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drm/gem: implement vma access management
[linux-2.6.git] / fs / btrfs / extent-tree.c
blob1204c8ef6f32751bd859d2ef1a2ab3444061f708
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 <linux/percpu_counter.h>
28 #include "compat.h"
29 #include "hash.h"
30 #include "ctree.h"
31 #include "disk-io.h"
32 #include "print-tree.h"
33 #include "transaction.h"
34 #include "volumes.h"
35 #include "raid56.h"
36 #include "locking.h"
37 #include "free-space-cache.h"
38 #include "math.h"
39
40 #undef SCRAMBLE_DELAYED_REFS
41
42 /*
43 * control flags for do_chunk_alloc's force field
44 * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
45 * if we really need one.
46 *
47 * CHUNK_ALLOC_LIMITED means to only try and allocate one
48 * if we have very few chunks already allocated. This is
49 * used as part of the clustering code to help make sure
50 * we have a good pool of storage to cluster in, without
51 * filling the FS with empty chunks
52 *
53 * CHUNK_ALLOC_FORCE means it must try to allocate one
54 *
55 */
56 enum {
57 CHUNK_ALLOC_NO_FORCE = 0,
58 CHUNK_ALLOC_LIMITED = 1,
59 CHUNK_ALLOC_FORCE = 2,
60 };
61
62 /*
63 * Control how reservations are dealt with.
64 *
65 * RESERVE_FREE - freeing a reservation.
66 * RESERVE_ALLOC - allocating space and we need to update bytes_may_use for
67 * ENOSPC accounting
68 * RESERVE_ALLOC_NO_ACCOUNT - allocating space and we should not update
69 * bytes_may_use as the ENOSPC accounting is done elsewhere
70 */
71 enum {
72 RESERVE_FREE = 0,
73 RESERVE_ALLOC = 1,
74 RESERVE_ALLOC_NO_ACCOUNT = 2,
75 };
76
77 static int update_block_group(struct btrfs_root *root,
78 u64 bytenr, u64 num_bytes, int alloc);
79 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
80 struct btrfs_root *root,
81 u64 bytenr, u64 num_bytes, u64 parent,
82 u64 root_objectid, u64 owner_objectid,
83 u64 owner_offset, int refs_to_drop,
84 struct btrfs_delayed_extent_op *extra_op);
85 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
86 struct extent_buffer *leaf,
87 struct btrfs_extent_item *ei);
88 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
89 struct btrfs_root *root,
90 u64 parent, u64 root_objectid,
91 u64 flags, u64 owner, u64 offset,
92 struct btrfs_key *ins, int ref_mod);
93 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
94 struct btrfs_root *root,
95 u64 parent, u64 root_objectid,
96 u64 flags, struct btrfs_disk_key *key,
97 int level, struct btrfs_key *ins);
98 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
99 struct btrfs_root *extent_root, u64 flags,
100 int force);
101 static int find_next_key(struct btrfs_path *path, int level,
102 struct btrfs_key *key);
103 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
104 int dump_block_groups);
105 static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
106 u64 num_bytes, int reserve);
107 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
108 u64 num_bytes);
109 int btrfs_pin_extent(struct btrfs_root *root,
110 u64 bytenr, u64 num_bytes, int reserved);
111
112 static noinline int
113 block_group_cache_done(struct btrfs_block_group_cache *cache)
114 {
115 smp_mb();
116 return cache->cached == BTRFS_CACHE_FINISHED;
117 }
118
119 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
120 {
121 return (cache->flags & bits) == bits;
122 }
123
124 static void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
125 {
126 atomic_inc(&cache->count);
127 }
128
129 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
130 {
131 if (atomic_dec_and_test(&cache->count)) {
132 WARN_ON(cache->pinned > 0);
133 WARN_ON(cache->reserved > 0);
134 kfree(cache->free_space_ctl);
135 kfree(cache);
136 }
137 }
138
139 /*
140 * this adds the block group to the fs_info rb tree for the block group
141 * cache
142 */
143 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
144 struct btrfs_block_group_cache *block_group)
145 {
146 struct rb_node **p;
147 struct rb_node *parent = NULL;
148 struct btrfs_block_group_cache *cache;
149
150 spin_lock(&info->block_group_cache_lock);
151 p = &info->block_group_cache_tree.rb_node;
152
153 while (*p) {
154 parent = *p;
155 cache = rb_entry(parent, struct btrfs_block_group_cache,
156 cache_node);
157 if (block_group->key.objectid < cache->key.objectid) {
158 p = &(*p)->rb_left;
159 } else if (block_group->key.objectid > cache->key.objectid) {
160 p = &(*p)->rb_right;
161 } else {
162 spin_unlock(&info->block_group_cache_lock);
163 return -EEXIST;
164 }
165 }
166
167 rb_link_node(&block_group->cache_node, parent, p);
168 rb_insert_color(&block_group->cache_node,
169 &info->block_group_cache_tree);
170
171 if (info->first_logical_byte > block_group->key.objectid)
172 info->first_logical_byte = block_group->key.objectid;
173
174 spin_unlock(&info->block_group_cache_lock);
175
176 return 0;
177 }
178
179 /*
180 * This will return the block group at or after bytenr if contains is 0, else
181 * it will return the block group that contains the bytenr
182 */
183 static struct btrfs_block_group_cache *
184 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
185 int contains)
186 {
187 struct btrfs_block_group_cache *cache, *ret = NULL;
188 struct rb_node *n;
189 u64 end, start;
190
191 spin_lock(&info->block_group_cache_lock);
192 n = info->block_group_cache_tree.rb_node;
193
194 while (n) {
195 cache = rb_entry(n, struct btrfs_block_group_cache,
196 cache_node);
197 end = cache->key.objectid + cache->key.offset - 1;
198 start = cache->key.objectid;
199
200 if (bytenr < start) {
201 if (!contains && (!ret || start < ret->key.objectid))
202 ret = cache;
203 n = n->rb_left;
204 } else if (bytenr > start) {
205 if (contains && bytenr <= end) {
206 ret = cache;
207 break;
208 }
209 n = n->rb_right;
210 } else {
211 ret = cache;
212 break;
213 }
214 }
215 if (ret) {
216 btrfs_get_block_group(ret);
217 if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
218 info->first_logical_byte = ret->key.objectid;
219 }
220 spin_unlock(&info->block_group_cache_lock);
221
222 return ret;
223 }
224
225 static int add_excluded_extent(struct btrfs_root *root,
226 u64 start, u64 num_bytes)
227 {
228 u64 end = start + num_bytes - 1;
229 set_extent_bits(&root->fs_info->freed_extents[0],
230 start, end, EXTENT_UPTODATE, GFP_NOFS);
231 set_extent_bits(&root->fs_info->freed_extents[1],
232 start, end, EXTENT_UPTODATE, GFP_NOFS);
233 return 0;
234 }
235
236 static void free_excluded_extents(struct btrfs_root *root,
237 struct btrfs_block_group_cache *cache)
238 {
239 u64 start, end;
240
241 start = cache->key.objectid;
242 end = start + cache->key.offset - 1;
243
244 clear_extent_bits(&root->fs_info->freed_extents[0],
245 start, end, EXTENT_UPTODATE, GFP_NOFS);
246 clear_extent_bits(&root->fs_info->freed_extents[1],
247 start, end, EXTENT_UPTODATE, GFP_NOFS);
248 }
249
250 static int exclude_super_stripes(struct btrfs_root *root,
251 struct btrfs_block_group_cache *cache)
252 {
253 u64 bytenr;
254 u64 *logical;
255 int stripe_len;
256 int i, nr, ret;
257
258 if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
259 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
260 cache->bytes_super += stripe_len;
261 ret = add_excluded_extent(root, cache->key.objectid,
262 stripe_len);
263 if (ret)
264 return ret;
265 }
266
267 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
268 bytenr = btrfs_sb_offset(i);
269 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
270 cache->key.objectid, bytenr,
271 0, &logical, &nr, &stripe_len);
272 if (ret)
273 return ret;
274
275 while (nr--) {
276 u64 start, len;
277
278 if (logical[nr] > cache->key.objectid +
279 cache->key.offset)
280 continue;
281
282 if (logical[nr] + stripe_len <= cache->key.objectid)
283 continue;
284
285 start = logical[nr];
286 if (start < cache->key.objectid) {
287 start = cache->key.objectid;
288 len = (logical[nr] + stripe_len) - start;
289 } else {
290 len = min_t(u64, stripe_len,
291 cache->key.objectid +
292 cache->key.offset - start);
293 }
294
295 cache->bytes_super += len;
296 ret = add_excluded_extent(root, start, len);
297 if (ret) {
298 kfree(logical);
299 return ret;
300 }
301 }
302
303 kfree(logical);
304 }
305 return 0;
306 }
307
308 static struct btrfs_caching_control *
309 get_caching_control(struct btrfs_block_group_cache *cache)
310 {
311 struct btrfs_caching_control *ctl;
312
313 spin_lock(&cache->lock);
314 if (cache->cached != BTRFS_CACHE_STARTED) {
315 spin_unlock(&cache->lock);
316 return NULL;
317 }
318
319 /* We're loading it the fast way, so we don't have a caching_ctl. */
320 if (!cache->caching_ctl) {
321 spin_unlock(&cache->lock);
322 return NULL;
323 }
324
325 ctl = cache->caching_ctl;
326 atomic_inc(&ctl->count);
327 spin_unlock(&cache->lock);
328 return ctl;
329 }
330
331 static void put_caching_control(struct btrfs_caching_control *ctl)
332 {
333 if (atomic_dec_and_test(&ctl->count))
334 kfree(ctl);
335 }
336
337 /*
338 * this is only called by cache_block_group, since we could have freed extents
339 * we need to check the pinned_extents for any extents that can't be used yet
340 * since their free space will be released as soon as the transaction commits.
341 */
342 static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
343 struct btrfs_fs_info *info, u64 start, u64 end)
344 {
345 u64 extent_start, extent_end, size, total_added = 0;
346 int ret;
347
348 while (start < end) {
349 ret = find_first_extent_bit(info->pinned_extents, start,
350 &extent_start, &extent_end,
351 EXTENT_DIRTY | EXTENT_UPTODATE,
352 NULL);
353 if (ret)
354 break;
355
356 if (extent_start <= start) {
357 start = extent_end + 1;
358 } else if (extent_start > start && extent_start < end) {
359 size = extent_start - start;
360 total_added += size;
361 ret = btrfs_add_free_space(block_group, start,
362 size);
363 BUG_ON(ret); /* -ENOMEM or logic error */
364 start = extent_end + 1;
365 } else {
366 break;
367 }
368 }
369
370 if (start < end) {
371 size = end - start;
372 total_added += size;
373 ret = btrfs_add_free_space(block_group, start, size);
374 BUG_ON(ret); /* -ENOMEM or logic error */
375 }
376
377 return total_added;
378 }
379
380 static noinline void caching_thread(struct btrfs_work *work)
381 {
382 struct btrfs_block_group_cache *block_group;
383 struct btrfs_fs_info *fs_info;
384 struct btrfs_caching_control *caching_ctl;
385 struct btrfs_root *extent_root;
386 struct btrfs_path *path;
387 struct extent_buffer *leaf;
388 struct btrfs_key key;
389 u64 total_found = 0;
390 u64 last = 0;
391 u32 nritems;
392 int ret = 0;
393
394 caching_ctl = container_of(work, struct btrfs_caching_control, work);
395 block_group = caching_ctl->block_group;
396 fs_info = block_group->fs_info;
397 extent_root = fs_info->extent_root;
398
399 path = btrfs_alloc_path();
400 if (!path)
401 goto out;
402
403 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
404
405 /*
406 * We don't want to deadlock with somebody trying to allocate a new
407 * extent for the extent root while also trying to search the extent
408 * root to add free space. So we skip locking and search the commit
409 * root, since its read-only
410 */
411 path->skip_locking = 1;
412 path->search_commit_root = 1;
413 path->reada = 1;
414
415 key.objectid = last;
416 key.offset = 0;
417 key.type = BTRFS_EXTENT_ITEM_KEY;
418 again:
419 mutex_lock(&caching_ctl->mutex);
420 /* need to make sure the commit_root doesn't disappear */
421 down_read(&fs_info->extent_commit_sem);
422
423 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
424 if (ret < 0)
425 goto err;
426
427 leaf = path->nodes[0];
428 nritems = btrfs_header_nritems(leaf);
429
430 while (1) {
431 if (btrfs_fs_closing(fs_info) > 1) {
432 last = (u64)-1;
433 break;
434 }
435
436 if (path->slots[0] < nritems) {
437 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
438 } else {
439 ret = find_next_key(path, 0, &key);
440 if (ret)
441 break;
442
443 if (need_resched()) {
444 caching_ctl->progress = last;
445 btrfs_release_path(path);
446 up_read(&fs_info->extent_commit_sem);
447 mutex_unlock(&caching_ctl->mutex);
448 cond_resched();
449 goto again;
450 }
451
452 ret = btrfs_next_leaf(extent_root, path);
453 if (ret < 0)
454 goto err;
455 if (ret)
456 break;
457 leaf = path->nodes[0];
458 nritems = btrfs_header_nritems(leaf);
459 continue;
460 }
461
462 if (key.objectid < block_group->key.objectid) {
463 path->slots[0]++;
464 continue;
465 }
466
467 if (key.objectid >= block_group->key.objectid +
468 block_group->key.offset)
469 break;
470
471 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
472 key.type == BTRFS_METADATA_ITEM_KEY) {
473 total_found += add_new_free_space(block_group,
474 fs_info, last,
475 key.objectid);
476 if (key.type == BTRFS_METADATA_ITEM_KEY)
477 last = key.objectid +
478 fs_info->tree_root->leafsize;
479 else
480 last = key.objectid + key.offset;
481
482 if (total_found > (1024 * 1024 * 2)) {
483 total_found = 0;
484 wake_up(&caching_ctl->wait);
485 }
486 }
487 path->slots[0]++;
488 }
489 ret = 0;
490
491 total_found += add_new_free_space(block_group, fs_info, last,
492 block_group->key.objectid +
493 block_group->key.offset);
494 caching_ctl->progress = (u64)-1;
495
496 spin_lock(&block_group->lock);
497 block_group->caching_ctl = NULL;
498 block_group->cached = BTRFS_CACHE_FINISHED;
499 spin_unlock(&block_group->lock);
500
501 err:
502 btrfs_free_path(path);
503 up_read(&fs_info->extent_commit_sem);
504
505 free_excluded_extents(extent_root, block_group);
506
507 mutex_unlock(&caching_ctl->mutex);
508 out:
509 wake_up(&caching_ctl->wait);
510
511 put_caching_control(caching_ctl);
512 btrfs_put_block_group(block_group);
513 }
514
515 static int cache_block_group(struct btrfs_block_group_cache *cache,
516 int load_cache_only)
517 {
518 DEFINE_WAIT(wait);
519 struct btrfs_fs_info *fs_info = cache->fs_info;
520 struct btrfs_caching_control *caching_ctl;
521 int ret = 0;
522
523 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
524 if (!caching_ctl)
525 return -ENOMEM;
526
527 INIT_LIST_HEAD(&caching_ctl->list);
528 mutex_init(&caching_ctl->mutex);
529 init_waitqueue_head(&caching_ctl->wait);
530 caching_ctl->block_group = cache;
531 caching_ctl->progress = cache->key.objectid;
532 atomic_set(&caching_ctl->count, 1);
533 caching_ctl->work.func = caching_thread;
534
535 spin_lock(&cache->lock);
536 /*
537 * This should be a rare occasion, but this could happen I think in the
538 * case where one thread starts to load the space cache info, and then
539 * some other thread starts a transaction commit which tries to do an
540 * allocation while the other thread is still loading the space cache
541 * info. The previous loop should have kept us from choosing this block
542 * group, but if we've moved to the state where we will wait on caching
543 * block groups we need to first check if we're doing a fast load here,
544 * so we can wait for it to finish, otherwise we could end up allocating
545 * from a block group who's cache gets evicted for one reason or
546 * another.
547 */
548 while (cache->cached == BTRFS_CACHE_FAST) {
549 struct btrfs_caching_control *ctl;
550
551 ctl = cache->caching_ctl;
552 atomic_inc(&ctl->count);
553 prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
554 spin_unlock(&cache->lock);
555
556 schedule();
557
558 finish_wait(&ctl->wait, &wait);
559 put_caching_control(ctl);
560 spin_lock(&cache->lock);
561 }
562
563 if (cache->cached != BTRFS_CACHE_NO) {
564 spin_unlock(&cache->lock);
565 kfree(caching_ctl);
566 return 0;
567 }
568 WARN_ON(cache->caching_ctl);
569 cache->caching_ctl = caching_ctl;
570 cache->cached = BTRFS_CACHE_FAST;
571 spin_unlock(&cache->lock);
572
573 if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) {
574 ret = load_free_space_cache(fs_info, cache);
575
576 spin_lock(&cache->lock);
577 if (ret == 1) {
578 cache->caching_ctl = NULL;
579 cache->cached = BTRFS_CACHE_FINISHED;
580 cache->last_byte_to_unpin = (u64)-1;
581 } else {
582 if (load_cache_only) {
583 cache->caching_ctl = NULL;
584 cache->cached = BTRFS_CACHE_NO;
585 } else {
586 cache->cached = BTRFS_CACHE_STARTED;
587 }
588 }
589 spin_unlock(&cache->lock);
590 wake_up(&caching_ctl->wait);
591 if (ret == 1) {
592 put_caching_control(caching_ctl);
593 free_excluded_extents(fs_info->extent_root, cache);
594 return 0;
595 }
596 } else {
597 /*
598 * We are not going to do the fast caching, set cached to the
599 * appropriate value and wakeup any waiters.
600 */
601 spin_lock(&cache->lock);
602 if (load_cache_only) {
603 cache->caching_ctl = NULL;
604 cache->cached = BTRFS_CACHE_NO;
605 } else {
606 cache->cached = BTRFS_CACHE_STARTED;
607 }
608 spin_unlock(&cache->lock);
609 wake_up(&caching_ctl->wait);
610 }
611
612 if (load_cache_only) {
613 put_caching_control(caching_ctl);
614 return 0;
615 }
616
617 down_write(&fs_info->extent_commit_sem);
618 atomic_inc(&caching_ctl->count);
619 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
620 up_write(&fs_info->extent_commit_sem);
621
622 btrfs_get_block_group(cache);
623
624 btrfs_queue_worker(&fs_info->caching_workers, &caching_ctl->work);
625
626 return ret;
627 }
628
629 /*
630 * return the block group that starts at or after bytenr
631 */
632 static struct btrfs_block_group_cache *
633 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
634 {
635 struct btrfs_block_group_cache *cache;
636
637 cache = block_group_cache_tree_search(info, bytenr, 0);
638
639 return cache;
640 }
641
642 /*
643 * return the block group that contains the given bytenr
644 */
645 struct btrfs_block_group_cache *btrfs_lookup_block_group(
646 struct btrfs_fs_info *info,
647 u64 bytenr)
648 {
649 struct btrfs_block_group_cache *cache;
650
651 cache = block_group_cache_tree_search(info, bytenr, 1);
652
653 return cache;
654 }
655
656 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
657 u64 flags)
658 {
659 struct list_head *head = &info->space_info;
660 struct btrfs_space_info *found;
661
662 flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
663
664 rcu_read_lock();
665 list_for_each_entry_rcu(found, head, list) {
666 if (found->flags & flags) {
667 rcu_read_unlock();
668 return found;
669 }
670 }
671 rcu_read_unlock();
672 return NULL;
673 }
674
675 /*
676 * after adding space to the filesystem, we need to clear the full flags
677 * on all the space infos.
678 */
679 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
680 {
681 struct list_head *head = &info->space_info;
682 struct btrfs_space_info *found;
683
684 rcu_read_lock();
685 list_for_each_entry_rcu(found, head, list)
686 found->full = 0;
687 rcu_read_unlock();
688 }
689
690 /* simple helper to search for an existing extent at a given offset */
691 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
692 {
693 int ret;
694 struct btrfs_key key;
695 struct btrfs_path *path;
696
697 path = btrfs_alloc_path();
698 if (!path)
699 return -ENOMEM;
700
701 key.objectid = start;
702 key.offset = len;
703 key.type = BTRFS_EXTENT_ITEM_KEY;
704 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
705 0, 0);
706 if (ret > 0) {
707 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
708 if (key.objectid == start &&
709 key.type == BTRFS_METADATA_ITEM_KEY)
710 ret = 0;
711 }
712 btrfs_free_path(path);
713 return ret;
714 }
715
716 /*
717 * helper function to lookup reference count and flags of a tree block.
718 *
719 * the head node for delayed ref is used to store the sum of all the
720 * reference count modifications queued up in the rbtree. the head
721 * node may also store the extent flags to set. This way you can check
722 * to see what the reference count and extent flags would be if all of
723 * the delayed refs are not processed.
724 */
725 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
726 struct btrfs_root *root, u64 bytenr,
727 u64 offset, int metadata, u64 *refs, u64 *flags)
728 {
729 struct btrfs_delayed_ref_head *head;
730 struct btrfs_delayed_ref_root *delayed_refs;
731 struct btrfs_path *path;
732 struct btrfs_extent_item *ei;
733 struct extent_buffer *leaf;
734 struct btrfs_key key;
735 u32 item_size;
736 u64 num_refs;
737 u64 extent_flags;
738 int ret;
739
740 /*
741 * If we don't have skinny metadata, don't bother doing anything
742 * different
743 */
744 if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) {
745 offset = root->leafsize;
746 metadata = 0;
747 }
748
749 path = btrfs_alloc_path();
750 if (!path)
751 return -ENOMEM;
752
753 if (metadata) {
754 key.objectid = bytenr;
755 key.type = BTRFS_METADATA_ITEM_KEY;
756 key.offset = offset;
757 } else {
758 key.objectid = bytenr;
759 key.type = BTRFS_EXTENT_ITEM_KEY;
760 key.offset = offset;
761 }
762
763 if (!trans) {
764 path->skip_locking = 1;
765 path->search_commit_root = 1;
766 }
767 again:
768 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
769 &key, path, 0, 0);
770 if (ret < 0)
771 goto out_free;
772
773 if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
774 key.type = BTRFS_EXTENT_ITEM_KEY;
775 key.offset = root->leafsize;
776 btrfs_release_path(path);
777 goto again;
778 }
779
780 if (ret == 0) {
781 leaf = path->nodes[0];
782 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
783 if (item_size >= sizeof(*ei)) {
784 ei = btrfs_item_ptr(leaf, path->slots[0],
785 struct btrfs_extent_item);
786 num_refs = btrfs_extent_refs(leaf, ei);
787 extent_flags = btrfs_extent_flags(leaf, ei);
788 } else {
789 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
790 struct btrfs_extent_item_v0 *ei0;
791 BUG_ON(item_size != sizeof(*ei0));
792 ei0 = btrfs_item_ptr(leaf, path->slots[0],
793 struct btrfs_extent_item_v0);
794 num_refs = btrfs_extent_refs_v0(leaf, ei0);
795 /* FIXME: this isn't correct for data */
796 extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
797 #else
798 BUG();
799 #endif
800 }
801 BUG_ON(num_refs == 0);
802 } else {
803 num_refs = 0;
804 extent_flags = 0;
805 ret = 0;
806 }
807
808 if (!trans)
809 goto out;
810
811 delayed_refs = &trans->transaction->delayed_refs;
812 spin_lock(&delayed_refs->lock);
813 head = btrfs_find_delayed_ref_head(trans, bytenr);
814 if (head) {
815 if (!mutex_trylock(&head->mutex)) {
816 atomic_inc(&head->node.refs);
817 spin_unlock(&delayed_refs->lock);
818
819 btrfs_release_path(path);
820
821 /*
822 * Mutex was contended, block until it's released and try
823 * again
824 */
825 mutex_lock(&head->mutex);
826 mutex_unlock(&head->mutex);
827 btrfs_put_delayed_ref(&head->node);
828 goto again;
829 }
830 if (head->extent_op && head->extent_op->update_flags)
831 extent_flags |= head->extent_op->flags_to_set;
832 else
833 BUG_ON(num_refs == 0);
834
835 num_refs += head->node.ref_mod;
836 mutex_unlock(&head->mutex);
837 }
838 spin_unlock(&delayed_refs->lock);
839 out:
840 WARN_ON(num_refs == 0);
841 if (refs)
842 *refs = num_refs;
843 if (flags)
844 *flags = extent_flags;
845 out_free:
846 btrfs_free_path(path);
847 return ret;
848 }
849
850 /*
851 * Back reference rules. Back refs have three main goals:
852 *
853 * 1) differentiate between all holders of references to an extent so that
854 * when a reference is dropped we can make sure it was a valid reference
855 * before freeing the extent.
856 *
857 * 2) Provide enough information to quickly find the holders of an extent
858 * if we notice a given block is corrupted or bad.
859 *
860 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
861 * maintenance. This is actually the same as #2, but with a slightly
862 * different use case.
863 *
864 * There are two kinds of back refs. The implicit back refs is optimized
865 * for pointers in non-shared tree blocks. For a given pointer in a block,
866 * back refs of this kind provide information about the block's owner tree
867 * and the pointer's key. These information allow us to find the block by
868 * b-tree searching. The full back refs is for pointers in tree blocks not
869 * referenced by their owner trees. The location of tree block is recorded
870 * in the back refs. Actually the full back refs is generic, and can be
871 * used in all cases the implicit back refs is used. The major shortcoming
872 * of the full back refs is its overhead. Every time a tree block gets
873 * COWed, we have to update back refs entry for all pointers in it.
874 *
875 * For a newly allocated tree block, we use implicit back refs for
876 * pointers in it. This means most tree related operations only involve
877 * implicit back refs. For a tree block created in old transaction, the
878 * only way to drop a reference to it is COW it. So we can detect the
879 * event that tree block loses its owner tree's reference and do the
880 * back refs conversion.
881 *
882 * When a tree block is COW'd through a tree, there are four cases:
883 *
884 * The reference count of the block is one and the tree is the block's
885 * owner tree. Nothing to do in this case.
886 *
887 * The reference count of the block is one and the tree is not the
888 * block's owner tree. In this case, full back refs is used for pointers
889 * in the block. Remove these full back refs, add implicit back refs for
890 * every pointers in the new block.
891 *
892 * The reference count of the block is greater than one and the tree is
893 * the block's owner tree. In this case, implicit back refs is used for
894 * pointers in the block. Add full back refs for every pointers in the
895 * block, increase lower level extents' reference counts. The original
896 * implicit back refs are entailed to the new block.
897 *
898 * The reference count of the block is greater than one and the tree is
899 * not the block's owner tree. Add implicit back refs for every pointer in
900 * the new block, increase lower level extents' reference count.
901 *
902 * Back Reference Key composing:
903 *
904 * The key objectid corresponds to the first byte in the extent,
905 * The key type is used to differentiate between types of back refs.
906 * There are different meanings of the key offset for different types
907 * of back refs.
908 *
909 * File extents can be referenced by:
910 *
911 * - multiple snapshots, subvolumes, or different generations in one subvol
912 * - different files inside a single subvolume
913 * - different offsets inside a file (bookend extents in file.c)
914 *
915 * The extent ref structure for the implicit back refs has fields for:
916 *
917 * - Objectid of the subvolume root
918 * - objectid of the file holding the reference
919 * - original offset in the file
920 * - how many bookend extents
921 *
922 * The key offset for the implicit back refs is hash of the first
923 * three fields.
924 *
925 * The extent ref structure for the full back refs has field for:
926 *
927 * - number of pointers in the tree leaf
928 *
929 * The key offset for the implicit back refs is the first byte of
930 * the tree leaf
931 *
932 * When a file extent is allocated, The implicit back refs is used.
933 * the fields are filled in:
934 *
935 * (root_key.objectid, inode objectid, offset in file, 1)
936 *
937 * When a file extent is removed file truncation, we find the
938 * corresponding implicit back refs and check the following fields:
939 *
940 * (btrfs_header_owner(leaf), inode objectid, offset in file)
941 *
942 * Btree extents can be referenced by:
943 *
944 * - Different subvolumes
945 *
946 * Both the implicit back refs and the full back refs for tree blocks
947 * only consist of key. The key offset for the implicit back refs is
948 * objectid of block's owner tree. The key offset for the full back refs
949 * is the first byte of parent block.
950 *
951 * When implicit back refs is used, information about the lowest key and
952 * level of the tree block are required. These information are stored in
953 * tree block info structure.
954 */
955
956 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
957 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
958 struct btrfs_root *root,
959 struct btrfs_path *path,
960 u64 owner, u32 extra_size)
961 {
962 struct btrfs_extent_item *item;
963 struct btrfs_extent_item_v0 *ei0;
964 struct btrfs_extent_ref_v0 *ref0;
965 struct btrfs_tree_block_info *bi;
966 struct extent_buffer *leaf;
967 struct btrfs_key key;
968 struct btrfs_key found_key;
969 u32 new_size = sizeof(*item);
970 u64 refs;
971 int ret;
972
973 leaf = path->nodes[0];
974 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
975
976 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
977 ei0 = btrfs_item_ptr(leaf, path->slots[0],
978 struct btrfs_extent_item_v0);
979 refs = btrfs_extent_refs_v0(leaf, ei0);
980
981 if (owner == (u64)-1) {
982 while (1) {
983 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
984 ret = btrfs_next_leaf(root, path);
985 if (ret < 0)
986 return ret;
987 BUG_ON(ret > 0); /* Corruption */
988 leaf = path->nodes[0];
989 }
990 btrfs_item_key_to_cpu(leaf, &found_key,
991 path->slots[0]);
992 BUG_ON(key.objectid != found_key.objectid);
993 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
994 path->slots[0]++;
995 continue;
996 }
997 ref0 = btrfs_item_ptr(leaf, path->slots[0],
998 struct btrfs_extent_ref_v0);
999 owner = btrfs_ref_objectid_v0(leaf, ref0);
1000 break;
1001 }
1002 }
1003 btrfs_release_path(path);
1004
1005 if (owner < BTRFS_FIRST_FREE_OBJECTID)
1006 new_size += sizeof(*bi);
1007
1008 new_size -= sizeof(*ei0);
1009 ret = btrfs_search_slot(trans, root, &key, path,
1010 new_size + extra_size, 1);
1011 if (ret < 0)
1012 return ret;
1013 BUG_ON(ret); /* Corruption */
1014
1015 btrfs_extend_item(root, path, new_size);
1016
1017 leaf = path->nodes[0];
1018 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1019 btrfs_set_extent_refs(leaf, item, refs);
1020 /* FIXME: get real generation */
1021 btrfs_set_extent_generation(leaf, item, 0);
1022 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1023 btrfs_set_extent_flags(leaf, item,
1024 BTRFS_EXTENT_FLAG_TREE_BLOCK |
1025 BTRFS_BLOCK_FLAG_FULL_BACKREF);
1026 bi = (struct btrfs_tree_block_info *)(item + 1);
1027 /* FIXME: get first key of the block */
1028 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
1029 btrfs_set_tree_block_level(leaf, bi, (int)owner);
1030 } else {
1031 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
1032 }
1033 btrfs_mark_buffer_dirty(leaf);
1034 return 0;
1035 }
1036 #endif
1037
1038 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
1039 {
1040 u32 high_crc = ~(u32)0;
1041 u32 low_crc = ~(u32)0;
1042 __le64 lenum;
1043
1044 lenum = cpu_to_le64(root_objectid);
1045 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
1046 lenum = cpu_to_le64(owner);
1047 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
1048 lenum = cpu_to_le64(offset);
1049 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
1050
1051 return ((u64)high_crc << 31) ^ (u64)low_crc;
1052 }
1053
1054 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
1055 struct btrfs_extent_data_ref *ref)
1056 {
1057 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
1058 btrfs_extent_data_ref_objectid(leaf, ref),
1059 btrfs_extent_data_ref_offset(leaf, ref));
1060 }
1061
1062 static int match_extent_data_ref(struct extent_buffer *leaf,
1063 struct btrfs_extent_data_ref *ref,
1064 u64 root_objectid, u64 owner, u64 offset)
1065 {
1066 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
1067 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
1068 btrfs_extent_data_ref_offset(leaf, ref) != offset)
1069 return 0;
1070 return 1;
1071 }
1072
1073 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
1074 struct btrfs_root *root,
1075 struct btrfs_path *path,
1076 u64 bytenr, u64 parent,
1077 u64 root_objectid,
1078 u64 owner, u64 offset)
1079 {
1080 struct btrfs_key key;
1081 struct btrfs_extent_data_ref *ref;
1082 struct extent_buffer *leaf;
1083 u32 nritems;
1084 int ret;
1085 int recow;
1086 int err = -ENOENT;
1087
1088 key.objectid = bytenr;
1089 if (parent) {
1090 key.type = BTRFS_SHARED_DATA_REF_KEY;
1091 key.offset = parent;
1092 } else {
1093 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1094 key.offset = hash_extent_data_ref(root_objectid,
1095 owner, offset);
1096 }
1097 again:
1098 recow = 0;
1099 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1100 if (ret < 0) {
1101 err = ret;
1102 goto fail;
1103 }
1104
1105 if (parent) {
1106 if (!ret)
1107 return 0;
1108 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1109 key.type = BTRFS_EXTENT_REF_V0_KEY;
1110 btrfs_release_path(path);
1111 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1112 if (ret < 0) {
1113 err = ret;
1114 goto fail;
1115 }
1116 if (!ret)
1117 return 0;
1118 #endif
1119 goto fail;
1120 }
1121
1122 leaf = path->nodes[0];
1123 nritems = btrfs_header_nritems(leaf);
1124 while (1) {
1125 if (path->slots[0] >= nritems) {
1126 ret = btrfs_next_leaf(root, path);
1127 if (ret < 0)
1128 err = ret;
1129 if (ret)
1130 goto fail;
1131
1132 leaf = path->nodes[0];
1133 nritems = btrfs_header_nritems(leaf);
1134 recow = 1;
1135 }
1136
1137 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1138 if (key.objectid != bytenr ||
1139 key.type != BTRFS_EXTENT_DATA_REF_KEY)
1140 goto fail;
1141
1142 ref = btrfs_item_ptr(leaf, path->slots[0],
1143 struct btrfs_extent_data_ref);
1144
1145 if (match_extent_data_ref(leaf, ref, root_objectid,
1146 owner, offset)) {
1147 if (recow) {
1148 btrfs_release_path(path);
1149 goto again;
1150 }
1151 err = 0;
1152 break;
1153 }
1154 path->slots[0]++;
1155 }
1156 fail:
1157 return err;
1158 }
1159
1160 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
1161 struct btrfs_root *root,
1162 struct btrfs_path *path,
1163 u64 bytenr, u64 parent,
1164 u64 root_objectid, u64 owner,
1165 u64 offset, int refs_to_add)
1166 {
1167 struct btrfs_key key;
1168 struct extent_buffer *leaf;
1169 u32 size;
1170 u32 num_refs;
1171 int ret;
1172
1173 key.objectid = bytenr;
1174 if (parent) {
1175 key.type = BTRFS_SHARED_DATA_REF_KEY;
1176 key.offset = parent;
1177 size = sizeof(struct btrfs_shared_data_ref);
1178 } else {
1179 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1180 key.offset = hash_extent_data_ref(root_objectid,
1181 owner, offset);
1182 size = sizeof(struct btrfs_extent_data_ref);
1183 }
1184
1185 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
1186 if (ret && ret != -EEXIST)
1187 goto fail;
1188
1189 leaf = path->nodes[0];
1190 if (parent) {
1191 struct btrfs_shared_data_ref *ref;
1192 ref = btrfs_item_ptr(leaf, path->slots[0],
1193 struct btrfs_shared_data_ref);
1194 if (ret == 0) {
1195 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
1196 } else {
1197 num_refs = btrfs_shared_data_ref_count(leaf, ref);
1198 num_refs += refs_to_add;
1199 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
1200 }
1201 } else {
1202 struct btrfs_extent_data_ref *ref;
1203 while (ret == -EEXIST) {
1204 ref = btrfs_item_ptr(leaf, path->slots[0],
1205 struct btrfs_extent_data_ref);
1206 if (match_extent_data_ref(leaf, ref, root_objectid,
1207 owner, offset))
1208 break;
1209 btrfs_release_path(path);
1210 key.offset++;
1211 ret = btrfs_insert_empty_item(trans, root, path, &key,
1212 size);
1213 if (ret && ret != -EEXIST)
1214 goto fail;
1215
1216 leaf = path->nodes[0];
1217 }
1218 ref = btrfs_item_ptr(leaf, path->slots[0],
1219 struct btrfs_extent_data_ref);
1220 if (ret == 0) {
1221 btrfs_set_extent_data_ref_root(leaf, ref,
1222 root_objectid);
1223 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
1224 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
1225 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
1226 } else {
1227 num_refs = btrfs_extent_data_ref_count(leaf, ref);
1228 num_refs += refs_to_add;
1229 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
1230 }
1231 }
1232 btrfs_mark_buffer_dirty(leaf);
1233 ret = 0;
1234 fail:
1235 btrfs_release_path(path);
1236 return ret;
1237 }
1238
1239 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
1240 struct btrfs_root *root,
1241 struct btrfs_path *path,
1242 int refs_to_drop)
1243 {
1244 struct btrfs_key key;
1245 struct btrfs_extent_data_ref *ref1 = NULL;
1246 struct btrfs_shared_data_ref *ref2 = NULL;
1247 struct extent_buffer *leaf;
1248 u32 num_refs = 0;
1249 int ret = 0;
1250
1251 leaf = path->nodes[0];
1252 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1253
1254 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1255 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1256 struct btrfs_extent_data_ref);
1257 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1258 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1259 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1260 struct btrfs_shared_data_ref);
1261 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1262 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1263 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1264 struct btrfs_extent_ref_v0 *ref0;
1265 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1266 struct btrfs_extent_ref_v0);
1267 num_refs = btrfs_ref_count_v0(leaf, ref0);
1268 #endif
1269 } else {
1270 BUG();
1271 }
1272
1273 BUG_ON(num_refs < refs_to_drop);
1274 num_refs -= refs_to_drop;
1275
1276 if (num_refs == 0) {
1277 ret = btrfs_del_item(trans, root, path);
1278 } else {
1279 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
1280 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
1281 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
1282 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
1283 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1284 else {
1285 struct btrfs_extent_ref_v0 *ref0;
1286 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1287 struct btrfs_extent_ref_v0);
1288 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
1289 }
1290 #endif
1291 btrfs_mark_buffer_dirty(leaf);
1292 }
1293 return ret;
1294 }
1295
1296 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
1297 struct btrfs_path *path,
1298 struct btrfs_extent_inline_ref *iref)
1299 {
1300 struct btrfs_key key;
1301 struct extent_buffer *leaf;
1302 struct btrfs_extent_data_ref *ref1;
1303 struct btrfs_shared_data_ref *ref2;
1304 u32 num_refs = 0;
1305
1306 leaf = path->nodes[0];
1307 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1308 if (iref) {
1309 if (btrfs_extent_inline_ref_type(leaf, iref) ==
1310 BTRFS_EXTENT_DATA_REF_KEY) {
1311 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
1312 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1313 } else {
1314 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
1315 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1316 }
1317 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1318 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1319 struct btrfs_extent_data_ref);
1320 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1321 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1322 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1323 struct btrfs_shared_data_ref);
1324 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1325 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1326 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1327 struct btrfs_extent_ref_v0 *ref0;
1328 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1329 struct btrfs_extent_ref_v0);
1330 num_refs = btrfs_ref_count_v0(leaf, ref0);
1331 #endif
1332 } else {
1333 WARN_ON(1);
1334 }
1335 return num_refs;
1336 }
1337
1338 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
1339 struct btrfs_root *root,
1340 struct btrfs_path *path,
1341 u64 bytenr, u64 parent,
1342 u64 root_objectid)
1343 {
1344 struct btrfs_key key;
1345 int ret;
1346
1347 key.objectid = bytenr;
1348 if (parent) {
1349 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1350 key.offset = parent;
1351 } else {
1352 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1353 key.offset = root_objectid;
1354 }
1355
1356 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1357 if (ret > 0)
1358 ret = -ENOENT;
1359 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1360 if (ret == -ENOENT && parent) {
1361 btrfs_release_path(path);
1362 key.type = BTRFS_EXTENT_REF_V0_KEY;
1363 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1364 if (ret > 0)
1365 ret = -ENOENT;
1366 }
1367 #endif
1368 return ret;
1369 }
1370
1371 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
1372 struct btrfs_root *root,
1373 struct btrfs_path *path,
1374 u64 bytenr, u64 parent,
1375 u64 root_objectid)
1376 {
1377 struct btrfs_key key;
1378 int ret;
1379
1380 key.objectid = bytenr;
1381 if (parent) {
1382 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1383 key.offset = parent;
1384 } else {
1385 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1386 key.offset = root_objectid;
1387 }
1388
1389 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1390 btrfs_release_path(path);
1391 return ret;
1392 }
1393
1394 static inline int extent_ref_type(u64 parent, u64 owner)
1395 {
1396 int type;
1397 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1398 if (parent > 0)
1399 type = BTRFS_SHARED_BLOCK_REF_KEY;
1400 else
1401 type = BTRFS_TREE_BLOCK_REF_KEY;
1402 } else {
1403 if (parent > 0)
1404 type = BTRFS_SHARED_DATA_REF_KEY;
1405 else
1406 type = BTRFS_EXTENT_DATA_REF_KEY;
1407 }
1408 return type;
1409 }
1410
1411 static int find_next_key(struct btrfs_path *path, int level,
1412 struct btrfs_key *key)
1413
1414 {
1415 for (; level < BTRFS_MAX_LEVEL; level++) {
1416 if (!path->nodes[level])
1417 break;
1418 if (path->slots[level] + 1 >=
1419 btrfs_header_nritems(path->nodes[level]))
1420 continue;
1421 if (level == 0)
1422 btrfs_item_key_to_cpu(path->nodes[level], key,
1423 path->slots[level] + 1);
1424 else
1425 btrfs_node_key_to_cpu(path->nodes[level], key,
1426 path->slots[level] + 1);
1427 return 0;
1428 }
1429 return 1;
1430 }
1431
1432 /*
1433 * look for inline back ref. if back ref is found, *ref_ret is set
1434 * to the address of inline back ref, and 0 is returned.
