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sh_eth: fix EESIPR values for SH77{34|63}
[linux/fpc-iii.git] / fs / btrfs / extent-tree.c
blobe97302f437a16db24db7d2aa6ae202cde3309fb6
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 "free-space-tree.h"
37 #include "math.h"
38 #include "sysfs.h"
39 #include "qgroup.h"
40
41 #undef SCRAMBLE_DELAYED_REFS
42
43 /*
44 * control flags for do_chunk_alloc's force field
45 * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
46 * if we really need one.
47 *
48 * CHUNK_ALLOC_LIMITED means to only try and allocate one
49 * if we have very few chunks already allocated. This is
50 * used as part of the clustering code to help make sure
51 * we have a good pool of storage to cluster in, without
52 * filling the FS with empty chunks
53 *
54 * CHUNK_ALLOC_FORCE means it must try to allocate one
55 *
56 */
57 enum {
58 CHUNK_ALLOC_NO_FORCE = 0,
59 CHUNK_ALLOC_LIMITED = 1,
60 CHUNK_ALLOC_FORCE = 2,
61 };
62
63 static int update_block_group(struct btrfs_trans_handle *trans,
64 struct btrfs_fs_info *fs_info, u64 bytenr,
65 u64 num_bytes, int alloc);
66 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
67 struct btrfs_fs_info *fs_info,
68 struct btrfs_delayed_ref_node *node, u64 parent,
69 u64 root_objectid, u64 owner_objectid,
70 u64 owner_offset, int refs_to_drop,
71 struct btrfs_delayed_extent_op *extra_op);
72 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
73 struct extent_buffer *leaf,
74 struct btrfs_extent_item *ei);
75 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
76 struct btrfs_fs_info *fs_info,
77 u64 parent, u64 root_objectid,
78 u64 flags, u64 owner, u64 offset,
79 struct btrfs_key *ins, int ref_mod);
80 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
81 struct btrfs_fs_info *fs_info,
82 u64 parent, u64 root_objectid,
83 u64 flags, struct btrfs_disk_key *key,
84 int level, struct btrfs_key *ins);
85 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
86 struct btrfs_fs_info *fs_info, u64 flags,
87 int force);
88 static int find_next_key(struct btrfs_path *path, int level,
89 struct btrfs_key *key);
90 static void dump_space_info(struct btrfs_fs_info *fs_info,
91 struct btrfs_space_info *info, u64 bytes,
92 int dump_block_groups);
93 static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
94 u64 ram_bytes, u64 num_bytes, int delalloc);
95 static int btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
96 u64 num_bytes, int delalloc);
97 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
98 u64 num_bytes);
99 static int __reserve_metadata_bytes(struct btrfs_root *root,
100 struct btrfs_space_info *space_info,
101 u64 orig_bytes,
102 enum btrfs_reserve_flush_enum flush);
103 static void space_info_add_new_bytes(struct btrfs_fs_info *fs_info,
104 struct btrfs_space_info *space_info,
105 u64 num_bytes);
106 static void space_info_add_old_bytes(struct btrfs_fs_info *fs_info,
107 struct btrfs_space_info *space_info,
108 u64 num_bytes);
109
110 static noinline int
111 block_group_cache_done(struct btrfs_block_group_cache *cache)
112 {
113 smp_mb();
114 return cache->cached == BTRFS_CACHE_FINISHED ||
115 cache->cached == BTRFS_CACHE_ERROR;
116 }
117
118 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
119 {
120 return (cache->flags & bits) == bits;
121 }
122
123 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
124 {
125 atomic_inc(&cache->count);
126 }
127
128 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
129 {
130 if (atomic_dec_and_test(&cache->count)) {
131 WARN_ON(cache->pinned > 0);
132 WARN_ON(cache->reserved > 0);
133 kfree(cache->free_space_ctl);
134 kfree(cache);
135 }
136 }
137
138 /*
139 * this adds the block group to the fs_info rb tree for the block group
140 * cache
141 */
142 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
143 struct btrfs_block_group_cache *block_group)
144 {
145 struct rb_node **p;
146 struct rb_node *parent = NULL;
147 struct btrfs_block_group_cache *cache;
148
149 spin_lock(&info->block_group_cache_lock);
150 p = &info->block_group_cache_tree.rb_node;
151
152 while (*p) {
153 parent = *p;
154 cache = rb_entry(parent, struct btrfs_block_group_cache,
155 cache_node);
156 if (block_group->key.objectid < cache->key.objectid) {
157 p = &(*p)->rb_left;
158 } else if (block_group->key.objectid > cache->key.objectid) {
159 p = &(*p)->rb_right;
160 } else {
161 spin_unlock(&info->block_group_cache_lock);
162 return -EEXIST;
163 }
164 }
165
166 rb_link_node(&block_group->cache_node, parent, p);
167 rb_insert_color(&block_group->cache_node,
168 &info->block_group_cache_tree);
169
170 if (info->first_logical_byte > block_group->key.objectid)
171 info->first_logical_byte = block_group->key.objectid;
172
173 spin_unlock(&info->block_group_cache_lock);
174
175 return 0;
176 }
177
178 /*
179 * This will return the block group at or after bytenr if contains is 0, else
180 * it will return the block group that contains the bytenr
181 */
182 static struct btrfs_block_group_cache *
183 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
184 int contains)
185 {
186 struct btrfs_block_group_cache *cache, *ret = NULL;
187 struct rb_node *n;
188 u64 end, start;
189
190 spin_lock(&info->block_group_cache_lock);
191 n = info->block_group_cache_tree.rb_node;
192
193 while (n) {
194 cache = rb_entry(n, struct btrfs_block_group_cache,
195 cache_node);
196 end = cache->key.objectid + cache->key.offset - 1;
197 start = cache->key.objectid;
198
199 if (bytenr < start) {
200 if (!contains && (!ret || start < ret->key.objectid))
201 ret = cache;
202 n = n->rb_left;
203 } else if (bytenr > start) {
204 if (contains && bytenr <= end) {
205 ret = cache;
206 break;
207 }
208 n = n->rb_right;
209 } else {
210 ret = cache;
211 break;
212 }
213 }
214 if (ret) {
215 btrfs_get_block_group(ret);
216 if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
217 info->first_logical_byte = ret->key.objectid;
218 }
219 spin_unlock(&info->block_group_cache_lock);
220
221 return ret;
222 }
223
224 static int add_excluded_extent(struct btrfs_fs_info *fs_info,
225 u64 start, u64 num_bytes)
226 {
227 u64 end = start + num_bytes - 1;
228 set_extent_bits(&fs_info->freed_extents[0],
229 start, end, EXTENT_UPTODATE);
230 set_extent_bits(&fs_info->freed_extents[1],
231 start, end, EXTENT_UPTODATE);
232 return 0;
233 }
234
235 static void free_excluded_extents(struct btrfs_fs_info *fs_info,
236 struct btrfs_block_group_cache *cache)
237 {
238 u64 start, end;
239
240 start = cache->key.objectid;
241 end = start + cache->key.offset - 1;
242
243 clear_extent_bits(&fs_info->freed_extents[0],
244 start, end, EXTENT_UPTODATE);
245 clear_extent_bits(&fs_info->freed_extents[1],
246 start, end, EXTENT_UPTODATE);
247 }
248
249 static int exclude_super_stripes(struct btrfs_fs_info *fs_info,
250 struct btrfs_block_group_cache *cache)
251 {
252 u64 bytenr;
253 u64 *logical;
254 int stripe_len;
255 int i, nr, ret;
256
257 if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
258 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
259 cache->bytes_super += stripe_len;
260 ret = add_excluded_extent(fs_info, cache->key.objectid,
261 stripe_len);
262 if (ret)
263 return ret;
264 }
265
266 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
267 bytenr = btrfs_sb_offset(i);
268 ret = btrfs_rmap_block(fs_info, cache->key.objectid,
269 bytenr, 0, &logical, &nr, &stripe_len);
270 if (ret)
271 return ret;
272
273 while (nr--) {
274 u64 start, len;
275
276 if (logical[nr] > cache->key.objectid +
277 cache->key.offset)
278 continue;
279
280 if (logical[nr] + stripe_len <= cache->key.objectid)
281 continue;
282
283 start = logical[nr];
284 if (start < cache->key.objectid) {
285 start = cache->key.objectid;
286 len = (logical[nr] + stripe_len) - start;
287 } else {
288 len = min_t(u64, stripe_len,
289 cache->key.objectid +
290 cache->key.offset - start);
291 }
292
293 cache->bytes_super += len;
294 ret = add_excluded_extent(fs_info, start, len);
295 if (ret) {
296 kfree(logical);
297 return ret;
298 }
299 }
300
301 kfree(logical);
302 }
303 return 0;
304 }
305
306 static struct btrfs_caching_control *
307 get_caching_control(struct btrfs_block_group_cache *cache)
308 {
309 struct btrfs_caching_control *ctl;
310
311 spin_lock(&cache->lock);
312 if (!cache->caching_ctl) {
313 spin_unlock(&cache->lock);
314 return NULL;
315 }
316
317 ctl = cache->caching_ctl;
318 atomic_inc(&ctl->count);
319 spin_unlock(&cache->lock);
320 return ctl;
321 }
322
323 static void put_caching_control(struct btrfs_caching_control *ctl)
324 {
325 if (atomic_dec_and_test(&ctl->count))
326 kfree(ctl);
327 }
328
329 #ifdef CONFIG_BTRFS_DEBUG
330 static void fragment_free_space(struct btrfs_block_group_cache *block_group)
331 {
332 struct btrfs_fs_info *fs_info = block_group->fs_info;
333 u64 start = block_group->key.objectid;
334 u64 len = block_group->key.offset;
335 u64 chunk = block_group->flags & BTRFS_BLOCK_GROUP_METADATA ?
336 fs_info->nodesize : fs_info->sectorsize;
337 u64 step = chunk << 1;
338
339 while (len > chunk) {
340 btrfs_remove_free_space(block_group, start, chunk);
341 start += step;
342 if (len < step)
343 len = 0;
344 else
345 len -= step;
346 }
347 }
348 #endif
349
350 /*
351 * this is only called by cache_block_group, since we could have freed extents
352 * we need to check the pinned_extents for any extents that can't be used yet
353 * since their free space will be released as soon as the transaction commits.
354 */
355 u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
356 struct btrfs_fs_info *info, u64 start, u64 end)
357 {
358 u64 extent_start, extent_end, size, total_added = 0;
359 int ret;
360
361 while (start < end) {
362 ret = find_first_extent_bit(info->pinned_extents, start,
363 &extent_start, &extent_end,
364 EXTENT_DIRTY | EXTENT_UPTODATE,
365 NULL);
366 if (ret)
367 break;
368
369 if (extent_start <= start) {
370 start = extent_end + 1;
371 } else if (extent_start > start && extent_start < end) {
372 size = extent_start - start;
373 total_added += size;
374 ret = btrfs_add_free_space(block_group, start,
375 size);
376 BUG_ON(ret); /* -ENOMEM or logic error */
377 start = extent_end + 1;
378 } else {
379 break;
380 }
381 }
382
383 if (start < end) {
384 size = end - start;
385 total_added += size;
386 ret = btrfs_add_free_space(block_group, start, size);
387 BUG_ON(ret); /* -ENOMEM or logic error */
388 }
389
390 return total_added;
391 }
392
393 static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)
394 {
395 struct btrfs_block_group_cache *block_group = caching_ctl->block_group;
396 struct btrfs_fs_info *fs_info = block_group->fs_info;
397 struct btrfs_root *extent_root = fs_info->extent_root;
398 struct btrfs_path *path;
399 struct extent_buffer *leaf;
400 struct btrfs_key key;
401 u64 total_found = 0;
402 u64 last = 0;
403 u32 nritems;
404 int ret;
405 bool wakeup = true;
406
407 path = btrfs_alloc_path();
408 if (!path)
409 return -ENOMEM;
410
411 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
412
413 #ifdef CONFIG_BTRFS_DEBUG
414 /*
415 * If we're fragmenting we don't want to make anybody think we can
416 * allocate from this block group until we've had a chance to fragment
417 * the free space.
418 */
419 if (btrfs_should_fragment_free_space(block_group))
420 wakeup = false;
421 #endif
422 /*
423 * We don't want to deadlock with somebody trying to allocate a new
424 * extent for the extent root while also trying to search the extent
425 * root to add free space. So we skip locking and search the commit
426 * root, since its read-only
427 */
428 path->skip_locking = 1;
429 path->search_commit_root = 1;
430 path->reada = READA_FORWARD;
431
432 key.objectid = last;
433 key.offset = 0;
434 key.type = BTRFS_EXTENT_ITEM_KEY;
435
436 next:
437 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
438 if (ret < 0)
439 goto out;
440
441 leaf = path->nodes[0];
442 nritems = btrfs_header_nritems(leaf);
443
444 while (1) {
445 if (btrfs_fs_closing(fs_info) > 1) {
446 last = (u64)-1;
447 break;
448 }
449
450 if (path->slots[0] < nritems) {
451 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
452 } else {
453 ret = find_next_key(path, 0, &key);
454 if (ret)
455 break;
456
457 if (need_resched() ||
458 rwsem_is_contended(&fs_info->commit_root_sem)) {
459 if (wakeup)
460 caching_ctl->progress = last;
461 btrfs_release_path(path);
462 up_read(&fs_info->commit_root_sem);
463 mutex_unlock(&caching_ctl->mutex);
464 cond_resched();
465 mutex_lock(&caching_ctl->mutex);
466 down_read(&fs_info->commit_root_sem);
467 goto next;
468 }
469
470 ret = btrfs_next_leaf(extent_root, path);
471 if (ret < 0)
472 goto out;
473 if (ret)
474 break;
475 leaf = path->nodes[0];
476 nritems = btrfs_header_nritems(leaf);
477 continue;
478 }
479
480 if (key.objectid < last) {
481 key.objectid = last;
482 key.offset = 0;
483 key.type = BTRFS_EXTENT_ITEM_KEY;
484
485 if (wakeup)
486 caching_ctl->progress = last;
487 btrfs_release_path(path);
488 goto next;
489 }
490
491 if (key.objectid < block_group->key.objectid) {
492 path->slots[0]++;
493 continue;
494 }
495
496 if (key.objectid >= block_group->key.objectid +
497 block_group->key.offset)
498 break;
499
500 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
501 key.type == BTRFS_METADATA_ITEM_KEY) {
502 total_found += add_new_free_space(block_group,
503 fs_info, last,
504 key.objectid);
505 if (key.type == BTRFS_METADATA_ITEM_KEY)
506 last = key.objectid +
507 fs_info->nodesize;
508 else
509 last = key.objectid + key.offset;
510
511 if (total_found > CACHING_CTL_WAKE_UP) {
512 total_found = 0;
513 if (wakeup)
514 wake_up(&caching_ctl->wait);
515 }
516 }
517 path->slots[0]++;
518 }
519 ret = 0;
520
521 total_found += add_new_free_space(block_group, fs_info, last,
522 block_group->key.objectid +
523 block_group->key.offset);
524 caching_ctl->progress = (u64)-1;
525
526 out:
527 btrfs_free_path(path);
528 return ret;
529 }
530
531 static noinline void caching_thread(struct btrfs_work *work)
532 {
533 struct btrfs_block_group_cache *block_group;
534 struct btrfs_fs_info *fs_info;
535 struct btrfs_caching_control *caching_ctl;
536 struct btrfs_root *extent_root;
537 int ret;
538
539 caching_ctl = container_of(work, struct btrfs_caching_control, work);
540 block_group = caching_ctl->block_group;
541 fs_info = block_group->fs_info;
542 extent_root = fs_info->extent_root;
543
544 mutex_lock(&caching_ctl->mutex);
545 down_read(&fs_info->commit_root_sem);
546
547 if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
548 ret = load_free_space_tree(caching_ctl);
549 else
550 ret = load_extent_tree_free(caching_ctl);
551
552 spin_lock(&block_group->lock);
553 block_group->caching_ctl = NULL;
554 block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED;
555 spin_unlock(&block_group->lock);
556
557 #ifdef CONFIG_BTRFS_DEBUG
558 if (btrfs_should_fragment_free_space(block_group)) {
559 u64 bytes_used;
560
561 spin_lock(&block_group->space_info->lock);
562 spin_lock(&block_group->lock);
563 bytes_used = block_group->key.offset -
564 btrfs_block_group_used(&block_group->item);
565 block_group->space_info->bytes_used += bytes_used >> 1;
566 spin_unlock(&block_group->lock);
567 spin_unlock(&block_group->space_info->lock);
568 fragment_free_space(block_group);
569 }
570 #endif
571
572 caching_ctl->progress = (u64)-1;
573
574 up_read(&fs_info->commit_root_sem);
575 free_excluded_extents(fs_info, block_group);
576 mutex_unlock(&caching_ctl->mutex);
577
578 wake_up(&caching_ctl->wait);
579
580 put_caching_control(caching_ctl);
581 btrfs_put_block_group(block_group);
582 }
583
584 static int cache_block_group(struct btrfs_block_group_cache *cache,
585 int load_cache_only)
586 {
587 DEFINE_WAIT(wait);
588 struct btrfs_fs_info *fs_info = cache->fs_info;
589 struct btrfs_caching_control *caching_ctl;
590 int ret = 0;
591
592 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
593 if (!caching_ctl)
594 return -ENOMEM;
595
596 INIT_LIST_HEAD(&caching_ctl->list);
597 mutex_init(&caching_ctl->mutex);
598 init_waitqueue_head(&caching_ctl->wait);
599 caching_ctl->block_group = cache;
600 caching_ctl->progress = cache->key.objectid;
601 atomic_set(&caching_ctl->count, 1);
602 btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
603 caching_thread, NULL, NULL);
604
605 spin_lock(&cache->lock);
606 /*
607 * This should be a rare occasion, but this could happen I think in the
608 * case where one thread starts to load the space cache info, and then
609 * some other thread starts a transaction commit which tries to do an
610 * allocation while the other thread is still loading the space cache
611 * info. The previous loop should have kept us from choosing this block
612 * group, but if we've moved to the state where we will wait on caching
613 * block groups we need to first check if we're doing a fast load here,
614 * so we can wait for it to finish, otherwise we could end up allocating
615 * from a block group who's cache gets evicted for one reason or
616 * another.
617 */
618 while (cache->cached == BTRFS_CACHE_FAST) {
619 struct btrfs_caching_control *ctl;
620
621 ctl = cache->caching_ctl;
622 atomic_inc(&ctl->count);
623 prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
624 spin_unlock(&cache->lock);
625
626 schedule();
627
628 finish_wait(&ctl->wait, &wait);
629 put_caching_control(ctl);
630 spin_lock(&cache->lock);
631 }
632
633 if (cache->cached != BTRFS_CACHE_NO) {
634 spin_unlock(&cache->lock);
635 kfree(caching_ctl);
636 return 0;
637 }
638 WARN_ON(cache->caching_ctl);
639 cache->caching_ctl = caching_ctl;
640 cache->cached = BTRFS_CACHE_FAST;
641 spin_unlock(&cache->lock);
642
643 if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) {
644 mutex_lock(&caching_ctl->mutex);
645 ret = load_free_space_cache(fs_info, cache);
646
647 spin_lock(&cache->lock);
648 if (ret == 1) {
649 cache->caching_ctl = NULL;
650 cache->cached = BTRFS_CACHE_FINISHED;
651 cache->last_byte_to_unpin = (u64)-1;
652 caching_ctl->progress = (u64)-1;
653 } else {
654 if (load_cache_only) {
655 cache->caching_ctl = NULL;
656 cache->cached = BTRFS_CACHE_NO;
657 } else {
658 cache->cached = BTRFS_CACHE_STARTED;
659 cache->has_caching_ctl = 1;
660 }
661 }
662 spin_unlock(&cache->lock);
663 #ifdef CONFIG_BTRFS_DEBUG
664 if (ret == 1 &&
665 btrfs_should_fragment_free_space(cache)) {
666 u64 bytes_used;
667
668 spin_lock(&cache->space_info->lock);
669 spin_lock(&cache->lock);
670 bytes_used = cache->key.offset -
671 btrfs_block_group_used(&cache->item);
672 cache->space_info->bytes_used += bytes_used >> 1;
673 spin_unlock(&cache->lock);
674 spin_unlock(&cache->space_info->lock);
675 fragment_free_space(cache);
676 }
677 #endif
678 mutex_unlock(&caching_ctl->mutex);
679
680 wake_up(&caching_ctl->wait);
681 if (ret == 1) {
682 put_caching_control(caching_ctl);
683 free_excluded_extents(fs_info, cache);
684 return 0;
685 }
686 } else {
687 /*
688 * We're either using the free space tree or no caching at all.
689 * Set cached to the appropriate value and wakeup any waiters.
690 */
691 spin_lock(&cache->lock);
692 if (load_cache_only) {
693 cache->caching_ctl = NULL;
694 cache->cached = BTRFS_CACHE_NO;
695 } else {
696 cache->cached = BTRFS_CACHE_STARTED;
697 cache->has_caching_ctl = 1;
698 }
699 spin_unlock(&cache->lock);
700 wake_up(&caching_ctl->wait);
701 }
702
703 if (load_cache_only) {
704 put_caching_control(caching_ctl);
705 return 0;
706 }
707
708 down_write(&fs_info->commit_root_sem);
709 atomic_inc(&caching_ctl->count);
710 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
711 up_write(&fs_info->commit_root_sem);
712
713 btrfs_get_block_group(cache);
714
715 btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
716
717 return ret;
718 }
719
720 /*
721 * return the block group that starts at or after bytenr
722 */
723 static struct btrfs_block_group_cache *
724 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
725 {
726 return block_group_cache_tree_search(info, bytenr, 0);
727 }
728
729 /*
730 * return the block group that contains the given bytenr
731 */
732 struct btrfs_block_group_cache *btrfs_lookup_block_group(
733 struct btrfs_fs_info *info,
734 u64 bytenr)
735 {
736 return block_group_cache_tree_search(info, bytenr, 1);
737 }
738
739 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
740 u64 flags)
741 {
742 struct list_head *head = &info->space_info;
743 struct btrfs_space_info *found;
744
745 flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
746
747 rcu_read_lock();
748 list_for_each_entry_rcu(found, head, list) {
749 if (found->flags & flags) {
750 rcu_read_unlock();
751 return found;
752 }
753 }
754 rcu_read_unlock();
755 return NULL;
756 }
757
758 /*
759 * after adding space to the filesystem, we need to clear the full flags
760 * on all the space infos.
761 */
762 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
763 {
764 struct list_head *head = &info->space_info;
765 struct btrfs_space_info *found;
766
767 rcu_read_lock();
768 list_for_each_entry_rcu(found, head, list)
769 found->full = 0;
770 rcu_read_unlock();
771 }
772
773 /* simple helper to search for an existing data extent at a given offset */
774 int btrfs_lookup_data_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len)
775 {
776 int ret;
777 struct btrfs_key key;
778 struct btrfs_path *path;
779
780 path = btrfs_alloc_path();
781 if (!path)
782 return -ENOMEM;
783
784 key.objectid = start;
785 key.offset = len;
786 key.type = BTRFS_EXTENT_ITEM_KEY;
787 ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
788 btrfs_free_path(path);
789 return ret;
790 }
791
792 /*
793 * helper function to lookup reference count and flags of a tree block.
794 *
795 * the head node for delayed ref is used to store the sum of all the
796 * reference count modifications queued up in the rbtree. the head
797 * node may also store the extent flags to set. This way you can check
798 * to see what the reference count and extent flags would be if all of
799 * the delayed refs are not processed.
800 */
801 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
802 struct btrfs_fs_info *fs_info, u64 bytenr,
803 u64 offset, int metadata, u64 *refs, u64 *flags)
804 {
805 struct btrfs_delayed_ref_head *head;
806 struct btrfs_delayed_ref_root *delayed_refs;
807 struct btrfs_path *path;
808 struct btrfs_extent_item *ei;
809 struct extent_buffer *leaf;
810 struct btrfs_key key;
811 u32 item_size;
812 u64 num_refs;
813 u64 extent_flags;
814 int ret;
815
816 /*
817 * If we don't have skinny metadata, don't bother doing anything
818 * different
819 */
820 if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA)) {
821 offset = fs_info->nodesize;
822 metadata = 0;
823 }
824
825 path = btrfs_alloc_path();
826 if (!path)
827 return -ENOMEM;
828
829 if (!trans) {
830 path->skip_locking = 1;
831 path->search_commit_root = 1;
832 }
833
834 search_again:
835 key.objectid = bytenr;
836 key.offset = offset;
837 if (metadata)
838 key.type = BTRFS_METADATA_ITEM_KEY;
839 else
840 key.type = BTRFS_EXTENT_ITEM_KEY;
841
842 ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);
843 if (ret < 0)
844 goto out_free;
845
846 if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
847 if (path->slots[0]) {
848 path->slots[0]--;
849 btrfs_item_key_to_cpu(path->nodes[0], &key,
850 path->slots[0]);
851 if (key.objectid == bytenr &&
852 key.type == BTRFS_EXTENT_ITEM_KEY &&
853 key.offset == fs_info->nodesize)
854 ret = 0;
855 }
856 }
857
858 if (ret == 0) {
859 leaf = path->nodes[0];
860 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
861 if (item_size >= sizeof(*ei)) {
862 ei = btrfs_item_ptr(leaf, path->slots[0],
863 struct btrfs_extent_item);
864 num_refs = btrfs_extent_refs(leaf, ei);
865 extent_flags = btrfs_extent_flags(leaf, ei);
866 } else {
867 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
868 struct btrfs_extent_item_v0 *ei0;
869 BUG_ON(item_size != sizeof(*ei0));
870 ei0 = btrfs_item_ptr(leaf, path->slots[0],
871 struct btrfs_extent_item_v0);
872 num_refs = btrfs_extent_refs_v0(leaf, ei0);
873 /* FIXME: this isn't correct for data */
874 extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
875 #else
876 BUG();
877 #endif
878 }
879 BUG_ON(num_refs == 0);
880 } else {
881 num_refs = 0;
882 extent_flags = 0;
883 ret = 0;
884 }
885
886 if (!trans)
887 goto out;
888
889 delayed_refs = &trans->transaction->delayed_refs;
890 spin_lock(&delayed_refs->lock);
891 head = btrfs_find_delayed_ref_head(trans, bytenr);
892 if (head) {
893 if (!mutex_trylock(&head->mutex)) {
894 atomic_inc(&head->node.refs);
895 spin_unlock(&delayed_refs->lock);
896
897 btrfs_release_path(path);
898
899 /*
900 * Mutex was contended, block until it's released and try
901 * again
902 */
903 mutex_lock(&head->mutex);
904 mutex_unlock(&head->mutex);
905 btrfs_put_delayed_ref(&head->node);
906 goto search_again;
907 }
908 spin_lock(&head->lock);
909 if (head->extent_op && head->extent_op->update_flags)
910 extent_flags |= head->extent_op->flags_to_set;
911 else
912 BUG_ON(num_refs == 0);
913
914 num_refs += head->node.ref_mod;
915 spin_unlock(&head->lock);
916 mutex_unlock(&head->mutex);
917 }
918 spin_unlock(&delayed_refs->lock);
919 out:
920 WARN_ON(num_refs == 0);
921 if (refs)
922 *refs = num_refs;
923 if (flags)
924 *flags = extent_flags;
925 out_free:
926 btrfs_free_path(path);
927 return ret;
928 }
929
930 /*
931 * Back reference rules. Back refs have three main goals:
932 *
933 * 1) differentiate between all holders of references to an extent so that
934 * when a reference is dropped we can make sure it was a valid reference
935 * before freeing the extent.
936 *
937 * 2) Provide enough information to quickly find the holders of an extent
938 * if we notice a given block is corrupted or bad.
939 *
940 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
941 * maintenance. This is actually the same as #2, but with a slightly
942 * different use case.
943 *
944 * There are two kinds of back refs. The implicit back refs is optimized
945 * for pointers in non-shared tree blocks. For a given pointer in a block,
946 * back refs of this kind provide information about the block's owner tree
947 * and the pointer's key. These information allow us to find the block by
948 * b-tree searching. The full back refs is for pointers in tree blocks not
949 * referenced by their owner trees. The location of tree block is recorded
950 * in the back refs. Actually the full back refs is generic, and can be
951 * used in all cases the implicit back refs is used. The major shortcoming
952 * of the full back refs is its overhead. Every time a tree block gets
953 * COWed, we have to update back refs entry for all pointers in it.
954 *
955 * For a newly allocated tree block, we use implicit back refs for
956 * pointers in it. This means most tree related operations only involve
957 * implicit back refs. For a tree block created in old transaction, the
958 * only way to drop a reference to it is COW it. So we can detect the
959 * event that tree block loses its owner tree's reference and do the
960 * back refs conversion.
961 *
962 * When a tree block is COWed through a tree, there are four cases:
963 *
964 * The reference count of the block is one and the tree is the block's
965 * owner tree. Nothing to do in this case.
966 *
967 * The reference count of the block is one and the tree is not the
968 * block's owner tree. In this case, full back refs is used for pointers
969 * in the block. Remove these full back refs, add implicit back refs for
970 * every pointers in the new block.
971 *
972 * The reference count of the block is greater than one and the tree is
973 * the block's owner tree. In this case, implicit back refs is used for
974 * pointers in the block. Add full back refs for every pointers in the
975 * block, increase lower level extents' reference counts. The original
976 * implicit back refs are entailed to the new block.
977 *
978 * The reference count of the block is greater than one and the tree is
979 * not the block's owner tree. Add implicit back refs for every pointer in
980 * the new block, increase lower level extents' reference count.
981 *
982 * Back Reference Key composing:
983 *
984 * The key objectid corresponds to the first byte in the extent,
985 * The key type is used to differentiate between types of back refs.
986 * There are different meanings of the key offset for different types
987 * of back refs.
988 *
989 * File extents can be referenced by:
990 *
991 * - multiple snapshots, subvolumes, or different generations in one subvol
992 * - different files inside a single subvolume
993 * - different offsets inside a file (bookend extents in file.c)
994 *
995 * The extent ref structure for the implicit back refs has fields for:
996 *
997 * - Objectid of the subvolume root
998 * - objectid of the file holding the reference
999 * - original offset in the file
1000 * - how many bookend extents
1001 *
1002 * The key offset for the implicit back refs is hash of the first
1003 * three fields.
1004 *
1005 * The extent ref structure for the full back refs has field for:
1006 *
1007 * - number of pointers in the tree leaf
1008 *
1009 * The key offset for the implicit back refs is the first byte of
1010 * the tree leaf
1011 *
1012 * When a file extent is allocated, The implicit back refs is used.
1013 * the fields are filled in:
1014 *
1015 * (root_key.objectid, inode objectid, offset in file, 1)
1016 *
1017 * When a file extent is removed file truncation, we find the
1018 * corresponding implicit back refs and check the following fields:
1019 *
1020 * (btrfs_header_owner(leaf), inode objectid, offset in file)
1021 *
1022 * Btree extents can be referenced by:
1023 *
1024 * - Different subvolumes
1025 *
1026 * Both the implicit back refs and the full back refs for tree blocks
1027 * only consist of key. The key offset for the implicit back refs is
1028 * objectid of block's owner tree. The key offset for the full back refs
1029 * is the first byte of parent block.
1030 *
1031 * When implicit back refs is used, information about the lowest key and
1032 * level of the tree block are required. These information are stored in
1033 * tree block info structure.
1034 */
1035
1036 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1037 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
1038 struct btrfs_root *root,
1039 struct btrfs_path *path,
1040 u64 owner, u32 extra_size)
1041 {
1042 struct btrfs_extent_item *item;
1043 struct btrfs_extent_item_v0 *ei0;
1044 struct btrfs_extent_ref_v0 *ref0;
1045 struct btrfs_tree_block_info *bi;
1046 struct extent_buffer *leaf;
1047 struct btrfs_key key;
1048 struct btrfs_key found_key;
1049 u32 new_size = sizeof(*item);
1050 u64 refs;
1051 int ret;
1052
1053 leaf = path->nodes[0];
1054 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
1055
1056 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1057 ei0 = btrfs_item_ptr(leaf, path->slots[0],
1058 struct btrfs_extent_item_v0);
1059 refs = btrfs_extent_refs_v0(leaf, ei0);
1060
1061 if (owner == (u64)-1) {
1062 while (1) {
1063 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1064 ret = btrfs_next_leaf(root, path);
1065 if (ret < 0)
1066 return ret;
1067 BUG_ON(ret > 0); /* Corruption */
1068 leaf = path->nodes[0];
1069 }
1070 btrfs_item_key_to_cpu(leaf, &found_key,
1071 path->slots[0]);
1072 BUG_ON(key.objectid != found_key.objectid);
1073 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
1074 path->slots[0]++;
1075 continue;
1076 }
1077 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1078 struct btrfs_extent_ref_v0);
1079 owner = btrfs_ref_objectid_v0(leaf, ref0);
1080 break;
1081 }
1082 }
1083 btrfs_release_path(path);
1084
1085 if (owner < BTRFS_FIRST_FREE_OBJECTID)
1086 new_size += sizeof(*bi);
1087
1088 new_size -= sizeof(*ei0);
1089 ret = btrfs_search_slot(trans, root, &key, path,
1090 new_size + extra_size, 1);
1091 if (ret < 0)
1092 return ret;
1093 BUG_ON(ret); /* Corruption */
1094
1095 btrfs_extend_item(root->fs_info, path, new_size);
1096
1097 leaf = path->nodes[0];
1098 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1099 btrfs_set_extent_refs(leaf, item, refs);
1100 /* FIXME: get real generation */
1101 btrfs_set_extent_generation(leaf, item, 0);
1102 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1103 btrfs_set_extent_flags(leaf, item,
1104 BTRFS_EXTENT_FLAG_TREE_BLOCK |
1105 BTRFS_BLOCK_FLAG_FULL_BACKREF);
1106 bi = (struct btrfs_tree_block_info *)(item + 1);
1107 /* FIXME: get first key of the block */
1108 memzero_extent_buffer(leaf, (unsigned long)bi, sizeof(*bi));
1109 btrfs_set_tree_block_level(leaf, bi, (int)owner);
1110 } else {
1111 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
1112 }
1113 btrfs_mark_buffer_dirty(leaf);
1114 return 0;
1115 }
1116 #endif
1117
1118 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
1119 {
1120 u32 high_crc = ~(u32)0;
1121 u32 low_crc = ~(u32)0;
1122 __le64 lenum;
1123
1124 lenum = cpu_to_le64(root_objectid);
1125 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
1126 lenum = cpu_to_le64(owner);
1127 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
1128 lenum = cpu_to_le64(offset);
1129 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
1130
1131 return ((u64)high_crc << 31) ^ (u64)low_crc;
1132 }
1133
1134 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
1135 struct btrfs_extent_data_ref *ref)
1136 {
1137 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
1138 btrfs_extent_data_ref_objectid(leaf, ref),
1139 btrfs_extent_data_ref_offset(leaf, ref));
1140 }
1141
1142 static int match_extent_data_ref(struct extent_buffer *leaf,
1143 struct btrfs_extent_data_ref *ref,
1144 u64 root_objectid, u64 owner, u64 offset)
1145 {
1146 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
1147 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
1148 btrfs_extent_data_ref_offset(leaf, ref) != offset)
1149 return 0;
1150 return 1;
1151 }
1152
1153 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
1154 struct btrfs_root *root,
1155 struct btrfs_path *path,
1156 u64 bytenr, u64 parent,
1157 u64 root_objectid,
1158 u64 owner, u64 offset)
1159 {
1160 struct btrfs_key key;
1161 struct btrfs_extent_data_ref *ref;
1162 struct extent_buffer *leaf;
1163 u32 nritems;
1164 int ret;
1165 int recow;
1166 int err = -ENOENT;
1167
1168 key.objectid = bytenr;
1169 if (parent) {
1170 key.type = BTRFS_SHARED_DATA_REF_KEY;
1171 key.offset = parent;
1172 } else {
1173 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1174 key.offset = hash_extent_data_ref(root_objectid,
1175 owner, offset);
1176 }
1177 again:
1178 recow = 0;
1179 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1180 if (ret < 0) {
1181 err = ret;
1182 goto fail;
1183 }
1184
1185 if (parent) {
1186 if (!ret)
1187 return 0;
1188 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1189 key.type = BTRFS_EXTENT_REF_V0_KEY;
1190 btrfs_release_path(path);
1191 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1192 if (ret < 0) {
1193 err = ret;
1194 goto fail;
1195 }
1196 if (!ret)
1197 return 0;
1198 #endif
1199 goto fail;
1200 }
1201
1202 leaf = path->nodes[0];
1203 nritems = btrfs_header_nritems(leaf);
1204 while (1) {
1205 if (path->slots[0] >= nritems) {
1206 ret = btrfs_next_leaf(root, path);
1207 if (ret < 0)
1208 err = ret;
1209 if (ret)
1210 goto fail;
1211
1212 leaf = path->nodes[0];
1213 nritems = btrfs_header_nritems(leaf);
1214 recow = 1;
1215 }
1216
1217 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1218 if (key.objectid != bytenr ||
1219 key.type != BTRFS_EXTENT_DATA_REF_KEY)
1220 goto fail;
1221
1222 ref = btrfs_item_ptr(leaf, path->slots[0],
1223 struct btrfs_extent_data_ref);
1224
1225 if (match_extent_data_ref(leaf, ref, root_objectid,
1226 owner, offset)) {
1227 if (recow) {
1228 btrfs_release_path(path);
1229 goto again;
1230 }
1231 err = 0;
1232 break;
1233 }
1234 path->slots[0]++;
1235 }
1236 fail:
1237 return err;
1238 }
1239
1240 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
1241 struct btrfs_root *root,
1242 struct btrfs_path *path,
1243 u64 bytenr, u64 parent,
1244 u64 root_objectid, u64 owner,
1245 u64 offset, int refs_to_add)
1246 {
1247 struct btrfs_key key;
1248 struct extent_buffer *leaf;
1249 u32 size;
1250 u32 num_refs;
1251 int ret;
1252
1253 key.objectid = bytenr;
1254 if (parent) {
1255 key.type = BTRFS_SHARED_DATA_REF_KEY;
1256 key.offset = parent;
1257 size = sizeof(struct btrfs_shared_data_ref);
1258 } else {
1259 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1260 key.offset = hash_extent_data_ref(root_objectid,
1261 owner, offset);
1262 size = sizeof(struct btrfs_extent_data_ref);
1263 }
1264
1265 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
1266 if (ret && ret != -EEXIST)
1267 goto fail;
1268
1269 leaf = path->nodes[0];
1270 if (parent) {
1271 struct btrfs_shared_data_ref *ref;
1272 ref = btrfs_item_ptr(leaf, path->slots[0],
1273 struct btrfs_shared_data_ref);
1274 if (ret == 0) {
1275 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
1276 } else {
1277 num_refs = btrfs_shared_data_ref_count(leaf, ref);
1278 num_refs += refs_to_add;
1279 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
1280 }
1281 } else {
1282 struct btrfs_extent_data_ref *ref;
1283 while (ret == -EEXIST) {
1284 ref = btrfs_item_ptr(leaf, path->slots[0],
1285 struct btrfs_extent_data_ref);
1286 if (match_extent_data_ref(leaf, ref, root_objectid,
1287 owner, offset))
1288 break;
1289 btrfs_release_path(path);
1290 key.offset++;
1291 ret = btrfs_insert_empty_item(trans, root, path, &key,
1292 size);
1293 if (ret && ret != -EEXIST)
1294 goto fail;
1295
1296 leaf = path->nodes[0];
1297 }
1298 ref = btrfs_item_ptr(leaf, path->slots[0],
1299 struct btrfs_extent_data_ref);
1300 if (ret == 0) {
1301 btrfs_set_extent_data_ref_root(leaf, ref,
1302 root_objectid);
1303 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
1304 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
1305 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
1306 } else {
1307 num_refs = btrfs_extent_data_ref_count(leaf, ref);
1308 num_refs += refs_to_add;
1309 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
1310 }
1311 }
1312 btrfs_mark_buffer_dirty(leaf);
1313 ret = 0;
1314 fail:
1315 btrfs_release_path(path);
1316 return ret;
1317 }
1318
1319 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
1320 struct btrfs_root *root,
1321 struct btrfs_path *path,
1322 int refs_to_drop, int *last_ref)
1323 {
1324 struct btrfs_key key;
1325 struct btrfs_extent_data_ref *ref1 = NULL;
1326 struct btrfs_shared_data_ref *ref2 = NULL;
1327 struct extent_buffer *leaf;
1328 u32 num_refs = 0;
1329 int ret = 0;
1330
1331 leaf = path->nodes[0];
1332 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1333
1334 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1335 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1336 struct btrfs_extent_data_ref);
1337 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1338 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1339 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1340 struct btrfs_shared_data_ref);
1341 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1342 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1343 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1344 struct btrfs_extent_ref_v0 *ref0;
1345 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1346 struct btrfs_extent_ref_v0);
1347 num_refs = btrfs_ref_count_v0(leaf, ref0);
1348 #endif
1349 } else {
1350 BUG();
1351 }
1352
1353 BUG_ON(num_refs < refs_to_drop);
1354 num_refs -= refs_to_drop;
1355
1356 if (num_refs == 0) {
1357 ret = btrfs_del_item(trans, root, path);
1358 *last_ref = 1;
1359 } else {
1360 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
1361 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
1362 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
1363 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
1364 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1365 else {
1366 struct btrfs_extent_ref_v0 *ref0;
1367 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1368 struct btrfs_extent_ref_v0);
1369 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
1370 }
1371 #endif
1372 btrfs_mark_buffer_dirty(leaf);
1373 }
1374 return ret;
1375 }
1376
1377 static noinline u32 extent_data_ref_count(struct btrfs_path *path,
1378 struct btrfs_extent_inline_ref *iref)
1379 {
1380 struct btrfs_key key;
1381 struct extent_buffer *leaf;
1382 struct btrfs_extent_data_ref *ref1;
1383 struct btrfs_shared_data_ref *ref2;
1384 u32 num_refs = 0;
1385
1386 leaf = path->nodes[0];
1387 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1388 if (iref) {
1389 if (btrfs_extent_inline_ref_type(leaf, iref) ==
1390 BTRFS_EXTENT_DATA_REF_KEY) {
1391 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
1392 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1393 } else {
1394 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
1395 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1396 }
1397 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1398 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1399 struct btrfs_extent_data_ref);
1400 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1401 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1402 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1403 struct btrfs_shared_data_ref);
1404 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1405 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1406 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1407 struct btrfs_extent_ref_v0 *ref0;
1408 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1409 struct btrfs_extent_ref_v0);
1410 num_refs = btrfs_ref_count_v0(leaf, ref0);
1411 #endif
1412 } else {
1413 WARN_ON(1);
1414 }
1415 return num_refs;
1416 }
1417
1418 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
1419 struct btrfs_root *root,
1420 struct btrfs_path *path,
1421 u64 bytenr, u64 parent,
1422 u64 root_objectid)
1423 {
1424 struct btrfs_key key;
1425 int ret;
1426
1427 key.objectid = bytenr;
1428 if (parent) {
1429 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1430 key.offset = parent;
1431 } else {
1432 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1433 key.offset = root_objectid;
1434 }
1435
1436 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1437 if (ret > 0)
1438 ret = -ENOENT;
1439 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1440 if (ret == -ENOENT && parent) {
1441 btrfs_release_path(path);
1442 key.type = BTRFS_EXTENT_REF_V0_KEY;
1443 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1444 if (ret > 0)
1445 ret = -ENOENT;
1446 }
1447 #endif
1448 return ret;
1449 }
1450
1451 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
1452 struct btrfs_root *root,
1453 struct btrfs_path *path,
1454 u64 bytenr, u64 parent,
1455 u64 root_objectid)
1456 {
1457 struct btrfs_key key;
1458 int ret;
1459
1460 key.objectid = bytenr;
1461 if (parent) {
1462 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1463 key.offset = parent;
1464 } else {
1465 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1466 key.offset = root_objectid;
1467 }
1468
1469 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1470 btrfs_release_path(path);
1471 return ret;
1472 }
1473
1474 static inline int extent_ref_type(u64 parent, u64 owner)
1475 {
1476 int type;
1477 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1478 if (parent > 0)
1479 type = BTRFS_SHARED_BLOCK_REF_KEY;
1480 else
1481 type = BTRFS_TREE_BLOCK_REF_KEY;
1482 } else {
1483 if (parent > 0)
1484 type = BTRFS_SHARED_DATA_REF_KEY;
1485 else
1486 type = BTRFS_EXTENT_DATA_REF_KEY;
1487 }
1488 return type;
1489 }
1490
1491 static int find_next_key(struct btrfs_path *path, int level,
1492 struct btrfs_key *key)
1493
1494 {
1495 for (; level < BTRFS_MAX_LEVEL; level++) {
1496 if (!path->nodes[level])
1497 break;
1498 if (path->slots[level] + 1 >=
1499 btrfs_header_nritems(path->nodes[level]))
1500 continue;
1501 if (level == 0)
1502 btrfs_item_key_to_cpu(path->nodes[level], key,
1503 path->slots[level] + 1);
1504 else
1505 btrfs_node_key_to_cpu(path->nodes[level], key,
1506 path->slots[level] + 1);
1507 return 0;
1508 }
1509 return 1;
1510 }
1511
1512 /*
1513 * look for inline back ref. if back ref is found, *ref_ret is set
1514 * to the address of inline back ref, and 0 is returned.
1515 *
1516 * if back ref isn't found, *ref_ret is set to the address where it
1517 * should be inserted, and -ENOENT is returned.
1518 *
1519 * if insert is true and there are too many inline back refs, the path
1520 * points to the extent item, and -EAGAIN is returned.
1521 *
1522 * NOTE: inline back refs are ordered in the same way that back ref
1523 * items in the tree are ordered.
