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Staging: merge 2.6.39-rc4 into staging-next
[zen-stable.git] / fs / btrfs / extent-tree.c
blob31f33ba56fe823d40ecf308f32eb777315548376
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 "compat.h"
27 #include "hash.h"
28 #include "ctree.h"
29 #include "disk-io.h"
30 #include "print-tree.h"
31 #include "transaction.h"
32 #include "volumes.h"
33 #include "locking.h"
34 #include "free-space-cache.h"
35
36 /* control flags for do_chunk_alloc's force field
37 * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
38 * if we really need one.
39 *
40 * CHUNK_ALLOC_FORCE means it must try to allocate one
41 *
42 * CHUNK_ALLOC_LIMITED means to only try and allocate one
43 * if we have very few chunks already allocated. This is
44 * used as part of the clustering code to help make sure
45 * we have a good pool of storage to cluster in, without
46 * filling the FS with empty chunks
47 *
48 */
49 enum {
50 CHUNK_ALLOC_NO_FORCE = 0,
51 CHUNK_ALLOC_FORCE = 1,
52 CHUNK_ALLOC_LIMITED = 2,
53 };
54
55 static int update_block_group(struct btrfs_trans_handle *trans,
56 struct btrfs_root *root,
57 u64 bytenr, u64 num_bytes, int alloc);
58 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
59 struct btrfs_root *root,
60 u64 bytenr, u64 num_bytes, u64 parent,
61 u64 root_objectid, u64 owner_objectid,
62 u64 owner_offset, int refs_to_drop,
63 struct btrfs_delayed_extent_op *extra_op);
64 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
65 struct extent_buffer *leaf,
66 struct btrfs_extent_item *ei);
67 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
68 struct btrfs_root *root,
69 u64 parent, u64 root_objectid,
70 u64 flags, u64 owner, u64 offset,
71 struct btrfs_key *ins, int ref_mod);
72 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
73 struct btrfs_root *root,
74 u64 parent, u64 root_objectid,
75 u64 flags, struct btrfs_disk_key *key,
76 int level, struct btrfs_key *ins);
77 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
78 struct btrfs_root *extent_root, u64 alloc_bytes,
79 u64 flags, int force);
80 static int find_next_key(struct btrfs_path *path, int level,
81 struct btrfs_key *key);
82 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
83 int dump_block_groups);
84
85 static noinline int
86 block_group_cache_done(struct btrfs_block_group_cache *cache)
87 {
88 smp_mb();
89 return cache->cached == BTRFS_CACHE_FINISHED;
90 }
91
92 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
93 {
94 return (cache->flags & bits) == bits;
95 }
96
97 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
98 {
99 atomic_inc(&cache->count);
100 }
101
102 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
103 {
104 if (atomic_dec_and_test(&cache->count)) {
105 WARN_ON(cache->pinned > 0);
106 WARN_ON(cache->reserved > 0);
107 WARN_ON(cache->reserved_pinned > 0);
108 kfree(cache);
109 }
110 }
111
112 /*
113 * this adds the block group to the fs_info rb tree for the block group
114 * cache
115 */
116 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
117 struct btrfs_block_group_cache *block_group)
118 {
119 struct rb_node **p;
120 struct rb_node *parent = NULL;
121 struct btrfs_block_group_cache *cache;
122
123 spin_lock(&info->block_group_cache_lock);
124 p = &info->block_group_cache_tree.rb_node;
125
126 while (*p) {
127 parent = *p;
128 cache = rb_entry(parent, struct btrfs_block_group_cache,
129 cache_node);
130 if (block_group->key.objectid < cache->key.objectid) {
131 p = &(*p)->rb_left;
132 } else if (block_group->key.objectid > cache->key.objectid) {
133 p = &(*p)->rb_right;
134 } else {
135 spin_unlock(&info->block_group_cache_lock);
136 return -EEXIST;
137 }
138 }
139
140 rb_link_node(&block_group->cache_node, parent, p);
141 rb_insert_color(&block_group->cache_node,
142 &info->block_group_cache_tree);
143 spin_unlock(&info->block_group_cache_lock);
144
145 return 0;
146 }
147
148 /*
149 * This will return the block group at or after bytenr if contains is 0, else
150 * it will return the block group that contains the bytenr
151 */
152 static struct btrfs_block_group_cache *
153 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
154 int contains)
155 {
156 struct btrfs_block_group_cache *cache, *ret = NULL;
157 struct rb_node *n;
158 u64 end, start;
159
160 spin_lock(&info->block_group_cache_lock);
161 n = info->block_group_cache_tree.rb_node;
162
163 while (n) {
164 cache = rb_entry(n, struct btrfs_block_group_cache,
165 cache_node);
166 end = cache->key.objectid + cache->key.offset - 1;
167 start = cache->key.objectid;
168
169 if (bytenr < start) {
170 if (!contains && (!ret || start < ret->key.objectid))
171 ret = cache;
172 n = n->rb_left;
173 } else if (bytenr > start) {
174 if (contains && bytenr <= end) {
175 ret = cache;
176 break;
177 }
178 n = n->rb_right;
179 } else {
180 ret = cache;
181 break;
182 }
183 }
184 if (ret)
185 btrfs_get_block_group(ret);
186 spin_unlock(&info->block_group_cache_lock);
187
188 return ret;
189 }
190
191 static int add_excluded_extent(struct btrfs_root *root,
192 u64 start, u64 num_bytes)
193 {
194 u64 end = start + num_bytes - 1;
195 set_extent_bits(&root->fs_info->freed_extents[0],
196 start, end, EXTENT_UPTODATE, GFP_NOFS);
197 set_extent_bits(&root->fs_info->freed_extents[1],
198 start, end, EXTENT_UPTODATE, GFP_NOFS);
199 return 0;
200 }
201
202 static void free_excluded_extents(struct btrfs_root *root,
203 struct btrfs_block_group_cache *cache)
204 {
205 u64 start, end;
206
207 start = cache->key.objectid;
208 end = start + cache->key.offset - 1;
209
210 clear_extent_bits(&root->fs_info->freed_extents[0],
211 start, end, EXTENT_UPTODATE, GFP_NOFS);
212 clear_extent_bits(&root->fs_info->freed_extents[1],
213 start, end, EXTENT_UPTODATE, GFP_NOFS);
214 }
215
216 static int exclude_super_stripes(struct btrfs_root *root,
217 struct btrfs_block_group_cache *cache)
218 {
219 u64 bytenr;
220 u64 *logical;
221 int stripe_len;
222 int i, nr, ret;
223
224 if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
225 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
226 cache->bytes_super += stripe_len;
227 ret = add_excluded_extent(root, cache->key.objectid,
228 stripe_len);
229 BUG_ON(ret);
230 }
231
232 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
233 bytenr = btrfs_sb_offset(i);
234 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
235 cache->key.objectid, bytenr,
236 0, &logical, &nr, &stripe_len);
237 BUG_ON(ret);
238
239 while (nr--) {
240 cache->bytes_super += stripe_len;
241 ret = add_excluded_extent(root, logical[nr],
242 stripe_len);
243 BUG_ON(ret);
244 }
245
246 kfree(logical);
247 }
248 return 0;
249 }
250
251 static struct btrfs_caching_control *
252 get_caching_control(struct btrfs_block_group_cache *cache)
253 {
254 struct btrfs_caching_control *ctl;
255
256 spin_lock(&cache->lock);
257 if (cache->cached != BTRFS_CACHE_STARTED) {
258 spin_unlock(&cache->lock);
259 return NULL;
260 }
261
262 /* We're loading it the fast way, so we don't have a caching_ctl. */
263 if (!cache->caching_ctl) {
264 spin_unlock(&cache->lock);
265 return NULL;
266 }
267
268 ctl = cache->caching_ctl;
269 atomic_inc(&ctl->count);
270 spin_unlock(&cache->lock);
271 return ctl;
272 }
273
274 static void put_caching_control(struct btrfs_caching_control *ctl)
275 {
276 if (atomic_dec_and_test(&ctl->count))
277 kfree(ctl);
278 }
279
280 /*
281 * this is only called by cache_block_group, since we could have freed extents
282 * we need to check the pinned_extents for any extents that can't be used yet
283 * since their free space will be released as soon as the transaction commits.
284 */
285 static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
286 struct btrfs_fs_info *info, u64 start, u64 end)
287 {
288 u64 extent_start, extent_end, size, total_added = 0;
289 int ret;
290
291 while (start < end) {
292 ret = find_first_extent_bit(info->pinned_extents, start,
293 &extent_start, &extent_end,
294 EXTENT_DIRTY | EXTENT_UPTODATE);
295 if (ret)
296 break;
297
298 if (extent_start <= start) {
299 start = extent_end + 1;
300 } else if (extent_start > start && extent_start < end) {
301 size = extent_start - start;
302 total_added += size;
303 ret = btrfs_add_free_space(block_group, start,
304 size);
305 BUG_ON(ret);
306 start = extent_end + 1;
307 } else {
308 break;
309 }
310 }
311
312 if (start < end) {
313 size = end - start;
314 total_added += size;
315 ret = btrfs_add_free_space(block_group, start, size);
316 BUG_ON(ret);
317 }
318
319 return total_added;
320 }
321
322 static int caching_kthread(void *data)
323 {
324 struct btrfs_block_group_cache *block_group = data;
325 struct btrfs_fs_info *fs_info = block_group->fs_info;
326 struct btrfs_caching_control *caching_ctl = block_group->caching_ctl;
327 struct btrfs_root *extent_root = fs_info->extent_root;
328 struct btrfs_path *path;
329 struct extent_buffer *leaf;
330 struct btrfs_key key;
331 u64 total_found = 0;
332 u64 last = 0;
333 u32 nritems;
334 int ret = 0;
335
336 path = btrfs_alloc_path();
337 if (!path)
338 return -ENOMEM;
339
340 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
341
342 /*
343 * We don't want to deadlock with somebody trying to allocate a new
344 * extent for the extent root while also trying to search the extent
345 * root to add free space. So we skip locking and search the commit
346 * root, since its read-only
347 */
348 path->skip_locking = 1;
349 path->search_commit_root = 1;
350 path->reada = 2;
351
352 key.objectid = last;
353 key.offset = 0;
354 key.type = BTRFS_EXTENT_ITEM_KEY;
355 again:
356 mutex_lock(&caching_ctl->mutex);
357 /* need to make sure the commit_root doesn't disappear */
358 down_read(&fs_info->extent_commit_sem);
359
360 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
361 if (ret < 0)
362 goto err;
363
364 leaf = path->nodes[0];
365 nritems = btrfs_header_nritems(leaf);
366
367 while (1) {
368 smp_mb();
369 if (fs_info->closing > 1) {
370 last = (u64)-1;
371 break;
372 }
373
374 if (path->slots[0] < nritems) {
375 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
376 } else {
377 ret = find_next_key(path, 0, &key);
378 if (ret)
379 break;
380
381 caching_ctl->progress = last;
382 btrfs_release_path(extent_root, path);
383 up_read(&fs_info->extent_commit_sem);
384 mutex_unlock(&caching_ctl->mutex);
385 if (btrfs_transaction_in_commit(fs_info))
386 schedule_timeout(1);
387 else
388 cond_resched();
389 goto again;
390 }
391
392 if (key.objectid < block_group->key.objectid) {
393 path->slots[0]++;
394 continue;
395 }
396
397 if (key.objectid >= block_group->key.objectid +
398 block_group->key.offset)
399 break;
400
401 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
402 total_found += add_new_free_space(block_group,
403 fs_info, last,
404 key.objectid);
405 last = key.objectid + key.offset;
406
407 if (total_found > (1024 * 1024 * 2)) {
408 total_found = 0;
409 wake_up(&caching_ctl->wait);
410 }
411 }
412 path->slots[0]++;
413 }
414 ret = 0;
415
416 total_found += add_new_free_space(block_group, fs_info, last,
417 block_group->key.objectid +
418 block_group->key.offset);
419 caching_ctl->progress = (u64)-1;
420
421 spin_lock(&block_group->lock);
422 block_group->caching_ctl = NULL;
423 block_group->cached = BTRFS_CACHE_FINISHED;
424 spin_unlock(&block_group->lock);
425
426 err:
427 btrfs_free_path(path);
428 up_read(&fs_info->extent_commit_sem);
429
430 free_excluded_extents(extent_root, block_group);
431
432 mutex_unlock(&caching_ctl->mutex);
433 wake_up(&caching_ctl->wait);
434
435 put_caching_control(caching_ctl);
436 atomic_dec(&block_group->space_info->caching_threads);
437 btrfs_put_block_group(block_group);
438
439 return 0;
440 }
441
442 static int cache_block_group(struct btrfs_block_group_cache *cache,
443 struct btrfs_trans_handle *trans,
444 struct btrfs_root *root,
445 int load_cache_only)
446 {
447 struct btrfs_fs_info *fs_info = cache->fs_info;
448 struct btrfs_caching_control *caching_ctl;
449 struct task_struct *tsk;
450 int ret = 0;
451
452 smp_mb();
453 if (cache->cached != BTRFS_CACHE_NO)
454 return 0;
455
456 /*
457 * We can't do the read from on-disk cache during a commit since we need
458 * to have the normal tree locking. Also if we are currently trying to
459 * allocate blocks for the tree root we can't do the fast caching since
460 * we likely hold important locks.
461 */
462 if (trans && (!trans->transaction->in_commit) &&
463 (root && root != root->fs_info->tree_root)) {
464 spin_lock(&cache->lock);
465 if (cache->cached != BTRFS_CACHE_NO) {
466 spin_unlock(&cache->lock);
467 return 0;
468 }
469 cache->cached = BTRFS_CACHE_STARTED;
470 spin_unlock(&cache->lock);
471
472 ret = load_free_space_cache(fs_info, cache);
473
474 spin_lock(&cache->lock);
475 if (ret == 1) {
476 cache->cached = BTRFS_CACHE_FINISHED;
477 cache->last_byte_to_unpin = (u64)-1;
478 } else {
479 cache->cached = BTRFS_CACHE_NO;
480 }
481 spin_unlock(&cache->lock);
482 if (ret == 1) {
483 free_excluded_extents(fs_info->extent_root, cache);
484 return 0;
485 }
486 }
487
488 if (load_cache_only)
489 return 0;
490
491 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
492 BUG_ON(!caching_ctl);
493
494 INIT_LIST_HEAD(&caching_ctl->list);
495 mutex_init(&caching_ctl->mutex);
496 init_waitqueue_head(&caching_ctl->wait);
497 caching_ctl->block_group = cache;
498 caching_ctl->progress = cache->key.objectid;
499 /* one for caching kthread, one for caching block group list */
500 atomic_set(&caching_ctl->count, 2);
501
502 spin_lock(&cache->lock);
503 if (cache->cached != BTRFS_CACHE_NO) {
504 spin_unlock(&cache->lock);
505 kfree(caching_ctl);
506 return 0;
507 }
508 cache->caching_ctl = caching_ctl;
509 cache->cached = BTRFS_CACHE_STARTED;
510 spin_unlock(&cache->lock);
511
512 down_write(&fs_info->extent_commit_sem);
513 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
514 up_write(&fs_info->extent_commit_sem);
515
516 atomic_inc(&cache->space_info->caching_threads);
517 btrfs_get_block_group(cache);
518
519 tsk = kthread_run(caching_kthread, cache, "btrfs-cache-%llu\n",
520 cache->key.objectid);
521 if (IS_ERR(tsk)) {
522 ret = PTR_ERR(tsk);
523 printk(KERN_ERR "error running thread %d\n", ret);
524 BUG();
525 }
526
527 return ret;
528 }
529
530 /*
531 * return the block group that starts at or after bytenr
532 */
533 static struct btrfs_block_group_cache *
534 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
535 {
536 struct btrfs_block_group_cache *cache;
537
538 cache = block_group_cache_tree_search(info, bytenr, 0);
539
540 return cache;
541 }
542
543 /*
544 * return the block group that contains the given bytenr
545 */
546 struct btrfs_block_group_cache *btrfs_lookup_block_group(
547 struct btrfs_fs_info *info,
548 u64 bytenr)
549 {
550 struct btrfs_block_group_cache *cache;
551
552 cache = block_group_cache_tree_search(info, bytenr, 1);
553
554 return cache;
555 }
556
557 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
558 u64 flags)
559 {
560 struct list_head *head = &info->space_info;
561 struct btrfs_space_info *found;
562
563 flags &= BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_SYSTEM |
564 BTRFS_BLOCK_GROUP_METADATA;
565
566 rcu_read_lock();
567 list_for_each_entry_rcu(found, head, list) {
568 if (found->flags & flags) {
569 rcu_read_unlock();
570 return found;
571 }
572 }
573 rcu_read_unlock();
574 return NULL;
575 }
576
577 /*
578 * after adding space to the filesystem, we need to clear the full flags
579 * on all the space infos.
580 */
581 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
582 {
583 struct list_head *head = &info->space_info;
584 struct btrfs_space_info *found;
585
586 rcu_read_lock();
587 list_for_each_entry_rcu(found, head, list)
588 found->full = 0;
589 rcu_read_unlock();
590 }
591
592 static u64 div_factor(u64 num, int factor)
593 {
594 if (factor == 10)
595 return num;
596 num *= factor;
597 do_div(num, 10);
598 return num;
599 }
600
601 static u64 div_factor_fine(u64 num, int factor)
602 {
603 if (factor == 100)
604 return num;
605 num *= factor;
606 do_div(num, 100);
607 return num;
608 }
609
610 u64 btrfs_find_block_group(struct btrfs_root *root,
611 u64 search_start, u64 search_hint, int owner)
612 {
613 struct btrfs_block_group_cache *cache;
614 u64 used;
615 u64 last = max(search_hint, search_start);
616 u64 group_start = 0;
617 int full_search = 0;
618 int factor = 9;
619 int wrapped = 0;
620 again:
621 while (1) {
622 cache = btrfs_lookup_first_block_group(root->fs_info, last);
623 if (!cache)
624 break;
625
626 spin_lock(&cache->lock);
627 last = cache->key.objectid + cache->key.offset;
628 used = btrfs_block_group_used(&cache->item);
629
630 if ((full_search || !cache->ro) &&
631 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
632 if (used + cache->pinned + cache->reserved <
633 div_factor(cache->key.offset, factor)) {
634 group_start = cache->key.objectid;
635 spin_unlock(&cache->lock);
636 btrfs_put_block_group(cache);
637 goto found;
638 }
639 }
640 spin_unlock(&cache->lock);
641 btrfs_put_block_group(cache);
642 cond_resched();
643 }
644 if (!wrapped) {
645 last = search_start;
646 wrapped = 1;
647 goto again;
648 }
649 if (!full_search && factor < 10) {
650 last = search_start;
651 full_search = 1;
652 factor = 10;
653 goto again;
654 }
655 found:
656 return group_start;
657 }
658
659 /* simple helper to search for an existing extent at a given offset */
660 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
661 {
662 int ret;
663 struct btrfs_key key;
664 struct btrfs_path *path;
665
666 path = btrfs_alloc_path();
667 BUG_ON(!path);
668 key.objectid = start;
669 key.offset = len;
670 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
671 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
672 0, 0);
673 btrfs_free_path(path);
674 return ret;
675 }
676
677 /*
678 * helper function to lookup reference count and flags of extent.
679 *
680 * the head node for delayed ref is used to store the sum of all the
681 * reference count modifications queued up in the rbtree. the head
682 * node may also store the extent flags to set. This way you can check
683 * to see what the reference count and extent flags would be if all of
684 * the delayed refs are not processed.
685 */
686 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
687 struct btrfs_root *root, u64 bytenr,
688 u64 num_bytes, u64 *refs, u64 *flags)
689 {
690 struct btrfs_delayed_ref_head *head;
691 struct btrfs_delayed_ref_root *delayed_refs;
692 struct btrfs_path *path;
693 struct btrfs_extent_item *ei;
694 struct extent_buffer *leaf;
695 struct btrfs_key key;
696 u32 item_size;
697 u64 num_refs;
698 u64 extent_flags;
699 int ret;
700
701 path = btrfs_alloc_path();
702 if (!path)
703 return -ENOMEM;
704
705 key.objectid = bytenr;
706 key.type = BTRFS_EXTENT_ITEM_KEY;
707 key.offset = num_bytes;
708 if (!trans) {
709 path->skip_locking = 1;
710 path->search_commit_root = 1;
711 }
712 again:
713 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
714 &key, path, 0, 0);
715 if (ret < 0)
716 goto out_free;
717
718 if (ret == 0) {
719 leaf = path->nodes[0];
720 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
721 if (item_size >= sizeof(*ei)) {
722 ei = btrfs_item_ptr(leaf, path->slots[0],
723 struct btrfs_extent_item);
724 num_refs = btrfs_extent_refs(leaf, ei);
725 extent_flags = btrfs_extent_flags(leaf, ei);
726 } else {
727 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
728 struct btrfs_extent_item_v0 *ei0;
729 BUG_ON(item_size != sizeof(*ei0));
730 ei0 = btrfs_item_ptr(leaf, path->slots[0],
731 struct btrfs_extent_item_v0);
732 num_refs = btrfs_extent_refs_v0(leaf, ei0);
733 /* FIXME: this isn't correct for data */
734 extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
735 #else
736 BUG();
737 #endif
738 }
739 BUG_ON(num_refs == 0);
740 } else {
741 num_refs = 0;
742 extent_flags = 0;
743 ret = 0;
744 }
745
746 if (!trans)
747 goto out;
748
749 delayed_refs = &trans->transaction->delayed_refs;
750 spin_lock(&delayed_refs->lock);
751 head = btrfs_find_delayed_ref_head(trans, bytenr);
752 if (head) {
753 if (!mutex_trylock(&head->mutex)) {
754 atomic_inc(&head->node.refs);
755 spin_unlock(&delayed_refs->lock);
756
757 btrfs_release_path(root->fs_info->extent_root, path);
758
759 mutex_lock(&head->mutex);
760 mutex_unlock(&head->mutex);
761 btrfs_put_delayed_ref(&head->node);
762 goto again;
763 }
764 if (head->extent_op && head->extent_op->update_flags)
765 extent_flags |= head->extent_op->flags_to_set;
766 else
767 BUG_ON(num_refs == 0);
768
769 num_refs += head->node.ref_mod;
770 mutex_unlock(&head->mutex);
771 }
772 spin_unlock(&delayed_refs->lock);
773 out:
774 WARN_ON(num_refs == 0);
775 if (refs)
776 *refs = num_refs;
777 if (flags)
778 *flags = extent_flags;
779 out_free:
780 btrfs_free_path(path);
781 return ret;
782 }
783
784 /*
785 * Back reference rules. Back refs have three main goals:
786 *
787 * 1) differentiate between all holders of references to an extent so that
788 * when a reference is dropped we can make sure it was a valid reference
789 * before freeing the extent.
790 *
791 * 2) Provide enough information to quickly find the holders of an extent
792 * if we notice a given block is corrupted or bad.
793 *
794 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
795 * maintenance. This is actually the same as #2, but with a slightly
796 * different use case.
797 *
798 * There are two kinds of back refs. The implicit back refs is optimized
799 * for pointers in non-shared tree blocks. For a given pointer in a block,
800 * back refs of this kind provide information about the block's owner tree
801 * and the pointer's key. These information allow us to find the block by
802 * b-tree searching. The full back refs is for pointers in tree blocks not
803 * referenced by their owner trees. The location of tree block is recorded
804 * in the back refs. Actually the full back refs is generic, and can be
805 * used in all cases the implicit back refs is used. The major shortcoming
806 * of the full back refs is its overhead. Every time a tree block gets
807 * COWed, we have to update back refs entry for all pointers in it.
808 *
809 * For a newly allocated tree block, we use implicit back refs for
810 * pointers in it. This means most tree related operations only involve
811 * implicit back refs. For a tree block created in old transaction, the
812 * only way to drop a reference to it is COW it. So we can detect the
813 * event that tree block loses its owner tree's reference and do the
814 * back refs conversion.
815 *
816 * When a tree block is COW'd through a tree, there are four cases:
817 *
818 * The reference count of the block is one and the tree is the block's
819 * owner tree. Nothing to do in this case.
820 *
821 * The reference count of the block is one and the tree is not the
822 * block's owner tree. In this case, full back refs is used for pointers
823 * in the block. Remove these full back refs, add implicit back refs for
824 * every pointers in the new block.
825 *
826 * The reference count of the block is greater than one and the tree is
827 * the block's owner tree. In this case, implicit back refs is used for
828 * pointers in the block. Add full back refs for every pointers in the
829 * block, increase lower level extents' reference counts. The original
830 * implicit back refs are entailed to the new block.
831 *
832 * The reference count of the block is greater than one and the tree is
833 * not the block's owner tree. Add implicit back refs for every pointer in
834 * the new block, increase lower level extents' reference count.
835 *
836 * Back Reference Key composing:
837 *
838 * The key objectid corresponds to the first byte in the extent,
839 * The key type is used to differentiate between types of back refs.
840 * There are different meanings of the key offset for different types
841 * of back refs.
842 *
843 * File extents can be referenced by:
844 *
845 * - multiple snapshots, subvolumes, or different generations in one subvol
846 * - different files inside a single subvolume
847 * - different offsets inside a file (bookend extents in file.c)
848 *
849 * The extent ref structure for the implicit back refs has fields for:
850 *
851 * - Objectid of the subvolume root
852 * - objectid of the file holding the reference
853 * - original offset in the file
854 * - how many bookend extents
855 *
856 * The key offset for the implicit back refs is hash of the first
857 * three fields.
858 *
859 * The extent ref structure for the full back refs has field for:
860 *
861 * - number of pointers in the tree leaf
862 *
863 * The key offset for the implicit back refs is the first byte of
864 * the tree leaf
865 *
866 * When a file extent is allocated, The implicit back refs is used.
867 * the fields are filled in:
868 *
869 * (root_key.objectid, inode objectid, offset in file, 1)
870 *
871 * When a file extent is removed file truncation, we find the
872 * corresponding implicit back refs and check the following fields:
873 *
874 * (btrfs_header_owner(leaf), inode objectid, offset in file)
875 *
876 * Btree extents can be referenced by:
877 *
878 * - Different subvolumes
879 *
880 * Both the implicit back refs and the full back refs for tree blocks
881 * only consist of key. The key offset for the implicit back refs is
882 * objectid of block's owner tree. The key offset for the full back refs
883 * is the first byte of parent block.
884 *
885 * When implicit back refs is used, information about the lowest key and
886 * level of the tree block are required. These information are stored in
887 * tree block info structure.
888 */
889
890 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
891 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
892 struct btrfs_root *root,
893 struct btrfs_path *path,
894 u64 owner, u32 extra_size)
895 {
896 struct btrfs_extent_item *item;
897 struct btrfs_extent_item_v0 *ei0;
898 struct btrfs_extent_ref_v0 *ref0;
899 struct btrfs_tree_block_info *bi;
900 struct extent_buffer *leaf;
901 struct btrfs_key key;
902 struct btrfs_key found_key;
903 u32 new_size = sizeof(*item);
904 u64 refs;
905 int ret;
906
907 leaf = path->nodes[0];
908 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
909
910 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
911 ei0 = btrfs_item_ptr(leaf, path->slots[0],
912 struct btrfs_extent_item_v0);
913 refs = btrfs_extent_refs_v0(leaf, ei0);
914
915 if (owner == (u64)-1) {
916 while (1) {
917 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
918 ret = btrfs_next_leaf(root, path);
919 if (ret < 0)
920 return ret;
921 BUG_ON(ret > 0);
922 leaf = path->nodes[0];
923 }
924 btrfs_item_key_to_cpu(leaf, &found_key,
925 path->slots[0]);
926 BUG_ON(key.objectid != found_key.objectid);
927 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
928 path->slots[0]++;
929 continue;
930 }
931 ref0 = btrfs_item_ptr(leaf, path->slots[0],
932 struct btrfs_extent_ref_v0);
933 owner = btrfs_ref_objectid_v0(leaf, ref0);
934 break;
935 }
936 }
937 btrfs_release_path(root, path);
938
939 if (owner < BTRFS_FIRST_FREE_OBJECTID)
940 new_size += sizeof(*bi);
941
942 new_size -= sizeof(*ei0);
943 ret = btrfs_search_slot(trans, root, &key, path,
944 new_size + extra_size, 1);
945 if (ret < 0)
946 return ret;
947 BUG_ON(ret);
948
949 ret = btrfs_extend_item(trans, root, path, new_size);
950 BUG_ON(ret);
951
952 leaf = path->nodes[0];
953 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
954 btrfs_set_extent_refs(leaf, item, refs);
955 /* FIXME: get real generation */
956 btrfs_set_extent_generation(leaf, item, 0);
957 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
958 btrfs_set_extent_flags(leaf, item,
959 BTRFS_EXTENT_FLAG_TREE_BLOCK |
960 BTRFS_BLOCK_FLAG_FULL_BACKREF);
961 bi = (struct btrfs_tree_block_info *)(item + 1);
962 /* FIXME: get first key of the block */
963 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
964 btrfs_set_tree_block_level(leaf, bi, (int)owner);
965 } else {
966 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
967 }
968 btrfs_mark_buffer_dirty(leaf);
969 return 0;
970 }
971 #endif
972
973 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
974 {
975 u32 high_crc = ~(u32)0;
976 u32 low_crc = ~(u32)0;
977 __le64 lenum;
978
979 lenum = cpu_to_le64(root_objectid);
980 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
981 lenum = cpu_to_le64(owner);
982 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
983 lenum = cpu_to_le64(offset);
984 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
985
986 return ((u64)high_crc << 31) ^ (u64)low_crc;
987 }
988
989 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
990 struct btrfs_extent_data_ref *ref)
991 {
992 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
993 btrfs_extent_data_ref_objectid(leaf, ref),
994 btrfs_extent_data_ref_offset(leaf, ref));
995 }
996
997 static int match_extent_data_ref(struct extent_buffer *leaf,
998 struct btrfs_extent_data_ref *ref,
999 u64 root_objectid, u64 owner, u64 offset)
1000 {
1001 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
1002 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
1003 btrfs_extent_data_ref_offset(leaf, ref) != offset)
1004 return 0;
1005 return 1;
1006 }
1007
1008 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
1009 struct btrfs_root *root,
1010 struct btrfs_path *path,
1011 u64 bytenr, u64 parent,
1012 u64 root_objectid,
1013 u64 owner, u64 offset)
1014 {
1015 struct btrfs_key key;
1016 struct btrfs_extent_data_ref *ref;
1017 struct extent_buffer *leaf;
1018 u32 nritems;
1019 int ret;
1020 int recow;
1021 int err = -ENOENT;
1022
1023 key.objectid = bytenr;
1024 if (parent) {
1025 key.type = BTRFS_SHARED_DATA_REF_KEY;
1026 key.offset = parent;
1027 } else {
1028 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1029 key.offset = hash_extent_data_ref(root_objectid,
1030 owner, offset);
1031 }
1032 again:
1033 recow = 0;
1034 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1035 if (ret < 0) {
1036 err = ret;
1037 goto fail;
1038 }
1039
1040 if (parent) {
1041 if (!ret)
1042 return 0;
1043 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1044 key.type = BTRFS_EXTENT_REF_V0_KEY;
1045 btrfs_release_path(root, path);
1046 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1047 if (ret < 0) {
1048 err = ret;
1049 goto fail;
1050 }
1051 if (!ret)
1052 return 0;
1053 #endif
1054 goto fail;
1055 }
1056
1057 leaf = path->nodes[0];
1058 nritems = btrfs_header_nritems(leaf);
1059 while (1) {
1060 if (path->slots[0] >= nritems) {
1061 ret = btrfs_next_leaf(root, path);
1062 if (ret < 0)
1063 err = ret;
1064 if (ret)
1065 goto fail;
1066
1067 leaf = path->nodes[0];
1068 nritems = btrfs_header_nritems(leaf);
1069 recow = 1;
1070 }
1071
1072 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1073 if (key.objectid != bytenr ||
1074 key.type != BTRFS_EXTENT_DATA_REF_KEY)
1075 goto fail;
1076
1077 ref = btrfs_item_ptr(leaf, path->slots[0],
1078 struct btrfs_extent_data_ref);
1079
1080 if (match_extent_data_ref(leaf, ref, root_objectid,
1081 owner, offset)) {
1082 if (recow) {
1083 btrfs_release_path(root, path);
1084 goto again;
1085 }
1086 err = 0;
1087 break;
1088 }
1089 path->slots[0]++;
1090 }
1091 fail:
1092 return err;
1093 }
1094
1095 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
1096 struct btrfs_root *root,
1097 struct btrfs_path *path,
1098 u64 bytenr, u64 parent,
1099 u64 root_objectid, u64 owner,
1100 u64 offset, int refs_to_add)
1101 {
1102 struct btrfs_key key;
1103 struct extent_buffer *leaf;
1104 u32 size;
1105 u32 num_refs;
1106 int ret;
1107
1108 key.objectid = bytenr;
1109 if (parent) {
1110 key.type = BTRFS_SHARED_DATA_REF_KEY;
1111 key.offset = parent;
1112 size = sizeof(struct btrfs_shared_data_ref);
1113 } else {
1114 key.type = BTRFS_EXTENT_DATA_REF_KEY;
1115 key.offset = hash_extent_data_ref(root_objectid,
1116 owner, offset);
1117 size = sizeof(struct btrfs_extent_data_ref);
1118 }
1119
1120 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
1121 if (ret && ret != -EEXIST)
1122 goto fail;
1123
1124 leaf = path->nodes[0];
1125 if (parent) {
1126 struct btrfs_shared_data_ref *ref;
1127 ref = btrfs_item_ptr(leaf, path->slots[0],
1128 struct btrfs_shared_data_ref);
1129 if (ret == 0) {
1130 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
1131 } else {
1132 num_refs = btrfs_shared_data_ref_count(leaf, ref);
1133 num_refs += refs_to_add;
1134 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
1135 }
1136 } else {
1137 struct btrfs_extent_data_ref *ref;
1138 while (ret == -EEXIST) {
1139 ref = btrfs_item_ptr(leaf, path->slots[0],
1140 struct btrfs_extent_data_ref);
1141 if (match_extent_data_ref(leaf, ref, root_objectid,
1142 owner, offset))
1143 break;
1144 btrfs_release_path(root, path);
1145 key.offset++;
1146 ret = btrfs_insert_empty_item(trans, root, path, &key,
1147 size);
1148 if (ret && ret != -EEXIST)
1149 goto fail;
1150
1151 leaf = path->nodes[0];
1152 }
1153 ref = btrfs_item_ptr(leaf, path->slots[0],
1154 struct btrfs_extent_data_ref);
1155 if (ret == 0) {
1156 btrfs_set_extent_data_ref_root(leaf, ref,
1157 root_objectid);
1158 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
1159 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
1160 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
1161 } else {
1162 num_refs = btrfs_extent_data_ref_count(leaf, ref);
1163 num_refs += refs_to_add;
1164 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
1165 }
1166 }
1167 btrfs_mark_buffer_dirty(leaf);
1168 ret = 0;
1169 fail:
1170 btrfs_release_path(root, path);
1171 return ret;
1172 }
1173
1174 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
1175 struct btrfs_root *root,
1176 struct btrfs_path *path,
1177 int refs_to_drop)
1178 {
1179 struct btrfs_key key;
1180 struct btrfs_extent_data_ref *ref1 = NULL;
1181 struct btrfs_shared_data_ref *ref2 = NULL;
1182 struct extent_buffer *leaf;
1183 u32 num_refs = 0;
1184 int ret = 0;
1185
1186 leaf = path->nodes[0];
1187 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1188
1189 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1190 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1191 struct btrfs_extent_data_ref);
1192 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1193 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1194 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1195 struct btrfs_shared_data_ref);
1196 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1197 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1198 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1199 struct btrfs_extent_ref_v0 *ref0;
1200 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1201 struct btrfs_extent_ref_v0);
1202 num_refs = btrfs_ref_count_v0(leaf, ref0);
1203 #endif
1204 } else {
1205 BUG();
1206 }
1207
1208 BUG_ON(num_refs < refs_to_drop);
1209 num_refs -= refs_to_drop;
1210
1211 if (num_refs == 0) {
1212 ret = btrfs_del_item(trans, root, path);
1213 } else {
1214 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
1215 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
1216 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
1217 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
1218 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1219 else {
1220 struct btrfs_extent_ref_v0 *ref0;
1221 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1222 struct btrfs_extent_ref_v0);
1223 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
1224 }
1225 #endif
1226 btrfs_mark_buffer_dirty(leaf);
1227 }
1228 return ret;
1229 }
1230
1231 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
1232 struct btrfs_path *path,
1233 struct btrfs_extent_inline_ref *iref)
1234 {
1235 struct btrfs_key key;
1236 struct extent_buffer *leaf;
1237 struct btrfs_extent_data_ref *ref1;
1238 struct btrfs_shared_data_ref *ref2;
1239 u32 num_refs = 0;
1240
1241 leaf = path->nodes[0];
1242 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1243 if (iref) {
1244 if (btrfs_extent_inline_ref_type(leaf, iref) ==
1245 BTRFS_EXTENT_DATA_REF_KEY) {
1246 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
1247 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1248 } else {
1249 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
1250 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1251 }
1252 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1253 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1254 struct btrfs_extent_data_ref);
1255 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1256 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1257 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1258 struct btrfs_shared_data_ref);
1259 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1260 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1261 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1262 struct btrfs_extent_ref_v0 *ref0;
1263 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1264 struct btrfs_extent_ref_v0);
1265 num_refs = btrfs_ref_count_v0(leaf, ref0);
1266 #endif
1267 } else {
1268 WARN_ON(1);
1269 }
1270 return num_refs;
1271 }
1272
1273 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
1274 struct btrfs_root *root,
1275 struct btrfs_path *path,
1276 u64 bytenr, u64 parent,
1277 u64 root_objectid)
1278 {
1279 struct btrfs_key key;
1280 int ret;
1281
1282 key.objectid = bytenr;
1283 if (parent) {
1284 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1285 key.offset = parent;
1286 } else {
1287 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1288 key.offset = root_objectid;
1289 }
1290
1291 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1292 if (ret > 0)
1293 ret = -ENOENT;
1294 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1295 if (ret == -ENOENT && parent) {
1296 btrfs_release_path(root, path);
1297 key.type = BTRFS_EXTENT_REF_V0_KEY;
1298 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1299 if (ret > 0)
1300 ret = -ENOENT;
1301 }
1302 #endif
1303 return ret;
1304 }
1305
1306 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
1307 struct btrfs_root *root,
1308 struct btrfs_path *path,
1309 u64 bytenr, u64 parent,
1310 u64 root_objectid)
1311 {
1312 struct btrfs_key key;
1313 int ret;
1314
1315 key.objectid = bytenr;
1316 if (parent) {
1317 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1318 key.offset = parent;
1319 } else {
1320 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1321 key.offset = root_objectid;
1322 }
1323
1324 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1325 btrfs_release_path(root, path);
1326 return ret;
1327 }
1328
1329 static inline int extent_ref_type(u64 parent, u64 owner)
1330 {
1331 int type;
1332 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1333 if (parent > 0)
1334 type = BTRFS_SHARED_BLOCK_REF_KEY;
1335 else
1336 type = BTRFS_TREE_BLOCK_REF_KEY;
1337 } else {
1338 if (parent > 0)
1339 type = BTRFS_SHARED_DATA_REF_KEY;
1340 else
1341 type = BTRFS_EXTENT_DATA_REF_KEY;
1342 }
1343 return type;
1344 }
1345
1346 static int find_next_key(struct btrfs_path *path, int level,
1347 struct btrfs_key *key)
1348
1349 {
1350 for (; level < BTRFS_MAX_LEVEL; level++) {
1351 if (!path->nodes[level])
1352 break;
1353 if (path->slots[level] + 1 >=
1354 btrfs_header_nritems(path->nodes[level]))
1355 continue;
1356 if (level == 0)
1357 btrfs_item_key_to_cpu(path->nodes[level], key,
1358 path->slots[level] + 1);
1359 else
1360 btrfs_node_key_to_cpu(path->nodes[level], key,
1361 path->slots[level] + 1);
1362 return 0;
1363 }
1364 return 1;
1365 }
1366
1367 /*
1368 * look for inline back ref. if back ref is found, *ref_ret is set
1369 * to the address of inline back ref, and 0 is returned.