1435 *
1436 * if back ref isn't found, *ref_ret is set to the address where it
1437 * should be inserted, and -ENOENT is returned.
1438 *
1439 * if insert is true and there are too many inline back refs, the path
1440 * points to the extent item, and -EAGAIN is returned.
1441 *
1442 * NOTE: inline back refs are ordered in the same way that back ref
1443 * items in the tree are ordered.
1444 */
1445 static noinline_for_stack
1446 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1447 struct btrfs_root *root,
1448 struct btrfs_path *path,
1449 struct btrfs_extent_inline_ref **ref_ret,
1450 u64 bytenr, u64 num_bytes,
1451 u64 parent, u64 root_objectid,
1452 u64 owner, u64 offset, int insert)
1453 {
1454 struct btrfs_key key;
1455 struct extent_buffer *leaf;
1456 struct btrfs_extent_item *ei;
1457 struct btrfs_extent_inline_ref *iref;
1458 u64 flags;
1459 u64 item_size;
1460 unsigned long ptr;
1461 unsigned long end;
1462 int extra_size;
1463 int type;
1464 int want;
1465 int ret;
1466 int err = 0;
1467 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
1468 SKINNY_METADATA);
1469
1470 key.objectid = bytenr;
1471 key.type = BTRFS_EXTENT_ITEM_KEY;
1472 key.offset = num_bytes;
1473
1474 want = extent_ref_type(parent, owner);
1475 if (insert) {
1476 extra_size = btrfs_extent_inline_ref_size(want);
1477 path->keep_locks = 1;
1478 } else
1479 extra_size = -1;
1480
1481 /*
1482 * Owner is our parent level, so we can just add one to get the level
1483 * for the block we are interested in.
1484 */
1485 if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) {
1486 key.type = BTRFS_METADATA_ITEM_KEY;
1487 key.offset = owner;
1488 }
1489
1490 again:
1491 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1492 if (ret < 0) {
1493 err = ret;
1494 goto out;
1495 }
1496
1497 /*
1498 * We may be a newly converted file system which still has the old fat
1499 * extent entries for metadata, so try and see if we have one of those.
1500 */
1501 if (ret > 0 && skinny_metadata) {
1502 skinny_metadata = false;
1503 if (path->slots[0]) {
1504 path->slots[0]--;
1505 btrfs_item_key_to_cpu(path->nodes[0], &key,
1506 path->slots[0]);
1507 if (key.objectid == bytenr &&
1508 key.type == BTRFS_EXTENT_ITEM_KEY &&
1509 key.offset == num_bytes)
1510 ret = 0;
1511 }
1512 if (ret) {
1513 key.type = BTRFS_EXTENT_ITEM_KEY;
1514 key.offset = num_bytes;
1515 btrfs_release_path(path);
1516 goto again;
1517 }
1518 }
1519
1520 if (ret && !insert) {
1521 err = -ENOENT;
1522 goto out;
1523 } else if (ret) {
1524 err = -EIO;
1525 WARN_ON(1);
1526 goto out;
1527 }
1528
1529 leaf = path->nodes[0];
1530 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1531 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1532 if (item_size < sizeof(*ei)) {
1533 if (!insert) {
1534 err = -ENOENT;
1535 goto out;
1536 }
1537 ret = convert_extent_item_v0(trans, root, path, owner,
1538 extra_size);
1539 if (ret < 0) {
1540 err = ret;
1541 goto out;
1542 }
1543 leaf = path->nodes[0];
1544 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1545 }
1546 #endif
1547 BUG_ON(item_size < sizeof(*ei));
1548
1549 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1550 flags = btrfs_extent_flags(leaf, ei);
1551
1552 ptr = (unsigned long)(ei + 1);
1553 end = (unsigned long)ei + item_size;
1554
1555 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
1556 ptr += sizeof(struct btrfs_tree_block_info);
1557 BUG_ON(ptr > end);
1558 }
1559
1560 err = -ENOENT;
1561 while (1) {
1562 if (ptr >= end) {
1563 WARN_ON(ptr > end);
1564 break;
1565 }
1566 iref = (struct btrfs_extent_inline_ref *)ptr;
1567 type = btrfs_extent_inline_ref_type(leaf, iref);
1568 if (want < type)
1569 break;
1570 if (want > type) {
1571 ptr += btrfs_extent_inline_ref_size(type);
1572 continue;
1573 }
1574
1575 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1576 struct btrfs_extent_data_ref *dref;
1577 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1578 if (match_extent_data_ref(leaf, dref, root_objectid,
1579 owner, offset)) {
1580 err = 0;
1581 break;
1582 }
1583 if (hash_extent_data_ref_item(leaf, dref) <
1584 hash_extent_data_ref(root_objectid, owner, offset))
1585 break;
1586 } else {
1587 u64 ref_offset;
1588 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1589 if (parent > 0) {
1590 if (parent == ref_offset) {
1591 err = 0;
1592 break;
1593 }
1594 if (ref_offset < parent)
1595 break;
1596 } else {
1597 if (root_objectid == ref_offset) {
1598 err = 0;
1599 break;
1600 }
1601 if (ref_offset < root_objectid)
1602 break;
1603 }
1604 }
1605 ptr += btrfs_extent_inline_ref_size(type);
1606 }
1607 if (err == -ENOENT && insert) {
1608 if (item_size + extra_size >=
1609 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1610 err = -EAGAIN;
1611 goto out;
1612 }
1613 /*
1614 * To add new inline back ref, we have to make sure
1615 * there is no corresponding back ref item.
1616 * For simplicity, we just do not add new inline back
1617 * ref if there is any kind of item for this block
1618 */
1619 if (find_next_key(path, 0, &key) == 0 &&
1620 key.objectid == bytenr &&
1621 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1622 err = -EAGAIN;
1623 goto out;
1624 }
1625 }
1626 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1627 out:
1628 if (insert) {
1629 path->keep_locks = 0;
1630 btrfs_unlock_up_safe(path, 1);
1631 }
1632 return err;
1633 }
1634
1635 /*
1636 * helper to add new inline back ref
1637 */
1638 static noinline_for_stack
1639 void setup_inline_extent_backref(struct btrfs_root *root,
1640 struct btrfs_path *path,
1641 struct btrfs_extent_inline_ref *iref,
1642 u64 parent, u64 root_objectid,
1643 u64 owner, u64 offset, int refs_to_add,
1644 struct btrfs_delayed_extent_op *extent_op)
1645 {
1646 struct extent_buffer *leaf;
1647 struct btrfs_extent_item *ei;
1648 unsigned long ptr;
1649 unsigned long end;
1650 unsigned long item_offset;
1651 u64 refs;
1652 int size;
1653 int type;
1654
1655 leaf = path->nodes[0];
1656 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1657 item_offset = (unsigned long)iref - (unsigned long)ei;
1658
1659 type = extent_ref_type(parent, owner);
1660 size = btrfs_extent_inline_ref_size(type);
1661
1662 btrfs_extend_item(root, path, size);
1663
1664 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1665 refs = btrfs_extent_refs(leaf, ei);
1666 refs += refs_to_add;
1667 btrfs_set_extent_refs(leaf, ei, refs);
1668 if (extent_op)
1669 __run_delayed_extent_op(extent_op, leaf, ei);
1670
1671 ptr = (unsigned long)ei + item_offset;
1672 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1673 if (ptr < end - size)
1674 memmove_extent_buffer(leaf, ptr + size, ptr,
1675 end - size - ptr);
1676
1677 iref = (struct btrfs_extent_inline_ref *)ptr;
1678 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1679 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1680 struct btrfs_extent_data_ref *dref;
1681 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1682 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1683 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1684 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1685 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1686 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1687 struct btrfs_shared_data_ref *sref;
1688 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1689 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1690 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1691 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1692 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1693 } else {
1694 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1695 }
1696 btrfs_mark_buffer_dirty(leaf);
1697 }
1698
1699 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1700 struct btrfs_root *root,
1701 struct btrfs_path *path,
1702 struct btrfs_extent_inline_ref **ref_ret,
1703 u64 bytenr, u64 num_bytes, u64 parent,
1704 u64 root_objectid, u64 owner, u64 offset)
1705 {
1706 int ret;
1707
1708 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1709 bytenr, num_bytes, parent,
1710 root_objectid, owner, offset, 0);
1711 if (ret != -ENOENT)
1712 return ret;
1713
1714 btrfs_release_path(path);
1715 *ref_ret = NULL;
1716
1717 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1718 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1719 root_objectid);
1720 } else {
1721 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1722 root_objectid, owner, offset);
1723 }
1724 return ret;
1725 }
1726
1727 /*
1728 * helper to update/remove inline back ref
1729 */
1730 static noinline_for_stack
1731 void update_inline_extent_backref(struct btrfs_root *root,
1732 struct btrfs_path *path,
1733 struct btrfs_extent_inline_ref *iref,
1734 int refs_to_mod,
1735 struct btrfs_delayed_extent_op *extent_op)
1736 {
1737 struct extent_buffer *leaf;
1738 struct btrfs_extent_item *ei;
1739 struct btrfs_extent_data_ref *dref = NULL;
1740 struct btrfs_shared_data_ref *sref = NULL;
1741 unsigned long ptr;
1742 unsigned long end;
1743 u32 item_size;
1744 int size;
1745 int type;
1746 u64 refs;
1747
1748 leaf = path->nodes[0];
1749 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1750 refs = btrfs_extent_refs(leaf, ei);
1751 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1752 refs += refs_to_mod;
1753 btrfs_set_extent_refs(leaf, ei, refs);
1754 if (extent_op)
1755 __run_delayed_extent_op(extent_op, leaf, ei);
1756
1757 type = btrfs_extent_inline_ref_type(leaf, iref);
1758
1759 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1760 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1761 refs = btrfs_extent_data_ref_count(leaf, dref);
1762 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1763 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1764 refs = btrfs_shared_data_ref_count(leaf, sref);
1765 } else {
1766 refs = 1;
1767 BUG_ON(refs_to_mod != -1);
1768 }
1769
1770 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1771 refs += refs_to_mod;
1772
1773 if (refs > 0) {
1774 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1775 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1776 else
1777 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1778 } else {
1779 size = btrfs_extent_inline_ref_size(type);
1780 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1781 ptr = (unsigned long)iref;
1782 end = (unsigned long)ei + item_size;
1783 if (ptr + size < end)
1784 memmove_extent_buffer(leaf, ptr, ptr + size,
1785 end - ptr - size);
1786 item_size -= size;
1787 btrfs_truncate_item(root, path, item_size, 1);
1788 }
1789 btrfs_mark_buffer_dirty(leaf);
1790 }
1791
1792 static noinline_for_stack
1793 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1794 struct btrfs_root *root,
1795 struct btrfs_path *path,
1796 u64 bytenr, u64 num_bytes, u64 parent,
1797 u64 root_objectid, u64 owner,
1798 u64 offset, int refs_to_add,
1799 struct btrfs_delayed_extent_op *extent_op)
1800 {
1801 struct btrfs_extent_inline_ref *iref;
1802 int ret;
1803
1804 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1805 bytenr, num_bytes, parent,
1806 root_objectid, owner, offset, 1);
1807 if (ret == 0) {
1808 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1809 update_inline_extent_backref(root, path, iref,
1810 refs_to_add, extent_op);
1811 } else if (ret == -ENOENT) {
1812 setup_inline_extent_backref(root, path, iref, parent,
1813 root_objectid, owner, offset,
1814 refs_to_add, extent_op);
1815 ret = 0;
1816 }
1817 return ret;
1818 }
1819
1820 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1821 struct btrfs_root *root,
1822 struct btrfs_path *path,
1823 u64 bytenr, u64 parent, u64 root_objectid,
1824 u64 owner, u64 offset, int refs_to_add)
1825 {
1826 int ret;
1827 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1828 BUG_ON(refs_to_add != 1);
1829 ret = insert_tree_block_ref(trans, root, path, bytenr,
1830 parent, root_objectid);
1831 } else {
1832 ret = insert_extent_data_ref(trans, root, path, bytenr,
1833 parent, root_objectid,
1834 owner, offset, refs_to_add);
1835 }
1836 return ret;
1837 }
1838
1839 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1840 struct btrfs_root *root,
1841 struct btrfs_path *path,
1842 struct btrfs_extent_inline_ref *iref,
1843 int refs_to_drop, int is_data)
1844 {
1845 int ret = 0;
1846
1847 BUG_ON(!is_data && refs_to_drop != 1);
1848 if (iref) {
1849 update_inline_extent_backref(root, path, iref,
1850 -refs_to_drop, NULL);
1851 } else if (is_data) {
1852 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1853 } else {
1854 ret = btrfs_del_item(trans, root, path);
1855 }
1856 return ret;
1857 }
1858
1859 static int btrfs_issue_discard(struct block_device *bdev,
1860 u64 start, u64 len)
1861 {
1862 return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
1863 }
1864
1865 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
1866 u64 num_bytes, u64 *actual_bytes)
1867 {
1868 int ret;
1869 u64 discarded_bytes = 0;
1870 struct btrfs_bio *bbio = NULL;
1871
1872
1873 /* Tell the block device(s) that the sectors can be discarded */
1874 ret = btrfs_map_block(root->fs_info, REQ_DISCARD,
1875 bytenr, &num_bytes, &bbio, 0);
1876 /* Error condition is -ENOMEM */
1877 if (!ret) {
1878 struct btrfs_bio_stripe *stripe = bbio->stripes;
1879 int i;
1880
1881
1882 for (i = 0; i < bbio->num_stripes; i++, stripe++) {
1883 if (!stripe->dev->can_discard)
1884 continue;
1885
1886 ret = btrfs_issue_discard(stripe->dev->bdev,
1887 stripe->physical,
1888 stripe->length);
1889 if (!ret)
1890 discarded_bytes += stripe->length;
1891 else if (ret != -EOPNOTSUPP)
1892 break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */
1893
1894 /*
1895 * Just in case we get back EOPNOTSUPP for some reason,
1896 * just ignore the return value so we don't screw up
1897 * people calling discard_extent.
1898 */
1899 ret = 0;
1900 }
1901 kfree(bbio);
1902 }
1903
1904 if (actual_bytes)
1905 *actual_bytes = discarded_bytes;
1906
1907
1908 if (ret == -EOPNOTSUPP)
1909 ret = 0;
1910 return ret;
1911 }
1912
1913 /* Can return -ENOMEM */
1914 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1915 struct btrfs_root *root,
1916 u64 bytenr, u64 num_bytes, u64 parent,
1917 u64 root_objectid, u64 owner, u64 offset, int for_cow)
1918 {
1919 int ret;
1920 struct btrfs_fs_info *fs_info = root->fs_info;
1921
1922 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
1923 root_objectid == BTRFS_TREE_LOG_OBJECTID);
1924
1925 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1926 ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
1927 num_bytes,
1928 parent, root_objectid, (int)owner,
1929 BTRFS_ADD_DELAYED_REF, NULL, for_cow);
1930 } else {
1931 ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
1932 num_bytes,
1933 parent, root_objectid, owner, offset,
1934 BTRFS_ADD_DELAYED_REF, NULL, for_cow);
1935 }
1936 return ret;
1937 }
1938
1939 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1940 struct btrfs_root *root,
1941 u64 bytenr, u64 num_bytes,
1942 u64 parent, u64 root_objectid,
1943 u64 owner, u64 offset, int refs_to_add,
1944 struct btrfs_delayed_extent_op *extent_op)
1945 {
1946 struct btrfs_path *path;
1947 struct extent_buffer *leaf;
1948 struct btrfs_extent_item *item;
1949 u64 refs;
1950 int ret;
1951 int err = 0;
1952
1953 path = btrfs_alloc_path();
1954 if (!path)
1955 return -ENOMEM;
1956
1957 path->reada = 1;
1958 path->leave_spinning = 1;
1959 /* this will setup the path even if it fails to insert the back ref */
1960 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1961 path, bytenr, num_bytes, parent,
1962 root_objectid, owner, offset,
1963 refs_to_add, extent_op);
1964 if (ret == 0)
1965 goto out;
1966
1967 if (ret != -EAGAIN) {
1968 err = ret;
1969 goto out;
1970 }
1971
1972 leaf = path->nodes[0];
1973 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1974 refs = btrfs_extent_refs(leaf, item);
1975 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1976 if (extent_op)
1977 __run_delayed_extent_op(extent_op, leaf, item);
1978
1979 btrfs_mark_buffer_dirty(leaf);
1980 btrfs_release_path(path);
1981
1982 path->reada = 1;
1983 path->leave_spinning = 1;
1984
1985 /* now insert the actual backref */
1986 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1987 path, bytenr, parent, root_objectid,
1988 owner, offset, refs_to_add);
1989 if (ret)
1990 btrfs_abort_transaction(trans, root, ret);
1991 out:
1992 btrfs_free_path(path);
1993 return err;
1994 }
1995
1996 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1997 struct btrfs_root *root,
1998 struct btrfs_delayed_ref_node *node,
1999 struct btrfs_delayed_extent_op *extent_op,
2000 int insert_reserved)
2001 {
2002 int ret = 0;
2003 struct btrfs_delayed_data_ref *ref;
2004 struct btrfs_key ins;
2005 u64 parent = 0;
2006 u64 ref_root = 0;
2007 u64 flags = 0;
2008
2009 ins.objectid = node->bytenr;
2010 ins.offset = node->num_bytes;
2011 ins.type = BTRFS_EXTENT_ITEM_KEY;
2012
2013 ref = btrfs_delayed_node_to_data_ref(node);
2014 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
2015 parent = ref->parent;
2016 else
2017 ref_root = ref->root;
2018
2019 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2020 if (extent_op)
2021 flags |= extent_op->flags_to_set;
2022 ret = alloc_reserved_file_extent(trans, root,
2023 parent, ref_root, flags,
2024 ref->objectid, ref->offset,
2025 &ins, node->ref_mod);
2026 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2027 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
2028 node->num_bytes, parent,
2029 ref_root, ref->objectid,
2030 ref->offset, node->ref_mod,
2031 extent_op);
2032 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2033 ret = __btrfs_free_extent(trans, root, node->bytenr,
2034 node->num_bytes, parent,
2035 ref_root, ref->objectid,
2036 ref->offset, node->ref_mod,
2037 extent_op);
2038 } else {
2039 BUG();
2040 }
2041 return ret;
2042 }
2043
2044 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
2045 struct extent_buffer *leaf,
2046 struct btrfs_extent_item *ei)
2047 {
2048 u64 flags = btrfs_extent_flags(leaf, ei);
2049 if (extent_op->update_flags) {
2050 flags |= extent_op->flags_to_set;
2051 btrfs_set_extent_flags(leaf, ei, flags);
2052 }
2053
2054 if (extent_op->update_key) {
2055 struct btrfs_tree_block_info *bi;
2056 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
2057 bi = (struct btrfs_tree_block_info *)(ei + 1);
2058 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
2059 }
2060 }
2061
2062 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
2063 struct btrfs_root *root,
2064 struct btrfs_delayed_ref_node *node,
2065 struct btrfs_delayed_extent_op *extent_op)
2066 {
2067 struct btrfs_key key;
2068 struct btrfs_path *path;
2069 struct btrfs_extent_item *ei;
2070 struct extent_buffer *leaf;
2071 u32 item_size;
2072 int ret;
2073 int err = 0;
2074 int metadata = !extent_op->is_data;
2075
2076 if (trans->aborted)
2077 return 0;
2078
2079 if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA))
2080 metadata = 0;
2081
2082 path = btrfs_alloc_path();
2083 if (!path)
2084 return -ENOMEM;
2085
2086 key.objectid = node->bytenr;
2087
2088 if (metadata) {
2089 key.type = BTRFS_METADATA_ITEM_KEY;
2090 key.offset = extent_op->level;
2091 } else {
2092 key.type = BTRFS_EXTENT_ITEM_KEY;
2093 key.offset = node->num_bytes;
2094 }
2095
2096 again:
2097 path->reada = 1;
2098 path->leave_spinning = 1;
2099 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
2100 path, 0, 1);
2101 if (ret < 0) {
2102 err = ret;
2103 goto out;
2104 }
2105 if (ret > 0) {
2106 if (metadata) {
2107 btrfs_release_path(path);
2108 metadata = 0;
2109
2110 key.offset = node->num_bytes;
2111 key.type = BTRFS_EXTENT_ITEM_KEY;
2112 goto again;
2113 }
2114 err = -EIO;
2115 goto out;
2116 }
2117
2118 leaf = path->nodes[0];
2119 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2120 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2121 if (item_size < sizeof(*ei)) {
2122 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
2123 path, (u64)-1, 0);
2124 if (ret < 0) {
2125 err = ret;
2126 goto out;
2127 }
2128 leaf = path->nodes[0];
2129 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2130 }
2131 #endif
2132 BUG_ON(item_size < sizeof(*ei));
2133 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2134 __run_delayed_extent_op(extent_op, leaf, ei);
2135
2136 btrfs_mark_buffer_dirty(leaf);
2137 out:
2138 btrfs_free_path(path);
2139 return err;
2140 }
2141
2142 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
2143 struct btrfs_root *root,
2144 struct btrfs_delayed_ref_node *node,
2145 struct btrfs_delayed_extent_op *extent_op,
2146 int insert_reserved)
2147 {
2148 int ret = 0;
2149 struct btrfs_delayed_tree_ref *ref;
2150 struct btrfs_key ins;
2151 u64 parent = 0;
2152 u64 ref_root = 0;
2153 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
2154 SKINNY_METADATA);
2155
2156 ref = btrfs_delayed_node_to_tree_ref(node);
2157 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2158 parent = ref->parent;
2159 else
2160 ref_root = ref->root;
2161
2162 ins.objectid = node->bytenr;
2163 if (skinny_metadata) {
2164 ins.offset = ref->level;
2165 ins.type = BTRFS_METADATA_ITEM_KEY;
2166 } else {
2167 ins.offset = node->num_bytes;
2168 ins.type = BTRFS_EXTENT_ITEM_KEY;
2169 }
2170
2171 BUG_ON(node->ref_mod != 1);
2172 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2173 BUG_ON(!extent_op || !extent_op->update_flags);
2174 ret = alloc_reserved_tree_block(trans, root,
2175 parent, ref_root,
2176 extent_op->flags_to_set,
2177 &extent_op->key,
2178 ref->level, &ins);
2179 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2180 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
2181 node->num_bytes, parent, ref_root,
2182 ref->level, 0, 1, extent_op);
2183 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2184 ret = __btrfs_free_extent(trans, root, node->bytenr,
2185 node->num_bytes, parent, ref_root,
2186 ref->level, 0, 1, extent_op);
2187 } else {
2188 BUG();
2189 }
2190 return ret;
2191 }
2192
2193 /* helper function to actually process a single delayed ref entry */
2194 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
2195 struct btrfs_root *root,
2196 struct btrfs_delayed_ref_node *node,
2197 struct btrfs_delayed_extent_op *extent_op,
2198 int insert_reserved)
2199 {
2200 int ret = 0;
2201
2202 if (trans->aborted)
2203 return 0;
2204
2205 if (btrfs_delayed_ref_is_head(node)) {
2206 struct btrfs_delayed_ref_head *head;
2207 /*
2208 * we've hit the end of the chain and we were supposed
2209 * to insert this extent into the tree. But, it got
2210 * deleted before we ever needed to insert it, so all
2211 * we have to do is clean up the accounting
2212 */
2213 BUG_ON(extent_op);
2214 head = btrfs_delayed_node_to_head(node);
2215 if (insert_reserved) {
2216 btrfs_pin_extent(root, node->bytenr,
2217 node->num_bytes, 1);
2218 if (head->is_data) {
2219 ret = btrfs_del_csums(trans, root,
2220 node->bytenr,
2221 node->num_bytes);
2222 }
2223 }
2224 return ret;
2225 }
2226
2227 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
2228 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2229 ret = run_delayed_tree_ref(trans, root, node, extent_op,
2230 insert_reserved);
2231 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
2232 node->type == BTRFS_SHARED_DATA_REF_KEY)
2233 ret = run_delayed_data_ref(trans, root, node, extent_op,
2234 insert_reserved);
2235 else
2236 BUG();
2237 return ret;
2238 }
2239
2240 static noinline struct btrfs_delayed_ref_node *
2241 select_delayed_ref(struct btrfs_delayed_ref_head *head)
2242 {
2243 struct rb_node *node;
2244 struct btrfs_delayed_ref_node *ref;
2245 int action = BTRFS_ADD_DELAYED_REF;
2246 again:
2247 /*
2248 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
2249 * this prevents ref count from going down to zero when
2250 * there still are pending delayed ref.
2251 */
2252 node = rb_prev(&head->node.rb_node);
2253 while (1) {
2254 if (!node)
2255 break;
2256 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2257 rb_node);
2258 if (ref->bytenr != head->node.bytenr)
2259 break;
2260 if (ref->action == action)
2261 return ref;
2262 node = rb_prev(node);
2263 }
2264 if (action == BTRFS_ADD_DELAYED_REF) {
2265 action = BTRFS_DROP_DELAYED_REF;
2266 goto again;
2267 }
2268 return NULL;
2269 }
2270
2271 /*
2272 * Returns 0 on success or if called with an already aborted transaction.
2273 * Returns -ENOMEM or -EIO on failure and will abort the transaction.
2274 */
2275 static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
2276 struct btrfs_root *root,
2277 struct list_head *cluster)
2278 {
2279 struct btrfs_delayed_ref_root *delayed_refs;
2280 struct btrfs_delayed_ref_node *ref;
2281 struct btrfs_delayed_ref_head *locked_ref = NULL;
2282 struct btrfs_delayed_extent_op *extent_op;
2283 struct btrfs_fs_info *fs_info = root->fs_info;
2284 int ret;
2285 int count = 0;
2286 int must_insert_reserved = 0;
2287
2288 delayed_refs = &trans->transaction->delayed_refs;
2289 while (1) {
2290 if (!locked_ref) {
2291 /* pick a new head ref from the cluster list */
2292 if (list_empty(cluster))
2293 break;
2294
2295 locked_ref = list_entry(cluster->next,
2296 struct btrfs_delayed_ref_head, cluster);
2297
2298 /* grab the lock that says we are going to process
2299 * all the refs for this head */
2300 ret = btrfs_delayed_ref_lock(trans, locked_ref);
2301
2302 /*
2303 * we may have dropped the spin lock to get the head
2304 * mutex lock, and that might have given someone else
2305 * time to free the head. If that's true, it has been
2306 * removed from our list and we can move on.
2307 */
2308 if (ret == -EAGAIN) {
2309 locked_ref = NULL;
2310 count++;
2311 continue;
2312 }
2313 }
2314
2315 /*
2316 * We need to try and merge add/drops of the same ref since we
2317 * can run into issues with relocate dropping the implicit ref
2318 * and then it being added back again before the drop can
2319 * finish. If we merged anything we need to re-loop so we can
2320 * get a good ref.
2321 */
2322 btrfs_merge_delayed_refs(trans, fs_info, delayed_refs,
2323 locked_ref);
2324
2325 /*
2326 * locked_ref is the head node, so we have to go one
2327 * node back for any delayed ref updates
2328 */
2329 ref = select_delayed_ref(locked_ref);
2330
2331 if (ref && ref->seq &&
2332 btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) {
2333 /*
2334 * there are still refs with lower seq numbers in the
2335 * process of being added. Don't run this ref yet.
2336 */
2337 list_del_init(&locked_ref->cluster);
2338 btrfs_delayed_ref_unlock(locked_ref);
2339 locked_ref = NULL;
2340 delayed_refs->num_heads_ready++;
2341 spin_unlock(&delayed_refs->lock);
2342 cond_resched();
2343 spin_lock(&delayed_refs->lock);
2344 continue;
2345 }
2346
2347 /*
2348 * record the must insert reserved flag before we
2349 * drop the spin lock.
2350 */
2351 must_insert_reserved = locked_ref->must_insert_reserved;
2352 locked_ref->must_insert_reserved = 0;
2353
2354 extent_op = locked_ref->extent_op;
2355 locked_ref->extent_op = NULL;
2356
2357 if (!ref) {
2358 /* All delayed refs have been processed, Go ahead
2359 * and send the head node to run_one_delayed_ref,
2360 * so that any accounting fixes can happen
2361 */
2362 ref = &locked_ref->node;
2363
2364 if (extent_op && must_insert_reserved) {
2365 btrfs_free_delayed_extent_op(extent_op);
2366 extent_op = NULL;
2367 }
2368
2369 if (extent_op) {
2370 spin_unlock(&delayed_refs->lock);
2371
2372 ret = run_delayed_extent_op(trans, root,
2373 ref, extent_op);
2374 btrfs_free_delayed_extent_op(extent_op);
2375
2376 if (ret) {
2377 btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret);
2378 spin_lock(&delayed_refs->lock);
2379 btrfs_delayed_ref_unlock(locked_ref);
2380 return ret;
2381 }
2382
2383 goto next;
2384 }
2385 }
2386
2387 ref->in_tree = 0;
2388 rb_erase(&ref->rb_node, &delayed_refs->root);
2389 delayed_refs->num_entries--;
2390 if (!btrfs_delayed_ref_is_head(ref)) {
2391 /*
2392 * when we play the delayed ref, also correct the
2393 * ref_mod on head
2394 */
2395 switch (ref->action) {
2396 case BTRFS_ADD_DELAYED_REF:
2397 case BTRFS_ADD_DELAYED_EXTENT:
2398 locked_ref->node.ref_mod -= ref->ref_mod;
2399 break;
2400 case BTRFS_DROP_DELAYED_REF:
2401 locked_ref->node.ref_mod += ref->ref_mod;
2402 break;
2403 default:
2404 WARN_ON(1);
2405 }
2406 }
2407 spin_unlock(&delayed_refs->lock);
2408
2409 ret = run_one_delayed_ref(trans, root, ref, extent_op,
2410 must_insert_reserved);
2411
2412 btrfs_free_delayed_extent_op(extent_op);
2413 if (ret) {
2414 btrfs_delayed_ref_unlock(locked_ref);
2415 btrfs_put_delayed_ref(ref);
2416 btrfs_debug(fs_info, "run_one_delayed_ref returned %d", ret);
2417 spin_lock(&delayed_refs->lock);
2418 return ret;
2419 }
2420
2421 /*
2422 * If this node is a head, that means all the refs in this head
2423 * have been dealt with, and we will pick the next head to deal
2424 * with, so we must unlock the head and drop it from the cluster
2425 * list before we release it.