1524 */
1525 static noinline_for_stack
1526 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1527 struct btrfs_root *root,
1528 struct btrfs_path *path,
1529 struct btrfs_extent_inline_ref **ref_ret,
1530 u64 bytenr, u64 num_bytes,
1531 u64 parent, u64 root_objectid,
1532 u64 owner, u64 offset, int insert)
1533 {
1534 struct btrfs_fs_info *fs_info = root->fs_info;
1535 struct btrfs_key key;
1536 struct extent_buffer *leaf;
1537 struct btrfs_extent_item *ei;
1538 struct btrfs_extent_inline_ref *iref;
1539 u64 flags;
1540 u64 item_size;
1541 unsigned long ptr;
1542 unsigned long end;
1543 int extra_size;
1544 int type;
1545 int want;
1546 int ret;
1547 int err = 0;
1548 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
1549
1550 key.objectid = bytenr;
1551 key.type = BTRFS_EXTENT_ITEM_KEY;
1552 key.offset = num_bytes;
1553
1554 want = extent_ref_type(parent, owner);
1555 if (insert) {
1556 extra_size = btrfs_extent_inline_ref_size(want);
1557 path->keep_locks = 1;
1558 } else
1559 extra_size = -1;
1560
1561 /*
1562 * Owner is our parent level, so we can just add one to get the level
1563 * for the block we are interested in.
1564 */
1565 if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) {
1566 key.type = BTRFS_METADATA_ITEM_KEY;
1567 key.offset = owner;
1568 }
1569
1570 again:
1571 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1572 if (ret < 0) {
1573 err = ret;
1574 goto out;
1575 }
1576
1577 /*
1578 * We may be a newly converted file system which still has the old fat
1579 * extent entries for metadata, so try and see if we have one of those.
1580 */
1581 if (ret > 0 && skinny_metadata) {
1582 skinny_metadata = false;
1583 if (path->slots[0]) {
1584 path->slots[0]--;
1585 btrfs_item_key_to_cpu(path->nodes[0], &key,
1586 path->slots[0]);
1587 if (key.objectid == bytenr &&
1588 key.type == BTRFS_EXTENT_ITEM_KEY &&
1589 key.offset == num_bytes)
1590 ret = 0;
1591 }
1592 if (ret) {
1593 key.objectid = bytenr;
1594 key.type = BTRFS_EXTENT_ITEM_KEY;
1595 key.offset = num_bytes;
1596 btrfs_release_path(path);
1597 goto again;
1598 }
1599 }
1600
1601 if (ret && !insert) {
1602 err = -ENOENT;
1603 goto out;
1604 } else if (WARN_ON(ret)) {
1605 err = -EIO;
1606 goto out;
1607 }
1608
1609 leaf = path->nodes[0];
1610 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1611 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1612 if (item_size < sizeof(*ei)) {
1613 if (!insert) {
1614 err = -ENOENT;
1615 goto out;
1616 }
1617 ret = convert_extent_item_v0(trans, root, path, owner,
1618 extra_size);
1619 if (ret < 0) {
1620 err = ret;
1621 goto out;
1622 }
1623 leaf = path->nodes[0];
1624 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1625 }
1626 #endif
1627 BUG_ON(item_size < sizeof(*ei));
1628
1629 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1630 flags = btrfs_extent_flags(leaf, ei);
1631
1632 ptr = (unsigned long)(ei + 1);
1633 end = (unsigned long)ei + item_size;
1634
1635 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
1636 ptr += sizeof(struct btrfs_tree_block_info);
1637 BUG_ON(ptr > end);
1638 }
1639
1640 err = -ENOENT;
1641 while (1) {
1642 if (ptr >= end) {
1643 WARN_ON(ptr > end);
1644 break;
1645 }
1646 iref = (struct btrfs_extent_inline_ref *)ptr;
1647 type = btrfs_extent_inline_ref_type(leaf, iref);
1648 if (want < type)
1649 break;
1650 if (want > type) {
1651 ptr += btrfs_extent_inline_ref_size(type);
1652 continue;
1653 }
1654
1655 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1656 struct btrfs_extent_data_ref *dref;
1657 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1658 if (match_extent_data_ref(leaf, dref, root_objectid,
1659 owner, offset)) {
1660 err = 0;
1661 break;
1662 }
1663 if (hash_extent_data_ref_item(leaf, dref) <
1664 hash_extent_data_ref(root_objectid, owner, offset))
1665 break;
1666 } else {
1667 u64 ref_offset;
1668 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1669 if (parent > 0) {
1670 if (parent == ref_offset) {
1671 err = 0;
1672 break;
1673 }
1674 if (ref_offset < parent)
1675 break;
1676 } else {
1677 if (root_objectid == ref_offset) {
1678 err = 0;
1679 break;
1680 }
1681 if (ref_offset < root_objectid)
1682 break;
1683 }
1684 }
1685 ptr += btrfs_extent_inline_ref_size(type);
1686 }
1687 if (err == -ENOENT && insert) {
1688 if (item_size + extra_size >=
1689 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1690 err = -EAGAIN;
1691 goto out;
1692 }
1693 /*
1694 * To add new inline back ref, we have to make sure
1695 * there is no corresponding back ref item.
1696 * For simplicity, we just do not add new inline back
1697 * ref if there is any kind of item for this block
1698 */
1699 if (find_next_key(path, 0, &key) == 0 &&
1700 key.objectid == bytenr &&
1701 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1702 err = -EAGAIN;
1703 goto out;
1704 }
1705 }
1706 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1707 out:
1708 if (insert) {
1709 path->keep_locks = 0;
1710 btrfs_unlock_up_safe(path, 1);
1711 }
1712 return err;
1713 }
1714
1715 /*
1716 * helper to add new inline back ref
1717 */
1718 static noinline_for_stack
1719 void setup_inline_extent_backref(struct btrfs_root *root,
1720 struct btrfs_path *path,
1721 struct btrfs_extent_inline_ref *iref,
1722 u64 parent, u64 root_objectid,
1723 u64 owner, u64 offset, int refs_to_add,
1724 struct btrfs_delayed_extent_op *extent_op)
1725 {
1726 struct extent_buffer *leaf;
1727 struct btrfs_extent_item *ei;
1728 unsigned long ptr;
1729 unsigned long end;
1730 unsigned long item_offset;
1731 u64 refs;
1732 int size;
1733 int type;
1734
1735 leaf = path->nodes[0];
1736 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1737 item_offset = (unsigned long)iref - (unsigned long)ei;
1738
1739 type = extent_ref_type(parent, owner);
1740 size = btrfs_extent_inline_ref_size(type);
1741
1742 btrfs_extend_item(root->fs_info, path, size);
1743
1744 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1745 refs = btrfs_extent_refs(leaf, ei);
1746 refs += refs_to_add;
1747 btrfs_set_extent_refs(leaf, ei, refs);
1748 if (extent_op)
1749 __run_delayed_extent_op(extent_op, leaf, ei);
1750
1751 ptr = (unsigned long)ei + item_offset;
1752 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1753 if (ptr < end - size)
1754 memmove_extent_buffer(leaf, ptr + size, ptr,
1755 end - size - ptr);
1756
1757 iref = (struct btrfs_extent_inline_ref *)ptr;
1758 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1759 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1760 struct btrfs_extent_data_ref *dref;
1761 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1762 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1763 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1764 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1765 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1766 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1767 struct btrfs_shared_data_ref *sref;
1768 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1769 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1770 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1771 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1772 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1773 } else {
1774 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1775 }
1776 btrfs_mark_buffer_dirty(leaf);
1777 }
1778
1779 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1780 struct btrfs_root *root,
1781 struct btrfs_path *path,
1782 struct btrfs_extent_inline_ref **ref_ret,
1783 u64 bytenr, u64 num_bytes, u64 parent,
1784 u64 root_objectid, u64 owner, u64 offset)
1785 {
1786 int ret;
1787
1788 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1789 bytenr, num_bytes, parent,
1790 root_objectid, owner, offset, 0);
1791 if (ret != -ENOENT)
1792 return ret;
1793
1794 btrfs_release_path(path);
1795 *ref_ret = NULL;
1796
1797 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1798 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1799 root_objectid);
1800 } else {
1801 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1802 root_objectid, owner, offset);
1803 }
1804 return ret;
1805 }
1806
1807 /*
1808 * helper to update/remove inline back ref
1809 */
1810 static noinline_for_stack
1811 void update_inline_extent_backref(struct btrfs_root *root,
1812 struct btrfs_path *path,
1813 struct btrfs_extent_inline_ref *iref,
1814 int refs_to_mod,
1815 struct btrfs_delayed_extent_op *extent_op,
1816 int *last_ref)
1817 {
1818 struct extent_buffer *leaf;
1819 struct btrfs_extent_item *ei;
1820 struct btrfs_extent_data_ref *dref = NULL;
1821 struct btrfs_shared_data_ref *sref = NULL;
1822 unsigned long ptr;
1823 unsigned long end;
1824 u32 item_size;
1825 int size;
1826 int type;
1827 u64 refs;
1828
1829 leaf = path->nodes[0];
1830 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1831 refs = btrfs_extent_refs(leaf, ei);
1832 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1833 refs += refs_to_mod;
1834 btrfs_set_extent_refs(leaf, ei, refs);
1835 if (extent_op)
1836 __run_delayed_extent_op(extent_op, leaf, ei);
1837
1838 type = btrfs_extent_inline_ref_type(leaf, iref);
1839
1840 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1841 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1842 refs = btrfs_extent_data_ref_count(leaf, dref);
1843 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1844 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1845 refs = btrfs_shared_data_ref_count(leaf, sref);
1846 } else {
1847 refs = 1;
1848 BUG_ON(refs_to_mod != -1);
1849 }
1850
1851 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1852 refs += refs_to_mod;
1853
1854 if (refs > 0) {
1855 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1856 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1857 else
1858 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1859 } else {
1860 *last_ref = 1;
1861 size = btrfs_extent_inline_ref_size(type);
1862 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1863 ptr = (unsigned long)iref;
1864 end = (unsigned long)ei + item_size;
1865 if (ptr + size < end)
1866 memmove_extent_buffer(leaf, ptr, ptr + size,
1867 end - ptr - size);
1868 item_size -= size;
1869 btrfs_truncate_item(root->fs_info, path, item_size, 1);
1870 }
1871 btrfs_mark_buffer_dirty(leaf);
1872 }
1873
1874 static noinline_for_stack
1875 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1876 struct btrfs_root *root,
1877 struct btrfs_path *path,
1878 u64 bytenr, u64 num_bytes, u64 parent,
1879 u64 root_objectid, u64 owner,
1880 u64 offset, int refs_to_add,
1881 struct btrfs_delayed_extent_op *extent_op)
1882 {
1883 struct btrfs_extent_inline_ref *iref;
1884 int ret;
1885
1886 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1887 bytenr, num_bytes, parent,
1888 root_objectid, owner, offset, 1);
1889 if (ret == 0) {
1890 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1891 update_inline_extent_backref(root, path, iref,
1892 refs_to_add, extent_op, NULL);
1893 } else if (ret == -ENOENT) {
1894 setup_inline_extent_backref(root, path, iref, parent,
1895 root_objectid, owner, offset,
1896 refs_to_add, extent_op);
1897 ret = 0;
1898 }
1899 return ret;
1900 }
1901
1902 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1903 struct btrfs_root *root,
1904 struct btrfs_path *path,
1905 u64 bytenr, u64 parent, u64 root_objectid,
1906 u64 owner, u64 offset, int refs_to_add)
1907 {
1908 int ret;
1909 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1910 BUG_ON(refs_to_add != 1);
1911 ret = insert_tree_block_ref(trans, root, path, bytenr,
1912 parent, root_objectid);
1913 } else {
1914 ret = insert_extent_data_ref(trans, root, path, bytenr,
1915 parent, root_objectid,
1916 owner, offset, refs_to_add);
1917 }
1918 return ret;
1919 }
1920
1921 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1922 struct btrfs_root *root,
1923 struct btrfs_path *path,
1924 struct btrfs_extent_inline_ref *iref,
1925 int refs_to_drop, int is_data, int *last_ref)
1926 {
1927 int ret = 0;
1928
1929 BUG_ON(!is_data && refs_to_drop != 1);
1930 if (iref) {
1931 update_inline_extent_backref(root, path, iref,
1932 -refs_to_drop, NULL, last_ref);
1933 } else if (is_data) {
1934 ret = remove_extent_data_ref(trans, root, path, refs_to_drop,
1935 last_ref);
1936 } else {
1937 *last_ref = 1;
1938 ret = btrfs_del_item(trans, root, path);
1939 }
1940 return ret;
1941 }
1942
1943 #define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
1944 static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len,
1945 u64 *discarded_bytes)
1946 {
1947 int j, ret = 0;
1948 u64 bytes_left, end;
1949 u64 aligned_start = ALIGN(start, 1 << 9);
1950
1951 if (WARN_ON(start != aligned_start)) {
1952 len -= aligned_start - start;
1953 len = round_down(len, 1 << 9);
1954 start = aligned_start;
1955 }
1956
1957 *discarded_bytes = 0;
1958
1959 if (!len)
1960 return 0;
1961
1962 end = start + len;
1963 bytes_left = len;
1964
1965 /* Skip any superblocks on this device. */
1966 for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) {
1967 u64 sb_start = btrfs_sb_offset(j);
1968 u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE;
1969 u64 size = sb_start - start;
1970
1971 if (!in_range(sb_start, start, bytes_left) &&
1972 !in_range(sb_end, start, bytes_left) &&
1973 !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE))
1974 continue;
1975
1976 /*
1977 * Superblock spans beginning of range. Adjust start and
1978 * try again.
1979 */
1980 if (sb_start <= start) {
1981 start += sb_end - start;
1982 if (start > end) {
1983 bytes_left = 0;
1984 break;
1985 }
1986 bytes_left = end - start;
1987 continue;
1988 }
1989
1990 if (size) {
1991 ret = blkdev_issue_discard(bdev, start >> 9, size >> 9,
1992 GFP_NOFS, 0);
1993 if (!ret)
1994 *discarded_bytes += size;
1995 else if (ret != -EOPNOTSUPP)
1996 return ret;
1997 }
1998
1999 start = sb_end;
2000 if (start > end) {
2001 bytes_left = 0;
2002 break;
2003 }
2004 bytes_left = end - start;
2005 }
2006
2007 if (bytes_left) {
2008 ret = blkdev_issue_discard(bdev, start >> 9, bytes_left >> 9,
2009 GFP_NOFS, 0);
2010 if (!ret)
2011 *discarded_bytes += bytes_left;
2012 }
2013 return ret;
2014 }
2015
2016 int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
2017 u64 num_bytes, u64 *actual_bytes)
2018 {
2019 int ret;
2020 u64 discarded_bytes = 0;
2021 struct btrfs_bio *bbio = NULL;
2022
2023
2024 /*
2025 * Avoid races with device replace and make sure our bbio has devices
2026 * associated to its stripes that don't go away while we are discarding.
2027 */
2028 btrfs_bio_counter_inc_blocked(fs_info);
2029 /* Tell the block device(s) that the sectors can be discarded */
2030 ret = btrfs_map_block(fs_info, BTRFS_MAP_DISCARD, bytenr, &num_bytes,
2031 &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 btrfs_bio_counter_dec(fs_info);
2062
2063 if (actual_bytes)
2064 *actual_bytes = discarded_bytes;
2065
2066
2067 if (ret == -EOPNOTSUPP)
2068 ret = 0;
2069 return ret;
2070 }
2071
2072 /* Can return -ENOMEM */
2073 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
2074 struct btrfs_fs_info *fs_info,
2075 u64 bytenr, u64 num_bytes, u64 parent,
2076 u64 root_objectid, u64 owner, u64 offset)
2077 {
2078 int ret;
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_fs_info *fs_info,
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_path *path;
2105 struct extent_buffer *leaf;
2106 struct btrfs_extent_item *item;
2107 struct btrfs_key key;
2108 u64 bytenr = node->bytenr;
2109 u64 num_bytes = node->num_bytes;
2110 u64 refs;
2111 int ret;
2112
2113 path = btrfs_alloc_path();
2114 if (!path)
2115 return -ENOMEM;
2116
2117 path->reada = READA_FORWARD;
2118 path->leave_spinning = 1;
2119 /* this will setup the path even if it fails to insert the back ref */
2120 ret = insert_inline_extent_backref(trans, fs_info->extent_root, path,
2121 bytenr, num_bytes, parent,
2122 root_objectid, owner, offset,
2123 refs_to_add, extent_op);
2124 if ((ret < 0 && ret != -EAGAIN) || !ret)
2125 goto out;
2126
2127 /*
2128 * Ok we had -EAGAIN which means we didn't have space to insert and
2129 * inline extent ref, so just update the reference count and add a
2130 * normal backref.
2131 */
2132 leaf = path->nodes[0];
2133 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2134 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2135 refs = btrfs_extent_refs(leaf, item);
2136 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
2137 if (extent_op)
2138 __run_delayed_extent_op(extent_op, leaf, item);
2139
2140 btrfs_mark_buffer_dirty(leaf);
2141 btrfs_release_path(path);
2142
2143 path->reada = READA_FORWARD;
2144 path->leave_spinning = 1;
2145 /* now insert the actual backref */
2146 ret = insert_extent_backref(trans, fs_info->extent_root,
2147 path, bytenr, parent, root_objectid,
2148 owner, offset, refs_to_add);
2149 if (ret)
2150 btrfs_abort_transaction(trans, ret);
2151 out:
2152 btrfs_free_path(path);
2153 return ret;
2154 }
2155
2156 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
2157 struct btrfs_fs_info *fs_info,
2158 struct btrfs_delayed_ref_node *node,
2159 struct btrfs_delayed_extent_op *extent_op,
2160 int insert_reserved)
2161 {
2162 int ret = 0;
2163 struct btrfs_delayed_data_ref *ref;
2164 struct btrfs_key ins;
2165 u64 parent = 0;
2166 u64 ref_root = 0;
2167 u64 flags = 0;
2168
2169 ins.objectid = node->bytenr;
2170 ins.offset = node->num_bytes;
2171 ins.type = BTRFS_EXTENT_ITEM_KEY;
2172
2173 ref = btrfs_delayed_node_to_data_ref(node);
2174 trace_run_delayed_data_ref(fs_info, node, ref, node->action);
2175
2176 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
2177 parent = ref->parent;
2178 ref_root = ref->root;
2179
2180 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2181 if (extent_op)
2182 flags |= extent_op->flags_to_set;
2183 ret = alloc_reserved_file_extent(trans, fs_info,
2184 parent, ref_root, flags,
2185 ref->objectid, ref->offset,
2186 &ins, node->ref_mod);
2187 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2188 ret = __btrfs_inc_extent_ref(trans, fs_info, node, parent,
2189 ref_root, ref->objectid,
2190 ref->offset, node->ref_mod,
2191 extent_op);
2192 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2193 ret = __btrfs_free_extent(trans, fs_info, node, parent,
2194 ref_root, ref->objectid,
2195 ref->offset, node->ref_mod,
2196 extent_op);
2197 } else {
2198 BUG();
2199 }
2200 return ret;
2201 }
2202
2203 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
2204 struct extent_buffer *leaf,
2205 struct btrfs_extent_item *ei)
2206 {
2207 u64 flags = btrfs_extent_flags(leaf, ei);
2208 if (extent_op->update_flags) {
2209 flags |= extent_op->flags_to_set;
2210 btrfs_set_extent_flags(leaf, ei, flags);
2211 }
2212
2213 if (extent_op->update_key) {
2214 struct btrfs_tree_block_info *bi;
2215 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
2216 bi = (struct btrfs_tree_block_info *)(ei + 1);
2217 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
2218 }
2219 }
2220
2221 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
2222 struct btrfs_fs_info *fs_info,
2223 struct btrfs_delayed_ref_node *node,
2224 struct btrfs_delayed_extent_op *extent_op)
2225 {
2226 struct btrfs_key key;
2227 struct btrfs_path *path;
2228 struct btrfs_extent_item *ei;
2229 struct extent_buffer *leaf;
2230 u32 item_size;
2231 int ret;
2232 int err = 0;
2233 int metadata = !extent_op->is_data;
2234
2235 if (trans->aborted)
2236 return 0;
2237
2238 if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2239 metadata = 0;
2240
2241 path = btrfs_alloc_path();
2242 if (!path)
2243 return -ENOMEM;
2244
2245 key.objectid = node->bytenr;
2246
2247 if (metadata) {
2248 key.type = BTRFS_METADATA_ITEM_KEY;
2249 key.offset = extent_op->level;
2250 } else {
2251 key.type = BTRFS_EXTENT_ITEM_KEY;
2252 key.offset = node->num_bytes;
2253 }
2254
2255 again:
2256 path->reada = READA_FORWARD;
2257 path->leave_spinning = 1;
2258 ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 1);
2259 if (ret < 0) {
2260 err = ret;
2261 goto out;
2262 }
2263 if (ret > 0) {
2264 if (metadata) {
2265 if (path->slots[0] > 0) {
2266 path->slots[0]--;
2267 btrfs_item_key_to_cpu(path->nodes[0], &key,
2268 path->slots[0]);
2269 if (key.objectid == node->bytenr &&
2270 key.type == BTRFS_EXTENT_ITEM_KEY &&
2271 key.offset == node->num_bytes)
2272 ret = 0;
2273 }
2274 if (ret > 0) {
2275 btrfs_release_path(path);
2276 metadata = 0;
2277
2278 key.objectid = node->bytenr;
2279 key.offset = node->num_bytes;
2280 key.type = BTRFS_EXTENT_ITEM_KEY;
2281 goto again;
2282 }
2283 } else {
2284 err = -EIO;
2285 goto out;
2286 }
2287 }
2288
2289 leaf = path->nodes[0];
2290 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2291 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2292 if (item_size < sizeof(*ei)) {
2293 ret = convert_extent_item_v0(trans, fs_info->extent_root,
2294 path, (u64)-1, 0);
2295 if (ret < 0) {
2296 err = ret;
2297 goto out;
2298 }
2299 leaf = path->nodes[0];
2300 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2301 }
2302 #endif
2303 BUG_ON(item_size < sizeof(*ei));
2304 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2305 __run_delayed_extent_op(extent_op, leaf, ei);
2306
2307 btrfs_mark_buffer_dirty(leaf);
2308 out:
2309 btrfs_free_path(path);
2310 return err;
2311 }
2312
2313 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
2314 struct btrfs_fs_info *fs_info,
2315 struct btrfs_delayed_ref_node *node,
2316 struct btrfs_delayed_extent_op *extent_op,
2317 int insert_reserved)
2318 {
2319 int ret = 0;
2320 struct btrfs_delayed_tree_ref *ref;
2321 struct btrfs_key ins;
2322 u64 parent = 0;
2323 u64 ref_root = 0;
2324 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
2325
2326 ref = btrfs_delayed_node_to_tree_ref(node);
2327 trace_run_delayed_tree_ref(fs_info, node, ref, node->action);
2328
2329 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2330 parent = ref->parent;
2331 ref_root = ref->root;
2332
2333 ins.objectid = node->bytenr;
2334 if (skinny_metadata) {
2335 ins.offset = ref->level;
2336 ins.type = BTRFS_METADATA_ITEM_KEY;
2337 } else {
2338 ins.offset = node->num_bytes;
2339 ins.type = BTRFS_EXTENT_ITEM_KEY;
2340 }
2341
2342 if (node->ref_mod != 1) {
2343 btrfs_err(fs_info,
2344 "btree block(%llu) has %d references rather than 1: action %d ref_root %llu parent %llu",
2345 node->bytenr, node->ref_mod, node->action, ref_root,
2346 parent);
2347 return -EIO;
2348 }
2349 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2350 BUG_ON(!extent_op || !extent_op->update_flags);
2351 ret = alloc_reserved_tree_block(trans, fs_info,
2352 parent, ref_root,
2353 extent_op->flags_to_set,
2354 &extent_op->key,
2355 ref->level, &ins);
2356 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2357 ret = __btrfs_inc_extent_ref(trans, fs_info, node,
2358 parent, ref_root,
2359 ref->level, 0, 1,
2360 extent_op);
2361 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2362 ret = __btrfs_free_extent(trans, fs_info, node,
2363 parent, ref_root,
2364 ref->level, 0, 1, extent_op);
2365 } else {
2366 BUG();
2367 }
2368 return ret;
2369 }
2370
2371 /* helper function to actually process a single delayed ref entry */
2372 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
2373 struct btrfs_fs_info *fs_info,
2374 struct btrfs_delayed_ref_node *node,
2375 struct btrfs_delayed_extent_op *extent_op,
2376 int insert_reserved)
2377 {
2378 int ret = 0;
2379
2380 if (trans->aborted) {
2381 if (insert_reserved)
2382 btrfs_pin_extent(fs_info, node->bytenr,
2383 node->num_bytes, 1);
2384 return 0;
2385 }
2386
2387 if (btrfs_delayed_ref_is_head(node)) {
2388 struct btrfs_delayed_ref_head *head;
2389 /*
2390 * we've hit the end of the chain and we were supposed
2391 * to insert this extent into the tree. But, it got
2392 * deleted before we ever needed to insert it, so all
2393 * we have to do is clean up the accounting
2394 */
2395 BUG_ON(extent_op);
2396 head = btrfs_delayed_node_to_head(node);
2397 trace_run_delayed_ref_head(fs_info, node, head, node->action);
2398
2399 if (insert_reserved) {
2400 btrfs_pin_extent(fs_info, node->bytenr,
2401 node->num_bytes, 1);
2402 if (head->is_data) {
2403 ret = btrfs_del_csums(trans, fs_info,
2404 node->bytenr,
2405 node->num_bytes);
2406 }
2407 }
2408
2409 /* Also free its reserved qgroup space */
2410 btrfs_qgroup_free_delayed_ref(fs_info, head->qgroup_ref_root,
2411 head->qgroup_reserved);
2412 return ret;
2413 }
2414
2415 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
2416 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2417 ret = run_delayed_tree_ref(trans, fs_info, node, extent_op,
2418 insert_reserved);
2419 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
2420 node->type == BTRFS_SHARED_DATA_REF_KEY)
2421 ret = run_delayed_data_ref(trans, fs_info, node, extent_op,
2422 insert_reserved);
2423 else
2424 BUG();
2425 return ret;
2426 }
2427
2428 static inline struct btrfs_delayed_ref_node *
2429 select_delayed_ref(struct btrfs_delayed_ref_head *head)
2430 {
2431 struct btrfs_delayed_ref_node *ref;
2432
2433 if (list_empty(&head->ref_list))
2434 return NULL;
2435
2436 /*
2437 * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first.
2438 * This is to prevent a ref count from going down to zero, which deletes
2439 * the extent item from the extent tree, when there still are references
2440 * to add, which would fail because they would not find the extent item.
2441 */
2442 if (!list_empty(&head->ref_add_list))
2443 return list_first_entry(&head->ref_add_list,
2444 struct btrfs_delayed_ref_node, add_list);
2445
2446 ref = list_first_entry(&head->ref_list, struct btrfs_delayed_ref_node,
2447 list);
2448 ASSERT(list_empty(&ref->add_list));
2449 return ref;
2450 }
2451
2452 /*
2453 * Returns 0 on success or if called with an already aborted transaction.
2454 * Returns -ENOMEM or -EIO on failure and will abort the transaction.
2455 */
2456 static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2457 struct btrfs_fs_info *fs_info,
2458 unsigned long nr)
2459 {
2460 struct btrfs_delayed_ref_root *delayed_refs;
2461 struct btrfs_delayed_ref_node *ref;
2462 struct btrfs_delayed_ref_head *locked_ref = NULL;
2463 struct btrfs_delayed_extent_op *extent_op;
2464 ktime_t start = ktime_get();
2465 int ret;
2466 unsigned long count = 0;
2467 unsigned long actual_count = 0;
2468 int must_insert_reserved = 0;
2469
2470 delayed_refs = &trans->transaction->delayed_refs;
2471 while (1) {
2472 if (!locked_ref) {
2473 if (count >= nr)
2474 break;
2475
2476 spin_lock(&delayed_refs->lock);
2477 locked_ref = btrfs_select_ref_head(trans);
2478 if (!locked_ref) {
2479 spin_unlock(&delayed_refs->lock);
2480 break;
2481 }
2482
2483 /* grab the lock that says we are going to process
2484 * all the refs for this head */
2485 ret = btrfs_delayed_ref_lock(trans, locked_ref);
2486 spin_unlock(&delayed_refs->lock);
2487 /*
2488 * we may have dropped the spin lock to get the head
2489 * mutex lock, and that might have given someone else
2490 * time to free the head. If that's true, it has been
2491 * removed from our list and we can move on.
2492 */
2493 if (ret == -EAGAIN) {
2494 locked_ref = NULL;
2495 count++;
2496 continue;
2497 }
2498 }
2499
2500 /*
2501 * We need to try and merge add/drops of the same ref since we
2502 * can run into issues with relocate dropping the implicit ref
2503 * and then it being added back again before the drop can
2504 * finish. If we merged anything we need to re-loop so we can
2505 * get a good ref.
2506 * Or we can get node references of the same type that weren't
2507 * merged when created due to bumps in the tree mod seq, and
2508 * we need to merge them to prevent adding an inline extent
2509 * backref before dropping it (triggering a BUG_ON at
2510 * insert_inline_extent_backref()).
2511 */
2512 spin_lock(&locked_ref->lock);
2513 btrfs_merge_delayed_refs(trans, fs_info, delayed_refs,
2514 locked_ref);
2515
2516 /*
2517 * locked_ref is the head node, so we have to go one
2518 * node back for any delayed ref updates
2519 */
2520 ref = select_delayed_ref(locked_ref);
2521
2522 if (ref && ref->seq &&
2523 btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) {
2524 spin_unlock(&locked_ref->lock);
2525 btrfs_delayed_ref_unlock(locked_ref);
2526 spin_lock(&delayed_refs->lock);
2527 locked_ref->processing = 0;
2528 delayed_refs->num_heads_ready++;
2529 spin_unlock(&delayed_refs->lock);
2530 locked_ref = NULL;
2531 cond_resched();
2532 count++;
2533 continue;
2534 }
2535
2536 /*
2537 * record the must insert reserved flag before we
2538 * drop the spin lock.
2539 */
2540 must_insert_reserved = locked_ref->must_insert_reserved;
2541 locked_ref->must_insert_reserved = 0;
2542
2543 extent_op = locked_ref->extent_op;
2544 locked_ref->extent_op = NULL;
2545
2546 if (!ref) {
2547
2548
2549 /* All delayed refs have been processed, Go ahead
2550 * and send the head node to run_one_delayed_ref,
2551 * so that any accounting fixes can happen
2552 */
2553 ref = &locked_ref->node;
2554
2555 if (extent_op && must_insert_reserved) {
2556 btrfs_free_delayed_extent_op(extent_op);
2557 extent_op = NULL;
2558 }
2559
2560 if (extent_op) {
2561 spin_unlock(&locked_ref->lock);
2562 ret = run_delayed_extent_op(trans, fs_info,
2563 ref, extent_op);
2564 btrfs_free_delayed_extent_op(extent_op);
2565
2566 if (ret) {
2567 /*
2568 * Need to reset must_insert_reserved if
2569 * there was an error so the abort stuff
2570 * can cleanup the reserved space
2571 * properly.
2572 */
2573 if (must_insert_reserved)
2574 locked_ref->must_insert_reserved = 1;
2575 locked_ref->processing = 0;
2576 btrfs_debug(fs_info,
2577 "run_delayed_extent_op returned %d",
2578 ret);
2579 btrfs_delayed_ref_unlock(locked_ref);
2580 return ret;
2581 }
2582 continue;
2583 }
2584
2585 /*
2586 * Need to drop our head ref lock and re-acquire the
2587 * delayed ref lock and then re-check to make sure
2588 * nobody got added.
2589 */
2590 spin_unlock(&locked_ref->lock);
2591 spin_lock(&delayed_refs->lock);
2592 spin_lock(&locked_ref->lock);
2593 if (!list_empty(&locked_ref->ref_list) ||
2594 locked_ref->extent_op) {
2595 spin_unlock(&locked_ref->lock);
2596 spin_unlock(&delayed_refs->lock);
2597 continue;
2598 }
2599 ref->in_tree = 0;
2600 delayed_refs->num_heads--;
2601 rb_erase(&locked_ref->href_node,
2602 &delayed_refs->href_root);
2603 spin_unlock(&delayed_refs->lock);
2604 } else {
2605 actual_count++;
2606 ref->in_tree = 0;
2607 list_del(&ref->list);
2608 if (!list_empty(&ref->add_list))
2609 list_del(&ref->add_list);
2610 }
2611 atomic_dec(&delayed_refs->num_entries);
2612
2613 if (!btrfs_delayed_ref_is_head(ref)) {
2614 /*
2615 * when we play the delayed ref, also correct the
2616 * ref_mod on head
2617 */
2618 switch (ref->action) {
2619 case BTRFS_ADD_DELAYED_REF:
2620 case BTRFS_ADD_DELAYED_EXTENT:
2621 locked_ref->node.ref_mod -= ref->ref_mod;
2622 break;
2623 case BTRFS_DROP_DELAYED_REF:
2624 locked_ref->node.ref_mod += ref->ref_mod;
2625 break;
2626 default:
2627 WARN_ON(1);
2628 }
2629 }
2630 spin_unlock(&locked_ref->lock);
2631
2632 ret = run_one_delayed_ref(trans, fs_info, ref, extent_op,
2633 must_insert_reserved);
2634
2635 btrfs_free_delayed_extent_op(extent_op);
2636 if (ret) {
2637 spin_lock(&delayed_refs->lock);
2638 locked_ref->processing = 0;
2639 delayed_refs->num_heads_ready++;
2640 spin_unlock(&delayed_refs->lock);
2641 btrfs_delayed_ref_unlock(locked_ref);
2642 btrfs_put_delayed_ref(ref);
2643 btrfs_debug(fs_info, "run_one_delayed_ref returned %d",
2644 ret);
2645 return ret;
2646 }
2647
2648 /*
2649 * If this node is a head, that means all the refs in this head
2650 * have been dealt with, and we will pick the next head to deal
2651 * with, so we must unlock the head and drop it from the cluster
2652 * list before we release it.
2653 */
2654 if (btrfs_delayed_ref_is_head(ref)) {
2655 if (locked_ref->is_data &&
2656 locked_ref->total_ref_mod < 0) {
2657 spin_lock(&delayed_refs->lock);
2658 delayed_refs->pending_csums -= ref->num_bytes;
2659 spin_unlock(&delayed_refs->lock);
2660 }
2661 btrfs_delayed_ref_unlock(locked_ref);
2662 locked_ref = NULL;
2663 }
2664 btrfs_put_delayed_ref(ref);
2665 count++;
2666 cond_resched();
2667 }
2668
2669 /*
2670 * We don't want to include ref heads since we can have empty ref heads
2671 * and those will drastically skew our runtime down since we just do
2672 * accounting, no actual extent tree updates.
2673 */
2674 if (actual_count > 0) {
2675 u64 runtime = ktime_to_ns(ktime_sub(ktime_get(), start));
2676 u64 avg;
2677
2678 /*
2679 * We weigh the current average higher than our current runtime
2680 * to avoid large swings in the average.
2681 */
2682 spin_lock(&delayed_refs->lock);
2683 avg = fs_info->avg_delayed_ref_runtime * 3 + runtime;
2684 fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */
2685 spin_unlock(&delayed_refs->lock);
2686 }
2687 return 0;
2688 }
2689
2690 #ifdef SCRAMBLE_DELAYED_REFS
2691 /*
2692 * Normally delayed refs get processed in ascending bytenr order. This
2693 * correlates in most cases to the order added. To expose dependencies on this
2694 * order, we start to process the tree in the middle instead of the beginning
2695 */
2696 static u64 find_middle(struct rb_root *root)
2697 {
2698 struct rb_node *n = root->rb_node;
2699 struct btrfs_delayed_ref_node *entry;
2700 int alt = 1;
2701 u64 middle;
2702 u64 first = 0, last = 0;
2703
2704 n = rb_first(root);
2705 if (n) {
2706 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2707 first = entry->bytenr;
2708 }
2709 n = rb_last(root);
2710 if (n) {
2711 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2712 last = entry->bytenr;
2713 }
2714 n = root->rb_node;
2715
2716 while (n) {
2717 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
2718 WARN_ON(!entry->in_tree);
2719
2720 middle = entry->bytenr;
2721
2722 if (alt)
2723 n = n->rb_left;
2724 else
2725 n = n->rb_right;
2726
2727 alt = 1 - alt;
2728 }
2729 return middle;
2730 }
2731 #endif
2732
2733 static inline u64 heads_to_leaves(struct btrfs_fs_info *fs_info, u64 heads)
2734 {
2735 u64 num_bytes;
2736
2737 num_bytes = heads * (sizeof(struct btrfs_extent_item) +
2738 sizeof(struct btrfs_extent_inline_ref));
2739 if (!btrfs_fs_incompat(fs_info, SKINNY_METADATA))
2740 num_bytes += heads * sizeof(struct btrfs_tree_block_info);
2741
2742 /*
2743 * We don't ever fill up leaves all the way so multiply by 2 just to be
2744 * closer to what we're really going to want to use.
2745 */
2746 return div_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(fs_info));
2747 }
2748
2749 /*
2750 * Takes the number of bytes to be csumm'ed and figures out how many leaves it
2751 * would require to store the csums for that many bytes.
2752 */
2753 u64 btrfs_csum_bytes_to_leaves(struct btrfs_fs_info *fs_info, u64 csum_bytes)
2754 {
2755 u64 csum_size;
2756 u64 num_csums_per_leaf;
2757 u64 num_csums;
2758
2759 csum_size = BTRFS_MAX_ITEM_SIZE(fs_info);
2760 num_csums_per_leaf = div64_u64(csum_size,
2761 (u64)btrfs_super_csum_size(fs_info->super_copy));
2762 num_csums = div64_u64(csum_bytes, fs_info->sectorsize);
2763 num_csums += num_csums_per_leaf - 1;
2764 num_csums = div64_u64(num_csums, num_csums_per_leaf);
2765 return num_csums;
2766 }
2767
2768 int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
2769 struct btrfs_fs_info *fs_info)
2770 {
2771 struct btrfs_block_rsv *global_rsv;
2772 u64 num_heads = trans->transaction->delayed_refs.num_heads_ready;
2773 u64 csum_bytes = trans->transaction->delayed_refs.pending_csums;
2774 u64 num_dirty_bgs = trans->transaction->num_dirty_bgs;
2775 u64 num_bytes, num_dirty_bgs_bytes;
2776 int ret = 0;
2777
2778 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
2779 num_heads = heads_to_leaves(fs_info, num_heads);
2780 if (num_heads > 1)
2781 num_bytes += (num_heads - 1) * fs_info->nodesize;
2782 num_bytes <<= 1;
2783 num_bytes += btrfs_csum_bytes_to_leaves(fs_info, csum_bytes) *
2784 fs_info->nodesize;
2785 num_dirty_bgs_bytes = btrfs_calc_trans_metadata_size(fs_info,
2786 num_dirty_bgs);
2787 global_rsv = &fs_info->global_block_rsv;
2788
2789 /*
2790 * If we can't allocate any more chunks lets make sure we have _lots_ of
2791 * wiggle room since running delayed refs can create more delayed refs.
2792 */
2793 if (global_rsv->space_info->full) {
2794 num_dirty_bgs_bytes <<= 1;
2795 num_bytes <<= 1;
2796 }
2797
2798 spin_lock(&global_rsv->lock);
2799 if (global_rsv->reserved <= num_bytes + num_dirty_bgs_bytes)
2800 ret = 1;
2801 spin_unlock(&global_rsv->lock);
2802 return ret;
2803 }
2804
2805 int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans,
2806 struct btrfs_fs_info *fs_info)
2807 {
2808 u64 num_entries =
2809 atomic_read(&trans->transaction->delayed_refs.num_entries);
2810 u64 avg_runtime;
2811 u64 val;
2812
2813 smp_mb();
2814 avg_runtime = fs_info->avg_delayed_ref_runtime;
2815 val = num_entries * avg_runtime;
2816 if (val >= NSEC_PER_SEC)
2817 return 1;
2818 if (val >= NSEC_PER_SEC / 2)
2819 return 2;
2820
2821 return btrfs_check_space_for_delayed_refs(trans, fs_info);
2822 }
2823
2824 struct async_delayed_refs {
2825 struct btrfs_root *root;
2826 u64 transid;
2827 int count;
2828 int error;
2829 int sync;
2830 struct completion wait;
2831 struct btrfs_work work;
2832 };
2833
2834 static inline struct async_delayed_refs *
2835 to_async_delayed_refs(struct btrfs_work *work)
2836 {
2837 return container_of(work, struct async_delayed_refs, work);
2838 }
2839
2840 static void delayed_ref_async_start(struct btrfs_work *work)
2841 {
2842 struct async_delayed_refs *async = to_async_delayed_refs(work);
2843 struct btrfs_trans_handle *trans;
2844 struct btrfs_fs_info *fs_info = async->root->fs_info;
2845 int ret;
2846
2847 /* if the commit is already started, we don't need to wait here */
2848 if (btrfs_transaction_blocked(fs_info))
2849 goto done;
2850
2851 trans = btrfs_join_transaction(async->root);
2852 if (IS_ERR(trans)) {
2853 async->error = PTR_ERR(trans);
2854 goto done;
2855 }
2856
2857 /*
2858 * trans->sync means that when we call end_transaction, we won't
2859 * wait on delayed refs
2860 */
2861 trans->sync = true;
2862
2863 /* Don't bother flushing if we got into a different transaction */
2864 if (trans->transid > async->transid)
2865 goto end;
2866
2867 ret = btrfs_run_delayed_refs(trans, fs_info, async->count);
2868 if (ret)
2869 async->error = ret;
2870 end:
2871 ret = btrfs_end_transaction(trans);
2872 if (ret && !async->error)
2873 async->error = ret;
2874 done:
2875 if (async->sync)
2876 complete(&async->wait);
2877 else
2878 kfree(async);
2879 }
2880
2881 int btrfs_async_run_delayed_refs(struct btrfs_fs_info *fs_info,
2882 unsigned long count, u64 transid, int wait)
2883 {
2884 struct async_delayed_refs *async;
2885 int ret;
2886
2887 async = kmalloc(sizeof(*async), GFP_NOFS);
2888 if (!async)
2889 return -ENOMEM;
2890
2891 async->root = fs_info->tree_root;
2892 async->count = count;
2893 async->error = 0;
2894 async->transid = transid;
2895 if (wait)
2896 async->sync = 1;
2897 else
2898 async->sync = 0;
2899 init_completion(&async->wait);
2900
2901 btrfs_init_work(&async->work, btrfs_extent_refs_helper,
2902 delayed_ref_async_start, NULL, NULL);
2903
2904 btrfs_queue_work(fs_info->extent_workers, &async->work);
2905
2906 if (wait) {
2907 wait_for_completion(&async->wait);
2908 ret = async->error;
2909 kfree(async);
2910 return ret;
2911 }
2912 return 0;
2913 }
2914
2915 /*
2916 * this starts processing the delayed reference count updates and
2917 * extent insertions we have queued up so far. count can be
2918 * 0, which means to process everything in the tree at the start
2919 * of the run (but not newly added entries), or it can be some target
2920 * number you'd like to process.
2921 *
2922 * Returns 0 on success or if called with an aborted transaction
2923 * Returns <0 on error and aborts the transaction
2924 */
2925 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2926 struct btrfs_fs_info *fs_info, unsigned long count)
2927 {
2928 struct rb_node *node;
2929 struct btrfs_delayed_ref_root *delayed_refs;
2930 struct btrfs_delayed_ref_head *head;
2931 int ret;
2932 int run_all = count == (unsigned long)-1;
2933 bool can_flush_pending_bgs = trans->can_flush_pending_bgs;
2934
2935 /* We'll clean this up in btrfs_cleanup_transaction */
2936 if (trans->aborted)
2937 return 0;
2938
2939 if (test_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags))
2940 return 0;
2941
2942 delayed_refs = &trans->transaction->delayed_refs;
2943 if (count == 0)
2944 count = atomic_read(&delayed_refs->num_entries) * 2;
2945
2946 again:
2947 #ifdef SCRAMBLE_DELAYED_REFS
2948 delayed_refs->run_delayed_start = find_middle(&delayed_refs->root);
2949 #endif
2950 trans->can_flush_pending_bgs = false;
2951 ret = __btrfs_run_delayed_refs(trans, fs_info, count);
2952 if (ret < 0) {
2953 btrfs_abort_transaction(trans, ret);
2954 return ret;
2955 }
2956
2957 if (run_all) {
2958 if (!list_empty(&trans->new_bgs))
2959 btrfs_create_pending_block_groups(trans, fs_info);
2960
2961 spin_lock(&delayed_refs->lock);
2962 node = rb_first(&delayed_refs->href_root);
2963 if (!node) {
2964 spin_unlock(&delayed_refs->lock);
2965 goto out;
2966 }
2967
2968 while (node) {
2969 head = rb_entry(node, struct btrfs_delayed_ref_head,
2970 href_node);
2971 if (btrfs_delayed_ref_is_head(&head->node)) {
2972 struct btrfs_delayed_ref_node *ref;
2973
2974 ref = &head->node;
2975 atomic_inc(&ref->refs);
2976
2977 spin_unlock(&delayed_refs->lock);
2978 /*
2979 * Mutex was contended, block until it's
2980 * released and try again
2981 */
2982 mutex_lock(&head->mutex);
2983 mutex_unlock(&head->mutex);
2984
2985 btrfs_put_delayed_ref(ref);
2986 cond_resched();
2987 goto again;
2988 } else {
2989 WARN_ON(1);
2990 }
2991 node = rb_next(node);
2992 }
2993 spin_unlock(&delayed_refs->lock);
2994 cond_resched();
2995 goto again;
2996 }
2997 out:
2998 assert_qgroups_uptodate(trans);
2999 trans->can_flush_pending_bgs = can_flush_pending_bgs;
3000 return 0;
3001 }
3002
3003 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
3004 struct btrfs_fs_info *fs_info,
3005 u64 bytenr, u64 num_bytes, u64 flags,
3006 int level, int is_data)
3007 {
3008 struct btrfs_delayed_extent_op *extent_op;
3009 int ret;
3010
3011 extent_op = btrfs_alloc_delayed_extent_op();
3012 if (!extent_op)
3013 return -ENOMEM;
3014
3015 extent_op->flags_to_set = flags;
3016 extent_op->update_flags = true;
3017 extent_op->update_key = false;
3018 extent_op->is_data = is_data ? true : false;
3019 extent_op->level = level;
3020
3021 ret = btrfs_add_delayed_extent_op(fs_info, trans, bytenr,
3022 num_bytes, extent_op);
3023 if (ret)
3024 btrfs_free_delayed_extent_op(extent_op);
3025 return ret;
3026 }
3027
3028 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
3029 struct btrfs_root *root,
3030 struct btrfs_path *path,
3031 u64 objectid, u64 offset, u64 bytenr)
3032 {
3033 struct btrfs_delayed_ref_head *head;
3034 struct btrfs_delayed_ref_node *ref;
3035 struct btrfs_delayed_data_ref *data_ref;
3036 struct btrfs_delayed_ref_root *delayed_refs;
3037 int ret = 0;
3038
3039 delayed_refs = &trans->transaction->delayed_refs;
3040 spin_lock(&delayed_refs->lock);
3041 head = btrfs_find_delayed_ref_head(trans, bytenr);
3042 if (!head) {
3043 spin_unlock(&delayed_refs->lock);
3044 return 0;
3045 }
3046
3047 if (!mutex_trylock(&head->mutex)) {
3048 atomic_inc(&head->node.refs);
3049 spin_unlock(&delayed_refs->lock);
3050
3051 btrfs_release_path(path);
3052
3053 /*
3054 * Mutex was contended, block until it's released and let
3055 * caller try again
3056 */
3057 mutex_lock(&head->mutex);
3058 mutex_unlock(&head->mutex);
3059 btrfs_put_delayed_ref(&head->node);
3060 return -EAGAIN;
3061 }
3062 spin_unlock(&delayed_refs->lock);
3063
3064 spin_lock(&head->lock);
3065 list_for_each_entry(ref, &head->ref_list, list) {
3066 /* If it's a shared ref we know a cross reference exists */
3067 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) {
3068 ret = 1;
3069 break;
3070 }
3071
3072 data_ref = btrfs_delayed_node_to_data_ref(ref);
3073
3074 /*
3075 * If our ref doesn't match the one we're currently looking at
3076 * then we have a cross reference.