1370 *
1371 * if back ref isn't found, *ref_ret is set to the address where it
1372 * should be inserted, and -ENOENT is returned.
1373 *
1374 * if insert is true and there are too many inline back refs, the path
1375 * points to the extent item, and -EAGAIN is returned.
1376 *
1377 * NOTE: inline back refs are ordered in the same way that back ref
1378 * items in the tree are ordered.
1379 */
1380 static noinline_for_stack
1381 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1382 struct btrfs_root *root,
1383 struct btrfs_path *path,
1384 struct btrfs_extent_inline_ref **ref_ret,
1385 u64 bytenr, u64 num_bytes,
1386 u64 parent, u64 root_objectid,
1387 u64 owner, u64 offset, int insert)
1388 {
1389 struct btrfs_key key;
1390 struct extent_buffer *leaf;
1391 struct btrfs_extent_item *ei;
1392 struct btrfs_extent_inline_ref *iref;
1393 u64 flags;
1394 u64 item_size;
1395 unsigned long ptr;
1396 unsigned long end;
1397 int extra_size;
1398 int type;
1399 int want;
1400 int ret;
1401 int err = 0;
1402
1403 key.objectid = bytenr;
1404 key.type = BTRFS_EXTENT_ITEM_KEY;
1405 key.offset = num_bytes;
1406
1407 want = extent_ref_type(parent, owner);
1408 if (insert) {
1409 extra_size = btrfs_extent_inline_ref_size(want);
1410 path->keep_locks = 1;
1411 } else
1412 extra_size = -1;
1413 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1414 if (ret < 0) {
1415 err = ret;
1416 goto out;
1417 }
1418 BUG_ON(ret);
1419
1420 leaf = path->nodes[0];
1421 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1422 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1423 if (item_size < sizeof(*ei)) {
1424 if (!insert) {
1425 err = -ENOENT;
1426 goto out;
1427 }
1428 ret = convert_extent_item_v0(trans, root, path, owner,
1429 extra_size);
1430 if (ret < 0) {
1431 err = ret;
1432 goto out;
1433 }
1434 leaf = path->nodes[0];
1435 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1436 }
1437 #endif
1438 BUG_ON(item_size < sizeof(*ei));
1439
1440 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1441 flags = btrfs_extent_flags(leaf, ei);
1442
1443 ptr = (unsigned long)(ei + 1);
1444 end = (unsigned long)ei + item_size;
1445
1446 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1447 ptr += sizeof(struct btrfs_tree_block_info);
1448 BUG_ON(ptr > end);
1449 } else {
1450 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
1451 }
1452
1453 err = -ENOENT;
1454 while (1) {
1455 if (ptr >= end) {
1456 WARN_ON(ptr > end);
1457 break;
1458 }
1459 iref = (struct btrfs_extent_inline_ref *)ptr;
1460 type = btrfs_extent_inline_ref_type(leaf, iref);
1461 if (want < type)
1462 break;
1463 if (want > type) {
1464 ptr += btrfs_extent_inline_ref_size(type);
1465 continue;
1466 }
1467
1468 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1469 struct btrfs_extent_data_ref *dref;
1470 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1471 if (match_extent_data_ref(leaf, dref, root_objectid,
1472 owner, offset)) {
1473 err = 0;
1474 break;
1475 }
1476 if (hash_extent_data_ref_item(leaf, dref) <
1477 hash_extent_data_ref(root_objectid, owner, offset))
1478 break;
1479 } else {
1480 u64 ref_offset;
1481 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1482 if (parent > 0) {
1483 if (parent == ref_offset) {
1484 err = 0;
1485 break;
1486 }
1487 if (ref_offset < parent)
1488 break;
1489 } else {
1490 if (root_objectid == ref_offset) {
1491 err = 0;
1492 break;
1493 }
1494 if (ref_offset < root_objectid)
1495 break;
1496 }
1497 }
1498 ptr += btrfs_extent_inline_ref_size(type);
1499 }
1500 if (err == -ENOENT && insert) {
1501 if (item_size + extra_size >=
1502 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1503 err = -EAGAIN;
1504 goto out;
1505 }
1506 /*
1507 * To add new inline back ref, we have to make sure
1508 * there is no corresponding back ref item.
1509 * For simplicity, we just do not add new inline back
1510 * ref if there is any kind of item for this block
1511 */
1512 if (find_next_key(path, 0, &key) == 0 &&
1513 key.objectid == bytenr &&
1514 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1515 err = -EAGAIN;
1516 goto out;
1517 }
1518 }
1519 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1520 out:
1521 if (insert) {
1522 path->keep_locks = 0;
1523 btrfs_unlock_up_safe(path, 1);
1524 }
1525 return err;
1526 }
1527
1528 /*
1529 * helper to add new inline back ref
1530 */
1531 static noinline_for_stack
1532 int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
1533 struct btrfs_root *root,
1534 struct btrfs_path *path,
1535 struct btrfs_extent_inline_ref *iref,
1536 u64 parent, u64 root_objectid,
1537 u64 owner, u64 offset, int refs_to_add,
1538 struct btrfs_delayed_extent_op *extent_op)
1539 {
1540 struct extent_buffer *leaf;
1541 struct btrfs_extent_item *ei;
1542 unsigned long ptr;
1543 unsigned long end;
1544 unsigned long item_offset;
1545 u64 refs;
1546 int size;
1547 int type;
1548 int ret;
1549
1550 leaf = path->nodes[0];
1551 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1552 item_offset = (unsigned long)iref - (unsigned long)ei;
1553
1554 type = extent_ref_type(parent, owner);
1555 size = btrfs_extent_inline_ref_size(type);
1556
1557 ret = btrfs_extend_item(trans, root, path, size);
1558 BUG_ON(ret);
1559
1560 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1561 refs = btrfs_extent_refs(leaf, ei);
1562 refs += refs_to_add;
1563 btrfs_set_extent_refs(leaf, ei, refs);
1564 if (extent_op)
1565 __run_delayed_extent_op(extent_op, leaf, ei);
1566
1567 ptr = (unsigned long)ei + item_offset;
1568 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1569 if (ptr < end - size)
1570 memmove_extent_buffer(leaf, ptr + size, ptr,
1571 end - size - ptr);
1572
1573 iref = (struct btrfs_extent_inline_ref *)ptr;
1574 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1575 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1576 struct btrfs_extent_data_ref *dref;
1577 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1578 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1579 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1580 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1581 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1582 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1583 struct btrfs_shared_data_ref *sref;
1584 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1585 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1586 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1587 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1588 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1589 } else {
1590 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1591 }
1592 btrfs_mark_buffer_dirty(leaf);
1593 return 0;
1594 }
1595
1596 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1597 struct btrfs_root *root,
1598 struct btrfs_path *path,
1599 struct btrfs_extent_inline_ref **ref_ret,
1600 u64 bytenr, u64 num_bytes, u64 parent,
1601 u64 root_objectid, u64 owner, u64 offset)
1602 {
1603 int ret;
1604
1605 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1606 bytenr, num_bytes, parent,
1607 root_objectid, owner, offset, 0);
1608 if (ret != -ENOENT)
1609 return ret;
1610
1611 btrfs_release_path(root, path);
1612 *ref_ret = NULL;
1613
1614 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1615 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1616 root_objectid);
1617 } else {
1618 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1619 root_objectid, owner, offset);
1620 }
1621 return ret;
1622 }
1623
1624 /*
1625 * helper to update/remove inline back ref
1626 */
1627 static noinline_for_stack
1628 int update_inline_extent_backref(struct btrfs_trans_handle *trans,
1629 struct btrfs_root *root,
1630 struct btrfs_path *path,
1631 struct btrfs_extent_inline_ref *iref,
1632 int refs_to_mod,
1633 struct btrfs_delayed_extent_op *extent_op)
1634 {
1635 struct extent_buffer *leaf;
1636 struct btrfs_extent_item *ei;
1637 struct btrfs_extent_data_ref *dref = NULL;
1638 struct btrfs_shared_data_ref *sref = NULL;
1639 unsigned long ptr;
1640 unsigned long end;
1641 u32 item_size;
1642 int size;
1643 int type;
1644 int ret;
1645 u64 refs;
1646
1647 leaf = path->nodes[0];
1648 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1649 refs = btrfs_extent_refs(leaf, ei);
1650 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1651 refs += refs_to_mod;
1652 btrfs_set_extent_refs(leaf, ei, refs);
1653 if (extent_op)
1654 __run_delayed_extent_op(extent_op, leaf, ei);
1655
1656 type = btrfs_extent_inline_ref_type(leaf, iref);
1657
1658 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1659 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1660 refs = btrfs_extent_data_ref_count(leaf, dref);
1661 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1662 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1663 refs = btrfs_shared_data_ref_count(leaf, sref);
1664 } else {
1665 refs = 1;
1666 BUG_ON(refs_to_mod != -1);
1667 }
1668
1669 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1670 refs += refs_to_mod;
1671
1672 if (refs > 0) {
1673 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1674 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1675 else
1676 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1677 } else {
1678 size = btrfs_extent_inline_ref_size(type);
1679 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1680 ptr = (unsigned long)iref;
1681 end = (unsigned long)ei + item_size;
1682 if (ptr + size < end)
1683 memmove_extent_buffer(leaf, ptr, ptr + size,
1684 end - ptr - size);
1685 item_size -= size;
1686 ret = btrfs_truncate_item(trans, root, path, item_size, 1);
1687 BUG_ON(ret);
1688 }
1689 btrfs_mark_buffer_dirty(leaf);
1690 return 0;
1691 }
1692
1693 static noinline_for_stack
1694 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1695 struct btrfs_root *root,
1696 struct btrfs_path *path,
1697 u64 bytenr, u64 num_bytes, u64 parent,
1698 u64 root_objectid, u64 owner,
1699 u64 offset, int refs_to_add,
1700 struct btrfs_delayed_extent_op *extent_op)
1701 {
1702 struct btrfs_extent_inline_ref *iref;
1703 int ret;
1704
1705 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1706 bytenr, num_bytes, parent,
1707 root_objectid, owner, offset, 1);
1708 if (ret == 0) {
1709 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1710 ret = update_inline_extent_backref(trans, root, path, iref,
1711 refs_to_add, extent_op);
1712 } else if (ret == -ENOENT) {
1713 ret = setup_inline_extent_backref(trans, root, path, iref,
1714 parent, root_objectid,
1715 owner, offset, refs_to_add,
1716 extent_op);
1717 }
1718 return ret;
1719 }
1720
1721 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1722 struct btrfs_root *root,
1723 struct btrfs_path *path,
1724 u64 bytenr, u64 parent, u64 root_objectid,
1725 u64 owner, u64 offset, int refs_to_add)
1726 {
1727 int ret;
1728 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1729 BUG_ON(refs_to_add != 1);
1730 ret = insert_tree_block_ref(trans, root, path, bytenr,
1731 parent, root_objectid);
1732 } else {
1733 ret = insert_extent_data_ref(trans, root, path, bytenr,
1734 parent, root_objectid,
1735 owner, offset, refs_to_add);
1736 }
1737 return ret;
1738 }
1739
1740 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1741 struct btrfs_root *root,
1742 struct btrfs_path *path,
1743 struct btrfs_extent_inline_ref *iref,
1744 int refs_to_drop, int is_data)
1745 {
1746 int ret;
1747
1748 BUG_ON(!is_data && refs_to_drop != 1);
1749 if (iref) {
1750 ret = update_inline_extent_backref(trans, root, path, iref,
1751 -refs_to_drop, NULL);
1752 } else if (is_data) {
1753 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1754 } else {
1755 ret = btrfs_del_item(trans, root, path);
1756 }
1757 return ret;
1758 }
1759
1760 static int btrfs_issue_discard(struct block_device *bdev,
1761 u64 start, u64 len)
1762 {
1763 return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
1764 }
1765
1766 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
1767 u64 num_bytes, u64 *actual_bytes)
1768 {
1769 int ret;
1770 u64 discarded_bytes = 0;
1771 struct btrfs_multi_bio *multi = NULL;
1772
1773
1774 /* Tell the block device(s) that the sectors can be discarded */
1775 ret = btrfs_map_block(&root->fs_info->mapping_tree, REQ_DISCARD,
1776 bytenr, &num_bytes, &multi, 0);
1777 if (!ret) {
1778 struct btrfs_bio_stripe *stripe = multi->stripes;
1779 int i;
1780
1781
1782 for (i = 0; i < multi->num_stripes; i++, stripe++) {
1783 ret = btrfs_issue_discard(stripe->dev->bdev,
1784 stripe->physical,
1785 stripe->length);
1786 if (!ret)
1787 discarded_bytes += stripe->length;
1788 else if (ret != -EOPNOTSUPP)
1789 break;
1790 }
1791 kfree(multi);
1792 }
1793 if (discarded_bytes && ret == -EOPNOTSUPP)
1794 ret = 0;
1795
1796 if (actual_bytes)
1797 *actual_bytes = discarded_bytes;
1798
1799
1800 return ret;
1801 }
1802
1803 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1804 struct btrfs_root *root,
1805 u64 bytenr, u64 num_bytes, u64 parent,
1806 u64 root_objectid, u64 owner, u64 offset)
1807 {
1808 int ret;
1809 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
1810 root_objectid == BTRFS_TREE_LOG_OBJECTID);
1811
1812 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1813 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
1814 parent, root_objectid, (int)owner,
1815 BTRFS_ADD_DELAYED_REF, NULL);
1816 } else {
1817 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
1818 parent, root_objectid, owner, offset,
1819 BTRFS_ADD_DELAYED_REF, NULL);
1820 }
1821 return ret;
1822 }
1823
1824 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1825 struct btrfs_root *root,
1826 u64 bytenr, u64 num_bytes,
1827 u64 parent, u64 root_objectid,
1828 u64 owner, u64 offset, int refs_to_add,
1829 struct btrfs_delayed_extent_op *extent_op)
1830 {
1831 struct btrfs_path *path;
1832 struct extent_buffer *leaf;
1833 struct btrfs_extent_item *item;
1834 u64 refs;
1835 int ret;
1836 int err = 0;
1837
1838 path = btrfs_alloc_path();
1839 if (!path)
1840 return -ENOMEM;
1841
1842 path->reada = 1;
1843 path->leave_spinning = 1;
1844 /* this will setup the path even if it fails to insert the back ref */
1845 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1846 path, bytenr, num_bytes, parent,
1847 root_objectid, owner, offset,
1848 refs_to_add, extent_op);
1849 if (ret == 0)
1850 goto out;
1851
1852 if (ret != -EAGAIN) {
1853 err = ret;
1854 goto out;
1855 }
1856
1857 leaf = path->nodes[0];
1858 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1859 refs = btrfs_extent_refs(leaf, item);
1860 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1861 if (extent_op)
1862 __run_delayed_extent_op(extent_op, leaf, item);
1863
1864 btrfs_mark_buffer_dirty(leaf);
1865 btrfs_release_path(root->fs_info->extent_root, path);
1866
1867 path->reada = 1;
1868 path->leave_spinning = 1;
1869
1870 /* now insert the actual backref */
1871 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1872 path, bytenr, parent, root_objectid,
1873 owner, offset, refs_to_add);
1874 BUG_ON(ret);
1875 out:
1876 btrfs_free_path(path);
1877 return err;
1878 }
1879
1880 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1881 struct btrfs_root *root,
1882 struct btrfs_delayed_ref_node *node,
1883 struct btrfs_delayed_extent_op *extent_op,
1884 int insert_reserved)
1885 {
1886 int ret = 0;
1887 struct btrfs_delayed_data_ref *ref;
1888 struct btrfs_key ins;
1889 u64 parent = 0;
1890 u64 ref_root = 0;
1891 u64 flags = 0;
1892
1893 ins.objectid = node->bytenr;
1894 ins.offset = node->num_bytes;
1895 ins.type = BTRFS_EXTENT_ITEM_KEY;
1896
1897 ref = btrfs_delayed_node_to_data_ref(node);
1898 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
1899 parent = ref->parent;
1900 else
1901 ref_root = ref->root;
1902
1903 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1904 if (extent_op) {
1905 BUG_ON(extent_op->update_key);
1906 flags |= extent_op->flags_to_set;
1907 }
1908 ret = alloc_reserved_file_extent(trans, root,
1909 parent, ref_root, flags,
1910 ref->objectid, ref->offset,
1911 &ins, node->ref_mod);
1912 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1913 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1914 node->num_bytes, parent,
1915 ref_root, ref->objectid,
1916 ref->offset, node->ref_mod,
1917 extent_op);
1918 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1919 ret = __btrfs_free_extent(trans, root, node->bytenr,
1920 node->num_bytes, parent,
1921 ref_root, ref->objectid,
1922 ref->offset, node->ref_mod,
1923 extent_op);
1924 } else {
1925 BUG();
1926 }
1927 return ret;
1928 }
1929
1930 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
1931 struct extent_buffer *leaf,
1932 struct btrfs_extent_item *ei)
1933 {
1934 u64 flags = btrfs_extent_flags(leaf, ei);
1935 if (extent_op->update_flags) {
1936 flags |= extent_op->flags_to_set;
1937 btrfs_set_extent_flags(leaf, ei, flags);
1938 }
1939
1940 if (extent_op->update_key) {
1941 struct btrfs_tree_block_info *bi;
1942 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
1943 bi = (struct btrfs_tree_block_info *)(ei + 1);
1944 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
1945 }
1946 }
1947
1948 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
1949 struct btrfs_root *root,
1950 struct btrfs_delayed_ref_node *node,
1951 struct btrfs_delayed_extent_op *extent_op)
1952 {
1953 struct btrfs_key key;
1954 struct btrfs_path *path;
1955 struct btrfs_extent_item *ei;
1956 struct extent_buffer *leaf;
1957 u32 item_size;
1958 int ret;
1959 int err = 0;
1960
1961 path = btrfs_alloc_path();
1962 if (!path)
1963 return -ENOMEM;
1964
1965 key.objectid = node->bytenr;
1966 key.type = BTRFS_EXTENT_ITEM_KEY;
1967 key.offset = node->num_bytes;
1968
1969 path->reada = 1;
1970 path->leave_spinning = 1;
1971 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
1972 path, 0, 1);
1973 if (ret < 0) {
1974 err = ret;
1975 goto out;
1976 }
1977 if (ret > 0) {
1978 err = -EIO;
1979 goto out;
1980 }
1981
1982 leaf = path->nodes[0];
1983 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1984 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1985 if (item_size < sizeof(*ei)) {
1986 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1987 path, (u64)-1, 0);
1988 if (ret < 0) {
1989 err = ret;
1990 goto out;
1991 }
1992 leaf = path->nodes[0];
1993 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1994 }
1995 #endif
1996 BUG_ON(item_size < sizeof(*ei));
1997 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1998 __run_delayed_extent_op(extent_op, leaf, ei);
1999
2000 btrfs_mark_buffer_dirty(leaf);
2001 out:
2002 btrfs_free_path(path);
2003 return err;
2004 }
2005
2006 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
2007 struct btrfs_root *root,
2008 struct btrfs_delayed_ref_node *node,
2009 struct btrfs_delayed_extent_op *extent_op,
2010 int insert_reserved)
2011 {
2012 int ret = 0;
2013 struct btrfs_delayed_tree_ref *ref;
2014 struct btrfs_key ins;
2015 u64 parent = 0;
2016 u64 ref_root = 0;
2017
2018 ins.objectid = node->bytenr;
2019 ins.offset = node->num_bytes;
2020 ins.type = BTRFS_EXTENT_ITEM_KEY;
2021
2022 ref = btrfs_delayed_node_to_tree_ref(node);
2023 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2024 parent = ref->parent;
2025 else
2026 ref_root = ref->root;
2027
2028 BUG_ON(node->ref_mod != 1);
2029 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
2030 BUG_ON(!extent_op || !extent_op->update_flags ||
2031 !extent_op->update_key);
2032 ret = alloc_reserved_tree_block(trans, root,
2033 parent, ref_root,
2034 extent_op->flags_to_set,
2035 &extent_op->key,
2036 ref->level, &ins);
2037 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
2038 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
2039 node->num_bytes, parent, ref_root,
2040 ref->level, 0, 1, extent_op);
2041 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
2042 ret = __btrfs_free_extent(trans, root, node->bytenr,
2043 node->num_bytes, parent, ref_root,
2044 ref->level, 0, 1, extent_op);
2045 } else {
2046 BUG();
2047 }
2048 return ret;
2049 }
2050
2051 /* helper function to actually process a single delayed ref entry */
2052 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
2053 struct btrfs_root *root,
2054 struct btrfs_delayed_ref_node *node,
2055 struct btrfs_delayed_extent_op *extent_op,
2056 int insert_reserved)
2057 {
2058 int ret;
2059 if (btrfs_delayed_ref_is_head(node)) {
2060 struct btrfs_delayed_ref_head *head;
2061 /*
2062 * we've hit the end of the chain and we were supposed
2063 * to insert this extent into the tree. But, it got
2064 * deleted before we ever needed to insert it, so all
2065 * we have to do is clean up the accounting
2066 */
2067 BUG_ON(extent_op);
2068 head = btrfs_delayed_node_to_head(node);
2069 if (insert_reserved) {
2070 btrfs_pin_extent(root, node->bytenr,
2071 node->num_bytes, 1);
2072 if (head->is_data) {
2073 ret = btrfs_del_csums(trans, root,
2074 node->bytenr,
2075 node->num_bytes);
2076 BUG_ON(ret);
2077 }
2078 }
2079 mutex_unlock(&head->mutex);
2080 return 0;
2081 }
2082
2083 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
2084 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
2085 ret = run_delayed_tree_ref(trans, root, node, extent_op,
2086 insert_reserved);
2087 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
2088 node->type == BTRFS_SHARED_DATA_REF_KEY)
2089 ret = run_delayed_data_ref(trans, root, node, extent_op,
2090 insert_reserved);
2091 else
2092 BUG();
2093 return ret;
2094 }
2095
2096 static noinline struct btrfs_delayed_ref_node *
2097 select_delayed_ref(struct btrfs_delayed_ref_head *head)
2098 {
2099 struct rb_node *node;
2100 struct btrfs_delayed_ref_node *ref;
2101 int action = BTRFS_ADD_DELAYED_REF;
2102 again:
2103 /*
2104 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
2105 * this prevents ref count from going down to zero when
2106 * there still are pending delayed ref.
2107 */
2108 node = rb_prev(&head->node.rb_node);
2109 while (1) {
2110 if (!node)
2111 break;
2112 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2113 rb_node);
2114 if (ref->bytenr != head->node.bytenr)
2115 break;
2116 if (ref->action == action)
2117 return ref;
2118 node = rb_prev(node);
2119 }
2120 if (action == BTRFS_ADD_DELAYED_REF) {
2121 action = BTRFS_DROP_DELAYED_REF;
2122 goto again;
2123 }
2124 return NULL;
2125 }
2126
2127 static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
2128 struct btrfs_root *root,
2129 struct list_head *cluster)
2130 {
2131 struct btrfs_delayed_ref_root *delayed_refs;
2132 struct btrfs_delayed_ref_node *ref;
2133 struct btrfs_delayed_ref_head *locked_ref = NULL;
2134 struct btrfs_delayed_extent_op *extent_op;
2135 int ret;
2136 int count = 0;
2137 int must_insert_reserved = 0;
2138
2139 delayed_refs = &trans->transaction->delayed_refs;
2140 while (1) {
2141 if (!locked_ref) {
2142 /* pick a new head ref from the cluster list */
2143 if (list_empty(cluster))
2144 break;
2145
2146 locked_ref = list_entry(cluster->next,
2147 struct btrfs_delayed_ref_head, cluster);
2148
2149 /* grab the lock that says we are going to process
2150 * all the refs for this head */
2151 ret = btrfs_delayed_ref_lock(trans, locked_ref);
2152
2153 /*
2154 * we may have dropped the spin lock to get the head
2155 * mutex lock, and that might have given someone else
2156 * time to free the head. If that's true, it has been
2157 * removed from our list and we can move on.
2158 */
2159 if (ret == -EAGAIN) {
2160 locked_ref = NULL;
2161 count++;
2162 continue;
2163 }
2164 }
2165
2166 /*
2167 * record the must insert reserved flag before we
2168 * drop the spin lock.
2169 */
2170 must_insert_reserved = locked_ref->must_insert_reserved;
2171 locked_ref->must_insert_reserved = 0;
2172
2173 extent_op = locked_ref->extent_op;
2174 locked_ref->extent_op = NULL;
2175
2176 /*
2177 * locked_ref is the head node, so we have to go one
2178 * node back for any delayed ref updates
2179 */
2180 ref = select_delayed_ref(locked_ref);
2181 if (!ref) {
2182 /* All delayed refs have been processed, Go ahead
2183 * and send the head node to run_one_delayed_ref,
2184 * so that any accounting fixes can happen
2185 */
2186 ref = &locked_ref->node;
2187
2188 if (extent_op && must_insert_reserved) {
2189 kfree(extent_op);
2190 extent_op = NULL;
2191 }
2192
2193 if (extent_op) {
2194 spin_unlock(&delayed_refs->lock);
2195
2196 ret = run_delayed_extent_op(trans, root,
2197 ref, extent_op);
2198 BUG_ON(ret);
2199 kfree(extent_op);
2200
2201 cond_resched();
2202 spin_lock(&delayed_refs->lock);
2203 continue;
2204 }
2205
2206 list_del_init(&locked_ref->cluster);
2207 locked_ref = NULL;
2208 }
2209
2210 ref->in_tree = 0;
2211 rb_erase(&ref->rb_node, &delayed_refs->root);
2212 delayed_refs->num_entries--;
2213
2214 spin_unlock(&delayed_refs->lock);
2215
2216 ret = run_one_delayed_ref(trans, root, ref, extent_op,
2217 must_insert_reserved);
2218 BUG_ON(ret);
2219
2220 btrfs_put_delayed_ref(ref);
2221 kfree(extent_op);
2222 count++;
2223
2224 cond_resched();
2225 spin_lock(&delayed_refs->lock);
2226 }
2227 return count;
2228 }
2229
2230 /*
2231 * this starts processing the delayed reference count updates and
2232 * extent insertions we have queued up so far. count can be
2233 * 0, which means to process everything in the tree at the start
2234 * of the run (but not newly added entries), or it can be some target
2235 * number you'd like to process.
