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btrfs: cleanup, stop casting for extent_map->lookup everywhere
[linux/fpc-iii.git] / fs / btrfs / extent-tree.c
blobafbfa7c36ff6fbe3bd917d1029a7f7117be62baf
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 "hash.h"
29 #include "tree-log.h"
30 #include "disk-io.h"
31 #include "print-tree.h"
32 #include "volumes.h"
33 #include "raid56.h"
34 #include "locking.h"
35 #include "free-space-cache.h"
36 #include "math.h"
37 #include "sysfs.h"
38 #include "qgroup.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_trans_handle *trans,
78 struct btrfs_root *root, u64 bytenr,
79 u64 num_bytes, int alloc);
80 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
81 struct btrfs_root *root,
82 struct btrfs_delayed_ref_node *node, u64 parent,
83 u64 root_objectid, u64 owner_objectid,
84 u64 owner_offset, int refs_to_drop,
85 struct btrfs_delayed_extent_op *extra_op);
86 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
87 struct extent_buffer *leaf,
88 struct btrfs_extent_item *ei);
89 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
90 struct btrfs_root *root,
91 u64 parent, u64 root_objectid,
92 u64 flags, u64 owner, u64 offset,
93 struct btrfs_key *ins, int ref_mod);
94 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
95 struct btrfs_root *root,
96 u64 parent, u64 root_objectid,
97 u64 flags, struct btrfs_disk_key *key,
98 int level, struct btrfs_key *ins);
99 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
100 struct btrfs_root *extent_root, u64 flags,
101 int force);
102 static int find_next_key(struct btrfs_path *path, int level,
103 struct btrfs_key *key);
104 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
105 int dump_block_groups);
106 static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
107 u64 num_bytes, int reserve,
108 int delalloc);
109 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
110 u64 num_bytes);
111 int btrfs_pin_extent(struct btrfs_root *root,
112 u64 bytenr, u64 num_bytes, int reserved);
113
114 static noinline int
115 block_group_cache_done(struct btrfs_block_group_cache *cache)
116 {
117 smp_mb();
118 return cache->cached == BTRFS_CACHE_FINISHED ||
119 cache->cached == BTRFS_CACHE_ERROR;
120 }
121
122 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
123 {
124 return (cache->flags & bits) == bits;
125 }
126
127 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
128 {
129 atomic_inc(&cache->count);
130 }
131
132 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
133 {
134 if (atomic_dec_and_test(&cache->count)) {
135 WARN_ON(cache->pinned > 0);
136 WARN_ON(cache->reserved > 0);
137 kfree(cache->free_space_ctl);
138 kfree(cache);
139 }
140 }
141
142 /*
143 * this adds the block group to the fs_info rb tree for the block group
144 * cache
145 */
146 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
147 struct btrfs_block_group_cache *block_group)
148 {
149 struct rb_node **p;
150 struct rb_node *parent = NULL;
151 struct btrfs_block_group_cache *cache;
152
153 spin_lock(&info->block_group_cache_lock);
154 p = &info->block_group_cache_tree.rb_node;
155
156 while (*p) {
157 parent = *p;
158 cache = rb_entry(parent, struct btrfs_block_group_cache,
159 cache_node);
160 if (block_group->key.objectid < cache->key.objectid) {
161 p = &(*p)->rb_left;
162 } else if (block_group->key.objectid > cache->key.objectid) {
163 p = &(*p)->rb_right;
164 } else {
165 spin_unlock(&info->block_group_cache_lock);
166 return -EEXIST;
167 }
168 }
169
170 rb_link_node(&block_group->cache_node, parent, p);
171 rb_insert_color(&block_group->cache_node,
172 &info->block_group_cache_tree);
173
174 if (info->first_logical_byte > block_group->key.objectid)
175 info->first_logical_byte = block_group->key.objectid;
176
177 spin_unlock(&info->block_group_cache_lock);
178
179 return 0;
180 }
181
182 /*
183 * This will return the block group at or after bytenr if contains is 0, else
184 * it will return the block group that contains the bytenr
185 */
186 static struct btrfs_block_group_cache *
187 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
188 int contains)
189 {
190 struct btrfs_block_group_cache *cache, *ret = NULL;
191 struct rb_node *n;
192 u64 end, start;
193
194 spin_lock(&info->block_group_cache_lock);
195 n = info->block_group_cache_tree.rb_node;
196
197 while (n) {
198 cache = rb_entry(n, struct btrfs_block_group_cache,
199 cache_node);
200 end = cache->key.objectid + cache->key.offset - 1;
201 start = cache->key.objectid;
202
203 if (bytenr < start) {
204 if (!contains && (!ret || start < ret->key.objectid))
205 ret = cache;
206 n = n->rb_left;
207 } else if (bytenr > start) {
208 if (contains && bytenr <= end) {
209 ret = cache;
210 break;
211 }
212 n = n->rb_right;
213 } else {
214 ret = cache;
215 break;
216 }
217 }
218 if (ret) {
219 btrfs_get_block_group(ret);
220 if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
221 info->first_logical_byte = ret->key.objectid;
222 }
223 spin_unlock(&info->block_group_cache_lock);
224
225 return ret;
226 }
227
228 static int add_excluded_extent(struct btrfs_root *root,
229 u64 start, u64 num_bytes)
230 {
231 u64 end = start + num_bytes - 1;
232 set_extent_bits(&root->fs_info->freed_extents[0],
233 start, end, EXTENT_UPTODATE, GFP_NOFS);
234 set_extent_bits(&root->fs_info->freed_extents[1],
235 start, end, EXTENT_UPTODATE, GFP_NOFS);
236 return 0;
237 }
238
239 static void free_excluded_extents(struct btrfs_root *root,
240 struct btrfs_block_group_cache *cache)
241 {
242 u64 start, end;
243
244 start = cache->key.objectid;
245 end = start + cache->key.offset - 1;
246
247 clear_extent_bits(&root->fs_info->freed_extents[0],
248 start, end, EXTENT_UPTODATE, GFP_NOFS);
249 clear_extent_bits(&root->fs_info->freed_extents[1],
250 start, end, EXTENT_UPTODATE, GFP_NOFS);
251 }
252
253 static int exclude_super_stripes(struct btrfs_root *root,
254 struct btrfs_block_group_cache *cache)
255 {
256 u64 bytenr;
257 u64 *logical;
258 int stripe_len;
259 int i, nr, ret;
260
261 if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
262 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
263 cache->bytes_super += stripe_len;
264 ret = add_excluded_extent(root, cache->key.objectid,
265 stripe_len);
266 if (ret)
267 return ret;
268 }
269
270 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
271 bytenr = btrfs_sb_offset(i);
272 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
273 cache->key.objectid, bytenr,
274 0, &logical, &nr, &stripe_len);
275 if (ret)
276 return ret;
277
278 while (nr--) {
279 u64 start, len;
280
281 if (logical[nr] > cache->key.objectid +
282 cache->key.offset)
283 continue;
284
285 if (logical[nr] + stripe_len <= cache->key.objectid)
286 continue;
287
288 start = logical[nr];
289 if (start < cache->key.objectid) {
290 start = cache->key.objectid;
291 len = (logical[nr] + stripe_len) - start;
292 } else {
293 len = min_t(u64, stripe_len,
294 cache->key.objectid +
295 cache->key.offset - start);
296 }
297
298 cache->bytes_super += len;
299 ret = add_excluded_extent(root, start, len);
300 if (ret) {
301 kfree(logical);
302 return ret;
303 }
304 }
305
306 kfree(logical);
307 }
308 return 0;
309 }
310
311 static struct btrfs_caching_control *
312 get_caching_control(struct btrfs_block_group_cache *cache)
313 {
314 struct btrfs_caching_control *ctl;
315
316 spin_lock(&cache->lock);
317 if (!cache->caching_ctl) {
318 spin_unlock(&cache->lock);
319 return NULL;
320 }
321
322 ctl = cache->caching_ctl;
323 atomic_inc(&ctl->count);
324 spin_unlock(&cache->lock);
325 return ctl;
326 }
327
328 static void put_caching_control(struct btrfs_caching_control *ctl)
329 {
330 if (atomic_dec_and_test(&ctl->count))
331 kfree(ctl);
332 }
333
334 #ifdef CONFIG_BTRFS_DEBUG
335 static void fragment_free_space(struct btrfs_root *root,
336 struct btrfs_block_group_cache *block_group)
337 {
338 u64 start = block_group->key.objectid;
339 u64 len = block_group->key.offset;
340 u64 chunk = block_group->flags & BTRFS_BLOCK_GROUP_METADATA ?
341 root->nodesize : root->sectorsize;
342 u64 step = chunk << 1;
343
344 while (len > chunk) {
345 btrfs_remove_free_space(block_group, start, chunk);
346 start += step;
347 if (len < step)
348 len = 0;
349 else
350 len -= step;
351 }
352 }
353 #endif
354
355 /*
356 * this is only called by cache_block_group, since we could have freed extents
357 * we need to check the pinned_extents for any extents that can't be used yet
358 * since their free space will be released as soon as the transaction commits.
359 */
360 static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
361 struct btrfs_fs_info *info, u64 start, u64 end)
362 {
363 u64 extent_start, extent_end, size, total_added = 0;
364 int ret;
365
366 while (start < end) {
367 ret = find_first_extent_bit(info->pinned_extents, start,
368 &extent_start, &extent_end,
369 EXTENT_DIRTY | EXTENT_UPTODATE,
370 NULL);
371 if (ret)
372 break;
373
374 if (extent_start <= start) {
375 start = extent_end + 1;
376 } else if (extent_start > start && extent_start < end) {
377 size = extent_start - start;
378 total_added += size;
379 ret = btrfs_add_free_space(block_group, start,
380 size);
381 BUG_ON(ret); /* -ENOMEM or logic error */
382 start = extent_end + 1;
383 } else {
384 break;
385 }
386 }
387
388 if (start < end) {
389 size = end - start;
390 total_added += size;
391 ret = btrfs_add_free_space(block_group, start, size);
392 BUG_ON(ret); /* -ENOMEM or logic error */
393 }
394
395 return total_added;
396 }
397
398 static noinline void caching_thread(struct btrfs_work *work)
399 {
400 struct btrfs_block_group_cache *block_group;
401 struct btrfs_fs_info *fs_info;
402 struct btrfs_caching_control *caching_ctl;
403 struct btrfs_root *extent_root;
404 struct btrfs_path *path;
405 struct extent_buffer *leaf;
406 struct btrfs_key key;
407 u64 total_found = 0;
408 u64 last = 0;
409 u32 nritems;
410 int ret = -ENOMEM;
411 bool wakeup = true;
412
413 caching_ctl = container_of(work, struct btrfs_caching_control, work);
414 block_group = caching_ctl->block_group;
415 fs_info = block_group->fs_info;
416 extent_root = fs_info->extent_root;
417
418 path = btrfs_alloc_path();
419 if (!path)
420 goto out;
421
422 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
423
424 #ifdef CONFIG_BTRFS_DEBUG
425 /*
426 * If we're fragmenting we don't want to make anybody think we can
427 * allocate from this block group until we've had a chance to fragment
428 * the free space.
429 */
430 if (btrfs_should_fragment_free_space(extent_root, block_group))
431 wakeup = false;
432 #endif
433 /*
434 * We don't want to deadlock with somebody trying to allocate a new
435 * extent for the extent root while also trying to search the extent
436 * root to add free space. So we skip locking and search the commit
437 * root, since its read-only
438 */
439 path->skip_locking = 1;
440 path->search_commit_root = 1;
441 path->reada = 1;
442
443 key.objectid = last;
444 key.offset = 0;
445 key.type = BTRFS_EXTENT_ITEM_KEY;
446 again:
447 mutex_lock(&caching_ctl->mutex);
448 /* need to make sure the commit_root doesn't disappear */
449 down_read(&fs_info->commit_root_sem);
450
451 next:
452 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
453 if (ret < 0)
454 goto err;
455
456 leaf = path->nodes[0];
457 nritems = btrfs_header_nritems(leaf);
458
459 while (1) {
460 if (btrfs_fs_closing(fs_info) > 1) {
461 last = (u64)-1;
462 break;
463 }
464
465 if (path->slots[0] < nritems) {
466 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
467 } else {
468 ret = find_next_key(path, 0, &key);
469 if (ret)
470 break;
471
472 if (need_resched() ||
473 rwsem_is_contended(&fs_info->commit_root_sem)) {
474 if (wakeup)
475 caching_ctl->progress = last;
476 btrfs_release_path(path);
477 up_read(&fs_info->commit_root_sem);
478 mutex_unlock(&caching_ctl->mutex);
479 cond_resched();
480 goto again;
481 }
482
483 ret = btrfs_next_leaf(extent_root, path);
484 if (ret < 0)
485 goto err;
486 if (ret)
487 break;
488 leaf = path->nodes[0];
489 nritems = btrfs_header_nritems(leaf);
490 continue;
491 }
492
493 if (key.objectid < last) {
494 key.objectid = last;
495 key.offset = 0;
496 key.type = BTRFS_EXTENT_ITEM_KEY;
497
498 if (wakeup)
499 caching_ctl->progress = last;
500 btrfs_release_path(path);
501 goto next;
502 }
503
504 if (key.objectid < block_group->key.objectid) {
505 path->slots[0]++;
506 continue;
507 }
508
509 if (key.objectid >= block_group->key.objectid +
510 block_group->key.offset)
511 break;
512
513 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
514 key.type == BTRFS_METADATA_ITEM_KEY) {
515 total_found += add_new_free_space(block_group,
516 fs_info, last,
517 key.objectid);
518 if (key.type == BTRFS_METADATA_ITEM_KEY)
519 last = key.objectid +
520 fs_info->tree_root->nodesize;
521 else
522 last = key.objectid + key.offset;
523
524 if (total_found > (1024 * 1024 * 2)) {
525 total_found = 0;
526 if (wakeup)
527 wake_up(&caching_ctl->wait);
528 }
529 }
530 path->slots[0]++;
531 }
532 ret = 0;
533
534 total_found += add_new_free_space(block_group, fs_info, last,
535 block_group->key.objectid +
536 block_group->key.offset);
537 spin_lock(&block_group->lock);
538 block_group->caching_ctl = NULL;
539 block_group->cached = BTRFS_CACHE_FINISHED;
540 spin_unlock(&block_group->lock);
541
542 #ifdef CONFIG_BTRFS_DEBUG
543 if (btrfs_should_fragment_free_space(extent_root, block_group)) {
544 u64 bytes_used;
545
546 spin_lock(&block_group->space_info->lock);
547 spin_lock(&block_group->lock);
548 bytes_used = block_group->key.offset -
549 btrfs_block_group_used(&block_group->item);
550 block_group->space_info->bytes_used += bytes_used >> 1;
551 spin_unlock(&block_group->lock);
552 spin_unlock(&block_group->space_info->lock);
553 fragment_free_space(extent_root, block_group);
554 }
555 #endif
556
557 caching_ctl->progress = (u64)-1;
558 err:
559 btrfs_free_path(path);
560 up_read(&fs_info->commit_root_sem);
561
562 free_excluded_extents(extent_root, block_group);
563
564 mutex_unlock(&caching_ctl->mutex);
565 out:
566 if (ret) {
567 spin_lock(&block_group->lock);
568 block_group->caching_ctl = NULL;
569 block_group->cached = BTRFS_CACHE_ERROR;
570 spin_unlock(&block_group->lock);
571 }
572 wake_up(&caching_ctl->wait);
573
574 put_caching_control(caching_ctl);
575 btrfs_put_block_group(block_group);
576 }
577
578 static int cache_block_group(struct btrfs_block_group_cache *cache,
579 int load_cache_only)
580 {
581 DEFINE_WAIT(wait);
582 struct btrfs_fs_info *fs_info = cache->fs_info;
583 struct btrfs_caching_control *caching_ctl;
584 int ret = 0;
585
586 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
587 if (!caching_ctl)
588 return -ENOMEM;
589
590 INIT_LIST_HEAD(&caching_ctl->list);
591 mutex_init(&caching_ctl->mutex);
592 init_waitqueue_head(&caching_ctl->wait);
593 caching_ctl->block_group = cache;
594 caching_ctl->progress = cache->key.objectid;
595 atomic_set(&caching_ctl->count, 1);
596 btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
597 caching_thread, NULL, NULL);
598
599 spin_lock(&cache->lock);
600 /*
601 * This should be a rare occasion, but this could happen I think in the
602 * case where one thread starts to load the space cache info, and then
603 * some other thread starts a transaction commit which tries to do an
604 * allocation while the other thread is still loading the space cache
605 * info. The previous loop should have kept us from choosing this block
606 * group, but if we've moved to the state where we will wait on caching
607 * block groups we need to first check if we're doing a fast load here,
608 * so we can wait for it to finish, otherwise we could end up allocating
609 * from a block group who's cache gets evicted for one reason or
610 * another.
611 */
612 while (cache->cached == BTRFS_CACHE_FAST) {
613 struct btrfs_caching_control *ctl;
614
615 ctl = cache->caching_ctl;
616 atomic_inc(&ctl->count);
617 prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
618 spin_unlock(&cache->lock);
619
620 schedule();
621
622 finish_wait(&ctl->wait, &wait);
623 put_caching_control(ctl);
624 spin_lock(&cache->lock);
625 }
626
627 if (cache->cached != BTRFS_CACHE_NO) {
628 spin_unlock(&cache->lock);
629 kfree(caching_ctl);
630 return 0;
631 }
632 WARN_ON(cache->caching_ctl);
633 cache->caching_ctl = caching_ctl;
634 cache->cached = BTRFS_CACHE_FAST;
635 spin_unlock(&cache->lock);
636
637 if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) {
638 mutex_lock(&caching_ctl->mutex);
639 ret = load_free_space_cache(fs_info, cache);
640
641 spin_lock(&cache->lock);
642 if (ret == 1) {
643 cache->caching_ctl = NULL;
644 cache->cached = BTRFS_CACHE_FINISHED;
645 cache->last_byte_to_unpin = (u64)-1;
646 caching_ctl->progress = (u64)-1;
647 } else {
648 if (load_cache_only) {
649 cache->caching_ctl = NULL;
650 cache->cached = BTRFS_CACHE_NO;
651 } else {
652 cache->cached = BTRFS_CACHE_STARTED;
653 cache->has_caching_ctl = 1;
654 }
655 }
656 spin_unlock(&cache->lock);
657 #ifdef CONFIG_BTRFS_DEBUG
658 if (ret == 1 &&
659 btrfs_should_fragment_free_space(fs_info->extent_root,
660 cache)) {
661 u64 bytes_used;
662
663 spin_lock(&cache->space_info->lock);
664 spin_lock(&cache->lock);
665 bytes_used = cache->key.offset -
666 btrfs_block_group_used(&cache->item);
667 cache->space_info->bytes_used += bytes_used >> 1;
668 spin_unlock(&cache->lock);
669 spin_unlock(&cache->space_info->lock);
670 fragment_free_space(fs_info->extent_root, cache);
671 }
672 #endif
673 mutex_unlock(&caching_ctl->mutex);
674
675 wake_up(&caching_ctl->wait);
676 if (ret == 1) {
677 put_caching_control(caching_ctl);
678 free_excluded_extents(fs_info->extent_root, cache);
679 return 0;
680 }
681 } else {
682 /*
683 * We are not going to do the fast caching, set cached to the
684 * appropriate value and wakeup any waiters.
685 */
686 spin_lock(&cache->lock);
687 if (load_cache_only) {
688 cache->caching_ctl = NULL;
689 cache->cached = BTRFS_CACHE_NO;
690 } else {
691 cache->cached = BTRFS_CACHE_STARTED;
692 cache->has_caching_ctl = 1;
693 }
694 spin_unlock(&cache->lock);
695 wake_up(&caching_ctl->wait);
696 }
697
698 if (load_cache_only) {
699 put_caching_control(caching_ctl);
700 return 0;
701 }
702
703 down_write(&fs_info->commit_root_sem);
704 atomic_inc(&caching_ctl->count);
705 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
706 up_write(&fs_info->commit_root_sem);
707
708 btrfs_get_block_group(cache);
709
710 btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
711
712 return ret;
713 }
714
715 /*
716 * return the block group that starts at or after bytenr
717 */
718 static struct btrfs_block_group_cache *
719 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
720 {
721 struct btrfs_block_group_cache *cache;
722
723 cache = block_group_cache_tree_search(info, bytenr, 0);
724
725 return cache;
726 }
727
728 /*
729 * return the block group that contains the given bytenr
730 */
731 struct btrfs_block_group_cache *btrfs_lookup_block_group(
732 struct btrfs_fs_info *info,
733 u64 bytenr)
734 {
735 struct btrfs_block_group_cache *cache;
736
737 cache = block_group_cache_tree_search(info, bytenr, 1);
738
739 return cache;
740 }
741
742 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
743 u64 flags)
744 {
745 struct list_head *head = &info->space_info;
746 struct btrfs_space_info *found;
747
748 flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
749
750 rcu_read_lock();
751 list_for_each_entry_rcu(found, head, list) {
752 if (found->flags & flags) {
753 rcu_read_unlock();
754 return found;
755 }
756 }
757 rcu_read_unlock();
758 return NULL;
759 }
760
761 /*
762 * after adding space to the filesystem, we need to clear the full flags
763 * on all the space infos.
764 */
765 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
766 {
767 struct list_head *head = &info->space_info;
768 struct btrfs_space_info *found;
769
770 rcu_read_lock();
771 list_for_each_entry_rcu(found, head, list)
772 found->full = 0;
773 rcu_read_unlock();
774 }
775
776 /* simple helper to search for an existing data extent at a given offset */
777 int btrfs_lookup_data_extent(struct btrfs_root *root, u64 start, u64 len)
778 {
779 int ret;
780 struct btrfs_key key;
781 struct btrfs_path *path;
782
783 path = btrfs_alloc_path();
784 if (!path)
785 return -ENOMEM;
786
787 key.objectid = start;
788 key.offset = len;
789 key.type = BTRFS_EXTENT_ITEM_KEY;
790 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
791 0, 0);
792 btrfs_free_path(path);
793 return ret;
794 }
795
796 /*
797 * helper function to lookup reference count and flags of a tree block.
798 *
799 * the head node for delayed ref is used to store the sum of all the
800 * reference count modifications queued up in the rbtree. the head
801 * node may also store the extent flags to set. This way you can check
802 * to see what the reference count and extent flags would be if all of
803 * the delayed refs are not processed.
804 */
805 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
806 struct btrfs_root *root, u64 bytenr,
807 u64 offset, int metadata, u64 *refs, u64 *flags)
808 {
809 struct btrfs_delayed_ref_head *head;
810 struct btrfs_delayed_ref_root *delayed_refs;
811 struct btrfs_path *path;
812 struct btrfs_extent_item *ei;
813 struct extent_buffer *leaf;
814 struct btrfs_key key;
815 u32 item_size;
816 u64 num_refs;
817 u64 extent_flags;
818 int ret;
819
820 /*
821 * If we don't have skinny metadata, don't bother doing anything
822 * different
823 */
824 if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) {
825 offset = root->nodesize;
826 metadata = 0;
827 }
828
829 path = btrfs_alloc_path();
830 if (!path)
831 return -ENOMEM;
832
833 if (!trans) {
834 path->skip_locking = 1;
835 path->search_commit_root = 1;
836 }
837
838 search_again:
839 key.objectid = bytenr;
840 key.offset = offset;
841 if (metadata)
842 key.type = BTRFS_METADATA_ITEM_KEY;
843 else
844 key.type = BTRFS_EXTENT_ITEM_KEY;
845
846 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
847 &key, path, 0, 0);
848 if (ret < 0)
849 goto out_free;
850
851 if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
852 if (path->slots[0]) {
853 path->slots[0]--;
854 btrfs_item_key_to_cpu(path->nodes[0], &key,
855 path->slots[0]);
856 if (key.objectid == bytenr &&
857 key.type == BTRFS_EXTENT_ITEM_KEY &&
858 key.offset == root->nodesize)
859 ret = 0;
860 }
861 }
862
863 if (ret == 0) {
864 leaf = path->nodes[0];
865 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
866 if (item_size >= sizeof(*ei)) {
867 ei = btrfs_item_ptr(leaf, path->slots[0],
868 struct btrfs_extent_item);
869 num_refs = btrfs_extent_refs(leaf, ei);
870 extent_flags = btrfs_extent_flags(leaf, ei);
871 } else {
872 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
873 struct btrfs_extent_item_v0 *ei0;
874 BUG_ON(item_size != sizeof(*ei0));
875 ei0 = btrfs_item_ptr(leaf, path->slots[0],
876 struct btrfs_extent_item_v0);
877 num_refs = btrfs_extent_refs_v0(leaf, ei0);
878 /* FIXME: this isn't correct for data */
879 extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
880 #else
881 BUG();
882 #endif
883 }
884 BUG_ON(num_refs == 0);
885 } else {
886 num_refs = 0;
887 extent_flags = 0;
888 ret = 0;
889 }
890
891 if (!trans)
892 goto out;
893
894 delayed_refs = &trans->transaction->delayed_refs;
895 spin_lock(&delayed_refs->lock);
896 head = btrfs_find_delayed_ref_head(trans, bytenr);
897 if (head) {
898 if (!mutex_trylock(&head->mutex)) {
899 atomic_inc(&head->node.refs);
900 spin_unlock(&delayed_refs->lock);
901
902 btrfs_release_path(path);
903
904 /*
905 * Mutex was contended, block until it's released and try
906 * again
907 */
908 mutex_lock(&head->mutex);
909 mutex_unlock(&head->mutex);
910 btrfs_put_delayed_ref(&head->node);
911 goto search_again;
912 }
913 spin_lock(&head->lock);
914 if (head->extent_op && head->extent_op->update_flags)
915 extent_flags |= head->extent_op->flags_to_set;
916 else
917 BUG_ON(num_refs == 0);
918
919 num_refs += head->node.ref_mod;
920 spin_unlock(&head->lock);
921 mutex_unlock(&head->mutex);
922 }
923 spin_unlock(&delayed_refs->lock);
924 out:
925 WARN_ON(num_refs == 0);
926 if (refs)
927 *refs = num_refs;
928 if (flags)
929 *flags = extent_flags;
930 out_free:
931 btrfs_free_path(path);
932 return ret;
933 }
934
935 /*
936 * Back reference rules. Back refs have three main goals:
937 *
938 * 1) differentiate between all holders of references to an extent so that
939 * when a reference is dropped we can make sure it was a valid reference
940 * before freeing the extent.
941 *
942 * 2) Provide enough information to quickly find the holders of an extent
943 * if we notice a given block is corrupted or bad.
944 *
945 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
946 * maintenance. This is actually the same as #2, but with a slightly
947 * different use case.
948 *
949 * There are two kinds of back refs. The implicit back refs is optimized
950 * for pointers in non-shared tree blocks. For a given pointer in a block,
951 * back refs of this kind provide information about the block's owner tree
952 * and the pointer's key. These information allow us to find the block by
953 * b-tree searching. The full back refs is for pointers in tree blocks not
954 * referenced by their owner trees. The location of tree block is recorded
955 * in the back refs. Actually the full back refs is generic, and can be
956 * used in all cases the implicit back refs is used. The major shortcoming
957 * of the full back refs is its overhead. Every time a tree block gets
958 * COWed, we have to update back refs entry for all pointers in it.
959 *
960 * For a newly allocated tree block, we use implicit back refs for
961 * pointers in it. This means most tree related operations only involve
962 * implicit back refs. For a tree block created in old transaction, the
963 * only way to drop a reference to it is COW it. So we can detect the
964 * event that tree block loses its owner tree's reference and do the
965 * back refs conversion.
966 *
967 * When a tree block is COW'd through a tree, there are four cases:
968 *
969 * The reference count of the block is one and the tree is the block's
970 * owner tree. Nothing to do in this case.
971 *
972 * The reference count of the block is one and the tree is not the
973 * block's owner tree. In this case, full back refs is used for pointers
974 * in the block. Remove these full back refs, add implicit back refs for
975 * every pointers in the new block.
976 *
977 * The reference count of the block is greater than one and the tree is
978 * the block's owner tree. In this case, implicit back refs is used for
979 * pointers in the block. Add full back refs for every pointers in the
980 * block, increase lower level extents' reference counts. The original
981 * implicit back refs are entailed to the new block.
982 *
983 * The reference count of the block is greater than one and the tree is
984 * not the block's owner tree. Add implicit back refs for every pointer in
985 * the new block, increase lower level extents' reference count.
986 *
987 * Back Reference Key composing:
988 *
989 * The key objectid corresponds to the first byte in the extent,
990 * The key type is used to differentiate between types of back refs.
991 * There are different meanings of the key offset for different types
992 * of back refs.
993 *
994 * File extents can be referenced by:
995 *
996 * - multiple snapshots, subvolumes, or different generations in one subvol
997 * - different files inside a single subvolume
998 * - different offsets inside a file (bookend extents in file.c)
999 *
1000 * The extent ref structure for the implicit back refs has fields for:
1001 *
1002 * - Objectid of the subvolume root
1003 * - objectid of the file holding the reference
1004 * - original offset in the file
1005 * - how many bookend extents
1006 *
1007 * The key offset for the implicit back refs is hash of the first
1008 * three fields.
1009 *
1010 * The extent ref structure for the full back refs has field for:
1011 *
1012 * - number of pointers in the tree leaf
1013 *
1014 * The key offset for the implicit back refs is the first byte of
1015 * the tree leaf
1016 *
1017 * When a file extent is allocated, The implicit back refs is used.
1018 * the fields are filled in:
1019 *
1020 * (root_key.objectid, inode objectid, offset in file, 1)
1021 *
1022 * When a file extent is removed file truncation, we find the
1023 * corresponding implicit back refs and check the following fields:
1024 *
1025 * (btrfs_header_owner(leaf), inode objectid, offset in file)
1026 *
1027 * Btree extents can be referenced by:
1028 *
1029 * - Different subvolumes
1030 *
1031 * Both the implicit back refs and the full back refs for tree blocks
1032 * only consist of key. The key offset for the implicit back refs is
1033 * objectid of block's owner tree. The key offset for the full back refs
1034 * is the first byte of parent block.
1035 *
1036 * When implicit back refs is used, information about the lowest key and
1037 * level of the tree block are required. These information are stored in
1038 * tree block info structure.
1039 */
1040
1041 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1042 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
1043 struct btrfs_root *root,
1044 struct btrfs_path *path,
1045 u64 owner, u32 extra_size)
1046 {
1047 struct btrfs_extent_item *item;
1048 struct btrfs_extent_item_v0 *ei0;
1049 struct btrfs_extent_ref_v0 *ref0;
1050 struct btrfs_tree_block_info *bi;
1051 struct extent_buffer *leaf;
1052 struct btrfs_key key;
1053 struct btrfs_key found_key;
1054 u32 new_size = sizeof(*item);
1055 u64 refs;
1056 int ret;
1057
1058 leaf = path->nodes[0];
1059 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
1060
1061 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1062 ei0 = btrfs_item_ptr(leaf, path->slots[0],
1063 struct btrfs_extent_item_v0);
1064 refs = btrfs_extent_refs_v0(leaf, ei0);
1065
1066 if (owner == (u64)-1) {
1067 while (1) {
1068 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1069 ret = btrfs_next_leaf(root, path);
1070 if (ret < 0)
1071 return ret;
1072 BUG_ON(ret > 0); /* Corruption */
1073 leaf = path->nodes[0];
1074 }
1075 btrfs_item_key_to_cpu(leaf, &found_key,
1076 path->slots[0]);
1077 BUG_ON(key.objectid != found_key.objectid);
1078 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
1079 path->slots[0]++;
1080 continue;
1081 }
1082 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1083 struct btrfs_extent_ref_v0);
1084 owner = btrfs_ref_objectid_v0(leaf, ref0);
1085 break;
1086 }
1087 }
1088 btrfs_release_path(path);
1089
1090 if (owner < BTRFS_FIRST_FREE_OBJECTID)
1091 new_size += sizeof(*bi);
1092
1093 new_size -= sizeof(*ei0);
1094 ret = btrfs_search_slot(trans, root, &key, path,
1095 new_size + extra_size, 1);
1096 if (ret < 0)
1097 return ret;
1098 BUG_ON(ret); /* Corruption */
1099
1100 btrfs_extend_item(root, path, new_size);
1101
1102 leaf = path->nodes[0];
1103 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1104 btrfs_set_extent_refs(leaf, item, refs);
1105 /* FIXME: get real generation */
1106 btrfs_set_extent_generation(leaf, item, 0);
1107 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1108 btrfs_set_extent_flags(leaf, item,
1109 BTRFS_EXTENT_FLAG_TREE_BLOCK |
1110 BTRFS_BLOCK_FLAG_FULL_BACKREF);
1111 bi = (struct btrfs_tree_block_info *)(item + 1);
1112 /* FIXME: get first key of the block */
1113 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
1114 btrfs_set_tree_block_level(leaf, bi, (int)owner);
1115 } else {
1116 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
1117 }
1118 btrfs_mark_buffer_dirty(leaf);
1119 return 0;
1120 }
1121 #endif
1122
1123 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
1124 {
1125 u32 high_crc = ~(u32)0;
1126 u32 low_crc = ~(u32)0;
1127 __le64 lenum;
1128
1129 lenum = cpu_to_le64(root_objectid);
1130 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
1131 lenum = cpu_to_le64(owner);
1132 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
1133 lenum = cpu_to_le64(offset);
1134 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
1135
1136 return ((u64)high_crc << 31) ^ (u64)low_crc;
1137 }
1138
1139 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
1140 struct btrfs_extent_data_ref *ref)
1141 {
1142 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
1143 btrfs_extent_data_ref_objectid(leaf, ref),
1144 btrfs_extent_data_ref_offset(leaf, ref));
1145 }
1146
1147 static int match_extent_data_ref(struct extent_buffer *leaf,
1148 struct btrfs_extent_data_ref *ref,
1149 u64 root_objectid, u64 owner, u64 offset)
1150 {
1151 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
1152 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
1153 btrfs_extent_data_ref_offset(leaf, ref) != offset)
1154 return 0;
1155 return 1;
1156 }
1157
1158 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
1159 struct btrfs_root *root,
1160 struct btrfs_path *path,
1161 u64 bytenr, u64 parent,
1162 u64 root_objectid,
1163 u64 owner, u64 offset)
1164 {
1165 struct btrfs_key key;
1166 struct btrfs_extent_data_ref *ref;
1167 struct extent_buffer *leaf;
1168 u32 nritems;
1169 int ret;
1170 int recow;
1171 int err = -ENOENT;
1172
1173 key.objectid = bytenr;
1174 if (parent) {
1175 key.type = BTRFS_SHARED_DATA_REF_KEY;
1176 key.offset = parent;
1177 } else {
1178 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1179 key.offset = hash_extent_data_ref(root_objectid,
1180 owner, offset);
1181 }
1182 again:
1183 recow = 0;
1184 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1185 if (ret < 0) {
1186 err = ret;
1187 goto fail;
1188 }
1189
1190 if (parent) {
1191 if (!ret)
1192 return 0;
1193 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1194 key.type = BTRFS_EXTENT_REF_V0_KEY;
1195 btrfs_release_path(path);
1196 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1197 if (ret < 0) {
1198 err = ret;
1199 goto fail;
1200 }
1201 if (!ret)
1202 return 0;
1203 #endif
1204 goto fail;
1205 }
1206
1207 leaf = path->nodes[0];
1208 nritems = btrfs_header_nritems(leaf);
1209 while (1) {
1210 if (path->slots[0] >= nritems) {
1211 ret = btrfs_next_leaf(root, path);
1212 if (ret < 0)
1213 err = ret;
1214 if (ret)
1215 goto fail;
1216
1217 leaf = path->nodes[0];
1218 nritems = btrfs_header_nritems(leaf);
1219 recow = 1;
1220 }
1221
1222 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1223 if (key.objectid != bytenr ||
1224 key.type != BTRFS_EXTENT_DATA_REF_KEY)
1225 goto fail;
1226
1227 ref = btrfs_item_ptr(leaf, path->slots[0],
1228 struct btrfs_extent_data_ref);
1229
1230 if (match_extent_data_ref(leaf, ref, root_objectid,
1231 owner, offset)) {
1232 if (recow) {
1233 btrfs_release_path(path);
1234 goto again;
1235 }
1236 err = 0;
1237 break;
1238 }
1239 path->slots[0]++;
1240 }
1241 fail:
1242 return err;
1243 }
1244
1245 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
1246 struct btrfs_root *root,
1247 struct btrfs_path *path,
1248 u64 bytenr, u64 parent,
1249 u64 root_objectid, u64 owner,
1250 u64 offset, int refs_to_add)
1251 {
1252 struct btrfs_key key;
1253 struct extent_buffer *leaf;
1254 u32 size;
1255 u32 num_refs;
1256 int ret;
1257
1258 key.objectid = bytenr;
1259 if (parent) {
1260 key.type = BTRFS_SHARED_DATA_REF_KEY;
1261 key.offset = parent;
1262 size = sizeof(struct btrfs_shared_data_ref);
1263 } else {
1264 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1265 key.offset = hash_extent_data_ref(root_objectid,
1266 owner, offset);
1267 size = sizeof(struct btrfs_extent_data_ref);
1268 }
1269
1270 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
1271 if (ret && ret != -EEXIST)
1272 goto fail;
1273
1274 leaf = path->nodes[0];
1275 if (parent) {
1276 struct btrfs_shared_data_ref *ref;
1277 ref = btrfs_item_ptr(leaf, path->slots[0],
1278 struct btrfs_shared_data_ref);
1279 if (ret == 0) {
1280 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
1281 } else {
1282 num_refs = btrfs_shared_data_ref_count(leaf, ref);
1283 num_refs += refs_to_add;
1284 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
1285 }
1286 } else {
1287 struct btrfs_extent_data_ref *ref;
1288 while (ret == -EEXIST) {
1289 ref = btrfs_item_ptr(leaf, path->slots[0],
1290 struct btrfs_extent_data_ref);
1291 if (match_extent_data_ref(leaf, ref, root_objectid,
1292 owner, offset))
1293 break;
1294 btrfs_release_path(path);
1295 key.offset++;
1296 ret = btrfs_insert_empty_item(trans, root, path, &key,
1297 size);
1298 if (ret && ret != -EEXIST)
1299 goto fail;
1300
1301 leaf = path->nodes[0];
1302 }
1303 ref = btrfs_item_ptr(leaf, path->slots[0],
1304 struct btrfs_extent_data_ref);
1305 if (ret == 0) {
1306 btrfs_set_extent_data_ref_root(leaf, ref,
1307 root_objectid);
1308 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
1309 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
1310 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
1311 } else {
1312 num_refs = btrfs_extent_data_ref_count(leaf, ref);
1313 num_refs += refs_to_add;
1314 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
1315 }
1316 }
1317 btrfs_mark_buffer_dirty(leaf);
1318 ret = 0;
1319 fail:
1320 btrfs_release_path(path);
1321 return ret;
1322 }
1323
1324 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
1325 struct btrfs_root *root,
1326 struct btrfs_path *path,
1327 int refs_to_drop, int *last_ref)
1328 {
1329 struct btrfs_key key;
1330 struct btrfs_extent_data_ref *ref1 = NULL;
1331 struct btrfs_shared_data_ref *ref2 = NULL;
1332 struct extent_buffer *leaf;
1333 u32 num_refs = 0;
1334 int ret = 0;
1335
1336 leaf = path->nodes[0];
1337 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1338
1339 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1340 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1341 struct btrfs_extent_data_ref);
1342 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1343 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1344 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1345 struct btrfs_shared_data_ref);
1346 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1347 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1348 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1349 struct btrfs_extent_ref_v0 *ref0;
1350 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1351 struct btrfs_extent_ref_v0);
1352 num_refs = btrfs_ref_count_v0(leaf, ref0);
1353 #endif
1354 } else {
1355 BUG();
1356 }
1357
1358 BUG_ON(num_refs < refs_to_drop);
1359 num_refs -= refs_to_drop;
1360
1361 if (num_refs == 0) {
1362 ret = btrfs_del_item(trans, root, path);
1363 *last_ref = 1;
1364 } else {
1365 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
1366 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
1367 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
1368 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
1369 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1370 else {
1371 struct btrfs_extent_ref_v0 *ref0;
1372 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1373 struct btrfs_extent_ref_v0);
1374 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
1375 }
1376 #endif
1377 btrfs_mark_buffer_dirty(leaf);
1378 }
1379 return ret;
1380 }
1381
1382 static noinline u32 extent_data_ref_count(struct btrfs_path *path,
1383 struct btrfs_extent_inline_ref *iref)
1384 {
1385 struct btrfs_key key;
1386 struct extent_buffer *leaf;
1387 struct btrfs_extent_data_ref *ref1;
1388 struct btrfs_shared_data_ref *ref2;
1389 u32 num_refs = 0;
1390
1391 leaf = path->nodes[0];
1392 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1393 if (iref) {
1394 if (btrfs_extent_inline_ref_type(leaf, iref) ==
1395 BTRFS_EXTENT_DATA_REF_KEY) {
1396 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
1397 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1398 } else {
1399 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
1400 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1401 }
1402 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1403 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1404 struct btrfs_extent_data_ref);
1405 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1406 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1407 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1408 struct btrfs_shared_data_ref);
1409 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1410 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1411 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1412 struct btrfs_extent_ref_v0 *ref0;
1413 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1414 struct btrfs_extent_ref_v0);
1415 num_refs = btrfs_ref_count_v0(leaf, ref0);
1416 #endif
1417 } else {
1418 WARN_ON(1);
1419 }
1420 return num_refs;
1421 }
1422
1423 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
1424 struct btrfs_root *root,
1425 struct btrfs_path *path,
1426 u64 bytenr, u64 parent,
1427 u64 root_objectid)
1428 {
1429 struct btrfs_key key;
1430 int ret;
1431
1432 key.objectid = bytenr;
1433 if (parent) {
1434 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1435 key.offset = parent;
1436 } else {
1437 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1438 key.offset = root_objectid;
1439 }
1440
1441 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1442 if (ret > 0)
1443 ret = -ENOENT;
1444 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1445 if (ret == -ENOENT && parent) {
1446 btrfs_release_path(path);
1447 key.type = BTRFS_EXTENT_REF_V0_KEY;
1448 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1449 if (ret > 0)
1450 ret = -ENOENT;
1451 }
1452 #endif
1453 return ret;
1454 }
1455
1456 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
1457 struct btrfs_root *root,
1458 struct btrfs_path *path,
1459 u64 bytenr, u64 parent,
1460 u64 root_objectid)
1461 {
1462 struct btrfs_key key;
1463 int ret;
1464
1465 key.objectid = bytenr;
1466 if (parent) {
1467 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1468 key.offset = parent;
1469 } else {
1470 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1471 key.offset = root_objectid;
1472 }
1473
1474 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1475 btrfs_release_path(path);
1476 return ret;
1477 }
1478
1479 static inline int extent_ref_type(u64 parent, u64 owner)
1480 {
1481 int type;
1482 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1483 if (parent > 0)
1484 type = BTRFS_SHARED_BLOCK_REF_KEY;
1485 else
1486 type = BTRFS_TREE_BLOCK_REF_KEY;
1487 } else {
1488 if (parent > 0)
1489 type = BTRFS_SHARED_DATA_REF_KEY;
1490 else
1491 type = BTRFS_EXTENT_DATA_REF_KEY;
1492 }
1493 return type;
1494 }
1495
1496 static int find_next_key(struct btrfs_path *path, int level,
1497 struct btrfs_key *key)
1498
1499 {
1500 for (; level < BTRFS_MAX_LEVEL; level++) {
1501 if (!path->nodes[level])
1502 break;
1503 if (path->slots[level] + 1 >=
1504 btrfs_header_nritems(path->nodes[level]))
1505 continue;
1506 if (level == 0)
1507 btrfs_item_key_to_cpu(path->nodes[level], key,
1508 path->slots[level] + 1);
1509 else
1510 btrfs_node_key_to_cpu(path->nodes[level], key,
1511 path->slots[level] + 1);
1512 return 0;
1513 }
1514 return 1;
1515 }
1516
1517 /*
1518 * look for inline back ref. if back ref is found, *ref_ret is set
1519 * to the address of inline back ref, and 0 is returned.
1520 *
1521 * if back ref isn't found, *ref_ret is set to the address where it
1522 * should be inserted, and -ENOENT is returned.
1523 *
1524 * if insert is true and there are too many inline back refs, the path
1525 * points to the extent item, and -EAGAIN is returned.
1526 *
1527 * NOTE: inline back refs are ordered in the same way that back ref
1528 * items in the tree are ordered.