3077 */
3078 if (data_ref->root != root->root_key.objectid ||
3079 data_ref->objectid != objectid ||
3080 data_ref->offset != offset) {
3081 ret = 1;
3082 break;
3083 }
3084 }
3085 spin_unlock(&head->lock);
3086 mutex_unlock(&head->mutex);
3087 return ret;
3088 }
3089
3090 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
3091 struct btrfs_root *root,
3092 struct btrfs_path *path,
3093 u64 objectid, u64 offset, u64 bytenr)
3094 {
3095 struct btrfs_fs_info *fs_info = root->fs_info;
3096 struct btrfs_root *extent_root = fs_info->extent_root;
3097 struct extent_buffer *leaf;
3098 struct btrfs_extent_data_ref *ref;
3099 struct btrfs_extent_inline_ref *iref;
3100 struct btrfs_extent_item *ei;
3101 struct btrfs_key key;
3102 u32 item_size;
3103 int ret;
3104
3105 key.objectid = bytenr;
3106 key.offset = (u64)-1;
3107 key.type = BTRFS_EXTENT_ITEM_KEY;
3108
3109 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
3110 if (ret < 0)
3111 goto out;
3112 BUG_ON(ret == 0); /* Corruption */
3113
3114 ret = -ENOENT;
3115 if (path->slots[0] == 0)
3116 goto out;
3117
3118 path->slots[0]--;
3119 leaf = path->nodes[0];
3120 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3121
3122 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
3123 goto out;
3124
3125 ret = 1;
3126 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
3127 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3128 if (item_size < sizeof(*ei)) {
3129 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3130 goto out;
3131 }
3132 #endif
3133 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
3134
3135 if (item_size != sizeof(*ei) +
3136 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
3137 goto out;
3138
3139 if (btrfs_extent_generation(leaf, ei) <=
3140 btrfs_root_last_snapshot(&root->root_item))
3141 goto out;
3142
3143 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
3144 if (btrfs_extent_inline_ref_type(leaf, iref) !=
3145 BTRFS_EXTENT_DATA_REF_KEY)
3146 goto out;
3147
3148 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
3149 if (btrfs_extent_refs(leaf, ei) !=
3150 btrfs_extent_data_ref_count(leaf, ref) ||
3151 btrfs_extent_data_ref_root(leaf, ref) !=
3152 root->root_key.objectid ||
3153 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
3154 btrfs_extent_data_ref_offset(leaf, ref) != offset)
3155 goto out;
3156
3157 ret = 0;
3158 out:
3159 return ret;
3160 }
3161
3162 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
3163 struct btrfs_root *root,
3164 u64 objectid, u64 offset, u64 bytenr)
3165 {
3166 struct btrfs_path *path;
3167 int ret;
3168 int ret2;
3169
3170 path = btrfs_alloc_path();
3171 if (!path)
3172 return -ENOENT;
3173
3174 do {
3175 ret = check_committed_ref(trans, root, path, objectid,
3176 offset, bytenr);
3177 if (ret && ret != -ENOENT)
3178 goto out;
3179
3180 ret2 = check_delayed_ref(trans, root, path, objectid,
3181 offset, bytenr);
3182 } while (ret2 == -EAGAIN);
3183
3184 if (ret2 && ret2 != -ENOENT) {
3185 ret = ret2;
3186 goto out;
3187 }
3188
3189 if (ret != -ENOENT || ret2 != -ENOENT)
3190 ret = 0;
3191 out:
3192 btrfs_free_path(path);
3193 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
3194 WARN_ON(ret > 0);
3195 return ret;
3196 }
3197
3198 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
3199 struct btrfs_root *root,
3200 struct extent_buffer *buf,
3201 int full_backref, int inc)
3202 {
3203 struct btrfs_fs_info *fs_info = root->fs_info;
3204 u64 bytenr;
3205 u64 num_bytes;
3206 u64 parent;
3207 u64 ref_root;
3208 u32 nritems;
3209 struct btrfs_key key;
3210 struct btrfs_file_extent_item *fi;
3211 int i;
3212 int level;
3213 int ret = 0;
3214 int (*process_func)(struct btrfs_trans_handle *,
3215 struct btrfs_fs_info *,
3216 u64, u64, u64, u64, u64, u64);
3217
3218
3219 if (btrfs_is_testing(fs_info))
3220 return 0;
3221
3222 ref_root = btrfs_header_owner(buf);
3223 nritems = btrfs_header_nritems(buf);
3224 level = btrfs_header_level(buf);
3225
3226 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state) && level == 0)
3227 return 0;
3228
3229 if (inc)
3230 process_func = btrfs_inc_extent_ref;
3231 else
3232 process_func = btrfs_free_extent;
3233
3234 if (full_backref)
3235 parent = buf->start;
3236 else
3237 parent = 0;
3238
3239 for (i = 0; i < nritems; i++) {
3240 if (level == 0) {
3241 btrfs_item_key_to_cpu(buf, &key, i);
3242 if (key.type != BTRFS_EXTENT_DATA_KEY)
3243 continue;
3244 fi = btrfs_item_ptr(buf, i,
3245 struct btrfs_file_extent_item);
3246 if (btrfs_file_extent_type(buf, fi) ==
3247 BTRFS_FILE_EXTENT_INLINE)
3248 continue;
3249 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
3250 if (bytenr == 0)
3251 continue;
3252
3253 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
3254 key.offset -= btrfs_file_extent_offset(buf, fi);
3255 ret = process_func(trans, fs_info, bytenr, num_bytes,
3256 parent, ref_root, key.objectid,
3257 key.offset);
3258 if (ret)
3259 goto fail;
3260 } else {
3261 bytenr = btrfs_node_blockptr(buf, i);
3262 num_bytes = fs_info->nodesize;
3263 ret = process_func(trans, fs_info, bytenr, num_bytes,
3264 parent, ref_root, level - 1, 0);
3265 if (ret)
3266 goto fail;
3267 }
3268 }
3269 return 0;
3270 fail:
3271 return ret;
3272 }
3273
3274 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3275 struct extent_buffer *buf, int full_backref)
3276 {
3277 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
3278 }
3279
3280 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3281 struct extent_buffer *buf, int full_backref)
3282 {
3283 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
3284 }
3285
3286 static int write_one_cache_group(struct btrfs_trans_handle *trans,
3287 struct btrfs_fs_info *fs_info,
3288 struct btrfs_path *path,
3289 struct btrfs_block_group_cache *cache)
3290 {
3291 int ret;
3292 struct btrfs_root *extent_root = fs_info->extent_root;
3293 unsigned long bi;
3294 struct extent_buffer *leaf;
3295
3296 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
3297 if (ret) {
3298 if (ret > 0)
3299 ret = -ENOENT;
3300 goto fail;
3301 }
3302
3303 leaf = path->nodes[0];
3304 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
3305 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
3306 btrfs_mark_buffer_dirty(leaf);
3307 fail:
3308 btrfs_release_path(path);
3309 return ret;
3310
3311 }
3312
3313 static struct btrfs_block_group_cache *
3314 next_block_group(struct btrfs_fs_info *fs_info,
3315 struct btrfs_block_group_cache *cache)
3316 {
3317 struct rb_node *node;
3318
3319 spin_lock(&fs_info->block_group_cache_lock);
3320
3321 /* If our block group was removed, we need a full search. */
3322 if (RB_EMPTY_NODE(&cache->cache_node)) {
3323 const u64 next_bytenr = cache->key.objectid + cache->key.offset;
3324
3325 spin_unlock(&fs_info->block_group_cache_lock);
3326 btrfs_put_block_group(cache);
3327 cache = btrfs_lookup_first_block_group(fs_info, next_bytenr); return cache;
3328 }
3329 node = rb_next(&cache->cache_node);
3330 btrfs_put_block_group(cache);
3331 if (node) {
3332 cache = rb_entry(node, struct btrfs_block_group_cache,
3333 cache_node);
3334 btrfs_get_block_group(cache);
3335 } else
3336 cache = NULL;
3337 spin_unlock(&fs_info->block_group_cache_lock);
3338 return cache;
3339 }
3340
3341 static int cache_save_setup(struct btrfs_block_group_cache *block_group,
3342 struct btrfs_trans_handle *trans,
3343 struct btrfs_path *path)
3344 {
3345 struct btrfs_fs_info *fs_info = block_group->fs_info;
3346 struct btrfs_root *root = fs_info->tree_root;
3347 struct inode *inode = NULL;
3348 u64 alloc_hint = 0;
3349 int dcs = BTRFS_DC_ERROR;
3350 u64 num_pages = 0;
3351 int retries = 0;
3352 int ret = 0;
3353
3354 /*
3355 * If this block group is smaller than 100 megs don't bother caching the
3356 * block group.
3357 */
3358 if (block_group->key.offset < (100 * SZ_1M)) {
3359 spin_lock(&block_group->lock);
3360 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
3361 spin_unlock(&block_group->lock);
3362 return 0;
3363 }
3364
3365 if (trans->aborted)
3366 return 0;
3367 again:
3368 inode = lookup_free_space_inode(root, block_group, path);
3369 if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
3370 ret = PTR_ERR(inode);
3371 btrfs_release_path(path);
3372 goto out;
3373 }
3374
3375 if (IS_ERR(inode)) {
3376 BUG_ON(retries);
3377 retries++;
3378
3379 if (block_group->ro)
3380 goto out_free;
3381
3382 ret = create_free_space_inode(root, trans, block_group, path);
3383 if (ret)
3384 goto out_free;
3385 goto again;
3386 }
3387
3388 /* We've already setup this transaction, go ahead and exit */
3389 if (block_group->cache_generation == trans->transid &&
3390 i_size_read(inode)) {
3391 dcs = BTRFS_DC_SETUP;
3392 goto out_put;
3393 }
3394
3395 /*
3396 * We want to set the generation to 0, that way if anything goes wrong
3397 * from here on out we know not to trust this cache when we load up next
3398 * time.
3399 */
3400 BTRFS_I(inode)->generation = 0;
3401 ret = btrfs_update_inode(trans, root, inode);
3402 if (ret) {
3403 /*
3404 * So theoretically we could recover from this, simply set the
3405 * super cache generation to 0 so we know to invalidate the
3406 * cache, but then we'd have to keep track of the block groups
3407 * that fail this way so we know we _have_ to reset this cache
3408 * before the next commit or risk reading stale cache. So to
3409 * limit our exposure to horrible edge cases lets just abort the
3410 * transaction, this only happens in really bad situations
3411 * anyway.
3412 */
3413 btrfs_abort_transaction(trans, ret);
3414 goto out_put;
3415 }
3416 WARN_ON(ret);
3417
3418 if (i_size_read(inode) > 0) {
3419 ret = btrfs_check_trunc_cache_free_space(fs_info,
3420 &fs_info->global_block_rsv);
3421 if (ret)
3422 goto out_put;
3423
3424 ret = btrfs_truncate_free_space_cache(root, trans, NULL, inode);
3425 if (ret)
3426 goto out_put;
3427 }
3428
3429 spin_lock(&block_group->lock);
3430 if (block_group->cached != BTRFS_CACHE_FINISHED ||
3431 !btrfs_test_opt(fs_info, SPACE_CACHE)) {
3432 /*
3433 * don't bother trying to write stuff out _if_
3434 * a) we're not cached,
3435 * b) we're with nospace_cache mount option.
3436 */
3437 dcs = BTRFS_DC_WRITTEN;
3438 spin_unlock(&block_group->lock);
3439 goto out_put;
3440 }
3441 spin_unlock(&block_group->lock);
3442
3443 /*
3444 * We hit an ENOSPC when setting up the cache in this transaction, just
3445 * skip doing the setup, we've already cleared the cache so we're safe.
3446 */
3447 if (test_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags)) {
3448 ret = -ENOSPC;
3449 goto out_put;
3450 }
3451
3452 /*
3453 * Try to preallocate enough space based on how big the block group is.
3454 * Keep in mind this has to include any pinned space which could end up
3455 * taking up quite a bit since it's not folded into the other space
3456 * cache.
3457 */
3458 num_pages = div_u64(block_group->key.offset, SZ_256M);
3459 if (!num_pages)
3460 num_pages = 1;
3461
3462 num_pages *= 16;
3463 num_pages *= PAGE_SIZE;
3464
3465 ret = btrfs_check_data_free_space(inode, 0, num_pages);
3466 if (ret)
3467 goto out_put;
3468
3469 ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
3470 num_pages, num_pages,
3471 &alloc_hint);
3472 /*
3473 * Our cache requires contiguous chunks so that we don't modify a bunch
3474 * of metadata or split extents when writing the cache out, which means
3475 * we can enospc if we are heavily fragmented in addition to just normal
3476 * out of space conditions. So if we hit this just skip setting up any
3477 * other block groups for this transaction, maybe we'll unpin enough
3478 * space the next time around.
3479 */
3480 if (!ret)
3481 dcs = BTRFS_DC_SETUP;
3482 else if (ret == -ENOSPC)
3483 set_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags);
3484
3485 out_put:
3486 iput(inode);
3487 out_free:
3488 btrfs_release_path(path);
3489 out:
3490 spin_lock(&block_group->lock);
3491 if (!ret && dcs == BTRFS_DC_SETUP)
3492 block_group->cache_generation = trans->transid;
3493 block_group->disk_cache_state = dcs;
3494 spin_unlock(&block_group->lock);
3495
3496 return ret;
3497 }
3498
3499 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
3500 struct btrfs_fs_info *fs_info)
3501 {
3502 struct btrfs_block_group_cache *cache, *tmp;
3503 struct btrfs_transaction *cur_trans = trans->transaction;
3504 struct btrfs_path *path;
3505
3506 if (list_empty(&cur_trans->dirty_bgs) ||
3507 !btrfs_test_opt(fs_info, SPACE_CACHE))
3508 return 0;
3509
3510 path = btrfs_alloc_path();
3511 if (!path)
3512 return -ENOMEM;
3513
3514 /* Could add new block groups, use _safe just in case */
3515 list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
3516 dirty_list) {
3517 if (cache->disk_cache_state == BTRFS_DC_CLEAR)
3518 cache_save_setup(cache, trans, path);
3519 }
3520
3521 btrfs_free_path(path);
3522 return 0;
3523 }
3524
3525 /*
3526 * transaction commit does final block group cache writeback during a
3527 * critical section where nothing is allowed to change the FS. This is
3528 * required in order for the cache to actually match the block group,
3529 * but can introduce a lot of latency into the commit.
3530 *
3531 * So, btrfs_start_dirty_block_groups is here to kick off block group
3532 * cache IO. There's a chance we'll have to redo some of it if the
3533 * block group changes again during the commit, but it greatly reduces
3534 * the commit latency by getting rid of the easy block groups while
3535 * we're still allowing others to join the commit.
3536 */
3537 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans,
3538 struct btrfs_fs_info *fs_info)
3539 {
3540 struct btrfs_block_group_cache *cache;
3541 struct btrfs_transaction *cur_trans = trans->transaction;
3542 int ret = 0;
3543 int should_put;
3544 struct btrfs_path *path = NULL;
3545 LIST_HEAD(dirty);
3546 struct list_head *io = &cur_trans->io_bgs;
3547 int num_started = 0;
3548 int loops = 0;
3549
3550 spin_lock(&cur_trans->dirty_bgs_lock);
3551 if (list_empty(&cur_trans->dirty_bgs)) {
3552 spin_unlock(&cur_trans->dirty_bgs_lock);
3553 return 0;
3554 }
3555 list_splice_init(&cur_trans->dirty_bgs, &dirty);
3556 spin_unlock(&cur_trans->dirty_bgs_lock);
3557
3558 again:
3559 /*
3560 * make sure all the block groups on our dirty list actually
3561 * exist
3562 */
3563 btrfs_create_pending_block_groups(trans, fs_info);
3564
3565 if (!path) {
3566 path = btrfs_alloc_path();
3567 if (!path)
3568 return -ENOMEM;
3569 }
3570
3571 /*
3572 * cache_write_mutex is here only to save us from balance or automatic
3573 * removal of empty block groups deleting this block group while we are
3574 * writing out the cache
3575 */
3576 mutex_lock(&trans->transaction->cache_write_mutex);
3577 while (!list_empty(&dirty)) {
3578 cache = list_first_entry(&dirty,
3579 struct btrfs_block_group_cache,
3580 dirty_list);
3581 /*
3582 * this can happen if something re-dirties a block
3583 * group that is already under IO. Just wait for it to
3584 * finish and then do it all again
3585 */
3586 if (!list_empty(&cache->io_list)) {
3587 list_del_init(&cache->io_list);
3588 btrfs_wait_cache_io(trans, cache, path);
3589 btrfs_put_block_group(cache);
3590 }
3591
3592
3593 /*
3594 * btrfs_wait_cache_io uses the cache->dirty_list to decide
3595 * if it should update the cache_state. Don't delete
3596 * until after we wait.
3597 *
3598 * Since we're not running in the commit critical section
3599 * we need the dirty_bgs_lock to protect from update_block_group
3600 */
3601 spin_lock(&cur_trans->dirty_bgs_lock);
3602 list_del_init(&cache->dirty_list);
3603 spin_unlock(&cur_trans->dirty_bgs_lock);
3604
3605 should_put = 1;
3606
3607 cache_save_setup(cache, trans, path);
3608
3609 if (cache->disk_cache_state == BTRFS_DC_SETUP) {
3610 cache->io_ctl.inode = NULL;
3611 ret = btrfs_write_out_cache(fs_info, trans,
3612 cache, path);
3613 if (ret == 0 && cache->io_ctl.inode) {
3614 num_started++;
3615 should_put = 0;
3616
3617 /*
3618 * the cache_write_mutex is protecting
3619 * the io_list
3620 */
3621 list_add_tail(&cache->io_list, io);
3622 } else {
3623 /*
3624 * if we failed to write the cache, the
3625 * generation will be bad and life goes on
3626 */
3627 ret = 0;
3628 }
3629 }
3630 if (!ret) {
3631 ret = write_one_cache_group(trans, fs_info,
3632 path, cache);
3633 /*
3634 * Our block group might still be attached to the list
3635 * of new block groups in the transaction handle of some
3636 * other task (struct btrfs_trans_handle->new_bgs). This
3637 * means its block group item isn't yet in the extent
3638 * tree. If this happens ignore the error, as we will
3639 * try again later in the critical section of the
3640 * transaction commit.
3641 */
3642 if (ret == -ENOENT) {
3643 ret = 0;
3644 spin_lock(&cur_trans->dirty_bgs_lock);
3645 if (list_empty(&cache->dirty_list)) {
3646 list_add_tail(&cache->dirty_list,
3647 &cur_trans->dirty_bgs);
3648 btrfs_get_block_group(cache);
3649 }
3650 spin_unlock(&cur_trans->dirty_bgs_lock);
3651 } else if (ret) {
3652 btrfs_abort_transaction(trans, ret);
3653 }
3654 }
3655
3656 /* if its not on the io list, we need to put the block group */
3657 if (should_put)
3658 btrfs_put_block_group(cache);
3659
3660 if (ret)
3661 break;
3662
3663 /*
3664 * Avoid blocking other tasks for too long. It might even save
3665 * us from writing caches for block groups that are going to be
3666 * removed.
3667 */
3668 mutex_unlock(&trans->transaction->cache_write_mutex);
3669 mutex_lock(&trans->transaction->cache_write_mutex);
3670 }
3671 mutex_unlock(&trans->transaction->cache_write_mutex);
3672
3673 /*
3674 * go through delayed refs for all the stuff we've just kicked off
3675 * and then loop back (just once)
3676 */
3677 ret = btrfs_run_delayed_refs(trans, fs_info, 0);
3678 if (!ret && loops == 0) {
3679 loops++;
3680 spin_lock(&cur_trans->dirty_bgs_lock);
3681 list_splice_init(&cur_trans->dirty_bgs, &dirty);
3682 /*
3683 * dirty_bgs_lock protects us from concurrent block group
3684 * deletes too (not just cache_write_mutex).
3685 */
3686 if (!list_empty(&dirty)) {
3687 spin_unlock(&cur_trans->dirty_bgs_lock);
3688 goto again;
3689 }
3690 spin_unlock(&cur_trans->dirty_bgs_lock);
3691 } else if (ret < 0) {
3692 btrfs_cleanup_dirty_bgs(cur_trans, fs_info);
3693 }
3694
3695 btrfs_free_path(path);
3696 return ret;
3697 }
3698
3699 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
3700 struct btrfs_fs_info *fs_info)
3701 {
3702 struct btrfs_block_group_cache *cache;
3703 struct btrfs_transaction *cur_trans = trans->transaction;
3704 int ret = 0;
3705 int should_put;
3706 struct btrfs_path *path;
3707 struct list_head *io = &cur_trans->io_bgs;
3708 int num_started = 0;
3709
3710 path = btrfs_alloc_path();
3711 if (!path)
3712 return -ENOMEM;
3713
3714 /*
3715 * Even though we are in the critical section of the transaction commit,
3716 * we can still have concurrent tasks adding elements to this
3717 * transaction's list of dirty block groups. These tasks correspond to
3718 * endio free space workers started when writeback finishes for a
3719 * space cache, which run inode.c:btrfs_finish_ordered_io(), and can
3720 * allocate new block groups as a result of COWing nodes of the root
3721 * tree when updating the free space inode. The writeback for the space
3722 * caches is triggered by an earlier call to
3723 * btrfs_start_dirty_block_groups() and iterations of the following
3724 * loop.
3725 * Also we want to do the cache_save_setup first and then run the
3726 * delayed refs to make sure we have the best chance at doing this all
3727 * in one shot.
3728 */
3729 spin_lock(&cur_trans->dirty_bgs_lock);
3730 while (!list_empty(&cur_trans->dirty_bgs)) {
3731 cache = list_first_entry(&cur_trans->dirty_bgs,
3732 struct btrfs_block_group_cache,
3733 dirty_list);
3734
3735 /*
3736 * this can happen if cache_save_setup re-dirties a block
3737 * group that is already under IO. Just wait for it to
3738 * finish and then do it all again
3739 */
3740 if (!list_empty(&cache->io_list)) {
3741 spin_unlock(&cur_trans->dirty_bgs_lock);
3742 list_del_init(&cache->io_list);
3743 btrfs_wait_cache_io(trans, cache, path);
3744 btrfs_put_block_group(cache);
3745 spin_lock(&cur_trans->dirty_bgs_lock);
3746 }
3747
3748 /*
3749 * don't remove from the dirty list until after we've waited
3750 * on any pending IO
3751 */
3752 list_del_init(&cache->dirty_list);
3753 spin_unlock(&cur_trans->dirty_bgs_lock);
3754 should_put = 1;
3755
3756 cache_save_setup(cache, trans, path);
3757
3758 if (!ret)
3759 ret = btrfs_run_delayed_refs(trans, fs_info,
3760 (unsigned long) -1);
3761
3762 if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
3763 cache->io_ctl.inode = NULL;
3764 ret = btrfs_write_out_cache(fs_info, trans,
3765 cache, path);
3766 if (ret == 0 && cache->io_ctl.inode) {
3767 num_started++;
3768 should_put = 0;
3769 list_add_tail(&cache->io_list, io);
3770 } else {
3771 /*
3772 * if we failed to write the cache, the
3773 * generation will be bad and life goes on
3774 */
3775 ret = 0;
3776 }
3777 }
3778 if (!ret) {
3779 ret = write_one_cache_group(trans, fs_info,
3780 path, cache);
3781 /*
3782 * One of the free space endio workers might have
3783 * created a new block group while updating a free space
3784 * cache's inode (at inode.c:btrfs_finish_ordered_io())
3785 * and hasn't released its transaction handle yet, in
3786 * which case the new block group is still attached to
3787 * its transaction handle and its creation has not
3788 * finished yet (no block group item in the extent tree
3789 * yet, etc). If this is the case, wait for all free
3790 * space endio workers to finish and retry. This is a
3791 * a very rare case so no need for a more efficient and
3792 * complex approach.
3793 */
3794 if (ret == -ENOENT) {
3795 wait_event(cur_trans->writer_wait,
3796 atomic_read(&cur_trans->num_writers) == 1);
3797 ret = write_one_cache_group(trans, fs_info,
3798 path, cache);
3799 }
3800 if (ret)
3801 btrfs_abort_transaction(trans, ret);
3802 }
3803
3804 /* if its not on the io list, we need to put the block group */
3805 if (should_put)
3806 btrfs_put_block_group(cache);
3807 spin_lock(&cur_trans->dirty_bgs_lock);
3808 }
3809 spin_unlock(&cur_trans->dirty_bgs_lock);
3810
3811 while (!list_empty(io)) {
3812 cache = list_first_entry(io, struct btrfs_block_group_cache,
3813 io_list);
3814 list_del_init(&cache->io_list);
3815 btrfs_wait_cache_io(trans, cache, path);
3816 btrfs_put_block_group(cache);
3817 }
3818
3819 btrfs_free_path(path);
3820 return ret;
3821 }
3822
3823 int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
3824 {
3825 struct btrfs_block_group_cache *block_group;
3826 int readonly = 0;
3827
3828 block_group = btrfs_lookup_block_group(fs_info, bytenr);
3829 if (!block_group || block_group->ro)
3830 readonly = 1;
3831 if (block_group)
3832 btrfs_put_block_group(block_group);
3833 return readonly;
3834 }
3835
3836 bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
3837 {
3838 struct btrfs_block_group_cache *bg;
3839 bool ret = true;
3840
3841 bg = btrfs_lookup_block_group(fs_info, bytenr);
3842 if (!bg)
3843 return false;
3844
3845 spin_lock(&bg->lock);
3846 if (bg->ro)
3847 ret = false;
3848 else
3849 atomic_inc(&bg->nocow_writers);
3850 spin_unlock(&bg->lock);
3851
3852 /* no put on block group, done by btrfs_dec_nocow_writers */
3853 if (!ret)
3854 btrfs_put_block_group(bg);
3855
3856 return ret;
3857
3858 }
3859
3860 void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr)
3861 {
3862 struct btrfs_block_group_cache *bg;
3863
3864 bg = btrfs_lookup_block_group(fs_info, bytenr);
3865 ASSERT(bg);
3866 if (atomic_dec_and_test(&bg->nocow_writers))
3867 wake_up_atomic_t(&bg->nocow_writers);
3868 /*
3869 * Once for our lookup and once for the lookup done by a previous call
3870 * to btrfs_inc_nocow_writers()
3871 */
3872 btrfs_put_block_group(bg);
3873 btrfs_put_block_group(bg);
3874 }
3875
3876 static int btrfs_wait_nocow_writers_atomic_t(atomic_t *a)
3877 {
3878 schedule();
3879 return 0;
3880 }
3881
3882 void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg)
3883 {
3884 wait_on_atomic_t(&bg->nocow_writers,
3885 btrfs_wait_nocow_writers_atomic_t,
3886 TASK_UNINTERRUPTIBLE);
3887 }
3888
3889 static const char *alloc_name(u64 flags)
3890 {
3891 switch (flags) {
3892 case BTRFS_BLOCK_GROUP_METADATA|BTRFS_BLOCK_GROUP_DATA:
3893 return "mixed";
3894 case BTRFS_BLOCK_GROUP_METADATA:
3895 return "metadata";
3896 case BTRFS_BLOCK_GROUP_DATA:
3897 return "data";
3898 case BTRFS_BLOCK_GROUP_SYSTEM:
3899 return "system";
3900 default:
3901 WARN_ON(1);
3902 return "invalid-combination";
3903 };
3904 }
3905
3906 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
3907 u64 total_bytes, u64 bytes_used,
3908 u64 bytes_readonly,
3909 struct btrfs_space_info **space_info)
3910 {
3911 struct btrfs_space_info *found;
3912 int i;
3913 int factor;
3914 int ret;
3915
3916 if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3917 BTRFS_BLOCK_GROUP_RAID10))
3918 factor = 2;
3919 else
3920 factor = 1;
3921
3922 found = __find_space_info(info, flags);
3923 if (found) {
3924 spin_lock(&found->lock);
3925 found->total_bytes += total_bytes;
3926 found->disk_total += total_bytes * factor;
3927 found->bytes_used += bytes_used;
3928 found->disk_used += bytes_used * factor;
3929 found->bytes_readonly += bytes_readonly;
3930 if (total_bytes > 0)
3931 found->full = 0;
3932 space_info_add_new_bytes(info, found, total_bytes -
3933 bytes_used - bytes_readonly);
3934 spin_unlock(&found->lock);
3935 *space_info = found;
3936 return 0;
3937 }
3938 found = kzalloc(sizeof(*found), GFP_NOFS);
3939 if (!found)
3940 return -ENOMEM;
3941
3942 ret = percpu_counter_init(&found->total_bytes_pinned, 0, GFP_KERNEL);
3943 if (ret) {
3944 kfree(found);
3945 return ret;
3946 }
3947
3948 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
3949 INIT_LIST_HEAD(&found->block_groups[i]);
3950 init_rwsem(&found->groups_sem);
3951 spin_lock_init(&found->lock);
3952 found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
3953 found->total_bytes = total_bytes;
3954 found->disk_total = total_bytes * factor;
3955 found->bytes_used = bytes_used;
3956 found->disk_used = bytes_used * factor;
3957 found->bytes_pinned = 0;
3958 found->bytes_reserved = 0;
3959 found->bytes_readonly = bytes_readonly;
3960 found->bytes_may_use = 0;
3961 found->full = 0;
3962 found->max_extent_size = 0;
3963 found->force_alloc = CHUNK_ALLOC_NO_FORCE;
3964 found->chunk_alloc = 0;
3965 found->flush = 0;
3966 init_waitqueue_head(&found->wait);
3967 INIT_LIST_HEAD(&found->ro_bgs);
3968 INIT_LIST_HEAD(&found->tickets);
3969 INIT_LIST_HEAD(&found->priority_tickets);
3970
3971 ret = kobject_init_and_add(&found->kobj, &space_info_ktype,
3972 info->space_info_kobj, "%s",
3973 alloc_name(found->flags));
3974 if (ret) {
3975 kfree(found);
3976 return ret;
3977 }
3978
3979 *space_info = found;
3980 list_add_rcu(&found->list, &info->space_info);
3981 if (flags & BTRFS_BLOCK_GROUP_DATA)
3982 info->data_sinfo = found;
3983
3984 return ret;
3985 }
3986
3987 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
3988 {
3989 u64 extra_flags = chunk_to_extended(flags) &
3990 BTRFS_EXTENDED_PROFILE_MASK;
3991
3992 write_seqlock(&fs_info->profiles_lock);
3993 if (flags & BTRFS_BLOCK_GROUP_DATA)
3994 fs_info->avail_data_alloc_bits |= extra_flags;
3995 if (flags & BTRFS_BLOCK_GROUP_METADATA)
3996 fs_info->avail_metadata_alloc_bits |= extra_flags;
3997 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
3998 fs_info->avail_system_alloc_bits |= extra_flags;
3999 write_sequnlock(&fs_info->profiles_lock);
4000 }
4001
4002 /*
4003 * returns target flags in extended format or 0 if restripe for this
4004 * chunk_type is not in progress
4005 *
4006 * should be called with either volume_mutex or balance_lock held
4007 */
4008 static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
4009 {
4010 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4011 u64 target = 0;
4012
4013 if (!bctl)
4014 return 0;
4015
4016 if (flags & BTRFS_BLOCK_GROUP_DATA &&
4017 bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
4018 target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
4019 } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
4020 bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
4021 target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
4022 } else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
4023 bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
4024 target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
4025 }
4026
4027 return target;
4028 }
4029
4030 /*
4031 * @flags: available profiles in extended format (see ctree.h)
4032 *
4033 * Returns reduced profile in chunk format. If profile changing is in
4034 * progress (either running or paused) picks the target profile (if it's
4035 * already available), otherwise falls back to plain reducing.
4036 */
4037 static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags)
4038 {
4039 u64 num_devices = fs_info->fs_devices->rw_devices;
4040 u64 target;
4041 u64 raid_type;
4042 u64 allowed = 0;
4043
4044 /*
4045 * see if restripe for this chunk_type is in progress, if so
4046 * try to reduce to the target profile
4047 */
4048 spin_lock(&fs_info->balance_lock);
4049 target = get_restripe_target(fs_info, flags);
4050 if (target) {
4051 /* pick target profile only if it's already available */
4052 if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
4053 spin_unlock(&fs_info->balance_lock);
4054 return extended_to_chunk(target);
4055 }
4056 }
4057 spin_unlock(&fs_info->balance_lock);
4058
4059 /* First, mask out the RAID levels which aren't possible */
4060 for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
4061 if (num_devices >= btrfs_raid_array[raid_type].devs_min)
4062 allowed |= btrfs_raid_group[raid_type];
4063 }
4064 allowed &= flags;
4065
4066 if (allowed & BTRFS_BLOCK_GROUP_RAID6)
4067 allowed = BTRFS_BLOCK_GROUP_RAID6;
4068 else if (allowed & BTRFS_BLOCK_GROUP_RAID5)
4069 allowed = BTRFS_BLOCK_GROUP_RAID5;
4070 else if (allowed & BTRFS_BLOCK_GROUP_RAID10)
4071 allowed = BTRFS_BLOCK_GROUP_RAID10;
4072 else if (allowed & BTRFS_BLOCK_GROUP_RAID1)
4073 allowed = BTRFS_BLOCK_GROUP_RAID1;
4074 else if (allowed & BTRFS_BLOCK_GROUP_RAID0)
4075 allowed = BTRFS_BLOCK_GROUP_RAID0;
4076
4077 flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
4078
4079 return extended_to_chunk(flags | allowed);
4080 }
4081
4082 static u64 get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags)
4083 {
4084 unsigned seq;
4085 u64 flags;
4086
4087 do {
4088 flags = orig_flags;
4089 seq = read_seqbegin(&fs_info->profiles_lock);
4090
4091 if (flags & BTRFS_BLOCK_GROUP_DATA)
4092 flags |= fs_info->avail_data_alloc_bits;
4093 else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
4094 flags |= fs_info->avail_system_alloc_bits;
4095 else if (flags & BTRFS_BLOCK_GROUP_METADATA)
4096 flags |= fs_info->avail_metadata_alloc_bits;
4097 } while (read_seqretry(&fs_info->profiles_lock, seq));
4098
4099 return btrfs_reduce_alloc_profile(fs_info, flags);
4100 }
4101
4102 u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
4103 {
4104 struct btrfs_fs_info *fs_info = root->fs_info;
4105 u64 flags;
4106 u64 ret;
4107
4108 if (data)
4109 flags = BTRFS_BLOCK_GROUP_DATA;
4110 else if (root == fs_info->chunk_root)
4111 flags = BTRFS_BLOCK_GROUP_SYSTEM;
4112 else
4113 flags = BTRFS_BLOCK_GROUP_METADATA;
4114
4115 ret = get_alloc_profile(fs_info, flags);
4116 return ret;
4117 }
4118
4119 int btrfs_alloc_data_chunk_ondemand(struct inode *inode, u64 bytes)
4120 {
4121 struct btrfs_space_info *data_sinfo;
4122 struct btrfs_root *root = BTRFS_I(inode)->root;
4123 struct btrfs_fs_info *fs_info = root->fs_info;
4124 u64 used;
4125 int ret = 0;
4126 int need_commit = 2;
4127 int have_pinned_space;
4128
4129 /* make sure bytes are sectorsize aligned */
4130 bytes = ALIGN(bytes, fs_info->sectorsize);
4131
4132 if (btrfs_is_free_space_inode(inode)) {
4133 need_commit = 0;
4134 ASSERT(current->journal_info);
4135 }
4136
4137 data_sinfo = fs_info->data_sinfo;
4138 if (!data_sinfo)
4139 goto alloc;
4140
4141 again:
4142 /* make sure we have enough space to handle the data first */
4143 spin_lock(&data_sinfo->lock);
4144 used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
4145 data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
4146 data_sinfo->bytes_may_use;
4147
4148 if (used + bytes > data_sinfo->total_bytes) {
4149 struct btrfs_trans_handle *trans;
4150
4151 /*
4152 * if we don't have enough free bytes in this space then we need
4153 * to alloc a new chunk.
4154 */
4155 if (!data_sinfo->full) {
4156 u64 alloc_target;
4157
4158 data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
4159 spin_unlock(&data_sinfo->lock);
4160 alloc:
4161 alloc_target = btrfs_get_alloc_profile(root, 1);
4162 /*
4163 * It is ugly that we don't call nolock join
4164 * transaction for the free space inode case here.
4165 * But it is safe because we only do the data space
4166 * reservation for the free space cache in the
4167 * transaction context, the common join transaction
4168 * just increase the counter of the current transaction
4169 * handler, doesn't try to acquire the trans_lock of
4170 * the fs.
4171 */
4172 trans = btrfs_join_transaction(root);
4173 if (IS_ERR(trans))
4174 return PTR_ERR(trans);
4175
4176 ret = do_chunk_alloc(trans, fs_info, alloc_target,
4177 CHUNK_ALLOC_NO_FORCE);
4178 btrfs_end_transaction(trans);
4179 if (ret < 0) {
4180 if (ret != -ENOSPC)
4181 return ret;
4182 else {
4183 have_pinned_space = 1;
4184 goto commit_trans;
4185 }
4186 }
4187
4188 if (!data_sinfo)
4189 data_sinfo = fs_info->data_sinfo;
4190
4191 goto again;
4192 }
4193
4194 /*
4195 * If we don't have enough pinned space to deal with this
4196 * allocation, and no removed chunk in current transaction,
4197 * don't bother committing the transaction.
4198 */
4199 have_pinned_space = percpu_counter_compare(
4200 &data_sinfo->total_bytes_pinned,
4201 used + bytes - data_sinfo->total_bytes);
4202 spin_unlock(&data_sinfo->lock);
4203
4204 /* commit the current transaction and try again */
4205 commit_trans:
4206 if (need_commit &&
4207 !atomic_read(&fs_info->open_ioctl_trans)) {
4208 need_commit--;
4209
4210 if (need_commit > 0) {
4211 btrfs_start_delalloc_roots(fs_info, 0, -1);
4212 btrfs_wait_ordered_roots(fs_info, -1, 0,
4213 (u64)-1);
4214 }
4215
4216 trans = btrfs_join_transaction(root);
4217 if (IS_ERR(trans))
4218 return PTR_ERR(trans);
4219 if (have_pinned_space >= 0 ||
4220 test_bit(BTRFS_TRANS_HAVE_FREE_BGS,
4221 &trans->transaction->flags) ||
4222 need_commit > 0) {
4223 ret = btrfs_commit_transaction(trans);
4224 if (ret)
4225 return ret;
4226 /*
4227 * The cleaner kthread might still be doing iput
4228 * operations. Wait for it to finish so that
4229 * more space is released.
4230 */
4231 mutex_lock(&fs_info->cleaner_delayed_iput_mutex);
4232 mutex_unlock(&fs_info->cleaner_delayed_iput_mutex);
4233 goto again;
4234 } else {
4235 btrfs_end_transaction(trans);
4236 }
4237 }
4238
4239 trace_btrfs_space_reservation(fs_info,
4240 "space_info:enospc",
4241 data_sinfo->flags, bytes, 1);
4242 return -ENOSPC;
4243 }
4244 data_sinfo->bytes_may_use += bytes;
4245 trace_btrfs_space_reservation(fs_info, "space_info",
4246 data_sinfo->flags, bytes, 1);
4247 spin_unlock(&data_sinfo->lock);
4248
4249 return ret;
4250 }
4251
4252 /*
4253 * New check_data_free_space() with ability for precious data reservation
4254 * Will replace old btrfs_check_data_free_space(), but for patch split,
4255 * add a new function first and then replace it.
4256 */
4257 int btrfs_check_data_free_space(struct inode *inode, u64 start, u64 len)
4258 {
4259 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4260 int ret;
4261
4262 /* align the range */
4263 len = round_up(start + len, fs_info->sectorsize) -
4264 round_down(start, fs_info->sectorsize);
4265 start = round_down(start, fs_info->sectorsize);
4266
4267 ret = btrfs_alloc_data_chunk_ondemand(inode, len);
4268 if (ret < 0)
4269 return ret;
4270
4271 /* Use new btrfs_qgroup_reserve_data to reserve precious data space. */
4272 ret = btrfs_qgroup_reserve_data(inode, start, len);
4273 if (ret)
4274 btrfs_free_reserved_data_space_noquota(inode, start, len);
4275 return ret;
4276 }
4277
4278 /*
4279 * Called if we need to clear a data reservation for this inode
4280 * Normally in a error case.
4281 *
4282 * This one will *NOT* use accurate qgroup reserved space API, just for case
4283 * which we can't sleep and is sure it won't affect qgroup reserved space.
4284 * Like clear_bit_hook().
4285 */
4286 void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start,
4287 u64 len)
4288 {
4289 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4290 struct btrfs_space_info *data_sinfo;
4291
4292 /* Make sure the range is aligned to sectorsize */
4293 len = round_up(start + len, fs_info->sectorsize) -
4294 round_down(start, fs_info->sectorsize);
4295 start = round_down(start, fs_info->sectorsize);
4296
4297 data_sinfo = fs_info->data_sinfo;
4298 spin_lock(&data_sinfo->lock);
4299 if (WARN_ON(data_sinfo->bytes_may_use < len))
4300 data_sinfo->bytes_may_use = 0;
4301 else
4302 data_sinfo->bytes_may_use -= len;
4303 trace_btrfs_space_reservation(fs_info, "space_info",
4304 data_sinfo->flags, len, 0);
4305 spin_unlock(&data_sinfo->lock);
4306 }
4307
4308 /*
4309 * Called if we need to clear a data reservation for this inode
4310 * Normally in a error case.
4311 *
4312 * This one will handle the per-inode data rsv map for accurate reserved
4313 * space framework.
4314 */
4315 void btrfs_free_reserved_data_space(struct inode *inode, u64 start, u64 len)
4316 {
4317 struct btrfs_root *root = BTRFS_I(inode)->root;
4318
4319 /* Make sure the range is aligned to sectorsize */
4320 len = round_up(start + len, root->fs_info->sectorsize) -
4321 round_down(start, root->fs_info->sectorsize);
4322 start = round_down(start, root->fs_info->sectorsize);
4323
4324 btrfs_free_reserved_data_space_noquota(inode, start, len);
4325 btrfs_qgroup_free_data(inode, start, len);
4326 }
4327
4328 static void force_metadata_allocation(struct btrfs_fs_info *info)
4329 {
4330 struct list_head *head = &info->space_info;
4331 struct btrfs_space_info *found;
4332
4333 rcu_read_lock();
4334 list_for_each_entry_rcu(found, head, list) {
4335 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
4336 found->force_alloc = CHUNK_ALLOC_FORCE;
4337 }
4338 rcu_read_unlock();
4339 }
4340
4341 static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
4342 {
4343 return (global->size << 1);
4344 }
4345
4346 static int should_alloc_chunk(struct btrfs_fs_info *fs_info,
4347 struct btrfs_space_info *sinfo, int force)
4348 {
4349 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
4350 u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
4351 u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
4352 u64 thresh;
4353
4354 if (force == CHUNK_ALLOC_FORCE)
4355 return 1;
4356
4357 /*
4358 * We need to take into account the global rsv because for all intents
4359 * and purposes it's used space. Don't worry about locking the
4360 * global_rsv, it doesn't change except when the transaction commits.
4361 */
4362 if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA)
4363 num_allocated += calc_global_rsv_need_space(global_rsv);
4364
4365 /*
4366 * in limited mode, we want to have some free space up to
4367 * about 1% of the FS size.