2236 */
2237 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2238 struct btrfs_root *root, unsigned long count)
2239 {
2240 struct rb_node *node;
2241 struct btrfs_delayed_ref_root *delayed_refs;
2242 struct btrfs_delayed_ref_node *ref;
2243 struct list_head cluster;
2244 int ret;
2245 int run_all = count == (unsigned long)-1;
2246 int run_most = 0;
2247
2248 if (root == root->fs_info->extent_root)
2249 root = root->fs_info->tree_root;
2250
2251 delayed_refs = &trans->transaction->delayed_refs;
2252 INIT_LIST_HEAD(&cluster);
2253 again:
2254 spin_lock(&delayed_refs->lock);
2255 if (count == 0) {
2256 count = delayed_refs->num_entries * 2;
2257 run_most = 1;
2258 }
2259 while (1) {
2260 if (!(run_all || run_most) &&
2261 delayed_refs->num_heads_ready < 64)
2262 break;
2263
2264 /*
2265 * go find something we can process in the rbtree. We start at
2266 * the beginning of the tree, and then build a cluster
2267 * of refs to process starting at the first one we are able to
2268 * lock
2269 */
2270 ret = btrfs_find_ref_cluster(trans, &cluster,
2271 delayed_refs->run_delayed_start);
2272 if (ret)
2273 break;
2274
2275 ret = run_clustered_refs(trans, root, &cluster);
2276 BUG_ON(ret < 0);
2277
2278 count -= min_t(unsigned long, ret, count);
2279
2280 if (count == 0)
2281 break;
2282 }
2283
2284 if (run_all) {
2285 node = rb_first(&delayed_refs->root);
2286 if (!node)
2287 goto out;
2288 count = (unsigned long)-1;
2289
2290 while (node) {
2291 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2292 rb_node);
2293 if (btrfs_delayed_ref_is_head(ref)) {
2294 struct btrfs_delayed_ref_head *head;
2295
2296 head = btrfs_delayed_node_to_head(ref);
2297 atomic_inc(&ref->refs);
2298
2299 spin_unlock(&delayed_refs->lock);
2300 mutex_lock(&head->mutex);
2301 mutex_unlock(&head->mutex);
2302
2303 btrfs_put_delayed_ref(ref);
2304 cond_resched();
2305 goto again;
2306 }
2307 node = rb_next(node);
2308 }
2309 spin_unlock(&delayed_refs->lock);
2310 schedule_timeout(1);
2311 goto again;
2312 }
2313 out:
2314 spin_unlock(&delayed_refs->lock);
2315 return 0;
2316 }
2317
2318 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2319 struct btrfs_root *root,
2320 u64 bytenr, u64 num_bytes, u64 flags,
2321 int is_data)
2322 {
2323 struct btrfs_delayed_extent_op *extent_op;
2324 int ret;
2325
2326 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2327 if (!extent_op)
2328 return -ENOMEM;
2329
2330 extent_op->flags_to_set = flags;
2331 extent_op->update_flags = 1;
2332 extent_op->update_key = 0;
2333 extent_op->is_data = is_data ? 1 : 0;
2334
2335 ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
2336 if (ret)
2337 kfree(extent_op);
2338 return ret;
2339 }
2340
2341 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
2342 struct btrfs_root *root,
2343 struct btrfs_path *path,
2344 u64 objectid, u64 offset, u64 bytenr)
2345 {
2346 struct btrfs_delayed_ref_head *head;
2347 struct btrfs_delayed_ref_node *ref;
2348 struct btrfs_delayed_data_ref *data_ref;
2349 struct btrfs_delayed_ref_root *delayed_refs;
2350 struct rb_node *node;
2351 int ret = 0;
2352
2353 ret = -ENOENT;
2354 delayed_refs = &trans->transaction->delayed_refs;
2355 spin_lock(&delayed_refs->lock);
2356 head = btrfs_find_delayed_ref_head(trans, bytenr);
2357 if (!head)
2358 goto out;
2359
2360 if (!mutex_trylock(&head->mutex)) {
2361 atomic_inc(&head->node.refs);
2362 spin_unlock(&delayed_refs->lock);
2363
2364 btrfs_release_path(root->fs_info->extent_root, path);
2365
2366 mutex_lock(&head->mutex);
2367 mutex_unlock(&head->mutex);
2368 btrfs_put_delayed_ref(&head->node);
2369 return -EAGAIN;
2370 }
2371
2372 node = rb_prev(&head->node.rb_node);
2373 if (!node)
2374 goto out_unlock;
2375
2376 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2377
2378 if (ref->bytenr != bytenr)
2379 goto out_unlock;
2380
2381 ret = 1;
2382 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
2383 goto out_unlock;
2384
2385 data_ref = btrfs_delayed_node_to_data_ref(ref);
2386
2387 node = rb_prev(node);
2388 if (node) {
2389 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2390 if (ref->bytenr == bytenr)
2391 goto out_unlock;
2392 }
2393
2394 if (data_ref->root != root->root_key.objectid ||
2395 data_ref->objectid != objectid || data_ref->offset != offset)
2396 goto out_unlock;
2397
2398 ret = 0;
2399 out_unlock:
2400 mutex_unlock(&head->mutex);
2401 out:
2402 spin_unlock(&delayed_refs->lock);
2403 return ret;
2404 }
2405
2406 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
2407 struct btrfs_root *root,
2408 struct btrfs_path *path,
2409 u64 objectid, u64 offset, u64 bytenr)
2410 {
2411 struct btrfs_root *extent_root = root->fs_info->extent_root;
2412 struct extent_buffer *leaf;
2413 struct btrfs_extent_data_ref *ref;
2414 struct btrfs_extent_inline_ref *iref;
2415 struct btrfs_extent_item *ei;
2416 struct btrfs_key key;
2417 u32 item_size;
2418 int ret;
2419
2420 key.objectid = bytenr;
2421 key.offset = (u64)-1;
2422 key.type = BTRFS_EXTENT_ITEM_KEY;
2423
2424 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2425 if (ret < 0)
2426 goto out;
2427 BUG_ON(ret == 0);
2428
2429 ret = -ENOENT;
2430 if (path->slots[0] == 0)
2431 goto out;
2432
2433 path->slots[0]--;
2434 leaf = path->nodes[0];
2435 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2436
2437 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2438 goto out;
2439
2440 ret = 1;
2441 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2442 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2443 if (item_size < sizeof(*ei)) {
2444 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
2445 goto out;
2446 }
2447 #endif
2448 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2449
2450 if (item_size != sizeof(*ei) +
2451 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2452 goto out;
2453
2454 if (btrfs_extent_generation(leaf, ei) <=
2455 btrfs_root_last_snapshot(&root->root_item))
2456 goto out;
2457
2458 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2459 if (btrfs_extent_inline_ref_type(leaf, iref) !=
2460 BTRFS_EXTENT_DATA_REF_KEY)
2461 goto out;
2462
2463 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2464 if (btrfs_extent_refs(leaf, ei) !=
2465 btrfs_extent_data_ref_count(leaf, ref) ||
2466 btrfs_extent_data_ref_root(leaf, ref) !=
2467 root->root_key.objectid ||
2468 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2469 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2470 goto out;
2471
2472 ret = 0;
2473 out:
2474 return ret;
2475 }
2476
2477 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
2478 struct btrfs_root *root,
2479 u64 objectid, u64 offset, u64 bytenr)
2480 {
2481 struct btrfs_path *path;
2482 int ret;
2483 int ret2;
2484
2485 path = btrfs_alloc_path();
2486 if (!path)
2487 return -ENOENT;
2488
2489 do {
2490 ret = check_committed_ref(trans, root, path, objectid,
2491 offset, bytenr);
2492 if (ret && ret != -ENOENT)
2493 goto out;
2494
2495 ret2 = check_delayed_ref(trans, root, path, objectid,
2496 offset, bytenr);
2497 } while (ret2 == -EAGAIN);
2498
2499 if (ret2 && ret2 != -ENOENT) {
2500 ret = ret2;
2501 goto out;
2502 }
2503
2504 if (ret != -ENOENT || ret2 != -ENOENT)
2505 ret = 0;
2506 out:
2507 btrfs_free_path(path);
2508 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
2509 WARN_ON(ret > 0);
2510 return ret;
2511 }
2512
2513 #if 0
2514 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2515 struct extent_buffer *buf, u32 nr_extents)
2516 {
2517 struct btrfs_key key;
2518 struct btrfs_file_extent_item *fi;
2519 u64 root_gen;
2520 u32 nritems;
2521 int i;
2522 int level;
2523 int ret = 0;
2524 int shared = 0;
2525
2526 if (!root->ref_cows)
2527 return 0;
2528
2529 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
2530 shared = 0;
2531 root_gen = root->root_key.offset;
2532 } else {
2533 shared = 1;
2534 root_gen = trans->transid - 1;
2535 }
2536
2537 level = btrfs_header_level(buf);
2538 nritems = btrfs_header_nritems(buf);
2539
2540 if (level == 0) {
2541 struct btrfs_leaf_ref *ref;
2542 struct btrfs_extent_info *info;
2543
2544 ref = btrfs_alloc_leaf_ref(root, nr_extents);
2545 if (!ref) {
2546 ret = -ENOMEM;
2547 goto out;
2548 }
2549
2550 ref->root_gen = root_gen;
2551 ref->bytenr = buf->start;
2552 ref->owner = btrfs_header_owner(buf);
2553 ref->generation = btrfs_header_generation(buf);
2554 ref->nritems = nr_extents;
2555 info = ref->extents;
2556
2557 for (i = 0; nr_extents > 0 && i < nritems; i++) {
2558 u64 disk_bytenr;
2559 btrfs_item_key_to_cpu(buf, &key, i);
2560 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2561 continue;
2562 fi = btrfs_item_ptr(buf, i,
2563 struct btrfs_file_extent_item);
2564 if (btrfs_file_extent_type(buf, fi) ==
2565 BTRFS_FILE_EXTENT_INLINE)
2566 continue;
2567 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2568 if (disk_bytenr == 0)
2569 continue;
2570
2571 info->bytenr = disk_bytenr;
2572 info->num_bytes =
2573 btrfs_file_extent_disk_num_bytes(buf, fi);
2574 info->objectid = key.objectid;
2575 info->offset = key.offset;
2576 info++;
2577 }
2578
2579 ret = btrfs_add_leaf_ref(root, ref, shared);
2580 if (ret == -EEXIST && shared) {
2581 struct btrfs_leaf_ref *old;
2582 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
2583 BUG_ON(!old);
2584 btrfs_remove_leaf_ref(root, old);
2585 btrfs_free_leaf_ref(root, old);
2586 ret = btrfs_add_leaf_ref(root, ref, shared);
2587 }
2588 WARN_ON(ret);
2589 btrfs_free_leaf_ref(root, ref);
2590 }
2591 out:
2592 return ret;
2593 }
2594
2595 /* when a block goes through cow, we update the reference counts of
2596 * everything that block points to. The internal pointers of the block
2597 * can be in just about any order, and it is likely to have clusters of
2598 * things that are close together and clusters of things that are not.
2599 *
2600 * To help reduce the seeks that come with updating all of these reference
2601 * counts, sort them by byte number before actual updates are done.
2602 *
2603 * struct refsort is used to match byte number to slot in the btree block.
2604 * we sort based on the byte number and then use the slot to actually
2605 * find the item.
2606 *
2607 * struct refsort is smaller than strcut btrfs_item and smaller than
2608 * struct btrfs_key_ptr. Since we're currently limited to the page size
2609 * for a btree block, there's no way for a kmalloc of refsorts for a
2610 * single node to be bigger than a page.
2611 */
2612 struct refsort {
2613 u64 bytenr;
2614 u32 slot;
2615 };
2616
2617 /*
2618 * for passing into sort()
2619 */
2620 static int refsort_cmp(const void *a_void, const void *b_void)
2621 {
2622 const struct refsort *a = a_void;
2623 const struct refsort *b = b_void;
2624
2625 if (a->bytenr < b->bytenr)
2626 return -1;
2627 if (a->bytenr > b->bytenr)
2628 return 1;
2629 return 0;
2630 }
2631 #endif
2632
2633 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2634 struct btrfs_root *root,
2635 struct extent_buffer *buf,
2636 int full_backref, int inc)
2637 {
2638 u64 bytenr;
2639 u64 num_bytes;
2640 u64 parent;
2641 u64 ref_root;
2642 u32 nritems;
2643 struct btrfs_key key;
2644 struct btrfs_file_extent_item *fi;
2645 int i;
2646 int level;
2647 int ret = 0;
2648 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
2649 u64, u64, u64, u64, u64, u64);
2650
2651 ref_root = btrfs_header_owner(buf);
2652 nritems = btrfs_header_nritems(buf);
2653 level = btrfs_header_level(buf);
2654
2655 if (!root->ref_cows && level == 0)
2656 return 0;
2657
2658 if (inc)
2659 process_func = btrfs_inc_extent_ref;
2660 else
2661 process_func = btrfs_free_extent;
2662
2663 if (full_backref)
2664 parent = buf->start;
2665 else
2666 parent = 0;
2667
2668 for (i = 0; i < nritems; i++) {
2669 if (level == 0) {
2670 btrfs_item_key_to_cpu(buf, &key, i);
2671 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2672 continue;
2673 fi = btrfs_item_ptr(buf, i,
2674 struct btrfs_file_extent_item);
2675 if (btrfs_file_extent_type(buf, fi) ==
2676 BTRFS_FILE_EXTENT_INLINE)
2677 continue;
2678 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2679 if (bytenr == 0)
2680 continue;
2681
2682 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
2683 key.offset -= btrfs_file_extent_offset(buf, fi);
2684 ret = process_func(trans, root, bytenr, num_bytes,
2685 parent, ref_root, key.objectid,
2686 key.offset);
2687 if (ret)
2688 goto fail;
2689 } else {
2690 bytenr = btrfs_node_blockptr(buf, i);
2691 num_bytes = btrfs_level_size(root, level - 1);
2692 ret = process_func(trans, root, bytenr, num_bytes,
2693 parent, ref_root, level - 1, 0);
2694 if (ret)
2695 goto fail;
2696 }
2697 }
2698 return 0;
2699 fail:
2700 BUG();
2701 return ret;
2702 }
2703
2704 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2705 struct extent_buffer *buf, int full_backref)
2706 {
2707 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
2708 }
2709
2710 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2711 struct extent_buffer *buf, int full_backref)
2712 {
2713 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
2714 }
2715
2716 static int write_one_cache_group(struct btrfs_trans_handle *trans,
2717 struct btrfs_root *root,
2718 struct btrfs_path *path,
2719 struct btrfs_block_group_cache *cache)
2720 {
2721 int ret;
2722 struct btrfs_root *extent_root = root->fs_info->extent_root;
2723 unsigned long bi;
2724 struct extent_buffer *leaf;
2725
2726 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
2727 if (ret < 0)
2728 goto fail;
2729 BUG_ON(ret);
2730
2731 leaf = path->nodes[0];
2732 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
2733 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
2734 btrfs_mark_buffer_dirty(leaf);
2735 btrfs_release_path(extent_root, path);
2736 fail:
2737 if (ret)
2738 return ret;
2739 return 0;
2740
2741 }
2742
2743 static struct btrfs_block_group_cache *
2744 next_block_group(struct btrfs_root *root,
2745 struct btrfs_block_group_cache *cache)
2746 {
2747 struct rb_node *node;
2748 spin_lock(&root->fs_info->block_group_cache_lock);
2749 node = rb_next(&cache->cache_node);
2750 btrfs_put_block_group(cache);
2751 if (node) {
2752 cache = rb_entry(node, struct btrfs_block_group_cache,
2753 cache_node);
2754 btrfs_get_block_group(cache);
2755 } else
2756 cache = NULL;
2757 spin_unlock(&root->fs_info->block_group_cache_lock);
2758 return cache;
2759 }
2760
2761 static int cache_save_setup(struct btrfs_block_group_cache *block_group,
2762 struct btrfs_trans_handle *trans,
2763 struct btrfs_path *path)
2764 {
2765 struct btrfs_root *root = block_group->fs_info->tree_root;
2766 struct inode *inode = NULL;
2767 u64 alloc_hint = 0;
2768 int dcs = BTRFS_DC_ERROR;
2769 int num_pages = 0;
2770 int retries = 0;
2771 int ret = 0;
2772
2773 /*
2774 * If this block group is smaller than 100 megs don't bother caching the
2775 * block group.
2776 */
2777 if (block_group->key.offset < (100 * 1024 * 1024)) {
2778 spin_lock(&block_group->lock);
2779 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
2780 spin_unlock(&block_group->lock);
2781 return 0;
2782 }
2783
2784 again:
2785 inode = lookup_free_space_inode(root, block_group, path);
2786 if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
2787 ret = PTR_ERR(inode);
2788 btrfs_release_path(root, path);
2789 goto out;
2790 }
2791
2792 if (IS_ERR(inode)) {
2793 BUG_ON(retries);
2794 retries++;
2795
2796 if (block_group->ro)
2797 goto out_free;
2798
2799 ret = create_free_space_inode(root, trans, block_group, path);
2800 if (ret)
2801 goto out_free;
2802 goto again;
2803 }
2804
2805 /*
2806 * We want to set the generation to 0, that way if anything goes wrong
2807 * from here on out we know not to trust this cache when we load up next
2808 * time.
2809 */
2810 BTRFS_I(inode)->generation = 0;
2811 ret = btrfs_update_inode(trans, root, inode);
2812 WARN_ON(ret);
2813
2814 if (i_size_read(inode) > 0) {
2815 ret = btrfs_truncate_free_space_cache(root, trans, path,
2816 inode);
2817 if (ret)
2818 goto out_put;
2819 }
2820
2821 spin_lock(&block_group->lock);
2822 if (block_group->cached != BTRFS_CACHE_FINISHED) {
2823 /* We're not cached, don't bother trying to write stuff out */
2824 dcs = BTRFS_DC_WRITTEN;
2825 spin_unlock(&block_group->lock);
2826 goto out_put;
2827 }
2828 spin_unlock(&block_group->lock);
2829
2830 num_pages = (int)div64_u64(block_group->key.offset, 1024 * 1024 * 1024);
2831 if (!num_pages)
2832 num_pages = 1;
2833
2834 /*
2835 * Just to make absolutely sure we have enough space, we're going to
2836 * preallocate 12 pages worth of space for each block group. In
2837 * practice we ought to use at most 8, but we need extra space so we can
2838 * add our header and have a terminator between the extents and the
2839 * bitmaps.
2840 */
2841 num_pages *= 16;
2842 num_pages *= PAGE_CACHE_SIZE;
2843
2844 ret = btrfs_check_data_free_space(inode, num_pages);
2845 if (ret)
2846 goto out_put;
2847
2848 ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
2849 num_pages, num_pages,
2850 &alloc_hint);
2851 if (!ret)
2852 dcs = BTRFS_DC_SETUP;
2853 btrfs_free_reserved_data_space(inode, num_pages);
2854 out_put:
2855 iput(inode);
2856 out_free:
2857 btrfs_release_path(root, path);
2858 out:
2859 spin_lock(&block_group->lock);
2860 block_group->disk_cache_state = dcs;
2861 spin_unlock(&block_group->lock);
2862
2863 return ret;
2864 }
2865
2866 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
2867 struct btrfs_root *root)
2868 {
2869 struct btrfs_block_group_cache *cache;
2870 int err = 0;
2871 struct btrfs_path *path;
2872 u64 last = 0;
2873
2874 path = btrfs_alloc_path();
2875 if (!path)
2876 return -ENOMEM;
2877
2878 again:
2879 while (1) {
2880 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2881 while (cache) {
2882 if (cache->disk_cache_state == BTRFS_DC_CLEAR)
2883 break;
2884 cache = next_block_group(root, cache);
2885 }
2886 if (!cache) {
2887 if (last == 0)
2888 break;
2889 last = 0;
2890 continue;
2891 }
2892 err = cache_save_setup(cache, trans, path);
2893 last = cache->key.objectid + cache->key.offset;
2894 btrfs_put_block_group(cache);
2895 }
2896
2897 while (1) {
2898 if (last == 0) {
2899 err = btrfs_run_delayed_refs(trans, root,
2900 (unsigned long)-1);
2901 BUG_ON(err);
2902 }
2903
2904 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2905 while (cache) {
2906 if (cache->disk_cache_state == BTRFS_DC_CLEAR) {
2907 btrfs_put_block_group(cache);
2908 goto again;
2909 }
2910
2911 if (cache->dirty)
2912 break;
2913 cache = next_block_group(root, cache);
2914 }
2915 if (!cache) {
2916 if (last == 0)
2917 break;
2918 last = 0;
2919 continue;
2920 }
2921
2922 if (cache->disk_cache_state == BTRFS_DC_SETUP)
2923 cache->disk_cache_state = BTRFS_DC_NEED_WRITE;
2924 cache->dirty = 0;
2925 last = cache->key.objectid + cache->key.offset;
2926
2927 err = write_one_cache_group(trans, root, path, cache);
2928 BUG_ON(err);
2929 btrfs_put_block_group(cache);
2930 }
2931
2932 while (1) {
2933 /*
2934 * I don't think this is needed since we're just marking our
2935 * preallocated extent as written, but just in case it can't
2936 * hurt.
2937 */
2938 if (last == 0) {
2939 err = btrfs_run_delayed_refs(trans, root,
2940 (unsigned long)-1);
2941 BUG_ON(err);
2942 }
2943
2944 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2945 while (cache) {
2946 /*
2947 * Really this shouldn't happen, but it could if we
2948 * couldn't write the entire preallocated extent and
2949 * splitting the extent resulted in a new block.
2950 */
2951 if (cache->dirty) {
2952 btrfs_put_block_group(cache);
2953 goto again;
2954 }
2955 if (cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
2956 break;
2957 cache = next_block_group(root, cache);
2958 }
2959 if (!cache) {
2960 if (last == 0)
2961 break;
2962 last = 0;
2963 continue;
2964 }
2965
2966 btrfs_write_out_cache(root, trans, cache, path);
2967
2968 /*
2969 * If we didn't have an error then the cache state is still
2970 * NEED_WRITE, so we can set it to WRITTEN.
2971 */
2972 if (cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
2973 cache->disk_cache_state = BTRFS_DC_WRITTEN;
2974 last = cache->key.objectid + cache->key.offset;
2975 btrfs_put_block_group(cache);
2976 }
2977
2978 btrfs_free_path(path);
2979 return 0;
2980 }
2981
2982 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
2983 {
2984 struct btrfs_block_group_cache *block_group;
2985 int readonly = 0;
2986
2987 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
2988 if (!block_group || block_group->ro)
2989 readonly = 1;
2990 if (block_group)
2991 btrfs_put_block_group(block_group);
2992 return readonly;
2993 }
2994
2995 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
2996 u64 total_bytes, u64 bytes_used,
2997 struct btrfs_space_info **space_info)
2998 {
2999 struct btrfs_space_info *found;
3000 int i;
3001 int factor;
3002
3003 if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3004 BTRFS_BLOCK_GROUP_RAID10))
3005 factor = 2;
3006 else
3007 factor = 1;
3008
3009 found = __find_space_info(info, flags);
3010 if (found) {
3011 spin_lock(&found->lock);
3012 found->total_bytes += total_bytes;
3013 found->disk_total += total_bytes * factor;
3014 found->bytes_used += bytes_used;
3015 found->disk_used += bytes_used * factor;
3016 found->full = 0;
3017 spin_unlock(&found->lock);
3018 *space_info = found;
3019 return 0;
3020 }
3021 found = kzalloc(sizeof(*found), GFP_NOFS);
3022 if (!found)
3023 return -ENOMEM;
3024
3025 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
3026 INIT_LIST_HEAD(&found->block_groups[i]);
3027 init_rwsem(&found->groups_sem);
3028 spin_lock_init(&found->lock);
3029 found->flags = flags & (BTRFS_BLOCK_GROUP_DATA |
3030 BTRFS_BLOCK_GROUP_SYSTEM |
3031 BTRFS_BLOCK_GROUP_METADATA);
3032 found->total_bytes = total_bytes;
3033 found->disk_total = total_bytes * factor;
3034 found->bytes_used = bytes_used;
3035 found->disk_used = bytes_used * factor;
3036 found->bytes_pinned = 0;
3037 found->bytes_reserved = 0;
3038 found->bytes_readonly = 0;
3039 found->bytes_may_use = 0;
3040 found->full = 0;
3041 found->force_alloc = CHUNK_ALLOC_NO_FORCE;
3042 found->chunk_alloc = 0;
3043 *space_info = found;
3044 list_add_rcu(&found->list, &info->space_info);
3045 atomic_set(&found->caching_threads, 0);
3046 return 0;
3047 }
3048
3049 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
3050 {
3051 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
3052 BTRFS_BLOCK_GROUP_RAID1 |
3053 BTRFS_BLOCK_GROUP_RAID10 |
3054 BTRFS_BLOCK_GROUP_DUP);
3055 if (extra_flags) {
3056 if (flags & BTRFS_BLOCK_GROUP_DATA)
3057 fs_info->avail_data_alloc_bits |= extra_flags;
3058 if (flags & BTRFS_BLOCK_GROUP_METADATA)
3059 fs_info->avail_metadata_alloc_bits |= extra_flags;
3060 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
3061 fs_info->avail_system_alloc_bits |= extra_flags;
3062 }
3063 }
3064
3065 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
3066 {
3067 /*
3068 * we add in the count of missing devices because we want
3069 * to make sure that any RAID levels on a degraded FS
3070 * continue to be honored.
3071 */
3072 u64 num_devices = root->fs_info->fs_devices->rw_devices +
3073 root->fs_info->fs_devices->missing_devices;
3074
3075 if (num_devices == 1)
3076 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
3077 if (num_devices < 4)
3078 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
3079
3080 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
3081 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
3082 BTRFS_BLOCK_GROUP_RAID10))) {
3083 flags &= ~BTRFS_BLOCK_GROUP_DUP;
3084 }
3085
3086 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
3087 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
3088 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
3089 }
3090
3091 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
3092 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
3093 (flags & BTRFS_BLOCK_GROUP_RAID10) |
3094 (flags & BTRFS_BLOCK_GROUP_DUP)))
3095 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
3096 return flags;
3097 }
3098
3099 static u64 get_alloc_profile(struct btrfs_root *root, u64 flags)
3100 {
3101 if (flags & BTRFS_BLOCK_GROUP_DATA)
3102 flags |= root->fs_info->avail_data_alloc_bits &
3103 root->fs_info->data_alloc_profile;
3104 else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
3105 flags |= root->fs_info->avail_system_alloc_bits &
3106 root->fs_info->system_alloc_profile;
3107 else if (flags & BTRFS_BLOCK_GROUP_METADATA)
3108 flags |= root->fs_info->avail_metadata_alloc_bits &
3109 root->fs_info->metadata_alloc_profile;
3110 return btrfs_reduce_alloc_profile(root, flags);
3111 }
3112
3113 u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
3114 {
3115 u64 flags;
3116
3117 if (data)
3118 flags = BTRFS_BLOCK_GROUP_DATA;
3119 else if (root == root->fs_info->chunk_root)
3120 flags = BTRFS_BLOCK_GROUP_SYSTEM;
3121 else
3122 flags = BTRFS_BLOCK_GROUP_METADATA;
3123
3124 return get_alloc_profile(root, flags);
3125 }
3126
3127 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
3128 {
3129 BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
3130 BTRFS_BLOCK_GROUP_DATA);
3131 }
3132
3133 /*
3134 * This will check the space that the inode allocates from to make sure we have
3135 * enough space for bytes.
3136 */
3137 int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
3138 {
3139 struct btrfs_space_info *data_sinfo;
3140 struct btrfs_root *root = BTRFS_I(inode)->root;
3141 u64 used;
3142 int ret = 0, committed = 0, alloc_chunk = 1;
3143
3144 /* make sure bytes are sectorsize aligned */
3145 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
3146
3147 if (root == root->fs_info->tree_root) {
3148 alloc_chunk = 0;
3149 committed = 1;
3150 }
3151
3152 data_sinfo = BTRFS_I(inode)->space_info;
3153 if (!data_sinfo)
3154 goto alloc;
3155
3156 again:
3157 /* make sure we have enough space to handle the data first */
3158 spin_lock(&data_sinfo->lock);
3159 used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
3160 data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
3161 data_sinfo->bytes_may_use;
3162
3163 if (used + bytes > data_sinfo->total_bytes) {
3164 struct btrfs_trans_handle *trans;
3165
3166 /*
3167 * if we don't have enough free bytes in this space then we need
3168 * to alloc a new chunk.
3169 */
3170 if (!data_sinfo->full && alloc_chunk) {
3171 u64 alloc_target;
3172
3173 data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
3174 spin_unlock(&data_sinfo->lock);
3175 alloc:
3176 alloc_target = btrfs_get_alloc_profile(root, 1);
3177 trans = btrfs_join_transaction(root, 1);
3178 if (IS_ERR(trans))
3179 return PTR_ERR(trans);
3180
3181 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3182 bytes + 2 * 1024 * 1024,
3183 alloc_target,
3184 CHUNK_ALLOC_NO_FORCE);
3185 btrfs_end_transaction(trans, root);
3186 if (ret < 0) {
3187 if (ret != -ENOSPC)
3188 return ret;
3189 else
3190 goto commit_trans;
3191 }
3192
3193 if (!data_sinfo) {
3194 btrfs_set_inode_space_info(root, inode);
3195 data_sinfo = BTRFS_I(inode)->space_info;
3196 }
3197 goto again;
3198 }
3199 spin_unlock(&data_sinfo->lock);
3200
3201 /* commit the current transaction and try again */
3202 commit_trans:
3203 if (!committed && !root->fs_info->open_ioctl_trans) {
3204 committed = 1;
3205 trans = btrfs_join_transaction(root, 1);
3206 if (IS_ERR(trans))
3207 return PTR_ERR(trans);
3208 ret = btrfs_commit_transaction(trans, root);
3209 if (ret)
3210 return ret;
3211 goto again;
3212 }
3213
3214 #if 0 /* I hope we never need this code again, just in case */
3215 printk(KERN_ERR "no space left, need %llu, %llu bytes_used, "
3216 "%llu bytes_reserved, " "%llu bytes_pinned, "
3217 "%llu bytes_readonly, %llu may use %llu total\n",
3218 (unsigned long long)bytes,
3219 (unsigned long long)data_sinfo->bytes_used,
3220 (unsigned long long)data_sinfo->bytes_reserved,
3221 (unsigned long long)data_sinfo->bytes_pinned,
3222 (unsigned long long)data_sinfo->bytes_readonly,
3223 (unsigned long long)data_sinfo->bytes_may_use,
3224 (unsigned long long)data_sinfo->total_bytes);
3225 #endif
3226 return -ENOSPC;
3227 }
3228 data_sinfo->bytes_may_use += bytes;
3229 BTRFS_I(inode)->reserved_bytes += bytes;
3230 spin_unlock(&data_sinfo->lock);
3231
3232 return 0;
3233 }
3234
3235 /*
3236 * called when we are clearing an delalloc extent from the
3237 * inode's io_tree or there was an error for whatever reason
3238 * after calling btrfs_check_data_free_space
3239 */
3240 void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
3241 {
3242 struct btrfs_root *root = BTRFS_I(inode)->root;
3243 struct btrfs_space_info *data_sinfo;
3244
3245 /* make sure bytes are sectorsize aligned */
3246 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
3247
3248 data_sinfo = BTRFS_I(inode)->space_info;
3249 spin_lock(&data_sinfo->lock);
3250 data_sinfo->bytes_may_use -= bytes;
3251 BTRFS_I(inode)->reserved_bytes -= bytes;
3252 spin_unlock(&data_sinfo->lock);
3253 }
3254
3255 static void force_metadata_allocation(struct btrfs_fs_info *info)
3256 {
3257 struct list_head *head = &info->space_info;
3258 struct btrfs_space_info *found;
3259
3260 rcu_read_lock();
3261 list_for_each_entry_rcu(found, head, list) {
3262 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
3263 found->force_alloc = CHUNK_ALLOC_FORCE;
3264 }
3265 rcu_read_unlock();
3266 }
3267
3268 static int should_alloc_chunk(struct btrfs_root *root,
3269 struct btrfs_space_info *sinfo, u64 alloc_bytes,
3270 int force)
3271 {
3272 u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
3273 u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
3274 u64 thresh;
3275
3276 if (force == CHUNK_ALLOC_FORCE)
3277 return 1;
3278
3279 /*
3280 * in limited mode, we want to have some free space up to
3281 * about 1% of the FS size.
3282 */
3283 if (force == CHUNK_ALLOC_LIMITED) {
3284 thresh = btrfs_super_total_bytes(&root->fs_info->super_copy);
3285 thresh = max_t(u64, 64 * 1024 * 1024,
3286 div_factor_fine(thresh, 1));
3287
3288 if (num_bytes - num_allocated < thresh)
3289 return 1;
3290 }
3291
3292 /*
3293 * we have two similar checks here, one based on percentage
3294 * and once based on a hard number of 256MB. The idea
3295 * is that if we have a good amount of free
3296 * room, don't allocate a chunk. A good mount is
3297 * less than 80% utilized of the chunks we have allocated,
3298 * or more than 256MB free
3299 */
3300 if (num_allocated + alloc_bytes + 256 * 1024 * 1024 < num_bytes)
3301 return 0;
3302
3303 if (num_allocated + alloc_bytes < div_factor(num_bytes, 8))
3304 return 0;
3305
3306 thresh = btrfs_super_total_bytes(&root->fs_info->super_copy);
3307
3308 /* 256MB or 5% of the FS */
3309 thresh = max_t(u64, 256 * 1024 * 1024, div_factor_fine(thresh, 5));
3310
3311 if (num_bytes > thresh && sinfo->bytes_used < div_factor(num_bytes, 3))
3312 return 0;
3313 return 1;
3314 }
3315
3316 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
3317 struct btrfs_root *extent_root, u64 alloc_bytes,
3318 u64 flags, int force)
3319 {
3320 struct btrfs_space_info *space_info;
3321 struct btrfs_fs_info *fs_info = extent_root->fs_info;
3322 int wait_for_alloc = 0;
3323 int ret = 0;
3324
3325 flags = btrfs_reduce_alloc_profile(extent_root, flags);
3326
3327 space_info = __find_space_info(extent_root->fs_info, flags);
3328 if (!space_info) {
3329 ret = update_space_info(extent_root->fs_info, flags,
3330 0, 0, &space_info);
3331 BUG_ON(ret);
3332 }
3333 BUG_ON(!space_info);
3334
3335 again:
3336 spin_lock(&space_info->lock);
3337 if (space_info->force_alloc)
3338 force = space_info->force_alloc;
3339 if (space_info->full) {
3340 spin_unlock(&space_info->lock);
3341 return 0;
3342 }
3343
3344 if (!should_alloc_chunk(extent_root, space_info, alloc_bytes, force)) {
3345 spin_unlock(&space_info->lock);
3346 return 0;
3347 } else if (space_info->chunk_alloc) {
3348 wait_for_alloc = 1;
3349 } else {
3350 space_info->chunk_alloc = 1;
3351 }
3352
3353 spin_unlock(&space_info->lock);
3354
3355 mutex_lock(&fs_info->chunk_mutex);
3356
3357 /*
3358 * The chunk_mutex is held throughout the entirety of a chunk
3359 * allocation, so once we've acquired the chunk_mutex we know that the
3360 * other guy is done and we need to recheck and see if we should
3361 * allocate.
3362 */
3363 if (wait_for_alloc) {
3364 mutex_unlock(&fs_info->chunk_mutex);
3365 wait_for_alloc = 0;
3366 goto again;
3367 }
3368
3369 /*
3370 * If we have mixed data/metadata chunks we want to make sure we keep
3371 * allocating mixed chunks instead of individual chunks.
3372 */
3373 if (btrfs_mixed_space_info(space_info))
3374 flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
3375
3376 /*
3377 * if we're doing a data chunk, go ahead and make sure that
3378 * we keep a reasonable number of metadata chunks allocated in the
3379 * FS as well.
3380 */
3381 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
3382 fs_info->data_chunk_allocations++;
3383 if (!(fs_info->data_chunk_allocations %
3384 fs_info->metadata_ratio))
3385 force_metadata_allocation(fs_info);
3386 }
3387
3388 ret = btrfs_alloc_chunk(trans, extent_root, flags);
3389 spin_lock(&space_info->lock);
3390 if (ret)
3391 space_info->full = 1;
3392 else
3393 ret = 1;
3394
3395 space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
3396 space_info->chunk_alloc = 0;
3397 spin_unlock(&space_info->lock);
3398 mutex_unlock(&extent_root->fs_info->chunk_mutex);
3399 return ret;
3400 }
3401
3402 /*
3403 * shrink metadata reservation for delalloc
3404 */
3405 static int shrink_delalloc(struct btrfs_trans_handle *trans,
3406 struct btrfs_root *root, u64 to_reclaim, int sync)
3407 {
3408 struct btrfs_block_rsv *block_rsv;
3409 struct btrfs_space_info *space_info;
3410 u64 reserved;
3411 u64 max_reclaim;
3412 u64 reclaimed = 0;
3413 long time_left;
3414 int nr_pages = (2 * 1024 * 1024) >> PAGE_CACHE_SHIFT;
3415 int loops = 0;
3416 unsigned long progress;
3417
3418 block_rsv = &root->fs_info->delalloc_block_rsv;
3419 space_info = block_rsv->space_info;
3420
3421 smp_mb();
3422 reserved = space_info->bytes_reserved;
3423 progress = space_info->reservation_progress;
3424
3425 if (reserved == 0)
3426 return 0;
3427
3428 max_reclaim = min(reserved, to_reclaim);
3429
3430 while (loops < 1024) {
3431 /* have the flusher threads jump in and do some IO */
3432 smp_mb();
3433 nr_pages = min_t(unsigned long, nr_pages,
3434 root->fs_info->delalloc_bytes >> PAGE_CACHE_SHIFT);
3435 writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages);
3436
3437 spin_lock(&space_info->lock);
3438 if (reserved > space_info->bytes_reserved)
3439 reclaimed += reserved - space_info->bytes_reserved;
3440 reserved = space_info->bytes_reserved;
3441 spin_unlock(&space_info->lock);
3442
3443 loops++;
3444
3445 if (reserved == 0 || reclaimed >= max_reclaim)
3446 break;
3447
3448 if (trans && trans->transaction->blocked)
3449 return -EAGAIN;
3450
3451 time_left = schedule_timeout_interruptible(1);
3452
3453 /* We were interrupted, exit */
3454 if (time_left)
3455 break;
3456
3457 /* we've kicked the IO a few times, if anything has been freed,
3458 * exit. There is no sense in looping here for a long time
3459 * when we really need to commit the transaction, or there are
3460 * just too many writers without enough free space
3461 */
3462
3463 if (loops > 3) {
3464 smp_mb();
3465 if (progress != space_info->reservation_progress)
3466 break;
3467 }
3468
3469 }
3470 return reclaimed >= to_reclaim;
3471 }
3472
3473 /*
3474 * Retries tells us how many times we've called reserve_metadata_bytes. The
3475 * idea is if this is the first call (retries == 0) then we will add to our
3476 * reserved count if we can't make the allocation in order to hold our place
3477 * while we go and try and free up space. That way for retries > 1 we don't try
3478 * and add space, we just check to see if the amount of unused space is >= the
3479 * total space, meaning that our reservation is valid.
3480 *
3481 * However if we don't intend to retry this reservation, pass -1 as retries so
3482 * that it short circuits this logic.
