1614 if (want < type)
1615 break;
1616 if (want > type) {
1617 ptr += btrfs_extent_inline_ref_size(type);
1618 continue;
1619 }
1620
1621 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1622 struct btrfs_extent_data_ref *dref;
1623 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1624 if (match_extent_data_ref(leaf, dref, root_objectid,
1625 owner, offset)) {
1626 err = 0;
1627 break;
1628 }
1629 if (hash_extent_data_ref_item(leaf, dref) <
1630 hash_extent_data_ref(root_objectid, owner, offset))
1631 break;
1632 } else {
1633 u64 ref_offset;
1634 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1635 if (parent > 0) {
1636 if (parent == ref_offset) {
1637 err = 0;
1638 break;
1639 }
1640 if (ref_offset < parent)
1641 break;
1642 } else {
1643 if (root_objectid == ref_offset) {
1644 err = 0;
1645 break;
1646 }
1647 if (ref_offset < root_objectid)
1648 break;
1649 }
1650 }
1651 ptr += btrfs_extent_inline_ref_size(type);
1652 }
1653 if (err == -ENOENT && insert) {
1654 if (item_size + extra_size >=
1655 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1656 err = -EAGAIN;
1657 goto out;
1658 }
1659 /*
1660 * To add new inline back ref, we have to make sure
1661 * there is no corresponding back ref item.
1662 * For simplicity, we just do not add new inline back
1663 * ref if there is any kind of item for this block
1664 */
1665 if (find_next_key(path, 0, &key) == 0 &&
1666 key.objectid == bytenr &&
1667 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1668 err = -EAGAIN;
1669 goto out;
1670 }
1671 }
1672 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1673 out:
1674 if (insert) {
1675 path->keep_locks = 0;
1676 btrfs_unlock_up_safe(path, 1);
1677 }
1678 return err;
1679 }
1680
1681 /*
1682 * helper to add new inline back ref
1683 */
1684 static noinline_for_stack
1685 void setup_inline_extent_backref(struct btrfs_root *root,
1686 struct btrfs_path *path,
1687 struct btrfs_extent_inline_ref *iref,
1688 u64 parent, u64 root_objectid,
1689 u64 owner, u64 offset, int refs_to_add,
1690 struct btrfs_delayed_extent_op *extent_op)
1691 {
1692 struct extent_buffer *leaf;
1693 struct btrfs_extent_item *ei;
1694 unsigned long ptr;
1695 unsigned long end;
1696 unsigned long item_offset;
1697 u64 refs;
1698 int size;
1699 int type;
1700
1701 leaf = path->nodes[0];
1702 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1703 item_offset = (unsigned long)iref - (unsigned long)ei;
1704
1705 type = extent_ref_type(parent, owner);
1706 size = btrfs_extent_inline_ref_size(type);
1707
1708 btrfs_extend_item(root, path, size);
1709
1710 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1711 refs = btrfs_extent_refs(leaf, ei);
1712 refs += refs_to_add;
1713 btrfs_set_extent_refs(leaf, ei, refs);
1714 if (extent_op)
1715 __run_delayed_extent_op(extent_op, leaf, ei);
1716
1717 ptr = (unsigned long)ei + item_offset;
1718 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1719 if (ptr < end - size)
1720 memmove_extent_buffer(leaf, ptr + size, ptr,
1721 end - size - ptr);
1722
1723 iref = (struct btrfs_extent_inline_ref *)ptr;
1724 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1725 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1726 struct btrfs_extent_data_ref *dref;
1727 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1728 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1729 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1730 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1731 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1732 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1733 struct btrfs_shared_data_ref *sref;
1734 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1735 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1736 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1737 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1738 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1739 } else {
1740 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1741 }
1742 btrfs_mark_buffer_dirty(leaf);
1743 }
1744
1745 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1746 struct btrfs_root *root,
1747 struct btrfs_path *path,
1748 struct btrfs_extent_inline_ref **ref_ret,
1749 u64 bytenr, u64 num_bytes, u64 parent,
1750 u64 root_objectid, u64 owner, u64 offset)
1751 {
1752 int ret;
1753
1754 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1755 bytenr, num_bytes, parent,
1756 root_objectid, owner, offset, 0);
1757 if (ret != -ENOENT)
1758 return ret;
1759
1760 btrfs_release_path(path);
1761 *ref_ret = NULL;
1762
1763 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1764 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1765 root_objectid);
1766 } else {
1767 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1768 root_objectid, owner, offset);
1769 }
1770 return ret;
1771 }
1772
1773 /*
1774 * helper to update/remove inline back ref
1775 */
1776 static noinline_for_stack
1777 void update_inline_extent_backref(struct btrfs_root *root,
1778 struct btrfs_path *path,
1779 struct btrfs_extent_inline_ref *iref,
1780 int refs_to_mod,
1781 struct btrfs_delayed_extent_op *extent_op)
1782 {
1783 struct extent_buffer *leaf;
1784 struct btrfs_extent_item *ei;
1785 struct btrfs_extent_data_ref *dref = NULL;
1786 struct btrfs_shared_data_ref *sref = NULL;
1787 unsigned long ptr;
1788 unsigned long end;
1789 u32 item_size;
1790 int size;
1791 int type;
1792 u64 refs;
1793
1794 leaf = path->nodes[0];
1795 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1796 refs = btrfs_extent_refs(leaf, ei);
1797 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1798 refs += refs_to_mod;
1799 btrfs_set_extent_refs(leaf, ei, refs);
1800 if (extent_op)
1801 __run_delayed_extent_op(extent_op, leaf, ei);
1802
1803 type = btrfs_extent_inline_ref_type(leaf, iref);
1804
1805 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1806 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1807 refs = btrfs_extent_data_ref_count(leaf, dref);
1808 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1809 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1810 refs = btrfs_shared_data_ref_count(leaf, sref);
1811 } else {
1812 refs = 1;
1813 BUG_ON(refs_to_mod != -1);
1814 }
1815
1816 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1817 refs += refs_to_mod;
1818
1819 if (refs > 0) {
1820 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1821 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1822 else
1823 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1824 } else {
1825 size = btrfs_extent_inline_ref_size(type);
1826 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1827 ptr = (unsigned long)iref;
1828 end = (unsigned long)ei + item_size;
1829 if (ptr + size < end)
1830 memmove_extent_buffer(leaf, ptr, ptr + size,
1831 end - ptr - size);
1832 item_size -= size;
1833 btrfs_truncate_item(root, path, item_size, 1);
1834 }
1835 btrfs_mark_buffer_dirty(leaf);
1836 }
1837
1838 static noinline_for_stack
1839 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1840 struct btrfs_root *root,
1841 struct btrfs_path *path,
1842 u64 bytenr, u64 num_bytes, u64 parent,
1843 u64 root_objectid, u64 owner,
1844 u64 offset, int refs_to_add,
1845 struct btrfs_delayed_extent_op *extent_op)
1846 {
1847 struct btrfs_extent_inline_ref *iref;
1848 int ret;
1849
1850 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1851 bytenr, num_bytes, parent,
1852 root_objectid, owner, offset, 1);
1853 if (ret == 0) {
1854 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1855 update_inline_extent_backref(root, path, iref,
1856 refs_to_add, extent_op);
1857 } else if (ret == -ENOENT) {
1858 setup_inline_extent_backref(root, path, iref, parent,
1859 root_objectid, owner, offset,
1860 refs_to_add, extent_op);
1861 ret = 0;
1862 }
1863 return ret;
1864 }
1865
1866 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1867 struct btrfs_root *root,
1868 struct btrfs_path *path,
1869 u64 bytenr, u64 parent, u64 root_objectid,
1870 u64 owner, u64 offset, int refs_to_add)
1871 {
1872 int ret;
1873 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1874 BUG_ON(refs_to_add != 1);
1875 ret = insert_tree_block_ref(trans, root, path, bytenr,
1876 parent, root_objectid);
1877 } else {
1878 ret = insert_extent_data_ref(trans, root, path, bytenr,
1879 parent, root_objectid,
1880 owner, offset, refs_to_add);
1881 }
1882 return ret;
1883 }
1884
1885 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1886 struct btrfs_root *root,
1887 struct btrfs_path *path,
1888 struct btrfs_extent_inline_ref *iref,
1889 int refs_to_drop, int is_data)
1890 {
1891 int ret = 0;
1892
1893 BUG_ON(!is_data && refs_to_drop != 1);
1894 if (iref) {
1895 update_inline_extent_backref(root, path, iref,
1896 -refs_to_drop, NULL);
1897 } else if (is_data) {
1898 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1899 } else {
1900 ret = btrfs_del_item(trans, root, path);
1901 }
1902 return ret;
1903 }
1904
1905 static int btrfs_issue_discard(struct block_device *bdev,
1906 u64 start, u64 len)
1907 {
1908 return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
1909 }
1910
1911 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
1912 u64 num_bytes, u64 *actual_bytes)
1913 {
1914 int ret;
1915 u64 discarded_bytes = 0;
1916 struct btrfs_bio *bbio = NULL;
1917
1918
1919 /* Tell the block device(s) that the sectors can be discarded */
1920 ret = btrfs_map_block(root->fs_info, REQ_DISCARD,
1921 bytenr, &num_bytes, &bbio, 0);
1922 /* Error condition is -ENOMEM */
1923 if (!ret) {
1924 struct btrfs_bio_stripe *stripe = bbio->stripes;
1925 int i;
1926
1927
1928 for (i = 0; i < bbio->num_stripes; i++, stripe++) {
1929 if (!stripe->dev->can_discard)
1930 continue;
1931
1932 ret = btrfs_issue_discard(stripe->dev->bdev,
1933 stripe->physical,
1934 stripe->length);
1935 if (!ret)
1936 discarded_bytes += stripe->length;
1937 else if (ret != -EOPNOTSUPP)
1938 break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */
1939
1940 /*
1941 * Just in case we get back EOPNOTSUPP for some reason,
1942 * just ignore the return value so we don't screw up
1943 * people calling discard_extent.
1944 */
1945 ret = 0;
1946 }
1947 kfree(bbio);
1948 }
1949
1950 if (actual_bytes)
1951 *actual_bytes = discarded_bytes;
1952
1953
1954 if (ret == -EOPNOTSUPP)
1955 ret = 0;
1956 return ret;
1957 }
1958
1959 /* Can return -ENOMEM */
1960 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1961 struct btrfs_root *root,
1962 u64 bytenr, u64 num_bytes, u64 parent,
1963 u64 root_objectid, u64 owner, u64 offset, int for_cow)
1964 {
1965 int ret;
1966 struct btrfs_fs_info *fs_info = root->fs_info;
1967
1968 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
1969 root_objectid == BTRFS_TREE_LOG_OBJECTID);
1970
1971 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1972 ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
1973 num_bytes,
1974 parent, root_objectid, (int)owner,
1975 BTRFS_ADD_DELAYED_REF, NULL, for_cow);
1976 } else {
1977 ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
1978 num_bytes,
1979 parent, root_objectid, owner, offset,
1980 BTRFS_ADD_DELAYED_REF, NULL, for_cow);
1981 }
1982 return ret;
1983 }
1984
1985 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1986 struct btrfs_root *root,
1987 u64 bytenr, u64 num_bytes,
1988 u64 parent, u64 root_objectid,
1989 u64 owner, u64 offset, int refs_to_add,
1990 struct btrfs_delayed_extent_op *extent_op)
1991 {
1992 struct btrfs_path *path;
1993 struct extent_buffer *leaf;
1994 struct btrfs_extent_item *item;
1995 u64 refs;
1996 int ret;
1997 int err = 0;
1998
1999 path = btrfs_alloc_path();
2000 if (!path)
2001 return -ENOMEM;
2002
2003 path->reada = 1;
2004 path->leave_spinning = 1;
2005 /* this will setup the path even if it fails to insert the back ref */
2006 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
2007 path, bytenr, num_bytes, parent,
2008 root_objectid, owner, offset,
2009 refs_to_add, extent_op);
2010 if (ret == 0)
2011 goto out;
2012
2013 if (ret != -EAGAIN) {
2014 err = ret;
2015 goto out;
2016 }
2017
2018 leaf = path->nodes[0];
2019 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2020 refs = btrfs_extent_refs(leaf, item);
2021 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
2022 if (extent_op)
2023 __run_delayed_extent_op(extent_op, leaf, item);
2024
2025 btrfs_mark_buffer_dirty(leaf);
2026 btrfs_release_path(path);
2027
2028 path->reada = 1;
2029 path->leave_spinning = 1;
2030
2031 /* now insert the actual backref */
2032 ret = insert_extent_backref(trans, root->fs_info->extent_root,
2033 path, bytenr, parent, root_objectid,
2034 owner, offset, refs_to_add);
2035 if (ret)
2036 btrfs_abort_transaction(trans, root, ret);
2037 out:
2038 btrfs_free_path(path);
2039 return err;
2040 }
2041
2042 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
2043 struct btrfs_root *root,
2044 struct btrfs_delayed_ref_node *node,
2045 struct btrfs_delayed_extent_op *extent_op,
2046 int insert_reserved)
2047 {
2048 int ret = 0;
2049 struct btrfs_delayed_data_ref *ref;
2050 struct btrfs_key ins;
2051 u64 parent = 0;
2052 u64 ref_root = 0;
2053 u64 flags = 0;
2054
2055 ins.objectid = node->bytenr;
2056 ins.offset = node->num_bytes;
2057 ins.type = BTRFS_EXTENT_ITEM_KEY;
2058
2059 ref = btrfs_delayed_node_to_data_ref(node);
2060 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
2061 parent = ref->parent;
2062 else
2063 ref_root = ref->root;
2064
2065 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2066 if (extent_op)
2067 flags |= extent_op->flags_to_set;
2068 ret = alloc_reserved_file_extent(trans, root,
2069 parent, ref_root, flags,
2070 ref->objectid, ref->offset,
2071 &ins, node->ref_mod);
2072 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2073 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
2074 node->num_bytes, parent,
2075 ref_root, ref->objectid,
2076 ref->offset, node->ref_mod,
2077 extent_op);
2078 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2079 ret = __btrfs_free_extent(trans, root, node->bytenr,
2080 node->num_bytes, parent,
2081 ref_root, ref->objectid,
2082 ref->offset, node->ref_mod,
2083 extent_op);
2084 } else {
2085 BUG();
2086 }
2087 return ret;
2088 }
2089
2090 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
2091 struct extent_buffer *leaf,
2092 struct btrfs_extent_item *ei)
2093 {
2094 u64 flags = btrfs_extent_flags(leaf, ei);
2095 if (extent_op->update_flags) {
2096 flags |= extent_op->flags_to_set;
2097 btrfs_set_extent_flags(leaf, ei, flags);
2098 }
2099
2100 if (extent_op->update_key) {
2101 struct btrfs_tree_block_info *bi;
2102 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
2103 bi = (struct btrfs_tree_block_info *)(ei + 1);
2104 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
2105 }
2106 }
2107
2108 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
2109 struct btrfs_root *root,
2110 struct btrfs_delayed_ref_node *node,
2111 struct btrfs_delayed_extent_op *extent_op)
2112 {
2113 struct btrfs_key key;
2114 struct btrfs_path *path;
2115 struct btrfs_extent_item *ei;
2116 struct extent_buffer *leaf;
2117 u32 item_size;
2118 int ret;
2119 int err = 0;
2120 int metadata = (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
2121 node->type == BTRFS_SHARED_BLOCK_REF_KEY);
2122
2123 if (trans->aborted)
2124 return 0;
2125
2126 if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA))
2127 metadata = 0;
2128
2129 path = btrfs_alloc_path();
2130 if (!path)
2131 return -ENOMEM;
2132
2133 key.objectid = node->bytenr;
2134
2135 if (metadata) {
2136 struct btrfs_delayed_tree_ref *tree_ref;
2137
2138 tree_ref = btrfs_delayed_node_to_tree_ref(node);
2139 key.type = BTRFS_METADATA_ITEM_KEY;
2140 key.offset = tree_ref->level;
2141 } else {
2142 key.type = BTRFS_EXTENT_ITEM_KEY;
2143 key.offset = node->num_bytes;
2144 }
2145
2146 again:
2147 path->reada = 1;
2148 path->leave_spinning = 1;
2149 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
2150 path, 0, 1);
2151 if (ret < 0) {
2152 err = ret;
2153 goto out;
2154 }
2155 if (ret > 0) {
2156 if (metadata) {
2157 btrfs_release_path(path);
2158 metadata = 0;
2159
2160 key.offset = node->num_bytes;
2161 key.type = BTRFS_EXTENT_ITEM_KEY;
2162 goto again;
2163 }
2164 err = -EIO;
2165 goto out;
2166 }
2167
2168 leaf = path->nodes[0];
2169 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2170 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2171 if (item_size < sizeof(*ei)) {
2172 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
2173 path, (u64)-1, 0);
2174 if (ret < 0) {
2175 err = ret;
2176 goto out;
2177 }
2178 leaf = path->nodes[0];
2179 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2180 }
2181 #endif
2182 BUG_ON(item_size < sizeof(*ei));
2183 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2184 __run_delayed_extent_op(extent_op, leaf, ei);
2185
2186 btrfs_mark_buffer_dirty(leaf);
2187 out:
2188 btrfs_free_path(path);
2189 return err;
2190 }
2191
2192 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
2193 struct btrfs_root *root,
2194 struct btrfs_delayed_ref_node *node,
2195 struct btrfs_delayed_extent_op *extent_op,
2196 int insert_reserved)
2197 {
2198 int ret = 0;
2199 struct btrfs_delayed_tree_ref *ref;
2200 struct btrfs_key ins;
2201 u64 parent = 0;
2202 u64 ref_root = 0;
2203 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
2204 SKINNY_METADATA);
2205
2206 ref = btrfs_delayed_node_to_tree_ref(node);
2207 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2208 parent = ref->parent;
2209 else
2210 ref_root = ref->root;
2211
2212 ins.objectid = node->bytenr;
2213 if (skinny_metadata) {
2214 ins.offset = ref->level;
2215 ins.type = BTRFS_METADATA_ITEM_KEY;
2216 } else {
2217 ins.offset = node->num_bytes;
2218 ins.type = BTRFS_EXTENT_ITEM_KEY;
2219 }
2220
2221 BUG_ON(node->ref_mod != 1);
2222 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2223 BUG_ON(!extent_op || !extent_op->update_flags);
2224 ret = alloc_reserved_tree_block(trans, root,
2225 parent, ref_root,
2226 extent_op->flags_to_set,
2227 &extent_op->key,
2228 ref->level, &ins);
2229 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2230 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
2231 node->num_bytes, parent, ref_root,
2232 ref->level, 0, 1, extent_op);
2233 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2234 ret = __btrfs_free_extent(trans, root, node->bytenr,
2235 node->num_bytes, parent, ref_root,
2236 ref->level, 0, 1, extent_op);
2237 } else {
2238 BUG();
2239 }
2240 return ret;
2241 }
2242
2243 /* helper function to actually process a single delayed ref entry */
2244 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
2245 struct btrfs_root *root,
2246 struct btrfs_delayed_ref_node *node,
2247 struct btrfs_delayed_extent_op *extent_op,
2248 int insert_reserved)
2249 {
2250 int ret = 0;
2251
2252 if (trans->aborted)
2253 return 0;
2254
2255 if (btrfs_delayed_ref_is_head(node)) {
2256 struct btrfs_delayed_ref_head *head;
2257 /*
2258 * we've hit the end of the chain and we were supposed
2259 * to insert this extent into the tree. But, it got
2260 * deleted before we ever needed to insert it, so all
2261 * we have to do is clean up the accounting
2262 */
2263 BUG_ON(extent_op);
2264 head = btrfs_delayed_node_to_head(node);
2265 if (insert_reserved) {
2266 btrfs_pin_extent(root, node->bytenr,
2267 node->num_bytes, 1);
2268 if (head->is_data) {
2269 ret = btrfs_del_csums(trans, root,
2270 node->bytenr,
2271 node->num_bytes);
2272 }
2273 }
2274 return ret;
2275 }
2276
2277 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
2278 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2279 ret = run_delayed_tree_ref(trans, root, node, extent_op,
2280 insert_reserved);
2281 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
2282 node->type == BTRFS_SHARED_DATA_REF_KEY)
2283 ret = run_delayed_data_ref(trans, root, node, extent_op,
2284 insert_reserved);
2285 else
2286 BUG();
2287 return ret;
2288 }
2289
2290 static noinline struct btrfs_delayed_ref_node *
2291 select_delayed_ref(struct btrfs_delayed_ref_head *head)
2292 {
2293 struct rb_node *node;
2294 struct btrfs_delayed_ref_node *ref;
2295 int action = BTRFS_ADD_DELAYED_REF;
2296 again:
2297 /*
2298 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
2299 * this prevents ref count from going down to zero when
2300 * there still are pending delayed ref.
2301 */
2302 node = rb_prev(&head->node.rb_node);
2303 while (1) {
2304 if (!node)
2305 break;
2306 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2307 rb_node);
2308 if (ref->bytenr != head->node.bytenr)
2309 break;
2310 if (ref->action == action)
2311 return ref;
2312 node = rb_prev(node);
2313 }
2314 if (action == BTRFS_ADD_DELAYED_REF) {
2315 action = BTRFS_DROP_DELAYED_REF;
2316 goto again;
2317 }
2318 return NULL;
2319 }
2320
2321 /*
2322 * Returns 0 on success or if called with an already aborted transaction.
2323 * Returns -ENOMEM or -EIO on failure and will abort the transaction.
2324 */
2325 static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
2326 struct btrfs_root *root,
2327 struct list_head *cluster)
2328 {
2329 struct btrfs_delayed_ref_root *delayed_refs;
2330 struct btrfs_delayed_ref_node *ref;
2331 struct btrfs_delayed_ref_head *locked_ref = NULL;
2332 struct btrfs_delayed_extent_op *extent_op;
2333 struct btrfs_fs_info *fs_info = root->fs_info;
2334 int ret;
2335 int count = 0;
2336 int must_insert_reserved = 0;
2337
2338 delayed_refs = &trans->transaction->delayed_refs;
2339 while (1) {
2340 if (!locked_ref) {
2341 /* pick a new head ref from the cluster list */
2342 if (list_empty(cluster))
2343 break;
2344
2345 locked_ref = list_entry(cluster->next,
2346 struct btrfs_delayed_ref_head, cluster);
2347
2348 /* grab the lock that says we are going to process
2349 * all the refs for this head */
2350 ret = btrfs_delayed_ref_lock(trans, locked_ref);
2351
2352 /*
2353 * we may have dropped the spin lock to get the head
2354 * mutex lock, and that might have given someone else
2355 * time to free the head. If that's true, it has been
2356 * removed from our list and we can move on.
2357 */
2358 if (ret == -EAGAIN) {
2359 locked_ref = NULL;
2360 count++;
2361 continue;
2362 }
2363 }
2364
2365 /*
2366 * We need to try and merge add/drops of the same ref since we
2367 * can run into issues with relocate dropping the implicit ref
2368 * and then it being added back again before the drop can
2369 * finish. If we merged anything we need to re-loop so we can
2370 * get a good ref.
2371 */
2372 btrfs_merge_delayed_refs(trans, fs_info, delayed_refs,
2373 locked_ref);
2374
2375 /*
2376 * locked_ref is the head node, so we have to go one
2377 * node back for any delayed ref updates
2378 */
2379 ref = select_delayed_ref(locked_ref);
2380
2381 if (ref && ref->seq &&
2382 btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) {
2383 /*
2384 * there are still refs with lower seq numbers in the
2385 * process of being added. Don't run this ref yet.
2386 */
2387 list_del_init(&locked_ref->cluster);
2388 btrfs_delayed_ref_unlock(locked_ref);
2389 locked_ref = NULL;
2390 delayed_refs->num_heads_ready++;
2391 spin_unlock(&delayed_refs->lock);
2392 cond_resched();
2393 spin_lock(&delayed_refs->lock);
2394 continue;
2395 }
2396
2397 /*
2398 * record the must insert reserved flag before we
2399 * drop the spin lock.
2400 */
2401 must_insert_reserved = locked_ref->must_insert_reserved;
2402 locked_ref->must_insert_reserved = 0;
2403
2404 extent_op = locked_ref->extent_op;
2405 locked_ref->extent_op = NULL;
2406
2407 if (!ref) {
2408 /* All delayed refs have been processed, Go ahead
2409 * and send the head node to run_one_delayed_ref,
2410 * so that any accounting fixes can happen
2411 */
2412 ref = &locked_ref->node;
2413
2414 if (extent_op && must_insert_reserved) {
2415 btrfs_free_delayed_extent_op(extent_op);
2416 extent_op = NULL;
2417 }
2418
2419 if (extent_op) {
2420 spin_unlock(&delayed_refs->lock);
2421
2422 ret = run_delayed_extent_op(trans, root,
2423 ref, extent_op);
2424 btrfs_free_delayed_extent_op(extent_op);
2425
2426 if (ret) {
2427 btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret);
2428 spin_lock(&delayed_refs->lock);
2429 btrfs_delayed_ref_unlock(locked_ref);
2430 return ret;
2431 }
2432
2433 goto next;
2434 }
2435 }
2436
2437 ref->in_tree = 0;
2438 rb_erase(&ref->rb_node, &delayed_refs->root);
2439 delayed_refs->num_entries--;
2440 if (!btrfs_delayed_ref_is_head(ref)) {
2441 /*
2442 * when we play the delayed ref, also correct the
2443 * ref_mod on head
2444 */
2445 switch (ref->action) {
2446 case BTRFS_ADD_DELAYED_REF:
2447 case BTRFS_ADD_DELAYED_EXTENT:
2448 locked_ref->node.ref_mod -= ref->ref_mod;
2449 break;
2450 case BTRFS_DROP_DELAYED_REF:
2451 locked_ref->node.ref_mod += ref->ref_mod;
2452 break;
2453 default:
2454 WARN_ON(1);
2455 }
2456 }
2457 spin_unlock(&delayed_refs->lock);
2458
2459 ret = run_one_delayed_ref(trans, root, ref, extent_op,
2460 must_insert_reserved);
2461
2462 btrfs_free_delayed_extent_op(extent_op);
2463 if (ret) {
2464 btrfs_delayed_ref_unlock(locked_ref);
2465 btrfs_put_delayed_ref(ref);
2466 btrfs_debug(fs_info, "run_one_delayed_ref returned %d", ret);
2467 spin_lock(&delayed_refs->lock);
2468 return ret;
2469 }
2470
2471 /*
2472 * If this node is a head, that means all the refs in this head
2473 * have been dealt with, and we will pick the next head to deal
2474 * with, so we must unlock the head and drop it from the cluster
2475 * list before we release it.
2476 */
2477 if (btrfs_delayed_ref_is_head(ref)) {
2478 list_del_init(&locked_ref->cluster);
2479 btrfs_delayed_ref_unlock(locked_ref);
2480 locked_ref = NULL;
2481 }
2482 btrfs_put_delayed_ref(ref);
2483 count++;
2484 next:
2485 cond_resched();
2486 spin_lock(&delayed_refs->lock);
2487 }
2488 return count;
2489 }
2490
2491 #ifdef SCRAMBLE_DELAYED_REFS
2492 /*
2493 * Normally delayed refs get processed in ascending bytenr order. This
2494 * correlates in most cases to the order added. To expose dependencies on this
2495 * order, we start to process the tree in the middle instead of the beginning
2496 */
2497 static u64 find_middle(struct rb_root *root)
2498 {
2499 struct rb_node *n = root->rb_node;
2500 struct btrfs_delayed_ref_node *entry;
2501 int alt = 1;
2502 u64 middle;
2503 u64 first = 0, last = 0;
2504
2505 n = rb_first(root);
2506 if (n) {
2507 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2508 first = entry->bytenr;
2509 }
2510 n = rb_last(root);
2511 if (n) {
2512 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2513 last = entry->bytenr;
2514 }
2515 n = root->rb_node;
2516
2517 while (n) {
2518 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2519 WARN_ON(!entry->in_tree);
2520
2521 middle = entry->bytenr;
2522
2523 if (alt)
2524 n = n->rb_left;
2525 else
2526 n = n->rb_right;
2527
2528 alt = 1 - alt;
2529 }
2530 return middle;
2531 }
2532 #endif
2533
2534 int btrfs_delayed_refs_qgroup_accounting(struct btrfs_trans_handle *trans,
2535 struct btrfs_fs_info *fs_info)
2536 {
2537 struct qgroup_update *qgroup_update;
2538 int ret = 0;
2539
2540 if (list_empty(&trans->qgroup_ref_list) !=
2541 !trans->delayed_ref_elem.seq) {
2542 /* list without seq or seq without list */
2543 btrfs_err(fs_info,
2544 "qgroup accounting update error, list is%s empty, seq is %#x.%x",
2545 list_empty(&trans->qgroup_ref_list) ? "" : " not",
2546 (u32)(trans->delayed_ref_elem.seq >> 32),
2547 (u32)trans->delayed_ref_elem.seq);
2548 BUG();
2549 }
2550
2551 if (!trans->delayed_ref_elem.seq)
2552 return 0;
2553
2554 while (!list_empty(&trans->qgroup_ref_list)) {
2555 qgroup_update = list_first_entry(&trans->qgroup_ref_list,
2556 struct qgroup_update, list);
2557 list_del(&qgroup_update->list);
2558 if (!ret)
2559 ret = btrfs_qgroup_account_ref(
2560 trans, fs_info, qgroup_update->node,
2561 qgroup_update->extent_op);
2562 kfree(qgroup_update);
2563 }
2564
2565 btrfs_put_tree_mod_seq(fs_info, &trans->delayed_ref_elem);
2566
2567 return ret;
2568 }
2569
2570 static int refs_newer(struct btrfs_delayed_ref_root *delayed_refs, int seq,
2571 int count)
2572 {
2573 int val = atomic_read(&delayed_refs->ref_seq);
2574
2575 if (val < seq || val >= seq + count)
2576 return 1;
2577 return 0;
2578 }
2579
2580 /*
2581 * this starts processing the delayed reference count updates and
2582 * extent insertions we have queued up so far. count can be
2583 * 0, which means to process everything in the tree at the start
2584 * of the run (but not newly added entries), or it can be some target
2585 * number you'd like to process.