4368 */
4369 if (force == CHUNK_ALLOC_LIMITED) {
4370 thresh = btrfs_super_total_bytes(fs_info->super_copy);
4371 thresh = max_t(u64, SZ_64M, div_factor_fine(thresh, 1));
4372
4373 if (num_bytes - num_allocated < thresh)
4374 return 1;
4375 }
4376
4377 if (num_allocated + SZ_2M < div_factor(num_bytes, 8))
4378 return 0;
4379 return 1;
4380 }
4381
4382 static u64 get_profile_num_devs(struct btrfs_fs_info *fs_info, u64 type)
4383 {
4384 u64 num_dev;
4385
4386 if (type & (BTRFS_BLOCK_GROUP_RAID10 |
4387 BTRFS_BLOCK_GROUP_RAID0 |
4388 BTRFS_BLOCK_GROUP_RAID5 |
4389 BTRFS_BLOCK_GROUP_RAID6))
4390 num_dev = fs_info->fs_devices->rw_devices;
4391 else if (type & BTRFS_BLOCK_GROUP_RAID1)
4392 num_dev = 2;
4393 else
4394 num_dev = 1; /* DUP or single */
4395
4396 return num_dev;
4397 }
4398
4399 /*
4400 * If @is_allocation is true, reserve space in the system space info necessary
4401 * for allocating a chunk, otherwise if it's false, reserve space necessary for
4402 * removing a chunk.
4403 */
4404 void check_system_chunk(struct btrfs_trans_handle *trans,
4405 struct btrfs_fs_info *fs_info, u64 type)
4406 {
4407 struct btrfs_space_info *info;
4408 u64 left;
4409 u64 thresh;
4410 int ret = 0;
4411 u64 num_devs;
4412
4413 /*
4414 * Needed because we can end up allocating a system chunk and for an
4415 * atomic and race free space reservation in the chunk block reserve.
4416 */
4417 ASSERT(mutex_is_locked(&fs_info->chunk_mutex));
4418
4419 info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
4420 spin_lock(&info->lock);
4421 left = info->total_bytes - info->bytes_used - info->bytes_pinned -
4422 info->bytes_reserved - info->bytes_readonly -
4423 info->bytes_may_use;
4424 spin_unlock(&info->lock);
4425
4426 num_devs = get_profile_num_devs(fs_info, type);
4427
4428 /* num_devs device items to update and 1 chunk item to add or remove */
4429 thresh = btrfs_calc_trunc_metadata_size(fs_info, num_devs) +
4430 btrfs_calc_trans_metadata_size(fs_info, 1);
4431
4432 if (left < thresh && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
4433 btrfs_info(fs_info, "left=%llu, need=%llu, flags=%llu",
4434 left, thresh, type);
4435 dump_space_info(fs_info, info, 0, 0);
4436 }
4437
4438 if (left < thresh) {
4439 u64 flags;
4440
4441 flags = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4442 /*
4443 * Ignore failure to create system chunk. We might end up not
4444 * needing it, as we might not need to COW all nodes/leafs from
4445 * the paths we visit in the chunk tree (they were already COWed
4446 * or created in the current transaction for example).
4447 */
4448 ret = btrfs_alloc_chunk(trans, fs_info, flags);
4449 }
4450
4451 if (!ret) {
4452 ret = btrfs_block_rsv_add(fs_info->chunk_root,
4453 &fs_info->chunk_block_rsv,
4454 thresh, BTRFS_RESERVE_NO_FLUSH);
4455 if (!ret)
4456 trans->chunk_bytes_reserved += thresh;
4457 }
4458 }
4459
4460 /*
4461 * If force is CHUNK_ALLOC_FORCE:
4462 * - return 1 if it successfully allocates a chunk,
4463 * - return errors including -ENOSPC otherwise.
4464 * If force is NOT CHUNK_ALLOC_FORCE:
4465 * - return 0 if it doesn't need to allocate a new chunk,
4466 * - return 1 if it successfully allocates a chunk,
4467 * - return errors including -ENOSPC otherwise.
4468 */
4469 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
4470 struct btrfs_fs_info *fs_info, u64 flags, int force)
4471 {
4472 struct btrfs_space_info *space_info;
4473 int wait_for_alloc = 0;
4474 int ret = 0;
4475
4476 /* Don't re-enter if we're already allocating a chunk */
4477 if (trans->allocating_chunk)
4478 return -ENOSPC;
4479
4480 space_info = __find_space_info(fs_info, flags);
4481 if (!space_info) {
4482 ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info);
4483 BUG_ON(ret); /* -ENOMEM */
4484 }
4485 BUG_ON(!space_info); /* Logic error */
4486
4487 again:
4488 spin_lock(&space_info->lock);
4489 if (force < space_info->force_alloc)
4490 force = space_info->force_alloc;
4491 if (space_info->full) {
4492 if (should_alloc_chunk(fs_info, space_info, force))
4493 ret = -ENOSPC;
4494 else
4495 ret = 0;
4496 spin_unlock(&space_info->lock);
4497 return ret;
4498 }
4499
4500 if (!should_alloc_chunk(fs_info, space_info, force)) {
4501 spin_unlock(&space_info->lock);
4502 return 0;
4503 } else if (space_info->chunk_alloc) {
4504 wait_for_alloc = 1;
4505 } else {
4506 space_info->chunk_alloc = 1;
4507 }
4508
4509 spin_unlock(&space_info->lock);
4510
4511 mutex_lock(&fs_info->chunk_mutex);
4512
4513 /*
4514 * The chunk_mutex is held throughout the entirety of a chunk
4515 * allocation, so once we've acquired the chunk_mutex we know that the
4516 * other guy is done and we need to recheck and see if we should
4517 * allocate.
4518 */
4519 if (wait_for_alloc) {
4520 mutex_unlock(&fs_info->chunk_mutex);
4521 wait_for_alloc = 0;
4522 goto again;
4523 }
4524
4525 trans->allocating_chunk = true;
4526
4527 /*
4528 * If we have mixed data/metadata chunks we want to make sure we keep
4529 * allocating mixed chunks instead of individual chunks.
4530 */
4531 if (btrfs_mixed_space_info(space_info))
4532 flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
4533
4534 /*
4535 * if we're doing a data chunk, go ahead and make sure that
4536 * we keep a reasonable number of metadata chunks allocated in the
4537 * FS as well.
4538 */
4539 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
4540 fs_info->data_chunk_allocations++;
4541 if (!(fs_info->data_chunk_allocations %
4542 fs_info->metadata_ratio))
4543 force_metadata_allocation(fs_info);
4544 }
4545
4546 /*
4547 * Check if we have enough space in SYSTEM chunk because we may need
4548 * to update devices.
4549 */
4550 check_system_chunk(trans, fs_info, flags);
4551
4552 ret = btrfs_alloc_chunk(trans, fs_info, flags);
4553 trans->allocating_chunk = false;
4554
4555 spin_lock(&space_info->lock);
4556 if (ret < 0 && ret != -ENOSPC)
4557 goto out;
4558 if (ret)
4559 space_info->full = 1;
4560 else
4561 ret = 1;
4562
4563 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
4564 out:
4565 space_info->chunk_alloc = 0;
4566 spin_unlock(&space_info->lock);
4567 mutex_unlock(&fs_info->chunk_mutex);
4568 /*
4569 * When we allocate a new chunk we reserve space in the chunk block
4570 * reserve to make sure we can COW nodes/leafs in the chunk tree or
4571 * add new nodes/leafs to it if we end up needing to do it when
4572 * inserting the chunk item and updating device items as part of the
4573 * second phase of chunk allocation, performed by
4574 * btrfs_finish_chunk_alloc(). So make sure we don't accumulate a
4575 * large number of new block groups to create in our transaction
4576 * handle's new_bgs list to avoid exhausting the chunk block reserve
4577 * in extreme cases - like having a single transaction create many new
4578 * block groups when starting to write out the free space caches of all
4579 * the block groups that were made dirty during the lifetime of the
4580 * transaction.
4581 */
4582 if (trans->can_flush_pending_bgs &&
4583 trans->chunk_bytes_reserved >= (u64)SZ_2M) {
4584 btrfs_create_pending_block_groups(trans, fs_info);
4585 btrfs_trans_release_chunk_metadata(trans);
4586 }
4587 return ret;
4588 }
4589
4590 static int can_overcommit(struct btrfs_root *root,
4591 struct btrfs_space_info *space_info, u64 bytes,
4592 enum btrfs_reserve_flush_enum flush)
4593 {
4594 struct btrfs_fs_info *fs_info = root->fs_info;
4595 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
4596 u64 profile;
4597 u64 space_size;
4598 u64 avail;
4599 u64 used;
4600
4601 /* Don't overcommit when in mixed mode. */
4602 if (space_info->flags & BTRFS_BLOCK_GROUP_DATA)
4603 return 0;
4604
4605 profile = btrfs_get_alloc_profile(root, 0);
4606 used = space_info->bytes_used + space_info->bytes_reserved +
4607 space_info->bytes_pinned + space_info->bytes_readonly;
4608
4609 /*
4610 * We only want to allow over committing if we have lots of actual space
4611 * free, but if we don't have enough space to handle the global reserve
4612 * space then we could end up having a real enospc problem when trying
4613 * to allocate a chunk or some other such important allocation.
4614 */
4615 spin_lock(&global_rsv->lock);
4616 space_size = calc_global_rsv_need_space(global_rsv);
4617 spin_unlock(&global_rsv->lock);
4618 if (used + space_size >= space_info->total_bytes)
4619 return 0;
4620
4621 used += space_info->bytes_may_use;
4622
4623 spin_lock(&fs_info->free_chunk_lock);
4624 avail = fs_info->free_chunk_space;
4625 spin_unlock(&fs_info->free_chunk_lock);
4626
4627 /*
4628 * If we have dup, raid1 or raid10 then only half of the free
4629 * space is actually useable. For raid56, the space info used
4630 * doesn't include the parity drive, so we don't have to
4631 * change the math
4632 */
4633 if (profile & (BTRFS_BLOCK_GROUP_DUP |
4634 BTRFS_BLOCK_GROUP_RAID1 |
4635 BTRFS_BLOCK_GROUP_RAID10))
4636 avail >>= 1;
4637
4638 /*
4639 * If we aren't flushing all things, let us overcommit up to
4640 * 1/2th of the space. If we can flush, don't let us overcommit
4641 * too much, let it overcommit up to 1/8 of the space.
4642 */
4643 if (flush == BTRFS_RESERVE_FLUSH_ALL)
4644 avail >>= 3;
4645 else
4646 avail >>= 1;
4647
4648 if (used + bytes < space_info->total_bytes + avail)
4649 return 1;
4650 return 0;
4651 }
4652
4653 static void btrfs_writeback_inodes_sb_nr(struct btrfs_fs_info *fs_info,
4654 unsigned long nr_pages, int nr_items)
4655 {
4656 struct super_block *sb = fs_info->sb;
4657
4658 if (down_read_trylock(&sb->s_umount)) {
4659 writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE);
4660 up_read(&sb->s_umount);
4661 } else {
4662 /*
4663 * We needn't worry the filesystem going from r/w to r/o though
4664 * we don't acquire ->s_umount mutex, because the filesystem
4665 * should guarantee the delalloc inodes list be empty after
4666 * the filesystem is readonly(all dirty pages are written to
4667 * the disk).
4668 */
4669 btrfs_start_delalloc_roots(fs_info, 0, nr_items);
4670 if (!current->journal_info)
4671 btrfs_wait_ordered_roots(fs_info, nr_items, 0, (u64)-1);
4672 }
4673 }
4674
4675 static inline int calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
4676 u64 to_reclaim)
4677 {
4678 u64 bytes;
4679 int nr;
4680
4681 bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
4682 nr = (int)div64_u64(to_reclaim, bytes);
4683 if (!nr)
4684 nr = 1;
4685 return nr;
4686 }
4687
4688 #define EXTENT_SIZE_PER_ITEM SZ_256K
4689
4690 /*
4691 * shrink metadata reservation for delalloc
4692 */
4693 static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
4694 bool wait_ordered)
4695 {
4696 struct btrfs_fs_info *fs_info = root->fs_info;
4697 struct btrfs_block_rsv *block_rsv;
4698 struct btrfs_space_info *space_info;
4699 struct btrfs_trans_handle *trans;
4700 u64 delalloc_bytes;
4701 u64 max_reclaim;
4702 long time_left;
4703 unsigned long nr_pages;
4704 int loops;
4705 int items;
4706 enum btrfs_reserve_flush_enum flush;
4707
4708 /* Calc the number of the pages we need flush for space reservation */
4709 items = calc_reclaim_items_nr(fs_info, to_reclaim);
4710 to_reclaim = (u64)items * EXTENT_SIZE_PER_ITEM;
4711
4712 trans = (struct btrfs_trans_handle *)current->journal_info;
4713 block_rsv = &fs_info->delalloc_block_rsv;
4714 space_info = block_rsv->space_info;
4715
4716 delalloc_bytes = percpu_counter_sum_positive(
4717 &fs_info->delalloc_bytes);
4718 if (delalloc_bytes == 0) {
4719 if (trans)
4720 return;
4721 if (wait_ordered)
4722 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
4723 return;
4724 }
4725
4726 loops = 0;
4727 while (delalloc_bytes && loops < 3) {
4728 max_reclaim = min(delalloc_bytes, to_reclaim);
4729 nr_pages = max_reclaim >> PAGE_SHIFT;
4730 btrfs_writeback_inodes_sb_nr(fs_info, nr_pages, items);
4731 /*
4732 * We need to wait for the async pages to actually start before
4733 * we do anything.
4734 */
4735 max_reclaim = atomic_read(&fs_info->async_delalloc_pages);
4736 if (!max_reclaim)
4737 goto skip_async;
4738
4739 if (max_reclaim <= nr_pages)
4740 max_reclaim = 0;
4741 else
4742 max_reclaim -= nr_pages;
4743
4744 wait_event(fs_info->async_submit_wait,
4745 atomic_read(&fs_info->async_delalloc_pages) <=
4746 (int)max_reclaim);
4747 skip_async:
4748 if (!trans)
4749 flush = BTRFS_RESERVE_FLUSH_ALL;
4750 else
4751 flush = BTRFS_RESERVE_NO_FLUSH;
4752 spin_lock(&space_info->lock);
4753 if (can_overcommit(root, space_info, orig, flush)) {
4754 spin_unlock(&space_info->lock);
4755 break;
4756 }
4757 if (list_empty(&space_info->tickets) &&
4758 list_empty(&space_info->priority_tickets)) {
4759 spin_unlock(&space_info->lock);
4760 break;
4761 }
4762 spin_unlock(&space_info->lock);
4763
4764 loops++;
4765 if (wait_ordered && !trans) {
4766 btrfs_wait_ordered_roots(fs_info, items, 0, (u64)-1);
4767 } else {
4768 time_left = schedule_timeout_killable(1);
4769 if (time_left)
4770 break;
4771 }
4772 delalloc_bytes = percpu_counter_sum_positive(
4773 &fs_info->delalloc_bytes);
4774 }
4775 }
4776
4777 /**
4778 * maybe_commit_transaction - possibly commit the transaction if its ok to
4779 * @root - the root we're allocating for
4780 * @bytes - the number of bytes we want to reserve
4781 * @force - force the commit
4782 *
4783 * This will check to make sure that committing the transaction will actually
4784 * get us somewhere and then commit the transaction if it does. Otherwise it
4785 * will return -ENOSPC.
4786 */
4787 static int may_commit_transaction(struct btrfs_root *root,
4788 struct btrfs_space_info *space_info,
4789 u64 bytes, int force)
4790 {
4791 struct btrfs_fs_info *fs_info = root->fs_info;
4792 struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_block_rsv;
4793 struct btrfs_trans_handle *trans;
4794
4795 trans = (struct btrfs_trans_handle *)current->journal_info;
4796 if (trans)
4797 return -EAGAIN;
4798
4799 if (force)
4800 goto commit;
4801
4802 /* See if there is enough pinned space to make this reservation */
4803 if (percpu_counter_compare(&space_info->total_bytes_pinned,
4804 bytes) >= 0)
4805 goto commit;
4806
4807 /*
4808 * See if there is some space in the delayed insertion reservation for
4809 * this reservation.
4810 */
4811 if (space_info != delayed_rsv->space_info)
4812 return -ENOSPC;
4813
4814 spin_lock(&delayed_rsv->lock);
4815 if (percpu_counter_compare(&space_info->total_bytes_pinned,
4816 bytes - delayed_rsv->size) >= 0) {
4817 spin_unlock(&delayed_rsv->lock);
4818 return -ENOSPC;
4819 }
4820 spin_unlock(&delayed_rsv->lock);
4821
4822 commit:
4823 trans = btrfs_join_transaction(root);
4824 if (IS_ERR(trans))
4825 return -ENOSPC;
4826
4827 return btrfs_commit_transaction(trans);
4828 }
4829
4830 struct reserve_ticket {
4831 u64 bytes;
4832 int error;
4833 struct list_head list;
4834 wait_queue_head_t wait;
4835 };
4836
4837 static int flush_space(struct btrfs_root *root,
4838 struct btrfs_space_info *space_info, u64 num_bytes,
4839 u64 orig_bytes, int state)
4840 {
4841 struct btrfs_fs_info *fs_info = root->fs_info;
4842 struct btrfs_trans_handle *trans;
4843 int nr;
4844 int ret = 0;
4845
4846 switch (state) {
4847 case FLUSH_DELAYED_ITEMS_NR:
4848 case FLUSH_DELAYED_ITEMS:
4849 if (state == FLUSH_DELAYED_ITEMS_NR)
4850 nr = calc_reclaim_items_nr(fs_info, num_bytes) * 2;
4851 else
4852 nr = -1;
4853
4854 trans = btrfs_join_transaction(root);
4855 if (IS_ERR(trans)) {
4856 ret = PTR_ERR(trans);
4857 break;
4858 }
4859 ret = btrfs_run_delayed_items_nr(trans, fs_info, nr);
4860 btrfs_end_transaction(trans);
4861 break;
4862 case FLUSH_DELALLOC:
4863 case FLUSH_DELALLOC_WAIT:
4864 shrink_delalloc(root, num_bytes * 2, orig_bytes,
4865 state == FLUSH_DELALLOC_WAIT);
4866 break;
4867 case ALLOC_CHUNK:
4868 trans = btrfs_join_transaction(root);
4869 if (IS_ERR(trans)) {
4870 ret = PTR_ERR(trans);
4871 break;
4872 }
4873 ret = do_chunk_alloc(trans, fs_info,
4874 btrfs_get_alloc_profile(root, 0),
4875 CHUNK_ALLOC_NO_FORCE);
4876 btrfs_end_transaction(trans);
4877 if (ret > 0 || ret == -ENOSPC)
4878 ret = 0;
4879 break;
4880 case COMMIT_TRANS:
4881 ret = may_commit_transaction(root, space_info, orig_bytes, 0);
4882 break;
4883 default:
4884 ret = -ENOSPC;
4885 break;
4886 }
4887
4888 trace_btrfs_flush_space(fs_info, space_info->flags, num_bytes,
4889 orig_bytes, state, ret);
4890 return ret;
4891 }
4892
4893 static inline u64
4894 btrfs_calc_reclaim_metadata_size(struct btrfs_root *root,
4895 struct btrfs_space_info *space_info)
4896 {
4897 struct reserve_ticket *ticket;
4898 u64 used;
4899 u64 expected;
4900 u64 to_reclaim = 0;
4901
4902 list_for_each_entry(ticket, &space_info->tickets, list)
4903 to_reclaim += ticket->bytes;
4904 list_for_each_entry(ticket, &space_info->priority_tickets, list)
4905 to_reclaim += ticket->bytes;
4906 if (to_reclaim)
4907 return to_reclaim;
4908
4909 to_reclaim = min_t(u64, num_online_cpus() * SZ_1M, SZ_16M);
4910 if (can_overcommit(root, space_info, to_reclaim,
4911 BTRFS_RESERVE_FLUSH_ALL))
4912 return 0;
4913
4914 used = space_info->bytes_used + space_info->bytes_reserved +
4915 space_info->bytes_pinned + space_info->bytes_readonly +
4916 space_info->bytes_may_use;
4917 if (can_overcommit(root, space_info, SZ_1M, BTRFS_RESERVE_FLUSH_ALL))
4918 expected = div_factor_fine(space_info->total_bytes, 95);
4919 else
4920 expected = div_factor_fine(space_info->total_bytes, 90);
4921
4922 if (used > expected)
4923 to_reclaim = used - expected;
4924 else
4925 to_reclaim = 0;
4926 to_reclaim = min(to_reclaim, space_info->bytes_may_use +
4927 space_info->bytes_reserved);
4928 return to_reclaim;
4929 }
4930
4931 static inline int need_do_async_reclaim(struct btrfs_space_info *space_info,
4932 struct btrfs_root *root, u64 used)
4933 {
4934 struct btrfs_fs_info *fs_info = root->fs_info;
4935 u64 thresh = div_factor_fine(space_info->total_bytes, 98);
4936
4937 /* If we're just plain full then async reclaim just slows us down. */
4938 if ((space_info->bytes_used + space_info->bytes_reserved) >= thresh)
4939 return 0;
4940
4941 if (!btrfs_calc_reclaim_metadata_size(root, space_info))
4942 return 0;
4943
4944 return (used >= thresh && !btrfs_fs_closing(fs_info) &&
4945 !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
4946 }
4947
4948 static void wake_all_tickets(struct list_head *head)
4949 {
4950 struct reserve_ticket *ticket;
4951
4952 while (!list_empty(head)) {
4953 ticket = list_first_entry(head, struct reserve_ticket, list);
4954 list_del_init(&ticket->list);
4955 ticket->error = -ENOSPC;
4956 wake_up(&ticket->wait);
4957 }
4958 }
4959
4960 /*
4961 * This is for normal flushers, we can wait all goddamned day if we want to. We
4962 * will loop and continuously try to flush as long as we are making progress.
4963 * We count progress as clearing off tickets each time we have to loop.
4964 */
4965 static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
4966 {
4967 struct btrfs_fs_info *fs_info;
4968 struct btrfs_space_info *space_info;
4969 u64 to_reclaim;
4970 int flush_state;
4971 int commit_cycles = 0;
4972 u64 last_tickets_id;
4973
4974 fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
4975 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
4976
4977 spin_lock(&space_info->lock);
4978 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info->fs_root,
4979 space_info);
4980 if (!to_reclaim) {
4981 space_info->flush = 0;
4982 spin_unlock(&space_info->lock);
4983 return;
4984 }
4985 last_tickets_id = space_info->tickets_id;
4986 spin_unlock(&space_info->lock);
4987
4988 flush_state = FLUSH_DELAYED_ITEMS_NR;
4989 do {
4990 struct reserve_ticket *ticket;
4991 int ret;
4992
4993 ret = flush_space(fs_info->fs_root, space_info, to_reclaim,
4994 to_reclaim, flush_state);
4995 spin_lock(&space_info->lock);
4996 if (list_empty(&space_info->tickets)) {
4997 space_info->flush = 0;
4998 spin_unlock(&space_info->lock);
4999 return;
5000 }
5001 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info->fs_root,
5002 space_info);
5003 ticket = list_first_entry(&space_info->tickets,
5004 struct reserve_ticket, list);
5005 if (last_tickets_id == space_info->tickets_id) {
5006 flush_state++;
5007 } else {
5008 last_tickets_id = space_info->tickets_id;
5009 flush_state = FLUSH_DELAYED_ITEMS_NR;
5010 if (commit_cycles)
5011 commit_cycles--;
5012 }
5013
5014 if (flush_state > COMMIT_TRANS) {
5015 commit_cycles++;
5016 if (commit_cycles > 2) {
5017 wake_all_tickets(&space_info->tickets);
5018 space_info->flush = 0;
5019 } else {
5020 flush_state = FLUSH_DELAYED_ITEMS_NR;
5021 }
5022 }
5023 spin_unlock(&space_info->lock);
5024 } while (flush_state <= COMMIT_TRANS);
5025 }
5026
5027 void btrfs_init_async_reclaim_work(struct work_struct *work)
5028 {
5029 INIT_WORK(work, btrfs_async_reclaim_metadata_space);
5030 }
5031
5032 static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
5033 struct btrfs_space_info *space_info,
5034 struct reserve_ticket *ticket)
5035 {
5036 u64 to_reclaim;
5037 int flush_state = FLUSH_DELAYED_ITEMS_NR;
5038
5039 spin_lock(&space_info->lock);
5040 to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info->fs_root,
5041 space_info);
5042 if (!to_reclaim) {
5043 spin_unlock(&space_info->lock);
5044 return;
5045 }
5046 spin_unlock(&space_info->lock);
5047
5048 do {
5049 flush_space(fs_info->fs_root, space_info, to_reclaim,
5050 to_reclaim, flush_state);
5051 flush_state++;
5052 spin_lock(&space_info->lock);
5053 if (ticket->bytes == 0) {
5054 spin_unlock(&space_info->lock);
5055 return;
5056 }
5057 spin_unlock(&space_info->lock);
5058
5059 /*
5060 * Priority flushers can't wait on delalloc without
5061 * deadlocking.
5062 */
5063 if (flush_state == FLUSH_DELALLOC ||
5064 flush_state == FLUSH_DELALLOC_WAIT)
5065 flush_state = ALLOC_CHUNK;
5066 } while (flush_state < COMMIT_TRANS);
5067 }
5068
5069 static int wait_reserve_ticket(struct btrfs_fs_info *fs_info,
5070 struct btrfs_space_info *space_info,
5071 struct reserve_ticket *ticket, u64 orig_bytes)
5072
5073 {
5074 DEFINE_WAIT(wait);
5075 int ret = 0;
5076
5077 spin_lock(&space_info->lock);
5078 while (ticket->bytes > 0 && ticket->error == 0) {
5079 ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE);
5080 if (ret) {
5081 ret = -EINTR;
5082 break;
5083 }
5084 spin_unlock(&space_info->lock);
5085
5086 schedule();
5087
5088 finish_wait(&ticket->wait, &wait);
5089 spin_lock(&space_info->lock);
5090 }
5091 if (!ret)
5092 ret = ticket->error;
5093 if (!list_empty(&ticket->list))
5094 list_del_init(&ticket->list);
5095 if (ticket->bytes && ticket->bytes < orig_bytes) {
5096 u64 num_bytes = orig_bytes - ticket->bytes;
5097 space_info->bytes_may_use -= num_bytes;
5098 trace_btrfs_space_reservation(fs_info, "space_info",
5099 space_info->flags, num_bytes, 0);
5100 }
5101 spin_unlock(&space_info->lock);
5102
5103 return ret;
5104 }
5105
5106 /**
5107 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
5108 * @root - the root we're allocating for
5109 * @space_info - the space info we want to allocate from
5110 * @orig_bytes - the number of bytes we want
5111 * @flush - whether or not we can flush to make our reservation
5112 *
5113 * This will reserve orig_bytes number of bytes from the space info associated
5114 * with the block_rsv. If there is not enough space it will make an attempt to
5115 * flush out space to make room. It will do this by flushing delalloc if
5116 * possible or committing the transaction. If flush is 0 then no attempts to
5117 * regain reservations will be made and this will fail if there is not enough
5118 * space already.
5119 */
5120 static int __reserve_metadata_bytes(struct btrfs_root *root,
5121 struct btrfs_space_info *space_info,
5122 u64 orig_bytes,
5123 enum btrfs_reserve_flush_enum flush)
5124 {
5125 struct btrfs_fs_info *fs_info = root->fs_info;
5126 struct reserve_ticket ticket;
5127 u64 used;
5128 int ret = 0;
5129
5130 ASSERT(orig_bytes);
5131 ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_ALL);
5132
5133 spin_lock(&space_info->lock);
5134 ret = -ENOSPC;
5135 used = space_info->bytes_used + space_info->bytes_reserved +
5136 space_info->bytes_pinned + space_info->bytes_readonly +
5137 space_info->bytes_may_use;
5138
5139 /*
5140 * If we have enough space then hooray, make our reservation and carry
5141 * on. If not see if we can overcommit, and if we can, hooray carry on.
5142 * If not things get more complicated.
5143 */
5144 if (used + orig_bytes <= space_info->total_bytes) {
5145 space_info->bytes_may_use += orig_bytes;
5146 trace_btrfs_space_reservation(fs_info, "space_info",
5147 space_info->flags, orig_bytes, 1);
5148 ret = 0;
5149 } else if (can_overcommit(root, space_info, orig_bytes, flush)) {
5150 space_info->bytes_may_use += orig_bytes;
5151 trace_btrfs_space_reservation(fs_info, "space_info",
5152 space_info->flags, orig_bytes, 1);
5153 ret = 0;
5154 }
5155
5156 /*
5157 * If we couldn't make a reservation then setup our reservation ticket
5158 * and kick the async worker if it's not already running.
5159 *
5160 * If we are a priority flusher then we just need to add our ticket to
5161 * the list and we will do our own flushing further down.
5162 */
5163 if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
5164 ticket.bytes = orig_bytes;
5165 ticket.error = 0;
5166 init_waitqueue_head(&ticket.wait);
5167 if (flush == BTRFS_RESERVE_FLUSH_ALL) {
5168 list_add_tail(&ticket.list, &space_info->tickets);
5169 if (!space_info->flush) {
5170 space_info->flush = 1;
5171 trace_btrfs_trigger_flush(fs_info,
5172 space_info->flags,
5173 orig_bytes, flush,
5174 "enospc");
5175 queue_work(system_unbound_wq,
5176 &root->fs_info->async_reclaim_work);
5177 }
5178 } else {
5179 list_add_tail(&ticket.list,
5180 &space_info->priority_tickets);
5181 }
5182 } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
5183 used += orig_bytes;
5184 /*
5185 * We will do the space reservation dance during log replay,
5186 * which means we won't have fs_info->fs_root set, so don't do
5187 * the async reclaim as we will panic.
5188 */
5189 if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags) &&
5190 need_do_async_reclaim(space_info, root, used) &&
5191 !work_busy(&fs_info->async_reclaim_work)) {
5192 trace_btrfs_trigger_flush(fs_info, space_info->flags,
5193 orig_bytes, flush, "preempt");
5194 queue_work(system_unbound_wq,
5195 &fs_info->async_reclaim_work);
5196 }
5197 }
5198 spin_unlock(&space_info->lock);
5199 if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
5200 return ret;
5201
5202 if (flush == BTRFS_RESERVE_FLUSH_ALL)
5203 return wait_reserve_ticket(fs_info, space_info, &ticket,
5204 orig_bytes);
5205
5206 ret = 0;
5207 priority_reclaim_metadata_space(fs_info, space_info, &ticket);
5208 spin_lock(&space_info->lock);
5209 if (ticket.bytes) {
5210 if (ticket.bytes < orig_bytes) {
5211 u64 num_bytes = orig_bytes - ticket.bytes;
5212 space_info->bytes_may_use -= num_bytes;
5213 trace_btrfs_space_reservation(fs_info, "space_info",
5214 space_info->flags,
5215 num_bytes, 0);
5216
5217 }
5218 list_del_init(&ticket.list);
5219 ret = -ENOSPC;
5220 }
5221 spin_unlock(&space_info->lock);
5222 ASSERT(list_empty(&ticket.list));
5223 return ret;
5224 }
5225
5226 /**
5227 * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
5228 * @root - the root we're allocating for
5229 * @block_rsv - the block_rsv we're allocating for
5230 * @orig_bytes - the number of bytes we want
5231 * @flush - whether or not we can flush to make our reservation
5232 *
5233 * This will reserve orgi_bytes number of bytes from the space info associated
5234 * with the block_rsv. If there is not enough space it will make an attempt to
5235 * flush out space to make room. It will do this by flushing delalloc if
5236 * possible or committing the transaction. If flush is 0 then no attempts to
5237 * regain reservations will be made and this will fail if there is not enough
5238 * space already.
5239 */
5240 static int reserve_metadata_bytes(struct btrfs_root *root,
5241 struct btrfs_block_rsv *block_rsv,
5242 u64 orig_bytes,
5243 enum btrfs_reserve_flush_enum flush)
5244 {
5245 struct btrfs_fs_info *fs_info = root->fs_info;
5246 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5247 int ret;
5248
5249 ret = __reserve_metadata_bytes(root, block_rsv->space_info, orig_bytes,
5250 flush);
5251 if (ret == -ENOSPC &&
5252 unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
5253 if (block_rsv != global_rsv &&
5254 !block_rsv_use_bytes(global_rsv, orig_bytes))
5255 ret = 0;
5256 }
5257 if (ret == -ENOSPC)
5258 trace_btrfs_space_reservation(fs_info, "space_info:enospc",
5259 block_rsv->space_info->flags,
5260 orig_bytes, 1);
5261 return ret;
5262 }
5263
5264 static struct btrfs_block_rsv *get_block_rsv(
5265 const struct btrfs_trans_handle *trans,
5266 const struct btrfs_root *root)
5267 {
5268 struct btrfs_fs_info *fs_info = root->fs_info;
5269 struct btrfs_block_rsv *block_rsv = NULL;
5270
5271 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
5272 (root == fs_info->csum_root && trans->adding_csums) ||
5273 (root == fs_info->uuid_root))
5274 block_rsv = trans->block_rsv;
5275
5276 if (!block_rsv)
5277 block_rsv = root->block_rsv;
5278
5279 if (!block_rsv)
5280 block_rsv = &fs_info->empty_block_rsv;
5281
5282 return block_rsv;
5283 }
5284
5285 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
5286 u64 num_bytes)
5287 {
5288 int ret = -ENOSPC;
5289 spin_lock(&block_rsv->lock);
5290 if (block_rsv->reserved >= num_bytes) {
5291 block_rsv->reserved -= num_bytes;
5292 if (block_rsv->reserved < block_rsv->size)
5293 block_rsv->full = 0;
5294 ret = 0;
5295 }
5296 spin_unlock(&block_rsv->lock);
5297 return ret;
5298 }
5299
5300 static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
5301 u64 num_bytes, int update_size)
5302 {
5303 spin_lock(&block_rsv->lock);
5304 block_rsv->reserved += num_bytes;
5305 if (update_size)
5306 block_rsv->size += num_bytes;
5307 else if (block_rsv->reserved >= block_rsv->size)
5308 block_rsv->full = 1;
5309 spin_unlock(&block_rsv->lock);
5310 }
5311
5312 int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
5313 struct btrfs_block_rsv *dest, u64 num_bytes,
5314 int min_factor)
5315 {
5316 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5317 u64 min_bytes;
5318
5319 if (global_rsv->space_info != dest->space_info)
5320 return -ENOSPC;
5321
5322 spin_lock(&global_rsv->lock);
5323 min_bytes = div_factor(global_rsv->size, min_factor);
5324 if (global_rsv->reserved < min_bytes + num_bytes) {
5325 spin_unlock(&global_rsv->lock);
5326 return -ENOSPC;
5327 }
5328 global_rsv->reserved -= num_bytes;
5329 if (global_rsv->reserved < global_rsv->size)
5330 global_rsv->full = 0;
5331 spin_unlock(&global_rsv->lock);
5332
5333 block_rsv_add_bytes(dest, num_bytes, 1);
5334 return 0;
5335 }
5336
5337 /*
5338 * This is for space we already have accounted in space_info->bytes_may_use, so
5339 * basically when we're returning space from block_rsv's.
5340 */
5341 static void space_info_add_old_bytes(struct btrfs_fs_info *fs_info,
5342 struct btrfs_space_info *space_info,
5343 u64 num_bytes)
5344 {
5345 struct reserve_ticket *ticket;
5346 struct list_head *head;
5347 u64 used;
5348 enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH;
5349 bool check_overcommit = false;
5350
5351 spin_lock(&space_info->lock);
5352 head = &space_info->priority_tickets;
5353
5354 /*
5355 * If we are over our limit then we need to check and see if we can
5356 * overcommit, and if we can't then we just need to free up our space
5357 * and not satisfy any requests.
5358 */
5359 used = space_info->bytes_used + space_info->bytes_reserved +
5360 space_info->bytes_pinned + space_info->bytes_readonly +
5361 space_info->bytes_may_use;
5362 if (used - num_bytes >= space_info->total_bytes)
5363 check_overcommit = true;
5364 again:
5365 while (!list_empty(head) && num_bytes) {
5366 ticket = list_first_entry(head, struct reserve_ticket,
5367 list);
5368 /*
5369 * We use 0 bytes because this space is already reserved, so
5370 * adding the ticket space would be a double count.
5371 */
5372 if (check_overcommit &&
5373 !can_overcommit(fs_info->extent_root, space_info, 0,
5374 flush))
5375 break;
5376 if (num_bytes >= ticket->bytes) {
5377 list_del_init(&ticket->list);
5378 num_bytes -= ticket->bytes;
5379 ticket->bytes = 0;
5380 space_info->tickets_id++;
5381 wake_up(&ticket->wait);
5382 } else {
5383 ticket->bytes -= num_bytes;
5384 num_bytes = 0;
5385 }
5386 }
5387
5388 if (num_bytes && head == &space_info->priority_tickets) {
5389 head = &space_info->tickets;
5390 flush = BTRFS_RESERVE_FLUSH_ALL;
5391 goto again;
5392 }
5393 space_info->bytes_may_use -= num_bytes;
5394 trace_btrfs_space_reservation(fs_info, "space_info",
5395 space_info->flags, num_bytes, 0);
5396 spin_unlock(&space_info->lock);
5397 }
5398
5399 /*
5400 * This is for newly allocated space that isn't accounted in
5401 * space_info->bytes_may_use yet. So if we allocate a chunk or unpin an extent
5402 * we use this helper.
5403 */
5404 static void space_info_add_new_bytes(struct btrfs_fs_info *fs_info,
5405 struct btrfs_space_info *space_info,
5406 u64 num_bytes)
5407 {
5408 struct reserve_ticket *ticket;
5409 struct list_head *head = &space_info->priority_tickets;
5410
5411 again:
5412 while (!list_empty(head) && num_bytes) {
5413 ticket = list_first_entry(head, struct reserve_ticket,
5414 list);
5415 if (num_bytes >= ticket->bytes) {
5416 trace_btrfs_space_reservation(fs_info, "space_info",
5417 space_info->flags,
5418 ticket->bytes, 1);
5419 list_del_init(&ticket->list);
5420 num_bytes -= ticket->bytes;
5421 space_info->bytes_may_use += ticket->bytes;
5422 ticket->bytes = 0;
5423 space_info->tickets_id++;
5424 wake_up(&ticket->wait);
5425 } else {
5426 trace_btrfs_space_reservation(fs_info, "space_info",
5427 space_info->flags,
5428 num_bytes, 1);
5429 space_info->bytes_may_use += num_bytes;
5430 ticket->bytes -= num_bytes;
5431 num_bytes = 0;
5432 }
5433 }
5434
5435 if (num_bytes && head == &space_info->priority_tickets) {
5436 head = &space_info->tickets;
5437 goto again;
5438 }
5439 }
5440
5441 static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
5442 struct btrfs_block_rsv *block_rsv,
5443 struct btrfs_block_rsv *dest, u64 num_bytes)
5444 {
5445 struct btrfs_space_info *space_info = block_rsv->space_info;
5446
5447 spin_lock(&block_rsv->lock);
5448 if (num_bytes == (u64)-1)
5449 num_bytes = block_rsv->size;
5450 block_rsv->size -= num_bytes;
5451 if (block_rsv->reserved >= block_rsv->size) {
5452 num_bytes = block_rsv->reserved - block_rsv->size;
5453 block_rsv->reserved = block_rsv->size;
5454 block_rsv->full = 1;
5455 } else {
5456 num_bytes = 0;
5457 }
5458 spin_unlock(&block_rsv->lock);
5459
5460 if (num_bytes > 0) {
5461 if (dest) {
5462 spin_lock(&dest->lock);
5463 if (!dest->full) {
5464 u64 bytes_to_add;
5465
5466 bytes_to_add = dest->size - dest->reserved;
5467 bytes_to_add = min(num_bytes, bytes_to_add);
5468 dest->reserved += bytes_to_add;
5469 if (dest->reserved >= dest->size)
5470 dest->full = 1;
5471 num_bytes -= bytes_to_add;
5472 }
5473 spin_unlock(&dest->lock);
5474 }
5475 if (num_bytes)
5476 space_info_add_old_bytes(fs_info, space_info,
5477 num_bytes);
5478 }
5479 }
5480
5481 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src,
5482 struct btrfs_block_rsv *dst, u64 num_bytes,
5483 int update_size)
5484 {
5485 int ret;
5486
5487 ret = block_rsv_use_bytes(src, num_bytes);
5488 if (ret)
5489 return ret;
5490
5491 block_rsv_add_bytes(dst, num_bytes, update_size);
5492 return 0;
5493 }
5494
5495 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
5496 {
5497 memset(rsv, 0, sizeof(*rsv));
5498 spin_lock_init(&rsv->lock);
5499 rsv->type = type;
5500 }
5501
5502 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
5503 unsigned short type)
5504 {
5505 struct btrfs_block_rsv *block_rsv;
5506
5507 block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
5508 if (!block_rsv)
5509 return NULL;
5510
5511 btrfs_init_block_rsv(block_rsv, type);
5512 block_rsv->space_info = __find_space_info(fs_info,
5513 BTRFS_BLOCK_GROUP_METADATA);
5514 return block_rsv;
5515 }
5516
5517 void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
5518 struct btrfs_block_rsv *rsv)
5519 {
5520 if (!rsv)
5521 return;
5522 btrfs_block_rsv_release(fs_info, rsv, (u64)-1);
5523 kfree(rsv);
5524 }
5525
5526 void __btrfs_free_block_rsv(struct btrfs_block_rsv *rsv)
5527 {
5528 kfree(rsv);
5529 }
5530
5531 int btrfs_block_rsv_add(struct btrfs_root *root,
5532 struct btrfs_block_rsv *block_rsv, u64 num_bytes,
5533 enum btrfs_reserve_flush_enum flush)
5534 {
5535 int ret;
5536
5537 if (num_bytes == 0)
5538 return 0;
5539
5540 ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
5541 if (!ret) {
5542 block_rsv_add_bytes(block_rsv, num_bytes, 1);
5543 return 0;
5544 }
5545
5546 return ret;
5547 }
5548
5549 int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_factor)
5550 {
5551 u64 num_bytes = 0;
5552 int ret = -ENOSPC;
5553
5554 if (!block_rsv)
5555 return 0;
5556
5557 spin_lock(&block_rsv->lock);
5558 num_bytes = div_factor(block_rsv->size, min_factor);
5559 if (block_rsv->reserved >= num_bytes)
5560 ret = 0;
5561 spin_unlock(&block_rsv->lock);
5562
5563 return ret;
5564 }
5565
5566 int btrfs_block_rsv_refill(struct btrfs_root *root,
5567 struct btrfs_block_rsv *block_rsv, u64 min_reserved,
5568 enum btrfs_reserve_flush_enum flush)
5569 {
5570 u64 num_bytes = 0;
5571 int ret = -ENOSPC;
5572
5573 if (!block_rsv)
5574 return 0;
5575
5576 spin_lock(&block_rsv->lock);
5577 num_bytes = min_reserved;
5578 if (block_rsv->reserved >= num_bytes)
5579 ret = 0;
5580 else
5581 num_bytes -= block_rsv->reserved;
5582 spin_unlock(&block_rsv->lock);
5583
5584 if (!ret)
5585 return 0;
5586
5587 ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
5588 if (!ret) {
5589 block_rsv_add_bytes(block_rsv, num_bytes, 0);
5590 return 0;
5591 }
5592
5593 return ret;
5594 }
5595
5596 void btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
5597 struct btrfs_block_rsv *block_rsv,
5598 u64 num_bytes)
5599 {
5600 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5601
5602 if (global_rsv == block_rsv ||
5603 block_rsv->space_info != global_rsv->space_info)
5604 global_rsv = NULL;
5605 block_rsv_release_bytes(fs_info, block_rsv, global_rsv, num_bytes);
5606 }
5607
5608 static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
5609 {
5610 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
5611 struct btrfs_space_info *sinfo = block_rsv->space_info;
5612 u64 num_bytes;
5613
5614 /*
5615 * The global block rsv is based on the size of the extent tree, the
5616 * checksum tree and the root tree. If the fs is empty we want to set
5617 * it to a minimal amount for safety.
5618 */
5619 num_bytes = btrfs_root_used(&fs_info->extent_root->root_item) +
5620 btrfs_root_used(&fs_info->csum_root->root_item) +
5621 btrfs_root_used(&fs_info->tree_root->root_item);
5622 num_bytes = max_t(u64, num_bytes, SZ_16M);
5623
5624 spin_lock(&sinfo->lock);
5625 spin_lock(&block_rsv->lock);
5626
5627 block_rsv->size = min_t(u64, num_bytes, SZ_512M);
5628
5629 if (block_rsv->reserved < block_rsv->size) {
5630 num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
5631 sinfo->bytes_reserved + sinfo->bytes_readonly +
5632 sinfo->bytes_may_use;
5633 if (sinfo->total_bytes > num_bytes) {
5634 num_bytes = sinfo->total_bytes - num_bytes;
5635 num_bytes = min(num_bytes,
5636 block_rsv->size - block_rsv->reserved);
5637 block_rsv->reserved += num_bytes;
5638 sinfo->bytes_may_use += num_bytes;
5639 trace_btrfs_space_reservation(fs_info, "space_info",
5640 sinfo->flags, num_bytes,
5641 1);
5642 }
5643 } else if (block_rsv->reserved > block_rsv->size) {
5644 num_bytes = block_rsv->reserved - block_rsv->size;
5645 sinfo->bytes_may_use -= num_bytes;
5646 trace_btrfs_space_reservation(fs_info, "space_info",
5647 sinfo->flags, num_bytes, 0);
5648 block_rsv->reserved = block_rsv->size;
5649 }
5650
5651 if (block_rsv->reserved == block_rsv->size)
5652 block_rsv->full = 1;
5653 else
5654 block_rsv->full = 0;
5655
5656 spin_unlock(&block_rsv->lock);
5657 spin_unlock(&sinfo->lock);
5658 }
5659
5660 static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
5661 {
5662 struct btrfs_space_info *space_info;
5663
5664 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
5665 fs_info->chunk_block_rsv.space_info = space_info;
5666
5667 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
5668 fs_info->global_block_rsv.space_info = space_info;
5669 fs_info->delalloc_block_rsv.space_info = space_info;
5670 fs_info->trans_block_rsv.space_info = space_info;
5671 fs_info->empty_block_rsv.space_info = space_info;
5672 fs_info->delayed_block_rsv.space_info = space_info;
5673
5674 fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
5675 fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
5676 fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
5677 fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
5678 if (fs_info->quota_root)
5679 fs_info->quota_root->block_rsv = &fs_info->global_block_rsv;
5680 fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
5681
5682 update_global_block_rsv(fs_info);
5683 }
5684
5685 static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
5686 {
5687 block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL,
5688 (u64)-1);
5689 WARN_ON(fs_info->delalloc_block_rsv.size > 0);
5690 WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
5691 WARN_ON(fs_info->trans_block_rsv.size > 0);
5692 WARN_ON(fs_info->trans_block_rsv.reserved > 0);
5693 WARN_ON(fs_info->chunk_block_rsv.size > 0);
5694 WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
5695 WARN_ON(fs_info->delayed_block_rsv.size > 0);
5696 WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
5697 }
5698
5699 void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
5700 struct btrfs_fs_info *fs_info)
5701 {
5702 if (!trans->block_rsv)
5703 return;
5704
5705 if (!trans->bytes_reserved)
5706 return;
5707
5708 trace_btrfs_space_reservation(fs_info, "transaction",
5709 trans->transid, trans->bytes_reserved, 0);
5710 btrfs_block_rsv_release(fs_info, trans->block_rsv,
5711 trans->bytes_reserved);
5712 trans->bytes_reserved = 0;
5713 }
5714
5715 /*
5716 * To be called after all the new block groups attached to the transaction
5717 * handle have been created (btrfs_create_pending_block_groups()).