3483 */
3484 static int reserve_metadata_bytes(struct btrfs_trans_handle *trans,
3485 struct btrfs_root *root,
3486 struct btrfs_block_rsv *block_rsv,
3487 u64 orig_bytes, int flush)
3488 {
3489 struct btrfs_space_info *space_info = block_rsv->space_info;
3490 u64 unused;
3491 u64 num_bytes = orig_bytes;
3492 int retries = 0;
3493 int ret = 0;
3494 bool reserved = false;
3495 bool committed = false;
3496
3497 again:
3498 ret = -ENOSPC;
3499 if (reserved)
3500 num_bytes = 0;
3501
3502 spin_lock(&space_info->lock);
3503 unused = space_info->bytes_used + space_info->bytes_reserved +
3504 space_info->bytes_pinned + space_info->bytes_readonly +
3505 space_info->bytes_may_use;
3506
3507 /*
3508 * The idea here is that we've not already over-reserved the block group
3509 * then we can go ahead and save our reservation first and then start
3510 * flushing if we need to. Otherwise if we've already overcommitted
3511 * lets start flushing stuff first and then come back and try to make
3512 * our reservation.
3513 */
3514 if (unused <= space_info->total_bytes) {
3515 unused = space_info->total_bytes - unused;
3516 if (unused >= num_bytes) {
3517 if (!reserved)
3518 space_info->bytes_reserved += orig_bytes;
3519 ret = 0;
3520 } else {
3521 /*
3522 * Ok set num_bytes to orig_bytes since we aren't
3523 * overocmmitted, this way we only try and reclaim what
3524 * we need.
3525 */
3526 num_bytes = orig_bytes;
3527 }
3528 } else {
3529 /*
3530 * Ok we're over committed, set num_bytes to the overcommitted
3531 * amount plus the amount of bytes that we need for this
3532 * reservation.
3533 */
3534 num_bytes = unused - space_info->total_bytes +
3535 (orig_bytes * (retries + 1));
3536 }
3537
3538 /*
3539 * Couldn't make our reservation, save our place so while we're trying
3540 * to reclaim space we can actually use it instead of somebody else
3541 * stealing it from us.
3542 */
3543 if (ret && !reserved) {
3544 space_info->bytes_reserved += orig_bytes;
3545 reserved = true;
3546 }
3547
3548 spin_unlock(&space_info->lock);
3549
3550 if (!ret)
3551 return 0;
3552
3553 if (!flush)
3554 goto out;
3555
3556 /*
3557 * We do synchronous shrinking since we don't actually unreserve
3558 * metadata until after the IO is completed.
3559 */
3560 ret = shrink_delalloc(trans, root, num_bytes, 1);
3561 if (ret > 0)
3562 return 0;
3563 else if (ret < 0)
3564 goto out;
3565
3566 /*
3567 * So if we were overcommitted it's possible that somebody else flushed
3568 * out enough space and we simply didn't have enough space to reclaim,
3569 * so go back around and try again.
3570 */
3571 if (retries < 2) {
3572 retries++;
3573 goto again;
3574 }
3575
3576 spin_lock(&space_info->lock);
3577 /*
3578 * Not enough space to be reclaimed, don't bother committing the
3579 * transaction.
3580 */
3581 if (space_info->bytes_pinned < orig_bytes)
3582 ret = -ENOSPC;
3583 spin_unlock(&space_info->lock);
3584 if (ret)
3585 goto out;
3586
3587 ret = -EAGAIN;
3588 if (trans || committed)
3589 goto out;
3590
3591 ret = -ENOSPC;
3592 trans = btrfs_join_transaction(root, 1);
3593 if (IS_ERR(trans))
3594 goto out;
3595 ret = btrfs_commit_transaction(trans, root);
3596 if (!ret) {
3597 trans = NULL;
3598 committed = true;
3599 goto again;
3600 }
3601
3602 out:
3603 if (reserved) {
3604 spin_lock(&space_info->lock);
3605 space_info->bytes_reserved -= orig_bytes;
3606 spin_unlock(&space_info->lock);
3607 }
3608
3609 return ret;
3610 }
3611
3612 static struct btrfs_block_rsv *get_block_rsv(struct btrfs_trans_handle *trans,
3613 struct btrfs_root *root)
3614 {
3615 struct btrfs_block_rsv *block_rsv;
3616 if (root->ref_cows)
3617 block_rsv = trans->block_rsv;
3618 else
3619 block_rsv = root->block_rsv;
3620
3621 if (!block_rsv)
3622 block_rsv = &root->fs_info->empty_block_rsv;
3623
3624 return block_rsv;
3625 }
3626
3627 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
3628 u64 num_bytes)
3629 {
3630 int ret = -ENOSPC;
3631 spin_lock(&block_rsv->lock);
3632 if (block_rsv->reserved >= num_bytes) {
3633 block_rsv->reserved -= num_bytes;
3634 if (block_rsv->reserved < block_rsv->size)
3635 block_rsv->full = 0;
3636 ret = 0;
3637 }
3638 spin_unlock(&block_rsv->lock);
3639 return ret;
3640 }
3641
3642 static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
3643 u64 num_bytes, int update_size)
3644 {
3645 spin_lock(&block_rsv->lock);
3646 block_rsv->reserved += num_bytes;
3647 if (update_size)
3648 block_rsv->size += num_bytes;
3649 else if (block_rsv->reserved >= block_rsv->size)
3650 block_rsv->full = 1;
3651 spin_unlock(&block_rsv->lock);
3652 }
3653
3654 void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv,
3655 struct btrfs_block_rsv *dest, u64 num_bytes)
3656 {
3657 struct btrfs_space_info *space_info = block_rsv->space_info;
3658
3659 spin_lock(&block_rsv->lock);
3660 if (num_bytes == (u64)-1)
3661 num_bytes = block_rsv->size;
3662 block_rsv->size -= num_bytes;
3663 if (block_rsv->reserved >= block_rsv->size) {
3664 num_bytes = block_rsv->reserved - block_rsv->size;
3665 block_rsv->reserved = block_rsv->size;
3666 block_rsv->full = 1;
3667 } else {
3668 num_bytes = 0;
3669 }
3670 spin_unlock(&block_rsv->lock);
3671
3672 if (num_bytes > 0) {
3673 if (dest) {
3674 spin_lock(&dest->lock);
3675 if (!dest->full) {
3676 u64 bytes_to_add;
3677
3678 bytes_to_add = dest->size - dest->reserved;
3679 bytes_to_add = min(num_bytes, bytes_to_add);
3680 dest->reserved += bytes_to_add;
3681 if (dest->reserved >= dest->size)
3682 dest->full = 1;
3683 num_bytes -= bytes_to_add;
3684 }
3685 spin_unlock(&dest->lock);
3686 }
3687 if (num_bytes) {
3688 spin_lock(&space_info->lock);
3689 space_info->bytes_reserved -= num_bytes;
3690 space_info->reservation_progress++;
3691 spin_unlock(&space_info->lock);
3692 }
3693 }
3694 }
3695
3696 static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
3697 struct btrfs_block_rsv *dst, u64 num_bytes)
3698 {
3699 int ret;
3700
3701 ret = block_rsv_use_bytes(src, num_bytes);
3702 if (ret)
3703 return ret;
3704
3705 block_rsv_add_bytes(dst, num_bytes, 1);
3706 return 0;
3707 }
3708
3709 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv)
3710 {
3711 memset(rsv, 0, sizeof(*rsv));
3712 spin_lock_init(&rsv->lock);
3713 atomic_set(&rsv->usage, 1);
3714 rsv->priority = 6;
3715 INIT_LIST_HEAD(&rsv->list);
3716 }
3717
3718 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
3719 {
3720 struct btrfs_block_rsv *block_rsv;
3721 struct btrfs_fs_info *fs_info = root->fs_info;
3722
3723 block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
3724 if (!block_rsv)
3725 return NULL;
3726
3727 btrfs_init_block_rsv(block_rsv);
3728 block_rsv->space_info = __find_space_info(fs_info,
3729 BTRFS_BLOCK_GROUP_METADATA);
3730 return block_rsv;
3731 }
3732
3733 void btrfs_free_block_rsv(struct btrfs_root *root,
3734 struct btrfs_block_rsv *rsv)
3735 {
3736 if (rsv && atomic_dec_and_test(&rsv->usage)) {
3737 btrfs_block_rsv_release(root, rsv, (u64)-1);
3738 if (!rsv->durable)
3739 kfree(rsv);
3740 }
3741 }
3742
3743 /*
3744 * make the block_rsv struct be able to capture freed space.
3745 * the captured space will re-add to the the block_rsv struct
3746 * after transaction commit
3747 */
3748 void btrfs_add_durable_block_rsv(struct btrfs_fs_info *fs_info,
3749 struct btrfs_block_rsv *block_rsv)
3750 {
3751 block_rsv->durable = 1;
3752 mutex_lock(&fs_info->durable_block_rsv_mutex);
3753 list_add_tail(&block_rsv->list, &fs_info->durable_block_rsv_list);
3754 mutex_unlock(&fs_info->durable_block_rsv_mutex);
3755 }
3756
3757 int btrfs_block_rsv_add(struct btrfs_trans_handle *trans,
3758 struct btrfs_root *root,
3759 struct btrfs_block_rsv *block_rsv,
3760 u64 num_bytes)
3761 {
3762 int ret;
3763
3764 if (num_bytes == 0)
3765 return 0;
3766
3767 ret = reserve_metadata_bytes(trans, root, block_rsv, num_bytes, 1);
3768 if (!ret) {
3769 block_rsv_add_bytes(block_rsv, num_bytes, 1);
3770 return 0;
3771 }
3772
3773 return ret;
3774 }
3775
3776 int btrfs_block_rsv_check(struct btrfs_trans_handle *trans,
3777 struct btrfs_root *root,
3778 struct btrfs_block_rsv *block_rsv,
3779 u64 min_reserved, int min_factor)
3780 {
3781 u64 num_bytes = 0;
3782 int commit_trans = 0;
3783 int ret = -ENOSPC;
3784
3785 if (!block_rsv)
3786 return 0;
3787
3788 spin_lock(&block_rsv->lock);
3789 if (min_factor > 0)
3790 num_bytes = div_factor(block_rsv->size, min_factor);
3791 if (min_reserved > num_bytes)
3792 num_bytes = min_reserved;
3793
3794 if (block_rsv->reserved >= num_bytes) {
3795 ret = 0;
3796 } else {
3797 num_bytes -= block_rsv->reserved;
3798 if (block_rsv->durable &&
3799 block_rsv->freed[0] + block_rsv->freed[1] >= num_bytes)
3800 commit_trans = 1;
3801 }
3802 spin_unlock(&block_rsv->lock);
3803 if (!ret)
3804 return 0;
3805
3806 if (block_rsv->refill_used) {
3807 ret = reserve_metadata_bytes(trans, root, block_rsv,
3808 num_bytes, 0);
3809 if (!ret) {
3810 block_rsv_add_bytes(block_rsv, num_bytes, 0);
3811 return 0;
3812 }
3813 }
3814
3815 if (commit_trans) {
3816 if (trans)
3817 return -EAGAIN;
3818
3819 trans = btrfs_join_transaction(root, 1);
3820 BUG_ON(IS_ERR(trans));
3821 ret = btrfs_commit_transaction(trans, root);
3822 return 0;
3823 }
3824
3825 return -ENOSPC;
3826 }
3827
3828 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
3829 struct btrfs_block_rsv *dst_rsv,
3830 u64 num_bytes)
3831 {
3832 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
3833 }
3834
3835 void btrfs_block_rsv_release(struct btrfs_root *root,
3836 struct btrfs_block_rsv *block_rsv,
3837 u64 num_bytes)
3838 {
3839 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
3840 if (global_rsv->full || global_rsv == block_rsv ||
3841 block_rsv->space_info != global_rsv->space_info)
3842 global_rsv = NULL;
3843 block_rsv_release_bytes(block_rsv, global_rsv, num_bytes);
3844 }
3845
3846 /*
3847 * helper to calculate size of global block reservation.
3848 * the desired value is sum of space used by extent tree,
3849 * checksum tree and root tree
3850 */
3851 static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
3852 {
3853 struct btrfs_space_info *sinfo;
3854 u64 num_bytes;
3855 u64 meta_used;
3856 u64 data_used;
3857 int csum_size = btrfs_super_csum_size(&fs_info->super_copy);
3858 #if 0
3859 /*
3860 * per tree used space accounting can be inaccuracy, so we
3861 * can't rely on it.
3862 */
3863 spin_lock(&fs_info->extent_root->accounting_lock);
3864 num_bytes = btrfs_root_used(&fs_info->extent_root->root_item);
3865 spin_unlock(&fs_info->extent_root->accounting_lock);
3866
3867 spin_lock(&fs_info->csum_root->accounting_lock);
3868 num_bytes += btrfs_root_used(&fs_info->csum_root->root_item);
3869 spin_unlock(&fs_info->csum_root->accounting_lock);
3870
3871 spin_lock(&fs_info->tree_root->accounting_lock);
3872 num_bytes += btrfs_root_used(&fs_info->tree_root->root_item);
3873 spin_unlock(&fs_info->tree_root->accounting_lock);
3874 #endif
3875 sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
3876 spin_lock(&sinfo->lock);
3877 data_used = sinfo->bytes_used;
3878 spin_unlock(&sinfo->lock);
3879
3880 sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
3881 spin_lock(&sinfo->lock);
3882 if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
3883 data_used = 0;
3884 meta_used = sinfo->bytes_used;
3885 spin_unlock(&sinfo->lock);
3886
3887 num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
3888 csum_size * 2;
3889 num_bytes += div64_u64(data_used + meta_used, 50);
3890
3891 if (num_bytes * 3 > meta_used)
3892 num_bytes = div64_u64(meta_used, 3);
3893
3894 return ALIGN(num_bytes, fs_info->extent_root->leafsize << 10);
3895 }
3896
3897 static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
3898 {
3899 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
3900 struct btrfs_space_info *sinfo = block_rsv->space_info;
3901 u64 num_bytes;
3902
3903 num_bytes = calc_global_metadata_size(fs_info);
3904
3905 spin_lock(&block_rsv->lock);
3906 spin_lock(&sinfo->lock);
3907
3908 block_rsv->size = num_bytes;
3909
3910 num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
3911 sinfo->bytes_reserved + sinfo->bytes_readonly +
3912 sinfo->bytes_may_use;
3913
3914 if (sinfo->total_bytes > num_bytes) {
3915 num_bytes = sinfo->total_bytes - num_bytes;
3916 block_rsv->reserved += num_bytes;
3917 sinfo->bytes_reserved += num_bytes;
3918 }
3919
3920 if (block_rsv->reserved >= block_rsv->size) {
3921 num_bytes = block_rsv->reserved - block_rsv->size;
3922 sinfo->bytes_reserved -= num_bytes;
3923 sinfo->reservation_progress++;
3924 block_rsv->reserved = block_rsv->size;
3925 block_rsv->full = 1;
3926 }
3927 #if 0
3928 printk(KERN_INFO"global block rsv size %llu reserved %llu\n",
3929 block_rsv->size, block_rsv->reserved);
3930 #endif
3931 spin_unlock(&sinfo->lock);
3932 spin_unlock(&block_rsv->lock);
3933 }
3934
3935 static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
3936 {
3937 struct btrfs_space_info *space_info;
3938
3939 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
3940 fs_info->chunk_block_rsv.space_info = space_info;
3941 fs_info->chunk_block_rsv.priority = 10;
3942
3943 space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
3944 fs_info->global_block_rsv.space_info = space_info;
3945 fs_info->global_block_rsv.priority = 10;
3946 fs_info->global_block_rsv.refill_used = 1;
3947 fs_info->delalloc_block_rsv.space_info = space_info;
3948 fs_info->trans_block_rsv.space_info = space_info;
3949 fs_info->empty_block_rsv.space_info = space_info;
3950 fs_info->empty_block_rsv.priority = 10;
3951
3952 fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
3953 fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
3954 fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
3955 fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
3956 fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
3957
3958 btrfs_add_durable_block_rsv(fs_info, &fs_info->global_block_rsv);
3959
3960 btrfs_add_durable_block_rsv(fs_info, &fs_info->delalloc_block_rsv);
3961
3962 update_global_block_rsv(fs_info);
3963 }
3964
3965 static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
3966 {
3967 block_rsv_release_bytes(&fs_info->global_block_rsv, NULL, (u64)-1);
3968 WARN_ON(fs_info->delalloc_block_rsv.size > 0);
3969 WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
3970 WARN_ON(fs_info->trans_block_rsv.size > 0);
3971 WARN_ON(fs_info->trans_block_rsv.reserved > 0);
3972 WARN_ON(fs_info->chunk_block_rsv.size > 0);
3973 WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
3974 }
3975
3976 static u64 calc_trans_metadata_size(struct btrfs_root *root, int num_items)
3977 {
3978 return (root->leafsize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
3979 3 * num_items;
3980 }
3981
3982 int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
3983 struct btrfs_root *root,
3984 int num_items)
3985 {
3986 u64 num_bytes;
3987 int ret;
3988
3989 if (num_items == 0 || root->fs_info->chunk_root == root)
3990 return 0;
3991
3992 num_bytes = calc_trans_metadata_size(root, num_items);
3993 ret = btrfs_block_rsv_add(trans, root, &root->fs_info->trans_block_rsv,
3994 num_bytes);
3995 if (!ret) {
3996 trans->bytes_reserved += num_bytes;
3997 trans->block_rsv = &root->fs_info->trans_block_rsv;
3998 }
3999 return ret;
4000 }
4001
4002 void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
4003 struct btrfs_root *root)
4004 {
4005 if (!trans->bytes_reserved)
4006 return;
4007
4008 BUG_ON(trans->block_rsv != &root->fs_info->trans_block_rsv);
4009 btrfs_block_rsv_release(root, trans->block_rsv,
4010 trans->bytes_reserved);
4011 trans->bytes_reserved = 0;
4012 }
4013
4014 int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
4015 struct inode *inode)
4016 {
4017 struct btrfs_root *root = BTRFS_I(inode)->root;
4018 struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
4019 struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
4020
4021 /*
4022 * one for deleting orphan item, one for updating inode and
4023 * two for calling btrfs_truncate_inode_items.
4024 *
4025 * btrfs_truncate_inode_items is a delete operation, it frees
4026 * more space than it uses in most cases. So two units of
4027 * metadata space should be enough for calling it many times.
4028 * If all of the metadata space is used, we can commit
4029 * transaction and use space it freed.
4030 */
4031 u64 num_bytes = calc_trans_metadata_size(root, 4);
4032 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
4033 }
4034
4035 void btrfs_orphan_release_metadata(struct inode *inode)
4036 {
4037 struct btrfs_root *root = BTRFS_I(inode)->root;
4038 u64 num_bytes = calc_trans_metadata_size(root, 4);
4039 btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
4040 }
4041
4042 int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
4043 struct btrfs_pending_snapshot *pending)
4044 {
4045 struct btrfs_root *root = pending->root;
4046 struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
4047 struct btrfs_block_rsv *dst_rsv = &pending->block_rsv;
4048 /*
4049 * two for root back/forward refs, two for directory entries
4050 * and one for root of the snapshot.
4051 */
4052 u64 num_bytes = calc_trans_metadata_size(root, 5);
4053 dst_rsv->space_info = src_rsv->space_info;
4054 return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
4055 }
4056
4057 static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes)
4058 {
4059 return num_bytes >>= 3;
4060 }
4061
4062 int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
4063 {
4064 struct btrfs_root *root = BTRFS_I(inode)->root;
4065 struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
4066 u64 to_reserve;
4067 int nr_extents;
4068 int reserved_extents;
4069 int ret;
4070
4071 if (btrfs_transaction_in_commit(root->fs_info))
4072 schedule_timeout(1);
4073
4074 num_bytes = ALIGN(num_bytes, root->sectorsize);
4075
4076 nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents) + 1;
4077 reserved_extents = atomic_read(&BTRFS_I(inode)->reserved_extents);
4078
4079 if (nr_extents > reserved_extents) {
4080 nr_extents -= reserved_extents;
4081 to_reserve = calc_trans_metadata_size(root, nr_extents);
4082 } else {
4083 nr_extents = 0;
4084 to_reserve = 0;
4085 }
4086
4087 to_reserve += calc_csum_metadata_size(inode, num_bytes);
4088 ret = reserve_metadata_bytes(NULL, root, block_rsv, to_reserve, 1);
4089 if (ret)
4090 return ret;
4091
4092 atomic_add(nr_extents, &BTRFS_I(inode)->reserved_extents);
4093 atomic_inc(&BTRFS_I(inode)->outstanding_extents);
4094
4095 block_rsv_add_bytes(block_rsv, to_reserve, 1);
4096
4097 if (block_rsv->size > 512 * 1024 * 1024)
4098 shrink_delalloc(NULL, root, to_reserve, 0);
4099
4100 return 0;
4101 }
4102
4103 void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
4104 {
4105 struct btrfs_root *root = BTRFS_I(inode)->root;
4106 u64 to_free;
4107 int nr_extents;
4108 int reserved_extents;
4109
4110 num_bytes = ALIGN(num_bytes, root->sectorsize);
4111 atomic_dec(&BTRFS_I(inode)->outstanding_extents);
4112 WARN_ON(atomic_read(&BTRFS_I(inode)->outstanding_extents) < 0);
4113
4114 reserved_extents = atomic_read(&BTRFS_I(inode)->reserved_extents);
4115 do {
4116 int old, new;
4117
4118 nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents);
4119 if (nr_extents >= reserved_extents) {
4120 nr_extents = 0;
4121 break;
4122 }
4123 old = reserved_extents;
4124 nr_extents = reserved_extents - nr_extents;
4125 new = reserved_extents - nr_extents;
4126 old = atomic_cmpxchg(&BTRFS_I(inode)->reserved_extents,
4127 reserved_extents, new);
4128 if (likely(old == reserved_extents))
4129 break;
4130 reserved_extents = old;
4131 } while (1);
4132
4133 to_free = calc_csum_metadata_size(inode, num_bytes);
4134 if (nr_extents > 0)
4135 to_free += calc_trans_metadata_size(root, nr_extents);
4136
4137 btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
4138 to_free);
4139 }
4140
4141 int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
4142 {
4143 int ret;
4144
4145 ret = btrfs_check_data_free_space(inode, num_bytes);
4146 if (ret)
4147 return ret;
4148
4149 ret = btrfs_delalloc_reserve_metadata(inode, num_bytes);
4150 if (ret) {
4151 btrfs_free_reserved_data_space(inode, num_bytes);
4152 return ret;
4153 }
4154
4155 return 0;
4156 }
4157
4158 void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
4159 {
4160 btrfs_delalloc_release_metadata(inode, num_bytes);
4161 btrfs_free_reserved_data_space(inode, num_bytes);
4162 }
4163
4164 static int update_block_group(struct btrfs_trans_handle *trans,
4165 struct btrfs_root *root,
4166 u64 bytenr, u64 num_bytes, int alloc)
4167 {
4168 struct btrfs_block_group_cache *cache = NULL;
4169 struct btrfs_fs_info *info = root->fs_info;
4170 u64 total = num_bytes;
4171 u64 old_val;
4172 u64 byte_in_group;
4173 int factor;
4174
4175 /* block accounting for super block */
4176 spin_lock(&info->delalloc_lock);
4177 old_val = btrfs_super_bytes_used(&info->super_copy);
4178 if (alloc)
4179 old_val += num_bytes;
4180 else
4181 old_val -= num_bytes;
4182 btrfs_set_super_bytes_used(&info->super_copy, old_val);
4183 spin_unlock(&info->delalloc_lock);
4184
4185 while (total) {
4186 cache = btrfs_lookup_block_group(info, bytenr);
4187 if (!cache)
4188 return -1;
4189 if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
4190 BTRFS_BLOCK_GROUP_RAID1 |
4191 BTRFS_BLOCK_GROUP_RAID10))
4192 factor = 2;
4193 else
4194 factor = 1;
4195 /*
4196 * If this block group has free space cache written out, we
4197 * need to make sure to load it if we are removing space. This
4198 * is because we need the unpinning stage to actually add the
4199 * space back to the block group, otherwise we will leak space.
4200 */
4201 if (!alloc && cache->cached == BTRFS_CACHE_NO)
4202 cache_block_group(cache, trans, NULL, 1);
4203
4204 byte_in_group = bytenr - cache->key.objectid;
4205 WARN_ON(byte_in_group > cache->key.offset);
4206
4207 spin_lock(&cache->space_info->lock);
4208 spin_lock(&cache->lock);
4209
4210 if (btrfs_super_cache_generation(&info->super_copy) != 0 &&
4211 cache->disk_cache_state < BTRFS_DC_CLEAR)
4212 cache->disk_cache_state = BTRFS_DC_CLEAR;
4213
4214 cache->dirty = 1;
4215 old_val = btrfs_block_group_used(&cache->item);
4216 num_bytes = min(total, cache->key.offset - byte_in_group);
4217 if (alloc) {
4218 old_val += num_bytes;
4219 btrfs_set_block_group_used(&cache->item, old_val);
4220 cache->reserved -= num_bytes;
4221 cache->space_info->bytes_reserved -= num_bytes;
4222 cache->space_info->reservation_progress++;
4223 cache->space_info->bytes_used += num_bytes;
4224 cache->space_info->disk_used += num_bytes * factor;
4225 spin_unlock(&cache->lock);
4226 spin_unlock(&cache->space_info->lock);
4227 } else {
4228 old_val -= num_bytes;
4229 btrfs_set_block_group_used(&cache->item, old_val);
4230 cache->pinned += num_bytes;
4231 cache->space_info->bytes_pinned += num_bytes;
4232 cache->space_info->bytes_used -= num_bytes;
4233 cache->space_info->disk_used -= num_bytes * factor;
4234 spin_unlock(&cache->lock);
4235 spin_unlock(&cache->space_info->lock);
4236
4237 set_extent_dirty(info->pinned_extents,
4238 bytenr, bytenr + num_bytes - 1,
4239 GFP_NOFS | __GFP_NOFAIL);
4240 }
4241 btrfs_put_block_group(cache);
4242 total -= num_bytes;
4243 bytenr += num_bytes;
4244 }
4245 return 0;
4246 }
4247
4248 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
4249 {
4250 struct btrfs_block_group_cache *cache;
4251 u64 bytenr;
4252
4253 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
4254 if (!cache)
4255 return 0;
4256
4257 bytenr = cache->key.objectid;
4258 btrfs_put_block_group(cache);
4259
4260 return bytenr;
4261 }
4262
4263 static int pin_down_extent(struct btrfs_root *root,
4264 struct btrfs_block_group_cache *cache,
4265 u64 bytenr, u64 num_bytes, int reserved)
4266 {
4267 spin_lock(&cache->space_info->lock);
4268 spin_lock(&cache->lock);
4269 cache->pinned += num_bytes;
4270 cache->space_info->bytes_pinned += num_bytes;
4271 if (reserved) {
4272 cache->reserved -= num_bytes;
4273 cache->space_info->bytes_reserved -= num_bytes;
4274 cache->space_info->reservation_progress++;
4275 }
4276 spin_unlock(&cache->lock);
4277 spin_unlock(&cache->space_info->lock);
4278
4279 set_extent_dirty(root->fs_info->pinned_extents, bytenr,
4280 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
4281 return 0;
4282 }
4283
4284 /*
4285 * this function must be called within transaction
4286 */
4287 int btrfs_pin_extent(struct btrfs_root *root,
4288 u64 bytenr, u64 num_bytes, int reserved)
4289 {
4290 struct btrfs_block_group_cache *cache;
4291
4292 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
4293 BUG_ON(!cache);
4294
4295 pin_down_extent(root, cache, bytenr, num_bytes, reserved);
4296
4297 btrfs_put_block_group(cache);
4298 return 0;
4299 }
4300
4301 /*
4302 * update size of reserved extents. this function may return -EAGAIN
4303 * if 'reserve' is true or 'sinfo' is false.
4304 */
4305 int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
4306 u64 num_bytes, int reserve, int sinfo)
4307 {
4308 int ret = 0;
4309 if (sinfo) {
4310 struct btrfs_space_info *space_info = cache->space_info;
4311 spin_lock(&space_info->lock);
4312 spin_lock(&cache->lock);
4313 if (reserve) {
4314 if (cache->ro) {
4315 ret = -EAGAIN;
4316 } else {
4317 cache->reserved += num_bytes;
4318 space_info->bytes_reserved += num_bytes;
4319 }
4320 } else {
4321 if (cache->ro)
4322 space_info->bytes_readonly += num_bytes;
4323 cache->reserved -= num_bytes;
4324 space_info->bytes_reserved -= num_bytes;
4325 space_info->reservation_progress++;
4326 }
4327 spin_unlock(&cache->lock);
4328 spin_unlock(&space_info->lock);
4329 } else {
4330 spin_lock(&cache->lock);
4331 if (cache->ro) {
4332 ret = -EAGAIN;
4333 } else {
4334 if (reserve)
4335 cache->reserved += num_bytes;
4336 else
4337 cache->reserved -= num_bytes;
4338 }
4339 spin_unlock(&cache->lock);
4340 }
4341 return ret;
4342 }
4343
4344 int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
4345 struct btrfs_root *root)
4346 {
4347 struct btrfs_fs_info *fs_info = root->fs_info;
4348 struct btrfs_caching_control *next;
4349 struct btrfs_caching_control *caching_ctl;
4350 struct btrfs_block_group_cache *cache;
4351
4352 down_write(&fs_info->extent_commit_sem);
4353
4354 list_for_each_entry_safe(caching_ctl, next,
4355 &fs_info->caching_block_groups, list) {
4356 cache = caching_ctl->block_group;
4357 if (block_group_cache_done(cache)) {
4358 cache->last_byte_to_unpin = (u64)-1;
4359 list_del_init(&caching_ctl->list);
4360 put_caching_control(caching_ctl);
4361 } else {
4362 cache->last_byte_to_unpin = caching_ctl->progress;
4363 }
4364 }
4365
4366 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
4367 fs_info->pinned_extents = &fs_info->freed_extents[1];
4368 else
4369 fs_info->pinned_extents = &fs_info->freed_extents[0];
4370
4371 up_write(&fs_info->extent_commit_sem);
4372
4373 update_global_block_rsv(fs_info);
4374 return 0;
4375 }
4376
4377 static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
4378 {
4379 struct btrfs_fs_info *fs_info = root->fs_info;
4380 struct btrfs_block_group_cache *cache = NULL;
4381 u64 len;
4382
4383 while (start <= end) {
4384 if (!cache ||
4385 start >= cache->key.objectid + cache->key.offset) {
4386 if (cache)
4387 btrfs_put_block_group(cache);
4388 cache = btrfs_lookup_block_group(fs_info, start);
4389 BUG_ON(!cache);
4390 }
4391
4392 len = cache->key.objectid + cache->key.offset - start;
4393 len = min(len, end + 1 - start);
4394
4395 if (start < cache->last_byte_to_unpin) {
4396 len = min(len, cache->last_byte_to_unpin - start);
4397 btrfs_add_free_space(cache, start, len);
4398 }
4399
4400 start += len;
4401
4402 spin_lock(&cache->space_info->lock);
4403 spin_lock(&cache->lock);
4404 cache->pinned -= len;
4405 cache->space_info->bytes_pinned -= len;
4406 if (cache->ro) {
4407 cache->space_info->bytes_readonly += len;
4408 } else if (cache->reserved_pinned > 0) {
4409 len = min(len, cache->reserved_pinned);
4410 cache->reserved_pinned -= len;
4411 cache->space_info->bytes_reserved += len;
4412 }
4413 spin_unlock(&cache->lock);
4414 spin_unlock(&cache->space_info->lock);
4415 }
4416
4417 if (cache)
4418 btrfs_put_block_group(cache);
4419 return 0;
4420 }
4421
4422 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
4423 struct btrfs_root *root)
4424 {
4425 struct btrfs_fs_info *fs_info = root->fs_info;
4426 struct extent_io_tree *unpin;
4427 struct btrfs_block_rsv *block_rsv;
4428 struct btrfs_block_rsv *next_rsv;
4429 u64 start;
4430 u64 end;
4431 int idx;
4432 int ret;
4433
4434 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
4435 unpin = &fs_info->freed_extents[1];
4436 else
4437 unpin = &fs_info->freed_extents[0];
4438
4439 while (1) {
4440 ret = find_first_extent_bit(unpin, 0, &start, &end,
4441 EXTENT_DIRTY);
4442 if (ret)
4443 break;
4444
4445 if (btrfs_test_opt(root, DISCARD))
4446 ret = btrfs_discard_extent(root, start,
4447 end + 1 - start, NULL);
4448
4449 clear_extent_dirty(unpin, start, end, GFP_NOFS);
4450 unpin_extent_range(root, start, end);
4451 cond_resched();
4452 }
4453
4454 mutex_lock(&fs_info->durable_block_rsv_mutex);
4455 list_for_each_entry_safe(block_rsv, next_rsv,
4456 &fs_info->durable_block_rsv_list, list) {
4457
4458 idx = trans->transid & 0x1;
4459 if (block_rsv->freed[idx] > 0) {
4460 block_rsv_add_bytes(block_rsv,
4461 block_rsv->freed[idx], 0);
4462 block_rsv->freed[idx] = 0;
4463 }
4464 if (atomic_read(&block_rsv->usage) == 0) {
4465 btrfs_block_rsv_release(root, block_rsv, (u64)-1);
4466
4467 if (block_rsv->freed[0] == 0 &&
4468 block_rsv->freed[1] == 0) {
4469 list_del_init(&block_rsv->list);
4470 kfree(block_rsv);
4471 }
4472 } else {
4473 btrfs_block_rsv_release(root, block_rsv, 0);
4474 }
4475 }
4476 mutex_unlock(&fs_info->durable_block_rsv_mutex);
4477
4478 return 0;
4479 }
4480
4481 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
4482 struct btrfs_root *root,
4483 u64 bytenr, u64 num_bytes, u64 parent,
4484 u64 root_objectid, u64 owner_objectid,
4485 u64 owner_offset, int refs_to_drop,
4486 struct btrfs_delayed_extent_op *extent_op)
4487 {
4488 struct btrfs_key key;
4489 struct btrfs_path *path;
4490 struct btrfs_fs_info *info = root->fs_info;
4491 struct btrfs_root *extent_root = info->extent_root;
4492 struct extent_buffer *leaf;
4493 struct btrfs_extent_item *ei;
4494 struct btrfs_extent_inline_ref *iref;
4495 int ret;
4496 int is_data;
4497 int extent_slot = 0;
4498 int found_extent = 0;
4499 int num_to_del = 1;
4500 u32 item_size;
4501 u64 refs;
4502
4503 path = btrfs_alloc_path();
4504 if (!path)
4505 return -ENOMEM;
4506
4507 path->reada = 1;
4508 path->leave_spinning = 1;
4509
4510 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
4511 BUG_ON(!is_data && refs_to_drop != 1);
4512
4513 ret = lookup_extent_backref(trans, extent_root, path, &iref,
4514 bytenr, num_bytes, parent,
4515 root_objectid, owner_objectid,
4516 owner_offset);
4517 if (ret == 0) {
4518 extent_slot = path->slots[0];
4519 while (extent_slot >= 0) {
4520 btrfs_item_key_to_cpu(path->nodes[0], &key,
4521 extent_slot);
4522 if (key.objectid != bytenr)
4523 break;
4524 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
4525 key.offset == num_bytes) {
4526 found_extent = 1;
4527 break;
4528 }
4529 if (path->slots[0] - extent_slot > 5)
4530 break;
4531 extent_slot--;
4532 }
4533 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
4534 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
4535 if (found_extent && item_size < sizeof(*ei))
4536 found_extent = 0;
4537 #endif
4538 if (!found_extent) {
4539 BUG_ON(iref);
4540 ret = remove_extent_backref(trans, extent_root, path,
4541 NULL, refs_to_drop,
4542 is_data);
4543 BUG_ON(ret);
4544 btrfs_release_path(extent_root, path);
4545 path->leave_spinning = 1;
4546
4547 key.objectid = bytenr;
4548 key.type = BTRFS_EXTENT_ITEM_KEY;
4549 key.offset = num_bytes;
4550
4551 ret = btrfs_search_slot(trans, extent_root,
4552 &key, path, -1, 1);
4553 if (ret) {
4554 printk(KERN_ERR "umm, got %d back from search"
4555 ", was looking for %llu\n", ret,
4556 (unsigned long long)bytenr);
4557 btrfs_print_leaf(extent_root, path->nodes[0]);
4558 }
4559 BUG_ON(ret);
4560 extent_slot = path->slots[0];
4561 }
4562 } else {
4563 btrfs_print_leaf(extent_root, path->nodes[0]);
4564 WARN_ON(1);
4565 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
4566 "parent %llu root %llu owner %llu offset %llu\n",
4567 (unsigned long long)bytenr,
4568 (unsigned long long)parent,
4569 (unsigned long long)root_objectid,
4570 (unsigned long long)owner_objectid,
4571 (unsigned long long)owner_offset);
4572 }
4573
4574 leaf = path->nodes[0];
4575 item_size = btrfs_item_size_nr(leaf, extent_slot);
4576 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
4577 if (item_size < sizeof(*ei)) {
4578 BUG_ON(found_extent || extent_slot != path->slots[0]);
4579 ret = convert_extent_item_v0(trans, extent_root, path,
4580 owner_objectid, 0);
4581 BUG_ON(ret < 0);
4582
4583 btrfs_release_path(extent_root, path);
4584 path->leave_spinning = 1;
4585
4586 key.objectid = bytenr;
4587 key.type = BTRFS_EXTENT_ITEM_KEY;
4588 key.offset = num_bytes;
4589
4590 ret = btrfs_search_slot(trans, extent_root, &key, path,
4591 -1, 1);
4592 if (ret) {
4593 printk(KERN_ERR "umm, got %d back from search"
4594 ", was looking for %llu\n", ret,
4595 (unsigned long long)bytenr);
4596 btrfs_print_leaf(extent_root, path->nodes[0]);
4597 }
4598 BUG_ON(ret);
4599 extent_slot = path->slots[0];
4600 leaf = path->nodes[0];
4601 item_size = btrfs_item_size_nr(leaf, extent_slot);
4602 }
4603 #endif
4604 BUG_ON(item_size < sizeof(*ei));
4605 ei = btrfs_item_ptr(leaf, extent_slot,
4606 struct btrfs_extent_item);
4607 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
4608 struct btrfs_tree_block_info *bi;
4609 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
4610 bi = (struct btrfs_tree_block_info *)(ei + 1);
4611 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
4612 }
4613
4614 refs = btrfs_extent_refs(leaf, ei);
4615 BUG_ON(refs < refs_to_drop);
4616 refs -= refs_to_drop;
4617
4618 if (refs > 0) {
4619 if (extent_op)
4620 __run_delayed_extent_op(extent_op, leaf, ei);
4621 /*
4622 * In the case of inline back ref, reference count will
4623 * be updated by remove_extent_backref
4624 */
4625 if (iref) {
4626 BUG_ON(!found_extent);
4627 } else {
4628 btrfs_set_extent_refs(leaf, ei, refs);
4629 btrfs_mark_buffer_dirty(leaf);
4630 }
4631 if (found_extent) {
4632 ret = remove_extent_backref(trans, extent_root, path,
4633 iref, refs_to_drop,
4634 is_data);
4635 BUG_ON(ret);
4636 }
4637 } else {
4638 if (found_extent) {
4639 BUG_ON(is_data && refs_to_drop !=
4640 extent_data_ref_count(root, path, iref));
4641 if (iref) {
4642 BUG_ON(path->slots[0] != extent_slot);
4643 } else {
4644 BUG_ON(path->slots[0] != extent_slot + 1);
4645 path->slots[0] = extent_slot;
4646 num_to_del = 2;
4647 }
4648 }
4649
4650 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
4651 num_to_del);
4652 BUG_ON(ret);
4653 btrfs_release_path(extent_root, path);
4654
4655 if (is_data) {
4656 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
4657 BUG_ON(ret);
4658 } else {
4659 invalidate_mapping_pages(info->btree_inode->i_mapping,
4660 bytenr >> PAGE_CACHE_SHIFT,
4661 (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
4662 }
4663
4664 ret = update_block_group(trans, root, bytenr, num_bytes, 0);
4665 BUG_ON(ret);
4666 }
4667 btrfs_free_path(path);
4668 return ret;
4669 }
4670
4671 /*
4672 * when we free an block, it is possible (and likely) that we free the last
4673 * delayed ref for that extent as well. This searches the delayed ref tree for
4674 * a given extent, and if there are no other delayed refs to be processed, it
4675 * removes it from the tree.