2426 */
2427 if (btrfs_delayed_ref_is_head(ref)) {
2428 list_del_init(&locked_ref->cluster);
2429 btrfs_delayed_ref_unlock(locked_ref);
2430 locked_ref = NULL;
2431 }
2432 btrfs_put_delayed_ref(ref);
2433 count++;
2434 next:
2435 cond_resched();
2436 spin_lock(&delayed_refs->lock);
2437 }
2438 return count;
2439 }
2440
2441 #ifdef SCRAMBLE_DELAYED_REFS
2442 /*
2443 * Normally delayed refs get processed in ascending bytenr order. This
2444 * correlates in most cases to the order added. To expose dependencies on this
2445 * order, we start to process the tree in the middle instead of the beginning
2446 */
2447 static u64 find_middle(struct rb_root *root)
2448 {
2449 struct rb_node *n = root->rb_node;
2450 struct btrfs_delayed_ref_node *entry;
2451 int alt = 1;
2452 u64 middle;
2453 u64 first = 0, last = 0;
2454
2455 n = rb_first(root);
2456 if (n) {
2457 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2458 first = entry->bytenr;
2459 }
2460 n = rb_last(root);
2461 if (n) {
2462 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2463 last = entry->bytenr;
2464 }
2465 n = root->rb_node;
2466
2467 while (n) {
2468 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2469 WARN_ON(!entry->in_tree);
2470
2471 middle = entry->bytenr;
2472
2473 if (alt)
2474 n = n->rb_left;
2475 else
2476 n = n->rb_right;
2477
2478 alt = 1 - alt;
2479 }
2480 return middle;
2481 }
2482 #endif
2483
2484 int btrfs_delayed_refs_qgroup_accounting(struct btrfs_trans_handle *trans,
2485 struct btrfs_fs_info *fs_info)
2486 {
2487 struct qgroup_update *qgroup_update;
2488 int ret = 0;
2489
2490 if (list_empty(&trans->qgroup_ref_list) !=
2491 !trans->delayed_ref_elem.seq) {
2492 /* list without seq or seq without list */
2493 btrfs_err(fs_info,
2494 "qgroup accounting update error, list is%s empty, seq is %#x.%x",
2495 list_empty(&trans->qgroup_ref_list) ? "" : " not",
2496 (u32)(trans->delayed_ref_elem.seq >> 32),
2497 (u32)trans->delayed_ref_elem.seq);
2498 BUG();
2499 }
2500
2501 if (!trans->delayed_ref_elem.seq)
2502 return 0;
2503
2504 while (!list_empty(&trans->qgroup_ref_list)) {
2505 qgroup_update = list_first_entry(&trans->qgroup_ref_list,
2506 struct qgroup_update, list);
2507 list_del(&qgroup_update->list);
2508 if (!ret)
2509 ret = btrfs_qgroup_account_ref(
2510 trans, fs_info, qgroup_update->node,
2511 qgroup_update->extent_op);
2512 kfree(qgroup_update);
2513 }
2514
2515 btrfs_put_tree_mod_seq(fs_info, &trans->delayed_ref_elem);
2516
2517 return ret;
2518 }
2519
2520 static int refs_newer(struct btrfs_delayed_ref_root *delayed_refs, int seq,
2521 int count)
2522 {
2523 int val = atomic_read(&delayed_refs->ref_seq);
2524
2525 if (val < seq || val >= seq + count)
2526 return 1;
2527 return 0;
2528 }
2529
2530 static inline u64 heads_to_leaves(struct btrfs_root *root, u64 heads)
2531 {
2532 u64 num_bytes;
2533
2534 num_bytes = heads * (sizeof(struct btrfs_extent_item) +
2535 sizeof(struct btrfs_extent_inline_ref));
2536 if (!btrfs_fs_incompat(root->fs_info, SKINNY_METADATA))
2537 num_bytes += heads * sizeof(struct btrfs_tree_block_info);
2538
2539 /*
2540 * We don't ever fill up leaves all the way so multiply by 2 just to be
2541 * closer to what we're really going to want to ouse.
2542 */
2543 return div64_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(root));
2544 }
2545
2546 int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans,
2547 struct btrfs_root *root)
2548 {
2549 struct btrfs_block_rsv *global_rsv;
2550 u64 num_heads = trans->transaction->delayed_refs.num_heads_ready;
2551 u64 num_bytes;
2552 int ret = 0;
2553
2554 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
2555 num_heads = heads_to_leaves(root, num_heads);
2556 if (num_heads > 1)
2557 num_bytes += (num_heads - 1) * root->leafsize;
2558 num_bytes <<= 1;
2559 global_rsv = &root->fs_info->global_block_rsv;
2560
2561 /*
2562 * If we can't allocate any more chunks lets make sure we have _lots_ of
2563 * wiggle room since running delayed refs can create more delayed refs.
2564 */
2565 if (global_rsv->space_info->full)
2566 num_bytes <<= 1;
2567
2568 spin_lock(&global_rsv->lock);
2569 if (global_rsv->reserved <= num_bytes)
2570 ret = 1;
2571 spin_unlock(&global_rsv->lock);
2572 return ret;
2573 }
2574
2575 /*
2576 * this starts processing the delayed reference count updates and
2577 * extent insertions we have queued up so far. count can be
2578 * 0, which means to process everything in the tree at the start
2579 * of the run (but not newly added entries), or it can be some target
2580 * number you'd like to process.
2581 *
2582 * Returns 0 on success or if called with an aborted transaction
2583 * Returns <0 on error and aborts the transaction
2584 */
2585 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2586 struct btrfs_root *root, unsigned long count)
2587 {
2588 struct rb_node *node;
2589 struct btrfs_delayed_ref_root *delayed_refs;
2590 struct btrfs_delayed_ref_node *ref;
2591 struct list_head cluster;
2592 int ret;
2593 u64 delayed_start;
2594 int run_all = count == (unsigned long)-1;
2595 int run_most = 0;
2596 int loops;
2597
2598 /* We'll clean this up in btrfs_cleanup_transaction */
2599 if (trans->aborted)
2600 return 0;
2601
2602 if (root == root->fs_info->extent_root)
2603 root = root->fs_info->tree_root;
2604
2605 btrfs_delayed_refs_qgroup_accounting(trans, root->fs_info);
2606
2607 delayed_refs = &trans->transaction->delayed_refs;
2608 INIT_LIST_HEAD(&cluster);
2609 if (count == 0) {
2610 count = delayed_refs->num_entries * 2;
2611 run_most = 1;
2612 }
2613
2614 if (!run_all && !run_most) {
2615 int old;
2616 int seq = atomic_read(&delayed_refs->ref_seq);
2617
2618 progress:
2619 old = atomic_cmpxchg(&delayed_refs->procs_running_refs, 0, 1);
2620 if (old) {
2621 DEFINE_WAIT(__wait);
2622 if (delayed_refs->flushing ||
2623 !btrfs_should_throttle_delayed_refs(trans, root))
2624 return 0;
2625
2626 prepare_to_wait(&delayed_refs->wait, &__wait,
2627 TASK_UNINTERRUPTIBLE);
2628
2629 old = atomic_cmpxchg(&delayed_refs->procs_running_refs, 0, 1);
2630 if (old) {
2631 schedule();
2632 finish_wait(&delayed_refs->wait, &__wait);
2633
2634 if (!refs_newer(delayed_refs, seq, 256))
2635 goto progress;
2636 else
2637 return 0;
2638 } else {
2639 finish_wait(&delayed_refs->wait, &__wait);
2640 goto again;
2641 }
2642 }
2643
2644 } else {
2645 atomic_inc(&delayed_refs->procs_running_refs);
2646 }
2647
2648 again:
2649 loops = 0;
2650 spin_lock(&delayed_refs->lock);
2651
2652 #ifdef SCRAMBLE_DELAYED_REFS
2653 delayed_refs->run_delayed_start = find_middle(&delayed_refs->root);
2654 #endif
2655
2656 while (1) {
2657 if (!(run_all || run_most) &&
2658 !btrfs_should_throttle_delayed_refs(trans, root))
2659 break;
2660
2661 /*
2662 * go find something we can process in the rbtree. We start at
2663 * the beginning of the tree, and then build a cluster
2664 * of refs to process starting at the first one we are able to
2665 * lock
2666 */
2667 delayed_start = delayed_refs->run_delayed_start;
2668 ret = btrfs_find_ref_cluster(trans, &cluster,
2669 delayed_refs->run_delayed_start);
2670 if (ret)
2671 break;
2672
2673 ret = run_clustered_refs(trans, root, &cluster);
2674 if (ret < 0) {
2675 btrfs_release_ref_cluster(&cluster);
2676 spin_unlock(&delayed_refs->lock);
2677 btrfs_abort_transaction(trans, root, ret);
2678 atomic_dec(&delayed_refs->procs_running_refs);
2679 wake_up(&delayed_refs->wait);
2680 return ret;
2681 }
2682
2683 atomic_add(ret, &delayed_refs->ref_seq);
2684
2685 count -= min_t(unsigned long, ret, count);
2686
2687 if (count == 0)
2688 break;
2689
2690 if (delayed_start >= delayed_refs->run_delayed_start) {
2691 if (loops == 0) {
2692 /*
2693 * btrfs_find_ref_cluster looped. let's do one
2694 * more cycle. if we don't run any delayed ref
2695 * during that cycle (because we can't because
2696 * all of them are blocked), bail out.
2697 */
2698 loops = 1;
2699 } else {
2700 /*
2701 * no runnable refs left, stop trying
2702 */
2703 BUG_ON(run_all);
2704 break;
2705 }
2706 }
2707 if (ret) {
2708 /* refs were run, let's reset staleness detection */
2709 loops = 0;
2710 }
2711 }
2712
2713 if (run_all) {
2714 if (!list_empty(&trans->new_bgs)) {
2715 spin_unlock(&delayed_refs->lock);
2716 btrfs_create_pending_block_groups(trans, root);
2717 spin_lock(&delayed_refs->lock);
2718 }
2719
2720 node = rb_first(&delayed_refs->root);
2721 if (!node)
2722 goto out;
2723 count = (unsigned long)-1;
2724
2725 while (node) {
2726 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2727 rb_node);
2728 if (btrfs_delayed_ref_is_head(ref)) {
2729 struct btrfs_delayed_ref_head *head;
2730
2731 head = btrfs_delayed_node_to_head(ref);
2732 atomic_inc(&ref->refs);
2733
2734 spin_unlock(&delayed_refs->lock);
2735 /*
2736 * Mutex was contended, block until it's
2737 * released and try again
2738 */
2739 mutex_lock(&head->mutex);
2740 mutex_unlock(&head->mutex);
2741
2742 btrfs_put_delayed_ref(ref);
2743 cond_resched();
2744 goto again;
2745 }
2746 node = rb_next(node);
2747 }
2748 spin_unlock(&delayed_refs->lock);
2749 schedule_timeout(1);
2750 goto again;
2751 }
2752 out:
2753 atomic_dec(&delayed_refs->procs_running_refs);
2754 smp_mb();
2755 if (waitqueue_active(&delayed_refs->wait))
2756 wake_up(&delayed_refs->wait);
2757
2758 spin_unlock(&delayed_refs->lock);
2759 assert_qgroups_uptodate(trans);
2760 return 0;
2761 }
2762
2763 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2764 struct btrfs_root *root,
2765 u64 bytenr, u64 num_bytes, u64 flags,
2766 int level, int is_data)
2767 {
2768 struct btrfs_delayed_extent_op *extent_op;
2769 int ret;
2770
2771 extent_op = btrfs_alloc_delayed_extent_op();
2772 if (!extent_op)
2773 return -ENOMEM;
2774
2775 extent_op->flags_to_set = flags;
2776 extent_op->update_flags = 1;
2777 extent_op->update_key = 0;
2778 extent_op->is_data = is_data ? 1 : 0;
2779 extent_op->level = level;
2780
2781 ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr,
2782 num_bytes, extent_op);
2783 if (ret)
2784 btrfs_free_delayed_extent_op(extent_op);
2785 return ret;
2786 }
2787
2788 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
2789 struct btrfs_root *root,
2790 struct btrfs_path *path,
2791 u64 objectid, u64 offset, u64 bytenr)
2792 {
2793 struct btrfs_delayed_ref_head *head;
2794 struct btrfs_delayed_ref_node *ref;
2795 struct btrfs_delayed_data_ref *data_ref;
2796 struct btrfs_delayed_ref_root *delayed_refs;
2797 struct rb_node *node;
2798 int ret = 0;
2799
2800 ret = -ENOENT;
2801 delayed_refs = &trans->transaction->delayed_refs;
2802 spin_lock(&delayed_refs->lock);
2803 head = btrfs_find_delayed_ref_head(trans, bytenr);
2804 if (!head)
2805 goto out;
2806
2807 if (!mutex_trylock(&head->mutex)) {
2808 atomic_inc(&head->node.refs);
2809 spin_unlock(&delayed_refs->lock);
2810
2811 btrfs_release_path(path);
2812
2813 /*
2814 * Mutex was contended, block until it's released and let
2815 * caller try again
2816 */
2817 mutex_lock(&head->mutex);
2818 mutex_unlock(&head->mutex);
2819 btrfs_put_delayed_ref(&head->node);
2820 return -EAGAIN;
2821 }
2822
2823 node = rb_prev(&head->node.rb_node);
2824 if (!node)
2825 goto out_unlock;
2826
2827 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2828
2829 if (ref->bytenr != bytenr)
2830 goto out_unlock;
2831
2832 ret = 1;
2833 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
2834 goto out_unlock;
2835
2836 data_ref = btrfs_delayed_node_to_data_ref(ref);
2837
2838 node = rb_prev(node);
2839 if (node) {
2840 int seq = ref->seq;
2841
2842 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2843 if (ref->bytenr == bytenr && ref->seq == seq)
2844 goto out_unlock;
2845 }
2846
2847 if (data_ref->root != root->root_key.objectid ||
2848 data_ref->objectid != objectid || data_ref->offset != offset)
2849 goto out_unlock;
2850
2851 ret = 0;
2852 out_unlock:
2853 mutex_unlock(&head->mutex);
2854 out:
2855 spin_unlock(&delayed_refs->lock);
2856 return ret;
2857 }
2858
2859 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
2860 struct btrfs_root *root,
2861 struct btrfs_path *path,
2862 u64 objectid, u64 offset, u64 bytenr)
2863 {
2864 struct btrfs_root *extent_root = root->fs_info->extent_root;
2865 struct extent_buffer *leaf;
2866 struct btrfs_extent_data_ref *ref;
2867 struct btrfs_extent_inline_ref *iref;
2868 struct btrfs_extent_item *ei;
2869 struct btrfs_key key;
2870 u32 item_size;
2871 int ret;
2872
2873 key.objectid = bytenr;
2874 key.offset = (u64)-1;
2875 key.type = BTRFS_EXTENT_ITEM_KEY;
2876
2877 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2878 if (ret < 0)
2879 goto out;
2880 BUG_ON(ret == 0); /* Corruption */
2881
2882 ret = -ENOENT;
2883 if (path->slots[0] == 0)
2884 goto out;
2885
2886 path->slots[0]--;
2887 leaf = path->nodes[0];
2888 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2889
2890 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2891 goto out;
2892
2893 ret = 1;
2894 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2895 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2896 if (item_size < sizeof(*ei)) {
2897 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
2898 goto out;
2899 }
2900 #endif
2901 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2902
2903 if (item_size != sizeof(*ei) +
2904 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2905 goto out;
2906
2907 if (btrfs_extent_generation(leaf, ei) <=
2908 btrfs_root_last_snapshot(&root->root_item))
2909 goto out;
2910
2911 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2912 if (btrfs_extent_inline_ref_type(leaf, iref) !=
2913 BTRFS_EXTENT_DATA_REF_KEY)
2914 goto out;
2915
2916 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2917 if (btrfs_extent_refs(leaf, ei) !=
2918 btrfs_extent_data_ref_count(leaf, ref) ||
2919 btrfs_extent_data_ref_root(leaf, ref) !=
2920 root->root_key.objectid ||
2921 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2922 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2923 goto out;
2924
2925 ret = 0;
2926 out:
2927 return ret;
2928 }
2929
2930 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
2931 struct btrfs_root *root,
2932 u64 objectid, u64 offset, u64 bytenr)
2933 {
2934 struct btrfs_path *path;
2935 int ret;
2936 int ret2;
2937
2938 path = btrfs_alloc_path();
2939 if (!path)
2940 return -ENOENT;
2941
2942 do {
2943 ret = check_committed_ref(trans, root, path, objectid,
2944 offset, bytenr);
2945 if (ret && ret != -ENOENT)
2946 goto out;
2947
2948 ret2 = check_delayed_ref(trans, root, path, objectid,
2949 offset, bytenr);
2950 } while (ret2 == -EAGAIN);
2951
2952 if (ret2 && ret2 != -ENOENT) {
2953 ret = ret2;
2954 goto out;
2955 }
2956
2957 if (ret != -ENOENT || ret2 != -ENOENT)
2958 ret = 0;
2959 out:
2960 btrfs_free_path(path);
2961 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
2962 WARN_ON(ret > 0);
2963 return ret;
2964 }
2965
2966 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2967 struct btrfs_root *root,
2968 struct extent_buffer *buf,
2969 int full_backref, int inc, int for_cow)
2970 {
2971 u64 bytenr;
2972 u64 num_bytes;
2973 u64 parent;
2974 u64 ref_root;
2975 u32 nritems;
2976 struct btrfs_key key;
2977 struct btrfs_file_extent_item *fi;
2978 int i;
2979 int level;
2980 int ret = 0;
2981 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
2982 u64, u64, u64, u64, u64, u64, int);
2983
2984 ref_root = btrfs_header_owner(buf);
2985 nritems = btrfs_header_nritems(buf);
2986 level = btrfs_header_level(buf);
2987
2988 if (!root->ref_cows && level == 0)
2989 return 0;
2990
2991 if (inc)
2992 process_func = btrfs_inc_extent_ref;
2993 else
2994 process_func = btrfs_free_extent;
2995
2996 if (full_backref)
2997 parent = buf->start;
2998 else
2999 parent = 0;
3000
3001 for (i = 0; i < nritems; i++) {
3002 if (level == 0) {
3003 btrfs_item_key_to_cpu(buf, &key, i);
3004 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
3005 continue;
3006 fi = btrfs_item_ptr(buf, i,
3007 struct btrfs_file_extent_item);
3008 if (btrfs_file_extent_type(buf, fi) ==
3009 BTRFS_FILE_EXTENT_INLINE)
3010 continue;
3011 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
3012 if (bytenr == 0)
3013 continue;
3014
3015 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
3016 key.offset -= btrfs_file_extent_offset(buf, fi);
3017 ret = process_func(trans, root, bytenr, num_bytes,
3018 parent, ref_root, key.objectid,
3019 key.offset, for_cow);
3020 if (ret)
3021 goto fail;
3022 } else {
3023 bytenr = btrfs_node_blockptr(buf, i);
3024 num_bytes = btrfs_level_size(root, level - 1);
3025 ret = process_func(trans, root, bytenr, num_bytes,
3026 parent, ref_root, level - 1, 0,
3027 for_cow);
3028 if (ret)
3029 goto fail;
3030 }
3031 }
3032 return 0;
3033 fail:
3034 return ret;
3035 }
3036
3037 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3038 struct extent_buffer *buf, int full_backref, int for_cow)
3039 {
3040 return __btrfs_mod_ref(trans, root, buf, full_backref, 1, for_cow);
3041 }
3042
3043 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3044 struct extent_buffer *buf, int full_backref, int for_cow)
3045 {
3046 return __btrfs_mod_ref(trans, root, buf, full_backref, 0, for_cow);
3047 }
3048
3049 static int write_one_cache_group(struct btrfs_trans_handle *trans,
3050 struct btrfs_root *root,
3051 struct btrfs_path *path,
3052 struct btrfs_block_group_cache *cache)
3053 {
3054 int ret;
3055 struct btrfs_root *extent_root = root->fs_info->extent_root;
3056 unsigned long bi;
3057 struct extent_buffer *leaf;
3058
3059 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
3060 if (ret < 0)
3061 goto fail;
3062 BUG_ON(ret); /* Corruption */
3063
3064 leaf = path->nodes[0];
3065 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
3066 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
3067 btrfs_mark_buffer_dirty(leaf);
3068 btrfs_release_path(path);
3069 fail:
3070 if (ret) {
3071 btrfs_abort_transaction(trans, root, ret);
3072 return ret;
3073 }
3074 return 0;
3075
3076 }
3077
3078 static struct btrfs_block_group_cache *
3079 next_block_group(struct btrfs_root *root,
3080 struct btrfs_block_group_cache *cache)
3081 {
3082 struct rb_node *node;
3083 spin_lock(&root->fs_info->block_group_cache_lock);
3084 node = rb_next(&cache->cache_node);
3085 btrfs_put_block_group(cache);
3086 if (node) {
3087 cache = rb_entry(node, struct btrfs_block_group_cache,
3088 cache_node);
3089 btrfs_get_block_group(cache);
3090 } else
3091 cache = NULL;
3092 spin_unlock(&root->fs_info->block_group_cache_lock);
3093 return cache;
3094 }
3095
3096 static int cache_save_setup(struct btrfs_block_group_cache *block_group,
3097 struct btrfs_trans_handle *trans,
3098 struct btrfs_path *path)
3099 {
3100 struct btrfs_root *root = block_group->fs_info->tree_root;
3101 struct inode *inode = NULL;
3102 u64 alloc_hint = 0;
3103 int dcs = BTRFS_DC_ERROR;
3104 int num_pages = 0;
3105 int retries = 0;
3106 int ret = 0;
3107
3108 /*
3109 * If this block group is smaller than 100 megs don't bother caching the
3110 * block group.
3111 */
3112 if (block_group->key.offset < (100 * 1024 * 1024)) {
3113 spin_lock(&block_group->lock);
3114 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
3115 spin_unlock(&block_group->lock);
3116 return 0;
3117 }
3118
3119 again:
3120 inode = lookup_free_space_inode(root, block_group, path);
3121 if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
3122 ret = PTR_ERR(inode);
3123 btrfs_release_path(path);
3124 goto out;
3125 }
3126
3127 if (IS_ERR(inode)) {
3128 BUG_ON(retries);
3129 retries++;
3130
3131 if (block_group->ro)
3132 goto out_free;
3133
3134 ret = create_free_space_inode(root, trans, block_group, path);
3135 if (ret)
3136 goto out_free;
3137 goto again;
3138 }
3139
3140 /* We've already setup this transaction, go ahead and exit */
3141 if (block_group->cache_generation == trans->transid &&
3142 i_size_read(inode)) {
3143 dcs = BTRFS_DC_SETUP;
3144 goto out_put;
3145 }
3146
3147 /*
3148 * We want to set the generation to 0, that way if anything goes wrong
3149 * from here on out we know not to trust this cache when we load up next
3150 * time.
3151 */
3152 BTRFS_I(inode)->generation = 0;
3153 ret = btrfs_update_inode(trans, root, inode);
3154 WARN_ON(ret);
3155
3156 if (i_size_read(inode) > 0) {
3157 ret = btrfs_check_trunc_cache_free_space(root,
3158 &root->fs_info->global_block_rsv);
3159 if (ret)
3160 goto out_put;
3161
3162 ret = btrfs_truncate_free_space_cache(root, trans, path,
3163 inode);
3164 if (ret)
3165 goto out_put;
3166 }
3167
3168 spin_lock(&block_group->lock);
3169 if (block_group->cached != BTRFS_CACHE_FINISHED ||
3170 !btrfs_test_opt(root, SPACE_CACHE)) {
3171 /*
3172 * don't bother trying to write stuff out _if_
3173 * a) we're not cached,
3174 * b) we're with nospace_cache mount option.
3175 */
3176 dcs = BTRFS_DC_WRITTEN;
3177 spin_unlock(&block_group->lock);
3178 goto out_put;
3179 }
3180 spin_unlock(&block_group->lock);
3181
3182 /*
3183 * Try to preallocate enough space based on how big the block group is.
3184 * Keep in mind this has to include any pinned space which could end up
3185 * taking up quite a bit since it's not folded into the other space
3186 * cache.
3187 */
3188 num_pages = (int)div64_u64(block_group->key.offset, 256 * 1024 * 1024);
3189 if (!num_pages)
3190 num_pages = 1;
3191
3192 num_pages *= 16;
3193 num_pages *= PAGE_CACHE_SIZE;
3194
3195 ret = btrfs_check_data_free_space(inode, num_pages);
3196 if (ret)
3197 goto out_put;
3198
3199 ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
3200 num_pages, num_pages,
3201 &alloc_hint);
3202 if (!ret)
3203 dcs = BTRFS_DC_SETUP;
3204 btrfs_free_reserved_data_space(inode, num_pages);
3205
3206 out_put:
3207 iput(inode);
3208 out_free:
3209 btrfs_release_path(path);
3210 out:
3211 spin_lock(&block_group->lock);
3212 if (!ret && dcs == BTRFS_DC_SETUP)
3213 block_group->cache_generation = trans->transid;
3214 block_group->disk_cache_state = dcs;
3215 spin_unlock(&block_group->lock);
3216
3217 return ret;
3218 }
3219
3220 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
3221 struct btrfs_root *root)
3222 {
3223 struct btrfs_block_group_cache *cache;
3224 int err = 0;
3225 struct btrfs_path *path;
3226 u64 last = 0;
3227
3228 path = btrfs_alloc_path();
3229 if (!path)
3230 return -ENOMEM;
3231
3232 again:
3233 while (1) {
3234 cache = btrfs_lookup_first_block_group(root->fs_info, last);
3235 while (cache) {
3236 if (cache->disk_cache_state == BTRFS_DC_CLEAR)
3237 break;
3238 cache = next_block_group(root, cache);
3239 }
3240 if (!cache) {
3241 if (last == 0)
3242 break;
3243 last = 0;
3244 continue;
3245 }
3246 err = cache_save_setup(cache, trans, path);
3247 last = cache->key.objectid + cache->key.offset;
3248 btrfs_put_block_group(cache);
3249 }
3250
3251 while (1) {
3252 if (last == 0) {
3253 err = btrfs_run_delayed_refs(trans, root,
3254 (unsigned long)-1);
3255 if (err) /* File system offline */
3256 goto out;
3257 }
3258
3259 cache = btrfs_lookup_first_block_group(root->fs_info, last);
3260 while (cache) {
3261 if (cache->disk_cache_state == BTRFS_DC_CLEAR) {
3262 btrfs_put_block_group(cache);
3263 goto again;
3264 }
3265
3266 if (cache->dirty)
3267 break;
3268 cache = next_block_group(root, cache);
3269 }
3270 if (!cache) {
3271 if (last == 0)
3272 break;
3273 last = 0;
3274 continue;
3275 }
3276
3277 if (cache->disk_cache_state == BTRFS_DC_SETUP)
3278 cache->disk_cache_state = BTRFS_DC_NEED_WRITE;
3279 cache->dirty = 0;
3280 last = cache->key.objectid + cache->key.offset;
3281
3282 err = write_one_cache_group(trans, root, path, cache);
3283 if (err) /* File system offline */
3284 goto out;
3285
3286 btrfs_put_block_group(cache);
3287 }
3288
3289 while (1) {
3290 /*
3291 * I don't think this is needed since we're just marking our
3292 * preallocated extent as written, but just in case it can't
3293 * hurt.
3294 */
3295 if (last == 0) {
3296 err = btrfs_run_delayed_refs(trans, root,
3297 (unsigned long)-1);
3298 if (err) /* File system offline */
3299 goto out;
3300 }
3301
3302 cache = btrfs_lookup_first_block_group(root->fs_info, last);
3303 while (cache) {
3304 /*
3305 * Really this shouldn't happen, but it could if we
3306 * couldn't write the entire preallocated extent and
3307 * splitting the extent resulted in a new block.
3308 */
3309 if (cache->dirty) {
3310 btrfs_put_block_group(cache);
3311 goto again;
3312 }
3313 if (cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
3314 break;
3315 cache = next_block_group(root, cache);
3316 }
3317 if (!cache) {
3318 if (last == 0)
3319 break;
3320 last = 0;
3321 continue;
3322 }
3323
3324 err = btrfs_write_out_cache(root, trans, cache, path);
3325
3326 /*
3327 * If we didn't have an error then the cache state is still
3328 * NEED_WRITE, so we can set it to WRITTEN.
3329 */
3330 if (!err && cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
3331 cache->disk_cache_state = BTRFS_DC_WRITTEN;
3332 last = cache->key.objectid + cache->key.offset;
3333 btrfs_put_block_group(cache);
3334 }
3335 out:
3336
3337 btrfs_free_path(path);
3338 return err;
3339 }
3340
3341 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
3342 {
3343 struct btrfs_block_group_cache *block_group;
3344 int readonly = 0;
3345
3346 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
3347 if (!block_group || block_group->ro)
3348 readonly = 1;
3349 if (block_group)
3350 btrfs_put_block_group(block_group);
3351 return readonly;
3352 }
3353
3354 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
3355 u64 total_bytes, u64 bytes_used,
3356 struct btrfs_space_info **space_info)
3357 {
3358 struct btrfs_space_info *found;
3359 int i;
3360 int factor;
3361 int ret;
3362
3363 if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3364 BTRFS_BLOCK_GROUP_RAID10))
3365 factor = 2;
3366 else
3367 factor = 1;
3368
3369 found = __find_space_info(info, flags);
3370 if (found) {
3371 spin_lock(&found->lock);
3372 found->total_bytes += total_bytes;
3373 found->disk_total += total_bytes * factor;
3374 found->bytes_used += bytes_used;
3375 found->disk_used += bytes_used * factor;
3376 found->full = 0;
3377 spin_unlock(&found->lock);
3378 *space_info = found;
3379 return 0;
3380 }
3381 found = kzalloc(sizeof(*found), GFP_NOFS);
3382 if (!found)
3383 return -ENOMEM;
3384
3385 ret = percpu_counter_init(&found->total_bytes_pinned, 0);
3386 if (ret) {
3387 kfree(found);
3388 return ret;
3389 }
3390
3391 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
3392 INIT_LIST_HEAD(&found->block_groups[i]);
3393 init_rwsem(&found->groups_sem);
3394 spin_lock_init(&found->lock);
3395 found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
3396 found->total_bytes = total_bytes;
3397 found->disk_total = total_bytes * factor;
3398 found->bytes_used = bytes_used;
3399 found->disk_used = bytes_used * factor;
3400 found->bytes_pinned = 0;
3401 found->bytes_reserved = 0;
3402 found->bytes_readonly = 0;
3403 found->bytes_may_use = 0;
3404 found->full = 0;
3405 found->force_alloc = CHUNK_ALLOC_NO_FORCE;
3406 found->chunk_alloc = 0;
3407 found->flush = 0;
3408 init_waitqueue_head(&found->wait);
3409 *space_info = found;
3410 list_add_rcu(&found->list, &info->space_info);
3411 if (flags & BTRFS_BLOCK_GROUP_DATA)
3412 info->data_sinfo = found;
3413 return 0;
3414 }
3415
3416 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
3417 {
3418 u64 extra_flags = chunk_to_extended(flags) &
3419 BTRFS_EXTENDED_PROFILE_MASK;
3420
3421 write_seqlock(&fs_info->profiles_lock);
3422 if (flags & BTRFS_BLOCK_GROUP_DATA)
3423 fs_info->avail_data_alloc_bits |= extra_flags;
3424 if (flags & BTRFS_BLOCK_GROUP_METADATA)
3425 fs_info->avail_metadata_alloc_bits |= extra_flags;
3426 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
3427 fs_info->avail_system_alloc_bits |= extra_flags;
3428 write_sequnlock(&fs_info->profiles_lock);
3429 }
3430
3431 /*
3432 * returns target flags in extended format or 0 if restripe for this
3433 * chunk_type is not in progress
3434 *
3435 * should be called with either volume_mutex or balance_lock held
3436 */
3437 static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
3438 {
3439 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3440 u64 target = 0;
3441
3442 if (!bctl)
3443 return 0;
3444
3445 if (flags & BTRFS_BLOCK_GROUP_DATA &&
3446 bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3447 target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
3448 } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
3449 bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3450 target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
3451 } else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
3452 bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3453 target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
3454 }
3455
3456 return target;
3457 }
3458
3459 /*
3460 * @flags: available profiles in extended format (see ctree.h)
3461 *
3462 * Returns reduced profile in chunk format. If profile changing is in
3463 * progress (either running or paused) picks the target profile (if it's
3464 * already available), otherwise falls back to plain reducing.
3465 */
3466 static u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
3467 {
3468 /*
3469 * we add in the count of missing devices because we want
3470 * to make sure that any RAID levels on a degraded FS
3471 * continue to be honored.
3472 */
3473 u64 num_devices = root->fs_info->fs_devices->rw_devices +
3474 root->fs_info->fs_devices->missing_devices;
3475 u64 target;
3476 u64 tmp;
3477
3478 /*
3479 * see if restripe for this chunk_type is in progress, if so
3480 * try to reduce to the target profile
3481 */
3482 spin_lock(&root->fs_info->balance_lock);
3483 target = get_restripe_target(root->fs_info, flags);
3484 if (target) {
3485 /* pick target profile only if it's already available */
3486 if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
3487 spin_unlock(&root->fs_info->balance_lock);
3488 return extended_to_chunk(target);
3489 }
3490 }
3491 spin_unlock(&root->fs_info->balance_lock);
3492
3493 /* First, mask out the RAID levels which aren't possible */
3494 if (num_devices == 1)
3495 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0 |
3496 BTRFS_BLOCK_GROUP_RAID5);
3497 if (num_devices < 3)
3498 flags &= ~BTRFS_BLOCK_GROUP_RAID6;
3499 if (num_devices < 4)
3500 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
3501
3502 tmp = flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3503 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID5 |
3504 BTRFS_BLOCK_GROUP_RAID6 | BTRFS_BLOCK_GROUP_RAID10);
3505 flags &= ~tmp;
3506
3507 if (tmp & BTRFS_BLOCK_GROUP_RAID6)
3508 tmp = BTRFS_BLOCK_GROUP_RAID6;
3509 else if (tmp & BTRFS_BLOCK_GROUP_RAID5)
3510 tmp = BTRFS_BLOCK_GROUP_RAID5;
3511 else if (tmp & BTRFS_BLOCK_GROUP_RAID10)
3512 tmp = BTRFS_BLOCK_GROUP_RAID10;
3513 else if (tmp & BTRFS_BLOCK_GROUP_RAID1)
3514 tmp = BTRFS_BLOCK_GROUP_RAID1;
3515 else if (tmp & BTRFS_BLOCK_GROUP_RAID0)
3516 tmp = BTRFS_BLOCK_GROUP_RAID0;
3517
3518 return extended_to_chunk(flags | tmp);
3519 }
3520
3521 static u64 get_alloc_profile(struct btrfs_root *root, u64 flags)
3522 {
3523 unsigned seq;
3524
3525 do {
3526 seq = read_seqbegin(&root->fs_info->profiles_lock);
3527
3528 if (flags & BTRFS_BLOCK_GROUP_DATA)
3529 flags |= root->fs_info->avail_data_alloc_bits;
3530 else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
3531 flags |= root->fs_info->avail_system_alloc_bits;
3532 else if (flags & BTRFS_BLOCK_GROUP_METADATA)
3533 flags |= root->fs_info->avail_metadata_alloc_bits;
3534 } while (read_seqretry(&root->fs_info->profiles_lock, seq));
3535
3536 return btrfs_reduce_alloc_profile(root, flags);
3537 }
3538
3539 u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
3540 {
3541 u64 flags;
3542 u64 ret;
3543
3544 if (data)
3545 flags = BTRFS_BLOCK_GROUP_DATA;
3546 else if (root == root->fs_info->chunk_root)
3547 flags = BTRFS_BLOCK_GROUP_SYSTEM;
3548 else
3549 flags = BTRFS_BLOCK_GROUP_METADATA;
3550
3551 ret = get_alloc_profile(root, flags);
3552 return ret;
3553 }
3554
3555 /*
3556 * This will check the space that the inode allocates from to make sure we have
3557 * enough space for bytes.