5718 */
5719 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans)
5720 {
5721 struct btrfs_fs_info *fs_info = trans->fs_info;
5722
5723 if (!trans->chunk_bytes_reserved)
5724 return;
5725
5726 WARN_ON_ONCE(!list_empty(&trans->new_bgs));
5727
5728 block_rsv_release_bytes(fs_info, &fs_info->chunk_block_rsv, NULL,
5729 trans->chunk_bytes_reserved);
5730 trans->chunk_bytes_reserved = 0;
5731 }
5732
5733 /* Can only return 0 or -ENOSPC */
5734 int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
5735 struct inode *inode)
5736 {
5737 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5738 struct btrfs_root *root = BTRFS_I(inode)->root;
5739 /*
5740 * We always use trans->block_rsv here as we will have reserved space
5741 * for our orphan when starting the transaction, using get_block_rsv()
5742 * here will sometimes make us choose the wrong block rsv as we could be
5743 * doing a reloc inode for a non refcounted root.
5744 */
5745 struct btrfs_block_rsv *src_rsv = trans->block_rsv;
5746 struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
5747
5748 /*
5749 * We need to hold space in order to delete our orphan item once we've
5750 * added it, so this takes the reservation so we can release it later
5751 * when we are truly done with the orphan item.
5752 */
5753 u64 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
5754
5755 trace_btrfs_space_reservation(fs_info, "orphan",
5756 btrfs_ino(inode), num_bytes, 1);
5757 return btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, 1);
5758 }
5759
5760 void btrfs_orphan_release_metadata(struct inode *inode)
5761 {
5762 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5763 struct btrfs_root *root = BTRFS_I(inode)->root;
5764 u64 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
5765
5766 trace_btrfs_space_reservation(fs_info, "orphan",
5767 btrfs_ino(inode), num_bytes, 0);
5768 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv, num_bytes);
5769 }
5770
5771 /*
5772 * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
5773 * root: the root of the parent directory
5774 * rsv: block reservation
5775 * items: the number of items that we need do reservation
5776 * qgroup_reserved: used to return the reserved size in qgroup
5777 *
5778 * This function is used to reserve the space for snapshot/subvolume
5779 * creation and deletion. Those operations are different with the
5780 * common file/directory operations, they change two fs/file trees
5781 * and root tree, the number of items that the qgroup reserves is
5782 * different with the free space reservation. So we can not use
5783 * the space reservation mechanism in start_transaction().
5784 */
5785 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
5786 struct btrfs_block_rsv *rsv,
5787 int items,
5788 u64 *qgroup_reserved,
5789 bool use_global_rsv)
5790 {
5791 u64 num_bytes;
5792 int ret;
5793 struct btrfs_fs_info *fs_info = root->fs_info;
5794 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5795
5796 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
5797 /* One for parent inode, two for dir entries */
5798 num_bytes = 3 * fs_info->nodesize;
5799 ret = btrfs_qgroup_reserve_meta(root, num_bytes);
5800 if (ret)
5801 return ret;
5802 } else {
5803 num_bytes = 0;
5804 }
5805
5806 *qgroup_reserved = num_bytes;
5807
5808 num_bytes = btrfs_calc_trans_metadata_size(fs_info, items);
5809 rsv->space_info = __find_space_info(fs_info,
5810 BTRFS_BLOCK_GROUP_METADATA);
5811 ret = btrfs_block_rsv_add(root, rsv, num_bytes,
5812 BTRFS_RESERVE_FLUSH_ALL);
5813
5814 if (ret == -ENOSPC && use_global_rsv)
5815 ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes, 1);
5816
5817 if (ret && *qgroup_reserved)
5818 btrfs_qgroup_free_meta(root, *qgroup_reserved);
5819
5820 return ret;
5821 }
5822
5823 void btrfs_subvolume_release_metadata(struct btrfs_fs_info *fs_info,
5824 struct btrfs_block_rsv *rsv,
5825 u64 qgroup_reserved)
5826 {
5827 btrfs_block_rsv_release(fs_info, rsv, (u64)-1);
5828 }
5829
5830 /**
5831 * drop_outstanding_extent - drop an outstanding extent
5832 * @inode: the inode we're dropping the extent for
5833 * @num_bytes: the number of bytes we're releasing.
5834 *
5835 * This is called when we are freeing up an outstanding extent, either called
5836 * after an error or after an extent is written. This will return the number of
5837 * reserved extents that need to be freed. This must be called with
5838 * BTRFS_I(inode)->lock held.
5839 */
5840 static unsigned drop_outstanding_extent(struct inode *inode, u64 num_bytes)
5841 {
5842 unsigned drop_inode_space = 0;
5843 unsigned dropped_extents = 0;
5844 unsigned num_extents = 0;
5845
5846 num_extents = (unsigned)div64_u64(num_bytes +
5847 BTRFS_MAX_EXTENT_SIZE - 1,
5848 BTRFS_MAX_EXTENT_SIZE);
5849 ASSERT(num_extents);
5850 ASSERT(BTRFS_I(inode)->outstanding_extents >= num_extents);
5851 BTRFS_I(inode)->outstanding_extents -= num_extents;
5852
5853 if (BTRFS_I(inode)->outstanding_extents == 0 &&
5854 test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
5855 &BTRFS_I(inode)->runtime_flags))
5856 drop_inode_space = 1;
5857
5858 /*
5859 * If we have more or the same amount of outstanding extents than we have
5860 * reserved then we need to leave the reserved extents count alone.
5861 */
5862 if (BTRFS_I(inode)->outstanding_extents >=
5863 BTRFS_I(inode)->reserved_extents)
5864 return drop_inode_space;
5865
5866 dropped_extents = BTRFS_I(inode)->reserved_extents -
5867 BTRFS_I(inode)->outstanding_extents;
5868 BTRFS_I(inode)->reserved_extents -= dropped_extents;
5869 return dropped_extents + drop_inode_space;
5870 }
5871
5872 /**
5873 * calc_csum_metadata_size - return the amount of metadata space that must be
5874 * reserved/freed for the given bytes.
5875 * @inode: the inode we're manipulating
5876 * @num_bytes: the number of bytes in question
5877 * @reserve: 1 if we are reserving space, 0 if we are freeing space
5878 *
5879 * This adjusts the number of csum_bytes in the inode and then returns the
5880 * correct amount of metadata that must either be reserved or freed. We
5881 * calculate how many checksums we can fit into one leaf and then divide the
5882 * number of bytes that will need to be checksumed by this value to figure out
5883 * how many checksums will be required. If we are adding bytes then the number
5884 * may go up and we will return the number of additional bytes that must be
5885 * reserved. If it is going down we will return the number of bytes that must
5886 * be freed.
5887 *
5888 * This must be called with BTRFS_I(inode)->lock held.
5889 */
5890 static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes,
5891 int reserve)
5892 {
5893 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5894 u64 old_csums, num_csums;
5895
5896 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM &&
5897 BTRFS_I(inode)->csum_bytes == 0)
5898 return 0;
5899
5900 old_csums = btrfs_csum_bytes_to_leaves(fs_info,
5901 BTRFS_I(inode)->csum_bytes);
5902 if (reserve)
5903 BTRFS_I(inode)->csum_bytes += num_bytes;
5904 else
5905 BTRFS_I(inode)->csum_bytes -= num_bytes;
5906 num_csums = btrfs_csum_bytes_to_leaves(fs_info,
5907 BTRFS_I(inode)->csum_bytes);
5908
5909 /* No change, no need to reserve more */
5910 if (old_csums == num_csums)
5911 return 0;
5912
5913 if (reserve)
5914 return btrfs_calc_trans_metadata_size(fs_info,
5915 num_csums - old_csums);
5916
5917 return btrfs_calc_trans_metadata_size(fs_info, old_csums - num_csums);
5918 }
5919
5920 int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
5921 {
5922 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5923 struct btrfs_root *root = BTRFS_I(inode)->root;
5924 struct btrfs_block_rsv *block_rsv = &fs_info->delalloc_block_rsv;
5925 u64 to_reserve = 0;
5926 u64 csum_bytes;
5927 unsigned nr_extents = 0;
5928 enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL;
5929 int ret = 0;
5930 bool delalloc_lock = true;
5931 u64 to_free = 0;
5932 unsigned dropped;
5933 bool release_extra = false;
5934
5935 /* If we are a free space inode we need to not flush since we will be in
5936 * the middle of a transaction commit. We also don't need the delalloc
5937 * mutex since we won't race with anybody. We need this mostly to make
5938 * lockdep shut its filthy mouth.
5939 *
5940 * If we have a transaction open (can happen if we call truncate_block
5941 * from truncate), then we need FLUSH_LIMIT so we don't deadlock.
5942 */
5943 if (btrfs_is_free_space_inode(inode)) {
5944 flush = BTRFS_RESERVE_NO_FLUSH;
5945 delalloc_lock = false;
5946 } else if (current->journal_info) {
5947 flush = BTRFS_RESERVE_FLUSH_LIMIT;
5948 }
5949
5950 if (flush != BTRFS_RESERVE_NO_FLUSH &&
5951 btrfs_transaction_in_commit(fs_info))
5952 schedule_timeout(1);
5953
5954 if (delalloc_lock)
5955 mutex_lock(&BTRFS_I(inode)->delalloc_mutex);
5956
5957 num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
5958
5959 spin_lock(&BTRFS_I(inode)->lock);
5960 nr_extents = (unsigned)div64_u64(num_bytes +
5961 BTRFS_MAX_EXTENT_SIZE - 1,
5962 BTRFS_MAX_EXTENT_SIZE);
5963 BTRFS_I(inode)->outstanding_extents += nr_extents;
5964
5965 nr_extents = 0;
5966 if (BTRFS_I(inode)->outstanding_extents >
5967 BTRFS_I(inode)->reserved_extents)
5968 nr_extents += BTRFS_I(inode)->outstanding_extents -
5969 BTRFS_I(inode)->reserved_extents;
5970
5971 /* We always want to reserve a slot for updating the inode. */
5972 to_reserve = btrfs_calc_trans_metadata_size(fs_info, nr_extents + 1);
5973 to_reserve += calc_csum_metadata_size(inode, num_bytes, 1);
5974 csum_bytes = BTRFS_I(inode)->csum_bytes;
5975 spin_unlock(&BTRFS_I(inode)->lock);
5976
5977 if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
5978 ret = btrfs_qgroup_reserve_meta(root,
5979 nr_extents * fs_info->nodesize);
5980 if (ret)
5981 goto out_fail;
5982 }
5983
5984 ret = btrfs_block_rsv_add(root, block_rsv, to_reserve, flush);
5985 if (unlikely(ret)) {
5986 btrfs_qgroup_free_meta(root,
5987 nr_extents * fs_info->nodesize);
5988 goto out_fail;
5989 }
5990
5991 spin_lock(&BTRFS_I(inode)->lock);
5992 if (test_and_set_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
5993 &BTRFS_I(inode)->runtime_flags)) {
5994 to_reserve -= btrfs_calc_trans_metadata_size(fs_info, 1);
5995 release_extra = true;
5996 }
5997 BTRFS_I(inode)->reserved_extents += nr_extents;
5998 spin_unlock(&BTRFS_I(inode)->lock);
5999
6000 if (delalloc_lock)
6001 mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
6002
6003 if (to_reserve)
6004 trace_btrfs_space_reservation(fs_info, "delalloc",
6005 btrfs_ino(inode), to_reserve, 1);
6006 if (release_extra)
6007 btrfs_block_rsv_release(fs_info, block_rsv,
6008 btrfs_calc_trans_metadata_size(fs_info, 1));
6009 return 0;
6010
6011 out_fail:
6012 spin_lock(&BTRFS_I(inode)->lock);
6013 dropped = drop_outstanding_extent(inode, num_bytes);
6014 /*
6015 * If the inodes csum_bytes is the same as the original
6016 * csum_bytes then we know we haven't raced with any free()ers
6017 * so we can just reduce our inodes csum bytes and carry on.
6018 */
6019 if (BTRFS_I(inode)->csum_bytes == csum_bytes) {
6020 calc_csum_metadata_size(inode, num_bytes, 0);
6021 } else {
6022 u64 orig_csum_bytes = BTRFS_I(inode)->csum_bytes;
6023 u64 bytes;
6024
6025 /*
6026 * This is tricky, but first we need to figure out how much we
6027 * freed from any free-ers that occurred during this
6028 * reservation, so we reset ->csum_bytes to the csum_bytes
6029 * before we dropped our lock, and then call the free for the
6030 * number of bytes that were freed while we were trying our
6031 * reservation.
6032 */
6033 bytes = csum_bytes - BTRFS_I(inode)->csum_bytes;
6034 BTRFS_I(inode)->csum_bytes = csum_bytes;
6035 to_free = calc_csum_metadata_size(inode, bytes, 0);
6036
6037
6038 /*
6039 * Now we need to see how much we would have freed had we not
6040 * been making this reservation and our ->csum_bytes were not
6041 * artificially inflated.
6042 */
6043 BTRFS_I(inode)->csum_bytes = csum_bytes - num_bytes;
6044 bytes = csum_bytes - orig_csum_bytes;
6045 bytes = calc_csum_metadata_size(inode, bytes, 0);
6046
6047 /*
6048 * Now reset ->csum_bytes to what it should be. If bytes is
6049 * more than to_free then we would have freed more space had we
6050 * not had an artificially high ->csum_bytes, so we need to free
6051 * the remainder. If bytes is the same or less then we don't
6052 * need to do anything, the other free-ers did the correct
6053 * thing.
6054 */
6055 BTRFS_I(inode)->csum_bytes = orig_csum_bytes - num_bytes;
6056 if (bytes > to_free)
6057 to_free = bytes - to_free;
6058 else
6059 to_free = 0;
6060 }
6061 spin_unlock(&BTRFS_I(inode)->lock);
6062 if (dropped)
6063 to_free += btrfs_calc_trans_metadata_size(fs_info, dropped);
6064
6065 if (to_free) {
6066 btrfs_block_rsv_release(fs_info, block_rsv, to_free);
6067 trace_btrfs_space_reservation(fs_info, "delalloc",
6068 btrfs_ino(inode), to_free, 0);
6069 }
6070 if (delalloc_lock)
6071 mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
6072 return ret;
6073 }
6074
6075 /**
6076 * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
6077 * @inode: the inode to release the reservation for
6078 * @num_bytes: the number of bytes we're releasing
6079 *
6080 * This will release the metadata reservation for an inode. This can be called
6081 * once we complete IO for a given set of bytes to release their metadata
6082 * reservations.
6083 */
6084 void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
6085 {
6086 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6087 u64 to_free = 0;
6088 unsigned dropped;
6089
6090 num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
6091 spin_lock(&BTRFS_I(inode)->lock);
6092 dropped = drop_outstanding_extent(inode, num_bytes);
6093
6094 if (num_bytes)
6095 to_free = calc_csum_metadata_size(inode, num_bytes, 0);
6096 spin_unlock(&BTRFS_I(inode)->lock);
6097 if (dropped > 0)
6098 to_free += btrfs_calc_trans_metadata_size(fs_info, dropped);
6099
6100 if (btrfs_is_testing(fs_info))
6101 return;
6102
6103 trace_btrfs_space_reservation(fs_info, "delalloc",
6104 btrfs_ino(inode), to_free, 0);
6105
6106 btrfs_block_rsv_release(fs_info, &fs_info->delalloc_block_rsv, to_free);
6107 }
6108
6109 /**
6110 * btrfs_delalloc_reserve_space - reserve data and metadata space for
6111 * delalloc
6112 * @inode: inode we're writing to
6113 * @start: start range we are writing to
6114 * @len: how long the range we are writing to
6115 *
6116 * This will do the following things
6117 *
6118 * o reserve space in data space info for num bytes
6119 * and reserve precious corresponding qgroup space
6120 * (Done in check_data_free_space)
6121 *
6122 * o reserve space for metadata space, based on the number of outstanding
6123 * extents and how much csums will be needed
6124 * also reserve metadata space in a per root over-reserve method.
6125 * o add to the inodes->delalloc_bytes
6126 * o add it to the fs_info's delalloc inodes list.
6127 * (Above 3 all done in delalloc_reserve_metadata)
6128 *
6129 * Return 0 for success
6130 * Return <0 for error(-ENOSPC or -EQUOT)
6131 */
6132 int btrfs_delalloc_reserve_space(struct inode *inode, u64 start, u64 len)
6133 {
6134 int ret;
6135
6136 ret = btrfs_check_data_free_space(inode, start, len);
6137 if (ret < 0)
6138 return ret;
6139 ret = btrfs_delalloc_reserve_metadata(inode, len);
6140 if (ret < 0)
6141 btrfs_free_reserved_data_space(inode, start, len);
6142 return ret;
6143 }
6144
6145 /**
6146 * btrfs_delalloc_release_space - release data and metadata space for delalloc
6147 * @inode: inode we're releasing space for
6148 * @start: start position of the space already reserved
6149 * @len: the len of the space already reserved
6150 *
6151 * This must be matched with a call to btrfs_delalloc_reserve_space. This is
6152 * called in the case that we don't need the metadata AND data reservations
6153 * anymore. So if there is an error or we insert an inline extent.
6154 *
6155 * This function will release the metadata space that was not used and will
6156 * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
6157 * list if there are no delalloc bytes left.
6158 * Also it will handle the qgroup reserved space.
6159 */
6160 void btrfs_delalloc_release_space(struct inode *inode, u64 start, u64 len)
6161 {
6162 btrfs_delalloc_release_metadata(inode, len);
6163 btrfs_free_reserved_data_space(inode, start, len);
6164 }
6165
6166 static int update_block_group(struct btrfs_trans_handle *trans,
6167 struct btrfs_fs_info *info, u64 bytenr,
6168 u64 num_bytes, int alloc)
6169 {
6170 struct btrfs_block_group_cache *cache = NULL;
6171 u64 total = num_bytes;
6172 u64 old_val;
6173 u64 byte_in_group;
6174 int factor;
6175
6176 /* block accounting for super block */
6177 spin_lock(&info->delalloc_root_lock);
6178 old_val = btrfs_super_bytes_used(info->super_copy);
6179 if (alloc)
6180 old_val += num_bytes;
6181 else
6182 old_val -= num_bytes;
6183 btrfs_set_super_bytes_used(info->super_copy, old_val);
6184 spin_unlock(&info->delalloc_root_lock);
6185
6186 while (total) {
6187 cache = btrfs_lookup_block_group(info, bytenr);
6188 if (!cache)
6189 return -ENOENT;
6190 if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
6191 BTRFS_BLOCK_GROUP_RAID1 |
6192 BTRFS_BLOCK_GROUP_RAID10))
6193 factor = 2;
6194 else
6195 factor = 1;
6196 /*
6197 * If this block group has free space cache written out, we
6198 * need to make sure to load it if we are removing space. This
6199 * is because we need the unpinning stage to actually add the
6200 * space back to the block group, otherwise we will leak space.
6201 */
6202 if (!alloc && cache->cached == BTRFS_CACHE_NO)
6203 cache_block_group(cache, 1);
6204
6205 byte_in_group = bytenr - cache->key.objectid;
6206 WARN_ON(byte_in_group > cache->key.offset);
6207
6208 spin_lock(&cache->space_info->lock);
6209 spin_lock(&cache->lock);
6210
6211 if (btrfs_test_opt(info, SPACE_CACHE) &&
6212 cache->disk_cache_state < BTRFS_DC_CLEAR)
6213 cache->disk_cache_state = BTRFS_DC_CLEAR;
6214
6215 old_val = btrfs_block_group_used(&cache->item);
6216 num_bytes = min(total, cache->key.offset - byte_in_group);
6217 if (alloc) {
6218 old_val += num_bytes;
6219 btrfs_set_block_group_used(&cache->item, old_val);
6220 cache->reserved -= num_bytes;
6221 cache->space_info->bytes_reserved -= num_bytes;
6222 cache->space_info->bytes_used += num_bytes;
6223 cache->space_info->disk_used += num_bytes * factor;
6224 spin_unlock(&cache->lock);
6225 spin_unlock(&cache->space_info->lock);
6226 } else {
6227 old_val -= num_bytes;
6228 btrfs_set_block_group_used(&cache->item, old_val);
6229 cache->pinned += num_bytes;
6230 cache->space_info->bytes_pinned += num_bytes;
6231 cache->space_info->bytes_used -= num_bytes;
6232 cache->space_info->disk_used -= num_bytes * factor;
6233 spin_unlock(&cache->lock);
6234 spin_unlock(&cache->space_info->lock);
6235
6236 trace_btrfs_space_reservation(info, "pinned",
6237 cache->space_info->flags,
6238 num_bytes, 1);
6239 set_extent_dirty(info->pinned_extents,
6240 bytenr, bytenr + num_bytes - 1,
6241 GFP_NOFS | __GFP_NOFAIL);
6242 }
6243
6244 spin_lock(&trans->transaction->dirty_bgs_lock);
6245 if (list_empty(&cache->dirty_list)) {
6246 list_add_tail(&cache->dirty_list,
6247 &trans->transaction->dirty_bgs);
6248 trans->transaction->num_dirty_bgs++;
6249 btrfs_get_block_group(cache);
6250 }
6251 spin_unlock(&trans->transaction->dirty_bgs_lock);
6252
6253 /*
6254 * No longer have used bytes in this block group, queue it for
6255 * deletion. We do this after adding the block group to the
6256 * dirty list to avoid races between cleaner kthread and space
6257 * cache writeout.
6258 */
6259 if (!alloc && old_val == 0) {
6260 spin_lock(&info->unused_bgs_lock);
6261 if (list_empty(&cache->bg_list)) {
6262 btrfs_get_block_group(cache);
6263 list_add_tail(&cache->bg_list,
6264 &info->unused_bgs);
6265 }
6266 spin_unlock(&info->unused_bgs_lock);
6267 }
6268
6269 btrfs_put_block_group(cache);
6270 total -= num_bytes;
6271 bytenr += num_bytes;
6272 }
6273 return 0;
6274 }
6275
6276 static u64 first_logical_byte(struct btrfs_fs_info *fs_info, u64 search_start)
6277 {
6278 struct btrfs_block_group_cache *cache;
6279 u64 bytenr;
6280
6281 spin_lock(&fs_info->block_group_cache_lock);
6282 bytenr = fs_info->first_logical_byte;
6283 spin_unlock(&fs_info->block_group_cache_lock);
6284
6285 if (bytenr < (u64)-1)
6286 return bytenr;
6287
6288 cache = btrfs_lookup_first_block_group(fs_info, search_start);
6289 if (!cache)
6290 return 0;
6291
6292 bytenr = cache->key.objectid;
6293 btrfs_put_block_group(cache);
6294
6295 return bytenr;
6296 }
6297
6298 static int pin_down_extent(struct btrfs_fs_info *fs_info,
6299 struct btrfs_block_group_cache *cache,
6300 u64 bytenr, u64 num_bytes, int reserved)
6301 {
6302 spin_lock(&cache->space_info->lock);
6303 spin_lock(&cache->lock);
6304 cache->pinned += num_bytes;
6305 cache->space_info->bytes_pinned += num_bytes;
6306 if (reserved) {
6307 cache->reserved -= num_bytes;
6308 cache->space_info->bytes_reserved -= num_bytes;
6309 }
6310 spin_unlock(&cache->lock);
6311 spin_unlock(&cache->space_info->lock);
6312
6313 trace_btrfs_space_reservation(fs_info, "pinned",
6314 cache->space_info->flags, num_bytes, 1);
6315 set_extent_dirty(fs_info->pinned_extents, bytenr,
6316 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
6317 return 0;
6318 }
6319
6320 /*
6321 * this function must be called within transaction
6322 */
6323 int btrfs_pin_extent(struct btrfs_fs_info *fs_info,
6324 u64 bytenr, u64 num_bytes, int reserved)
6325 {
6326 struct btrfs_block_group_cache *cache;
6327
6328 cache = btrfs_lookup_block_group(fs_info, bytenr);
6329 BUG_ON(!cache); /* Logic error */
6330
6331 pin_down_extent(fs_info, cache, bytenr, num_bytes, reserved);
6332
6333 btrfs_put_block_group(cache);
6334 return 0;
6335 }
6336
6337 /*
6338 * this function must be called within transaction
6339 */
6340 int btrfs_pin_extent_for_log_replay(struct btrfs_fs_info *fs_info,
6341 u64 bytenr, u64 num_bytes)
6342 {
6343 struct btrfs_block_group_cache *cache;
6344 int ret;
6345
6346 cache = btrfs_lookup_block_group(fs_info, bytenr);
6347 if (!cache)
6348 return -EINVAL;
6349
6350 /*
6351 * pull in the free space cache (if any) so that our pin
6352 * removes the free space from the cache. We have load_only set
6353 * to one because the slow code to read in the free extents does check
6354 * the pinned extents.
6355 */
6356 cache_block_group(cache, 1);
6357
6358 pin_down_extent(fs_info, cache, bytenr, num_bytes, 0);
6359
6360 /* remove us from the free space cache (if we're there at all) */
6361 ret = btrfs_remove_free_space(cache, bytenr, num_bytes);
6362 btrfs_put_block_group(cache);
6363 return ret;
6364 }
6365
6366 static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
6367 u64 start, u64 num_bytes)
6368 {
6369 int ret;
6370 struct btrfs_block_group_cache *block_group;
6371 struct btrfs_caching_control *caching_ctl;
6372
6373 block_group = btrfs_lookup_block_group(fs_info, start);
6374 if (!block_group)
6375 return -EINVAL;
6376
6377 cache_block_group(block_group, 0);
6378 caching_ctl = get_caching_control(block_group);
6379
6380 if (!caching_ctl) {
6381 /* Logic error */
6382 BUG_ON(!block_group_cache_done(block_group));
6383 ret = btrfs_remove_free_space(block_group, start, num_bytes);
6384 } else {
6385 mutex_lock(&caching_ctl->mutex);
6386
6387 if (start >= caching_ctl->progress) {
6388 ret = add_excluded_extent(fs_info, start, num_bytes);
6389 } else if (start + num_bytes <= caching_ctl->progress) {
6390 ret = btrfs_remove_free_space(block_group,
6391 start, num_bytes);
6392 } else {
6393 num_bytes = caching_ctl->progress - start;
6394 ret = btrfs_remove_free_space(block_group,
6395 start, num_bytes);
6396 if (ret)
6397 goto out_lock;
6398
6399 num_bytes = (start + num_bytes) -
6400 caching_ctl->progress;
6401 start = caching_ctl->progress;
6402 ret = add_excluded_extent(fs_info, start, num_bytes);
6403 }
6404 out_lock:
6405 mutex_unlock(&caching_ctl->mutex);
6406 put_caching_control(caching_ctl);
6407 }
6408 btrfs_put_block_group(block_group);
6409 return ret;
6410 }
6411
6412 int btrfs_exclude_logged_extents(struct btrfs_fs_info *fs_info,
6413 struct extent_buffer *eb)
6414 {
6415 struct btrfs_file_extent_item *item;
6416 struct btrfs_key key;
6417 int found_type;
6418 int i;
6419
6420 if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS))
6421 return 0;
6422
6423 for (i = 0; i < btrfs_header_nritems(eb); i++) {
6424 btrfs_item_key_to_cpu(eb, &key, i);
6425 if (key.type != BTRFS_EXTENT_DATA_KEY)
6426 continue;
6427 item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
6428 found_type = btrfs_file_extent_type(eb, item);
6429 if (found_type == BTRFS_FILE_EXTENT_INLINE)
6430 continue;
6431 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
6432 continue;
6433 key.objectid = btrfs_file_extent_disk_bytenr(eb, item);
6434 key.offset = btrfs_file_extent_disk_num_bytes(eb, item);
6435 __exclude_logged_extent(fs_info, key.objectid, key.offset);
6436 }
6437
6438 return 0;
6439 }
6440
6441 static void
6442 btrfs_inc_block_group_reservations(struct btrfs_block_group_cache *bg)
6443 {
6444 atomic_inc(&bg->reservations);
6445 }
6446
6447 void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
6448 const u64 start)
6449 {
6450 struct btrfs_block_group_cache *bg;
6451
6452 bg = btrfs_lookup_block_group(fs_info, start);
6453 ASSERT(bg);
6454 if (atomic_dec_and_test(&bg->reservations))
6455 wake_up_atomic_t(&bg->reservations);
6456 btrfs_put_block_group(bg);
6457 }
6458
6459 static int btrfs_wait_bg_reservations_atomic_t(atomic_t *a)
6460 {
6461 schedule();
6462 return 0;
6463 }
6464
6465 void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg)
6466 {
6467 struct btrfs_space_info *space_info = bg->space_info;
6468
6469 ASSERT(bg->ro);
6470
6471 if (!(bg->flags & BTRFS_BLOCK_GROUP_DATA))
6472 return;
6473
6474 /*
6475 * Our block group is read only but before we set it to read only,
6476 * some task might have had allocated an extent from it already, but it
6477 * has not yet created a respective ordered extent (and added it to a
6478 * root's list of ordered extents).
6479 * Therefore wait for any task currently allocating extents, since the
6480 * block group's reservations counter is incremented while a read lock
6481 * on the groups' semaphore is held and decremented after releasing
6482 * the read access on that semaphore and creating the ordered extent.
6483 */
6484 down_write(&space_info->groups_sem);
6485 up_write(&space_info->groups_sem);
6486
6487 wait_on_atomic_t(&bg->reservations,
6488 btrfs_wait_bg_reservations_atomic_t,
6489 TASK_UNINTERRUPTIBLE);
6490 }
6491
6492 /**
6493 * btrfs_add_reserved_bytes - update the block_group and space info counters
6494 * @cache: The cache we are manipulating
6495 * @ram_bytes: The number of bytes of file content, and will be same to
6496 * @num_bytes except for the compress path.
6497 * @num_bytes: The number of bytes in question
6498 * @delalloc: The blocks are allocated for the delalloc write
6499 *
6500 * This is called by the allocator when it reserves space. If this is a
6501 * reservation and the block group has become read only we cannot make the
6502 * reservation and return -EAGAIN, otherwise this function always succeeds.
6503 */
6504 static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
6505 u64 ram_bytes, u64 num_bytes, int delalloc)
6506 {
6507 struct btrfs_space_info *space_info = cache->space_info;
6508 int ret = 0;
6509
6510 spin_lock(&space_info->lock);
6511 spin_lock(&cache->lock);
6512 if (cache->ro) {
6513 ret = -EAGAIN;
6514 } else {
6515 cache->reserved += num_bytes;
6516 space_info->bytes_reserved += num_bytes;
6517
6518 trace_btrfs_space_reservation(cache->fs_info,
6519 "space_info", space_info->flags,
6520 ram_bytes, 0);
6521 space_info->bytes_may_use -= ram_bytes;
6522 if (delalloc)
6523 cache->delalloc_bytes += num_bytes;
6524 }
6525 spin_unlock(&cache->lock);
6526 spin_unlock(&space_info->lock);
6527 return ret;
6528 }
6529
6530 /**
6531 * btrfs_free_reserved_bytes - update the block_group and space info counters
6532 * @cache: The cache we are manipulating
6533 * @num_bytes: The number of bytes in question
6534 * @delalloc: The blocks are allocated for the delalloc write
6535 *
6536 * This is called by somebody who is freeing space that was never actually used
6537 * on disk. For example if you reserve some space for a new leaf in transaction
6538 * A and before transaction A commits you free that leaf, you call this with
6539 * reserve set to 0 in order to clear the reservation.
6540 */
6541
6542 static int btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
6543 u64 num_bytes, int delalloc)
6544 {
6545 struct btrfs_space_info *space_info = cache->space_info;
6546 int ret = 0;
6547
6548 spin_lock(&space_info->lock);
6549 spin_lock(&cache->lock);
6550 if (cache->ro)
6551 space_info->bytes_readonly += num_bytes;
6552 cache->reserved -= num_bytes;
6553 space_info->bytes_reserved -= num_bytes;
6554
6555 if (delalloc)
6556 cache->delalloc_bytes -= num_bytes;
6557 spin_unlock(&cache->lock);
6558 spin_unlock(&space_info->lock);
6559 return ret;
6560 }
6561 void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
6562 struct btrfs_fs_info *fs_info)
6563 {
6564 struct btrfs_caching_control *next;
6565 struct btrfs_caching_control *caching_ctl;
6566 struct btrfs_block_group_cache *cache;
6567
6568 down_write(&fs_info->commit_root_sem);
6569
6570 list_for_each_entry_safe(caching_ctl, next,
6571 &fs_info->caching_block_groups, list) {
6572 cache = caching_ctl->block_group;
6573 if (block_group_cache_done(cache)) {
6574 cache->last_byte_to_unpin = (u64)-1;
6575 list_del_init(&caching_ctl->list);
6576 put_caching_control(caching_ctl);
6577 } else {
6578 cache->last_byte_to_unpin = caching_ctl->progress;
6579 }
6580 }
6581
6582 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
6583 fs_info->pinned_extents = &fs_info->freed_extents[1];
6584 else
6585 fs_info->pinned_extents = &fs_info->freed_extents[0];
6586
6587 up_write(&fs_info->commit_root_sem);
6588
6589 update_global_block_rsv(fs_info);
6590 }
6591
6592 /*
6593 * Returns the free cluster for the given space info and sets empty_cluster to
6594 * what it should be based on the mount options.
6595 */
6596 static struct btrfs_free_cluster *
6597 fetch_cluster_info(struct btrfs_fs_info *fs_info,
6598 struct btrfs_space_info *space_info, u64 *empty_cluster)
6599 {
6600 struct btrfs_free_cluster *ret = NULL;
6601 bool ssd = btrfs_test_opt(fs_info, SSD);
6602
6603 *empty_cluster = 0;
6604 if (btrfs_mixed_space_info(space_info))
6605 return ret;
6606
6607 if (ssd)
6608 *empty_cluster = SZ_2M;
6609 if (space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
6610 ret = &fs_info->meta_alloc_cluster;
6611 if (!ssd)
6612 *empty_cluster = SZ_64K;
6613 } else if ((space_info->flags & BTRFS_BLOCK_GROUP_DATA) && ssd) {
6614 ret = &fs_info->data_alloc_cluster;
6615 }
6616
6617 return ret;
6618 }
6619
6620 static int unpin_extent_range(struct btrfs_fs_info *fs_info,
6621 u64 start, u64 end,
6622 const bool return_free_space)
6623 {
6624 struct btrfs_block_group_cache *cache = NULL;
6625 struct btrfs_space_info *space_info;
6626 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
6627 struct btrfs_free_cluster *cluster = NULL;
6628 u64 len;
6629 u64 total_unpinned = 0;
6630 u64 empty_cluster = 0;
6631 bool readonly;
6632
6633 while (start <= end) {
6634 readonly = false;
6635 if (!cache ||
6636 start >= cache->key.objectid + cache->key.offset) {
6637 if (cache)
6638 btrfs_put_block_group(cache);
6639 total_unpinned = 0;
6640 cache = btrfs_lookup_block_group(fs_info, start);
6641 BUG_ON(!cache); /* Logic error */
6642
6643 cluster = fetch_cluster_info(fs_info,
6644 cache->space_info,
6645 &empty_cluster);
6646 empty_cluster <<= 1;
6647 }
6648
6649 len = cache->key.objectid + cache->key.offset - start;
6650 len = min(len, end + 1 - start);
6651
6652 if (start < cache->last_byte_to_unpin) {
6653 len = min(len, cache->last_byte_to_unpin - start);
6654 if (return_free_space)
6655 btrfs_add_free_space(cache, start, len);
6656 }
6657
6658 start += len;
6659 total_unpinned += len;
6660 space_info = cache->space_info;
6661
6662 /*
6663 * If this space cluster has been marked as fragmented and we've
6664 * unpinned enough in this block group to potentially allow a
6665 * cluster to be created inside of it go ahead and clear the
6666 * fragmented check.
6667 */
6668 if (cluster && cluster->fragmented &&
6669 total_unpinned > empty_cluster) {
6670 spin_lock(&cluster->lock);
6671 cluster->fragmented = 0;
6672 spin_unlock(&cluster->lock);
6673 }
6674
6675 spin_lock(&space_info->lock);
6676 spin_lock(&cache->lock);
6677 cache->pinned -= len;
6678 space_info->bytes_pinned -= len;
6679
6680 trace_btrfs_space_reservation(fs_info, "pinned",
6681 space_info->flags, len, 0);
6682 space_info->max_extent_size = 0;
6683 percpu_counter_add(&space_info->total_bytes_pinned, -len);
6684 if (cache->ro) {
6685 space_info->bytes_readonly += len;
6686 readonly = true;
6687 }
6688 spin_unlock(&cache->lock);
6689 if (!readonly && return_free_space &&
6690 global_rsv->space_info == space_info) {
6691 u64 to_add = len;
6692 WARN_ON(!return_free_space);
6693 spin_lock(&global_rsv->lock);
6694 if (!global_rsv->full) {
6695 to_add = min(len, global_rsv->size -
6696 global_rsv->reserved);
6697 global_rsv->reserved += to_add;
6698 space_info->bytes_may_use += to_add;
6699 if (global_rsv->reserved >= global_rsv->size)
6700 global_rsv->full = 1;
6701 trace_btrfs_space_reservation(fs_info,
6702 "space_info",
6703 space_info->flags,
6704 to_add, 1);
6705 len -= to_add;
6706 }
6707 spin_unlock(&global_rsv->lock);
6708 /* Add to any tickets we may have */
6709 if (len)
6710 space_info_add_new_bytes(fs_info, space_info,
6711 len);
6712 }
6713 spin_unlock(&space_info->lock);
6714 }
6715
6716 if (cache)
6717 btrfs_put_block_group(cache);
6718 return 0;
6719 }
6720
6721 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
6722 struct btrfs_fs_info *fs_info)
6723 {
6724 struct btrfs_block_group_cache *block_group, *tmp;
6725 struct list_head *deleted_bgs;
6726 struct extent_io_tree *unpin;
6727 u64 start;
6728 u64 end;
6729 int ret;
6730
6731 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
6732 unpin = &fs_info->freed_extents[1];
6733 else
6734 unpin = &fs_info->freed_extents[0];
6735
6736 while (!trans->aborted) {
6737 mutex_lock(&fs_info->unused_bg_unpin_mutex);
6738 ret = find_first_extent_bit(unpin, 0, &start, &end,
6739 EXTENT_DIRTY, NULL);
6740 if (ret) {
6741 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
6742 break;
6743 }
6744
6745 if (btrfs_test_opt(fs_info, DISCARD))
6746 ret = btrfs_discard_extent(fs_info, start,
6747 end + 1 - start, NULL);
6748
6749 clear_extent_dirty(unpin, start, end);
6750 unpin_extent_range(fs_info, start, end, true);
6751 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
6752 cond_resched();
6753 }
6754
6755 /*
6756 * Transaction is finished. We don't need the lock anymore. We
6757 * do need to clean up the block groups in case of a transaction
6758 * abort.
6759 */
6760 deleted_bgs = &trans->transaction->deleted_bgs;
6761 list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) {
6762 u64 trimmed = 0;
6763
6764 ret = -EROFS;
6765 if (!trans->aborted)
6766 ret = btrfs_discard_extent(fs_info,
6767 block_group->key.objectid,
6768 block_group->key.offset,
6769 &trimmed);
6770
6771 list_del_init(&block_group->bg_list);
6772 btrfs_put_block_group_trimming(block_group);
6773 btrfs_put_block_group(block_group);
6774
6775 if (ret) {
6776 const char *errstr = btrfs_decode_error(ret);
6777 btrfs_warn(fs_info,
6778 "Discard failed while removing blockgroup: errno=%d %s\n",
6779 ret, errstr);
6780 }
6781 }
6782
6783 return 0;
6784 }
6785
6786 static void add_pinned_bytes(struct btrfs_fs_info *fs_info, u64 num_bytes,
6787 u64 owner, u64 root_objectid)
6788 {
6789 struct btrfs_space_info *space_info;
6790 u64 flags;
6791
6792 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
6793 if (root_objectid == BTRFS_CHUNK_TREE_OBJECTID)
6794 flags = BTRFS_BLOCK_GROUP_SYSTEM;
6795 else
6796 flags = BTRFS_BLOCK_GROUP_METADATA;
6797 } else {
6798 flags = BTRFS_BLOCK_GROUP_DATA;
6799 }
6800
6801 space_info = __find_space_info(fs_info, flags);
6802 BUG_ON(!space_info); /* Logic bug */
6803 percpu_counter_add(&space_info->total_bytes_pinned, num_bytes);
6804 }
6805
6806
6807 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
6808 struct btrfs_fs_info *info,
6809 struct btrfs_delayed_ref_node *node, u64 parent,
6810 u64 root_objectid, u64 owner_objectid,
6811 u64 owner_offset, int refs_to_drop,
6812 struct btrfs_delayed_extent_op *extent_op)
6813 {
6814 struct btrfs_key key;
6815 struct btrfs_path *path;
6816 struct btrfs_root *extent_root = info->extent_root;
6817 struct extent_buffer *leaf;
6818 struct btrfs_extent_item *ei;
6819 struct btrfs_extent_inline_ref *iref;
6820 int ret;
6821 int is_data;
6822 int extent_slot = 0;
6823 int found_extent = 0;
6824 int num_to_del = 1;
6825 u32 item_size;
6826 u64 refs;
6827 u64 bytenr = node->bytenr;
6828 u64 num_bytes = node->num_bytes;
6829 int last_ref = 0;
6830 bool skinny_metadata = btrfs_fs_incompat(info, SKINNY_METADATA);
6831
6832 path = btrfs_alloc_path();
6833 if (!path)
6834 return -ENOMEM;
6835
6836 path->reada = READA_FORWARD;
6837 path->leave_spinning = 1;
6838
6839 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
6840 BUG_ON(!is_data && refs_to_drop != 1);
6841
6842 if (is_data)
6843 skinny_metadata = 0;
6844
6845 ret = lookup_extent_backref(trans, extent_root, path, &iref,
6846 bytenr, num_bytes, parent,
6847 root_objectid, owner_objectid,
6848 owner_offset);
6849 if (ret == 0) {
6850 extent_slot = path->slots[0];
6851 while (extent_slot >= 0) {
6852 btrfs_item_key_to_cpu(path->nodes[0], &key,
6853 extent_slot);
6854 if (key.objectid != bytenr)
6855 break;
6856 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
6857 key.offset == num_bytes) {
6858 found_extent = 1;
6859 break;
6860 }
6861 if (key.type == BTRFS_METADATA_ITEM_KEY &&
6862 key.offset == owner_objectid) {
6863 found_extent = 1;
6864 break;
6865 }
6866 if (path->slots[0] - extent_slot > 5)
6867 break;
6868 extent_slot--;
6869 }
6870 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
6871 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
6872 if (found_extent && item_size < sizeof(*ei))
6873 found_extent = 0;
6874 #endif
6875 if (!found_extent) {
6876 BUG_ON(iref);
6877 ret = remove_extent_backref(trans, extent_root, path,
6878 NULL, refs_to_drop,
6879 is_data, &last_ref);
6880 if (ret) {
6881 btrfs_abort_transaction(trans, ret);
6882 goto out;
6883 }
6884 btrfs_release_path(path);
6885 path->leave_spinning = 1;
6886
6887 key.objectid = bytenr;
6888 key.type = BTRFS_EXTENT_ITEM_KEY;
6889 key.offset = num_bytes;
6890
6891 if (!is_data && skinny_metadata) {
6892 key.type = BTRFS_METADATA_ITEM_KEY;
6893 key.offset = owner_objectid;
6894 }
6895
6896 ret = btrfs_search_slot(trans, extent_root,
6897 &key, path, -1, 1);
6898 if (ret > 0 && skinny_metadata && path->slots[0]) {
6899 /*
6900 * Couldn't find our skinny metadata item,
6901 * see if we have ye olde extent item.
