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Btrfs: fail to mount if we have problems reading the block groups
[deliverable/linux.git] / fs / btrfs / extent-tree.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/pagemap.h>
20 #include <linux/writeback.h>
21 #include <linux/blkdev.h>
22 #include <linux/sort.h>
23 #include <linux/rcupdate.h>
24 #include <linux/kthread.h>
25 #include "compat.h"
26 #include "hash.h"
27 #include "ctree.h"
28 #include "disk-io.h"
29 #include "print-tree.h"
30 #include "transaction.h"
31 #include "volumes.h"
32 #include "locking.h"
33 #include "free-space-cache.h"
34
35 static int update_block_group(struct btrfs_trans_handle *trans,
36 struct btrfs_root *root,
37 u64 bytenr, u64 num_bytes, int alloc,
38 int mark_free);
39 static int update_reserved_extents(struct btrfs_block_group_cache *cache,
40 u64 num_bytes, int reserve);
41 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
42 struct btrfs_root *root,
43 u64 bytenr, u64 num_bytes, u64 parent,
44 u64 root_objectid, u64 owner_objectid,
45 u64 owner_offset, int refs_to_drop,
46 struct btrfs_delayed_extent_op *extra_op);
47 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
48 struct extent_buffer *leaf,
49 struct btrfs_extent_item *ei);
50 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
51 struct btrfs_root *root,
52 u64 parent, u64 root_objectid,
53 u64 flags, u64 owner, u64 offset,
54 struct btrfs_key *ins, int ref_mod);
55 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
56 struct btrfs_root *root,
57 u64 parent, u64 root_objectid,
58 u64 flags, struct btrfs_disk_key *key,
59 int level, struct btrfs_key *ins);
60 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
61 struct btrfs_root *extent_root, u64 alloc_bytes,
62 u64 flags, int force);
63 static int pin_down_bytes(struct btrfs_trans_handle *trans,
64 struct btrfs_root *root,
65 struct btrfs_path *path,
66 u64 bytenr, u64 num_bytes,
67 int is_data, int reserved,
68 struct extent_buffer **must_clean);
69 static int find_next_key(struct btrfs_path *path, int level,
70 struct btrfs_key *key);
71 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
72 int dump_block_groups);
73
74 static noinline int
75 block_group_cache_done(struct btrfs_block_group_cache *cache)
76 {
77 smp_mb();
78 return cache->cached == BTRFS_CACHE_FINISHED;
79 }
80
81 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
82 {
83 return (cache->flags & bits) == bits;
84 }
85
86 void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
87 {
88 atomic_inc(&cache->count);
89 }
90
91 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
92 {
93 if (atomic_dec_and_test(&cache->count))
94 kfree(cache);
95 }
96
97 /*
98 * this adds the block group to the fs_info rb tree for the block group
99 * cache
100 */
101 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
102 struct btrfs_block_group_cache *block_group)
103 {
104 struct rb_node **p;
105 struct rb_node *parent = NULL;
106 struct btrfs_block_group_cache *cache;
107
108 spin_lock(&info->block_group_cache_lock);
109 p = &info->block_group_cache_tree.rb_node;
110
111 while (*p) {
112 parent = *p;
113 cache = rb_entry(parent, struct btrfs_block_group_cache,
114 cache_node);
115 if (block_group->key.objectid < cache->key.objectid) {
116 p = &(*p)->rb_left;
117 } else if (block_group->key.objectid > cache->key.objectid) {
118 p = &(*p)->rb_right;
119 } else {
120 spin_unlock(&info->block_group_cache_lock);
121 return -EEXIST;
122 }
123 }
124
125 rb_link_node(&block_group->cache_node, parent, p);
126 rb_insert_color(&block_group->cache_node,
127 &info->block_group_cache_tree);
128 spin_unlock(&info->block_group_cache_lock);
129
130 return 0;
131 }
132
133 /*
134 * This will return the block group at or after bytenr if contains is 0, else
135 * it will return the block group that contains the bytenr
136 */
137 static struct btrfs_block_group_cache *
138 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
139 int contains)
140 {
141 struct btrfs_block_group_cache *cache, *ret = NULL;
142 struct rb_node *n;
143 u64 end, start;
144
145 spin_lock(&info->block_group_cache_lock);
146 n = info->block_group_cache_tree.rb_node;
147
148 while (n) {
149 cache = rb_entry(n, struct btrfs_block_group_cache,
150 cache_node);
151 end = cache->key.objectid + cache->key.offset - 1;
152 start = cache->key.objectid;
153
154 if (bytenr < start) {
155 if (!contains && (!ret || start < ret->key.objectid))
156 ret = cache;
157 n = n->rb_left;
158 } else if (bytenr > start) {
159 if (contains && bytenr <= end) {
160 ret = cache;
161 break;
162 }
163 n = n->rb_right;
164 } else {
165 ret = cache;
166 break;
167 }