1529 */
1530 static noinline_for_stack
1531 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1532 struct btrfs_root *root,
1533 struct btrfs_path *path,
1534 struct btrfs_extent_inline_ref **ref_ret,
1535 u64 bytenr, u64 num_bytes,
1536 u64 parent, u64 root_objectid,
1537 u64 owner, u64 offset, int insert)
1538 {
1539 struct btrfs_key key;
1540 struct extent_buffer *leaf;
1541 struct btrfs_extent_item *ei;
1542 struct btrfs_extent_inline_ref *iref;
1543 u64 flags;
1544 u64 item_size;
1545 unsigned long ptr;
1546 unsigned long end;
1547 int extra_size;
1548 int type;
1549 int want;
1550 int ret;
1551 int err = 0;
1552 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
1553 SKINNY_METADATA);
1554
1555 key.objectid = bytenr;
1556 key.type = BTRFS_EXTENT_ITEM_KEY;
1557 key.offset = num_bytes;
1558
1559 want = extent_ref_type(parent, owner);
1560 if (insert) {
1561 extra_size = btrfs_extent_inline_ref_size(want);
1562 path->keep_locks = 1;
1563 } else
1564 extra_size = -1;
1565
1566 /*
1567 * Owner is our parent level, so we can just add one to get the level
1568 * for the block we are interested in.
1569 */
1570 if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) {
1571 key.type = BTRFS_METADATA_ITEM_KEY;
1572 key.offset = owner;
1573 }
1574
1575 again:
1576 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1577 if (ret < 0) {
1578 err = ret;
1579 goto out;
1580 }
1581
1582 /*
1583 * We may be a newly converted file system which still has the old fat
1584 * extent entries for metadata, so try and see if we have one of those.
1585 */
1586 if (ret > 0 && skinny_metadata) {
1587 skinny_metadata = false;
1588 if (path->slots[0]) {
1589 path->slots[0]--;
1590 btrfs_item_key_to_cpu(path->nodes[0], &key,
1591 path->slots[0]);
1592 if (key.objectid == bytenr &&
1593 key.type == BTRFS_EXTENT_ITEM_KEY &&
1594 key.offset == num_bytes)
1595 ret = 0;
1596 }
1597 if (ret) {
1598 key.objectid = bytenr;
1599 key.type = BTRFS_EXTENT_ITEM_KEY;
1600 key.offset = num_bytes;
1601 btrfs_release_path(path);
1602 goto again;
1603 }
1604 }
1605
1606 if (ret && !insert) {
1607 err = -ENOENT;
1608 goto out;
1609 } else if (WARN_ON(ret)) {
1610 err = -EIO;
1611 goto out;
1612 }
1613
1614 leaf = path->nodes[0];
1615 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1616 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1617 if (item_size < sizeof(*ei)) {
1618 if (!insert) {
1619 err = -ENOENT;
1620 goto out;
1621 }
1622 ret = convert_extent_item_v0(trans, root, path, owner,
1623 extra_size);
1624 if (ret < 0) {
1625 err = ret;
1626 goto out;
1627 }
1628 leaf = path->nodes[0];
1629 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1630 }
1631 #endif
1632 BUG_ON(item_size < sizeof(*ei));
1633
1634 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1635 flags = btrfs_extent_flags(leaf, ei);
1636
1637 ptr = (unsigned long)(ei + 1);
1638 end = (unsigned long)ei + item_size;
1639
1640 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
1641 ptr += sizeof(struct btrfs_tree_block_info);
1642 BUG_ON(ptr > end);
1643 }
1644
1645 err = -ENOENT;
1646 while (1) {
1647 if (ptr >= end) {
1648 WARN_ON(ptr > end);
1649 break;
1650 }
1651 iref = (struct btrfs_extent_inline_ref *)ptr;
1652 type = btrfs_extent_inline_ref_type(leaf, iref);
1653 if (want < type)
1654 break;
1655 if (want > type) {
1656 ptr += btrfs_extent_inline_ref_size(type);
1657 continue;
1658 }
1659
1660 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1661 struct btrfs_extent_data_ref *dref;
1662 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1663 if (match_extent_data_ref(leaf, dref, root_objectid,
1664 owner, offset)) {
1665 err = 0;
1666 break;
1667 }
1668 if (hash_extent_data_ref_item(leaf, dref) <
1669 hash_extent_data_ref(root_objectid, owner, offset))
1670 break;
1671 } else {
1672 u64 ref_offset;
1673 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1674 if (parent > 0) {
1675 if (parent == ref_offset) {
1676 err = 0;
1677 break;
1678 }
1679 if (ref_offset < parent)
1680 break;
1681 } else {
1682 if (root_objectid == ref_offset) {
1683 err = 0;
1684 break;
1685 }
1686 if (ref_offset < root_objectid)
1687 break;
1688 }
1689 }
1690 ptr += btrfs_extent_inline_ref_size(type);
1691 }
1692 if (err == -ENOENT && insert) {
1693 if (item_size + extra_size >=
1694 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1695 err = -EAGAIN;
1696 goto out;
1697 }
1698 /*
1699 * To add new inline back ref, we have to make sure
1700 * there is no corresponding back ref item.
1701 * For simplicity, we just do not add new inline back
1702 * ref if there is any kind of item for this block
1703 */
1704 if (find_next_key(path, 0, &key) == 0 &&
1705 key.objectid == bytenr &&
1706 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1707 err = -EAGAIN;
1708 goto out;
1709 }
1710 }
1711 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1712 out:
1713 if (insert) {
1714 path->keep_locks = 0;
1715 btrfs_unlock_up_safe(path, 1);
1716 }
1717 return err;
1718 }
1719
1720 /*
1721 * helper to add new inline back ref
1722 */
1723 static noinline_for_stack
1724 void setup_inline_extent_backref(struct btrfs_root *root,
1725 struct btrfs_path *path,
1726 struct btrfs_extent_inline_ref *iref,
1727 u64 parent, u64 root_objectid,
1728 u64 owner, u64 offset, int refs_to_add,
1729 struct btrfs_delayed_extent_op *extent_op)
1730 {
1731 struct extent_buffer *leaf;
1732 struct btrfs_extent_item *ei;
1733 unsigned long ptr;
1734 unsigned long end;
1735 unsigned long item_offset;
1736 u64 refs;
1737 int size;
1738 int type;
1739
1740 leaf = path->nodes[0];
1741 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1742 item_offset = (unsigned long)iref - (unsigned long)ei;
1743
1744 type = extent_ref_type(parent, owner);
1745 size = btrfs_extent_inline_ref_size(type);
1746
1747 btrfs_extend_item(root, path, size);
1748
1749 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1750 refs = btrfs_extent_refs(leaf, ei);
1751 refs += refs_to_add;
1752 btrfs_set_extent_refs(leaf, ei, refs);
1753 if (extent_op)
1754 __run_delayed_extent_op(extent_op, leaf, ei);
1755
1756 ptr = (unsigned long)ei + item_offset;
1757 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1758 if (ptr < end - size)
1759 memmove_extent_buffer(leaf, ptr + size, ptr,
1760 end - size - ptr);
1761
1762 iref = (struct btrfs_extent_inline_ref *)ptr;
1763 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1764 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1765 struct btrfs_extent_data_ref *dref;
1766 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1767 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1768 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1769 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1770 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1771 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1772 struct btrfs_shared_data_ref *sref;
1773 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1774 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1775 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1776 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1777 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1778 } else {
1779 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1780 }
1781 btrfs_mark_buffer_dirty(leaf);
1782 }
1783
1784 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1785 struct btrfs_root *root,
1786 struct btrfs_path *path,
1787 struct btrfs_extent_inline_ref **ref_ret,
1788 u64 bytenr, u64 num_bytes, u64 parent,
1789 u64 root_objectid, u64 owner, u64 offset)
1790 {
1791 int ret;
1792
1793 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1794 bytenr, num_bytes, parent,
1795 root_objectid, owner, offset, 0);
1796 if (ret != -ENOENT)
1797 return ret;
1798
1799 btrfs_release_path(path);
1800 *ref_ret = NULL;
1801
1802 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1803 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1804 root_objectid);
1805 } else {
1806 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1807 root_objectid, owner, offset);
1808 }
1809 return ret;
1810 }
1811
1812 /*
1813 * helper to update/remove inline back ref
1814 */
1815 static noinline_for_stack
1816 void update_inline_extent_backref(struct btrfs_root *root,
1817 struct btrfs_path *path,
1818 struct btrfs_extent_inline_ref *iref,
1819 int refs_to_mod,
1820 struct btrfs_delayed_extent_op *extent_op,
1821 int *last_ref)
1822 {
1823 struct extent_buffer *leaf;
1824 struct btrfs_extent_item *ei;
1825 struct btrfs_extent_data_ref *dref = NULL;
1826 struct btrfs_shared_data_ref *sref = NULL;
1827 unsigned long ptr;
1828 unsigned long end;
1829 u32 item_size;
1830 int size;
1831 int type;
1832 u64 refs;
1833
1834 leaf = path->nodes[0];
1835 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1836 refs = btrfs_extent_refs(leaf, ei);
1837 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1838 refs += refs_to_mod;
1839 btrfs_set_extent_refs(leaf, ei, refs);
1840 if (extent_op)
1841 __run_delayed_extent_op(extent_op, leaf, ei);
1842
1843 type = btrfs_extent_inline_ref_type(leaf, iref);
1844
1845 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1846 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1847 refs = btrfs_extent_data_ref_count(leaf, dref);
1848 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1849 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1850 refs = btrfs_shared_data_ref_count(leaf, sref);
1851 } else {
1852 refs = 1;
1853 BUG_ON(refs_to_mod != -1);
1854 }
1855
1856 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1857 refs += refs_to_mod;
1858
1859 if (refs > 0) {
1860 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1861 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1862 else
1863 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1864 } else {
1865 *last_ref = 1;
1866 size = btrfs_extent_inline_ref_size(type);
1867 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1868 ptr = (unsigned long)iref;
1869 end = (unsigned long)ei + item_size;
1870 if (ptr + size < end)
1871 memmove_extent_buffer(leaf, ptr, ptr + size,
1872 end - ptr - size);
1873 item_size -= size;
1874 btrfs_truncate_item(root, path, item_size, 1);
1875 }
1876 btrfs_mark_buffer_dirty(leaf);
1877 }
1878
1879 static noinline_for_stack
1880 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1881 struct btrfs_root *root,
1882 struct btrfs_path *path,
1883 u64 bytenr, u64 num_bytes, u64 parent,
1884 u64 root_objectid, u64 owner,
1885 u64 offset, int refs_to_add,
1886 struct btrfs_delayed_extent_op *extent_op)
1887 {
1888 struct btrfs_extent_inline_ref *iref;
1889 int ret;
1890
1891 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1892 bytenr, num_bytes, parent,
1893 root_objectid, owner, offset, 1);
1894 if (ret == 0) {
1895 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1896 update_inline_extent_backref(root, path, iref,
1897 refs_to_add, extent_op, NULL);
1898 } else if (ret == -ENOENT) {
1899 setup_inline_extent_backref(root, path, iref, parent,
1900 root_objectid, owner, offset,
1901 refs_to_add, extent_op);
1902 ret = 0;
1903 }
1904 return ret;
1905 }
1906
1907 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1908 struct btrfs_root *root,
1909 struct btrfs_path *path,
1910 u64 bytenr, u64 parent, u64 root_objectid,
1911 u64 owner, u64 offset, int refs_to_add)
1912 {
1913 int ret;
1914 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1915 BUG_ON(refs_to_add != 1);
1916 ret = insert_tree_block_ref(trans, root, path, bytenr,
1917 parent, root_objectid);
1918 } else {
1919 ret = insert_extent_data_ref(trans, root, path, bytenr,
1920 parent, root_objectid,
1921 owner, offset, refs_to_add);
1922 }
1923 return ret;
1924 }
1925
1926 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1927 struct btrfs_root *root,
1928 struct btrfs_path *path,
1929 struct btrfs_extent_inline_ref *iref,
1930 int refs_to_drop, int is_data, int *last_ref)
1931 {
1932 int ret = 0;
1933
1934 BUG_ON(!is_data && refs_to_drop != 1);
1935 if (iref) {
1936 update_inline_extent_backref(root, path, iref,
1937 -refs_to_drop, NULL, last_ref);
1938 } else if (is_data) {
1939 ret = remove_extent_data_ref(trans, root, path, refs_to_drop,
1940 last_ref);
1941 } else {
1942 *last_ref = 1;
1943 ret = btrfs_del_item(trans, root, path);
1944 }
1945 return ret;
1946 }
1947
1948 #define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
1949 static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len,
1950 u64 *discarded_bytes)
1951 {
1952 int j, ret = 0;
1953 u64 bytes_left, end;
1954 u64 aligned_start = ALIGN(start, 1 << 9);
1955
1956 if (WARN_ON(start != aligned_start)) {
1957 len -= aligned_start - start;
1958 len = round_down(len, 1 << 9);
1959 start = aligned_start;
1960 }
1961
1962 *discarded_bytes = 0;
1963
1964 if (!len)
1965 return 0;
1966
1967 end = start + len;
1968 bytes_left = len;
1969
1970 /* Skip any superblocks on this device. */
1971 for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) {
1972 u64 sb_start = btrfs_sb_offset(j);
1973 u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE;
1974 u64 size = sb_start - start;
1975
1976 if (!in_range(sb_start, start, bytes_left) &&
1977 !in_range(sb_end, start, bytes_left) &&
1978 !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE))
1979 continue;
1980
1981 /*
1982 * Superblock spans beginning of range. Adjust start and
1983 * try again.
1984 */
1985 if (sb_start <= start) {
1986 start += sb_end - start;
1987 if (start > end) {
1988 bytes_left = 0;
1989 break;
1990 }
1991 bytes_left = end - start;
1992 continue;
1993 }
1994
1995 if (size) {
1996 ret = blkdev_issue_discard(bdev, start >> 9, size >> 9,
1997 GFP_NOFS, 0);
1998 if (!ret)
1999 *discarded_bytes += size;
2000 else if (ret != -EOPNOTSUPP)
2001 return ret;
2002 }
2003
2004 start = sb_end;
2005 if (start > end) {
2006 bytes_left = 0;
2007 break;
2008 }
2009 bytes_left = end - start;
2010 }
2011
2012 if (bytes_left) {
2013 ret = blkdev_issue_discard(bdev, start >> 9, bytes_left >> 9,
2014 GFP_NOFS, 0);
2015 if (!ret)
2016 *discarded_bytes += bytes_left;
2017 }
2018 return ret;
2019 }
2020
2021 int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
2022 u64 num_bytes, u64 *actual_bytes)
2023 {
2024 int ret;
2025 u64 discarded_bytes = 0;
2026 struct btrfs_bio *bbio = NULL;
2027
2028
2029 /* Tell the block device(s) that the sectors can be discarded */
2030 ret = btrfs_map_block(root->fs_info, REQ_DISCARD,
2031 bytenr, &num_bytes, &bbio, 0);
2032 /* Error condition is -ENOMEM */
2033 if (!ret) {
2034 struct btrfs_bio_stripe *stripe = bbio->stripes;
2035 int i;
2036
2037
2038 for (i = 0; i < bbio->num_stripes; i++, stripe++) {
2039 u64 bytes;
2040 if (!stripe->dev->can_discard)
2041 continue;
2042
2043 ret = btrfs_issue_discard(stripe->dev->bdev,
2044 stripe->physical,
2045 stripe->length,
2046 &bytes);
2047 if (!ret)
2048 discarded_bytes += bytes;
2049 else if (ret != -EOPNOTSUPP)
2050 break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */
2051
2052 /*
2053 * Just in case we get back EOPNOTSUPP for some reason,
2054 * just ignore the return value so we don't screw up
2055 * people calling discard_extent.
2056 */
2057 ret = 0;
2058 }
2059 btrfs_put_bbio(bbio);
2060 }
2061
2062 if (actual_bytes)
2063 *actual_bytes = discarded_bytes;
2064
2065
2066 if (ret == -EOPNOTSUPP)
2067 ret = 0;
2068 return ret;
2069 }
2070
2071 /* Can return -ENOMEM */
2072 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
2073 struct btrfs_root *root,
2074 u64 bytenr, u64 num_bytes, u64 parent,
2075 u64 root_objectid, u64 owner, u64 offset)
2076 {
2077 int ret;
2078 struct btrfs_fs_info *fs_info = root->fs_info;
2079
2080 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
2081 root_objectid == BTRFS_TREE_LOG_OBJECTID);
2082
2083 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
2084 ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
2085 num_bytes,
2086 parent, root_objectid, (int)owner,
2087 BTRFS_ADD_DELAYED_REF, NULL);
2088 } else {
2089 ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
2090 num_bytes, parent, root_objectid,
2091 owner, offset, 0,
2092 BTRFS_ADD_DELAYED_REF, NULL);
2093 }
2094 return ret;
2095 }
2096
2097 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
2098 struct btrfs_root *root,
2099 struct btrfs_delayed_ref_node *node,
2100 u64 parent, u64 root_objectid,
2101 u64 owner, u64 offset, int refs_to_add,
2102 struct btrfs_delayed_extent_op *extent_op)
2103 {
2104 struct btrfs_fs_info *fs_info = root->fs_info;
2105 struct btrfs_path *path;
2106 struct extent_buffer *leaf;
2107 struct btrfs_extent_item *item;
2108 struct btrfs_key key;
2109 u64 bytenr = node->bytenr;
2110 u64 num_bytes = node->num_bytes;
2111 u64 refs;
2112 int ret;
2113
2114 path = btrfs_alloc_path();
2115 if (!path)
2116 return -ENOMEM;
2117
2118 path->reada = 1;
2119 path->leave_spinning = 1;
2120 /* this will setup the path even if it fails to insert the back ref */
2121 ret = insert_inline_extent_backref(trans, fs_info->extent_root, path,
2122 bytenr, num_bytes, parent,
2123 root_objectid, owner, offset,
2124 refs_to_add, extent_op);
2125 if ((ret < 0 && ret != -EAGAIN) || !ret)
2126 goto out;
2127
2128 /*
2129 * Ok we had -EAGAIN which means we didn't have space to insert and
2130 * inline extent ref, so just update the reference count and add a
2131 * normal backref.
2132 */
2133 leaf = path->nodes[0];
2134 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2135 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2136 refs = btrfs_extent_refs(leaf, item);
2137 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
2138 if (extent_op)
2139 __run_delayed_extent_op(extent_op, leaf, item);
2140
2141 btrfs_mark_buffer_dirty(leaf);
2142 btrfs_release_path(path);
2143
2144 path->reada = 1;
2145 path->leave_spinning = 1;
2146 /* now insert the actual backref */
2147 ret = insert_extent_backref(trans, root->fs_info->extent_root,
2148 path, bytenr, parent, root_objectid,
2149 owner, offset, refs_to_add);
2150 if (ret)
2151 btrfs_abort_transaction(trans, root, ret);
2152 out:
2153 btrfs_free_path(path);
2154 return ret;
2155 }
2156
2157 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
2158 struct btrfs_root *root,
2159 struct btrfs_delayed_ref_node *node,
2160 struct btrfs_delayed_extent_op *extent_op,
2161 int insert_reserved)
2162 {
2163 int ret = 0;
2164 struct btrfs_delayed_data_ref *ref;
2165 struct btrfs_key ins;
2166 u64 parent = 0;
2167 u64 ref_root = 0;
2168 u64 flags = 0;
2169
2170 ins.objectid = node->bytenr;
2171 ins.offset = node->num_bytes;
2172 ins.type = BTRFS_EXTENT_ITEM_KEY;
2173
2174 ref = btrfs_delayed_node_to_data_ref(node);
2175 trace_run_delayed_data_ref(node, ref, node->action);
2176
2177 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
2178 parent = ref->parent;
2179 ref_root = ref->root;
2180
2181 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2182 if (extent_op)
2183 flags |= extent_op->flags_to_set;
2184 ret = alloc_reserved_file_extent(trans, root,
2185 parent, ref_root, flags,
2186 ref->objectid, ref->offset,
2187 &ins, node->ref_mod);
2188 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2189 ret = __btrfs_inc_extent_ref(trans, root, node, parent,
2190 ref_root, ref->objectid,
2191 ref->offset, node->ref_mod,
2192 extent_op);
2193 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2194 ret = __btrfs_free_extent(trans, root, node, parent,
2195 ref_root, ref->objectid,
2196 ref->offset, node->ref_mod,
2197 extent_op);
2198 } else {
2199 BUG();
2200 }
2201 return ret;
2202 }
2203
2204 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
2205 struct extent_buffer *leaf,
2206 struct btrfs_extent_item *ei)
2207 {
2208 u64 flags = btrfs_extent_flags(leaf, ei);
2209 if (extent_op->update_flags) {
2210 flags |= extent_op->flags_to_set;
2211 btrfs_set_extent_flags(leaf, ei, flags);
2212 }
2213
2214 if (extent_op->update_key) {
2215 struct btrfs_tree_block_info *bi;
2216 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
2217 bi = (struct btrfs_tree_block_info *)(ei + 1);
2218 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
2219 }
2220 }
2221
2222 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
2223 struct btrfs_root *root,
2224 struct btrfs_delayed_ref_node *node,
2225 struct btrfs_delayed_extent_op *extent_op)
2226 {
2227 struct btrfs_key key;
2228 struct btrfs_path *path;
2229 struct btrfs_extent_item *ei;
2230 struct extent_buffer *leaf;
2231 u32 item_size;
2232 int ret;
2233 int err = 0;
2234 int metadata = !extent_op->is_data;
2235
2236 if (trans->aborted)
2237 return 0;
2238
2239 if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA))
2240 metadata = 0;
2241
2242 path = btrfs_alloc_path();
2243 if (!path)
2244 return -ENOMEM;
2245
2246 key.objectid = node->bytenr;
2247
2248 if (metadata) {
2249 key.type = BTRFS_METADATA_ITEM_KEY;
2250 key.offset = extent_op->level;
2251 } else {
2252 key.type = BTRFS_EXTENT_ITEM_KEY;
2253 key.offset = node->num_bytes;
2254 }
2255
2256 again:
2257 path->reada = 1;
2258 path->leave_spinning = 1;
2259 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
2260 path, 0, 1);
2261 if (ret < 0) {
2262 err = ret;
2263 goto out;
2264 }
2265 if (ret > 0) {
2266 if (metadata) {
2267 if (path->slots[0] > 0) {
2268 path->slots[0]--;
2269 btrfs_item_key_to_cpu(path->nodes[0], &key,
2270 path->slots[0]);
2271 if (key.objectid == node->bytenr &&
2272 key.type == BTRFS_EXTENT_ITEM_KEY &&
2273 key.offset == node->num_bytes)
2274 ret = 0;
2275 }
2276 if (ret > 0) {
2277 btrfs_release_path(path);
2278 metadata = 0;
2279
2280 key.objectid = node->bytenr;
2281 key.offset = node->num_bytes;
2282 key.type = BTRFS_EXTENT_ITEM_KEY;
2283 goto again;
2284 }
2285 } else {
2286 err = -EIO;
2287 goto out;
2288 }
2289 }
2290
2291 leaf = path->nodes[0];
2292 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2293 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2294 if (item_size < sizeof(*ei)) {
2295 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
2296 path, (u64)-1, 0);
2297 if (ret < 0) {
2298 err = ret;
2299 goto out;
2300 }
2301 leaf = path->nodes[0];
2302 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2303 }
2304 #endif
2305 BUG_ON(item_size < sizeof(*ei));
2306 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2307 __run_delayed_extent_op(extent_op, leaf, ei);
2308
2309 btrfs_mark_buffer_dirty(leaf);
2310 out:
2311 btrfs_free_path(path);
2312 return err;
2313 }
2314
2315 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
2316 struct btrfs_root *root,
2317 struct btrfs_delayed_ref_node *node,
2318 struct btrfs_delayed_extent_op *extent_op,
2319 int insert_reserved)
2320 {
2321 int ret = 0;
2322 struct btrfs_delayed_tree_ref *ref;
2323 struct btrfs_key ins;
2324 u64 parent = 0;
2325 u64 ref_root = 0;
2326 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
2327 SKINNY_METADATA);
2328
2329 ref = btrfs_delayed_node_to_tree_ref(node);
2330 trace_run_delayed_tree_ref(node, ref, node->action);
2331
2332 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2333 parent = ref->parent;
2334 ref_root = ref->root;
2335
2336 ins.objectid = node->bytenr;
2337 if (skinny_metadata) {
2338 ins.offset = ref->level;
2339 ins.type = BTRFS_METADATA_ITEM_KEY;
2340 } else {
2341 ins.offset = node->num_bytes;
2342 ins.type = BTRFS_EXTENT_ITEM_KEY;
2343 }
2344
2345 BUG_ON(node->ref_mod != 1);
2346 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2347 BUG_ON(!extent_op || !extent_op->update_flags);
2348 ret = alloc_reserved_tree_block(trans, root,
2349 parent, ref_root,
2350 extent_op->flags_to_set,
2351 &extent_op->key,
2352 ref->level, &ins);
2353 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2354 ret = __btrfs_inc_extent_ref(trans, root, node,
2355 parent, ref_root,
2356 ref->level, 0, 1,
2357 extent_op);
2358 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2359 ret = __btrfs_free_extent(trans, root, node,
2360 parent, ref_root,
2361 ref->level, 0, 1, extent_op);
2362 } else {
2363 BUG();
2364 }
2365 return ret;
2366 }
2367
2368 /* helper function to actually process a single delayed ref entry */
2369 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
2370 struct btrfs_root *root,
2371 struct btrfs_delayed_ref_node *node,
2372 struct btrfs_delayed_extent_op *extent_op,
2373 int insert_reserved)
2374 {
2375 int ret = 0;
2376
2377 if (trans->aborted) {
2378 if (insert_reserved)
2379 btrfs_pin_extent(root, node->bytenr,
2380 node->num_bytes, 1);
2381 return 0;
2382 }
2383
2384 if (btrfs_delayed_ref_is_head(node)) {
2385 struct btrfs_delayed_ref_head *head;
2386 /*
2387 * we've hit the end of the chain and we were supposed
2388 * to insert this extent into the tree. But, it got
2389 * deleted before we ever needed to insert it, so all
2390 * we have to do is clean up the accounting
2391 */
2392 BUG_ON(extent_op);
2393 head = btrfs_delayed_node_to_head(node);
2394 trace_run_delayed_ref_head(node, head, node->action);
2395
2396 if (insert_reserved) {
2397 btrfs_pin_extent(root, node->bytenr,
2398 node->num_bytes, 1);
2399 if (head->is_data) {
2400 ret = btrfs_del_csums(trans, root,
2401 node->bytenr,
2402 node->num_bytes);
2403 }
2404 }
2405
2406 /* Also free its reserved qgroup space */
2407 btrfs_qgroup_free_delayed_ref(root->fs_info,
2408 head->qgroup_ref_root,
2409 head->qgroup_reserved);
2410 return ret;
2411 }
2412
2413 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
2414 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2415 ret = run_delayed_tree_ref(trans, root, node, extent_op,
2416 insert_reserved);
2417 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
2418 node->type == BTRFS_SHARED_DATA_REF_KEY)
2419 ret = run_delayed_data_ref(trans, root, node, extent_op,
2420 insert_reserved);
2421 else
2422 BUG();
2423 return ret;
2424 }
2425
2426 static inline struct btrfs_delayed_ref_node *
2427 select_delayed_ref(struct btrfs_delayed_ref_head *head)
2428 {
2429 struct btrfs_delayed_ref_node *ref;
2430
2431 if (list_empty(&head->ref_list))
2432 return NULL;
2433
2434 /*
2435 * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first.
2436 * This is to prevent a ref count from going down to zero, which deletes
2437 * the extent item from the extent tree, when there still are references
2438 * to add, which would fail because they would not find the extent item.
2439 */
2440 list_for_each_entry(ref, &head->ref_list, list) {
2441 if (ref->action == BTRFS_ADD_DELAYED_REF)
2442 return ref;
2443 }
2444
2445 return list_entry(head->ref_list.next, struct btrfs_delayed_ref_node,
2446 list);
2447 }
2448
2449 /*
2450 * Returns 0 on success or if called with an already aborted transaction.
2451 * Returns -ENOMEM or -EIO on failure and will abort the transaction.
2452 */
2453 static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2454 struct btrfs_root *root,
2455 unsigned long nr)
2456 {
2457 struct btrfs_delayed_ref_root *delayed_refs;
2458 struct btrfs_delayed_ref_node *ref;
2459 struct btrfs_delayed_ref_head *locked_ref = NULL;
2460 struct btrfs_delayed_extent_op *extent_op;
2461 struct btrfs_fs_info *fs_info = root->fs_info;
2462 ktime_t start = ktime_get();
2463 int ret;
2464 unsigned long count = 0;
2465 unsigned long actual_count = 0;
2466 int must_insert_reserved = 0;
2467
2468 delayed_refs = &trans->transaction->delayed_refs;
2469 while (1) {
2470 if (!locked_ref) {
2471 if (count >= nr)
2472 break;
2473
2474 spin_lock(&delayed_refs->lock);
2475 locked_ref = btrfs_select_ref_head(trans);
2476 if (!locked_ref) {
2477 spin_unlock(&delayed_refs->lock);
2478 break;
2479 }
2480
2481 /* grab the lock that says we are going to process
2482 * all the refs for this head */
2483 ret = btrfs_delayed_ref_lock(trans, locked_ref);
2484 spin_unlock(&delayed_refs->lock);
2485 /*
2486 * we may have dropped the spin lock to get the head
2487 * mutex lock, and that might have given someone else
2488 * time to free the head. If that's true, it has been
2489 * removed from our list and we can move on.
2490 */
2491 if (ret == -EAGAIN) {
2492 locked_ref = NULL;
2493 count++;
2494 continue;
2495 }
2496 }
2497
2498 /*
2499 * We need to try and merge add/drops of the same ref since we
2500 * can run into issues with relocate dropping the implicit ref
2501 * and then it being added back again before the drop can
2502 * finish. If we merged anything we need to re-loop so we can
2503 * get a good ref.
2504 * Or we can get node references of the same type that weren't
2505 * merged when created due to bumps in the tree mod seq, and
2506 * we need to merge them to prevent adding an inline extent
2507 * backref before dropping it (triggering a BUG_ON at
2508 * insert_inline_extent_backref()).
2509 */
2510 spin_lock(&locked_ref->lock);
2511 btrfs_merge_delayed_refs(trans, fs_info, delayed_refs,
2512 locked_ref);
2513
2514 /*
2515 * locked_ref is the head node, so we have to go one
2516 * node back for any delayed ref updates
2517 */
2518 ref = select_delayed_ref(locked_ref);
2519
2520 if (ref && ref->seq &&
2521 btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) {
2522 spin_unlock(&locked_ref->lock);
2523 spin_lock(&delayed_refs->lock);
2524 locked_ref->processing = 0;
2525 delayed_refs->num_heads_ready++;
2526 spin_unlock(&delayed_refs->lock);
2527 btrfs_delayed_ref_unlock(locked_ref);
2528 locked_ref = NULL;
2529 cond_resched();
2530 count++;
2531 continue;
2532 }
2533
2534 /*
2535 * record the must insert reserved flag before we
2536 * drop the spin lock.
2537 */
2538 must_insert_reserved = locked_ref->must_insert_reserved;
2539 locked_ref->must_insert_reserved = 0;
2540
2541 extent_op = locked_ref->extent_op;
2542 locked_ref->extent_op = NULL;
2543
2544 if (!ref) {
2545
2546
2547 /* All delayed refs have been processed, Go ahead
2548 * and send the head node to run_one_delayed_ref,
2549 * so that any accounting fixes can happen
2550 */
2551 ref = &locked_ref->node;
2552
2553 if (extent_op && must_insert_reserved) {
2554 btrfs_free_delayed_extent_op(extent_op);
2555 extent_op = NULL;
2556 }
2557
2558 if (extent_op) {
2559 spin_unlock(&locked_ref->lock);
2560 ret = run_delayed_extent_op(trans, root,
2561 ref, extent_op);
2562 btrfs_free_delayed_extent_op(extent_op);
2563
2564 if (ret) {
2565 /*
2566 * Need to reset must_insert_reserved if
2567 * there was an error so the abort stuff
2568 * can cleanup the reserved space
2569 * properly.
2570 */
2571 if (must_insert_reserved)
2572 locked_ref->must_insert_reserved = 1;
2573 spin_lock(&delayed_refs->lock);
2574 locked_ref->processing = 0;
2575 delayed_refs->num_heads_ready++;
2576 spin_unlock(&delayed_refs->lock);
2577 btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret);
2578 btrfs_delayed_ref_unlock(locked_ref);
2579 return ret;
2580 }
2581 continue;
2582 }
2583
2584 /*
2585 * Need to drop our head ref lock and re-aqcuire the
2586 * delayed ref lock and then re-check to make sure
2587 * nobody got added.
2588 */
2589 spin_unlock(&locked_ref->lock);
2590 spin_lock(&delayed_refs->lock);
2591 spin_lock(&locked_ref->lock);
2592 if (!list_empty(&locked_ref->ref_list) ||
2593 locked_ref->extent_op) {
2594 spin_unlock(&locked_ref->lock);
2595 spin_unlock(&delayed_refs->lock);
2596 continue;
2597 }
2598 ref->in_tree = 0;
2599 delayed_refs->num_heads--;
2600 rb_erase(&locked_ref->href_node,
2601 &delayed_refs->href_root);
2602 spin_unlock(&delayed_refs->lock);
2603 } else {
2604 actual_count++;
2605 ref->in_tree = 0;
2606 list_del(&ref->list);
2607 }
2608 atomic_dec(&delayed_refs->num_entries);
2609
2610 if (!btrfs_delayed_ref_is_head(ref)) {
2611 /*
2612 * when we play the delayed ref, also correct the
2613 * ref_mod on head
2614 */
2615 switch (ref->action) {
2616 case BTRFS_ADD_DELAYED_REF:
2617 case BTRFS_ADD_DELAYED_EXTENT:
2618 locked_ref->node.ref_mod -= ref->ref_mod;
2619 break;
2620 case BTRFS_DROP_DELAYED_REF:
2621 locked_ref->node.ref_mod += ref->ref_mod;
2622 break;
2623 default:
2624 WARN_ON(1);
2625 }
2626 }
2627 spin_unlock(&locked_ref->lock);
2628
2629 ret = run_one_delayed_ref(trans, root, ref, extent_op,
2630 must_insert_reserved);
2631
2632 btrfs_free_delayed_extent_op(extent_op);
2633 if (ret) {
2634 locked_ref->processing = 0;
2635 btrfs_delayed_ref_unlock(locked_ref);
2636 btrfs_put_delayed_ref(ref);
2637 btrfs_debug(fs_info, "run_one_delayed_ref returned %d", ret);
2638 return ret;
2639 }
2640
2641 /*
2642 * If this node is a head, that means all the refs in this head
2643 * have been dealt with, and we will pick the next head to deal
2644 * with, so we must unlock the head and drop it from the cluster
2645 * list before we release it.
2646 */
2647 if (btrfs_delayed_ref_is_head(ref)) {
2648 if (locked_ref->is_data &&
2649 locked_ref->total_ref_mod < 0) {
2650 spin_lock(&delayed_refs->lock);
2651 delayed_refs->pending_csums -= ref->num_bytes;
2652 spin_unlock(&delayed_refs->lock);
2653 }
2654 btrfs_delayed_ref_unlock(locked_ref);
2655 locked_ref = NULL;
2656 }
2657 btrfs_put_delayed_ref(ref);
2658 count++;
2659 cond_resched();
2660 }
2661
2662 /*
2663 * We don't want to include ref heads since we can have empty ref heads
2664 * and those will drastically skew our runtime down since we just do
2665 * accounting, no actual extent tree updates.
2666 */
2667 if (actual_count > 0) {
2668 u64 runtime = ktime_to_ns(ktime_sub(ktime_get(), start));
2669 u64 avg;
2670
2671 /*
2672 * We weigh the current average higher than our current runtime
2673 * to avoid large swings in the average.
2674 */
2675 spin_lock(&delayed_refs->lock);
2676 avg = fs_info->avg_delayed_ref_runtime * 3 + runtime;
2677 fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */
2678 spin_unlock(&delayed_refs->lock);
2679 }
2680 return 0;
2681 }
2682
2683 #ifdef SCRAMBLE_DELAYED_REFS
2684 /*
2685 * Normally delayed refs get processed in ascending bytenr order. This
2686 * correlates in most cases to the order added. To expose dependencies on this
2687 * order, we start to process the tree in the middle instead of the beginning
2688 */
2689 static u64 find_middle(struct rb_root *root)
2690 {
2691 struct rb_node *n = root->rb_node;
2692 struct btrfs_delayed_ref_node *entry;
2693 int alt = 1;
2694 u64 middle;
2695 u64 first = 0, last = 0;
2696
2697 n = rb_first(root);
2698 if (n) {
2699 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2700 first = entry->bytenr;
2701 }
2702 n = rb_last(root);
2703 if (n) {
2704 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2705 last = entry->bytenr;
2706 }
2707 n = root->rb_node;
2708
2709 while (n) {
2710 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2711 WARN_ON(!entry->in_tree);
2712
2713 middle = entry->bytenr;
2714
2715 if (alt)
2716 n = n->rb_left;
2717 else
2718 n = n->rb_right;
2719
2720 alt = 1 - alt;
2721 }
2722 return middle;
2723 }
2724 #endif
2725
2726 static inline u64 heads_to_leaves(struct btrfs_root *root, u64 heads)
2727 {
2728 u64 num_bytes;
2729
2730 num_bytes = heads * (sizeof(struct btrfs_extent_item) +
2731 sizeof(struct btrfs_extent_inline_ref));
2732 if (!btrfs_fs_incompat(root->fs_info, SKINNY_METADATA))
2733 num_bytes += heads * sizeof(struct btrfs_tree_block_info);
2734
2735 /*
2736 * We don't ever fill up leaves all the way so multiply by 2 just to be
2737 * closer to what we're really going to want to ouse.
2738 */
2739 return div_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(root));
2740 }
2741
2742 /*
2743 * Takes the number of bytes to be csumm'ed and figures out how many leaves it
2744 * would require to store the csums for that many bytes.
2745 */
2746 u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes)
2747 {
2748 u64 csum_size;
2749 u64 num_csums_per_leaf;
2750 u64 num_csums;
2751
2752 csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item);
2753 num_csums_per_leaf = div64_u64(csum_size,
2754 (u64)btrfs_super_csum_size(root->fs_info->super_copy));
2755 num_csums = div64_u64(csum_bytes, root->sectorsize);
2756 num_csums += num_csums_per_leaf - 1;
2757 num_csums = div64_u64(num_csums, num_csums_per_leaf);
2758 return num_csums;
2759 }
2760
2761 int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
2762 struct btrfs_root *root)
2763 {
2764 struct btrfs_block_rsv *global_rsv;
2765 u64 num_heads = trans->transaction->delayed_refs.num_heads_ready;
2766 u64 csum_bytes = trans->transaction->delayed_refs.pending_csums;
2767 u64 num_dirty_bgs = trans->transaction->num_dirty_bgs;
2768 u64 num_bytes, num_dirty_bgs_bytes;
2769 int ret = 0;
2770
2771 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
2772 num_heads = heads_to_leaves(root, num_heads);
2773 if (num_heads > 1)
2774 num_bytes += (num_heads - 1) * root->nodesize;
2775 num_bytes <<= 1;
2776 num_bytes += btrfs_csum_bytes_to_leaves(root, csum_bytes) * root->nodesize;
2777 num_dirty_bgs_bytes = btrfs_calc_trans_metadata_size(root,
2778 num_dirty_bgs);
2779 global_rsv = &root->fs_info->global_block_rsv;
2780
2781 /*
2782 * If we can't allocate any more chunks lets make sure we have _lots_ of
2783 * wiggle room since running delayed refs can create more delayed refs.
2784 */
2785 if (global_rsv->space_info->full) {
2786 num_dirty_bgs_bytes <<= 1;
2787 num_bytes <<= 1;
2788 }
2789
2790 spin_lock(&global_rsv->lock);
2791 if (global_rsv->reserved <= num_bytes + num_dirty_bgs_bytes)
2792 ret = 1;
2793 spin_unlock(&global_rsv->lock);
2794 return ret;
2795 }
2796
2797 int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans,
2798 struct btrfs_root *root)
2799 {
2800 struct btrfs_fs_info *fs_info = root->fs_info;
2801 u64 num_entries =
2802 atomic_read(&trans->transaction->delayed_refs.num_entries);
2803 u64 avg_runtime;
2804 u64 val;
2805
2806 smp_mb();
2807 avg_runtime = fs_info->avg_delayed_ref_runtime;
2808 val = num_entries * avg_runtime;
2809 if (num_entries * avg_runtime >= NSEC_PER_SEC)
2810 return 1;
2811 if (val >= NSEC_PER_SEC / 2)
2812 return 2;
2813
2814 return btrfs_check_space_for_delayed_refs(trans, root);
2815 }
2816
2817 struct async_delayed_refs {
2818 struct btrfs_root *root;
2819 int count;
2820 int error;
2821 int sync;
2822 struct completion wait;
2823 struct btrfs_work work;
2824 };
2825
2826 static void delayed_ref_async_start(struct btrfs_work *work)
2827 {
2828 struct async_delayed_refs *async;
2829 struct btrfs_trans_handle *trans;
2830 int ret;
2831
2832 async = container_of(work, struct async_delayed_refs, work);
2833
2834 trans = btrfs_join_transaction(async->root);
2835 if (IS_ERR(trans)) {
2836 async->error = PTR_ERR(trans);
2837 goto done;
2838 }
2839
2840 /*
2841 * trans->sync means that when we call end_transaciton, we won't
2842 * wait on delayed refs
2843 */
2844 trans->sync = true;
2845 ret = btrfs_run_delayed_refs(trans, async->root, async->count);
2846 if (ret)
2847 async->error = ret;
2848
2849 ret = btrfs_end_transaction(trans, async->root);
2850 if (ret && !async->error)
2851 async->error = ret;
2852 done:
2853 if (async->sync)
2854 complete(&async->wait);
2855 else
2856 kfree(async);
2857 }
2858
2859 int btrfs_async_run_delayed_refs(struct btrfs_root *root,
2860 unsigned long count, int wait)
2861 {
2862 struct async_delayed_refs *async;
2863 int ret;
2864
2865 async = kmalloc(sizeof(*async), GFP_NOFS);
2866 if (!async)
2867 return -ENOMEM;
2868
2869 async->root = root->fs_info->tree_root;
2870 async->count = count;
2871 async->error = 0;
2872 if (wait)
2873 async->sync = 1;
2874 else
2875 async->sync = 0;
2876 init_completion(&async->wait);
2877
2878 btrfs_init_work(&async->work, btrfs_extent_refs_helper,
2879 delayed_ref_async_start, NULL, NULL);
2880
2881 btrfs_queue_work(root->fs_info->extent_workers, &async->work);
2882
2883 if (wait) {
2884 wait_for_completion(&async->wait);
2885 ret = async->error;
2886 kfree(async);
2887 return ret;
2888 }
2889 return 0;
2890 }
2891
2892 /*
2893 * this starts processing the delayed reference count updates and
2894 * extent insertions we have queued up so far. count can be
2895 * 0, which means to process everything in the tree at the start
2896 * of the run (but not newly added entries), or it can be some target
2897 * number you'd like to process.