3558 */
3559 int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
3560 {
3561 struct btrfs_space_info *data_sinfo;
3562 struct btrfs_root *root = BTRFS_I(inode)->root;
3563 struct btrfs_fs_info *fs_info = root->fs_info;
3564 u64 used;
3565 int ret = 0, committed = 0, alloc_chunk = 1;
3566
3567 /* make sure bytes are sectorsize aligned */
3568 bytes = ALIGN(bytes, root->sectorsize);
3569
3570 if (root == root->fs_info->tree_root ||
3571 BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID) {
3572 alloc_chunk = 0;
3573 committed = 1;
3574 }
3575
3576 data_sinfo = fs_info->data_sinfo;
3577 if (!data_sinfo)
3578 goto alloc;
3579
3580 again:
3581 /* make sure we have enough space to handle the data first */
3582 spin_lock(&data_sinfo->lock);
3583 used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
3584 data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
3585 data_sinfo->bytes_may_use;
3586
3587 if (used + bytes > data_sinfo->total_bytes) {
3588 struct btrfs_trans_handle *trans;
3589
3590 /*
3591 * if we don't have enough free bytes in this space then we need
3592 * to alloc a new chunk.
3593 */
3594 if (!data_sinfo->full && alloc_chunk) {
3595 u64 alloc_target;
3596
3597 data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
3598 spin_unlock(&data_sinfo->lock);
3599 alloc:
3600 alloc_target = btrfs_get_alloc_profile(root, 1);
3601 trans = btrfs_join_transaction(root);
3602 if (IS_ERR(trans))
3603 return PTR_ERR(trans);
3604
3605 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3606 alloc_target,
3607 CHUNK_ALLOC_NO_FORCE);
3608 btrfs_end_transaction(trans, root);
3609 if (ret < 0) {
3610 if (ret != -ENOSPC)
3611 return ret;
3612 else
3613 goto commit_trans;
3614 }
3615
3616 if (!data_sinfo)
3617 data_sinfo = fs_info->data_sinfo;
3618
3619 goto again;
3620 }
3621
3622 /*
3623 * If we don't have enough pinned space to deal with this
3624 * allocation don't bother committing the transaction.
3625 */
3626 if (percpu_counter_compare(&data_sinfo->total_bytes_pinned,
3627 bytes) < 0)
3628 committed = 1;
3629 spin_unlock(&data_sinfo->lock);
3630
3631 /* commit the current transaction and try again */
3632 commit_trans:
3633 if (!committed &&
3634 !atomic_read(&root->fs_info->open_ioctl_trans)) {
3635 committed = 1;
3636
3637 trans = btrfs_join_transaction(root);
3638 if (IS_ERR(trans))
3639 return PTR_ERR(trans);
3640 ret = btrfs_commit_transaction(trans, root);
3641 if (ret)
3642 return ret;
3643 goto again;
3644 }
3645
3646 return -ENOSPC;
3647 }
3648 data_sinfo->bytes_may_use += bytes;
3649 trace_btrfs_space_reservation(root->fs_info, "space_info",
3650 data_sinfo->flags, bytes, 1);
3651 spin_unlock(&data_sinfo->lock);
3652
3653 return 0;
3654 }
3655
3656 /*
3657 * Called if we need to clear a data reservation for this inode.
3658 */
3659 void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
3660 {
3661 struct btrfs_root *root = BTRFS_I(inode)->root;
3662 struct btrfs_space_info *data_sinfo;
3663
3664 /* make sure bytes are sectorsize aligned */
3665 bytes = ALIGN(bytes, root->sectorsize);
3666
3667 data_sinfo = root->fs_info->data_sinfo;
3668 spin_lock(&data_sinfo->lock);
3669 WARN_ON(data_sinfo->bytes_may_use < bytes);
3670 data_sinfo->bytes_may_use -= bytes;
3671 trace_btrfs_space_reservation(root->fs_info, "space_info",
3672 data_sinfo->flags, bytes, 0);
3673 spin_unlock(&data_sinfo->lock);
3674 }
3675
3676 static void force_metadata_allocation(struct btrfs_fs_info *info)
3677 {
3678 struct list_head *head = &info->space_info;
3679 struct btrfs_space_info *found;
3680
3681 rcu_read_lock();
3682 list_for_each_entry_rcu(found, head, list) {
3683 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
3684 found->force_alloc = CHUNK_ALLOC_FORCE;
3685 }
3686 rcu_read_unlock();
3687 }
3688
3689 static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
3690 {
3691 return (global->size << 1);
3692 }
3693
3694 static int should_alloc_chunk(struct btrfs_root *root,
3695 struct btrfs_space_info *sinfo, int force)
3696 {
3697 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
3698 u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
3699 u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
3700 u64 thresh;
3701
3702 if (force == CHUNK_ALLOC_FORCE)
3703 return 1;
3704
3705 /*
3706 * We need to take into account the global rsv because for all intents
3707 * and purposes it's used space. Don't worry about locking the
3708 * global_rsv, it doesn't change except when the transaction commits.
3709 */
3710 if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA)
3711 num_allocated += calc_global_rsv_need_space(global_rsv);
3712
3713 /*
3714 * in limited mode, we want to have some free space up to
3715 * about 1% of the FS size.
3716 */
3717 if (force == CHUNK_ALLOC_LIMITED) {
3718 thresh = btrfs_super_total_bytes(root->fs_info->super_copy);
3719 thresh = max_t(u64, 64 * 1024 * 1024,
3720 div_factor_fine(thresh, 1));
3721
3722 if (num_bytes - num_allocated < thresh)
3723 return 1;
3724 }
3725
3726 if (num_allocated + 2 * 1024 * 1024 < div_factor(num_bytes, 8))
3727 return 0;
3728 return 1;
3729 }
3730
3731 static u64 get_system_chunk_thresh(struct btrfs_root *root, u64 type)
3732 {
3733 u64 num_dev;
3734
3735 if (type & (BTRFS_BLOCK_GROUP_RAID10 |
3736 BTRFS_BLOCK_GROUP_RAID0 |
3737 BTRFS_BLOCK_GROUP_RAID5 |
3738 BTRFS_BLOCK_GROUP_RAID6))
3739 num_dev = root->fs_info->fs_devices->rw_devices;
3740 else if (type & BTRFS_BLOCK_GROUP_RAID1)
3741 num_dev = 2;
3742 else
3743 num_dev = 1; /* DUP or single */
3744
3745 /* metadata for updaing devices and chunk tree */
3746 return btrfs_calc_trans_metadata_size(root, num_dev + 1);
3747 }
3748
3749 static void check_system_chunk(struct btrfs_trans_handle *trans,
3750 struct btrfs_root *root, u64 type)
3751 {
3752 struct btrfs_space_info *info;
3753 u64 left;
3754 u64 thresh;
3755
3756 info = __find_space_info(root->fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
3757 spin_lock(&info->lock);
3758 left = info->total_bytes - info->bytes_used - info->bytes_pinned -
3759 info->bytes_reserved - info->bytes_readonly;
3760 spin_unlock(&info->lock);
3761
3762 thresh = get_system_chunk_thresh(root, type);
3763 if (left < thresh && btrfs_test_opt(root, ENOSPC_DEBUG)) {
3764 btrfs_info(root->fs_info, "left=%llu, need=%llu, flags=%llu",
3765 left, thresh, type);
3766 dump_space_info(info, 0, 0);
3767 }
3768
3769 if (left < thresh) {
3770 u64 flags;
3771
3772 flags = btrfs_get_alloc_profile(root->fs_info->chunk_root, 0);
3773 btrfs_alloc_chunk(trans, root, flags);
3774 }
3775 }
3776
3777 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
3778 struct btrfs_root *extent_root, u64 flags, int force)
3779 {
3780 struct btrfs_space_info *space_info;
3781 struct btrfs_fs_info *fs_info = extent_root->fs_info;
3782 int wait_for_alloc = 0;
3783 int ret = 0;
3784
3785 /* Don't re-enter if we're already allocating a chunk */
3786 if (trans->allocating_chunk)
3787 return -ENOSPC;
3788
3789 space_info = __find_space_info(extent_root->fs_info, flags);
3790 if (!space_info) {
3791 ret = update_space_info(extent_root->fs_info, flags,
3792 0, 0, &space_info);
3793 BUG_ON(ret); /* -ENOMEM */
3794 }
3795 BUG_ON(!space_info); /* Logic error */
3796
3797 again:
3798 spin_lock(&space_info->lock);
3799 if (force < space_info->force_alloc)
3800 force = space_info->force_alloc;
3801 if (space_info->full) {
3802 spin_unlock(&space_info->lock);
3803 return 0;
3804 }
3805
3806 if (!should_alloc_chunk(extent_root, space_info, force)) {
3807 spin_unlock(&space_info->lock);
3808 return 0;
3809 } else if (space_info->chunk_alloc) {
3810 wait_for_alloc = 1;
3811 } else {
3812 space_info->chunk_alloc = 1;
3813 }
3814
3815 spin_unlock(&space_info->lock);
3816
3817 mutex_lock(&fs_info->chunk_mutex);
3818
3819 /*
3820 * The chunk_mutex is held throughout the entirety of a chunk
3821 * allocation, so once we've acquired the chunk_mutex we know that the
3822 * other guy is done and we need to recheck and see if we should
3823 * allocate.
3824 */
3825 if (wait_for_alloc) {
3826 mutex_unlock(&fs_info->chunk_mutex);
3827 wait_for_alloc = 0;
3828 goto again;
3829 }
3830
3831 trans->allocating_chunk = true;
3832
3833 /*
3834 * If we have mixed data/metadata chunks we want to make sure we keep
3835 * allocating mixed chunks instead of individual chunks.
3836 */
3837 if (btrfs_mixed_space_info(space_info))
3838 flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
3839
3840 /*
3841 * if we're doing a data chunk, go ahead and make sure that
3842 * we keep a reasonable number of metadata chunks allocated in the
3843 * FS as well.
3844 */
3845 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
3846 fs_info->data_chunk_allocations++;
3847 if (!(fs_info->data_chunk_allocations %
3848 fs_info->metadata_ratio))
3849 force_metadata_allocation(fs_info);
3850 }
3851
3852 /*
3853 * Check if we have enough space in SYSTEM chunk because we may need
3854 * to update devices.
3855 */
3856 check_system_chunk(trans, extent_root, flags);
3857
3858 ret = btrfs_alloc_chunk(trans, extent_root, flags);
3859 trans->allocating_chunk = false;
3860
3861 spin_lock(&space_info->lock);
3862 if (ret < 0 && ret != -ENOSPC)
3863 goto out;
3864 if (ret)
3865 space_info->full = 1;
3866 else
3867 ret = 1;
3868
3869 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
3870 out:
3871 space_info->chunk_alloc = 0;
3872 spin_unlock(&space_info->lock);
3873 mutex_unlock(&fs_info->chunk_mutex);
3874 return ret;
3875 }
3876
3877 static int can_overcommit(struct btrfs_root *root,
3878 struct btrfs_space_info *space_info, u64 bytes,
3879 enum btrfs_reserve_flush_enum flush)
3880 {
3881 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
3882 u64 profile = btrfs_get_alloc_profile(root, 0);
3883 u64 space_size;
3884 u64 avail;
3885 u64 used;
3886 u64 to_add;
3887
3888 used = space_info->bytes_used + space_info->bytes_reserved +
3889 space_info->bytes_pinned + space_info->bytes_readonly;
3890
3891 /*
3892 * We only want to allow over committing if we have lots of actual space
3893 * free, but if we don't have enough space to handle the global reserve
3894 * space then we could end up having a real enospc problem when trying
3895 * to allocate a chunk or some other such important allocation.
3896 */
3897 spin_lock(&global_rsv->lock);
3898 space_size = calc_global_rsv_need_space(global_rsv);
3899 spin_unlock(&global_rsv->lock);
3900 if (used + space_size >= space_info->total_bytes)
3901 return 0;
3902
3903 used += space_info->bytes_may_use;
3904
3905 spin_lock(&root->fs_info->free_chunk_lock);
3906 avail = root->fs_info->free_chunk_space;
3907 spin_unlock(&root->fs_info->free_chunk_lock);
3908
3909 /*
3910 * If we have dup, raid1 or raid10 then only half of the free
3911 * space is actually useable. For raid56, the space info used
3912 * doesn't include the parity drive, so we don't have to
3913 * change the math
3914 */
3915 if (profile & (BTRFS_BLOCK_GROUP_DUP |
3916 BTRFS_BLOCK_GROUP_RAID1 |
3917 BTRFS_BLOCK_GROUP_RAID10))
3918 avail >>= 1;
3919
3920 to_add = space_info->total_bytes;
3921
3922 /*
3923 * If we aren't flushing all things, let us overcommit up to
3924 * 1/2th of the space. If we can flush, don't let us overcommit
3925 * too much, let it overcommit up to 1/8 of the space.
3926 */
3927 if (flush == BTRFS_RESERVE_FLUSH_ALL)
3928 to_add >>= 3;
3929 else
3930 to_add >>= 1;
3931
3932 /*
3933 * Limit the overcommit to the amount of free space we could possibly
3934 * allocate for chunks.
3935 */
3936 to_add = min(avail, to_add);
3937
3938 if (used + bytes < space_info->total_bytes + to_add)
3939 return 1;
3940 return 0;
3941 }
3942
3943 static void btrfs_writeback_inodes_sb_nr(struct btrfs_root *root,
3944 unsigned long nr_pages)
3945 {
3946 struct super_block *sb = root->fs_info->sb;
3947
3948 if (down_read_trylock(&sb->s_umount)) {
3949 writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE);
3950 up_read(&sb->s_umount);
3951 } else {
3952 /*
3953 * We needn't worry the filesystem going from r/w to r/o though
3954 * we don't acquire ->s_umount mutex, because the filesystem
3955 * should guarantee the delalloc inodes list be empty after
3956 * the filesystem is readonly(all dirty pages are written to
3957 * the disk).
3958 */
3959 btrfs_start_all_delalloc_inodes(root->fs_info, 0);
3960 if (!current->journal_info)
3961 btrfs_wait_all_ordered_extents(root->fs_info, 0);
3962 }
3963 }
3964
3965 /*
3966 * shrink metadata reservation for delalloc
3967 */
3968 static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
3969 bool wait_ordered)
3970 {
3971 struct btrfs_block_rsv *block_rsv;
3972 struct btrfs_space_info *space_info;
3973 struct btrfs_trans_handle *trans;
3974 u64 delalloc_bytes;
3975 u64 max_reclaim;
3976 long time_left;
3977 unsigned long nr_pages = (2 * 1024 * 1024) >> PAGE_CACHE_SHIFT;
3978 int loops = 0;
3979 enum btrfs_reserve_flush_enum flush;
3980
3981 trans = (struct btrfs_trans_handle *)current->journal_info;
3982 block_rsv = &root->fs_info->delalloc_block_rsv;
3983 space_info = block_rsv->space_info;
3984
3985 smp_mb();
3986 delalloc_bytes = percpu_counter_sum_positive(
3987 &root->fs_info->delalloc_bytes);
3988 if (delalloc_bytes == 0) {
3989 if (trans)
3990 return;
3991 btrfs_wait_all_ordered_extents(root->fs_info, 0);
3992 return;
3993 }
3994
3995 while (delalloc_bytes && loops < 3) {
3996 max_reclaim = min(delalloc_bytes, to_reclaim);
3997 nr_pages = max_reclaim >> PAGE_CACHE_SHIFT;
3998 btrfs_writeback_inodes_sb_nr(root, nr_pages);
3999 /*
4000 * We need to wait for the async pages to actually start before
4001 * we do anything.
4002 */
4003 wait_event(root->fs_info->async_submit_wait,
4004 !atomic_read(&root->fs_info->async_delalloc_pages));
4005
4006 if (!trans)
4007 flush = BTRFS_RESERVE_FLUSH_ALL;
4008 else
4009 flush = BTRFS_RESERVE_NO_FLUSH;
4010 spin_lock(&space_info->lock);
4011 if (can_overcommit(root, space_info, orig, flush)) {
4012 spin_unlock(&space_info->lock);
4013 break;
4014 }
4015 spin_unlock(&space_info->lock);
4016
4017 loops++;
4018 if (wait_ordered && !trans) {
4019 btrfs_wait_all_ordered_extents(root->fs_info, 0);
4020 } else {
4021 time_left = schedule_timeout_killable(1);
4022 if (time_left)
4023 break;
4024 }
4025 smp_mb();
4026 delalloc_bytes = percpu_counter_sum_positive(
4027 &root->fs_info->delalloc_bytes);
4028 }
4029 }
4030
4031 /**
4032 * maybe_commit_transaction - possibly commit the transaction if its ok to
4033 * @root - the root we're allocating for
4034 * @bytes - the number of bytes we want to reserve
4035 * @force - force the commit
4036 *
4037 * This will check to make sure that committing the transaction will actually
4038 * get us somewhere and then commit the transaction if it does. Otherwise it
4039 * will return -ENOSPC.
4040 */
4041 static int may_commit_transaction(struct btrfs_root *root,
4042 struct btrfs_space_info *space_info,
4043 u64 bytes, int force)
4044 {
4045 struct btrfs_block_rsv *delayed_rsv = &root->fs_info->delayed_block_rsv;
4046 struct btrfs_trans_handle *trans;
4047
4048 trans = (struct btrfs_trans_handle *)current->journal_info;
4049 if (trans)
4050 return -EAGAIN;
4051
4052 if (force)
4053 goto commit;
4054
4055 /* See if there is enough pinned space to make this reservation */
4056 spin_lock(&space_info->lock);
4057 if (percpu_counter_compare(&space_info->total_bytes_pinned,
4058 bytes) >= 0) {
4059 spin_unlock(&space_info->lock);
4060 goto commit;
4061 }
4062 spin_unlock(&space_info->lock);
4063
4064 /*
4065 * See if there is some space in the delayed insertion reservation for
4066 * this reservation.
4067 */
4068 if (space_info != delayed_rsv->space_info)
4069 return -ENOSPC;
4070
4071 spin_lock(&space_info->lock);
4072 spin_lock(&delayed_rsv->lock);
4073 if (percpu_counter_compare(&space_info->total_bytes_pinned,
4074 bytes - delayed_rsv->size) >= 0) {
4075 spin_unlock(&delayed_rsv->lock);
4076 spin_unlock(&space_info->lock);
4077 return -ENOSPC;
4078 }
4079 spin_unlock(&delayed_rsv->lock);
4080 spin_unlock(&space_info->lock);
4081
4082 commit:
4083 trans = btrfs_join_transaction(root);
4084 if (IS_ERR(trans))
4085 return -ENOSPC;
4086
4087 return btrfs_commit_transaction(trans, root);
4088 }
4089
4090 enum flush_state {
4091 FLUSH_DELAYED_ITEMS_NR = 1,
4092 FLUSH_DELAYED_ITEMS = 2,
4093 FLUSH_DELALLOC = 3,
4094 FLUSH_DELALLOC_WAIT = 4,
4095 ALLOC_CHUNK = 5,
4096 COMMIT_TRANS = 6,
4097 };
4098
4099 static int flush_space(struct btrfs_root *root,
4100 struct btrfs_space_info *space_info, u64 num_bytes,
4101 u64 orig_bytes, int state)
4102 {
4103 struct btrfs_trans_handle *trans;
4104 int nr;
4105 int ret = 0;
4106
4107 switch (state) {
4108 case FLUSH_DELAYED_ITEMS_NR:
4109 case FLUSH_DELAYED_ITEMS:
4110 if (state == FLUSH_DELAYED_ITEMS_NR) {
4111 u64 bytes = btrfs_calc_trans_metadata_size(root, 1);
4112
4113 nr = (int)div64_u64(num_bytes, bytes);
4114 if (!nr)
4115 nr = 1;
4116 nr *= 2;
4117 } else {
4118 nr = -1;
4119 }
4120 trans = btrfs_join_transaction(root);
4121 if (IS_ERR(trans)) {
4122 ret = PTR_ERR(trans);
4123 break;
4124 }
4125 ret = btrfs_run_delayed_items_nr(trans, root, nr);
4126 btrfs_end_transaction(trans, root);
4127 break;
4128 case FLUSH_DELALLOC:
4129 case FLUSH_DELALLOC_WAIT:
4130 shrink_delalloc(root, num_bytes, orig_bytes,
4131 state == FLUSH_DELALLOC_WAIT);
4132 break;
4133 case ALLOC_CHUNK:
4134 trans = btrfs_join_transaction(root);
4135 if (IS_ERR(trans)) {
4136 ret = PTR_ERR(trans);
4137 break;
4138 }
4139 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4140 btrfs_get_alloc_profile(root, 0),
4141 CHUNK_ALLOC_NO_FORCE);
4142 btrfs_end_transaction(trans, root);
4143 if (ret == -ENOSPC)
4144 ret = 0;
4145 break;
4146 case COMMIT_TRANS:
4147 ret = may_commit_transaction(root, space_info, orig_bytes, 0);
4148 break;
4149 default:
4150 ret = -ENOSPC;
4151 break;
4152 }
4153
4154 return ret;
4155 }
4156 /**
4157 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
4158 * @root - the root we're allocating for
4159 * @block_rsv - the block_rsv we're allocating for
4160 * @orig_bytes - the number of bytes we want
4161 * @flush - whether or not we can flush to make our reservation
4162 *
4163 * This will reserve orgi_bytes number of bytes from the space info associated
4164 * with the block_rsv. If there is not enough space it will make an attempt to
4165 * flush out space to make room. It will do this by flushing delalloc if
4166 * possible or committing the transaction. If flush is 0 then no attempts to
4167 * regain reservations will be made and this will fail if there is not enough
4168 * space already.
4169 */
4170 static int reserve_metadata_bytes(struct btrfs_root *root,
4171 struct btrfs_block_rsv *block_rsv,
4172 u64 orig_bytes,
4173 enum btrfs_reserve_flush_enum flush)
4174 {
4175 struct btrfs_space_info *space_info = block_rsv->space_info;
4176 u64 used;
4177 u64 num_bytes = orig_bytes;
4178 int flush_state = FLUSH_DELAYED_ITEMS_NR;
4179 int ret = 0;
4180 bool flushing = false;
4181
4182 again:
4183 ret = 0;
4184 spin_lock(&space_info->lock);
4185 /*
4186 * We only want to wait if somebody other than us is flushing and we
4187 * are actually allowed to flush all things.
4188 */
4189 while (flush == BTRFS_RESERVE_FLUSH_ALL && !flushing &&
4190 space_info->flush) {
4191 spin_unlock(&space_info->lock);
4192 /*
4193 * If we have a trans handle we can't wait because the flusher
4194 * may have to commit the transaction, which would mean we would
4195 * deadlock since we are waiting for the flusher to finish, but
4196 * hold the current transaction open.
4197 */
4198 if (current->journal_info)
4199 return -EAGAIN;
4200 ret = wait_event_killable(space_info->wait, !space_info->flush);
4201 /* Must have been killed, return */
4202 if (ret)
4203 return -EINTR;
4204
4205 spin_lock(&space_info->lock);
4206 }
4207
4208 ret = -ENOSPC;
4209 used = space_info->bytes_used + space_info->bytes_reserved +
4210 space_info->bytes_pinned + space_info->bytes_readonly +
4211 space_info->bytes_may_use;
4212
4213 /*
4214 * The idea here is that we've not already over-reserved the block group
4215 * then we can go ahead and save our reservation first and then start
4216 * flushing if we need to. Otherwise if we've already overcommitted
4217 * lets start flushing stuff first and then come back and try to make
4218 * our reservation.
4219 */
4220 if (used <= space_info->total_bytes) {
4221 if (used + orig_bytes <= space_info->total_bytes) {
4222 space_info->bytes_may_use += orig_bytes;
4223 trace_btrfs_space_reservation(root->fs_info,
4224 "space_info", space_info->flags, orig_bytes, 1);
4225 ret = 0;
4226 } else {
4227 /*
4228 * Ok set num_bytes to orig_bytes since we aren't
4229 * overocmmitted, this way we only try and reclaim what
4230 * we need.
4231 */
4232 num_bytes = orig_bytes;
4233 }
4234 } else {
4235 /*
4236 * Ok we're over committed, set num_bytes to the overcommitted
4237 * amount plus the amount of bytes that we need for this
4238 * reservation.
4239 */
4240 num_bytes = used - space_info->total_bytes +
4241 (orig_bytes * 2);
4242 }
4243
4244 if (ret && can_overcommit(root, space_info, orig_bytes, flush)) {
4245 space_info->bytes_may_use += orig_bytes;
4246 trace_btrfs_space_reservation(root->fs_info, "space_info",
4247 space_info->flags, orig_bytes,
4248 1);
4249 ret = 0;
4250 }
4251
4252 /*
4253 * Couldn't make our reservation, save our place so while we're trying
4254 * to reclaim space we can actually use it instead of somebody else
4255 * stealing it from us.
4256 *
4257 * We make the other tasks wait for the flush only when we can flush
4258 * all things.
4259 */
4260 if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
4261 flushing = true;
4262 space_info->flush = 1;
4263 }
4264
4265 spin_unlock(&space_info->lock);
4266
4267 if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
4268 goto out;
4269
4270 ret = flush_space(root, space_info, num_bytes, orig_bytes,
4271 flush_state);
4272 flush_state++;
4273
4274 /*
4275 * If we are FLUSH_LIMIT, we can not flush delalloc, or the deadlock
4276 * would happen. So skip delalloc flush.
4277 */
4278 if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
4279 (flush_state == FLUSH_DELALLOC ||
4280 flush_state == FLUSH_DELALLOC_WAIT))
4281 flush_state = ALLOC_CHUNK;
4282
4283 if (!ret)
4284 goto again;
4285 else if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
4286 flush_state < COMMIT_TRANS)
4287 goto again;
4288 else if (flush == BTRFS_RESERVE_FLUSH_ALL &&
4289 flush_state <= COMMIT_TRANS)
4290 goto again;
4291
4292 out:
4293 if (ret == -ENOSPC &&
4294 unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
4295 struct btrfs_block_rsv *global_rsv =
4296 &root->fs_info->global_block_rsv;
4297
4298 if (block_rsv != global_rsv &&
4299 !block_rsv_use_bytes(global_rsv, orig_bytes))
4300 ret = 0;
4301 }
4302 if (flushing) {
4303 spin_lock(&space_info->lock);
4304 space_info->flush = 0;
4305 wake_up_all(&space_info->wait);
4306 spin_unlock(&space_info->lock);
4307 }
4308 return ret;
4309 }
4310
4311 static struct btrfs_block_rsv *get_block_rsv(
4312 const struct btrfs_trans_handle *trans,
4313 const struct btrfs_root *root)
4314 {
4315 struct btrfs_block_rsv *block_rsv = NULL;
4316
4317 if (root->ref_cows)
4318 block_rsv = trans->block_rsv;
4319
4320 if (root == root->fs_info->csum_root && trans->adding_csums)
4321 block_rsv = trans->block_rsv;
4322
4323 if (!block_rsv)
4324 block_rsv = root->block_rsv;
4325
4326 if (!block_rsv)
4327 block_rsv = &root->fs_info->empty_block_rsv;
4328
4329 return block_rsv;
4330 }
4331
4332 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
4333 u64 num_bytes)
4334 {
4335 int ret = -ENOSPC;
4336 spin_lock(&block_rsv->lock);
4337 if (block_rsv->reserved >= num_bytes) {
4338 block_rsv->reserved -= num_bytes;
4339 if (block_rsv->reserved < block_rsv->size)
4340 block_rsv->full = 0;
4341 ret = 0;
4342 }
4343 spin_unlock(&block_rsv->lock);
4344 return ret;
4345 }
4346
4347 static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
4348 u64 num_bytes, int update_size)
4349 {
4350 spin_lock(&block_rsv->lock);
4351 block_rsv->reserved += num_bytes;
4352 if (update_size)
4353 block_rsv->size += num_bytes;
4354 else if (block_rsv->reserved >= block_rsv->size)
4355 block_rsv->full = 1;
4356 spin_unlock(&block_rsv->lock);
4357 }
4358
4359 int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
4360 struct btrfs_block_rsv *dest, u64 num_bytes,
4361 int min_factor)
4362 {
4363 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
4364 u64 min_bytes;
4365
4366 if (global_rsv->space_info != dest->space_info)
4367 return -ENOSPC;
4368
4369 spin_lock(&global_rsv->lock);
4370 min_bytes = div_factor(global_rsv->size, min_factor);
4371 if (global_rsv->reserved < min_bytes + num_bytes) {
4372 spin_unlock(&global_rsv->lock);
4373 return -ENOSPC;
4374 }
4375 global_rsv->reserved -= num_bytes;
4376 if (global_rsv->reserved < global_rsv->size)
4377 global_rsv->full = 0;
4378 spin_unlock(&global_rsv->lock);
4379
4380 block_rsv_add_bytes(dest, num_bytes, 1);
4381 return 0;
4382 }
4383
4384 static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
4385 struct btrfs_block_rsv *block_rsv,
4386 struct btrfs_block_rsv *dest, u64 num_bytes)
4387 {
4388 struct btrfs_space_info *space_info = block_rsv->space_info;
4389
4390 spin_lock(&block_rsv->lock);
4391 if (num_bytes == (u64)-1)
4392 num_bytes = block_rsv->size;
4393 block_rsv->size -= num_bytes;
4394 if (block_rsv->reserved >= block_rsv->size) {
4395 num_bytes = block_rsv->reserved - block_rsv->size;
4396 block_rsv->reserved = block_rsv->size;
4397 block_rsv->full = 1;
4398 } else {
4399 num_bytes = 0;
4400 }
4401 spin_unlock(&block_rsv->lock);
4402
4403 if (num_bytes > 0) {
4404 if (dest) {
4405 spin_lock(&dest->lock);
4406 if (!dest->full) {
4407 u64 bytes_to_add;
4408
4409 bytes_to_add = dest->size - dest->reserved;
4410 bytes_to_add = min(num_bytes, bytes_to_add);
4411 dest->reserved += bytes_to_add;
4412 if (dest->reserved >= dest->size)
4413 dest->full = 1;
4414 num_bytes -= bytes_to_add;
4415 }
4416 spin_unlock(&dest->lock);
4417 }
4418 if (num_bytes) {
4419 spin_lock(&space_info->lock);
4420 space_info->bytes_may_use -= num_bytes;
4421 trace_btrfs_space_reservation(fs_info, "space_info",
4422 space_info->flags, num_bytes, 0);
4423 space_info->reservation_progress++;
4424 spin_unlock(&space_info->lock);
4425 }
4426 }
4427 }
4428
4429 static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
4430 struct btrfs_block_rsv *dst, u64 num_bytes)
4431 {
4432 int ret;
4433
4434 ret = block_rsv_use_bytes(src, num_bytes);
4435 if (ret)
4436 return ret;
4437
4438 block_rsv_add_bytes(dst, num_bytes, 1);
4439 return 0;
4440 }
4441
4442 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
4443 {
4444 memset(rsv, 0, sizeof(*rsv));
4445 spin_lock_init(&rsv->lock);
4446 rsv->type = type;
4447 }
4448
4449 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root,
4450 unsigned short type)
4451 {
4452 struct btrfs_block_rsv *block_rsv;
4453 struct btrfs_fs_info *fs_info = root->fs_info;
4454
4455 block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
4456 if (!block_rsv)
4457 return NULL;
4458
4459 btrfs_init_block_rsv(block_rsv, type);
4460 block_rsv->space_info = __find_space_info(fs_info,
4461 BTRFS_BLOCK_GROUP_METADATA);
4462 return block_rsv;
4463 }
4464
4465 void btrfs_free_block_rsv(struct btrfs_root *root,
4466 struct btrfs_block_rsv *rsv)
4467 {
4468 if (!rsv)
4469 return;
4470 btrfs_block_rsv_release(root, rsv, (u64)-1);
4471 kfree(rsv);
4472 }
4473
4474 int btrfs_block_rsv_add(struct btrfs_root *root,
4475 struct btrfs_block_rsv *block_rsv, u64 num_bytes,
4476 enum btrfs_reserve_flush_enum flush)
4477 {
4478 int ret;
4479
4480 if (num_bytes == 0)
4481 return 0;
4482
4483 ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
4484 if (!ret) {
4485 block_rsv_add_bytes(block_rsv, num_bytes, 1);
4486 return 0;
4487 }
4488
4489 return ret;
4490 }
4491
4492 int btrfs_block_rsv_check(struct btrfs_root *root,
4493 struct btrfs_block_rsv *block_rsv, int min_factor)
4494 {
4495 u64 num_bytes = 0;
4496 int ret = -ENOSPC;
4497
4498 if (!block_rsv)
4499 return 0;
4500
4501 spin_lock(&block_rsv->lock);
4502 num_bytes = div_factor(block_rsv->size, min_factor);
4503 if (block_rsv->reserved >= num_bytes)
4504 ret = 0;
4505 spin_unlock(&block_rsv->lock);
4506
4507 return ret;
4508 }
4509
4510 int btrfs_block_rsv_refill(struct btrfs_root *root,
4511 struct btrfs_block_rsv *block_rsv, u64 min_reserved,
4512 enum btrfs_reserve_flush_enum flush)
4513 {
4514 u64 num_bytes = 0;
4515 int ret = -ENOSPC;
4516
4517 if (!block_rsv)
4518 return 0;
4519
4520 spin_lock(&block_rsv->lock);
4521 num_bytes = min_reserved;
4522 if (block_rsv->reserved >= num_bytes)
4523 ret = 0;
4524 else
4525 num_bytes -= block_rsv->reserved;
4526 spin_unlock(&block_rsv->lock);
4527
4528 if (!ret)
4529 return 0;
4530
4531 ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
4532 if (!ret) {
4533 block_rsv_add_bytes(block_rsv, num_bytes, 0);
4534 return 0;
4535 }
4536
4537 return ret;
4538 }
4539
4540 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
4541 struct btrfs_block_rsv *dst_rsv,
4542 u64 num_bytes)
4543 {
4544 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
4545 }
4546
4547 void btrfs_block_rsv_release(struct btrfs_root *root,
4548 struct btrfs_block_rsv *block_rsv,
4549 u64 num_bytes)
4550 {
4551 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
4552 if (global_rsv->full || global_rsv == block_rsv ||
4553 block_rsv->space_info != global_rsv->space_info)
4554 global_rsv = NULL;
4555 block_rsv_release_bytes(root->fs_info, block_rsv, global_rsv,
4556 num_bytes);
4557 }
4558
4559 /*
4560 * helper to calculate size of global block reservation.