2586 *
2587 * Returns 0 on success or if called with an aborted transaction
2588 * Returns <0 on error and aborts the transaction
2589 */
2590 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2591 struct btrfs_root *root, unsigned long count)
2592 {
2593 struct rb_node *node;
2594 struct btrfs_delayed_ref_root *delayed_refs;
2595 struct btrfs_delayed_ref_node *ref;
2596 struct list_head cluster;
2597 int ret;
2598 u64 delayed_start;
2599 int run_all = count == (unsigned long)-1;
2600 int run_most = 0;
2601 int loops;
2602
2603 /* We'll clean this up in btrfs_cleanup_transaction */
2604 if (trans->aborted)
2605 return 0;
2606
2607 if (root == root->fs_info->extent_root)
2608 root = root->fs_info->tree_root;
2609
2610 btrfs_delayed_refs_qgroup_accounting(trans, root->fs_info);
2611
2612 delayed_refs = &trans->transaction->delayed_refs;
2613 INIT_LIST_HEAD(&cluster);
2614 if (count == 0) {
2615 count = delayed_refs->num_entries * 2;
2616 run_most = 1;
2617 }
2618
2619 if (!run_all && !run_most) {
2620 int old;
2621 int seq = atomic_read(&delayed_refs->ref_seq);
2622
2623 progress:
2624 old = atomic_cmpxchg(&delayed_refs->procs_running_refs, 0, 1);
2625 if (old) {
2626 DEFINE_WAIT(__wait);
2627 if (delayed_refs->num_entries < 16348)
2628 return 0;
2629
2630 prepare_to_wait(&delayed_refs->wait, &__wait,
2631 TASK_UNINTERRUPTIBLE);
2632
2633 old = atomic_cmpxchg(&delayed_refs->procs_running_refs, 0, 1);
2634 if (old) {
2635 schedule();
2636 finish_wait(&delayed_refs->wait, &__wait);
2637
2638 if (!refs_newer(delayed_refs, seq, 256))
2639 goto progress;
2640 else
2641 return 0;
2642 } else {
2643 finish_wait(&delayed_refs->wait, &__wait);
2644 goto again;
2645 }
2646 }
2647
2648 } else {
2649 atomic_inc(&delayed_refs->procs_running_refs);
2650 }
2651
2652 again:
2653 loops = 0;
2654 spin_lock(&delayed_refs->lock);
2655
2656 #ifdef SCRAMBLE_DELAYED_REFS
2657 delayed_refs->run_delayed_start = find_middle(&delayed_refs->root);
2658 #endif
2659
2660 while (1) {
2661 if (!(run_all || run_most) &&
2662 delayed_refs->num_heads_ready < 64)
2663 break;
2664
2665 /*
2666 * go find something we can process in the rbtree. We start at
2667 * the beginning of the tree, and then build a cluster
2668 * of refs to process starting at the first one we are able to
2669 * lock
2670 */
2671 delayed_start = delayed_refs->run_delayed_start;
2672 ret = btrfs_find_ref_cluster(trans, &cluster,
2673 delayed_refs->run_delayed_start);
2674 if (ret)
2675 break;
2676
2677 ret = run_clustered_refs(trans, root, &cluster);
2678 if (ret < 0) {
2679 btrfs_release_ref_cluster(&cluster);
2680 spin_unlock(&delayed_refs->lock);
2681 btrfs_abort_transaction(trans, root, ret);
2682 atomic_dec(&delayed_refs->procs_running_refs);
2683 return ret;
2684 }
2685
2686 atomic_add(ret, &delayed_refs->ref_seq);
2687
2688 count -= min_t(unsigned long, ret, count);
2689
2690 if (count == 0)
2691 break;
2692
2693 if (delayed_start >= delayed_refs->run_delayed_start) {
2694 if (loops == 0) {
2695 /*
2696 * btrfs_find_ref_cluster looped. let's do one
2697 * more cycle. if we don't run any delayed ref
2698 * during that cycle (because we can't because
2699 * all of them are blocked), bail out.
2700 */
2701 loops = 1;
2702 } else {
2703 /*
2704 * no runnable refs left, stop trying
2705 */
2706 BUG_ON(run_all);
2707 break;
2708 }
2709 }
2710 if (ret) {
2711 /* refs were run, let's reset staleness detection */
2712 loops = 0;
2713 }
2714 }
2715
2716 if (run_all) {
2717 if (!list_empty(&trans->new_bgs)) {
2718 spin_unlock(&delayed_refs->lock);
2719 btrfs_create_pending_block_groups(trans, root);
2720 spin_lock(&delayed_refs->lock);
2721 }
2722
2723 node = rb_first(&delayed_refs->root);
2724 if (!node)
2725 goto out;
2726 count = (unsigned long)-1;
2727
2728 while (node) {
2729 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2730 rb_node);
2731 if (btrfs_delayed_ref_is_head(ref)) {
2732 struct btrfs_delayed_ref_head *head;
2733
2734 head = btrfs_delayed_node_to_head(ref);
2735 atomic_inc(&ref->refs);
2736
2737 spin_unlock(&delayed_refs->lock);
2738 /*
2739 * Mutex was contended, block until it's
2740 * released and try again
2741 */
2742 mutex_lock(&head->mutex);
2743 mutex_unlock(&head->mutex);
2744
2745 btrfs_put_delayed_ref(ref);
2746 cond_resched();
2747 goto again;
2748 }
2749 node = rb_next(node);
2750 }
2751 spin_unlock(&delayed_refs->lock);
2752 schedule_timeout(1);
2753 goto again;
2754 }
2755 out:
2756 atomic_dec(&delayed_refs->procs_running_refs);
2757 smp_mb();
2758 if (waitqueue_active(&delayed_refs->wait))
2759 wake_up(&delayed_refs->wait);
2760
2761 spin_unlock(&delayed_refs->lock);
2762 assert_qgroups_uptodate(trans);
2763 return 0;
2764 }
2765
2766 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2767 struct btrfs_root *root,
2768 u64 bytenr, u64 num_bytes, u64 flags,
2769 int is_data)
2770 {
2771 struct btrfs_delayed_extent_op *extent_op;
2772 int ret;
2773
2774 extent_op = btrfs_alloc_delayed_extent_op();
2775 if (!extent_op)
2776 return -ENOMEM;
2777
2778 extent_op->flags_to_set = flags;
2779 extent_op->update_flags = 1;
2780 extent_op->update_key = 0;
2781 extent_op->is_data = is_data ? 1 : 0;
2782
2783 ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr,
2784 num_bytes, extent_op);
2785 if (ret)
2786 btrfs_free_delayed_extent_op(extent_op);
2787 return ret;
2788 }
2789
2790 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
2791 struct btrfs_root *root,
2792 struct btrfs_path *path,
2793 u64 objectid, u64 offset, u64 bytenr)
2794 {
2795 struct btrfs_delayed_ref_head *head;
2796 struct btrfs_delayed_ref_node *ref;
2797 struct btrfs_delayed_data_ref *data_ref;
2798 struct btrfs_delayed_ref_root *delayed_refs;
2799 struct rb_node *node;
2800 int ret = 0;
2801
2802 ret = -ENOENT;
2803 delayed_refs = &trans->transaction->delayed_refs;
2804 spin_lock(&delayed_refs->lock);
2805 head = btrfs_find_delayed_ref_head(trans, bytenr);
2806 if (!head)
2807 goto out;
2808
2809 if (!mutex_trylock(&head->mutex)) {
2810 atomic_inc(&head->node.refs);
2811 spin_unlock(&delayed_refs->lock);
2812
2813 btrfs_release_path(path);
2814
2815 /*
2816 * Mutex was contended, block until it's released and let
2817 * caller try again
2818 */
2819 mutex_lock(&head->mutex);
2820 mutex_unlock(&head->mutex);
2821 btrfs_put_delayed_ref(&head->node);
2822 return -EAGAIN;
2823 }
2824
2825 node = rb_prev(&head->node.rb_node);
2826 if (!node)
2827 goto out_unlock;
2828
2829 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2830
2831 if (ref->bytenr != bytenr)
2832 goto out_unlock;
2833
2834 ret = 1;
2835 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
2836 goto out_unlock;
2837
2838 data_ref = btrfs_delayed_node_to_data_ref(ref);
2839
2840 node = rb_prev(node);
2841 if (node) {
2842 int seq = ref->seq;
2843
2844 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2845 if (ref->bytenr == bytenr && ref->seq == seq)
2846 goto out_unlock;
2847 }
2848
2849 if (data_ref->root != root->root_key.objectid ||
2850 data_ref->objectid != objectid || data_ref->offset != offset)
2851 goto out_unlock;
2852
2853 ret = 0;
2854 out_unlock:
2855 mutex_unlock(&head->mutex);
2856 out:
2857 spin_unlock(&delayed_refs->lock);
2858 return ret;
2859 }
2860
2861 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
2862 struct btrfs_root *root,
2863 struct btrfs_path *path,
2864 u64 objectid, u64 offset, u64 bytenr)
2865 {
2866 struct btrfs_root *extent_root = root->fs_info->extent_root;
2867 struct extent_buffer *leaf;
2868 struct btrfs_extent_data_ref *ref;
2869 struct btrfs_extent_inline_ref *iref;
2870 struct btrfs_extent_item *ei;
2871 struct btrfs_key key;
2872 u32 item_size;
2873 int ret;
2874
2875 key.objectid = bytenr;
2876 key.offset = (u64)-1;
2877 key.type = BTRFS_EXTENT_ITEM_KEY;
2878
2879 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2880 if (ret < 0)
2881 goto out;
2882 BUG_ON(ret == 0); /* Corruption */
2883
2884 ret = -ENOENT;
2885 if (path->slots[0] == 0)
2886 goto out;
2887
2888 path->slots[0]--;
2889 leaf = path->nodes[0];
2890 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2891
2892 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2893 goto out;
2894
2895 ret = 1;
2896 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2897 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2898 if (item_size < sizeof(*ei)) {
2899 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
2900 goto out;
2901 }
2902 #endif
2903 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2904
2905 if (item_size != sizeof(*ei) +
2906 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2907 goto out;
2908
2909 if (btrfs_extent_generation(leaf, ei) <=
2910 btrfs_root_last_snapshot(&root->root_item))
2911 goto out;
2912
2913 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2914 if (btrfs_extent_inline_ref_type(leaf, iref) !=
2915 BTRFS_EXTENT_DATA_REF_KEY)
2916 goto out;
2917
2918 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2919 if (btrfs_extent_refs(leaf, ei) !=
2920 btrfs_extent_data_ref_count(leaf, ref) ||
2921 btrfs_extent_data_ref_root(leaf, ref) !=
2922 root->root_key.objectid ||
2923 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2924 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2925 goto out;
2926
2927 ret = 0;
2928 out:
2929 return ret;
2930 }
2931
2932 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
2933 struct btrfs_root *root,
2934 u64 objectid, u64 offset, u64 bytenr)
2935 {
2936 struct btrfs_path *path;
2937 int ret;
2938 int ret2;
2939
2940 path = btrfs_alloc_path();
2941 if (!path)
2942 return -ENOENT;
2943
2944 do {
2945 ret = check_committed_ref(trans, root, path, objectid,
2946 offset, bytenr);
2947 if (ret && ret != -ENOENT)
2948 goto out;
2949
2950 ret2 = check_delayed_ref(trans, root, path, objectid,
2951 offset, bytenr);
2952 } while (ret2 == -EAGAIN);
2953
2954 if (ret2 && ret2 != -ENOENT) {
2955 ret = ret2;
2956 goto out;
2957 }
2958
2959 if (ret != -ENOENT || ret2 != -ENOENT)
2960 ret = 0;
2961 out:
2962 btrfs_free_path(path);
2963 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
2964 WARN_ON(ret > 0);
2965 return ret;
2966 }
2967
2968 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2969 struct btrfs_root *root,
2970 struct extent_buffer *buf,
2971 int full_backref, int inc, int for_cow)
2972 {
2973 u64 bytenr;
2974 u64 num_bytes;
2975 u64 parent;
2976 u64 ref_root;
2977 u32 nritems;
2978 struct btrfs_key key;
2979 struct btrfs_file_extent_item *fi;
2980 int i;
2981 int level;
2982 int ret = 0;
2983 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
2984 u64, u64, u64, u64, u64, u64, int);
2985
2986 ref_root = btrfs_header_owner(buf);
2987 nritems = btrfs_header_nritems(buf);
2988 level = btrfs_header_level(buf);
2989
2990 if (!root->ref_cows && level == 0)
2991 return 0;
2992
2993 if (inc)
2994 process_func = btrfs_inc_extent_ref;
2995 else
2996 process_func = btrfs_free_extent;
2997
2998 if (full_backref)
2999 parent = buf->start;
3000 else
3001 parent = 0;
3002
3003 for (i = 0; i < nritems; i++) {
3004 if (level == 0) {
3005 btrfs_item_key_to_cpu(buf, &key, i);
3006 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
3007 continue;
3008 fi = btrfs_item_ptr(buf, i,
3009 struct btrfs_file_extent_item);
3010 if (btrfs_file_extent_type(buf, fi) ==
3011 BTRFS_FILE_EXTENT_INLINE)
3012 continue;
3013 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
3014 if (bytenr == 0)
3015 continue;
3016
3017 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
3018 key.offset -= btrfs_file_extent_offset(buf, fi);
3019 ret = process_func(trans, root, bytenr, num_bytes,
3020 parent, ref_root, key.objectid,
3021 key.offset, for_cow);
3022 if (ret)
3023 goto fail;
3024 } else {
3025 bytenr = btrfs_node_blockptr(buf, i);
3026 num_bytes = btrfs_level_size(root, level - 1);
3027 ret = process_func(trans, root, bytenr, num_bytes,
3028 parent, ref_root, level - 1, 0,
3029 for_cow);
3030 if (ret)
3031 goto fail;
3032 }
3033 }
3034 return 0;
3035 fail:
3036 return ret;
3037 }
3038
3039 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3040 struct extent_buffer *buf, int full_backref, int for_cow)
3041 {
3042 return __btrfs_mod_ref(trans, root, buf, full_backref, 1, for_cow);
3043 }
3044
3045 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3046 struct extent_buffer *buf, int full_backref, int for_cow)
3047 {
3048 return __btrfs_mod_ref(trans, root, buf, full_backref, 0, for_cow);
3049 }
3050
3051 static int write_one_cache_group(struct btrfs_trans_handle *trans,
3052 struct btrfs_root *root,
3053 struct btrfs_path *path,
3054 struct btrfs_block_group_cache *cache)
3055 {
3056 int ret;
3057 struct btrfs_root *extent_root = root->fs_info->extent_root;
3058 unsigned long bi;
3059 struct extent_buffer *leaf;
3060
3061 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
3062 if (ret < 0)
3063 goto fail;
3064 BUG_ON(ret); /* Corruption */
3065
3066 leaf = path->nodes[0];
3067 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
3068 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
3069 btrfs_mark_buffer_dirty(leaf);
3070 btrfs_release_path(path);
3071 fail:
3072 if (ret) {
3073 btrfs_abort_transaction(trans, root, ret);
3074 return ret;
3075 }
3076 return 0;
3077
3078 }
3079
3080 static struct btrfs_block_group_cache *
3081 next_block_group(struct btrfs_root *root,
3082 struct btrfs_block_group_cache *cache)
3083 {
3084 struct rb_node *node;
3085 spin_lock(&root->fs_info->block_group_cache_lock);
3086 node = rb_next(&cache->cache_node);
3087 btrfs_put_block_group(cache);
3088 if (node) {
3089 cache = rb_entry(node, struct btrfs_block_group_cache,
3090 cache_node);
3091 btrfs_get_block_group(cache);
3092 } else
3093 cache = NULL;
3094 spin_unlock(&root->fs_info->block_group_cache_lock);
3095 return cache;
3096 }
3097
3098 static int cache_save_setup(struct btrfs_block_group_cache *block_group,
3099 struct btrfs_trans_handle *trans,
3100 struct btrfs_path *path)
3101 {
3102 struct btrfs_root *root = block_group->fs_info->tree_root;
3103 struct inode *inode = NULL;
3104 u64 alloc_hint = 0;
3105 int dcs = BTRFS_DC_ERROR;
3106 int num_pages = 0;
3107 int retries = 0;
3108 int ret = 0;
3109
3110 /*
3111 * If this block group is smaller than 100 megs don't bother caching the
3112 * block group.
3113 */
3114 if (block_group->key.offset < (100 * 1024 * 1024)) {
3115 spin_lock(&block_group->lock);
3116 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
3117 spin_unlock(&block_group->lock);
3118 return 0;
3119 }
3120
3121 again:
3122 inode = lookup_free_space_inode(root, block_group, path);
3123 if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
3124 ret = PTR_ERR(inode);
3125 btrfs_release_path(path);
3126 goto out;
3127 }
3128
3129 if (IS_ERR(inode)) {
3130 BUG_ON(retries);
3131 retries++;
3132
3133 if (block_group->ro)
3134 goto out_free;
3135
3136 ret = create_free_space_inode(root, trans, block_group, path);
3137 if (ret)
3138 goto out_free;
3139 goto again;
3140 }
3141
3142 /* We've already setup this transaction, go ahead and exit */
3143 if (block_group->cache_generation == trans->transid &&
3144 i_size_read(inode)) {
3145 dcs = BTRFS_DC_SETUP;
3146 goto out_put;
3147 }
3148
3149 /*
3150 * We want to set the generation to 0, that way if anything goes wrong
3151 * from here on out we know not to trust this cache when we load up next
3152 * time.
3153 */
3154 BTRFS_I(inode)->generation = 0;
3155 ret = btrfs_update_inode(trans, root, inode);
3156 WARN_ON(ret);
3157
3158 if (i_size_read(inode) > 0) {
3159 ret = btrfs_truncate_free_space_cache(root, trans, path,
3160 inode);
3161 if (ret)
3162 goto out_put;
3163 }
3164
3165 spin_lock(&block_group->lock);
3166 if (block_group->cached != BTRFS_CACHE_FINISHED ||
3167 !btrfs_test_opt(root, SPACE_CACHE)) {
3168 /*
3169 * don't bother trying to write stuff out _if_
3170 * a) we're not cached,
3171 * b) we're with nospace_cache mount option.
3172 */
3173 dcs = BTRFS_DC_WRITTEN;
3174 spin_unlock(&block_group->lock);
3175 goto out_put;
3176 }
3177 spin_unlock(&block_group->lock);
3178
3179 /*
3180 * Try to preallocate enough space based on how big the block group is.
3181 * Keep in mind this has to include any pinned space which could end up
3182 * taking up quite a bit since it's not folded into the other space
3183 * cache.
3184 */
3185 num_pages = (int)div64_u64(block_group->key.offset, 256 * 1024 * 1024);
3186 if (!num_pages)
3187 num_pages = 1;
3188
3189 num_pages *= 16;
3190 num_pages *= PAGE_CACHE_SIZE;
3191
3192 ret = btrfs_check_data_free_space(inode, num_pages);
3193 if (ret)
3194 goto out_put;
3195
3196 ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
3197 num_pages, num_pages,
3198 &alloc_hint);
3199 if (!ret)
3200 dcs = BTRFS_DC_SETUP;
3201 btrfs_free_reserved_data_space(inode, num_pages);
3202
3203 out_put:
3204 iput(inode);
3205 out_free:
3206 btrfs_release_path(path);
3207 out:
3208 spin_lock(&block_group->lock);
3209 if (!ret && dcs == BTRFS_DC_SETUP)
3210 block_group->cache_generation = trans->transid;
3211 block_group->disk_cache_state = dcs;
3212 spin_unlock(&block_group->lock);
3213
3214 return ret;
3215 }
3216
3217 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
3218 struct btrfs_root *root)
3219 {
3220 struct btrfs_block_group_cache *cache;
3221 int err = 0;
3222 struct btrfs_path *path;
3223 u64 last = 0;
3224
3225 path = btrfs_alloc_path();
3226 if (!path)
3227 return -ENOMEM;
3228
3229 again:
3230 while (1) {
3231 cache = btrfs_lookup_first_block_group(root->fs_info, last);
3232 while (cache) {
3233 if (cache->disk_cache_state == BTRFS_DC_CLEAR)
3234 break;
3235 cache = next_block_group(root, cache);
3236 }
3237 if (!cache) {
3238 if (last == 0)
3239 break;
3240 last = 0;
3241 continue;
3242 }
3243 err = cache_save_setup(cache, trans, path);
3244 last = cache->key.objectid + cache->key.offset;
3245 btrfs_put_block_group(cache);
3246 }
3247
3248 while (1) {
3249 if (last == 0) {
3250 err = btrfs_run_delayed_refs(trans, root,
3251 (unsigned long)-1);
3252 if (err) /* File system offline */
3253 goto out;
3254 }
3255
3256 cache = btrfs_lookup_first_block_group(root->fs_info, last);
3257 while (cache) {
3258 if (cache->disk_cache_state == BTRFS_DC_CLEAR) {
3259 btrfs_put_block_group(cache);
3260 goto again;
3261 }
3262
3263 if (cache->dirty)
3264 break;
3265 cache = next_block_group(root, cache);
3266 }
3267 if (!cache) {
3268 if (last == 0)
3269 break;
3270 last = 0;
3271 continue;
3272 }
3273
3274 if (cache->disk_cache_state == BTRFS_DC_SETUP)
3275 cache->disk_cache_state = BTRFS_DC_NEED_WRITE;
3276 cache->dirty = 0;
3277 last = cache->key.objectid + cache->key.offset;
3278
3279 err = write_one_cache_group(trans, root, path, cache);
3280 if (err) /* File system offline */
3281 goto out;
3282
3283 btrfs_put_block_group(cache);
3284 }
3285
3286 while (1) {
3287 /*
3288 * I don't think this is needed since we're just marking our
3289 * preallocated extent as written, but just in case it can't
3290 * hurt.
3291 */
3292 if (last == 0) {
3293 err = btrfs_run_delayed_refs(trans, root,
3294 (unsigned long)-1);
3295 if (err) /* File system offline */
3296 goto out;
3297 }
3298
3299 cache = btrfs_lookup_first_block_group(root->fs_info, last);
3300 while (cache) {
3301 /*
3302 * Really this shouldn't happen, but it could if we
3303 * couldn't write the entire preallocated extent and
3304 * splitting the extent resulted in a new block.
3305 */
3306 if (cache->dirty) {
3307 btrfs_put_block_group(cache);
3308 goto again;
3309 }
3310 if (cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
3311 break;
3312 cache = next_block_group(root, cache);
3313 }
3314 if (!cache) {
3315 if (last == 0)
3316 break;
3317 last = 0;
3318 continue;
3319 }
3320
3321 err = btrfs_write_out_cache(root, trans, cache, path);
3322
3323 /*
3324 * If we didn't have an error then the cache state is still
3325 * NEED_WRITE, so we can set it to WRITTEN.
3326 */
3327 if (!err && cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
3328 cache->disk_cache_state = BTRFS_DC_WRITTEN;
3329 last = cache->key.objectid + cache->key.offset;
3330 btrfs_put_block_group(cache);
3331 }
3332 out:
3333
3334 btrfs_free_path(path);
3335 return err;
3336 }
3337
3338 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
3339 {
3340 struct btrfs_block_group_cache *block_group;
3341 int readonly = 0;
3342
3343 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
3344 if (!block_group || block_group->ro)
3345 readonly = 1;
3346 if (block_group)
3347 btrfs_put_block_group(block_group);
3348 return readonly;
3349 }
3350
3351 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
3352 u64 total_bytes, u64 bytes_used,
3353 struct btrfs_space_info **space_info)
3354 {
3355 struct btrfs_space_info *found;
3356 int i;
3357 int factor;
3358
3359 if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3360 BTRFS_BLOCK_GROUP_RAID10))
3361 factor = 2;
3362 else
3363 factor = 1;
3364
3365 found = __find_space_info(info, flags);
3366 if (found) {
3367 spin_lock(&found->lock);
3368 found->total_bytes += total_bytes;
3369 found->disk_total += total_bytes * factor;
3370 found->bytes_used += bytes_used;
3371 found->disk_used += bytes_used * factor;
3372 found->full = 0;
3373 spin_unlock(&found->lock);
3374 *space_info = found;
3375 return 0;
3376 }
3377 found = kzalloc(sizeof(*found), GFP_NOFS);
3378 if (!found)
3379 return -ENOMEM;
3380
3381 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
3382 INIT_LIST_HEAD(&found->block_groups[i]);
3383 init_rwsem(&found->groups_sem);
3384 spin_lock_init(&found->lock);
3385 found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
3386 found->total_bytes = total_bytes;
3387 found->disk_total = total_bytes * factor;
3388 found->bytes_used = bytes_used;
3389 found->disk_used = bytes_used * factor;
3390 found->bytes_pinned = 0;
3391 found->bytes_reserved = 0;
3392 found->bytes_readonly = 0;
3393 found->bytes_may_use = 0;
3394 found->full = 0;
3395 found->force_alloc = CHUNK_ALLOC_NO_FORCE;
3396 found->chunk_alloc = 0;
3397 found->flush = 0;
3398 init_waitqueue_head(&found->wait);
3399 *space_info = found;
3400 list_add_rcu(&found->list, &info->space_info);
3401 if (flags & BTRFS_BLOCK_GROUP_DATA)
3402 info->data_sinfo = found;
3403 return 0;
3404 }
3405
3406 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
3407 {
3408 u64 extra_flags = chunk_to_extended(flags) &
3409 BTRFS_EXTENDED_PROFILE_MASK;
3410
3411 write_seqlock(&fs_info->profiles_lock);
3412 if (flags & BTRFS_BLOCK_GROUP_DATA)
3413 fs_info->avail_data_alloc_bits |= extra_flags;
3414 if (flags & BTRFS_BLOCK_GROUP_METADATA)
3415 fs_info->avail_metadata_alloc_bits |= extra_flags;
3416 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
3417 fs_info->avail_system_alloc_bits |= extra_flags;
3418 write_sequnlock(&fs_info->profiles_lock);
3419 }
3420
3421 /*
3422 * returns target flags in extended format or 0 if restripe for this
3423 * chunk_type is not in progress
3424 *
3425 * should be called with either volume_mutex or balance_lock held
3426 */
3427 static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
3428 {
3429 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3430 u64 target = 0;
3431
3432 if (!bctl)
3433 return 0;
3434
3435 if (flags & BTRFS_BLOCK_GROUP_DATA &&
3436 bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3437 target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
3438 } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
3439 bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3440 target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
3441 } else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
3442 bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3443 target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
3444 }
3445
3446 return target;
3447 }
3448
3449 /*
3450 * @flags: available profiles in extended format (see ctree.h)
3451 *
3452 * Returns reduced profile in chunk format. If profile changing is in
3453 * progress (either running or paused) picks the target profile (if it's
3454 * already available), otherwise falls back to plain reducing.
3455 */
3456 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
3457 {
3458 /*
3459 * we add in the count of missing devices because we want
3460 * to make sure that any RAID levels on a degraded FS
3461 * continue to be honored.