2898 *
2899 * Returns 0 on success or if called with an aborted transaction
2900 * Returns <0 on error and aborts the transaction
2901 */
2902 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2903 struct btrfs_root *root, unsigned long count)
2904 {
2905 struct rb_node *node;
2906 struct btrfs_delayed_ref_root *delayed_refs;
2907 struct btrfs_delayed_ref_head *head;
2908 int ret;
2909 int run_all = count == (unsigned long)-1;
2910 bool can_flush_pending_bgs = trans->can_flush_pending_bgs;
2911
2912 /* We'll clean this up in btrfs_cleanup_transaction */
2913 if (trans->aborted)
2914 return 0;
2915
2916 if (root == root->fs_info->extent_root)
2917 root = root->fs_info->tree_root;
2918
2919 delayed_refs = &trans->transaction->delayed_refs;
2920 if (count == 0)
2921 count = atomic_read(&delayed_refs->num_entries) * 2;
2922
2923 again:
2924 #ifdef SCRAMBLE_DELAYED_REFS
2925 delayed_refs->run_delayed_start = find_middle(&delayed_refs->root);
2926 #endif
2927 trans->can_flush_pending_bgs = false;
2928 ret = __btrfs_run_delayed_refs(trans, root, count);
2929 if (ret < 0) {
2930 btrfs_abort_transaction(trans, root, ret);
2931 return ret;
2932 }
2933
2934 if (run_all) {
2935 if (!list_empty(&trans->new_bgs))
2936 btrfs_create_pending_block_groups(trans, root);
2937
2938 spin_lock(&delayed_refs->lock);
2939 node = rb_first(&delayed_refs->href_root);
2940 if (!node) {
2941 spin_unlock(&delayed_refs->lock);
2942 goto out;
2943 }
2944 count = (unsigned long)-1;
2945
2946 while (node) {
2947 head = rb_entry(node, struct btrfs_delayed_ref_head,
2948 href_node);
2949 if (btrfs_delayed_ref_is_head(&head->node)) {
2950 struct btrfs_delayed_ref_node *ref;
2951
2952 ref = &head->node;
2953 atomic_inc(&ref->refs);
2954
2955 spin_unlock(&delayed_refs->lock);
2956 /*
2957 * Mutex was contended, block until it's
2958 * released and try again
2959 */
2960 mutex_lock(&head->mutex);
2961 mutex_unlock(&head->mutex);
2962
2963 btrfs_put_delayed_ref(ref);
2964 cond_resched();
2965 goto again;
2966 } else {
2967 WARN_ON(1);
2968 }
2969 node = rb_next(node);
2970 }
2971 spin_unlock(&delayed_refs->lock);
2972 cond_resched();
2973 goto again;
2974 }
2975 out:
2976 assert_qgroups_uptodate(trans);
2977 trans->can_flush_pending_bgs = can_flush_pending_bgs;
2978 return 0;
2979 }
2980
2981 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2982 struct btrfs_root *root,
2983 u64 bytenr, u64 num_bytes, u64 flags,
2984 int level, int is_data)
2985 {
2986 struct btrfs_delayed_extent_op *extent_op;
2987 int ret;
2988
2989 extent_op = btrfs_alloc_delayed_extent_op();
2990 if (!extent_op)
2991 return -ENOMEM;
2992
2993 extent_op->flags_to_set = flags;
2994 extent_op->update_flags = 1;
2995 extent_op->update_key = 0;
2996 extent_op->is_data = is_data ? 1 : 0;
2997 extent_op->level = level;
2998
2999 ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr,
3000 num_bytes, extent_op);
3001 if (ret)
3002 btrfs_free_delayed_extent_op(extent_op);
3003 return ret;
3004 }
3005
3006 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
3007 struct btrfs_root *root,
3008 struct btrfs_path *path,
3009 u64 objectid, u64 offset, u64 bytenr)
3010 {
3011 struct btrfs_delayed_ref_head *head;
3012 struct btrfs_delayed_ref_node *ref;
3013 struct btrfs_delayed_data_ref *data_ref;
3014 struct btrfs_delayed_ref_root *delayed_refs;
3015 int ret = 0;
3016
3017 delayed_refs = &trans->transaction->delayed_refs;
3018 spin_lock(&delayed_refs->lock);
3019 head = btrfs_find_delayed_ref_head(trans, bytenr);
3020 if (!head) {
3021 spin_unlock(&delayed_refs->lock);
3022 return 0;
3023 }
3024
3025 if (!mutex_trylock(&head->mutex)) {
3026 atomic_inc(&head->node.refs);
3027 spin_unlock(&delayed_refs->lock);
3028
3029 btrfs_release_path(path);
3030
3031 /*
3032 * Mutex was contended, block until it's released and let
3033 * caller try again
3034 */
3035 mutex_lock(&head->mutex);
3036 mutex_unlock(&head->mutex);
3037 btrfs_put_delayed_ref(&head->node);
3038 return -EAGAIN;
3039 }
3040 spin_unlock(&delayed_refs->lock);
3041
3042 spin_lock(&head->lock);
3043 list_for_each_entry(ref, &head->ref_list, list) {
3044 /* If it's a shared ref we know a cross reference exists */
3045 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) {
3046 ret = 1;
3047 break;
3048 }
3049
3050 data_ref = btrfs_delayed_node_to_data_ref(ref);
3051
3052 /*
3053 * If our ref doesn't match the one we're currently looking at
3054 * then we have a cross reference.
3055 */
3056 if (data_ref->root != root->root_key.objectid ||
3057 data_ref->objectid != objectid ||
3058 data_ref->offset != offset) {
3059 ret = 1;
3060 break;
3061 }
3062 }
3063 spin_unlock(&head->lock);
3064 mutex_unlock(&head->mutex);
3065 return ret;
3066 }
3067
3068 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
3069 struct btrfs_root *root,
3070 struct btrfs_path *path,
3071 u64 objectid, u64 offset, u64 bytenr)
3072 {
3073 struct btrfs_root *extent_root = root->fs_info->extent_root;
3074 struct extent_buffer *leaf;
3075 struct btrfs_extent_data_ref *ref;
3076 struct btrfs_extent_inline_ref *iref;
3077 struct btrfs_extent_item *ei;
3078 struct btrfs_key key;
3079 u32 item_size;
3080 int ret;
3081
3082 key.objectid = bytenr;
3083 key.offset = (u64)-1;
3084 key.type = BTRFS_EXTENT_ITEM_KEY;
3085
3086 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
3087 if (ret < 0)
3088 goto out;
3089 BUG_ON(ret == 0); /* Corruption */
3090
3091 ret = -ENOENT;
3092 if (path->slots[0] == 0)
3093 goto out;
3094
3095 path->slots[0]--;
3096 leaf = path->nodes[0];
3097 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3098
3099 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
3100 goto out;
3101
3102 ret = 1;
3103 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
3104 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3105 if (item_size < sizeof(*ei)) {
3106 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3107 goto out;
3108 }
3109 #endif
3110 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
3111
3112 if (item_size != sizeof(*ei) +
3113 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
3114 goto out;
3115
3116 if (btrfs_extent_generation(leaf, ei) <=
3117 btrfs_root_last_snapshot(&root->root_item))
3118 goto out;
3119
3120 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
3121 if (btrfs_extent_inline_ref_type(leaf, iref) !=
3122 BTRFS_EXTENT_DATA_REF_KEY)
3123 goto out;
3124
3125 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
3126 if (btrfs_extent_refs(leaf, ei) !=
3127 btrfs_extent_data_ref_count(leaf, ref) ||
3128 btrfs_extent_data_ref_root(leaf, ref) !=
3129 root->root_key.objectid ||
3130 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
3131 btrfs_extent_data_ref_offset(leaf, ref) != offset)
3132 goto out;
3133
3134 ret = 0;
3135 out:
3136 return ret;
3137 }
3138
3139 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
3140 struct btrfs_root *root,
3141 u64 objectid, u64 offset, u64 bytenr)
3142 {
3143 struct btrfs_path *path;
3144 int ret;
3145 int ret2;
3146
3147 path = btrfs_alloc_path();
3148 if (!path)
3149 return -ENOENT;
3150
3151 do {
3152 ret = check_committed_ref(trans, root, path, objectid,
3153 offset, bytenr);
3154 if (ret && ret != -ENOENT)
3155 goto out;
3156
3157 ret2 = check_delayed_ref(trans, root, path, objectid,
3158 offset, bytenr);
3159 } while (ret2 == -EAGAIN);
3160
3161 if (ret2 && ret2 != -ENOENT) {
3162 ret = ret2;
3163 goto out;
3164 }
3165
3166 if (ret != -ENOENT || ret2 != -ENOENT)
3167 ret = 0;
3168 out:
3169 btrfs_free_path(path);
3170 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
3171 WARN_ON(ret > 0);
3172 return ret;
3173 }
3174
3175 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
3176 struct btrfs_root *root,
3177 struct extent_buffer *buf,
3178 int full_backref, int inc)
3179 {
3180 u64 bytenr;
3181 u64 num_bytes;
3182 u64 parent;
3183 u64 ref_root;
3184 u32 nritems;
3185 struct btrfs_key key;
3186 struct btrfs_file_extent_item *fi;
3187 int i;
3188 int level;
3189 int ret = 0;
3190 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
3191 u64, u64, u64, u64, u64, u64);
3192
3193
3194 if (btrfs_test_is_dummy_root(root))
3195 return 0;
3196
3197 ref_root = btrfs_header_owner(buf);
3198 nritems = btrfs_header_nritems(buf);
3199 level = btrfs_header_level(buf);
3200
3201 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state) && level == 0)
3202 return 0;
3203
3204 if (inc)
3205 process_func = btrfs_inc_extent_ref;
3206 else
3207 process_func = btrfs_free_extent;
3208
3209 if (full_backref)
3210 parent = buf->start;
3211 else
3212 parent = 0;
3213
3214 for (i = 0; i < nritems; i++) {
3215 if (level == 0) {
3216 btrfs_item_key_to_cpu(buf, &key, i);
3217 if (key.type != BTRFS_EXTENT_DATA_KEY)
3218 continue;
3219 fi = btrfs_item_ptr(buf, i,
3220 struct btrfs_file_extent_item);
3221 if (btrfs_file_extent_type(buf, fi) ==
3222 BTRFS_FILE_EXTENT_INLINE)
3223 continue;
3224 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
3225 if (bytenr == 0)
3226 continue;
3227
3228 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
3229 key.offset -= btrfs_file_extent_offset(buf, fi);
3230 ret = process_func(trans, root, bytenr, num_bytes,
3231 parent, ref_root, key.objectid,
3232 key.offset);
3233 if (ret)
3234 goto fail;
3235 } else {
3236 bytenr = btrfs_node_blockptr(buf, i);
3237 num_bytes = root->nodesize;
3238 ret = process_func(trans, root, bytenr, num_bytes,
3239 parent, ref_root, level - 1, 0);
3240 if (ret)
3241 goto fail;
3242 }
3243 }
3244 return 0;
3245 fail:
3246 return ret;
3247 }
3248
3249 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3250 struct extent_buffer *buf, int full_backref)
3251 {
3252 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
3253 }
3254
3255 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3256 struct extent_buffer *buf, int full_backref)
3257 {
3258 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
3259 }
3260
3261 static int write_one_cache_group(struct btrfs_trans_handle *trans,
3262 struct btrfs_root *root,
3263 struct btrfs_path *path,
3264 struct btrfs_block_group_cache *cache)
3265 {
3266 int ret;
3267 struct btrfs_root *extent_root = root->fs_info->extent_root;
3268 unsigned long bi;
3269 struct extent_buffer *leaf;
3270
3271 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
3272 if (ret) {
3273 if (ret > 0)
3274 ret = -ENOENT;
3275 goto fail;
3276 }
3277
3278 leaf = path->nodes[0];
3279 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
3280 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
3281 btrfs_mark_buffer_dirty(leaf);
3282 fail:
3283 btrfs_release_path(path);
3284 return ret;
3285
3286 }
3287
3288 static struct btrfs_block_group_cache *
3289 next_block_group(struct btrfs_root *root,
3290 struct btrfs_block_group_cache *cache)
3291 {
3292 struct rb_node *node;
3293
3294 spin_lock(&root->fs_info->block_group_cache_lock);
3295
3296 /* If our block group was removed, we need a full search. */
3297 if (RB_EMPTY_NODE(&cache->cache_node)) {
3298 const u64 next_bytenr = cache->key.objectid + cache->key.offset;
3299
3300 spin_unlock(&root->fs_info->block_group_cache_lock);
3301 btrfs_put_block_group(cache);
3302 cache = btrfs_lookup_first_block_group(root->fs_info,
3303 next_bytenr);
3304 return cache;
3305 }
3306 node = rb_next(&cache->cache_node);
3307 btrfs_put_block_group(cache);
3308 if (node) {
3309 cache = rb_entry(node, struct btrfs_block_group_cache,
3310 cache_node);
3311 btrfs_get_block_group(cache);
3312 } else
3313 cache = NULL;
3314 spin_unlock(&root->fs_info->block_group_cache_lock);
3315 return cache;
3316 }
3317
3318 static int cache_save_setup(struct btrfs_block_group_cache *block_group,
3319 struct btrfs_trans_handle *trans,
3320 struct btrfs_path *path)
3321 {
3322 struct btrfs_root *root = block_group->fs_info->tree_root;
3323 struct inode *inode = NULL;
3324 u64 alloc_hint = 0;
3325 int dcs = BTRFS_DC_ERROR;
3326 u64 num_pages = 0;
3327 int retries = 0;
3328 int ret = 0;
3329
3330 /*
3331 * If this block group is smaller than 100 megs don't bother caching the
3332 * block group.
3333 */
3334 if (block_group->key.offset < (100 * 1024 * 1024)) {
3335 spin_lock(&block_group->lock);
3336 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
3337 spin_unlock(&block_group->lock);
3338 return 0;
3339 }
3340
3341 if (trans->aborted)
3342 return 0;
3343 again:
3344 inode = lookup_free_space_inode(root, block_group, path);
3345 if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
3346 ret = PTR_ERR(inode);
3347 btrfs_release_path(path);
3348 goto out;
3349 }
3350
3351 if (IS_ERR(inode)) {
3352 BUG_ON(retries);
3353 retries++;
3354
3355 if (block_group->ro)
3356 goto out_free;
3357
3358 ret = create_free_space_inode(root, trans, block_group, path);
3359 if (ret)
3360 goto out_free;
3361 goto again;
3362 }
3363
3364 /*
3365 * We want to set the generation to 0, that way if anything goes wrong
3366 * from here on out we know not to trust this cache when we load up next
3367 * time.
3368 */
3369 BTRFS_I(inode)->generation = 0;
3370 ret = btrfs_update_inode(trans, root, inode);
3371 if (ret) {
3372 /*
3373 * So theoretically we could recover from this, simply set the
3374 * super cache generation to 0 so we know to invalidate the
3375 * cache, but then we'd have to keep track of the block groups
3376 * that fail this way so we know we _have_ to reset this cache
3377 * before the next commit or risk reading stale cache. So to
3378 * limit our exposure to horrible edge cases lets just abort the
3379 * transaction, this only happens in really bad situations
3380 * anyway.
3381 */
3382 btrfs_abort_transaction(trans, root, ret);
3383 goto out_put;
3384 }
3385 WARN_ON(ret);
3386
3387 /* We've already setup this transaction, go ahead and exit */
3388 if (block_group->cache_generation == trans->transid &&
3389 i_size_read(inode)) {
3390 dcs = BTRFS_DC_SETUP;
3391 goto out_put;
3392 }
3393
3394 if (i_size_read(inode) > 0) {
3395 ret = btrfs_check_trunc_cache_free_space(root,
3396 &root->fs_info->global_block_rsv);
3397 if (ret)
3398 goto out_put;
3399
3400 ret = btrfs_truncate_free_space_cache(root, trans, NULL, inode);
3401 if (ret)
3402 goto out_put;
3403 }
3404
3405 spin_lock(&block_group->lock);
3406 if (block_group->cached != BTRFS_CACHE_FINISHED ||
3407 !btrfs_test_opt(root, SPACE_CACHE)) {
3408 /*
3409 * don't bother trying to write stuff out _if_
3410 * a) we're not cached,
3411 * b) we're with nospace_cache mount option.
3412 */
3413 dcs = BTRFS_DC_WRITTEN;
3414 spin_unlock(&block_group->lock);
3415 goto out_put;
3416 }
3417 spin_unlock(&block_group->lock);
3418
3419 /*
3420 * We hit an ENOSPC when setting up the cache in this transaction, just
3421 * skip doing the setup, we've already cleared the cache so we're safe.
3422 */
3423 if (test_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags)) {
3424 ret = -ENOSPC;
3425 goto out_put;
3426 }
3427
3428 /*
3429 * Try to preallocate enough space based on how big the block group is.
3430 * Keep in mind this has to include any pinned space which could end up
3431 * taking up quite a bit since it's not folded into the other space
3432 * cache.
3433 */
3434 num_pages = div_u64(block_group->key.offset, 256 * 1024 * 1024);
3435 if (!num_pages)
3436 num_pages = 1;
3437
3438 num_pages *= 16;
3439 num_pages *= PAGE_CACHE_SIZE;
3440
3441 ret = btrfs_check_data_free_space(inode, 0, num_pages);
3442 if (ret)
3443 goto out_put;
3444
3445 ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
3446 num_pages, num_pages,
3447 &alloc_hint);
3448 /*
3449 * Our cache requires contiguous chunks so that we don't modify a bunch
3450 * of metadata or split extents when writing the cache out, which means
3451 * we can enospc if we are heavily fragmented in addition to just normal
3452 * out of space conditions. So if we hit this just skip setting up any
3453 * other block groups for this transaction, maybe we'll unpin enough
3454 * space the next time around.
3455 */
3456 if (!ret)
3457 dcs = BTRFS_DC_SETUP;
3458 else if (ret == -ENOSPC)
3459 set_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags);
3460 btrfs_free_reserved_data_space(inode, 0, num_pages);
3461
3462 out_put:
3463 iput(inode);
3464 out_free:
3465 btrfs_release_path(path);
3466 out:
3467 spin_lock(&block_group->lock);
3468 if (!ret && dcs == BTRFS_DC_SETUP)
3469 block_group->cache_generation = trans->transid;
3470 block_group->disk_cache_state = dcs;
3471 spin_unlock(&block_group->lock);
3472
3473 return ret;
3474 }
3475
3476 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
3477 struct btrfs_root *root)
3478 {
3479 struct btrfs_block_group_cache *cache, *tmp;
3480 struct btrfs_transaction *cur_trans = trans->transaction;
3481 struct btrfs_path *path;
3482
3483 if (list_empty(&cur_trans->dirty_bgs) ||
3484 !btrfs_test_opt(root, SPACE_CACHE))
3485 return 0;
3486
3487 path = btrfs_alloc_path();
3488 if (!path)
3489 return -ENOMEM;
3490
3491 /* Could add new block groups, use _safe just in case */
3492 list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
3493 dirty_list) {
3494 if (cache->disk_cache_state == BTRFS_DC_CLEAR)
3495 cache_save_setup(cache, trans, path);
3496 }
3497
3498 btrfs_free_path(path);
3499 return 0;
3500 }
3501
3502 /*
3503 * transaction commit does final block group cache writeback during a
3504 * critical section where nothing is allowed to change the FS. This is
3505 * required in order for the cache to actually match the block group,
3506 * but can introduce a lot of latency into the commit.
3507 *
3508 * So, btrfs_start_dirty_block_groups is here to kick off block group
3509 * cache IO. There's a chance we'll have to redo some of it if the
3510 * block group changes again during the commit, but it greatly reduces
3511 * the commit latency by getting rid of the easy block groups while
3512 * we're still allowing others to join the commit.
3513 */
3514 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans,
3515 struct btrfs_root *root)
3516 {
3517 struct btrfs_block_group_cache *cache;
3518 struct btrfs_transaction *cur_trans = trans->transaction;
3519 int ret = 0;
3520 int should_put;
3521 struct btrfs_path *path = NULL;
3522 LIST_HEAD(dirty);
3523 struct list_head *io = &cur_trans->io_bgs;
3524 int num_started = 0;
3525 int loops = 0;
3526
3527 spin_lock(&cur_trans->dirty_bgs_lock);
3528 if (list_empty(&cur_trans->dirty_bgs)) {
3529 spin_unlock(&cur_trans->dirty_bgs_lock);
3530 return 0;
3531 }
3532 list_splice_init(&cur_trans->dirty_bgs, &dirty);
3533 spin_unlock(&cur_trans->dirty_bgs_lock);
3534
3535 again:
3536 /*
3537 * make sure all the block groups on our dirty list actually
3538 * exist
3539 */
3540 btrfs_create_pending_block_groups(trans, root);
3541
3542 if (!path) {
3543 path = btrfs_alloc_path();
3544 if (!path)
3545 return -ENOMEM;
3546 }
3547
3548 /*
3549 * cache_write_mutex is here only to save us from balance or automatic
3550 * removal of empty block groups deleting this block group while we are
3551 * writing out the cache
3552 */
3553 mutex_lock(&trans->transaction->cache_write_mutex);
3554 while (!list_empty(&dirty)) {
3555 cache = list_first_entry(&dirty,
3556 struct btrfs_block_group_cache,
3557 dirty_list);
3558 /*
3559 * this can happen if something re-dirties a block
3560 * group that is already under IO. Just wait for it to
3561 * finish and then do it all again
3562 */
3563 if (!list_empty(&cache->io_list)) {
3564 list_del_init(&cache->io_list);
3565 btrfs_wait_cache_io(root, trans, cache,
3566 &cache->io_ctl, path,
3567 cache->key.objectid);
3568 btrfs_put_block_group(cache);
3569 }
3570
3571
3572 /*
3573 * btrfs_wait_cache_io uses the cache->dirty_list to decide
3574 * if it should update the cache_state. Don't delete
3575 * until after we wait.
3576 *
3577 * Since we're not running in the commit critical section
3578 * we need the dirty_bgs_lock to protect from update_block_group
3579 */
3580 spin_lock(&cur_trans->dirty_bgs_lock);
3581 list_del_init(&cache->dirty_list);
3582 spin_unlock(&cur_trans->dirty_bgs_lock);
3583
3584 should_put = 1;
3585
3586 cache_save_setup(cache, trans, path);
3587
3588 if (cache->disk_cache_state == BTRFS_DC_SETUP) {
3589 cache->io_ctl.inode = NULL;
3590 ret = btrfs_write_out_cache(root, trans, cache, path);
3591 if (ret == 0 && cache->io_ctl.inode) {
3592 num_started++;
3593 should_put = 0;
3594
3595 /*
3596 * the cache_write_mutex is protecting
3597 * the io_list
3598 */
3599 list_add_tail(&cache->io_list, io);
3600 } else {
3601 /*
3602 * if we failed to write the cache, the
3603 * generation will be bad and life goes on
3604 */
3605 ret = 0;
3606 }
3607 }
3608 if (!ret) {
3609 ret = write_one_cache_group(trans, root, path, cache);
3610 /*
3611 * Our block group might still be attached to the list
3612 * of new block groups in the transaction handle of some
3613 * other task (struct btrfs_trans_handle->new_bgs). This
3614 * means its block group item isn't yet in the extent
3615 * tree. If this happens ignore the error, as we will
3616 * try again later in the critical section of the
3617 * transaction commit.
3618 */
3619 if (ret == -ENOENT) {
3620 ret = 0;
3621 spin_lock(&cur_trans->dirty_bgs_lock);
3622 if (list_empty(&cache->dirty_list)) {
3623 list_add_tail(&cache->dirty_list,
3624 &cur_trans->dirty_bgs);
3625 btrfs_get_block_group(cache);
3626 }
3627 spin_unlock(&cur_trans->dirty_bgs_lock);
3628 } else if (ret) {
3629 btrfs_abort_transaction(trans, root, ret);
3630 }
3631 }
3632
3633 /* if its not on the io list, we need to put the block group */
3634 if (should_put)
3635 btrfs_put_block_group(cache);
3636
3637 if (ret)
3638 break;
3639
3640 /*
3641 * Avoid blocking other tasks for too long. It might even save
3642 * us from writing caches for block groups that are going to be
3643 * removed.
3644 */
3645 mutex_unlock(&trans->transaction->cache_write_mutex);
3646 mutex_lock(&trans->transaction->cache_write_mutex);
3647 }
3648 mutex_unlock(&trans->transaction->cache_write_mutex);
3649
3650 /*
3651 * go through delayed refs for all the stuff we've just kicked off
3652 * and then loop back (just once)
3653 */
3654 ret = btrfs_run_delayed_refs(trans, root, 0);
3655 if (!ret && loops == 0) {
3656 loops++;
3657 spin_lock(&cur_trans->dirty_bgs_lock);
3658 list_splice_init(&cur_trans->dirty_bgs, &dirty);
3659 /*
3660 * dirty_bgs_lock protects us from concurrent block group
3661 * deletes too (not just cache_write_mutex).
3662 */
3663 if (!list_empty(&dirty)) {
3664 spin_unlock(&cur_trans->dirty_bgs_lock);
3665 goto again;
3666 }
3667 spin_unlock(&cur_trans->dirty_bgs_lock);
3668 }
3669
3670 btrfs_free_path(path);
3671 return ret;
3672 }
3673
3674 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
3675 struct btrfs_root *root)
3676 {
3677 struct btrfs_block_group_cache *cache;
3678 struct btrfs_transaction *cur_trans = trans->transaction;
3679 int ret = 0;
3680 int should_put;
3681 struct btrfs_path *path;
3682 struct list_head *io = &cur_trans->io_bgs;
3683 int num_started = 0;
3684
3685 path = btrfs_alloc_path();
3686 if (!path)
3687 return -ENOMEM;
3688
3689 /*
3690 * We don't need the lock here since we are protected by the transaction
3691 * commit. We want to do the cache_save_setup first and then run the
3692 * delayed refs to make sure we have the best chance at doing this all
3693 * in one shot.
3694 */
3695 while (!list_empty(&cur_trans->dirty_bgs)) {
3696 cache = list_first_entry(&cur_trans->dirty_bgs,
3697 struct btrfs_block_group_cache,
3698 dirty_list);
3699
3700 /*
3701 * this can happen if cache_save_setup re-dirties a block
3702 * group that is already under IO. Just wait for it to
3703 * finish and then do it all again
3704 */
3705 if (!list_empty(&cache->io_list)) {
3706 list_del_init(&cache->io_list);
3707 btrfs_wait_cache_io(root, trans, cache,
3708 &cache->io_ctl, path,
3709 cache->key.objectid);
3710 btrfs_put_block_group(cache);
3711 }
3712
3713 /*
3714 * don't remove from the dirty list until after we've waited
3715 * on any pending IO
3716 */
3717 list_del_init(&cache->dirty_list);
3718 should_put = 1;
3719
3720 cache_save_setup(cache, trans, path);
3721
3722 if (!ret)
3723 ret = btrfs_run_delayed_refs(trans, root, (unsigned long) -1);
3724
3725 if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
3726 cache->io_ctl.inode = NULL;
3727 ret = btrfs_write_out_cache(root, trans, cache, path);
3728 if (ret == 0 && cache->io_ctl.inode) {
3729 num_started++;
3730 should_put = 0;
3731 list_add_tail(&cache->io_list, io);
3732 } else {
3733 /*
3734 * if we failed to write the cache, the
3735 * generation will be bad and life goes on
3736 */
3737 ret = 0;
3738 }
3739 }
3740 if (!ret) {
3741 ret = write_one_cache_group(trans, root, path, cache);
3742 if (ret)
3743 btrfs_abort_transaction(trans, root, ret);
3744 }
3745
3746 /* if its not on the io list, we need to put the block group */
3747 if (should_put)
3748 btrfs_put_block_group(cache);
3749 }
3750
3751 while (!list_empty(io)) {
3752 cache = list_first_entry(io, struct btrfs_block_group_cache,
3753 io_list);
3754 list_del_init(&cache->io_list);
3755 btrfs_wait_cache_io(root, trans, cache,
3756 &cache->io_ctl, path, cache->key.objectid);
3757 btrfs_put_block_group(cache);
3758 }
3759
3760 btrfs_free_path(path);
3761 return ret;
3762 }
3763
3764 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
3765 {
3766 struct btrfs_block_group_cache *block_group;
3767 int readonly = 0;
3768
3769 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
3770 if (!block_group || block_group->ro)
3771 readonly = 1;
3772 if (block_group)
3773 btrfs_put_block_group(block_group);
3774 return readonly;
3775 }
3776
3777 static const char *alloc_name(u64 flags)
3778 {
3779 switch (flags) {
3780 case BTRFS_BLOCK_GROUP_METADATA|BTRFS_BLOCK_GROUP_DATA:
3781 return "mixed";
3782 case BTRFS_BLOCK_GROUP_METADATA:
3783 return "metadata";
3784 case BTRFS_BLOCK_GROUP_DATA:
3785 return "data";
3786 case BTRFS_BLOCK_GROUP_SYSTEM:
3787 return "system";
3788 default:
3789 WARN_ON(1);
3790 return "invalid-combination";
3791 };
3792 }
3793
3794 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
3795 u64 total_bytes, u64 bytes_used,
3796 struct btrfs_space_info **space_info)
3797 {
3798 struct btrfs_space_info *found;
3799 int i;
3800 int factor;
3801 int ret;
3802
3803 if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3804 BTRFS_BLOCK_GROUP_RAID10))
3805 factor = 2;
3806 else
3807 factor = 1;
3808
3809 found = __find_space_info(info, flags);
3810 if (found) {
3811 spin_lock(&found->lock);
3812 found->total_bytes += total_bytes;
3813 found->disk_total += total_bytes * factor;
3814 found->bytes_used += bytes_used;
3815 found->disk_used += bytes_used * factor;
3816 if (total_bytes > 0)
3817 found->full = 0;
3818 spin_unlock(&found->lock);
3819 *space_info = found;
3820 return 0;
3821 }
3822 found = kzalloc(sizeof(*found), GFP_NOFS);
3823 if (!found)
3824 return -ENOMEM;
3825
3826 ret = percpu_counter_init(&found->total_bytes_pinned, 0, GFP_KERNEL);
3827 if (ret) {
3828 kfree(found);
3829 return ret;
3830 }
3831
3832 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
3833 INIT_LIST_HEAD(&found->block_groups[i]);
3834 init_rwsem(&found->groups_sem);
3835 spin_lock_init(&found->lock);
3836 found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
3837 found->total_bytes = total_bytes;
3838 found->disk_total = total_bytes * factor;
3839 found->bytes_used = bytes_used;
3840 found->disk_used = bytes_used * factor;
3841 found->bytes_pinned = 0;
3842 found->bytes_reserved = 0;
3843 found->bytes_readonly = 0;
3844 found->bytes_may_use = 0;
3845 found->full = 0;
3846 found->max_extent_size = 0;
3847 found->force_alloc = CHUNK_ALLOC_NO_FORCE;
3848 found->chunk_alloc = 0;
3849 found->flush = 0;
3850 init_waitqueue_head(&found->wait);
3851 INIT_LIST_HEAD(&found->ro_bgs);
3852
3853 ret = kobject_init_and_add(&found->kobj, &space_info_ktype,
3854 info->space_info_kobj, "%s",
3855 alloc_name(found->flags));
3856 if (ret) {
3857 percpu_counter_destroy(&found->total_bytes_pinned);
3858 kfree(found);
3859 return ret;
3860 }
3861
3862 *space_info = found;
3863 list_add_rcu(&found->list, &info->space_info);
3864 if (flags & BTRFS_BLOCK_GROUP_DATA)
3865 info->data_sinfo = found;
3866
3867 return ret;
3868 }
3869
3870 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
3871 {
3872 u64 extra_flags = chunk_to_extended(flags) &
3873 BTRFS_EXTENDED_PROFILE_MASK;
3874
3875 write_seqlock(&fs_info->profiles_lock);
3876 if (flags & BTRFS_BLOCK_GROUP_DATA)
3877 fs_info->avail_data_alloc_bits |= extra_flags;
3878 if (flags & BTRFS_BLOCK_GROUP_METADATA)
3879 fs_info->avail_metadata_alloc_bits |= extra_flags;
3880 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
3881 fs_info->avail_system_alloc_bits |= extra_flags;
3882 write_sequnlock(&fs_info->profiles_lock);
3883 }
3884
3885 /*
3886 * returns target flags in extended format or 0 if restripe for this
3887 * chunk_type is not in progress
3888 *
3889 * should be called with either volume_mutex or balance_lock held
3890 */
3891 static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
3892 {
3893 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3894 u64 target = 0;
3895
3896 if (!bctl)
3897 return 0;
3898
3899 if (flags & BTRFS_BLOCK_GROUP_DATA &&
3900 bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3901 target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
3902 } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
3903 bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3904 target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
3905 } else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
3906 bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3907 target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
3908 }
3909
3910 return target;
3911 }
3912
3913 /*
3914 * @flags: available profiles in extended format (see ctree.h)
3915 *
3916 * Returns reduced profile in chunk format. If profile changing is in
3917 * progress (either running or paused) picks the target profile (if it's
3918 * already available), otherwise falls back to plain reducing.
3919 */
3920 static u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
3921 {
3922 u64 num_devices = root->fs_info->fs_devices->rw_devices;
3923 u64 target;
3924 u64 raid_type;
3925 u64 allowed = 0;
3926
3927 /*
3928 * see if restripe for this chunk_type is in progress, if so
3929 * try to reduce to the target profile
3930 */
3931 spin_lock(&root->fs_info->balance_lock);
3932 target = get_restripe_target(root->fs_info, flags);
3933 if (target) {
3934 /* pick target profile only if it's already available */
3935 if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
3936 spin_unlock(&root->fs_info->balance_lock);
3937 return extended_to_chunk(target);
3938 }
3939 }
3940 spin_unlock(&root->fs_info->balance_lock);
3941
3942 /* First, mask out the RAID levels which aren't possible */
3943 for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
3944 if (num_devices >= btrfs_raid_array[raid_type].devs_min)
3945 allowed |= btrfs_raid_group[raid_type];
3946 }
3947 allowed &= flags;
3948
3949 if (allowed & BTRFS_BLOCK_GROUP_RAID6)
3950 allowed = BTRFS_BLOCK_GROUP_RAID6;
3951 else if (allowed & BTRFS_BLOCK_GROUP_RAID5)
3952 allowed = BTRFS_BLOCK_GROUP_RAID5;
3953 else if (allowed & BTRFS_BLOCK_GROUP_RAID10)
3954 allowed = BTRFS_BLOCK_GROUP_RAID10;
3955 else if (allowed & BTRFS_BLOCK_GROUP_RAID1)
3956 allowed = BTRFS_BLOCK_GROUP_RAID1;
3957 else if (allowed & BTRFS_BLOCK_GROUP_RAID0)
3958 allowed = BTRFS_BLOCK_GROUP_RAID0;
3959
3960 flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
3961
3962 return extended_to_chunk(flags | allowed);
3963 }
3964
3965 static u64 get_alloc_profile(struct btrfs_root *root, u64 orig_flags)
3966 {
3967 unsigned seq;
3968 u64 flags;
3969
3970 do {
3971 flags = orig_flags;
3972 seq = read_seqbegin(&root->fs_info->profiles_lock);
3973
3974 if (flags & BTRFS_BLOCK_GROUP_DATA)
3975 flags |= root->fs_info->avail_data_alloc_bits;
3976 else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
3977 flags |= root->fs_info->avail_system_alloc_bits;
3978 else if (flags & BTRFS_BLOCK_GROUP_METADATA)
3979 flags |= root->fs_info->avail_metadata_alloc_bits;
3980 } while (read_seqretry(&root->fs_info->profiles_lock, seq));
3981
3982 return btrfs_reduce_alloc_profile(root, flags);
3983 }
3984
3985 u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
3986 {
3987 u64 flags;
3988 u64 ret;
3989
3990 if (data)
3991 flags = BTRFS_BLOCK_GROUP_DATA;
3992 else if (root == root->fs_info->chunk_root)
3993 flags = BTRFS_BLOCK_GROUP_SYSTEM;
3994 else
3995 flags = BTRFS_BLOCK_GROUP_METADATA;
3996
3997 ret = get_alloc_profile(root, flags);
3998 return ret;
3999 }
4000
4001 int btrfs_alloc_data_chunk_ondemand(struct inode *inode, u64 bytes)
4002 {
4003 struct btrfs_space_info *data_sinfo;
4004 struct btrfs_root *root = BTRFS_I(inode)->root;
4005 struct btrfs_fs_info *fs_info = root->fs_info;
4006 u64 used;
4007 int ret = 0;
4008 int need_commit = 2;
4009 int have_pinned_space;
4010
4011 /* make sure bytes are sectorsize aligned */
4012 bytes = ALIGN(bytes, root->sectorsize);
4013
4014 if (btrfs_is_free_space_inode(inode)) {
4015 need_commit = 0;
4016 ASSERT(current->journal_info);
4017 }
4018
4019 data_sinfo = fs_info->data_sinfo;
4020 if (!data_sinfo)
4021 goto alloc;
4022
4023 again:
4024 /* make sure we have enough space to handle the data first */
4025 spin_lock(&data_sinfo->lock);
4026 used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
4027 data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
4028 data_sinfo->bytes_may_use;
4029
4030 if (used + bytes > data_sinfo->total_bytes) {
4031 struct btrfs_trans_handle *trans;
4032
4033 /*
4034 * if we don't have enough free bytes in this space then we need
4035 * to alloc a new chunk.
4036 */
4037 if (!data_sinfo->full) {
4038 u64 alloc_target;
4039
4040 data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
4041 spin_unlock(&data_sinfo->lock);
4042 alloc:
4043 alloc_target = btrfs_get_alloc_profile(root, 1);
4044 /*
4045 * It is ugly that we don't call nolock join
4046 * transaction for the free space inode case here.
4047 * But it is safe because we only do the data space
4048 * reservation for the free space cache in the
4049 * transaction context, the common join transaction
4050 * just increase the counter of the current transaction
4051 * handler, doesn't try to acquire the trans_lock of
4052 * the fs.
4053 */
4054 trans = btrfs_join_transaction(root);
4055 if (IS_ERR(trans))
4056 return PTR_ERR(trans);
4057
4058 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4059 alloc_target,
4060 CHUNK_ALLOC_NO_FORCE);
4061 btrfs_end_transaction(trans, root);
4062 if (ret < 0) {
4063 if (ret != -ENOSPC)
4064 return ret;
4065 else {
4066 have_pinned_space = 1;
4067 goto commit_trans;
4068 }
4069 }
4070
4071 if (!data_sinfo)
4072 data_sinfo = fs_info->data_sinfo;
4073
4074 goto again;
4075 }
4076
4077 /*
4078 * If we don't have enough pinned space to deal with this
4079 * allocation, and no removed chunk in current transaction,
4080 * don't bother committing the transaction.
4081 */
4082 have_pinned_space = percpu_counter_compare(
4083 &data_sinfo->total_bytes_pinned,
4084 used + bytes - data_sinfo->total_bytes);
4085 spin_unlock(&data_sinfo->lock);
4086
4087 /* commit the current transaction and try again */
4088 commit_trans:
4089 if (need_commit &&
4090 !atomic_read(&root->fs_info->open_ioctl_trans)) {
4091 need_commit--;
4092
4093 if (need_commit > 0) {
4094 btrfs_start_delalloc_roots(fs_info, 0, -1);
4095 btrfs_wait_ordered_roots(fs_info, -1);
4096 }
4097
4098 trans = btrfs_join_transaction(root);
4099 if (IS_ERR(trans))
4100 return PTR_ERR(trans);
4101 if (have_pinned_space >= 0 ||
4102 test_bit(BTRFS_TRANS_HAVE_FREE_BGS,
4103 &trans->transaction->flags) ||
4104 need_commit > 0) {
4105 ret = btrfs_commit_transaction(trans, root);
4106 if (ret)
4107 return ret;
4108 /*
4109 * The cleaner kthread might still be doing iput
4110 * operations. Wait for it to finish so that
4111 * more space is released.
4112 */
4113 mutex_lock(&root->fs_info->cleaner_delayed_iput_mutex);
4114 mutex_unlock(&root->fs_info->cleaner_delayed_iput_mutex);
4115 goto again;
4116 } else {
4117 btrfs_end_transaction(trans, root);
4118 }
4119 }
4120
4121 trace_btrfs_space_reservation(root->fs_info,
4122 "space_info:enospc",
4123 data_sinfo->flags, bytes, 1);
4124 return -ENOSPC;
4125 }
4126 data_sinfo->bytes_may_use += bytes;
4127 trace_btrfs_space_reservation(root->fs_info, "space_info",
4128 data_sinfo->flags, bytes, 1);
4129 spin_unlock(&data_sinfo->lock);
4130
4131 return 0;
4132 }
4133
4134 /*
4135 * New check_data_free_space() with ability for precious data reservation
4136 * Will replace old btrfs_check_data_free_space(), but for patch split,
4137 * add a new function first and then replace it.
4138 */
4139 int btrfs_check_data_free_space(struct inode *inode, u64 start, u64 len)
4140 {
4141 struct btrfs_root *root = BTRFS_I(inode)->root;
4142 int ret;
4143
4144 /* align the range */
4145 len = round_up(start + len, root->sectorsize) -
4146 round_down(start, root->sectorsize);
4147 start = round_down(start, root->sectorsize);
4148
4149 ret = btrfs_alloc_data_chunk_ondemand(inode, len);
4150 if (ret < 0)
4151 return ret;
4152
4153 /*
4154 * Use new btrfs_qgroup_reserve_data to reserve precious data space
4155 *
4156 * TODO: Find a good method to avoid reserve data space for NOCOW
4157 * range, but don't impact performance on quota disable case.
4158 */
4159 ret = btrfs_qgroup_reserve_data(inode, start, len);
4160 return ret;
4161 }
4162
4163 /*
4164 * Called if we need to clear a data reservation for this inode
4165 * Normally in a error case.
4166 *
4167 * This one will *NOT* use accurate qgroup reserved space API, just for case
4168 * which we can't sleep and is sure it won't affect qgroup reserved space.
4169 * Like clear_bit_hook().
4170 */
4171 void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start,
4172 u64 len)
4173 {
4174 struct btrfs_root *root = BTRFS_I(inode)->root;
4175 struct btrfs_space_info *data_sinfo;
4176
4177 /* Make sure the range is aligned to sectorsize */
4178 len = round_up(start + len, root->sectorsize) -
4179 round_down(start, root->sectorsize);
4180 start = round_down(start, root->sectorsize);
4181
4182 data_sinfo = root->fs_info->data_sinfo;
4183 spin_lock(&data_sinfo->lock);
4184 if (WARN_ON(data_sinfo->bytes_may_use < len))
4185 data_sinfo->bytes_may_use = 0;
4186 else
4187 data_sinfo->bytes_may_use -= len;
4188 trace_btrfs_space_reservation(root->fs_info, "space_info",
4189 data_sinfo->flags, len, 0);
4190 spin_unlock(&data_sinfo->lock);
4191 }
4192
4193 /*
4194 * Called if we need to clear a data reservation for this inode
4195 * Normally in a error case.
4196 *
4197 * This one will handle the per-indoe data rsv map for accurate reserved
4198 * space framework.
4199 */
4200 void btrfs_free_reserved_data_space(struct inode *inode, u64 start, u64 len)
4201 {
4202 btrfs_free_reserved_data_space_noquota(inode, start, len);
4203 btrfs_qgroup_free_data(inode, start, len);
4204 }
4205
4206 static void force_metadata_allocation(struct btrfs_fs_info *info)
4207 {
4208 struct list_head *head = &info->space_info;
4209 struct btrfs_space_info *found;
4210
4211 rcu_read_lock();
4212 list_for_each_entry_rcu(found, head, list) {
4213 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
4214 found->force_alloc = CHUNK_ALLOC_FORCE;
4215 }
4216 rcu_read_unlock();
4217 }
4218
4219 static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
4220 {
4221 return (global->size << 1);
4222 }
4223
4224 static int should_alloc_chunk(struct btrfs_root *root,
4225 struct btrfs_space_info *sinfo, int force)
4226 {
4227 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
4228 u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
4229 u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
4230 u64 thresh;
4231
4232 if (force == CHUNK_ALLOC_FORCE)
4233 return 1;
4234
4235 /*
4236 * We need to take into account the global rsv because for all intents
4237 * and purposes it's used space. Don't worry about locking the
4238 * global_rsv, it doesn't change except when the transaction commits.
4239 */
4240 if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA)
4241 num_allocated += calc_global_rsv_need_space(global_rsv);
4242
4243 /*
4244 * in limited mode, we want to have some free space up to
4245 * about 1% of the FS size.
4246 */
4247 if (force == CHUNK_ALLOC_LIMITED) {
4248 thresh = btrfs_super_total_bytes(root->fs_info->super_copy);
4249 thresh = max_t(u64, 64 * 1024 * 1024,
4250 div_factor_fine(thresh, 1));
4251
4252 if (num_bytes - num_allocated < thresh)
4253 return 1;
4254 }
4255
4256 if (num_allocated + 2 * 1024 * 1024 < div_factor(num_bytes, 8))
4257 return 0;
4258 return 1;
4259 }
4260
4261 static u64 get_profile_num_devs(struct btrfs_root *root, u64 type)
4262 {
4263 u64 num_dev;
4264
4265 if (type & (BTRFS_BLOCK_GROUP_RAID10 |
4266 BTRFS_BLOCK_GROUP_RAID0 |
4267 BTRFS_BLOCK_GROUP_RAID5 |
4268 BTRFS_BLOCK_GROUP_RAID6))
4269 num_dev = root->fs_info->fs_devices->rw_devices;
4270 else if (type & BTRFS_BLOCK_GROUP_RAID1)
4271 num_dev = 2;
4272 else
4273 num_dev = 1; /* DUP or single */
4274
4275 return num_dev;
4276 }
4277
4278 /*
4279 * If @is_allocation is true, reserve space in the system space info necessary
4280 * for allocating a chunk, otherwise if it's false, reserve space necessary for
4281 * removing a chunk.