6902 */
6903 path->slots[0]--;
6904 btrfs_item_key_to_cpu(path->nodes[0], &key,
6905 path->slots[0]);
6906 if (key.objectid == bytenr &&
6907 key.type == BTRFS_EXTENT_ITEM_KEY &&
6908 key.offset == num_bytes)
6909 ret = 0;
6910 }
6911
6912 if (ret > 0 && skinny_metadata) {
6913 skinny_metadata = false;
6914 key.objectid = bytenr;
6915 key.type = BTRFS_EXTENT_ITEM_KEY;
6916 key.offset = num_bytes;
6917 btrfs_release_path(path);
6918 ret = btrfs_search_slot(trans, extent_root,
6919 &key, path, -1, 1);
6920 }
6921
6922 if (ret) {
6923 btrfs_err(info,
6924 "umm, got %d back from search, was looking for %llu",
6925 ret, bytenr);
6926 if (ret > 0)
6927 btrfs_print_leaf(info, path->nodes[0]);
6928 }
6929 if (ret < 0) {
6930 btrfs_abort_transaction(trans, ret);
6931 goto out;
6932 }
6933 extent_slot = path->slots[0];
6934 }
6935 } else if (WARN_ON(ret == -ENOENT)) {
6936 btrfs_print_leaf(info, path->nodes[0]);
6937 btrfs_err(info,
6938 "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu",
6939 bytenr, parent, root_objectid, owner_objectid,
6940 owner_offset);
6941 btrfs_abort_transaction(trans, ret);
6942 goto out;
6943 } else {
6944 btrfs_abort_transaction(trans, ret);
6945 goto out;
6946 }
6947
6948 leaf = path->nodes[0];
6949 item_size = btrfs_item_size_nr(leaf, extent_slot);
6950 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
6951 if (item_size < sizeof(*ei)) {
6952 BUG_ON(found_extent || extent_slot != path->slots[0]);
6953 ret = convert_extent_item_v0(trans, extent_root, path,
6954 owner_objectid, 0);
6955 if (ret < 0) {
6956 btrfs_abort_transaction(trans, ret);
6957 goto out;
6958 }
6959
6960 btrfs_release_path(path);
6961 path->leave_spinning = 1;
6962
6963 key.objectid = bytenr;
6964 key.type = BTRFS_EXTENT_ITEM_KEY;
6965 key.offset = num_bytes;
6966
6967 ret = btrfs_search_slot(trans, extent_root, &key, path,
6968 -1, 1);
6969 if (ret) {
6970 btrfs_err(info,
6971 "umm, got %d back from search, was looking for %llu",
6972 ret, bytenr);
6973 btrfs_print_leaf(info, path->nodes[0]);
6974 }
6975 if (ret < 0) {
6976 btrfs_abort_transaction(trans, ret);
6977 goto out;
6978 }
6979
6980 extent_slot = path->slots[0];
6981 leaf = path->nodes[0];
6982 item_size = btrfs_item_size_nr(leaf, extent_slot);
6983 }
6984 #endif
6985 BUG_ON(item_size < sizeof(*ei));
6986 ei = btrfs_item_ptr(leaf, extent_slot,
6987 struct btrfs_extent_item);
6988 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
6989 key.type == BTRFS_EXTENT_ITEM_KEY) {
6990 struct btrfs_tree_block_info *bi;
6991 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
6992 bi = (struct btrfs_tree_block_info *)(ei + 1);
6993 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
6994 }
6995
6996 refs = btrfs_extent_refs(leaf, ei);
6997 if (refs < refs_to_drop) {
6998 btrfs_err(info,
6999 "trying to drop %d refs but we only have %Lu for bytenr %Lu",
7000 refs_to_drop, refs, bytenr);
7001 ret = -EINVAL;
7002 btrfs_abort_transaction(trans, ret);
7003 goto out;
7004 }
7005 refs -= refs_to_drop;
7006
7007 if (refs > 0) {
7008 if (extent_op)
7009 __run_delayed_extent_op(extent_op, leaf, ei);
7010 /*
7011 * In the case of inline back ref, reference count will
7012 * be updated by remove_extent_backref
7013 */
7014 if (iref) {
7015 BUG_ON(!found_extent);
7016 } else {
7017 btrfs_set_extent_refs(leaf, ei, refs);
7018 btrfs_mark_buffer_dirty(leaf);
7019 }
7020 if (found_extent) {
7021 ret = remove_extent_backref(trans, extent_root, path,
7022 iref, refs_to_drop,
7023 is_data, &last_ref);
7024 if (ret) {
7025 btrfs_abort_transaction(trans, ret);
7026 goto out;
7027 }
7028 }
7029 add_pinned_bytes(info, -num_bytes, owner_objectid,
7030 root_objectid);
7031 } else {
7032 if (found_extent) {
7033 BUG_ON(is_data && refs_to_drop !=
7034 extent_data_ref_count(path, iref));
7035 if (iref) {
7036 BUG_ON(path->slots[0] != extent_slot);
7037 } else {
7038 BUG_ON(path->slots[0] != extent_slot + 1);
7039 path->slots[0] = extent_slot;
7040 num_to_del = 2;
7041 }
7042 }
7043
7044 last_ref = 1;
7045 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
7046 num_to_del);
7047 if (ret) {
7048 btrfs_abort_transaction(trans, ret);
7049 goto out;
7050 }
7051 btrfs_release_path(path);
7052
7053 if (is_data) {
7054 ret = btrfs_del_csums(trans, info, bytenr, num_bytes);
7055 if (ret) {
7056 btrfs_abort_transaction(trans, ret);
7057 goto out;
7058 }
7059 }
7060
7061 ret = add_to_free_space_tree(trans, info, bytenr, num_bytes);
7062 if (ret) {
7063 btrfs_abort_transaction(trans, ret);
7064 goto out;
7065 }
7066
7067 ret = update_block_group(trans, info, bytenr, num_bytes, 0);
7068 if (ret) {
7069 btrfs_abort_transaction(trans, ret);
7070 goto out;
7071 }
7072 }
7073 btrfs_release_path(path);
7074
7075 out:
7076 btrfs_free_path(path);
7077 return ret;
7078 }
7079
7080 /*
7081 * when we free an block, it is possible (and likely) that we free the last
7082 * delayed ref for that extent as well. This searches the delayed ref tree for
7083 * a given extent, and if there are no other delayed refs to be processed, it
7084 * removes it from the tree.
7085 */
7086 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
7087 u64 bytenr)
7088 {
7089 struct btrfs_delayed_ref_head *head;
7090 struct btrfs_delayed_ref_root *delayed_refs;
7091 int ret = 0;
7092
7093 delayed_refs = &trans->transaction->delayed_refs;
7094 spin_lock(&delayed_refs->lock);
7095 head = btrfs_find_delayed_ref_head(trans, bytenr);
7096 if (!head)
7097 goto out_delayed_unlock;
7098
7099 spin_lock(&head->lock);
7100 if (!list_empty(&head->ref_list))
7101 goto out;
7102
7103 if (head->extent_op) {
7104 if (!head->must_insert_reserved)
7105 goto out;
7106 btrfs_free_delayed_extent_op(head->extent_op);
7107 head->extent_op = NULL;
7108 }
7109
7110 /*
7111 * waiting for the lock here would deadlock. If someone else has it
7112 * locked they are already in the process of dropping it anyway
7113 */
7114 if (!mutex_trylock(&head->mutex))
7115 goto out;
7116
7117 /*
7118 * at this point we have a head with no other entries. Go
7119 * ahead and process it.
7120 */
7121 head->node.in_tree = 0;
7122 rb_erase(&head->href_node, &delayed_refs->href_root);
7123
7124 atomic_dec(&delayed_refs->num_entries);
7125
7126 /*
7127 * we don't take a ref on the node because we're removing it from the
7128 * tree, so we just steal the ref the tree was holding.
7129 */
7130 delayed_refs->num_heads--;
7131 if (head->processing == 0)
7132 delayed_refs->num_heads_ready--;
7133 head->processing = 0;
7134 spin_unlock(&head->lock);
7135 spin_unlock(&delayed_refs->lock);
7136
7137 BUG_ON(head->extent_op);
7138 if (head->must_insert_reserved)
7139 ret = 1;
7140
7141 mutex_unlock(&head->mutex);
7142 btrfs_put_delayed_ref(&head->node);
7143 return ret;
7144 out:
7145 spin_unlock(&head->lock);
7146
7147 out_delayed_unlock:
7148 spin_unlock(&delayed_refs->lock);
7149 return 0;
7150 }
7151
7152 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
7153 struct btrfs_root *root,
7154 struct extent_buffer *buf,
7155 u64 parent, int last_ref)
7156 {
7157 struct btrfs_fs_info *fs_info = root->fs_info;
7158 int pin = 1;
7159 int ret;
7160
7161 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
7162 ret = btrfs_add_delayed_tree_ref(fs_info, trans,
7163 buf->start, buf->len,
7164 parent,
7165 root->root_key.objectid,
7166 btrfs_header_level(buf),
7167 BTRFS_DROP_DELAYED_REF, NULL);
7168 BUG_ON(ret); /* -ENOMEM */
7169 }
7170
7171 if (!last_ref)
7172 return;
7173
7174 if (btrfs_header_generation(buf) == trans->transid) {
7175 struct btrfs_block_group_cache *cache;
7176
7177 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
7178 ret = check_ref_cleanup(trans, buf->start);
7179 if (!ret)
7180 goto out;
7181 }
7182
7183 cache = btrfs_lookup_block_group(fs_info, buf->start);
7184
7185 if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
7186 pin_down_extent(fs_info, cache, buf->start,
7187 buf->len, 1);
7188 btrfs_put_block_group(cache);
7189 goto out;
7190 }
7191
7192 WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
7193
7194 btrfs_add_free_space(cache, buf->start, buf->len);
7195 btrfs_free_reserved_bytes(cache, buf->len, 0);
7196 btrfs_put_block_group(cache);
7197 trace_btrfs_reserved_extent_free(fs_info, buf->start, buf->len);
7198 pin = 0;
7199 }
7200 out:
7201 if (pin)
7202 add_pinned_bytes(fs_info, buf->len, btrfs_header_level(buf),
7203 root->root_key.objectid);
7204
7205 /*
7206 * Deleting the buffer, clear the corrupt flag since it doesn't matter
7207 * anymore.
7208 */
7209 clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
7210 }
7211
7212 /* Can return -ENOMEM */
7213 int btrfs_free_extent(struct btrfs_trans_handle *trans,
7214 struct btrfs_fs_info *fs_info,
7215 u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
7216 u64 owner, u64 offset)
7217 {
7218 int ret;
7219
7220 if (btrfs_is_testing(fs_info))
7221 return 0;
7222
7223 add_pinned_bytes(fs_info, num_bytes, owner, root_objectid);
7224
7225 /*
7226 * tree log blocks never actually go into the extent allocation
7227 * tree, just update pinning info and exit early.
7228 */
7229 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
7230 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
7231 /* unlocks the pinned mutex */
7232 btrfs_pin_extent(fs_info, bytenr, num_bytes, 1);
7233 ret = 0;
7234 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
7235 ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
7236 num_bytes,
7237 parent, root_objectid, (int)owner,
7238 BTRFS_DROP_DELAYED_REF, NULL);
7239 } else {
7240 ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
7241 num_bytes,
7242 parent, root_objectid, owner,
7243 offset, 0,
7244 BTRFS_DROP_DELAYED_REF, NULL);
7245 }
7246 return ret;
7247 }
7248
7249 /*
7250 * when we wait for progress in the block group caching, its because
7251 * our allocation attempt failed at least once. So, we must sleep
7252 * and let some progress happen before we try again.
7253 *
7254 * This function will sleep at least once waiting for new free space to
7255 * show up, and then it will check the block group free space numbers
7256 * for our min num_bytes. Another option is to have it go ahead
7257 * and look in the rbtree for a free extent of a given size, but this
7258 * is a good start.
7259 *
7260 * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
7261 * any of the information in this block group.
7262 */
7263 static noinline void
7264 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
7265 u64 num_bytes)
7266 {
7267 struct btrfs_caching_control *caching_ctl;
7268
7269 caching_ctl = get_caching_control(cache);
7270 if (!caching_ctl)
7271 return;
7272
7273 wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
7274 (cache->free_space_ctl->free_space >= num_bytes));
7275
7276 put_caching_control(caching_ctl);
7277 }
7278
7279 static noinline int
7280 wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
7281 {
7282 struct btrfs_caching_control *caching_ctl;
7283 int ret = 0;
7284
7285 caching_ctl = get_caching_control(cache);
7286 if (!caching_ctl)
7287 return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
7288
7289 wait_event(caching_ctl->wait, block_group_cache_done(cache));
7290 if (cache->cached == BTRFS_CACHE_ERROR)
7291 ret = -EIO;
7292 put_caching_control(caching_ctl);
7293 return ret;
7294 }
7295
7296 int __get_raid_index(u64 flags)
7297 {
7298 if (flags & BTRFS_BLOCK_GROUP_RAID10)
7299 return BTRFS_RAID_RAID10;
7300 else if (flags & BTRFS_BLOCK_GROUP_RAID1)
7301 return BTRFS_RAID_RAID1;
7302 else if (flags & BTRFS_BLOCK_GROUP_DUP)
7303 return BTRFS_RAID_DUP;
7304 else if (flags & BTRFS_BLOCK_GROUP_RAID0)
7305 return BTRFS_RAID_RAID0;
7306 else if (flags & BTRFS_BLOCK_GROUP_RAID5)
7307 return BTRFS_RAID_RAID5;
7308 else if (flags & BTRFS_BLOCK_GROUP_RAID6)
7309 return BTRFS_RAID_RAID6;
7310
7311 return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
7312 }
7313
7314 int get_block_group_index(struct btrfs_block_group_cache *cache)
7315 {
7316 return __get_raid_index(cache->flags);
7317 }
7318
7319 static const char *btrfs_raid_type_names[BTRFS_NR_RAID_TYPES] = {
7320 [BTRFS_RAID_RAID10] = "raid10",
7321 [BTRFS_RAID_RAID1] = "raid1",
7322 [BTRFS_RAID_DUP] = "dup",
7323 [BTRFS_RAID_RAID0] = "raid0",
7324 [BTRFS_RAID_SINGLE] = "single",
7325 [BTRFS_RAID_RAID5] = "raid5",
7326 [BTRFS_RAID_RAID6] = "raid6",
7327 };
7328
7329 static const char *get_raid_name(enum btrfs_raid_types type)
7330 {
7331 if (type >= BTRFS_NR_RAID_TYPES)
7332 return NULL;
7333
7334 return btrfs_raid_type_names[type];
7335 }
7336
7337 enum btrfs_loop_type {
7338 LOOP_CACHING_NOWAIT = 0,
7339 LOOP_CACHING_WAIT = 1,
7340 LOOP_ALLOC_CHUNK = 2,
7341 LOOP_NO_EMPTY_SIZE = 3,
7342 };
7343
7344 static inline void
7345 btrfs_lock_block_group(struct btrfs_block_group_cache *cache,
7346 int delalloc)
7347 {
7348 if (delalloc)
7349 down_read(&cache->data_rwsem);
7350 }
7351
7352 static inline void
7353 btrfs_grab_block_group(struct btrfs_block_group_cache *cache,
7354 int delalloc)
7355 {
7356 btrfs_get_block_group(cache);
7357 if (delalloc)
7358 down_read(&cache->data_rwsem);
7359 }
7360
7361 static struct btrfs_block_group_cache *
7362 btrfs_lock_cluster(struct btrfs_block_group_cache *block_group,
7363 struct btrfs_free_cluster *cluster,
7364 int delalloc)
7365 {
7366 struct btrfs_block_group_cache *used_bg = NULL;
7367
7368 spin_lock(&cluster->refill_lock);
7369 while (1) {
7370 used_bg = cluster->block_group;
7371 if (!used_bg)
7372 return NULL;
7373
7374 if (used_bg == block_group)
7375 return used_bg;
7376
7377 btrfs_get_block_group(used_bg);
7378
7379 if (!delalloc)
7380 return used_bg;
7381
7382 if (down_read_trylock(&used_bg->data_rwsem))
7383 return used_bg;
7384
7385 spin_unlock(&cluster->refill_lock);
7386
7387 down_read(&used_bg->data_rwsem);
7388
7389 spin_lock(&cluster->refill_lock);
7390 if (used_bg == cluster->block_group)
7391 return used_bg;
7392
7393 up_read(&used_bg->data_rwsem);
7394 btrfs_put_block_group(used_bg);
7395 }
7396 }
7397
7398 static inline void
7399 btrfs_release_block_group(struct btrfs_block_group_cache *cache,
7400 int delalloc)
7401 {
7402 if (delalloc)
7403 up_read(&cache->data_rwsem);
7404 btrfs_put_block_group(cache);
7405 }
7406
7407 /*
7408 * walks the btree of allocated extents and find a hole of a given size.
7409 * The key ins is changed to record the hole:
7410 * ins->objectid == start position
7411 * ins->flags = BTRFS_EXTENT_ITEM_KEY
7412 * ins->offset == the size of the hole.
7413 * Any available blocks before search_start are skipped.
7414 *
7415 * If there is no suitable free space, we will record the max size of
7416 * the free space extent currently.
7417 */
7418 static noinline int find_free_extent(struct btrfs_root *orig_root,
7419 u64 ram_bytes, u64 num_bytes, u64 empty_size,
7420 u64 hint_byte, struct btrfs_key *ins,
7421 u64 flags, int delalloc)
7422 {
7423 struct btrfs_fs_info *fs_info = orig_root->fs_info;
7424 int ret = 0;
7425 struct btrfs_root *root = fs_info->extent_root;
7426 struct btrfs_free_cluster *last_ptr = NULL;
7427 struct btrfs_block_group_cache *block_group = NULL;
7428 u64 search_start = 0;
7429 u64 max_extent_size = 0;
7430 u64 empty_cluster = 0;
7431 struct btrfs_space_info *space_info;
7432 int loop = 0;
7433 int index = __get_raid_index(flags);
7434 bool failed_cluster_refill = false;
7435 bool failed_alloc = false;
7436 bool use_cluster = true;
7437 bool have_caching_bg = false;
7438 bool orig_have_caching_bg = false;
7439 bool full_search = false;
7440
7441 WARN_ON(num_bytes < fs_info->sectorsize);
7442 ins->type = BTRFS_EXTENT_ITEM_KEY;
7443 ins->objectid = 0;
7444 ins->offset = 0;
7445
7446 trace_find_free_extent(fs_info, num_bytes, empty_size, flags);
7447
7448 space_info = __find_space_info(fs_info, flags);
7449 if (!space_info) {
7450 btrfs_err(fs_info, "No space info for %llu", flags);
7451 return -ENOSPC;
7452 }
7453
7454 /*
7455 * If our free space is heavily fragmented we may not be able to make
7456 * big contiguous allocations, so instead of doing the expensive search
7457 * for free space, simply return ENOSPC with our max_extent_size so we
7458 * can go ahead and search for a more manageable chunk.
7459 *
7460 * If our max_extent_size is large enough for our allocation simply
7461 * disable clustering since we will likely not be able to find enough
7462 * space to create a cluster and induce latency trying.
7463 */
7464 if (unlikely(space_info->max_extent_size)) {
7465 spin_lock(&space_info->lock);
7466 if (space_info->max_extent_size &&
7467 num_bytes > space_info->max_extent_size) {
7468 ins->offset = space_info->max_extent_size;
7469 spin_unlock(&space_info->lock);
7470 return -ENOSPC;
7471 } else if (space_info->max_extent_size) {
7472 use_cluster = false;
7473 }
7474 spin_unlock(&space_info->lock);
7475 }
7476
7477 last_ptr = fetch_cluster_info(fs_info, space_info, &empty_cluster);
7478 if (last_ptr) {
7479 spin_lock(&last_ptr->lock);
7480 if (last_ptr->block_group)
7481 hint_byte = last_ptr->window_start;
7482 if (last_ptr->fragmented) {
7483 /*
7484 * We still set window_start so we can keep track of the
7485 * last place we found an allocation to try and save
7486 * some time.
7487 */
7488 hint_byte = last_ptr->window_start;
7489 use_cluster = false;
7490 }
7491 spin_unlock(&last_ptr->lock);
7492 }
7493
7494 search_start = max(search_start, first_logical_byte(fs_info, 0));
7495 search_start = max(search_start, hint_byte);
7496 if (search_start == hint_byte) {
7497 block_group = btrfs_lookup_block_group(fs_info, search_start);
7498 /*
7499 * we don't want to use the block group if it doesn't match our
7500 * allocation bits, or if its not cached.
7501 *
7502 * However if we are re-searching with an ideal block group
7503 * picked out then we don't care that the block group is cached.
7504 */
7505 if (block_group && block_group_bits(block_group, flags) &&
7506 block_group->cached != BTRFS_CACHE_NO) {
7507 down_read(&space_info->groups_sem);
7508 if (list_empty(&block_group->list) ||
7509 block_group->ro) {
7510 /*
7511 * someone is removing this block group,
7512 * we can't jump into the have_block_group
7513 * target because our list pointers are not
7514 * valid
7515 */
7516 btrfs_put_block_group(block_group);
7517 up_read(&space_info->groups_sem);
7518 } else {
7519 index = get_block_group_index(block_group);
7520 btrfs_lock_block_group(block_group, delalloc);
7521 goto have_block_group;
7522 }
7523 } else if (block_group) {
7524 btrfs_put_block_group(block_group);
7525 }
7526 }
7527 search:
7528 have_caching_bg = false;
7529 if (index == 0 || index == __get_raid_index(flags))
7530 full_search = true;
7531 down_read(&space_info->groups_sem);
7532 list_for_each_entry(block_group, &space_info->block_groups[index],
7533 list) {
7534 u64 offset;
7535 int cached;
7536
7537 btrfs_grab_block_group(block_group, delalloc);
7538 search_start = block_group->key.objectid;
7539
7540 /*
7541 * this can happen if we end up cycling through all the
7542 * raid types, but we want to make sure we only allocate
7543 * for the proper type.
7544 */
7545 if (!block_group_bits(block_group, flags)) {
7546 u64 extra = BTRFS_BLOCK_GROUP_DUP |
7547 BTRFS_BLOCK_GROUP_RAID1 |
7548 BTRFS_BLOCK_GROUP_RAID5 |
7549 BTRFS_BLOCK_GROUP_RAID6 |
7550 BTRFS_BLOCK_GROUP_RAID10;
7551
7552 /*
7553 * if they asked for extra copies and this block group
7554 * doesn't provide them, bail. This does allow us to
7555 * fill raid0 from raid1.
7556 */
7557 if ((flags & extra) && !(block_group->flags & extra))
7558 goto loop;
7559 }
7560
7561 have_block_group:
7562 cached = block_group_cache_done(block_group);
7563 if (unlikely(!cached)) {
7564 have_caching_bg = true;
7565 ret = cache_block_group(block_group, 0);
7566 BUG_ON(ret < 0);
7567 ret = 0;
7568 }
7569
7570 if (unlikely(block_group->cached == BTRFS_CACHE_ERROR))
7571 goto loop;
7572 if (unlikely(block_group->ro))
7573 goto loop;
7574
7575 /*
7576 * Ok we want to try and use the cluster allocator, so
7577 * lets look there
7578 */
7579 if (last_ptr && use_cluster) {
7580 struct btrfs_block_group_cache *used_block_group;
7581 unsigned long aligned_cluster;
7582 /*
7583 * the refill lock keeps out other
7584 * people trying to start a new cluster
7585 */
7586 used_block_group = btrfs_lock_cluster(block_group,
7587 last_ptr,
7588 delalloc);
7589 if (!used_block_group)
7590 goto refill_cluster;
7591
7592 if (used_block_group != block_group &&
7593 (used_block_group->ro ||
7594 !block_group_bits(used_block_group, flags)))
7595 goto release_cluster;
7596
7597 offset = btrfs_alloc_from_cluster(used_block_group,
7598 last_ptr,
7599 num_bytes,
7600 used_block_group->key.objectid,
7601 &max_extent_size);
7602 if (offset) {
7603 /* we have a block, we're done */
7604 spin_unlock(&last_ptr->refill_lock);
7605 trace_btrfs_reserve_extent_cluster(fs_info,
7606 used_block_group,
7607 search_start, num_bytes);
7608 if (used_block_group != block_group) {
7609 btrfs_release_block_group(block_group,
7610 delalloc);
7611 block_group = used_block_group;
7612 }
7613 goto checks;
7614 }
7615
7616 WARN_ON(last_ptr->block_group != used_block_group);
7617 release_cluster:
7618 /* If we are on LOOP_NO_EMPTY_SIZE, we can't
7619 * set up a new clusters, so lets just skip it
7620 * and let the allocator find whatever block
7621 * it can find. If we reach this point, we
7622 * will have tried the cluster allocator
7623 * plenty of times and not have found
7624 * anything, so we are likely way too
7625 * fragmented for the clustering stuff to find
7626 * anything.
7627 *
7628 * However, if the cluster is taken from the
7629 * current block group, release the cluster
7630 * first, so that we stand a better chance of
7631 * succeeding in the unclustered
7632 * allocation. */
7633 if (loop >= LOOP_NO_EMPTY_SIZE &&
7634 used_block_group != block_group) {
7635 spin_unlock(&last_ptr->refill_lock);
7636 btrfs_release_block_group(used_block_group,
7637 delalloc);
7638 goto unclustered_alloc;
7639 }
7640
7641 /*
7642 * this cluster didn't work out, free it and
7643 * start over
7644 */
7645 btrfs_return_cluster_to_free_space(NULL, last_ptr);
7646
7647 if (used_block_group != block_group)
7648 btrfs_release_block_group(used_block_group,
7649 delalloc);
7650 refill_cluster:
7651 if (loop >= LOOP_NO_EMPTY_SIZE) {
7652 spin_unlock(&last_ptr->refill_lock);
7653 goto unclustered_alloc;
7654 }
7655
7656 aligned_cluster = max_t(unsigned long,
7657 empty_cluster + empty_size,
7658 block_group->full_stripe_len);
7659
7660 /* allocate a cluster in this block group */
7661 ret = btrfs_find_space_cluster(fs_info, block_group,
7662 last_ptr, search_start,
7663 num_bytes,
7664 aligned_cluster);
7665 if (ret == 0) {
7666 /*
7667 * now pull our allocation out of this
7668 * cluster
7669 */
7670 offset = btrfs_alloc_from_cluster(block_group,
7671 last_ptr,
7672 num_bytes,
7673 search_start,
7674 &max_extent_size);
7675 if (offset) {
7676 /* we found one, proceed */
7677 spin_unlock(&last_ptr->refill_lock);
7678 trace_btrfs_reserve_extent_cluster(fs_info,
7679 block_group, search_start,
7680 num_bytes);
7681 goto checks;
7682 }
7683 } else if (!cached && loop > LOOP_CACHING_NOWAIT
7684 && !failed_cluster_refill) {
7685 spin_unlock(&last_ptr->refill_lock);
7686
7687 failed_cluster_refill = true;
7688 wait_block_group_cache_progress(block_group,
7689 num_bytes + empty_cluster + empty_size);
7690 goto have_block_group;
7691 }
7692
7693 /*
7694 * at this point we either didn't find a cluster
7695 * or we weren't able to allocate a block from our
7696 * cluster. Free the cluster we've been trying
7697 * to use, and go to the next block group
7698 */
7699 btrfs_return_cluster_to_free_space(NULL, last_ptr);
7700 spin_unlock(&last_ptr->refill_lock);
7701 goto loop;
7702 }
7703
7704 unclustered_alloc:
7705 /*
7706 * We are doing an unclustered alloc, set the fragmented flag so
7707 * we don't bother trying to setup a cluster again until we get
7708 * more space.
7709 */
7710 if (unlikely(last_ptr)) {
7711 spin_lock(&last_ptr->lock);
7712 last_ptr->fragmented = 1;
7713 spin_unlock(&last_ptr->lock);
7714 }
7715 spin_lock(&block_group->free_space_ctl->tree_lock);
7716 if (cached &&
7717 block_group->free_space_ctl->free_space <
7718 num_bytes + empty_cluster + empty_size) {
7719 if (block_group->free_space_ctl->free_space >
7720 max_extent_size)
7721 max_extent_size =
7722 block_group->free_space_ctl->free_space;
7723 spin_unlock(&block_group->free_space_ctl->tree_lock);
7724 goto loop;
7725 }
7726 spin_unlock(&block_group->free_space_ctl->tree_lock);
7727
7728 offset = btrfs_find_space_for_alloc(block_group, search_start,
7729 num_bytes, empty_size,
7730 &max_extent_size);
7731 /*
7732 * If we didn't find a chunk, and we haven't failed on this
7733 * block group before, and this block group is in the middle of
7734 * caching and we are ok with waiting, then go ahead and wait
7735 * for progress to be made, and set failed_alloc to true.
7736 *
7737 * If failed_alloc is true then we've already waited on this
7738 * block group once and should move on to the next block group.
7739 */
7740 if (!offset && !failed_alloc && !cached &&
7741 loop > LOOP_CACHING_NOWAIT) {
7742 wait_block_group_cache_progress(block_group,
7743 num_bytes + empty_size);
7744 failed_alloc = true;
7745 goto have_block_group;
7746 } else if (!offset) {
7747 goto loop;
7748 }
7749 checks:
7750 search_start = ALIGN(offset, fs_info->stripesize);
7751
7752 /* move on to the next group */
7753 if (search_start + num_bytes >
7754 block_group->key.objectid + block_group->key.offset) {
7755 btrfs_add_free_space(block_group, offset, num_bytes);
7756 goto loop;
7757 }
7758
7759 if (offset < search_start)
7760 btrfs_add_free_space(block_group, offset,
7761 search_start - offset);
7762 BUG_ON(offset > search_start);
7763
7764 ret = btrfs_add_reserved_bytes(block_group, ram_bytes,
7765 num_bytes, delalloc);
7766 if (ret == -EAGAIN) {
7767 btrfs_add_free_space(block_group, offset, num_bytes);
7768 goto loop;
7769 }
7770 btrfs_inc_block_group_reservations(block_group);
7771
7772 /* we are all good, lets return */
7773 ins->objectid = search_start;
7774 ins->offset = num_bytes;
7775
7776 trace_btrfs_reserve_extent(fs_info, block_group,
7777 search_start, num_bytes);
7778 btrfs_release_block_group(block_group, delalloc);
7779 break;
7780 loop:
7781 failed_cluster_refill = false;
7782 failed_alloc = false;
7783 BUG_ON(index != get_block_group_index(block_group));
7784 btrfs_release_block_group(block_group, delalloc);
7785 }
7786 up_read(&space_info->groups_sem);
7787
7788 if ((loop == LOOP_CACHING_NOWAIT) && have_caching_bg
7789 && !orig_have_caching_bg)
7790 orig_have_caching_bg = true;
7791
7792 if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg)
7793 goto search;
7794
7795 if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
7796 goto search;
7797
7798 /*
7799 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
7800 * caching kthreads as we move along
7801 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
7802 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
7803 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
7804 * again
7805 */
7806 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) {
7807 index = 0;
7808 if (loop == LOOP_CACHING_NOWAIT) {
7809 /*
7810 * We want to skip the LOOP_CACHING_WAIT step if we
7811 * don't have any uncached bgs and we've already done a
7812 * full search through.
7813 */
7814 if (orig_have_caching_bg || !full_search)
7815 loop = LOOP_CACHING_WAIT;
7816 else
7817 loop = LOOP_ALLOC_CHUNK;
7818 } else {
7819 loop++;
7820 }
7821
7822 if (loop == LOOP_ALLOC_CHUNK) {
7823 struct btrfs_trans_handle *trans;
7824 int exist = 0;
7825
7826 trans = current->journal_info;
7827 if (trans)
7828 exist = 1;
7829 else
7830 trans = btrfs_join_transaction(root);
7831
7832 if (IS_ERR(trans)) {
7833 ret = PTR_ERR(trans);
7834 goto out;
7835 }
7836
7837 ret = do_chunk_alloc(trans, fs_info, flags,
7838 CHUNK_ALLOC_FORCE);
7839
7840 /*
7841 * If we can't allocate a new chunk we've already looped
7842 * through at least once, move on to the NO_EMPTY_SIZE
7843 * case.
7844 */
7845 if (ret == -ENOSPC)
7846 loop = LOOP_NO_EMPTY_SIZE;
7847
7848 /*
7849 * Do not bail out on ENOSPC since we
7850 * can do more things.
7851 */
7852 if (ret < 0 && ret != -ENOSPC)
7853 btrfs_abort_transaction(trans, ret);
7854 else
7855 ret = 0;
7856 if (!exist)
7857 btrfs_end_transaction(trans);
7858 if (ret)
7859 goto out;
7860 }
7861
7862 if (loop == LOOP_NO_EMPTY_SIZE) {
7863 /*
7864 * Don't loop again if we already have no empty_size and
7865 * no empty_cluster.
7866 */
7867 if (empty_size == 0 &&
7868 empty_cluster == 0) {
7869 ret = -ENOSPC;
7870 goto out;
7871 }
7872 empty_size = 0;
7873 empty_cluster = 0;
7874 }
7875
7876 goto search;
7877 } else if (!ins->objectid) {
7878 ret = -ENOSPC;
7879 } else if (ins->objectid) {
7880 if (!use_cluster && last_ptr) {
7881 spin_lock(&last_ptr->lock);
7882 last_ptr->window_start = ins->objectid;
7883 spin_unlock(&last_ptr->lock);
7884 }
7885 ret = 0;
7886 }
7887 out:
7888 if (ret == -ENOSPC) {
7889 spin_lock(&space_info->lock);
7890 space_info->max_extent_size = max_extent_size;
7891 spin_unlock(&space_info->lock);
7892 ins->offset = max_extent_size;
7893 }
7894 return ret;
7895 }
7896
7897 static void dump_space_info(struct btrfs_fs_info *fs_info,
7898 struct btrfs_space_info *info, u64 bytes,
7899 int dump_block_groups)
7900 {
7901 struct btrfs_block_group_cache *cache;
7902 int index = 0;
7903
7904 spin_lock(&info->lock);
7905 btrfs_info(fs_info, "space_info %llu has %llu free, is %sfull",
7906 info->flags,
7907 info->total_bytes - info->bytes_used - info->bytes_pinned -
7908 info->bytes_reserved - info->bytes_readonly -
7909 info->bytes_may_use, (info->full) ? "" : "not ");
7910 btrfs_info(fs_info,
7911 "space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu",
7912 info->total_bytes, info->bytes_used, info->bytes_pinned,
7913 info->bytes_reserved, info->bytes_may_use,
7914 info->bytes_readonly);
7915 spin_unlock(&info->lock);
7916
7917 if (!dump_block_groups)
7918 return;
7919
7920 down_read(&info->groups_sem);
7921 again:
7922 list_for_each_entry(cache, &info->block_groups[index], list) {
7923 spin_lock(&cache->lock);
7924 btrfs_info(fs_info,
7925 "block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s",
7926 cache->key.objectid, cache->key.offset,
7927 btrfs_block_group_used(&cache->item), cache->pinned,
7928 cache->reserved, cache->ro ? "[readonly]" : "");
7929 btrfs_dump_free_space(cache, bytes);
7930 spin_unlock(&cache->lock);
7931 }
7932 if (++index < BTRFS_NR_RAID_TYPES)
7933 goto again;
7934 up_read(&info->groups_sem);
7935 }
7936
7937 int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes,
7938 u64 num_bytes, u64 min_alloc_size,
7939 u64 empty_size, u64 hint_byte,
7940 struct btrfs_key *ins, int is_data, int delalloc)
7941 {
7942 struct btrfs_fs_info *fs_info = root->fs_info;
7943 bool final_tried = num_bytes == min_alloc_size;
7944 u64 flags;
7945 int ret;
7946
7947 flags = btrfs_get_alloc_profile(root, is_data);
7948 again:
7949 WARN_ON(num_bytes < fs_info->sectorsize);
7950 ret = find_free_extent(root, ram_bytes, num_bytes, empty_size,
7951 hint_byte, ins, flags, delalloc);
7952 if (!ret && !is_data) {
7953 btrfs_dec_block_group_reservations(fs_info, ins->objectid);
7954 } else if (ret == -ENOSPC) {
7955 if (!final_tried && ins->offset) {
7956 num_bytes = min(num_bytes >> 1, ins->offset);
7957 num_bytes = round_down(num_bytes,
7958 fs_info->sectorsize);
7959 num_bytes = max(num_bytes, min_alloc_size);
7960 ram_bytes = num_bytes;
7961 if (num_bytes == min_alloc_size)
7962 final_tried = true;
7963 goto again;
7964 } else if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
7965 struct btrfs_space_info *sinfo;
7966
7967 sinfo = __find_space_info(fs_info, flags);
7968 btrfs_err(fs_info,
7969 "allocation failed flags %llu, wanted %llu",
7970 flags, num_bytes);
7971 if (sinfo)
7972 dump_space_info(fs_info, sinfo, num_bytes, 1);
7973 }
7974 }
7975
7976 return ret;
7977 }
7978
7979 static int __btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info,
7980 u64 start, u64 len,
7981 int pin, int delalloc)
7982 {
7983 struct btrfs_block_group_cache *cache;
7984 int ret = 0;
7985
7986 cache = btrfs_lookup_block_group(fs_info, start);
7987 if (!cache) {
7988 btrfs_err(fs_info, "Unable to find block group for %llu",
7989 start);
7990 return -ENOSPC;
7991 }
7992
7993 if (pin)
7994 pin_down_extent(fs_info, cache, start, len, 1);
7995 else {
7996 if (btrfs_test_opt(fs_info, DISCARD))
7997 ret = btrfs_discard_extent(fs_info, start, len, NULL);
7998 btrfs_add_free_space(cache, start, len);
7999 btrfs_free_reserved_bytes(cache, len, delalloc);
8000 trace_btrfs_reserved_extent_free(fs_info, start, len);
8001 }
8002
8003 btrfs_put_block_group(cache);
8004 return ret;
8005 }
8006
8007 int btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info,
8008 u64 start, u64 len, int delalloc)
8009 {
8010 return __btrfs_free_reserved_extent(fs_info, start, len, 0, delalloc);
8011 }
8012
8013 int btrfs_free_and_pin_reserved_extent(struct btrfs_fs_info *fs_info,
8014 u64 start, u64 len)
8015 {
8016 return __btrfs_free_reserved_extent(fs_info, start, len, 1, 0);
8017 }
8018
8019 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
8020 struct btrfs_fs_info *fs_info,
8021 u64 parent, u64 root_objectid,
8022 u64 flags, u64 owner, u64 offset,
8023 struct btrfs_key *ins, int ref_mod)
8024 {
8025 int ret;
8026 struct btrfs_extent_item *extent_item;
8027 struct btrfs_extent_inline_ref *iref;
8028 struct btrfs_path *path;
8029 struct extent_buffer *leaf;
8030 int type;
8031 u32 size;
8032
8033 if (parent > 0)
8034 type = BTRFS_SHARED_DATA_REF_KEY;
8035 else
8036 type = BTRFS_EXTENT_DATA_REF_KEY;
8037
8038 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
8039
8040 path = btrfs_alloc_path();
8041 if (!path)
8042 return -ENOMEM;
8043
8044 path->leave_spinning = 1;
8045 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
8046 ins, size);
8047 if (ret) {
8048 btrfs_free_path(path);
8049 return ret;
8050 }
8051
8052 leaf = path->nodes[0];
8053 extent_item = btrfs_item_ptr(leaf, path->slots[0],
8054 struct btrfs_extent_item);
8055 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
8056 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
8057 btrfs_set_extent_flags(leaf, extent_item,
8058 flags | BTRFS_EXTENT_FLAG_DATA);
8059
8060 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
8061 btrfs_set_extent_inline_ref_type(leaf, iref, type);
8062 if (parent > 0) {
8063 struct btrfs_shared_data_ref *ref;
8064 ref = (struct btrfs_shared_data_ref *)(iref + 1);
8065 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
8066 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
8067 } else {
8068 struct btrfs_extent_data_ref *ref;
8069 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
8070 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
8071 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
8072 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
8073 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
8074 }
8075
8076 btrfs_mark_buffer_dirty(path->nodes[0]);
8077 btrfs_free_path(path);
8078
8079 ret = remove_from_free_space_tree(trans, fs_info, ins->objectid,
8080 ins->offset);
8081 if (ret)
8082 return ret;
8083
8084 ret = update_block_group(trans, fs_info, ins->objectid, ins->offset, 1);
8085 if (ret) { /* -ENOENT, logic error */
8086 btrfs_err(fs_info, "update block group failed for %llu %llu",
8087 ins->objectid, ins->offset);
8088 BUG();
8089 }
8090 trace_btrfs_reserved_extent_alloc(fs_info, ins->objectid, ins->offset);
8091 return ret;
8092 }
8093
8094 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
8095 struct btrfs_fs_info *fs_info,
8096 u64 parent, u64 root_objectid,
8097 u64 flags, struct btrfs_disk_key *key,
8098 int level, struct btrfs_key *ins)
8099 {
8100 int ret;
8101 struct btrfs_extent_item *extent_item;
8102 struct btrfs_tree_block_info *block_info;
8103 struct btrfs_extent_inline_ref *iref;
8104 struct btrfs_path *path;
8105 struct extent_buffer *leaf;
8106 u32 size = sizeof(*extent_item) + sizeof(*iref);
8107 u64 num_bytes = ins->offset;
8108 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
8109
8110 if (!skinny_metadata)
8111 size += sizeof(*block_info);
8112
8113 path = btrfs_alloc_path();
8114 if (!path) {
8115 btrfs_free_and_pin_reserved_extent(fs_info, ins->objectid,
8116 fs_info->nodesize);
8117 return -ENOMEM;
8118 }
8119
8120 path->leave_spinning = 1;
8121 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
8122 ins, size);
8123 if (ret) {
8124 btrfs_free_path(path);
8125 btrfs_free_and_pin_reserved_extent(fs_info, ins->objectid,
8126 fs_info->nodesize);
8127 return ret;
8128 }
8129
8130 leaf = path->nodes[0];
8131 extent_item = btrfs_item_ptr(leaf, path->slots[0],
8132 struct btrfs_extent_item);
8133 btrfs_set_extent_refs(leaf, extent_item, 1);
8134 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
8135 btrfs_set_extent_flags(leaf, extent_item,
8136 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
8137
8138 if (skinny_metadata) {
8139 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
8140 num_bytes = fs_info->nodesize;
8141 } else {
8142 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
8143 btrfs_set_tree_block_key(leaf, block_info, key);
8144 btrfs_set_tree_block_level(leaf, block_info, level);
8145 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
8146 }
8147
8148 if (parent > 0) {
8149 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
8150 btrfs_set_extent_inline_ref_type(leaf, iref,
8151 BTRFS_SHARED_BLOCK_REF_KEY);
8152 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
8153 } else {
8154 btrfs_set_extent_inline_ref_type(leaf, iref,
8155 BTRFS_TREE_BLOCK_REF_KEY);
8156 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
8157 }
8158
8159 btrfs_mark_buffer_dirty(leaf);
8160 btrfs_free_path(path);
8161
8162 ret = remove_from_free_space_tree(trans, fs_info, ins->objectid,
8163 num_bytes);
8164 if (ret)
8165 return ret;
8166
8167 ret = update_block_group(trans, fs_info, ins->objectid,
8168 fs_info->nodesize, 1);
8169 if (ret) { /* -ENOENT, logic error */
8170 btrfs_err(fs_info, "update block group failed for %llu %llu",
8171 ins->objectid, ins->offset);
8172 BUG();
8173 }
8174
8175 trace_btrfs_reserved_extent_alloc(fs_info, ins->objectid,
8176 fs_info->nodesize);
8177 return ret;
8178 }
8179
8180 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
8181 u64 root_objectid, u64 owner,
8182 u64 offset, u64 ram_bytes,
8183 struct btrfs_key *ins)
8184 {
8185 struct btrfs_fs_info *fs_info = trans->fs_info;
8186 int ret;
8187
8188 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
8189
8190 ret = btrfs_add_delayed_data_ref(fs_info, trans, ins->objectid,
8191 ins->offset, 0,
8192 root_objectid, owner, offset,
8193 ram_bytes, BTRFS_ADD_DELAYED_EXTENT,
8194 NULL);
8195 return ret;
8196 }
8197
8198 /*
8199 * this is used by the tree logging recovery code. It records that
8200 * an extent has been allocated and makes sure to clear the free
8201 * space cache bits as well
8202 */
8203 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
8204 struct btrfs_fs_info *fs_info,
8205 u64 root_objectid, u64 owner, u64 offset,
8206 struct btrfs_key *ins)
8207 {
8208 int ret;
8209 struct btrfs_block_group_cache *block_group;
8210 struct btrfs_space_info *space_info;
8211
8212 /*
8213 * Mixed block groups will exclude before processing the log so we only
8214 * need to do the exclude dance if this fs isn't mixed.
8215 */
8216 if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
8217 ret = __exclude_logged_extent(fs_info, ins->objectid,
8218 ins->offset);
8219 if (ret)
8220 return ret;
8221 }
8222
8223 block_group = btrfs_lookup_block_group(fs_info, ins->objectid);
8224 if (!block_group)
8225 return -EINVAL;
8226
8227 space_info = block_group->space_info;
8228 spin_lock(&space_info->lock);
8229 spin_lock(&block_group->lock);
8230 space_info->bytes_reserved += ins->offset;
8231 block_group->reserved += ins->offset;
8232 spin_unlock(&block_group->lock);
8233 spin_unlock(&space_info->lock);
8234
8235 ret = alloc_reserved_file_extent(trans, fs_info, 0, root_objectid,
8236 0, owner, offset, ins, 1);
8237 btrfs_put_block_group(block_group);
8238 return ret;
8239 }
8240
8241 static struct extent_buffer *
8242 btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
8243 u64 bytenr, int level)
8244 {
8245 struct btrfs_fs_info *fs_info = root->fs_info;
8246 struct extent_buffer *buf;
8247
8248 buf = btrfs_find_create_tree_block(fs_info, bytenr);
8249 if (IS_ERR(buf))
8250 return buf;
8251
8252 btrfs_set_header_generation(buf, trans->transid);
8253 btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
8254 btrfs_tree_lock(buf);
8255 clean_tree_block(trans, fs_info, buf);
8256 clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
8257
8258 btrfs_set_lock_blocking(buf);
8259 set_extent_buffer_uptodate(buf);
8260
8261 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
8262 buf->log_index = root->log_transid % 2;
8263 /*
8264 * we allow two log transactions at a time, use different
8265 * EXENT bit to differentiate dirty pages.