4676 */
4677 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
4678 struct btrfs_root *root, u64 bytenr)
4679 {
4680 struct btrfs_delayed_ref_head *head;
4681 struct btrfs_delayed_ref_root *delayed_refs;
4682 struct btrfs_delayed_ref_node *ref;
4683 struct rb_node *node;
4684 int ret = 0;
4685
4686 delayed_refs = &trans->transaction->delayed_refs;
4687 spin_lock(&delayed_refs->lock);
4688 head = btrfs_find_delayed_ref_head(trans, bytenr);
4689 if (!head)
4690 goto out;
4691
4692 node = rb_prev(&head->node.rb_node);
4693 if (!node)
4694 goto out;
4695
4696 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
4697
4698 /* there are still entries for this ref, we can't drop it */
4699 if (ref->bytenr == bytenr)
4700 goto out;
4701
4702 if (head->extent_op) {
4703 if (!head->must_insert_reserved)
4704 goto out;
4705 kfree(head->extent_op);
4706 head->extent_op = NULL;
4707 }
4708
4709 /*
4710 * waiting for the lock here would deadlock. If someone else has it
4711 * locked they are already in the process of dropping it anyway
4712 */
4713 if (!mutex_trylock(&head->mutex))
4714 goto out;
4715
4716 /*
4717 * at this point we have a head with no other entries. Go
4718 * ahead and process it.
4719 */
4720 head->node.in_tree = 0;
4721 rb_erase(&head->node.rb_node, &delayed_refs->root);
4722
4723 delayed_refs->num_entries--;
4724
4725 /*
4726 * we don't take a ref on the node because we're removing it from the
4727 * tree, so we just steal the ref the tree was holding.
4728 */
4729 delayed_refs->num_heads--;
4730 if (list_empty(&head->cluster))
4731 delayed_refs->num_heads_ready--;
4732
4733 list_del_init(&head->cluster);
4734 spin_unlock(&delayed_refs->lock);
4735
4736 BUG_ON(head->extent_op);
4737 if (head->must_insert_reserved)
4738 ret = 1;
4739
4740 mutex_unlock(&head->mutex);
4741 btrfs_put_delayed_ref(&head->node);
4742 return ret;
4743 out:
4744 spin_unlock(&delayed_refs->lock);
4745 return 0;
4746 }
4747
4748 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
4749 struct btrfs_root *root,
4750 struct extent_buffer *buf,
4751 u64 parent, int last_ref)
4752 {
4753 struct btrfs_block_rsv *block_rsv;
4754 struct btrfs_block_group_cache *cache = NULL;
4755 int ret;
4756
4757 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4758 ret = btrfs_add_delayed_tree_ref(trans, buf->start, buf->len,
4759 parent, root->root_key.objectid,
4760 btrfs_header_level(buf),
4761 BTRFS_DROP_DELAYED_REF, NULL);
4762 BUG_ON(ret);
4763 }
4764
4765 if (!last_ref)
4766 return;
4767
4768 block_rsv = get_block_rsv(trans, root);
4769 cache = btrfs_lookup_block_group(root->fs_info, buf->start);
4770 if (block_rsv->space_info != cache->space_info)
4771 goto out;
4772
4773 if (btrfs_header_generation(buf) == trans->transid) {
4774 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4775 ret = check_ref_cleanup(trans, root, buf->start);
4776 if (!ret)
4777 goto pin;
4778 }
4779
4780 if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
4781 pin_down_extent(root, cache, buf->start, buf->len, 1);
4782 goto pin;
4783 }
4784
4785 WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
4786
4787 btrfs_add_free_space(cache, buf->start, buf->len);
4788 ret = btrfs_update_reserved_bytes(cache, buf->len, 0, 0);
4789 if (ret == -EAGAIN) {
4790 /* block group became read-only */
4791 btrfs_update_reserved_bytes(cache, buf->len, 0, 1);
4792 goto out;
4793 }
4794
4795 ret = 1;
4796 spin_lock(&block_rsv->lock);
4797 if (block_rsv->reserved < block_rsv->size) {
4798 block_rsv->reserved += buf->len;
4799 ret = 0;
4800 }
4801 spin_unlock(&block_rsv->lock);
4802
4803 if (ret) {
4804 spin_lock(&cache->space_info->lock);
4805 cache->space_info->bytes_reserved -= buf->len;
4806 cache->space_info->reservation_progress++;
4807 spin_unlock(&cache->space_info->lock);
4808 }
4809 goto out;
4810 }
4811 pin:
4812 if (block_rsv->durable && !cache->ro) {
4813 ret = 0;
4814 spin_lock(&cache->lock);
4815 if (!cache->ro) {
4816 cache->reserved_pinned += buf->len;
4817 ret = 1;
4818 }
4819 spin_unlock(&cache->lock);
4820
4821 if (ret) {
4822 spin_lock(&block_rsv->lock);
4823 block_rsv->freed[trans->transid & 0x1] += buf->len;
4824 spin_unlock(&block_rsv->lock);
4825 }
4826 }
4827 out:
4828 /*
4829 * Deleting the buffer, clear the corrupt flag since it doesn't matter
4830 * anymore.
4831 */
4832 clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
4833 btrfs_put_block_group(cache);
4834 }
4835
4836 int btrfs_free_extent(struct btrfs_trans_handle *trans,
4837 struct btrfs_root *root,
4838 u64 bytenr, u64 num_bytes, u64 parent,
4839 u64 root_objectid, u64 owner, u64 offset)
4840 {
4841 int ret;
4842
4843 /*
4844 * tree log blocks never actually go into the extent allocation
4845 * tree, just update pinning info and exit early.
4846 */
4847 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
4848 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
4849 /* unlocks the pinned mutex */
4850 btrfs_pin_extent(root, bytenr, num_bytes, 1);
4851 ret = 0;
4852 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
4853 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
4854 parent, root_objectid, (int)owner,
4855 BTRFS_DROP_DELAYED_REF, NULL);
4856 BUG_ON(ret);
4857 } else {
4858 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
4859 parent, root_objectid, owner,
4860 offset, BTRFS_DROP_DELAYED_REF, NULL);
4861 BUG_ON(ret);
4862 }
4863 return ret;
4864 }
4865
4866 static u64 stripe_align(struct btrfs_root *root, u64 val)
4867 {
4868 u64 mask = ((u64)root->stripesize - 1);
4869 u64 ret = (val + mask) & ~mask;
4870 return ret;
4871 }
4872
4873 /*
4874 * when we wait for progress in the block group caching, its because
4875 * our allocation attempt failed at least once. So, we must sleep
4876 * and let some progress happen before we try again.
4877 *
4878 * This function will sleep at least once waiting for new free space to
4879 * show up, and then it will check the block group free space numbers
4880 * for our min num_bytes. Another option is to have it go ahead
4881 * and look in the rbtree for a free extent of a given size, but this
4882 * is a good start.
4883 */
4884 static noinline int
4885 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
4886 u64 num_bytes)
4887 {
4888 struct btrfs_caching_control *caching_ctl;
4889 DEFINE_WAIT(wait);
4890
4891 caching_ctl = get_caching_control(cache);
4892 if (!caching_ctl)
4893 return 0;
4894
4895 wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
4896 (cache->free_space >= num_bytes));
4897
4898 put_caching_control(caching_ctl);
4899 return 0;
4900 }
4901
4902 static noinline int
4903 wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
4904 {
4905 struct btrfs_caching_control *caching_ctl;
4906 DEFINE_WAIT(wait);
4907
4908 caching_ctl = get_caching_control(cache);
4909 if (!caching_ctl)
4910 return 0;
4911
4912 wait_event(caching_ctl->wait, block_group_cache_done(cache));
4913
4914 put_caching_control(caching_ctl);
4915 return 0;
4916 }
4917
4918 static int get_block_group_index(struct btrfs_block_group_cache *cache)
4919 {
4920 int index;
4921 if (cache->flags & BTRFS_BLOCK_GROUP_RAID10)
4922 index = 0;
4923 else if (cache->flags & BTRFS_BLOCK_GROUP_RAID1)
4924 index = 1;
4925 else if (cache->flags & BTRFS_BLOCK_GROUP_DUP)
4926 index = 2;
4927 else if (cache->flags & BTRFS_BLOCK_GROUP_RAID0)
4928 index = 3;
4929 else
4930 index = 4;
4931 return index;
4932 }
4933
4934 enum btrfs_loop_type {
4935 LOOP_FIND_IDEAL = 0,
4936 LOOP_CACHING_NOWAIT = 1,
4937 LOOP_CACHING_WAIT = 2,
4938 LOOP_ALLOC_CHUNK = 3,
4939 LOOP_NO_EMPTY_SIZE = 4,
4940 };
4941
4942 /*
4943 * walks the btree of allocated extents and find a hole of a given size.
4944 * The key ins is changed to record the hole:
4945 * ins->objectid == block start
4946 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4947 * ins->offset == number of blocks
4948 * Any available blocks before search_start are skipped.
4949 */
4950 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
4951 struct btrfs_root *orig_root,
4952 u64 num_bytes, u64 empty_size,
4953 u64 search_start, u64 search_end,
4954 u64 hint_byte, struct btrfs_key *ins,
4955 int data)
4956 {
4957 int ret = 0;
4958 struct btrfs_root *root = orig_root->fs_info->extent_root;
4959 struct btrfs_free_cluster *last_ptr = NULL;
4960 struct btrfs_block_group_cache *block_group = NULL;
4961 int empty_cluster = 2 * 1024 * 1024;
4962 int allowed_chunk_alloc = 0;
4963 int done_chunk_alloc = 0;
4964 struct btrfs_space_info *space_info;
4965 int last_ptr_loop = 0;
4966 int loop = 0;
4967 int index = 0;
4968 bool found_uncached_bg = false;
4969 bool failed_cluster_refill = false;
4970 bool failed_alloc = false;
4971 bool use_cluster = true;
4972 u64 ideal_cache_percent = 0;
4973 u64 ideal_cache_offset = 0;
4974
4975 WARN_ON(num_bytes < root->sectorsize);
4976 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
4977 ins->objectid = 0;
4978 ins->offset = 0;
4979
4980 space_info = __find_space_info(root->fs_info, data);
4981 if (!space_info) {
4982 printk(KERN_ERR "No space info for %d\n", data);
4983 return -ENOSPC;
4984 }
4985
4986 /*
4987 * If the space info is for both data and metadata it means we have a
4988 * small filesystem and we can't use the clustering stuff.
4989 */
4990 if (btrfs_mixed_space_info(space_info))
4991 use_cluster = false;
4992
4993 if (orig_root->ref_cows || empty_size)
4994 allowed_chunk_alloc = 1;
4995
4996 if (data & BTRFS_BLOCK_GROUP_METADATA && use_cluster) {
4997 last_ptr = &root->fs_info->meta_alloc_cluster;
4998 if (!btrfs_test_opt(root, SSD))
4999 empty_cluster = 64 * 1024;
5000 }
5001
5002 if ((data & BTRFS_BLOCK_GROUP_DATA) && use_cluster &&
5003 btrfs_test_opt(root, SSD)) {
5004 last_ptr = &root->fs_info->data_alloc_cluster;
5005 }
5006
5007 if (last_ptr) {
5008 spin_lock(&last_ptr->lock);
5009 if (last_ptr->block_group)
5010 hint_byte = last_ptr->window_start;
5011 spin_unlock(&last_ptr->lock);
5012 }
5013
5014 search_start = max(search_start, first_logical_byte(root, 0));
5015 search_start = max(search_start, hint_byte);
5016
5017 if (!last_ptr)
5018 empty_cluster = 0;
5019
5020 if (search_start == hint_byte) {
5021 ideal_cache:
5022 block_group = btrfs_lookup_block_group(root->fs_info,
5023 search_start);
5024 /*
5025 * we don't want to use the block group if it doesn't match our
5026 * allocation bits, or if its not cached.
5027 *
5028 * However if we are re-searching with an ideal block group
5029 * picked out then we don't care that the block group is cached.
5030 */
5031 if (block_group && block_group_bits(block_group, data) &&
5032 (block_group->cached != BTRFS_CACHE_NO ||
5033 search_start == ideal_cache_offset)) {
5034 down_read(&space_info->groups_sem);
5035 if (list_empty(&block_group->list) ||
5036 block_group->ro) {
5037 /*
5038 * someone is removing this block group,
5039 * we can't jump into the have_block_group
5040 * target because our list pointers are not
5041 * valid
5042 */
5043 btrfs_put_block_group(block_group);
5044 up_read(&space_info->groups_sem);
5045 } else {
5046 index = get_block_group_index(block_group);
5047 goto have_block_group;
5048 }
5049 } else if (block_group) {
5050 btrfs_put_block_group(block_group);
5051 }
5052 }
5053 search:
5054 down_read(&space_info->groups_sem);
5055 list_for_each_entry(block_group, &space_info->block_groups[index],
5056 list) {
5057 u64 offset;
5058 int cached;
5059
5060 btrfs_get_block_group(block_group);
5061 search_start = block_group->key.objectid;
5062
5063 /*
5064 * this can happen if we end up cycling through all the
5065 * raid types, but we want to make sure we only allocate
5066 * for the proper type.
5067 */
5068 if (!block_group_bits(block_group, data)) {
5069 u64 extra = BTRFS_BLOCK_GROUP_DUP |
5070 BTRFS_BLOCK_GROUP_RAID1 |
5071 BTRFS_BLOCK_GROUP_RAID10;
5072
5073 /*
5074 * if they asked for extra copies and this block group
5075 * doesn't provide them, bail. This does allow us to
5076 * fill raid0 from raid1.
5077 */
5078 if ((data & extra) && !(block_group->flags & extra))
5079 goto loop;
5080 }
5081
5082 have_block_group:
5083 if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
5084 u64 free_percent;
5085
5086 ret = cache_block_group(block_group, trans,
5087 orig_root, 1);
5088 if (block_group->cached == BTRFS_CACHE_FINISHED)
5089 goto have_block_group;
5090
5091 free_percent = btrfs_block_group_used(&block_group->item);
5092 free_percent *= 100;
5093 free_percent = div64_u64(free_percent,
5094 block_group->key.offset);
5095 free_percent = 100 - free_percent;
5096 if (free_percent > ideal_cache_percent &&
5097 likely(!block_group->ro)) {
5098 ideal_cache_offset = block_group->key.objectid;
5099 ideal_cache_percent = free_percent;
5100 }
5101
5102 /*
5103 * We only want to start kthread caching if we are at
5104 * the point where we will wait for caching to make
5105 * progress, or if our ideal search is over and we've
5106 * found somebody to start caching.
5107 */
5108 if (loop > LOOP_CACHING_NOWAIT ||
5109 (loop > LOOP_FIND_IDEAL &&
5110 atomic_read(&space_info->caching_threads) < 2)) {
5111 ret = cache_block_group(block_group, trans,
5112 orig_root, 0);
5113 BUG_ON(ret);
5114 }
5115 found_uncached_bg = true;
5116
5117 /*
5118 * If loop is set for cached only, try the next block
5119 * group.
5120 */
5121 if (loop == LOOP_FIND_IDEAL)
5122 goto loop;
5123 }
5124
5125 cached = block_group_cache_done(block_group);
5126 if (unlikely(!cached))
5127 found_uncached_bg = true;
5128
5129 if (unlikely(block_group->ro))
5130 goto loop;
5131
5132 /*
5133 * Ok we want to try and use the cluster allocator, so lets look
5134 * there, unless we are on LOOP_NO_EMPTY_SIZE, since we will
5135 * have tried the cluster allocator plenty of times at this
5136 * point and not have found anything, so we are likely way too
5137 * fragmented for the clustering stuff to find anything, so lets
5138 * just skip it and let the allocator find whatever block it can
5139 * find
5140 */
5141 if (last_ptr && loop < LOOP_NO_EMPTY_SIZE) {
5142 /*
5143 * the refill lock keeps out other
5144 * people trying to start a new cluster
5145 */
5146 spin_lock(&last_ptr->refill_lock);
5147 if (last_ptr->block_group &&
5148 (last_ptr->block_group->ro ||
5149 !block_group_bits(last_ptr->block_group, data))) {
5150 offset = 0;
5151 goto refill_cluster;
5152 }
5153
5154 offset = btrfs_alloc_from_cluster(block_group, last_ptr,
5155 num_bytes, search_start);
5156 if (offset) {
5157 /* we have a block, we're done */
5158 spin_unlock(&last_ptr->refill_lock);
5159 goto checks;
5160 }
5161
5162 spin_lock(&last_ptr->lock);
5163 /*
5164 * whoops, this cluster doesn't actually point to
5165 * this block group. Get a ref on the block
5166 * group is does point to and try again
5167 */
5168 if (!last_ptr_loop && last_ptr->block_group &&
5169 last_ptr->block_group != block_group) {
5170
5171 btrfs_put_block_group(block_group);
5172 block_group = last_ptr->block_group;
5173 btrfs_get_block_group(block_group);
5174 spin_unlock(&last_ptr->lock);
5175 spin_unlock(&last_ptr->refill_lock);
5176
5177 last_ptr_loop = 1;
5178 search_start = block_group->key.objectid;
5179 /*
5180 * we know this block group is properly
5181 * in the list because
5182 * btrfs_remove_block_group, drops the
5183 * cluster before it removes the block
5184 * group from the list
5185 */
5186 goto have_block_group;
5187 }
5188 spin_unlock(&last_ptr->lock);
5189 refill_cluster:
5190 /*
5191 * this cluster didn't work out, free it and
5192 * start over
5193 */
5194 btrfs_return_cluster_to_free_space(NULL, last_ptr);
5195
5196 last_ptr_loop = 0;
5197
5198 /* allocate a cluster in this block group */
5199 ret = btrfs_find_space_cluster(trans, root,
5200 block_group, last_ptr,
5201 offset, num_bytes,
5202 empty_cluster + empty_size);
5203 if (ret == 0) {
5204 /*
5205 * now pull our allocation out of this
5206 * cluster
5207 */
5208 offset = btrfs_alloc_from_cluster(block_group,
5209 last_ptr, num_bytes,
5210 search_start);
5211 if (offset) {
5212 /* we found one, proceed */
5213 spin_unlock(&last_ptr->refill_lock);
5214 goto checks;
5215 }
5216 } else if (!cached && loop > LOOP_CACHING_NOWAIT
5217 && !failed_cluster_refill) {
5218 spin_unlock(&last_ptr->refill_lock);
5219
5220 failed_cluster_refill = true;
5221 wait_block_group_cache_progress(block_group,
5222 num_bytes + empty_cluster + empty_size);
5223 goto have_block_group;
5224 }
5225
5226 /*
5227 * at this point we either didn't find a cluster
5228 * or we weren't able to allocate a block from our
5229 * cluster. Free the cluster we've been trying
5230 * to use, and go to the next block group
5231 */
5232 btrfs_return_cluster_to_free_space(NULL, last_ptr);
5233 spin_unlock(&last_ptr->refill_lock);
5234 goto loop;
5235 }
5236
5237 offset = btrfs_find_space_for_alloc(block_group, search_start,
5238 num_bytes, empty_size);
5239 /*
5240 * If we didn't find a chunk, and we haven't failed on this
5241 * block group before, and this block group is in the middle of
5242 * caching and we are ok with waiting, then go ahead and wait
5243 * for progress to be made, and set failed_alloc to true.
5244 *
5245 * If failed_alloc is true then we've already waited on this
5246 * block group once and should move on to the next block group.
5247 */
5248 if (!offset && !failed_alloc && !cached &&
5249 loop > LOOP_CACHING_NOWAIT) {
5250 wait_block_group_cache_progress(block_group,
5251 num_bytes + empty_size);
5252 failed_alloc = true;
5253 goto have_block_group;
5254 } else if (!offset) {
5255 goto loop;
5256 }
5257 checks:
5258 search_start = stripe_align(root, offset);
5259 /* move on to the next group */
5260 if (search_start + num_bytes >= search_end) {
5261 btrfs_add_free_space(block_group, offset, num_bytes);
5262 goto loop;
5263 }
5264
5265 /* move on to the next group */
5266 if (search_start + num_bytes >
5267 block_group->key.objectid + block_group->key.offset) {
5268 btrfs_add_free_space(block_group, offset, num_bytes);
5269 goto loop;
5270 }
5271
5272 ins->objectid = search_start;
5273 ins->offset = num_bytes;
5274
5275 if (offset < search_start)
5276 btrfs_add_free_space(block_group, offset,
5277 search_start - offset);
5278 BUG_ON(offset > search_start);
5279
5280 ret = btrfs_update_reserved_bytes(block_group, num_bytes, 1,
5281 (data & BTRFS_BLOCK_GROUP_DATA));
5282 if (ret == -EAGAIN) {
5283 btrfs_add_free_space(block_group, offset, num_bytes);
5284 goto loop;
5285 }
5286
5287 /* we are all good, lets return */
5288 ins->objectid = search_start;
5289 ins->offset = num_bytes;
5290
5291 if (offset < search_start)
5292 btrfs_add_free_space(block_group, offset,
5293 search_start - offset);
5294 BUG_ON(offset > search_start);
5295 break;
5296 loop:
5297 failed_cluster_refill = false;
5298 failed_alloc = false;
5299 BUG_ON(index != get_block_group_index(block_group));
5300 btrfs_put_block_group(block_group);
5301 }
5302 up_read(&space_info->groups_sem);
5303
5304 if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
5305 goto search;
5306
5307 /* LOOP_FIND_IDEAL, only search caching/cached bg's, and don't wait for
5308 * for them to make caching progress. Also
5309 * determine the best possible bg to cache
5310 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
5311 * caching kthreads as we move along
5312 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
5313 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
5314 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
5315 * again
5316 */
5317 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE &&
5318 (found_uncached_bg || empty_size || empty_cluster ||
5319 allowed_chunk_alloc)) {
5320 index = 0;
5321 if (loop == LOOP_FIND_IDEAL && found_uncached_bg) {
5322 found_uncached_bg = false;
5323 loop++;
5324 if (!ideal_cache_percent &&
5325 atomic_read(&space_info->caching_threads))
5326 goto search;
5327
5328 /*
5329 * 1 of the following 2 things have happened so far
5330 *
5331 * 1) We found an ideal block group for caching that
5332 * is mostly full and will cache quickly, so we might
5333 * as well wait for it.
5334 *
5335 * 2) We searched for cached only and we didn't find
5336 * anything, and we didn't start any caching kthreads
5337 * either, so chances are we will loop through and
5338 * start a couple caching kthreads, and then come back
5339 * around and just wait for them. This will be slower
5340 * because we will have 2 caching kthreads reading at
5341 * the same time when we could have just started one
5342 * and waited for it to get far enough to give us an
5343 * allocation, so go ahead and go to the wait caching
5344 * loop.
5345 */
5346 loop = LOOP_CACHING_WAIT;
5347 search_start = ideal_cache_offset;
5348 ideal_cache_percent = 0;
5349 goto ideal_cache;
5350 } else if (loop == LOOP_FIND_IDEAL) {
5351 /*
5352 * Didn't find a uncached bg, wait on anything we find
5353 * next.
5354 */
5355 loop = LOOP_CACHING_WAIT;
5356 goto search;
5357 }
5358
5359 if (loop < LOOP_CACHING_WAIT) {
5360 loop++;
5361 goto search;
5362 }
5363
5364 if (loop == LOOP_ALLOC_CHUNK) {
5365 empty_size = 0;
5366 empty_cluster = 0;
5367 }
5368
5369 if (allowed_chunk_alloc) {
5370 ret = do_chunk_alloc(trans, root, num_bytes +
5371 2 * 1024 * 1024, data,
5372 CHUNK_ALLOC_LIMITED);
5373 allowed_chunk_alloc = 0;
5374 done_chunk_alloc = 1;
5375 } else if (!done_chunk_alloc &&
5376 space_info->force_alloc == CHUNK_ALLOC_NO_FORCE) {
5377 space_info->force_alloc = CHUNK_ALLOC_LIMITED;
5378 }
5379
5380 if (loop < LOOP_NO_EMPTY_SIZE) {
5381 loop++;
5382 goto search;
5383 }
5384 ret = -ENOSPC;
5385 } else if (!ins->objectid) {
5386 ret = -ENOSPC;
5387 }
5388
5389 /* we found what we needed */
5390 if (ins->objectid) {
5391 if (!(data & BTRFS_BLOCK_GROUP_DATA))
5392 trans->block_group = block_group->key.objectid;
5393
5394 btrfs_put_block_group(block_group);
5395 ret = 0;
5396 }
5397
5398 return ret;
5399 }
5400
5401 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
5402 int dump_block_groups)
5403 {
5404 struct btrfs_block_group_cache *cache;
5405 int index = 0;
5406
5407 spin_lock(&info->lock);
5408 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
5409 (unsigned long long)(info->total_bytes - info->bytes_used -
5410 info->bytes_pinned - info->bytes_reserved -
5411 info->bytes_readonly),
5412 (info->full) ? "" : "not ");
5413 printk(KERN_INFO "space_info total=%llu, used=%llu, pinned=%llu, "
5414 "reserved=%llu, may_use=%llu, readonly=%llu\n",
5415 (unsigned long long)info->total_bytes,
5416 (unsigned long long)info->bytes_used,
5417 (unsigned long long)info->bytes_pinned,
5418 (unsigned long long)info->bytes_reserved,
5419 (unsigned long long)info->bytes_may_use,
5420 (unsigned long long)info->bytes_readonly);
5421 spin_unlock(&info->lock);
5422
5423 if (!dump_block_groups)
5424 return;
5425
5426 down_read(&info->groups_sem);
5427 again:
5428 list_for_each_entry(cache, &info->block_groups[index], list) {
5429 spin_lock(&cache->lock);
5430 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
5431 "%llu pinned %llu reserved\n",
5432 (unsigned long long)cache->key.objectid,
5433 (unsigned long long)cache->key.offset,
5434 (unsigned long long)btrfs_block_group_used(&cache->item),
5435 (unsigned long long)cache->pinned,
5436 (unsigned long long)cache->reserved);
5437 btrfs_dump_free_space(cache, bytes);
5438 spin_unlock(&cache->lock);
5439 }
5440 if (++index < BTRFS_NR_RAID_TYPES)
5441 goto again;
5442 up_read(&info->groups_sem);
5443 }
5444
5445 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
5446 struct btrfs_root *root,
5447 u64 num_bytes, u64 min_alloc_size,
5448 u64 empty_size, u64 hint_byte,
5449 u64 search_end, struct btrfs_key *ins,
5450 u64 data)
5451 {
5452 int ret;
5453 u64 search_start = 0;
5454
5455 data = btrfs_get_alloc_profile(root, data);
5456 again:
5457 /*
5458 * the only place that sets empty_size is btrfs_realloc_node, which
5459 * is not called recursively on allocations
5460 */
5461 if (empty_size || root->ref_cows)
5462 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
5463 num_bytes + 2 * 1024 * 1024, data,
5464 CHUNK_ALLOC_NO_FORCE);
5465
5466 WARN_ON(num_bytes < root->sectorsize);
5467 ret = find_free_extent(trans, root, num_bytes, empty_size,
5468 search_start, search_end, hint_byte,
5469 ins, data);
5470
5471 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
5472 num_bytes = num_bytes >> 1;
5473 num_bytes = num_bytes & ~(root->sectorsize - 1);
5474 num_bytes = max(num_bytes, min_alloc_size);
5475 do_chunk_alloc(trans, root->fs_info->extent_root,
5476 num_bytes, data, CHUNK_ALLOC_FORCE);
5477 goto again;
5478 }
5479 if (ret == -ENOSPC && btrfs_test_opt(root, ENOSPC_DEBUG)) {
5480 struct btrfs_space_info *sinfo;
5481
5482 sinfo = __find_space_info(root->fs_info, data);
5483 printk(KERN_ERR "btrfs allocation failed flags %llu, "
5484 "wanted %llu\n", (unsigned long long)data,
5485 (unsigned long long)num_bytes);
5486 dump_space_info(sinfo, num_bytes, 1);
5487 }
5488
5489 trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset);
5490
5491 return ret;
5492 }
5493
5494 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
5495 {
5496 struct btrfs_block_group_cache *cache;
5497 int ret = 0;
5498
5499 cache = btrfs_lookup_block_group(root->fs_info, start);
5500 if (!cache) {
5501 printk(KERN_ERR "Unable to find block group for %llu\n",
5502 (unsigned long long)start);
5503 return -ENOSPC;
5504 }
5505
5506 if (btrfs_test_opt(root, DISCARD))
5507 ret = btrfs_discard_extent(root, start, len, NULL);
5508
5509 btrfs_add_free_space(cache, start, len);
5510 btrfs_update_reserved_bytes(cache, len, 0, 1);
5511 btrfs_put_block_group(cache);
5512
5513 trace_btrfs_reserved_extent_free(root, start, len);
5514
5515 return ret;
5516 }
5517
5518 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
5519 struct btrfs_root *root,
5520 u64 parent, u64 root_objectid,
5521 u64 flags, u64 owner, u64 offset,
5522 struct btrfs_key *ins, int ref_mod)
5523 {
5524 int ret;
5525 struct btrfs_fs_info *fs_info = root->fs_info;
5526 struct btrfs_extent_item *extent_item;
5527 struct btrfs_extent_inline_ref *iref;
5528 struct btrfs_path *path;
5529 struct extent_buffer *leaf;
5530 int type;
5531 u32 size;
5532
5533 if (parent > 0)
5534 type = BTRFS_SHARED_DATA_REF_KEY;
5535 else
5536 type = BTRFS_EXTENT_DATA_REF_KEY;
5537
5538 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
5539
5540 path = btrfs_alloc_path();
5541 if (!path)
5542 return -ENOMEM;
5543
5544 path->leave_spinning = 1;
5545 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
5546 ins, size);
5547 BUG_ON(ret);
5548
5549 leaf = path->nodes[0];
5550 extent_item = btrfs_item_ptr(leaf, path->slots[0],
5551 struct btrfs_extent_item);
5552 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
5553 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
5554 btrfs_set_extent_flags(leaf, extent_item,
5555 flags | BTRFS_EXTENT_FLAG_DATA);
5556
5557 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
5558 btrfs_set_extent_inline_ref_type(leaf, iref, type);
5559 if (parent > 0) {
5560 struct btrfs_shared_data_ref *ref;
5561 ref = (struct btrfs_shared_data_ref *)(iref + 1);
5562 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
5563 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
5564 } else {
5565 struct btrfs_extent_data_ref *ref;
5566 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
5567 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
5568 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
5569 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
5570 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
5571 }
5572
5573 btrfs_mark_buffer_dirty(path->nodes[0]);
5574 btrfs_free_path(path);
5575
5576 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
5577 if (ret) {
5578 printk(KERN_ERR "btrfs update block group failed for %llu "
5579 "%llu\n", (unsigned long long)ins->objectid,
5580 (unsigned long long)ins->offset);
5581 BUG();
5582 }
5583 return ret;
5584 }
5585
5586 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
5587 struct btrfs_root *root,
5588 u64 parent, u64 root_objectid,
5589 u64 flags, struct btrfs_disk_key *key,
5590 int level, struct btrfs_key *ins)
5591 {
5592 int ret;
5593 struct btrfs_fs_info *fs_info = root->fs_info;
5594 struct btrfs_extent_item *extent_item;
5595 struct btrfs_tree_block_info *block_info;
5596 struct btrfs_extent_inline_ref *iref;
5597 struct btrfs_path *path;
5598 struct extent_buffer *leaf;
5599 u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
5600
5601 path = btrfs_alloc_path();
5602 BUG_ON(!path);
5603
5604 path->leave_spinning = 1;
5605 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
5606 ins, size);
5607 BUG_ON(ret);
5608
5609 leaf = path->nodes[0];
5610 extent_item = btrfs_item_ptr(leaf, path->slots[0],
5611 struct btrfs_extent_item);
5612 btrfs_set_extent_refs(leaf, extent_item, 1);
5613 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
5614 btrfs_set_extent_flags(leaf, extent_item,
5615 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
5616 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
5617
5618 btrfs_set_tree_block_key(leaf, block_info, key);
5619 btrfs_set_tree_block_level(leaf, block_info, level);
5620
5621 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
5622 if (parent > 0) {
5623 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
5624 btrfs_set_extent_inline_ref_type(leaf, iref,
5625 BTRFS_SHARED_BLOCK_REF_KEY);
5626 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
5627 } else {
5628 btrfs_set_extent_inline_ref_type(leaf, iref,
5629 BTRFS_TREE_BLOCK_REF_KEY);
5630 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
5631 }
5632
5633 btrfs_mark_buffer_dirty(leaf);
5634 btrfs_free_path(path);
5635
5636 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
5637 if (ret) {
5638 printk(KERN_ERR "btrfs update block group failed for %llu "
5639 "%llu\n", (unsigned long long)ins->objectid,
5640 (unsigned long long)ins->offset);
5641 BUG();
5642 }
5643 return ret;
5644 }
5645
5646 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
5647 struct btrfs_root *root,
5648 u64 root_objectid, u64 owner,
5649 u64 offset, struct btrfs_key *ins)
5650 {
5651 int ret;
5652
5653 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
5654
5655 ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
5656 0, root_objectid, owner, offset,
5657 BTRFS_ADD_DELAYED_EXTENT, NULL);
5658 return ret;
5659 }
5660
5661 /*
5662 * this is used by the tree logging recovery code. It records that
5663 * an extent has been allocated and makes sure to clear the free
5664 * space cache bits as well
5665 */
5666 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
5667 struct btrfs_root *root,
5668 u64 root_objectid, u64 owner, u64 offset,
5669 struct btrfs_key *ins)
5670 {
5671 int ret;
5672 struct btrfs_block_group_cache *block_group;
5673 struct btrfs_caching_control *caching_ctl;
5674 u64 start = ins->objectid;
5675 u64 num_bytes = ins->offset;
5676
5677 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
5678 cache_block_group(block_group, trans, NULL, 0);
5679 caching_ctl = get_caching_control(block_group);
5680
5681 if (!caching_ctl) {
5682 BUG_ON(!block_group_cache_done(block_group));
5683 ret = btrfs_remove_free_space(block_group, start, num_bytes);
5684 BUG_ON(ret);
5685 } else {
5686 mutex_lock(&caching_ctl->mutex);
5687
5688 if (start >= caching_ctl->progress) {
5689 ret = add_excluded_extent(root, start, num_bytes);
5690 BUG_ON(ret);
5691 } else if (start + num_bytes <= caching_ctl->progress) {
5692 ret = btrfs_remove_free_space(block_group,
5693 start, num_bytes);
5694 BUG_ON(ret);
5695 } else {
5696 num_bytes = caching_ctl->progress - start;
5697 ret = btrfs_remove_free_space(block_group,
5698 start, num_bytes);
5699 BUG_ON(ret);
5700
5701 start = caching_ctl->progress;
5702 num_bytes = ins->objectid + ins->offset -
5703 caching_ctl->progress;
5704 ret = add_excluded_extent(root, start, num_bytes);
5705 BUG_ON(ret);
5706 }
5707
5708 mutex_unlock(&caching_ctl->mutex);
5709 put_caching_control(caching_ctl);
5710 }
5711
5712 ret = btrfs_update_reserved_bytes(block_group, ins->offset, 1, 1);
5713 BUG_ON(ret);
5714 btrfs_put_block_group(block_group);
5715 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
5716 0, owner, offset, ins, 1);
5717 return ret;
5718 }
5719
5720 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
5721 struct btrfs_root *root,
5722 u64 bytenr, u32 blocksize,
5723 int level)
5724 {
5725 struct extent_buffer *buf;
5726
5727 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
5728 if (!buf)
5729 return ERR_PTR(-ENOMEM);
5730 btrfs_set_header_generation(buf, trans->transid);
5731 btrfs_set_buffer_lockdep_class(buf, level);
5732 btrfs_tree_lock(buf);
5733 clean_tree_block(trans, root, buf);
5734
5735 btrfs_set_lock_blocking(buf);
5736 btrfs_set_buffer_uptodate(buf);
5737
5738 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
5739 /*
5740 * we allow two log transactions at a time, use different
5741 * EXENT bit to differentiate dirty pages.