4282 */
4283 void check_system_chunk(struct btrfs_trans_handle *trans,
4284 struct btrfs_root *root,
4285 u64 type)
4286 {
4287 struct btrfs_space_info *info;
4288 u64 left;
4289 u64 thresh;
4290 int ret = 0;
4291 u64 num_devs;
4292
4293 /*
4294 * Needed because we can end up allocating a system chunk and for an
4295 * atomic and race free space reservation in the chunk block reserve.
4296 */
4297 ASSERT(mutex_is_locked(&root->fs_info->chunk_mutex));
4298
4299 info = __find_space_info(root->fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
4300 spin_lock(&info->lock);
4301 left = info->total_bytes - info->bytes_used - info->bytes_pinned -
4302 info->bytes_reserved - info->bytes_readonly -
4303 info->bytes_may_use;
4304 spin_unlock(&info->lock);
4305
4306 num_devs = get_profile_num_devs(root, type);
4307
4308 /* num_devs device items to update and 1 chunk item to add or remove */
4309 thresh = btrfs_calc_trunc_metadata_size(root, num_devs) +
4310 btrfs_calc_trans_metadata_size(root, 1);
4311
4312 if (left < thresh && btrfs_test_opt(root, ENOSPC_DEBUG)) {
4313 btrfs_info(root->fs_info, "left=%llu, need=%llu, flags=%llu",
4314 left, thresh, type);
4315 dump_space_info(info, 0, 0);
4316 }
4317
4318 if (left < thresh) {
4319 u64 flags;
4320
4321 flags = btrfs_get_alloc_profile(root->fs_info->chunk_root, 0);
4322 /*
4323 * Ignore failure to create system chunk. We might end up not
4324 * needing it, as we might not need to COW all nodes/leafs from
4325 * the paths we visit in the chunk tree (they were already COWed
4326 * or created in the current transaction for example).
4327 */
4328 ret = btrfs_alloc_chunk(trans, root, flags);
4329 }
4330
4331 if (!ret) {
4332 ret = btrfs_block_rsv_add(root->fs_info->chunk_root,
4333 &root->fs_info->chunk_block_rsv,
4334 thresh, BTRFS_RESERVE_NO_FLUSH);
4335 if (!ret)
4336 trans->chunk_bytes_reserved += thresh;
4337 }
4338 }
4339
4340 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
4341 struct btrfs_root *extent_root, u64 flags, int force)
4342 {
4343 struct btrfs_space_info *space_info;
4344 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4345 int wait_for_alloc = 0;
4346 int ret = 0;
4347
4348 /* Don't re-enter if we're already allocating a chunk */
4349 if (trans->allocating_chunk)
4350 return -ENOSPC;
4351
4352 space_info = __find_space_info(extent_root->fs_info, flags);
4353 if (!space_info) {
4354 ret = update_space_info(extent_root->fs_info, flags,
4355 0, 0, &space_info);
4356 BUG_ON(ret); /* -ENOMEM */
4357 }
4358 BUG_ON(!space_info); /* Logic error */
4359
4360 again:
4361 spin_lock(&space_info->lock);
4362 if (force < space_info->force_alloc)
4363 force = space_info->force_alloc;
4364 if (space_info->full) {
4365 if (should_alloc_chunk(extent_root, space_info, force))
4366 ret = -ENOSPC;
4367 else
4368 ret = 0;
4369 spin_unlock(&space_info->lock);
4370 return ret;
4371 }
4372
4373 if (!should_alloc_chunk(extent_root, space_info, force)) {
4374 spin_unlock(&space_info->lock);
4375 return 0;
4376 } else if (space_info->chunk_alloc) {
4377 wait_for_alloc = 1;
4378 } else {
4379 space_info->chunk_alloc = 1;
4380 }
4381
4382 spin_unlock(&space_info->lock);
4383
4384 mutex_lock(&fs_info->chunk_mutex);
4385
4386 /*
4387 * The chunk_mutex is held throughout the entirety of a chunk
4388 * allocation, so once we've acquired the chunk_mutex we know that the
4389 * other guy is done and we need to recheck and see if we should
4390 * allocate.
4391 */
4392 if (wait_for_alloc) {
4393 mutex_unlock(&fs_info->chunk_mutex);
4394 wait_for_alloc = 0;
4395 cond_resched();
4396 goto again;
4397 }
4398
4399 trans->allocating_chunk = true;
4400
4401 /*
4402 * If we have mixed data/metadata chunks we want to make sure we keep
4403 * allocating mixed chunks instead of individual chunks.
4404 */
4405 if (btrfs_mixed_space_info(space_info))
4406 flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
4407
4408 /*
4409 * if we're doing a data chunk, go ahead and make sure that
4410 * we keep a reasonable number of metadata chunks allocated in the
4411 * FS as well.
4412 */
4413 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
4414 fs_info->data_chunk_allocations++;
4415 if (!(fs_info->data_chunk_allocations %
4416 fs_info->metadata_ratio))
4417 force_metadata_allocation(fs_info);
4418 }
4419
4420 /*
4421 * Check if we have enough space in SYSTEM chunk because we may need
4422 * to update devices.
4423 */
4424 check_system_chunk(trans, extent_root, flags);
4425
4426 ret = btrfs_alloc_chunk(trans, extent_root, flags);
4427 trans->allocating_chunk = false;
4428
4429 spin_lock(&space_info->lock);
4430 if (ret < 0 && ret != -ENOSPC)
4431 goto out;
4432 if (ret)
4433 space_info->full = 1;
4434 else
4435 ret = 1;
4436
4437 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
4438 out:
4439 space_info->chunk_alloc = 0;
4440 spin_unlock(&space_info->lock);
4441 mutex_unlock(&fs_info->chunk_mutex);
4442 /*
4443 * When we allocate a new chunk we reserve space in the chunk block
4444 * reserve to make sure we can COW nodes/leafs in the chunk tree or
4445 * add new nodes/leafs to it if we end up needing to do it when
4446 * inserting the chunk item and updating device items as part of the
4447 * second phase of chunk allocation, performed by
4448 * btrfs_finish_chunk_alloc(). So make sure we don't accumulate a
4449 * large number of new block groups to create in our transaction
4450 * handle's new_bgs list to avoid exhausting the chunk block reserve
4451 * in extreme cases - like having a single transaction create many new
4452 * block groups when starting to write out the free space caches of all
4453 * the block groups that were made dirty during the lifetime of the
4454 * transaction.
4455 */
4456 if (trans->can_flush_pending_bgs &&
4457 trans->chunk_bytes_reserved >= (2 * 1024 * 1024ull)) {
4458 btrfs_create_pending_block_groups(trans, trans->root);
4459 btrfs_trans_release_chunk_metadata(trans);
4460 }
4461 return ret;
4462 }
4463
4464 static int can_overcommit(struct btrfs_root *root,
4465 struct btrfs_space_info *space_info, u64 bytes,
4466 enum btrfs_reserve_flush_enum flush)
4467 {
4468 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
4469 u64 profile = btrfs_get_alloc_profile(root, 0);
4470 u64 space_size;
4471 u64 avail;
4472 u64 used;
4473
4474 used = space_info->bytes_used + space_info->bytes_reserved +
4475 space_info->bytes_pinned + space_info->bytes_readonly;
4476
4477 /*
4478 * We only want to allow over committing if we have lots of actual space
4479 * free, but if we don't have enough space to handle the global reserve
4480 * space then we could end up having a real enospc problem when trying
4481 * to allocate a chunk or some other such important allocation.
4482 */
4483 spin_lock(&global_rsv->lock);
4484 space_size = calc_global_rsv_need_space(global_rsv);
4485 spin_unlock(&global_rsv->lock);
4486 if (used + space_size >= space_info->total_bytes)
4487 return 0;
4488
4489 used += space_info->bytes_may_use;
4490
4491 spin_lock(&root->fs_info->free_chunk_lock);
4492 avail = root->fs_info->free_chunk_space;
4493 spin_unlock(&root->fs_info->free_chunk_lock);
4494
4495 /*
4496 * If we have dup, raid1 or raid10 then only half of the free
4497 * space is actually useable. For raid56, the space info used
4498 * doesn't include the parity drive, so we don't have to
4499 * change the math
4500 */
4501 if (profile & (BTRFS_BLOCK_GROUP_DUP |
4502 BTRFS_BLOCK_GROUP_RAID1 |
4503 BTRFS_BLOCK_GROUP_RAID10))
4504 avail >>= 1;
4505
4506 /*
4507 * If we aren't flushing all things, let us overcommit up to
4508 * 1/2th of the space. If we can flush, don't let us overcommit
4509 * too much, let it overcommit up to 1/8 of the space.
4510 */
4511 if (flush == BTRFS_RESERVE_FLUSH_ALL)
4512 avail >>= 3;
4513 else
4514 avail >>= 1;
4515
4516 if (used + bytes < space_info->total_bytes + avail)
4517 return 1;
4518 return 0;
4519 }
4520
4521 static void btrfs_writeback_inodes_sb_nr(struct btrfs_root *root,
4522 unsigned long nr_pages, int nr_items)
4523 {
4524 struct super_block *sb = root->fs_info->sb;
4525
4526 if (down_read_trylock(&sb->s_umount)) {
4527 writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE);
4528 up_read(&sb->s_umount);
4529 } else {
4530 /*
4531 * We needn't worry the filesystem going from r/w to r/o though
4532 * we don't acquire ->s_umount mutex, because the filesystem
4533 * should guarantee the delalloc inodes list be empty after
4534 * the filesystem is readonly(all dirty pages are written to
4535 * the disk).
4536 */
4537 btrfs_start_delalloc_roots(root->fs_info, 0, nr_items);
4538 if (!current->journal_info)
4539 btrfs_wait_ordered_roots(root->fs_info, nr_items);
4540 }
4541 }
4542
4543 static inline int calc_reclaim_items_nr(struct btrfs_root *root, u64 to_reclaim)
4544 {
4545 u64 bytes;
4546 int nr;
4547
4548 bytes = btrfs_calc_trans_metadata_size(root, 1);
4549 nr = (int)div64_u64(to_reclaim, bytes);
4550 if (!nr)
4551 nr = 1;
4552 return nr;
4553 }
4554
4555 #define EXTENT_SIZE_PER_ITEM (256 * 1024)
4556
4557 /*
4558 * shrink metadata reservation for delalloc
4559 */
4560 static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
4561 bool wait_ordered)
4562 {
4563 struct btrfs_block_rsv *block_rsv;
4564 struct btrfs_space_info *space_info;
4565 struct btrfs_trans_handle *trans;
4566 u64 delalloc_bytes;
4567 u64 max_reclaim;
4568 long time_left;
4569 unsigned long nr_pages;
4570 int loops;
4571 int items;
4572 enum btrfs_reserve_flush_enum flush;
4573
4574 /* Calc the number of the pages we need flush for space reservation */
4575 items = calc_reclaim_items_nr(root, to_reclaim);
4576 to_reclaim = items * EXTENT_SIZE_PER_ITEM;
4577
4578 trans = (struct btrfs_trans_handle *)current->journal_info;
4579 block_rsv = &root->fs_info->delalloc_block_rsv;
4580 space_info = block_rsv->space_info;
4581
4582 delalloc_bytes = percpu_counter_sum_positive(
4583 &root->fs_info->delalloc_bytes);
4584 if (delalloc_bytes == 0) {
4585 if (trans)
4586 return;
4587 if (wait_ordered)
4588 btrfs_wait_ordered_roots(root->fs_info, items);
4589 return;
4590 }
4591
4592 loops = 0;
4593 while (delalloc_bytes && loops < 3) {
4594 max_reclaim = min(delalloc_bytes, to_reclaim);
4595 nr_pages = max_reclaim >> PAGE_CACHE_SHIFT;
4596 btrfs_writeback_inodes_sb_nr(root, nr_pages, items);
4597 /*
4598 * We need to wait for the async pages to actually start before
4599 * we do anything.
4600 */
4601 max_reclaim = atomic_read(&root->fs_info->async_delalloc_pages);
4602 if (!max_reclaim)
4603 goto skip_async;
4604
4605 if (max_reclaim <= nr_pages)
4606 max_reclaim = 0;
4607 else
4608 max_reclaim -= nr_pages;
4609
4610 wait_event(root->fs_info->async_submit_wait,
4611 atomic_read(&root->fs_info->async_delalloc_pages) <=
4612 (int)max_reclaim);
4613 skip_async:
4614 if (!trans)
4615 flush = BTRFS_RESERVE_FLUSH_ALL;
4616 else
4617 flush = BTRFS_RESERVE_NO_FLUSH;
4618 spin_lock(&space_info->lock);
4619 if (can_overcommit(root, space_info, orig, flush)) {
4620 spin_unlock(&space_info->lock);
4621 break;
4622 }
4623 spin_unlock(&space_info->lock);
4624
4625 loops++;
4626 if (wait_ordered && !trans) {
4627 btrfs_wait_ordered_roots(root->fs_info, items);
4628 } else {
4629 time_left = schedule_timeout_killable(1);
4630 if (time_left)
4631 break;
4632 }
4633 delalloc_bytes = percpu_counter_sum_positive(
4634 &root->fs_info->delalloc_bytes);
4635 }
4636 }
4637
4638 /**
4639 * maybe_commit_transaction - possibly commit the transaction if its ok to
4640 * @root - the root we're allocating for
4641 * @bytes - the number of bytes we want to reserve
4642 * @force - force the commit
4643 *
4644 * This will check to make sure that committing the transaction will actually
4645 * get us somewhere and then commit the transaction if it does. Otherwise it
4646 * will return -ENOSPC.
4647 */
4648 static int may_commit_transaction(struct btrfs_root *root,
4649 struct btrfs_space_info *space_info,
4650 u64 bytes, int force)
4651 {
4652 struct btrfs_block_rsv *delayed_rsv = &root->fs_info->delayed_block_rsv;
4653 struct btrfs_trans_handle *trans;
4654
4655 trans = (struct btrfs_trans_handle *)current->journal_info;
4656 if (trans)
4657 return -EAGAIN;
4658
4659 if (force)
4660 goto commit;
4661
4662 /* See if there is enough pinned space to make this reservation */
4663 if (percpu_counter_compare(&space_info->total_bytes_pinned,
4664 bytes) >= 0)
4665 goto commit;
4666
4667 /*
4668 * See if there is some space in the delayed insertion reservation for
4669 * this reservation.
4670 */
4671 if (space_info != delayed_rsv->space_info)
4672 return -ENOSPC;
4673
4674 spin_lock(&delayed_rsv->lock);
4675 if (percpu_counter_compare(&space_info->total_bytes_pinned,
4676 bytes - delayed_rsv->size) >= 0) {
4677 spin_unlock(&delayed_rsv->lock);
4678 return -ENOSPC;
4679 }
4680 spin_unlock(&delayed_rsv->lock);
4681
4682 commit:
4683 trans = btrfs_join_transaction(root);
4684 if (IS_ERR(trans))
4685 return -ENOSPC;
4686
4687 return btrfs_commit_transaction(trans, root);
4688 }
4689
4690 enum flush_state {
4691 FLUSH_DELAYED_ITEMS_NR = 1,
4692 FLUSH_DELAYED_ITEMS = 2,
4693 FLUSH_DELALLOC = 3,
4694 FLUSH_DELALLOC_WAIT = 4,
4695 ALLOC_CHUNK = 5,
4696 COMMIT_TRANS = 6,
4697 };
4698
4699 static int flush_space(struct btrfs_root *root,
4700 struct btrfs_space_info *space_info, u64 num_bytes,
4701 u64 orig_bytes, int state)
4702 {
4703 struct btrfs_trans_handle *trans;
4704 int nr;
4705 int ret = 0;
4706
4707 switch (state) {
4708 case FLUSH_DELAYED_ITEMS_NR:
4709 case FLUSH_DELAYED_ITEMS:
4710 if (state == FLUSH_DELAYED_ITEMS_NR)
4711 nr = calc_reclaim_items_nr(root, num_bytes) * 2;
4712 else
4713 nr = -1;
4714
4715 trans = btrfs_join_transaction(root);
4716 if (IS_ERR(trans)) {
4717 ret = PTR_ERR(trans);
4718 break;
4719 }
4720 ret = btrfs_run_delayed_items_nr(trans, root, nr);
4721 btrfs_end_transaction(trans, root);
4722 break;
4723 case FLUSH_DELALLOC:
4724 case FLUSH_DELALLOC_WAIT:
4725 shrink_delalloc(root, num_bytes * 2, orig_bytes,
4726 state == FLUSH_DELALLOC_WAIT);
4727 break;
4728 case ALLOC_CHUNK:
4729 trans = btrfs_join_transaction(root);
4730 if (IS_ERR(trans)) {
4731 ret = PTR_ERR(trans);
4732 break;
4733 }
4734 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4735 btrfs_get_alloc_profile(root, 0),
4736 CHUNK_ALLOC_NO_FORCE);
4737 btrfs_end_transaction(trans, root);
4738 if (ret == -ENOSPC)
4739 ret = 0;
4740 break;
4741 case COMMIT_TRANS:
4742 ret = may_commit_transaction(root, space_info, orig_bytes, 0);
4743 break;
4744 default:
4745 ret = -ENOSPC;
4746 break;
4747 }
4748
4749 return ret;
4750 }
4751
4752 static inline u64
4753 btrfs_calc_reclaim_metadata_size(struct btrfs_root *root,
4754 struct btrfs_space_info *space_info)
4755 {
4756 u64 used;
4757 u64 expected;
4758 u64 to_reclaim;
4759
4760 to_reclaim = min_t(u64, num_online_cpus() * 1024 * 1024,
4761 16 * 1024 * 1024);
4762 spin_lock(&space_info->lock);
4763 if (can_overcommit(root, space_info, to_reclaim,
4764 BTRFS_RESERVE_FLUSH_ALL)) {
4765 to_reclaim = 0;
4766 goto out;
4767 }
4768
4769 used = space_info->bytes_used + space_info->bytes_reserved +
4770 space_info->bytes_pinned + space_info->bytes_readonly +
4771 space_info->bytes_may_use;
4772 if (can_overcommit(root, space_info, 1024 * 1024,
4773 BTRFS_RESERVE_FLUSH_ALL))
4774 expected = div_factor_fine(space_info->total_bytes, 95);
4775 else
4776 expected = div_factor_fine(space_info->total_bytes, 90);
4777
4778 if (used > expected)
4779 to_reclaim = used - expected;
4780 else
4781 to_reclaim = 0;
4782 to_reclaim = min(to_reclaim, space_info->bytes_may_use +
4783 space_info->bytes_reserved);
4784 out:
4785 spin_unlock(&space_info->lock);
4786
4787 return to_reclaim;
4788 }
4789
4790 static inline int need_do_async_reclaim(struct btrfs_space_info *space_info,
4791 struct btrfs_fs_info *fs_info, u64 used)
4792 {
4793 u64 thresh = div_factor_fine(space_info->total_bytes, 98);
4794
4795 /* If we're just plain full then async reclaim just slows us down. */
4796 if (space_info->bytes_used >= thresh)
4797 return 0;
4798
4799 return (used >= thresh && !btrfs_fs_closing(fs_info) &&
4800 !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
4801 }
4802
4803 static int btrfs_need_do_async_reclaim(struct btrfs_space_info *space_info,
4804 struct btrfs_fs_info *fs_info,
4805 int flush_state)
4806 {
4807 u64 used;
4808
4809 spin_lock(&space_info->lock);
4810 /*
4811 * We run out of space and have not got any free space via flush_space,
4812 * so don't bother doing async reclaim.
4813 */
4814 if (flush_state > COMMIT_TRANS && space_info->full) {
4815 spin_unlock(&space_info->lock);
4816 return 0;
4817 }
4818
4819 used = space_info->bytes_used + space_info->bytes_reserved +
4820 space_info->bytes_pinned + space_info->bytes_readonly +
4821 space_info->bytes_may_use;
4822 if (need_do_async_reclaim(space_info, fs_info, used)) {
4823 spin_unlock(&space_info->lock);
4824 return 1;
4825 }
4826 spin_unlock(&space_info->lock);
4827
4828 return 0;
4829 }
4830
4831 static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
4832 {
4833 struct btrfs_fs_info *fs_info;
4834 struct btrfs_space_info *space_info;
4835 u64 to_reclaim;
4836 int flush_state;
4837
4838 fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
4839 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
4840
4841 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info->fs_root,
4842 space_info);
4843 if (!to_reclaim)
4844 return;
4845
4846 flush_state = FLUSH_DELAYED_ITEMS_NR;
4847 do {
4848 flush_space(fs_info->fs_root, space_info, to_reclaim,
4849 to_reclaim, flush_state);
4850 flush_state++;
4851 if (!btrfs_need_do_async_reclaim(space_info, fs_info,
4852 flush_state))
4853 return;
4854 } while (flush_state < COMMIT_TRANS);
4855 }
4856
4857 void btrfs_init_async_reclaim_work(struct work_struct *work)
4858 {
4859 INIT_WORK(work, btrfs_async_reclaim_metadata_space);
4860 }
4861
4862 /**
4863 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
4864 * @root - the root we're allocating for
4865 * @block_rsv - the block_rsv we're allocating for
4866 * @orig_bytes - the number of bytes we want
4867 * @flush - whether or not we can flush to make our reservation
4868 *
4869 * This will reserve orgi_bytes number of bytes from the space info associated
4870 * with the block_rsv. If there is not enough space it will make an attempt to
4871 * flush out space to make room. It will do this by flushing delalloc if
4872 * possible or committing the transaction. If flush is 0 then no attempts to
4873 * regain reservations will be made and this will fail if there is not enough
4874 * space already.
4875 */
4876 static int reserve_metadata_bytes(struct btrfs_root *root,
4877 struct btrfs_block_rsv *block_rsv,
4878 u64 orig_bytes,
4879 enum btrfs_reserve_flush_enum flush)
4880 {
4881 struct btrfs_space_info *space_info = block_rsv->space_info;
4882 u64 used;
4883 u64 num_bytes = orig_bytes;
4884 int flush_state = FLUSH_DELAYED_ITEMS_NR;
4885 int ret = 0;
4886 bool flushing = false;
4887
4888 again:
4889 ret = 0;
4890 spin_lock(&space_info->lock);
4891 /*
4892 * We only want to wait if somebody other than us is flushing and we
4893 * are actually allowed to flush all things.
4894 */
4895 while (flush == BTRFS_RESERVE_FLUSH_ALL && !flushing &&
4896 space_info->flush) {
4897 spin_unlock(&space_info->lock);
4898 /*
4899 * If we have a trans handle we can't wait because the flusher
4900 * may have to commit the transaction, which would mean we would
4901 * deadlock since we are waiting for the flusher to finish, but
4902 * hold the current transaction open.
4903 */
4904 if (current->journal_info)
4905 return -EAGAIN;
4906 ret = wait_event_killable(space_info->wait, !space_info->flush);
4907 /* Must have been killed, return */
4908 if (ret)
4909 return -EINTR;
4910
4911 spin_lock(&space_info->lock);
4912 }
4913
4914 ret = -ENOSPC;
4915 used = space_info->bytes_used + space_info->bytes_reserved +
4916 space_info->bytes_pinned + space_info->bytes_readonly +
4917 space_info->bytes_may_use;
4918
4919 /*
4920 * The idea here is that we've not already over-reserved the block group
4921 * then we can go ahead and save our reservation first and then start
4922 * flushing if we need to. Otherwise if we've already overcommitted
4923 * lets start flushing stuff first and then come back and try to make
4924 * our reservation.
4925 */
4926 if (used <= space_info->total_bytes) {
4927 if (used + orig_bytes <= space_info->total_bytes) {
4928 space_info->bytes_may_use += orig_bytes;
4929 trace_btrfs_space_reservation(root->fs_info,
4930 "space_info", space_info->flags, orig_bytes, 1);
4931 ret = 0;
4932 } else {
4933 /*
4934 * Ok set num_bytes to orig_bytes since we aren't
4935 * overocmmitted, this way we only try and reclaim what
4936 * we need.
4937 */
4938 num_bytes = orig_bytes;
4939 }
4940 } else {
4941 /*
4942 * Ok we're over committed, set num_bytes to the overcommitted
4943 * amount plus the amount of bytes that we need for this
4944 * reservation.
4945 */
4946 num_bytes = used - space_info->total_bytes +
4947 (orig_bytes * 2);
4948 }
4949
4950 if (ret && can_overcommit(root, space_info, orig_bytes, flush)) {
4951 space_info->bytes_may_use += orig_bytes;
4952 trace_btrfs_space_reservation(root->fs_info, "space_info",
4953 space_info->flags, orig_bytes,
4954 1);
4955 ret = 0;
4956 }
4957
4958 /*
4959 * Couldn't make our reservation, save our place so while we're trying
4960 * to reclaim space we can actually use it instead of somebody else
4961 * stealing it from us.
4962 *
4963 * We make the other tasks wait for the flush only when we can flush
4964 * all things.
4965 */
4966 if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
4967 flushing = true;
4968 space_info->flush = 1;
4969 } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
4970 used += orig_bytes;
4971 /*
4972 * We will do the space reservation dance during log replay,
4973 * which means we won't have fs_info->fs_root set, so don't do
4974 * the async reclaim as we will panic.
4975 */
4976 if (!root->fs_info->log_root_recovering &&
4977 need_do_async_reclaim(space_info, root->fs_info, used) &&
4978 !work_busy(&root->fs_info->async_reclaim_work))
4979 queue_work(system_unbound_wq,
4980 &root->fs_info->async_reclaim_work);
4981 }
4982 spin_unlock(&space_info->lock);
4983
4984 if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
4985 goto out;
4986
4987 ret = flush_space(root, space_info, num_bytes, orig_bytes,
4988 flush_state);
4989 flush_state++;
4990
4991 /*
4992 * If we are FLUSH_LIMIT, we can not flush delalloc, or the deadlock
4993 * would happen. So skip delalloc flush.
4994 */
4995 if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
4996 (flush_state == FLUSH_DELALLOC ||
4997 flush_state == FLUSH_DELALLOC_WAIT))
4998 flush_state = ALLOC_CHUNK;
4999
5000 if (!ret)
5001 goto again;
5002 else if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
5003 flush_state < COMMIT_TRANS)
5004 goto again;
5005 else if (flush == BTRFS_RESERVE_FLUSH_ALL &&
5006 flush_state <= COMMIT_TRANS)
5007 goto again;
5008
5009 out:
5010 if (ret == -ENOSPC &&
5011 unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
5012 struct btrfs_block_rsv *global_rsv =
5013 &root->fs_info->global_block_rsv;
5014
5015 if (block_rsv != global_rsv &&
5016 !block_rsv_use_bytes(global_rsv, orig_bytes))
5017 ret = 0;
5018 }
5019 if (ret == -ENOSPC)
5020 trace_btrfs_space_reservation(root->fs_info,
5021 "space_info:enospc",
5022 space_info->flags, orig_bytes, 1);
5023 if (flushing) {
5024 spin_lock(&space_info->lock);
5025 space_info->flush = 0;
5026 wake_up_all(&space_info->wait);
5027 spin_unlock(&space_info->lock);
5028 }
5029 return ret;
5030 }
5031
5032 static struct btrfs_block_rsv *get_block_rsv(
5033 const struct btrfs_trans_handle *trans,
5034 const struct btrfs_root *root)
5035 {
5036 struct btrfs_block_rsv *block_rsv = NULL;
5037
5038 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
5039 (root == root->fs_info->csum_root && trans->adding_csums) ||
5040 (root == root->fs_info->uuid_root))
5041 block_rsv = trans->block_rsv;
5042
5043 if (!block_rsv)
5044 block_rsv = root->block_rsv;
5045
5046 if (!block_rsv)
5047 block_rsv = &root->fs_info->empty_block_rsv;
5048
5049 return block_rsv;
5050 }
5051
5052 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
5053 u64 num_bytes)
5054 {
5055 int ret = -ENOSPC;
5056 spin_lock(&block_rsv->lock);
5057 if (block_rsv->reserved >= num_bytes) {
5058 block_rsv->reserved -= num_bytes;
5059 if (block_rsv->reserved < block_rsv->size)
5060 block_rsv->full = 0;
5061 ret = 0;
5062 }
5063 spin_unlock(&block_rsv->lock);
5064 return ret;
5065 }
5066
5067 static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
5068 u64 num_bytes, int update_size)
5069 {
5070 spin_lock(&block_rsv->lock);
5071 block_rsv->reserved += num_bytes;
5072 if (update_size)
5073 block_rsv->size += num_bytes;
5074 else if (block_rsv->reserved >= block_rsv->size)
5075 block_rsv->full = 1;
5076 spin_unlock(&block_rsv->lock);
5077 }
5078
5079 int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
5080 struct btrfs_block_rsv *dest, u64 num_bytes,
5081 int min_factor)
5082 {
5083 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5084 u64 min_bytes;
5085
5086 if (global_rsv->space_info != dest->space_info)
5087 return -ENOSPC;
5088
5089 spin_lock(&global_rsv->lock);
5090 min_bytes = div_factor(global_rsv->size, min_factor);
5091 if (global_rsv->reserved < min_bytes + num_bytes) {
5092 spin_unlock(&global_rsv->lock);
5093 return -ENOSPC;
5094 }
5095 global_rsv->reserved -= num_bytes;
5096 if (global_rsv->reserved < global_rsv->size)
5097 global_rsv->full = 0;
5098 spin_unlock(&global_rsv->lock);
5099
5100 block_rsv_add_bytes(dest, num_bytes, 1);
5101 return 0;
5102 }
5103
5104 static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
5105 struct btrfs_block_rsv *block_rsv,
5106 struct btrfs_block_rsv *dest, u64 num_bytes)
5107 {
5108 struct btrfs_space_info *space_info = block_rsv->space_info;
5109
5110 spin_lock(&block_rsv->lock);
5111 if (num_bytes == (u64)-1)
5112 num_bytes = block_rsv->size;
5113 block_rsv->size -= num_bytes;
5114 if (block_rsv->reserved >= block_rsv->size) {
5115 num_bytes = block_rsv->reserved - block_rsv->size;
5116 block_rsv->reserved = block_rsv->size;
5117 block_rsv->full = 1;
5118 } else {
5119 num_bytes = 0;
5120 }
5121 spin_unlock(&block_rsv->lock);
5122
5123 if (num_bytes > 0) {
5124 if (dest) {
5125 spin_lock(&dest->lock);
5126 if (!dest->full) {
5127 u64 bytes_to_add;
5128
5129 bytes_to_add = dest->size - dest->reserved;
5130 bytes_to_add = min(num_bytes, bytes_to_add);
5131 dest->reserved += bytes_to_add;
5132 if (dest->reserved >= dest->size)
5133 dest->full = 1;
5134 num_bytes -= bytes_to_add;
5135 }
5136 spin_unlock(&dest->lock);
5137 }
5138 if (num_bytes) {
5139 spin_lock(&space_info->lock);
5140 space_info->bytes_may_use -= num_bytes;
5141 trace_btrfs_space_reservation(fs_info, "space_info",
5142 space_info->flags, num_bytes, 0);
5143 spin_unlock(&space_info->lock);
5144 }
5145 }
5146 }
5147
5148 static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
5149 struct btrfs_block_rsv *dst, u64 num_bytes)
5150 {
5151 int ret;
5152
5153 ret = block_rsv_use_bytes(src, num_bytes);
5154 if (ret)
5155 return ret;
5156
5157 block_rsv_add_bytes(dst, num_bytes, 1);
5158 return 0;
5159 }
5160
5161 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
5162 {
5163 memset(rsv, 0, sizeof(*rsv));
5164 spin_lock_init(&rsv->lock);
5165 rsv->type = type;
5166 }
5167
5168 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root,
5169 unsigned short type)
5170 {
5171 struct btrfs_block_rsv *block_rsv;
5172 struct btrfs_fs_info *fs_info = root->fs_info;
5173
5174 block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
5175 if (!block_rsv)
5176 return NULL;
5177
5178 btrfs_init_block_rsv(block_rsv, type);
5179 block_rsv->space_info = __find_space_info(fs_info,
5180 BTRFS_BLOCK_GROUP_METADATA);
5181 return block_rsv;
5182 }
5183
5184 void btrfs_free_block_rsv(struct btrfs_root *root,
5185 struct btrfs_block_rsv *rsv)
5186 {
5187 if (!rsv)
5188 return;
5189 btrfs_block_rsv_release(root, rsv, (u64)-1);
5190 kfree(rsv);
5191 }
5192
5193 void __btrfs_free_block_rsv(struct btrfs_block_rsv *rsv)
5194 {
5195 kfree(rsv);
5196 }
5197
5198 int btrfs_block_rsv_add(struct btrfs_root *root,
5199 struct btrfs_block_rsv *block_rsv, u64 num_bytes,
5200 enum btrfs_reserve_flush_enum flush)
5201 {
5202 int ret;
5203
5204 if (num_bytes == 0)
5205 return 0;
5206
5207 ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
5208 if (!ret) {
5209 block_rsv_add_bytes(block_rsv, num_bytes, 1);
5210 return 0;
5211 }
5212
5213 return ret;
5214 }
5215
5216 int btrfs_block_rsv_check(struct btrfs_root *root,
5217 struct btrfs_block_rsv *block_rsv, int min_factor)
5218 {
5219 u64 num_bytes = 0;
5220 int ret = -ENOSPC;
5221
5222 if (!block_rsv)
5223 return 0;
5224
5225 spin_lock(&block_rsv->lock);
5226 num_bytes = div_factor(block_rsv->size, min_factor);
5227 if (block_rsv->reserved >= num_bytes)
5228 ret = 0;
5229 spin_unlock(&block_rsv->lock);
5230
5231 return ret;
5232 }
5233
5234 int btrfs_block_rsv_refill(struct btrfs_root *root,
5235 struct btrfs_block_rsv *block_rsv, u64 min_reserved,
5236 enum btrfs_reserve_flush_enum flush)
5237 {
5238 u64 num_bytes = 0;
5239 int ret = -ENOSPC;
5240
5241 if (!block_rsv)
5242 return 0;
5243
5244 spin_lock(&block_rsv->lock);
5245 num_bytes = min_reserved;
5246 if (block_rsv->reserved >= num_bytes)
5247 ret = 0;
5248 else
5249 num_bytes -= block_rsv->reserved;
5250 spin_unlock(&block_rsv->lock);
5251
5252 if (!ret)
5253 return 0;
5254
5255 ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
5256 if (!ret) {
5257 block_rsv_add_bytes(block_rsv, num_bytes, 0);
5258 return 0;
5259 }
5260
5261 return ret;
5262 }
5263
5264 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
5265 struct btrfs_block_rsv *dst_rsv,
5266 u64 num_bytes)
5267 {
5268 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
5269 }
5270
5271 void btrfs_block_rsv_release(struct btrfs_root *root,
5272 struct btrfs_block_rsv *block_rsv,
5273 u64 num_bytes)
5274 {
5275 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
5276 if (global_rsv == block_rsv ||
5277 block_rsv->space_info != global_rsv->space_info)
5278 global_rsv = NULL;
5279 block_rsv_release_bytes(root->fs_info, block_rsv, global_rsv,
5280 num_bytes);
5281 }
5282
5283 /*
5284 * helper to calculate size of global block reservation.
5285 * the desired value is sum of space used by extent tree,
5286 * checksum tree and root tree
5287 */
5288 static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
5289 {
5290 struct btrfs_space_info *sinfo;
5291 u64 num_bytes;
5292 u64 meta_used;
5293 u64 data_used;
5294 int csum_size = btrfs_super_csum_size(fs_info->super_copy);
5295
5296 sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
5297 spin_lock(&sinfo->lock);
5298 data_used = sinfo->bytes_used;
5299 spin_unlock(&sinfo->lock);
5300
5301 sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
5302 spin_lock(&sinfo->lock);
5303 if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
5304 data_used = 0;
5305 meta_used = sinfo->bytes_used;
5306 spin_unlock(&sinfo->lock);
5307
5308 num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
5309 csum_size * 2;
5310 num_bytes += div_u64(data_used + meta_used, 50);
5311
5312 if (num_bytes * 3 > meta_used)
5313 num_bytes = div_u64(meta_used, 3);
5314
5315 return ALIGN(num_bytes, fs_info->extent_root->nodesize << 10);
5316 }
5317
5318 static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
5319 {
5320 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
5321 struct btrfs_space_info *sinfo = block_rsv->space_info;
5322 u64 num_bytes;
5323
5324 num_bytes = calc_global_metadata_size(fs_info);
5325
5326 spin_lock(&sinfo->lock);
5327 spin_lock(&block_rsv->lock);
5328
5329 block_rsv->size = min_t(u64, num_bytes, 512 * 1024 * 1024);
5330
5331 num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
5332 sinfo->bytes_reserved + sinfo->bytes_readonly +
5333 sinfo->bytes_may_use;
5334
5335 if (sinfo->total_bytes > num_bytes) {
5336 num_bytes = sinfo->total_bytes - num_bytes;
5337 block_rsv->reserved += num_bytes;
5338 sinfo->bytes_may_use += num_bytes;
5339 trace_btrfs_space_reservation(fs_info, "space_info",
5340 sinfo->flags, num_bytes, 1);
5341 }
5342
5343 if (block_rsv->reserved >= block_rsv->size) {
5344 num_bytes = block_rsv->reserved - block_rsv->size;
5345 sinfo->bytes_may_use -= num_bytes;
5346 trace_btrfs_space_reservation(fs_info, "space_info",
5347 sinfo->flags, num_bytes, 0);
5348 block_rsv->reserved = block_rsv->size;
5349 block_rsv->full = 1;
5350 }
5351
5352 spin_unlock(&block_rsv->lock);
5353 spin_unlock(&sinfo->lock);
5354 }
5355
5356 static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
5357 {
5358 struct btrfs_space_info *space_info;
5359
5360 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
5361 fs_info->chunk_block_rsv.space_info = space_info;
5362
5363 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
5364 fs_info->global_block_rsv.space_info = space_info;
5365 fs_info->delalloc_block_rsv.space_info = space_info;
5366 fs_info->trans_block_rsv.space_info = space_info;
5367 fs_info->empty_block_rsv.space_info = space_info;
5368 fs_info->delayed_block_rsv.space_info = space_info;
5369
5370 fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
5371 fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
5372 fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
5373 fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
5374 if (fs_info->quota_root)
5375 fs_info->quota_root->block_rsv = &fs_info->global_block_rsv;
5376 fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
5377
5378 update_global_block_rsv(fs_info);
5379 }
5380
5381 static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
5382 {
5383 block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL,
5384 (u64)-1);
5385 WARN_ON(fs_info->delalloc_block_rsv.size > 0);
5386 WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
5387 WARN_ON(fs_info->trans_block_rsv.size > 0);
5388 WARN_ON(fs_info->trans_block_rsv.reserved > 0);
5389 WARN_ON(fs_info->chunk_block_rsv.size > 0);
5390 WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
5391 WARN_ON(fs_info->delayed_block_rsv.size > 0);
5392 WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
5393 }
5394
5395 void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
5396 struct btrfs_root *root)
5397 {
5398 if (!trans->block_rsv)
5399 return;
5400
5401 if (!trans->bytes_reserved)
5402 return;
5403
5404 trace_btrfs_space_reservation(root->fs_info, "transaction",
5405 trans->transid, trans->bytes_reserved, 0);
5406 btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved);
5407 trans->bytes_reserved = 0;
5408 }
5409
5410 /*
5411 * To be called after all the new block groups attached to the transaction
5412 * handle have been created (btrfs_create_pending_block_groups()).
5413 */
5414 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans)
5415 {
5416 struct btrfs_fs_info *fs_info = trans->root->fs_info;
5417
5418 if (!trans->chunk_bytes_reserved)
5419 return;
5420
5421 WARN_ON_ONCE(!list_empty(&trans->new_bgs));
5422
5423 block_rsv_release_bytes(fs_info, &fs_info->chunk_block_rsv, NULL,
5424 trans->chunk_bytes_reserved);
5425 trans->chunk_bytes_reserved = 0;
5426 }
5427
5428 /* Can only return 0 or -ENOSPC */
5429 int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
5430 struct inode *inode)
5431 {
5432 struct btrfs_root *root = BTRFS_I(inode)->root;
5433 struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
5434 struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
5435
5436 /*
5437 * We need to hold space in order to delete our orphan item once we've
5438 * added it, so this takes the reservation so we can release it later
5439 * when we are truly done with the orphan item.
5440 */
5441 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
5442 trace_btrfs_space_reservation(root->fs_info, "orphan",
5443 btrfs_ino(inode), num_bytes, 1);
5444 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
5445 }
5446
5447 void btrfs_orphan_release_metadata(struct inode *inode)
5448 {
5449 struct btrfs_root *root = BTRFS_I(inode)->root;
5450 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
5451 trace_btrfs_space_reservation(root->fs_info, "orphan",
5452 btrfs_ino(inode), num_bytes, 0);
5453 btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
5454 }
5455
5456 /*
5457 * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
5458 * root: the root of the parent directory
5459 * rsv: block reservation
5460 * items: the number of items that we need do reservation
5461 * qgroup_reserved: used to return the reserved size in qgroup
5462 *
5463 * This function is used to reserve the space for snapshot/subvolume
5464 * creation and deletion. Those operations are different with the
5465 * common file/directory operations, they change two fs/file trees
5466 * and root tree, the number of items that the qgroup reserves is
5467 * different with the free space reservation. So we can not use
5468 * the space reseravtion mechanism in start_transaction().
5469 */
5470 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
5471 struct btrfs_block_rsv *rsv,
5472 int items,
5473 u64 *qgroup_reserved,
5474 bool use_global_rsv)
5475 {
5476 u64 num_bytes;
5477 int ret;
5478 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
5479
5480 if (root->fs_info->quota_enabled) {
5481 /* One for parent inode, two for dir entries */
5482 num_bytes = 3 * root->nodesize;
5483 ret = btrfs_qgroup_reserve_meta(root, num_bytes);
5484 if (ret)
5485 return ret;
5486 } else {
5487 num_bytes = 0;
5488 }
5489
5490 *qgroup_reserved = num_bytes;
5491
5492 num_bytes = btrfs_calc_trans_metadata_size(root, items);
5493 rsv->space_info = __find_space_info(root->fs_info,
5494 BTRFS_BLOCK_GROUP_METADATA);
5495 ret = btrfs_block_rsv_add(root, rsv, num_bytes,
5496 BTRFS_RESERVE_FLUSH_ALL);
5497
5498 if (ret == -ENOSPC && use_global_rsv)
5499 ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes);
5500
5501 if (ret && *qgroup_reserved)
5502 btrfs_qgroup_free_meta(root, *qgroup_reserved);
5503
5504 return ret;
5505 }
5506
5507 void btrfs_subvolume_release_metadata(struct btrfs_root *root,
5508 struct btrfs_block_rsv *rsv,
5509 u64 qgroup_reserved)
5510 {
5511 btrfs_block_rsv_release(root, rsv, (u64)-1);
5512 }
5513
5514 /**
5515 * drop_outstanding_extent - drop an outstanding extent
5516 * @inode: the inode we're dropping the extent for
5517 * @num_bytes: the number of bytes we're relaseing.
5518 *
5519 * This is called when we are freeing up an outstanding extent, either called
5520 * after an error or after an extent is written. This will return the number of
5521 * reserved extents that need to be freed. This must be called with
5522 * BTRFS_I(inode)->lock held.
5523 */
5524 static unsigned drop_outstanding_extent(struct inode *inode, u64 num_bytes)
5525 {
5526 unsigned drop_inode_space = 0;
5527 unsigned dropped_extents = 0;
5528 unsigned num_extents = 0;
5529
5530 num_extents = (unsigned)div64_u64(num_bytes +
5531 BTRFS_MAX_EXTENT_SIZE - 1,
5532 BTRFS_MAX_EXTENT_SIZE);
5533 ASSERT(num_extents);
5534 ASSERT(BTRFS_I(inode)->outstanding_extents >= num_extents);
5535 BTRFS_I(inode)->outstanding_extents -= num_extents;
5536
5537 if (BTRFS_I(inode)->outstanding_extents == 0 &&
5538 test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
5539 &BTRFS_I(inode)->runtime_flags))
5540 drop_inode_space = 1;
5541
5542 /*
5543 * If we have more or the same amount of outsanding extents than we have
5544 * reserved then we need to leave the reserved extents count alone.