4561 * the desired value is sum of space used by extent tree,
4562 * checksum tree and root tree
4563 */
4564 static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
4565 {
4566 struct btrfs_space_info *sinfo;
4567 u64 num_bytes;
4568 u64 meta_used;
4569 u64 data_used;
4570 int csum_size = btrfs_super_csum_size(fs_info->super_copy);
4571
4572 sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
4573 spin_lock(&sinfo->lock);
4574 data_used = sinfo->bytes_used;
4575 spin_unlock(&sinfo->lock);
4576
4577 sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
4578 spin_lock(&sinfo->lock);
4579 if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
4580 data_used = 0;
4581 meta_used = sinfo->bytes_used;
4582 spin_unlock(&sinfo->lock);
4583
4584 num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
4585 csum_size * 2;
4586 num_bytes += div64_u64(data_used + meta_used, 50);
4587
4588 if (num_bytes * 3 > meta_used)
4589 num_bytes = div64_u64(meta_used, 3);
4590
4591 return ALIGN(num_bytes, fs_info->extent_root->leafsize << 10);
4592 }
4593
4594 static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
4595 {
4596 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4597 struct btrfs_space_info *sinfo = block_rsv->space_info;
4598 u64 num_bytes;
4599
4600 num_bytes = calc_global_metadata_size(fs_info);
4601
4602 spin_lock(&sinfo->lock);
4603 spin_lock(&block_rsv->lock);
4604
4605 block_rsv->size = min_t(u64, num_bytes, 512 * 1024 * 1024);
4606
4607 num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
4608 sinfo->bytes_reserved + sinfo->bytes_readonly +
4609 sinfo->bytes_may_use;
4610
4611 if (sinfo->total_bytes > num_bytes) {
4612 num_bytes = sinfo->total_bytes - num_bytes;
4613 block_rsv->reserved += num_bytes;
4614 sinfo->bytes_may_use += num_bytes;
4615 trace_btrfs_space_reservation(fs_info, "space_info",
4616 sinfo->flags, num_bytes, 1);
4617 }
4618
4619 if (block_rsv->reserved >= block_rsv->size) {
4620 num_bytes = block_rsv->reserved - block_rsv->size;
4621 sinfo->bytes_may_use -= num_bytes;
4622 trace_btrfs_space_reservation(fs_info, "space_info",
4623 sinfo->flags, num_bytes, 0);
4624 sinfo->reservation_progress++;
4625 block_rsv->reserved = block_rsv->size;
4626 block_rsv->full = 1;
4627 }
4628
4629 spin_unlock(&block_rsv->lock);
4630 spin_unlock(&sinfo->lock);
4631 }
4632
4633 static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
4634 {
4635 struct btrfs_space_info *space_info;
4636
4637 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
4638 fs_info->chunk_block_rsv.space_info = space_info;
4639
4640 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
4641 fs_info->global_block_rsv.space_info = space_info;
4642 fs_info->delalloc_block_rsv.space_info = space_info;
4643 fs_info->trans_block_rsv.space_info = space_info;
4644 fs_info->empty_block_rsv.space_info = space_info;
4645 fs_info->delayed_block_rsv.space_info = space_info;
4646
4647 fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
4648 fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
4649 fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
4650 fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
4651 if (fs_info->quota_root)
4652 fs_info->quota_root->block_rsv = &fs_info->global_block_rsv;
4653 fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
4654
4655 update_global_block_rsv(fs_info);
4656 }
4657
4658 static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
4659 {
4660 block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL,
4661 (u64)-1);
4662 WARN_ON(fs_info->delalloc_block_rsv.size > 0);
4663 WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
4664 WARN_ON(fs_info->trans_block_rsv.size > 0);
4665 WARN_ON(fs_info->trans_block_rsv.reserved > 0);
4666 WARN_ON(fs_info->chunk_block_rsv.size > 0);
4667 WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
4668 WARN_ON(fs_info->delayed_block_rsv.size > 0);
4669 WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
4670 }
4671
4672 void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
4673 struct btrfs_root *root)
4674 {
4675 if (!trans->block_rsv)
4676 return;
4677
4678 if (!trans->bytes_reserved)
4679 return;
4680
4681 trace_btrfs_space_reservation(root->fs_info, "transaction",
4682 trans->transid, trans->bytes_reserved, 0);
4683 btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved);
4684 trans->bytes_reserved = 0;
4685 }
4686
4687 /* Can only return 0 or -ENOSPC */
4688 int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
4689 struct inode *inode)
4690 {
4691 struct btrfs_root *root = BTRFS_I(inode)->root;
4692 struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
4693 struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
4694
4695 /*
4696 * We need to hold space in order to delete our orphan item once we've
4697 * added it, so this takes the reservation so we can release it later
4698 * when we are truly done with the orphan item.
4699 */
4700 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
4701 trace_btrfs_space_reservation(root->fs_info, "orphan",
4702 btrfs_ino(inode), num_bytes, 1);
4703 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
4704 }
4705
4706 void btrfs_orphan_release_metadata(struct inode *inode)
4707 {
4708 struct btrfs_root *root = BTRFS_I(inode)->root;
4709 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
4710 trace_btrfs_space_reservation(root->fs_info, "orphan",
4711 btrfs_ino(inode), num_bytes, 0);
4712 btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
4713 }
4714
4715 /*
4716 * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
4717 * root: the root of the parent directory
4718 * rsv: block reservation
4719 * items: the number of items that we need do reservation
4720 * qgroup_reserved: used to return the reserved size in qgroup
4721 *
4722 * This function is used to reserve the space for snapshot/subvolume
4723 * creation and deletion. Those operations are different with the
4724 * common file/directory operations, they change two fs/file trees
4725 * and root tree, the number of items that the qgroup reserves is
4726 * different with the free space reservation. So we can not use
4727 * the space reseravtion mechanism in start_transaction().
4728 */
4729 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
4730 struct btrfs_block_rsv *rsv,
4731 int items,
4732 u64 *qgroup_reserved)
4733 {
4734 u64 num_bytes;
4735 int ret;
4736
4737 if (root->fs_info->quota_enabled) {
4738 /* One for parent inode, two for dir entries */
4739 num_bytes = 3 * root->leafsize;
4740 ret = btrfs_qgroup_reserve(root, num_bytes);
4741 if (ret)
4742 return ret;
4743 } else {
4744 num_bytes = 0;
4745 }
4746
4747 *qgroup_reserved = num_bytes;
4748
4749 num_bytes = btrfs_calc_trans_metadata_size(root, items);
4750 rsv->space_info = __find_space_info(root->fs_info,
4751 BTRFS_BLOCK_GROUP_METADATA);
4752 ret = btrfs_block_rsv_add(root, rsv, num_bytes,
4753 BTRFS_RESERVE_FLUSH_ALL);
4754 if (ret) {
4755 if (*qgroup_reserved)
4756 btrfs_qgroup_free(root, *qgroup_reserved);
4757 }
4758
4759 return ret;
4760 }
4761
4762 void btrfs_subvolume_release_metadata(struct btrfs_root *root,
4763 struct btrfs_block_rsv *rsv,
4764 u64 qgroup_reserved)
4765 {
4766 btrfs_block_rsv_release(root, rsv, (u64)-1);
4767 if (qgroup_reserved)
4768 btrfs_qgroup_free(root, qgroup_reserved);
4769 }
4770
4771 /**
4772 * drop_outstanding_extent - drop an outstanding extent
4773 * @inode: the inode we're dropping the extent for
4774 *
4775 * This is called when we are freeing up an outstanding extent, either called
4776 * after an error or after an extent is written. This will return the number of
4777 * reserved extents that need to be freed. This must be called with
4778 * BTRFS_I(inode)->lock held.
4779 */
4780 static unsigned drop_outstanding_extent(struct inode *inode)
4781 {
4782 unsigned drop_inode_space = 0;
4783 unsigned dropped_extents = 0;
4784
4785 BUG_ON(!BTRFS_I(inode)->outstanding_extents);
4786 BTRFS_I(inode)->outstanding_extents--;
4787
4788 if (BTRFS_I(inode)->outstanding_extents == 0 &&
4789 test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
4790 &BTRFS_I(inode)->runtime_flags))
4791 drop_inode_space = 1;
4792
4793 /*
4794 * If we have more or the same amount of outsanding extents than we have
4795 * reserved then we need to leave the reserved extents count alone.
4796 */
4797 if (BTRFS_I(inode)->outstanding_extents >=
4798 BTRFS_I(inode)->reserved_extents)
4799 return drop_inode_space;
4800
4801 dropped_extents = BTRFS_I(inode)->reserved_extents -
4802 BTRFS_I(inode)->outstanding_extents;
4803 BTRFS_I(inode)->reserved_extents -= dropped_extents;
4804 return dropped_extents + drop_inode_space;
4805 }
4806
4807 /**
4808 * calc_csum_metadata_size - return the amount of metada space that must be
4809 * reserved/free'd for the given bytes.
4810 * @inode: the inode we're manipulating
4811 * @num_bytes: the number of bytes in question
4812 * @reserve: 1 if we are reserving space, 0 if we are freeing space
4813 *
4814 * This adjusts the number of csum_bytes in the inode and then returns the
4815 * correct amount of metadata that must either be reserved or freed. We
4816 * calculate how many checksums we can fit into one leaf and then divide the
4817 * number of bytes that will need to be checksumed by this value to figure out
4818 * how many checksums will be required. If we are adding bytes then the number
4819 * may go up and we will return the number of additional bytes that must be
4820 * reserved. If it is going down we will return the number of bytes that must
4821 * be freed.
4822 *
4823 * This must be called with BTRFS_I(inode)->lock held.
4824 */
4825 static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes,
4826 int reserve)
4827 {
4828 struct btrfs_root *root = BTRFS_I(inode)->root;
4829 u64 csum_size;
4830 int num_csums_per_leaf;
4831 int num_csums;
4832 int old_csums;
4833
4834 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM &&
4835 BTRFS_I(inode)->csum_bytes == 0)
4836 return 0;
4837
4838 old_csums = (int)div64_u64(BTRFS_I(inode)->csum_bytes, root->sectorsize);
4839 if (reserve)
4840 BTRFS_I(inode)->csum_bytes += num_bytes;
4841 else
4842 BTRFS_I(inode)->csum_bytes -= num_bytes;
4843 csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item);
4844 num_csums_per_leaf = (int)div64_u64(csum_size,
4845 sizeof(struct btrfs_csum_item) +
4846 sizeof(struct btrfs_disk_key));
4847 num_csums = (int)div64_u64(BTRFS_I(inode)->csum_bytes, root->sectorsize);
4848 num_csums = num_csums + num_csums_per_leaf - 1;
4849 num_csums = num_csums / num_csums_per_leaf;
4850
4851 old_csums = old_csums + num_csums_per_leaf - 1;
4852 old_csums = old_csums / num_csums_per_leaf;
4853
4854 /* No change, no need to reserve more */
4855 if (old_csums == num_csums)
4856 return 0;
4857
4858 if (reserve)
4859 return btrfs_calc_trans_metadata_size(root,
4860 num_csums - old_csums);
4861
4862 return btrfs_calc_trans_metadata_size(root, old_csums - num_csums);
4863 }
4864
4865 int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
4866 {
4867 struct btrfs_root *root = BTRFS_I(inode)->root;
4868 struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
4869 u64 to_reserve = 0;
4870 u64 csum_bytes;
4871 unsigned nr_extents = 0;
4872 int extra_reserve = 0;
4873 enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL;
4874 int ret = 0;
4875 bool delalloc_lock = true;
4876 u64 to_free = 0;
4877 unsigned dropped;
4878
4879 /* If we are a free space inode we need to not flush since we will be in
4880 * the middle of a transaction commit. We also don't need the delalloc
4881 * mutex since we won't race with anybody. We need this mostly to make
4882 * lockdep shut its filthy mouth.
4883 */
4884 if (btrfs_is_free_space_inode(inode)) {
4885 flush = BTRFS_RESERVE_NO_FLUSH;
4886 delalloc_lock = false;
4887 }
4888
4889 if (flush != BTRFS_RESERVE_NO_FLUSH &&
4890 btrfs_transaction_in_commit(root->fs_info))
4891 schedule_timeout(1);
4892
4893 if (delalloc_lock)
4894 mutex_lock(&BTRFS_I(inode)->delalloc_mutex);
4895
4896 num_bytes = ALIGN(num_bytes, root->sectorsize);
4897
4898 spin_lock(&BTRFS_I(inode)->lock);
4899 BTRFS_I(inode)->outstanding_extents++;
4900
4901 if (BTRFS_I(inode)->outstanding_extents >
4902 BTRFS_I(inode)->reserved_extents)
4903 nr_extents = BTRFS_I(inode)->outstanding_extents -
4904 BTRFS_I(inode)->reserved_extents;
4905
4906 /*
4907 * Add an item to reserve for updating the inode when we complete the
4908 * delalloc io.
4909 */
4910 if (!test_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
4911 &BTRFS_I(inode)->runtime_flags)) {
4912 nr_extents++;
4913 extra_reserve = 1;
4914 }
4915
4916 to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
4917 to_reserve += calc_csum_metadata_size(inode, num_bytes, 1);
4918 csum_bytes = BTRFS_I(inode)->csum_bytes;
4919 spin_unlock(&BTRFS_I(inode)->lock);
4920
4921 if (root->fs_info->quota_enabled) {
4922 ret = btrfs_qgroup_reserve(root, num_bytes +
4923 nr_extents * root->leafsize);
4924 if (ret)
4925 goto out_fail;
4926 }
4927
4928 ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush);
4929 if (unlikely(ret)) {
4930 if (root->fs_info->quota_enabled)
4931 btrfs_qgroup_free(root, num_bytes +
4932 nr_extents * root->leafsize);
4933 goto out_fail;
4934 }
4935
4936 spin_lock(&BTRFS_I(inode)->lock);
4937 if (extra_reserve) {
4938 set_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
4939 &BTRFS_I(inode)->runtime_flags);
4940 nr_extents--;
4941 }
4942 BTRFS_I(inode)->reserved_extents += nr_extents;
4943 spin_unlock(&BTRFS_I(inode)->lock);
4944
4945 if (delalloc_lock)
4946 mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
4947
4948 if (to_reserve)
4949 trace_btrfs_space_reservation(root->fs_info,"delalloc",
4950 btrfs_ino(inode), to_reserve, 1);
4951 block_rsv_add_bytes(block_rsv, to_reserve, 1);
4952
4953 return 0;
4954
4955 out_fail:
4956 spin_lock(&BTRFS_I(inode)->lock);
4957 dropped = drop_outstanding_extent(inode);
4958 /*
4959 * If the inodes csum_bytes is the same as the original
4960 * csum_bytes then we know we haven't raced with any free()ers
4961 * so we can just reduce our inodes csum bytes and carry on.
4962 */
4963 if (BTRFS_I(inode)->csum_bytes == csum_bytes) {
4964 calc_csum_metadata_size(inode, num_bytes, 0);
4965 } else {
4966 u64 orig_csum_bytes = BTRFS_I(inode)->csum_bytes;
4967 u64 bytes;
4968
4969 /*
4970 * This is tricky, but first we need to figure out how much we
4971 * free'd from any free-ers that occured during this
4972 * reservation, so we reset ->csum_bytes to the csum_bytes
4973 * before we dropped our lock, and then call the free for the
4974 * number of bytes that were freed while we were trying our
4975 * reservation.
4976 */
4977 bytes = csum_bytes - BTRFS_I(inode)->csum_bytes;
4978 BTRFS_I(inode)->csum_bytes = csum_bytes;
4979 to_free = calc_csum_metadata_size(inode, bytes, 0);
4980
4981
4982 /*
4983 * Now we need to see how much we would have freed had we not
4984 * been making this reservation and our ->csum_bytes were not
4985 * artificially inflated.
4986 */
4987 BTRFS_I(inode)->csum_bytes = csum_bytes - num_bytes;
4988 bytes = csum_bytes - orig_csum_bytes;
4989 bytes = calc_csum_metadata_size(inode, bytes, 0);
4990
4991 /*
4992 * Now reset ->csum_bytes to what it should be. If bytes is
4993 * more than to_free then we would have free'd more space had we
4994 * not had an artificially high ->csum_bytes, so we need to free
4995 * the remainder. If bytes is the same or less then we don't
4996 * need to do anything, the other free-ers did the correct
4997 * thing.
4998 */
4999 BTRFS_I(inode)->csum_bytes = orig_csum_bytes - num_bytes;
5000 if (bytes > to_free)
5001 to_free = bytes - to_free;
5002 else
5003 to_free = 0;
5004 }
5005 spin_unlock(&BTRFS_I(inode)->lock);
5006 if (dropped)
5007 to_free += btrfs_calc_trans_metadata_size(root, dropped);
5008
5009 if (to_free) {
5010 btrfs_block_rsv_release(root, block_rsv, to_free);
5011 trace_btrfs_space_reservation(root->fs_info, "delalloc",
5012 btrfs_ino(inode), to_free, 0);
5013 }
5014 if (delalloc_lock)
5015 mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
5016 return ret;
5017 }
5018
5019 /**
5020 * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
5021 * @inode: the inode to release the reservation for
5022 * @num_bytes: the number of bytes we're releasing
5023 *
5024 * This will release the metadata reservation for an inode. This can be called
5025 * once we complete IO for a given set of bytes to release their metadata
5026 * reservations.
5027 */
5028 void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
5029 {
5030 struct btrfs_root *root = BTRFS_I(inode)->root;
5031 u64 to_free = 0;
5032 unsigned dropped;
5033
5034 num_bytes = ALIGN(num_bytes, root->sectorsize);
5035 spin_lock(&BTRFS_I(inode)->lock);
5036 dropped = drop_outstanding_extent(inode);
5037
5038 if (num_bytes)
5039 to_free = calc_csum_metadata_size(inode, num_bytes, 0);
5040 spin_unlock(&BTRFS_I(inode)->lock);
5041 if (dropped > 0)
5042 to_free += btrfs_calc_trans_metadata_size(root, dropped);
5043
5044 trace_btrfs_space_reservation(root->fs_info, "delalloc",
5045 btrfs_ino(inode), to_free, 0);
5046 if (root->fs_info->quota_enabled) {
5047 btrfs_qgroup_free(root, num_bytes +
5048 dropped * root->leafsize);
5049 }
5050
5051 btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
5052 to_free);
5053 }
5054
5055 /**
5056 * btrfs_delalloc_reserve_space - reserve data and metadata space for delalloc
5057 * @inode: inode we're writing to
5058 * @num_bytes: the number of bytes we want to allocate
5059 *
5060 * This will do the following things
5061 *
5062 * o reserve space in the data space info for num_bytes
5063 * o reserve space in the metadata space info based on number of outstanding
5064 * extents and how much csums will be needed
5065 * o add to the inodes ->delalloc_bytes
5066 * o add it to the fs_info's delalloc inodes list.
5067 *
5068 * This will return 0 for success and -ENOSPC if there is no space left.
5069 */
5070 int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
5071 {
5072 int ret;
5073
5074 ret = btrfs_check_data_free_space(inode, num_bytes);
5075 if (ret)
5076 return ret;
5077
5078 ret = btrfs_delalloc_reserve_metadata(inode, num_bytes);
5079 if (ret) {
5080 btrfs_free_reserved_data_space(inode, num_bytes);
5081 return ret;
5082 }
5083
5084 return 0;
5085 }
5086
5087 /**
5088 * btrfs_delalloc_release_space - release data and metadata space for delalloc
5089 * @inode: inode we're releasing space for
5090 * @num_bytes: the number of bytes we want to free up
5091 *
5092 * This must be matched with a call to btrfs_delalloc_reserve_space. This is
5093 * called in the case that we don't need the metadata AND data reservations
5094 * anymore. So if there is an error or we insert an inline extent.
5095 *
5096 * This function will release the metadata space that was not used and will
5097 * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
5098 * list if there are no delalloc bytes left.
5099 */
5100 void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
5101 {
5102 btrfs_delalloc_release_metadata(inode, num_bytes);
5103 btrfs_free_reserved_data_space(inode, num_bytes);
5104 }
5105
5106 static int update_block_group(struct btrfs_root *root,
5107 u64 bytenr, u64 num_bytes, int alloc)
5108 {
5109 struct btrfs_block_group_cache *cache = NULL;
5110 struct btrfs_fs_info *info = root->fs_info;
5111 u64 total = num_bytes;
5112 u64 old_val;
5113 u64 byte_in_group;
5114 int factor;
5115
5116 /* block accounting for super block */
5117 spin_lock(&info->delalloc_root_lock);
5118 old_val = btrfs_super_bytes_used(info->super_copy);
5119 if (alloc)
5120 old_val += num_bytes;
5121 else
5122 old_val -= num_bytes;
5123 btrfs_set_super_bytes_used(info->super_copy, old_val);
5124 spin_unlock(&info->delalloc_root_lock);
5125
5126 while (total) {
5127 cache = btrfs_lookup_block_group(info, bytenr);
5128 if (!cache)
5129 return -ENOENT;
5130 if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
5131 BTRFS_BLOCK_GROUP_RAID1 |
5132 BTRFS_BLOCK_GROUP_RAID10))
5133 factor = 2;
5134 else
5135 factor = 1;
5136 /*
5137 * If this block group has free space cache written out, we
5138 * need to make sure to load it if we are removing space. This
5139 * is because we need the unpinning stage to actually add the
5140 * space back to the block group, otherwise we will leak space.
5141 */
5142 if (!alloc && cache->cached == BTRFS_CACHE_NO)
5143 cache_block_group(cache, 1);
5144
5145 byte_in_group = bytenr - cache->key.objectid;
5146 WARN_ON(byte_in_group > cache->key.offset);
5147
5148 spin_lock(&cache->space_info->lock);
5149 spin_lock(&cache->lock);
5150
5151 if (btrfs_test_opt(root, SPACE_CACHE) &&
5152 cache->disk_cache_state < BTRFS_DC_CLEAR)
5153 cache->disk_cache_state = BTRFS_DC_CLEAR;
5154
5155 cache->dirty = 1;
5156 old_val = btrfs_block_group_used(&cache->item);
5157 num_bytes = min(total, cache->key.offset - byte_in_group);
5158 if (alloc) {
5159 old_val += num_bytes;
5160 btrfs_set_block_group_used(&cache->item, old_val);
5161 cache->reserved -= num_bytes;
5162 cache->space_info->bytes_reserved -= num_bytes;
5163 cache->space_info->bytes_used += num_bytes;
5164 cache->space_info->disk_used += num_bytes * factor;
5165 spin_unlock(&cache->lock);
5166 spin_unlock(&cache->space_info->lock);
5167 } else {
5168 old_val -= num_bytes;
5169 btrfs_set_block_group_used(&cache->item, old_val);
5170 cache->pinned += num_bytes;
5171 cache->space_info->bytes_pinned += num_bytes;
5172 cache->space_info->bytes_used -= num_bytes;
5173 cache->space_info->disk_used -= num_bytes * factor;
5174 spin_unlock(&cache->lock);
5175 spin_unlock(&cache->space_info->lock);
5176
5177 set_extent_dirty(info->pinned_extents,
5178 bytenr, bytenr + num_bytes - 1,
5179 GFP_NOFS | __GFP_NOFAIL);
5180 }
5181 btrfs_put_block_group(cache);
5182 total -= num_bytes;
5183 bytenr += num_bytes;
5184 }
5185 return 0;
5186 }
5187
5188 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
5189 {
5190 struct btrfs_block_group_cache *cache;
5191 u64 bytenr;
5192
5193 spin_lock(&root->fs_info->block_group_cache_lock);
5194 bytenr = root->fs_info->first_logical_byte;
5195 spin_unlock(&root->fs_info->block_group_cache_lock);
5196
5197 if (bytenr < (u64)-1)
5198 return bytenr;
5199
5200 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
5201 if (!cache)
5202 return 0;
5203
5204 bytenr = cache->key.objectid;
5205 btrfs_put_block_group(cache);
5206
5207 return bytenr;
5208 }
5209
5210 static int pin_down_extent(struct btrfs_root *root,
5211 struct btrfs_block_group_cache *cache,
5212 u64 bytenr, u64 num_bytes, int reserved)
5213 {
5214 spin_lock(&cache->space_info->lock);
5215 spin_lock(&cache->lock);
5216 cache->pinned += num_bytes;
5217 cache->space_info->bytes_pinned += num_bytes;
5218 if (reserved) {
5219 cache->reserved -= num_bytes;
5220 cache->space_info->bytes_reserved -= num_bytes;
5221 }
5222 spin_unlock(&cache->lock);
5223 spin_unlock(&cache->space_info->lock);
5224
5225 set_extent_dirty(root->fs_info->pinned_extents, bytenr,
5226 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
5227 return 0;
5228 }
5229
5230 /*
5231 * this function must be called within transaction
5232 */
5233 int btrfs_pin_extent(struct btrfs_root *root,
5234 u64 bytenr, u64 num_bytes, int reserved)
5235 {
5236 struct btrfs_block_group_cache *cache;
5237
5238 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
5239 BUG_ON(!cache); /* Logic error */
5240
5241 pin_down_extent(root, cache, bytenr, num_bytes, reserved);
5242
5243 btrfs_put_block_group(cache);
5244 return 0;
5245 }
5246
5247 /*
5248 * this function must be called within transaction
5249 */
5250 int btrfs_pin_extent_for_log_replay(struct btrfs_root *root,
5251 u64 bytenr, u64 num_bytes)
5252 {
5253 struct btrfs_block_group_cache *cache;
5254 int ret;
5255
5256 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
5257 if (!cache)
5258 return -EINVAL;
5259
5260 /*
5261 * pull in the free space cache (if any) so that our pin
5262 * removes the free space from the cache. We have load_only set
5263 * to one because the slow code to read in the free extents does check
5264 * the pinned extents.
5265 */
5266 cache_block_group(cache, 1);
5267
5268 pin_down_extent(root, cache, bytenr, num_bytes, 0);
5269
5270 /* remove us from the free space cache (if we're there at all) */
5271 ret = btrfs_remove_free_space(cache, bytenr, num_bytes);
5272 btrfs_put_block_group(cache);
5273 return ret;
5274 }
5275
5276 static int __exclude_logged_extent(struct btrfs_root *root, u64 start, u64 num_bytes)
5277 {
5278 int ret;
5279 struct btrfs_block_group_cache *block_group;
5280 struct btrfs_caching_control *caching_ctl;
5281
5282 block_group = btrfs_lookup_block_group(root->fs_info, start);
5283 if (!block_group)
5284 return -EINVAL;
5285
5286 cache_block_group(block_group, 0);
5287 caching_ctl = get_caching_control(block_group);
5288
5289 if (!caching_ctl) {
5290 /* Logic error */
5291 BUG_ON(!block_group_cache_done(block_group));
5292 ret = btrfs_remove_free_space(block_group, start, num_bytes);
5293 } else {
5294 mutex_lock(&caching_ctl->mutex);
5295
5296 if (start >= caching_ctl->progress) {
5297 ret = add_excluded_extent(root, start, num_bytes);
5298 } else if (start + num_bytes <= caching_ctl->progress) {
5299 ret = btrfs_remove_free_space(block_group,
5300 start, num_bytes);
5301 } else {
5302 num_bytes = caching_ctl->progress - start;
5303 ret = btrfs_remove_free_space(block_group,
5304 start, num_bytes);
5305 if (ret)
5306 goto out_lock;
5307
5308 num_bytes = (start + num_bytes) -
5309 caching_ctl->progress;
5310 start = caching_ctl->progress;
5311 ret = add_excluded_extent(root, start, num_bytes);
5312 }
5313 out_lock:
5314 mutex_unlock(&caching_ctl->mutex);
5315 put_caching_control(caching_ctl);
5316 }
5317 btrfs_put_block_group(block_group);
5318 return ret;
5319 }
5320
5321 int btrfs_exclude_logged_extents(struct btrfs_root *log,
5322 struct extent_buffer *eb)
5323 {
5324 struct btrfs_file_extent_item *item;
5325 struct btrfs_key key;
5326 int found_type;
5327 int i;
5328
5329 if (!btrfs_fs_incompat(log->fs_info, MIXED_GROUPS))
5330 return 0;
5331
5332 for (i = 0; i < btrfs_header_nritems(eb); i++) {
5333 btrfs_item_key_to_cpu(eb, &key, i);
5334 if (key.type != BTRFS_EXTENT_DATA_KEY)
5335 continue;
5336 item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
5337 found_type = btrfs_file_extent_type(eb, item);
5338 if (found_type == BTRFS_FILE_EXTENT_INLINE)
5339 continue;
5340 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
5341 continue;
5342 key.objectid = btrfs_file_extent_disk_bytenr(eb, item);
5343 key.offset = btrfs_file_extent_disk_num_bytes(eb, item);
5344 __exclude_logged_extent(log, key.objectid, key.offset);
5345 }
5346
5347 return 0;
5348 }
5349
5350 /**
5351 * btrfs_update_reserved_bytes - update the block_group and space info counters
5352 * @cache: The cache we are manipulating
5353 * @num_bytes: The number of bytes in question
5354 * @reserve: One of the reservation enums
5355 *
5356 * This is called by the allocator when it reserves space, or by somebody who is
5357 * freeing space that was never actually used on disk. For example if you
5358 * reserve some space for a new leaf in transaction A and before transaction A
5359 * commits you free that leaf, you call this with reserve set to 0 in order to
5360 * clear the reservation.
5361 *
5362 * Metadata reservations should be called with RESERVE_ALLOC so we do the proper
5363 * ENOSPC accounting. For data we handle the reservation through clearing the
5364 * delalloc bits in the io_tree. We have to do this since we could end up
5365 * allocating less disk space for the amount of data we have reserved in the
5366 * case of compression.
5367 *
5368 * If this is a reservation and the block group has become read only we cannot
5369 * make the reservation and return -EAGAIN, otherwise this function always
5370 * succeeds.
5371 */
5372 static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
5373 u64 num_bytes, int reserve)
5374 {
5375 struct btrfs_space_info *space_info = cache->space_info;
5376 int ret = 0;
5377
5378 spin_lock(&space_info->lock);
5379 spin_lock(&cache->lock);
5380 if (reserve != RESERVE_FREE) {
5381 if (cache->ro) {
5382 ret = -EAGAIN;
5383 } else {
5384 cache->reserved += num_bytes;
5385 space_info->bytes_reserved += num_bytes;
5386 if (reserve == RESERVE_ALLOC) {
5387 trace_btrfs_space_reservation(cache->fs_info,
5388 "space_info", space_info->flags,
5389 num_bytes, 0);
5390 space_info->bytes_may_use -= num_bytes;
5391 }
5392 }
5393 } else {
5394 if (cache->ro)
5395 space_info->bytes_readonly += num_bytes;
5396 cache->reserved -= num_bytes;
5397 space_info->bytes_reserved -= num_bytes;
5398 space_info->reservation_progress++;
5399 }
5400 spin_unlock(&cache->lock);
5401 spin_unlock(&space_info->lock);
5402 return ret;
5403 }
5404
5405 void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
5406 struct btrfs_root *root)
5407 {
5408 struct btrfs_fs_info *fs_info = root->fs_info;
5409 struct btrfs_caching_control *next;
5410 struct btrfs_caching_control *caching_ctl;
5411 struct btrfs_block_group_cache *cache;
5412 struct btrfs_space_info *space_info;
5413
5414 down_write(&fs_info->extent_commit_sem);
5415
5416 list_for_each_entry_safe(caching_ctl, next,
5417 &fs_info->caching_block_groups, list) {
5418 cache = caching_ctl->block_group;
5419 if (block_group_cache_done(cache)) {
5420 cache->last_byte_to_unpin = (u64)-1;
5421 list_del_init(&caching_ctl->list);
5422 put_caching_control(caching_ctl);
5423 } else {
5424 cache->last_byte_to_unpin = caching_ctl->progress;
5425 }
5426 }
5427
5428 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
5429 fs_info->pinned_extents = &fs_info->freed_extents[1];
5430 else
5431 fs_info->pinned_extents = &fs_info->freed_extents[0];
5432
5433 up_write(&fs_info->extent_commit_sem);
5434
5435 list_for_each_entry_rcu(space_info, &fs_info->space_info, list)
5436 percpu_counter_set(&space_info->total_bytes_pinned, 0);
5437
5438 update_global_block_rsv(fs_info);
5439 }
5440
5441 static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
5442 {
5443 struct btrfs_fs_info *fs_info = root->fs_info;
5444 struct btrfs_block_group_cache *cache = NULL;
5445 struct btrfs_space_info *space_info;
5446 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5447 u64 len;
5448 bool readonly;
5449
5450 while (start <= end) {
5451 readonly = false;
5452 if (!cache ||
5453 start >= cache->key.objectid + cache->key.offset) {
5454 if (cache)
5455 btrfs_put_block_group(cache);
5456 cache = btrfs_lookup_block_group(fs_info, start);
5457 BUG_ON(!cache); /* Logic error */
5458 }
5459
5460 len = cache->key.objectid + cache->key.offset - start;
5461 len = min(len, end + 1 - start);
5462
5463 if (start < cache->last_byte_to_unpin) {
5464 len = min(len, cache->last_byte_to_unpin - start);
5465 btrfs_add_free_space(cache, start, len);
5466 }
5467
5468 start += len;
5469 space_info = cache->space_info;
5470
5471 spin_lock(&space_info->lock);
5472 spin_lock(&cache->lock);
5473 cache->pinned -= len;
5474 space_info->bytes_pinned -= len;
5475 if (cache->ro) {
5476 space_info->bytes_readonly += len;
5477 readonly = true;
5478 }
5479 spin_unlock(&cache->lock);
5480 if (!readonly && global_rsv->space_info == space_info) {
5481 spin_lock(&global_rsv->lock);
5482 if (!global_rsv->full) {
5483 len = min(len, global_rsv->size -
5484 global_rsv->reserved);
5485 global_rsv->reserved += len;
5486 space_info->bytes_may_use += len;
5487 if (global_rsv->reserved >= global_rsv->size)
5488 global_rsv->full = 1;
5489 }
5490 spin_unlock(&global_rsv->lock);
5491 }
5492 spin_unlock(&space_info->lock);
5493 }
5494
5495 if (cache)
5496 btrfs_put_block_group(cache);
5497 return 0;
5498 }
5499
5500 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
5501 struct btrfs_root *root)
5502 {
5503 struct btrfs_fs_info *fs_info = root->fs_info;
5504 struct extent_io_tree *unpin;
5505 u64 start;
5506 u64 end;
5507 int ret;
5508
5509 if (trans->aborted)
5510 return 0;
5511
5512 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
5513 unpin = &fs_info->freed_extents[1];
5514 else
5515 unpin = &fs_info->freed_extents[0];
5516
5517 while (1) {
5518 ret = find_first_extent_bit(unpin, 0, &start, &end,
5519 EXTENT_DIRTY, NULL);
5520 if (ret)
5521 break;
5522
5523 if (btrfs_test_opt(root, DISCARD))
5524 ret = btrfs_discard_extent(root, start,
5525 end + 1 - start, NULL);
5526
5527 clear_extent_dirty(unpin, start, end, GFP_NOFS);
5528 unpin_extent_range(root, start, end);
5529 cond_resched();
5530 }
5531
5532 return 0;
5533 }
5534
5535 static void add_pinned_bytes(struct btrfs_fs_info *fs_info, u64 num_bytes,
5536 u64 owner, u64 root_objectid)
5537 {
5538 struct btrfs_space_info *space_info;
5539 u64 flags;
5540
5541 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
5542 if (root_objectid == BTRFS_CHUNK_TREE_OBJECTID)
5543 flags = BTRFS_BLOCK_GROUP_SYSTEM;
5544 else
5545 flags = BTRFS_BLOCK_GROUP_METADATA;
5546 } else {
5547 flags = BTRFS_BLOCK_GROUP_DATA;
5548 }
5549
5550 space_info = __find_space_info(fs_info, flags);
5551 BUG_ON(!space_info); /* Logic bug */
5552 percpu_counter_add(&space_info->total_bytes_pinned, num_bytes);
5553 }
5554
5555
5556 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
5557 struct btrfs_root *root,
5558 u64 bytenr, u64 num_bytes, u64 parent,
5559 u64 root_objectid, u64 owner_objectid,
5560 u64 owner_offset, int refs_to_drop,
5561 struct btrfs_delayed_extent_op *extent_op)
5562 {
5563 struct btrfs_key key;
5564 struct btrfs_path *path;
5565 struct btrfs_fs_info *info = root->fs_info;
5566 struct btrfs_root *extent_root = info->extent_root;
5567 struct extent_buffer *leaf;
5568 struct btrfs_extent_item *ei;
5569 struct btrfs_extent_inline_ref *iref;
5570 int ret;
5571 int is_data;
5572 int extent_slot = 0;
5573 int found_extent = 0;
5574 int num_to_del = 1;
5575 u32 item_size;
5576 u64 refs;
5577 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
5578 SKINNY_METADATA);
5579
5580 path = btrfs_alloc_path();
5581 if (!path)
5582 return -ENOMEM;
5583
5584 path->reada = 1;
5585 path->leave_spinning = 1;
5586
5587 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
5588 BUG_ON(!is_data && refs_to_drop != 1);
5589
5590 if (is_data)
5591 skinny_metadata = 0;
5592
5593 ret = lookup_extent_backref(trans, extent_root, path, &iref,
5594 bytenr, num_bytes, parent,
5595 root_objectid, owner_objectid,
5596 owner_offset);
5597 if (ret == 0) {
5598 extent_slot = path->slots[0];
5599 while (extent_slot >= 0) {
5600 btrfs_item_key_to_cpu(path->nodes[0], &key,
5601 extent_slot);
5602 if (key.objectid != bytenr)
5603 break;
5604 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
5605 key.offset == num_bytes) {
5606 found_extent = 1;
5607 break;
5608 }
5609 if (key.type == BTRFS_METADATA_ITEM_KEY &&
5610 key.offset == owner_objectid) {
5611 found_extent = 1;
5612 break;
5613 }
5614 if (path->slots[0] - extent_slot > 5)
5615 break;
5616 extent_slot--;
5617 }
5618 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
5619 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
5620 if (found_extent && item_size < sizeof(*ei))
5621 found_extent = 0;
5622 #endif
5623 if (!found_extent) {
5624 BUG_ON(iref);
5625 ret = remove_extent_backref(trans, extent_root, path,
5626 NULL, refs_to_drop,
5627 is_data);
5628 if (ret) {
5629 btrfs_abort_transaction(trans, extent_root, ret);
5630 goto out;
5631 }
5632 btrfs_release_path(path);
5633 path->leave_spinning = 1;
5634
5635 key.objectid = bytenr;
5636 key.type = BTRFS_EXTENT_ITEM_KEY;
5637 key.offset = num_bytes;
5638
5639 if (!is_data && skinny_metadata) {
5640 key.type = BTRFS_METADATA_ITEM_KEY;
5641 key.offset = owner_objectid;
5642 }
5643
5644 ret = btrfs_search_slot(trans, extent_root,
5645 &key, path, -1, 1);
5646 if (ret > 0 && skinny_metadata && path->slots[0]) {
5647 /*
5648 * Couldn't find our skinny metadata item,
5649 * see if we have ye olde extent item.