3462 */
3463 u64 num_devices = root->fs_info->fs_devices->rw_devices +
3464 root->fs_info->fs_devices->missing_devices;
3465 u64 target;
3466 u64 tmp;
3467
3468 /*
3469 * see if restripe for this chunk_type is in progress, if so
3470 * try to reduce to the target profile
3471 */
3472 spin_lock(&root->fs_info->balance_lock);
3473 target = get_restripe_target(root->fs_info, flags);
3474 if (target) {
3475 /* pick target profile only if it's already available */
3476 if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
3477 spin_unlock(&root->fs_info->balance_lock);
3478 return extended_to_chunk(target);
3479 }
3480 }
3481 spin_unlock(&root->fs_info->balance_lock);
3482
3483 /* First, mask out the RAID levels which aren't possible */
3484 if (num_devices == 1)
3485 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0 |
3486 BTRFS_BLOCK_GROUP_RAID5);
3487 if (num_devices < 3)
3488 flags &= ~BTRFS_BLOCK_GROUP_RAID6;
3489 if (num_devices < 4)
3490 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
3491
3492 tmp = flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3493 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID5 |
3494 BTRFS_BLOCK_GROUP_RAID6 | BTRFS_BLOCK_GROUP_RAID10);
3495 flags &= ~tmp;
3496
3497 if (tmp & BTRFS_BLOCK_GROUP_RAID6)
3498 tmp = BTRFS_BLOCK_GROUP_RAID6;
3499 else if (tmp & BTRFS_BLOCK_GROUP_RAID5)
3500 tmp = BTRFS_BLOCK_GROUP_RAID5;
3501 else if (tmp & BTRFS_BLOCK_GROUP_RAID10)
3502 tmp = BTRFS_BLOCK_GROUP_RAID10;
3503 else if (tmp & BTRFS_BLOCK_GROUP_RAID1)
3504 tmp = BTRFS_BLOCK_GROUP_RAID1;
3505 else if (tmp & BTRFS_BLOCK_GROUP_RAID0)
3506 tmp = BTRFS_BLOCK_GROUP_RAID0;
3507
3508 return extended_to_chunk(flags | tmp);
3509 }
3510
3511 static u64 get_alloc_profile(struct btrfs_root *root, u64 flags)
3512 {
3513 unsigned seq;
3514
3515 do {
3516 seq = read_seqbegin(&root->fs_info->profiles_lock);
3517
3518 if (flags & BTRFS_BLOCK_GROUP_DATA)
3519 flags |= root->fs_info->avail_data_alloc_bits;
3520 else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
3521 flags |= root->fs_info->avail_system_alloc_bits;
3522 else if (flags & BTRFS_BLOCK_GROUP_METADATA)
3523 flags |= root->fs_info->avail_metadata_alloc_bits;
3524 } while (read_seqretry(&root->fs_info->profiles_lock, seq));
3525
3526 return btrfs_reduce_alloc_profile(root, flags);
3527 }
3528
3529 u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
3530 {
3531 u64 flags;
3532 u64 ret;
3533
3534 if (data)
3535 flags = BTRFS_BLOCK_GROUP_DATA;
3536 else if (root == root->fs_info->chunk_root)
3537 flags = BTRFS_BLOCK_GROUP_SYSTEM;
3538 else
3539 flags = BTRFS_BLOCK_GROUP_METADATA;
3540
3541 ret = get_alloc_profile(root, flags);
3542 return ret;
3543 }
3544
3545 /*
3546 * This will check the space that the inode allocates from to make sure we have
3547 * enough space for bytes.
3548 */
3549 int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
3550 {
3551 struct btrfs_space_info *data_sinfo;
3552 struct btrfs_root *root = BTRFS_I(inode)->root;
3553 struct btrfs_fs_info *fs_info = root->fs_info;
3554 u64 used;
3555 int ret = 0, committed = 0, alloc_chunk = 1;
3556
3557 /* make sure bytes are sectorsize aligned */
3558 bytes = ALIGN(bytes, root->sectorsize);
3559
3560 if (root == root->fs_info->tree_root ||
3561 BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID) {
3562 alloc_chunk = 0;
3563 committed = 1;
3564 }
3565
3566 data_sinfo = fs_info->data_sinfo;
3567 if (!data_sinfo)
3568 goto alloc;
3569
3570 again:
3571 /* make sure we have enough space to handle the data first */
3572 spin_lock(&data_sinfo->lock);
3573 used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
3574 data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
3575 data_sinfo->bytes_may_use;
3576
3577 if (used + bytes > data_sinfo->total_bytes) {
3578 struct btrfs_trans_handle *trans;
3579
3580 /*
3581 * if we don't have enough free bytes in this space then we need
3582 * to alloc a new chunk.
3583 */
3584 if (!data_sinfo->full && alloc_chunk) {
3585 u64 alloc_target;
3586
3587 data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
3588 spin_unlock(&data_sinfo->lock);
3589 alloc:
3590 alloc_target = btrfs_get_alloc_profile(root, 1);
3591 trans = btrfs_join_transaction(root);
3592 if (IS_ERR(trans))
3593 return PTR_ERR(trans);
3594
3595 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3596 alloc_target,
3597 CHUNK_ALLOC_NO_FORCE);
3598 btrfs_end_transaction(trans, root);
3599 if (ret < 0) {
3600 if (ret != -ENOSPC)
3601 return ret;
3602 else
3603 goto commit_trans;
3604 }
3605
3606 if (!data_sinfo)
3607 data_sinfo = fs_info->data_sinfo;
3608
3609 goto again;
3610 }
3611
3612 /*
3613 * If we have less pinned bytes than we want to allocate then
3614 * don't bother committing the transaction, it won't help us.
3615 */
3616 if (data_sinfo->bytes_pinned < bytes)
3617 committed = 1;
3618 spin_unlock(&data_sinfo->lock);
3619
3620 /* commit the current transaction and try again */
3621 commit_trans:
3622 if (!committed &&
3623 !atomic_read(&root->fs_info->open_ioctl_trans)) {
3624 committed = 1;
3625 trans = btrfs_join_transaction(root);
3626 if (IS_ERR(trans))
3627 return PTR_ERR(trans);
3628 ret = btrfs_commit_transaction(trans, root);
3629 if (ret)
3630 return ret;
3631 goto again;
3632 }
3633
3634 return -ENOSPC;
3635 }
3636 data_sinfo->bytes_may_use += bytes;
3637 trace_btrfs_space_reservation(root->fs_info, "space_info",
3638 data_sinfo->flags, bytes, 1);
3639 spin_unlock(&data_sinfo->lock);
3640
3641 return 0;
3642 }
3643
3644 /*
3645 * Called if we need to clear a data reservation for this inode.
3646 */
3647 void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
3648 {
3649 struct btrfs_root *root = BTRFS_I(inode)->root;
3650 struct btrfs_space_info *data_sinfo;
3651
3652 /* make sure bytes are sectorsize aligned */
3653 bytes = ALIGN(bytes, root->sectorsize);
3654
3655 data_sinfo = root->fs_info->data_sinfo;
3656 spin_lock(&data_sinfo->lock);
3657 data_sinfo->bytes_may_use -= bytes;
3658 trace_btrfs_space_reservation(root->fs_info, "space_info",
3659 data_sinfo->flags, bytes, 0);
3660 spin_unlock(&data_sinfo->lock);
3661 }
3662
3663 static void force_metadata_allocation(struct btrfs_fs_info *info)
3664 {
3665 struct list_head *head = &info->space_info;
3666 struct btrfs_space_info *found;
3667
3668 rcu_read_lock();
3669 list_for_each_entry_rcu(found, head, list) {
3670 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
3671 found->force_alloc = CHUNK_ALLOC_FORCE;
3672 }
3673 rcu_read_unlock();
3674 }
3675
3676 static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
3677 {
3678 return (global->size << 1);
3679 }
3680
3681 static int should_alloc_chunk(struct btrfs_root *root,
3682 struct btrfs_space_info *sinfo, int force)
3683 {
3684 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
3685 u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
3686 u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
3687 u64 thresh;
3688
3689 if (force == CHUNK_ALLOC_FORCE)
3690 return 1;
3691
3692 /*
3693 * We need to take into account the global rsv because for all intents
3694 * and purposes it's used space. Don't worry about locking the
3695 * global_rsv, it doesn't change except when the transaction commits.
3696 */
3697 if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA)
3698 num_allocated += calc_global_rsv_need_space(global_rsv);
3699
3700 /*
3701 * in limited mode, we want to have some free space up to
3702 * about 1% of the FS size.
3703 */
3704 if (force == CHUNK_ALLOC_LIMITED) {
3705 thresh = btrfs_super_total_bytes(root->fs_info->super_copy);
3706 thresh = max_t(u64, 64 * 1024 * 1024,
3707 div_factor_fine(thresh, 1));
3708
3709 if (num_bytes - num_allocated < thresh)
3710 return 1;
3711 }
3712
3713 if (num_allocated + 2 * 1024 * 1024 < div_factor(num_bytes, 8))
3714 return 0;
3715 return 1;
3716 }
3717
3718 static u64 get_system_chunk_thresh(struct btrfs_root *root, u64 type)
3719 {
3720 u64 num_dev;
3721
3722 if (type & (BTRFS_BLOCK_GROUP_RAID10 |
3723 BTRFS_BLOCK_GROUP_RAID0 |
3724 BTRFS_BLOCK_GROUP_RAID5 |
3725 BTRFS_BLOCK_GROUP_RAID6))
3726 num_dev = root->fs_info->fs_devices->rw_devices;
3727 else if (type & BTRFS_BLOCK_GROUP_RAID1)
3728 num_dev = 2;
3729 else
3730 num_dev = 1; /* DUP or single */
3731
3732 /* metadata for updaing devices and chunk tree */
3733 return btrfs_calc_trans_metadata_size(root, num_dev + 1);
3734 }
3735
3736 static void check_system_chunk(struct btrfs_trans_handle *trans,
3737 struct btrfs_root *root, u64 type)
3738 {
3739 struct btrfs_space_info *info;
3740 u64 left;
3741 u64 thresh;
3742
3743 info = __find_space_info(root->fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
3744 spin_lock(&info->lock);
3745 left = info->total_bytes - info->bytes_used - info->bytes_pinned -
3746 info->bytes_reserved - info->bytes_readonly;
3747 spin_unlock(&info->lock);
3748
3749 thresh = get_system_chunk_thresh(root, type);
3750 if (left < thresh && btrfs_test_opt(root, ENOSPC_DEBUG)) {
3751 btrfs_info(root->fs_info, "left=%llu, need=%llu, flags=%llu",
3752 left, thresh, type);
3753 dump_space_info(info, 0, 0);
3754 }
3755
3756 if (left < thresh) {
3757 u64 flags;
3758
3759 flags = btrfs_get_alloc_profile(root->fs_info->chunk_root, 0);
3760 btrfs_alloc_chunk(trans, root, flags);
3761 }
3762 }
3763
3764 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
3765 struct btrfs_root *extent_root, u64 flags, int force)
3766 {
3767 struct btrfs_space_info *space_info;
3768 struct btrfs_fs_info *fs_info = extent_root->fs_info;
3769 int wait_for_alloc = 0;
3770 int ret = 0;
3771
3772 /* Don't re-enter if we're already allocating a chunk */
3773 if (trans->allocating_chunk)
3774 return -ENOSPC;
3775
3776 space_info = __find_space_info(extent_root->fs_info, flags);
3777 if (!space_info) {
3778 ret = update_space_info(extent_root->fs_info, flags,
3779 0, 0, &space_info);
3780 BUG_ON(ret); /* -ENOMEM */
3781 }
3782 BUG_ON(!space_info); /* Logic error */
3783
3784 again:
3785 spin_lock(&space_info->lock);
3786 if (force < space_info->force_alloc)
3787 force = space_info->force_alloc;
3788 if (space_info->full) {
3789 spin_unlock(&space_info->lock);
3790 return 0;
3791 }
3792
3793 if (!should_alloc_chunk(extent_root, space_info, force)) {
3794 spin_unlock(&space_info->lock);
3795 return 0;
3796 } else if (space_info->chunk_alloc) {
3797 wait_for_alloc = 1;
3798 } else {
3799 space_info->chunk_alloc = 1;
3800 }
3801
3802 spin_unlock(&space_info->lock);
3803
3804 mutex_lock(&fs_info->chunk_mutex);
3805
3806 /*
3807 * The chunk_mutex is held throughout the entirety of a chunk
3808 * allocation, so once we've acquired the chunk_mutex we know that the
3809 * other guy is done and we need to recheck and see if we should
3810 * allocate.
3811 */
3812 if (wait_for_alloc) {
3813 mutex_unlock(&fs_info->chunk_mutex);
3814 wait_for_alloc = 0;
3815 goto again;
3816 }
3817
3818 trans->allocating_chunk = true;
3819
3820 /*
3821 * If we have mixed data/metadata chunks we want to make sure we keep
3822 * allocating mixed chunks instead of individual chunks.
3823 */
3824 if (btrfs_mixed_space_info(space_info))
3825 flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
3826
3827 /*
3828 * if we're doing a data chunk, go ahead and make sure that
3829 * we keep a reasonable number of metadata chunks allocated in the
3830 * FS as well.
3831 */
3832 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
3833 fs_info->data_chunk_allocations++;
3834 if (!(fs_info->data_chunk_allocations %
3835 fs_info->metadata_ratio))
3836 force_metadata_allocation(fs_info);
3837 }
3838
3839 /*
3840 * Check if we have enough space in SYSTEM chunk because we may need
3841 * to update devices.
3842 */
3843 check_system_chunk(trans, extent_root, flags);
3844
3845 ret = btrfs_alloc_chunk(trans, extent_root, flags);
3846 trans->allocating_chunk = false;
3847
3848 spin_lock(&space_info->lock);
3849 if (ret < 0 && ret != -ENOSPC)
3850 goto out;
3851 if (ret)
3852 space_info->full = 1;
3853 else
3854 ret = 1;
3855
3856 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
3857 out:
3858 space_info->chunk_alloc = 0;
3859 spin_unlock(&space_info->lock);
3860 mutex_unlock(&fs_info->chunk_mutex);
3861 return ret;
3862 }
3863
3864 static int can_overcommit(struct btrfs_root *root,
3865 struct btrfs_space_info *space_info, u64 bytes,
3866 enum btrfs_reserve_flush_enum flush)
3867 {
3868 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
3869 u64 profile = btrfs_get_alloc_profile(root, 0);
3870 u64 space_size;
3871 u64 avail;
3872 u64 used;
3873 u64 to_add;
3874
3875 used = space_info->bytes_used + space_info->bytes_reserved +
3876 space_info->bytes_pinned + space_info->bytes_readonly;
3877
3878 /*
3879 * We only want to allow over committing if we have lots of actual space
3880 * free, but if we don't have enough space to handle the global reserve
3881 * space then we could end up having a real enospc problem when trying
3882 * to allocate a chunk or some other such important allocation.
3883 */
3884 spin_lock(&global_rsv->lock);
3885 space_size = calc_global_rsv_need_space(global_rsv);
3886 spin_unlock(&global_rsv->lock);
3887 if (used + space_size >= space_info->total_bytes)
3888 return 0;
3889
3890 used += space_info->bytes_may_use;
3891
3892 spin_lock(&root->fs_info->free_chunk_lock);
3893 avail = root->fs_info->free_chunk_space;
3894 spin_unlock(&root->fs_info->free_chunk_lock);
3895
3896 /*
3897 * If we have dup, raid1 or raid10 then only half of the free
3898 * space is actually useable. For raid56, the space info used
3899 * doesn't include the parity drive, so we don't have to
3900 * change the math
3901 */
3902 if (profile & (BTRFS_BLOCK_GROUP_DUP |
3903 BTRFS_BLOCK_GROUP_RAID1 |
3904 BTRFS_BLOCK_GROUP_RAID10))
3905 avail >>= 1;
3906
3907 to_add = space_info->total_bytes;
3908
3909 /*
3910 * If we aren't flushing all things, let us overcommit up to
3911 * 1/2th of the space. If we can flush, don't let us overcommit
3912 * too much, let it overcommit up to 1/8 of the space.
3913 */
3914 if (flush == BTRFS_RESERVE_FLUSH_ALL)
3915 to_add >>= 3;
3916 else
3917 to_add >>= 1;
3918
3919 /*
3920 * Limit the overcommit to the amount of free space we could possibly
3921 * allocate for chunks.
3922 */
3923 to_add = min(avail, to_add);
3924
3925 if (used + bytes < space_info->total_bytes + to_add)
3926 return 1;
3927 return 0;
3928 }
3929
3930 void btrfs_writeback_inodes_sb_nr(struct btrfs_root *root,
3931 unsigned long nr_pages)
3932 {
3933 struct super_block *sb = root->fs_info->sb;
3934 int started;
3935
3936 /* If we can not start writeback, just sync all the delalloc file. */
3937 started = try_to_writeback_inodes_sb_nr(sb, nr_pages,
3938 WB_REASON_FS_FREE_SPACE);
3939 if (!started) {
3940 /*
3941 * We needn't worry the filesystem going from r/w to r/o though
3942 * we don't acquire ->s_umount mutex, because the filesystem
3943 * should guarantee the delalloc inodes list be empty after
3944 * the filesystem is readonly(all dirty pages are written to
3945 * the disk).
3946 */
3947 btrfs_start_delalloc_inodes(root, 0);
3948 if (!current->journal_info)
3949 btrfs_wait_ordered_extents(root, 0);
3950 }
3951 }
3952
3953 /*
3954 * shrink metadata reservation for delalloc
3955 */
3956 static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
3957 bool wait_ordered)
3958 {
3959 struct btrfs_block_rsv *block_rsv;
3960 struct btrfs_space_info *space_info;
3961 struct btrfs_trans_handle *trans;
3962 u64 delalloc_bytes;
3963 u64 max_reclaim;
3964 long time_left;
3965 unsigned long nr_pages = (2 * 1024 * 1024) >> PAGE_CACHE_SHIFT;
3966 int loops = 0;
3967 enum btrfs_reserve_flush_enum flush;
3968
3969 trans = (struct btrfs_trans_handle *)current->journal_info;
3970 block_rsv = &root->fs_info->delalloc_block_rsv;
3971 space_info = block_rsv->space_info;
3972
3973 smp_mb();
3974 delalloc_bytes = percpu_counter_sum_positive(
3975 &root->fs_info->delalloc_bytes);
3976 if (delalloc_bytes == 0) {
3977 if (trans)
3978 return;
3979 btrfs_wait_ordered_extents(root, 0);
3980 return;
3981 }
3982
3983 while (delalloc_bytes && loops < 3) {
3984 max_reclaim = min(delalloc_bytes, to_reclaim);
3985 nr_pages = max_reclaim >> PAGE_CACHE_SHIFT;
3986 btrfs_writeback_inodes_sb_nr(root, nr_pages);
3987 /*
3988 * We need to wait for the async pages to actually start before
3989 * we do anything.
3990 */
3991 wait_event(root->fs_info->async_submit_wait,
3992 !atomic_read(&root->fs_info->async_delalloc_pages));
3993
3994 if (!trans)
3995 flush = BTRFS_RESERVE_FLUSH_ALL;
3996 else
3997 flush = BTRFS_RESERVE_NO_FLUSH;
3998 spin_lock(&space_info->lock);
3999 if (can_overcommit(root, space_info, orig, flush)) {
4000 spin_unlock(&space_info->lock);
4001 break;
4002 }
4003 spin_unlock(&space_info->lock);
4004
4005 loops++;
4006 if (wait_ordered && !trans) {
4007 btrfs_wait_ordered_extents(root, 0);
4008 } else {
4009 time_left = schedule_timeout_killable(1);
4010 if (time_left)
4011 break;
4012 }
4013 smp_mb();
4014 delalloc_bytes = percpu_counter_sum_positive(
4015 &root->fs_info->delalloc_bytes);
4016 }
4017 }
4018
4019 /**
4020 * maybe_commit_transaction - possibly commit the transaction if its ok to
4021 * @root - the root we're allocating for
4022 * @bytes - the number of bytes we want to reserve
4023 * @force - force the commit
4024 *
4025 * This will check to make sure that committing the transaction will actually
4026 * get us somewhere and then commit the transaction if it does. Otherwise it
4027 * will return -ENOSPC.
4028 */
4029 static int may_commit_transaction(struct btrfs_root *root,
4030 struct btrfs_space_info *space_info,
4031 u64 bytes, int force)
4032 {
4033 struct btrfs_block_rsv *delayed_rsv = &root->fs_info->delayed_block_rsv;
4034 struct btrfs_trans_handle *trans;
4035
4036 trans = (struct btrfs_trans_handle *)current->journal_info;
4037 if (trans)
4038 return -EAGAIN;
4039
4040 if (force)
4041 goto commit;
4042
4043 /* See if there is enough pinned space to make this reservation */
4044 spin_lock(&space_info->lock);
4045 if (space_info->bytes_pinned >= bytes) {
4046 spin_unlock(&space_info->lock);
4047 goto commit;
4048 }
4049 spin_unlock(&space_info->lock);
4050
4051 /*
4052 * See if there is some space in the delayed insertion reservation for
4053 * this reservation.
4054 */
4055 if (space_info != delayed_rsv->space_info)
4056 return -ENOSPC;
4057
4058 spin_lock(&space_info->lock);
4059 spin_lock(&delayed_rsv->lock);
4060 if (space_info->bytes_pinned + delayed_rsv->size < bytes) {
4061 spin_unlock(&delayed_rsv->lock);
4062 spin_unlock(&space_info->lock);
4063 return -ENOSPC;
4064 }
4065 spin_unlock(&delayed_rsv->lock);
4066 spin_unlock(&space_info->lock);
4067
4068 commit:
4069 trans = btrfs_join_transaction(root);
4070 if (IS_ERR(trans))
4071 return -ENOSPC;
4072
4073 return btrfs_commit_transaction(trans, root);
4074 }
4075
4076 enum flush_state {
4077 FLUSH_DELAYED_ITEMS_NR = 1,
4078 FLUSH_DELAYED_ITEMS = 2,
4079 FLUSH_DELALLOC = 3,
4080 FLUSH_DELALLOC_WAIT = 4,
4081 ALLOC_CHUNK = 5,
4082 COMMIT_TRANS = 6,
4083 };
4084
4085 static int flush_space(struct btrfs_root *root,
4086 struct btrfs_space_info *space_info, u64 num_bytes,
4087 u64 orig_bytes, int state)
4088 {
4089 struct btrfs_trans_handle *trans;
4090 int nr;
4091 int ret = 0;
4092
4093 switch (state) {
4094 case FLUSH_DELAYED_ITEMS_NR:
4095 case FLUSH_DELAYED_ITEMS:
4096 if (state == FLUSH_DELAYED_ITEMS_NR) {
4097 u64 bytes = btrfs_calc_trans_metadata_size(root, 1);
4098
4099 nr = (int)div64_u64(num_bytes, bytes);
4100 if (!nr)
4101 nr = 1;
4102 nr *= 2;
4103 } else {
4104 nr = -1;
4105 }
4106 trans = btrfs_join_transaction(root);
4107 if (IS_ERR(trans)) {
4108 ret = PTR_ERR(trans);
4109 break;
4110 }
4111 ret = btrfs_run_delayed_items_nr(trans, root, nr);
4112 btrfs_end_transaction(trans, root);
4113 break;
4114 case FLUSH_DELALLOC:
4115 case FLUSH_DELALLOC_WAIT:
4116 shrink_delalloc(root, num_bytes, orig_bytes,
4117 state == FLUSH_DELALLOC_WAIT);
4118 break;
4119 case ALLOC_CHUNK:
4120 trans = btrfs_join_transaction(root);
4121 if (IS_ERR(trans)) {
4122 ret = PTR_ERR(trans);
4123 break;
4124 }
4125 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4126 btrfs_get_alloc_profile(root, 0),
4127 CHUNK_ALLOC_NO_FORCE);
4128 btrfs_end_transaction(trans, root);
4129 if (ret == -ENOSPC)
4130 ret = 0;
4131 break;
4132 case COMMIT_TRANS:
4133 ret = may_commit_transaction(root, space_info, orig_bytes, 0);
4134 break;
4135 default:
4136 ret = -ENOSPC;
4137 break;
4138 }
4139
4140 return ret;
4141 }
4142 /**
4143 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
4144 * @root - the root we're allocating for
4145 * @block_rsv - the block_rsv we're allocating for
4146 * @orig_bytes - the number of bytes we want
4147 * @flush - whether or not we can flush to make our reservation
4148 *
4149 * This will reserve orgi_bytes number of bytes from the space info associated
4150 * with the block_rsv. If there is not enough space it will make an attempt to
4151 * flush out space to make room. It will do this by flushing delalloc if
4152 * possible or committing the transaction. If flush is 0 then no attempts to
4153 * regain reservations will be made and this will fail if there is not enough
4154 * space already.
4155 */
4156 static int reserve_metadata_bytes(struct btrfs_root *root,
4157 struct btrfs_block_rsv *block_rsv,
4158 u64 orig_bytes,
4159 enum btrfs_reserve_flush_enum flush)
4160 {
4161 struct btrfs_space_info *space_info = block_rsv->space_info;
4162 u64 used;
4163 u64 num_bytes = orig_bytes;
4164 int flush_state = FLUSH_DELAYED_ITEMS_NR;
4165 int ret = 0;
4166 bool flushing = false;
4167
4168 again:
4169 ret = 0;
4170 spin_lock(&space_info->lock);
4171 /*
4172 * We only want to wait if somebody other than us is flushing and we
4173 * are actually allowed to flush all things.
4174 */
4175 while (flush == BTRFS_RESERVE_FLUSH_ALL && !flushing &&
4176 space_info->flush) {
4177 spin_unlock(&space_info->lock);
4178 /*
4179 * If we have a trans handle we can't wait because the flusher
4180 * may have to commit the transaction, which would mean we would
4181 * deadlock since we are waiting for the flusher to finish, but
4182 * hold the current transaction open.
4183 */
4184 if (current->journal_info)
4185 return -EAGAIN;
4186 ret = wait_event_killable(space_info->wait, !space_info->flush);
4187 /* Must have been killed, return */
4188 if (ret)
4189 return -EINTR;
4190
4191 spin_lock(&space_info->lock);
4192 }
4193
4194 ret = -ENOSPC;
4195 used = space_info->bytes_used + space_info->bytes_reserved +
4196 space_info->bytes_pinned + space_info->bytes_readonly +
4197 space_info->bytes_may_use;
4198
4199 /*
4200 * The idea here is that we've not already over-reserved the block group
4201 * then we can go ahead and save our reservation first and then start
4202 * flushing if we need to. Otherwise if we've already overcommitted
4203 * lets start flushing stuff first and then come back and try to make
4204 * our reservation.
4205 */
4206 if (used <= space_info->total_bytes) {
4207 if (used + orig_bytes <= space_info->total_bytes) {
4208 space_info->bytes_may_use += orig_bytes;
4209 trace_btrfs_space_reservation(root->fs_info,
4210 "space_info", space_info->flags, orig_bytes, 1);
4211 ret = 0;
4212 } else {
4213 /*
4214 * Ok set num_bytes to orig_bytes since we aren't
4215 * overocmmitted, this way we only try and reclaim what
4216 * we need.
4217 */
4218 num_bytes = orig_bytes;
4219 }
4220 } else {
4221 /*
4222 * Ok we're over committed, set num_bytes to the overcommitted
4223 * amount plus the amount of bytes that we need for this
4224 * reservation.
4225 */
4226 num_bytes = used - space_info->total_bytes +
4227 (orig_bytes * 2);
4228 }
4229
4230 if (ret && can_overcommit(root, space_info, orig_bytes, flush)) {
4231 space_info->bytes_may_use += orig_bytes;
4232 trace_btrfs_space_reservation(root->fs_info, "space_info",
4233 space_info->flags, orig_bytes,
4234 1);
4235 ret = 0;
4236 }
4237
4238 /*
4239 * Couldn't make our reservation, save our place so while we're trying
4240 * to reclaim space we can actually use it instead of somebody else
4241 * stealing it from us.
4242 *
4243 * We make the other tasks wait for the flush only when we can flush
4244 * all things.
4245 */
4246 if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
4247 flushing = true;
4248 space_info->flush = 1;
4249 }
4250
4251 spin_unlock(&space_info->lock);
4252
4253 if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
4254 goto out;
4255
4256 ret = flush_space(root, space_info, num_bytes, orig_bytes,
4257 flush_state);
4258 flush_state++;
4259
4260 /*
4261 * If we are FLUSH_LIMIT, we can not flush delalloc, or the deadlock
4262 * would happen. So skip delalloc flush.