5742 */
5743 if (root->log_transid % 2 == 0)
5744 set_extent_dirty(&root->dirty_log_pages, buf->start,
5745 buf->start + buf->len - 1, GFP_NOFS);
5746 else
5747 set_extent_new(&root->dirty_log_pages, buf->start,
5748 buf->start + buf->len - 1, GFP_NOFS);
5749 } else {
5750 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
5751 buf->start + buf->len - 1, GFP_NOFS);
5752 }
5753 trans->blocks_used++;
5754 /* this returns a buffer locked for blocking */
5755 return buf;
5756 }
5757
5758 static struct btrfs_block_rsv *
5759 use_block_rsv(struct btrfs_trans_handle *trans,
5760 struct btrfs_root *root, u32 blocksize)
5761 {
5762 struct btrfs_block_rsv *block_rsv;
5763 struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
5764 int ret;
5765
5766 block_rsv = get_block_rsv(trans, root);
5767
5768 if (block_rsv->size == 0) {
5769 ret = reserve_metadata_bytes(trans, root, block_rsv,
5770 blocksize, 0);
5771 /*
5772 * If we couldn't reserve metadata bytes try and use some from
5773 * the global reserve.
5774 */
5775 if (ret && block_rsv != global_rsv) {
5776 ret = block_rsv_use_bytes(global_rsv, blocksize);
5777 if (!ret)
5778 return global_rsv;
5779 return ERR_PTR(ret);
5780 } else if (ret) {
5781 return ERR_PTR(ret);
5782 }
5783 return block_rsv;
5784 }
5785
5786 ret = block_rsv_use_bytes(block_rsv, blocksize);
5787 if (!ret)
5788 return block_rsv;
5789 if (ret) {
5790 WARN_ON(1);
5791 ret = reserve_metadata_bytes(trans, root, block_rsv, blocksize,
5792 0);
5793 if (!ret) {
5794 spin_lock(&block_rsv->lock);
5795 block_rsv->size += blocksize;
5796 spin_unlock(&block_rsv->lock);
5797 return block_rsv;
5798 } else if (ret && block_rsv != global_rsv) {
5799 ret = block_rsv_use_bytes(global_rsv, blocksize);
5800 if (!ret)
5801 return global_rsv;
5802 }
5803 }
5804
5805 return ERR_PTR(-ENOSPC);
5806 }
5807
5808 static void unuse_block_rsv(struct btrfs_block_rsv *block_rsv, u32 blocksize)
5809 {
5810 block_rsv_add_bytes(block_rsv, blocksize, 0);
5811 block_rsv_release_bytes(block_rsv, NULL, 0);
5812 }
5813
5814 /*
5815 * finds a free extent and does all the dirty work required for allocation
5816 * returns the key for the extent through ins, and a tree buffer for
5817 * the first block of the extent through buf.
5818 *
5819 * returns the tree buffer or NULL.
5820 */
5821 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
5822 struct btrfs_root *root, u32 blocksize,
5823 u64 parent, u64 root_objectid,
5824 struct btrfs_disk_key *key, int level,
5825 u64 hint, u64 empty_size)
5826 {
5827 struct btrfs_key ins;
5828 struct btrfs_block_rsv *block_rsv;
5829 struct extent_buffer *buf;
5830 u64 flags = 0;
5831 int ret;
5832
5833
5834 block_rsv = use_block_rsv(trans, root, blocksize);
5835 if (IS_ERR(block_rsv))
5836 return ERR_CAST(block_rsv);
5837
5838 ret = btrfs_reserve_extent(trans, root, blocksize, blocksize,
5839 empty_size, hint, (u64)-1, &ins, 0);
5840 if (ret) {
5841 unuse_block_rsv(block_rsv, blocksize);
5842 return ERR_PTR(ret);
5843 }
5844
5845 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
5846 blocksize, level);
5847 BUG_ON(IS_ERR(buf));
5848
5849 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
5850 if (parent == 0)
5851 parent = ins.objectid;
5852 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
5853 } else
5854 BUG_ON(parent > 0);
5855
5856 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
5857 struct btrfs_delayed_extent_op *extent_op;
5858 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
5859 BUG_ON(!extent_op);
5860 if (key)
5861 memcpy(&extent_op->key, key, sizeof(extent_op->key));
5862 else
5863 memset(&extent_op->key, 0, sizeof(extent_op->key));
5864 extent_op->flags_to_set = flags;
5865 extent_op->update_key = 1;
5866 extent_op->update_flags = 1;
5867 extent_op->is_data = 0;
5868
5869 ret = btrfs_add_delayed_tree_ref(trans, ins.objectid,
5870 ins.offset, parent, root_objectid,
5871 level, BTRFS_ADD_DELAYED_EXTENT,
5872 extent_op);
5873 BUG_ON(ret);
5874 }
5875 return buf;
5876 }
5877
5878 struct walk_control {
5879 u64 refs[BTRFS_MAX_LEVEL];
5880 u64 flags[BTRFS_MAX_LEVEL];
5881 struct btrfs_key update_progress;
5882 int stage;
5883 int level;
5884 int shared_level;
5885 int update_ref;
5886 int keep_locks;
5887 int reada_slot;
5888 int reada_count;
5889 };
5890
5891 #define DROP_REFERENCE 1
5892 #define UPDATE_BACKREF 2
5893
5894 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
5895 struct btrfs_root *root,
5896 struct walk_control *wc,
5897 struct btrfs_path *path)
5898 {
5899 u64 bytenr;
5900 u64 generation;
5901 u64 refs;
5902 u64 flags;
5903 u32 nritems;
5904 u32 blocksize;
5905 struct btrfs_key key;
5906 struct extent_buffer *eb;
5907 int ret;
5908 int slot;
5909 int nread = 0;
5910
5911 if (path->slots[wc->level] < wc->reada_slot) {
5912 wc->reada_count = wc->reada_count * 2 / 3;
5913 wc->reada_count = max(wc->reada_count, 2);
5914 } else {
5915 wc->reada_count = wc->reada_count * 3 / 2;
5916 wc->reada_count = min_t(int, wc->reada_count,
5917 BTRFS_NODEPTRS_PER_BLOCK(root));
5918 }
5919
5920 eb = path->nodes[wc->level];
5921 nritems = btrfs_header_nritems(eb);
5922 blocksize = btrfs_level_size(root, wc->level - 1);
5923
5924 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
5925 if (nread >= wc->reada_count)
5926 break;
5927
5928 cond_resched();
5929 bytenr = btrfs_node_blockptr(eb, slot);
5930 generation = btrfs_node_ptr_generation(eb, slot);
5931
5932 if (slot == path->slots[wc->level])
5933 goto reada;
5934
5935 if (wc->stage == UPDATE_BACKREF &&
5936 generation <= root->root_key.offset)
5937 continue;
5938
5939 /* We don't lock the tree block, it's OK to be racy here */
5940 ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
5941 &refs, &flags);
5942 BUG_ON(ret);
5943 BUG_ON(refs == 0);
5944
5945 if (wc->stage == DROP_REFERENCE) {
5946 if (refs == 1)
5947 goto reada;
5948
5949 if (wc->level == 1 &&
5950 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5951 continue;
5952 if (!wc->update_ref ||
5953 generation <= root->root_key.offset)
5954 continue;
5955 btrfs_node_key_to_cpu(eb, &key, slot);
5956 ret = btrfs_comp_cpu_keys(&key,
5957 &wc->update_progress);
5958 if (ret < 0)
5959 continue;
5960 } else {
5961 if (wc->level == 1 &&
5962 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5963 continue;
5964 }
5965 reada:
5966 ret = readahead_tree_block(root, bytenr, blocksize,
5967 generation);
5968 if (ret)
5969 break;
5970 nread++;
5971 }
5972 wc->reada_slot = slot;
5973 }
5974
5975 /*
5976 * hepler to process tree block while walking down the tree.
5977 *
5978 * when wc->stage == UPDATE_BACKREF, this function updates
5979 * back refs for pointers in the block.
5980 *
5981 * NOTE: return value 1 means we should stop walking down.
5982 */
5983 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
5984 struct btrfs_root *root,
5985 struct btrfs_path *path,
5986 struct walk_control *wc, int lookup_info)
5987 {
5988 int level = wc->level;
5989 struct extent_buffer *eb = path->nodes[level];
5990 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5991 int ret;
5992
5993 if (wc->stage == UPDATE_BACKREF &&
5994 btrfs_header_owner(eb) != root->root_key.objectid)
5995 return 1;
5996
5997 /*
5998 * when reference count of tree block is 1, it won't increase
5999 * again. once full backref flag is set, we never clear it.
6000 */
6001 if (lookup_info &&
6002 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
6003 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
6004 BUG_ON(!path->locks[level]);
6005 ret = btrfs_lookup_extent_info(trans, root,
6006 eb->start, eb->len,
6007 &wc->refs[level],
6008 &wc->flags[level]);
6009 BUG_ON(ret);
6010 BUG_ON(wc->refs[level] == 0);
6011 }
6012
6013 if (wc->stage == DROP_REFERENCE) {
6014 if (wc->refs[level] > 1)
6015 return 1;
6016
6017 if (path->locks[level] && !wc->keep_locks) {
6018 btrfs_tree_unlock(eb);
6019 path->locks[level] = 0;
6020 }
6021 return 0;
6022 }
6023
6024 /* wc->stage == UPDATE_BACKREF */
6025 if (!(wc->flags[level] & flag)) {
6026 BUG_ON(!path->locks[level]);
6027 ret = btrfs_inc_ref(trans, root, eb, 1);
6028 BUG_ON(ret);
6029 ret = btrfs_dec_ref(trans, root, eb, 0);
6030 BUG_ON(ret);
6031 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
6032 eb->len, flag, 0);
6033 BUG_ON(ret);
6034 wc->flags[level] |= flag;
6035 }
6036
6037 /*
6038 * the block is shared by multiple trees, so it's not good to
6039 * keep the tree lock
6040 */
6041 if (path->locks[level] && level > 0) {
6042 btrfs_tree_unlock(eb);
6043 path->locks[level] = 0;
6044 }
6045 return 0;
6046 }
6047
6048 /*
6049 * hepler to process tree block pointer.
6050 *
6051 * when wc->stage == DROP_REFERENCE, this function checks
6052 * reference count of the block pointed to. if the block
6053 * is shared and we need update back refs for the subtree
6054 * rooted at the block, this function changes wc->stage to
6055 * UPDATE_BACKREF. if the block is shared and there is no
6056 * need to update back, this function drops the reference
6057 * to the block.
6058 *
6059 * NOTE: return value 1 means we should stop walking down.
6060 */
6061 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
6062 struct btrfs_root *root,
6063 struct btrfs_path *path,
6064 struct walk_control *wc, int *lookup_info)
6065 {
6066 u64 bytenr;
6067 u64 generation;
6068 u64 parent;
6069 u32 blocksize;
6070 struct btrfs_key key;
6071 struct extent_buffer *next;
6072 int level = wc->level;
6073 int reada = 0;
6074 int ret = 0;
6075
6076 generation = btrfs_node_ptr_generation(path->nodes[level],
6077 path->slots[level]);
6078 /*
6079 * if the lower level block was created before the snapshot
6080 * was created, we know there is no need to update back refs
6081 * for the subtree
6082 */
6083 if (wc->stage == UPDATE_BACKREF &&
6084 generation <= root->root_key.offset) {
6085 *lookup_info = 1;
6086 return 1;
6087 }
6088
6089 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
6090 blocksize = btrfs_level_size(root, level - 1);
6091
6092 next = btrfs_find_tree_block(root, bytenr, blocksize);
6093 if (!next) {
6094 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
6095 if (!next)
6096 return -ENOMEM;
6097 reada = 1;
6098 }
6099 btrfs_tree_lock(next);
6100 btrfs_set_lock_blocking(next);
6101
6102 ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
6103 &wc->refs[level - 1],
6104 &wc->flags[level - 1]);
6105 BUG_ON(ret);
6106 BUG_ON(wc->refs[level - 1] == 0);
6107 *lookup_info = 0;
6108
6109 if (wc->stage == DROP_REFERENCE) {
6110 if (wc->refs[level - 1] > 1) {
6111 if (level == 1 &&
6112 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
6113 goto skip;
6114
6115 if (!wc->update_ref ||
6116 generation <= root->root_key.offset)
6117 goto skip;
6118
6119 btrfs_node_key_to_cpu(path->nodes[level], &key,
6120 path->slots[level]);
6121 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
6122 if (ret < 0)
6123 goto skip;
6124
6125 wc->stage = UPDATE_BACKREF;
6126 wc->shared_level = level - 1;
6127 }
6128 } else {
6129 if (level == 1 &&
6130 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
6131 goto skip;
6132 }
6133
6134 if (!btrfs_buffer_uptodate(next, generation)) {
6135 btrfs_tree_unlock(next);
6136 free_extent_buffer(next);
6137 next = NULL;
6138 *lookup_info = 1;
6139 }
6140
6141 if (!next) {
6142 if (reada && level == 1)
6143 reada_walk_down(trans, root, wc, path);
6144 next = read_tree_block(root, bytenr, blocksize, generation);
6145 if (!next)
6146 return -EIO;
6147 btrfs_tree_lock(next);
6148 btrfs_set_lock_blocking(next);
6149 }
6150
6151 level--;
6152 BUG_ON(level != btrfs_header_level(next));
6153 path->nodes[level] = next;
6154 path->slots[level] = 0;
6155 path->locks[level] = 1;
6156 wc->level = level;
6157 if (wc->level == 1)
6158 wc->reada_slot = 0;
6159 return 0;
6160 skip:
6161 wc->refs[level - 1] = 0;
6162 wc->flags[level - 1] = 0;
6163 if (wc->stage == DROP_REFERENCE) {
6164 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
6165 parent = path->nodes[level]->start;
6166 } else {
6167 BUG_ON(root->root_key.objectid !=
6168 btrfs_header_owner(path->nodes[level]));
6169 parent = 0;
6170 }
6171
6172 ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
6173 root->root_key.objectid, level - 1, 0);
6174 BUG_ON(ret);
6175 }
6176 btrfs_tree_unlock(next);
6177 free_extent_buffer(next);
6178 *lookup_info = 1;
6179 return 1;
6180 }
6181
6182 /*
6183 * hepler to process tree block while walking up the tree.
6184 *
6185 * when wc->stage == DROP_REFERENCE, this function drops
6186 * reference count on the block.
6187 *
6188 * when wc->stage == UPDATE_BACKREF, this function changes
6189 * wc->stage back to DROP_REFERENCE if we changed wc->stage
6190 * to UPDATE_BACKREF previously while processing the block.
6191 *
6192 * NOTE: return value 1 means we should stop walking up.
6193 */
6194 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
6195 struct btrfs_root *root,
6196 struct btrfs_path *path,
6197 struct walk_control *wc)
6198 {
6199 int ret;
6200 int level = wc->level;
6201 struct extent_buffer *eb = path->nodes[level];
6202 u64 parent = 0;
6203
6204 if (wc->stage == UPDATE_BACKREF) {
6205 BUG_ON(wc->shared_level < level);
6206 if (level < wc->shared_level)
6207 goto out;
6208
6209 ret = find_next_key(path, level + 1, &wc->update_progress);
6210 if (ret > 0)
6211 wc->update_ref = 0;
6212
6213 wc->stage = DROP_REFERENCE;
6214 wc->shared_level = -1;
6215 path->slots[level] = 0;
6216
6217 /*
6218 * check reference count again if the block isn't locked.
6219 * we should start walking down the tree again if reference
6220 * count is one.
6221 */
6222 if (!path->locks[level]) {
6223 BUG_ON(level == 0);
6224 btrfs_tree_lock(eb);
6225 btrfs_set_lock_blocking(eb);
6226 path->locks[level] = 1;
6227
6228 ret = btrfs_lookup_extent_info(trans, root,
6229 eb->start, eb->len,
6230 &wc->refs[level],
6231 &wc->flags[level]);
6232 BUG_ON(ret);
6233 BUG_ON(wc->refs[level] == 0);
6234 if (wc->refs[level] == 1) {
6235 btrfs_tree_unlock(eb);
6236 path->locks[level] = 0;
6237 return 1;
6238 }
6239 }
6240 }
6241
6242 /* wc->stage == DROP_REFERENCE */
6243 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
6244
6245 if (wc->refs[level] == 1) {
6246 if (level == 0) {
6247 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
6248 ret = btrfs_dec_ref(trans, root, eb, 1);
6249 else
6250 ret = btrfs_dec_ref(trans, root, eb, 0);
6251 BUG_ON(ret);
6252 }
6253 /* make block locked assertion in clean_tree_block happy */
6254 if (!path->locks[level] &&
6255 btrfs_header_generation(eb) == trans->transid) {
6256 btrfs_tree_lock(eb);
6257 btrfs_set_lock_blocking(eb);
6258 path->locks[level] = 1;
6259 }
6260 clean_tree_block(trans, root, eb);
6261 }
6262
6263 if (eb == root->node) {
6264 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
6265 parent = eb->start;
6266 else
6267 BUG_ON(root->root_key.objectid !=
6268 btrfs_header_owner(eb));
6269 } else {
6270 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
6271 parent = path->nodes[level + 1]->start;
6272 else
6273 BUG_ON(root->root_key.objectid !=
6274 btrfs_header_owner(path->nodes[level + 1]));
6275 }
6276
6277 btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
6278 out:
6279 wc->refs[level] = 0;
6280 wc->flags[level] = 0;
6281 return 0;
6282 }
6283
6284 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
6285 struct btrfs_root *root,
6286 struct btrfs_path *path,
6287 struct walk_control *wc)
6288 {
6289 int level = wc->level;
6290 int lookup_info = 1;
6291 int ret;
6292
6293 while (level >= 0) {
6294 ret = walk_down_proc(trans, root, path, wc, lookup_info);
6295 if (ret > 0)
6296 break;
6297
6298 if (level == 0)
6299 break;
6300
6301 if (path->slots[level] >=
6302 btrfs_header_nritems(path->nodes[level]))
6303 break;
6304
6305 ret = do_walk_down(trans, root, path, wc, &lookup_info);
6306 if (ret > 0) {
6307 path->slots[level]++;
6308 continue;
6309 } else if (ret < 0)
6310 return ret;
6311 level = wc->level;
6312 }
6313 return 0;
6314 }
6315
6316 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
6317 struct btrfs_root *root,
6318 struct btrfs_path *path,
6319 struct walk_control *wc, int max_level)
6320 {
6321 int level = wc->level;
6322 int ret;
6323
6324 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
6325 while (level < max_level && path->nodes[level]) {
6326 wc->level = level;
6327 if (path->slots[level] + 1 <
6328 btrfs_header_nritems(path->nodes[level])) {
6329 path->slots[level]++;
6330 return 0;
6331 } else {
6332 ret = walk_up_proc(trans, root, path, wc);
6333 if (ret > 0)
6334 return 0;
6335
6336 if (path->locks[level]) {
6337 btrfs_tree_unlock(path->nodes[level]);
6338 path->locks[level] = 0;
6339 }
6340 free_extent_buffer(path->nodes[level]);
6341 path->nodes[level] = NULL;
6342 level++;
6343 }
6344 }
6345 return 1;
6346 }
6347
6348 /*
6349 * drop a subvolume tree.
6350 *
6351 * this function traverses the tree freeing any blocks that only
6352 * referenced by the tree.
6353 *
6354 * when a shared tree block is found. this function decreases its
6355 * reference count by one. if update_ref is true, this function
6356 * also make sure backrefs for the shared block and all lower level
6357 * blocks are properly updated.
6358 */
6359 int btrfs_drop_snapshot(struct btrfs_root *root,
6360 struct btrfs_block_rsv *block_rsv, int update_ref)
6361 {
6362 struct btrfs_path *path;
6363 struct btrfs_trans_handle *trans;
6364 struct btrfs_root *tree_root = root->fs_info->tree_root;
6365 struct btrfs_root_item *root_item = &root->root_item;
6366 struct walk_control *wc;
6367 struct btrfs_key key;
6368 int err = 0;
6369 int ret;
6370 int level;
6371
6372 path = btrfs_alloc_path();
6373 BUG_ON(!path);
6374
6375 wc = kzalloc(sizeof(*wc), GFP_NOFS);
6376 BUG_ON(!wc);
6377
6378 trans = btrfs_start_transaction(tree_root, 0);
6379 BUG_ON(IS_ERR(trans));
6380
6381 if (block_rsv)
6382 trans->block_rsv = block_rsv;
6383
6384 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
6385 level = btrfs_header_level(root->node);
6386 path->nodes[level] = btrfs_lock_root_node(root);
6387 btrfs_set_lock_blocking(path->nodes[level]);
6388 path->slots[level] = 0;
6389 path->locks[level] = 1;
6390 memset(&wc->update_progress, 0,
6391 sizeof(wc->update_progress));
6392 } else {
6393 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
6394 memcpy(&wc->update_progress, &key,
6395 sizeof(wc->update_progress));
6396
6397 level = root_item->drop_level;
6398 BUG_ON(level == 0);
6399 path->lowest_level = level;
6400 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6401 path->lowest_level = 0;
6402 if (ret < 0) {
6403 err = ret;
6404 goto out;
6405 }
6406 WARN_ON(ret > 0);
6407
6408 /*
6409 * unlock our path, this is safe because only this
6410 * function is allowed to delete this snapshot
6411 */
6412 btrfs_unlock_up_safe(path, 0);
6413
6414 level = btrfs_header_level(root->node);
6415 while (1) {
6416 btrfs_tree_lock(path->nodes[level]);
6417 btrfs_set_lock_blocking(path->nodes[level]);
6418
6419 ret = btrfs_lookup_extent_info(trans, root,
6420 path->nodes[level]->start,
6421 path->nodes[level]->len,
6422 &wc->refs[level],
6423 &wc->flags[level]);
6424 BUG_ON(ret);
6425 BUG_ON(wc->refs[level] == 0);
6426
6427 if (level == root_item->drop_level)
6428 break;
6429
6430 btrfs_tree_unlock(path->nodes[level]);
6431 WARN_ON(wc->refs[level] != 1);
6432 level--;
6433 }
6434 }
6435
6436 wc->level = level;
6437 wc->shared_level = -1;
6438 wc->stage = DROP_REFERENCE;
6439 wc->update_ref = update_ref;
6440 wc->keep_locks = 0;
6441 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
6442
6443 while (1) {
6444 ret = walk_down_tree(trans, root, path, wc);
6445 if (ret < 0) {
6446 err = ret;
6447 break;
6448 }
6449
6450 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
6451 if (ret < 0) {
6452 err = ret;
6453 break;
6454 }
6455
6456 if (ret > 0) {
6457 BUG_ON(wc->stage != DROP_REFERENCE);
6458 break;
6459 }
6460
6461 if (wc->stage == DROP_REFERENCE) {
6462 level = wc->level;
6463 btrfs_node_key(path->nodes[level],
6464 &root_item->drop_progress,
6465 path->slots[level]);
6466 root_item->drop_level = level;
6467 }
6468
6469 BUG_ON(wc->level == 0);
6470 if (btrfs_should_end_transaction(trans, tree_root)) {
6471 ret = btrfs_update_root(trans, tree_root,
6472 &root->root_key,
6473 root_item);
6474 BUG_ON(ret);
6475
6476 btrfs_end_transaction_throttle(trans, tree_root);
6477 trans = btrfs_start_transaction(tree_root, 0);
6478 BUG_ON(IS_ERR(trans));
6479 if (block_rsv)
6480 trans->block_rsv = block_rsv;
6481 }
6482 }
6483 btrfs_release_path(root, path);
6484 BUG_ON(err);
6485
6486 ret = btrfs_del_root(trans, tree_root, &root->root_key);
6487 BUG_ON(ret);
6488
6489 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
6490 ret = btrfs_find_last_root(tree_root, root->root_key.objectid,
6491 NULL, NULL);
6492 BUG_ON(ret < 0);
6493 if (ret > 0) {
6494 /* if we fail to delete the orphan item this time
6495 * around, it'll get picked up the next time.
6496 *
6497 * The most common failure here is just -ENOENT.
6498 */
6499 btrfs_del_orphan_item(trans, tree_root,
6500 root->root_key.objectid);
6501 }
6502 }
6503
6504 if (root->in_radix) {
6505 btrfs_free_fs_root(tree_root->fs_info, root);
6506 } else {
6507 free_extent_buffer(root->node);
6508 free_extent_buffer(root->commit_root);
6509 kfree(root);
6510 }
6511 out:
6512 btrfs_end_transaction_throttle(trans, tree_root);
6513 kfree(wc);
6514 btrfs_free_path(path);
6515 return err;
6516 }
6517
6518 /*
6519 * drop subtree rooted at tree block 'node'.