8266 */
8267 if (buf->log_index == 0)
8268 set_extent_dirty(&root->dirty_log_pages, buf->start,
8269 buf->start + buf->len - 1, GFP_NOFS);
8270 else
8271 set_extent_new(&root->dirty_log_pages, buf->start,
8272 buf->start + buf->len - 1);
8273 } else {
8274 buf->log_index = -1;
8275 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
8276 buf->start + buf->len - 1, GFP_NOFS);
8277 }
8278 trans->dirty = true;
8279 /* this returns a buffer locked for blocking */
8280 return buf;
8281 }
8282
8283 static struct btrfs_block_rsv *
8284 use_block_rsv(struct btrfs_trans_handle *trans,
8285 struct btrfs_root *root, u32 blocksize)
8286 {
8287 struct btrfs_fs_info *fs_info = root->fs_info;
8288 struct btrfs_block_rsv *block_rsv;
8289 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
8290 int ret;
8291 bool global_updated = false;
8292
8293 block_rsv = get_block_rsv(trans, root);
8294
8295 if (unlikely(block_rsv->size == 0))
8296 goto try_reserve;
8297 again:
8298 ret = block_rsv_use_bytes(block_rsv, blocksize);
8299 if (!ret)
8300 return block_rsv;
8301
8302 if (block_rsv->failfast)
8303 return ERR_PTR(ret);
8304
8305 if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
8306 global_updated = true;
8307 update_global_block_rsv(fs_info);
8308 goto again;
8309 }
8310
8311 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
8312 static DEFINE_RATELIMIT_STATE(_rs,
8313 DEFAULT_RATELIMIT_INTERVAL * 10,
8314 /*DEFAULT_RATELIMIT_BURST*/ 1);
8315 if (__ratelimit(&_rs))
8316 WARN(1, KERN_DEBUG
8317 "BTRFS: block rsv returned %d\n", ret);
8318 }
8319 try_reserve:
8320 ret = reserve_metadata_bytes(root, block_rsv, blocksize,
8321 BTRFS_RESERVE_NO_FLUSH);
8322 if (!ret)
8323 return block_rsv;
8324 /*
8325 * If we couldn't reserve metadata bytes try and use some from
8326 * the global reserve if its space type is the same as the global
8327 * reservation.
8328 */
8329 if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
8330 block_rsv->space_info == global_rsv->space_info) {
8331 ret = block_rsv_use_bytes(global_rsv, blocksize);
8332 if (!ret)
8333 return global_rsv;
8334 }
8335 return ERR_PTR(ret);
8336 }
8337
8338 static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
8339 struct btrfs_block_rsv *block_rsv, u32 blocksize)
8340 {
8341 block_rsv_add_bytes(block_rsv, blocksize, 0);
8342 block_rsv_release_bytes(fs_info, block_rsv, NULL, 0);
8343 }
8344
8345 /*
8346 * finds a free extent and does all the dirty work required for allocation
8347 * returns the tree buffer or an ERR_PTR on error.
8348 */
8349 struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
8350 struct btrfs_root *root,
8351 u64 parent, u64 root_objectid,
8352 struct btrfs_disk_key *key, int level,
8353 u64 hint, u64 empty_size)
8354 {
8355 struct btrfs_fs_info *fs_info = root->fs_info;
8356 struct btrfs_key ins;
8357 struct btrfs_block_rsv *block_rsv;
8358 struct extent_buffer *buf;
8359 struct btrfs_delayed_extent_op *extent_op;
8360 u64 flags = 0;
8361 int ret;
8362 u32 blocksize = fs_info->nodesize;
8363 bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
8364
8365 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
8366 if (btrfs_is_testing(fs_info)) {
8367 buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr,
8368 level);
8369 if (!IS_ERR(buf))
8370 root->alloc_bytenr += blocksize;
8371 return buf;
8372 }
8373 #endif
8374
8375 block_rsv = use_block_rsv(trans, root, blocksize);
8376 if (IS_ERR(block_rsv))
8377 return ERR_CAST(block_rsv);
8378
8379 ret = btrfs_reserve_extent(root, blocksize, blocksize, blocksize,
8380 empty_size, hint, &ins, 0, 0);
8381 if (ret)
8382 goto out_unuse;
8383
8384 buf = btrfs_init_new_buffer(trans, root, ins.objectid, level);
8385 if (IS_ERR(buf)) {
8386 ret = PTR_ERR(buf);
8387 goto out_free_reserved;
8388 }
8389
8390 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
8391 if (parent == 0)
8392 parent = ins.objectid;
8393 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
8394 } else
8395 BUG_ON(parent > 0);
8396
8397 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
8398 extent_op = btrfs_alloc_delayed_extent_op();
8399 if (!extent_op) {
8400 ret = -ENOMEM;
8401 goto out_free_buf;
8402 }
8403 if (key)
8404 memcpy(&extent_op->key, key, sizeof(extent_op->key));
8405 else
8406 memset(&extent_op->key, 0, sizeof(extent_op->key));
8407 extent_op->flags_to_set = flags;
8408 extent_op->update_key = skinny_metadata ? false : true;
8409 extent_op->update_flags = true;
8410 extent_op->is_data = false;
8411 extent_op->level = level;
8412
8413 ret = btrfs_add_delayed_tree_ref(fs_info, trans,
8414 ins.objectid, ins.offset,
8415 parent, root_objectid, level,
8416 BTRFS_ADD_DELAYED_EXTENT,
8417 extent_op);
8418 if (ret)
8419 goto out_free_delayed;
8420 }
8421 return buf;
8422
8423 out_free_delayed:
8424 btrfs_free_delayed_extent_op(extent_op);
8425 out_free_buf:
8426 free_extent_buffer(buf);
8427 out_free_reserved:
8428 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 0);
8429 out_unuse:
8430 unuse_block_rsv(fs_info, block_rsv, blocksize);
8431 return ERR_PTR(ret);
8432 }
8433
8434 struct walk_control {
8435 u64 refs[BTRFS_MAX_LEVEL];
8436 u64 flags[BTRFS_MAX_LEVEL];
8437 struct btrfs_key update_progress;
8438 int stage;
8439 int level;
8440 int shared_level;
8441 int update_ref;
8442 int keep_locks;
8443 int reada_slot;
8444 int reada_count;
8445 int for_reloc;
8446 };
8447
8448 #define DROP_REFERENCE 1
8449 #define UPDATE_BACKREF 2
8450
8451 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
8452 struct btrfs_root *root,
8453 struct walk_control *wc,
8454 struct btrfs_path *path)
8455 {
8456 struct btrfs_fs_info *fs_info = root->fs_info;
8457 u64 bytenr;
8458 u64 generation;
8459 u64 refs;
8460 u64 flags;
8461 u32 nritems;
8462 struct btrfs_key key;
8463 struct extent_buffer *eb;
8464 int ret;
8465 int slot;
8466 int nread = 0;
8467
8468 if (path->slots[wc->level] < wc->reada_slot) {
8469 wc->reada_count = wc->reada_count * 2 / 3;
8470 wc->reada_count = max(wc->reada_count, 2);
8471 } else {
8472 wc->reada_count = wc->reada_count * 3 / 2;
8473 wc->reada_count = min_t(int, wc->reada_count,
8474 BTRFS_NODEPTRS_PER_BLOCK(fs_info));
8475 }
8476
8477 eb = path->nodes[wc->level];
8478 nritems = btrfs_header_nritems(eb);
8479
8480 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
8481 if (nread >= wc->reada_count)
8482 break;
8483
8484 cond_resched();
8485 bytenr = btrfs_node_blockptr(eb, slot);
8486 generation = btrfs_node_ptr_generation(eb, slot);
8487
8488 if (slot == path->slots[wc->level])
8489 goto reada;
8490
8491 if (wc->stage == UPDATE_BACKREF &&
8492 generation <= root->root_key.offset)
8493 continue;
8494
8495 /* We don't lock the tree block, it's OK to be racy here */
8496 ret = btrfs_lookup_extent_info(trans, fs_info, bytenr,
8497 wc->level - 1, 1, &refs,
8498 &flags);
8499 /* We don't care about errors in readahead. */
8500 if (ret < 0)
8501 continue;
8502 BUG_ON(refs == 0);
8503
8504 if (wc->stage == DROP_REFERENCE) {
8505 if (refs == 1)
8506 goto reada;
8507
8508 if (wc->level == 1 &&
8509 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8510 continue;
8511 if (!wc->update_ref ||
8512 generation <= root->root_key.offset)
8513 continue;
8514 btrfs_node_key_to_cpu(eb, &key, slot);
8515 ret = btrfs_comp_cpu_keys(&key,
8516 &wc->update_progress);
8517 if (ret < 0)
8518 continue;
8519 } else {
8520 if (wc->level == 1 &&
8521 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8522 continue;
8523 }
8524 reada:
8525 readahead_tree_block(fs_info, bytenr);
8526 nread++;
8527 }
8528 wc->reada_slot = slot;
8529 }
8530
8531 /*
8532 * helper to process tree block while walking down the tree.
8533 *
8534 * when wc->stage == UPDATE_BACKREF, this function updates
8535 * back refs for pointers in the block.
8536 *
8537 * NOTE: return value 1 means we should stop walking down.
8538 */
8539 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
8540 struct btrfs_root *root,
8541 struct btrfs_path *path,
8542 struct walk_control *wc, int lookup_info)
8543 {
8544 struct btrfs_fs_info *fs_info = root->fs_info;
8545 int level = wc->level;
8546 struct extent_buffer *eb = path->nodes[level];
8547 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
8548 int ret;
8549
8550 if (wc->stage == UPDATE_BACKREF &&
8551 btrfs_header_owner(eb) != root->root_key.objectid)
8552 return 1;
8553
8554 /*
8555 * when reference count of tree block is 1, it won't increase
8556 * again. once full backref flag is set, we never clear it.
8557 */
8558 if (lookup_info &&
8559 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
8560 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
8561 BUG_ON(!path->locks[level]);
8562 ret = btrfs_lookup_extent_info(trans, fs_info,
8563 eb->start, level, 1,
8564 &wc->refs[level],
8565 &wc->flags[level]);
8566 BUG_ON(ret == -ENOMEM);
8567 if (ret)
8568 return ret;
8569 BUG_ON(wc->refs[level] == 0);
8570 }
8571
8572 if (wc->stage == DROP_REFERENCE) {
8573 if (wc->refs[level] > 1)
8574 return 1;
8575
8576 if (path->locks[level] && !wc->keep_locks) {
8577 btrfs_tree_unlock_rw(eb, path->locks[level]);
8578 path->locks[level] = 0;
8579 }
8580 return 0;
8581 }
8582
8583 /* wc->stage == UPDATE_BACKREF */
8584 if (!(wc->flags[level] & flag)) {
8585 BUG_ON(!path->locks[level]);
8586 ret = btrfs_inc_ref(trans, root, eb, 1);
8587 BUG_ON(ret); /* -ENOMEM */
8588 ret = btrfs_dec_ref(trans, root, eb, 0);
8589 BUG_ON(ret); /* -ENOMEM */
8590 ret = btrfs_set_disk_extent_flags(trans, fs_info, eb->start,
8591 eb->len, flag,
8592 btrfs_header_level(eb), 0);
8593 BUG_ON(ret); /* -ENOMEM */
8594 wc->flags[level] |= flag;
8595 }
8596
8597 /*
8598 * the block is shared by multiple trees, so it's not good to
8599 * keep the tree lock
8600 */
8601 if (path->locks[level] && level > 0) {
8602 btrfs_tree_unlock_rw(eb, path->locks[level]);
8603 path->locks[level] = 0;
8604 }
8605 return 0;
8606 }
8607
8608 /*
8609 * helper to process tree block pointer.
8610 *
8611 * when wc->stage == DROP_REFERENCE, this function checks
8612 * reference count of the block pointed to. if the block
8613 * is shared and we need update back refs for the subtree
8614 * rooted at the block, this function changes wc->stage to
8615 * UPDATE_BACKREF. if the block is shared and there is no
8616 * need to update back, this function drops the reference
8617 * to the block.
8618 *
8619 * NOTE: return value 1 means we should stop walking down.
8620 */
8621 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
8622 struct btrfs_root *root,
8623 struct btrfs_path *path,
8624 struct walk_control *wc, int *lookup_info)
8625 {
8626 struct btrfs_fs_info *fs_info = root->fs_info;
8627 u64 bytenr;
8628 u64 generation;
8629 u64 parent;
8630 u32 blocksize;
8631 struct btrfs_key key;
8632 struct extent_buffer *next;
8633 int level = wc->level;
8634 int reada = 0;
8635 int ret = 0;
8636 bool need_account = false;
8637
8638 generation = btrfs_node_ptr_generation(path->nodes[level],
8639 path->slots[level]);
8640 /*
8641 * if the lower level block was created before the snapshot
8642 * was created, we know there is no need to update back refs
8643 * for the subtree
8644 */
8645 if (wc->stage == UPDATE_BACKREF &&
8646 generation <= root->root_key.offset) {
8647 *lookup_info = 1;
8648 return 1;
8649 }
8650
8651 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
8652 blocksize = fs_info->nodesize;
8653
8654 next = find_extent_buffer(fs_info, bytenr);
8655 if (!next) {
8656 next = btrfs_find_create_tree_block(fs_info, bytenr);
8657 if (IS_ERR(next))
8658 return PTR_ERR(next);
8659
8660 btrfs_set_buffer_lockdep_class(root->root_key.objectid, next,
8661 level - 1);
8662 reada = 1;
8663 }
8664 btrfs_tree_lock(next);
8665 btrfs_set_lock_blocking(next);
8666
8667 ret = btrfs_lookup_extent_info(trans, fs_info, bytenr, level - 1, 1,
8668 &wc->refs[level - 1],
8669 &wc->flags[level - 1]);
8670 if (ret < 0)
8671 goto out_unlock;
8672
8673 if (unlikely(wc->refs[level - 1] == 0)) {
8674 btrfs_err(fs_info, "Missing references.");
8675 ret = -EIO;
8676 goto out_unlock;
8677 }
8678 *lookup_info = 0;
8679
8680 if (wc->stage == DROP_REFERENCE) {
8681 if (wc->refs[level - 1] > 1) {
8682 need_account = true;
8683 if (level == 1 &&
8684 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8685 goto skip;
8686
8687 if (!wc->update_ref ||
8688 generation <= root->root_key.offset)
8689 goto skip;
8690
8691 btrfs_node_key_to_cpu(path->nodes[level], &key,
8692 path->slots[level]);
8693 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
8694 if (ret < 0)
8695 goto skip;
8696
8697 wc->stage = UPDATE_BACKREF;
8698 wc->shared_level = level - 1;
8699 }
8700 } else {
8701 if (level == 1 &&
8702 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
8703 goto skip;
8704 }
8705
8706 if (!btrfs_buffer_uptodate(next, generation, 0)) {
8707 btrfs_tree_unlock(next);
8708 free_extent_buffer(next);
8709 next = NULL;
8710 *lookup_info = 1;
8711 }
8712
8713 if (!next) {
8714 if (reada && level == 1)
8715 reada_walk_down(trans, root, wc, path);
8716 next = read_tree_block(fs_info, bytenr, generation);
8717 if (IS_ERR(next)) {
8718 return PTR_ERR(next);
8719 } else if (!extent_buffer_uptodate(next)) {
8720 free_extent_buffer(next);
8721 return -EIO;
8722 }
8723 btrfs_tree_lock(next);
8724 btrfs_set_lock_blocking(next);
8725 }
8726
8727 level--;
8728 ASSERT(level == btrfs_header_level(next));
8729 if (level != btrfs_header_level(next)) {
8730 btrfs_err(root->fs_info, "mismatched level");
8731 ret = -EIO;
8732 goto out_unlock;
8733 }
8734 path->nodes[level] = next;
8735 path->slots[level] = 0;
8736 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
8737 wc->level = level;
8738 if (wc->level == 1)
8739 wc->reada_slot = 0;
8740 return 0;
8741 skip:
8742 wc->refs[level - 1] = 0;
8743 wc->flags[level - 1] = 0;
8744 if (wc->stage == DROP_REFERENCE) {
8745 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
8746 parent = path->nodes[level]->start;
8747 } else {
8748 ASSERT(root->root_key.objectid ==
8749 btrfs_header_owner(path->nodes[level]));
8750 if (root->root_key.objectid !=
8751 btrfs_header_owner(path->nodes[level])) {
8752 btrfs_err(root->fs_info,
8753 "mismatched block owner");
8754 ret = -EIO;
8755 goto out_unlock;
8756 }
8757 parent = 0;
8758 }
8759
8760 if (need_account) {
8761 ret = btrfs_qgroup_trace_subtree(trans, root, next,
8762 generation, level - 1);
8763 if (ret) {
8764 btrfs_err_rl(fs_info,
8765 "Error %d accounting shared subtree. Quota is out of sync, rescan required.",
8766 ret);
8767 }
8768 }
8769 ret = btrfs_free_extent(trans, fs_info, bytenr, blocksize,
8770 parent, root->root_key.objectid,
8771 level - 1, 0);
8772 if (ret)
8773 goto out_unlock;
8774 }
8775
8776 *lookup_info = 1;
8777 ret = 1;
8778
8779 out_unlock:
8780 btrfs_tree_unlock(next);
8781 free_extent_buffer(next);
8782
8783 return ret;
8784 }
8785
8786 /*
8787 * helper to process tree block while walking up the tree.
8788 *
8789 * when wc->stage == DROP_REFERENCE, this function drops
8790 * reference count on the block.
8791 *
8792 * when wc->stage == UPDATE_BACKREF, this function changes
8793 * wc->stage back to DROP_REFERENCE if we changed wc->stage
8794 * to UPDATE_BACKREF previously while processing the block.
8795 *
8796 * NOTE: return value 1 means we should stop walking up.
8797 */
8798 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
8799 struct btrfs_root *root,
8800 struct btrfs_path *path,
8801 struct walk_control *wc)
8802 {
8803 struct btrfs_fs_info *fs_info = root->fs_info;
8804 int ret;
8805 int level = wc->level;
8806 struct extent_buffer *eb = path->nodes[level];
8807 u64 parent = 0;
8808
8809 if (wc->stage == UPDATE_BACKREF) {
8810 BUG_ON(wc->shared_level < level);
8811 if (level < wc->shared_level)
8812 goto out;
8813
8814 ret = find_next_key(path, level + 1, &wc->update_progress);
8815 if (ret > 0)
8816 wc->update_ref = 0;
8817
8818 wc->stage = DROP_REFERENCE;
8819 wc->shared_level = -1;
8820 path->slots[level] = 0;
8821
8822 /*
8823 * check reference count again if the block isn't locked.
8824 * we should start walking down the tree again if reference
8825 * count is one.
8826 */
8827 if (!path->locks[level]) {
8828 BUG_ON(level == 0);
8829 btrfs_tree_lock(eb);
8830 btrfs_set_lock_blocking(eb);
8831 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
8832
8833 ret = btrfs_lookup_extent_info(trans, fs_info,
8834 eb->start, level, 1,
8835 &wc->refs[level],
8836 &wc->flags[level]);
8837 if (ret < 0) {
8838 btrfs_tree_unlock_rw(eb, path->locks[level]);
8839 path->locks[level] = 0;
8840 return ret;
8841 }
8842 BUG_ON(wc->refs[level] == 0);
8843 if (wc->refs[level] == 1) {
8844 btrfs_tree_unlock_rw(eb, path->locks[level]);
8845 path->locks[level] = 0;
8846 return 1;
8847 }
8848 }
8849 }
8850
8851 /* wc->stage == DROP_REFERENCE */
8852 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
8853
8854 if (wc->refs[level] == 1) {
8855 if (level == 0) {
8856 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
8857 ret = btrfs_dec_ref(trans, root, eb, 1);
8858 else
8859 ret = btrfs_dec_ref(trans, root, eb, 0);
8860 BUG_ON(ret); /* -ENOMEM */
8861 ret = btrfs_qgroup_trace_leaf_items(trans, fs_info, eb);
8862 if (ret) {
8863 btrfs_err_rl(fs_info,
8864 "error %d accounting leaf items. Quota is out of sync, rescan required.",
8865 ret);
8866 }
8867 }
8868 /* make block locked assertion in clean_tree_block happy */
8869 if (!path->locks[level] &&
8870 btrfs_header_generation(eb) == trans->transid) {
8871 btrfs_tree_lock(eb);
8872 btrfs_set_lock_blocking(eb);
8873 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
8874 }
8875 clean_tree_block(trans, fs_info, eb);
8876 }
8877
8878 if (eb == root->node) {
8879 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
8880 parent = eb->start;
8881 else
8882 BUG_ON(root->root_key.objectid !=
8883 btrfs_header_owner(eb));
8884 } else {
8885 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
8886 parent = path->nodes[level + 1]->start;
8887 else
8888 BUG_ON(root->root_key.objectid !=
8889 btrfs_header_owner(path->nodes[level + 1]));
8890 }
8891
8892 btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
8893 out:
8894 wc->refs[level] = 0;
8895 wc->flags[level] = 0;
8896 return 0;
8897 }
8898
8899 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
8900 struct btrfs_root *root,
8901 struct btrfs_path *path,
8902 struct walk_control *wc)
8903 {
8904 int level = wc->level;
8905 int lookup_info = 1;
8906 int ret;
8907
8908 while (level >= 0) {
8909 ret = walk_down_proc(trans, root, path, wc, lookup_info);
8910 if (ret > 0)
8911 break;
8912
8913 if (level == 0)
8914 break;
8915
8916 if (path->slots[level] >=
8917 btrfs_header_nritems(path->nodes[level]))
8918 break;
8919
8920 ret = do_walk_down(trans, root, path, wc, &lookup_info);
8921 if (ret > 0) {
8922 path->slots[level]++;
8923 continue;
8924 } else if (ret < 0)
8925 return ret;
8926 level = wc->level;
8927 }
8928 return 0;
8929 }
8930
8931 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
8932 struct btrfs_root *root,
8933 struct btrfs_path *path,
8934 struct walk_control *wc, int max_level)
8935 {
8936 int level = wc->level;
8937 int ret;
8938
8939 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
8940 while (level < max_level && path->nodes[level]) {
8941 wc->level = level;
8942 if (path->slots[level] + 1 <
8943 btrfs_header_nritems(path->nodes[level])) {
8944 path->slots[level]++;
8945 return 0;
8946 } else {
8947 ret = walk_up_proc(trans, root, path, wc);
8948 if (ret > 0)
8949 return 0;
8950
8951 if (path->locks[level]) {
8952 btrfs_tree_unlock_rw(path->nodes[level],
8953 path->locks[level]);
8954 path->locks[level] = 0;
8955 }
8956 free_extent_buffer(path->nodes[level]);
8957 path->nodes[level] = NULL;
8958 level++;
8959 }
8960 }
8961 return 1;
8962 }
8963
8964 /*
8965 * drop a subvolume tree.
8966 *
8967 * this function traverses the tree freeing any blocks that only
8968 * referenced by the tree.
8969 *
8970 * when a shared tree block is found. this function decreases its
8971 * reference count by one. if update_ref is true, this function
8972 * also make sure backrefs for the shared block and all lower level
8973 * blocks are properly updated.
8974 *
8975 * If called with for_reloc == 0, may exit early with -EAGAIN
8976 */
8977 int btrfs_drop_snapshot(struct btrfs_root *root,
8978 struct btrfs_block_rsv *block_rsv, int update_ref,
8979 int for_reloc)
8980 {
8981 struct btrfs_fs_info *fs_info = root->fs_info;
8982 struct btrfs_path *path;
8983 struct btrfs_trans_handle *trans;
8984 struct btrfs_root *tree_root = fs_info->tree_root;
8985 struct btrfs_root_item *root_item = &root->root_item;
8986 struct walk_control *wc;
8987 struct btrfs_key key;
8988 int err = 0;
8989 int ret;
8990 int level;
8991 bool root_dropped = false;
8992
8993 btrfs_debug(fs_info, "Drop subvolume %llu", root->objectid);
8994
8995 path = btrfs_alloc_path();
8996 if (!path) {
8997 err = -ENOMEM;
8998 goto out;
8999 }
9000
9001 wc = kzalloc(sizeof(*wc), GFP_NOFS);
9002 if (!wc) {
9003 btrfs_free_path(path);
9004 err = -ENOMEM;
9005 goto out;
9006 }
9007
9008 trans = btrfs_start_transaction(tree_root, 0);
9009 if (IS_ERR(trans)) {
9010 err = PTR_ERR(trans);
9011 goto out_free;
9012 }
9013
9014 if (block_rsv)
9015 trans->block_rsv = block_rsv;
9016
9017 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
9018 level = btrfs_header_level(root->node);
9019 path->nodes[level] = btrfs_lock_root_node(root);
9020 btrfs_set_lock_blocking(path->nodes[level]);
9021 path->slots[level] = 0;
9022 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
9023 memset(&wc->update_progress, 0,
9024 sizeof(wc->update_progress));
9025 } else {
9026 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
9027 memcpy(&wc->update_progress, &key,
9028 sizeof(wc->update_progress));
9029
9030 level = root_item->drop_level;
9031 BUG_ON(level == 0);
9032 path->lowest_level = level;
9033 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
9034 path->lowest_level = 0;
9035 if (ret < 0) {
9036 err = ret;
9037 goto out_end_trans;
9038 }
9039 WARN_ON(ret > 0);
9040
9041 /*
9042 * unlock our path, this is safe because only this
9043 * function is allowed to delete this snapshot
9044 */
9045 btrfs_unlock_up_safe(path, 0);
9046
9047 level = btrfs_header_level(root->node);
9048 while (1) {
9049 btrfs_tree_lock(path->nodes[level]);
9050 btrfs_set_lock_blocking(path->nodes[level]);
9051 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
9052
9053 ret = btrfs_lookup_extent_info(trans, fs_info,
9054 path->nodes[level]->start,
9055 level, 1, &wc->refs[level],
9056 &wc->flags[level]);
9057 if (ret < 0) {
9058 err = ret;
9059 goto out_end_trans;
9060 }
9061 BUG_ON(wc->refs[level] == 0);
9062
9063 if (level == root_item->drop_level)
9064 break;
9065
9066 btrfs_tree_unlock(path->nodes[level]);
9067 path->locks[level] = 0;
9068 WARN_ON(wc->refs[level] != 1);
9069 level--;
9070 }
9071 }
9072
9073 wc->level = level;
9074 wc->shared_level = -1;
9075 wc->stage = DROP_REFERENCE;
9076 wc->update_ref = update_ref;
9077 wc->keep_locks = 0;
9078 wc->for_reloc = for_reloc;
9079 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info);
9080
9081 while (1) {
9082
9083 ret = walk_down_tree(trans, root, path, wc);
9084 if (ret < 0) {
9085 err = ret;
9086 break;
9087 }
9088
9089 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
9090 if (ret < 0) {
9091 err = ret;
9092 break;
9093 }
9094
9095 if (ret > 0) {
9096 BUG_ON(wc->stage != DROP_REFERENCE);
9097 break;
9098 }
9099
9100 if (wc->stage == DROP_REFERENCE) {
9101 level = wc->level;
9102 btrfs_node_key(path->nodes[level],
9103 &root_item->drop_progress,
9104 path->slots[level]);
9105 root_item->drop_level = level;
9106 }
9107
9108 BUG_ON(wc->level == 0);
9109 if (btrfs_should_end_transaction(trans) ||
9110 (!for_reloc && btrfs_need_cleaner_sleep(fs_info))) {
9111 ret = btrfs_update_root(trans, tree_root,
9112 &root->root_key,
9113 root_item);
9114 if (ret) {
9115 btrfs_abort_transaction(trans, ret);
9116 err = ret;
9117 goto out_end_trans;
9118 }
9119
9120 btrfs_end_transaction_throttle(trans);
9121 if (!for_reloc && btrfs_need_cleaner_sleep(fs_info)) {
9122 btrfs_debug(fs_info,
9123 "drop snapshot early exit");
9124 err = -EAGAIN;
9125 goto out_free;
9126 }
9127
9128 trans = btrfs_start_transaction(tree_root, 0);
9129 if (IS_ERR(trans)) {
9130 err = PTR_ERR(trans);
9131 goto out_free;
9132 }
9133 if (block_rsv)
9134 trans->block_rsv = block_rsv;
9135 }
9136 }
9137 btrfs_release_path(path);
9138 if (err)
9139 goto out_end_trans;
9140
9141 ret = btrfs_del_root(trans, tree_root, &root->root_key);
9142 if (ret) {
9143 btrfs_abort_transaction(trans, ret);
9144 goto out_end_trans;
9145 }
9146
9147 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
9148 ret = btrfs_find_root(tree_root, &root->root_key, path,
9149 NULL, NULL);
9150 if (ret < 0) {
9151 btrfs_abort_transaction(trans, ret);
9152 err = ret;
9153 goto out_end_trans;
9154 } else if (ret > 0) {
9155 /* if we fail to delete the orphan item this time
9156 * around, it'll get picked up the next time.
9157 *
9158 * The most common failure here is just -ENOENT.
9159 */
9160 btrfs_del_orphan_item(trans, tree_root,
9161 root->root_key.objectid);
9162 }
9163 }
9164
9165 if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state)) {
9166 btrfs_add_dropped_root(trans, root);
9167 } else {
9168 free_extent_buffer(root->node);
9169 free_extent_buffer(root->commit_root);
9170 btrfs_put_fs_root(root);
9171 }
9172 root_dropped = true;
9173 out_end_trans:
9174 btrfs_end_transaction_throttle(trans);
9175 out_free:
9176 kfree(wc);
9177 btrfs_free_path(path);
9178 out:
9179 /*
9180 * So if we need to stop dropping the snapshot for whatever reason we
9181 * need to make sure to add it back to the dead root list so that we
9182 * keep trying to do the work later. This also cleans up roots if we
9183 * don't have it in the radix (like when we recover after a power fail
9184 * or unmount) so we don't leak memory.
9185 */
9186 if (!for_reloc && root_dropped == false)
9187 btrfs_add_dead_root(root);
9188 if (err && err != -EAGAIN)
9189 btrfs_handle_fs_error(fs_info, err, NULL);
9190 return err;
9191 }
9192
9193 /*
9194 * drop subtree rooted at tree block 'node'.
9195 *
9196 * NOTE: this function will unlock and release tree block 'node'
9197 * only used by relocation code
9198 */
9199 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
9200 struct btrfs_root *root,
9201 struct extent_buffer *node,
9202 struct extent_buffer *parent)
9203 {
9204 struct btrfs_fs_info *fs_info = root->fs_info;
9205 struct btrfs_path *path;
9206 struct walk_control *wc;
9207 int level;
9208 int parent_level;
9209 int ret = 0;
9210 int wret;
9211
9212 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
9213
9214 path = btrfs_alloc_path();
9215 if (!path)
9216 return -ENOMEM;
9217
9218 wc = kzalloc(sizeof(*wc), GFP_NOFS);
9219 if (!wc) {
9220 btrfs_free_path(path);
9221 return -ENOMEM;
9222 }
9223
9224 btrfs_assert_tree_locked(parent);
9225 parent_level = btrfs_header_level(parent);
9226 extent_buffer_get(parent);
9227 path->nodes[parent_level] = parent;
9228 path->slots[parent_level] = btrfs_header_nritems(parent);
9229
9230 btrfs_assert_tree_locked(node);
9231 level = btrfs_header_level(node);
9232 path->nodes[level] = node;
9233 path->slots[level] = 0;
9234 path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
9235
9236 wc->refs[parent_level] = 1;
9237 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
9238 wc->level = level;
9239 wc->shared_level = -1;
9240 wc->stage = DROP_REFERENCE;
9241 wc->update_ref = 0;
9242 wc->keep_locks = 1;
9243 wc->for_reloc = 1;
9244 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info);
9245
9246 while (1) {
9247 wret = walk_down_tree(trans, root, path, wc);
9248 if (wret < 0) {
9249 ret = wret;
9250 break;
9251 }
9252
9253 wret = walk_up_tree(trans, root, path, wc, parent_level);
9254 if (wret < 0)
9255 ret = wret;
9256 if (wret != 0)
9257 break;
9258 }
9259
9260 kfree(wc);
9261 btrfs_free_path(path);
9262 return ret;
9263 }
9264
9265 static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags)
9266 {
9267 u64 num_devices;
9268 u64 stripped;
9269
9270 /*
9271 * if restripe for this chunk_type is on pick target profile and
9272 * return, otherwise do the usual balance
9273 */
9274 stripped = get_restripe_target(fs_info, flags);
9275 if (stripped)
9276 return extended_to_chunk(stripped);
9277
9278 num_devices = fs_info->fs_devices->rw_devices;
9279
9280 stripped = BTRFS_BLOCK_GROUP_RAID0 |
9281 BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
9282 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
9283
9284 if (num_devices == 1) {
9285 stripped |= BTRFS_BLOCK_GROUP_DUP;
9286 stripped = flags & ~stripped;
9287
9288 /* turn raid0 into single device chunks */
9289 if (flags & BTRFS_BLOCK_GROUP_RAID0)
9290 return stripped;
9291
9292 /* turn mirroring into duplication */
9293 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
9294 BTRFS_BLOCK_GROUP_RAID10))
9295 return stripped | BTRFS_BLOCK_GROUP_DUP;
9296 } else {
9297 /* they already had raid on here, just return */
9298 if (flags & stripped)
9299 return flags;
9300
9301 stripped |= BTRFS_BLOCK_GROUP_DUP;
9302 stripped = flags & ~stripped;
9303
9304 /* switch duplicated blocks with raid1 */
9305 if (flags & BTRFS_BLOCK_GROUP_DUP)
9306 return stripped | BTRFS_BLOCK_GROUP_RAID1;
9307
9308 /* this is drive concat, leave it alone */
9309 }
9310
9311 return flags;
9312 }
9313
9314 static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
9315 {
9316 struct btrfs_space_info *sinfo = cache->space_info;
9317 u64 num_bytes;
9318 u64 min_allocable_bytes;
9319 int ret = -ENOSPC;
9320
9321 /*
9322 * We need some metadata space and system metadata space for
9323 * allocating chunks in some corner cases until we force to set
9324 * it to be readonly.
9325 */
9326 if ((sinfo->flags &
9327 (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
9328 !force)
9329 min_allocable_bytes = SZ_1M;
9330 else
9331 min_allocable_bytes = 0;
9332
9333 spin_lock(&sinfo->lock);
9334 spin_lock(&cache->lock);
9335
9336 if (cache->ro) {
9337 cache->ro++;
9338 ret = 0;
9339 goto out;
9340 }
9341
9342 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
9343 cache->bytes_super - btrfs_block_group_used(&cache->item);
9344
9345 if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
9346 sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
9347 min_allocable_bytes <= sinfo->total_bytes) {
9348 sinfo->bytes_readonly += num_bytes;
9349 cache->ro++;
9350 list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
9351 ret = 0;
9352 }
9353 out:
9354 spin_unlock(&cache->lock);
9355 spin_unlock(&sinfo->lock);
9356 return ret;
9357 }
9358
9359 int btrfs_inc_block_group_ro(struct btrfs_root *root,
9360 struct btrfs_block_group_cache *cache)
9361
9362 {
9363 struct btrfs_fs_info *fs_info = root->fs_info;
9364 struct btrfs_trans_handle *trans;
9365 u64 alloc_flags;
9366 int ret;
9367
9368 again:
9369 trans = btrfs_join_transaction(root);
9370 if (IS_ERR(trans))
9371 return PTR_ERR(trans);
9372
9373 /*
9374 * we're not allowed to set block groups readonly after the dirty
9375 * block groups cache has started writing. If it already started,
9376 * back off and let this transaction commit
9377 */
9378 mutex_lock(&fs_info->ro_block_group_mutex);
9379 if (test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &trans->transaction->flags)) {
9380 u64 transid = trans->transid;
9381
9382 mutex_unlock(&fs_info->ro_block_group_mutex);
9383 btrfs_end_transaction(trans);
9384
9385 ret = btrfs_wait_for_commit(fs_info, transid);
9386 if (ret)
9387 return ret;
9388 goto again;
9389 }
9390
9391 /*
9392 * if we are changing raid levels, try to allocate a corresponding
9393 * block group with the new raid level.
9394 */
9395 alloc_flags = update_block_group_flags(fs_info, cache->flags);
9396 if (alloc_flags != cache->flags) {
9397 ret = do_chunk_alloc(trans, fs_info, alloc_flags,
9398 CHUNK_ALLOC_FORCE);
9399 /*
9400 * ENOSPC is allowed here, we may have enough space
9401 * already allocated at the new raid level to
9402 * carry on
9403 */
9404 if (ret == -ENOSPC)
9405 ret = 0;
9406 if (ret < 0)
9407 goto out;
9408 }
9409
9410 ret = inc_block_group_ro(cache, 0);
9411 if (!ret)
9412 goto out;
9413 alloc_flags = get_alloc_profile(fs_info, cache->space_info->flags);
9414 ret = do_chunk_alloc(trans, fs_info, alloc_flags,
9415 CHUNK_ALLOC_FORCE);
9416 if (ret < 0)
9417 goto out;
9418 ret = inc_block_group_ro(cache, 0);
9419 out:
9420 if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
9421 alloc_flags = update_block_group_flags(fs_info, cache->flags);
9422 mutex_lock(&fs_info->chunk_mutex);
9423 check_system_chunk(trans, fs_info, alloc_flags);
9424 mutex_unlock(&fs_info->chunk_mutex);
9425 }
9426 mutex_unlock(&fs_info->ro_block_group_mutex);
9427
9428 btrfs_end_transaction(trans);
9429 return ret;
9430 }
9431
9432 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
9433 struct btrfs_fs_info *fs_info, u64 type)
9434 {
9435 u64 alloc_flags = get_alloc_profile(fs_info, type);
9436
9437 return do_chunk_alloc(trans, fs_info, alloc_flags, CHUNK_ALLOC_FORCE);
9438 }
9439
9440 /*
9441 * helper to account the unused space of all the readonly block group in the
9442 * space_info. takes mirrors into account.
9443 */
9444 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
9445 {
9446 struct btrfs_block_group_cache *block_group;
9447 u64 free_bytes = 0;
9448 int factor;
9449
9450 /* It's df, we don't care if it's racy */
9451 if (list_empty(&sinfo->ro_bgs))
9452 return 0;
9453
9454 spin_lock(&sinfo->lock);
9455 list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) {
9456 spin_lock(&block_group->lock);
9457
9458 if (!block_group->ro) {
9459 spin_unlock(&block_group->lock);
9460 continue;
9461 }
9462
9463 if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
9464 BTRFS_BLOCK_GROUP_RAID10 |
9465 BTRFS_BLOCK_GROUP_DUP))
9466 factor = 2;
9467 else
9468 factor = 1;
9469
9470 free_bytes += (block_group->key.offset -
9471 btrfs_block_group_used(&block_group->item)) *
9472 factor;
9473
9474 spin_unlock(&block_group->lock);
9475 }
9476 spin_unlock(&sinfo->lock);
9477
9478 return free_bytes;
9479 }
9480
9481 void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache)
9482 {
9483 struct btrfs_space_info *sinfo = cache->space_info;
9484 u64 num_bytes;
9485
9486 BUG_ON(!cache->ro);
9487
9488 spin_lock(&sinfo->lock);
9489 spin_lock(&cache->lock);
9490 if (!--cache->ro) {
9491 num_bytes = cache->key.offset - cache->reserved -
9492 cache->pinned - cache->bytes_super -
9493 btrfs_block_group_used(&cache->item);
9494 sinfo->bytes_readonly -= num_bytes;
9495 list_del_init(&cache->ro_list);
9496 }
9497 spin_unlock(&cache->lock);
9498 spin_unlock(&sinfo->lock);
9499 }
9500
9501 /*
9502 * checks to see if its even possible to relocate this block group.
9503 *
9504 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
9505 * ok to go ahead and try.
9506 */
9507 int btrfs_can_relocate(struct btrfs_fs_info *fs_info, u64 bytenr)
9508 {
9509 struct btrfs_root *root = fs_info->extent_root;
9510 struct btrfs_block_group_cache *block_group;
9511 struct btrfs_space_info *space_info;
9512 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
9513 struct btrfs_device *device;
9514 struct btrfs_trans_handle *trans;
9515 u64 min_free;
9516 u64 dev_min = 1;
9517 u64 dev_nr = 0;
9518 u64 target;
9519 int debug;
9520 int index;
9521 int full = 0;
9522 int ret = 0;
9523
9524 debug = btrfs_test_opt(fs_info, ENOSPC_DEBUG);
9525
9526 block_group = btrfs_lookup_block_group(fs_info, bytenr);
9527
9528 /* odd, couldn't find the block group, leave it alone */
9529 if (!block_group) {
9530 if (debug)
9531 btrfs_warn(fs_info,
9532 "can't find block group for bytenr %llu",
9533 bytenr);
9534 return -1;
9535 }
9536
9537 min_free = btrfs_block_group_used(&block_group->item);
9538
9539 /* no bytes used, we're good */
9540 if (!min_free)
9541 goto out;
9542
9543 space_info = block_group->space_info;
9544 spin_lock(&space_info->lock);
9545
9546 full = space_info->full;
9547
9548 /*
9549 * if this is the last block group we have in this space, we can't
9550 * relocate it unless we're able to allocate a new chunk below.
9551 *
9552 * Otherwise, we need to make sure we have room in the space to handle
9553 * all of the extents from this block group. If we can, we're good
9554 */
9555 if ((space_info->total_bytes != block_group->key.offset) &&
9556 (space_info->bytes_used + space_info->bytes_reserved +
9557 space_info->bytes_pinned + space_info->bytes_readonly +
9558 min_free < space_info->total_bytes)) {
9559 spin_unlock(&space_info->lock);
9560 goto out;
9561 }
9562 spin_unlock(&space_info->lock);
9563
9564 /*
9565 * ok we don't have enough space, but maybe we have free space on our
9566 * devices to allocate new chunks for relocation, so loop through our
9567 * alloc devices and guess if we have enough space. if this block
9568 * group is going to be restriped, run checks against the target
9569 * profile instead of the current one.
9570 */
9571 ret = -1;
9572
9573 /*
9574 * index:
9575 * 0: raid10
9576 * 1: raid1
9577 * 2: dup
9578 * 3: raid0
9579 * 4: single
9580 */
9581 target = get_restripe_target(fs_info, block_group->flags);
9582 if (target) {
9583 index = __get_raid_index(extended_to_chunk(target));
9584 } else {
9585 /*
9586 * this is just a balance, so if we were marked as full
9587 * we know there is no space for a new chunk
9588 */
9589 if (full) {
9590 if (debug)
9591 btrfs_warn(fs_info,
9592 "no space to alloc new chunk for block group %llu",
9593 block_group->key.objectid);
9594 goto out;
9595 }
9596
9597 index = get_block_group_index(block_group);
9598 }
9599
9600 if (index == BTRFS_RAID_RAID10) {
9601 dev_min = 4;
9602 /* Divide by 2 */
9603 min_free >>= 1;
9604 } else if (index == BTRFS_RAID_RAID1) {
9605 dev_min = 2;
9606 } else if (index == BTRFS_RAID_DUP) {
9607 /* Multiply by 2 */
9608 min_free <<= 1;
9609 } else if (index == BTRFS_RAID_RAID0) {
9610 dev_min = fs_devices->rw_devices;
9611 min_free = div64_u64(min_free, dev_min);
9612 }
9613
9614 /* We need to do this so that we can look at pending chunks */
9615 trans = btrfs_join_transaction(root);
9616 if (IS_ERR(trans)) {
9617 ret = PTR_ERR(trans);
9618 goto out;
9619 }
9620
9621 mutex_lock(&fs_info->chunk_mutex);
9622 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
9623 u64 dev_offset;
9624
9625 /*
9626 * check to make sure we can actually find a chunk with enough
9627 * space to fit our block group in.
9628 */
9629 if (device->total_bytes > device->bytes_used + min_free &&
9630 !device->is_tgtdev_for_dev_replace) {
9631 ret = find_free_dev_extent(trans, device, min_free,
9632 &dev_offset, NULL);
9633 if (!ret)
9634 dev_nr++;
9635
9636 if (dev_nr >= dev_min)
9637 break;
9638
9639 ret = -1;
9640 }
9641 }
9642 if (debug && ret == -1)
9643 btrfs_warn(fs_info,
9644 "no space to allocate a new chunk for block group %llu",
9645 block_group->key.objectid);
9646 mutex_unlock(&fs_info->chunk_mutex);
9647 btrfs_end_transaction(trans);
9648 out:
9649 btrfs_put_block_group(block_group);
9650 return ret;
9651 }
9652
9653 static int find_first_block_group(struct btrfs_fs_info *fs_info,
9654 struct btrfs_path *path,
9655 struct btrfs_key *key)
9656 {
9657 struct btrfs_root *root = fs_info->extent_root;
9658 int ret = 0;
9659 struct btrfs_key found_key;
9660 struct extent_buffer *leaf;
9661 int slot;
9662
9663 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
9664 if (ret < 0)
9665 goto out;
9666
9667 while (1) {
9668 slot = path->slots[0];
9669 leaf = path->nodes[0];
9670 if (slot >= btrfs_header_nritems(leaf)) {
9671 ret = btrfs_next_leaf(root, path);
9672 if (ret == 0)
9673 continue;
9674 if (ret < 0)
9675 goto out;
9676 break;
9677 }
9678 btrfs_item_key_to_cpu(leaf, &found_key, slot);
9679
9680 if (found_key.objectid >= key->objectid &&
9681 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
9682 struct extent_map_tree *em_tree;
9683 struct extent_map *em;
9684
9685 em_tree = &root->fs_info->mapping_tree.map_tree;
9686 read_lock(&em_tree->lock);
9687 em = lookup_extent_mapping(em_tree, found_key.objectid,
9688 found_key.offset);
9689 read_unlock(&em_tree->lock);
9690 if (!em) {
9691 btrfs_err(fs_info,
9692 "logical %llu len %llu found bg but no related chunk",
9693 found_key.objectid, found_key.offset);
9694 ret = -ENOENT;
9695 } else {
9696 ret = 0;
9697 }
9698 free_extent_map(em);
9699 goto out;
9700 }
9701 path->slots[0]++;
9702 }
9703 out:
9704 return ret;
9705 }
9706
9707 void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
9708 {
9709 struct btrfs_block_group_cache *block_group;
9710 u64 last = 0;
9711
9712 while (1) {
9713 struct inode *inode;
9714
9715 block_group = btrfs_lookup_first_block_group(info, last);
9716 while (block_group) {
9717 spin_lock(&block_group->lock);
9718 if (block_group->iref)
9719 break;
9720 spin_unlock(&block_group->lock);
9721 block_group = next_block_group(info, block_group);
9722 }
9723 if (!block_group) {
9724 if (last == 0)
9725 break;
9726 last = 0;
9727 continue;
9728 }
9729
9730 inode = block_group->inode;
9731 block_group->iref = 0;
9732 block_group->inode = NULL;
9733 spin_unlock(&block_group->lock);
9734 ASSERT(block_group->io_ctl.inode == NULL);
9735 iput(inode);
9736 last = block_group->key.objectid + block_group->key.offset;
9737 btrfs_put_block_group(block_group);
9738 }
9739 }
9740
9741 int btrfs_free_block_groups(struct btrfs_fs_info *info)
9742 {
9743 struct btrfs_block_group_cache *block_group;
9744 struct btrfs_space_info *space_info;
9745 struct btrfs_caching_control *caching_ctl;
9746 struct rb_node *n;
9747
9748 down_write(&info->commit_root_sem);
9749 while (!list_empty(&info->caching_block_groups)) {
9750 caching_ctl = list_entry(info->caching_block_groups.next,
9751 struct btrfs_caching_control, list);
9752 list_del(&caching_ctl->list);
9753 put_caching_control(caching_ctl);
9754 }
9755 up_write(&info->commit_root_sem);
9756
9757 spin_lock(&info->unused_bgs_lock);
9758 while (!list_empty(&info->unused_bgs)) {
9759 block_group = list_first_entry(&info->unused_bgs,
9760 struct btrfs_block_group_cache,
9761 bg_list);
9762 list_del_init(&block_group->bg_list);
9763 btrfs_put_block_group(block_group);
9764 }
9765 spin_unlock(&info->unused_bgs_lock);
9766
9767 spin_lock(&info->block_group_cache_lock);
9768 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
9769 block_group = rb_entry(n, struct btrfs_block_group_cache,
9770 cache_node);
9771 rb_erase(&block_group->cache_node,
9772 &info->block_group_cache_tree);
9773 RB_CLEAR_NODE(&block_group->cache_node);
9774 spin_unlock(&info->block_group_cache_lock);
9775
9776 down_write(&block_group->space_info->groups_sem);
9777 list_del(&block_group->list);
9778 up_write(&block_group->space_info->groups_sem);
9779
9780 if (block_group->cached == BTRFS_CACHE_STARTED)
9781 wait_block_group_cache_done(block_group);
9782
9783 /*
9784 * We haven't cached this block group, which means we could
9785 * possibly have excluded extents on this block group.