4263 */
4264 if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
4265 (flush_state == FLUSH_DELALLOC ||
4266 flush_state == FLUSH_DELALLOC_WAIT))
4267 flush_state = ALLOC_CHUNK;
4268
4269 if (!ret)
4270 goto again;
4271 else if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
4272 flush_state < COMMIT_TRANS)
4273 goto again;
4274 else if (flush == BTRFS_RESERVE_FLUSH_ALL &&
4275 flush_state <= COMMIT_TRANS)
4276 goto again;
4277
4278 out:
4279 if (ret == -ENOSPC &&
4280 unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
4281 struct btrfs_block_rsv *global_rsv =
4282 &root->fs_info->global_block_rsv;
4283
4284 if (block_rsv != global_rsv &&
4285 !block_rsv_use_bytes(global_rsv, orig_bytes))
4286 ret = 0;
4287 }
4288 if (flushing) {
4289 spin_lock(&space_info->lock);
4290 space_info->flush = 0;
4291 wake_up_all(&space_info->wait);
4292 spin_unlock(&space_info->lock);
4293 }
4294 return ret;
4295 }
4296
4297 static struct btrfs_block_rsv *get_block_rsv(
4298 const struct btrfs_trans_handle *trans,
4299 const struct btrfs_root *root)
4300 {
4301 struct btrfs_block_rsv *block_rsv = NULL;
4302
4303 if (root->ref_cows)
4304 block_rsv = trans->block_rsv;
4305
4306 if (root == root->fs_info->csum_root && trans->adding_csums)
4307 block_rsv = trans->block_rsv;
4308
4309 if (!block_rsv)
4310 block_rsv = root->block_rsv;
4311
4312 if (!block_rsv)
4313 block_rsv = &root->fs_info->empty_block_rsv;
4314
4315 return block_rsv;
4316 }
4317
4318 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
4319 u64 num_bytes)
4320 {
4321 int ret = -ENOSPC;
4322 spin_lock(&block_rsv->lock);
4323 if (block_rsv->reserved >= num_bytes) {
4324 block_rsv->reserved -= num_bytes;
4325 if (block_rsv->reserved < block_rsv->size)
4326 block_rsv->full = 0;
4327 ret = 0;
4328 }
4329 spin_unlock(&block_rsv->lock);
4330 return ret;
4331 }
4332
4333 static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
4334 u64 num_bytes, int update_size)
4335 {
4336 spin_lock(&block_rsv->lock);
4337 block_rsv->reserved += num_bytes;
4338 if (update_size)
4339 block_rsv->size += num_bytes;
4340 else if (block_rsv->reserved >= block_rsv->size)
4341 block_rsv->full = 1;
4342 spin_unlock(&block_rsv->lock);
4343 }
4344
4345 static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
4346 struct btrfs_block_rsv *block_rsv,
4347 struct btrfs_block_rsv *dest, u64 num_bytes)
4348 {
4349 struct btrfs_space_info *space_info = block_rsv->space_info;
4350
4351 spin_lock(&block_rsv->lock);
4352 if (num_bytes == (u64)-1)
4353 num_bytes = block_rsv->size;
4354 block_rsv->size -= num_bytes;
4355 if (block_rsv->reserved >= block_rsv->size) {
4356 num_bytes = block_rsv->reserved - block_rsv->size;
4357 block_rsv->reserved = block_rsv->size;
4358 block_rsv->full = 1;
4359 } else {
4360 num_bytes = 0;
4361 }
4362 spin_unlock(&block_rsv->lock);
4363
4364 if (num_bytes > 0) {
4365 if (dest) {
4366 spin_lock(&dest->lock);
4367 if (!dest->full) {
4368 u64 bytes_to_add;
4369
4370 bytes_to_add = dest->size - dest->reserved;
4371 bytes_to_add = min(num_bytes, bytes_to_add);
4372 dest->reserved += bytes_to_add;
4373 if (dest->reserved >= dest->size)
4374 dest->full = 1;
4375 num_bytes -= bytes_to_add;
4376 }
4377 spin_unlock(&dest->lock);
4378 }
4379 if (num_bytes) {
4380 spin_lock(&space_info->lock);
4381 space_info->bytes_may_use -= num_bytes;
4382 trace_btrfs_space_reservation(fs_info, "space_info",
4383 space_info->flags, num_bytes, 0);
4384 space_info->reservation_progress++;
4385 spin_unlock(&space_info->lock);
4386 }
4387 }
4388 }
4389
4390 static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
4391 struct btrfs_block_rsv *dst, u64 num_bytes)
4392 {
4393 int ret;
4394
4395 ret = block_rsv_use_bytes(src, num_bytes);
4396 if (ret)
4397 return ret;
4398
4399 block_rsv_add_bytes(dst, num_bytes, 1);
4400 return 0;
4401 }
4402
4403 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
4404 {
4405 memset(rsv, 0, sizeof(*rsv));
4406 spin_lock_init(&rsv->lock);
4407 rsv->type = type;
4408 }
4409
4410 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root,
4411 unsigned short type)
4412 {
4413 struct btrfs_block_rsv *block_rsv;
4414 struct btrfs_fs_info *fs_info = root->fs_info;
4415
4416 block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
4417 if (!block_rsv)
4418 return NULL;
4419
4420 btrfs_init_block_rsv(block_rsv, type);
4421 block_rsv->space_info = __find_space_info(fs_info,
4422 BTRFS_BLOCK_GROUP_METADATA);
4423 return block_rsv;
4424 }
4425
4426 void btrfs_free_block_rsv(struct btrfs_root *root,
4427 struct btrfs_block_rsv *rsv)
4428 {
4429 if (!rsv)
4430 return;
4431 btrfs_block_rsv_release(root, rsv, (u64)-1);
4432 kfree(rsv);
4433 }
4434
4435 int btrfs_block_rsv_add(struct btrfs_root *root,
4436 struct btrfs_block_rsv *block_rsv, u64 num_bytes,
4437 enum btrfs_reserve_flush_enum flush)
4438 {
4439 int ret;
4440
4441 if (num_bytes == 0)
4442 return 0;
4443
4444 ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
4445 if (!ret) {
4446 block_rsv_add_bytes(block_rsv, num_bytes, 1);
4447 return 0;
4448 }
4449
4450 return ret;
4451 }
4452
4453 int btrfs_block_rsv_check(struct btrfs_root *root,
4454 struct btrfs_block_rsv *block_rsv, int min_factor)
4455 {
4456 u64 num_bytes = 0;
4457 int ret = -ENOSPC;
4458
4459 if (!block_rsv)
4460 return 0;
4461
4462 spin_lock(&block_rsv->lock);
4463 num_bytes = div_factor(block_rsv->size, min_factor);
4464 if (block_rsv->reserved >= num_bytes)
4465 ret = 0;
4466 spin_unlock(&block_rsv->lock);
4467
4468 return ret;
4469 }
4470
4471 int btrfs_block_rsv_refill(struct btrfs_root *root,
4472 struct btrfs_block_rsv *block_rsv, u64 min_reserved,
4473 enum btrfs_reserve_flush_enum flush)
4474 {
4475 u64 num_bytes = 0;
4476 int ret = -ENOSPC;
4477
4478 if (!block_rsv)
4479 return 0;
4480
4481 spin_lock(&block_rsv->lock);
4482 num_bytes = min_reserved;
4483 if (block_rsv->reserved >= num_bytes)
4484 ret = 0;
4485 else
4486 num_bytes -= block_rsv->reserved;
4487 spin_unlock(&block_rsv->lock);
4488
4489 if (!ret)
4490 return 0;
4491
4492 ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
4493 if (!ret) {
4494 block_rsv_add_bytes(block_rsv, num_bytes, 0);
4495 return 0;
4496 }
4497
4498 return ret;
4499 }
4500
4501 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
4502 struct btrfs_block_rsv *dst_rsv,
4503 u64 num_bytes)
4504 {
4505 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
4506 }
4507
4508 void btrfs_block_rsv_release(struct btrfs_root *root,
4509 struct btrfs_block_rsv *block_rsv,
4510 u64 num_bytes)
4511 {
4512 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
4513 if (global_rsv->full || global_rsv == block_rsv ||
4514 block_rsv->space_info != global_rsv->space_info)
4515 global_rsv = NULL;
4516 block_rsv_release_bytes(root->fs_info, block_rsv, global_rsv,
4517 num_bytes);
4518 }
4519
4520 /*
4521 * helper to calculate size of global block reservation.
4522 * the desired value is sum of space used by extent tree,
4523 * checksum tree and root tree
4524 */
4525 static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
4526 {
4527 struct btrfs_space_info *sinfo;
4528 u64 num_bytes;
4529 u64 meta_used;
4530 u64 data_used;
4531 int csum_size = btrfs_super_csum_size(fs_info->super_copy);
4532
4533 sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
4534 spin_lock(&sinfo->lock);
4535 data_used = sinfo->bytes_used;
4536 spin_unlock(&sinfo->lock);
4537
4538 sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
4539 spin_lock(&sinfo->lock);
4540 if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
4541 data_used = 0;
4542 meta_used = sinfo->bytes_used;
4543 spin_unlock(&sinfo->lock);
4544
4545 num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
4546 csum_size * 2;
4547 num_bytes += div64_u64(data_used + meta_used, 50);
4548
4549 if (num_bytes * 3 > meta_used)
4550 num_bytes = div64_u64(meta_used, 3);
4551
4552 return ALIGN(num_bytes, fs_info->extent_root->leafsize << 10);
4553 }
4554
4555 static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
4556 {
4557 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4558 struct btrfs_space_info *sinfo = block_rsv->space_info;
4559 u64 num_bytes;
4560
4561 num_bytes = calc_global_metadata_size(fs_info);
4562
4563 spin_lock(&sinfo->lock);
4564 spin_lock(&block_rsv->lock);
4565
4566 block_rsv->size = min_t(u64, num_bytes, 512 * 1024 * 1024);
4567
4568 num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
4569 sinfo->bytes_reserved + sinfo->bytes_readonly +
4570 sinfo->bytes_may_use;
4571
4572 if (sinfo->total_bytes > num_bytes) {
4573 num_bytes = sinfo->total_bytes - num_bytes;
4574 block_rsv->reserved += num_bytes;
4575 sinfo->bytes_may_use += num_bytes;
4576 trace_btrfs_space_reservation(fs_info, "space_info",
4577 sinfo->flags, num_bytes, 1);
4578 }
4579
4580 if (block_rsv->reserved >= block_rsv->size) {
4581 num_bytes = block_rsv->reserved - block_rsv->size;
4582 sinfo->bytes_may_use -= num_bytes;
4583 trace_btrfs_space_reservation(fs_info, "space_info",
4584 sinfo->flags, num_bytes, 0);
4585 sinfo->reservation_progress++;
4586 block_rsv->reserved = block_rsv->size;
4587 block_rsv->full = 1;
4588 }
4589
4590 spin_unlock(&block_rsv->lock);
4591 spin_unlock(&sinfo->lock);
4592 }
4593
4594 static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
4595 {
4596 struct btrfs_space_info *space_info;
4597
4598 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
4599 fs_info->chunk_block_rsv.space_info = space_info;
4600
4601 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
4602 fs_info->global_block_rsv.space_info = space_info;
4603 fs_info->delalloc_block_rsv.space_info = space_info;
4604 fs_info->trans_block_rsv.space_info = space_info;
4605 fs_info->empty_block_rsv.space_info = space_info;
4606 fs_info->delayed_block_rsv.space_info = space_info;
4607
4608 fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
4609 fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
4610 fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
4611 fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
4612 fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
4613
4614 update_global_block_rsv(fs_info);
4615 }
4616
4617 static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
4618 {
4619 block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL,
4620 (u64)-1);
4621 WARN_ON(fs_info->delalloc_block_rsv.size > 0);
4622 WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
4623 WARN_ON(fs_info->trans_block_rsv.size > 0);
4624 WARN_ON(fs_info->trans_block_rsv.reserved > 0);
4625 WARN_ON(fs_info->chunk_block_rsv.size > 0);
4626 WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
4627 WARN_ON(fs_info->delayed_block_rsv.size > 0);
4628 WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
4629 }
4630
4631 void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
4632 struct btrfs_root *root)
4633 {
4634 if (!trans->block_rsv)
4635 return;
4636
4637 if (!trans->bytes_reserved)
4638 return;
4639
4640 trace_btrfs_space_reservation(root->fs_info, "transaction",
4641 trans->transid, trans->bytes_reserved, 0);
4642 btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved);
4643 trans->bytes_reserved = 0;
4644 }
4645
4646 /* Can only return 0 or -ENOSPC */
4647 int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
4648 struct inode *inode)
4649 {
4650 struct btrfs_root *root = BTRFS_I(inode)->root;
4651 struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
4652 struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
4653
4654 /*
4655 * We need to hold space in order to delete our orphan item once we've
4656 * added it, so this takes the reservation so we can release it later
4657 * when we are truly done with the orphan item.
4658 */
4659 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
4660 trace_btrfs_space_reservation(root->fs_info, "orphan",
4661 btrfs_ino(inode), num_bytes, 1);
4662 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
4663 }
4664
4665 void btrfs_orphan_release_metadata(struct inode *inode)
4666 {
4667 struct btrfs_root *root = BTRFS_I(inode)->root;
4668 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
4669 trace_btrfs_space_reservation(root->fs_info, "orphan",
4670 btrfs_ino(inode), num_bytes, 0);
4671 btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
4672 }
4673
4674 /*
4675 * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
4676 * root: the root of the parent directory
4677 * rsv: block reservation
4678 * items: the number of items that we need do reservation
4679 * qgroup_reserved: used to return the reserved size in qgroup
4680 *
4681 * This function is used to reserve the space for snapshot/subvolume
4682 * creation and deletion. Those operations are different with the
4683 * common file/directory operations, they change two fs/file trees
4684 * and root tree, the number of items that the qgroup reserves is
4685 * different with the free space reservation. So we can not use
4686 * the space reseravtion mechanism in start_transaction().
4687 */
4688 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
4689 struct btrfs_block_rsv *rsv,
4690 int items,
4691 u64 *qgroup_reserved)
4692 {
4693 u64 num_bytes;
4694 int ret;
4695
4696 if (root->fs_info->quota_enabled) {
4697 /* One for parent inode, two for dir entries */
4698 num_bytes = 3 * root->leafsize;
4699 ret = btrfs_qgroup_reserve(root, num_bytes);
4700 if (ret)
4701 return ret;
4702 } else {
4703 num_bytes = 0;
4704 }
4705
4706 *qgroup_reserved = num_bytes;
4707
4708 num_bytes = btrfs_calc_trans_metadata_size(root, items);
4709 rsv->space_info = __find_space_info(root->fs_info,
4710 BTRFS_BLOCK_GROUP_METADATA);
4711 ret = btrfs_block_rsv_add(root, rsv, num_bytes,
4712 BTRFS_RESERVE_FLUSH_ALL);
4713 if (ret) {
4714 if (*qgroup_reserved)
4715 btrfs_qgroup_free(root, *qgroup_reserved);
4716 }
4717
4718 return ret;
4719 }
4720
4721 void btrfs_subvolume_release_metadata(struct btrfs_root *root,
4722 struct btrfs_block_rsv *rsv,
4723 u64 qgroup_reserved)
4724 {
4725 btrfs_block_rsv_release(root, rsv, (u64)-1);
4726 if (qgroup_reserved)
4727 btrfs_qgroup_free(root, qgroup_reserved);
4728 }
4729
4730 /**
4731 * drop_outstanding_extent - drop an outstanding extent
4732 * @inode: the inode we're dropping the extent for
4733 *
4734 * This is called when we are freeing up an outstanding extent, either called
4735 * after an error or after an extent is written. This will return the number of
4736 * reserved extents that need to be freed. This must be called with
4737 * BTRFS_I(inode)->lock held.
4738 */
4739 static unsigned drop_outstanding_extent(struct inode *inode)
4740 {
4741 unsigned drop_inode_space = 0;
4742 unsigned dropped_extents = 0;
4743
4744 BUG_ON(!BTRFS_I(inode)->outstanding_extents);
4745 BTRFS_I(inode)->outstanding_extents--;
4746
4747 if (BTRFS_I(inode)->outstanding_extents == 0 &&
4748 test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
4749 &BTRFS_I(inode)->runtime_flags))
4750 drop_inode_space = 1;
4751
4752 /*
4753 * If we have more or the same amount of outsanding extents than we have
4754 * reserved then we need to leave the reserved extents count alone.
4755 */
4756 if (BTRFS_I(inode)->outstanding_extents >=
4757 BTRFS_I(inode)->reserved_extents)
4758 return drop_inode_space;
4759
4760 dropped_extents = BTRFS_I(inode)->reserved_extents -
4761 BTRFS_I(inode)->outstanding_extents;
4762 BTRFS_I(inode)->reserved_extents -= dropped_extents;
4763 return dropped_extents + drop_inode_space;
4764 }
4765
4766 /**
4767 * calc_csum_metadata_size - return the amount of metada space that must be
4768 * reserved/free'd for the given bytes.
4769 * @inode: the inode we're manipulating
4770 * @num_bytes: the number of bytes in question
4771 * @reserve: 1 if we are reserving space, 0 if we are freeing space
4772 *
4773 * This adjusts the number of csum_bytes in the inode and then returns the
4774 * correct amount of metadata that must either be reserved or freed. We
4775 * calculate how many checksums we can fit into one leaf and then divide the
4776 * number of bytes that will need to be checksumed by this value to figure out
4777 * how many checksums will be required. If we are adding bytes then the number
4778 * may go up and we will return the number of additional bytes that must be
4779 * reserved. If it is going down we will return the number of bytes that must
4780 * be freed.
4781 *
4782 * This must be called with BTRFS_I(inode)->lock held.
4783 */
4784 static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes,
4785 int reserve)
4786 {
4787 struct btrfs_root *root = BTRFS_I(inode)->root;
4788 u64 csum_size;
4789 int num_csums_per_leaf;
4790 int num_csums;
4791 int old_csums;
4792
4793 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM &&
4794 BTRFS_I(inode)->csum_bytes == 0)
4795 return 0;
4796
4797 old_csums = (int)div64_u64(BTRFS_I(inode)->csum_bytes, root->sectorsize);
4798 if (reserve)
4799 BTRFS_I(inode)->csum_bytes += num_bytes;
4800 else
4801 BTRFS_I(inode)->csum_bytes -= num_bytes;
4802 csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item);
4803 num_csums_per_leaf = (int)div64_u64(csum_size,
4804 sizeof(struct btrfs_csum_item) +
4805 sizeof(struct btrfs_disk_key));
4806 num_csums = (int)div64_u64(BTRFS_I(inode)->csum_bytes, root->sectorsize);
4807 num_csums = num_csums + num_csums_per_leaf - 1;
4808 num_csums = num_csums / num_csums_per_leaf;
4809
4810 old_csums = old_csums + num_csums_per_leaf - 1;
4811 old_csums = old_csums / num_csums_per_leaf;
4812
4813 /* No change, no need to reserve more */
4814 if (old_csums == num_csums)
4815 return 0;
4816
4817 if (reserve)
4818 return btrfs_calc_trans_metadata_size(root,
4819 num_csums - old_csums);
4820
4821 return btrfs_calc_trans_metadata_size(root, old_csums - num_csums);
4822 }
4823
4824 int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
4825 {
4826 struct btrfs_root *root = BTRFS_I(inode)->root;
4827 struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
4828 u64 to_reserve = 0;
4829 u64 csum_bytes;
4830 unsigned nr_extents = 0;
4831 int extra_reserve = 0;
4832 enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL;
4833 int ret = 0;
4834 bool delalloc_lock = true;
4835 u64 to_free = 0;
4836 unsigned dropped;
4837
4838 /* If we are a free space inode we need to not flush since we will be in
4839 * the middle of a transaction commit. We also don't need the delalloc
4840 * mutex since we won't race with anybody. We need this mostly to make
4841 * lockdep shut its filthy mouth.
4842 */
4843 if (btrfs_is_free_space_inode(inode)) {
4844 flush = BTRFS_RESERVE_NO_FLUSH;
4845 delalloc_lock = false;
4846 }
4847
4848 if (flush != BTRFS_RESERVE_NO_FLUSH &&
4849 btrfs_transaction_in_commit(root->fs_info))
4850 schedule_timeout(1);
4851
4852 if (delalloc_lock)
4853 mutex_lock(&BTRFS_I(inode)->delalloc_mutex);
4854
4855 num_bytes = ALIGN(num_bytes, root->sectorsize);
4856
4857 spin_lock(&BTRFS_I(inode)->lock);
4858 BTRFS_I(inode)->outstanding_extents++;
4859
4860 if (BTRFS_I(inode)->outstanding_extents >
4861 BTRFS_I(inode)->reserved_extents)
4862 nr_extents = BTRFS_I(inode)->outstanding_extents -
4863 BTRFS_I(inode)->reserved_extents;
4864
4865 /*
4866 * Add an item to reserve for updating the inode when we complete the
4867 * delalloc io.
4868 */
4869 if (!test_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
4870 &BTRFS_I(inode)->runtime_flags)) {
4871 nr_extents++;
4872 extra_reserve = 1;
4873 }
4874
4875 to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
4876 to_reserve += calc_csum_metadata_size(inode, num_bytes, 1);
4877 csum_bytes = BTRFS_I(inode)->csum_bytes;
4878 spin_unlock(&BTRFS_I(inode)->lock);
4879
4880 if (root->fs_info->quota_enabled) {
4881 ret = btrfs_qgroup_reserve(root, num_bytes +
4882 nr_extents * root->leafsize);
4883 if (ret)
4884 goto out_fail;
4885 }
4886
4887 ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush);
4888 if (unlikely(ret)) {
4889 if (root->fs_info->quota_enabled)
4890 btrfs_qgroup_free(root, num_bytes +
4891 nr_extents * root->leafsize);
4892 goto out_fail;
4893 }
4894
4895 spin_lock(&BTRFS_I(inode)->lock);
4896 if (extra_reserve) {
4897 set_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
4898 &BTRFS_I(inode)->runtime_flags);
4899 nr_extents--;
4900 }
4901 BTRFS_I(inode)->reserved_extents += nr_extents;
4902 spin_unlock(&BTRFS_I(inode)->lock);
4903
4904 if (delalloc_lock)
4905 mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
4906
4907 if (to_reserve)
4908 trace_btrfs_space_reservation(root->fs_info,"delalloc",
4909 btrfs_ino(inode), to_reserve, 1);
4910 block_rsv_add_bytes(block_rsv, to_reserve, 1);
4911
4912 return 0;
4913
4914 out_fail:
4915 spin_lock(&BTRFS_I(inode)->lock);
4916 dropped = drop_outstanding_extent(inode);
4917 /*
4918 * If the inodes csum_bytes is the same as the original
4919 * csum_bytes then we know we haven't raced with any free()ers
4920 * so we can just reduce our inodes csum bytes and carry on.
4921 */
4922 if (BTRFS_I(inode)->csum_bytes == csum_bytes) {
4923 calc_csum_metadata_size(inode, num_bytes, 0);
4924 } else {
4925 u64 orig_csum_bytes = BTRFS_I(inode)->csum_bytes;
4926 u64 bytes;
4927
4928 /*
4929 * This is tricky, but first we need to figure out how much we
4930 * free'd from any free-ers that occured during this
4931 * reservation, so we reset ->csum_bytes to the csum_bytes
4932 * before we dropped our lock, and then call the free for the
4933 * number of bytes that were freed while we were trying our
4934 * reservation.
4935 */
4936 bytes = csum_bytes - BTRFS_I(inode)->csum_bytes;
4937 BTRFS_I(inode)->csum_bytes = csum_bytes;
4938 to_free = calc_csum_metadata_size(inode, bytes, 0);
4939
4940
4941 /*
4942 * Now we need to see how much we would have freed had we not
4943 * been making this reservation and our ->csum_bytes were not
4944 * artificially inflated.
4945 */
4946 BTRFS_I(inode)->csum_bytes = csum_bytes - num_bytes;
4947 bytes = csum_bytes - orig_csum_bytes;
4948 bytes = calc_csum_metadata_size(inode, bytes, 0);
4949
4950 /*
4951 * Now reset ->csum_bytes to what it should be. If bytes is
4952 * more than to_free then we would have free'd more space had we
4953 * not had an artificially high ->csum_bytes, so we need to free
4954 * the remainder. If bytes is the same or less then we don't
4955 * need to do anything, the other free-ers did the correct
4956 * thing.
4957 */
4958 BTRFS_I(inode)->csum_bytes = orig_csum_bytes - num_bytes;
4959 if (bytes > to_free)
4960 to_free = bytes - to_free;
4961 else
4962 to_free = 0;
4963 }
4964 spin_unlock(&BTRFS_I(inode)->lock);
4965 if (dropped)
4966 to_free += btrfs_calc_trans_metadata_size(root, dropped);
4967
4968 if (to_free) {
4969 btrfs_block_rsv_release(root, block_rsv, to_free);
4970 trace_btrfs_space_reservation(root->fs_info, "delalloc",
4971 btrfs_ino(inode), to_free, 0);
4972 }
4973 if (delalloc_lock)
4974 mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
4975 return ret;
4976 }
4977
4978 /**
4979 * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
4980 * @inode: the inode to release the reservation for
4981 * @num_bytes: the number of bytes we're releasing
4982 *
4983 * This will release the metadata reservation for an inode. This can be called
4984 * once we complete IO for a given set of bytes to release their metadata
4985 * reservations.
4986 */
4987 void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
4988 {
4989 struct btrfs_root *root = BTRFS_I(inode)->root;
4990 u64 to_free = 0;
4991 unsigned dropped;
4992
4993 num_bytes = ALIGN(num_bytes, root->sectorsize);
4994 spin_lock(&BTRFS_I(inode)->lock);
4995 dropped = drop_outstanding_extent(inode);
4996
4997 if (num_bytes)
4998 to_free = calc_csum_metadata_size(inode, num_bytes, 0);
4999 spin_unlock(&BTRFS_I(inode)->lock);
5000 if (dropped > 0)
5001 to_free += btrfs_calc_trans_metadata_size(root, dropped);
5002
5003 trace_btrfs_space_reservation(root->fs_info, "delalloc",
5004 btrfs_ino(inode), to_free, 0);
5005 if (root->fs_info->quota_enabled) {
5006 btrfs_qgroup_free(root, num_bytes +
5007 dropped * root->leafsize);
5008 }
5009
5010 btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
5011 to_free);
5012 }
5013
5014 /**
5015 * btrfs_delalloc_reserve_space - reserve data and metadata space for delalloc
5016 * @inode: inode we're writing to
5017 * @num_bytes: the number of bytes we want to allocate
5018 *
5019 * This will do the following things
5020 *
5021 * o reserve space in the data space info for num_bytes
5022 * o reserve space in the metadata space info based on number of outstanding
5023 * extents and how much csums will be needed
5024 * o add to the inodes ->delalloc_bytes
5025 * o add it to the fs_info's delalloc inodes list.
5026 *
5027 * This will return 0 for success and -ENOSPC if there is no space left.
5028 */
5029 int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
5030 {
5031 int ret;
5032
5033 ret = btrfs_check_data_free_space(inode, num_bytes);
5034 if (ret)
5035 return ret;
5036
5037 ret = btrfs_delalloc_reserve_metadata(inode, num_bytes);
5038 if (ret) {
5039 btrfs_free_reserved_data_space(inode, num_bytes);
5040 return ret;
5041 }
5042
5043 return 0;
5044 }
5045
5046 /**
5047 * btrfs_delalloc_release_space - release data and metadata space for delalloc
5048 * @inode: inode we're releasing space for
5049 * @num_bytes: the number of bytes we want to free up
5050 *
5051 * This must be matched with a call to btrfs_delalloc_reserve_space. This is
5052 * called in the case that we don't need the metadata AND data reservations
5053 * anymore. So if there is an error or we insert an inline extent.
5054 *
5055 * This function will release the metadata space that was not used and will
5056 * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
5057 * list if there are no delalloc bytes left.
5058 */
5059 void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
5060 {
5061 btrfs_delalloc_release_metadata(inode, num_bytes);
5062 btrfs_free_reserved_data_space(inode, num_bytes);
5063 }
5064
5065 static int update_block_group(struct btrfs_root *root,
5066 u64 bytenr, u64 num_bytes, int alloc)
5067 {
5068 struct btrfs_block_group_cache *cache = NULL;
5069 struct btrfs_fs_info *info = root->fs_info;
5070 u64 total = num_bytes;
5071 u64 old_val;
5072 u64 byte_in_group;
5073 int factor;
5074
5075 /* block accounting for super block */
5076 spin_lock(&info->delalloc_lock);
5077 old_val = btrfs_super_bytes_used(info->super_copy);
5078 if (alloc)
5079 old_val += num_bytes;
5080 else
5081 old_val -= num_bytes;
5082 btrfs_set_super_bytes_used(info->super_copy, old_val);
5083 spin_unlock(&info->delalloc_lock);
5084
5085 while (total) {
5086 cache = btrfs_lookup_block_group(info, bytenr);
5087 if (!cache)
5088 return -ENOENT;
5089 if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
5090 BTRFS_BLOCK_GROUP_RAID1 |
5091 BTRFS_BLOCK_GROUP_RAID10))
5092 factor = 2;
5093 else
5094 factor = 1;
5095 /*
5096 * If this block group has free space cache written out, we
5097 * need to make sure to load it if we are removing space. This
5098 * is because we need the unpinning stage to actually add the
5099 * space back to the block group, otherwise we will leak space.