5545 */
5546 if (BTRFS_I(inode)->outstanding_extents >=
5547 BTRFS_I(inode)->reserved_extents)
5548 return drop_inode_space;
5549
5550 dropped_extents = BTRFS_I(inode)->reserved_extents -
5551 BTRFS_I(inode)->outstanding_extents;
5552 BTRFS_I(inode)->reserved_extents -= dropped_extents;
5553 return dropped_extents + drop_inode_space;
5554 }
5555
5556 /**
5557 * calc_csum_metadata_size - return the amount of metada space that must be
5558 * reserved/free'd for the given bytes.
5559 * @inode: the inode we're manipulating
5560 * @num_bytes: the number of bytes in question
5561 * @reserve: 1 if we are reserving space, 0 if we are freeing space
5562 *
5563 * This adjusts the number of csum_bytes in the inode and then returns the
5564 * correct amount of metadata that must either be reserved or freed. We
5565 * calculate how many checksums we can fit into one leaf and then divide the
5566 * number of bytes that will need to be checksumed by this value to figure out
5567 * how many checksums will be required. If we are adding bytes then the number
5568 * may go up and we will return the number of additional bytes that must be
5569 * reserved. If it is going down we will return the number of bytes that must
5570 * be freed.
5571 *
5572 * This must be called with BTRFS_I(inode)->lock held.
5573 */
5574 static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes,
5575 int reserve)
5576 {
5577 struct btrfs_root *root = BTRFS_I(inode)->root;
5578 u64 old_csums, num_csums;
5579
5580 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM &&
5581 BTRFS_I(inode)->csum_bytes == 0)
5582 return 0;
5583
5584 old_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
5585 if (reserve)
5586 BTRFS_I(inode)->csum_bytes += num_bytes;
5587 else
5588 BTRFS_I(inode)->csum_bytes -= num_bytes;
5589 num_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
5590
5591 /* No change, no need to reserve more */
5592 if (old_csums == num_csums)
5593 return 0;
5594
5595 if (reserve)
5596 return btrfs_calc_trans_metadata_size(root,
5597 num_csums - old_csums);
5598
5599 return btrfs_calc_trans_metadata_size(root, old_csums - num_csums);
5600 }
5601
5602 int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
5603 {
5604 struct btrfs_root *root = BTRFS_I(inode)->root;
5605 struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
5606 u64 to_reserve = 0;
5607 u64 csum_bytes;
5608 unsigned nr_extents = 0;
5609 int extra_reserve = 0;
5610 enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL;
5611 int ret = 0;
5612 bool delalloc_lock = true;
5613 u64 to_free = 0;
5614 unsigned dropped;
5615
5616 /* If we are a free space inode we need to not flush since we will be in
5617 * the middle of a transaction commit. We also don't need the delalloc
5618 * mutex since we won't race with anybody. We need this mostly to make
5619 * lockdep shut its filthy mouth.
5620 */
5621 if (btrfs_is_free_space_inode(inode)) {
5622 flush = BTRFS_RESERVE_NO_FLUSH;
5623 delalloc_lock = false;
5624 }
5625
5626 if (flush != BTRFS_RESERVE_NO_FLUSH &&
5627 btrfs_transaction_in_commit(root->fs_info))
5628 schedule_timeout(1);
5629
5630 if (delalloc_lock)
5631 mutex_lock(&BTRFS_I(inode)->delalloc_mutex);
5632
5633 num_bytes = ALIGN(num_bytes, root->sectorsize);
5634
5635 spin_lock(&BTRFS_I(inode)->lock);
5636 nr_extents = (unsigned)div64_u64(num_bytes +
5637 BTRFS_MAX_EXTENT_SIZE - 1,
5638 BTRFS_MAX_EXTENT_SIZE);
5639 BTRFS_I(inode)->outstanding_extents += nr_extents;
5640 nr_extents = 0;
5641
5642 if (BTRFS_I(inode)->outstanding_extents >
5643 BTRFS_I(inode)->reserved_extents)
5644 nr_extents = BTRFS_I(inode)->outstanding_extents -
5645 BTRFS_I(inode)->reserved_extents;
5646
5647 /*
5648 * Add an item to reserve for updating the inode when we complete the
5649 * delalloc io.
5650 */
5651 if (!test_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
5652 &BTRFS_I(inode)->runtime_flags)) {
5653 nr_extents++;
5654 extra_reserve = 1;
5655 }
5656
5657 to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
5658 to_reserve += calc_csum_metadata_size(inode, num_bytes, 1);
5659 csum_bytes = BTRFS_I(inode)->csum_bytes;
5660 spin_unlock(&BTRFS_I(inode)->lock);
5661
5662 if (root->fs_info->quota_enabled) {
5663 ret = btrfs_qgroup_reserve_meta(root,
5664 nr_extents * root->nodesize);
5665 if (ret)
5666 goto out_fail;
5667 }
5668
5669 ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush);
5670 if (unlikely(ret)) {
5671 btrfs_qgroup_free_meta(root, nr_extents * root->nodesize);
5672 goto out_fail;
5673 }
5674
5675 spin_lock(&BTRFS_I(inode)->lock);
5676 if (extra_reserve) {
5677 set_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
5678 &BTRFS_I(inode)->runtime_flags);
5679 nr_extents--;
5680 }
5681 BTRFS_I(inode)->reserved_extents += nr_extents;
5682 spin_unlock(&BTRFS_I(inode)->lock);
5683
5684 if (delalloc_lock)
5685 mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
5686
5687 if (to_reserve)
5688 trace_btrfs_space_reservation(root->fs_info, "delalloc",
5689 btrfs_ino(inode), to_reserve, 1);
5690 block_rsv_add_bytes(block_rsv, to_reserve, 1);
5691
5692 return 0;
5693
5694 out_fail:
5695 spin_lock(&BTRFS_I(inode)->lock);
5696 dropped = drop_outstanding_extent(inode, num_bytes);
5697 /*
5698 * If the inodes csum_bytes is the same as the original
5699 * csum_bytes then we know we haven't raced with any free()ers
5700 * so we can just reduce our inodes csum bytes and carry on.
5701 */
5702 if (BTRFS_I(inode)->csum_bytes == csum_bytes) {
5703 calc_csum_metadata_size(inode, num_bytes, 0);
5704 } else {
5705 u64 orig_csum_bytes = BTRFS_I(inode)->csum_bytes;
5706 u64 bytes;
5707
5708 /*
5709 * This is tricky, but first we need to figure out how much we
5710 * free'd from any free-ers that occured during this
5711 * reservation, so we reset ->csum_bytes to the csum_bytes
5712 * before we dropped our lock, and then call the free for the
5713 * number of bytes that were freed while we were trying our
5714 * reservation.
5715 */
5716 bytes = csum_bytes - BTRFS_I(inode)->csum_bytes;
5717 BTRFS_I(inode)->csum_bytes = csum_bytes;
5718 to_free = calc_csum_metadata_size(inode, bytes, 0);
5719
5720
5721 /*
5722 * Now we need to see how much we would have freed had we not
5723 * been making this reservation and our ->csum_bytes were not
5724 * artificially inflated.
5725 */
5726 BTRFS_I(inode)->csum_bytes = csum_bytes - num_bytes;
5727 bytes = csum_bytes - orig_csum_bytes;
5728 bytes = calc_csum_metadata_size(inode, bytes, 0);
5729
5730 /*
5731 * Now reset ->csum_bytes to what it should be. If bytes is
5732 * more than to_free then we would have free'd more space had we
5733 * not had an artificially high ->csum_bytes, so we need to free
5734 * the remainder. If bytes is the same or less then we don't
5735 * need to do anything, the other free-ers did the correct
5736 * thing.
5737 */
5738 BTRFS_I(inode)->csum_bytes = orig_csum_bytes - num_bytes;
5739 if (bytes > to_free)
5740 to_free = bytes - to_free;
5741 else
5742 to_free = 0;
5743 }
5744 spin_unlock(&BTRFS_I(inode)->lock);
5745 if (dropped)
5746 to_free += btrfs_calc_trans_metadata_size(root, dropped);
5747
5748 if (to_free) {
5749 btrfs_block_rsv_release(root, block_rsv, to_free);
5750 trace_btrfs_space_reservation(root->fs_info, "delalloc",
5751 btrfs_ino(inode), to_free, 0);
5752 }
5753 if (delalloc_lock)
5754 mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
5755 return ret;
5756 }
5757
5758 /**
5759 * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
5760 * @inode: the inode to release the reservation for
5761 * @num_bytes: the number of bytes we're releasing
5762 *
5763 * This will release the metadata reservation for an inode. This can be called
5764 * once we complete IO for a given set of bytes to release their metadata
5765 * reservations.
5766 */
5767 void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
5768 {
5769 struct btrfs_root *root = BTRFS_I(inode)->root;
5770 u64 to_free = 0;
5771 unsigned dropped;
5772
5773 num_bytes = ALIGN(num_bytes, root->sectorsize);
5774 spin_lock(&BTRFS_I(inode)->lock);
5775 dropped = drop_outstanding_extent(inode, num_bytes);
5776
5777 if (num_bytes)
5778 to_free = calc_csum_metadata_size(inode, num_bytes, 0);
5779 spin_unlock(&BTRFS_I(inode)->lock);
5780 if (dropped > 0)
5781 to_free += btrfs_calc_trans_metadata_size(root, dropped);
5782
5783 if (btrfs_test_is_dummy_root(root))
5784 return;
5785
5786 trace_btrfs_space_reservation(root->fs_info, "delalloc",
5787 btrfs_ino(inode), to_free, 0);
5788
5789 btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
5790 to_free);
5791 }
5792
5793 /**
5794 * btrfs_delalloc_reserve_space - reserve data and metadata space for
5795 * delalloc
5796 * @inode: inode we're writing to
5797 * @start: start range we are writing to
5798 * @len: how long the range we are writing to
5799 *
5800 * TODO: This function will finally replace old btrfs_delalloc_reserve_space()
5801 *
5802 * This will do the following things
5803 *
5804 * o reserve space in data space info for num bytes
5805 * and reserve precious corresponding qgroup space
5806 * (Done in check_data_free_space)
5807 *
5808 * o reserve space for metadata space, based on the number of outstanding
5809 * extents and how much csums will be needed
5810 * also reserve metadata space in a per root over-reserve method.
5811 * o add to the inodes->delalloc_bytes
5812 * o add it to the fs_info's delalloc inodes list.
5813 * (Above 3 all done in delalloc_reserve_metadata)
5814 *
5815 * Return 0 for success
5816 * Return <0 for error(-ENOSPC or -EQUOT)
5817 */
5818 int btrfs_delalloc_reserve_space(struct inode *inode, u64 start, u64 len)
5819 {
5820 int ret;
5821
5822 ret = btrfs_check_data_free_space(inode, start, len);
5823 if (ret < 0)
5824 return ret;
5825 ret = btrfs_delalloc_reserve_metadata(inode, len);
5826 if (ret < 0)
5827 btrfs_free_reserved_data_space(inode, start, len);
5828 return ret;
5829 }
5830
5831 /**
5832 * btrfs_delalloc_release_space - release data and metadata space for delalloc
5833 * @inode: inode we're releasing space for
5834 * @start: start position of the space already reserved
5835 * @len: the len of the space already reserved
5836 *
5837 * This must be matched with a call to btrfs_delalloc_reserve_space. This is
5838 * called in the case that we don't need the metadata AND data reservations
5839 * anymore. So if there is an error or we insert an inline extent.
5840 *
5841 * This function will release the metadata space that was not used and will
5842 * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
5843 * list if there are no delalloc bytes left.
5844 * Also it will handle the qgroup reserved space.
5845 */
5846 void btrfs_delalloc_release_space(struct inode *inode, u64 start, u64 len)
5847 {
5848 btrfs_delalloc_release_metadata(inode, len);
5849 btrfs_free_reserved_data_space(inode, start, len);
5850 }
5851
5852 static int update_block_group(struct btrfs_trans_handle *trans,
5853 struct btrfs_root *root, u64 bytenr,
5854 u64 num_bytes, int alloc)
5855 {
5856 struct btrfs_block_group_cache *cache = NULL;
5857 struct btrfs_fs_info *info = root->fs_info;
5858 u64 total = num_bytes;
5859 u64 old_val;
5860 u64 byte_in_group;
5861 int factor;
5862
5863 /* block accounting for super block */
5864 spin_lock(&info->delalloc_root_lock);
5865 old_val = btrfs_super_bytes_used(info->super_copy);
5866 if (alloc)
5867 old_val += num_bytes;
5868 else
5869 old_val -= num_bytes;
5870 btrfs_set_super_bytes_used(info->super_copy, old_val);
5871 spin_unlock(&info->delalloc_root_lock);
5872
5873 while (total) {
5874 cache = btrfs_lookup_block_group(info, bytenr);
5875 if (!cache)
5876 return -ENOENT;
5877 if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
5878 BTRFS_BLOCK_GROUP_RAID1 |
5879 BTRFS_BLOCK_GROUP_RAID10))
5880 factor = 2;
5881 else
5882 factor = 1;
5883 /*
5884 * If this block group has free space cache written out, we
5885 * need to make sure to load it if we are removing space. This
5886 * is because we need the unpinning stage to actually add the
5887 * space back to the block group, otherwise we will leak space.
5888 */
5889 if (!alloc && cache->cached == BTRFS_CACHE_NO)
5890 cache_block_group(cache, 1);
5891
5892 byte_in_group = bytenr - cache->key.objectid;
5893 WARN_ON(byte_in_group > cache->key.offset);
5894
5895 spin_lock(&cache->space_info->lock);
5896 spin_lock(&cache->lock);
5897
5898 if (btrfs_test_opt(root, SPACE_CACHE) &&
5899 cache->disk_cache_state < BTRFS_DC_CLEAR)
5900 cache->disk_cache_state = BTRFS_DC_CLEAR;
5901
5902 old_val = btrfs_block_group_used(&cache->item);
5903 num_bytes = min(total, cache->key.offset - byte_in_group);
5904 if (alloc) {
5905 old_val += num_bytes;
5906 btrfs_set_block_group_used(&cache->item, old_val);
5907 cache->reserved -= num_bytes;
5908 cache->space_info->bytes_reserved -= num_bytes;
5909 cache->space_info->bytes_used += num_bytes;
5910 cache->space_info->disk_used += num_bytes * factor;
5911 spin_unlock(&cache->lock);
5912 spin_unlock(&cache->space_info->lock);
5913 } else {
5914 old_val -= num_bytes;
5915 btrfs_set_block_group_used(&cache->item, old_val);
5916 cache->pinned += num_bytes;
5917 cache->space_info->bytes_pinned += num_bytes;
5918 cache->space_info->bytes_used -= num_bytes;
5919 cache->space_info->disk_used -= num_bytes * factor;
5920 spin_unlock(&cache->lock);
5921 spin_unlock(&cache->space_info->lock);
5922
5923 set_extent_dirty(info->pinned_extents,
5924 bytenr, bytenr + num_bytes - 1,
5925 GFP_NOFS | __GFP_NOFAIL);
5926 }
5927
5928 spin_lock(&trans->transaction->dirty_bgs_lock);
5929 if (list_empty(&cache->dirty_list)) {
5930 list_add_tail(&cache->dirty_list,
5931 &trans->transaction->dirty_bgs);
5932 trans->transaction->num_dirty_bgs++;
5933 btrfs_get_block_group(cache);
5934 }
5935 spin_unlock(&trans->transaction->dirty_bgs_lock);
5936
5937 /*
5938 * No longer have used bytes in this block group, queue it for
5939 * deletion. We do this after adding the block group to the
5940 * dirty list to avoid races between cleaner kthread and space
5941 * cache writeout.
5942 */
5943 if (!alloc && old_val == 0) {
5944 spin_lock(&info->unused_bgs_lock);
5945 if (list_empty(&cache->bg_list)) {
5946 btrfs_get_block_group(cache);
5947 list_add_tail(&cache->bg_list,
5948 &info->unused_bgs);
5949 }
5950 spin_unlock(&info->unused_bgs_lock);
5951 }
5952
5953 btrfs_put_block_group(cache);
5954 total -= num_bytes;
5955 bytenr += num_bytes;
5956 }
5957 return 0;
5958 }
5959
5960 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
5961 {
5962 struct btrfs_block_group_cache *cache;
5963 u64 bytenr;
5964
5965 spin_lock(&root->fs_info->block_group_cache_lock);
5966 bytenr = root->fs_info->first_logical_byte;
5967 spin_unlock(&root->fs_info->block_group_cache_lock);
5968
5969 if (bytenr < (u64)-1)
5970 return bytenr;
5971
5972 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
5973 if (!cache)
5974 return 0;
5975
5976 bytenr = cache->key.objectid;
5977 btrfs_put_block_group(cache);
5978
5979 return bytenr;
5980 }
5981
5982 static int pin_down_extent(struct btrfs_root *root,
5983 struct btrfs_block_group_cache *cache,
5984 u64 bytenr, u64 num_bytes, int reserved)
5985 {
5986 spin_lock(&cache->space_info->lock);
5987 spin_lock(&cache->lock);
5988 cache->pinned += num_bytes;
5989 cache->space_info->bytes_pinned += num_bytes;
5990 if (reserved) {
5991 cache->reserved -= num_bytes;
5992 cache->space_info->bytes_reserved -= num_bytes;
5993 }
5994 spin_unlock(&cache->lock);
5995 spin_unlock(&cache->space_info->lock);
5996
5997 set_extent_dirty(root->fs_info->pinned_extents, bytenr,
5998 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
5999 if (reserved)
6000 trace_btrfs_reserved_extent_free(root, bytenr, num_bytes);
6001 return 0;
6002 }
6003
6004 /*
6005 * this function must be called within transaction
6006 */
6007 int btrfs_pin_extent(struct btrfs_root *root,
6008 u64 bytenr, u64 num_bytes, int reserved)
6009 {
6010 struct btrfs_block_group_cache *cache;
6011
6012 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
6013 BUG_ON(!cache); /* Logic error */
6014
6015 pin_down_extent(root, cache, bytenr, num_bytes, reserved);
6016
6017 btrfs_put_block_group(cache);
6018 return 0;
6019 }
6020
6021 /*
6022 * this function must be called within transaction
6023 */
6024 int btrfs_pin_extent_for_log_replay(struct btrfs_root *root,
6025 u64 bytenr, u64 num_bytes)
6026 {
6027 struct btrfs_block_group_cache *cache;
6028 int ret;
6029
6030 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
6031 if (!cache)
6032 return -EINVAL;
6033
6034 /*
6035 * pull in the free space cache (if any) so that our pin
6036 * removes the free space from the cache. We have load_only set
6037 * to one because the slow code to read in the free extents does check
6038 * the pinned extents.
6039 */
6040 cache_block_group(cache, 1);
6041
6042 pin_down_extent(root, cache, bytenr, num_bytes, 0);
6043
6044 /* remove us from the free space cache (if we're there at all) */
6045 ret = btrfs_remove_free_space(cache, bytenr, num_bytes);
6046 btrfs_put_block_group(cache);
6047 return ret;
6048 }
6049
6050 static int __exclude_logged_extent(struct btrfs_root *root, u64 start, u64 num_bytes)
6051 {
6052 int ret;
6053 struct btrfs_block_group_cache *block_group;
6054 struct btrfs_caching_control *caching_ctl;
6055
6056 block_group = btrfs_lookup_block_group(root->fs_info, start);
6057 if (!block_group)
6058 return -EINVAL;
6059
6060 cache_block_group(block_group, 0);
6061 caching_ctl = get_caching_control(block_group);
6062
6063 if (!caching_ctl) {
6064 /* Logic error */
6065 BUG_ON(!block_group_cache_done(block_group));
6066 ret = btrfs_remove_free_space(block_group, start, num_bytes);
6067 } else {
6068 mutex_lock(&caching_ctl->mutex);
6069
6070 if (start >= caching_ctl->progress) {
6071 ret = add_excluded_extent(root, start, num_bytes);
6072 } else if (start + num_bytes <= caching_ctl->progress) {
6073 ret = btrfs_remove_free_space(block_group,
6074 start, num_bytes);
6075 } else {
6076 num_bytes = caching_ctl->progress - start;
6077 ret = btrfs_remove_free_space(block_group,
6078 start, num_bytes);
6079 if (ret)
6080 goto out_lock;
6081
6082 num_bytes = (start + num_bytes) -
6083 caching_ctl->progress;
6084 start = caching_ctl->progress;
6085 ret = add_excluded_extent(root, start, num_bytes);
6086 }
6087 out_lock:
6088 mutex_unlock(&caching_ctl->mutex);
6089 put_caching_control(caching_ctl);
6090 }
6091 btrfs_put_block_group(block_group);
6092 return ret;
6093 }
6094
6095 int btrfs_exclude_logged_extents(struct btrfs_root *log,
6096 struct extent_buffer *eb)
6097 {
6098 struct btrfs_file_extent_item *item;
6099 struct btrfs_key key;
6100 int found_type;
6101 int i;
6102
6103 if (!btrfs_fs_incompat(log->fs_info, MIXED_GROUPS))
6104 return 0;
6105
6106 for (i = 0; i < btrfs_header_nritems(eb); i++) {
6107 btrfs_item_key_to_cpu(eb, &key, i);
6108 if (key.type != BTRFS_EXTENT_DATA_KEY)
6109 continue;
6110 item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
6111 found_type = btrfs_file_extent_type(eb, item);
6112 if (found_type == BTRFS_FILE_EXTENT_INLINE)
6113 continue;
6114 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
6115 continue;
6116 key.objectid = btrfs_file_extent_disk_bytenr(eb, item);
6117 key.offset = btrfs_file_extent_disk_num_bytes(eb, item);
6118 __exclude_logged_extent(log, key.objectid, key.offset);
6119 }
6120
6121 return 0;
6122 }
6123
6124 /**
6125 * btrfs_update_reserved_bytes - update the block_group and space info counters
6126 * @cache: The cache we are manipulating
6127 * @num_bytes: The number of bytes in question
6128 * @reserve: One of the reservation enums
6129 * @delalloc: The blocks are allocated for the delalloc write
6130 *
6131 * This is called by the allocator when it reserves space, or by somebody who is
6132 * freeing space that was never actually used on disk. For example if you
6133 * reserve some space for a new leaf in transaction A and before transaction A
6134 * commits you free that leaf, you call this with reserve set to 0 in order to
6135 * clear the reservation.
6136 *
6137 * Metadata reservations should be called with RESERVE_ALLOC so we do the proper
6138 * ENOSPC accounting. For data we handle the reservation through clearing the
6139 * delalloc bits in the io_tree. We have to do this since we could end up
6140 * allocating less disk space for the amount of data we have reserved in the
6141 * case of compression.
6142 *
6143 * If this is a reservation and the block group has become read only we cannot
6144 * make the reservation and return -EAGAIN, otherwise this function always
6145 * succeeds.
6146 */
6147 static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
6148 u64 num_bytes, int reserve, int delalloc)
6149 {
6150 struct btrfs_space_info *space_info = cache->space_info;
6151 int ret = 0;
6152
6153 spin_lock(&space_info->lock);
6154 spin_lock(&cache->lock);
6155 if (reserve != RESERVE_FREE) {
6156 if (cache->ro) {
6157 ret = -EAGAIN;
6158 } else {
6159 cache->reserved += num_bytes;
6160 space_info->bytes_reserved += num_bytes;
6161 if (reserve == RESERVE_ALLOC) {
6162 trace_btrfs_space_reservation(cache->fs_info,
6163 "space_info", space_info->flags,
6164 num_bytes, 0);
6165 space_info->bytes_may_use -= num_bytes;
6166 }
6167
6168 if (delalloc)
6169 cache->delalloc_bytes += num_bytes;
6170 }
6171 } else {
6172 if (cache->ro)
6173 space_info->bytes_readonly += num_bytes;
6174 cache->reserved -= num_bytes;
6175 space_info->bytes_reserved -= num_bytes;
6176
6177 if (delalloc)
6178 cache->delalloc_bytes -= num_bytes;
6179 }
6180 spin_unlock(&cache->lock);
6181 spin_unlock(&space_info->lock);
6182 return ret;
6183 }
6184
6185 void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
6186 struct btrfs_root *root)
6187 {
6188 struct btrfs_fs_info *fs_info = root->fs_info;
6189 struct btrfs_caching_control *next;
6190 struct btrfs_caching_control *caching_ctl;
6191 struct btrfs_block_group_cache *cache;
6192
6193 down_write(&fs_info->commit_root_sem);
6194
6195 list_for_each_entry_safe(caching_ctl, next,
6196 &fs_info->caching_block_groups, list) {
6197 cache = caching_ctl->block_group;
6198 if (block_group_cache_done(cache)) {
6199 cache->last_byte_to_unpin = (u64)-1;
6200 list_del_init(&caching_ctl->list);
6201 put_caching_control(caching_ctl);
6202 } else {
6203 cache->last_byte_to_unpin = caching_ctl->progress;
6204 }
6205 }
6206
6207 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
6208 fs_info->pinned_extents = &fs_info->freed_extents[1];
6209 else
6210 fs_info->pinned_extents = &fs_info->freed_extents[0];
6211
6212 up_write(&fs_info->commit_root_sem);
6213
6214 update_global_block_rsv(fs_info);
6215 }
6216
6217 /*
6218 * Returns the free cluster for the given space info and sets empty_cluster to
6219 * what it should be based on the mount options.
6220 */
6221 static struct btrfs_free_cluster *
6222 fetch_cluster_info(struct btrfs_root *root, struct btrfs_space_info *space_info,
6223 u64 *empty_cluster)
6224 {
6225 struct btrfs_free_cluster *ret = NULL;
6226 bool ssd = btrfs_test_opt(root, SSD);
6227
6228 *empty_cluster = 0;
6229 if (btrfs_mixed_space_info(space_info))
6230 return ret;
6231
6232 if (ssd)
6233 *empty_cluster = 2 * 1024 * 1024;
6234 if (space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
6235 ret = &root->fs_info->meta_alloc_cluster;
6236 if (!ssd)
6237 *empty_cluster = 64 * 1024;
6238 } else if ((space_info->flags & BTRFS_BLOCK_GROUP_DATA) && ssd) {
6239 ret = &root->fs_info->data_alloc_cluster;
6240 }
6241
6242 return ret;
6243 }
6244
6245 static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end,
6246 const bool return_free_space)
6247 {
6248 struct btrfs_fs_info *fs_info = root->fs_info;
6249 struct btrfs_block_group_cache *cache = NULL;
6250 struct btrfs_space_info *space_info;
6251 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
6252 struct btrfs_free_cluster *cluster = NULL;
6253 u64 len;
6254 u64 total_unpinned = 0;
6255 u64 empty_cluster = 0;
6256 bool readonly;
6257
6258 while (start <= end) {
6259 readonly = false;
6260 if (!cache ||
6261 start >= cache->key.objectid + cache->key.offset) {
6262 if (cache)
6263 btrfs_put_block_group(cache);
6264 total_unpinned = 0;
6265 cache = btrfs_lookup_block_group(fs_info, start);
6266 BUG_ON(!cache); /* Logic error */
6267
6268 cluster = fetch_cluster_info(root,
6269 cache->space_info,
6270 &empty_cluster);
6271 empty_cluster <<= 1;
6272 }
6273
6274 len = cache->key.objectid + cache->key.offset - start;
6275 len = min(len, end + 1 - start);
6276
6277 if (start < cache->last_byte_to_unpin) {
6278 len = min(len, cache->last_byte_to_unpin - start);
6279 if (return_free_space)
6280 btrfs_add_free_space(cache, start, len);
6281 }
6282
6283 start += len;
6284 total_unpinned += len;
6285 space_info = cache->space_info;
6286
6287 /*
6288 * If this space cluster has been marked as fragmented and we've
6289 * unpinned enough in this block group to potentially allow a
6290 * cluster to be created inside of it go ahead and clear the
6291 * fragmented check.
6292 */
6293 if (cluster && cluster->fragmented &&
6294 total_unpinned > empty_cluster) {
6295 spin_lock(&cluster->lock);
6296 cluster->fragmented = 0;
6297 spin_unlock(&cluster->lock);
6298 }
6299
6300 spin_lock(&space_info->lock);
6301 spin_lock(&cache->lock);
6302 cache->pinned -= len;
6303 space_info->bytes_pinned -= len;
6304 space_info->max_extent_size = 0;
6305 percpu_counter_add(&space_info->total_bytes_pinned, -len);
6306 if (cache->ro) {
6307 space_info->bytes_readonly += len;
6308 readonly = true;
6309 }
6310 spin_unlock(&cache->lock);
6311 if (!readonly && global_rsv->space_info == space_info) {
6312 spin_lock(&global_rsv->lock);
6313 if (!global_rsv->full) {
6314 len = min(len, global_rsv->size -
6315 global_rsv->reserved);
6316 global_rsv->reserved += len;
6317 space_info->bytes_may_use += len;
6318 if (global_rsv->reserved >= global_rsv->size)
6319 global_rsv->full = 1;
6320 }
6321 spin_unlock(&global_rsv->lock);
6322 }
6323 spin_unlock(&space_info->lock);
6324 }
6325
6326 if (cache)
6327 btrfs_put_block_group(cache);
6328 return 0;
6329 }
6330
6331 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
6332 struct btrfs_root *root)
6333 {
6334 struct btrfs_fs_info *fs_info = root->fs_info;
6335 struct btrfs_block_group_cache *block_group, *tmp;
6336 struct list_head *deleted_bgs;
6337 struct extent_io_tree *unpin;
6338 u64 start;
6339 u64 end;
6340 int ret;
6341
6342 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
6343 unpin = &fs_info->freed_extents[1];
6344 else
6345 unpin = &fs_info->freed_extents[0];
6346
6347 while (!trans->aborted) {
6348 mutex_lock(&fs_info->unused_bg_unpin_mutex);
6349 ret = find_first_extent_bit(unpin, 0, &start, &end,
6350 EXTENT_DIRTY, NULL);
6351 if (ret) {
6352 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
6353 break;
6354 }
6355
6356 if (btrfs_test_opt(root, DISCARD))
6357 ret = btrfs_discard_extent(root, start,
6358 end + 1 - start, NULL);
6359
6360 clear_extent_dirty(unpin, start, end, GFP_NOFS);
6361 unpin_extent_range(root, start, end, true);
6362 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
6363 cond_resched();
6364 }
6365
6366 /*
6367 * Transaction is finished. We don't need the lock anymore. We
6368 * do need to clean up the block groups in case of a transaction
6369 * abort.
6370 */
6371 deleted_bgs = &trans->transaction->deleted_bgs;
6372 list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) {
6373 u64 trimmed = 0;
6374
6375 ret = -EROFS;
6376 if (!trans->aborted)
6377 ret = btrfs_discard_extent(root,
6378 block_group->key.objectid,
6379 block_group->key.offset,
6380 &trimmed);
6381
6382 list_del_init(&block_group->bg_list);
6383 btrfs_put_block_group_trimming(block_group);
6384 btrfs_put_block_group(block_group);
6385
6386 if (ret) {
6387 const char *errstr = btrfs_decode_error(ret);
6388 btrfs_warn(fs_info,
6389 "Discard failed while removing blockgroup: errno=%d %s\n",
6390 ret, errstr);
6391 }
6392 }
6393
6394 return 0;
6395 }
6396
6397 static void add_pinned_bytes(struct btrfs_fs_info *fs_info, u64 num_bytes,
6398 u64 owner, u64 root_objectid)
6399 {
6400 struct btrfs_space_info *space_info;
6401 u64 flags;
6402
6403 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
6404 if (root_objectid == BTRFS_CHUNK_TREE_OBJECTID)
6405 flags = BTRFS_BLOCK_GROUP_SYSTEM;
6406 else
6407 flags = BTRFS_BLOCK_GROUP_METADATA;
6408 } else {
6409 flags = BTRFS_BLOCK_GROUP_DATA;
6410 }
6411
6412 space_info = __find_space_info(fs_info, flags);
6413 BUG_ON(!space_info); /* Logic bug */
6414 percpu_counter_add(&space_info->total_bytes_pinned, num_bytes);
6415 }
6416
6417
6418 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
6419 struct btrfs_root *root,
6420 struct btrfs_delayed_ref_node *node, u64 parent,
6421 u64 root_objectid, u64 owner_objectid,
6422 u64 owner_offset, int refs_to_drop,
6423 struct btrfs_delayed_extent_op *extent_op)
6424 {
6425 struct btrfs_key key;
6426 struct btrfs_path *path;
6427 struct btrfs_fs_info *info = root->fs_info;
6428 struct btrfs_root *extent_root = info->extent_root;
6429 struct extent_buffer *leaf;
6430 struct btrfs_extent_item *ei;
6431 struct btrfs_extent_inline_ref *iref;
6432 int ret;
6433 int is_data;
6434 int extent_slot = 0;
6435 int found_extent = 0;
6436 int num_to_del = 1;
6437 u32 item_size;
6438 u64 refs;
6439 u64 bytenr = node->bytenr;
6440 u64 num_bytes = node->num_bytes;
6441 int last_ref = 0;
6442 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
6443 SKINNY_METADATA);
6444
6445 path = btrfs_alloc_path();
6446 if (!path)
6447 return -ENOMEM;
6448
6449 path->reada = 1;
6450 path->leave_spinning = 1;
6451
6452 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
6453 BUG_ON(!is_data && refs_to_drop != 1);
6454
6455 if (is_data)
6456 skinny_metadata = 0;
6457
6458 ret = lookup_extent_backref(trans, extent_root, path, &iref,
6459 bytenr, num_bytes, parent,
6460 root_objectid, owner_objectid,
6461 owner_offset);
6462 if (ret == 0) {
6463 extent_slot = path->slots[0];
6464 while (extent_slot >= 0) {
6465 btrfs_item_key_to_cpu(path->nodes[0], &key,
6466 extent_slot);
6467 if (key.objectid != bytenr)
6468 break;
6469 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
6470 key.offset == num_bytes) {
6471 found_extent = 1;
6472 break;
6473 }
6474 if (key.type == BTRFS_METADATA_ITEM_KEY &&
6475 key.offset == owner_objectid) {
6476 found_extent = 1;
6477 break;
6478 }
6479 if (path->slots[0] - extent_slot > 5)
6480 break;
6481 extent_slot--;
6482 }
6483 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
6484 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
6485 if (found_extent && item_size < sizeof(*ei))
6486 found_extent = 0;
6487 #endif
6488 if (!found_extent) {
6489 BUG_ON(iref);
6490 ret = remove_extent_backref(trans, extent_root, path,
6491 NULL, refs_to_drop,
6492 is_data, &last_ref);
6493 if (ret) {
6494 btrfs_abort_transaction(trans, extent_root, ret);
6495 goto out;
6496 }
6497 btrfs_release_path(path);
6498 path->leave_spinning = 1;
6499
6500 key.objectid = bytenr;
6501 key.type = BTRFS_EXTENT_ITEM_KEY;
6502 key.offset = num_bytes;
6503
6504 if (!is_data && skinny_metadata) {
6505 key.type = BTRFS_METADATA_ITEM_KEY;
6506 key.offset = owner_objectid;
6507 }
6508
6509 ret = btrfs_search_slot(trans, extent_root,
6510 &key, path, -1, 1);
6511 if (ret > 0 && skinny_metadata && path->slots[0]) {
6512 /*
6513 * Couldn't find our skinny metadata item,
6514 * see if we have ye olde extent item.
6515 */
6516 path->slots[0]--;
6517 btrfs_item_key_to_cpu(path->nodes[0], &key,
6518 path->slots[0]);
6519 if (key.objectid == bytenr &&
6520 key.type == BTRFS_EXTENT_ITEM_KEY &&
6521 key.offset == num_bytes)
6522 ret = 0;
6523 }
6524
6525 if (ret > 0 && skinny_metadata) {
6526 skinny_metadata = false;
6527 key.objectid = bytenr;
6528 key.type = BTRFS_EXTENT_ITEM_KEY;
6529 key.offset = num_bytes;
6530 btrfs_release_path(path);
6531 ret = btrfs_search_slot(trans, extent_root,
6532 &key, path, -1, 1);
6533 }
6534
6535 if (ret) {
6536 btrfs_err(info, "umm, got %d back from search, was looking for %llu",
6537 ret, bytenr);
6538 if (ret > 0)
6539 btrfs_print_leaf(extent_root,
6540 path->nodes[0]);
6541 }
6542 if (ret < 0) {
6543 btrfs_abort_transaction(trans, extent_root, ret);
6544 goto out;
6545 }
6546 extent_slot = path->slots[0];
6547 }
6548 } else if (WARN_ON(ret == -ENOENT)) {
6549 btrfs_print_leaf(extent_root, path->nodes[0]);
6550 btrfs_err(info,
6551 "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu",
6552 bytenr, parent, root_objectid, owner_objectid,
6553 owner_offset);
6554 btrfs_abort_transaction(trans, extent_root, ret);
6555 goto out;
6556 } else {
6557 btrfs_abort_transaction(trans, extent_root, ret);
6558 goto out;
6559 }
6560
6561 leaf = path->nodes[0];
6562 item_size = btrfs_item_size_nr(leaf, extent_slot);
6563 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
6564 if (item_size < sizeof(*ei)) {
6565 BUG_ON(found_extent || extent_slot != path->slots[0]);
6566 ret = convert_extent_item_v0(trans, extent_root, path,
6567 owner_objectid, 0);
6568 if (ret < 0) {
6569 btrfs_abort_transaction(trans, extent_root, ret);
6570 goto out;
6571 }
6572
6573 btrfs_release_path(path);
6574 path->leave_spinning = 1;
6575
6576 key.objectid = bytenr;
6577 key.type = BTRFS_EXTENT_ITEM_KEY;
6578 key.offset = num_bytes;
6579
6580 ret = btrfs_search_slot(trans, extent_root, &key, path,
6581 -1, 1);
6582 if (ret) {
6583 btrfs_err(info, "umm, got %d back from search, was looking for %llu",
6584 ret, bytenr);
6585 btrfs_print_leaf(extent_root, path->nodes[0]);
6586 }
6587 if (ret < 0) {
6588 btrfs_abort_transaction(trans, extent_root, ret);
6589 goto out;
6590 }
6591
6592 extent_slot = path->slots[0];
6593 leaf = path->nodes[0];
6594 item_size = btrfs_item_size_nr(leaf, extent_slot);
6595 }
6596 #endif
6597 BUG_ON(item_size < sizeof(*ei));
6598 ei = btrfs_item_ptr(leaf, extent_slot,
6599 struct btrfs_extent_item);
6600 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
6601 key.type == BTRFS_EXTENT_ITEM_KEY) {
6602 struct btrfs_tree_block_info *bi;
6603 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
6604 bi = (struct btrfs_tree_block_info *)(ei + 1);
6605 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
6606 }
6607
6608 refs = btrfs_extent_refs(leaf, ei);
6609 if (refs < refs_to_drop) {
6610 btrfs_err(info, "trying to drop %d refs but we only have %Lu "
6611 "for bytenr %Lu", refs_to_drop, refs, bytenr);
6612 ret = -EINVAL;
6613 btrfs_abort_transaction(trans, extent_root, ret);
6614 goto out;
6615 }
6616 refs -= refs_to_drop;
6617
6618 if (refs > 0) {
6619 if (extent_op)
6620 __run_delayed_extent_op(extent_op, leaf, ei);
6621 /*
6622 * In the case of inline back ref, reference count will
6623 * be updated by remove_extent_backref
6624 */
6625 if (iref) {
6626 BUG_ON(!found_extent);
6627 } else {
6628 btrfs_set_extent_refs(leaf, ei, refs);
6629 btrfs_mark_buffer_dirty(leaf);
6630 }
6631 if (found_extent) {
6632 ret = remove_extent_backref(trans, extent_root, path,
6633 iref, refs_to_drop,
6634 is_data, &last_ref);
6635 if (ret) {
6636 btrfs_abort_transaction(trans, extent_root, ret);
6637 goto out;
6638 }
6639 }
6640 add_pinned_bytes(root->fs_info, -num_bytes, owner_objectid,
6641 root_objectid);
6642 } else {
6643 if (found_extent) {
6644 BUG_ON(is_data && refs_to_drop !=
6645 extent_data_ref_count(path, iref));
6646 if (iref) {
6647 BUG_ON(path->slots[0] != extent_slot);
6648 } else {
6649 BUG_ON(path->slots[0] != extent_slot + 1);
6650 path->slots[0] = extent_slot;
6651 num_to_del = 2;
6652 }
6653 }
6654
6655 last_ref = 1;
6656 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
6657 num_to_del);
6658 if (ret) {
6659 btrfs_abort_transaction(trans, extent_root, ret);
6660 goto out;
6661 }
6662 btrfs_release_path(path);
6663
6664 if (is_data) {
6665 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
6666 if (ret) {
6667 btrfs_abort_transaction(trans, extent_root, ret);
6668 goto out;
6669 }
6670 }
6671
6672 ret = update_block_group(trans, root, bytenr, num_bytes, 0);
6673 if (ret) {
6674 btrfs_abort_transaction(trans, extent_root, ret);
6675 goto out;
6676 }
6677 }
6678 btrfs_release_path(path);
6679
6680 out:
6681 btrfs_free_path(path);
6682 return ret;
6683 }
6684
6685 /*
6686 * when we free an block, it is possible (and likely) that we free the last
6687 * delayed ref for that extent as well. This searches the delayed ref tree for
6688 * a given extent, and if there are no other delayed refs to be processed, it
6689 * removes it from the tree.
6690 */
6691 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
6692 struct btrfs_root *root, u64 bytenr)
6693 {
6694 struct btrfs_delayed_ref_head *head;
6695 struct btrfs_delayed_ref_root *delayed_refs;
6696 int ret = 0;
6697
6698 delayed_refs = &trans->transaction->delayed_refs;
6699 spin_lock(&delayed_refs->lock);
6700 head = btrfs_find_delayed_ref_head(trans, bytenr);
6701 if (!head)
6702 goto out_delayed_unlock;
6703
6704 spin_lock(&head->lock);
6705 if (!list_empty(&head->ref_list))
6706 goto out;
6707
6708 if (head->extent_op) {
6709 if (!head->must_insert_reserved)
6710 goto out;
6711 btrfs_free_delayed_extent_op(head->extent_op);
6712 head->extent_op = NULL;
6713 }
6714
6715 /*
6716 * waiting for the lock here would deadlock. If someone else has it
6717 * locked they are already in the process of dropping it anyway
6718 */
6719 if (!mutex_trylock(&head->mutex))
6720 goto out;
6721
6722 /*
6723 * at this point we have a head with no other entries. Go
6724 * ahead and process it.
6725 */
6726 head->node.in_tree = 0;
6727 rb_erase(&head->href_node, &delayed_refs->href_root);
6728
6729 atomic_dec(&delayed_refs->num_entries);
6730
6731 /*
6732 * we don't take a ref on the node because we're removing it from the
6733 * tree, so we just steal the ref the tree was holding.
6734 */
6735 delayed_refs->num_heads--;
6736 if (head->processing == 0)
6737 delayed_refs->num_heads_ready--;
6738 head->processing = 0;
6739 spin_unlock(&head->lock);
6740 spin_unlock(&delayed_refs->lock);
6741
6742 BUG_ON(head->extent_op);
6743 if (head->must_insert_reserved)
6744 ret = 1;
6745
6746 mutex_unlock(&head->mutex);
6747 btrfs_put_delayed_ref(&head->node);
6748 return ret;
6749 out:
6750 spin_unlock(&head->lock);
6751
6752 out_delayed_unlock:
6753 spin_unlock(&delayed_refs->lock);
6754 return 0;
6755 }
6756
6757 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
6758 struct btrfs_root *root,
6759 struct extent_buffer *buf,
6760 u64 parent, int last_ref)
6761 {
6762 int pin = 1;
6763 int ret;
6764
6765 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
6766 ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
6767 buf->start, buf->len,
6768 parent, root->root_key.objectid,
6769 btrfs_header_level(buf),
6770 BTRFS_DROP_DELAYED_REF, NULL);
6771 BUG_ON(ret); /* -ENOMEM */
6772 }
6773
6774 if (!last_ref)
6775 return;
6776
6777 if (btrfs_header_generation(buf) == trans->transid) {
6778 struct btrfs_block_group_cache *cache;
6779
6780 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
6781 ret = check_ref_cleanup(trans, root, buf->start);
6782 if (!ret)
6783 goto out;
6784 }
6785
6786 cache = btrfs_lookup_block_group(root->fs_info, buf->start);
6787
6788 if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
6789 pin_down_extent(root, cache, buf->start, buf->len, 1);
6790 btrfs_put_block_group(cache);
6791 goto out;
6792 }
6793
6794 WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
6795
6796 btrfs_add_free_space(cache, buf->start, buf->len);
6797 btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE, 0);
6798 btrfs_put_block_group(cache);
6799 trace_btrfs_reserved_extent_free(root, buf->start, buf->len);
6800 pin = 0;
6801 }
6802 out:
6803 if (pin)
6804 add_pinned_bytes(root->fs_info, buf->len,
6805 btrfs_header_level(buf),
6806 root->root_key.objectid);
6807
6808 /*
6809 * Deleting the buffer, clear the corrupt flag since it doesn't matter
6810 * anymore.