6520 *
6521 * NOTE: this function will unlock and release tree block 'node'
6522 */
6523 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
6524 struct btrfs_root *root,
6525 struct extent_buffer *node,
6526 struct extent_buffer *parent)
6527 {
6528 struct btrfs_path *path;
6529 struct walk_control *wc;
6530 int level;
6531 int parent_level;
6532 int ret = 0;
6533 int wret;
6534
6535 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
6536
6537 path = btrfs_alloc_path();
6538 if (!path)
6539 return -ENOMEM;
6540
6541 wc = kzalloc(sizeof(*wc), GFP_NOFS);
6542 if (!wc) {
6543 btrfs_free_path(path);
6544 return -ENOMEM;
6545 }
6546
6547 btrfs_assert_tree_locked(parent);
6548 parent_level = btrfs_header_level(parent);
6549 extent_buffer_get(parent);
6550 path->nodes[parent_level] = parent;
6551 path->slots[parent_level] = btrfs_header_nritems(parent);
6552
6553 btrfs_assert_tree_locked(node);
6554 level = btrfs_header_level(node);
6555 path->nodes[level] = node;
6556 path->slots[level] = 0;
6557 path->locks[level] = 1;
6558
6559 wc->refs[parent_level] = 1;
6560 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
6561 wc->level = level;
6562 wc->shared_level = -1;
6563 wc->stage = DROP_REFERENCE;
6564 wc->update_ref = 0;
6565 wc->keep_locks = 1;
6566 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
6567
6568 while (1) {
6569 wret = walk_down_tree(trans, root, path, wc);
6570 if (wret < 0) {
6571 ret = wret;
6572 break;
6573 }
6574
6575 wret = walk_up_tree(trans, root, path, wc, parent_level);
6576 if (wret < 0)
6577 ret = wret;
6578 if (wret != 0)
6579 break;
6580 }
6581
6582 kfree(wc);
6583 btrfs_free_path(path);
6584 return ret;
6585 }
6586
6587 #if 0
6588 static unsigned long calc_ra(unsigned long start, unsigned long last,
6589 unsigned long nr)
6590 {
6591 return min(last, start + nr - 1);
6592 }
6593
6594 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
6595 u64 len)
6596 {
6597 u64 page_start;
6598 u64 page_end;
6599 unsigned long first_index;
6600 unsigned long last_index;
6601 unsigned long i;
6602 struct page *page;
6603 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6604 struct file_ra_state *ra;
6605 struct btrfs_ordered_extent *ordered;
6606 unsigned int total_read = 0;
6607 unsigned int total_dirty = 0;
6608 int ret = 0;
6609
6610 ra = kzalloc(sizeof(*ra), GFP_NOFS);
6611 if (!ra)
6612 return -ENOMEM;
6613
6614 mutex_lock(&inode->i_mutex);
6615 first_index = start >> PAGE_CACHE_SHIFT;
6616 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
6617
6618 /* make sure the dirty trick played by the caller work */
6619 ret = invalidate_inode_pages2_range(inode->i_mapping,
6620 first_index, last_index);
6621 if (ret)
6622 goto out_unlock;
6623
6624 file_ra_state_init(ra, inode->i_mapping);
6625
6626 for (i = first_index ; i <= last_index; i++) {
6627 if (total_read % ra->ra_pages == 0) {
6628 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
6629 calc_ra(i, last_index, ra->ra_pages));
6630 }
6631 total_read++;
6632 again:
6633 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
6634 BUG_ON(1);
6635 page = grab_cache_page(inode->i_mapping, i);
6636 if (!page) {
6637 ret = -ENOMEM;
6638 goto out_unlock;
6639 }
6640 if (!PageUptodate(page)) {
6641 btrfs_readpage(NULL, page);
6642 lock_page(page);
6643 if (!PageUptodate(page)) {
6644 unlock_page(page);
6645 page_cache_release(page);
6646 ret = -EIO;
6647 goto out_unlock;
6648 }
6649 }
6650 wait_on_page_writeback(page);
6651
6652 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
6653 page_end = page_start + PAGE_CACHE_SIZE - 1;
6654 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
6655
6656 ordered = btrfs_lookup_ordered_extent(inode, page_start);
6657 if (ordered) {
6658 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
6659 unlock_page(page);
6660 page_cache_release(page);
6661 btrfs_start_ordered_extent(inode, ordered, 1);
6662 btrfs_put_ordered_extent(ordered);
6663 goto again;
6664 }
6665 set_page_extent_mapped(page);
6666
6667 if (i == first_index)
6668 set_extent_bits(io_tree, page_start, page_end,
6669 EXTENT_BOUNDARY, GFP_NOFS);
6670 btrfs_set_extent_delalloc(inode, page_start, page_end);
6671
6672 set_page_dirty(page);
6673 total_dirty++;
6674
6675 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
6676 unlock_page(page);
6677 page_cache_release(page);
6678 }
6679
6680 out_unlock:
6681 kfree(ra);
6682 mutex_unlock(&inode->i_mutex);
6683 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
6684 return ret;
6685 }
6686
6687 static noinline int relocate_data_extent(struct inode *reloc_inode,
6688 struct btrfs_key *extent_key,
6689 u64 offset)
6690 {
6691 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
6692 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
6693 struct extent_map *em;
6694 u64 start = extent_key->objectid - offset;
6695 u64 end = start + extent_key->offset - 1;
6696
6697 em = alloc_extent_map(GFP_NOFS);
6698 BUG_ON(!em);
6699
6700 em->start = start;
6701 em->len = extent_key->offset;
6702 em->block_len = extent_key->offset;
6703 em->block_start = extent_key->objectid;
6704 em->bdev = root->fs_info->fs_devices->latest_bdev;
6705 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6706
6707 /* setup extent map to cheat btrfs_readpage */
6708 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
6709 while (1) {
6710 int ret;
6711 write_lock(&em_tree->lock);
6712 ret = add_extent_mapping(em_tree, em);
6713 write_unlock(&em_tree->lock);
6714 if (ret != -EEXIST) {
6715 free_extent_map(em);
6716 break;
6717 }
6718 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
6719 }
6720 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
6721
6722 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
6723 }
6724
6725 struct btrfs_ref_path {
6726 u64 extent_start;
6727 u64 nodes[BTRFS_MAX_LEVEL];
6728 u64 root_objectid;
6729 u64 root_generation;
6730 u64 owner_objectid;
6731 u32 num_refs;
6732 int lowest_level;
6733 int current_level;
6734 int shared_level;
6735
6736 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
6737 u64 new_nodes[BTRFS_MAX_LEVEL];
6738 };
6739
6740 struct disk_extent {
6741 u64 ram_bytes;
6742 u64 disk_bytenr;
6743 u64 disk_num_bytes;
6744 u64 offset;
6745 u64 num_bytes;
6746 u8 compression;
6747 u8 encryption;
6748 u16 other_encoding;
6749 };
6750
6751 static int is_cowonly_root(u64 root_objectid)
6752 {
6753 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
6754 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
6755 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
6756 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
6757 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
6758 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
6759 return 1;
6760 return 0;
6761 }
6762
6763 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
6764 struct btrfs_root *extent_root,
6765 struct btrfs_ref_path *ref_path,
6766 int first_time)
6767 {
6768 struct extent_buffer *leaf;
6769 struct btrfs_path *path;
6770 struct btrfs_extent_ref *ref;
6771 struct btrfs_key key;
6772 struct btrfs_key found_key;
6773 u64 bytenr;
6774 u32 nritems;
6775 int level;
6776 int ret = 1;
6777
6778 path = btrfs_alloc_path();
6779 if (!path)
6780 return -ENOMEM;
6781
6782 if (first_time) {
6783 ref_path->lowest_level = -1;
6784 ref_path->current_level = -1;
6785 ref_path->shared_level = -1;
6786 goto walk_up;
6787 }
6788 walk_down:
6789 level = ref_path->current_level - 1;
6790 while (level >= -1) {
6791 u64 parent;
6792 if (level < ref_path->lowest_level)
6793 break;
6794
6795 if (level >= 0)
6796 bytenr = ref_path->nodes[level];
6797 else
6798 bytenr = ref_path->extent_start;
6799 BUG_ON(bytenr == 0);
6800
6801 parent = ref_path->nodes[level + 1];
6802 ref_path->nodes[level + 1] = 0;
6803 ref_path->current_level = level;
6804 BUG_ON(parent == 0);
6805
6806 key.objectid = bytenr;
6807 key.offset = parent + 1;
6808 key.type = BTRFS_EXTENT_REF_KEY;
6809
6810 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
6811 if (ret < 0)
6812 goto out;
6813 BUG_ON(ret == 0);
6814
6815 leaf = path->nodes[0];
6816 nritems = btrfs_header_nritems(leaf);
6817 if (path->slots[0] >= nritems) {
6818 ret = btrfs_next_leaf(extent_root, path);
6819 if (ret < 0)
6820 goto out;
6821 if (ret > 0)
6822 goto next;
6823 leaf = path->nodes[0];
6824 }
6825
6826 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6827 if (found_key.objectid == bytenr &&
6828 found_key.type == BTRFS_EXTENT_REF_KEY) {
6829 if (level < ref_path->shared_level)
6830 ref_path->shared_level = level;
6831 goto found;
6832 }
6833 next:
6834 level--;
6835 btrfs_release_path(extent_root, path);
6836 cond_resched();
6837 }
6838 /* reached lowest level */
6839 ret = 1;
6840 goto out;
6841 walk_up:
6842 level = ref_path->current_level;
6843 while (level < BTRFS_MAX_LEVEL - 1) {
6844 u64 ref_objectid;
6845
6846 if (level >= 0)
6847 bytenr = ref_path->nodes[level];
6848 else
6849 bytenr = ref_path->extent_start;
6850
6851 BUG_ON(bytenr == 0);
6852
6853 key.objectid = bytenr;
6854 key.offset = 0;
6855 key.type = BTRFS_EXTENT_REF_KEY;
6856
6857 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
6858 if (ret < 0)
6859 goto out;
6860
6861 leaf = path->nodes[0];
6862 nritems = btrfs_header_nritems(leaf);
6863 if (path->slots[0] >= nritems) {
6864 ret = btrfs_next_leaf(extent_root, path);
6865 if (ret < 0)
6866 goto out;
6867 if (ret > 0) {
6868 /* the extent was freed by someone */
6869 if (ref_path->lowest_level == level)
6870 goto out;
6871 btrfs_release_path(extent_root, path);
6872 goto walk_down;
6873 }
6874 leaf = path->nodes[0];
6875 }
6876
6877 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6878 if (found_key.objectid != bytenr ||
6879 found_key.type != BTRFS_EXTENT_REF_KEY) {
6880 /* the extent was freed by someone */
6881 if (ref_path->lowest_level == level) {
6882 ret = 1;
6883 goto out;
6884 }
6885 btrfs_release_path(extent_root, path);
6886 goto walk_down;
6887 }
6888 found:
6889 ref = btrfs_item_ptr(leaf, path->slots[0],
6890 struct btrfs_extent_ref);
6891 ref_objectid = btrfs_ref_objectid(leaf, ref);
6892 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
6893 if (first_time) {
6894 level = (int)ref_objectid;
6895 BUG_ON(level >= BTRFS_MAX_LEVEL);
6896 ref_path->lowest_level = level;
6897 ref_path->current_level = level;
6898 ref_path->nodes[level] = bytenr;
6899 } else {
6900 WARN_ON(ref_objectid != level);
6901 }
6902 } else {
6903 WARN_ON(level != -1);
6904 }
6905 first_time = 0;
6906
6907 if (ref_path->lowest_level == level) {
6908 ref_path->owner_objectid = ref_objectid;
6909 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
6910 }
6911
6912 /*
6913 * the block is tree root or the block isn't in reference
6914 * counted tree.
6915 */
6916 if (found_key.objectid == found_key.offset ||
6917 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
6918 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
6919 ref_path->root_generation =
6920 btrfs_ref_generation(leaf, ref);
6921 if (level < 0) {
6922 /* special reference from the tree log */
6923 ref_path->nodes[0] = found_key.offset;
6924 ref_path->current_level = 0;
6925 }
6926 ret = 0;
6927 goto out;
6928 }
6929
6930 level++;
6931 BUG_ON(ref_path->nodes[level] != 0);
6932 ref_path->nodes[level] = found_key.offset;
6933 ref_path->current_level = level;
6934
6935 /*
6936 * the reference was created in the running transaction,
6937 * no need to continue walking up.
6938 */
6939 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
6940 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
6941 ref_path->root_generation =
6942 btrfs_ref_generation(leaf, ref);
6943 ret = 0;
6944 goto out;
6945 }
6946
6947 btrfs_release_path(extent_root, path);
6948 cond_resched();
6949 }
6950 /* reached max tree level, but no tree root found. */
6951 BUG();
6952 out:
6953 btrfs_free_path(path);
6954 return ret;
6955 }
6956
6957 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
6958 struct btrfs_root *extent_root,
6959 struct btrfs_ref_path *ref_path,
6960 u64 extent_start)
6961 {
6962 memset(ref_path, 0, sizeof(*ref_path));
6963 ref_path->extent_start = extent_start;
6964
6965 return __next_ref_path(trans, extent_root, ref_path, 1);
6966 }
6967
6968 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
6969 struct btrfs_root *extent_root,
6970 struct btrfs_ref_path *ref_path)
6971 {
6972 return __next_ref_path(trans, extent_root, ref_path, 0);
6973 }
6974
6975 static noinline int get_new_locations(struct inode *reloc_inode,
6976 struct btrfs_key *extent_key,
6977 u64 offset, int no_fragment,
6978 struct disk_extent **extents,
6979 int *nr_extents)
6980 {
6981 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
6982 struct btrfs_path *path;
6983 struct btrfs_file_extent_item *fi;
6984 struct extent_buffer *leaf;
6985 struct disk_extent *exts = *extents;
6986 struct btrfs_key found_key;
6987 u64 cur_pos;
6988 u64 last_byte;
6989 u32 nritems;
6990 int nr = 0;
6991 int max = *nr_extents;
6992 int ret;
6993
6994 WARN_ON(!no_fragment && *extents);
6995 if (!exts) {
6996 max = 1;
6997 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
6998 if (!exts)
6999 return -ENOMEM;
7000 }
7001
7002 path = btrfs_alloc_path();
7003 if (!path) {
7004 if (exts != *extents)
7005 kfree(exts);
7006 return -ENOMEM;
7007 }
7008
7009 cur_pos = extent_key->objectid - offset;
7010 last_byte = extent_key->objectid + extent_key->offset;
7011 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
7012 cur_pos, 0);
7013 if (ret < 0)
7014 goto out;
7015 if (ret > 0) {
7016 ret = -ENOENT;
7017 goto out;
7018 }
7019
7020 while (1) {
7021 leaf = path->nodes[0];
7022 nritems = btrfs_header_nritems(leaf);
7023 if (path->slots[0] >= nritems) {
7024 ret = btrfs_next_leaf(root, path);
7025 if (ret < 0)
7026 goto out;
7027 if (ret > 0)
7028 break;
7029 leaf = path->nodes[0];
7030 }
7031
7032 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7033 if (found_key.offset != cur_pos ||
7034 found_key.type != BTRFS_EXTENT_DATA_KEY ||
7035 found_key.objectid != reloc_inode->i_ino)
7036 break;
7037
7038 fi = btrfs_item_ptr(leaf, path->slots[0],
7039 struct btrfs_file_extent_item);
7040 if (btrfs_file_extent_type(leaf, fi) !=
7041 BTRFS_FILE_EXTENT_REG ||
7042 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
7043 break;
7044
7045 if (nr == max) {
7046 struct disk_extent *old = exts;
7047 max *= 2;
7048 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
7049 if (!exts) {
7050 ret = -ENOMEM;
7051 goto out;
7052 }
7053 memcpy(exts, old, sizeof(*exts) * nr);
7054 if (old != *extents)
7055 kfree(old);
7056 }
7057
7058 exts[nr].disk_bytenr =
7059 btrfs_file_extent_disk_bytenr(leaf, fi);
7060 exts[nr].disk_num_bytes =
7061 btrfs_file_extent_disk_num_bytes(leaf, fi);
7062 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
7063 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
7064 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7065 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
7066 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
7067 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
7068 fi);
7069 BUG_ON(exts[nr].offset > 0);
7070 BUG_ON(exts[nr].compression || exts[nr].encryption);
7071 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
7072
7073 cur_pos += exts[nr].num_bytes;
7074 nr++;
7075
7076 if (cur_pos + offset >= last_byte)
7077 break;
7078
7079 if (no_fragment) {
7080 ret = 1;
7081 goto out;
7082 }
7083 path->slots[0]++;
7084 }
7085
7086 BUG_ON(cur_pos + offset > last_byte);
7087 if (cur_pos + offset < last_byte) {
7088 ret = -ENOENT;
7089 goto out;
7090 }
7091 ret = 0;
7092 out:
7093 btrfs_free_path(path);
7094 if (ret) {
7095 if (exts != *extents)
7096 kfree(exts);
7097 } else {
7098 *extents = exts;
7099 *nr_extents = nr;
7100 }
7101 return ret;
7102 }
7103
7104 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
7105 struct btrfs_root *root,
7106 struct btrfs_path *path,
7107 struct btrfs_key *extent_key,
7108 struct btrfs_key *leaf_key,
7109 struct btrfs_ref_path *ref_path,
7110 struct disk_extent *new_extents,
7111 int nr_extents)
7112 {
7113 struct extent_buffer *leaf;
7114 struct btrfs_file_extent_item *fi;
7115 struct inode *inode = NULL;
7116 struct btrfs_key key;
7117 u64 lock_start = 0;
7118 u64 lock_end = 0;
7119 u64 num_bytes;
7120 u64 ext_offset;
7121 u64 search_end = (u64)-1;
7122 u32 nritems;
7123 int nr_scaned = 0;
7124 int extent_locked = 0;
7125 int extent_type;
7126 int ret;
7127
7128 memcpy(&key, leaf_key, sizeof(key));
7129 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
7130 if (key.objectid < ref_path->owner_objectid ||
7131 (key.objectid == ref_path->owner_objectid &&
7132 key.type < BTRFS_EXTENT_DATA_KEY)) {
7133 key.objectid = ref_path->owner_objectid;
7134 key.type = BTRFS_EXTENT_DATA_KEY;
7135 key.offset = 0;
7136 }
7137 }
7138
7139 while (1) {
7140 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
7141 if (ret < 0)
7142 goto out;
7143
7144 leaf = path->nodes[0];
7145 nritems = btrfs_header_nritems(leaf);
7146 next:
7147 if (extent_locked && ret > 0) {
7148 /*
7149 * the file extent item was modified by someone
7150 * before the extent got locked.
7151 */
7152 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
7153 lock_end, GFP_NOFS);
7154 extent_locked = 0;
7155 }
7156
7157 if (path->slots[0] >= nritems) {
7158 if (++nr_scaned > 2)
7159 break;
7160
7161 BUG_ON(extent_locked);
7162 ret = btrfs_next_leaf(root, path);
7163 if (ret < 0)
7164 goto out;
7165 if (ret > 0)
7166 break;
7167 leaf = path->nodes[0];
7168 nritems = btrfs_header_nritems(leaf);
7169 }
7170
7171 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
7172
7173 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
7174 if ((key.objectid > ref_path->owner_objectid) ||
7175 (key.objectid == ref_path->owner_objectid &&
7176 key.type > BTRFS_EXTENT_DATA_KEY) ||
7177 key.offset >= search_end)
7178 break;
7179 }
7180
7181 if (inode && key.objectid != inode->i_ino) {
7182 BUG_ON(extent_locked);
7183 btrfs_release_path(root, path);
7184 mutex_unlock(&inode->i_mutex);
7185 iput(inode);
7186 inode = NULL;
7187 continue;
7188 }
7189
7190 if (key.type != BTRFS_EXTENT_DATA_KEY) {
7191 path->slots[0]++;
7192 ret = 1;
7193 goto next;
7194 }
7195 fi = btrfs_item_ptr(leaf, path->slots[0],
7196 struct btrfs_file_extent_item);
7197 extent_type = btrfs_file_extent_type(leaf, fi);
7198 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
7199 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
7200 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
7201 extent_key->objectid)) {
7202 path->slots[0]++;
7203 ret = 1;
7204 goto next;
7205 }
7206
7207 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
7208 ext_offset = btrfs_file_extent_offset(leaf, fi);
7209
7210 if (search_end == (u64)-1) {
7211 search_end = key.offset - ext_offset +
7212 btrfs_file_extent_ram_bytes(leaf, fi);
7213 }
7214
7215 if (!extent_locked) {
7216 lock_start = key.offset;
7217 lock_end = lock_start + num_bytes - 1;
7218 } else {
7219 if (lock_start > key.offset ||
7220 lock_end + 1 < key.offset + num_bytes) {
7221 unlock_extent(&BTRFS_I(inode)->io_tree,
7222 lock_start, lock_end, GFP_NOFS);
7223 extent_locked = 0;
7224 }
7225 }
7226
7227 if (!inode) {
7228 btrfs_release_path(root, path);
7229
7230 inode = btrfs_iget_locked(root->fs_info->sb,
7231 key.objectid, root);
7232 if (inode->i_state & I_NEW) {
7233 BTRFS_I(inode)->root = root;
7234 BTRFS_I(inode)->location.objectid =
7235 key.objectid;
7236 BTRFS_I(inode)->location.type =
7237 BTRFS_INODE_ITEM_KEY;
7238 BTRFS_I(inode)->location.offset = 0;
7239 btrfs_read_locked_inode(inode);
7240 unlock_new_inode(inode);
7241 }
7242 /*
7243 * some code call btrfs_commit_transaction while
7244 * holding the i_mutex, so we can't use mutex_lock
7245 * here.
7246 */
7247 if (is_bad_inode(inode) ||
7248 !mutex_trylock(&inode->i_mutex)) {
7249 iput(inode);
7250 inode = NULL;
7251 key.offset = (u64)-1;
7252 goto skip;
7253 }
7254 }
7255
7256 if (!extent_locked) {
7257 struct btrfs_ordered_extent *ordered;
7258
7259 btrfs_release_path(root, path);
7260
7261 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
7262 lock_end, GFP_NOFS);
7263 ordered = btrfs_lookup_first_ordered_extent(inode,
7264 lock_end);
7265 if (ordered &&
7266 ordered->file_offset <= lock_end &&
7267 ordered->file_offset + ordered->len > lock_start) {
7268 unlock_extent(&BTRFS_I(inode)->io_tree,
7269 lock_start, lock_end, GFP_NOFS);
7270 btrfs_start_ordered_extent(inode, ordered, 1);
7271 btrfs_put_ordered_extent(ordered);
7272 key.offset += num_bytes;
7273 goto skip;
7274 }
7275 if (ordered)
7276 btrfs_put_ordered_extent(ordered);
7277
7278 extent_locked = 1;
7279 continue;
7280 }
7281
7282 if (nr_extents == 1) {
7283 /* update extent pointer in place */
7284 btrfs_set_file_extent_disk_bytenr(leaf, fi,
7285 new_extents[0].disk_bytenr);
7286 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
7287 new_extents[0].disk_num_bytes);
7288 btrfs_mark_buffer_dirty(leaf);
7289
7290 btrfs_drop_extent_cache(inode, key.offset,
7291 key.offset + num_bytes - 1, 0);
7292
7293 ret = btrfs_inc_extent_ref(trans, root,
7294 new_extents[0].disk_bytenr,
7295 new_extents[0].disk_num_bytes,
7296 leaf->start,
7297 root->root_key.objectid,
7298 trans->transid,
7299 key.objectid);
7300 BUG_ON(ret);
7301
7302 ret = btrfs_free_extent(trans, root,
7303 extent_key->objectid,
7304 extent_key->offset,
7305 leaf->start,
7306 btrfs_header_owner(leaf),
7307 btrfs_header_generation(leaf),
7308 key.objectid, 0);
7309 BUG_ON(ret);
7310
7311 btrfs_release_path(root, path);
7312 key.offset += num_bytes;
7313 } else {
7314 BUG_ON(1);
7315 #if 0
7316 u64 alloc_hint;
7317 u64 extent_len;
7318 int i;
7319 /*
7320 * drop old extent pointer at first, then insert the
7321 * new pointers one bye one
7322 */
7323 btrfs_release_path(root, path);
7324 ret = btrfs_drop_extents(trans, root, inode, key.offset,
7325 key.offset + num_bytes,
7326 key.offset, &alloc_hint);
7327 BUG_ON(ret);
7328
7329 for (i = 0; i < nr_extents; i++) {
7330 if (ext_offset >= new_extents[i].num_bytes) {
7331 ext_offset -= new_extents[i].num_bytes;
7332 continue;
7333 }
7334 extent_len = min(new_extents[i].num_bytes -
7335 ext_offset, num_bytes);
7336
7337 ret = btrfs_insert_empty_item(trans, root,
7338 path, &key,
7339 sizeof(*fi));
7340 BUG_ON(ret);
7341
7342 leaf = path->nodes[0];
7343 fi = btrfs_item_ptr(leaf, path->slots[0],
7344 struct btrfs_file_extent_item);
7345 btrfs_set_file_extent_generation(leaf, fi,
7346 trans->transid);
7347 btrfs_set_file_extent_type(leaf, fi,
7348 BTRFS_FILE_EXTENT_REG);
7349 btrfs_set_file_extent_disk_bytenr(leaf, fi,
7350 new_extents[i].disk_bytenr);
7351 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
7352 new_extents[i].disk_num_bytes);
7353 btrfs_set_file_extent_ram_bytes(leaf, fi,
7354 new_extents[i].ram_bytes);
7355
7356 btrfs_set_file_extent_compression(leaf, fi,
7357 new_extents[i].compression);
7358 btrfs_set_file_extent_encryption(leaf, fi,
7359 new_extents[i].encryption);
7360 btrfs_set_file_extent_other_encoding(leaf, fi,
7361 new_extents[i].other_encoding);
7362
7363 btrfs_set_file_extent_num_bytes(leaf, fi,
7364 extent_len);
7365 ext_offset += new_extents[i].offset;
7366 btrfs_set_file_extent_offset(leaf, fi,
7367 ext_offset);
7368 btrfs_mark_buffer_dirty(leaf);
7369
7370 btrfs_drop_extent_cache(inode, key.offset,
7371 key.offset + extent_len - 1, 0);
7372
7373 ret = btrfs_inc_extent_ref(trans, root,
7374 new_extents[i].disk_bytenr,
7375 new_extents[i].disk_num_bytes,
7376 leaf->start,
7377 root->root_key.objectid,
7378 trans->transid, key.objectid);
7379 BUG_ON(ret);
7380 btrfs_release_path(root, path);
7381
7382 inode_add_bytes(inode, extent_len);
7383
7384 ext_offset = 0;
7385 num_bytes -= extent_len;
7386 key.offset += extent_len;
7387
7388 if (num_bytes == 0)
7389 break;
7390 }
7391 BUG_ON(i >= nr_extents);
7392 #endif
7393 }
7394
7395 if (extent_locked) {
7396 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
7397 lock_end, GFP_NOFS);
7398 extent_locked = 0;
7399 }
7400 skip:
7401 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
7402 key.offset >= search_end)
7403 break;
7404
7405 cond_resched();
7406 }
7407 ret = 0;
7408 out:
7409 btrfs_release_path(root, path);
7410 if (inode) {
7411 mutex_unlock(&inode->i_mutex);
7412 if (extent_locked) {
7413 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
7414 lock_end, GFP_NOFS);
7415 }
7416 iput(inode);
7417 }
7418 return ret;
7419 }
7420
7421 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
7422 struct btrfs_root *root,
7423 struct extent_buffer *buf, u64 orig_start)
7424 {
7425 int level;
7426 int ret;
7427
7428 BUG_ON(btrfs_header_generation(buf) != trans->transid);
7429 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
7430
7431 level = btrfs_header_level(buf);
7432 if (level == 0) {
7433 struct btrfs_leaf_ref *ref;
7434 struct btrfs_leaf_ref *orig_ref;
7435
7436 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
7437 if (!orig_ref)
7438 return -ENOENT;
7439
7440 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
7441 if (!ref) {
7442 btrfs_free_leaf_ref(root, orig_ref);
7443 return -ENOMEM;
7444 }
7445
7446 ref->nritems = orig_ref->nritems;
7447 memcpy(ref->extents, orig_ref->extents,
7448 sizeof(ref->extents[0]) * ref->nritems);
7449
7450 btrfs_free_leaf_ref(root, orig_ref);
7451
7452 ref->root_gen = trans->transid;
7453 ref->bytenr = buf->start;
7454 ref->owner = btrfs_header_owner(buf);
7455 ref->generation = btrfs_header_generation(buf);
7456
7457 ret = btrfs_add_leaf_ref(root, ref, 0);
7458 WARN_ON(ret);
7459 btrfs_free_leaf_ref(root, ref);
7460 }
7461 return 0;
7462 }
7463
7464 static noinline int invalidate_extent_cache(struct btrfs_root *root,
7465 struct extent_buffer *leaf,
7466 struct btrfs_block_group_cache *group,
7467 struct btrfs_root *target_root)
7468 {
7469 struct btrfs_key key;
7470 struct inode *inode = NULL;
7471 struct btrfs_file_extent_item *fi;
7472 struct extent_state *cached_state = NULL;
7473 u64 num_bytes;
7474 u64 skip_objectid = 0;
7475 u32 nritems;
7476 u32 i;
7477
7478 nritems = btrfs_header_nritems(leaf);
7479 for (i = 0; i < nritems; i++) {
7480 btrfs_item_key_to_cpu(leaf, &key, i);
7481 if (key.objectid == skip_objectid ||
7482 key.type != BTRFS_EXTENT_DATA_KEY)
7483 continue;
7484 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
7485 if (btrfs_file_extent_type(leaf, fi) ==
7486 BTRFS_FILE_EXTENT_INLINE)
7487 continue;
7488 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
7489 continue;
7490 if (!inode || inode->i_ino != key.objectid) {
7491 iput(inode);
7492 inode = btrfs_ilookup(target_root->fs_info->sb,
7493 key.objectid, target_root, 1);
7494 }
7495 if (!inode) {
7496 skip_objectid = key.objectid;
7497 continue;
7498 }
7499 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
7500
7501 lock_extent_bits(&BTRFS_I(inode)->io_tree, key.offset,
7502 key.offset + num_bytes - 1, 0, &cached_state,
7503 GFP_NOFS);
7504 btrfs_drop_extent_cache(inode, key.offset,
7505 key.offset + num_bytes - 1, 1);
7506 unlock_extent_cached(&BTRFS_I(inode)->io_tree, key.offset,
7507 key.offset + num_bytes - 1, &cached_state,
7508 GFP_NOFS);
7509 cond_resched();
7510 }
7511 iput(inode);
7512 return 0;
7513 }
7514
7515 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
7516 struct btrfs_root *root,
7517 struct extent_buffer *leaf,
7518 struct btrfs_block_group_cache *group,
7519 struct inode *reloc_inode)
7520 {
7521 struct btrfs_key key;
7522 struct btrfs_key extent_key;
7523 struct btrfs_file_extent_item *fi;
7524 struct btrfs_leaf_ref *ref;
7525 struct disk_extent *new_extent;
7526 u64 bytenr;
7527 u64 num_bytes;
7528 u32 nritems;
7529 u32 i;
7530 int ext_index;
7531 int nr_extent;
7532 int ret;
7533
7534 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
7535 if (!new_extent)
7536 return -ENOMEM;
7537
7538 ref = btrfs_lookup_leaf_ref(root, leaf->start);
7539 BUG_ON(!ref);
7540
7541 ext_index = -1;
7542 nritems = btrfs_header_nritems(leaf);
7543 for (i = 0; i < nritems; i++) {
7544 btrfs_item_key_to_cpu(leaf, &key, i);
7545 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
7546 continue;
7547 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
7548 if (btrfs_file_extent_type(leaf, fi) ==
7549 BTRFS_FILE_EXTENT_INLINE)
7550 continue;
7551 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7552 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
7553 if (bytenr == 0)
7554 continue;
7555
7556 ext_index++;
7557 if (bytenr >= group->key.objectid + group->key.offset ||
7558 bytenr + num_bytes <= group->key.objectid)
7559 continue;
7560
7561 extent_key.objectid = bytenr;
7562 extent_key.offset = num_bytes;
7563 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
7564 nr_extent = 1;
7565 ret = get_new_locations(reloc_inode, &extent_key,
7566 group->key.objectid, 1,
7567 &new_extent, &nr_extent);
7568 if (ret > 0)
7569 continue;
7570 BUG_ON(ret < 0);
7571
7572 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
7573 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
7574 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
7575 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
7576
7577 btrfs_set_file_extent_disk_bytenr(leaf, fi,
7578 new_extent->disk_bytenr);
7579 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
7580 new_extent->disk_num_bytes);
7581 btrfs_mark_buffer_dirty(leaf);
7582
7583 ret = btrfs_inc_extent_ref(trans, root,
7584 new_extent->disk_bytenr,
7585 new_extent->disk_num_bytes,
7586 leaf->start,
7587 root->root_key.objectid,
7588 trans->transid, key.objectid);
7589 BUG_ON(ret);
7590
7591 ret = btrfs_free_extent(trans, root,
7592 bytenr, num_bytes, leaf->start,
7593 btrfs_header_owner(leaf),
7594 btrfs_header_generation(leaf),
7595 key.objectid, 0);
7596 BUG_ON(ret);
7597 cond_resched();
7598 }
7599 kfree(new_extent);
7600 BUG_ON(ext_index + 1 != ref->nritems);
7601 btrfs_free_leaf_ref(root, ref);
7602 return 0;
7603 }
7604
7605 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
7606 struct btrfs_root *root)
7607 {
7608 struct btrfs_root *reloc_root;
7609 int ret;
7610
7611 if (root->reloc_root) {
7612 reloc_root = root->reloc_root;
7613 root->reloc_root = NULL;
7614 list_add(&reloc_root->dead_list,
7615 &root->fs_info->dead_reloc_roots);
7616
7617 btrfs_set_root_bytenr(&reloc_root->root_item,
7618 reloc_root->node->start);
7619 btrfs_set_root_level(&root->root_item,
7620 btrfs_header_level(reloc_root->node));
7621 memset(&reloc_root->root_item.drop_progress, 0,
7622 sizeof(struct btrfs_disk_key));
7623 reloc_root->root_item.drop_level = 0;
7624
7625 ret = btrfs_update_root(trans, root->fs_info->tree_root,
7626 &reloc_root->root_key,
7627 &reloc_root->root_item);
7628 BUG_ON(ret);
7629 }
7630 return 0;
7631 }
7632
7633 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
7634 {
7635 struct btrfs_trans_handle *trans;
7636 struct btrfs_root *reloc_root;
7637 struct btrfs_root *prev_root = NULL;
7638 struct list_head dead_roots;
7639 int ret;
7640 unsigned long nr;
7641
7642 INIT_LIST_HEAD(&dead_roots);
7643 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
7644
7645 while (!list_empty(&dead_roots)) {
7646 reloc_root = list_entry(dead_roots.prev,
7647 struct btrfs_root, dead_list);
7648 list_del_init(&reloc_root->dead_list);
7649
7650 BUG_ON(reloc_root->commit_root != NULL);
7651 while (1) {
7652 trans = btrfs_join_transaction(root, 1);
7653 BUG_ON(IS_ERR(trans));
7654
7655 mutex_lock(&root->fs_info->drop_mutex);
7656 ret = btrfs_drop_snapshot(trans, reloc_root);
7657 if (ret != -EAGAIN)
7658 break;
7659 mutex_unlock(&root->fs_info->drop_mutex);
7660
7661 nr = trans->blocks_used;
7662 ret = btrfs_end_transaction(trans, root);
7663 BUG_ON(ret);
7664 btrfs_btree_balance_dirty(root, nr);
7665 }
7666
7667 free_extent_buffer(reloc_root->node);
7668
7669 ret = btrfs_del_root(trans, root->fs_info->tree_root,
7670 &reloc_root->root_key);
7671 BUG_ON(ret);
7672 mutex_unlock(&root->fs_info->drop_mutex);
7673
7674 nr = trans->blocks_used;
7675 ret = btrfs_end_transaction(trans, root);
7676 BUG_ON(ret);
7677 btrfs_btree_balance_dirty(root, nr);
7678
7679 kfree(prev_root);
7680 prev_root = reloc_root;
7681 }
7682 if (prev_root) {
7683 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
7684 kfree(prev_root);
7685 }
7686 return 0;
7687 }
7688
7689 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
7690 {
7691 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
7692 return 0;
7693 }
7694
7695 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
7696 {
7697 struct btrfs_root *reloc_root;
7698 struct btrfs_trans_handle *trans;
7699 struct btrfs_key location;
7700 int found;
7701 int ret;
7702
7703 mutex_lock(&root->fs_info->tree_reloc_mutex);
7704 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
7705 BUG_ON(ret);
7706 found = !list_empty(&root->fs_info->dead_reloc_roots);
7707 mutex_unlock(&root->fs_info->tree_reloc_mutex);
7708
7709 if (found) {
7710 trans = btrfs_start_transaction(root, 1);
7711 BUG_ON(IS_ERR(trans));
7712 ret = btrfs_commit_transaction(trans, root);
7713 BUG_ON(ret);
7714 }
7715
7716 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
7717 location.offset = (u64)-1;
7718 location.type = BTRFS_ROOT_ITEM_KEY;
7719
7720 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
7721 BUG_ON(!reloc_root);
7722 ret = btrfs_orphan_cleanup(reloc_root);
7723 BUG_ON(ret);
7724 return 0;
7725 }
7726
7727 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
7728 struct btrfs_root *root)
7729 {
7730 struct btrfs_root *reloc_root;
7731 struct extent_buffer *eb;
7732 struct btrfs_root_item *root_item;
7733 struct btrfs_key root_key;
7734 int ret;
7735
7736 BUG_ON(!root->ref_cows);
7737 if (root->reloc_root)
7738 return 0;
7739
7740 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
7741 if (!root_item)
7742 return -ENOMEM;
7743
7744 ret = btrfs_copy_root(trans, root, root->commit_root,
7745 &eb, BTRFS_TREE_RELOC_OBJECTID);
7746 BUG_ON(ret);
7747
7748 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
7749 root_key.offset = root->root_key.objectid;
7750 root_key.type = BTRFS_ROOT_ITEM_KEY;
7751
7752 memcpy(root_item, &root->root_item, sizeof(root_item));
7753 btrfs_set_root_refs(root_item, 0);
7754 btrfs_set_root_bytenr(root_item, eb->start);
7755 btrfs_set_root_level(root_item, btrfs_header_level(eb));
7756 btrfs_set_root_generation(root_item, trans->transid);
7757
7758 btrfs_tree_unlock(eb);
7759 free_extent_buffer(eb);
7760
7761 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
7762 &root_key, root_item);
7763 BUG_ON(ret);
7764 kfree(root_item);
7765
7766 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
7767 &root_key);
7768 BUG_ON(IS_ERR(reloc_root));
7769 reloc_root->last_trans = trans->transid;
7770 reloc_root->commit_root = NULL;
7771 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
7772
7773 root->reloc_root = reloc_root;
7774 return 0;
7775 }
7776
7777 /*
7778 * Core function of space balance.
7779 *
7780 * The idea is using reloc trees to relocate tree blocks in reference
7781 * counted roots. There is one reloc tree for each subvol, and all
7782 * reloc trees share same root key objectid. Reloc trees are snapshots
7783 * of the latest committed roots of subvols (root->commit_root).
7784 *
7785 * To relocate a tree block referenced by a subvol, there are two steps.
7786 * COW the block through subvol's reloc tree, then update block pointer
7787 * in the subvol to point to the new block. Since all reloc trees share
7788 * same root key objectid, doing special handing for tree blocks owned
7789 * by them is easy. Once a tree block has been COWed in one reloc tree,
7790 * we can use the resulting new block directly when the same block is
7791 * required to COW again through other reloc trees. By this way, relocated
7792 * tree blocks are shared between reloc trees, so they are also shared
7793 * between subvols.