5100 */
5101 if (!alloc && cache->cached == BTRFS_CACHE_NO)
5102 cache_block_group(cache, 1);
5103
5104 byte_in_group = bytenr - cache->key.objectid;
5105 WARN_ON(byte_in_group > cache->key.offset);
5106
5107 spin_lock(&cache->space_info->lock);
5108 spin_lock(&cache->lock);
5109
5110 if (btrfs_test_opt(root, SPACE_CACHE) &&
5111 cache->disk_cache_state < BTRFS_DC_CLEAR)
5112 cache->disk_cache_state = BTRFS_DC_CLEAR;
5113
5114 cache->dirty = 1;
5115 old_val = btrfs_block_group_used(&cache->item);
5116 num_bytes = min(total, cache->key.offset - byte_in_group);
5117 if (alloc) {
5118 old_val += num_bytes;
5119 btrfs_set_block_group_used(&cache->item, old_val);
5120 cache->reserved -= num_bytes;
5121 cache->space_info->bytes_reserved -= num_bytes;
5122 cache->space_info->bytes_used += num_bytes;
5123 cache->space_info->disk_used += num_bytes * factor;
5124 spin_unlock(&cache->lock);
5125 spin_unlock(&cache->space_info->lock);
5126 } else {
5127 old_val -= num_bytes;
5128 btrfs_set_block_group_used(&cache->item, old_val);
5129 cache->pinned += num_bytes;
5130 cache->space_info->bytes_pinned += num_bytes;
5131 cache->space_info->bytes_used -= num_bytes;
5132 cache->space_info->disk_used -= num_bytes * factor;
5133 spin_unlock(&cache->lock);
5134 spin_unlock(&cache->space_info->lock);
5135
5136 set_extent_dirty(info->pinned_extents,
5137 bytenr, bytenr + num_bytes - 1,
5138 GFP_NOFS | __GFP_NOFAIL);
5139 }
5140 btrfs_put_block_group(cache);
5141 total -= num_bytes;
5142 bytenr += num_bytes;
5143 }
5144 return 0;
5145 }
5146
5147 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
5148 {
5149 struct btrfs_block_group_cache *cache;
5150 u64 bytenr;
5151
5152 spin_lock(&root->fs_info->block_group_cache_lock);
5153 bytenr = root->fs_info->first_logical_byte;
5154 spin_unlock(&root->fs_info->block_group_cache_lock);
5155
5156 if (bytenr < (u64)-1)
5157 return bytenr;
5158
5159 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
5160 if (!cache)
5161 return 0;
5162
5163 bytenr = cache->key.objectid;
5164 btrfs_put_block_group(cache);
5165
5166 return bytenr;
5167 }
5168
5169 static int pin_down_extent(struct btrfs_root *root,
5170 struct btrfs_block_group_cache *cache,
5171 u64 bytenr, u64 num_bytes, int reserved)
5172 {
5173 spin_lock(&cache->space_info->lock);
5174 spin_lock(&cache->lock);
5175 cache->pinned += num_bytes;
5176 cache->space_info->bytes_pinned += num_bytes;
5177 if (reserved) {
5178 cache->reserved -= num_bytes;
5179 cache->space_info->bytes_reserved -= num_bytes;
5180 }
5181 spin_unlock(&cache->lock);
5182 spin_unlock(&cache->space_info->lock);
5183
5184 set_extent_dirty(root->fs_info->pinned_extents, bytenr,
5185 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
5186 return 0;
5187 }
5188
5189 /*
5190 * this function must be called within transaction
5191 */
5192 int btrfs_pin_extent(struct btrfs_root *root,
5193 u64 bytenr, u64 num_bytes, int reserved)
5194 {
5195 struct btrfs_block_group_cache *cache;
5196
5197 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
5198 BUG_ON(!cache); /* Logic error */
5199
5200 pin_down_extent(root, cache, bytenr, num_bytes, reserved);
5201
5202 btrfs_put_block_group(cache);
5203 return 0;
5204 }
5205
5206 /*
5207 * this function must be called within transaction
5208 */
5209 int btrfs_pin_extent_for_log_replay(struct btrfs_root *root,
5210 u64 bytenr, u64 num_bytes)
5211 {
5212 struct btrfs_block_group_cache *cache;
5213
5214 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
5215 BUG_ON(!cache); /* Logic error */
5216
5217 /*
5218 * pull in the free space cache (if any) so that our pin
5219 * removes the free space from the cache. We have load_only set
5220 * to one because the slow code to read in the free extents does check
5221 * the pinned extents.
5222 */
5223 cache_block_group(cache, 1);
5224
5225 pin_down_extent(root, cache, bytenr, num_bytes, 0);
5226
5227 /* remove us from the free space cache (if we're there at all) */
5228 btrfs_remove_free_space(cache, bytenr, num_bytes);
5229 btrfs_put_block_group(cache);
5230 return 0;
5231 }
5232
5233 /**
5234 * btrfs_update_reserved_bytes - update the block_group and space info counters
5235 * @cache: The cache we are manipulating
5236 * @num_bytes: The number of bytes in question
5237 * @reserve: One of the reservation enums
5238 *
5239 * This is called by the allocator when it reserves space, or by somebody who is
5240 * freeing space that was never actually used on disk. For example if you
5241 * reserve some space for a new leaf in transaction A and before transaction A
5242 * commits you free that leaf, you call this with reserve set to 0 in order to
5243 * clear the reservation.
5244 *
5245 * Metadata reservations should be called with RESERVE_ALLOC so we do the proper
5246 * ENOSPC accounting. For data we handle the reservation through clearing the
5247 * delalloc bits in the io_tree. We have to do this since we could end up
5248 * allocating less disk space for the amount of data we have reserved in the
5249 * case of compression.
5250 *
5251 * If this is a reservation and the block group has become read only we cannot
5252 * make the reservation and return -EAGAIN, otherwise this function always
5253 * succeeds.
5254 */
5255 static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
5256 u64 num_bytes, int reserve)
5257 {
5258 struct btrfs_space_info *space_info = cache->space_info;
5259 int ret = 0;
5260
5261 spin_lock(&space_info->lock);
5262 spin_lock(&cache->lock);
5263 if (reserve != RESERVE_FREE) {
5264 if (cache->ro) {
5265 ret = -EAGAIN;
5266 } else {
5267 cache->reserved += num_bytes;
5268 space_info->bytes_reserved += num_bytes;
5269 if (reserve == RESERVE_ALLOC) {
5270 trace_btrfs_space_reservation(cache->fs_info,
5271 "space_info", space_info->flags,
5272 num_bytes, 0);
5273 space_info->bytes_may_use -= num_bytes;
5274 }
5275 }
5276 } else {
5277 if (cache->ro)
5278 space_info->bytes_readonly += num_bytes;
5279 cache->reserved -= num_bytes;
5280 space_info->bytes_reserved -= num_bytes;
5281 space_info->reservation_progress++;
5282 }
5283 spin_unlock(&cache->lock);
5284 spin_unlock(&space_info->lock);
5285 return ret;
5286 }
5287
5288 void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
5289 struct btrfs_root *root)
5290 {
5291 struct btrfs_fs_info *fs_info = root->fs_info;
5292 struct btrfs_caching_control *next;
5293 struct btrfs_caching_control *caching_ctl;
5294 struct btrfs_block_group_cache *cache;
5295
5296 down_write(&fs_info->extent_commit_sem);
5297
5298 list_for_each_entry_safe(caching_ctl, next,
5299 &fs_info->caching_block_groups, list) {
5300 cache = caching_ctl->block_group;
5301 if (block_group_cache_done(cache)) {
5302 cache->last_byte_to_unpin = (u64)-1;
5303 list_del_init(&caching_ctl->list);
5304 put_caching_control(caching_ctl);
5305 } else {
5306 cache->last_byte_to_unpin = caching_ctl->progress;
5307 }
5308 }
5309
5310 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
5311 fs_info->pinned_extents = &fs_info->freed_extents[1];
5312 else
5313 fs_info->pinned_extents = &fs_info->freed_extents[0];
5314
5315 up_write(&fs_info->extent_commit_sem);
5316
5317 update_global_block_rsv(fs_info);
5318 }
5319
5320 static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
5321 {
5322 struct btrfs_fs_info *fs_info = root->fs_info;
5323 struct btrfs_block_group_cache *cache = NULL;
5324 struct btrfs_space_info *space_info;
5325 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5326 u64 len;
5327 bool readonly;
5328
5329 while (start <= end) {
5330 readonly = false;
5331 if (!cache ||
5332 start >= cache->key.objectid + cache->key.offset) {
5333 if (cache)
5334 btrfs_put_block_group(cache);
5335 cache = btrfs_lookup_block_group(fs_info, start);
5336 BUG_ON(!cache); /* Logic error */
5337 }
5338
5339 len = cache->key.objectid + cache->key.offset - start;
5340 len = min(len, end + 1 - start);
5341
5342 if (start < cache->last_byte_to_unpin) {
5343 len = min(len, cache->last_byte_to_unpin - start);
5344 btrfs_add_free_space(cache, start, len);
5345 }
5346
5347 start += len;
5348 space_info = cache->space_info;
5349
5350 spin_lock(&space_info->lock);
5351 spin_lock(&cache->lock);
5352 cache->pinned -= len;
5353 space_info->bytes_pinned -= len;
5354 if (cache->ro) {
5355 space_info->bytes_readonly += len;
5356 readonly = true;
5357 }
5358 spin_unlock(&cache->lock);
5359 if (!readonly && global_rsv->space_info == space_info) {
5360 spin_lock(&global_rsv->lock);
5361 if (!global_rsv->full) {
5362 len = min(len, global_rsv->size -
5363 global_rsv->reserved);
5364 global_rsv->reserved += len;
5365 space_info->bytes_may_use += len;
5366 if (global_rsv->reserved >= global_rsv->size)
5367 global_rsv->full = 1;
5368 }
5369 spin_unlock(&global_rsv->lock);
5370 }
5371 spin_unlock(&space_info->lock);
5372 }
5373
5374 if (cache)
5375 btrfs_put_block_group(cache);
5376 return 0;
5377 }
5378
5379 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
5380 struct btrfs_root *root)
5381 {
5382 struct btrfs_fs_info *fs_info = root->fs_info;
5383 struct extent_io_tree *unpin;
5384 u64 start;
5385 u64 end;
5386 int ret;
5387
5388 if (trans->aborted)
5389 return 0;
5390
5391 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
5392 unpin = &fs_info->freed_extents[1];
5393 else
5394 unpin = &fs_info->freed_extents[0];
5395
5396 while (1) {
5397 ret = find_first_extent_bit(unpin, 0, &start, &end,
5398 EXTENT_DIRTY, NULL);
5399 if (ret)
5400 break;
5401
5402 if (btrfs_test_opt(root, DISCARD))
5403 ret = btrfs_discard_extent(root, start,
5404 end + 1 - start, NULL);
5405
5406 clear_extent_dirty(unpin, start, end, GFP_NOFS);
5407 unpin_extent_range(root, start, end);
5408 cond_resched();
5409 }
5410
5411 return 0;
5412 }
5413
5414 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
5415 struct btrfs_root *root,
5416 u64 bytenr, u64 num_bytes, u64 parent,
5417 u64 root_objectid, u64 owner_objectid,
5418 u64 owner_offset, int refs_to_drop,
5419 struct btrfs_delayed_extent_op *extent_op)
5420 {
5421 struct btrfs_key key;
5422 struct btrfs_path *path;
5423 struct btrfs_fs_info *info = root->fs_info;
5424 struct btrfs_root *extent_root = info->extent_root;
5425 struct extent_buffer *leaf;
5426 struct btrfs_extent_item *ei;
5427 struct btrfs_extent_inline_ref *iref;
5428 int ret;
5429 int is_data;
5430 int extent_slot = 0;
5431 int found_extent = 0;
5432 int num_to_del = 1;
5433 u32 item_size;
5434 u64 refs;
5435 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
5436 SKINNY_METADATA);
5437
5438 path = btrfs_alloc_path();
5439 if (!path)
5440 return -ENOMEM;
5441
5442 path->reada = 1;
5443 path->leave_spinning = 1;
5444
5445 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
5446 BUG_ON(!is_data && refs_to_drop != 1);
5447
5448 if (is_data)
5449 skinny_metadata = 0;
5450
5451 ret = lookup_extent_backref(trans, extent_root, path, &iref,
5452 bytenr, num_bytes, parent,
5453 root_objectid, owner_objectid,
5454 owner_offset);
5455 if (ret == 0) {
5456 extent_slot = path->slots[0];
5457 while (extent_slot >= 0) {
5458 btrfs_item_key_to_cpu(path->nodes[0], &key,
5459 extent_slot);
5460 if (key.objectid != bytenr)
5461 break;
5462 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
5463 key.offset == num_bytes) {
5464 found_extent = 1;
5465 break;
5466 }
5467 if (key.type == BTRFS_METADATA_ITEM_KEY &&
5468 key.offset == owner_objectid) {
5469 found_extent = 1;
5470 break;
5471 }
5472 if (path->slots[0] - extent_slot > 5)
5473 break;
5474 extent_slot--;
5475 }
5476 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
5477 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
5478 if (found_extent && item_size < sizeof(*ei))
5479 found_extent = 0;
5480 #endif
5481 if (!found_extent) {
5482 BUG_ON(iref);
5483 ret = remove_extent_backref(trans, extent_root, path,
5484 NULL, refs_to_drop,
5485 is_data);
5486 if (ret) {
5487 btrfs_abort_transaction(trans, extent_root, ret);
5488 goto out;
5489 }
5490 btrfs_release_path(path);
5491 path->leave_spinning = 1;
5492
5493 key.objectid = bytenr;
5494 key.type = BTRFS_EXTENT_ITEM_KEY;
5495 key.offset = num_bytes;
5496
5497 if (!is_data && skinny_metadata) {
5498 key.type = BTRFS_METADATA_ITEM_KEY;
5499 key.offset = owner_objectid;
5500 }
5501
5502 ret = btrfs_search_slot(trans, extent_root,
5503 &key, path, -1, 1);
5504 if (ret > 0 && skinny_metadata && path->slots[0]) {
5505 /*
5506 * Couldn't find our skinny metadata item,
5507 * see if we have ye olde extent item.
5508 */
5509 path->slots[0]--;
5510 btrfs_item_key_to_cpu(path->nodes[0], &key,
5511 path->slots[0]);
5512 if (key.objectid == bytenr &&
5513 key.type == BTRFS_EXTENT_ITEM_KEY &&
5514 key.offset == num_bytes)
5515 ret = 0;
5516 }
5517
5518 if (ret > 0 && skinny_metadata) {
5519 skinny_metadata = false;
5520 key.type = BTRFS_EXTENT_ITEM_KEY;
5521 key.offset = num_bytes;
5522 btrfs_release_path(path);
5523 ret = btrfs_search_slot(trans, extent_root,
5524 &key, path, -1, 1);
5525 }
5526
5527 if (ret) {
5528 btrfs_err(info, "umm, got %d back from search, was looking for %llu",
5529 ret, (unsigned long long)bytenr);
5530 if (ret > 0)
5531 btrfs_print_leaf(extent_root,
5532 path->nodes[0]);
5533 }
5534 if (ret < 0) {
5535 btrfs_abort_transaction(trans, extent_root, ret);
5536 goto out;
5537 }
5538 extent_slot = path->slots[0];
5539 }
5540 } else if (ret == -ENOENT) {
5541 btrfs_print_leaf(extent_root, path->nodes[0]);
5542 WARN_ON(1);
5543 btrfs_err(info,
5544 "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu",
5545 (unsigned long long)bytenr,
5546 (unsigned long long)parent,
5547 (unsigned long long)root_objectid,
5548 (unsigned long long)owner_objectid,
5549 (unsigned long long)owner_offset);
5550 } else {
5551 btrfs_abort_transaction(trans, extent_root, ret);
5552 goto out;
5553 }
5554
5555 leaf = path->nodes[0];
5556 item_size = btrfs_item_size_nr(leaf, extent_slot);
5557 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
5558 if (item_size < sizeof(*ei)) {
5559 BUG_ON(found_extent || extent_slot != path->slots[0]);
5560 ret = convert_extent_item_v0(trans, extent_root, path,
5561 owner_objectid, 0);
5562 if (ret < 0) {
5563 btrfs_abort_transaction(trans, extent_root, ret);
5564 goto out;
5565 }
5566
5567 btrfs_release_path(path);
5568 path->leave_spinning = 1;
5569
5570 key.objectid = bytenr;
5571 key.type = BTRFS_EXTENT_ITEM_KEY;
5572 key.offset = num_bytes;
5573
5574 ret = btrfs_search_slot(trans, extent_root, &key, path,
5575 -1, 1);
5576 if (ret) {
5577 btrfs_err(info, "umm, got %d back from search, was looking for %llu",
5578 ret, (unsigned long long)bytenr);
5579 btrfs_print_leaf(extent_root, path->nodes[0]);
5580 }
5581 if (ret < 0) {
5582 btrfs_abort_transaction(trans, extent_root, ret);
5583 goto out;
5584 }
5585
5586 extent_slot = path->slots[0];
5587 leaf = path->nodes[0];
5588 item_size = btrfs_item_size_nr(leaf, extent_slot);
5589 }
5590 #endif
5591 BUG_ON(item_size < sizeof(*ei));
5592 ei = btrfs_item_ptr(leaf, extent_slot,
5593 struct btrfs_extent_item);
5594 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
5595 key.type == BTRFS_EXTENT_ITEM_KEY) {
5596 struct btrfs_tree_block_info *bi;
5597 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
5598 bi = (struct btrfs_tree_block_info *)(ei + 1);
5599 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
5600 }
5601
5602 refs = btrfs_extent_refs(leaf, ei);
5603 if (refs < refs_to_drop) {
5604 btrfs_err(info, "trying to drop %d refs but we only have %Lu "
5605 "for bytenr %Lu\n", refs_to_drop, refs, bytenr);
5606 ret = -EINVAL;
5607 btrfs_abort_transaction(trans, extent_root, ret);
5608 goto out;
5609 }
5610 refs -= refs_to_drop;
5611
5612 if (refs > 0) {
5613 if (extent_op)
5614 __run_delayed_extent_op(extent_op, leaf, ei);
5615 /*
5616 * In the case of inline back ref, reference count will
5617 * be updated by remove_extent_backref
5618 */
5619 if (iref) {
5620 BUG_ON(!found_extent);
5621 } else {
5622 btrfs_set_extent_refs(leaf, ei, refs);
5623 btrfs_mark_buffer_dirty(leaf);
5624 }
5625 if (found_extent) {
5626 ret = remove_extent_backref(trans, extent_root, path,
5627 iref, refs_to_drop,
5628 is_data);
5629 if (ret) {
5630 btrfs_abort_transaction(trans, extent_root, ret);
5631 goto out;
5632 }
5633 }
5634 } else {
5635 if (found_extent) {
5636 BUG_ON(is_data && refs_to_drop !=
5637 extent_data_ref_count(root, path, iref));
5638 if (iref) {
5639 BUG_ON(path->slots[0] != extent_slot);
5640 } else {
5641 BUG_ON(path->slots[0] != extent_slot + 1);
5642 path->slots[0] = extent_slot;
5643 num_to_del = 2;
5644 }
5645 }
5646
5647 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
5648 num_to_del);
5649 if (ret) {
5650 btrfs_abort_transaction(trans, extent_root, ret);
5651 goto out;
5652 }
5653 btrfs_release_path(path);
5654
5655 if (is_data) {
5656 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
5657 if (ret) {
5658 btrfs_abort_transaction(trans, extent_root, ret);
5659 goto out;
5660 }
5661 }
5662
5663 ret = update_block_group(root, bytenr, num_bytes, 0);
5664 if (ret) {
5665 btrfs_abort_transaction(trans, extent_root, ret);
5666 goto out;
5667 }
5668 }
5669 out:
5670 btrfs_free_path(path);
5671 return ret;
5672 }
5673
5674 /*
5675 * when we free an block, it is possible (and likely) that we free the last
5676 * delayed ref for that extent as well. This searches the delayed ref tree for
5677 * a given extent, and if there are no other delayed refs to be processed, it
5678 * removes it from the tree.
5679 */
5680 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
5681 struct btrfs_root *root, u64 bytenr)
5682 {
5683 struct btrfs_delayed_ref_head *head;
5684 struct btrfs_delayed_ref_root *delayed_refs;
5685 struct btrfs_delayed_ref_node *ref;
5686 struct rb_node *node;
5687 int ret = 0;
5688
5689 delayed_refs = &trans->transaction->delayed_refs;
5690 spin_lock(&delayed_refs->lock);
5691 head = btrfs_find_delayed_ref_head(trans, bytenr);
5692 if (!head)
5693 goto out;
5694
5695 node = rb_prev(&head->node.rb_node);
5696 if (!node)
5697 goto out;
5698
5699 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
5700
5701 /* there are still entries for this ref, we can't drop it */
5702 if (ref->bytenr == bytenr)
5703 goto out;
5704
5705 if (head->extent_op) {
5706 if (!head->must_insert_reserved)
5707 goto out;
5708 btrfs_free_delayed_extent_op(head->extent_op);
5709 head->extent_op = NULL;
5710 }
5711
5712 /*
5713 * waiting for the lock here would deadlock. If someone else has it
5714 * locked they are already in the process of dropping it anyway
5715 */
5716 if (!mutex_trylock(&head->mutex))
5717 goto out;
5718
5719 /*
5720 * at this point we have a head with no other entries. Go
5721 * ahead and process it.
5722 */
5723 head->node.in_tree = 0;
5724 rb_erase(&head->node.rb_node, &delayed_refs->root);
5725
5726 delayed_refs->num_entries--;
5727
5728 /*
5729 * we don't take a ref on the node because we're removing it from the
5730 * tree, so we just steal the ref the tree was holding.
5731 */
5732 delayed_refs->num_heads--;
5733 if (list_empty(&head->cluster))
5734 delayed_refs->num_heads_ready--;
5735
5736 list_del_init(&head->cluster);
5737 spin_unlock(&delayed_refs->lock);
5738
5739 BUG_ON(head->extent_op);
5740 if (head->must_insert_reserved)
5741 ret = 1;
5742
5743 mutex_unlock(&head->mutex);
5744 btrfs_put_delayed_ref(&head->node);
5745 return ret;
5746 out:
5747 spin_unlock(&delayed_refs->lock);
5748 return 0;
5749 }
5750
5751 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
5752 struct btrfs_root *root,
5753 struct extent_buffer *buf,
5754 u64 parent, int last_ref)
5755 {
5756 struct btrfs_block_group_cache *cache = NULL;
5757 int ret;
5758
5759 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
5760 ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
5761 buf->start, buf->len,
5762 parent, root->root_key.objectid,
5763 btrfs_header_level(buf),
5764 BTRFS_DROP_DELAYED_REF, NULL, 0);
5765 BUG_ON(ret); /* -ENOMEM */
5766 }
5767
5768 if (!last_ref)
5769 return;
5770
5771 cache = btrfs_lookup_block_group(root->fs_info, buf->start);
5772
5773 if (btrfs_header_generation(buf) == trans->transid) {
5774 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
5775 ret = check_ref_cleanup(trans, root, buf->start);
5776 if (!ret)
5777 goto out;
5778 }
5779
5780 if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
5781 pin_down_extent(root, cache, buf->start, buf->len, 1);
5782 goto out;
5783 }
5784
5785 WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
5786
5787 btrfs_add_free_space(cache, buf->start, buf->len);
5788 btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE);
5789 }
5790 out:
5791 /*
5792 * Deleting the buffer, clear the corrupt flag since it doesn't matter
5793 * anymore.
5794 */
5795 clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
5796 btrfs_put_block_group(cache);
5797 }
5798
5799 /* Can return -ENOMEM */
5800 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
5801 u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
5802 u64 owner, u64 offset, int for_cow)
5803 {
5804 int ret;
5805 struct btrfs_fs_info *fs_info = root->fs_info;
5806
5807 /*
5808 * tree log blocks never actually go into the extent allocation
5809 * tree, just update pinning info and exit early.
5810 */
5811 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
5812 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
5813 /* unlocks the pinned mutex */
5814 btrfs_pin_extent(root, bytenr, num_bytes, 1);
5815 ret = 0;
5816 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
5817 ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
5818 num_bytes,
5819 parent, root_objectid, (int)owner,
5820 BTRFS_DROP_DELAYED_REF, NULL, for_cow);
5821 } else {
5822 ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
5823 num_bytes,
5824 parent, root_objectid, owner,
5825 offset, BTRFS_DROP_DELAYED_REF,
5826 NULL, for_cow);
5827 }
5828 return ret;
5829 }
5830
5831 static u64 stripe_align(struct btrfs_root *root,
5832 struct btrfs_block_group_cache *cache,
5833 u64 val, u64 num_bytes)
5834 {
5835 u64 ret = ALIGN(val, root->stripesize);
5836 return ret;
5837 }
5838
5839 /*
5840 * when we wait for progress in the block group caching, its because
5841 * our allocation attempt failed at least once. So, we must sleep
5842 * and let some progress happen before we try again.
5843 *
5844 * This function will sleep at least once waiting for new free space to
5845 * show up, and then it will check the block group free space numbers
5846 * for our min num_bytes. Another option is to have it go ahead
5847 * and look in the rbtree for a free extent of a given size, but this
5848 * is a good start.
5849 */
5850 static noinline int
5851 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
5852 u64 num_bytes)
5853 {
5854 struct btrfs_caching_control *caching_ctl;
5855
5856 caching_ctl = get_caching_control(cache);
5857 if (!caching_ctl)
5858 return 0;
5859
5860 wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
5861 (cache->free_space_ctl->free_space >= num_bytes));
5862
5863 put_caching_control(caching_ctl);
5864 return 0;
5865 }
5866
5867 static noinline int
5868 wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
5869 {
5870 struct btrfs_caching_control *caching_ctl;
5871
5872 caching_ctl = get_caching_control(cache);
5873 if (!caching_ctl)
5874 return 0;
5875
5876 wait_event(caching_ctl->wait, block_group_cache_done(cache));
5877
5878 put_caching_control(caching_ctl);
5879 return 0;
5880 }
5881
5882 int __get_raid_index(u64 flags)
5883 {
5884 if (flags & BTRFS_BLOCK_GROUP_RAID10)
5885 return BTRFS_RAID_RAID10;
5886 else if (flags & BTRFS_BLOCK_GROUP_RAID1)
5887 return BTRFS_RAID_RAID1;
5888 else if (flags & BTRFS_BLOCK_GROUP_DUP)
5889 return BTRFS_RAID_DUP;
5890 else if (flags & BTRFS_BLOCK_GROUP_RAID0)
5891 return BTRFS_RAID_RAID0;
5892 else if (flags & BTRFS_BLOCK_GROUP_RAID5)
5893 return BTRFS_RAID_RAID5;
5894 else if (flags & BTRFS_BLOCK_GROUP_RAID6)
5895 return BTRFS_RAID_RAID6;
5896
5897 return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
5898 }
5899
5900 static int get_block_group_index(struct btrfs_block_group_cache *cache)
5901 {
5902 return __get_raid_index(cache->flags);
5903 }
5904
5905 enum btrfs_loop_type {
5906 LOOP_CACHING_NOWAIT = 0,
5907 LOOP_CACHING_WAIT = 1,
5908 LOOP_ALLOC_CHUNK = 2,
5909 LOOP_NO_EMPTY_SIZE = 3,
5910 };
5911
5912 /*
5913 * walks the btree of allocated extents and find a hole of a given size.
5914 * The key ins is changed to record the hole:
5915 * ins->objectid == block start
5916 * ins->flags = BTRFS_EXTENT_ITEM_KEY
5917 * ins->offset == number of blocks
5918 * Any available blocks before search_start are skipped.
5919 */
5920 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
5921 struct btrfs_root *orig_root,
5922 u64 num_bytes, u64 empty_size,
5923 u64 hint_byte, struct btrfs_key *ins,
5924 u64 data)
5925 {
5926 int ret = 0;
5927 struct btrfs_root *root = orig_root->fs_info->extent_root;
5928 struct btrfs_free_cluster *last_ptr = NULL;
5929 struct btrfs_block_group_cache *block_group = NULL;
5930 struct btrfs_block_group_cache *used_block_group;
5931 u64 search_start = 0;
5932 int empty_cluster = 2 * 1024 * 1024;
5933 struct btrfs_space_info *space_info;
5934 int loop = 0;
5935 int index = __get_raid_index(data);
5936 int alloc_type = (data & BTRFS_BLOCK_GROUP_DATA) ?
5937 RESERVE_ALLOC_NO_ACCOUNT : RESERVE_ALLOC;
5938 bool found_uncached_bg = false;
5939 bool failed_cluster_refill = false;
5940 bool failed_alloc = false;
5941 bool use_cluster = true;
5942 bool have_caching_bg = false;
5943
5944 WARN_ON(num_bytes < root->sectorsize);
5945 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
5946 ins->objectid = 0;
5947 ins->offset = 0;
5948
5949 trace_find_free_extent(orig_root, num_bytes, empty_size, data);
5950
5951 space_info = __find_space_info(root->fs_info, data);
5952 if (!space_info) {
5953 btrfs_err(root->fs_info, "No space info for %llu", data);
5954 return -ENOSPC;
5955 }
5956
5957 /*
5958 * If the space info is for both data and metadata it means we have a
5959 * small filesystem and we can't use the clustering stuff.
5960 */
5961 if (btrfs_mixed_space_info(space_info))
5962 use_cluster = false;
5963
5964 if (data & BTRFS_BLOCK_GROUP_METADATA && use_cluster) {
5965 last_ptr = &root->fs_info->meta_alloc_cluster;
5966 if (!btrfs_test_opt(root, SSD))
5967 empty_cluster = 64 * 1024;
5968 }
5969
5970 if ((data & BTRFS_BLOCK_GROUP_DATA) && use_cluster &&
5971 btrfs_test_opt(root, SSD)) {
5972 last_ptr = &root->fs_info->data_alloc_cluster;
5973 }
5974
5975 if (last_ptr) {
5976 spin_lock(&last_ptr->lock);
5977 if (last_ptr->block_group)
5978 hint_byte = last_ptr->window_start;
5979 spin_unlock(&last_ptr->lock);
5980 }
5981
5982 search_start = max(search_start, first_logical_byte(root, 0));
5983 search_start = max(search_start, hint_byte);
5984
5985 if (!last_ptr)
5986 empty_cluster = 0;
5987
5988 if (search_start == hint_byte) {
5989 block_group = btrfs_lookup_block_group(root->fs_info,
5990 search_start);
5991 used_block_group = block_group;
5992 /*
5993 * we don't want to use the block group if it doesn't match our
5994 * allocation bits, or if its not cached.