5650 */
5651 path->slots[0]--;
5652 btrfs_item_key_to_cpu(path->nodes[0], &key,
5653 path->slots[0]);
5654 if (key.objectid == bytenr &&
5655 key.type == BTRFS_EXTENT_ITEM_KEY &&
5656 key.offset == num_bytes)
5657 ret = 0;
5658 }
5659
5660 if (ret > 0 && skinny_metadata) {
5661 skinny_metadata = false;
5662 key.type = BTRFS_EXTENT_ITEM_KEY;
5663 key.offset = num_bytes;
5664 btrfs_release_path(path);
5665 ret = btrfs_search_slot(trans, extent_root,
5666 &key, path, -1, 1);
5667 }
5668
5669 if (ret) {
5670 btrfs_err(info, "umm, got %d back from search, was looking for %llu",
5671 ret, (unsigned long long)bytenr);
5672 if (ret > 0)
5673 btrfs_print_leaf(extent_root,
5674 path->nodes[0]);
5675 }
5676 if (ret < 0) {
5677 btrfs_abort_transaction(trans, extent_root, ret);
5678 goto out;
5679 }
5680 extent_slot = path->slots[0];
5681 }
5682 } else if (ret == -ENOENT) {
5683 btrfs_print_leaf(extent_root, path->nodes[0]);
5684 WARN_ON(1);
5685 btrfs_err(info,
5686 "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu",
5687 (unsigned long long)bytenr,
5688 (unsigned long long)parent,
5689 (unsigned long long)root_objectid,
5690 (unsigned long long)owner_objectid,
5691 (unsigned long long)owner_offset);
5692 } else {
5693 btrfs_abort_transaction(trans, extent_root, ret);
5694 goto out;
5695 }
5696
5697 leaf = path->nodes[0];
5698 item_size = btrfs_item_size_nr(leaf, extent_slot);
5699 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
5700 if (item_size < sizeof(*ei)) {
5701 BUG_ON(found_extent || extent_slot != path->slots[0]);
5702 ret = convert_extent_item_v0(trans, extent_root, path,
5703 owner_objectid, 0);
5704 if (ret < 0) {
5705 btrfs_abort_transaction(trans, extent_root, ret);
5706 goto out;
5707 }
5708
5709 btrfs_release_path(path);
5710 path->leave_spinning = 1;
5711
5712 key.objectid = bytenr;
5713 key.type = BTRFS_EXTENT_ITEM_KEY;
5714 key.offset = num_bytes;
5715
5716 ret = btrfs_search_slot(trans, extent_root, &key, path,
5717 -1, 1);
5718 if (ret) {
5719 btrfs_err(info, "umm, got %d back from search, was looking for %llu",
5720 ret, (unsigned long long)bytenr);
5721 btrfs_print_leaf(extent_root, path->nodes[0]);
5722 }
5723 if (ret < 0) {
5724 btrfs_abort_transaction(trans, extent_root, ret);
5725 goto out;
5726 }
5727
5728 extent_slot = path->slots[0];
5729 leaf = path->nodes[0];
5730 item_size = btrfs_item_size_nr(leaf, extent_slot);
5731 }
5732 #endif
5733 BUG_ON(item_size < sizeof(*ei));
5734 ei = btrfs_item_ptr(leaf, extent_slot,
5735 struct btrfs_extent_item);
5736 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
5737 key.type == BTRFS_EXTENT_ITEM_KEY) {
5738 struct btrfs_tree_block_info *bi;
5739 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
5740 bi = (struct btrfs_tree_block_info *)(ei + 1);
5741 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
5742 }
5743
5744 refs = btrfs_extent_refs(leaf, ei);
5745 if (refs < refs_to_drop) {
5746 btrfs_err(info, "trying to drop %d refs but we only have %Lu "
5747 "for bytenr %Lu\n", refs_to_drop, refs, bytenr);
5748 ret = -EINVAL;
5749 btrfs_abort_transaction(trans, extent_root, ret);
5750 goto out;
5751 }
5752 refs -= refs_to_drop;
5753
5754 if (refs > 0) {
5755 if (extent_op)
5756 __run_delayed_extent_op(extent_op, leaf, ei);
5757 /*
5758 * In the case of inline back ref, reference count will
5759 * be updated by remove_extent_backref
5760 */
5761 if (iref) {
5762 BUG_ON(!found_extent);
5763 } else {
5764 btrfs_set_extent_refs(leaf, ei, refs);
5765 btrfs_mark_buffer_dirty(leaf);
5766 }
5767 if (found_extent) {
5768 ret = remove_extent_backref(trans, extent_root, path,
5769 iref, refs_to_drop,
5770 is_data);
5771 if (ret) {
5772 btrfs_abort_transaction(trans, extent_root, ret);
5773 goto out;
5774 }
5775 }
5776 add_pinned_bytes(root->fs_info, -num_bytes, owner_objectid,
5777 root_objectid);
5778 } else {
5779 if (found_extent) {
5780 BUG_ON(is_data && refs_to_drop !=
5781 extent_data_ref_count(root, path, iref));
5782 if (iref) {
5783 BUG_ON(path->slots[0] != extent_slot);
5784 } else {
5785 BUG_ON(path->slots[0] != extent_slot + 1);
5786 path->slots[0] = extent_slot;
5787 num_to_del = 2;
5788 }
5789 }
5790
5791 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
5792 num_to_del);
5793 if (ret) {
5794 btrfs_abort_transaction(trans, extent_root, ret);
5795 goto out;
5796 }
5797 btrfs_release_path(path);
5798
5799 if (is_data) {
5800 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
5801 if (ret) {
5802 btrfs_abort_transaction(trans, extent_root, ret);
5803 goto out;
5804 }
5805 }
5806
5807 ret = update_block_group(root, bytenr, num_bytes, 0);
5808 if (ret) {
5809 btrfs_abort_transaction(trans, extent_root, ret);
5810 goto out;
5811 }
5812 }
5813 out:
5814 btrfs_free_path(path);
5815 return ret;
5816 }
5817
5818 /*
5819 * when we free an block, it is possible (and likely) that we free the last
5820 * delayed ref for that extent as well. This searches the delayed ref tree for
5821 * a given extent, and if there are no other delayed refs to be processed, it
5822 * removes it from the tree.
5823 */
5824 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
5825 struct btrfs_root *root, u64 bytenr)
5826 {
5827 struct btrfs_delayed_ref_head *head;
5828 struct btrfs_delayed_ref_root *delayed_refs;
5829 struct btrfs_delayed_ref_node *ref;
5830 struct rb_node *node;
5831 int ret = 0;
5832
5833 delayed_refs = &trans->transaction->delayed_refs;
5834 spin_lock(&delayed_refs->lock);
5835 head = btrfs_find_delayed_ref_head(trans, bytenr);
5836 if (!head)
5837 goto out;
5838
5839 node = rb_prev(&head->node.rb_node);
5840 if (!node)
5841 goto out;
5842
5843 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
5844
5845 /* there are still entries for this ref, we can't drop it */
5846 if (ref->bytenr == bytenr)
5847 goto out;
5848
5849 if (head->extent_op) {
5850 if (!head->must_insert_reserved)
5851 goto out;
5852 btrfs_free_delayed_extent_op(head->extent_op);
5853 head->extent_op = NULL;
5854 }
5855
5856 /*
5857 * waiting for the lock here would deadlock. If someone else has it
5858 * locked they are already in the process of dropping it anyway
5859 */
5860 if (!mutex_trylock(&head->mutex))
5861 goto out;
5862
5863 /*
5864 * at this point we have a head with no other entries. Go
5865 * ahead and process it.
5866 */
5867 head->node.in_tree = 0;
5868 rb_erase(&head->node.rb_node, &delayed_refs->root);
5869
5870 delayed_refs->num_entries--;
5871
5872 /*
5873 * we don't take a ref on the node because we're removing it from the
5874 * tree, so we just steal the ref the tree was holding.
5875 */
5876 delayed_refs->num_heads--;
5877 if (list_empty(&head->cluster))
5878 delayed_refs->num_heads_ready--;
5879
5880 list_del_init(&head->cluster);
5881 spin_unlock(&delayed_refs->lock);
5882
5883 BUG_ON(head->extent_op);
5884 if (head->must_insert_reserved)
5885 ret = 1;
5886
5887 mutex_unlock(&head->mutex);
5888 btrfs_put_delayed_ref(&head->node);
5889 return ret;
5890 out:
5891 spin_unlock(&delayed_refs->lock);
5892 return 0;
5893 }
5894
5895 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
5896 struct btrfs_root *root,
5897 struct extent_buffer *buf,
5898 u64 parent, int last_ref)
5899 {
5900 struct btrfs_block_group_cache *cache = NULL;
5901 int pin = 1;
5902 int ret;
5903
5904 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
5905 ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
5906 buf->start, buf->len,
5907 parent, root->root_key.objectid,
5908 btrfs_header_level(buf),
5909 BTRFS_DROP_DELAYED_REF, NULL, 0);
5910 BUG_ON(ret); /* -ENOMEM */
5911 }
5912
5913 if (!last_ref)
5914 return;
5915
5916 cache = btrfs_lookup_block_group(root->fs_info, buf->start);
5917
5918 if (btrfs_header_generation(buf) == trans->transid) {
5919 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
5920 ret = check_ref_cleanup(trans, root, buf->start);
5921 if (!ret)
5922 goto out;
5923 }
5924
5925 if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
5926 pin_down_extent(root, cache, buf->start, buf->len, 1);
5927 goto out;
5928 }
5929
5930 WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
5931
5932 btrfs_add_free_space(cache, buf->start, buf->len);
5933 btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE);
5934 pin = 0;
5935 }
5936 out:
5937 if (pin)
5938 add_pinned_bytes(root->fs_info, buf->len,
5939 btrfs_header_level(buf),
5940 root->root_key.objectid);
5941
5942 /*
5943 * Deleting the buffer, clear the corrupt flag since it doesn't matter
5944 * anymore.
5945 */
5946 clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
5947 btrfs_put_block_group(cache);
5948 }
5949
5950 /* Can return -ENOMEM */
5951 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
5952 u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
5953 u64 owner, u64 offset, int for_cow)
5954 {
5955 int ret;
5956 struct btrfs_fs_info *fs_info = root->fs_info;
5957
5958 add_pinned_bytes(root->fs_info, num_bytes, owner, root_objectid);
5959
5960 /*
5961 * tree log blocks never actually go into the extent allocation
5962 * tree, just update pinning info and exit early.
5963 */
5964 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
5965 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
5966 /* unlocks the pinned mutex */
5967 btrfs_pin_extent(root, bytenr, num_bytes, 1);
5968 ret = 0;
5969 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
5970 ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
5971 num_bytes,
5972 parent, root_objectid, (int)owner,
5973 BTRFS_DROP_DELAYED_REF, NULL, for_cow);
5974 } else {
5975 ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
5976 num_bytes,
5977 parent, root_objectid, owner,
5978 offset, BTRFS_DROP_DELAYED_REF,
5979 NULL, for_cow);
5980 }
5981 return ret;
5982 }
5983
5984 static u64 stripe_align(struct btrfs_root *root,
5985 struct btrfs_block_group_cache *cache,
5986 u64 val, u64 num_bytes)
5987 {
5988 u64 ret = ALIGN(val, root->stripesize);
5989 return ret;
5990 }
5991
5992 /*
5993 * when we wait for progress in the block group caching, its because
5994 * our allocation attempt failed at least once. So, we must sleep
5995 * and let some progress happen before we try again.
5996 *
5997 * This function will sleep at least once waiting for new free space to
5998 * show up, and then it will check the block group free space numbers
5999 * for our min num_bytes. Another option is to have it go ahead
6000 * and look in the rbtree for a free extent of a given size, but this
6001 * is a good start.
6002 */
6003 static noinline int
6004 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
6005 u64 num_bytes)
6006 {
6007 struct btrfs_caching_control *caching_ctl;
6008
6009 caching_ctl = get_caching_control(cache);
6010 if (!caching_ctl)
6011 return 0;
6012
6013 wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
6014 (cache->free_space_ctl->free_space >= num_bytes));
6015
6016 put_caching_control(caching_ctl);
6017 return 0;
6018 }
6019
6020 static noinline int
6021 wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
6022 {
6023 struct btrfs_caching_control *caching_ctl;
6024
6025 caching_ctl = get_caching_control(cache);
6026 if (!caching_ctl)
6027 return 0;
6028
6029 wait_event(caching_ctl->wait, block_group_cache_done(cache));
6030
6031 put_caching_control(caching_ctl);
6032 return 0;
6033 }
6034
6035 int __get_raid_index(u64 flags)
6036 {
6037 if (flags & BTRFS_BLOCK_GROUP_RAID10)
6038 return BTRFS_RAID_RAID10;
6039 else if (flags & BTRFS_BLOCK_GROUP_RAID1)
6040 return BTRFS_RAID_RAID1;
6041 else if (flags & BTRFS_BLOCK_GROUP_DUP)
6042 return BTRFS_RAID_DUP;
6043 else if (flags & BTRFS_BLOCK_GROUP_RAID0)
6044 return BTRFS_RAID_RAID0;
6045 else if (flags & BTRFS_BLOCK_GROUP_RAID5)
6046 return BTRFS_RAID_RAID5;
6047 else if (flags & BTRFS_BLOCK_GROUP_RAID6)
6048 return BTRFS_RAID_RAID6;
6049
6050 return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
6051 }
6052
6053 static int get_block_group_index(struct btrfs_block_group_cache *cache)
6054 {
6055 return __get_raid_index(cache->flags);
6056 }
6057
6058 enum btrfs_loop_type {
6059 LOOP_CACHING_NOWAIT = 0,
6060 LOOP_CACHING_WAIT = 1,
6061 LOOP_ALLOC_CHUNK = 2,
6062 LOOP_NO_EMPTY_SIZE = 3,
6063 };
6064
6065 /*
6066 * walks the btree of allocated extents and find a hole of a given size.
6067 * The key ins is changed to record the hole:
6068 * ins->objectid == block start
6069 * ins->flags = BTRFS_EXTENT_ITEM_KEY
6070 * ins->offset == number of blocks
6071 * Any available blocks before search_start are skipped.
6072 */
6073 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
6074 struct btrfs_root *orig_root,
6075 u64 num_bytes, u64 empty_size,
6076 u64 hint_byte, struct btrfs_key *ins,
6077 u64 flags)
6078 {
6079 int ret = 0;
6080 struct btrfs_root *root = orig_root->fs_info->extent_root;
6081 struct btrfs_free_cluster *last_ptr = NULL;
6082 struct btrfs_block_group_cache *block_group = NULL;
6083 struct btrfs_block_group_cache *used_block_group;
6084 u64 search_start = 0;
6085 int empty_cluster = 2 * 1024 * 1024;
6086 struct btrfs_space_info *space_info;
6087 int loop = 0;
6088 int index = __get_raid_index(flags);
6089 int alloc_type = (flags & BTRFS_BLOCK_GROUP_DATA) ?
6090 RESERVE_ALLOC_NO_ACCOUNT : RESERVE_ALLOC;
6091 bool found_uncached_bg = false;
6092 bool failed_cluster_refill = false;
6093 bool failed_alloc = false;
6094 bool use_cluster = true;
6095 bool have_caching_bg = false;
6096
6097 WARN_ON(num_bytes < root->sectorsize);
6098 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
6099 ins->objectid = 0;
6100 ins->offset = 0;
6101
6102 trace_find_free_extent(orig_root, num_bytes, empty_size, flags);
6103
6104 space_info = __find_space_info(root->fs_info, flags);
6105 if (!space_info) {
6106 btrfs_err(root->fs_info, "No space info for %llu", flags);
6107 return -ENOSPC;
6108 }
6109
6110 /*
6111 * If the space info is for both data and metadata it means we have a
6112 * small filesystem and we can't use the clustering stuff.
6113 */
6114 if (btrfs_mixed_space_info(space_info))
6115 use_cluster = false;
6116
6117 if (flags & BTRFS_BLOCK_GROUP_METADATA && use_cluster) {
6118 last_ptr = &root->fs_info->meta_alloc_cluster;
6119 if (!btrfs_test_opt(root, SSD))
6120 empty_cluster = 64 * 1024;
6121 }
6122
6123 if ((flags & BTRFS_BLOCK_GROUP_DATA) && use_cluster &&
6124 btrfs_test_opt(root, SSD)) {
6125 last_ptr = &root->fs_info->data_alloc_cluster;
6126 }
6127
6128 if (last_ptr) {
6129 spin_lock(&last_ptr->lock);
6130 if (last_ptr->block_group)
6131 hint_byte = last_ptr->window_start;
6132 spin_unlock(&last_ptr->lock);
6133 }
6134
6135 search_start = max(search_start, first_logical_byte(root, 0));
6136 search_start = max(search_start, hint_byte);
6137
6138 if (!last_ptr)
6139 empty_cluster = 0;
6140
6141 if (search_start == hint_byte) {
6142 block_group = btrfs_lookup_block_group(root->fs_info,
6143 search_start);
6144 used_block_group = block_group;
6145 /*
6146 * we don't want to use the block group if it doesn't match our
6147 * allocation bits, or if its not cached.
6148 *
6149 * However if we are re-searching with an ideal block group
6150 * picked out then we don't care that the block group is cached.
6151 */
6152 if (block_group && block_group_bits(block_group, flags) &&
6153 block_group->cached != BTRFS_CACHE_NO) {
6154 down_read(&space_info->groups_sem);
6155 if (list_empty(&block_group->list) ||
6156 block_group->ro) {
6157 /*
6158 * someone is removing this block group,
6159 * we can't jump into the have_block_group
6160 * target because our list pointers are not
6161 * valid
6162 */
6163 btrfs_put_block_group(block_group);
6164 up_read(&space_info->groups_sem);
6165 } else {
6166 index = get_block_group_index(block_group);
6167 goto have_block_group;
6168 }
6169 } else if (block_group) {
6170 btrfs_put_block_group(block_group);
6171 }
6172 }
6173 search:
6174 have_caching_bg = false;
6175 down_read(&space_info->groups_sem);
6176 list_for_each_entry(block_group, &space_info->block_groups[index],
6177 list) {
6178 u64 offset;
6179 int cached;
6180
6181 used_block_group = block_group;
6182 btrfs_get_block_group(block_group);
6183 search_start = block_group->key.objectid;
6184
6185 /*
6186 * this can happen if we end up cycling through all the
6187 * raid types, but we want to make sure we only allocate
6188 * for the proper type.
6189 */
6190 if (!block_group_bits(block_group, flags)) {
6191 u64 extra = BTRFS_BLOCK_GROUP_DUP |
6192 BTRFS_BLOCK_GROUP_RAID1 |
6193 BTRFS_BLOCK_GROUP_RAID5 |
6194 BTRFS_BLOCK_GROUP_RAID6 |
6195 BTRFS_BLOCK_GROUP_RAID10;
6196
6197 /*
6198 * if they asked for extra copies and this block group
6199 * doesn't provide them, bail. This does allow us to
6200 * fill raid0 from raid1.
6201 */
6202 if ((flags & extra) && !(block_group->flags & extra))
6203 goto loop;
6204 }
6205
6206 have_block_group:
6207 cached = block_group_cache_done(block_group);
6208 if (unlikely(!cached)) {
6209 found_uncached_bg = true;
6210 ret = cache_block_group(block_group, 0);
6211 BUG_ON(ret < 0);
6212 ret = 0;
6213 }
6214
6215 if (unlikely(block_group->ro))
6216 goto loop;
6217
6218 /*
6219 * Ok we want to try and use the cluster allocator, so
6220 * lets look there
6221 */
6222 if (last_ptr) {
6223 unsigned long aligned_cluster;
6224 /*
6225 * the refill lock keeps out other
6226 * people trying to start a new cluster
6227 */
6228 spin_lock(&last_ptr->refill_lock);
6229 used_block_group = last_ptr->block_group;
6230 if (used_block_group != block_group &&
6231 (!used_block_group ||
6232 used_block_group->ro ||
6233 !block_group_bits(used_block_group, flags))) {
6234 used_block_group = block_group;
6235 goto refill_cluster;
6236 }
6237
6238 if (used_block_group != block_group)
6239 btrfs_get_block_group(used_block_group);
6240
6241 offset = btrfs_alloc_from_cluster(used_block_group,
6242 last_ptr, num_bytes, used_block_group->key.objectid);
6243 if (offset) {
6244 /* we have a block, we're done */
6245 spin_unlock(&last_ptr->refill_lock);
6246 trace_btrfs_reserve_extent_cluster(root,
6247 block_group, search_start, num_bytes);
6248 goto checks;
6249 }
6250
6251 WARN_ON(last_ptr->block_group != used_block_group);
6252 if (used_block_group != block_group) {
6253 btrfs_put_block_group(used_block_group);
6254 used_block_group = block_group;
6255 }
6256 refill_cluster:
6257 BUG_ON(used_block_group != block_group);
6258 /* If we are on LOOP_NO_EMPTY_SIZE, we can't
6259 * set up a new clusters, so lets just skip it
6260 * and let the allocator find whatever block
6261 * it can find. If we reach this point, we
6262 * will have tried the cluster allocator
6263 * plenty of times and not have found
6264 * anything, so we are likely way too
6265 * fragmented for the clustering stuff to find
6266 * anything.
6267 *
6268 * However, if the cluster is taken from the
6269 * current block group, release the cluster
6270 * first, so that we stand a better chance of
6271 * succeeding in the unclustered
6272 * allocation. */
6273 if (loop >= LOOP_NO_EMPTY_SIZE &&
6274 last_ptr->block_group != block_group) {
6275 spin_unlock(&last_ptr->refill_lock);
6276 goto unclustered_alloc;
6277 }
6278
6279 /*
6280 * this cluster didn't work out, free it and
6281 * start over
6282 */
6283 btrfs_return_cluster_to_free_space(NULL, last_ptr);
6284
6285 if (loop >= LOOP_NO_EMPTY_SIZE) {
6286 spin_unlock(&last_ptr->refill_lock);
6287 goto unclustered_alloc;
6288 }
6289
6290 aligned_cluster = max_t(unsigned long,
6291 empty_cluster + empty_size,
6292 block_group->full_stripe_len);
6293
6294 /* allocate a cluster in this block group */
6295 ret = btrfs_find_space_cluster(trans, root,
6296 block_group, last_ptr,
6297 search_start, num_bytes,
6298 aligned_cluster);
6299 if (ret == 0) {
6300 /*
6301 * now pull our allocation out of this
6302 * cluster
6303 */
6304 offset = btrfs_alloc_from_cluster(block_group,
6305 last_ptr, num_bytes,
6306 search_start);
6307 if (offset) {
6308 /* we found one, proceed */
6309 spin_unlock(&last_ptr->refill_lock);
6310 trace_btrfs_reserve_extent_cluster(root,
6311 block_group, search_start,
6312 num_bytes);
6313 goto checks;
6314 }
6315 } else if (!cached && loop > LOOP_CACHING_NOWAIT
6316 && !failed_cluster_refill) {
6317 spin_unlock(&last_ptr->refill_lock);
6318
6319 failed_cluster_refill = true;
6320 wait_block_group_cache_progress(block_group,
6321 num_bytes + empty_cluster + empty_size);
6322 goto have_block_group;
6323 }
6324
6325 /*
6326 * at this point we either didn't find a cluster
6327 * or we weren't able to allocate a block from our
6328 * cluster. Free the cluster we've been trying
6329 * to use, and go to the next block group
6330 */
6331 btrfs_return_cluster_to_free_space(NULL, last_ptr);
6332 spin_unlock(&last_ptr->refill_lock);
6333 goto loop;
6334 }
6335
6336 unclustered_alloc:
6337 spin_lock(&block_group->free_space_ctl->tree_lock);
6338 if (cached &&
6339 block_group->free_space_ctl->free_space <
6340 num_bytes + empty_cluster + empty_size) {
6341 spin_unlock(&block_group->free_space_ctl->tree_lock);
6342 goto loop;
6343 }
6344 spin_unlock(&block_group->free_space_ctl->tree_lock);
6345
6346 offset = btrfs_find_space_for_alloc(block_group, search_start,
6347 num_bytes, empty_size);
6348 /*
6349 * If we didn't find a chunk, and we haven't failed on this
6350 * block group before, and this block group is in the middle of
6351 * caching and we are ok with waiting, then go ahead and wait
6352 * for progress to be made, and set failed_alloc to true.
6353 *
6354 * If failed_alloc is true then we've already waited on this
6355 * block group once and should move on to the next block group.
6356 */
6357 if (!offset && !failed_alloc && !cached &&
6358 loop > LOOP_CACHING_NOWAIT) {
6359 wait_block_group_cache_progress(block_group,
6360 num_bytes + empty_size);
6361 failed_alloc = true;
6362 goto have_block_group;
6363 } else if (!offset) {
6364 if (!cached)
6365 have_caching_bg = true;
6366 goto loop;
6367 }
6368 checks:
6369 search_start = stripe_align(root, used_block_group,
6370 offset, num_bytes);
6371
6372 /* move on to the next group */
6373 if (search_start + num_bytes >
6374 used_block_group->key.objectid + used_block_group->key.offset) {
6375 btrfs_add_free_space(used_block_group, offset, num_bytes);
6376 goto loop;
6377 }
6378
6379 if (offset < search_start)
6380 btrfs_add_free_space(used_block_group, offset,
6381 search_start - offset);
6382 BUG_ON(offset > search_start);
6383
6384 ret = btrfs_update_reserved_bytes(used_block_group, num_bytes,
6385 alloc_type);
6386 if (ret == -EAGAIN) {
6387 btrfs_add_free_space(used_block_group, offset, num_bytes);
6388 goto loop;
6389 }
6390
6391 /* we are all good, lets return */
6392 ins->objectid = search_start;
6393 ins->offset = num_bytes;
6394
6395 trace_btrfs_reserve_extent(orig_root, block_group,
6396 search_start, num_bytes);
6397 if (used_block_group != block_group)
6398 btrfs_put_block_group(used_block_group);
6399 btrfs_put_block_group(block_group);
6400 break;
6401 loop:
6402 failed_cluster_refill = false;
6403 failed_alloc = false;
6404 BUG_ON(index != get_block_group_index(block_group));
6405 if (used_block_group != block_group)
6406 btrfs_put_block_group(used_block_group);
6407 btrfs_put_block_group(block_group);
6408 }
6409 up_read(&space_info->groups_sem);
6410
6411 if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg)
6412 goto search;
6413
6414 if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
6415 goto search;
6416
6417 /*
6418 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
6419 * caching kthreads as we move along
6420 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
6421 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
6422 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
6423 * again
6424 */
6425 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) {
6426 index = 0;
6427 loop++;
6428 if (loop == LOOP_ALLOC_CHUNK) {
6429 ret = do_chunk_alloc(trans, root, flags,
6430 CHUNK_ALLOC_FORCE);
6431 /*
6432 * Do not bail out on ENOSPC since we
6433 * can do more things.
6434 */
6435 if (ret < 0 && ret != -ENOSPC) {
6436 btrfs_abort_transaction(trans,
6437 root, ret);
6438 goto out;
6439 }
6440 }
6441
6442 if (loop == LOOP_NO_EMPTY_SIZE) {
6443 empty_size = 0;
6444 empty_cluster = 0;
6445 }
6446
6447 goto search;
6448 } else if (!ins->objectid) {
6449 ret = -ENOSPC;
6450 } else if (ins->objectid) {
6451 ret = 0;
6452 }
6453 out:
6454
6455 return ret;
6456 }
6457
6458 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
6459 int dump_block_groups)
6460 {
6461 struct btrfs_block_group_cache *cache;
6462 int index = 0;
6463
6464 spin_lock(&info->lock);
6465 printk(KERN_INFO "space_info %llu has %llu free, is %sfull\n",
6466 (unsigned long long)info->flags,
6467 (unsigned long long)(info->total_bytes - info->bytes_used -
6468 info->bytes_pinned - info->bytes_reserved -
6469 info->bytes_readonly),
6470 (info->full) ? "" : "not ");
6471 printk(KERN_INFO "space_info total=%llu, used=%llu, pinned=%llu, "
6472 "reserved=%llu, may_use=%llu, readonly=%llu\n",
6473 (unsigned long long)info->total_bytes,
6474 (unsigned long long)info->bytes_used,
6475 (unsigned long long)info->bytes_pinned,
6476 (unsigned long long)info->bytes_reserved,
6477 (unsigned long long)info->bytes_may_use,
6478 (unsigned long long)info->bytes_readonly);
6479 spin_unlock(&info->lock);
6480
6481 if (!dump_block_groups)
6482 return;
6483
6484 down_read(&info->groups_sem);
6485 again:
6486 list_for_each_entry(cache, &info->block_groups[index], list) {
6487 spin_lock(&cache->lock);
6488 printk(KERN_INFO "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s\n",
6489 (unsigned long long)cache->key.objectid,
6490 (unsigned long long)cache->key.offset,
6491 (unsigned long long)btrfs_block_group_used(&cache->item),
6492 (unsigned long long)cache->pinned,
6493 (unsigned long long)cache->reserved,
6494 cache->ro ? "[readonly]" : "");
6495 btrfs_dump_free_space(cache, bytes);
6496 spin_unlock(&cache->lock);
6497 }
6498 if (++index < BTRFS_NR_RAID_TYPES)
6499 goto again;
6500 up_read(&info->groups_sem);
6501 }
6502
6503 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
6504 struct btrfs_root *root,
6505 u64 num_bytes, u64 min_alloc_size,
6506 u64 empty_size, u64 hint_byte,
6507 struct btrfs_key *ins, int is_data)
6508 {
6509 bool final_tried = false;
6510 u64 flags;
6511 int ret;
6512
6513 flags = btrfs_get_alloc_profile(root, is_data);
6514 again:
6515 WARN_ON(num_bytes < root->sectorsize);
6516 ret = find_free_extent(trans, root, num_bytes, empty_size,
6517 hint_byte, ins, flags);
6518
6519 if (ret == -ENOSPC) {
6520 if (!final_tried) {
6521 num_bytes = num_bytes >> 1;
6522 num_bytes = round_down(num_bytes, root->sectorsize);
6523 num_bytes = max(num_bytes, min_alloc_size);
6524 if (num_bytes == min_alloc_size)
6525 final_tried = true;
6526 goto again;
6527 } else if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
6528 struct btrfs_space_info *sinfo;
6529
6530 sinfo = __find_space_info(root->fs_info, flags);
6531 btrfs_err(root->fs_info, "allocation failed flags %llu, wanted %llu",
6532 (unsigned long long)flags,
6533 (unsigned long long)num_bytes);
6534 if (sinfo)
6535 dump_space_info(sinfo, num_bytes, 1);
6536 }
6537 }
6538
6539 trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset);
6540
6541 return ret;
6542 }
6543
6544 static int __btrfs_free_reserved_extent(struct btrfs_root *root,
6545 u64 start, u64 len, int pin)
6546 {
6547 struct btrfs_block_group_cache *cache;
6548 int ret = 0;
6549
6550 cache = btrfs_lookup_block_group(root->fs_info, start);
6551 if (!cache) {
6552 btrfs_err(root->fs_info, "Unable to find block group for %llu",
6553 (unsigned long long)start);
6554 return -ENOSPC;
6555 }
6556
6557 if (btrfs_test_opt(root, DISCARD))
6558 ret = btrfs_discard_extent(root, start, len, NULL);
6559
6560 if (pin)
6561 pin_down_extent(root, cache, start, len, 1);
6562 else {
6563 btrfs_add_free_space(cache, start, len);
6564 btrfs_update_reserved_bytes(cache, len, RESERVE_FREE);
6565 }
6566 btrfs_put_block_group(cache);
6567
6568 trace_btrfs_reserved_extent_free(root, start, len);
6569
6570 return ret;
6571 }
6572
6573 int btrfs_free_reserved_extent(struct btrfs_root *root,
6574 u64 start, u64 len)
6575 {
6576 return __btrfs_free_reserved_extent(root, start, len, 0);
6577 }
6578
6579 int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
6580 u64 start, u64 len)
6581 {
6582 return __btrfs_free_reserved_extent(root, start, len, 1);
6583 }
6584
6585 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
6586 struct btrfs_root *root,
6587 u64 parent, u64 root_objectid,
6588 u64 flags, u64 owner, u64 offset,
6589 struct btrfs_key *ins, int ref_mod)
6590 {
6591 int ret;
6592 struct btrfs_fs_info *fs_info = root->fs_info;
6593 struct btrfs_extent_item *extent_item;
6594 struct btrfs_extent_inline_ref *iref;
6595 struct btrfs_path *path;
6596 struct extent_buffer *leaf;
6597 int type;
6598 u32 size;
6599
6600 if (parent > 0)
6601 type = BTRFS_SHARED_DATA_REF_KEY;
6602 else
6603 type = BTRFS_EXTENT_DATA_REF_KEY;
6604
6605 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
6606
6607 path = btrfs_alloc_path();
6608 if (!path)
6609 return -ENOMEM;
6610
6611 path->leave_spinning = 1;
6612 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
6613 ins, size);
6614 if (ret) {
6615 btrfs_free_path(path);
6616 return ret;
6617 }
6618
6619 leaf = path->nodes[0];
6620 extent_item = btrfs_item_ptr(leaf, path->slots[0],
6621 struct btrfs_extent_item);
6622 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
6623 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
6624 btrfs_set_extent_flags(leaf, extent_item,
6625 flags | BTRFS_EXTENT_FLAG_DATA);
6626
6627 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
6628 btrfs_set_extent_inline_ref_type(leaf, iref, type);
6629 if (parent > 0) {
6630 struct btrfs_shared_data_ref *ref;
6631 ref = (struct btrfs_shared_data_ref *)(iref + 1);
6632 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
6633 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
6634 } else {
6635 struct btrfs_extent_data_ref *ref;
6636 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
6637 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
6638 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
6639 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
6640 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
6641 }
6642
6643 btrfs_mark_buffer_dirty(path->nodes[0]);
6644 btrfs_free_path(path);
6645
6646 ret = update_block_group(root, ins->objectid, ins->offset, 1);
6647 if (ret) { /* -ENOENT, logic error */
6648 btrfs_err(fs_info, "update block group failed for %llu %llu",
6649 (unsigned long long)ins->objectid,
6650 (unsigned long long)ins->offset);
6651 BUG();
6652 }
6653 return ret;
6654 }
6655
6656 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
6657 struct btrfs_root *root,
6658 u64 parent, u64 root_objectid,
6659 u64 flags, struct btrfs_disk_key *key,
6660 int level, struct btrfs_key *ins)
6661 {
6662 int ret;
6663 struct btrfs_fs_info *fs_info = root->fs_info;
6664 struct btrfs_extent_item *extent_item;
6665 struct btrfs_tree_block_info *block_info;
6666 struct btrfs_extent_inline_ref *iref;
6667 struct btrfs_path *path;
6668 struct extent_buffer *leaf;
6669 u32 size = sizeof(*extent_item) + sizeof(*iref);
6670 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
6671 SKINNY_METADATA);
6672
6673 if (!skinny_metadata)
6674 size += sizeof(*block_info);
6675
6676 path = btrfs_alloc_path();
6677 if (!path)
6678 return -ENOMEM;
6679
6680 path->leave_spinning = 1;
6681 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
6682 ins, size);
6683 if (ret) {
6684 btrfs_free_path(path);
6685 return ret;
6686 }
6687
6688 leaf = path->nodes[0];
6689 extent_item = btrfs_item_ptr(leaf, path->slots[0],
6690 struct btrfs_extent_item);
6691 btrfs_set_extent_refs(leaf, extent_item, 1);
6692 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
6693 btrfs_set_extent_flags(leaf, extent_item,
6694 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
6695
6696 if (skinny_metadata) {
6697 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
6698 } else {
6699 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
6700 btrfs_set_tree_block_key(leaf, block_info, key);
6701 btrfs_set_tree_block_level(leaf, block_info, level);
6702 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
6703 }
6704
6705 if (parent > 0) {
6706 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
6707 btrfs_set_extent_inline_ref_type(leaf, iref,
6708 BTRFS_SHARED_BLOCK_REF_KEY);
6709 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
6710 } else {
6711 btrfs_set_extent_inline_ref_type(leaf, iref,
6712 BTRFS_TREE_BLOCK_REF_KEY);
6713 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
6714 }
6715
6716 btrfs_mark_buffer_dirty(leaf);
6717 btrfs_free_path(path);
6718
6719 ret = update_block_group(root, ins->objectid, root->leafsize, 1);
6720 if (ret) { /* -ENOENT, logic error */
6721 btrfs_err(fs_info, "update block group failed for %llu %llu",
6722 (unsigned long long)ins->objectid,
6723 (unsigned long long)ins->offset);
6724 BUG();
6725 }
6726 return ret;
6727 }
6728
6729 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
6730 struct btrfs_root *root,
6731 u64 root_objectid, u64 owner,
6732 u64 offset, struct btrfs_key *ins)
6733 {
6734 int ret;
6735
6736 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
6737
6738 ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid,
6739 ins->offset, 0,
6740 root_objectid, owner, offset,
6741 BTRFS_ADD_DELAYED_EXTENT, NULL, 0);
6742 return ret;
6743 }
6744
6745 /*
6746 * this is used by the tree logging recovery code. It records that
6747 * an extent has been allocated and makes sure to clear the free
6748 * space cache bits as well
6749 */
6750 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
6751 struct btrfs_root *root,
6752 u64 root_objectid, u64 owner, u64 offset,
6753 struct btrfs_key *ins)
6754 {
6755 int ret;
6756 struct btrfs_block_group_cache *block_group;
6757
6758 /*
6759 * Mixed block groups will exclude before processing the log so we only
6760 * need to do the exlude dance if this fs isn't mixed.