7794 */
7795 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
7796 struct btrfs_root *root,
7797 struct btrfs_path *path,
7798 struct btrfs_key *first_key,
7799 struct btrfs_ref_path *ref_path,
7800 struct btrfs_block_group_cache *group,
7801 struct inode *reloc_inode)
7802 {
7803 struct btrfs_root *reloc_root;
7804 struct extent_buffer *eb = NULL;
7805 struct btrfs_key *keys;
7806 u64 *nodes;
7807 int level;
7808 int shared_level;
7809 int lowest_level = 0;
7810 int ret;
7811
7812 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
7813 lowest_level = ref_path->owner_objectid;
7814
7815 if (!root->ref_cows) {
7816 path->lowest_level = lowest_level;
7817 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
7818 BUG_ON(ret < 0);
7819 path->lowest_level = 0;
7820 btrfs_release_path(root, path);
7821 return 0;
7822 }
7823
7824 mutex_lock(&root->fs_info->tree_reloc_mutex);
7825 ret = init_reloc_tree(trans, root);
7826 BUG_ON(ret);
7827 reloc_root = root->reloc_root;
7828
7829 shared_level = ref_path->shared_level;
7830 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
7831
7832 keys = ref_path->node_keys;
7833 nodes = ref_path->new_nodes;
7834 memset(&keys[shared_level + 1], 0,
7835 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
7836 memset(&nodes[shared_level + 1], 0,
7837 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
7838
7839 if (nodes[lowest_level] == 0) {
7840 path->lowest_level = lowest_level;
7841 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
7842 0, 1);
7843 BUG_ON(ret);
7844 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
7845 eb = path->nodes[level];
7846 if (!eb || eb == reloc_root->node)
7847 break;
7848 nodes[level] = eb->start;
7849 if (level == 0)
7850 btrfs_item_key_to_cpu(eb, &keys[level], 0);
7851 else
7852 btrfs_node_key_to_cpu(eb, &keys[level], 0);
7853 }
7854 if (nodes[0] &&
7855 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
7856 eb = path->nodes[0];
7857 ret = replace_extents_in_leaf(trans, reloc_root, eb,
7858 group, reloc_inode);
7859 BUG_ON(ret);
7860 }
7861 btrfs_release_path(reloc_root, path);
7862 } else {
7863 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
7864 lowest_level);
7865 BUG_ON(ret);
7866 }
7867
7868 /*
7869 * replace tree blocks in the fs tree with tree blocks in
7870 * the reloc tree.
7871 */
7872 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
7873 BUG_ON(ret < 0);
7874
7875 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
7876 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
7877 0, 0);
7878 BUG_ON(ret);
7879 extent_buffer_get(path->nodes[0]);
7880 eb = path->nodes[0];
7881 btrfs_release_path(reloc_root, path);
7882 ret = invalidate_extent_cache(reloc_root, eb, group, root);
7883 BUG_ON(ret);
7884 free_extent_buffer(eb);
7885 }
7886
7887 mutex_unlock(&root->fs_info->tree_reloc_mutex);
7888 path->lowest_level = 0;
7889 return 0;
7890 }
7891
7892 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
7893 struct btrfs_root *root,
7894 struct btrfs_path *path,
7895 struct btrfs_key *first_key,
7896 struct btrfs_ref_path *ref_path)
7897 {
7898 int ret;
7899
7900 ret = relocate_one_path(trans, root, path, first_key,
7901 ref_path, NULL, NULL);
7902 BUG_ON(ret);
7903
7904 return 0;
7905 }
7906
7907 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
7908 struct btrfs_root *extent_root,
7909 struct btrfs_path *path,
7910 struct btrfs_key *extent_key)
7911 {
7912 int ret;
7913
7914 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
7915 if (ret)
7916 goto out;
7917 ret = btrfs_del_item(trans, extent_root, path);
7918 out:
7919 btrfs_release_path(extent_root, path);
7920 return ret;
7921 }
7922
7923 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
7924 struct btrfs_ref_path *ref_path)
7925 {
7926 struct btrfs_key root_key;
7927
7928 root_key.objectid = ref_path->root_objectid;
7929 root_key.type = BTRFS_ROOT_ITEM_KEY;
7930 if (is_cowonly_root(ref_path->root_objectid))
7931 root_key.offset = 0;
7932 else
7933 root_key.offset = (u64)-1;
7934
7935 return btrfs_read_fs_root_no_name(fs_info, &root_key);
7936 }
7937
7938 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
7939 struct btrfs_path *path,
7940 struct btrfs_key *extent_key,
7941 struct btrfs_block_group_cache *group,
7942 struct inode *reloc_inode, int pass)
7943 {
7944 struct btrfs_trans_handle *trans;
7945 struct btrfs_root *found_root;
7946 struct btrfs_ref_path *ref_path = NULL;
7947 struct disk_extent *new_extents = NULL;
7948 int nr_extents = 0;
7949 int loops;
7950 int ret;
7951 int level;
7952 struct btrfs_key first_key;
7953 u64 prev_block = 0;
7954
7955
7956 trans = btrfs_start_transaction(extent_root, 1);
7957 BUG_ON(IS_ERR(trans));
7958
7959 if (extent_key->objectid == 0) {
7960 ret = del_extent_zero(trans, extent_root, path, extent_key);
7961 goto out;
7962 }
7963
7964 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
7965 if (!ref_path) {
7966 ret = -ENOMEM;
7967 goto out;
7968 }
7969
7970 for (loops = 0; ; loops++) {
7971 if (loops == 0) {
7972 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
7973 extent_key->objectid);
7974 } else {
7975 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
7976 }
7977 if (ret < 0)
7978 goto out;
7979 if (ret > 0)
7980 break;
7981
7982 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
7983 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
7984 continue;
7985
7986 found_root = read_ref_root(extent_root->fs_info, ref_path);
7987 BUG_ON(!found_root);
7988 /*
7989 * for reference counted tree, only process reference paths
7990 * rooted at the latest committed root.
7991 */
7992 if (found_root->ref_cows &&
7993 ref_path->root_generation != found_root->root_key.offset)
7994 continue;
7995
7996 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
7997 if (pass == 0) {
7998 /*
7999 * copy data extents to new locations
8000 */
8001 u64 group_start = group->key.objectid;
8002 ret = relocate_data_extent(reloc_inode,
8003 extent_key,
8004 group_start);
8005 if (ret < 0)
8006 goto out;
8007 break;
8008 }
8009 level = 0;
8010 } else {
8011 level = ref_path->owner_objectid;
8012 }
8013
8014 if (prev_block != ref_path->nodes[level]) {
8015 struct extent_buffer *eb;
8016 u64 block_start = ref_path->nodes[level];
8017 u64 block_size = btrfs_level_size(found_root, level);
8018
8019 eb = read_tree_block(found_root, block_start,
8020 block_size, 0);
8021 if (!eb) {
8022 ret = -EIO;
8023 goto out;
8024 }
8025 btrfs_tree_lock(eb);
8026 BUG_ON(level != btrfs_header_level(eb));
8027
8028 if (level == 0)
8029 btrfs_item_key_to_cpu(eb, &first_key, 0);
8030 else
8031 btrfs_node_key_to_cpu(eb, &first_key, 0);
8032
8033 btrfs_tree_unlock(eb);
8034 free_extent_buffer(eb);
8035 prev_block = block_start;
8036 }
8037
8038 mutex_lock(&extent_root->fs_info->trans_mutex);
8039 btrfs_record_root_in_trans(found_root);
8040 mutex_unlock(&extent_root->fs_info->trans_mutex);
8041 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
8042 /*
8043 * try to update data extent references while
8044 * keeping metadata shared between snapshots.
8045 */
8046 if (pass == 1) {
8047 ret = relocate_one_path(trans, found_root,
8048 path, &first_key, ref_path,
8049 group, reloc_inode);
8050 if (ret < 0)
8051 goto out;
8052 continue;
8053 }
8054 /*
8055 * use fallback method to process the remaining
8056 * references.
8057 */
8058 if (!new_extents) {
8059 u64 group_start = group->key.objectid;
8060 new_extents = kmalloc(sizeof(*new_extents),
8061 GFP_NOFS);
8062 nr_extents = 1;
8063 ret = get_new_locations(reloc_inode,
8064 extent_key,
8065 group_start, 1,
8066 &new_extents,
8067 &nr_extents);
8068 if (ret)
8069 goto out;
8070 }
8071 ret = replace_one_extent(trans, found_root,
8072 path, extent_key,
8073 &first_key, ref_path,
8074 new_extents, nr_extents);
8075 } else {
8076 ret = relocate_tree_block(trans, found_root, path,
8077 &first_key, ref_path);
8078 }
8079 if (ret < 0)
8080 goto out;
8081 }
8082 ret = 0;
8083 out:
8084 btrfs_end_transaction(trans, extent_root);
8085 kfree(new_extents);
8086 kfree(ref_path);
8087 return ret;
8088 }
8089 #endif
8090
8091 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
8092 {
8093 u64 num_devices;
8094 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
8095 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
8096
8097 /*
8098 * we add in the count of missing devices because we want
8099 * to make sure that any RAID levels on a degraded FS
8100 * continue to be honored.
8101 */
8102 num_devices = root->fs_info->fs_devices->rw_devices +
8103 root->fs_info->fs_devices->missing_devices;
8104
8105 if (num_devices == 1) {
8106 stripped |= BTRFS_BLOCK_GROUP_DUP;
8107 stripped = flags & ~stripped;
8108
8109 /* turn raid0 into single device chunks */
8110 if (flags & BTRFS_BLOCK_GROUP_RAID0)
8111 return stripped;
8112
8113 /* turn mirroring into duplication */
8114 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
8115 BTRFS_BLOCK_GROUP_RAID10))
8116 return stripped | BTRFS_BLOCK_GROUP_DUP;
8117 return flags;
8118 } else {
8119 /* they already had raid on here, just return */
8120 if (flags & stripped)
8121 return flags;
8122
8123 stripped |= BTRFS_BLOCK_GROUP_DUP;
8124 stripped = flags & ~stripped;
8125
8126 /* switch duplicated blocks with raid1 */
8127 if (flags & BTRFS_BLOCK_GROUP_DUP)
8128 return stripped | BTRFS_BLOCK_GROUP_RAID1;
8129
8130 /* turn single device chunks into raid0 */
8131 return stripped | BTRFS_BLOCK_GROUP_RAID0;
8132 }
8133 return flags;
8134 }
8135
8136 static int set_block_group_ro(struct btrfs_block_group_cache *cache)
8137 {
8138 struct btrfs_space_info *sinfo = cache->space_info;
8139 u64 num_bytes;
8140 int ret = -ENOSPC;
8141
8142 if (cache->ro)
8143 return 0;
8144
8145 spin_lock(&sinfo->lock);
8146 spin_lock(&cache->lock);
8147 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
8148 cache->bytes_super - btrfs_block_group_used(&cache->item);
8149
8150 if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
8151 sinfo->bytes_may_use + sinfo->bytes_readonly +
8152 cache->reserved_pinned + num_bytes <= sinfo->total_bytes) {
8153 sinfo->bytes_readonly += num_bytes;
8154 sinfo->bytes_reserved += cache->reserved_pinned;
8155 cache->reserved_pinned = 0;
8156 cache->ro = 1;
8157 ret = 0;
8158 }
8159
8160 spin_unlock(&cache->lock);
8161 spin_unlock(&sinfo->lock);
8162 return ret;
8163 }
8164
8165 int btrfs_set_block_group_ro(struct btrfs_root *root,
8166 struct btrfs_block_group_cache *cache)
8167
8168 {
8169 struct btrfs_trans_handle *trans;
8170 u64 alloc_flags;
8171 int ret;
8172
8173 BUG_ON(cache->ro);
8174
8175 trans = btrfs_join_transaction(root, 1);
8176 BUG_ON(IS_ERR(trans));
8177
8178 alloc_flags = update_block_group_flags(root, cache->flags);
8179 if (alloc_flags != cache->flags)
8180 do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
8181 CHUNK_ALLOC_FORCE);
8182
8183 ret = set_block_group_ro(cache);
8184 if (!ret)
8185 goto out;
8186 alloc_flags = get_alloc_profile(root, cache->space_info->flags);
8187 ret = do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
8188 CHUNK_ALLOC_FORCE);
8189 if (ret < 0)
8190 goto out;
8191 ret = set_block_group_ro(cache);
8192 out:
8193 btrfs_end_transaction(trans, root);
8194 return ret;
8195 }
8196
8197 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
8198 struct btrfs_root *root, u64 type)
8199 {
8200 u64 alloc_flags = get_alloc_profile(root, type);
8201 return do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
8202 CHUNK_ALLOC_FORCE);
8203 }
8204
8205 /*
8206 * helper to account the unused space of all the readonly block group in the
8207 * list. takes mirrors into account.
8208 */
8209 static u64 __btrfs_get_ro_block_group_free_space(struct list_head *groups_list)
8210 {
8211 struct btrfs_block_group_cache *block_group;
8212 u64 free_bytes = 0;
8213 int factor;
8214
8215 list_for_each_entry(block_group, groups_list, list) {
8216 spin_lock(&block_group->lock);
8217
8218 if (!block_group->ro) {
8219 spin_unlock(&block_group->lock);
8220 continue;
8221 }
8222
8223 if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
8224 BTRFS_BLOCK_GROUP_RAID10 |
8225 BTRFS_BLOCK_GROUP_DUP))
8226 factor = 2;
8227 else
8228 factor = 1;
8229
8230 free_bytes += (block_group->key.offset -
8231 btrfs_block_group_used(&block_group->item)) *
8232 factor;
8233
8234 spin_unlock(&block_group->lock);
8235 }
8236
8237 return free_bytes;
8238 }
8239
8240 /*
8241 * helper to account the unused space of all the readonly block group in the
8242 * space_info. takes mirrors into account.
8243 */
8244 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
8245 {
8246 int i;
8247 u64 free_bytes = 0;
8248
8249 spin_lock(&sinfo->lock);
8250
8251 for(i = 0; i < BTRFS_NR_RAID_TYPES; i++)
8252 if (!list_empty(&sinfo->block_groups[i]))
8253 free_bytes += __btrfs_get_ro_block_group_free_space(
8254 &sinfo->block_groups[i]);
8255
8256 spin_unlock(&sinfo->lock);
8257
8258 return free_bytes;
8259 }
8260
8261 int btrfs_set_block_group_rw(struct btrfs_root *root,
8262 struct btrfs_block_group_cache *cache)
8263 {
8264 struct btrfs_space_info *sinfo = cache->space_info;
8265 u64 num_bytes;
8266
8267 BUG_ON(!cache->ro);
8268
8269 spin_lock(&sinfo->lock);
8270 spin_lock(&cache->lock);
8271 num_bytes = cache->key.offset - cache->reserved - cache->pinned -
8272 cache->bytes_super - btrfs_block_group_used(&cache->item);
8273 sinfo->bytes_readonly -= num_bytes;
8274 cache->ro = 0;
8275 spin_unlock(&cache->lock);
8276 spin_unlock(&sinfo->lock);
8277 return 0;
8278 }
8279
8280 /*
8281 * checks to see if its even possible to relocate this block group.
8282 *
8283 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
8284 * ok to go ahead and try.
8285 */
8286 int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
8287 {
8288 struct btrfs_block_group_cache *block_group;
8289 struct btrfs_space_info *space_info;
8290 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
8291 struct btrfs_device *device;
8292 int full = 0;
8293 int ret = 0;
8294
8295 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
8296
8297 /* odd, couldn't find the block group, leave it alone */
8298 if (!block_group)
8299 return -1;
8300
8301 /* no bytes used, we're good */
8302 if (!btrfs_block_group_used(&block_group->item))
8303 goto out;
8304
8305 space_info = block_group->space_info;
8306 spin_lock(&space_info->lock);
8307
8308 full = space_info->full;
8309
8310 /*
8311 * if this is the last block group we have in this space, we can't
8312 * relocate it unless we're able to allocate a new chunk below.
8313 *
8314 * Otherwise, we need to make sure we have room in the space to handle
8315 * all of the extents from this block group. If we can, we're good
8316 */
8317 if ((space_info->total_bytes != block_group->key.offset) &&
8318 (space_info->bytes_used + space_info->bytes_reserved +
8319 space_info->bytes_pinned + space_info->bytes_readonly +
8320 btrfs_block_group_used(&block_group->item) <
8321 space_info->total_bytes)) {
8322 spin_unlock(&space_info->lock);
8323 goto out;
8324 }
8325 spin_unlock(&space_info->lock);
8326
8327 /*
8328 * ok we don't have enough space, but maybe we have free space on our
8329 * devices to allocate new chunks for relocation, so loop through our
8330 * alloc devices and guess if we have enough space. However, if we
8331 * were marked as full, then we know there aren't enough chunks, and we
8332 * can just return.
8333 */
8334 ret = -1;
8335 if (full)
8336 goto out;
8337
8338 mutex_lock(&root->fs_info->chunk_mutex);
8339 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
8340 u64 min_free = btrfs_block_group_used(&block_group->item);
8341 u64 dev_offset;
8342
8343 /*
8344 * check to make sure we can actually find a chunk with enough
8345 * space to fit our block group in.
8346 */
8347 if (device->total_bytes > device->bytes_used + min_free) {
8348 ret = find_free_dev_extent(NULL, device, min_free,
8349 &dev_offset, NULL);
8350 if (!ret)
8351 break;
8352 ret = -1;
8353 }
8354 }
8355 mutex_unlock(&root->fs_info->chunk_mutex);
8356 out:
8357 btrfs_put_block_group(block_group);
8358 return ret;
8359 }
8360
8361 static int find_first_block_group(struct btrfs_root *root,
8362 struct btrfs_path *path, struct btrfs_key *key)
8363 {
8364 int ret = 0;
8365 struct btrfs_key found_key;
8366 struct extent_buffer *leaf;
8367 int slot;
8368
8369 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
8370 if (ret < 0)
8371 goto out;
8372
8373 while (1) {
8374 slot = path->slots[0];
8375 leaf = path->nodes[0];
8376 if (slot >= btrfs_header_nritems(leaf)) {
8377 ret = btrfs_next_leaf(root, path);
8378 if (ret == 0)
8379 continue;
8380 if (ret < 0)
8381 goto out;
8382 break;
8383 }
8384 btrfs_item_key_to_cpu(leaf, &found_key, slot);
8385
8386 if (found_key.objectid >= key->objectid &&
8387 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
8388 ret = 0;
8389 goto out;
8390 }
8391 path->slots[0]++;
8392 }
8393 out:
8394 return ret;
8395 }
8396
8397 void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
8398 {
8399 struct btrfs_block_group_cache *block_group;
8400 u64 last = 0;
8401
8402 while (1) {
8403 struct inode *inode;
8404
8405 block_group = btrfs_lookup_first_block_group(info, last);
8406 while (block_group) {
8407 spin_lock(&block_group->lock);
8408 if (block_group->iref)
8409 break;
8410 spin_unlock(&block_group->lock);
8411 block_group = next_block_group(info->tree_root,
8412 block_group);
8413 }
8414 if (!block_group) {
8415 if (last == 0)
8416 break;
8417 last = 0;
8418 continue;
8419 }
8420
8421 inode = block_group->inode;
8422 block_group->iref = 0;
8423 block_group->inode = NULL;
8424 spin_unlock(&block_group->lock);
8425 iput(inode);
8426 last = block_group->key.objectid + block_group->key.offset;
8427 btrfs_put_block_group(block_group);
8428 }
8429 }
8430
8431 int btrfs_free_block_groups(struct btrfs_fs_info *info)
8432 {
8433 struct btrfs_block_group_cache *block_group;
8434 struct btrfs_space_info *space_info;
8435 struct btrfs_caching_control *caching_ctl;
8436 struct rb_node *n;
8437
8438 down_write(&info->extent_commit_sem);
8439 while (!list_empty(&info->caching_block_groups)) {
8440 caching_ctl = list_entry(info->caching_block_groups.next,
8441 struct btrfs_caching_control, list);
8442 list_del(&caching_ctl->list);
8443 put_caching_control(caching_ctl);
8444 }
8445 up_write(&info->extent_commit_sem);
8446
8447 spin_lock(&info->block_group_cache_lock);
8448 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
8449 block_group = rb_entry(n, struct btrfs_block_group_cache,
8450 cache_node);
8451 rb_erase(&block_group->cache_node,
8452 &info->block_group_cache_tree);
8453 spin_unlock(&info->block_group_cache_lock);
8454
8455 down_write(&block_group->space_info->groups_sem);
8456 list_del(&block_group->list);
8457 up_write(&block_group->space_info->groups_sem);
8458
8459 if (block_group->cached == BTRFS_CACHE_STARTED)
8460 wait_block_group_cache_done(block_group);
8461
8462 /*
8463 * We haven't cached this block group, which means we could
8464 * possibly have excluded extents on this block group.
8465 */
8466 if (block_group->cached == BTRFS_CACHE_NO)
8467 free_excluded_extents(info->extent_root, block_group);
8468
8469 btrfs_remove_free_space_cache(block_group);
8470 btrfs_put_block_group(block_group);
8471
8472 spin_lock(&info->block_group_cache_lock);
8473 }
8474 spin_unlock(&info->block_group_cache_lock);
8475
8476 /* now that all the block groups are freed, go through and
8477 * free all the space_info structs. This is only called during
8478 * the final stages of unmount, and so we know nobody is
8479 * using them. We call synchronize_rcu() once before we start,
8480 * just to be on the safe side.
8481 */
8482 synchronize_rcu();
8483
8484 release_global_block_rsv(info);
8485
8486 while(!list_empty(&info->space_info)) {
8487 space_info = list_entry(info->space_info.next,
8488 struct btrfs_space_info,
8489 list);
8490 if (space_info->bytes_pinned > 0 ||
8491 space_info->bytes_reserved > 0) {
8492 WARN_ON(1);
8493 dump_space_info(space_info, 0, 0);
8494 }
8495 list_del(&space_info->list);
8496 kfree(space_info);
8497 }
8498 return 0;
8499 }
8500
8501 static void __link_block_group(struct btrfs_space_info *space_info,
8502 struct btrfs_block_group_cache *cache)
8503 {
8504 int index = get_block_group_index(cache);
8505
8506 down_write(&space_info->groups_sem);
8507 list_add_tail(&cache->list, &space_info->block_groups[index]);
8508 up_write(&space_info->groups_sem);
8509 }
8510
8511 int btrfs_read_block_groups(struct btrfs_root *root)
8512 {
8513 struct btrfs_path *path;
8514 int ret;
8515 struct btrfs_block_group_cache *cache;
8516 struct btrfs_fs_info *info = root->fs_info;
8517 struct btrfs_space_info *space_info;
8518 struct btrfs_key key;
8519 struct btrfs_key found_key;
8520 struct extent_buffer *leaf;
8521 int need_clear = 0;
8522 u64 cache_gen;
8523
8524 root = info->extent_root;
8525 key.objectid = 0;
8526 key.offset = 0;
8527 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
8528 path = btrfs_alloc_path();
8529 if (!path)
8530 return -ENOMEM;
8531
8532 cache_gen = btrfs_super_cache_generation(&root->fs_info->super_copy);
8533 if (cache_gen != 0 &&
8534 btrfs_super_generation(&root->fs_info->super_copy) != cache_gen)
8535 need_clear = 1;
8536 if (btrfs_test_opt(root, CLEAR_CACHE))
8537 need_clear = 1;
8538 if (!btrfs_test_opt(root, SPACE_CACHE) && cache_gen)
8539 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
8540
8541 while (1) {
8542 ret = find_first_block_group(root, path, &key);
8543 if (ret > 0)
8544 break;
8545 if (ret != 0)
8546 goto error;
8547 leaf = path->nodes[0];
8548 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
8549 cache = kzalloc(sizeof(*cache), GFP_NOFS);
8550 if (!cache) {
8551 ret = -ENOMEM;
8552 goto error;
8553 }
8554
8555 atomic_set(&cache->count, 1);
8556 spin_lock_init(&cache->lock);
8557 spin_lock_init(&cache->tree_lock);
8558 cache->fs_info = info;
8559 INIT_LIST_HEAD(&cache->list);
8560 INIT_LIST_HEAD(&cache->cluster_list);
8561
8562 if (need_clear)
8563 cache->disk_cache_state = BTRFS_DC_CLEAR;
8564
8565 /*
8566 * we only want to have 32k of ram per block group for keeping
8567 * track of free space, and if we pass 1/2 of that we want to
8568 * start converting things over to using bitmaps
8569 */
8570 cache->extents_thresh = ((1024 * 32) / 2) /
8571 sizeof(struct btrfs_free_space);
8572
8573 read_extent_buffer(leaf, &cache->item,
8574 btrfs_item_ptr_offset(leaf, path->slots[0]),
8575 sizeof(cache->item));
8576 memcpy(&cache->key, &found_key, sizeof(found_key));
8577
8578 key.objectid = found_key.objectid + found_key.offset;
8579 btrfs_release_path(root, path);
8580 cache->flags = btrfs_block_group_flags(&cache->item);
8581 cache->sectorsize = root->sectorsize;
8582
8583 /*
8584 * We need to exclude the super stripes now so that the space
8585 * info has super bytes accounted for, otherwise we'll think
8586 * we have more space than we actually do.
8587 */
8588 exclude_super_stripes(root, cache);
8589
8590 /*
8591 * check for two cases, either we are full, and therefore
8592 * don't need to bother with the caching work since we won't
8593 * find any space, or we are empty, and we can just add all
8594 * the space in and be done with it. This saves us _alot_ of
8595 * time, particularly in the full case.
8596 */
8597 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
8598 cache->last_byte_to_unpin = (u64)-1;
8599 cache->cached = BTRFS_CACHE_FINISHED;
8600 free_excluded_extents(root, cache);
8601 } else if (btrfs_block_group_used(&cache->item) == 0) {
8602 cache->last_byte_to_unpin = (u64)-1;
8603 cache->cached = BTRFS_CACHE_FINISHED;
8604 add_new_free_space(cache, root->fs_info,
8605 found_key.objectid,
8606 found_key.objectid +
8607 found_key.offset);
8608 free_excluded_extents(root, cache);
8609 }
8610
8611 ret = update_space_info(info, cache->flags, found_key.offset,
8612 btrfs_block_group_used(&cache->item),
8613 &space_info);
8614 BUG_ON(ret);
8615 cache->space_info = space_info;
8616 spin_lock(&cache->space_info->lock);
8617 cache->space_info->bytes_readonly += cache->bytes_super;
8618 spin_unlock(&cache->space_info->lock);
8619
8620 __link_block_group(space_info, cache);
8621
8622 ret = btrfs_add_block_group_cache(root->fs_info, cache);
8623 BUG_ON(ret);
8624
8625 set_avail_alloc_bits(root->fs_info, cache->flags);
8626 if (btrfs_chunk_readonly(root, cache->key.objectid))
8627 set_block_group_ro(cache);
8628 }
8629
8630 list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
8631 if (!(get_alloc_profile(root, space_info->flags) &
8632 (BTRFS_BLOCK_GROUP_RAID10 |
8633 BTRFS_BLOCK_GROUP_RAID1 |
8634 BTRFS_BLOCK_GROUP_DUP)))
8635 continue;
8636 /*
8637 * avoid allocating from un-mirrored block group if there are
8638 * mirrored block groups.
8639 */
8640 list_for_each_entry(cache, &space_info->block_groups[3], list)
8641 set_block_group_ro(cache);
8642 list_for_each_entry(cache, &space_info->block_groups[4], list)
8643 set_block_group_ro(cache);
8644 }
8645
8646 init_global_block_rsv(info);
8647 ret = 0;
8648 error:
8649 btrfs_free_path(path);
8650 return ret;
8651 }
8652
8653 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
8654 struct btrfs_root *root, u64 bytes_used,
8655 u64 type, u64 chunk_objectid, u64 chunk_offset,
8656 u64 size)
8657 {
8658 int ret;
8659 struct btrfs_root *extent_root;
8660 struct btrfs_block_group_cache *cache;
8661
8662 extent_root = root->fs_info->extent_root;
8663
8664 root->fs_info->last_trans_log_full_commit = trans->transid;
8665
8666 cache = kzalloc(sizeof(*cache), GFP_NOFS);
8667 if (!cache)
8668 return -ENOMEM;
8669
8670 cache->key.objectid = chunk_offset;
8671 cache->key.offset = size;
8672 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
8673 cache->sectorsize = root->sectorsize;
8674 cache->fs_info = root->fs_info;
8675
8676 /*
8677 * we only want to have 32k of ram per block group for keeping track
8678 * of free space, and if we pass 1/2 of that we want to start
8679 * converting things over to using bitmaps
8680 */
8681 cache->extents_thresh = ((1024 * 32) / 2) /
8682 sizeof(struct btrfs_free_space);
8683 atomic_set(&cache->count, 1);
8684 spin_lock_init(&cache->lock);
8685 spin_lock_init(&cache->tree_lock);
8686 INIT_LIST_HEAD(&cache->list);
8687 INIT_LIST_HEAD(&cache->cluster_list);
8688
8689 btrfs_set_block_group_used(&cache->item, bytes_used);
8690 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
8691 cache->flags = type;
8692 btrfs_set_block_group_flags(&cache->item, type);
8693
8694 cache->last_byte_to_unpin = (u64)-1;
8695 cache->cached = BTRFS_CACHE_FINISHED;
8696 exclude_super_stripes(root, cache);
8697
8698 add_new_free_space(cache, root->fs_info, chunk_offset,
8699 chunk_offset + size);
8700
8701 free_excluded_extents(root, cache);
8702
8703 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
8704 &cache->space_info);
8705 BUG_ON(ret);
8706
8707 spin_lock(&cache->space_info->lock);
8708 cache->space_info->bytes_readonly += cache->bytes_super;
8709 spin_unlock(&cache->space_info->lock);
8710
8711 __link_block_group(cache->space_info, cache);
8712
8713 ret = btrfs_add_block_group_cache(root->fs_info, cache);
8714 BUG_ON(ret);
8715
8716 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
8717 sizeof(cache->item));
8718 BUG_ON(ret);
8719
8720 set_avail_alloc_bits(extent_root->fs_info, type);
8721
8722 return 0;
8723 }
8724
8725 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
8726 struct btrfs_root *root, u64 group_start)
8727 {
8728 struct btrfs_path *path;
8729 struct btrfs_block_group_cache *block_group;
8730 struct btrfs_free_cluster *cluster;
8731 struct btrfs_root *tree_root = root->fs_info->tree_root;
8732 struct btrfs_key key;
8733 struct inode *inode;
8734 int ret;
8735 int factor;
8736
8737 root = root->fs_info->extent_root;
8738
8739 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
8740 BUG_ON(!block_group);
8741 BUG_ON(!block_group->ro);
8742
8743 /*
8744 * Free the reserved super bytes from this block group before
8745 * remove it.
8746 */
8747 free_excluded_extents(root, block_group);
8748
8749 memcpy(&key, &block_group->key, sizeof(key));
8750 if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
8751 BTRFS_BLOCK_GROUP_RAID1 |
8752 BTRFS_BLOCK_GROUP_RAID10))
8753 factor = 2;
8754 else
8755 factor = 1;
8756
8757 /* make sure this block group isn't part of an allocation cluster */
8758 cluster = &root->fs_info->data_alloc_cluster;
8759 spin_lock(&cluster->refill_lock);
8760 btrfs_return_cluster_to_free_space(block_group, cluster);
8761 spin_unlock(&cluster->refill_lock);
8762
8763 /*
8764 * make sure this block group isn't part of a metadata
8765 * allocation cluster
8766 */
8767 cluster = &root->fs_info->meta_alloc_cluster;
8768 spin_lock(&cluster->refill_lock);
8769 btrfs_return_cluster_to_free_space(block_group, cluster);
8770 spin_unlock(&cluster->refill_lock);
8771
8772 path = btrfs_alloc_path();
8773 BUG_ON(!path);
8774
8775 inode = lookup_free_space_inode(root, block_group, path);
8776 if (!IS_ERR(inode)) {
8777 btrfs_orphan_add(trans, inode);
8778 clear_nlink(inode);
8779 /* One for the block groups ref */
8780 spin_lock(&block_group->lock);
8781 if (block_group->iref) {
8782 block_group->iref = 0;
8783 block_group->inode = NULL;
8784 spin_unlock(&block_group->lock);
8785 iput(inode);
8786 } else {
8787 spin_unlock(&block_group->lock);
8788 }
8789 /* One for our lookup ref */
8790 iput(inode);
8791 }
8792
8793 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
8794 key.offset = block_group->key.objectid;
8795 key.type = 0;
8796
8797 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
8798 if (ret < 0)
8799 goto out;
8800 if (ret > 0)
8801 btrfs_release_path(tree_root, path);
8802 if (ret == 0) {
8803 ret = btrfs_del_item(trans, tree_root, path);
8804 if (ret)
8805 goto out;
8806 btrfs_release_path(tree_root, path);
8807 }
8808
8809 spin_lock(&root->fs_info->block_group_cache_lock);
8810 rb_erase(&block_group->cache_node,
8811 &root->fs_info->block_group_cache_tree);
8812 spin_unlock(&root->fs_info->block_group_cache_lock);
8813
8814 down_write(&block_group->space_info->groups_sem);
8815 /*
8816 * we must use list_del_init so people can check to see if they
8817 * are still on the list after taking the semaphore
8818 */
8819 list_del_init(&block_group->list);
8820 up_write(&block_group->space_info->groups_sem);
8821
8822 if (block_group->cached == BTRFS_CACHE_STARTED)
8823 wait_block_group_cache_done(block_group);
8824
8825 btrfs_remove_free_space_cache(block_group);
8826
8827 spin_lock(&block_group->space_info->lock);
8828 block_group->space_info->total_bytes -= block_group->key.offset;
8829 block_group->space_info->bytes_readonly -= block_group->key.offset;
8830 block_group->space_info->disk_total -= block_group->key.offset * factor;
8831 spin_unlock(&block_group->space_info->lock);
8832
8833 memcpy(&key, &block_group->key, sizeof(key));
8834
8835 btrfs_clear_space_info_full(root->fs_info);
8836
8837 btrfs_put_block_group(block_group);
8838 btrfs_put_block_group(block_group);
8839
8840 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
8841 if (ret > 0)
8842 ret = -EIO;
8843 if (ret < 0)
8844 goto out;
8845
8846 ret = btrfs_del_item(trans, root, path);
8847 out:
8848 btrfs_free_path(path);
8849 return ret;
8850 }
8851
8852 int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
8853 {
8854 struct btrfs_space_info *space_info;
8855 int ret;
8856
8857 ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM, 0, 0,
8858 &space_info);
8859 if (ret)
8860 return ret;
8861
8862 ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA, 0, 0,
8863 &space_info);
8864 if (ret)
8865 return ret;
8866
8867 ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA, 0, 0,
8868 &space_info);
8869 if (ret)
8870 return ret;
8871
8872 return ret;
8873 }
8874
8875 int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
8876 {
8877 return unpin_extent_range(root, start, end);
8878 }
8879
8880 int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
8881 u64 num_bytes, u64 *actual_bytes)
8882 {
8883 return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
8884 }
8885
8886 int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
8887 {
8888 struct btrfs_fs_info *fs_info = root->fs_info;
8889 struct btrfs_block_group_cache *cache = NULL;
8890 u64 group_trimmed;
8891 u64 start;
8892 u64 end;
8893 u64 trimmed = 0;
8894 int ret = 0;
8895
8896 cache = btrfs_lookup_block_group(fs_info, range->start);
8897
8898 while (cache) {
8899 if (cache->key.objectid >= (range->start + range->len)) {
8900 btrfs_put_block_group(cache);
8901 break;
8902 }
8903
8904 start = max(range->start, cache->key.objectid);
8905 end = min(range->start + range->len,
8906 cache->key.objectid + cache->key.offset);
8907
8908 if (end - start >= range->minlen) {
8909 if (!block_group_cache_done(cache)) {
8910 ret = cache_block_group(cache, NULL, root, 0);
8911 if (!ret)
8912 wait_block_group_cache_done(cache);
8913 }
8914 ret = btrfs_trim_block_group(cache,
8915 &group_trimmed,
8916 start,
8917 end,
8918 range->minlen);
8919
8920 trimmed += group_trimmed;
8921 if (ret) {
8922 btrfs_put_block_group(cache);
8923 break;
8924 }
8925 }
8926
8927 cache = next_block_group(fs_info->tree_root, cache);
8928 }
8929
8930 range->len = trimmed;
8931 return ret;
8932 }