5995 *
5996 * However if we are re-searching with an ideal block group
5997 * picked out then we don't care that the block group is cached.
5998 */
5999 if (block_group && block_group_bits(block_group, data) &&
6000 block_group->cached != BTRFS_CACHE_NO) {
6001 down_read(&space_info->groups_sem);
6002 if (list_empty(&block_group->list) ||
6003 block_group->ro) {
6004 /*
6005 * someone is removing this block group,
6006 * we can't jump into the have_block_group
6007 * target because our list pointers are not
6008 * valid
6009 */
6010 btrfs_put_block_group(block_group);
6011 up_read(&space_info->groups_sem);
6012 } else {
6013 index = get_block_group_index(block_group);
6014 goto have_block_group;
6015 }
6016 } else if (block_group) {
6017 btrfs_put_block_group(block_group);
6018 }
6019 }
6020 search:
6021 have_caching_bg = false;
6022 down_read(&space_info->groups_sem);
6023 list_for_each_entry(block_group, &space_info->block_groups[index],
6024 list) {
6025 u64 offset;
6026 int cached;
6027
6028 used_block_group = block_group;
6029 btrfs_get_block_group(block_group);
6030 search_start = block_group->key.objectid;
6031
6032 /*
6033 * this can happen if we end up cycling through all the
6034 * raid types, but we want to make sure we only allocate
6035 * for the proper type.
6036 */
6037 if (!block_group_bits(block_group, data)) {
6038 u64 extra = BTRFS_BLOCK_GROUP_DUP |
6039 BTRFS_BLOCK_GROUP_RAID1 |
6040 BTRFS_BLOCK_GROUP_RAID5 |
6041 BTRFS_BLOCK_GROUP_RAID6 |
6042 BTRFS_BLOCK_GROUP_RAID10;
6043
6044 /*
6045 * if they asked for extra copies and this block group
6046 * doesn't provide them, bail. This does allow us to
6047 * fill raid0 from raid1.
6048 */
6049 if ((data & extra) && !(block_group->flags & extra))
6050 goto loop;
6051 }
6052
6053 have_block_group:
6054 cached = block_group_cache_done(block_group);
6055 if (unlikely(!cached)) {
6056 found_uncached_bg = true;
6057 ret = cache_block_group(block_group, 0);
6058 BUG_ON(ret < 0);
6059 ret = 0;
6060 }
6061
6062 if (unlikely(block_group->ro))
6063 goto loop;
6064
6065 /*
6066 * Ok we want to try and use the cluster allocator, so
6067 * lets look there
6068 */
6069 if (last_ptr) {
6070 unsigned long aligned_cluster;
6071 /*
6072 * the refill lock keeps out other
6073 * people trying to start a new cluster
6074 */
6075 spin_lock(&last_ptr->refill_lock);
6076 used_block_group = last_ptr->block_group;
6077 if (used_block_group != block_group &&
6078 (!used_block_group ||
6079 used_block_group->ro ||
6080 !block_group_bits(used_block_group, data))) {
6081 used_block_group = block_group;
6082 goto refill_cluster;
6083 }
6084
6085 if (used_block_group != block_group)
6086 btrfs_get_block_group(used_block_group);
6087
6088 offset = btrfs_alloc_from_cluster(used_block_group,
6089 last_ptr, num_bytes, used_block_group->key.objectid);
6090 if (offset) {
6091 /* we have a block, we're done */
6092 spin_unlock(&last_ptr->refill_lock);
6093 trace_btrfs_reserve_extent_cluster(root,
6094 block_group, search_start, num_bytes);
6095 goto checks;
6096 }
6097
6098 WARN_ON(last_ptr->block_group != used_block_group);
6099 if (used_block_group != block_group) {
6100 btrfs_put_block_group(used_block_group);
6101 used_block_group = block_group;
6102 }
6103 refill_cluster:
6104 BUG_ON(used_block_group != block_group);
6105 /* If we are on LOOP_NO_EMPTY_SIZE, we can't
6106 * set up a new clusters, so lets just skip it
6107 * and let the allocator find whatever block
6108 * it can find. If we reach this point, we
6109 * will have tried the cluster allocator
6110 * plenty of times and not have found
6111 * anything, so we are likely way too
6112 * fragmented for the clustering stuff to find
6113 * anything.
6114 *
6115 * However, if the cluster is taken from the
6116 * current block group, release the cluster
6117 * first, so that we stand a better chance of
6118 * succeeding in the unclustered
6119 * allocation. */
6120 if (loop >= LOOP_NO_EMPTY_SIZE &&
6121 last_ptr->block_group != block_group) {
6122 spin_unlock(&last_ptr->refill_lock);
6123 goto unclustered_alloc;
6124 }
6125
6126 /*
6127 * this cluster didn't work out, free it and
6128 * start over
6129 */
6130 btrfs_return_cluster_to_free_space(NULL, last_ptr);
6131
6132 if (loop >= LOOP_NO_EMPTY_SIZE) {
6133 spin_unlock(&last_ptr->refill_lock);
6134 goto unclustered_alloc;
6135 }
6136
6137 aligned_cluster = max_t(unsigned long,
6138 empty_cluster + empty_size,
6139 block_group->full_stripe_len);
6140
6141 /* allocate a cluster in this block group */
6142 ret = btrfs_find_space_cluster(trans, root,
6143 block_group, last_ptr,
6144 search_start, num_bytes,
6145 aligned_cluster);
6146 if (ret == 0) {
6147 /*
6148 * now pull our allocation out of this
6149 * cluster
6150 */
6151 offset = btrfs_alloc_from_cluster(block_group,
6152 last_ptr, num_bytes,
6153 search_start);
6154 if (offset) {
6155 /* we found one, proceed */
6156 spin_unlock(&last_ptr->refill_lock);
6157 trace_btrfs_reserve_extent_cluster(root,
6158 block_group, search_start,
6159 num_bytes);
6160 goto checks;
6161 }
6162 } else if (!cached && loop > LOOP_CACHING_NOWAIT
6163 && !failed_cluster_refill) {
6164 spin_unlock(&last_ptr->refill_lock);
6165
6166 failed_cluster_refill = true;
6167 wait_block_group_cache_progress(block_group,
6168 num_bytes + empty_cluster + empty_size);
6169 goto have_block_group;
6170 }
6171
6172 /*
6173 * at this point we either didn't find a cluster
6174 * or we weren't able to allocate a block from our
6175 * cluster. Free the cluster we've been trying
6176 * to use, and go to the next block group
6177 */
6178 btrfs_return_cluster_to_free_space(NULL, last_ptr);
6179 spin_unlock(&last_ptr->refill_lock);
6180 goto loop;
6181 }
6182
6183 unclustered_alloc:
6184 spin_lock(&block_group->free_space_ctl->tree_lock);
6185 if (cached &&
6186 block_group->free_space_ctl->free_space <
6187 num_bytes + empty_cluster + empty_size) {
6188 spin_unlock(&block_group->free_space_ctl->tree_lock);
6189 goto loop;
6190 }
6191 spin_unlock(&block_group->free_space_ctl->tree_lock);
6192
6193 offset = btrfs_find_space_for_alloc(block_group, search_start,
6194 num_bytes, empty_size);
6195 /*
6196 * If we didn't find a chunk, and we haven't failed on this
6197 * block group before, and this block group is in the middle of
6198 * caching and we are ok with waiting, then go ahead and wait
6199 * for progress to be made, and set failed_alloc to true.
6200 *
6201 * If failed_alloc is true then we've already waited on this
6202 * block group once and should move on to the next block group.
6203 */
6204 if (!offset && !failed_alloc && !cached &&
6205 loop > LOOP_CACHING_NOWAIT) {
6206 wait_block_group_cache_progress(block_group,
6207 num_bytes + empty_size);
6208 failed_alloc = true;
6209 goto have_block_group;
6210 } else if (!offset) {
6211 if (!cached)
6212 have_caching_bg = true;
6213 goto loop;
6214 }
6215 checks:
6216 search_start = stripe_align(root, used_block_group,
6217 offset, num_bytes);
6218
6219 /* move on to the next group */
6220 if (search_start + num_bytes >
6221 used_block_group->key.objectid + used_block_group->key.offset) {
6222 btrfs_add_free_space(used_block_group, offset, num_bytes);
6223 goto loop;
6224 }
6225
6226 if (offset < search_start)
6227 btrfs_add_free_space(used_block_group, offset,
6228 search_start - offset);
6229 BUG_ON(offset > search_start);
6230
6231 ret = btrfs_update_reserved_bytes(used_block_group, num_bytes,
6232 alloc_type);
6233 if (ret == -EAGAIN) {
6234 btrfs_add_free_space(used_block_group, offset, num_bytes);
6235 goto loop;
6236 }
6237
6238 /* we are all good, lets return */
6239 ins->objectid = search_start;
6240 ins->offset = num_bytes;
6241
6242 trace_btrfs_reserve_extent(orig_root, block_group,
6243 search_start, num_bytes);
6244 if (used_block_group != block_group)
6245 btrfs_put_block_group(used_block_group);
6246 btrfs_put_block_group(block_group);
6247 break;
6248 loop:
6249 failed_cluster_refill = false;
6250 failed_alloc = false;
6251 BUG_ON(index != get_block_group_index(block_group));
6252 if (used_block_group != block_group)
6253 btrfs_put_block_group(used_block_group);
6254 btrfs_put_block_group(block_group);
6255 }
6256 up_read(&space_info->groups_sem);
6257
6258 if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg)
6259 goto search;
6260
6261 if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
6262 goto search;
6263
6264 /*
6265 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
6266 * caching kthreads as we move along
6267 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
6268 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
6269 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
6270 * again
6271 */
6272 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) {
6273 index = 0;
6274 loop++;
6275 if (loop == LOOP_ALLOC_CHUNK) {
6276 ret = do_chunk_alloc(trans, root, data,
6277 CHUNK_ALLOC_FORCE);
6278 /*
6279 * Do not bail out on ENOSPC since we
6280 * can do more things.
6281 */
6282 if (ret < 0 && ret != -ENOSPC) {
6283 btrfs_abort_transaction(trans,
6284 root, ret);
6285 goto out;
6286 }
6287 }
6288
6289 if (loop == LOOP_NO_EMPTY_SIZE) {
6290 empty_size = 0;
6291 empty_cluster = 0;
6292 }
6293
6294 goto search;
6295 } else if (!ins->objectid) {
6296 ret = -ENOSPC;
6297 } else if (ins->objectid) {
6298 ret = 0;
6299 }
6300 out:
6301
6302 return ret;
6303 }
6304
6305 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
6306 int dump_block_groups)
6307 {
6308 struct btrfs_block_group_cache *cache;
6309 int index = 0;
6310
6311 spin_lock(&info->lock);
6312 printk(KERN_INFO "space_info %llu has %llu free, is %sfull\n",
6313 (unsigned long long)info->flags,
6314 (unsigned long long)(info->total_bytes - info->bytes_used -
6315 info->bytes_pinned - info->bytes_reserved -
6316 info->bytes_readonly),
6317 (info->full) ? "" : "not ");
6318 printk(KERN_INFO "space_info total=%llu, used=%llu, pinned=%llu, "
6319 "reserved=%llu, may_use=%llu, readonly=%llu\n",
6320 (unsigned long long)info->total_bytes,
6321 (unsigned long long)info->bytes_used,
6322 (unsigned long long)info->bytes_pinned,
6323 (unsigned long long)info->bytes_reserved,
6324 (unsigned long long)info->bytes_may_use,
6325 (unsigned long long)info->bytes_readonly);
6326 spin_unlock(&info->lock);
6327
6328 if (!dump_block_groups)
6329 return;
6330
6331 down_read(&info->groups_sem);
6332 again:
6333 list_for_each_entry(cache, &info->block_groups[index], list) {
6334 spin_lock(&cache->lock);
6335 printk(KERN_INFO "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s\n",
6336 (unsigned long long)cache->key.objectid,
6337 (unsigned long long)cache->key.offset,
6338 (unsigned long long)btrfs_block_group_used(&cache->item),
6339 (unsigned long long)cache->pinned,
6340 (unsigned long long)cache->reserved,
6341 cache->ro ? "[readonly]" : "");
6342 btrfs_dump_free_space(cache, bytes);
6343 spin_unlock(&cache->lock);
6344 }
6345 if (++index < BTRFS_NR_RAID_TYPES)
6346 goto again;
6347 up_read(&info->groups_sem);
6348 }
6349
6350 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
6351 struct btrfs_root *root,
6352 u64 num_bytes, u64 min_alloc_size,
6353 u64 empty_size, u64 hint_byte,
6354 struct btrfs_key *ins, u64 data)
6355 {
6356 bool final_tried = false;
6357 int ret;
6358
6359 data = btrfs_get_alloc_profile(root, data);
6360 again:
6361 WARN_ON(num_bytes < root->sectorsize);
6362 ret = find_free_extent(trans, root, num_bytes, empty_size,
6363 hint_byte, ins, data);
6364
6365 if (ret == -ENOSPC) {
6366 if (!final_tried) {
6367 num_bytes = num_bytes >> 1;
6368 num_bytes = round_down(num_bytes, root->sectorsize);
6369 num_bytes = max(num_bytes, min_alloc_size);
6370 if (num_bytes == min_alloc_size)
6371 final_tried = true;
6372 goto again;
6373 } else if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
6374 struct btrfs_space_info *sinfo;
6375
6376 sinfo = __find_space_info(root->fs_info, data);
6377 btrfs_err(root->fs_info, "allocation failed flags %llu, wanted %llu",
6378 (unsigned long long)data,
6379 (unsigned long long)num_bytes);
6380 if (sinfo)
6381 dump_space_info(sinfo, num_bytes, 1);
6382 }
6383 }
6384
6385 trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset);
6386
6387 return ret;
6388 }
6389
6390 static int __btrfs_free_reserved_extent(struct btrfs_root *root,
6391 u64 start, u64 len, int pin)
6392 {
6393 struct btrfs_block_group_cache *cache;
6394 int ret = 0;
6395
6396 cache = btrfs_lookup_block_group(root->fs_info, start);
6397 if (!cache) {
6398 btrfs_err(root->fs_info, "Unable to find block group for %llu",
6399 (unsigned long long)start);
6400 return -ENOSPC;
6401 }
6402
6403 if (btrfs_test_opt(root, DISCARD))
6404 ret = btrfs_discard_extent(root, start, len, NULL);
6405
6406 if (pin)
6407 pin_down_extent(root, cache, start, len, 1);
6408 else {
6409 btrfs_add_free_space(cache, start, len);
6410 btrfs_update_reserved_bytes(cache, len, RESERVE_FREE);
6411 }
6412 btrfs_put_block_group(cache);
6413
6414 trace_btrfs_reserved_extent_free(root, start, len);
6415
6416 return ret;
6417 }
6418
6419 int btrfs_free_reserved_extent(struct btrfs_root *root,
6420 u64 start, u64 len)
6421 {
6422 return __btrfs_free_reserved_extent(root, start, len, 0);
6423 }
6424
6425 int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
6426 u64 start, u64 len)
6427 {
6428 return __btrfs_free_reserved_extent(root, start, len, 1);
6429 }
6430
6431 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
6432 struct btrfs_root *root,
6433 u64 parent, u64 root_objectid,
6434 u64 flags, u64 owner, u64 offset,
6435 struct btrfs_key *ins, int ref_mod)
6436 {
6437 int ret;
6438 struct btrfs_fs_info *fs_info = root->fs_info;
6439 struct btrfs_extent_item *extent_item;
6440 struct btrfs_extent_inline_ref *iref;
6441 struct btrfs_path *path;
6442 struct extent_buffer *leaf;
6443 int type;
6444 u32 size;
6445
6446 if (parent > 0)
6447 type = BTRFS_SHARED_DATA_REF_KEY;
6448 else
6449 type = BTRFS_EXTENT_DATA_REF_KEY;
6450
6451 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
6452
6453 path = btrfs_alloc_path();
6454 if (!path)
6455 return -ENOMEM;
6456
6457 path->leave_spinning = 1;
6458 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
6459 ins, size);
6460 if (ret) {
6461 btrfs_free_path(path);
6462 return ret;
6463 }
6464
6465 leaf = path->nodes[0];
6466 extent_item = btrfs_item_ptr(leaf, path->slots[0],
6467 struct btrfs_extent_item);
6468 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
6469 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
6470 btrfs_set_extent_flags(leaf, extent_item,
6471 flags | BTRFS_EXTENT_FLAG_DATA);
6472
6473 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
6474 btrfs_set_extent_inline_ref_type(leaf, iref, type);
6475 if (parent > 0) {
6476 struct btrfs_shared_data_ref *ref;
6477 ref = (struct btrfs_shared_data_ref *)(iref + 1);
6478 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
6479 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
6480 } else {
6481 struct btrfs_extent_data_ref *ref;
6482 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
6483 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
6484 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
6485 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
6486 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
6487 }
6488
6489 btrfs_mark_buffer_dirty(path->nodes[0]);
6490 btrfs_free_path(path);
6491
6492 ret = update_block_group(root, ins->objectid, ins->offset, 1);
6493 if (ret) { /* -ENOENT, logic error */
6494 btrfs_err(fs_info, "update block group failed for %llu %llu",
6495 (unsigned long long)ins->objectid,
6496 (unsigned long long)ins->offset);
6497 BUG();
6498 }
6499 return ret;
6500 }
6501
6502 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
6503 struct btrfs_root *root,
6504 u64 parent, u64 root_objectid,
6505 u64 flags, struct btrfs_disk_key *key,
6506 int level, struct btrfs_key *ins)
6507 {
6508 int ret;
6509 struct btrfs_fs_info *fs_info = root->fs_info;
6510 struct btrfs_extent_item *extent_item;
6511 struct btrfs_tree_block_info *block_info;
6512 struct btrfs_extent_inline_ref *iref;
6513 struct btrfs_path *path;
6514 struct extent_buffer *leaf;
6515 u32 size = sizeof(*extent_item) + sizeof(*iref);
6516 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
6517 SKINNY_METADATA);
6518
6519 if (!skinny_metadata)
6520 size += sizeof(*block_info);
6521
6522 path = btrfs_alloc_path();
6523 if (!path)
6524 return -ENOMEM;
6525
6526 path->leave_spinning = 1;
6527 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
6528 ins, size);
6529 if (ret) {
6530 btrfs_free_path(path);
6531 return ret;
6532 }
6533
6534 leaf = path->nodes[0];
6535 extent_item = btrfs_item_ptr(leaf, path->slots[0],
6536 struct btrfs_extent_item);
6537 btrfs_set_extent_refs(leaf, extent_item, 1);
6538 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
6539 btrfs_set_extent_flags(leaf, extent_item,
6540 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
6541
6542 if (skinny_metadata) {
6543 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
6544 } else {
6545 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
6546 btrfs_set_tree_block_key(leaf, block_info, key);
6547 btrfs_set_tree_block_level(leaf, block_info, level);
6548 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
6549 }
6550
6551 if (parent > 0) {
6552 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
6553 btrfs_set_extent_inline_ref_type(leaf, iref,
6554 BTRFS_SHARED_BLOCK_REF_KEY);
6555 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
6556 } else {
6557 btrfs_set_extent_inline_ref_type(leaf, iref,
6558 BTRFS_TREE_BLOCK_REF_KEY);
6559 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
6560 }
6561
6562 btrfs_mark_buffer_dirty(leaf);
6563 btrfs_free_path(path);
6564
6565 ret = update_block_group(root, ins->objectid, root->leafsize, 1);
6566 if (ret) { /* -ENOENT, logic error */
6567 btrfs_err(fs_info, "update block group failed for %llu %llu",
6568 (unsigned long long)ins->objectid,
6569 (unsigned long long)ins->offset);
6570 BUG();
6571 }
6572 return ret;
6573 }
6574
6575 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
6576 struct btrfs_root *root,
6577 u64 root_objectid, u64 owner,
6578 u64 offset, struct btrfs_key *ins)
6579 {
6580 int ret;
6581
6582 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
6583
6584 ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid,
6585 ins->offset, 0,
6586 root_objectid, owner, offset,
6587 BTRFS_ADD_DELAYED_EXTENT, NULL, 0);
6588 return ret;
6589 }
6590
6591 /*
6592 * this is used by the tree logging recovery code. It records that
6593 * an extent has been allocated and makes sure to clear the free
6594 * space cache bits as well
6595 */
6596 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
6597 struct btrfs_root *root,
6598 u64 root_objectid, u64 owner, u64 offset,
6599 struct btrfs_key *ins)
6600 {
6601 int ret;
6602 struct btrfs_block_group_cache *block_group;
6603 struct btrfs_caching_control *caching_ctl;
6604 u64 start = ins->objectid;
6605 u64 num_bytes = ins->offset;
6606
6607 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
6608 cache_block_group(block_group, 0);
6609 caching_ctl = get_caching_control(block_group);
6610
6611 if (!caching_ctl) {
6612 BUG_ON(!block_group_cache_done(block_group));
6613 ret = btrfs_remove_free_space(block_group, start, num_bytes);
6614 BUG_ON(ret); /* -ENOMEM */
6615 } else {
6616 mutex_lock(&caching_ctl->mutex);
6617
6618 if (start >= caching_ctl->progress) {
6619 ret = add_excluded_extent(root, start, num_bytes);
6620 BUG_ON(ret); /* -ENOMEM */
6621 } else if (start + num_bytes <= caching_ctl->progress) {
6622 ret = btrfs_remove_free_space(block_group,
6623 start, num_bytes);
6624 BUG_ON(ret); /* -ENOMEM */
6625 } else {
6626 num_bytes = caching_ctl->progress - start;
6627 ret = btrfs_remove_free_space(block_group,
6628 start, num_bytes);
6629 BUG_ON(ret); /* -ENOMEM */
6630
6631 start = caching_ctl->progress;
6632 num_bytes = ins->objectid + ins->offset -
6633 caching_ctl->progress;
6634 ret = add_excluded_extent(root, start, num_bytes);
6635 BUG_ON(ret); /* -ENOMEM */
6636 }
6637
6638 mutex_unlock(&caching_ctl->mutex);
6639 put_caching_control(caching_ctl);
6640 }
6641
6642 ret = btrfs_update_reserved_bytes(block_group, ins->offset,
6643 RESERVE_ALLOC_NO_ACCOUNT);
6644 BUG_ON(ret); /* logic error */
6645 btrfs_put_block_group(block_group);
6646 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
6647 0, owner, offset, ins, 1);
6648 return ret;
6649 }
6650
6651 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
6652 struct btrfs_root *root,
6653 u64 bytenr, u32 blocksize,
6654 int level)
6655 {
6656 struct extent_buffer *buf;
6657
6658 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
6659 if (!buf)
6660 return ERR_PTR(-ENOMEM);
6661 btrfs_set_header_generation(buf, trans->transid);
6662 btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
6663 btrfs_tree_lock(buf);
6664 clean_tree_block(trans, root, buf);
6665 clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
6666
6667 btrfs_set_lock_blocking(buf);
6668 btrfs_set_buffer_uptodate(buf);
6669
6670 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
6671 /*
6672 * we allow two log transactions at a time, use different
6673 * EXENT bit to differentiate dirty pages.
6674 */
6675 if (root->log_transid % 2 == 0)
6676 set_extent_dirty(&root->dirty_log_pages, buf->start,
6677 buf->start + buf->len - 1, GFP_NOFS);
6678 else
6679 set_extent_new(&root->dirty_log_pages, buf->start,
6680 buf->start + buf->len - 1, GFP_NOFS);
6681 } else {
6682 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
6683 buf->start + buf->len - 1, GFP_NOFS);
6684 }
6685 trans->blocks_used++;
6686 /* this returns a buffer locked for blocking */
6687 return buf;
6688 }
6689
6690 static struct btrfs_block_rsv *
6691 use_block_rsv(struct btrfs_trans_handle *trans,
6692 struct btrfs_root *root, u32 blocksize)
6693 {
6694 struct btrfs_block_rsv *block_rsv;
6695 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
6696 int ret;
6697
6698 block_rsv = get_block_rsv(trans, root);
6699
6700 if (block_rsv->size == 0) {
6701 ret = reserve_metadata_bytes(root, block_rsv, blocksize,
6702 BTRFS_RESERVE_NO_FLUSH);
6703 /*
6704 * If we couldn't reserve metadata bytes try and use some from
6705 * the global reserve.
6706 */
6707 if (ret && block_rsv != global_rsv) {
6708 ret = block_rsv_use_bytes(global_rsv, blocksize);
6709 if (!ret)
6710 return global_rsv;
6711 return ERR_PTR(ret);
6712 } else if (ret) {
6713 return ERR_PTR(ret);
6714 }
6715 return block_rsv;
6716 }
6717
6718 ret = block_rsv_use_bytes(block_rsv, blocksize);
6719 if (!ret)
6720 return block_rsv;
6721 if (ret && !block_rsv->failfast) {
6722 if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
6723 static DEFINE_RATELIMIT_STATE(_rs,
6724 DEFAULT_RATELIMIT_INTERVAL * 10,
6725 /*DEFAULT_RATELIMIT_BURST*/ 1);
6726 if (__ratelimit(&_rs))
6727 WARN(1, KERN_DEBUG
6728 "btrfs: block rsv returned %d\n", ret);
6729 }
6730 ret = reserve_metadata_bytes(root, block_rsv, blocksize,
6731 BTRFS_RESERVE_NO_FLUSH);
6732 if (!ret) {
6733 return block_rsv;
6734 } else if (ret && block_rsv != global_rsv) {
6735 ret = block_rsv_use_bytes(global_rsv, blocksize);
6736 if (!ret)
6737 return global_rsv;
6738 }
6739 }
6740
6741 return ERR_PTR(-ENOSPC);
6742 }
6743
6744 static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
6745 struct btrfs_block_rsv *block_rsv, u32 blocksize)
6746 {
6747 block_rsv_add_bytes(block_rsv, blocksize, 0);
6748 block_rsv_release_bytes(fs_info, block_rsv, NULL, 0);
6749 }
6750
6751 /*
6752 * finds a free extent and does all the dirty work required for allocation
6753 * returns the key for the extent through ins, and a tree buffer for
6754 * the first block of the extent through buf.
6755 *
6756 * returns the tree buffer or NULL.
6757 */
6758 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
6759 struct btrfs_root *root, u32 blocksize,
6760 u64 parent, u64 root_objectid,
6761 struct btrfs_disk_key *key, int level,
6762 u64 hint, u64 empty_size)
6763 {
6764 struct btrfs_key ins;
6765 struct btrfs_block_rsv *block_rsv;
6766 struct extent_buffer *buf;
6767 u64 flags = 0;
6768 int ret;
6769 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
6770 SKINNY_METADATA);
6771
6772 block_rsv = use_block_rsv(trans, root, blocksize);
6773 if (IS_ERR(block_rsv))
6774 return ERR_CAST(block_rsv);
6775
6776 ret = btrfs_reserve_extent(trans, root, blocksize, blocksize,
6777 empty_size, hint, &ins, 0);
6778 if (ret) {
6779 unuse_block_rsv(root->fs_info, block_rsv, blocksize);
6780 return ERR_PTR(ret);
6781 }
6782
6783 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
6784 blocksize, level);
6785 BUG_ON(IS_ERR(buf)); /* -ENOMEM */
6786
6787 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
6788 if (parent == 0)
6789 parent = ins.objectid;
6790 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
6791 } else
6792 BUG_ON(parent > 0);
6793
6794 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
6795 struct btrfs_delayed_extent_op *extent_op;
6796 extent_op = btrfs_alloc_delayed_extent_op();
6797 BUG_ON(!extent_op); /* -ENOMEM */
6798 if (key)
6799 memcpy(&extent_op->key, key, sizeof(extent_op->key));
6800 else
6801 memset(&extent_op->key, 0, sizeof(extent_op->key));
6802 extent_op->flags_to_set = flags;
6803 if (skinny_metadata)
6804 extent_op->update_key = 0;
6805 else
6806 extent_op->update_key = 1;
6807 extent_op->update_flags = 1;
6808 extent_op->is_data = 0;
6809
6810 ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
6811 ins.objectid,
6812 ins.offset, parent, root_objectid,
6813 level, BTRFS_ADD_DELAYED_EXTENT,
6814 extent_op, 0);
6815 BUG_ON(ret); /* -ENOMEM */
6816 }
6817 return buf;
6818 }
6819
6820 struct walk_control {
6821 u64 refs[BTRFS_MAX_LEVEL];
6822 u64 flags[BTRFS_MAX_LEVEL];
6823 struct btrfs_key update_progress;
6824 int stage;
6825 int level;
6826 int shared_level;
6827 int update_ref;
6828 int keep_locks;
6829 int reada_slot;
6830 int reada_count;
6831 int for_reloc;
6832 };
6833
6834 #define DROP_REFERENCE 1
6835 #define UPDATE_BACKREF 2
6836
6837 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
6838 struct btrfs_root *root,
6839 struct walk_control *wc,
6840 struct btrfs_path *path)
6841 {
6842 u64 bytenr;
6843 u64 generation;
6844 u64 refs;
6845 u64 flags;
6846 u32 nritems;
6847 u32 blocksize;
6848 struct btrfs_key key;
6849 struct extent_buffer *eb;
6850 int ret;
6851 int slot;
6852 int nread = 0;
6853
6854 if (path->slots[wc->level] < wc->reada_slot) {
6855 wc->reada_count = wc->reada_count * 2 / 3;
6856 wc->reada_count = max(wc->reada_count, 2);
6857 } else {
6858 wc->reada_count = wc->reada_count * 3 / 2;
6859 wc->reada_count = min_t(int, wc->reada_count,
6860 BTRFS_NODEPTRS_PER_BLOCK(root));
6861 }
6862
6863 eb = path->nodes[wc->level];
6864 nritems = btrfs_header_nritems(eb);
6865 blocksize = btrfs_level_size(root, wc->level - 1);
6866
6867 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
6868 if (nread >= wc->reada_count)
6869 break;
6870
6871 cond_resched();
6872 bytenr = btrfs_node_blockptr(eb, slot);
6873 generation = btrfs_node_ptr_generation(eb, slot);
6874
6875 if (slot == path->slots[wc->level])
6876 goto reada;
6877
6878 if (wc->stage == UPDATE_BACKREF &&
6879 generation <= root->root_key.offset)
6880 continue;
6881
6882 /* We don't lock the tree block, it's OK to be racy here */
6883 ret = btrfs_lookup_extent_info(trans, root, bytenr,
6884 wc->level - 1, 1, &refs,
6885 &flags);
6886 /* We don't care about errors in readahead. */
6887 if (ret < 0)
6888 continue;
6889 BUG_ON(refs == 0);
6890
6891 if (wc->stage == DROP_REFERENCE) {
6892 if (refs == 1)
6893 goto reada;
6894
6895 if (wc->level == 1 &&
6896 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
6897 continue;
6898 if (!wc->update_ref ||
6899 generation <= root->root_key.offset)
6900 continue;
6901 btrfs_node_key_to_cpu(eb, &key, slot);
6902 ret = btrfs_comp_cpu_keys(&key,
6903 &wc->update_progress);
6904 if (ret < 0)
6905 continue;
6906 } else {
6907 if (wc->level == 1 &&
6908 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
6909 continue;
6910 }
6911 reada:
6912 ret = readahead_tree_block(root, bytenr, blocksize,
6913 generation);
6914 if (ret)
6915 break;
6916 nread++;
6917 }
6918 wc->reada_slot = slot;
6919 }
6920
6921 /*
6922 * helper to process tree block while walking down the tree.