6761 */
6762 if (!btrfs_fs_incompat(root->fs_info, MIXED_GROUPS)) {
6763 ret = __exclude_logged_extent(root, ins->objectid, ins->offset);
6764 if (ret)
6765 return ret;
6766 }
6767
6768 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
6769 if (!block_group)
6770 return -EINVAL;
6771
6772 ret = btrfs_update_reserved_bytes(block_group, ins->offset,
6773 RESERVE_ALLOC_NO_ACCOUNT);
6774 BUG_ON(ret); /* logic error */
6775 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
6776 0, owner, offset, ins, 1);
6777 btrfs_put_block_group(block_group);
6778 return ret;
6779 }
6780
6781 static struct extent_buffer *
6782 btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
6783 u64 bytenr, u32 blocksize, int level)
6784 {
6785 struct extent_buffer *buf;
6786
6787 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
6788 if (!buf)
6789 return ERR_PTR(-ENOMEM);
6790 btrfs_set_header_generation(buf, trans->transid);
6791 btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
6792 btrfs_tree_lock(buf);
6793 clean_tree_block(trans, root, buf);
6794 clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
6795
6796 btrfs_set_lock_blocking(buf);
6797 btrfs_set_buffer_uptodate(buf);
6798
6799 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
6800 /*
6801 * we allow two log transactions at a time, use different
6802 * EXENT bit to differentiate dirty pages.
6803 */
6804 if (root->log_transid % 2 == 0)
6805 set_extent_dirty(&root->dirty_log_pages, buf->start,
6806 buf->start + buf->len - 1, GFP_NOFS);
6807 else
6808 set_extent_new(&root->dirty_log_pages, buf->start,
6809 buf->start + buf->len - 1, GFP_NOFS);
6810 } else {
6811 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
6812 buf->start + buf->len - 1, GFP_NOFS);
6813 }
6814 trans->blocks_used++;
6815 /* this returns a buffer locked for blocking */
6816 return buf;
6817 }
6818
6819 static struct btrfs_block_rsv *
6820 use_block_rsv(struct btrfs_trans_handle *trans,
6821 struct btrfs_root *root, u32 blocksize)
6822 {
6823 struct btrfs_block_rsv *block_rsv;
6824 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
6825 int ret;
6826 bool global_updated = false;
6827
6828 block_rsv = get_block_rsv(trans, root);
6829
6830 if (unlikely(block_rsv->size == 0))
6831 goto try_reserve;
6832 again:
6833 ret = block_rsv_use_bytes(block_rsv, blocksize);
6834 if (!ret)
6835 return block_rsv;
6836
6837 if (block_rsv->failfast)
6838 return ERR_PTR(ret);
6839
6840 if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
6841 global_updated = true;
6842 update_global_block_rsv(root->fs_info);
6843 goto again;
6844 }
6845
6846 if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
6847 static DEFINE_RATELIMIT_STATE(_rs,
6848 DEFAULT_RATELIMIT_INTERVAL * 10,
6849 /*DEFAULT_RATELIMIT_BURST*/ 1);
6850 if (__ratelimit(&_rs))
6851 WARN(1, KERN_DEBUG
6852 "btrfs: block rsv returned %d\n", ret);
6853 }
6854 try_reserve:
6855 ret = reserve_metadata_bytes(root, block_rsv, blocksize,
6856 BTRFS_RESERVE_NO_FLUSH);
6857 if (!ret)
6858 return block_rsv;
6859 /*
6860 * If we couldn't reserve metadata bytes try and use some from
6861 * the global reserve if its space type is the same as the global
6862 * reservation.
6863 */
6864 if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
6865 block_rsv->space_info == global_rsv->space_info) {
6866 ret = block_rsv_use_bytes(global_rsv, blocksize);
6867 if (!ret)
6868 return global_rsv;
6869 }
6870 return ERR_PTR(ret);
6871 }
6872
6873 static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
6874 struct btrfs_block_rsv *block_rsv, u32 blocksize)
6875 {
6876 block_rsv_add_bytes(block_rsv, blocksize, 0);
6877 block_rsv_release_bytes(fs_info, block_rsv, NULL, 0);
6878 }
6879
6880 /*
6881 * finds a free extent and does all the dirty work required for allocation
6882 * returns the key for the extent through ins, and a tree buffer for
6883 * the first block of the extent through buf.
6884 *
6885 * returns the tree buffer or NULL.
6886 */
6887 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
6888 struct btrfs_root *root, u32 blocksize,
6889 u64 parent, u64 root_objectid,
6890 struct btrfs_disk_key *key, int level,
6891 u64 hint, u64 empty_size)
6892 {
6893 struct btrfs_key ins;
6894 struct btrfs_block_rsv *block_rsv;
6895 struct extent_buffer *buf;
6896 u64 flags = 0;
6897 int ret;
6898 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
6899 SKINNY_METADATA);
6900
6901 block_rsv = use_block_rsv(trans, root, blocksize);
6902 if (IS_ERR(block_rsv))
6903 return ERR_CAST(block_rsv);
6904
6905 ret = btrfs_reserve_extent(trans, root, blocksize, blocksize,
6906 empty_size, hint, &ins, 0);
6907 if (ret) {
6908 unuse_block_rsv(root->fs_info, block_rsv, blocksize);
6909 return ERR_PTR(ret);
6910 }
6911
6912 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
6913 blocksize, level);
6914 BUG_ON(IS_ERR(buf)); /* -ENOMEM */
6915
6916 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
6917 if (parent == 0)
6918 parent = ins.objectid;
6919 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
6920 } else
6921 BUG_ON(parent > 0);
6922
6923 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
6924 struct btrfs_delayed_extent_op *extent_op;
6925 extent_op = btrfs_alloc_delayed_extent_op();
6926 BUG_ON(!extent_op); /* -ENOMEM */
6927 if (key)
6928 memcpy(&extent_op->key, key, sizeof(extent_op->key));
6929 else
6930 memset(&extent_op->key, 0, sizeof(extent_op->key));
6931 extent_op->flags_to_set = flags;
6932 if (skinny_metadata)
6933 extent_op->update_key = 0;
6934 else
6935 extent_op->update_key = 1;
6936 extent_op->update_flags = 1;
6937 extent_op->is_data = 0;
6938 extent_op->level = level;
6939
6940 ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
6941 ins.objectid,
6942 ins.offset, parent, root_objectid,
6943 level, BTRFS_ADD_DELAYED_EXTENT,
6944 extent_op, 0);
6945 BUG_ON(ret); /* -ENOMEM */
6946 }
6947 return buf;
6948 }
6949
6950 struct walk_control {
6951 u64 refs[BTRFS_MAX_LEVEL];
6952 u64 flags[BTRFS_MAX_LEVEL];
6953 struct btrfs_key update_progress;
6954 int stage;
6955 int level;
6956 int shared_level;
6957 int update_ref;
6958 int keep_locks;
6959 int reada_slot;
6960 int reada_count;
6961 int for_reloc;
6962 };
6963
6964 #define DROP_REFERENCE 1
6965 #define UPDATE_BACKREF 2
6966
6967 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
6968 struct btrfs_root *root,
6969 struct walk_control *wc,
6970 struct btrfs_path *path)
6971 {
6972 u64 bytenr;
6973 u64 generation;
6974 u64 refs;
6975 u64 flags;
6976 u32 nritems;
6977 u32 blocksize;
6978 struct btrfs_key key;
6979 struct extent_buffer *eb;
6980 int ret;
6981 int slot;
6982 int nread = 0;
6983
6984 if (path->slots[wc->level] < wc->reada_slot) {
6985 wc->reada_count = wc->reada_count * 2 / 3;
6986 wc->reada_count = max(wc->reada_count, 2);
6987 } else {
6988 wc->reada_count = wc->reada_count * 3 / 2;
6989 wc->reada_count = min_t(int, wc->reada_count,
6990 BTRFS_NODEPTRS_PER_BLOCK(root));
6991 }
6992
6993 eb = path->nodes[wc->level];
6994 nritems = btrfs_header_nritems(eb);
6995 blocksize = btrfs_level_size(root, wc->level - 1);
6996
6997 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
6998 if (nread >= wc->reada_count)
6999 break;
7000
7001 cond_resched();
7002 bytenr = btrfs_node_blockptr(eb, slot);
7003 generation = btrfs_node_ptr_generation(eb, slot);
7004
7005 if (slot == path->slots[wc->level])
7006 goto reada;
7007
7008 if (wc->stage == UPDATE_BACKREF &&
7009 generation <= root->root_key.offset)
7010 continue;
7011
7012 /* We don't lock the tree block, it's OK to be racy here */
7013 ret = btrfs_lookup_extent_info(trans, root, bytenr,
7014 wc->level - 1, 1, &refs,
7015 &flags);
7016 /* We don't care about errors in readahead. */
7017 if (ret < 0)
7018 continue;
7019 BUG_ON(refs == 0);
7020
7021 if (wc->stage == DROP_REFERENCE) {
7022 if (refs == 1)
7023 goto reada;
7024
7025 if (wc->level == 1 &&
7026 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
7027 continue;
7028 if (!wc->update_ref ||
7029 generation <= root->root_key.offset)
7030 continue;
7031 btrfs_node_key_to_cpu(eb, &key, slot);
7032 ret = btrfs_comp_cpu_keys(&key,
7033 &wc->update_progress);
7034 if (ret < 0)
7035 continue;
7036 } else {
7037 if (wc->level == 1 &&
7038 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
7039 continue;
7040 }
7041 reada:
7042 ret = readahead_tree_block(root, bytenr, blocksize,
7043 generation);
7044 if (ret)
7045 break;
7046 nread++;
7047 }
7048 wc->reada_slot = slot;
7049 }
7050
7051 /*
7052 * helper to process tree block while walking down the tree.
7053 *
7054 * when wc->stage == UPDATE_BACKREF, this function updates
7055 * back refs for pointers in the block.
7056 *
7057 * NOTE: return value 1 means we should stop walking down.
7058 */
7059 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
7060 struct btrfs_root *root,
7061 struct btrfs_path *path,
7062 struct walk_control *wc, int lookup_info)
7063 {
7064 int level = wc->level;
7065 struct extent_buffer *eb = path->nodes[level];
7066 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
7067 int ret;
7068
7069 if (wc->stage == UPDATE_BACKREF &&
7070 btrfs_header_owner(eb) != root->root_key.objectid)
7071 return 1;
7072
7073 /*
7074 * when reference count of tree block is 1, it won't increase
7075 * again. once full backref flag is set, we never clear it.
7076 */
7077 if (lookup_info &&
7078 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
7079 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
7080 BUG_ON(!path->locks[level]);
7081 ret = btrfs_lookup_extent_info(trans, root,
7082 eb->start, level, 1,
7083 &wc->refs[level],
7084 &wc->flags[level]);
7085 BUG_ON(ret == -ENOMEM);
7086 if (ret)
7087 return ret;
7088 BUG_ON(wc->refs[level] == 0);
7089 }
7090
7091 if (wc->stage == DROP_REFERENCE) {
7092 if (wc->refs[level] > 1)
7093 return 1;
7094
7095 if (path->locks[level] && !wc->keep_locks) {
7096 btrfs_tree_unlock_rw(eb, path->locks[level]);
7097 path->locks[level] = 0;
7098 }
7099 return 0;
7100 }
7101
7102 /* wc->stage == UPDATE_BACKREF */
7103 if (!(wc->flags[level] & flag)) {
7104 BUG_ON(!path->locks[level]);
7105 ret = btrfs_inc_ref(trans, root, eb, 1, wc->for_reloc);
7106 BUG_ON(ret); /* -ENOMEM */
7107 ret = btrfs_dec_ref(trans, root, eb, 0, wc->for_reloc);
7108 BUG_ON(ret); /* -ENOMEM */
7109 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
7110 eb->len, flag,
7111 btrfs_header_level(eb), 0);
7112 BUG_ON(ret); /* -ENOMEM */
7113 wc->flags[level] |= flag;
7114 }
7115
7116 /*
7117 * the block is shared by multiple trees, so it's not good to
7118 * keep the tree lock
7119 */
7120 if (path->locks[level] && level > 0) {
7121 btrfs_tree_unlock_rw(eb, path->locks[level]);
7122 path->locks[level] = 0;
7123 }
7124 return 0;
7125 }
7126
7127 /*
7128 * helper to process tree block pointer.
7129 *
7130 * when wc->stage == DROP_REFERENCE, this function checks
7131 * reference count of the block pointed to. if the block
7132 * is shared and we need update back refs for the subtree
7133 * rooted at the block, this function changes wc->stage to
7134 * UPDATE_BACKREF. if the block is shared and there is no
7135 * need to update back, this function drops the reference
7136 * to the block.
7137 *
7138 * NOTE: return value 1 means we should stop walking down.
7139 */
7140 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
7141 struct btrfs_root *root,
7142 struct btrfs_path *path,
7143 struct walk_control *wc, int *lookup_info)
7144 {
7145 u64 bytenr;
7146 u64 generation;
7147 u64 parent;
7148 u32 blocksize;
7149 struct btrfs_key key;
7150 struct extent_buffer *next;
7151 int level = wc->level;
7152 int reada = 0;
7153 int ret = 0;
7154
7155 generation = btrfs_node_ptr_generation(path->nodes[level],
7156 path->slots[level]);
7157 /*
7158 * if the lower level block was created before the snapshot
7159 * was created, we know there is no need to update back refs
7160 * for the subtree
7161 */
7162 if (wc->stage == UPDATE_BACKREF &&
7163 generation <= root->root_key.offset) {
7164 *lookup_info = 1;
7165 return 1;
7166 }
7167
7168 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
7169 blocksize = btrfs_level_size(root, level - 1);
7170
7171 next = btrfs_find_tree_block(root, bytenr, blocksize);
7172 if (!next) {
7173 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
7174 if (!next)
7175 return -ENOMEM;
7176 reada = 1;
7177 }
7178 btrfs_tree_lock(next);
7179 btrfs_set_lock_blocking(next);
7180
7181 ret = btrfs_lookup_extent_info(trans, root, bytenr, level - 1, 1,
7182 &wc->refs[level - 1],
7183 &wc->flags[level - 1]);
7184 if (ret < 0) {
7185 btrfs_tree_unlock(next);
7186 return ret;
7187 }
7188
7189 if (unlikely(wc->refs[level - 1] == 0)) {
7190 btrfs_err(root->fs_info, "Missing references.");
7191 BUG();
7192 }
7193 *lookup_info = 0;
7194
7195 if (wc->stage == DROP_REFERENCE) {
7196 if (wc->refs[level - 1] > 1) {
7197 if (level == 1 &&
7198 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
7199 goto skip;
7200
7201 if (!wc->update_ref ||
7202 generation <= root->root_key.offset)
7203 goto skip;
7204
7205 btrfs_node_key_to_cpu(path->nodes[level], &key,
7206 path->slots[level]);
7207 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
7208 if (ret < 0)
7209 goto skip;
7210
7211 wc->stage = UPDATE_BACKREF;
7212 wc->shared_level = level - 1;
7213 }
7214 } else {
7215 if (level == 1 &&
7216 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
7217 goto skip;
7218 }
7219
7220 if (!btrfs_buffer_uptodate(next, generation, 0)) {
7221 btrfs_tree_unlock(next);
7222 free_extent_buffer(next);
7223 next = NULL;
7224 *lookup_info = 1;
7225 }
7226
7227 if (!next) {
7228 if (reada && level == 1)
7229 reada_walk_down(trans, root, wc, path);
7230 next = read_tree_block(root, bytenr, blocksize, generation);
7231 if (!next || !extent_buffer_uptodate(next)) {
7232 free_extent_buffer(next);
7233 return -EIO;
7234 }
7235 btrfs_tree_lock(next);
7236 btrfs_set_lock_blocking(next);
7237 }
7238
7239 level--;
7240 BUG_ON(level != btrfs_header_level(next));
7241 path->nodes[level] = next;
7242 path->slots[level] = 0;
7243 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
7244 wc->level = level;
7245 if (wc->level == 1)
7246 wc->reada_slot = 0;
7247 return 0;
7248 skip:
7249 wc->refs[level - 1] = 0;
7250 wc->flags[level - 1] = 0;
7251 if (wc->stage == DROP_REFERENCE) {
7252 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
7253 parent = path->nodes[level]->start;
7254 } else {
7255 BUG_ON(root->root_key.objectid !=
7256 btrfs_header_owner(path->nodes[level]));
7257 parent = 0;
7258 }
7259
7260 ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
7261 root->root_key.objectid, level - 1, 0, 0);
7262 BUG_ON(ret); /* -ENOMEM */
7263 }
7264 btrfs_tree_unlock(next);
7265 free_extent_buffer(next);
7266 *lookup_info = 1;
7267 return 1;
7268 }
7269
7270 /*
7271 * helper to process tree block while walking up the tree.
7272 *
7273 * when wc->stage == DROP_REFERENCE, this function drops
7274 * reference count on the block.
7275 *
7276 * when wc->stage == UPDATE_BACKREF, this function changes
7277 * wc->stage back to DROP_REFERENCE if we changed wc->stage
7278 * to UPDATE_BACKREF previously while processing the block.
7279 *
7280 * NOTE: return value 1 means we should stop walking up.
7281 */
7282 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
7283 struct btrfs_root *root,
7284 struct btrfs_path *path,
7285 struct walk_control *wc)
7286 {
7287 int ret;
7288 int level = wc->level;
7289 struct extent_buffer *eb = path->nodes[level];
7290 u64 parent = 0;
7291
7292 if (wc->stage == UPDATE_BACKREF) {
7293 BUG_ON(wc->shared_level < level);
7294 if (level < wc->shared_level)
7295 goto out;
7296
7297 ret = find_next_key(path, level + 1, &wc->update_progress);
7298 if (ret > 0)
7299 wc->update_ref = 0;
7300
7301 wc->stage = DROP_REFERENCE;
7302 wc->shared_level = -1;
7303 path->slots[level] = 0;
7304
7305 /*
7306 * check reference count again if the block isn't locked.
7307 * we should start walking down the tree again if reference
7308 * count is one.
7309 */
7310 if (!path->locks[level]) {
7311 BUG_ON(level == 0);
7312 btrfs_tree_lock(eb);
7313 btrfs_set_lock_blocking(eb);
7314 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
7315
7316 ret = btrfs_lookup_extent_info(trans, root,
7317 eb->start, level, 1,
7318 &wc->refs[level],
7319 &wc->flags[level]);
7320 if (ret < 0) {
7321 btrfs_tree_unlock_rw(eb, path->locks[level]);
7322 path->locks[level] = 0;
7323 return ret;
7324 }
7325 BUG_ON(wc->refs[level] == 0);
7326 if (wc->refs[level] == 1) {
7327 btrfs_tree_unlock_rw(eb, path->locks[level]);
7328 path->locks[level] = 0;
7329 return 1;
7330 }
7331 }
7332 }
7333
7334 /* wc->stage == DROP_REFERENCE */
7335 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
7336
7337 if (wc->refs[level] == 1) {
7338 if (level == 0) {
7339 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
7340 ret = btrfs_dec_ref(trans, root, eb, 1,
7341 wc->for_reloc);
7342 else
7343 ret = btrfs_dec_ref(trans, root, eb, 0,
7344 wc->for_reloc);
7345 BUG_ON(ret); /* -ENOMEM */
7346 }
7347 /* make block locked assertion in clean_tree_block happy */
7348 if (!path->locks[level] &&
7349 btrfs_header_generation(eb) == trans->transid) {
7350 btrfs_tree_lock(eb);
7351 btrfs_set_lock_blocking(eb);
7352 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
7353 }
7354 clean_tree_block(trans, root, eb);
7355 }
7356
7357 if (eb == root->node) {
7358 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
7359 parent = eb->start;
7360 else
7361 BUG_ON(root->root_key.objectid !=
7362 btrfs_header_owner(eb));
7363 } else {
7364 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
7365 parent = path->nodes[level + 1]->start;
7366 else
7367 BUG_ON(root->root_key.objectid !=
7368 btrfs_header_owner(path->nodes[level + 1]));
7369 }
7370
7371 btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
7372 out:
7373 wc->refs[level] = 0;
7374 wc->flags[level] = 0;
7375 return 0;
7376 }
7377
7378 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
7379 struct btrfs_root *root,
7380 struct btrfs_path *path,
7381 struct walk_control *wc)
7382 {
7383 int level = wc->level;
7384 int lookup_info = 1;
7385 int ret;
7386
7387 while (level >= 0) {
7388 ret = walk_down_proc(trans, root, path, wc, lookup_info);
7389 if (ret > 0)
7390 break;
7391
7392 if (level == 0)
7393 break;
7394
7395 if (path->slots[level] >=
7396 btrfs_header_nritems(path->nodes[level]))
7397 break;
7398
7399 ret = do_walk_down(trans, root, path, wc, &lookup_info);
7400 if (ret > 0) {
7401 path->slots[level]++;
7402 continue;
7403 } else if (ret < 0)
7404 return ret;
7405 level = wc->level;
7406 }
7407 return 0;
7408 }
7409
7410 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
7411 struct btrfs_root *root,
7412 struct btrfs_path *path,
7413 struct walk_control *wc, int max_level)
7414 {
7415 int level = wc->level;
7416 int ret;
7417
7418 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
7419 while (level < max_level && path->nodes[level]) {
7420 wc->level = level;
7421 if (path->slots[level] + 1 <
7422 btrfs_header_nritems(path->nodes[level])) {
7423 path->slots[level]++;
7424 return 0;
7425 } else {
7426 ret = walk_up_proc(trans, root, path, wc);
7427 if (ret > 0)
7428 return 0;
7429
7430 if (path->locks[level]) {
7431 btrfs_tree_unlock_rw(path->nodes[level],
7432 path->locks[level]);
7433 path->locks[level] = 0;
7434 }
7435 free_extent_buffer(path->nodes[level]);
7436 path->nodes[level] = NULL;
7437 level++;
7438 }
7439 }
7440 return 1;
7441 }
7442
7443 /*
7444 * drop a subvolume tree.
7445 *
7446 * this function traverses the tree freeing any blocks that only
7447 * referenced by the tree.
7448 *
7449 * when a shared tree block is found. this function decreases its
7450 * reference count by one. if update_ref is true, this function
7451 * also make sure backrefs for the shared block and all lower level
7452 * blocks are properly updated.
7453 *
7454 * If called with for_reloc == 0, may exit early with -EAGAIN
7455 */
7456 int btrfs_drop_snapshot(struct btrfs_root *root,
7457 struct btrfs_block_rsv *block_rsv, int update_ref,
7458 int for_reloc)
7459 {
7460 struct btrfs_path *path;
7461 struct btrfs_trans_handle *trans;
7462 struct btrfs_root *tree_root = root->fs_info->tree_root;
7463 struct btrfs_root_item *root_item = &root->root_item;
7464 struct walk_control *wc;
7465 struct btrfs_key key;
7466 int err = 0;
7467 int ret;
7468 int level;
7469 bool root_dropped = false;
7470
7471 path = btrfs_alloc_path();
7472 if (!path) {
7473 err = -ENOMEM;
7474 goto out;
7475 }
7476
7477 wc = kzalloc(sizeof(*wc), GFP_NOFS);
7478 if (!wc) {
7479 btrfs_free_path(path);
7480 err = -ENOMEM;
7481 goto out;
7482 }
7483
7484 trans = btrfs_start_transaction(tree_root, 0);
7485 if (IS_ERR(trans)) {
7486 err = PTR_ERR(trans);
7487 goto out_free;
7488 }
7489
7490 if (block_rsv)
7491 trans->block_rsv = block_rsv;
7492
7493 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
7494 level = btrfs_header_level(root->node);
7495 path->nodes[level] = btrfs_lock_root_node(root);
7496 btrfs_set_lock_blocking(path->nodes[level]);
7497 path->slots[level] = 0;
7498 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
7499 memset(&wc->update_progress, 0,
7500 sizeof(wc->update_progress));
7501 } else {
7502 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
7503 memcpy(&wc->update_progress, &key,
7504 sizeof(wc->update_progress));
7505
7506 level = root_item->drop_level;
7507 BUG_ON(level == 0);
7508 path->lowest_level = level;
7509 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
7510 path->lowest_level = 0;
7511 if (ret < 0) {
7512 err = ret;
7513 goto out_end_trans;
7514 }
7515 WARN_ON(ret > 0);
7516
7517 /*
7518 * unlock our path, this is safe because only this
7519 * function is allowed to delete this snapshot
7520 */
7521 btrfs_unlock_up_safe(path, 0);
7522
7523 level = btrfs_header_level(root->node);
7524 while (1) {
7525 btrfs_tree_lock(path->nodes[level]);
7526 btrfs_set_lock_blocking(path->nodes[level]);
7527 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
7528
7529 ret = btrfs_lookup_extent_info(trans, root,
7530 path->nodes[level]->start,
7531 level, 1, &wc->refs[level],
7532 &wc->flags[level]);
7533 if (ret < 0) {
7534 err = ret;
7535 goto out_end_trans;
7536 }
7537 BUG_ON(wc->refs[level] == 0);
7538
7539 if (level == root_item->drop_level)
7540 break;
7541
7542 btrfs_tree_unlock(path->nodes[level]);
7543 path->locks[level] = 0;
7544 WARN_ON(wc->refs[level] != 1);
7545 level--;
7546 }
7547 }
7548
7549 wc->level = level;
7550 wc->shared_level = -1;
7551 wc->stage = DROP_REFERENCE;
7552 wc->update_ref = update_ref;
7553 wc->keep_locks = 0;
7554 wc->for_reloc = for_reloc;
7555 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
7556
7557 while (1) {
7558
7559 ret = walk_down_tree(trans, root, path, wc);
7560 if (ret < 0) {
7561 err = ret;
7562 break;
7563 }
7564
7565 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
7566 if (ret < 0) {
7567 err = ret;
7568 break;
7569 }
7570
7571 if (ret > 0) {
7572 BUG_ON(wc->stage != DROP_REFERENCE);
7573 break;
7574 }
7575
7576 if (wc->stage == DROP_REFERENCE) {
7577 level = wc->level;
7578 btrfs_node_key(path->nodes[level],
7579 &root_item->drop_progress,
7580 path->slots[level]);
7581 root_item->drop_level = level;
7582 }
7583
7584 BUG_ON(wc->level == 0);
7585 if (btrfs_should_end_transaction(trans, tree_root) ||
7586 (!for_reloc && btrfs_need_cleaner_sleep(root))) {
7587 ret = btrfs_update_root(trans, tree_root,
7588 &root->root_key,
7589 root_item);
7590 if (ret) {
7591 btrfs_abort_transaction(trans, tree_root, ret);
7592 err = ret;
7593 goto out_end_trans;
7594 }
7595
7596 btrfs_end_transaction_throttle(trans, tree_root);
7597 if (!for_reloc && btrfs_need_cleaner_sleep(root)) {
7598 pr_debug("btrfs: drop snapshot early exit\n");
7599 err = -EAGAIN;
7600 goto out_free;
7601 }
7602
7603 trans = btrfs_start_transaction(tree_root, 0);
7604 if (IS_ERR(trans)) {
7605 err = PTR_ERR(trans);
7606 goto out_free;
7607 }
7608 if (block_rsv)
7609 trans->block_rsv = block_rsv;
7610 }
7611 }
7612 btrfs_release_path(path);
7613 if (err)
7614 goto out_end_trans;
7615
7616 ret = btrfs_del_root(trans, tree_root, &root->root_key);
7617 if (ret) {
7618 btrfs_abort_transaction(trans, tree_root, ret);
7619 goto out_end_trans;
7620 }
7621
7622 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
7623 ret = btrfs_find_root(tree_root, &root->root_key, path,
7624 NULL, NULL);
7625 if (ret < 0) {
7626 btrfs_abort_transaction(trans, tree_root, ret);
7627 err = ret;
7628 goto out_end_trans;
7629 } else if (ret > 0) {
7630 /* if we fail to delete the orphan item this time
7631 * around, it'll get picked up the next time.
7632 *
7633 * The most common failure here is just -ENOENT.
7634 */
7635 btrfs_del_orphan_item(trans, tree_root,
7636 root->root_key.objectid);
7637 }
7638 }
7639
7640 if (root->in_radix) {
7641 btrfs_drop_and_free_fs_root(tree_root->fs_info, root);
7642 } else {
7643 free_extent_buffer(root->node);
7644 free_extent_buffer(root->commit_root);
7645 btrfs_put_fs_root(root);
7646 }
7647 root_dropped = true;
7648 out_end_trans:
7649 btrfs_end_transaction_throttle(trans, tree_root);
7650 out_free:
7651 kfree(wc);
7652 btrfs_free_path(path);
7653 out:
7654 /*
7655 * So if we need to stop dropping the snapshot for whatever reason we
7656 * need to make sure to add it back to the dead root list so that we
7657 * keep trying to do the work later. This also cleans up roots if we
7658 * don't have it in the radix (like when we recover after a power fail
7659 * or unmount) so we don't leak memory.
7660 */
7661 if (root_dropped == false)
7662 btrfs_add_dead_root(root);
7663 if (err)
7664 btrfs_std_error(root->fs_info, err);
7665 return err;
7666 }
7667
7668 /*
7669 * drop subtree rooted at tree block 'node'.
7670 *
7671 * NOTE: this function will unlock and release tree block 'node'
7672 * only used by relocation code
7673 */
7674 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
7675 struct btrfs_root *root,
7676 struct extent_buffer *node,
7677 struct extent_buffer *parent)
7678 {
7679 struct btrfs_path *path;
7680 struct walk_control *wc;
7681 int level;
7682 int parent_level;
7683 int ret = 0;
7684 int wret;
7685
7686 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
7687
7688 path = btrfs_alloc_path();
7689 if (!path)
7690 return -ENOMEM;
7691
7692 wc = kzalloc(sizeof(*wc), GFP_NOFS);
7693 if (!wc) {
7694 btrfs_free_path(path);
7695 return -ENOMEM;
7696 }
7697
7698 btrfs_assert_tree_locked(parent);
7699 parent_level = btrfs_header_level(parent);
7700 extent_buffer_get(parent);
7701 path->nodes[parent_level] = parent;
7702 path->slots[parent_level] = btrfs_header_nritems(parent);
7703
7704 btrfs_assert_tree_locked(node);
7705 level = btrfs_header_level(node);
7706 path->nodes[level] = node;
7707 path->slots[level] = 0;
7708 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
7709
7710 wc->refs[parent_level] = 1;
7711 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
7712 wc->level = level;
7713 wc->shared_level = -1;
7714 wc->stage = DROP_REFERENCE;
7715 wc->update_ref = 0;
7716 wc->keep_locks = 1;
7717 wc->for_reloc = 1;
7718 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
7719
7720 while (1) {
7721 wret = walk_down_tree(trans, root, path, wc);
7722 if (wret < 0) {
7723 ret = wret;
7724 break;
7725 }
7726
7727 wret = walk_up_tree(trans, root, path, wc, parent_level);
7728 if (wret < 0)
7729 ret = wret;
7730 if (wret != 0)
7731 break;
7732 }
7733
7734 kfree(wc);
7735 btrfs_free_path(path);
7736 return ret;
7737 }
7738
7739 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
7740 {
7741 u64 num_devices;
7742 u64 stripped;
7743
7744 /*
7745 * if restripe for this chunk_type is on pick target profile and
7746 * return, otherwise do the usual balance
7747 */
7748 stripped = get_restripe_target(root->fs_info, flags);
7749 if (stripped)
7750 return extended_to_chunk(stripped);
7751
7752 /*
7753 * we add in the count of missing devices because we want
7754 * to make sure that any RAID levels on a degraded FS
7755 * continue to be honored.