6811 */
6812 clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
6813 }
6814
6815 /* Can return -ENOMEM */
6816 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
6817 u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
6818 u64 owner, u64 offset)
6819 {
6820 int ret;
6821 struct btrfs_fs_info *fs_info = root->fs_info;
6822
6823 if (btrfs_test_is_dummy_root(root))
6824 return 0;
6825
6826 add_pinned_bytes(root->fs_info, num_bytes, owner, root_objectid);
6827
6828 /*
6829 * tree log blocks never actually go into the extent allocation
6830 * tree, just update pinning info and exit early.
6831 */
6832 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
6833 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
6834 /* unlocks the pinned mutex */
6835 btrfs_pin_extent(root, bytenr, num_bytes, 1);
6836 ret = 0;
6837 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
6838 ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
6839 num_bytes,
6840 parent, root_objectid, (int)owner,
6841 BTRFS_DROP_DELAYED_REF, NULL);
6842 } else {
6843 ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
6844 num_bytes,
6845 parent, root_objectid, owner,
6846 offset, 0,
6847 BTRFS_DROP_DELAYED_REF, NULL);
6848 }
6849 return ret;
6850 }
6851
6852 /*
6853 * when we wait for progress in the block group caching, its because
6854 * our allocation attempt failed at least once. So, we must sleep
6855 * and let some progress happen before we try again.
6856 *
6857 * This function will sleep at least once waiting for new free space to
6858 * show up, and then it will check the block group free space numbers
6859 * for our min num_bytes. Another option is to have it go ahead
6860 * and look in the rbtree for a free extent of a given size, but this
6861 * is a good start.
6862 *
6863 * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
6864 * any of the information in this block group.
6865 */
6866 static noinline void
6867 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
6868 u64 num_bytes)
6869 {
6870 struct btrfs_caching_control *caching_ctl;
6871
6872 caching_ctl = get_caching_control(cache);
6873 if (!caching_ctl)
6874 return;
6875
6876 wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
6877 (cache->free_space_ctl->free_space >= num_bytes));
6878
6879 put_caching_control(caching_ctl);
6880 }
6881
6882 static noinline int
6883 wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
6884 {
6885 struct btrfs_caching_control *caching_ctl;
6886 int ret = 0;
6887
6888 caching_ctl = get_caching_control(cache);
6889 if (!caching_ctl)
6890 return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
6891
6892 wait_event(caching_ctl->wait, block_group_cache_done(cache));
6893 if (cache->cached == BTRFS_CACHE_ERROR)
6894 ret = -EIO;
6895 put_caching_control(caching_ctl);
6896 return ret;
6897 }
6898
6899 int __get_raid_index(u64 flags)
6900 {
6901 if (flags & BTRFS_BLOCK_GROUP_RAID10)
6902 return BTRFS_RAID_RAID10;
6903 else if (flags & BTRFS_BLOCK_GROUP_RAID1)
6904 return BTRFS_RAID_RAID1;
6905 else if (flags & BTRFS_BLOCK_GROUP_DUP)
6906 return BTRFS_RAID_DUP;
6907 else if (flags & BTRFS_BLOCK_GROUP_RAID0)
6908 return BTRFS_RAID_RAID0;
6909 else if (flags & BTRFS_BLOCK_GROUP_RAID5)
6910 return BTRFS_RAID_RAID5;
6911 else if (flags & BTRFS_BLOCK_GROUP_RAID6)
6912 return BTRFS_RAID_RAID6;
6913
6914 return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
6915 }
6916
6917 int get_block_group_index(struct btrfs_block_group_cache *cache)
6918 {
6919 return __get_raid_index(cache->flags);
6920 }
6921
6922 static const char *btrfs_raid_type_names[BTRFS_NR_RAID_TYPES] = {
6923 [BTRFS_RAID_RAID10] = "raid10",
6924 [BTRFS_RAID_RAID1] = "raid1",
6925 [BTRFS_RAID_DUP] = "dup",
6926 [BTRFS_RAID_RAID0] = "raid0",
6927 [BTRFS_RAID_SINGLE] = "single",
6928 [BTRFS_RAID_RAID5] = "raid5",
6929 [BTRFS_RAID_RAID6] = "raid6",
6930 };
6931
6932 static const char *get_raid_name(enum btrfs_raid_types type)
6933 {
6934 if (type >= BTRFS_NR_RAID_TYPES)
6935 return NULL;
6936
6937 return btrfs_raid_type_names[type];
6938 }
6939
6940 enum btrfs_loop_type {
6941 LOOP_CACHING_NOWAIT = 0,
6942 LOOP_CACHING_WAIT = 1,
6943 LOOP_ALLOC_CHUNK = 2,
6944 LOOP_NO_EMPTY_SIZE = 3,
6945 };
6946
6947 static inline void
6948 btrfs_lock_block_group(struct btrfs_block_group_cache *cache,
6949 int delalloc)
6950 {
6951 if (delalloc)
6952 down_read(&cache->data_rwsem);
6953 }
6954
6955 static inline void
6956 btrfs_grab_block_group(struct btrfs_block_group_cache *cache,
6957 int delalloc)
6958 {
6959 btrfs_get_block_group(cache);
6960 if (delalloc)
6961 down_read(&cache->data_rwsem);
6962 }
6963
6964 static struct btrfs_block_group_cache *
6965 btrfs_lock_cluster(struct btrfs_block_group_cache *block_group,
6966 struct btrfs_free_cluster *cluster,
6967 int delalloc)
6968 {
6969 struct btrfs_block_group_cache *used_bg;
6970 bool locked = false;
6971 again:
6972 spin_lock(&cluster->refill_lock);
6973 if (locked) {
6974 if (used_bg == cluster->block_group)
6975 return used_bg;
6976
6977 up_read(&used_bg->data_rwsem);
6978 btrfs_put_block_group(used_bg);
6979 }
6980
6981 used_bg = cluster->block_group;
6982 if (!used_bg)
6983 return NULL;
6984
6985 if (used_bg == block_group)
6986 return used_bg;
6987
6988 btrfs_get_block_group(used_bg);
6989
6990 if (!delalloc)
6991 return used_bg;
6992
6993 if (down_read_trylock(&used_bg->data_rwsem))
6994 return used_bg;
6995
6996 spin_unlock(&cluster->refill_lock);
6997 down_read(&used_bg->data_rwsem);
6998 locked = true;
6999 goto again;
7000 }
7001
7002 static inline void
7003 btrfs_release_block_group(struct btrfs_block_group_cache *cache,
7004 int delalloc)
7005 {
7006 if (delalloc)
7007 up_read(&cache->data_rwsem);
7008 btrfs_put_block_group(cache);
7009 }
7010
7011 /*
7012 * walks the btree of allocated extents and find a hole of a given size.
7013 * The key ins is changed to record the hole:
7014 * ins->objectid == start position
7015 * ins->flags = BTRFS_EXTENT_ITEM_KEY
7016 * ins->offset == the size of the hole.
7017 * Any available blocks before search_start are skipped.
7018 *
7019 * If there is no suitable free space, we will record the max size of
7020 * the free space extent currently.
7021 */
7022 static noinline int find_free_extent(struct btrfs_root *orig_root,
7023 u64 num_bytes, u64 empty_size,
7024 u64 hint_byte, struct btrfs_key *ins,
7025 u64 flags, int delalloc)
7026 {
7027 int ret = 0;
7028 struct btrfs_root *root = orig_root->fs_info->extent_root;
7029 struct btrfs_free_cluster *last_ptr = NULL;
7030 struct btrfs_block_group_cache *block_group = NULL;
7031 u64 search_start = 0;
7032 u64 max_extent_size = 0;
7033 u64 empty_cluster = 0;
7034 struct btrfs_space_info *space_info;
7035 int loop = 0;
7036 int index = __get_raid_index(flags);
7037 int alloc_type = (flags & BTRFS_BLOCK_GROUP_DATA) ?
7038 RESERVE_ALLOC_NO_ACCOUNT : RESERVE_ALLOC;
7039 bool failed_cluster_refill = false;
7040 bool failed_alloc = false;
7041 bool use_cluster = true;
7042 bool have_caching_bg = false;
7043 bool orig_have_caching_bg = false;
7044 bool full_search = false;
7045
7046 WARN_ON(num_bytes < root->sectorsize);
7047 ins->type = BTRFS_EXTENT_ITEM_KEY;
7048 ins->objectid = 0;
7049 ins->offset = 0;
7050
7051 trace_find_free_extent(orig_root, num_bytes, empty_size, flags);
7052
7053 space_info = __find_space_info(root->fs_info, flags);
7054 if (!space_info) {
7055 btrfs_err(root->fs_info, "No space info for %llu", flags);
7056 return -ENOSPC;
7057 }
7058
7059 /*
7060 * If our free space is heavily fragmented we may not be able to make
7061 * big contiguous allocations, so instead of doing the expensive search
7062 * for free space, simply return ENOSPC with our max_extent_size so we
7063 * can go ahead and search for a more manageable chunk.
7064 *
7065 * If our max_extent_size is large enough for our allocation simply
7066 * disable clustering since we will likely not be able to find enough
7067 * space to create a cluster and induce latency trying.
7068 */
7069 if (unlikely(space_info->max_extent_size)) {
7070 spin_lock(&space_info->lock);
7071 if (space_info->max_extent_size &&
7072 num_bytes > space_info->max_extent_size) {
7073 ins->offset = space_info->max_extent_size;
7074 spin_unlock(&space_info->lock);
7075 return -ENOSPC;
7076 } else if (space_info->max_extent_size) {
7077 use_cluster = false;
7078 }
7079 spin_unlock(&space_info->lock);
7080 }
7081
7082 last_ptr = fetch_cluster_info(orig_root, space_info, &empty_cluster);
7083 if (last_ptr) {
7084 spin_lock(&last_ptr->lock);
7085 if (last_ptr->block_group)
7086 hint_byte = last_ptr->window_start;
7087 if (last_ptr->fragmented) {
7088 /*
7089 * We still set window_start so we can keep track of the
7090 * last place we found an allocation to try and save
7091 * some time.
7092 */
7093 hint_byte = last_ptr->window_start;
7094 use_cluster = false;
7095 }
7096 spin_unlock(&last_ptr->lock);
7097 }
7098
7099 search_start = max(search_start, first_logical_byte(root, 0));
7100 search_start = max(search_start, hint_byte);
7101 if (search_start == hint_byte) {
7102 block_group = btrfs_lookup_block_group(root->fs_info,
7103 search_start);
7104 /*
7105 * we don't want to use the block group if it doesn't match our
7106 * allocation bits, or if its not cached.
7107 *
7108 * However if we are re-searching with an ideal block group
7109 * picked out then we don't care that the block group is cached.
7110 */
7111 if (block_group && block_group_bits(block_group, flags) &&
7112 block_group->cached != BTRFS_CACHE_NO) {
7113 down_read(&space_info->groups_sem);
7114 if (list_empty(&block_group->list) ||
7115 block_group->ro) {
7116 /*
7117 * someone is removing this block group,
7118 * we can't jump into the have_block_group
7119 * target because our list pointers are not
7120 * valid
7121 */
7122 btrfs_put_block_group(block_group);
7123 up_read(&space_info->groups_sem);
7124 } else {
7125 index = get_block_group_index(block_group);
7126 btrfs_lock_block_group(block_group, delalloc);
7127 goto have_block_group;
7128 }
7129 } else if (block_group) {
7130 btrfs_put_block_group(block_group);
7131 }
7132 }
7133 search:
7134 have_caching_bg = false;
7135 if (index == 0 || index == __get_raid_index(flags))
7136 full_search = true;
7137 down_read(&space_info->groups_sem);
7138 list_for_each_entry(block_group, &space_info->block_groups[index],
7139 list) {
7140 u64 offset;
7141 int cached;
7142
7143 btrfs_grab_block_group(block_group, delalloc);
7144 search_start = block_group->key.objectid;
7145
7146 /*
7147 * this can happen if we end up cycling through all the
7148 * raid types, but we want to make sure we only allocate
7149 * for the proper type.
7150 */
7151 if (!block_group_bits(block_group, flags)) {
7152 u64 extra = BTRFS_BLOCK_GROUP_DUP |
7153 BTRFS_BLOCK_GROUP_RAID1 |
7154 BTRFS_BLOCK_GROUP_RAID5 |
7155 BTRFS_BLOCK_GROUP_RAID6 |
7156 BTRFS_BLOCK_GROUP_RAID10;
7157
7158 /*
7159 * if they asked for extra copies and this block group
7160 * doesn't provide them, bail. This does allow us to
7161 * fill raid0 from raid1.
7162 */
7163 if ((flags & extra) && !(block_group->flags & extra))
7164 goto loop;
7165 }
7166
7167 have_block_group:
7168 cached = block_group_cache_done(block_group);
7169 if (unlikely(!cached)) {
7170 have_caching_bg = true;
7171 ret = cache_block_group(block_group, 0);
7172 BUG_ON(ret < 0);
7173 ret = 0;
7174 }
7175
7176 if (unlikely(block_group->cached == BTRFS_CACHE_ERROR))
7177 goto loop;
7178 if (unlikely(block_group->ro))
7179 goto loop;
7180
7181 /*
7182 * Ok we want to try and use the cluster allocator, so
7183 * lets look there
7184 */
7185 if (last_ptr && use_cluster) {
7186 struct btrfs_block_group_cache *used_block_group;
7187 unsigned long aligned_cluster;
7188 /*
7189 * the refill lock keeps out other
7190 * people trying to start a new cluster
7191 */
7192 used_block_group = btrfs_lock_cluster(block_group,
7193 last_ptr,
7194 delalloc);
7195 if (!used_block_group)
7196 goto refill_cluster;
7197
7198 if (used_block_group != block_group &&
7199 (used_block_group->ro ||
7200 !block_group_bits(used_block_group, flags)))
7201 goto release_cluster;
7202
7203 offset = btrfs_alloc_from_cluster(used_block_group,
7204 last_ptr,
7205 num_bytes,
7206 used_block_group->key.objectid,
7207 &max_extent_size);
7208 if (offset) {
7209 /* we have a block, we're done */
7210 spin_unlock(&last_ptr->refill_lock);
7211 trace_btrfs_reserve_extent_cluster(root,
7212 used_block_group,
7213 search_start, num_bytes);
7214 if (used_block_group != block_group) {
7215 btrfs_release_block_group(block_group,
7216 delalloc);
7217 block_group = used_block_group;
7218 }
7219 goto checks;
7220 }
7221
7222 WARN_ON(last_ptr->block_group != used_block_group);
7223 release_cluster:
7224 /* If we are on LOOP_NO_EMPTY_SIZE, we can't
7225 * set up a new clusters, so lets just skip it
7226 * and let the allocator find whatever block
7227 * it can find. If we reach this point, we
7228 * will have tried the cluster allocator
7229 * plenty of times and not have found
7230 * anything, so we are likely way too
7231 * fragmented for the clustering stuff to find
7232 * anything.
7233 *
7234 * However, if the cluster is taken from the
7235 * current block group, release the cluster
7236 * first, so that we stand a better chance of
7237 * succeeding in the unclustered
7238 * allocation. */
7239 if (loop >= LOOP_NO_EMPTY_SIZE &&
7240 used_block_group != block_group) {
7241 spin_unlock(&last_ptr->refill_lock);
7242 btrfs_release_block_group(used_block_group,
7243 delalloc);
7244 goto unclustered_alloc;
7245 }
7246
7247 /*
7248 * this cluster didn't work out, free it and
7249 * start over
7250 */
7251 btrfs_return_cluster_to_free_space(NULL, last_ptr);
7252
7253 if (used_block_group != block_group)
7254 btrfs_release_block_group(used_block_group,
7255 delalloc);
7256 refill_cluster:
7257 if (loop >= LOOP_NO_EMPTY_SIZE) {
7258 spin_unlock(&last_ptr->refill_lock);
7259 goto unclustered_alloc;
7260 }
7261
7262 aligned_cluster = max_t(unsigned long,
7263 empty_cluster + empty_size,
7264 block_group->full_stripe_len);
7265
7266 /* allocate a cluster in this block group */
7267 ret = btrfs_find_space_cluster(root, block_group,
7268 last_ptr, search_start,
7269 num_bytes,
7270 aligned_cluster);
7271 if (ret == 0) {
7272 /*
7273 * now pull our allocation out of this
7274 * cluster
7275 */
7276 offset = btrfs_alloc_from_cluster(block_group,
7277 last_ptr,
7278 num_bytes,
7279 search_start,
7280 &max_extent_size);
7281 if (offset) {
7282 /* we found one, proceed */
7283 spin_unlock(&last_ptr->refill_lock);
7284 trace_btrfs_reserve_extent_cluster(root,
7285 block_group, search_start,
7286 num_bytes);
7287 goto checks;
7288 }
7289 } else if (!cached && loop > LOOP_CACHING_NOWAIT
7290 && !failed_cluster_refill) {
7291 spin_unlock(&last_ptr->refill_lock);
7292
7293 failed_cluster_refill = true;
7294 wait_block_group_cache_progress(block_group,
7295 num_bytes + empty_cluster + empty_size);
7296 goto have_block_group;
7297 }
7298
7299 /*
7300 * at this point we either didn't find a cluster
7301 * or we weren't able to allocate a block from our
7302 * cluster. Free the cluster we've been trying
7303 * to use, and go to the next block group
7304 */
7305 btrfs_return_cluster_to_free_space(NULL, last_ptr);
7306 spin_unlock(&last_ptr->refill_lock);
7307 goto loop;
7308 }
7309
7310 unclustered_alloc:
7311 /*
7312 * We are doing an unclustered alloc, set the fragmented flag so
7313 * we don't bother trying to setup a cluster again until we get
7314 * more space.
7315 */
7316 if (unlikely(last_ptr)) {
7317 spin_lock(&last_ptr->lock);
7318 last_ptr->fragmented = 1;
7319 spin_unlock(&last_ptr->lock);
7320 }
7321 spin_lock(&block_group->free_space_ctl->tree_lock);
7322 if (cached &&
7323 block_group->free_space_ctl->free_space <
7324 num_bytes + empty_cluster + empty_size) {
7325 if (block_group->free_space_ctl->free_space >
7326 max_extent_size)
7327 max_extent_size =
7328 block_group->free_space_ctl->free_space;
7329 spin_unlock(&block_group->free_space_ctl->tree_lock);
7330 goto loop;
7331 }
7332 spin_unlock(&block_group->free_space_ctl->tree_lock);
7333
7334 offset = btrfs_find_space_for_alloc(block_group, search_start,
7335 num_bytes, empty_size,
7336 &max_extent_size);
7337 /*
7338 * If we didn't find a chunk, and we haven't failed on this
7339 * block group before, and this block group is in the middle of
7340 * caching and we are ok with waiting, then go ahead and wait
7341 * for progress to be made, and set failed_alloc to true.
7342 *
7343 * If failed_alloc is true then we've already waited on this
7344 * block group once and should move on to the next block group.
7345 */
7346 if (!offset && !failed_alloc && !cached &&
7347 loop > LOOP_CACHING_NOWAIT) {
7348 wait_block_group_cache_progress(block_group,
7349 num_bytes + empty_size);
7350 failed_alloc = true;
7351 goto have_block_group;
7352 } else if (!offset) {
7353 goto loop;
7354 }
7355 checks:
7356 search_start = ALIGN(offset, root->stripesize);
7357
7358 /* move on to the next group */
7359 if (search_start + num_bytes >
7360 block_group->key.objectid + block_group->key.offset) {
7361 btrfs_add_free_space(block_group, offset, num_bytes);
7362 goto loop;
7363 }
7364
7365 if (offset < search_start)
7366 btrfs_add_free_space(block_group, offset,
7367 search_start - offset);
7368 BUG_ON(offset > search_start);
7369
7370 ret = btrfs_update_reserved_bytes(block_group, num_bytes,
7371 alloc_type, delalloc);
7372 if (ret == -EAGAIN) {
7373 btrfs_add_free_space(block_group, offset, num_bytes);
7374 goto loop;
7375 }
7376
7377 /* we are all good, lets return */
7378 ins->objectid = search_start;
7379 ins->offset = num_bytes;
7380
7381 trace_btrfs_reserve_extent(orig_root, block_group,
7382 search_start, num_bytes);
7383 btrfs_release_block_group(block_group, delalloc);
7384 break;
7385 loop:
7386 failed_cluster_refill = false;
7387 failed_alloc = false;
7388 BUG_ON(index != get_block_group_index(block_group));
7389 btrfs_release_block_group(block_group, delalloc);
7390 }
7391 up_read(&space_info->groups_sem);
7392
7393 if ((loop == LOOP_CACHING_NOWAIT) && have_caching_bg
7394 && !orig_have_caching_bg)
7395 orig_have_caching_bg = true;
7396
7397 if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg)
7398 goto search;
7399
7400 if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
7401 goto search;
7402
7403 /*
7404 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
7405 * caching kthreads as we move along
7406 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
7407 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
7408 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
7409 * again
7410 */
7411 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) {
7412 index = 0;
7413 if (loop == LOOP_CACHING_NOWAIT) {
7414 /*
7415 * We want to skip the LOOP_CACHING_WAIT step if we
7416 * don't have any unached bgs and we've alrelady done a
7417 * full search through.
7418 */
7419 if (orig_have_caching_bg || !full_search)
7420 loop = LOOP_CACHING_WAIT;
7421 else
7422 loop = LOOP_ALLOC_CHUNK;
7423 } else {
7424 loop++;
7425 }
7426
7427 if (loop == LOOP_ALLOC_CHUNK) {
7428 struct btrfs_trans_handle *trans;
7429 int exist = 0;
7430
7431 trans = current->journal_info;
7432 if (trans)
7433 exist = 1;
7434 else
7435 trans = btrfs_join_transaction(root);
7436
7437 if (IS_ERR(trans)) {
7438 ret = PTR_ERR(trans);
7439 goto out;
7440 }
7441
7442 ret = do_chunk_alloc(trans, root, flags,
7443 CHUNK_ALLOC_FORCE);
7444
7445 /*
7446 * If we can't allocate a new chunk we've already looped
7447 * through at least once, move on to the NO_EMPTY_SIZE
7448 * case.
7449 */
7450 if (ret == -ENOSPC)
7451 loop = LOOP_NO_EMPTY_SIZE;
7452
7453 /*
7454 * Do not bail out on ENOSPC since we
7455 * can do more things.
7456 */
7457 if (ret < 0 && ret != -ENOSPC)
7458 btrfs_abort_transaction(trans,
7459 root, ret);
7460 else
7461 ret = 0;
7462 if (!exist)
7463 btrfs_end_transaction(trans, root);
7464 if (ret)
7465 goto out;
7466 }
7467
7468 if (loop == LOOP_NO_EMPTY_SIZE) {
7469 /*
7470 * Don't loop again if we already have no empty_size and
7471 * no empty_cluster.
7472 */
7473 if (empty_size == 0 &&
7474 empty_cluster == 0) {
7475 ret = -ENOSPC;
7476 goto out;
7477 }
7478 empty_size = 0;
7479 empty_cluster = 0;
7480 }
7481
7482 goto search;
7483 } else if (!ins->objectid) {
7484 ret = -ENOSPC;
7485 } else if (ins->objectid) {
7486 if (!use_cluster && last_ptr) {
7487 spin_lock(&last_ptr->lock);
7488 last_ptr->window_start = ins->objectid;
7489 spin_unlock(&last_ptr->lock);
7490 }
7491 ret = 0;
7492 }
7493 out:
7494 if (ret == -ENOSPC) {
7495 spin_lock(&space_info->lock);
7496 space_info->max_extent_size = max_extent_size;
7497 spin_unlock(&space_info->lock);
7498 ins->offset = max_extent_size;
7499 }
7500 return ret;
7501 }
7502
7503 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
7504 int dump_block_groups)
7505 {
7506 struct btrfs_block_group_cache *cache;
7507 int index = 0;
7508
7509 spin_lock(&info->lock);
7510 printk(KERN_INFO "BTRFS: space_info %llu has %llu free, is %sfull\n",
7511 info->flags,
7512 info->total_bytes - info->bytes_used - info->bytes_pinned -
7513 info->bytes_reserved - info->bytes_readonly,
7514 (info->full) ? "" : "not ");
7515 printk(KERN_INFO "BTRFS: space_info total=%llu, used=%llu, pinned=%llu, "
7516 "reserved=%llu, may_use=%llu, readonly=%llu\n",
7517 info->total_bytes, info->bytes_used, info->bytes_pinned,
7518 info->bytes_reserved, info->bytes_may_use,
7519 info->bytes_readonly);
7520 spin_unlock(&info->lock);
7521
7522 if (!dump_block_groups)
7523 return;
7524
7525 down_read(&info->groups_sem);
7526 again:
7527 list_for_each_entry(cache, &info->block_groups[index], list) {
7528 spin_lock(&cache->lock);
7529 printk(KERN_INFO "BTRFS: "
7530 "block group %llu has %llu bytes, "
7531 "%llu used %llu pinned %llu reserved %s\n",
7532 cache->key.objectid, cache->key.offset,
7533 btrfs_block_group_used(&cache->item), cache->pinned,
7534 cache->reserved, cache->ro ? "[readonly]" : "");
7535 btrfs_dump_free_space(cache, bytes);
7536 spin_unlock(&cache->lock);
7537 }
7538 if (++index < BTRFS_NR_RAID_TYPES)
7539 goto again;
7540 up_read(&info->groups_sem);
7541 }
7542
7543 int btrfs_reserve_extent(struct btrfs_root *root,
7544 u64 num_bytes, u64 min_alloc_size,
7545 u64 empty_size, u64 hint_byte,
7546 struct btrfs_key *ins, int is_data, int delalloc)
7547 {
7548 bool final_tried = num_bytes == min_alloc_size;
7549 u64 flags;
7550 int ret;
7551
7552 flags = btrfs_get_alloc_profile(root, is_data);
7553 again:
7554 WARN_ON(num_bytes < root->sectorsize);
7555 ret = find_free_extent(root, num_bytes, empty_size, hint_byte, ins,
7556 flags, delalloc);
7557
7558 if (ret == -ENOSPC) {
7559 if (!final_tried && ins->offset) {
7560 num_bytes = min(num_bytes >> 1, ins->offset);
7561 num_bytes = round_down(num_bytes, root->sectorsize);
7562 num_bytes = max(num_bytes, min_alloc_size);
7563 if (num_bytes == min_alloc_size)
7564 final_tried = true;
7565 goto again;
7566 } else if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
7567 struct btrfs_space_info *sinfo;
7568
7569 sinfo = __find_space_info(root->fs_info, flags);
7570 btrfs_err(root->fs_info, "allocation failed flags %llu, wanted %llu",
7571 flags, num_bytes);
7572 if (sinfo)
7573 dump_space_info(sinfo, num_bytes, 1);
7574 }
7575 }
7576
7577 return ret;
7578 }
7579
7580 static int __btrfs_free_reserved_extent(struct btrfs_root *root,
7581 u64 start, u64 len,
7582 int pin, int delalloc)
7583 {
7584 struct btrfs_block_group_cache *cache;
7585 int ret = 0;
7586
7587 cache = btrfs_lookup_block_group(root->fs_info, start);
7588 if (!cache) {
7589 btrfs_err(root->fs_info, "Unable to find block group for %llu",
7590 start);
7591 return -ENOSPC;
7592 }
7593
7594 if (pin)
7595 pin_down_extent(root, cache, start, len, 1);
7596 else {
7597 if (btrfs_test_opt(root, DISCARD))
7598 ret = btrfs_discard_extent(root, start, len, NULL);
7599 btrfs_add_free_space(cache, start, len);
7600 btrfs_update_reserved_bytes(cache, len, RESERVE_FREE, delalloc);
7601 }
7602
7603 btrfs_put_block_group(cache);
7604
7605 trace_btrfs_reserved_extent_free(root, start, len);
7606
7607 return ret;
7608 }
7609
7610 int btrfs_free_reserved_extent(struct btrfs_root *root,
7611 u64 start, u64 len, int delalloc)
7612 {
7613 return __btrfs_free_reserved_extent(root, start, len, 0, delalloc);
7614 }
7615
7616 int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
7617 u64 start, u64 len)
7618 {
7619 return __btrfs_free_reserved_extent(root, start, len, 1, 0);
7620 }
7621
7622 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
7623 struct btrfs_root *root,
7624 u64 parent, u64 root_objectid,
7625 u64 flags, u64 owner, u64 offset,
7626 struct btrfs_key *ins, int ref_mod)
7627 {
7628 int ret;
7629 struct btrfs_fs_info *fs_info = root->fs_info;
7630 struct btrfs_extent_item *extent_item;
7631 struct btrfs_extent_inline_ref *iref;
7632 struct btrfs_path *path;
7633 struct extent_buffer *leaf;
7634 int type;
7635 u32 size;
7636
7637 if (parent > 0)
7638 type = BTRFS_SHARED_DATA_REF_KEY;
7639 else
7640 type = BTRFS_EXTENT_DATA_REF_KEY;
7641
7642 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
7643
7644 path = btrfs_alloc_path();
7645 if (!path)
7646 return -ENOMEM;
7647
7648 path->leave_spinning = 1;
7649 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
7650 ins, size);
7651 if (ret) {
7652 btrfs_free_path(path);
7653 return ret;
7654 }
7655
7656 leaf = path->nodes[0];
7657 extent_item = btrfs_item_ptr(leaf, path->slots[0],
7658 struct btrfs_extent_item);
7659 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
7660 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
7661 btrfs_set_extent_flags(leaf, extent_item,
7662 flags | BTRFS_EXTENT_FLAG_DATA);
7663
7664 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
7665 btrfs_set_extent_inline_ref_type(leaf, iref, type);
7666 if (parent > 0) {
7667 struct btrfs_shared_data_ref *ref;
7668 ref = (struct btrfs_shared_data_ref *)(iref + 1);
7669 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
7670 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
7671 } else {
7672 struct btrfs_extent_data_ref *ref;
7673 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
7674 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
7675 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
7676 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
7677 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
7678 }
7679
7680 btrfs_mark_buffer_dirty(path->nodes[0]);
7681 btrfs_free_path(path);
7682
7683 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
7684 if (ret) { /* -ENOENT, logic error */
7685 btrfs_err(fs_info, "update block group failed for %llu %llu",
7686 ins->objectid, ins->offset);
7687 BUG();
7688 }
7689 trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset);
7690 return ret;
7691 }
7692
7693 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
7694 struct btrfs_root *root,
7695 u64 parent, u64 root_objectid,
7696 u64 flags, struct btrfs_disk_key *key,
7697 int level, struct btrfs_key *ins)
7698 {
7699 int ret;
7700 struct btrfs_fs_info *fs_info = root->fs_info;
7701 struct btrfs_extent_item *extent_item;
7702 struct btrfs_tree_block_info *block_info;
7703 struct btrfs_extent_inline_ref *iref;
7704 struct btrfs_path *path;
7705 struct extent_buffer *leaf;
7706 u32 size = sizeof(*extent_item) + sizeof(*iref);
7707 u64 num_bytes = ins->offset;
7708 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
7709 SKINNY_METADATA);
7710
7711 if (!skinny_metadata)
7712 size += sizeof(*block_info);
7713
7714 path = btrfs_alloc_path();
7715 if (!path) {
7716 btrfs_free_and_pin_reserved_extent(root, ins->objectid,
7717 root->nodesize);
7718 return -ENOMEM;
7719 }
7720
7721 path->leave_spinning = 1;
7722 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
7723 ins, size);
7724 if (ret) {
7725 btrfs_free_path(path);
7726 btrfs_free_and_pin_reserved_extent(root, ins->objectid,
7727 root->nodesize);
7728 return ret;
7729 }
7730
7731 leaf = path->nodes[0];
7732 extent_item = btrfs_item_ptr(leaf, path->slots[0],
7733 struct btrfs_extent_item);
7734 btrfs_set_extent_refs(leaf, extent_item, 1);
7735 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
7736 btrfs_set_extent_flags(leaf, extent_item,
7737 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
7738
7739 if (skinny_metadata) {
7740 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
7741 num_bytes = root->nodesize;
7742 } else {
7743 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
7744 btrfs_set_tree_block_key(leaf, block_info, key);
7745 btrfs_set_tree_block_level(leaf, block_info, level);
7746 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
7747 }
7748
7749 if (parent > 0) {
7750 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
7751 btrfs_set_extent_inline_ref_type(leaf, iref,
7752 BTRFS_SHARED_BLOCK_REF_KEY);
7753 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
7754 } else {
7755 btrfs_set_extent_inline_ref_type(leaf, iref,
7756 BTRFS_TREE_BLOCK_REF_KEY);
7757 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
7758 }
7759
7760 btrfs_mark_buffer_dirty(leaf);
7761 btrfs_free_path(path);
7762
7763 ret = update_block_group(trans, root, ins->objectid, root->nodesize,
7764 1);
7765 if (ret) { /* -ENOENT, logic error */
7766 btrfs_err(fs_info, "update block group failed for %llu %llu",
7767 ins->objectid, ins->offset);
7768 BUG();
7769 }
7770
7771 trace_btrfs_reserved_extent_alloc(root, ins->objectid, root->nodesize);
7772 return ret;
7773 }
7774
7775 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
7776 struct btrfs_root *root,
7777 u64 root_objectid, u64 owner,
7778 u64 offset, u64 ram_bytes,
7779 struct btrfs_key *ins)
7780 {
7781 int ret;
7782
7783 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
7784
7785 ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid,
7786 ins->offset, 0,
7787 root_objectid, owner, offset,
7788 ram_bytes, BTRFS_ADD_DELAYED_EXTENT,
7789 NULL);
7790 return ret;
7791 }
7792
7793 /*
7794 * this is used by the tree logging recovery code. It records that
7795 * an extent has been allocated and makes sure to clear the free
7796 * space cache bits as well
7797 */
7798 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
7799 struct btrfs_root *root,
7800 u64 root_objectid, u64 owner, u64 offset,
7801 struct btrfs_key *ins)
7802 {
7803 int ret;
7804 struct btrfs_block_group_cache *block_group;
7805
7806 /*
7807 * Mixed block groups will exclude before processing the log so we only
7808 * need to do the exlude dance if this fs isn't mixed.
7809 */
7810 if (!btrfs_fs_incompat(root->fs_info, MIXED_GROUPS)) {
7811 ret = __exclude_logged_extent(root, ins->objectid, ins->offset);
7812 if (ret)
7813 return ret;
7814 }
7815
7816 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
7817 if (!block_group)
7818 return -EINVAL;
7819
7820 ret = btrfs_update_reserved_bytes(block_group, ins->offset,
7821 RESERVE_ALLOC_NO_ACCOUNT, 0);
7822 BUG_ON(ret); /* logic error */
7823 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
7824 0, owner, offset, ins, 1);
7825 btrfs_put_block_group(block_group);
7826 return ret;
7827 }
7828
7829 static struct extent_buffer *
7830 btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
7831 u64 bytenr, int level)
7832 {
7833 struct extent_buffer *buf;
7834
7835 buf = btrfs_find_create_tree_block(root, bytenr);
7836 if (!buf)
7837 return ERR_PTR(-ENOMEM);
7838
7839 /*
7840 * Extra safety check in case the extent tree is corrupted and extent
7841 * allocator chooses to use a tree block which is already used and
7842 * locked.
7843 */
7844 if (buf->lock_owner == current->pid) {
7845 btrfs_err_rl(root->fs_info,
7846 "tree block %llu owner %llu already locked by pid=%d, extent tree corruption detected",
7847 buf->start, btrfs_header_owner(buf), current->pid);
7848 free_extent_buffer(buf);
7849 return ERR_PTR(-EUCLEAN);
7850 }
7851
7852 btrfs_set_header_generation(buf, trans->transid);
7853 btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
7854 btrfs_tree_lock(buf);
7855 clean_tree_block(trans, root->fs_info, buf);
7856 clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
7857
7858 btrfs_set_lock_blocking(buf);
7859 btrfs_set_buffer_uptodate(buf);
7860
7861 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
7862 buf->log_index = root->log_transid % 2;
7863 /*
7864 * we allow two log transactions at a time, use different
7865 * EXENT bit to differentiate dirty pages.
7866 */
7867 if (buf->log_index == 0)
7868 set_extent_dirty(&root->dirty_log_pages, buf->start,
7869 buf->start + buf->len - 1, GFP_NOFS);
7870 else
7871 set_extent_new(&root->dirty_log_pages, buf->start,
7872 buf->start + buf->len - 1, GFP_NOFS);
7873 } else {
7874 buf->log_index = -1;
7875 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
7876 buf->start + buf->len - 1, GFP_NOFS);
7877 }
7878 trans->dirty = true;
7879 /* this returns a buffer locked for blocking */
7880 return buf;
7881 }
7882
7883 static struct btrfs_block_rsv *
7884 use_block_rsv(struct btrfs_trans_handle *trans,
7885 struct btrfs_root *root, u32 blocksize)
7886 {
7887 struct btrfs_block_rsv *block_rsv;
7888 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
7889 int ret;
7890 bool global_updated = false;
7891
7892 block_rsv = get_block_rsv(trans, root);
7893
7894 if (unlikely(block_rsv->size == 0))
7895 goto try_reserve;
7896 again:
7897 ret = block_rsv_use_bytes(block_rsv, blocksize);
7898 if (!ret)
7899 return block_rsv;
7900
7901 if (block_rsv->failfast)
7902 return ERR_PTR(ret);
7903
7904 if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
7905 global_updated = true;
7906 update_global_block_rsv(root->fs_info);
7907 goto again;
7908 }
7909
7910 if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
7911 static DEFINE_RATELIMIT_STATE(_rs,
7912 DEFAULT_RATELIMIT_INTERVAL * 10,
7913 /*DEFAULT_RATELIMIT_BURST*/ 1);
7914 if (__ratelimit(&_rs))
7915 WARN(1, KERN_DEBUG
7916 "BTRFS: block rsv returned %d\n", ret);
7917 }
7918 try_reserve:
7919 ret = reserve_metadata_bytes(root, block_rsv, blocksize,
7920 BTRFS_RESERVE_NO_FLUSH);
7921 if (!ret)
7922 return block_rsv;
7923 /*
7924 * If we couldn't reserve metadata bytes try and use some from
7925 * the global reserve if its space type is the same as the global
7926 * reservation.
7927 */
7928 if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
7929 block_rsv->space_info == global_rsv->space_info) {
7930 ret = block_rsv_use_bytes(global_rsv, blocksize);
7931 if (!ret)
7932 return global_rsv;
7933 }
7934 return ERR_PTR(ret);
7935 }
7936
7937 static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
7938 struct btrfs_block_rsv *block_rsv, u32 blocksize)
7939 {
7940 block_rsv_add_bytes(block_rsv, blocksize, 0);
7941 block_rsv_release_bytes(fs_info, block_rsv, NULL, 0);
7942 }
7943
7944 /*
7945 * finds a free extent and does all the dirty work required for allocation
7946 * returns the tree buffer or an ERR_PTR on error.
7947 */
7948 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
7949 struct btrfs_root *root,
7950 u64 parent, u64 root_objectid,
7951 struct btrfs_disk_key *key, int level,
7952 u64 hint, u64 empty_size)
7953 {
7954 struct btrfs_key ins;
7955 struct btrfs_block_rsv *block_rsv;
7956 struct extent_buffer *buf;
7957 struct btrfs_delayed_extent_op *extent_op;
7958 u64 flags = 0;
7959 int ret;
7960 u32 blocksize = root->nodesize;
7961 bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
7962 SKINNY_METADATA);
7963
7964 if (btrfs_test_is_dummy_root(root)) {
7965 buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr,
7966 level);
7967 if (!IS_ERR(buf))
7968 root->alloc_bytenr += blocksize;
7969 return buf;
7970 }
7971
7972 block_rsv = use_block_rsv(trans, root, blocksize);
7973 if (IS_ERR(block_rsv))
7974 return ERR_CAST(block_rsv);
7975
7976 ret = btrfs_reserve_extent(root, blocksize, blocksize,
7977 empty_size, hint, &ins, 0, 0);
7978 if (ret)
7979 goto out_unuse;
7980
7981 buf = btrfs_init_new_buffer(trans, root, ins.objectid, level);
7982 if (IS_ERR(buf)) {
7983 ret = PTR_ERR(buf);
7984 goto out_free_reserved;
7985 }
7986
7987 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
7988 if (parent == 0)
7989 parent = ins.objectid;
7990 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
7991 } else
7992 BUG_ON(parent > 0);
7993
7994 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
7995 extent_op = btrfs_alloc_delayed_extent_op();
7996 if (!extent_op) {
7997 ret = -ENOMEM;
7998 goto out_free_buf;
7999 }
8000 if (key)
8001 memcpy(&extent_op->key, key, sizeof(extent_op->key));
8002 else
8003 memset(&extent_op->key, 0, sizeof(extent_op->key));
8004 extent_op->flags_to_set = flags;
8005 if (skinny_metadata)
8006 extent_op->update_key = 0;
8007 else
8008 extent_op->update_key = 1;
8009 extent_op->update_flags = 1;
8010 extent_op->is_data = 0;
8011 extent_op->level = level;
8012
8013 ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
8014 ins.objectid, ins.offset,
8015 parent, root_objectid, level,
8016 BTRFS_ADD_DELAYED_EXTENT,
8017 extent_op);
8018 if (ret)
8019 goto out_free_delayed;
8020 }
8021 return buf;
8022
8023 out_free_delayed:
8024 btrfs_free_delayed_extent_op(extent_op);
8025 out_free_buf:
8026 free_extent_buffer(buf);
8027 out_free_reserved:
8028 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 0);
8029 out_unuse:
8030 unuse_block_rsv(root->fs_info, block_rsv, blocksize);
8031 return ERR_PTR(ret);
8032 }
8033
8034 struct walk_control {
8035 u64 refs[BTRFS_MAX_LEVEL];
8036 u64 flags[BTRFS_MAX_LEVEL];
8037 struct btrfs_key update_progress;
8038 int stage;
8039 int level;
8040 int shared_level;
8041 int update_ref;
8042 int keep_locks;
8043 int reada_slot;
8044 int reada_count;
8045 int for_reloc;
8046 };
8047
8048 #define DROP_REFERENCE 1
8049 #define UPDATE_BACKREF 2
8050
8051 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
8052 struct btrfs_root *root,
8053 struct walk_control *wc,
8054 struct btrfs_path *path)
8055 {
8056 u64 bytenr;
8057 u64 generation;
8058 u64 refs;
8059 u64 flags;
8060 u32 nritems;
8061 u32 blocksize;
8062 struct btrfs_key key;
8063 struct extent_buffer *eb;
8064 int ret;
8065 int slot;
8066 int nread = 0;
8067
8068 if (path->slots[wc->level] < wc->reada_slot) {
8069 wc->reada_count = wc->reada_count * 2 / 3;
8070 wc->reada_count = max(wc->reada_count, 2);
8071 } else {
8072 wc->reada_count = wc->reada_count * 3 / 2;
8073 wc->reada_count = min_t(int, wc->reada_count,
8074 BTRFS_NODEPTRS_PER_BLOCK(root));
8075 }
8076
8077 eb = path->nodes[wc->level];
8078 nritems = btrfs_header_nritems(eb);
8079 blocksize = root->nodesize;
8080
8081 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
8082 if (nread >= wc->reada_count)
8083 break;
8084
8085 cond_resched();
8086 bytenr = btrfs_node_blockptr(eb, slot);
8087 generation = btrfs_node_ptr_generation(eb, slot);
8088
8089 if (slot == path->slots[wc->level])
8090 goto reada;
8091
8092 if (wc->stage == UPDATE_BACKREF &&
8093 generation <= root->root_key.offset)
8094 continue;
8095
8096 /* We don't lock the tree block, it's OK to be racy here */
8097 ret = btrfs_lookup_extent_info(trans, root, bytenr,
8098 wc->level - 1, 1, &refs,
8099 &flags);
8100 /* We don't care about errors in readahead. */
8101 if (ret < 0)
8102 continue;
8103 BUG_ON(refs == 0);
8104
8105 if (wc->stage == DROP_REFERENCE) {
8106 if (refs == 1)
8107 goto reada;
8108
8109 if (wc->level == 1 &&
8110 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8111 continue;
8112 if (!wc->update_ref ||
8113 generation <= root->root_key.offset)
8114 continue;
8115 btrfs_node_key_to_cpu(eb, &key, slot);
8116 ret = btrfs_comp_cpu_keys(&key,
8117 &wc->update_progress);
8118 if (ret < 0)
8119 continue;
8120 } else {
8121 if (wc->level == 1 &&
8122 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8123 continue;
8124 }
8125 reada:
8126 readahead_tree_block(root, bytenr);
8127 nread++;
8128 }
8129 wc->reada_slot = slot;
8130 }
8131
8132 /*
8133 * These may not be seen by the usual inc/dec ref code so we have to
8134 * add them here.