6923 *
6924 * when wc->stage == UPDATE_BACKREF, this function updates
6925 * back refs for pointers in the block.
6926 *
6927 * NOTE: return value 1 means we should stop walking down.
6928 */
6929 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
6930 struct btrfs_root *root,
6931 struct btrfs_path *path,
6932 struct walk_control *wc, int lookup_info)
6933 {
6934 int level = wc->level;
6935 struct extent_buffer *eb = path->nodes[level];
6936 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
6937 int ret;
6938
6939 if (wc->stage == UPDATE_BACKREF &&
6940 btrfs_header_owner(eb) != root->root_key.objectid)
6941 return 1;
6942
6943 /*
6944 * when reference count of tree block is 1, it won't increase
6945 * again. once full backref flag is set, we never clear it.
6946 */
6947 if (lookup_info &&
6948 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
6949 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
6950 BUG_ON(!path->locks[level]);
6951 ret = btrfs_lookup_extent_info(trans, root,
6952 eb->start, level, 1,
6953 &wc->refs[level],
6954 &wc->flags[level]);
6955 BUG_ON(ret == -ENOMEM);
6956 if (ret)
6957 return ret;
6958 BUG_ON(wc->refs[level] == 0);
6959 }
6960
6961 if (wc->stage == DROP_REFERENCE) {
6962 if (wc->refs[level] > 1)
6963 return 1;
6964
6965 if (path->locks[level] && !wc->keep_locks) {
6966 btrfs_tree_unlock_rw(eb, path->locks[level]);
6967 path->locks[level] = 0;
6968 }
6969 return 0;
6970 }
6971
6972 /* wc->stage == UPDATE_BACKREF */
6973 if (!(wc->flags[level] & flag)) {
6974 BUG_ON(!path->locks[level]);
6975 ret = btrfs_inc_ref(trans, root, eb, 1, wc->for_reloc);
6976 BUG_ON(ret); /* -ENOMEM */
6977 ret = btrfs_dec_ref(trans, root, eb, 0, wc->for_reloc);
6978 BUG_ON(ret); /* -ENOMEM */
6979 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
6980 eb->len, flag, 0);
6981 BUG_ON(ret); /* -ENOMEM */
6982 wc->flags[level] |= flag;
6983 }
6984
6985 /*
6986 * the block is shared by multiple trees, so it's not good to
6987 * keep the tree lock
6988 */
6989 if (path->locks[level] && level > 0) {
6990 btrfs_tree_unlock_rw(eb, path->locks[level]);
6991 path->locks[level] = 0;
6992 }
6993 return 0;
6994 }
6995
6996 /*
6997 * helper to process tree block pointer.
6998 *
6999 * when wc->stage == DROP_REFERENCE, this function checks
7000 * reference count of the block pointed to. if the block
7001 * is shared and we need update back refs for the subtree
7002 * rooted at the block, this function changes wc->stage to
7003 * UPDATE_BACKREF. if the block is shared and there is no
7004 * need to update back, this function drops the reference
7005 * to the block.
7006 *
7007 * NOTE: return value 1 means we should stop walking down.
7008 */
7009 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
7010 struct btrfs_root *root,
7011 struct btrfs_path *path,
7012 struct walk_control *wc, int *lookup_info)
7013 {
7014 u64 bytenr;
7015 u64 generation;
7016 u64 parent;
7017 u32 blocksize;
7018 struct btrfs_key key;
7019 struct extent_buffer *next;
7020 int level = wc->level;
7021 int reada = 0;
7022 int ret = 0;
7023
7024 generation = btrfs_node_ptr_generation(path->nodes[level],
7025 path->slots[level]);
7026 /*
7027 * if the lower level block was created before the snapshot
7028 * was created, we know there is no need to update back refs
7029 * for the subtree
7030 */
7031 if (wc->stage == UPDATE_BACKREF &&
7032 generation <= root->root_key.offset) {
7033 *lookup_info = 1;
7034 return 1;
7035 }
7036
7037 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
7038 blocksize = btrfs_level_size(root, level - 1);
7039
7040 next = btrfs_find_tree_block(root, bytenr, blocksize);
7041 if (!next) {
7042 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
7043 if (!next)
7044 return -ENOMEM;
7045 reada = 1;
7046 }
7047 btrfs_tree_lock(next);
7048 btrfs_set_lock_blocking(next);
7049
7050 ret = btrfs_lookup_extent_info(trans, root, bytenr, level - 1, 1,
7051 &wc->refs[level - 1],
7052 &wc->flags[level - 1]);
7053 if (ret < 0) {
7054 btrfs_tree_unlock(next);
7055 return ret;
7056 }
7057
7058 if (unlikely(wc->refs[level - 1] == 0)) {
7059 btrfs_err(root->fs_info, "Missing references.");
7060 BUG();
7061 }
7062 *lookup_info = 0;
7063
7064 if (wc->stage == DROP_REFERENCE) {
7065 if (wc->refs[level - 1] > 1) {
7066 if (level == 1 &&
7067 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
7068 goto skip;
7069
7070 if (!wc->update_ref ||
7071 generation <= root->root_key.offset)
7072 goto skip;
7073
7074 btrfs_node_key_to_cpu(path->nodes[level], &key,
7075 path->slots[level]);
7076 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
7077 if (ret < 0)
7078 goto skip;
7079
7080 wc->stage = UPDATE_BACKREF;
7081 wc->shared_level = level - 1;
7082 }
7083 } else {
7084 if (level == 1 &&
7085 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
7086 goto skip;
7087 }
7088
7089 if (!btrfs_buffer_uptodate(next, generation, 0)) {
7090 btrfs_tree_unlock(next);
7091 free_extent_buffer(next);
7092 next = NULL;
7093 *lookup_info = 1;
7094 }
7095
7096 if (!next) {
7097 if (reada && level == 1)
7098 reada_walk_down(trans, root, wc, path);
7099 next = read_tree_block(root, bytenr, blocksize, generation);
7100 if (!next || !extent_buffer_uptodate(next)) {
7101 free_extent_buffer(next);
7102 return -EIO;
7103 }
7104 btrfs_tree_lock(next);
7105 btrfs_set_lock_blocking(next);
7106 }
7107
7108 level--;
7109 BUG_ON(level != btrfs_header_level(next));
7110 path->nodes[level] = next;
7111 path->slots[level] = 0;
7112 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
7113 wc->level = level;
7114 if (wc->level == 1)
7115 wc->reada_slot = 0;
7116 return 0;
7117 skip:
7118 wc->refs[level - 1] = 0;
7119 wc->flags[level - 1] = 0;
7120 if (wc->stage == DROP_REFERENCE) {
7121 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
7122 parent = path->nodes[level]->start;
7123 } else {
7124 BUG_ON(root->root_key.objectid !=
7125 btrfs_header_owner(path->nodes[level]));
7126 parent = 0;
7127 }
7128
7129 ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
7130 root->root_key.objectid, level - 1, 0, 0);
7131 BUG_ON(ret); /* -ENOMEM */
7132 }
7133 btrfs_tree_unlock(next);
7134 free_extent_buffer(next);
7135 *lookup_info = 1;
7136 return 1;
7137 }
7138
7139 /*
7140 * helper to process tree block while walking up the tree.
7141 *
7142 * when wc->stage == DROP_REFERENCE, this function drops
7143 * reference count on the block.
7144 *
7145 * when wc->stage == UPDATE_BACKREF, this function changes
7146 * wc->stage back to DROP_REFERENCE if we changed wc->stage
7147 * to UPDATE_BACKREF previously while processing the block.
7148 *
7149 * NOTE: return value 1 means we should stop walking up.
7150 */
7151 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
7152 struct btrfs_root *root,
7153 struct btrfs_path *path,
7154 struct walk_control *wc)
7155 {
7156 int ret;
7157 int level = wc->level;
7158 struct extent_buffer *eb = path->nodes[level];
7159 u64 parent = 0;
7160
7161 if (wc->stage == UPDATE_BACKREF) {
7162 BUG_ON(wc->shared_level < level);
7163 if (level < wc->shared_level)
7164 goto out;
7165
7166 ret = find_next_key(path, level + 1, &wc->update_progress);
7167 if (ret > 0)
7168 wc->update_ref = 0;
7169
7170 wc->stage = DROP_REFERENCE;
7171 wc->shared_level = -1;
7172 path->slots[level] = 0;
7173
7174 /*
7175 * check reference count again if the block isn't locked.
7176 * we should start walking down the tree again if reference
7177 * count is one.
7178 */
7179 if (!path->locks[level]) {
7180 BUG_ON(level == 0);
7181 btrfs_tree_lock(eb);
7182 btrfs_set_lock_blocking(eb);
7183 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
7184
7185 ret = btrfs_lookup_extent_info(trans, root,
7186 eb->start, level, 1,
7187 &wc->refs[level],
7188 &wc->flags[level]);
7189 if (ret < 0) {
7190 btrfs_tree_unlock_rw(eb, path->locks[level]);
7191 path->locks[level] = 0;
7192 return ret;
7193 }
7194 BUG_ON(wc->refs[level] == 0);
7195 if (wc->refs[level] == 1) {
7196 btrfs_tree_unlock_rw(eb, path->locks[level]);
7197 path->locks[level] = 0;
7198 return 1;
7199 }
7200 }
7201 }
7202
7203 /* wc->stage == DROP_REFERENCE */
7204 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
7205
7206 if (wc->refs[level] == 1) {
7207 if (level == 0) {
7208 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
7209 ret = btrfs_dec_ref(trans, root, eb, 1,
7210 wc->for_reloc);
7211 else
7212 ret = btrfs_dec_ref(trans, root, eb, 0,
7213 wc->for_reloc);
7214 BUG_ON(ret); /* -ENOMEM */
7215 }
7216 /* make block locked assertion in clean_tree_block happy */
7217 if (!path->locks[level] &&
7218 btrfs_header_generation(eb) == trans->transid) {
7219 btrfs_tree_lock(eb);
7220 btrfs_set_lock_blocking(eb);
7221 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
7222 }
7223 clean_tree_block(trans, root, eb);
7224 }
7225
7226 if (eb == root->node) {
7227 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
7228 parent = eb->start;
7229 else
7230 BUG_ON(root->root_key.objectid !=
7231 btrfs_header_owner(eb));
7232 } else {
7233 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
7234 parent = path->nodes[level + 1]->start;
7235 else
7236 BUG_ON(root->root_key.objectid !=
7237 btrfs_header_owner(path->nodes[level + 1]));
7238 }
7239
7240 btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
7241 out:
7242 wc->refs[level] = 0;
7243 wc->flags[level] = 0;
7244 return 0;
7245 }
7246
7247 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
7248 struct btrfs_root *root,
7249 struct btrfs_path *path,
7250 struct walk_control *wc)
7251 {
7252 int level = wc->level;
7253 int lookup_info = 1;
7254 int ret;
7255
7256 while (level >= 0) {
7257 ret = walk_down_proc(trans, root, path, wc, lookup_info);
7258 if (ret > 0)
7259 break;
7260
7261 if (level == 0)
7262 break;
7263
7264 if (path->slots[level] >=
7265 btrfs_header_nritems(path->nodes[level]))
7266 break;
7267
7268 ret = do_walk_down(trans, root, path, wc, &lookup_info);
7269 if (ret > 0) {
7270 path->slots[level]++;
7271 continue;
7272 } else if (ret < 0)
7273 return ret;
7274 level = wc->level;
7275 }
7276 return 0;
7277 }
7278
7279 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
7280 struct btrfs_root *root,
7281 struct btrfs_path *path,
7282 struct walk_control *wc, int max_level)
7283 {
7284 int level = wc->level;
7285 int ret;
7286
7287 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
7288 while (level < max_level && path->nodes[level]) {
7289 wc->level = level;
7290 if (path->slots[level] + 1 <
7291 btrfs_header_nritems(path->nodes[level])) {
7292 path->slots[level]++;
7293 return 0;
7294 } else {
7295 ret = walk_up_proc(trans, root, path, wc);
7296 if (ret > 0)
7297 return 0;
7298
7299 if (path->locks[level]) {
7300 btrfs_tree_unlock_rw(path->nodes[level],
7301 path->locks[level]);
7302 path->locks[level] = 0;
7303 }
7304 free_extent_buffer(path->nodes[level]);
7305 path->nodes[level] = NULL;
7306 level++;
7307 }
7308 }
7309 return 1;
7310 }
7311
7312 /*
7313 * drop a subvolume tree.
7314 *
7315 * this function traverses the tree freeing any blocks that only
7316 * referenced by the tree.
7317 *
7318 * when a shared tree block is found. this function decreases its
7319 * reference count by one. if update_ref is true, this function
7320 * also make sure backrefs for the shared block and all lower level
7321 * blocks are properly updated.
7322 *
7323 * If called with for_reloc == 0, may exit early with -EAGAIN
7324 */
7325 int btrfs_drop_snapshot(struct btrfs_root *root,
7326 struct btrfs_block_rsv *block_rsv, int update_ref,
7327 int for_reloc)
7328 {
7329 struct btrfs_path *path;
7330 struct btrfs_trans_handle *trans;
7331 struct btrfs_root *tree_root = root->fs_info->tree_root;
7332 struct btrfs_root_item *root_item = &root->root_item;
7333 struct walk_control *wc;
7334 struct btrfs_key key;
7335 int err = 0;
7336 int ret;
7337 int level;
7338
7339 path = btrfs_alloc_path();
7340 if (!path) {
7341 err = -ENOMEM;
7342 goto out;
7343 }
7344
7345 wc = kzalloc(sizeof(*wc), GFP_NOFS);
7346 if (!wc) {
7347 btrfs_free_path(path);
7348 err = -ENOMEM;
7349 goto out;
7350 }
7351
7352 trans = btrfs_start_transaction(tree_root, 0);
7353 if (IS_ERR(trans)) {
7354 err = PTR_ERR(trans);
7355 goto out_free;
7356 }
7357
7358 if (block_rsv)
7359 trans->block_rsv = block_rsv;
7360
7361 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
7362 level = btrfs_header_level(root->node);
7363 path->nodes[level] = btrfs_lock_root_node(root);
7364 btrfs_set_lock_blocking(path->nodes[level]);
7365 path->slots[level] = 0;
7366 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
7367 memset(&wc->update_progress, 0,
7368 sizeof(wc->update_progress));
7369 } else {
7370 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
7371 memcpy(&wc->update_progress, &key,
7372 sizeof(wc->update_progress));
7373
7374 level = root_item->drop_level;
7375 BUG_ON(level == 0);
7376 path->lowest_level = level;
7377 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
7378 path->lowest_level = 0;
7379 if (ret < 0) {
7380 err = ret;
7381 goto out_end_trans;
7382 }
7383 WARN_ON(ret > 0);
7384
7385 /*
7386 * unlock our path, this is safe because only this
7387 * function is allowed to delete this snapshot
7388 */
7389 btrfs_unlock_up_safe(path, 0);
7390
7391 level = btrfs_header_level(root->node);
7392 while (1) {
7393 btrfs_tree_lock(path->nodes[level]);
7394 btrfs_set_lock_blocking(path->nodes[level]);
7395
7396 ret = btrfs_lookup_extent_info(trans, root,
7397 path->nodes[level]->start,
7398 level, 1, &wc->refs[level],
7399 &wc->flags[level]);
7400 if (ret < 0) {
7401 err = ret;
7402 goto out_end_trans;
7403 }
7404 BUG_ON(wc->refs[level] == 0);
7405
7406 if (level == root_item->drop_level)
7407 break;
7408
7409 btrfs_tree_unlock(path->nodes[level]);
7410 WARN_ON(wc->refs[level] != 1);
7411 level--;
7412 }
7413 }
7414
7415 wc->level = level;
7416 wc->shared_level = -1;
7417 wc->stage = DROP_REFERENCE;
7418 wc->update_ref = update_ref;
7419 wc->keep_locks = 0;
7420 wc->for_reloc = for_reloc;
7421 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
7422
7423 while (1) {
7424 if (!for_reloc && btrfs_fs_closing(root->fs_info)) {
7425 pr_debug("btrfs: drop snapshot early exit\n");
7426 err = -EAGAIN;
7427 goto out_end_trans;
7428 }
7429
7430 ret = walk_down_tree(trans, root, path, wc);
7431 if (ret < 0) {
7432 err = ret;
7433 break;
7434 }
7435
7436 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
7437 if (ret < 0) {
7438 err = ret;
7439 break;
7440 }
7441
7442 if (ret > 0) {
7443 BUG_ON(wc->stage != DROP_REFERENCE);
7444 break;
7445 }
7446
7447 if (wc->stage == DROP_REFERENCE) {
7448 level = wc->level;
7449 btrfs_node_key(path->nodes[level],
7450 &root_item->drop_progress,
7451 path->slots[level]);
7452 root_item->drop_level = level;
7453 }
7454
7455 BUG_ON(wc->level == 0);
7456 if (btrfs_should_end_transaction(trans, tree_root)) {
7457 ret = btrfs_update_root(trans, tree_root,
7458 &root->root_key,
7459 root_item);
7460 if (ret) {
7461 btrfs_abort_transaction(trans, tree_root, ret);
7462 err = ret;
7463 goto out_end_trans;
7464 }
7465
7466 btrfs_end_transaction_throttle(trans, tree_root);
7467 trans = btrfs_start_transaction(tree_root, 0);
7468 if (IS_ERR(trans)) {
7469 err = PTR_ERR(trans);
7470 goto out_free;
7471 }
7472 if (block_rsv)
7473 trans->block_rsv = block_rsv;
7474 }
7475 }
7476 btrfs_release_path(path);
7477 if (err)
7478 goto out_end_trans;
7479
7480 ret = btrfs_del_root(trans, tree_root, &root->root_key);
7481 if (ret) {
7482 btrfs_abort_transaction(trans, tree_root, ret);
7483 goto out_end_trans;
7484 }
7485
7486 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
7487 ret = btrfs_find_last_root(tree_root, root->root_key.objectid,
7488 NULL, NULL);
7489 if (ret < 0) {
7490 btrfs_abort_transaction(trans, tree_root, ret);
7491 err = ret;
7492 goto out_end_trans;
7493 } else if (ret > 0) {
7494 /* if we fail to delete the orphan item this time
7495 * around, it'll get picked up the next time.
7496 *
7497 * The most common failure here is just -ENOENT.
7498 */
7499 btrfs_del_orphan_item(trans, tree_root,
7500 root->root_key.objectid);
7501 }
7502 }
7503
7504 if (root->in_radix) {
7505 btrfs_free_fs_root(tree_root->fs_info, root);
7506 } else {
7507 free_extent_buffer(root->node);
7508 free_extent_buffer(root->commit_root);
7509 kfree(root);
7510 }
7511 out_end_trans:
7512 btrfs_end_transaction_throttle(trans, tree_root);
7513 out_free:
7514 kfree(wc);
7515 btrfs_free_path(path);
7516 out:
7517 if (err)
7518 btrfs_std_error(root->fs_info, err);
7519 return err;
7520 }
7521
7522 /*
7523 * drop subtree rooted at tree block 'node'.
7524 *
7525 * NOTE: this function will unlock and release tree block 'node'
7526 * only used by relocation code
7527 */
7528 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
7529 struct btrfs_root *root,
7530 struct extent_buffer *node,
7531 struct extent_buffer *parent)
7532 {
7533 struct btrfs_path *path;
7534 struct walk_control *wc;
7535 int level;
7536 int parent_level;
7537 int ret = 0;
7538 int wret;
7539
7540 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
7541
7542 path = btrfs_alloc_path();
7543 if (!path)
7544 return -ENOMEM;
7545
7546 wc = kzalloc(sizeof(*wc), GFP_NOFS);
7547 if (!wc) {
7548 btrfs_free_path(path);
7549 return -ENOMEM;
7550 }
7551
7552 btrfs_assert_tree_locked(parent);
7553 parent_level = btrfs_header_level(parent);
7554 extent_buffer_get(parent);
7555 path->nodes[parent_level] = parent;
7556 path->slots[parent_level] = btrfs_header_nritems(parent);
7557
7558 btrfs_assert_tree_locked(node);
7559 level = btrfs_header_level(node);
7560 path->nodes[level] = node;
7561 path->slots[level] = 0;
7562 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
7563
7564 wc->refs[parent_level] = 1;
7565 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
7566 wc->level = level;
7567 wc->shared_level = -1;
7568 wc->stage = DROP_REFERENCE;
7569 wc->update_ref = 0;
7570 wc->keep_locks = 1;
7571 wc->for_reloc = 1;
7572 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
7573
7574 while (1) {
7575 wret = walk_down_tree(trans, root, path, wc);
7576 if (wret < 0) {
7577 ret = wret;
7578 break;
7579 }
7580
7581 wret = walk_up_tree(trans, root, path, wc, parent_level);
7582 if (wret < 0)
7583 ret = wret;
7584 if (wret != 0)
7585 break;
7586 }
7587
7588 kfree(wc);
7589 btrfs_free_path(path);
7590 return ret;
7591 }
7592
7593 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
7594 {
7595 u64 num_devices;
7596 u64 stripped;
7597
7598 /*
7599 * if restripe for this chunk_type is on pick target profile and
7600 * return, otherwise do the usual balance
7601 */
7602 stripped = get_restripe_target(root->fs_info, flags);
7603 if (stripped)
7604 return extended_to_chunk(stripped);
7605
7606 /*
7607 * we add in the count of missing devices because we want
7608 * to make sure that any RAID levels on a degraded FS
7609 * continue to be honored.
7610 */
7611 num_devices = root->fs_info->fs_devices->rw_devices +
7612 root->fs_info->fs_devices->missing_devices;
7613
7614 stripped = BTRFS_BLOCK_GROUP_RAID0 |
7615 BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
7616 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
7617
7618 if (num_devices == 1) {
7619 stripped |= BTRFS_BLOCK_GROUP_DUP;
7620 stripped = flags & ~stripped;
7621
7622 /* turn raid0 into single device chunks */
7623 if (flags & BTRFS_BLOCK_GROUP_RAID0)
7624 return stripped;
7625
7626 /* turn mirroring into duplication */
7627 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
7628 BTRFS_BLOCK_GROUP_RAID10))
7629 return stripped | BTRFS_BLOCK_GROUP_DUP;
7630 } else {
7631 /* they already had raid on here, just return */
7632 if (flags & stripped)
7633 return flags;
7634
7635 stripped |= BTRFS_BLOCK_GROUP_DUP;
7636 stripped = flags & ~stripped;
7637
7638 /* switch duplicated blocks with raid1 */
7639 if (flags & BTRFS_BLOCK_GROUP_DUP)
7640 return stripped | BTRFS_BLOCK_GROUP_RAID1;
7641
7642 /* this is drive concat, leave it alone */
7643 }
7644
7645 return flags;
7646 }
7647
7648 static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
7649 {
7650 struct btrfs_space_info *sinfo = cache->space_info;
7651 u64 num_bytes;
7652 u64 min_allocable_bytes;
7653 int ret = -ENOSPC;
7654
7655
7656 /*
7657 * We need some metadata space and system metadata space for
7658 * allocating chunks in some corner cases until we force to set
7659 * it to be readonly.
7660 */
7661 if ((sinfo->flags &
7662 (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
7663 !force)
7664 min_allocable_bytes = 1 * 1024 * 1024;
7665 else
7666 min_allocable_bytes = 0;
7667
7668 spin_lock(&sinfo->lock);
7669 spin_lock(&cache->lock);
7670
7671 if (cache->ro) {
7672 ret = 0;
7673 goto out;
7674 }
7675
7676 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
7677 cache->bytes_super - btrfs_block_group_used(&cache->item);
7678
7679 if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
7680 sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
7681 min_allocable_bytes <= sinfo->total_bytes) {
7682 sinfo->bytes_readonly += num_bytes;
7683 cache->ro = 1;
7684 ret = 0;
7685 }
7686 out:
7687 spin_unlock(&cache->lock);
7688 spin_unlock(&sinfo->lock);
7689 return ret;
7690 }
7691
7692 int btrfs_set_block_group_ro(struct btrfs_root *root,
7693 struct btrfs_block_group_cache *cache)
7694
7695 {
7696 struct btrfs_trans_handle *trans;
7697 u64 alloc_flags;
7698 int ret;
7699
7700 BUG_ON(cache->ro);
7701
7702 trans = btrfs_join_transaction(root);
7703 if (IS_ERR(trans))
7704 return PTR_ERR(trans);
7705
7706 alloc_flags = update_block_group_flags(root, cache->flags);
7707 if (alloc_flags != cache->flags) {
7708 ret = do_chunk_alloc(trans, root, alloc_flags,
7709 CHUNK_ALLOC_FORCE);
7710 if (ret < 0)
7711 goto out;
7712 }
7713
7714 ret = set_block_group_ro(cache, 0);
7715 if (!ret)
7716 goto out;
7717 alloc_flags = get_alloc_profile(root, cache->space_info->flags);
7718 ret = do_chunk_alloc(trans, root, alloc_flags,
7719 CHUNK_ALLOC_FORCE);
7720 if (ret < 0)
7721 goto out;
7722 ret = set_block_group_ro(cache, 0);
7723 out:
7724 btrfs_end_transaction(trans, root);
7725 return ret;
7726 }
7727
7728 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
7729 struct btrfs_root *root, u64 type)
7730 {
7731 u64 alloc_flags = get_alloc_profile(root, type);
7732 return do_chunk_alloc(trans, root, alloc_flags,
7733 CHUNK_ALLOC_FORCE);
7734 }
7735
7736 /*
7737 * helper to account the unused space of all the readonly block group in the
7738 * list. takes mirrors into account.
7739 */
7740 static u64 __btrfs_get_ro_block_group_free_space(struct list_head *groups_list)
7741 {
7742 struct btrfs_block_group_cache *block_group;
7743 u64 free_bytes = 0;
7744 int factor;
7745
7746 list_for_each_entry(block_group, groups_list, list) {
7747 spin_lock(&block_group->lock);
7748
7749 if (!block_group->ro) {
7750 spin_unlock(&block_group->lock);
7751 continue;
7752 }
7753
7754 if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
7755 BTRFS_BLOCK_GROUP_RAID10 |
7756 BTRFS_BLOCK_GROUP_DUP))
7757 factor = 2;
7758 else
7759 factor = 1;
7760
7761 free_bytes += (block_group->key.offset -
7762 btrfs_block_group_used(&block_group->item)) *
7763 factor;
7764
7765 spin_unlock(&block_group->lock);
7766 }
7767
7768 return free_bytes;
7769 }
7770
7771 /*
7772 * helper to account the unused space of all the readonly block group in the
7773 * space_info. takes mirrors into account.