7756 */
7757 num_devices = root->fs_info->fs_devices->rw_devices +
7758 root->fs_info->fs_devices->missing_devices;
7759
7760 stripped = BTRFS_BLOCK_GROUP_RAID0 |
7761 BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
7762 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
7763
7764 if (num_devices == 1) {
7765 stripped |= BTRFS_BLOCK_GROUP_DUP;
7766 stripped = flags & ~stripped;
7767
7768 /* turn raid0 into single device chunks */
7769 if (flags & BTRFS_BLOCK_GROUP_RAID0)
7770 return stripped;
7771
7772 /* turn mirroring into duplication */
7773 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
7774 BTRFS_BLOCK_GROUP_RAID10))
7775 return stripped | BTRFS_BLOCK_GROUP_DUP;
7776 } else {
7777 /* they already had raid on here, just return */
7778 if (flags & stripped)
7779 return flags;
7780
7781 stripped |= BTRFS_BLOCK_GROUP_DUP;
7782 stripped = flags & ~stripped;
7783
7784 /* switch duplicated blocks with raid1 */
7785 if (flags & BTRFS_BLOCK_GROUP_DUP)
7786 return stripped | BTRFS_BLOCK_GROUP_RAID1;
7787
7788 /* this is drive concat, leave it alone */
7789 }
7790
7791 return flags;
7792 }
7793
7794 static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
7795 {
7796 struct btrfs_space_info *sinfo = cache->space_info;
7797 u64 num_bytes;
7798 u64 min_allocable_bytes;
7799 int ret = -ENOSPC;
7800
7801
7802 /*
7803 * We need some metadata space and system metadata space for
7804 * allocating chunks in some corner cases until we force to set
7805 * it to be readonly.
7806 */
7807 if ((sinfo->flags &
7808 (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
7809 !force)
7810 min_allocable_bytes = 1 * 1024 * 1024;
7811 else
7812 min_allocable_bytes = 0;
7813
7814 spin_lock(&sinfo->lock);
7815 spin_lock(&cache->lock);
7816
7817 if (cache->ro) {
7818 ret = 0;
7819 goto out;
7820 }
7821
7822 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
7823 cache->bytes_super - btrfs_block_group_used(&cache->item);
7824
7825 if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
7826 sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
7827 min_allocable_bytes <= sinfo->total_bytes) {
7828 sinfo->bytes_readonly += num_bytes;
7829 cache->ro = 1;
7830 ret = 0;
7831 }
7832 out:
7833 spin_unlock(&cache->lock);
7834 spin_unlock(&sinfo->lock);
7835 return ret;
7836 }
7837
7838 int btrfs_set_block_group_ro(struct btrfs_root *root,
7839 struct btrfs_block_group_cache *cache)
7840
7841 {
7842 struct btrfs_trans_handle *trans;
7843 u64 alloc_flags;
7844 int ret;
7845
7846 BUG_ON(cache->ro);
7847
7848 trans = btrfs_join_transaction(root);
7849 if (IS_ERR(trans))
7850 return PTR_ERR(trans);
7851
7852 alloc_flags = update_block_group_flags(root, cache->flags);
7853 if (alloc_flags != cache->flags) {
7854 ret = do_chunk_alloc(trans, root, alloc_flags,
7855 CHUNK_ALLOC_FORCE);
7856 if (ret < 0)
7857 goto out;
7858 }
7859
7860 ret = set_block_group_ro(cache, 0);
7861 if (!ret)
7862 goto out;
7863 alloc_flags = get_alloc_profile(root, cache->space_info->flags);
7864 ret = do_chunk_alloc(trans, root, alloc_flags,
7865 CHUNK_ALLOC_FORCE);
7866 if (ret < 0)
7867 goto out;
7868 ret = set_block_group_ro(cache, 0);
7869 out:
7870 btrfs_end_transaction(trans, root);
7871 return ret;
7872 }
7873
7874 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
7875 struct btrfs_root *root, u64 type)
7876 {
7877 u64 alloc_flags = get_alloc_profile(root, type);
7878 return do_chunk_alloc(trans, root, alloc_flags,
7879 CHUNK_ALLOC_FORCE);
7880 }
7881
7882 /*
7883 * helper to account the unused space of all the readonly block group in the
7884 * list. takes mirrors into account.
7885 */
7886 static u64 __btrfs_get_ro_block_group_free_space(struct list_head *groups_list)
7887 {
7888 struct btrfs_block_group_cache *block_group;
7889 u64 free_bytes = 0;
7890 int factor;
7891
7892 list_for_each_entry(block_group, groups_list, list) {
7893 spin_lock(&block_group->lock);
7894
7895 if (!block_group->ro) {
7896 spin_unlock(&block_group->lock);
7897 continue;
7898 }
7899
7900 if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
7901 BTRFS_BLOCK_GROUP_RAID10 |
7902 BTRFS_BLOCK_GROUP_DUP))
7903 factor = 2;
7904 else
7905 factor = 1;
7906
7907 free_bytes += (block_group->key.offset -
7908 btrfs_block_group_used(&block_group->item)) *
7909 factor;
7910
7911 spin_unlock(&block_group->lock);
7912 }
7913
7914 return free_bytes;
7915 }
7916
7917 /*
7918 * helper to account the unused space of all the readonly block group in the
7919 * space_info. takes mirrors into account.
7920 */
7921 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
7922 {
7923 int i;
7924 u64 free_bytes = 0;
7925
7926 spin_lock(&sinfo->lock);
7927
7928 for(i = 0; i < BTRFS_NR_RAID_TYPES; i++)
7929 if (!list_empty(&sinfo->block_groups[i]))
7930 free_bytes += __btrfs_get_ro_block_group_free_space(
7931 &sinfo->block_groups[i]);
7932
7933 spin_unlock(&sinfo->lock);
7934
7935 return free_bytes;
7936 }
7937
7938 void btrfs_set_block_group_rw(struct btrfs_root *root,
7939 struct btrfs_block_group_cache *cache)
7940 {
7941 struct btrfs_space_info *sinfo = cache->space_info;
7942 u64 num_bytes;
7943
7944 BUG_ON(!cache->ro);
7945
7946 spin_lock(&sinfo->lock);
7947 spin_lock(&cache->lock);
7948 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
7949 cache->bytes_super - btrfs_block_group_used(&cache->item);
7950 sinfo->bytes_readonly -= num_bytes;
7951 cache->ro = 0;
7952 spin_unlock(&cache->lock);
7953 spin_unlock(&sinfo->lock);
7954 }
7955
7956 /*
7957 * checks to see if its even possible to relocate this block group.
7958 *
7959 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
7960 * ok to go ahead and try.
7961 */
7962 int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
7963 {
7964 struct btrfs_block_group_cache *block_group;
7965 struct btrfs_space_info *space_info;
7966 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
7967 struct btrfs_device *device;
7968 struct btrfs_trans_handle *trans;
7969 u64 min_free;
7970 u64 dev_min = 1;
7971 u64 dev_nr = 0;
7972 u64 target;
7973 int index;
7974 int full = 0;
7975 int ret = 0;
7976
7977 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
7978
7979 /* odd, couldn't find the block group, leave it alone */
7980 if (!block_group)
7981 return -1;
7982
7983 min_free = btrfs_block_group_used(&block_group->item);
7984
7985 /* no bytes used, we're good */
7986 if (!min_free)
7987 goto out;
7988
7989 space_info = block_group->space_info;
7990 spin_lock(&space_info->lock);
7991
7992 full = space_info->full;
7993
7994 /*
7995 * if this is the last block group we have in this space, we can't
7996 * relocate it unless we're able to allocate a new chunk below.
7997 *
7998 * Otherwise, we need to make sure we have room in the space to handle
7999 * all of the extents from this block group. If we can, we're good
8000 */
8001 if ((space_info->total_bytes != block_group->key.offset) &&
8002 (space_info->bytes_used + space_info->bytes_reserved +
8003 space_info->bytes_pinned + space_info->bytes_readonly +
8004 min_free < space_info->total_bytes)) {
8005 spin_unlock(&space_info->lock);
8006 goto out;
8007 }
8008 spin_unlock(&space_info->lock);
8009
8010 /*
8011 * ok we don't have enough space, but maybe we have free space on our
8012 * devices to allocate new chunks for relocation, so loop through our
8013 * alloc devices and guess if we have enough space. if this block
8014 * group is going to be restriped, run checks against the target
8015 * profile instead of the current one.
8016 */
8017 ret = -1;
8018
8019 /*
8020 * index:
8021 * 0: raid10
8022 * 1: raid1
8023 * 2: dup
8024 * 3: raid0
8025 * 4: single
8026 */
8027 target = get_restripe_target(root->fs_info, block_group->flags);
8028 if (target) {
8029 index = __get_raid_index(extended_to_chunk(target));
8030 } else {
8031 /*
8032 * this is just a balance, so if we were marked as full
8033 * we know there is no space for a new chunk
8034 */
8035 if (full)
8036 goto out;
8037
8038 index = get_block_group_index(block_group);
8039 }
8040
8041 if (index == BTRFS_RAID_RAID10) {
8042 dev_min = 4;
8043 /* Divide by 2 */
8044 min_free >>= 1;
8045 } else if (index == BTRFS_RAID_RAID1) {
8046 dev_min = 2;
8047 } else if (index == BTRFS_RAID_DUP) {
8048 /* Multiply by 2 */
8049 min_free <<= 1;
8050 } else if (index == BTRFS_RAID_RAID0) {
8051 dev_min = fs_devices->rw_devices;
8052 do_div(min_free, dev_min);
8053 }
8054
8055 /* We need to do this so that we can look at pending chunks */
8056 trans = btrfs_join_transaction(root);
8057 if (IS_ERR(trans)) {
8058 ret = PTR_ERR(trans);
8059 goto out;
8060 }
8061
8062 mutex_lock(&root->fs_info->chunk_mutex);
8063 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
8064 u64 dev_offset;
8065
8066 /*
8067 * check to make sure we can actually find a chunk with enough
8068 * space to fit our block group in.
8069 */
8070 if (device->total_bytes > device->bytes_used + min_free &&
8071 !device->is_tgtdev_for_dev_replace) {
8072 ret = find_free_dev_extent(trans, device, min_free,
8073 &dev_offset, NULL);
8074 if (!ret)
8075 dev_nr++;
8076
8077 if (dev_nr >= dev_min)
8078 break;
8079
8080 ret = -1;
8081 }
8082 }
8083 mutex_unlock(&root->fs_info->chunk_mutex);
8084 btrfs_end_transaction(trans, root);
8085 out:
8086 btrfs_put_block_group(block_group);
8087 return ret;
8088 }
8089
8090 static int find_first_block_group(struct btrfs_root *root,
8091 struct btrfs_path *path, struct btrfs_key *key)
8092 {
8093 int ret = 0;
8094 struct btrfs_key found_key;
8095 struct extent_buffer *leaf;
8096 int slot;
8097
8098 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
8099 if (ret < 0)
8100 goto out;
8101
8102 while (1) {
8103 slot = path->slots[0];
8104 leaf = path->nodes[0];
8105 if (slot >= btrfs_header_nritems(leaf)) {
8106 ret = btrfs_next_leaf(root, path);
8107 if (ret == 0)
8108 continue;
8109 if (ret < 0)
8110 goto out;
8111 break;
8112 }
8113 btrfs_item_key_to_cpu(leaf, &found_key, slot);
8114
8115 if (found_key.objectid >= key->objectid &&
8116 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
8117 ret = 0;
8118 goto out;
8119 }
8120 path->slots[0]++;
8121 }
8122 out:
8123 return ret;
8124 }
8125
8126 void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
8127 {
8128 struct btrfs_block_group_cache *block_group;
8129 u64 last = 0;
8130
8131 while (1) {
8132 struct inode *inode;
8133
8134 block_group = btrfs_lookup_first_block_group(info, last);
8135 while (block_group) {
8136 spin_lock(&block_group->lock);
8137 if (block_group->iref)
8138 break;
8139 spin_unlock(&block_group->lock);
8140 block_group = next_block_group(info->tree_root,
8141 block_group);
8142 }
8143 if (!block_group) {
8144 if (last == 0)
8145 break;
8146 last = 0;
8147 continue;
8148 }
8149
8150 inode = block_group->inode;
8151 block_group->iref = 0;
8152 block_group->inode = NULL;
8153 spin_unlock(&block_group->lock);
8154 iput(inode);
8155 last = block_group->key.objectid + block_group->key.offset;
8156 btrfs_put_block_group(block_group);
8157 }
8158 }
8159
8160 int btrfs_free_block_groups(struct btrfs_fs_info *info)
8161 {
8162 struct btrfs_block_group_cache *block_group;
8163 struct btrfs_space_info *space_info;
8164 struct btrfs_caching_control *caching_ctl;
8165 struct rb_node *n;
8166
8167 down_write(&info->extent_commit_sem);
8168 while (!list_empty(&info->caching_block_groups)) {
8169 caching_ctl = list_entry(info->caching_block_groups.next,
8170 struct btrfs_caching_control, list);
8171 list_del(&caching_ctl->list);
8172 put_caching_control(caching_ctl);
8173 }
8174 up_write(&info->extent_commit_sem);
8175
8176 spin_lock(&info->block_group_cache_lock);
8177 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
8178 block_group = rb_entry(n, struct btrfs_block_group_cache,
8179 cache_node);
8180 rb_erase(&block_group->cache_node,
8181 &info->block_group_cache_tree);
8182 spin_unlock(&info->block_group_cache_lock);
8183
8184 down_write(&block_group->space_info->groups_sem);
8185 list_del(&block_group->list);
8186 up_write(&block_group->space_info->groups_sem);
8187
8188 if (block_group->cached == BTRFS_CACHE_STARTED)
8189 wait_block_group_cache_done(block_group);
8190
8191 /*
8192 * We haven't cached this block group, which means we could
8193 * possibly have excluded extents on this block group.
8194 */
8195 if (block_group->cached == BTRFS_CACHE_NO)
8196 free_excluded_extents(info->extent_root, block_group);
8197
8198 btrfs_remove_free_space_cache(block_group);
8199 btrfs_put_block_group(block_group);
8200
8201 spin_lock(&info->block_group_cache_lock);
8202 }
8203 spin_unlock(&info->block_group_cache_lock);
8204
8205 /* now that all the block groups are freed, go through and
8206 * free all the space_info structs. This is only called during
8207 * the final stages of unmount, and so we know nobody is
8208 * using them. We call synchronize_rcu() once before we start,
8209 * just to be on the safe side.
8210 */
8211 synchronize_rcu();
8212
8213 release_global_block_rsv(info);
8214
8215 while(!list_empty(&info->space_info)) {
8216 space_info = list_entry(info->space_info.next,
8217 struct btrfs_space_info,
8218 list);
8219 if (btrfs_test_opt(info->tree_root, ENOSPC_DEBUG)) {
8220 if (space_info->bytes_pinned > 0 ||
8221 space_info->bytes_reserved > 0 ||
8222 space_info->bytes_may_use > 0) {
8223 WARN_ON(1);
8224 dump_space_info(space_info, 0, 0);
8225 }
8226 }
8227 percpu_counter_destroy(&space_info->total_bytes_pinned);
8228 list_del(&space_info->list);
8229 kfree(space_info);
8230 }
8231 return 0;
8232 }
8233
8234 static void __link_block_group(struct btrfs_space_info *space_info,
8235 struct btrfs_block_group_cache *cache)
8236 {
8237 int index = get_block_group_index(cache);
8238
8239 down_write(&space_info->groups_sem);
8240 list_add_tail(&cache->list, &space_info->block_groups[index]);
8241 up_write(&space_info->groups_sem);
8242 }
8243
8244 int btrfs_read_block_groups(struct btrfs_root *root)
8245 {
8246 struct btrfs_path *path;
8247 int ret;
8248 struct btrfs_block_group_cache *cache;
8249 struct btrfs_fs_info *info = root->fs_info;
8250 struct btrfs_space_info *space_info;
8251 struct btrfs_key key;
8252 struct btrfs_key found_key;
8253 struct extent_buffer *leaf;
8254 int need_clear = 0;
8255 u64 cache_gen;
8256
8257 root = info->extent_root;
8258 key.objectid = 0;
8259 key.offset = 0;
8260 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
8261 path = btrfs_alloc_path();
8262 if (!path)
8263 return -ENOMEM;
8264 path->reada = 1;
8265
8266 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
8267 if (btrfs_test_opt(root, SPACE_CACHE) &&
8268 btrfs_super_generation(root->fs_info->super_copy) != cache_gen)
8269 need_clear = 1;
8270 if (btrfs_test_opt(root, CLEAR_CACHE))
8271 need_clear = 1;
8272
8273 while (1) {
8274 ret = find_first_block_group(root, path, &key);
8275 if (ret > 0)
8276 break;
8277 if (ret != 0)
8278 goto error;
8279 leaf = path->nodes[0];
8280 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
8281 cache = kzalloc(sizeof(*cache), GFP_NOFS);
8282 if (!cache) {
8283 ret = -ENOMEM;
8284 goto error;
8285 }
8286 cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
8287 GFP_NOFS);
8288 if (!cache->free_space_ctl) {
8289 kfree(cache);
8290 ret = -ENOMEM;
8291 goto error;
8292 }
8293
8294 atomic_set(&cache->count, 1);
8295 spin_lock_init(&cache->lock);
8296 cache->fs_info = info;
8297 INIT_LIST_HEAD(&cache->list);
8298 INIT_LIST_HEAD(&cache->cluster_list);
8299
8300 if (need_clear) {
8301 /*
8302 * When we mount with old space cache, we need to
8303 * set BTRFS_DC_CLEAR and set dirty flag.
8304 *
8305 * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
8306 * truncate the old free space cache inode and
8307 * setup a new one.
8308 * b) Setting 'dirty flag' makes sure that we flush
8309 * the new space cache info onto disk.
8310 */
8311 cache->disk_cache_state = BTRFS_DC_CLEAR;
8312 if (btrfs_test_opt(root, SPACE_CACHE))
8313 cache->dirty = 1;
8314 }
8315
8316 read_extent_buffer(leaf, &cache->item,
8317 btrfs_item_ptr_offset(leaf, path->slots[0]),
8318 sizeof(cache->item));
8319 memcpy(&cache->key, &found_key, sizeof(found_key));
8320
8321 key.objectid = found_key.objectid + found_key.offset;
8322 btrfs_release_path(path);
8323 cache->flags = btrfs_block_group_flags(&cache->item);
8324 cache->sectorsize = root->sectorsize;
8325 cache->full_stripe_len = btrfs_full_stripe_len(root,
8326 &root->fs_info->mapping_tree,
8327 found_key.objectid);
8328 btrfs_init_free_space_ctl(cache);
8329
8330 /*
8331 * We need to exclude the super stripes now so that the space
8332 * info has super bytes accounted for, otherwise we'll think
8333 * we have more space than we actually do.
8334 */
8335 ret = exclude_super_stripes(root, cache);
8336 if (ret) {
8337 /*
8338 * We may have excluded something, so call this just in
8339 * case.
8340 */
8341 free_excluded_extents(root, cache);
8342 kfree(cache->free_space_ctl);
8343 kfree(cache);
8344 goto error;
8345 }
8346
8347 /*
8348 * check for two cases, either we are full, and therefore
8349 * don't need to bother with the caching work since we won't
8350 * find any space, or we are empty, and we can just add all
8351 * the space in and be done with it. This saves us _alot_ of
8352 * time, particularly in the full case.
8353 */
8354 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
8355 cache->last_byte_to_unpin = (u64)-1;
8356 cache->cached = BTRFS_CACHE_FINISHED;
8357 free_excluded_extents(root, cache);
8358 } else if (btrfs_block_group_used(&cache->item) == 0) {
8359 cache->last_byte_to_unpin = (u64)-1;
8360 cache->cached = BTRFS_CACHE_FINISHED;
8361 add_new_free_space(cache, root->fs_info,
8362 found_key.objectid,
8363 found_key.objectid +
8364 found_key.offset);
8365 free_excluded_extents(root, cache);
8366 }
8367
8368 ret = btrfs_add_block_group_cache(root->fs_info, cache);
8369 if (ret) {
8370 btrfs_remove_free_space_cache(cache);
8371 btrfs_put_block_group(cache);
8372 goto error;
8373 }
8374
8375 ret = update_space_info(info, cache->flags, found_key.offset,
8376 btrfs_block_group_used(&cache->item),
8377 &space_info);
8378 if (ret) {
8379 btrfs_remove_free_space_cache(cache);
8380 spin_lock(&info->block_group_cache_lock);
8381 rb_erase(&cache->cache_node,
8382 &info->block_group_cache_tree);
8383 spin_unlock(&info->block_group_cache_lock);
8384 btrfs_put_block_group(cache);
8385 goto error;
8386 }
8387
8388 cache->space_info = space_info;
8389 spin_lock(&cache->space_info->lock);
8390 cache->space_info->bytes_readonly += cache->bytes_super;
8391 spin_unlock(&cache->space_info->lock);
8392
8393 __link_block_group(space_info, cache);
8394
8395 set_avail_alloc_bits(root->fs_info, cache->flags);
8396 if (btrfs_chunk_readonly(root, cache->key.objectid))
8397 set_block_group_ro(cache, 1);
8398 }
8399
8400 list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
8401 if (!(get_alloc_profile(root, space_info->flags) &
8402 (BTRFS_BLOCK_GROUP_RAID10 |
8403 BTRFS_BLOCK_GROUP_RAID1 |
8404 BTRFS_BLOCK_GROUP_RAID5 |
8405 BTRFS_BLOCK_GROUP_RAID6 |
8406 BTRFS_BLOCK_GROUP_DUP)))
8407 continue;
8408 /*
8409 * avoid allocating from un-mirrored block group if there are
8410 * mirrored block groups.
8411 */
8412 list_for_each_entry(cache, &space_info->block_groups[3], list)
8413 set_block_group_ro(cache, 1);
8414 list_for_each_entry(cache, &space_info->block_groups[4], list)
8415 set_block_group_ro(cache, 1);
8416 }
8417
8418 init_global_block_rsv(info);
8419 ret = 0;
8420 error:
8421 btrfs_free_path(path);
8422 return ret;
8423 }
8424
8425 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
8426 struct btrfs_root *root)
8427 {
8428 struct btrfs_block_group_cache *block_group, *tmp;
8429 struct btrfs_root *extent_root = root->fs_info->extent_root;
8430 struct btrfs_block_group_item item;
8431 struct btrfs_key key;
8432 int ret = 0;
8433
8434 list_for_each_entry_safe(block_group, tmp, &trans->new_bgs,
8435 new_bg_list) {
8436 list_del_init(&block_group->new_bg_list);
8437
8438 if (ret)
8439 continue;
8440
8441 spin_lock(&block_group->lock);
8442 memcpy(&item, &block_group->item, sizeof(item));
8443 memcpy(&key, &block_group->key, sizeof(key));
8444 spin_unlock(&block_group->lock);
8445
8446 ret = btrfs_insert_item(trans, extent_root, &key, &item,
8447 sizeof(item));
8448 if (ret)
8449 btrfs_abort_transaction(trans, extent_root, ret);
8450 ret = btrfs_finish_chunk_alloc(trans, extent_root,
8451 key.objectid, key.offset);
8452 if (ret)
8453 btrfs_abort_transaction(trans, extent_root, ret);
8454 }
8455 }
8456
8457 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
8458 struct btrfs_root *root, u64 bytes_used,
8459 u64 type, u64 chunk_objectid, u64 chunk_offset,
8460 u64 size)
8461 {
8462 int ret;
8463 struct btrfs_root *extent_root;
8464 struct btrfs_block_group_cache *cache;
8465
8466 extent_root = root->fs_info->extent_root;
8467
8468 root->fs_info->last_trans_log_full_commit = trans->transid;
8469
8470 cache = kzalloc(sizeof(*cache), GFP_NOFS);
8471 if (!cache)
8472 return -ENOMEM;
8473 cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
8474 GFP_NOFS);
8475 if (!cache->free_space_ctl) {
8476 kfree(cache);
8477 return -ENOMEM;
8478 }
8479
8480 cache->key.objectid = chunk_offset;
8481 cache->key.offset = size;
8482 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
8483 cache->sectorsize = root->sectorsize;
8484 cache->fs_info = root->fs_info;
8485 cache->full_stripe_len = btrfs_full_stripe_len(root,
8486 &root->fs_info->mapping_tree,
8487 chunk_offset);
8488
8489 atomic_set(&cache->count, 1);
8490 spin_lock_init(&cache->lock);
8491 INIT_LIST_HEAD(&cache->list);
8492 INIT_LIST_HEAD(&cache->cluster_list);
8493 INIT_LIST_HEAD(&cache->new_bg_list);
8494
8495 btrfs_init_free_space_ctl(cache);
8496
8497 btrfs_set_block_group_used(&cache->item, bytes_used);
8498 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
8499 cache->flags = type;
8500 btrfs_set_block_group_flags(&cache->item, type);
8501
8502 cache->last_byte_to_unpin = (u64)-1;
8503 cache->cached = BTRFS_CACHE_FINISHED;
8504 ret = exclude_super_stripes(root, cache);
8505 if (ret) {
8506 /*
8507 * We may have excluded something, so call this just in
8508 * case.
8509 */
8510 free_excluded_extents(root, cache);
8511 kfree(cache->free_space_ctl);
8512 kfree(cache);
8513 return ret;
8514 }
8515
8516 add_new_free_space(cache, root->fs_info, chunk_offset,
8517 chunk_offset + size);
8518
8519 free_excluded_extents(root, cache);
8520
8521 ret = btrfs_add_block_group_cache(root->fs_info, cache);
8522 if (ret) {
8523 btrfs_remove_free_space_cache(cache);
8524 btrfs_put_block_group(cache);
8525 return ret;
8526 }
8527
8528 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
8529 &cache->space_info);
8530 if (ret) {
8531 btrfs_remove_free_space_cache(cache);
8532 spin_lock(&root->fs_info->block_group_cache_lock);
8533 rb_erase(&cache->cache_node,
8534 &root->fs_info->block_group_cache_tree);
8535 spin_unlock(&root->fs_info->block_group_cache_lock);
8536 btrfs_put_block_group(cache);
8537 return ret;
8538 }
8539 update_global_block_rsv(root->fs_info);
8540
8541 spin_lock(&cache->space_info->lock);
8542 cache->space_info->bytes_readonly += cache->bytes_super;
8543 spin_unlock(&cache->space_info->lock);
8544
8545 __link_block_group(cache->space_info, cache);
8546
8547 list_add_tail(&cache->new_bg_list, &trans->new_bgs);
8548
8549 set_avail_alloc_bits(extent_root->fs_info, type);
8550
8551 return 0;
8552 }
8553
8554 static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
8555 {
8556 u64 extra_flags = chunk_to_extended(flags) &
8557 BTRFS_EXTENDED_PROFILE_MASK;
8558
8559 write_seqlock(&fs_info->profiles_lock);
8560 if (flags & BTRFS_BLOCK_GROUP_DATA)
8561 fs_info->avail_data_alloc_bits &= ~extra_flags;
8562 if (flags & BTRFS_BLOCK_GROUP_METADATA)
8563 fs_info->avail_metadata_alloc_bits &= ~extra_flags;
8564 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
8565 fs_info->avail_system_alloc_bits &= ~extra_flags;
8566 write_sequnlock(&fs_info->profiles_lock);
8567 }
8568
8569 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
8570 struct btrfs_root *root, u64 group_start)
8571 {
8572 struct btrfs_path *path;
8573 struct btrfs_block_group_cache *block_group;
8574 struct btrfs_free_cluster *cluster;
8575 struct btrfs_root *tree_root = root->fs_info->tree_root;
8576 struct btrfs_key key;
8577 struct inode *inode;
8578 int ret;
8579 int index;
8580 int factor;
8581
8582 root = root->fs_info->extent_root;
8583
8584 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
8585 BUG_ON(!block_group);
8586 BUG_ON(!block_group->ro);
8587
8588 /*
8589 * Free the reserved super bytes from this block group before
8590 * remove it.
8591 */
8592 free_excluded_extents(root, block_group);
8593
8594 memcpy(&key, &block_group->key, sizeof(key));
8595 index = get_block_group_index(block_group);
8596 if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
8597 BTRFS_BLOCK_GROUP_RAID1 |
8598 BTRFS_BLOCK_GROUP_RAID10))
8599 factor = 2;
8600 else
8601 factor = 1;
8602
8603 /* make sure this block group isn't part of an allocation cluster */
8604 cluster = &root->fs_info->data_alloc_cluster;
8605 spin_lock(&cluster->refill_lock);
8606 btrfs_return_cluster_to_free_space(block_group, cluster);
8607 spin_unlock(&cluster->refill_lock);
8608
8609 /*
8610 * make sure this block group isn't part of a metadata
8611 * allocation cluster
8612 */
8613 cluster = &root->fs_info->meta_alloc_cluster;
8614 spin_lock(&cluster->refill_lock);
8615 btrfs_return_cluster_to_free_space(block_group, cluster);
8616 spin_unlock(&cluster->refill_lock);
8617
8618 path = btrfs_alloc_path();
8619 if (!path) {
8620 ret = -ENOMEM;
8621 goto out;
8622 }
8623
8624 inode = lookup_free_space_inode(tree_root, block_group, path);
8625 if (!IS_ERR(inode)) {
8626 ret = btrfs_orphan_add(trans, inode);
8627 if (ret) {
8628 btrfs_add_delayed_iput(inode);
8629 goto out;
8630 }
8631 clear_nlink(inode);
8632 /* One for the block groups ref */
8633 spin_lock(&block_group->lock);
8634 if (block_group->iref) {
8635 block_group->iref = 0;
8636 block_group->inode = NULL;
8637 spin_unlock(&block_group->lock);
8638 iput(inode);
8639 } else {
8640 spin_unlock(&block_group->lock);
8641 }
8642 /* One for our lookup ref */
8643 btrfs_add_delayed_iput(inode);
8644 }
8645
8646 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
8647 key.offset = block_group->key.objectid;
8648 key.type = 0;
8649
8650 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
8651 if (ret < 0)
8652 goto out;
8653 if (ret > 0)
8654 btrfs_release_path(path);
8655 if (ret == 0) {
8656 ret = btrfs_del_item(trans, tree_root, path);
8657 if (ret)
8658 goto out;
8659 btrfs_release_path(path);
8660 }
8661
8662 spin_lock(&root->fs_info->block_group_cache_lock);
8663 rb_erase(&block_group->cache_node,
8664 &root->fs_info->block_group_cache_tree);
8665
8666 if (root->fs_info->first_logical_byte == block_group->key.objectid)
8667 root->fs_info->first_logical_byte = (u64)-1;
8668 spin_unlock(&root->fs_info->block_group_cache_lock);
8669
8670 down_write(&block_group->space_info->groups_sem);
8671 /*
8672 * we must use list_del_init so people can check to see if they
8673 * are still on the list after taking the semaphore
8674 */
8675 list_del_init(&block_group->list);
8676 if (list_empty(&block_group->space_info->block_groups[index]))
8677 clear_avail_alloc_bits(root->fs_info, block_group->flags);
8678 up_write(&block_group->space_info->groups_sem);
8679
8680 if (block_group->cached == BTRFS_CACHE_STARTED)
8681 wait_block_group_cache_done(block_group);
8682
8683 btrfs_remove_free_space_cache(block_group);
8684
8685 spin_lock(&block_group->space_info->lock);
8686 block_group->space_info->total_bytes -= block_group->key.offset;
8687 block_group->space_info->bytes_readonly -= block_group->key.offset;
8688 block_group->space_info->disk_total -= block_group->key.offset * factor;
8689 spin_unlock(&block_group->space_info->lock);
8690
8691 memcpy(&key, &block_group->key, sizeof(key));
8692
8693 btrfs_clear_space_info_full(root->fs_info);
8694
8695 btrfs_put_block_group(block_group);
8696 btrfs_put_block_group(block_group);
8697
8698 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
8699 if (ret > 0)
8700 ret = -EIO;
8701 if (ret < 0)
8702 goto out;
8703
8704 ret = btrfs_del_item(trans, root, path);
8705 out:
8706 btrfs_free_path(path);
8707 return ret;
8708 }
8709
8710 int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
8711 {
8712 struct btrfs_space_info *space_info;
8713 struct btrfs_super_block *disk_super;
8714 u64 features;
8715 u64 flags;
8716 int mixed = 0;
8717 int ret;
8718
8719 disk_super = fs_info->super_copy;
8720 if (!btrfs_super_root(disk_super))
8721 return 1;
8722
8723 features = btrfs_super_incompat_flags(disk_super);
8724 if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
8725 mixed = 1;
8726
8727 flags = BTRFS_BLOCK_GROUP_SYSTEM;
8728 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
8729 if (ret)
8730 goto out;
8731
8732 if (mixed) {
8733 flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
8734 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
8735 } else {
8736 flags = BTRFS_BLOCK_GROUP_METADATA;
8737 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
8738 if (ret)
8739 goto out;
8740
8741 flags = BTRFS_BLOCK_GROUP_DATA;
8742 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
8743 }
8744 out:
8745 return ret;
8746 }
8747
8748 int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
8749 {
8750 return unpin_extent_range(root, start, end);
8751 }
8752
8753 int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
8754 u64 num_bytes, u64 *actual_bytes)
8755 {
8756 return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
8757 }
8758
8759 int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
8760 {
8761 struct btrfs_fs_info *fs_info = root->fs_info;
8762 struct btrfs_block_group_cache *cache = NULL;
8763 u64 group_trimmed;
8764 u64 start;
8765 u64 end;
8766 u64 trimmed = 0;
8767 u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
8768 int ret = 0;
8769
8770 /*
8771 * try to trim all FS space, our block group may start from non-zero.
8772 */
8773 if (range->len == total_bytes)
8774 cache = btrfs_lookup_first_block_group(fs_info, range->start);
8775 else
8776 cache = btrfs_lookup_block_group(fs_info, range->start);
8777
8778 while (cache) {
8779 if (cache->key.objectid >= (range->start + range->len)) {
8780 btrfs_put_block_group(cache);
8781 break;
8782 }
8783
8784 start = max(range->start, cache->key.objectid);
8785 end = min(range->start + range->len,
8786 cache->key.objectid + cache->key.offset);
8787
8788 if (end - start >= range->minlen) {
8789 if (!block_group_cache_done(cache)) {
8790 ret = cache_block_group(cache, 0);
8791 if (ret) {
8792 btrfs_put_block_group(cache);
8793 break;
8794 }
8795 ret = wait_block_group_cache_done(cache);
8796 if (ret) {
8797 btrfs_put_block_group(cache);
8798 break;
8799 }
8800 }
8801 ret = btrfs_trim_block_group(cache,
8802 &group_trimmed,
8803 start,
8804 end,
8805 range->minlen);
8806
8807 trimmed += group_trimmed;
8808 if (ret) {
8809 btrfs_put_block_group(cache);
8810 break;
8811 }
8812 }
8813
8814 cache = next_block_group(fs_info->tree_root, cache);
8815 }
8816
8817 range->len = trimmed;
8818 return ret;
8819 }
Linus' kernel tree