8135 */
8136 static int record_one_subtree_extent(struct btrfs_trans_handle *trans,
8137 struct btrfs_root *root, u64 bytenr,
8138 u64 num_bytes)
8139 {
8140 struct btrfs_qgroup_extent_record *qrecord;
8141 struct btrfs_delayed_ref_root *delayed_refs;
8142
8143 qrecord = kmalloc(sizeof(*qrecord), GFP_NOFS);
8144 if (!qrecord)
8145 return -ENOMEM;
8146
8147 qrecord->bytenr = bytenr;
8148 qrecord->num_bytes = num_bytes;
8149 qrecord->old_roots = NULL;
8150
8151 delayed_refs = &trans->transaction->delayed_refs;
8152 spin_lock(&delayed_refs->lock);
8153 if (btrfs_qgroup_insert_dirty_extent(delayed_refs, qrecord))
8154 kfree(qrecord);
8155 spin_unlock(&delayed_refs->lock);
8156
8157 return 0;
8158 }
8159
8160 static int account_leaf_items(struct btrfs_trans_handle *trans,
8161 struct btrfs_root *root,
8162 struct extent_buffer *eb)
8163 {
8164 int nr = btrfs_header_nritems(eb);
8165 int i, extent_type, ret;
8166 struct btrfs_key key;
8167 struct btrfs_file_extent_item *fi;
8168 u64 bytenr, num_bytes;
8169
8170 /* We can be called directly from walk_up_proc() */
8171 if (!root->fs_info->quota_enabled)
8172 return 0;
8173
8174 for (i = 0; i < nr; i++) {
8175 btrfs_item_key_to_cpu(eb, &key, i);
8176
8177 if (key.type != BTRFS_EXTENT_DATA_KEY)
8178 continue;
8179
8180 fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
8181 /* filter out non qgroup-accountable extents */
8182 extent_type = btrfs_file_extent_type(eb, fi);
8183
8184 if (extent_type == BTRFS_FILE_EXTENT_INLINE)
8185 continue;
8186
8187 bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
8188 if (!bytenr)
8189 continue;
8190
8191 num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
8192
8193 ret = record_one_subtree_extent(trans, root, bytenr, num_bytes);
8194 if (ret)
8195 return ret;
8196 }
8197 return 0;
8198 }
8199
8200 /*
8201 * Walk up the tree from the bottom, freeing leaves and any interior
8202 * nodes which have had all slots visited. If a node (leaf or
8203 * interior) is freed, the node above it will have it's slot
8204 * incremented. The root node will never be freed.
8205 *
8206 * At the end of this function, we should have a path which has all
8207 * slots incremented to the next position for a search. If we need to
8208 * read a new node it will be NULL and the node above it will have the
8209 * correct slot selected for a later read.
8210 *
8211 * If we increment the root nodes slot counter past the number of
8212 * elements, 1 is returned to signal completion of the search.
8213 */
8214 static int adjust_slots_upwards(struct btrfs_root *root,
8215 struct btrfs_path *path, int root_level)
8216 {
8217 int level = 0;
8218 int nr, slot;
8219 struct extent_buffer *eb;
8220
8221 if (root_level == 0)
8222 return 1;
8223
8224 while (level <= root_level) {
8225 eb = path->nodes[level];
8226 nr = btrfs_header_nritems(eb);
8227 path->slots[level]++;
8228 slot = path->slots[level];
8229 if (slot >= nr || level == 0) {
8230 /*
8231 * Don't free the root - we will detect this
8232 * condition after our loop and return a
8233 * positive value for caller to stop walking the tree.
8234 */
8235 if (level != root_level) {
8236 btrfs_tree_unlock_rw(eb, path->locks[level]);
8237 path->locks[level] = 0;
8238
8239 free_extent_buffer(eb);
8240 path->nodes[level] = NULL;
8241 path->slots[level] = 0;
8242 }
8243 } else {
8244 /*
8245 * We have a valid slot to walk back down
8246 * from. Stop here so caller can process these
8247 * new nodes.
8248 */
8249 break;
8250 }
8251
8252 level++;
8253 }
8254
8255 eb = path->nodes[root_level];
8256 if (path->slots[root_level] >= btrfs_header_nritems(eb))
8257 return 1;
8258
8259 return 0;
8260 }
8261
8262 /*
8263 * root_eb is the subtree root and is locked before this function is called.
8264 */
8265 static int account_shared_subtree(struct btrfs_trans_handle *trans,
8266 struct btrfs_root *root,
8267 struct extent_buffer *root_eb,
8268 u64 root_gen,
8269 int root_level)
8270 {
8271 int ret = 0;
8272 int level;
8273 struct extent_buffer *eb = root_eb;
8274 struct btrfs_path *path = NULL;
8275
8276 BUG_ON(root_level < 0 || root_level > BTRFS_MAX_LEVEL);
8277 BUG_ON(root_eb == NULL);
8278
8279 if (!root->fs_info->quota_enabled)
8280 return 0;
8281
8282 if (!extent_buffer_uptodate(root_eb)) {
8283 ret = btrfs_read_buffer(root_eb, root_gen);
8284 if (ret)
8285 goto out;
8286 }
8287
8288 if (root_level == 0) {
8289 ret = account_leaf_items(trans, root, root_eb);
8290 goto out;
8291 }
8292
8293 path = btrfs_alloc_path();
8294 if (!path)
8295 return -ENOMEM;
8296
8297 /*
8298 * Walk down the tree. Missing extent blocks are filled in as
8299 * we go. Metadata is accounted every time we read a new
8300 * extent block.
8301 *
8302 * When we reach a leaf, we account for file extent items in it,
8303 * walk back up the tree (adjusting slot pointers as we go)
8304 * and restart the search process.
8305 */
8306 extent_buffer_get(root_eb); /* For path */
8307 path->nodes[root_level] = root_eb;
8308 path->slots[root_level] = 0;
8309 path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
8310 walk_down:
8311 level = root_level;
8312 while (level >= 0) {
8313 if (path->nodes[level] == NULL) {
8314 int parent_slot;
8315 u64 child_gen;
8316 u64 child_bytenr;
8317
8318 /* We need to get child blockptr/gen from
8319 * parent before we can read it. */
8320 eb = path->nodes[level + 1];
8321 parent_slot = path->slots[level + 1];
8322 child_bytenr = btrfs_node_blockptr(eb, parent_slot);
8323 child_gen = btrfs_node_ptr_generation(eb, parent_slot);
8324
8325 eb = read_tree_block(root, child_bytenr, child_gen);
8326 if (IS_ERR(eb)) {
8327 ret = PTR_ERR(eb);
8328 goto out;
8329 } else if (!extent_buffer_uptodate(eb)) {
8330 free_extent_buffer(eb);
8331 ret = -EIO;
8332 goto out;
8333 }
8334
8335 path->nodes[level] = eb;
8336 path->slots[level] = 0;
8337
8338 btrfs_tree_read_lock(eb);
8339 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
8340 path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
8341
8342 ret = record_one_subtree_extent(trans, root, child_bytenr,
8343 root->nodesize);
8344 if (ret)
8345 goto out;
8346 }
8347
8348 if (level == 0) {
8349 ret = account_leaf_items(trans, root, path->nodes[level]);
8350 if (ret)
8351 goto out;
8352
8353 /* Nonzero return here means we completed our search */
8354 ret = adjust_slots_upwards(root, path, root_level);
8355 if (ret)
8356 break;
8357
8358 /* Restart search with new slots */
8359 goto walk_down;
8360 }
8361
8362 level--;
8363 }
8364
8365 ret = 0;
8366 out:
8367 btrfs_free_path(path);
8368
8369 return ret;
8370 }
8371
8372 /*
8373 * helper to process tree block while walking down the tree.
8374 *
8375 * when wc->stage == UPDATE_BACKREF, this function updates
8376 * back refs for pointers in the block.
8377 *
8378 * NOTE: return value 1 means we should stop walking down.
8379 */
8380 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
8381 struct btrfs_root *root,
8382 struct btrfs_path *path,
8383 struct walk_control *wc, int lookup_info)
8384 {
8385 int level = wc->level;
8386 struct extent_buffer *eb = path->nodes[level];
8387 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
8388 int ret;
8389
8390 if (wc->stage == UPDATE_BACKREF &&
8391 btrfs_header_owner(eb) != root->root_key.objectid)
8392 return 1;
8393
8394 /*
8395 * when reference count of tree block is 1, it won't increase
8396 * again. once full backref flag is set, we never clear it.
8397 */
8398 if (lookup_info &&
8399 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
8400 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
8401 BUG_ON(!path->locks[level]);
8402 ret = btrfs_lookup_extent_info(trans, root,
8403 eb->start, level, 1,
8404 &wc->refs[level],
8405 &wc->flags[level]);
8406 BUG_ON(ret == -ENOMEM);
8407 if (ret)
8408 return ret;
8409 BUG_ON(wc->refs[level] == 0);
8410 }
8411
8412 if (wc->stage == DROP_REFERENCE) {
8413 if (wc->refs[level] > 1)
8414 return 1;
8415
8416 if (path->locks[level] && !wc->keep_locks) {
8417 btrfs_tree_unlock_rw(eb, path->locks[level]);
8418 path->locks[level] = 0;
8419 }
8420 return 0;
8421 }
8422
8423 /* wc->stage == UPDATE_BACKREF */
8424 if (!(wc->flags[level] & flag)) {
8425 BUG_ON(!path->locks[level]);
8426 ret = btrfs_inc_ref(trans, root, eb, 1);
8427 BUG_ON(ret); /* -ENOMEM */
8428 ret = btrfs_dec_ref(trans, root, eb, 0);
8429 BUG_ON(ret); /* -ENOMEM */
8430 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
8431 eb->len, flag,
8432 btrfs_header_level(eb), 0);
8433 BUG_ON(ret); /* -ENOMEM */
8434 wc->flags[level] |= flag;
8435 }
8436
8437 /*
8438 * the block is shared by multiple trees, so it's not good to
8439 * keep the tree lock
8440 */
8441 if (path->locks[level] && level > 0) {
8442 btrfs_tree_unlock_rw(eb, path->locks[level]);
8443 path->locks[level] = 0;
8444 }
8445 return 0;
8446 }
8447
8448 /*
8449 * helper to process tree block pointer.
8450 *
8451 * when wc->stage == DROP_REFERENCE, this function checks
8452 * reference count of the block pointed to. if the block
8453 * is shared and we need update back refs for the subtree
8454 * rooted at the block, this function changes wc->stage to
8455 * UPDATE_BACKREF. if the block is shared and there is no
8456 * need to update back, this function drops the reference
8457 * to the block.
8458 *
8459 * NOTE: return value 1 means we should stop walking down.
8460 */
8461 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
8462 struct btrfs_root *root,
8463 struct btrfs_path *path,
8464 struct walk_control *wc, int *lookup_info)
8465 {
8466 u64 bytenr;
8467 u64 generation;
8468 u64 parent;
8469 u32 blocksize;
8470 struct btrfs_key key;
8471 struct extent_buffer *next;
8472 int level = wc->level;
8473 int reada = 0;
8474 int ret = 0;
8475 bool need_account = false;
8476
8477 generation = btrfs_node_ptr_generation(path->nodes[level],
8478 path->slots[level]);
8479 /*
8480 * if the lower level block was created before the snapshot
8481 * was created, we know there is no need to update back refs
8482 * for the subtree
8483 */
8484 if (wc->stage == UPDATE_BACKREF &&
8485 generation <= root->root_key.offset) {
8486 *lookup_info = 1;
8487 return 1;
8488 }
8489
8490 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
8491 blocksize = root->nodesize;
8492
8493 next = btrfs_find_tree_block(root->fs_info, bytenr);
8494 if (!next) {
8495 next = btrfs_find_create_tree_block(root, bytenr);
8496 if (!next)
8497 return -ENOMEM;
8498 btrfs_set_buffer_lockdep_class(root->root_key.objectid, next,
8499 level - 1);
8500 reada = 1;
8501 }
8502 btrfs_tree_lock(next);
8503 btrfs_set_lock_blocking(next);
8504
8505 ret = btrfs_lookup_extent_info(trans, root, bytenr, level - 1, 1,
8506 &wc->refs[level - 1],
8507 &wc->flags[level - 1]);
8508 if (ret < 0)
8509 goto out_unlock;
8510
8511 if (unlikely(wc->refs[level - 1] == 0)) {
8512 btrfs_err(root->fs_info, "Missing references.");
8513 ret = -EIO;
8514 goto out_unlock;
8515 }
8516 *lookup_info = 0;
8517
8518 if (wc->stage == DROP_REFERENCE) {
8519 if (wc->refs[level - 1] > 1) {
8520 need_account = true;
8521 if (level == 1 &&
8522 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8523 goto skip;
8524
8525 if (!wc->update_ref ||
8526 generation <= root->root_key.offset)
8527 goto skip;
8528
8529 btrfs_node_key_to_cpu(path->nodes[level], &key,
8530 path->slots[level]);
8531 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
8532 if (ret < 0)
8533 goto skip;
8534
8535 wc->stage = UPDATE_BACKREF;
8536 wc->shared_level = level - 1;
8537 }
8538 } else {
8539 if (level == 1 &&
8540 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8541 goto skip;
8542 }
8543
8544 if (!btrfs_buffer_uptodate(next, generation, 0)) {
8545 btrfs_tree_unlock(next);
8546 free_extent_buffer(next);
8547 next = NULL;
8548 *lookup_info = 1;
8549 }
8550
8551 if (!next) {
8552 if (reada && level == 1)
8553 reada_walk_down(trans, root, wc, path);
8554 next = read_tree_block(root, bytenr, generation);
8555 if (IS_ERR(next)) {
8556 return PTR_ERR(next);
8557 } else if (!extent_buffer_uptodate(next)) {
8558 free_extent_buffer(next);
8559 return -EIO;
8560 }
8561 btrfs_tree_lock(next);
8562 btrfs_set_lock_blocking(next);
8563 }
8564
8565 level--;
8566 ASSERT(level == btrfs_header_level(next));
8567 if (level != btrfs_header_level(next)) {
8568 btrfs_err(root->fs_info, "mismatched level");
8569 ret = -EIO;
8570 goto out_unlock;
8571 }
8572 path->nodes[level] = next;
8573 path->slots[level] = 0;
8574 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
8575 wc->level = level;
8576 if (wc->level == 1)
8577 wc->reada_slot = 0;
8578 return 0;
8579 skip:
8580 wc->refs[level - 1] = 0;
8581 wc->flags[level - 1] = 0;
8582 if (wc->stage == DROP_REFERENCE) {
8583 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
8584 parent = path->nodes[level]->start;
8585 } else {
8586 ASSERT(root->root_key.objectid ==
8587 btrfs_header_owner(path->nodes[level]));
8588 if (root->root_key.objectid !=
8589 btrfs_header_owner(path->nodes[level])) {
8590 btrfs_err(root->fs_info,
8591 "mismatched block owner");
8592 ret = -EIO;
8593 goto out_unlock;
8594 }
8595 parent = 0;
8596 }
8597
8598 if (need_account) {
8599 ret = account_shared_subtree(trans, root, next,
8600 generation, level - 1);
8601 if (ret) {
8602 btrfs_err_rl(root->fs_info,
8603 "Error "
8604 "%d accounting shared subtree. Quota "
8605 "is out of sync, rescan required.",
8606 ret);
8607 }
8608 }
8609 ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
8610 root->root_key.objectid, level - 1, 0);
8611 if (ret)
8612 goto out_unlock;
8613 }
8614
8615 *lookup_info = 1;
8616 ret = 1;
8617
8618 out_unlock:
8619 btrfs_tree_unlock(next);
8620 free_extent_buffer(next);
8621
8622 return ret;
8623 }
8624
8625 /*
8626 * helper to process tree block while walking up the tree.
8627 *
8628 * when wc->stage == DROP_REFERENCE, this function drops
8629 * reference count on the block.
8630 *
8631 * when wc->stage == UPDATE_BACKREF, this function changes
8632 * wc->stage back to DROP_REFERENCE if we changed wc->stage
8633 * to UPDATE_BACKREF previously while processing the block.
8634 *
8635 * NOTE: return value 1 means we should stop walking up.
8636 */
8637 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
8638 struct btrfs_root *root,
8639 struct btrfs_path *path,
8640 struct walk_control *wc)
8641 {
8642 int ret;
8643 int level = wc->level;
8644 struct extent_buffer *eb = path->nodes[level];
8645 u64 parent = 0;
8646
8647 if (wc->stage == UPDATE_BACKREF) {
8648 BUG_ON(wc->shared_level < level);
8649 if (level < wc->shared_level)
8650 goto out;
8651
8652 ret = find_next_key(path, level + 1, &wc->update_progress);
8653 if (ret > 0)
8654 wc->update_ref = 0;
8655
8656 wc->stage = DROP_REFERENCE;
8657 wc->shared_level = -1;
8658 path->slots[level] = 0;
8659
8660 /*
8661 * check reference count again if the block isn't locked.
8662 * we should start walking down the tree again if reference
8663 * count is one.
8664 */
8665 if (!path->locks[level]) {
8666 BUG_ON(level == 0);
8667 btrfs_tree_lock(eb);
8668 btrfs_set_lock_blocking(eb);
8669 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
8670
8671 ret = btrfs_lookup_extent_info(trans, root,
8672 eb->start, level, 1,
8673 &wc->refs[level],
8674 &wc->flags[level]);
8675 if (ret < 0) {
8676 btrfs_tree_unlock_rw(eb, path->locks[level]);
8677 path->locks[level] = 0;
8678 return ret;
8679 }
8680 BUG_ON(wc->refs[level] == 0);
8681 if (wc->refs[level] == 1) {
8682 btrfs_tree_unlock_rw(eb, path->locks[level]);
8683 path->locks[level] = 0;
8684 return 1;
8685 }
8686 }
8687 }
8688
8689 /* wc->stage == DROP_REFERENCE */
8690 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
8691
8692 if (wc->refs[level] == 1) {
8693 if (level == 0) {
8694 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
8695 ret = btrfs_dec_ref(trans, root, eb, 1);
8696 else
8697 ret = btrfs_dec_ref(trans, root, eb, 0);
8698 BUG_ON(ret); /* -ENOMEM */
8699 ret = account_leaf_items(trans, root, eb);
8700 if (ret) {
8701 btrfs_err_rl(root->fs_info,
8702 "error "
8703 "%d accounting leaf items. Quota "
8704 "is out of sync, rescan required.",
8705 ret);
8706 }
8707 }
8708 /* make block locked assertion in clean_tree_block happy */
8709 if (!path->locks[level] &&
8710 btrfs_header_generation(eb) == trans->transid) {
8711 btrfs_tree_lock(eb);
8712 btrfs_set_lock_blocking(eb);
8713 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
8714 }
8715 clean_tree_block(trans, root->fs_info, eb);
8716 }
8717
8718 if (eb == root->node) {
8719 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
8720 parent = eb->start;
8721 else if (root->root_key.objectid != btrfs_header_owner(eb))
8722 goto owner_mismatch;
8723 } else {
8724 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
8725 parent = path->nodes[level + 1]->start;
8726 else if (root->root_key.objectid !=
8727 btrfs_header_owner(path->nodes[level + 1]))
8728 goto owner_mismatch;
8729 }
8730
8731 btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
8732 out:
8733 wc->refs[level] = 0;
8734 wc->flags[level] = 0;
8735 return 0;
8736
8737 owner_mismatch:
8738 btrfs_err_rl(root->fs_info, "unexpected tree owner, have %llu expect %llu",
8739 btrfs_header_owner(eb), root->root_key.objectid);
8740 return -EUCLEAN;
8741 }
8742
8743 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
8744 struct btrfs_root *root,
8745 struct btrfs_path *path,
8746 struct walk_control *wc)
8747 {
8748 int level = wc->level;
8749 int lookup_info = 1;
8750 int ret;
8751
8752 while (level >= 0) {
8753 ret = walk_down_proc(trans, root, path, wc, lookup_info);
8754 if (ret > 0)
8755 break;
8756
8757 if (level == 0)
8758 break;
8759
8760 if (path->slots[level] >=
8761 btrfs_header_nritems(path->nodes[level]))
8762 break;
8763
8764 ret = do_walk_down(trans, root, path, wc, &lookup_info);
8765 if (ret > 0) {
8766 path->slots[level]++;
8767 continue;
8768 } else if (ret < 0)
8769 return ret;
8770 level = wc->level;
8771 }
8772 return 0;
8773 }
8774
8775 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
8776 struct btrfs_root *root,
8777 struct btrfs_path *path,
8778 struct walk_control *wc, int max_level)
8779 {
8780 int level = wc->level;
8781 int ret;
8782
8783 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
8784 while (level < max_level && path->nodes[level]) {
8785 wc->level = level;
8786 if (path->slots[level] + 1 <
8787 btrfs_header_nritems(path->nodes[level])) {
8788 path->slots[level]++;
8789 return 0;
8790 } else {
8791 ret = walk_up_proc(trans, root, path, wc);
8792 if (ret > 0)
8793 return 0;
8794 if (ret < 0)
8795 return ret;
8796
8797 if (path->locks[level]) {
8798 btrfs_tree_unlock_rw(path->nodes[level],
8799 path->locks[level]);
8800 path->locks[level] = 0;
8801 }
8802 free_extent_buffer(path->nodes[level]);
8803 path->nodes[level] = NULL;
8804 level++;
8805 }
8806 }
8807 return 1;
8808 }
8809
8810 /*
8811 * drop a subvolume tree.
8812 *
8813 * this function traverses the tree freeing any blocks that only
8814 * referenced by the tree.
8815 *
8816 * when a shared tree block is found. this function decreases its
8817 * reference count by one. if update_ref is true, this function
8818 * also make sure backrefs for the shared block and all lower level
8819 * blocks are properly updated.
8820 *
8821 * If called with for_reloc == 0, may exit early with -EAGAIN
8822 */
8823 int btrfs_drop_snapshot(struct btrfs_root *root,
8824 struct btrfs_block_rsv *block_rsv, int update_ref,
8825 int for_reloc)
8826 {
8827 struct btrfs_path *path;
8828 struct btrfs_trans_handle *trans;
8829 struct btrfs_root *tree_root = root->fs_info->tree_root;
8830 struct btrfs_root_item *root_item = &root->root_item;
8831 struct walk_control *wc;
8832 struct btrfs_key key;
8833 int err = 0;
8834 int ret;
8835 int level;
8836 bool root_dropped = false;
8837
8838 btrfs_debug(root->fs_info, "Drop subvolume %llu", root->objectid);
8839
8840 path = btrfs_alloc_path();
8841 if (!path) {
8842 err = -ENOMEM;
8843 goto out;
8844 }
8845
8846 wc = kzalloc(sizeof(*wc), GFP_NOFS);
8847 if (!wc) {
8848 btrfs_free_path(path);
8849 err = -ENOMEM;
8850 goto out;
8851 }
8852
8853 trans = btrfs_start_transaction(tree_root, 0);
8854 if (IS_ERR(trans)) {
8855 err = PTR_ERR(trans);
8856 goto out_free;
8857 }
8858
8859 if (block_rsv)
8860 trans->block_rsv = block_rsv;
8861
8862 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
8863 level = btrfs_header_level(root->node);
8864 path->nodes[level] = btrfs_lock_root_node(root);
8865 btrfs_set_lock_blocking(path->nodes[level]);
8866 path->slots[level] = 0;
8867 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
8868 memset(&wc->update_progress, 0,
8869 sizeof(wc->update_progress));
8870 } else {
8871 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
8872 memcpy(&wc->update_progress, &key,
8873 sizeof(wc->update_progress));
8874
8875 level = root_item->drop_level;
8876 BUG_ON(level == 0);
8877 path->lowest_level = level;
8878 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
8879 path->lowest_level = 0;
8880 if (ret < 0) {
8881 err = ret;
8882 goto out_end_trans;
8883 }
8884 WARN_ON(ret > 0);
8885
8886 /*
8887 * unlock our path, this is safe because only this
8888 * function is allowed to delete this snapshot
8889 */
8890 btrfs_unlock_up_safe(path, 0);
8891
8892 level = btrfs_header_level(root->node);
8893 while (1) {
8894 btrfs_tree_lock(path->nodes[level]);
8895 btrfs_set_lock_blocking(path->nodes[level]);
8896 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
8897
8898 ret = btrfs_lookup_extent_info(trans, root,
8899 path->nodes[level]->start,
8900 level, 1, &wc->refs[level],
8901 &wc->flags[level]);
8902 if (ret < 0) {
8903 err = ret;
8904 goto out_end_trans;
8905 }
8906 BUG_ON(wc->refs[level] == 0);
8907
8908 if (level == root_item->drop_level)
8909 break;
8910
8911 btrfs_tree_unlock(path->nodes[level]);
8912 path->locks[level] = 0;
8913 WARN_ON(wc->refs[level] != 1);
8914 level--;
8915 }
8916 }
8917
8918 wc->level = level;
8919 wc->shared_level = -1;
8920 wc->stage = DROP_REFERENCE;
8921 wc->update_ref = update_ref;
8922 wc->keep_locks = 0;
8923 wc->for_reloc = for_reloc;
8924 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
8925
8926 while (1) {
8927
8928 ret = walk_down_tree(trans, root, path, wc);
8929 if (ret < 0) {
8930 err = ret;
8931 break;
8932 }
8933
8934 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
8935 if (ret < 0) {
8936 err = ret;
8937 break;
8938 }
8939
8940 if (ret > 0) {
8941 BUG_ON(wc->stage != DROP_REFERENCE);
8942 break;
8943 }
8944
8945 if (wc->stage == DROP_REFERENCE) {
8946 level = wc->level;
8947 btrfs_node_key(path->nodes[level],
8948 &root_item->drop_progress,
8949 path->slots[level]);
8950 root_item->drop_level = level;
8951 }
8952
8953 BUG_ON(wc->level == 0);
8954 if (btrfs_should_end_transaction(trans, tree_root) ||
8955 (!for_reloc && btrfs_need_cleaner_sleep(root))) {
8956 ret = btrfs_update_root(trans, tree_root,
8957 &root->root_key,
8958 root_item);
8959 if (ret) {
8960 btrfs_abort_transaction(trans, tree_root, ret);
8961 err = ret;
8962 goto out_end_trans;
8963 }
8964
8965 btrfs_end_transaction_throttle(trans, tree_root);
8966 if (!for_reloc && btrfs_need_cleaner_sleep(root)) {
8967 pr_debug("BTRFS: drop snapshot early exit\n");
8968 err = -EAGAIN;
8969 goto out_free;
8970 }
8971
8972 trans = btrfs_start_transaction(tree_root, 0);
8973 if (IS_ERR(trans)) {
8974 err = PTR_ERR(trans);
8975 goto out_free;
8976 }
8977 if (block_rsv)
8978 trans->block_rsv = block_rsv;
8979 }
8980 }
8981 btrfs_release_path(path);
8982 if (err)
8983 goto out_end_trans;
8984
8985 ret = btrfs_del_root(trans, tree_root, &root->root_key);
8986 if (ret) {
8987 btrfs_abort_transaction(trans, tree_root, ret);
8988 goto out_end_trans;
8989 }
8990
8991 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
8992 ret = btrfs_find_root(tree_root, &root->root_key, path,
8993 NULL, NULL);
8994 if (ret < 0) {
8995 btrfs_abort_transaction(trans, tree_root, ret);
8996 err = ret;
8997 goto out_end_trans;
8998 } else if (ret > 0) {
8999 /* if we fail to delete the orphan item this time
9000 * around, it'll get picked up the next time.
9001 *
9002 * The most common failure here is just -ENOENT.
9003 */
9004 btrfs_del_orphan_item(trans, tree_root,
9005 root->root_key.objectid);
9006 }
9007 }
9008
9009 if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state)) {
9010 btrfs_add_dropped_root(trans, root);
9011 } else {
9012 free_extent_buffer(root->node);
9013 free_extent_buffer(root->commit_root);
9014 btrfs_put_fs_root(root);
9015 }
9016 root_dropped = true;
9017 out_end_trans:
9018 btrfs_end_transaction_throttle(trans, tree_root);
9019 out_free:
9020 kfree(wc);
9021 btrfs_free_path(path);
9022 out:
9023 /*
9024 * So if we need to stop dropping the snapshot for whatever reason we
9025 * need to make sure to add it back to the dead root list so that we
9026 * keep trying to do the work later. This also cleans up roots if we
9027 * don't have it in the radix (like when we recover after a power fail
9028 * or unmount) so we don't leak memory.
9029 */
9030 if (!for_reloc && root_dropped == false)
9031 btrfs_add_dead_root(root);
9032 if (err && err != -EAGAIN)
9033 btrfs_std_error(root->fs_info, err, NULL);
9034 return err;
9035 }
9036
9037 /*
9038 * drop subtree rooted at tree block 'node'.
9039 *
9040 * NOTE: this function will unlock and release tree block 'node'
9041 * only used by relocation code
9042 */
9043 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
9044 struct btrfs_root *root,
9045 struct extent_buffer *node,
9046 struct extent_buffer *parent)
9047 {
9048 struct btrfs_path *path;
9049 struct walk_control *wc;
9050 int level;
9051 int parent_level;
9052 int ret = 0;
9053 int wret;
9054
9055 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
9056
9057 path = btrfs_alloc_path();
9058 if (!path)
9059 return -ENOMEM;
9060
9061 wc = kzalloc(sizeof(*wc), GFP_NOFS);
9062 if (!wc) {
9063 btrfs_free_path(path);
9064 return -ENOMEM;
9065 }
9066
9067 btrfs_assert_tree_locked(parent);
9068 parent_level = btrfs_header_level(parent);
9069 extent_buffer_get(parent);
9070 path->nodes[parent_level] = parent;
9071 path->slots[parent_level] = btrfs_header_nritems(parent);
9072
9073 btrfs_assert_tree_locked(node);
9074 level = btrfs_header_level(node);
9075 path->nodes[level] = node;
9076 path->slots[level] = 0;
9077 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
9078
9079 wc->refs[parent_level] = 1;
9080 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
9081 wc->level = level;
9082 wc->shared_level = -1;
9083 wc->stage = DROP_REFERENCE;
9084 wc->update_ref = 0;
9085 wc->keep_locks = 1;
9086 wc->for_reloc = 1;
9087 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
9088
9089 while (1) {
9090 wret = walk_down_tree(trans, root, path, wc);
9091 if (wret < 0) {
9092 ret = wret;
9093 break;
9094 }
9095
9096 wret = walk_up_tree(trans, root, path, wc, parent_level);
9097 if (wret < 0)
9098 ret = wret;
9099 if (wret != 0)
9100 break;
9101 }
9102
9103 kfree(wc);
9104 btrfs_free_path(path);
9105 return ret;
9106 }
9107
9108 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
9109 {
9110 u64 num_devices;
9111 u64 stripped;
9112
9113 /*
9114 * if restripe for this chunk_type is on pick target profile and
9115 * return, otherwise do the usual balance
9116 */
9117 stripped = get_restripe_target(root->fs_info, flags);
9118 if (stripped)
9119 return extended_to_chunk(stripped);
9120
9121 num_devices = root->fs_info->fs_devices->rw_devices;
9122
9123 stripped = BTRFS_BLOCK_GROUP_RAID0 |
9124 BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
9125 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
9126
9127 if (num_devices == 1) {
9128 stripped |= BTRFS_BLOCK_GROUP_DUP;
9129 stripped = flags & ~stripped;
9130
9131 /* turn raid0 into single device chunks */
9132 if (flags & BTRFS_BLOCK_GROUP_RAID0)
9133 return stripped;
9134
9135 /* turn mirroring into duplication */
9136 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
9137 BTRFS_BLOCK_GROUP_RAID10))
9138 return stripped | BTRFS_BLOCK_GROUP_DUP;
9139 } else {
9140 /* they already had raid on here, just return */
9141 if (flags & stripped)
9142 return flags;
9143
9144 stripped |= BTRFS_BLOCK_GROUP_DUP;
9145 stripped = flags & ~stripped;
9146
9147 /* switch duplicated blocks with raid1 */
9148 if (flags & BTRFS_BLOCK_GROUP_DUP)
9149 return stripped | BTRFS_BLOCK_GROUP_RAID1;
9150
9151 /* this is drive concat, leave it alone */
9152 }
9153
9154 return flags;
9155 }
9156
9157 static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
9158 {
9159 struct btrfs_space_info *sinfo = cache->space_info;
9160 u64 num_bytes;
9161 u64 min_allocable_bytes;
9162 int ret = -ENOSPC;
9163
9164 /*
9165 * We need some metadata space and system metadata space for
9166 * allocating chunks in some corner cases until we force to set
9167 * it to be readonly.
9168 */
9169 if ((sinfo->flags &
9170 (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
9171 !force)
9172 min_allocable_bytes = 1 * 1024 * 1024;
9173 else
9174 min_allocable_bytes = 0;
9175
9176 spin_lock(&sinfo->lock);
9177 spin_lock(&cache->lock);
9178
9179 if (cache->ro) {
9180 cache->ro++;
9181 ret = 0;
9182 goto out;
9183 }
9184
9185 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
9186 cache->bytes_super - btrfs_block_group_used(&cache->item);
9187
9188 if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
9189 sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
9190 min_allocable_bytes <= sinfo->total_bytes) {
9191 sinfo->bytes_readonly += num_bytes;
9192 cache->ro++;
9193 list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
9194 ret = 0;
9195 }
9196 out:
9197 spin_unlock(&cache->lock);
9198 spin_unlock(&sinfo->lock);
9199 return ret;
9200 }
9201
9202 int btrfs_inc_block_group_ro(struct btrfs_root *root,
9203 struct btrfs_block_group_cache *cache)
9204
9205 {
9206 struct btrfs_trans_handle *trans;
9207 u64 alloc_flags;
9208 int ret;
9209
9210 again:
9211 trans = btrfs_join_transaction(root);
9212 if (IS_ERR(trans))
9213 return PTR_ERR(trans);
9214
9215 /*
9216 * we're not allowed to set block groups readonly after the dirty
9217 * block groups cache has started writing. If it already started,
9218 * back off and let this transaction commit
9219 */
9220 mutex_lock(&root->fs_info->ro_block_group_mutex);
9221 if (test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &trans->transaction->flags)) {
9222 u64 transid = trans->transid;
9223
9224 mutex_unlock(&root->fs_info->ro_block_group_mutex);
9225 btrfs_end_transaction(trans, root);
9226
9227 ret = btrfs_wait_for_commit(root, transid);
9228 if (ret)
9229 return ret;
9230 goto again;
9231 }
9232
9233 /*
9234 * if we are changing raid levels, try to allocate a corresponding
9235 * block group with the new raid level.
9236 */
9237 alloc_flags = update_block_group_flags(root, cache->flags);
9238 if (alloc_flags != cache->flags) {
9239 ret = do_chunk_alloc(trans, root, alloc_flags,
9240 CHUNK_ALLOC_FORCE);
9241 /*
9242 * ENOSPC is allowed here, we may have enough space
9243 * already allocated at the new raid level to
9244 * carry on
9245 */
9246 if (ret == -ENOSPC)
9247 ret = 0;
9248 if (ret < 0)
9249 goto out;
9250 }
9251
9252 ret = inc_block_group_ro(cache, 0);
9253 if (!ret)
9254 goto out;
9255 alloc_flags = get_alloc_profile(root, cache->space_info->flags);
9256 ret = do_chunk_alloc(trans, root, alloc_flags,
9257 CHUNK_ALLOC_FORCE);
9258 if (ret < 0)
9259 goto out;
9260 ret = inc_block_group_ro(cache, 0);
9261 out:
9262 if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
9263 alloc_flags = update_block_group_flags(root, cache->flags);
9264 lock_chunks(root->fs_info->chunk_root);
9265 check_system_chunk(trans, root, alloc_flags);
9266 unlock_chunks(root->fs_info->chunk_root);
9267 }
9268 mutex_unlock(&root->fs_info->ro_block_group_mutex);
9269
9270 btrfs_end_transaction(trans, root);
9271 return ret;
9272 }
9273
9274 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
9275 struct btrfs_root *root, u64 type)
9276 {
9277 u64 alloc_flags = get_alloc_profile(root, type);
9278 return do_chunk_alloc(trans, root, alloc_flags,
9279 CHUNK_ALLOC_FORCE);
9280 }
9281
9282 /*
9283 * helper to account the unused space of all the readonly block group in the
9284 * space_info. takes mirrors into account.
9285 */
9286 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
9287 {
9288 struct btrfs_block_group_cache *block_group;
9289 u64 free_bytes = 0;
9290 int factor;
9291
9292 /* It's df, we don't care if it's racey */
9293 if (list_empty(&sinfo->ro_bgs))
9294 return 0;
9295
9296 spin_lock(&sinfo->lock);
9297 list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) {
9298 spin_lock(&block_group->lock);
9299
9300 if (!block_group->ro) {
9301 spin_unlock(&block_group->lock);
9302 continue;
9303 }
9304
9305 if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
9306 BTRFS_BLOCK_GROUP_RAID10 |
9307 BTRFS_BLOCK_GROUP_DUP))
9308 factor = 2;
9309 else
9310 factor = 1;
9311
9312 free_bytes += (block_group->key.offset -
9313 btrfs_block_group_used(&block_group->item)) *
9314 factor;
9315
9316 spin_unlock(&block_group->lock);
9317 }
9318 spin_unlock(&sinfo->lock);
9319
9320 return free_bytes;
9321 }
9322
9323 void btrfs_dec_block_group_ro(struct btrfs_root *root,
9324 struct btrfs_block_group_cache *cache)
9325 {
9326 struct btrfs_space_info *sinfo = cache->space_info;
9327 u64 num_bytes;
9328
9329 BUG_ON(!cache->ro);
9330
9331 spin_lock(&sinfo->lock);
9332 spin_lock(&cache->lock);
9333 if (!--cache->ro) {
9334 num_bytes = cache->key.offset - cache->reserved -
9335 cache->pinned - cache->bytes_super -
9336 btrfs_block_group_used(&cache->item);
9337 sinfo->bytes_readonly -= num_bytes;
9338 list_del_init(&cache->ro_list);
9339 }
9340 spin_unlock(&cache->lock);
9341 spin_unlock(&sinfo->lock);
9342 }
9343
9344 /*
9345 * checks to see if its even possible to relocate this block group.
9346 *
9347 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
9348 * ok to go ahead and try.
9349 */
9350 int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
9351 {
9352 struct btrfs_block_group_cache *block_group;
9353 struct btrfs_space_info *space_info;
9354 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
9355 struct btrfs_device *device;
9356 struct btrfs_trans_handle *trans;
9357 u64 min_free;
9358 u64 dev_min = 1;
9359 u64 dev_nr = 0;
9360 u64 target;
9361 int index;
9362 int full = 0;
9363 int ret = 0;
9364
9365 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
9366
9367 /* odd, couldn't find the block group, leave it alone */
9368 if (!block_group)
9369 return -1;
9370
9371 min_free = btrfs_block_group_used(&block_group->item);
9372
9373 /* no bytes used, we're good */
9374 if (!min_free)
9375 goto out;
9376
9377 space_info = block_group->space_info;
9378 spin_lock(&space_info->lock);
9379
9380 full = space_info->full;
9381
9382 /*
9383 * if this is the last block group we have in this space, we can't
9384 * relocate it unless we're able to allocate a new chunk below.
9385 *
9386 * Otherwise, we need to make sure we have room in the space to handle
9387 * all of the extents from this block group. If we can, we're good
9388 */
9389 if ((space_info->total_bytes != block_group->key.offset) &&
9390 (space_info->bytes_used + space_info->bytes_reserved +
9391 space_info->bytes_pinned + space_info->bytes_readonly +
9392 min_free < space_info->total_bytes)) {
9393 spin_unlock(&space_info->lock);
9394 goto out;
9395 }
9396 spin_unlock(&space_info->lock);
9397
9398 /*
9399 * ok we don't have enough space, but maybe we have free space on our
9400 * devices to allocate new chunks for relocation, so loop through our
9401 * alloc devices and guess if we have enough space. if this block
9402 * group is going to be restriped, run checks against the target
9403 * profile instead of the current one.
9404 */
9405 ret = -1;
9406
9407 /*
9408 * index:
9409 * 0: raid10
9410 * 1: raid1
9411 * 2: dup
9412 * 3: raid0
9413 * 4: single
9414 */
9415 target = get_restripe_target(root->fs_info, block_group->flags);
9416 if (target) {
9417 index = __get_raid_index(extended_to_chunk(target));
9418 } else {
9419 /*
9420 * this is just a balance, so if we were marked as full
9421 * we know there is no space for a new chunk
9422 */
9423 if (full)
9424 goto out;
9425
9426 index = get_block_group_index(block_group);
9427 }
9428
9429 if (index == BTRFS_RAID_RAID10) {
9430 dev_min = 4;
9431 /* Divide by 2 */
9432 min_free >>= 1;
9433 } else if (index == BTRFS_RAID_RAID1) {
9434 dev_min = 2;
9435 } else if (index == BTRFS_RAID_DUP) {
9436 /* Multiply by 2 */
9437 min_free <<= 1;
9438 } else if (index == BTRFS_RAID_RAID0) {
9439 dev_min = fs_devices->rw_devices;
9440 min_free = div64_u64(min_free, dev_min);
9441 }
9442
9443 /* We need to do this so that we can look at pending chunks */
9444 trans = btrfs_join_transaction(root);
9445 if (IS_ERR(trans)) {
9446 ret = PTR_ERR(trans);
9447 goto out;
9448 }
9449
9450 mutex_lock(&root->fs_info->chunk_mutex);
9451 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
9452 u64 dev_offset;
9453
9454 /*
9455 * check to make sure we can actually find a chunk with enough
9456 * space to fit our block group in.
9457 */
9458 if (device->total_bytes > device->bytes_used + min_free &&
9459 !device->is_tgtdev_for_dev_replace) {
9460 ret = find_free_dev_extent(trans, device, min_free,
9461 &dev_offset, NULL);
9462 if (!ret)
9463 dev_nr++;
9464
9465 if (dev_nr >= dev_min)
9466 break;
9467
9468 ret = -1;
9469 }
9470 }
9471 mutex_unlock(&root->fs_info->chunk_mutex);
9472 btrfs_end_transaction(trans, root);
9473 out:
9474 btrfs_put_block_group(block_group);
9475 return ret;
9476 }
9477
9478 static int find_first_block_group(struct btrfs_root *root,
9479 struct btrfs_path *path, struct btrfs_key *key)
9480 {
9481 int ret = 0;
9482 struct btrfs_key found_key;
9483 struct extent_buffer *leaf;
9484 int slot;
9485
9486 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
9487 if (ret < 0)
9488 goto out;
9489
9490 while (1) {
9491 slot = path->slots[0];
9492 leaf = path->nodes[0];
9493 if (slot >= btrfs_header_nritems(leaf)) {
9494 ret = btrfs_next_leaf(root, path);
9495 if (ret == 0)
9496 continue;
9497 if (ret < 0)
9498 goto out;
9499 break;
9500 }
9501 btrfs_item_key_to_cpu(leaf, &found_key, slot);
9502
9503 if (found_key.objectid >= key->objectid &&
9504 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
9505 ret = 0;
9506 goto out;
9507 }
9508 path->slots[0]++;
9509 }
9510 out:
9511 return ret;
9512 }
9513
9514 void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
9515 {
9516 struct btrfs_block_group_cache *block_group;
9517 u64 last = 0;
9518
9519 while (1) {
9520 struct inode *inode;
9521
9522 block_group = btrfs_lookup_first_block_group(info, last);
9523 while (block_group) {
9524 wait_block_group_cache_done(block_group);
9525 spin_lock(&block_group->lock);
9526 if (block_group->iref)
9527 break;
9528 spin_unlock(&block_group->lock);
9529 block_group = next_block_group(info->tree_root,
9530 block_group);
9531 }
9532 if (!block_group) {
9533 if (last == 0)
9534 break;
9535 last = 0;
9536 continue;
9537 }
9538
9539 inode = block_group->inode;
9540 block_group->iref = 0;
9541 block_group->inode = NULL;
9542 spin_unlock(&block_group->lock);
9543 iput(inode);
9544 last = block_group->key.objectid + block_group->key.offset;
9545 btrfs_put_block_group(block_group);
9546 }
9547 }
9548
9549 int btrfs_free_block_groups(struct btrfs_fs_info *info)
9550 {
9551 struct btrfs_block_group_cache *block_group;
9552 struct btrfs_space_info *space_info;
9553 struct btrfs_caching_control *caching_ctl;
9554 struct rb_node *n;
9555
9556 down_write(&info->commit_root_sem);
9557 while (!list_empty(&info->caching_block_groups)) {
9558 caching_ctl = list_entry(info->caching_block_groups.next,
9559 struct btrfs_caching_control, list);
9560 list_del(&caching_ctl->list);
9561 put_caching_control(caching_ctl);
9562 }
9563 up_write(&info->commit_root_sem);
9564
9565 spin_lock(&info->unused_bgs_lock);
9566 while (!list_empty(&info->unused_bgs)) {
9567 block_group = list_first_entry(&info->unused_bgs,
9568 struct btrfs_block_group_cache,
9569 bg_list);
9570 list_del_init(&block_group->bg_list);
9571 btrfs_put_block_group(block_group);
9572 }
9573 spin_unlock(&info->unused_bgs_lock);
9574
9575 spin_lock(&info->block_group_cache_lock);
9576 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
9577 block_group = rb_entry(n, struct btrfs_block_group_cache,
9578 cache_node);
9579 rb_erase(&block_group->cache_node,
9580 &info->block_group_cache_tree);
9581 RB_CLEAR_NODE(&block_group->cache_node);
9582 spin_unlock(&info->block_group_cache_lock);
9583
9584 down_write(&block_group->space_info->groups_sem);
9585 list_del(&block_group->list);
9586 up_write(&block_group->space_info->groups_sem);
9587
9588 if (block_group->cached == BTRFS_CACHE_STARTED)
9589 wait_block_group_cache_done(block_group);
9590
9591 /*
9592 * We haven't cached this block group, which means we could
9593 * possibly have excluded extents on this block group.