7774 */
7775 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
7776 {
7777 int i;
7778 u64 free_bytes = 0;
7779
7780 spin_lock(&sinfo->lock);
7781
7782 for(i = 0; i < BTRFS_NR_RAID_TYPES; i++)
7783 if (!list_empty(&sinfo->block_groups[i]))
7784 free_bytes += __btrfs_get_ro_block_group_free_space(
7785 &sinfo->block_groups[i]);
7786
7787 spin_unlock(&sinfo->lock);
7788
7789 return free_bytes;
7790 }
7791
7792 void btrfs_set_block_group_rw(struct btrfs_root *root,
7793 struct btrfs_block_group_cache *cache)
7794 {
7795 struct btrfs_space_info *sinfo = cache->space_info;
7796 u64 num_bytes;
7797
7798 BUG_ON(!cache->ro);
7799
7800 spin_lock(&sinfo->lock);
7801 spin_lock(&cache->lock);
7802 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
7803 cache->bytes_super - btrfs_block_group_used(&cache->item);
7804 sinfo->bytes_readonly -= num_bytes;
7805 cache->ro = 0;
7806 spin_unlock(&cache->lock);
7807 spin_unlock(&sinfo->lock);
7808 }
7809
7810 /*
7811 * checks to see if its even possible to relocate this block group.
7812 *
7813 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
7814 * ok to go ahead and try.
7815 */
7816 int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
7817 {
7818 struct btrfs_block_group_cache *block_group;
7819 struct btrfs_space_info *space_info;
7820 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
7821 struct btrfs_device *device;
7822 u64 min_free;
7823 u64 dev_min = 1;
7824 u64 dev_nr = 0;
7825 u64 target;
7826 int index;
7827 int full = 0;
7828 int ret = 0;
7829
7830 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
7831
7832 /* odd, couldn't find the block group, leave it alone */
7833 if (!block_group)
7834 return -1;
7835
7836 min_free = btrfs_block_group_used(&block_group->item);
7837
7838 /* no bytes used, we're good */
7839 if (!min_free)
7840 goto out;
7841
7842 space_info = block_group->space_info;
7843 spin_lock(&space_info->lock);
7844
7845 full = space_info->full;
7846
7847 /*
7848 * if this is the last block group we have in this space, we can't
7849 * relocate it unless we're able to allocate a new chunk below.
7850 *
7851 * Otherwise, we need to make sure we have room in the space to handle
7852 * all of the extents from this block group. If we can, we're good
7853 */
7854 if ((space_info->total_bytes != block_group->key.offset) &&
7855 (space_info->bytes_used + space_info->bytes_reserved +
7856 space_info->bytes_pinned + space_info->bytes_readonly +
7857 min_free < space_info->total_bytes)) {
7858 spin_unlock(&space_info->lock);
7859 goto out;
7860 }
7861 spin_unlock(&space_info->lock);
7862
7863 /*
7864 * ok we don't have enough space, but maybe we have free space on our
7865 * devices to allocate new chunks for relocation, so loop through our
7866 * alloc devices and guess if we have enough space. if this block
7867 * group is going to be restriped, run checks against the target
7868 * profile instead of the current one.
7869 */
7870 ret = -1;
7871
7872 /*
7873 * index:
7874 * 0: raid10
7875 * 1: raid1
7876 * 2: dup
7877 * 3: raid0
7878 * 4: single
7879 */
7880 target = get_restripe_target(root->fs_info, block_group->flags);
7881 if (target) {
7882 index = __get_raid_index(extended_to_chunk(target));
7883 } else {
7884 /*
7885 * this is just a balance, so if we were marked as full
7886 * we know there is no space for a new chunk
7887 */
7888 if (full)
7889 goto out;
7890
7891 index = get_block_group_index(block_group);
7892 }
7893
7894 if (index == BTRFS_RAID_RAID10) {
7895 dev_min = 4;
7896 /* Divide by 2 */
7897 min_free >>= 1;
7898 } else if (index == BTRFS_RAID_RAID1) {
7899 dev_min = 2;
7900 } else if (index == BTRFS_RAID_DUP) {
7901 /* Multiply by 2 */
7902 min_free <<= 1;
7903 } else if (index == BTRFS_RAID_RAID0) {
7904 dev_min = fs_devices->rw_devices;
7905 do_div(min_free, dev_min);
7906 }
7907
7908 mutex_lock(&root->fs_info->chunk_mutex);
7909 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
7910 u64 dev_offset;
7911
7912 /*
7913 * check to make sure we can actually find a chunk with enough
7914 * space to fit our block group in.
7915 */
7916 if (device->total_bytes > device->bytes_used + min_free &&
7917 !device->is_tgtdev_for_dev_replace) {
7918 ret = find_free_dev_extent(device, min_free,
7919 &dev_offset, NULL);
7920 if (!ret)
7921 dev_nr++;
7922
7923 if (dev_nr >= dev_min)
7924 break;
7925
7926 ret = -1;
7927 }
7928 }
7929 mutex_unlock(&root->fs_info->chunk_mutex);
7930 out:
7931 btrfs_put_block_group(block_group);
7932 return ret;
7933 }
7934
7935 static int find_first_block_group(struct btrfs_root *root,
7936 struct btrfs_path *path, struct btrfs_key *key)
7937 {
7938 int ret = 0;
7939 struct btrfs_key found_key;
7940 struct extent_buffer *leaf;
7941 int slot;
7942
7943 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
7944 if (ret < 0)
7945 goto out;
7946
7947 while (1) {
7948 slot = path->slots[0];
7949 leaf = path->nodes[0];
7950 if (slot >= btrfs_header_nritems(leaf)) {
7951 ret = btrfs_next_leaf(root, path);
7952 if (ret == 0)
7953 continue;
7954 if (ret < 0)
7955 goto out;
7956 break;
7957 }
7958 btrfs_item_key_to_cpu(leaf, &found_key, slot);
7959
7960 if (found_key.objectid >= key->objectid &&
7961 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
7962 ret = 0;
7963 goto out;
7964 }
7965 path->slots[0]++;
7966 }
7967 out:
7968 return ret;
7969 }
7970
7971 void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
7972 {
7973 struct btrfs_block_group_cache *block_group;
7974 u64 last = 0;
7975
7976 while (1) {
7977 struct inode *inode;
7978
7979 block_group = btrfs_lookup_first_block_group(info, last);
7980 while (block_group) {
7981 spin_lock(&block_group->lock);
7982 if (block_group->iref)
7983 break;
7984 spin_unlock(&block_group->lock);
7985 block_group = next_block_group(info->tree_root,
7986 block_group);
7987 }
7988 if (!block_group) {
7989 if (last == 0)
7990 break;
7991 last = 0;
7992 continue;
7993 }
7994
7995 inode = block_group->inode;
7996 block_group->iref = 0;
7997 block_group->inode = NULL;
7998 spin_unlock(&block_group->lock);
7999 iput(inode);
8000 last = block_group->key.objectid + block_group->key.offset;
8001 btrfs_put_block_group(block_group);
8002 }
8003 }
8004
8005 int btrfs_free_block_groups(struct btrfs_fs_info *info)
8006 {
8007 struct btrfs_block_group_cache *block_group;
8008 struct btrfs_space_info *space_info;
8009 struct btrfs_caching_control *caching_ctl;
8010 struct rb_node *n;
8011
8012 down_write(&info->extent_commit_sem);
8013 while (!list_empty(&info->caching_block_groups)) {
8014 caching_ctl = list_entry(info->caching_block_groups.next,
8015 struct btrfs_caching_control, list);
8016 list_del(&caching_ctl->list);
8017 put_caching_control(caching_ctl);
8018 }
8019 up_write(&info->extent_commit_sem);
8020
8021 spin_lock(&info->block_group_cache_lock);
8022 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
8023 block_group = rb_entry(n, struct btrfs_block_group_cache,
8024 cache_node);
8025 rb_erase(&block_group->cache_node,
8026 &info->block_group_cache_tree);
8027 spin_unlock(&info->block_group_cache_lock);
8028
8029 down_write(&block_group->space_info->groups_sem);
8030 list_del(&block_group->list);
8031 up_write(&block_group->space_info->groups_sem);
8032
8033 if (block_group->cached == BTRFS_CACHE_STARTED)
8034 wait_block_group_cache_done(block_group);
8035
8036 /*
8037 * We haven't cached this block group, which means we could
8038 * possibly have excluded extents on this block group.
8039 */
8040 if (block_group->cached == BTRFS_CACHE_NO)
8041 free_excluded_extents(info->extent_root, block_group);
8042
8043 btrfs_remove_free_space_cache(block_group);
8044 btrfs_put_block_group(block_group);
8045
8046 spin_lock(&info->block_group_cache_lock);
8047 }
8048 spin_unlock(&info->block_group_cache_lock);
8049
8050 /* now that all the block groups are freed, go through and
8051 * free all the space_info structs. This is only called during
8052 * the final stages of unmount, and so we know nobody is
8053 * using them. We call synchronize_rcu() once before we start,
8054 * just to be on the safe side.
8055 */
8056 synchronize_rcu();
8057
8058 release_global_block_rsv(info);
8059
8060 while(!list_empty(&info->space_info)) {
8061 space_info = list_entry(info->space_info.next,
8062 struct btrfs_space_info,
8063 list);
8064 if (btrfs_test_opt(info->tree_root, ENOSPC_DEBUG)) {
8065 if (space_info->bytes_pinned > 0 ||
8066 space_info->bytes_reserved > 0 ||
8067 space_info->bytes_may_use > 0) {
8068 WARN_ON(1);
8069 dump_space_info(space_info, 0, 0);
8070 }
8071 }
8072 list_del(&space_info->list);
8073 kfree(space_info);
8074 }
8075 return 0;
8076 }
8077
8078 static void __link_block_group(struct btrfs_space_info *space_info,
8079 struct btrfs_block_group_cache *cache)
8080 {
8081 int index = get_block_group_index(cache);
8082
8083 down_write(&space_info->groups_sem);
8084 list_add_tail(&cache->list, &space_info->block_groups[index]);
8085 up_write(&space_info->groups_sem);
8086 }
8087
8088 int btrfs_read_block_groups(struct btrfs_root *root)
8089 {
8090 struct btrfs_path *path;
8091 int ret;
8092 struct btrfs_block_group_cache *cache;
8093 struct btrfs_fs_info *info = root->fs_info;
8094 struct btrfs_space_info *space_info;
8095 struct btrfs_key key;
8096 struct btrfs_key found_key;
8097 struct extent_buffer *leaf;
8098 int need_clear = 0;
8099 u64 cache_gen;
8100
8101 root = info->extent_root;
8102 key.objectid = 0;
8103 key.offset = 0;
8104 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
8105 path = btrfs_alloc_path();
8106 if (!path)
8107 return -ENOMEM;
8108 path->reada = 1;
8109
8110 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
8111 if (btrfs_test_opt(root, SPACE_CACHE) &&
8112 btrfs_super_generation(root->fs_info->super_copy) != cache_gen)
8113 need_clear = 1;
8114 if (btrfs_test_opt(root, CLEAR_CACHE))
8115 need_clear = 1;
8116
8117 while (1) {
8118 ret = find_first_block_group(root, path, &key);
8119 if (ret > 0)
8120 break;
8121 if (ret != 0)
8122 goto error;
8123 leaf = path->nodes[0];
8124 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
8125 cache = kzalloc(sizeof(*cache), GFP_NOFS);
8126 if (!cache) {
8127 ret = -ENOMEM;
8128 goto error;
8129 }
8130 cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
8131 GFP_NOFS);
8132 if (!cache->free_space_ctl) {
8133 kfree(cache);
8134 ret = -ENOMEM;
8135 goto error;
8136 }
8137
8138 atomic_set(&cache->count, 1);
8139 spin_lock_init(&cache->lock);
8140 cache->fs_info = info;
8141 INIT_LIST_HEAD(&cache->list);
8142 INIT_LIST_HEAD(&cache->cluster_list);
8143
8144 if (need_clear) {
8145 /*
8146 * When we mount with old space cache, we need to
8147 * set BTRFS_DC_CLEAR and set dirty flag.
8148 *
8149 * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
8150 * truncate the old free space cache inode and
8151 * setup a new one.
8152 * b) Setting 'dirty flag' makes sure that we flush
8153 * the new space cache info onto disk.
8154 */
8155 cache->disk_cache_state = BTRFS_DC_CLEAR;
8156 if (btrfs_test_opt(root, SPACE_CACHE))
8157 cache->dirty = 1;
8158 }
8159
8160 read_extent_buffer(leaf, &cache->item,
8161 btrfs_item_ptr_offset(leaf, path->slots[0]),
8162 sizeof(cache->item));
8163 memcpy(&cache->key, &found_key, sizeof(found_key));
8164
8165 key.objectid = found_key.objectid + found_key.offset;
8166 btrfs_release_path(path);
8167 cache->flags = btrfs_block_group_flags(&cache->item);
8168 cache->sectorsize = root->sectorsize;
8169 cache->full_stripe_len = btrfs_full_stripe_len(root,
8170 &root->fs_info->mapping_tree,
8171 found_key.objectid);
8172 btrfs_init_free_space_ctl(cache);
8173
8174 /*
8175 * We need to exclude the super stripes now so that the space
8176 * info has super bytes accounted for, otherwise we'll think
8177 * we have more space than we actually do.
8178 */
8179 ret = exclude_super_stripes(root, cache);
8180 if (ret) {
8181 /*
8182 * We may have excluded something, so call this just in
8183 * case.
8184 */
8185 free_excluded_extents(root, cache);
8186 kfree(cache->free_space_ctl);
8187 kfree(cache);
8188 goto error;
8189 }
8190
8191 /*
8192 * check for two cases, either we are full, and therefore
8193 * don't need to bother with the caching work since we won't
8194 * find any space, or we are empty, and we can just add all
8195 * the space in and be done with it. This saves us _alot_ of
8196 * time, particularly in the full case.
8197 */
8198 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
8199 cache->last_byte_to_unpin = (u64)-1;
8200 cache->cached = BTRFS_CACHE_FINISHED;
8201 free_excluded_extents(root, cache);
8202 } else if (btrfs_block_group_used(&cache->item) == 0) {
8203 cache->last_byte_to_unpin = (u64)-1;
8204 cache->cached = BTRFS_CACHE_FINISHED;
8205 add_new_free_space(cache, root->fs_info,
8206 found_key.objectid,
8207 found_key.objectid +
8208 found_key.offset);
8209 free_excluded_extents(root, cache);
8210 }
8211
8212 ret = btrfs_add_block_group_cache(root->fs_info, cache);
8213 if (ret) {
8214 btrfs_remove_free_space_cache(cache);
8215 btrfs_put_block_group(cache);
8216 goto error;
8217 }
8218
8219 ret = update_space_info(info, cache->flags, found_key.offset,
8220 btrfs_block_group_used(&cache->item),
8221 &space_info);
8222 if (ret) {
8223 btrfs_remove_free_space_cache(cache);
8224 spin_lock(&info->block_group_cache_lock);
8225 rb_erase(&cache->cache_node,
8226 &info->block_group_cache_tree);
8227 spin_unlock(&info->block_group_cache_lock);
8228 btrfs_put_block_group(cache);
8229 goto error;
8230 }
8231
8232 cache->space_info = space_info;
8233 spin_lock(&cache->space_info->lock);
8234 cache->space_info->bytes_readonly += cache->bytes_super;
8235 spin_unlock(&cache->space_info->lock);
8236
8237 __link_block_group(space_info, cache);
8238
8239 set_avail_alloc_bits(root->fs_info, cache->flags);
8240 if (btrfs_chunk_readonly(root, cache->key.objectid))
8241 set_block_group_ro(cache, 1);
8242 }
8243
8244 list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
8245 if (!(get_alloc_profile(root, space_info->flags) &
8246 (BTRFS_BLOCK_GROUP_RAID10 |
8247 BTRFS_BLOCK_GROUP_RAID1 |
8248 BTRFS_BLOCK_GROUP_RAID5 |
8249 BTRFS_BLOCK_GROUP_RAID6 |
8250 BTRFS_BLOCK_GROUP_DUP)))
8251 continue;
8252 /*
8253 * avoid allocating from un-mirrored block group if there are
8254 * mirrored block groups.
8255 */
8256 list_for_each_entry(cache, &space_info->block_groups[3], list)
8257 set_block_group_ro(cache, 1);
8258 list_for_each_entry(cache, &space_info->block_groups[4], list)
8259 set_block_group_ro(cache, 1);
8260 }
8261
8262 init_global_block_rsv(info);
8263 ret = 0;
8264 error:
8265 btrfs_free_path(path);
8266 return ret;
8267 }
8268
8269 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
8270 struct btrfs_root *root)
8271 {
8272 struct btrfs_block_group_cache *block_group, *tmp;
8273 struct btrfs_root *extent_root = root->fs_info->extent_root;
8274 struct btrfs_block_group_item item;
8275 struct btrfs_key key;
8276 int ret = 0;
8277
8278 list_for_each_entry_safe(block_group, tmp, &trans->new_bgs,
8279 new_bg_list) {
8280 list_del_init(&block_group->new_bg_list);
8281
8282 if (ret)
8283 continue;
8284
8285 spin_lock(&block_group->lock);
8286 memcpy(&item, &block_group->item, sizeof(item));
8287 memcpy(&key, &block_group->key, sizeof(key));
8288 spin_unlock(&block_group->lock);
8289
8290 ret = btrfs_insert_item(trans, extent_root, &key, &item,
8291 sizeof(item));
8292 if (ret)
8293 btrfs_abort_transaction(trans, extent_root, ret);
8294 }
8295 }
8296
8297 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
8298 struct btrfs_root *root, u64 bytes_used,
8299 u64 type, u64 chunk_objectid, u64 chunk_offset,
8300 u64 size)
8301 {
8302 int ret;
8303 struct btrfs_root *extent_root;
8304 struct btrfs_block_group_cache *cache;
8305
8306 extent_root = root->fs_info->extent_root;
8307
8308 root->fs_info->last_trans_log_full_commit = trans->transid;
8309
8310 cache = kzalloc(sizeof(*cache), GFP_NOFS);
8311 if (!cache)
8312 return -ENOMEM;
8313 cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
8314 GFP_NOFS);
8315 if (!cache->free_space_ctl) {
8316 kfree(cache);
8317 return -ENOMEM;
8318 }
8319
8320 cache->key.objectid = chunk_offset;
8321 cache->key.offset = size;
8322 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
8323 cache->sectorsize = root->sectorsize;
8324 cache->fs_info = root->fs_info;
8325 cache->full_stripe_len = btrfs_full_stripe_len(root,
8326 &root->fs_info->mapping_tree,
8327 chunk_offset);
8328
8329 atomic_set(&cache->count, 1);
8330 spin_lock_init(&cache->lock);
8331 INIT_LIST_HEAD(&cache->list);
8332 INIT_LIST_HEAD(&cache->cluster_list);
8333 INIT_LIST_HEAD(&cache->new_bg_list);
8334
8335 btrfs_init_free_space_ctl(cache);
8336
8337 btrfs_set_block_group_used(&cache->item, bytes_used);
8338 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
8339 cache->flags = type;
8340 btrfs_set_block_group_flags(&cache->item, type);
8341
8342 cache->last_byte_to_unpin = (u64)-1;
8343 cache->cached = BTRFS_CACHE_FINISHED;
8344 ret = exclude_super_stripes(root, cache);
8345 if (ret) {
8346 /*
8347 * We may have excluded something, so call this just in
8348 * case.
8349 */
8350 free_excluded_extents(root, cache);
8351 kfree(cache->free_space_ctl);
8352 kfree(cache);
8353 return ret;
8354 }
8355
8356 add_new_free_space(cache, root->fs_info, chunk_offset,
8357 chunk_offset + size);
8358
8359 free_excluded_extents(root, cache);
8360
8361 ret = btrfs_add_block_group_cache(root->fs_info, cache);
8362 if (ret) {
8363 btrfs_remove_free_space_cache(cache);
8364 btrfs_put_block_group(cache);
8365 return ret;
8366 }
8367
8368 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
8369 &cache->space_info);
8370 if (ret) {
8371 btrfs_remove_free_space_cache(cache);
8372 spin_lock(&root->fs_info->block_group_cache_lock);
8373 rb_erase(&cache->cache_node,
8374 &root->fs_info->block_group_cache_tree);
8375 spin_unlock(&root->fs_info->block_group_cache_lock);
8376 btrfs_put_block_group(cache);
8377 return ret;
8378 }
8379 update_global_block_rsv(root->fs_info);
8380
8381 spin_lock(&cache->space_info->lock);
8382 cache->space_info->bytes_readonly += cache->bytes_super;
8383 spin_unlock(&cache->space_info->lock);
8384
8385 __link_block_group(cache->space_info, cache);
8386
8387 list_add_tail(&cache->new_bg_list, &trans->new_bgs);
8388
8389 set_avail_alloc_bits(extent_root->fs_info, type);
8390
8391 return 0;
8392 }
8393
8394 static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
8395 {
8396 u64 extra_flags = chunk_to_extended(flags) &
8397 BTRFS_EXTENDED_PROFILE_MASK;
8398
8399 write_seqlock(&fs_info->profiles_lock);
8400 if (flags & BTRFS_BLOCK_GROUP_DATA)
8401 fs_info->avail_data_alloc_bits &= ~extra_flags;
8402 if (flags & BTRFS_BLOCK_GROUP_METADATA)
8403 fs_info->avail_metadata_alloc_bits &= ~extra_flags;
8404 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
8405 fs_info->avail_system_alloc_bits &= ~extra_flags;
8406 write_sequnlock(&fs_info->profiles_lock);
8407 }
8408
8409 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
8410 struct btrfs_root *root, u64 group_start)
8411 {
8412 struct btrfs_path *path;
8413 struct btrfs_block_group_cache *block_group;
8414 struct btrfs_free_cluster *cluster;
8415 struct btrfs_root *tree_root = root->fs_info->tree_root;
8416 struct btrfs_key key;
8417 struct inode *inode;
8418 int ret;
8419 int index;
8420 int factor;
8421
8422 root = root->fs_info->extent_root;
8423
8424 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
8425 BUG_ON(!block_group);
8426 BUG_ON(!block_group->ro);
8427
8428 /*
8429 * Free the reserved super bytes from this block group before
8430 * remove it.
8431 */
8432 free_excluded_extents(root, block_group);
8433
8434 memcpy(&key, &block_group->key, sizeof(key));
8435 index = get_block_group_index(block_group);
8436 if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
8437 BTRFS_BLOCK_GROUP_RAID1 |
8438 BTRFS_BLOCK_GROUP_RAID10))
8439 factor = 2;
8440 else
8441 factor = 1;
8442
8443 /* make sure this block group isn't part of an allocation cluster */
8444 cluster = &root->fs_info->data_alloc_cluster;
8445 spin_lock(&cluster->refill_lock);
8446 btrfs_return_cluster_to_free_space(block_group, cluster);
8447 spin_unlock(&cluster->refill_lock);
8448
8449 /*
8450 * make sure this block group isn't part of a metadata
8451 * allocation cluster
8452 */
8453 cluster = &root->fs_info->meta_alloc_cluster;
8454 spin_lock(&cluster->refill_lock);
8455 btrfs_return_cluster_to_free_space(block_group, cluster);
8456 spin_unlock(&cluster->refill_lock);
8457
8458 path = btrfs_alloc_path();
8459 if (!path) {
8460 ret = -ENOMEM;
8461 goto out;
8462 }
8463
8464 inode = lookup_free_space_inode(tree_root, block_group, path);
8465 if (!IS_ERR(inode)) {
8466 ret = btrfs_orphan_add(trans, inode);
8467 if (ret) {
8468 btrfs_add_delayed_iput(inode);
8469 goto out;
8470 }
8471 clear_nlink(inode);
8472 /* One for the block groups ref */
8473 spin_lock(&block_group->lock);
8474 if (block_group->iref) {
8475 block_group->iref = 0;
8476 block_group->inode = NULL;
8477 spin_unlock(&block_group->lock);
8478 iput(inode);
8479 } else {
8480 spin_unlock(&block_group->lock);
8481 }
8482 /* One for our lookup ref */
8483 btrfs_add_delayed_iput(inode);
8484 }
8485
8486 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
8487 key.offset = block_group->key.objectid;
8488 key.type = 0;
8489
8490 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
8491 if (ret < 0)
8492 goto out;
8493 if (ret > 0)
8494 btrfs_release_path(path);
8495 if (ret == 0) {
8496 ret = btrfs_del_item(trans, tree_root, path);
8497 if (ret)
8498 goto out;
8499 btrfs_release_path(path);
8500 }
8501
8502 spin_lock(&root->fs_info->block_group_cache_lock);
8503 rb_erase(&block_group->cache_node,
8504 &root->fs_info->block_group_cache_tree);
8505
8506 if (root->fs_info->first_logical_byte == block_group->key.objectid)
8507 root->fs_info->first_logical_byte = (u64)-1;
8508 spin_unlock(&root->fs_info->block_group_cache_lock);
8509
8510 down_write(&block_group->space_info->groups_sem);
8511 /*
8512 * we must use list_del_init so people can check to see if they
8513 * are still on the list after taking the semaphore
8514 */
8515 list_del_init(&block_group->list);
8516 if (list_empty(&block_group->space_info->block_groups[index]))
8517 clear_avail_alloc_bits(root->fs_info, block_group->flags);
8518 up_write(&block_group->space_info->groups_sem);
8519
8520 if (block_group->cached == BTRFS_CACHE_STARTED)
8521 wait_block_group_cache_done(block_group);
8522
8523 btrfs_remove_free_space_cache(block_group);
8524
8525 spin_lock(&block_group->space_info->lock);
8526 block_group->space_info->total_bytes -= block_group->key.offset;
8527 block_group->space_info->bytes_readonly -= block_group->key.offset;
8528 block_group->space_info->disk_total -= block_group->key.offset * factor;
8529 spin_unlock(&block_group->space_info->lock);
8530
8531 memcpy(&key, &block_group->key, sizeof(key));
8532
8533 btrfs_clear_space_info_full(root->fs_info);
8534
8535 btrfs_put_block_group(block_group);
8536 btrfs_put_block_group(block_group);
8537
8538 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
8539 if (ret > 0)
8540 ret = -EIO;
8541 if (ret < 0)
8542 goto out;
8543
8544 ret = btrfs_del_item(trans, root, path);
8545 out:
8546 btrfs_free_path(path);
8547 return ret;
8548 }
8549
8550 int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
8551 {
8552 struct btrfs_space_info *space_info;
8553 struct btrfs_super_block *disk_super;
8554 u64 features;
8555 u64 flags;
8556 int mixed = 0;
8557 int ret;
8558
8559 disk_super = fs_info->super_copy;
8560 if (!btrfs_super_root(disk_super))
8561 return 1;
8562
8563 features = btrfs_super_incompat_flags(disk_super);
8564 if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
8565 mixed = 1;
8566
8567 flags = BTRFS_BLOCK_GROUP_SYSTEM;
8568 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
8569 if (ret)
8570 goto out;
8571
8572 if (mixed) {
8573 flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
8574 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
8575 } else {
8576 flags = BTRFS_BLOCK_GROUP_METADATA;
8577 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
8578 if (ret)
8579 goto out;
8580
8581 flags = BTRFS_BLOCK_GROUP_DATA;
8582 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
8583 }
8584 out:
8585 return ret;
8586 }
8587
8588 int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
8589 {
8590 return unpin_extent_range(root, start, end);
8591 }
8592
8593 int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
8594 u64 num_bytes, u64 *actual_bytes)
8595 {
8596 return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
8597 }
8598
8599 int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
8600 {
8601 struct btrfs_fs_info *fs_info = root->fs_info;
8602 struct btrfs_block_group_cache *cache = NULL;
8603 u64 group_trimmed;
8604 u64 start;
8605 u64 end;
8606 u64 trimmed = 0;
8607 u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
8608 int ret = 0;
8609
8610 /*
8611 * try to trim all FS space, our block group may start from non-zero.
8612 */
8613 if (range->len == total_bytes)
8614 cache = btrfs_lookup_first_block_group(fs_info, range->start);
8615 else
8616 cache = btrfs_lookup_block_group(fs_info, range->start);
8617
8618 while (cache) {
8619 if (cache->key.objectid >= (range->start + range->len)) {
8620 btrfs_put_block_group(cache);
8621 break;
8622 }
8623
8624 start = max(range->start, cache->key.objectid);
8625 end = min(range->start + range->len,
8626 cache->key.objectid + cache->key.offset);
8627
8628 if (end - start >= range->minlen) {
8629 if (!block_group_cache_done(cache)) {
8630 ret = cache_block_group(cache, 0);
8631 if (!ret)
8632 wait_block_group_cache_done(cache);
8633 }
8634 ret = btrfs_trim_block_group(cache,
8635 &group_trimmed,
8636 start,
8637 end,
8638 range->minlen);
8639
8640 trimmed += group_trimmed;
8641 if (ret) {
8642 btrfs_put_block_group(cache);
8643 break;
8644 }
8645 }
8646
8647 cache = next_block_group(fs_info->tree_root, cache);
8648 }
8649
8650 range->len = trimmed;
8651 return ret;
8652 }
Linux kernel - Deliverables
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