9786 */
9787 if (block_group->cached == BTRFS_CACHE_NO ||
9788 block_group->cached == BTRFS_CACHE_ERROR)
9789 free_excluded_extents(info, block_group);
9790
9791 btrfs_remove_free_space_cache(block_group);
9792 ASSERT(list_empty(&block_group->dirty_list));
9793 ASSERT(list_empty(&block_group->io_list));
9794 ASSERT(list_empty(&block_group->bg_list));
9795 ASSERT(atomic_read(&block_group->count) == 1);
9796 btrfs_put_block_group(block_group);
9797
9798 spin_lock(&info->block_group_cache_lock);
9799 }
9800 spin_unlock(&info->block_group_cache_lock);
9801
9802 /* now that all the block groups are freed, go through and
9803 * free all the space_info structs. This is only called during
9804 * the final stages of unmount, and so we know nobody is
9805 * using them. We call synchronize_rcu() once before we start,
9806 * just to be on the safe side.
9807 */
9808 synchronize_rcu();
9809
9810 release_global_block_rsv(info);
9811
9812 while (!list_empty(&info->space_info)) {
9813 int i;
9814
9815 space_info = list_entry(info->space_info.next,
9816 struct btrfs_space_info,
9817 list);
9818
9819 /*
9820 * Do not hide this behind enospc_debug, this is actually
9821 * important and indicates a real bug if this happens.
9822 */
9823 if (WARN_ON(space_info->bytes_pinned > 0 ||
9824 space_info->bytes_reserved > 0 ||
9825 space_info->bytes_may_use > 0))
9826 dump_space_info(info, space_info, 0, 0);
9827 list_del(&space_info->list);
9828 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
9829 struct kobject *kobj;
9830 kobj = space_info->block_group_kobjs[i];
9831 space_info->block_group_kobjs[i] = NULL;
9832 if (kobj) {
9833 kobject_del(kobj);
9834 kobject_put(kobj);
9835 }
9836 }
9837 kobject_del(&space_info->kobj);
9838 kobject_put(&space_info->kobj);
9839 }
9840 return 0;
9841 }
9842
9843 static void __link_block_group(struct btrfs_space_info *space_info,
9844 struct btrfs_block_group_cache *cache)
9845 {
9846 int index = get_block_group_index(cache);
9847 bool first = false;
9848
9849 down_write(&space_info->groups_sem);
9850 if (list_empty(&space_info->block_groups[index]))
9851 first = true;
9852 list_add_tail(&cache->list, &space_info->block_groups[index]);
9853 up_write(&space_info->groups_sem);
9854
9855 if (first) {
9856 struct raid_kobject *rkobj;
9857 int ret;
9858
9859 rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
9860 if (!rkobj)
9861 goto out_err;
9862 rkobj->raid_type = index;
9863 kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
9864 ret = kobject_add(&rkobj->kobj, &space_info->kobj,
9865 "%s", get_raid_name(index));
9866 if (ret) {
9867 kobject_put(&rkobj->kobj);
9868 goto out_err;
9869 }
9870 space_info->block_group_kobjs[index] = &rkobj->kobj;
9871 }
9872
9873 return;
9874 out_err:
9875 btrfs_warn(cache->fs_info,
9876 "failed to add kobject for block cache, ignoring");
9877 }
9878
9879 static struct btrfs_block_group_cache *
9880 btrfs_create_block_group_cache(struct btrfs_fs_info *fs_info,
9881 u64 start, u64 size)
9882 {
9883 struct btrfs_block_group_cache *cache;
9884
9885 cache = kzalloc(sizeof(*cache), GFP_NOFS);
9886 if (!cache)
9887 return NULL;
9888
9889 cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
9890 GFP_NOFS);
9891 if (!cache->free_space_ctl) {
9892 kfree(cache);
9893 return NULL;
9894 }
9895
9896 cache->key.objectid = start;
9897 cache->key.offset = size;
9898 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
9899
9900 cache->sectorsize = fs_info->sectorsize;
9901 cache->fs_info = fs_info;
9902 cache->full_stripe_len = btrfs_full_stripe_len(fs_info,
9903 &fs_info->mapping_tree,
9904 start);
9905 set_free_space_tree_thresholds(cache);
9906
9907 atomic_set(&cache->count, 1);
9908 spin_lock_init(&cache->lock);
9909 init_rwsem(&cache->data_rwsem);
9910 INIT_LIST_HEAD(&cache->list);
9911 INIT_LIST_HEAD(&cache->cluster_list);
9912 INIT_LIST_HEAD(&cache->bg_list);
9913 INIT_LIST_HEAD(&cache->ro_list);
9914 INIT_LIST_HEAD(&cache->dirty_list);
9915 INIT_LIST_HEAD(&cache->io_list);
9916 btrfs_init_free_space_ctl(cache);
9917 atomic_set(&cache->trimming, 0);
9918 mutex_init(&cache->free_space_lock);
9919
9920 return cache;
9921 }
9922
9923 int btrfs_read_block_groups(struct btrfs_fs_info *info)
9924 {
9925 struct btrfs_path *path;
9926 int ret;
9927 struct btrfs_block_group_cache *cache;
9928 struct btrfs_space_info *space_info;
9929 struct btrfs_key key;
9930 struct btrfs_key found_key;
9931 struct extent_buffer *leaf;
9932 int need_clear = 0;
9933 u64 cache_gen;
9934 u64 feature;
9935 int mixed;
9936
9937 feature = btrfs_super_incompat_flags(info->super_copy);
9938 mixed = !!(feature & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS);
9939
9940 key.objectid = 0;
9941 key.offset = 0;
9942 key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
9943 path = btrfs_alloc_path();
9944 if (!path)
9945 return -ENOMEM;
9946 path->reada = READA_FORWARD;
9947
9948 cache_gen = btrfs_super_cache_generation(info->super_copy);
9949 if (btrfs_test_opt(info, SPACE_CACHE) &&
9950 btrfs_super_generation(info->super_copy) != cache_gen)
9951 need_clear = 1;
9952 if (btrfs_test_opt(info, CLEAR_CACHE))
9953 need_clear = 1;
9954
9955 while (1) {
9956 ret = find_first_block_group(info, path, &key);
9957 if (ret > 0)
9958 break;
9959 if (ret != 0)
9960 goto error;
9961
9962 leaf = path->nodes[0];
9963 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
9964
9965 cache = btrfs_create_block_group_cache(info, found_key.objectid,
9966 found_key.offset);
9967 if (!cache) {
9968 ret = -ENOMEM;
9969 goto error;
9970 }
9971
9972 if (need_clear) {
9973 /*
9974 * When we mount with old space cache, we need to
9975 * set BTRFS_DC_CLEAR and set dirty flag.
9976 *
9977 * a) Setting 'BTRFS_DC_CLEAR' makes sure that we
9978 * truncate the old free space cache inode and
9979 * setup a new one.
9980 * b) Setting 'dirty flag' makes sure that we flush
9981 * the new space cache info onto disk.
9982 */
9983 if (btrfs_test_opt(info, SPACE_CACHE))
9984 cache->disk_cache_state = BTRFS_DC_CLEAR;
9985 }
9986
9987 read_extent_buffer(leaf, &cache->item,
9988 btrfs_item_ptr_offset(leaf, path->slots[0]),
9989 sizeof(cache->item));
9990 cache->flags = btrfs_block_group_flags(&cache->item);
9991 if (!mixed &&
9992 ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
9993 (cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
9994 btrfs_err(info,
9995 "bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups",
9996 cache->key.objectid);
9997 ret = -EINVAL;
9998 goto error;
9999 }
10000
10001 key.objectid = found_key.objectid + found_key.offset;
10002 btrfs_release_path(path);
10003
10004 /*
10005 * We need to exclude the super stripes now so that the space
10006 * info has super bytes accounted for, otherwise we'll think
10007 * we have more space than we actually do.
10008 */
10009 ret = exclude_super_stripes(info, cache);
10010 if (ret) {
10011 /*
10012 * We may have excluded something, so call this just in
10013 * case.
10014 */
10015 free_excluded_extents(info, cache);
10016 btrfs_put_block_group(cache);
10017 goto error;
10018 }
10019
10020 /*
10021 * check for two cases, either we are full, and therefore
10022 * don't need to bother with the caching work since we won't
10023 * find any space, or we are empty, and we can just add all
10024 * the space in and be done with it. This saves us _alot_ of
10025 * time, particularly in the full case.
10026 */
10027 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
10028 cache->last_byte_to_unpin = (u64)-1;
10029 cache->cached = BTRFS_CACHE_FINISHED;
10030 free_excluded_extents(info, cache);
10031 } else if (btrfs_block_group_used(&cache->item) == 0) {
10032 cache->last_byte_to_unpin = (u64)-1;
10033 cache->cached = BTRFS_CACHE_FINISHED;
10034 add_new_free_space(cache, info,
10035 found_key.objectid,
10036 found_key.objectid +
10037 found_key.offset);
10038 free_excluded_extents(info, cache);
10039 }
10040
10041 ret = btrfs_add_block_group_cache(info, cache);
10042 if (ret) {
10043 btrfs_remove_free_space_cache(cache);
10044 btrfs_put_block_group(cache);
10045 goto error;
10046 }
10047
10048 trace_btrfs_add_block_group(info, cache, 0);
10049 ret = update_space_info(info, cache->flags, found_key.offset,
10050 btrfs_block_group_used(&cache->item),
10051 cache->bytes_super, &space_info);
10052 if (ret) {
10053 btrfs_remove_free_space_cache(cache);
10054 spin_lock(&info->block_group_cache_lock);
10055 rb_erase(&cache->cache_node,
10056 &info->block_group_cache_tree);
10057 RB_CLEAR_NODE(&cache->cache_node);
10058 spin_unlock(&info->block_group_cache_lock);
10059 btrfs_put_block_group(cache);
10060 goto error;
10061 }
10062
10063 cache->space_info = space_info;
10064
10065 __link_block_group(space_info, cache);
10066
10067 set_avail_alloc_bits(info, cache->flags);
10068 if (btrfs_chunk_readonly(info, cache->key.objectid)) {
10069 inc_block_group_ro(cache, 1);
10070 } else if (btrfs_block_group_used(&cache->item) == 0) {
10071 spin_lock(&info->unused_bgs_lock);
10072 /* Should always be true but just in case. */
10073 if (list_empty(&cache->bg_list)) {
10074 btrfs_get_block_group(cache);
10075 list_add_tail(&cache->bg_list,
10076 &info->unused_bgs);
10077 }
10078 spin_unlock(&info->unused_bgs_lock);
10079 }
10080 }
10081
10082 list_for_each_entry_rcu(space_info, &info->space_info, list) {
10083 if (!(get_alloc_profile(info, space_info->flags) &
10084 (BTRFS_BLOCK_GROUP_RAID10 |
10085 BTRFS_BLOCK_GROUP_RAID1 |
10086 BTRFS_BLOCK_GROUP_RAID5 |
10087 BTRFS_BLOCK_GROUP_RAID6 |
10088 BTRFS_BLOCK_GROUP_DUP)))
10089 continue;
10090 /*
10091 * avoid allocating from un-mirrored block group if there are
10092 * mirrored block groups.
10093 */
10094 list_for_each_entry(cache,
10095 &space_info->block_groups[BTRFS_RAID_RAID0],
10096 list)
10097 inc_block_group_ro(cache, 1);
10098 list_for_each_entry(cache,
10099 &space_info->block_groups[BTRFS_RAID_SINGLE],
10100 list)
10101 inc_block_group_ro(cache, 1);
10102 }
10103
10104 init_global_block_rsv(info);
10105 ret = 0;
10106 error:
10107 btrfs_free_path(path);
10108 return ret;
10109 }
10110
10111 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
10112 struct btrfs_fs_info *fs_info)
10113 {
10114 struct btrfs_block_group_cache *block_group, *tmp;
10115 struct btrfs_root *extent_root = fs_info->extent_root;
10116 struct btrfs_block_group_item item;
10117 struct btrfs_key key;
10118 int ret = 0;
10119 bool can_flush_pending_bgs = trans->can_flush_pending_bgs;
10120
10121 trans->can_flush_pending_bgs = false;
10122 list_for_each_entry_safe(block_group, tmp, &trans->new_bgs, bg_list) {
10123 if (ret)
10124 goto next;
10125
10126 spin_lock(&block_group->lock);
10127 memcpy(&item, &block_group->item, sizeof(item));
10128 memcpy(&key, &block_group->key, sizeof(key));
10129 spin_unlock(&block_group->lock);
10130
10131 ret = btrfs_insert_item(trans, extent_root, &key, &item,
10132 sizeof(item));
10133 if (ret)
10134 btrfs_abort_transaction(trans, ret);
10135 ret = btrfs_finish_chunk_alloc(trans, fs_info, key.objectid,
10136 key.offset);
10137 if (ret)
10138 btrfs_abort_transaction(trans, ret);
10139 add_block_group_free_space(trans, fs_info, block_group);
10140 /* already aborted the transaction if it failed. */
10141 next:
10142 list_del_init(&block_group->bg_list);
10143 }
10144 trans->can_flush_pending_bgs = can_flush_pending_bgs;
10145 }
10146
10147 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
10148 struct btrfs_fs_info *fs_info, u64 bytes_used,
10149 u64 type, u64 chunk_objectid, u64 chunk_offset,
10150 u64 size)
10151 {
10152 struct btrfs_block_group_cache *cache;
10153 int ret;
10154
10155 btrfs_set_log_full_commit(fs_info, trans);
10156
10157 cache = btrfs_create_block_group_cache(fs_info, chunk_offset, size);
10158 if (!cache)
10159 return -ENOMEM;
10160
10161 btrfs_set_block_group_used(&cache->item, bytes_used);
10162 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
10163 btrfs_set_block_group_flags(&cache->item, type);
10164
10165 cache->flags = type;
10166 cache->last_byte_to_unpin = (u64)-1;
10167 cache->cached = BTRFS_CACHE_FINISHED;
10168 cache->needs_free_space = 1;
10169 ret = exclude_super_stripes(fs_info, cache);
10170 if (ret) {
10171 /*
10172 * We may have excluded something, so call this just in
10173 * case.
10174 */
10175 free_excluded_extents(fs_info, cache);
10176 btrfs_put_block_group(cache);
10177 return ret;
10178 }
10179
10180 add_new_free_space(cache, fs_info, chunk_offset, chunk_offset + size);
10181
10182 free_excluded_extents(fs_info, cache);
10183
10184 #ifdef CONFIG_BTRFS_DEBUG
10185 if (btrfs_should_fragment_free_space(cache)) {
10186 u64 new_bytes_used = size - bytes_used;
10187
10188 bytes_used += new_bytes_used >> 1;
10189 fragment_free_space(cache);
10190 }
10191 #endif
10192 /*
10193 * Call to ensure the corresponding space_info object is created and
10194 * assigned to our block group, but don't update its counters just yet.
10195 * We want our bg to be added to the rbtree with its ->space_info set.
10196 */
10197 ret = update_space_info(fs_info, cache->flags, 0, 0, 0,
10198 &cache->space_info);
10199 if (ret) {
10200 btrfs_remove_free_space_cache(cache);
10201 btrfs_put_block_group(cache);
10202 return ret;
10203 }
10204
10205 ret = btrfs_add_block_group_cache(fs_info, cache);
10206 if (ret) {
10207 btrfs_remove_free_space_cache(cache);
10208 btrfs_put_block_group(cache);
10209 return ret;
10210 }
10211
10212 /*
10213 * Now that our block group has its ->space_info set and is inserted in
10214 * the rbtree, update the space info's counters.
10215 */
10216 trace_btrfs_add_block_group(fs_info, cache, 1);
10217 ret = update_space_info(fs_info, cache->flags, size, bytes_used,
10218 cache->bytes_super, &cache->space_info);
10219 if (ret) {
10220 btrfs_remove_free_space_cache(cache);
10221 spin_lock(&fs_info->block_group_cache_lock);
10222 rb_erase(&cache->cache_node,
10223 &fs_info->block_group_cache_tree);
10224 RB_CLEAR_NODE(&cache->cache_node);
10225 spin_unlock(&fs_info->block_group_cache_lock);
10226 btrfs_put_block_group(cache);
10227 return ret;
10228 }
10229 update_global_block_rsv(fs_info);
10230
10231 __link_block_group(cache->space_info, cache);
10232
10233 list_add_tail(&cache->bg_list, &trans->new_bgs);
10234
10235 set_avail_alloc_bits(fs_info, type);
10236 return 0;
10237 }
10238
10239 static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
10240 {
10241 u64 extra_flags = chunk_to_extended(flags) &
10242 BTRFS_EXTENDED_PROFILE_MASK;
10243
10244 write_seqlock(&fs_info->profiles_lock);
10245 if (flags & BTRFS_BLOCK_GROUP_DATA)
10246 fs_info->avail_data_alloc_bits &= ~extra_flags;
10247 if (flags & BTRFS_BLOCK_GROUP_METADATA)
10248 fs_info->avail_metadata_alloc_bits &= ~extra_flags;
10249 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
10250 fs_info->avail_system_alloc_bits &= ~extra_flags;
10251 write_sequnlock(&fs_info->profiles_lock);
10252 }
10253
10254 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
10255 struct btrfs_fs_info *fs_info, u64 group_start,
10256 struct extent_map *em)
10257 {
10258 struct btrfs_root *root = fs_info->extent_root;
10259 struct btrfs_path *path;
10260 struct btrfs_block_group_cache *block_group;
10261 struct btrfs_free_cluster *cluster;
10262 struct btrfs_root *tree_root = fs_info->tree_root;
10263 struct btrfs_key key;
10264 struct inode *inode;
10265 struct kobject *kobj = NULL;
10266 int ret;
10267 int index;
10268 int factor;
10269 struct btrfs_caching_control *caching_ctl = NULL;
10270 bool remove_em;
10271
10272 block_group = btrfs_lookup_block_group(fs_info, group_start);
10273 BUG_ON(!block_group);
10274 BUG_ON(!block_group->ro);
10275
10276 /*
10277 * Free the reserved super bytes from this block group before
10278 * remove it.
10279 */
10280 free_excluded_extents(fs_info, block_group);
10281
10282 memcpy(&key, &block_group->key, sizeof(key));
10283 index = get_block_group_index(block_group);
10284 if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
10285 BTRFS_BLOCK_GROUP_RAID1 |
10286 BTRFS_BLOCK_GROUP_RAID10))
10287 factor = 2;
10288 else
10289 factor = 1;
10290
10291 /* make sure this block group isn't part of an allocation cluster */
10292 cluster = &fs_info->data_alloc_cluster;
10293 spin_lock(&cluster->refill_lock);
10294 btrfs_return_cluster_to_free_space(block_group, cluster);
10295 spin_unlock(&cluster->refill_lock);
10296
10297 /*
10298 * make sure this block group isn't part of a metadata
10299 * allocation cluster
10300 */
10301 cluster = &fs_info->meta_alloc_cluster;
10302 spin_lock(&cluster->refill_lock);
10303 btrfs_return_cluster_to_free_space(block_group, cluster);
10304 spin_unlock(&cluster->refill_lock);
10305
10306 path = btrfs_alloc_path();
10307 if (!path) {
10308 ret = -ENOMEM;
10309 goto out;
10310 }
10311
10312 /*
10313 * get the inode first so any iput calls done for the io_list
10314 * aren't the final iput (no unlinks allowed now)
10315 */
10316 inode = lookup_free_space_inode(tree_root, block_group, path);
10317
10318 mutex_lock(&trans->transaction->cache_write_mutex);
10319 /*
10320 * make sure our free spache cache IO is done before remove the
10321 * free space inode
10322 */
10323 spin_lock(&trans->transaction->dirty_bgs_lock);
10324 if (!list_empty(&block_group->io_list)) {
10325 list_del_init(&block_group->io_list);
10326
10327 WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
10328
10329 spin_unlock(&trans->transaction->dirty_bgs_lock);
10330 btrfs_wait_cache_io(trans, block_group, path);
10331 btrfs_put_block_group(block_group);
10332 spin_lock(&trans->transaction->dirty_bgs_lock);
10333 }
10334
10335 if (!list_empty(&block_group->dirty_list)) {
10336 list_del_init(&block_group->dirty_list);
10337 btrfs_put_block_group(block_group);
10338 }
10339 spin_unlock(&trans->transaction->dirty_bgs_lock);
10340 mutex_unlock(&trans->transaction->cache_write_mutex);
10341
10342 if (!IS_ERR(inode)) {
10343 ret = btrfs_orphan_add(trans, inode);
10344 if (ret) {
10345 btrfs_add_delayed_iput(inode);
10346 goto out;
10347 }
10348 clear_nlink(inode);
10349 /* One for the block groups ref */
10350 spin_lock(&block_group->lock);
10351 if (block_group->iref) {
10352 block_group->iref = 0;
10353 block_group->inode = NULL;
10354 spin_unlock(&block_group->lock);
10355 iput(inode);
10356 } else {
10357 spin_unlock(&block_group->lock);
10358 }
10359 /* One for our lookup ref */
10360 btrfs_add_delayed_iput(inode);
10361 }
10362
10363 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
10364 key.offset = block_group->key.objectid;
10365 key.type = 0;
10366
10367 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
10368 if (ret < 0)
10369 goto out;
10370 if (ret > 0)
10371 btrfs_release_path(path);
10372 if (ret == 0) {
10373 ret = btrfs_del_item(trans, tree_root, path);
10374 if (ret)
10375 goto out;
10376 btrfs_release_path(path);
10377 }
10378
10379 spin_lock(&fs_info->block_group_cache_lock);
10380 rb_erase(&block_group->cache_node,
10381 &fs_info->block_group_cache_tree);
10382 RB_CLEAR_NODE(&block_group->cache_node);
10383
10384 if (fs_info->first_logical_byte == block_group->key.objectid)
10385 fs_info->first_logical_byte = (u64)-1;
10386 spin_unlock(&fs_info->block_group_cache_lock);
10387
10388 down_write(&block_group->space_info->groups_sem);
10389 /*
10390 * we must use list_del_init so people can check to see if they
10391 * are still on the list after taking the semaphore
10392 */
10393 list_del_init(&block_group->list);
10394 if (list_empty(&block_group->space_info->block_groups[index])) {
10395 kobj = block_group->space_info->block_group_kobjs[index];
10396 block_group->space_info->block_group_kobjs[index] = NULL;
10397 clear_avail_alloc_bits(fs_info, block_group->flags);
10398 }
10399 up_write(&block_group->space_info->groups_sem);
10400 if (kobj) {
10401 kobject_del(kobj);
10402 kobject_put(kobj);
10403 }
10404
10405 if (block_group->has_caching_ctl)
10406 caching_ctl = get_caching_control(block_group);
10407 if (block_group->cached == BTRFS_CACHE_STARTED)
10408 wait_block_group_cache_done(block_group);
10409 if (block_group->has_caching_ctl) {
10410 down_write(&fs_info->commit_root_sem);
10411 if (!caching_ctl) {
10412 struct btrfs_caching_control *ctl;
10413
10414 list_for_each_entry(ctl,
10415 &fs_info->caching_block_groups, list)
10416 if (ctl->block_group == block_group) {
10417 caching_ctl = ctl;
10418 atomic_inc(&caching_ctl->count);
10419 break;
10420 }
10421 }
10422 if (caching_ctl)
10423 list_del_init(&caching_ctl->list);
10424 up_write(&fs_info->commit_root_sem);
10425 if (caching_ctl) {
10426 /* Once for the caching bgs list and once for us. */
10427 put_caching_control(caching_ctl);
10428 put_caching_control(caching_ctl);
10429 }
10430 }
10431
10432 spin_lock(&trans->transaction->dirty_bgs_lock);
10433 if (!list_empty(&block_group->dirty_list)) {
10434 WARN_ON(1);
10435 }
10436 if (!list_empty(&block_group->io_list)) {
10437 WARN_ON(1);
10438 }
10439 spin_unlock(&trans->transaction->dirty_bgs_lock);
10440 btrfs_remove_free_space_cache(block_group);
10441
10442 spin_lock(&block_group->space_info->lock);
10443 list_del_init(&block_group->ro_list);
10444
10445 if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
10446 WARN_ON(block_group->space_info->total_bytes
10447 < block_group->key.offset);
10448 WARN_ON(block_group->space_info->bytes_readonly
10449 < block_group->key.offset);
10450 WARN_ON(block_group->space_info->disk_total
10451 < block_group->key.offset * factor);
10452 }
10453 block_group->space_info->total_bytes -= block_group->key.offset;
10454 block_group->space_info->bytes_readonly -= block_group->key.offset;
10455 block_group->space_info->disk_total -= block_group->key.offset * factor;
10456
10457 spin_unlock(&block_group->space_info->lock);
10458
10459 memcpy(&key, &block_group->key, sizeof(key));
10460
10461 mutex_lock(&fs_info->chunk_mutex);
10462 if (!list_empty(&em->list)) {
10463 /* We're in the transaction->pending_chunks list. */
10464 free_extent_map(em);
10465 }
10466 spin_lock(&block_group->lock);
10467 block_group->removed = 1;
10468 /*
10469 * At this point trimming can't start on this block group, because we
10470 * removed the block group from the tree fs_info->block_group_cache_tree
10471 * so no one can't find it anymore and even if someone already got this
10472 * block group before we removed it from the rbtree, they have already
10473 * incremented block_group->trimming - if they didn't, they won't find
10474 * any free space entries because we already removed them all when we
10475 * called btrfs_remove_free_space_cache().
10476 *
10477 * And we must not remove the extent map from the fs_info->mapping_tree
10478 * to prevent the same logical address range and physical device space
10479 * ranges from being reused for a new block group. This is because our
10480 * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
10481 * completely transactionless, so while it is trimming a range the
10482 * currently running transaction might finish and a new one start,
10483 * allowing for new block groups to be created that can reuse the same
10484 * physical device locations unless we take this special care.
10485 *
10486 * There may also be an implicit trim operation if the file system
10487 * is mounted with -odiscard. The same protections must remain
10488 * in place until the extents have been discarded completely when
10489 * the transaction commit has completed.
10490 */
10491 remove_em = (atomic_read(&block_group->trimming) == 0);
10492 /*
10493 * Make sure a trimmer task always sees the em in the pinned_chunks list
10494 * if it sees block_group->removed == 1 (needs to lock block_group->lock
10495 * before checking block_group->removed).
10496 */
10497 if (!remove_em) {
10498 /*
10499 * Our em might be in trans->transaction->pending_chunks which
10500 * is protected by fs_info->chunk_mutex ([lock|unlock]_chunks),
10501 * and so is the fs_info->pinned_chunks list.
10502 *
10503 * So at this point we must be holding the chunk_mutex to avoid
10504 * any races with chunk allocation (more specifically at
10505 * volumes.c:contains_pending_extent()), to ensure it always
10506 * sees the em, either in the pending_chunks list or in the
10507 * pinned_chunks list.
10508 */
10509 list_move_tail(&em->list, &fs_info->pinned_chunks);
10510 }
10511 spin_unlock(&block_group->lock);
10512
10513 if (remove_em) {
10514 struct extent_map_tree *em_tree;
10515
10516 em_tree = &fs_info->mapping_tree.map_tree;
10517 write_lock(&em_tree->lock);
10518 /*
10519 * The em might be in the pending_chunks list, so make sure the
10520 * chunk mutex is locked, since remove_extent_mapping() will
10521 * delete us from that list.
10522 */
10523 remove_extent_mapping(em_tree, em);
10524 write_unlock(&em_tree->lock);
10525 /* once for the tree */
10526 free_extent_map(em);
10527 }
10528
10529 mutex_unlock(&fs_info->chunk_mutex);
10530
10531 ret = remove_block_group_free_space(trans, fs_info, block_group);
10532 if (ret)
10533 goto out;
10534
10535 btrfs_put_block_group(block_group);
10536 btrfs_put_block_group(block_group);
10537
10538 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
10539 if (ret > 0)
10540 ret = -EIO;
10541 if (ret < 0)
10542 goto out;
10543
10544 ret = btrfs_del_item(trans, root, path);
10545 out:
10546 btrfs_free_path(path);
10547 return ret;
10548 }
10549
10550 struct btrfs_trans_handle *
10551 btrfs_start_trans_remove_block_group(struct btrfs_fs_info *fs_info,
10552 const u64 chunk_offset)
10553 {
10554 struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
10555 struct extent_map *em;
10556 struct map_lookup *map;
10557 unsigned int num_items;
10558
10559 read_lock(&em_tree->lock);
10560 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
10561 read_unlock(&em_tree->lock);
10562 ASSERT(em && em->start == chunk_offset);
10563
10564 /*
10565 * We need to reserve 3 + N units from the metadata space info in order
10566 * to remove a block group (done at btrfs_remove_chunk() and at
10567 * btrfs_remove_block_group()), which are used for:
10568 *
10569 * 1 unit for adding the free space inode's orphan (located in the tree
10570 * of tree roots).
10571 * 1 unit for deleting the block group item (located in the extent
10572 * tree).
10573 * 1 unit for deleting the free space item (located in tree of tree
10574 * roots).
10575 * N units for deleting N device extent items corresponding to each
10576 * stripe (located in the device tree).
10577 *
10578 * In order to remove a block group we also need to reserve units in the
10579 * system space info in order to update the chunk tree (update one or
10580 * more device items and remove one chunk item), but this is done at
10581 * btrfs_remove_chunk() through a call to check_system_chunk().
10582 */
10583 map = em->map_lookup;
10584 num_items = 3 + map->num_stripes;
10585 free_extent_map(em);
10586
10587 return btrfs_start_transaction_fallback_global_rsv(fs_info->extent_root,
10588 num_items, 1);
10589 }
10590
10591 /*
10592 * Process the unused_bgs list and remove any that don't have any allocated
10593 * space inside of them.
10594 */
10595 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
10596 {
10597 struct btrfs_block_group_cache *block_group;
10598 struct btrfs_space_info *space_info;
10599 struct btrfs_trans_handle *trans;
10600 int ret = 0;
10601
10602 if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
10603 return;
10604
10605 spin_lock(&fs_info->unused_bgs_lock);
10606 while (!list_empty(&fs_info->unused_bgs)) {
10607 u64 start, end;
10608 int trimming;
10609
10610 block_group = list_first_entry(&fs_info->unused_bgs,
10611 struct btrfs_block_group_cache,
10612 bg_list);
10613 list_del_init(&block_group->bg_list);
10614
10615 space_info = block_group->space_info;
10616
10617 if (ret || btrfs_mixed_space_info(space_info)) {
10618 btrfs_put_block_group(block_group);
10619 continue;
10620 }
10621 spin_unlock(&fs_info->unused_bgs_lock);
10622
10623 mutex_lock(&fs_info->delete_unused_bgs_mutex);
10624
10625 /* Don't want to race with allocators so take the groups_sem */
10626 down_write(&space_info->groups_sem);
10627 spin_lock(&block_group->lock);
10628 if (block_group->reserved ||
10629 btrfs_block_group_used(&block_group->item) ||
10630 block_group->ro ||
10631 list_is_singular(&block_group->list)) {
10632 /*
10633 * We want to bail if we made new allocations or have
10634 * outstanding allocations in this block group. We do
10635 * the ro check in case balance is currently acting on
10636 * this block group.
10637 */
10638 spin_unlock(&block_group->lock);
10639 up_write(&space_info->groups_sem);
10640 goto next;
10641 }
10642 spin_unlock(&block_group->lock);
10643
10644 /* We don't want to force the issue, only flip if it's ok. */
10645 ret = inc_block_group_ro(block_group, 0);
10646 up_write(&space_info->groups_sem);
10647 if (ret < 0) {
10648 ret = 0;
10649 goto next;
10650 }
10651
10652 /*
10653 * Want to do this before we do anything else so we can recover
10654 * properly if we fail to join the transaction.
10655 */
10656 trans = btrfs_start_trans_remove_block_group(fs_info,
10657 block_group->key.objectid);
10658 if (IS_ERR(trans)) {
10659 btrfs_dec_block_group_ro(block_group);
10660 ret = PTR_ERR(trans);
10661 goto next;
10662 }
10663
10664 /*
10665 * We could have pending pinned extents for this block group,
10666 * just delete them, we don't care about them anymore.
10667 */
10668 start = block_group->key.objectid;
10669 end = start + block_group->key.offset - 1;
10670 /*
10671 * Hold the unused_bg_unpin_mutex lock to avoid racing with
10672 * btrfs_finish_extent_commit(). If we are at transaction N,
10673 * another task might be running finish_extent_commit() for the
10674 * previous transaction N - 1, and have seen a range belonging
10675 * to the block group in freed_extents[] before we were able to
10676 * clear the whole block group range from freed_extents[]. This
10677 * means that task can lookup for the block group after we
10678 * unpinned it from freed_extents[] and removed it, leading to
10679 * a BUG_ON() at btrfs_unpin_extent_range().
10680 */
10681 mutex_lock(&fs_info->unused_bg_unpin_mutex);
10682 ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
10683 EXTENT_DIRTY);
10684 if (ret) {
10685 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
10686 btrfs_dec_block_group_ro(block_group);
10687 goto end_trans;
10688 }
10689 ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
10690 EXTENT_DIRTY);
10691 if (ret) {
10692 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
10693 btrfs_dec_block_group_ro(block_group);
10694 goto end_trans;
10695 }
10696 mutex_unlock(&fs_info->unused_bg_unpin_mutex);
10697
10698 /* Reset pinned so btrfs_put_block_group doesn't complain */
10699 spin_lock(&space_info->lock);
10700 spin_lock(&block_group->lock);
10701
10702 space_info->bytes_pinned -= block_group->pinned;
10703 space_info->bytes_readonly += block_group->pinned;
10704 percpu_counter_add(&space_info->total_bytes_pinned,
10705 -block_group->pinned);
10706 block_group->pinned = 0;
10707
10708 spin_unlock(&block_group->lock);
10709 spin_unlock(&space_info->lock);
10710
10711 /* DISCARD can flip during remount */
10712 trimming = btrfs_test_opt(fs_info, DISCARD);
10713
10714 /* Implicit trim during transaction commit. */
10715 if (trimming)
10716 btrfs_get_block_group_trimming(block_group);
10717
10718 /*
10719 * Btrfs_remove_chunk will abort the transaction if things go
10720 * horribly wrong.
10721 */
10722 ret = btrfs_remove_chunk(trans, fs_info,
10723 block_group->key.objectid);
10724
10725 if (ret) {
10726 if (trimming)
10727 btrfs_put_block_group_trimming(block_group);
10728 goto end_trans;
10729 }
10730
10731 /*
10732 * If we're not mounted with -odiscard, we can just forget
10733 * about this block group. Otherwise we'll need to wait
10734 * until transaction commit to do the actual discard.
10735 */
10736 if (trimming) {
10737 spin_lock(&fs_info->unused_bgs_lock);
10738 /*
10739 * A concurrent scrub might have added us to the list
10740 * fs_info->unused_bgs, so use a list_move operation
10741 * to add the block group to the deleted_bgs list.
10742 */
10743 list_move(&block_group->bg_list,
10744 &trans->transaction->deleted_bgs);
10745 spin_unlock(&fs_info->unused_bgs_lock);
10746 btrfs_get_block_group(block_group);
10747 }
10748 end_trans:
10749 btrfs_end_transaction(trans);
10750 next:
10751 mutex_unlock(&fs_info->delete_unused_bgs_mutex);
10752 btrfs_put_block_group(block_group);
10753 spin_lock(&fs_info->unused_bgs_lock);
10754 }
10755 spin_unlock(&fs_info->unused_bgs_lock);
10756 }
10757
10758 int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
10759 {
10760 struct btrfs_space_info *space_info;
10761 struct btrfs_super_block *disk_super;
10762 u64 features;
10763 u64 flags;
10764 int mixed = 0;
10765 int ret;
10766
10767 disk_super = fs_info->super_copy;
10768 if (!btrfs_super_root(disk_super))
10769 return -EINVAL;
10770
10771 features = btrfs_super_incompat_flags(disk_super);
10772 if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
10773 mixed = 1;
10774
10775 flags = BTRFS_BLOCK_GROUP_SYSTEM;
10776 ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info);
10777 if (ret)
10778 goto out;
10779
10780 if (mixed) {
10781 flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
10782 ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info);
10783 } else {
10784 flags = BTRFS_BLOCK_GROUP_METADATA;
10785 ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info);
10786 if (ret)
10787 goto out;
10788
10789 flags = BTRFS_BLOCK_GROUP_DATA;
10790 ret = update_space_info(fs_info, flags, 0, 0, 0, &space_info);
10791 }
10792 out:
10793 return ret;
10794 }
10795
10796 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
10797 u64 start, u64 end)
10798 {
10799 return unpin_extent_range(fs_info, start, end, false);
10800 }
10801
10802 /*
10803 * It used to be that old block groups would be left around forever.
10804 * Iterating over them would be enough to trim unused space. Since we
10805 * now automatically remove them, we also need to iterate over unallocated
10806 * space.
10807 *
10808 * We don't want a transaction for this since the discard may take a
10809 * substantial amount of time. We don't require that a transaction be
10810 * running, but we do need to take a running transaction into account
10811 * to ensure that we're not discarding chunks that were released in
10812 * the current transaction.
10813 *
10814 * Holding the chunks lock will prevent other threads from allocating
10815 * or releasing chunks, but it won't prevent a running transaction
10816 * from committing and releasing the memory that the pending chunks
10817 * list head uses. For that, we need to take a reference to the
10818 * transaction.
10819 */
10820 static int btrfs_trim_free_extents(struct btrfs_device *device,
10821 u64 minlen, u64 *trimmed)
10822 {
10823 u64 start = 0, len = 0;
10824 int ret;
10825
10826 *trimmed = 0;
10827
10828 /* Not writeable = nothing to do. */
10829 if (!device->writeable)
10830 return 0;
10831
10832 /* No free space = nothing to do. */
10833 if (device->total_bytes <= device->bytes_used)
10834 return 0;
10835
10836 ret = 0;
10837
10838 while (1) {
10839 struct btrfs_fs_info *fs_info = device->fs_info;
10840 struct btrfs_transaction *trans;
10841 u64 bytes;
10842
10843 ret = mutex_lock_interruptible(&fs_info->chunk_mutex);
10844 if (ret)
10845 return ret;
10846
10847 down_read(&fs_info->commit_root_sem);
10848
10849 spin_lock(&fs_info->trans_lock);
10850 trans = fs_info->running_transaction;
10851 if (trans)
10852 atomic_inc(&trans->use_count);
10853 spin_unlock(&fs_info->trans_lock);
10854
10855 ret = find_free_dev_extent_start(trans, device, minlen, start,
10856 &start, &len);
10857 if (trans)
10858 btrfs_put_transaction(trans);
10859
10860 if (ret) {
10861 up_read(&fs_info->commit_root_sem);
10862 mutex_unlock(&fs_info->chunk_mutex);
10863 if (ret == -ENOSPC)
10864 ret = 0;
10865 break;
10866 }
10867
10868 ret = btrfs_issue_discard(device->bdev, start, len, &bytes);
10869 up_read(&fs_info->commit_root_sem);
10870 mutex_unlock(&fs_info->chunk_mutex);
10871
10872 if (ret)
10873 break;
10874
10875 start += len;
10876 *trimmed += bytes;
10877
10878 if (fatal_signal_pending(current)) {
10879 ret = -ERESTARTSYS;
10880 break;
10881 }
10882
10883 cond_resched();
10884 }
10885
10886 return ret;
10887 }
10888
10889 int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
10890 {
10891 struct btrfs_block_group_cache *cache = NULL;
10892 struct btrfs_device *device;
10893 struct list_head *devices;
10894 u64 group_trimmed;
10895 u64 start;
10896 u64 end;
10897 u64 trimmed = 0;
10898 u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
10899 int ret = 0;
10900
10901 /*
10902 * try to trim all FS space, our block group may start from non-zero.
10903 */
10904 if (range->len == total_bytes)
10905 cache = btrfs_lookup_first_block_group(fs_info, range->start);
10906 else
10907 cache = btrfs_lookup_block_group(fs_info, range->start);
10908
10909 while (cache) {
10910 if (cache->key.objectid >= (range->start + range->len)) {
10911 btrfs_put_block_group(cache);
10912 break;
10913 }
10914
10915 start = max(range->start, cache->key.objectid);
10916 end = min(range->start + range->len,
10917 cache->key.objectid + cache->key.offset);
10918
10919 if (end - start >= range->minlen) {
10920 if (!block_group_cache_done(cache)) {
10921 ret = cache_block_group(cache, 0);
10922 if (ret) {
10923 btrfs_put_block_group(cache);
10924 break;
10925 }
10926 ret = wait_block_group_cache_done(cache);
10927 if (ret) {
10928 btrfs_put_block_group(cache);
10929 break;
10930 }
10931 }
10932 ret = btrfs_trim_block_group(cache,
10933 &group_trimmed,
10934 start,
10935 end,
10936 range->minlen);
10937
10938 trimmed += group_trimmed;
10939 if (ret) {
10940 btrfs_put_block_group(cache);
10941 break;
10942 }
10943 }
10944
10945 cache = next_block_group(fs_info, cache);
10946 }
10947
10948 mutex_lock(&fs_info->fs_devices->device_list_mutex);
10949 devices = &fs_info->fs_devices->alloc_list;
10950 list_for_each_entry(device, devices, dev_alloc_list) {
10951 ret = btrfs_trim_free_extents(device, range->minlen,
10952 &group_trimmed);
10953 if (ret)
10954 break;
10955
10956 trimmed += group_trimmed;
10957 }
10958 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
10959
10960 range->len = trimmed;
10961 return ret;
10962 }
10963
10964 /*
10965 * btrfs_{start,end}_write_no_snapshoting() are similar to
10966 * mnt_{want,drop}_write(), they are used to prevent some tasks from writing
10967 * data into the page cache through nocow before the subvolume is snapshoted,
10968 * but flush the data into disk after the snapshot creation, or to prevent
10969 * operations while snapshoting is ongoing and that cause the snapshot to be
10970 * inconsistent (writes followed by expanding truncates for example).
10971 */
10972 void btrfs_end_write_no_snapshoting(struct btrfs_root *root)
10973 {
10974 percpu_counter_dec(&root->subv_writers->counter);
10975 /*
10976 * Make sure counter is updated before we wake up waiters.
10977 */
10978 smp_mb();
10979 if (waitqueue_active(&root->subv_writers->wait))
10980 wake_up(&root->subv_writers->wait);
10981 }
10982
10983 int btrfs_start_write_no_snapshoting(struct btrfs_root *root)
10984 {
10985 if (atomic_read(&root->will_be_snapshoted))
10986 return 0;
10987
10988 percpu_counter_inc(&root->subv_writers->counter);
10989 /*
10990 * Make sure counter is updated before we check for snapshot creation.
10991 */
10992 smp_mb();
10993 if (atomic_read(&root->will_be_snapshoted)) {
10994 btrfs_end_write_no_snapshoting(root);
10995 return 0;
10996 }
10997 return 1;
10998 }
10999
11000 static int wait_snapshoting_atomic_t(atomic_t *a)
11001 {
11002 schedule();
11003 return 0;
11004 }
11005
11006 void btrfs_wait_for_snapshot_creation(struct btrfs_root *root)
11007 {
11008 while (true) {
11009 int ret;
11010
11011 ret = btrfs_start_write_no_snapshoting(root);
11012 if (ret)
11013 break;
11014 wait_on_atomic_t(&root->will_be_snapshoted,
11015 wait_snapshoting_atomic_t,
11016 TASK_UNINTERRUPTIBLE);
11017 }
11018 }
Linux with added FPC-III support