9594 */
9595 if (block_group->cached == BTRFS_CACHE_NO ||
9596 block_group->cached == BTRFS_CACHE_ERROR)
9597 free_excluded_extents(info->extent_root, block_group);
9598
9599 btrfs_remove_free_space_cache(block_group);
9600 btrfs_put_block_group(block_group);
9601
9602 spin_lock(&info->block_group_cache_lock);
9603 }
9604 spin_unlock(&info->block_group_cache_lock);
9605
9606 /* now that all the block groups are freed, go through and
9607 * free all the space_info structs. This is only called during
9608 * the final stages of unmount, and so we know nobody is
9609 * using them. We call synchronize_rcu() once before we start,
9610 * just to be on the safe side.
9611 */
9612 synchronize_rcu();
9613
9614 release_global_block_rsv(info);
9615
9616 while (!list_empty(&info->space_info)) {
9617 int i;
9618
9619 space_info = list_entry(info->space_info.next,
9620 struct btrfs_space_info,
9621 list);
9622 if (btrfs_test_opt(info->tree_root, ENOSPC_DEBUG)) {
9623 if (WARN_ON(space_info->bytes_pinned > 0 ||
9624 space_info->bytes_reserved > 0 ||
9625 space_info->bytes_may_use > 0)) {
9626 dump_space_info(space_info, 0, 0);
9627 }
9628 }
9629 list_del(&space_info->list);
9630 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
9631 struct kobject *kobj;
9632 kobj = space_info->block_group_kobjs[i];
9633 space_info->block_group_kobjs[i] = NULL;
9634 if (kobj) {
9635 kobject_del(kobj);
9636 kobject_put(kobj);
9637 }
9638 }
9639 kobject_del(&space_info->kobj);
9640 kobject_put(&space_info->kobj);
9641 }
9642 return 0;
9643 }
9644
9645 static void __link_block_group(struct btrfs_space_info *space_info,
9646 struct btrfs_block_group_cache *cache)
9647 {
9648 int index = get_block_group_index(cache);
9649 bool first = false;
9650
9651 down_write(&space_info->groups_sem);
9652 if (list_empty(&space_info->block_groups[index]))
9653 first = true;
9654 list_add_tail(&cache->list, &space_info->block_groups[index]);
9655 up_write(&space_info->groups_sem);
9656
9657 if (first) {
9658 struct raid_kobject *rkobj;
9659 int ret;
9660
9661 rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
9662 if (!rkobj)
9663 goto out_err;
9664 rkobj->raid_type = index;
9665 kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
9666 ret = kobject_add(&rkobj->kobj, &space_info->kobj,
9667 "%s", get_raid_name(index));
9668 if (ret) {
9669 kobject_put(&rkobj->kobj);
9670 goto out_err;
9671 }
9672 space_info->block_group_kobjs[index] = &rkobj->kobj;
9673 }
9674
9675 return;
9676 out_err:
9677 pr_warn("BTRFS: failed to add kobject for block cache. ignoring.\n");
9678 }
9679
9680 static struct btrfs_block_group_cache *
9681 btrfs_create_block_group_cache(struct btrfs_root *root, u64 start, u64 size)
9682 {
9683 struct btrfs_block_group_cache *cache;
9684
9685 cache = kzalloc(sizeof(*cache), GFP_NOFS);
9686 if (!cache)
9687 return NULL;
9688
9689 cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
9690 GFP_NOFS);
9691 if (!cache->free_space_ctl) {
9692 kfree(cache);
9693 return NULL;
9694 }
9695
9696 cache->key.objectid = start;
9697 cache->key.offset = size;
9698 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
9699
9700 cache->sectorsize = root->sectorsize;
9701 cache->fs_info = root->fs_info;
9702 cache->full_stripe_len = btrfs_full_stripe_len(root,
9703 &root->fs_info->mapping_tree,
9704 start);
9705 atomic_set(&cache->count, 1);
9706 spin_lock_init(&cache->lock);
9707 init_rwsem(&cache->data_rwsem);
9708 INIT_LIST_HEAD(&cache->list);
9709 INIT_LIST_HEAD(&cache->cluster_list);
9710 INIT_LIST_HEAD(&cache->bg_list);
9711 INIT_LIST_HEAD(&cache->ro_list);
9712 INIT_LIST_HEAD(&cache->dirty_list);
9713 INIT_LIST_HEAD(&cache->io_list);
9714 btrfs_init_free_space_ctl(cache);
9715 atomic_set(&cache->trimming, 0);
9716
9717 return cache;
9718 }
9719
9720 int btrfs_read_block_groups(struct btrfs_root *root)
9721 {
9722 struct btrfs_path *path;
9723 int ret;
9724 struct btrfs_block_group_cache *cache;
9725 struct btrfs_fs_info *info = root->fs_info;
9726 struct btrfs_space_info *space_info;
9727 struct btrfs_key key;
9728 struct btrfs_key found_key;
9729 struct extent_buffer *leaf;
9730 int need_clear = 0;
9731 u64 cache_gen;
9732 u64 feature;
9733 int mixed;
9734
9735 feature = btrfs_super_incompat_flags(info->super_copy);
9736 mixed = !!(feature & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS);
9737
9738 root = info->extent_root;
9739 key.objectid = 0;
9740 key.offset = 0;
9741 key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
9742 path = btrfs_alloc_path();
9743 if (!path)
9744 return -ENOMEM;
9745 path->reada = 1;
9746
9747 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
9748 if (btrfs_test_opt(root, SPACE_CACHE) &&
9749 btrfs_super_generation(root->fs_info->super_copy) != cache_gen)
9750 need_clear = 1;
9751 if (btrfs_test_opt(root, CLEAR_CACHE))
9752 need_clear = 1;
9753
9754 while (1) {
9755 ret = find_first_block_group(root, path, &key);
9756 if (ret > 0)
9757 break;
9758 if (ret != 0)
9759 goto error;
9760
9761 leaf = path->nodes[0];
9762 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
9763
9764 cache = btrfs_create_block_group_cache(root, found_key.objectid,
9765 found_key.offset);
9766 if (!cache) {
9767 ret = -ENOMEM;
9768 goto error;
9769 }
9770
9771 if (need_clear) {
9772 /*
9773 * When we mount with old space cache, we need to
9774 * set BTRFS_DC_CLEAR and set dirty flag.
9775 *
9776 * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
9777 * truncate the old free space cache inode and
9778 * setup a new one.
9779 * b) Setting 'dirty flag' makes sure that we flush
9780 * the new space cache info onto disk.
9781 */
9782 if (btrfs_test_opt(root, SPACE_CACHE))
9783 cache->disk_cache_state = BTRFS_DC_CLEAR;
9784 }
9785
9786 read_extent_buffer(leaf, &cache->item,
9787 btrfs_item_ptr_offset(leaf, path->slots[0]),
9788 sizeof(cache->item));
9789 cache->flags = btrfs_block_group_flags(&cache->item);
9790 if (!mixed &&
9791 ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
9792 (cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
9793 btrfs_err(info,
9794 "bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups",
9795 cache->key.objectid);
9796 ret = -EINVAL;
9797 goto error;
9798 }
9799
9800 key.objectid = found_key.objectid + found_key.offset;
9801 btrfs_release_path(path);
9802
9803 /*
9804 * We need to exclude the super stripes now so that the space
9805 * info has super bytes accounted for, otherwise we'll think
9806 * we have more space than we actually do.
9807 */
9808 ret = exclude_super_stripes(root, cache);
9809 if (ret) {
9810 /*
9811 * We may have excluded something, so call this just in
9812 * case.
9813 */
9814 free_excluded_extents(root, cache);
9815 btrfs_put_block_group(cache);
9816 goto error;
9817 }
9818
9819 /*
9820 * check for two cases, either we are full, and therefore
9821 * don't need to bother with the caching work since we won't
9822 * find any space, or we are empty, and we can just add all
9823 * the space in and be done with it. This saves us _alot_ of
9824 * time, particularly in the full case.
9825 */
9826 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
9827 cache->last_byte_to_unpin = (u64)-1;
9828 cache->cached = BTRFS_CACHE_FINISHED;
9829 free_excluded_extents(root, cache);
9830 } else if (btrfs_block_group_used(&cache->item) == 0) {
9831 cache->last_byte_to_unpin = (u64)-1;
9832 cache->cached = BTRFS_CACHE_FINISHED;
9833 add_new_free_space(cache, root->fs_info,
9834 found_key.objectid,
9835 found_key.objectid +
9836 found_key.offset);
9837 free_excluded_extents(root, cache);
9838 }
9839
9840 ret = btrfs_add_block_group_cache(root->fs_info, cache);
9841 if (ret) {
9842 btrfs_remove_free_space_cache(cache);
9843 btrfs_put_block_group(cache);
9844 goto error;
9845 }
9846
9847 ret = update_space_info(info, cache->flags, found_key.offset,
9848 btrfs_block_group_used(&cache->item),
9849 &space_info);
9850 if (ret) {
9851 btrfs_remove_free_space_cache(cache);
9852 spin_lock(&info->block_group_cache_lock);
9853 rb_erase(&cache->cache_node,
9854 &info->block_group_cache_tree);
9855 RB_CLEAR_NODE(&cache->cache_node);
9856 spin_unlock(&info->block_group_cache_lock);
9857 btrfs_put_block_group(cache);
9858 goto error;
9859 }
9860
9861 cache->space_info = space_info;
9862 spin_lock(&cache->space_info->lock);
9863 cache->space_info->bytes_readonly += cache->bytes_super;
9864 spin_unlock(&cache->space_info->lock);
9865
9866 __link_block_group(space_info, cache);
9867
9868 set_avail_alloc_bits(root->fs_info, cache->flags);
9869 if (btrfs_chunk_readonly(root, cache->key.objectid)) {
9870 inc_block_group_ro(cache, 1);
9871 } else if (btrfs_block_group_used(&cache->item) == 0) {
9872 spin_lock(&info->unused_bgs_lock);
9873 /* Should always be true but just in case. */
9874 if (list_empty(&cache->bg_list)) {
9875 btrfs_get_block_group(cache);
9876 list_add_tail(&cache->bg_list,
9877 &info->unused_bgs);
9878 }
9879 spin_unlock(&info->unused_bgs_lock);
9880 }
9881 }
9882
9883 list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
9884 if (!(get_alloc_profile(root, space_info->flags) &
9885 (BTRFS_BLOCK_GROUP_RAID10 |
9886 BTRFS_BLOCK_GROUP_RAID1 |
9887 BTRFS_BLOCK_GROUP_RAID5 |
9888 BTRFS_BLOCK_GROUP_RAID6 |
9889 BTRFS_BLOCK_GROUP_DUP)))
9890 continue;
9891 /*
9892 * avoid allocating from un-mirrored block group if there are
9893 * mirrored block groups.
9894 */
9895 list_for_each_entry(cache,
9896 &space_info->block_groups[BTRFS_RAID_RAID0],
9897 list)
9898 inc_block_group_ro(cache, 1);
9899 list_for_each_entry(cache,
9900 &space_info->block_groups[BTRFS_RAID_SINGLE],
9901 list)
9902 inc_block_group_ro(cache, 1);
9903 }
9904
9905 init_global_block_rsv(info);
9906 ret = 0;
9907 error:
9908 btrfs_free_path(path);
9909 return ret;
9910 }
9911
9912 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
9913 struct btrfs_root *root)
9914 {
9915 struct btrfs_block_group_cache *block_group;
9916 struct btrfs_root *extent_root = root->fs_info->extent_root;
9917 struct btrfs_block_group_item item;
9918 struct btrfs_key key;
9919 int ret = 0;
9920 bool can_flush_pending_bgs = trans->can_flush_pending_bgs;
9921
9922 trans->can_flush_pending_bgs = false;
9923 while (!list_empty(&trans->new_bgs)) {
9924 block_group = list_first_entry(&trans->new_bgs,
9925 struct btrfs_block_group_cache,
9926 bg_list);
9927 if (ret)
9928 goto next;
9929
9930 spin_lock(&block_group->lock);
9931 memcpy(&item, &block_group->item, sizeof(item));
9932 memcpy(&key, &block_group->key, sizeof(key));
9933 spin_unlock(&block_group->lock);
9934
9935 ret = btrfs_insert_item(trans, extent_root, &key, &item,
9936 sizeof(item));
9937 if (ret)
9938 btrfs_abort_transaction(trans, extent_root, ret);
9939 ret = btrfs_finish_chunk_alloc(trans, extent_root,
9940 key.objectid, key.offset);
9941 if (ret)
9942 btrfs_abort_transaction(trans, extent_root, ret);
9943 next:
9944 list_del_init(&block_group->bg_list);
9945 }
9946 trans->can_flush_pending_bgs = can_flush_pending_bgs;
9947 }
9948
9949 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
9950 struct btrfs_root *root, u64 bytes_used,
9951 u64 type, u64 chunk_objectid, u64 chunk_offset,
9952 u64 size)
9953 {
9954 int ret;
9955 struct btrfs_root *extent_root;
9956 struct btrfs_block_group_cache *cache;
9957
9958 extent_root = root->fs_info->extent_root;
9959
9960 btrfs_set_log_full_commit(root->fs_info, trans);
9961
9962 cache = btrfs_create_block_group_cache(root, chunk_offset, size);
9963 if (!cache)
9964 return -ENOMEM;
9965
9966 btrfs_set_block_group_used(&cache->item, bytes_used);
9967 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
9968 btrfs_set_block_group_flags(&cache->item, type);
9969
9970 cache->flags = type;
9971 cache->last_byte_to_unpin = (u64)-1;
9972 cache->cached = BTRFS_CACHE_FINISHED;
9973 ret = exclude_super_stripes(root, cache);
9974 if (ret) {
9975 /*
9976 * We may have excluded something, so call this just in
9977 * case.
9978 */
9979 free_excluded_extents(root, cache);
9980 btrfs_put_block_group(cache);
9981 return ret;
9982 }
9983
9984 add_new_free_space(cache, root->fs_info, chunk_offset,
9985 chunk_offset + size);
9986
9987 free_excluded_extents(root, cache);
9988
9989 #ifdef CONFIG_BTRFS_DEBUG
9990 if (btrfs_should_fragment_free_space(root, cache)) {
9991 u64 new_bytes_used = size - bytes_used;
9992
9993 bytes_used += new_bytes_used >> 1;
9994 fragment_free_space(root, cache);
9995 }
9996 #endif
9997 /*
9998 * Call to ensure the corresponding space_info object is created and
9999 * assigned to our block group, but don't update its counters just yet.
10000 * We want our bg to be added to the rbtree with its ->space_info set.
10001 */
10002 ret = update_space_info(root->fs_info, cache->flags, 0, 0,
10003 &cache->space_info);
10004 if (ret) {
10005 btrfs_remove_free_space_cache(cache);
10006 btrfs_put_block_group(cache);
10007 return ret;
10008 }
10009
10010 ret = btrfs_add_block_group_cache(root->fs_info, cache);
10011 if (ret) {
10012 btrfs_remove_free_space_cache(cache);
10013 btrfs_put_block_group(cache);
10014 return ret;
10015 }
10016
10017 /*
10018 * Now that our block group has its ->space_info set and is inserted in
10019 * the rbtree, update the space info's counters.
10020 */
10021 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
10022 &cache->space_info);
10023 if (ret) {
10024 btrfs_remove_free_space_cache(cache);
10025 spin_lock(&root->fs_info->block_group_cache_lock);
10026 rb_erase(&cache->cache_node,
10027 &root->fs_info->block_group_cache_tree);
10028 RB_CLEAR_NODE(&cache->cache_node);
10029 spin_unlock(&root->fs_info->block_group_cache_lock);
10030 btrfs_put_block_group(cache);
10031 return ret;
10032 }
10033 update_global_block_rsv(root->fs_info);
10034
10035 spin_lock(&cache->space_info->lock);
10036 cache->space_info->bytes_readonly += cache->bytes_super;
10037 spin_unlock(&cache->space_info->lock);
10038
10039 __link_block_group(cache->space_info, cache);
10040
10041 list_add_tail(&cache->bg_list, &trans->new_bgs);
10042
10043 set_avail_alloc_bits(extent_root->fs_info, type);
10044
10045 return 0;
10046 }
10047
10048 static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
10049 {
10050 u64 extra_flags = chunk_to_extended(flags) &
10051 BTRFS_EXTENDED_PROFILE_MASK;
10052
10053 write_seqlock(&fs_info->profiles_lock);
10054 if (flags & BTRFS_BLOCK_GROUP_DATA)
10055 fs_info->avail_data_alloc_bits &= ~extra_flags;
10056 if (flags & BTRFS_BLOCK_GROUP_METADATA)
10057 fs_info->avail_metadata_alloc_bits &= ~extra_flags;
10058 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
10059 fs_info->avail_system_alloc_bits &= ~extra_flags;
10060 write_sequnlock(&fs_info->profiles_lock);
10061 }
10062
10063 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
10064 struct btrfs_root *root, u64 group_start,
10065 struct extent_map *em)
10066 {
10067 struct btrfs_path *path;
10068 struct btrfs_block_group_cache *block_group;
10069 struct btrfs_free_cluster *cluster;
10070 struct btrfs_root *tree_root = root->fs_info->tree_root;
10071 struct btrfs_key key;
10072 struct inode *inode;
10073 struct kobject *kobj = NULL;
10074 int ret;
10075 int index;
10076 int factor;
10077 struct btrfs_caching_control *caching_ctl = NULL;
10078 bool remove_em;
10079
10080 root = root->fs_info->extent_root;
10081
10082 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
10083 BUG_ON(!block_group);
10084 BUG_ON(!block_group->ro);
10085
10086 /*
10087 * Free the reserved super bytes from this block group before
10088 * remove it.
10089 */
10090 free_excluded_extents(root, block_group);
10091
10092 memcpy(&key, &block_group->key, sizeof(key));
10093 index = get_block_group_index(block_group);
10094 if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
10095 BTRFS_BLOCK_GROUP_RAID1 |
10096 BTRFS_BLOCK_GROUP_RAID10))
10097 factor = 2;
10098 else
10099 factor = 1;
10100
10101 /* make sure this block group isn't part of an allocation cluster */
10102 cluster = &root->fs_info->data_alloc_cluster;
10103 spin_lock(&cluster->refill_lock);
10104 btrfs_return_cluster_to_free_space(block_group, cluster);
10105 spin_unlock(&cluster->refill_lock);
10106
10107 /*
10108 * make sure this block group isn't part of a metadata
10109 * allocation cluster
10110 */
10111 cluster = &root->fs_info->meta_alloc_cluster;
10112 spin_lock(&cluster->refill_lock);
10113 btrfs_return_cluster_to_free_space(block_group, cluster);
10114 spin_unlock(&cluster->refill_lock);
10115
10116 path = btrfs_alloc_path();
10117 if (!path) {
10118 ret = -ENOMEM;
10119 goto out;
10120 }
10121
10122 /*
10123 * get the inode first so any iput calls done for the io_list
10124 * aren't the final iput (no unlinks allowed now)
10125 */
10126 inode = lookup_free_space_inode(tree_root, block_group, path);
10127
10128 mutex_lock(&trans->transaction->cache_write_mutex);
10129 /*
10130 * make sure our free spache cache IO is done before remove the
10131 * free space inode
10132 */
10133 spin_lock(&trans->transaction->dirty_bgs_lock);
10134 if (!list_empty(&block_group->io_list)) {
10135 list_del_init(&block_group->io_list);
10136
10137 WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
10138
10139 spin_unlock(&trans->transaction->dirty_bgs_lock);
10140 btrfs_wait_cache_io(root, trans, block_group,
10141 &block_group->io_ctl, path,
10142 block_group->key.objectid);
10143 btrfs_put_block_group(block_group);
10144 spin_lock(&trans->transaction->dirty_bgs_lock);
10145 }
10146
10147 if (!list_empty(&block_group->dirty_list)) {
10148 list_del_init(&block_group->dirty_list);
10149 btrfs_put_block_group(block_group);
10150 }
10151 spin_unlock(&trans->transaction->dirty_bgs_lock);
10152 mutex_unlock(&trans->transaction->cache_write_mutex);
10153
10154 if (!IS_ERR(inode)) {
10155 ret = btrfs_orphan_add(trans, inode);
10156 if (ret) {
10157 btrfs_add_delayed_iput(inode);
10158 goto out;
10159 }
10160 clear_nlink(inode);
10161 /* One for the block groups ref */
10162 spin_lock(&block_group->lock);
10163 if (block_group->iref) {
10164 block_group->iref = 0;
10165 block_group->inode = NULL;
10166 spin_unlock(&block_group->lock);
10167 iput(inode);
10168 } else {
10169 spin_unlock(&block_group->lock);
10170 }
10171 /* One for our lookup ref */
10172 btrfs_add_delayed_iput(inode);
10173 }
10174
10175 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
10176 key.offset = block_group->key.objectid;
10177 key.type = 0;
10178
10179 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
10180 if (ret < 0)
10181 goto out;
10182 if (ret > 0)
10183 btrfs_release_path(path);
10184 if (ret == 0) {
10185 ret = btrfs_del_item(trans, tree_root, path);
10186 if (ret)
10187 goto out;
10188 btrfs_release_path(path);
10189 }
10190
10191 spin_lock(&root->fs_info->block_group_cache_lock);
10192 rb_erase(&block_group->cache_node,
10193 &root->fs_info->block_group_cache_tree);
10194 RB_CLEAR_NODE(&block_group->cache_node);
10195
10196 if (root->fs_info->first_logical_byte == block_group->key.objectid)
10197 root->fs_info->first_logical_byte = (u64)-1;
10198 spin_unlock(&root->fs_info->block_group_cache_lock);
10199
10200 down_write(&block_group->space_info->groups_sem);
10201 /*
10202 * we must use list_del_init so people can check to see if they
10203 * are still on the list after taking the semaphore
10204 */
10205 list_del_init(&block_group->list);
10206 if (list_empty(&block_group->space_info->block_groups[index])) {
10207 kobj = block_group->space_info->block_group_kobjs[index];
10208 block_group->space_info->block_group_kobjs[index] = NULL;
10209 clear_avail_alloc_bits(root->fs_info, block_group->flags);
10210 }
10211 up_write(&block_group->space_info->groups_sem);
10212 if (kobj) {
10213 kobject_del(kobj);
10214 kobject_put(kobj);
10215 }
10216
10217 if (block_group->has_caching_ctl)
10218 caching_ctl = get_caching_control(block_group);
10219 if (block_group->cached == BTRFS_CACHE_STARTED)
10220 wait_block_group_cache_done(block_group);
10221 if (block_group->has_caching_ctl) {
10222 down_write(&root->fs_info->commit_root_sem);
10223 if (!caching_ctl) {
10224 struct btrfs_caching_control *ctl;
10225
10226 list_for_each_entry(ctl,
10227 &root->fs_info->caching_block_groups, list)
10228 if (ctl->block_group == block_group) {
10229 caching_ctl = ctl;
10230 atomic_inc(&caching_ctl->count);
10231 break;
10232 }
10233 }
10234 if (caching_ctl)
10235 list_del_init(&caching_ctl->list);
10236 up_write(&root->fs_info->commit_root_sem);
10237 if (caching_ctl) {
10238 /* Once for the caching bgs list and once for us. */
10239 put_caching_control(caching_ctl);
10240 put_caching_control(caching_ctl);
10241 }
10242 }
10243
10244 spin_lock(&trans->transaction->dirty_bgs_lock);
10245 if (!list_empty(&block_group->dirty_list)) {
10246 WARN_ON(1);
10247 }
10248 if (!list_empty(&block_group->io_list)) {
10249 WARN_ON(1);
10250 }
10251 spin_unlock(&trans->transaction->dirty_bgs_lock);
10252 btrfs_remove_free_space_cache(block_group);
10253
10254 spin_lock(&block_group->space_info->lock);
10255 list_del_init(&block_group->ro_list);
10256
10257 if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
10258 WARN_ON(block_group->space_info->total_bytes
10259 < block_group->key.offset);
10260 WARN_ON(block_group->space_info->bytes_readonly
10261 < block_group->key.offset);
10262 WARN_ON(block_group->space_info->disk_total
10263 < block_group->key.offset * factor);
10264 }
10265 block_group->space_info->total_bytes -= block_group->key.offset;
10266 block_group->space_info->bytes_readonly -= block_group->key.offset;
10267 block_group->space_info->disk_total -= block_group->key.offset * factor;
10268
10269 spin_unlock(&block_group->space_info->lock);
10270
10271 memcpy(&key, &block_group->key, sizeof(key));
10272
10273 lock_chunks(root);
10274 if (!list_empty(&em->list)) {
10275 /* We're in the transaction->pending_chunks list. */
10276 free_extent_map(em);
10277 }
10278 spin_lock(&block_group->lock);
10279 block_group->removed = 1;
10280 /*
10281 * At this point trimming can't start on this block group, because we
10282 * removed the block group from the tree fs_info->block_group_cache_tree
10283 * so no one can't find it anymore and even if someone already got this
10284 * block group before we removed it from the rbtree, they have already
10285 * incremented block_group->trimming - if they didn't, they won't find
10286 * any free space entries because we already removed them all when we
10287 * called btrfs_remove_free_space_cache().
10288 *
10289 * And we must not remove the extent map from the fs_info->mapping_tree
10290 * to prevent the same logical address range and physical device space
10291 * ranges from being reused for a new block group. This is because our
10292 * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
10293 * completely transactionless, so while it is trimming a range the
10294 * currently running transaction might finish and a new one start,
10295 * allowing for new block groups to be created that can reuse the same
10296 * physical device locations unless we take this special care.
10297 *
10298 * There may also be an implicit trim operation if the file system
10299 * is mounted with -odiscard. The same protections must remain
10300 * in place until the extents have been discarded completely when
10301 * the transaction commit has completed.
10302 */
10303 remove_em = (atomic_read(&block_group->trimming) == 0);
10304 /*
10305 * Make sure a trimmer task always sees the em in the pinned_chunks list
10306 * if it sees block_group->removed == 1 (needs to lock block_group->lock
10307 * before checking block_group->removed).
10308 */
10309 if (!remove_em) {
10310 /*
10311 * Our em might be in trans->transaction->pending_chunks which
10312 * is protected by fs_info->chunk_mutex ([lock|unlock]_chunks),
10313 * and so is the fs_info->pinned_chunks list.
10314 *
10315 * So at this point we must be holding the chunk_mutex to avoid
10316 * any races with chunk allocation (more specifically at
10317 * volumes.c:contains_pending_extent()), to ensure it always
10318 * sees the em, either in the pending_chunks list or in the
10319 * pinned_chunks list.
10320 */
10321 list_move_tail(&em->list, &root->fs_info->pinned_chunks);
10322 }
10323 spin_unlock(&block_group->lock);
10324
10325 if (remove_em) {
10326 struct extent_map_tree *em_tree;
10327
10328 em_tree = &root->fs_info->mapping_tree.map_tree;
10329 write_lock(&em_tree->lock);
10330 /*
10331 * The em might be in the pending_chunks list, so make sure the
10332 * chunk mutex is locked, since remove_extent_mapping() will
10333 * delete us from that list.
10334 */
10335 remove_extent_mapping(em_tree, em);
10336 write_unlock(&em_tree->lock);
10337 /* once for the tree */
10338 free_extent_map(em);
10339 }
10340
10341 unlock_chunks(root);
10342
10343 btrfs_put_block_group(block_group);
10344 btrfs_put_block_group(block_group);
10345
10346 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
10347 if (ret > 0)
10348 ret = -EIO;
10349 if (ret < 0)
10350 goto out;
10351
10352 ret = btrfs_del_item(trans, root, path);
10353 out:
10354 btrfs_free_path(path);
10355 return ret;
10356 }
10357
10358 struct btrfs_trans_handle *
10359 btrfs_start_trans_remove_block_group(struct btrfs_fs_info *fs_info,
10360 const u64 chunk_offset)
10361 {
10362 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
10363 struct extent_map *em;
10364 struct map_lookup *map;
10365 unsigned int num_items;
10366
10367 read_lock(&em_tree->lock);
10368 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
10369 read_unlock(&em_tree->lock);
10370 ASSERT(em && em->start == chunk_offset);
10371
10372 /*
10373 * We need to reserve 3 + N units from the metadata space info in order
10374 * to remove a block group (done at btrfs_remove_chunk() and at
10375 * btrfs_remove_block_group()), which are used for:
10376 *
10377 * 1 unit for adding the free space inode's orphan (located in the tree
10378 * of tree roots).
10379 * 1 unit for deleting the block group item (located in the extent
10380 * tree).
10381 * 1 unit for deleting the free space item (located in tree of tree
10382 * roots).
10383 * N units for deleting N device extent items corresponding to each
10384 * stripe (located in the device tree).
10385 *
10386 * In order to remove a block group we also need to reserve units in the
10387 * system space info in order to update the chunk tree (update one or
10388 * more device items and remove one chunk item), but this is done at
10389 * btrfs_remove_chunk() through a call to check_system_chunk().
10390 */
10391 map = em->map_lookup;
10392 num_items = 3 + map->num_stripes;
10393 free_extent_map(em);
10394
10395 return btrfs_start_transaction_fallback_global_rsv(fs_info->extent_root,
10396 num_items, 1);
10397 }
10398
10399 /*
10400 * Process the unused_bgs list and remove any that don't have any allocated
10401 * space inside of them.
10402 */
10403 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
10404 {
10405 struct btrfs_block_group_cache *block_group;
10406 struct btrfs_space_info *space_info;
10407 struct btrfs_root *root = fs_info->extent_root;
10408 struct btrfs_trans_handle *trans;
10409 int ret = 0;
10410
10411 if (!fs_info->open)
10412 return;
10413
10414 spin_lock(&fs_info->unused_bgs_lock);
10415 while (!list_empty(&fs_info->unused_bgs)) {
10416 u64 start, end;
10417 int trimming;
10418
10419 block_group = list_first_entry(&fs_info->unused_bgs,
10420 struct btrfs_block_group_cache,
10421 bg_list);
10422 list_del_init(&block_group->bg_list);
10423
10424 space_info = block_group->space_info;
10425
10426 if (ret || btrfs_mixed_space_info(space_info)) {
10427 btrfs_put_block_group(block_group);
10428 continue;
10429 }
10430 spin_unlock(&fs_info->unused_bgs_lock);
10431
10432 mutex_lock(&fs_info->delete_unused_bgs_mutex);
10433
10434 /* Don't want to race with allocators so take the groups_sem */
10435 down_write(&space_info->groups_sem);
10436 spin_lock(&block_group->lock);
10437 if (block_group->reserved || block_group->pinned ||
10438 btrfs_block_group_used(&block_group->item) ||
10439 block_group->ro ||
10440 list_is_singular(&block_group->list)) {
10441 /*
10442 * We want to bail if we made new allocations or have
10443 * outstanding allocations in this block group. We do
10444 * the ro check in case balance is currently acting on
10445 * this block group.
10446 */
10447 spin_unlock(&block_group->lock);
10448 up_write(&space_info->groups_sem);
10449 goto next;
10450 }
10451 spin_unlock(&block_group->lock);
10452
10453 /* We don't want to force the issue, only flip if it's ok. */
10454 ret = inc_block_group_ro(block_group, 0);
10455 up_write(&space_info->groups_sem);
10456 if (ret < 0) {
10457 ret = 0;
10458 goto next;
10459 }
10460
10461 /*
10462 * Want to do this before we do anything else so we can recover
10463 * properly if we fail to join the transaction.
10464 */
10465 trans = btrfs_start_trans_remove_block_group(fs_info,
10466 block_group->key.objectid);
10467 if (IS_ERR(trans)) {
10468 btrfs_dec_block_group_ro(root, block_group);
10469 ret = PTR_ERR(trans);
10470 goto next;
10471 }
10472
10473 /*
10474 * We could have pending pinned extents for this block group,
10475 * just delete them, we don't care about them anymore.
10476 */
10477 start = block_group->key.objectid;
10478 end = start + block_group->key.offset - 1;
10479 /*
10480 * Hold the unused_bg_unpin_mutex lock to avoid racing with
10481 * btrfs_finish_extent_commit(). If we are at transaction N,
10482 * another task might be running finish_extent_commit() for the
10483 * previous transaction N - 1, and have seen a range belonging
10484 * to the block group in freed_extents[] before we were able to
10485 * clear the whole block group range from freed_extents[]. This
10486 * means that task can lookup for the block group after we
10487 * unpinned it from freed_extents[] and removed it, leading to
10488 * a BUG_ON() at btrfs_unpin_extent_range().
10489 */
10490 mutex_lock(&fs_info->unused_bg_unpin_mutex);
10491 ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
10492 EXTENT_DIRTY, GFP_NOFS);
10493 if (ret) {
10494 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
10495 btrfs_dec_block_group_ro(root, block_group);
10496 goto end_trans;
10497 }
10498 ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
10499 EXTENT_DIRTY, GFP_NOFS);
10500 if (ret) {
10501 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
10502 btrfs_dec_block_group_ro(root, block_group);
10503 goto end_trans;
10504 }
10505 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
10506
10507 /* Reset pinned so btrfs_put_block_group doesn't complain */
10508 spin_lock(&space_info->lock);
10509 spin_lock(&block_group->lock);
10510
10511 space_info->bytes_pinned -= block_group->pinned;
10512 space_info->bytes_readonly += block_group->pinned;
10513 percpu_counter_add(&space_info->total_bytes_pinned,
10514 -block_group->pinned);
10515 block_group->pinned = 0;
10516
10517 spin_unlock(&block_group->lock);
10518 spin_unlock(&space_info->lock);
10519
10520 /* DISCARD can flip during remount */
10521 trimming = btrfs_test_opt(root, DISCARD);
10522
10523 /* Implicit trim during transaction commit. */
10524 if (trimming)
10525 btrfs_get_block_group_trimming(block_group);
10526
10527 /*
10528 * Btrfs_remove_chunk will abort the transaction if things go
10529 * horribly wrong.
10530 */
10531 ret = btrfs_remove_chunk(trans, root,
10532 block_group->key.objectid);
10533
10534 if (ret) {
10535 if (trimming)
10536 btrfs_put_block_group_trimming(block_group);
10537 goto end_trans;
10538 }
10539
10540 /*
10541 * If we're not mounted with -odiscard, we can just forget
10542 * about this block group. Otherwise we'll need to wait
10543 * until transaction commit to do the actual discard.
10544 */
10545 if (trimming) {
10546 spin_lock(&fs_info->unused_bgs_lock);
10547 /*
10548 * A concurrent scrub might have added us to the list
10549 * fs_info->unused_bgs, so use a list_move operation
10550 * to add the block group to the deleted_bgs list.
10551 */
10552 list_move(&block_group->bg_list,
10553 &trans->transaction->deleted_bgs);
10554 spin_unlock(&fs_info->unused_bgs_lock);
10555 btrfs_get_block_group(block_group);
10556 }
10557 end_trans:
10558 btrfs_end_transaction(trans, root);
10559 next:
10560 mutex_unlock(&fs_info->delete_unused_bgs_mutex);
10561 btrfs_put_block_group(block_group);
10562 spin_lock(&fs_info->unused_bgs_lock);
10563 }
10564 spin_unlock(&fs_info->unused_bgs_lock);
10565 }
10566
10567 int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
10568 {
10569 struct btrfs_space_info *space_info;
10570 struct btrfs_super_block *disk_super;
10571 u64 features;
10572 u64 flags;
10573 int mixed = 0;
10574 int ret;
10575
10576 disk_super = fs_info->super_copy;
10577 if (!btrfs_super_root(disk_super))
10578 return 1;
10579
10580 features = btrfs_super_incompat_flags(disk_super);
10581 if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
10582 mixed = 1;
10583
10584 flags = BTRFS_BLOCK_GROUP_SYSTEM;
10585 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
10586 if (ret)
10587 goto out;
10588
10589 if (mixed) {
10590 flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
10591 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
10592 } else {
10593 flags = BTRFS_BLOCK_GROUP_METADATA;
10594 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
10595 if (ret)
10596 goto out;
10597
10598 flags = BTRFS_BLOCK_GROUP_DATA;
10599 ret = update_space_info(fs_info, flags, 0, 0, &space_info);
10600 }
10601 out:
10602 return ret;
10603 }
10604
10605 int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
10606 {
10607 return unpin_extent_range(root, start, end, false);
10608 }
10609
10610 /*
10611 * It used to be that old block groups would be left around forever.
10612 * Iterating over them would be enough to trim unused space. Since we
10613 * now automatically remove them, we also need to iterate over unallocated
10614 * space.
10615 *
10616 * We don't want a transaction for this since the discard may take a
10617 * substantial amount of time. We don't require that a transaction be
10618 * running, but we do need to take a running transaction into account
10619 * to ensure that we're not discarding chunks that were released in
10620 * the current transaction.
10621 *
10622 * Holding the chunks lock will prevent other threads from allocating
10623 * or releasing chunks, but it won't prevent a running transaction
10624 * from committing and releasing the memory that the pending chunks
10625 * list head uses. For that, we need to take a reference to the
10626 * transaction.
10627 */
10628 static int btrfs_trim_free_extents(struct btrfs_device *device,
10629 u64 minlen, u64 *trimmed)
10630 {
10631 u64 start = 0, len = 0;
10632 int ret;
10633
10634 *trimmed = 0;
10635
10636 /* Discard not supported = nothing to do. */
10637 if (!blk_queue_discard(bdev_get_queue(device->bdev)))
10638 return 0;
10639
10640 /* Not writeable = nothing to do. */
10641 if (!device->writeable)
10642 return 0;
10643
10644 /* No free space = nothing to do. */
10645 if (device->total_bytes <= device->bytes_used)
10646 return 0;
10647
10648 ret = 0;
10649
10650 while (1) {
10651 struct btrfs_fs_info *fs_info = device->dev_root->fs_info;
10652 struct btrfs_transaction *trans;
10653 u64 bytes;
10654
10655 ret = mutex_lock_interruptible(&fs_info->chunk_mutex);
10656 if (ret)
10657 return ret;
10658
10659 down_read(&fs_info->commit_root_sem);
10660
10661 spin_lock(&fs_info->trans_lock);
10662 trans = fs_info->running_transaction;
10663 if (trans)
10664 atomic_inc(&trans->use_count);
10665 spin_unlock(&fs_info->trans_lock);
10666
10667 ret = find_free_dev_extent_start(trans, device, minlen, start,
10668 &start, &len);
10669 if (trans)
10670 btrfs_put_transaction(trans);
10671
10672 if (ret) {
10673 up_read(&fs_info->commit_root_sem);
10674 mutex_unlock(&fs_info->chunk_mutex);
10675 if (ret == -ENOSPC)
10676 ret = 0;
10677 break;
10678 }
10679
10680 ret = btrfs_issue_discard(device->bdev, start, len, &bytes);
10681 up_read(&fs_info->commit_root_sem);
10682 mutex_unlock(&fs_info->chunk_mutex);
10683
10684 if (ret)
10685 break;
10686
10687 start += len;
10688 *trimmed += bytes;
10689
10690 if (fatal_signal_pending(current)) {
10691 ret = -ERESTARTSYS;
10692 break;
10693 }
10694
10695 cond_resched();
10696 }
10697
10698 return ret;
10699 }
10700
10701 int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
10702 {
10703 struct btrfs_fs_info *fs_info = root->fs_info;
10704 struct btrfs_block_group_cache *cache = NULL;
10705 struct btrfs_device *device;
10706 struct list_head *devices;
10707 u64 group_trimmed;
10708 u64 start;
10709 u64 end;
10710 u64 trimmed = 0;
10711 int ret = 0;
10712
10713 cache = btrfs_lookup_first_block_group(fs_info, range->start);
10714 while (cache) {
10715 if (cache->key.objectid >= (range->start + range->len)) {
10716 btrfs_put_block_group(cache);
10717 break;
10718 }
10719
10720 start = max(range->start, cache->key.objectid);
10721 end = min(range->start + range->len,
10722 cache->key.objectid + cache->key.offset);
10723
10724 if (end - start >= range->minlen) {
10725 if (!block_group_cache_done(cache)) {
10726 ret = cache_block_group(cache, 0);
10727 if (ret) {
10728 btrfs_put_block_group(cache);
10729 break;
10730 }
10731 ret = wait_block_group_cache_done(cache);
10732 if (ret) {
10733 btrfs_put_block_group(cache);
10734 break;
10735 }
10736 }
10737 ret = btrfs_trim_block_group(cache,
10738 &group_trimmed,
10739 start,
10740 end,
10741 range->minlen);
10742
10743 trimmed += group_trimmed;
10744 if (ret) {
10745 btrfs_put_block_group(cache);
10746 break;
10747 }
10748 }
10749
10750 cache = next_block_group(fs_info->tree_root, cache);
10751 }
10752
10753 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
10754 devices = &root->fs_info->fs_devices->devices;
10755 list_for_each_entry(device, devices, dev_list) {
10756 ret = btrfs_trim_free_extents(device, range->minlen,
10757 &group_trimmed);
10758 if (ret)
10759 break;
10760
10761 trimmed += group_trimmed;
10762 }
10763 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
10764
10765 range->len = trimmed;
10766 return ret;
10767 }
10768
10769 /*
10770 * btrfs_{start,end}_write_no_snapshoting() are similar to
10771 * mnt_{want,drop}_write(), they are used to prevent some tasks from writing
10772 * data into the page cache through nocow before the subvolume is snapshoted,
10773 * but flush the data into disk after the snapshot creation, or to prevent
10774 * operations while snapshoting is ongoing and that cause the snapshot to be
10775 * inconsistent (writes followed by expanding truncates for example).
10776 */
10777 void btrfs_end_write_no_snapshoting(struct btrfs_root *root)
10778 {
10779 percpu_counter_dec(&root->subv_writers->counter);
10780 /*
10781 * Make sure counter is updated before we wake up waiters.
10782 */
10783 smp_mb();
10784 if (waitqueue_active(&root->subv_writers->wait))
10785 wake_up(&root->subv_writers->wait);
10786 }
10787
10788 int btrfs_start_write_no_snapshoting(struct btrfs_root *root)
10789 {
10790 if (atomic_read(&root->will_be_snapshoted))
10791 return 0;
10792
10793 percpu_counter_inc(&root->subv_writers->counter);
10794 /*
10795 * Make sure counter is updated before we check for snapshot creation.
10796 */
10797 smp_mb();
10798 if (atomic_read(&root->will_be_snapshoted)) {
10799 btrfs_end_write_no_snapshoting(root);
10800 return 0;
10801 }
10802 return 1;
10803 }
Linux with added FPC-III support