168 }
169 if (ret)
170 btrfs_get_block_group(ret);
171 spin_unlock(&info->block_group_cache_lock);
172
173 return ret;
174 }
175
176 static int add_excluded_extent(struct btrfs_root *root,
177 u64 start, u64 num_bytes)
178 {
179 u64 end = start + num_bytes - 1;
180 set_extent_bits(&root->fs_info->freed_extents[0],
181 start, end, EXTENT_UPTODATE, GFP_NOFS);
182 set_extent_bits(&root->fs_info->freed_extents[1],
183 start, end, EXTENT_UPTODATE, GFP_NOFS);
184 return 0;
185 }
186
187 static void free_excluded_extents(struct btrfs_root *root,
188 struct btrfs_block_group_cache *cache)
189 {
190 u64 start, end;
191
192 start = cache->key.objectid;
193 end = start + cache->key.offset - 1;
194
195 clear_extent_bits(&root->fs_info->freed_extents[0],
196 start, end, EXTENT_UPTODATE, GFP_NOFS);
197 clear_extent_bits(&root->fs_info->freed_extents[1],
198 start, end, EXTENT_UPTODATE, GFP_NOFS);
199 }
200
201 static int exclude_super_stripes(struct btrfs_root *root,
202 struct btrfs_block_group_cache *cache)
203 {
204 u64 bytenr;
205 u64 *logical;
206 int stripe_len;
207 int i, nr, ret;
208
209 if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
210 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
211 cache->bytes_super += stripe_len;
212 ret = add_excluded_extent(root, cache->key.objectid,
213 stripe_len);
214 BUG_ON(ret);
215 }
216
217 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
218 bytenr = btrfs_sb_offset(i);
219 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
220 cache->key.objectid, bytenr,
221 0, &logical, &nr, &stripe_len);
222 BUG_ON(ret);
223
224 while (nr--) {
225 cache->bytes_super += stripe_len;
226 ret = add_excluded_extent(root, logical[nr],
227 stripe_len);
228 BUG_ON(ret);
229 }
230
231 kfree(logical);
232 }
233 return 0;
234 }
235
236 static struct btrfs_caching_control *
237 get_caching_control(struct btrfs_block_group_cache *cache)
238 {
239 struct btrfs_caching_control *ctl;
240
241 spin_lock(&cache->lock);
242 if (cache->cached != BTRFS_CACHE_STARTED) {
243 spin_unlock(&cache->lock);
244 return NULL;
245 }
246
247 ctl = cache->caching_ctl;
248 atomic_inc(&ctl->count);
249 spin_unlock(&cache->lock);
250 return ctl;
251 }
252
253 static void put_caching_control(struct btrfs_caching_control *ctl)
254 {
255 if (atomic_dec_and_test(&ctl->count))
256 kfree(ctl);
257 }
258
259 /*
260 * this is only called by cache_block_group, since we could have freed extents
261 * we need to check the pinned_extents for any extents that can't be used yet
262 * since their free space will be released as soon as the transaction commits.
263 */
264 static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
265 struct btrfs_fs_info *info, u64 start, u64 end)
266 {
267 u64 extent_start, extent_end, size, total_added = 0;
268 int ret;
269
270 while (start < end) {
271 ret = find_first_extent_bit(info->pinned_extents, start,
272 &extent_start, &extent_end,
273 EXTENT_DIRTY | EXTENT_UPTODATE);
274 if (ret)
275 break;
276
277 if (extent_start <= start) {
278 start = extent_end + 1;
279 } else if (extent_start > start && extent_start < end) {
280 size = extent_start - start;
281 total_added += size;
282 ret = btrfs_add_free_space(block_group, start,
283 size);
284 BUG_ON(ret);
285 start = extent_end + 1;
286 } else {
287 break;
288 }
289 }
290
291 if (start < end) {
292 size = end - start;
293 total_added += size;
294 ret = btrfs_add_free_space(block_group, start, size);
295 BUG_ON(ret);
296 }
297
298 return total_added;
299 }
300
301 static int caching_kthread(void *data)
302 {
303 struct btrfs_block_group_cache *block_group = data;
304 struct btrfs_fs_info *fs_info = block_group->fs_info;
305 struct btrfs_caching_control *caching_ctl = block_group->caching_ctl;
306 struct btrfs_root *extent_root = fs_info->extent_root;
307 struct btrfs_path *path;
308 struct extent_buffer *leaf;
309 struct btrfs_key key;
310 u64 total_found = 0;
311 u64 last = 0;
312 u32 nritems;
313 int ret = 0;
314
315 path = btrfs_alloc_path();
316 if (!path)
317 return -ENOMEM;
318
319 exclude_super_stripes(extent_root, block_group);
320 spin_lock(&block_group->space_info->lock);
321 block_group->space_info->bytes_super += block_group->bytes_super;
322 spin_unlock(&block_group->space_info->lock);
323
324 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
325
326 /*
327 * We don't want to deadlock with somebody trying to allocate a new
328 * extent for the extent root while also trying to search the extent
329 * root to add free space. So we skip locking and search the commit
330 * root, since its read-only
331 */
332 path->skip_locking = 1;
333 path->search_commit_root = 1;
334 path->reada = 2;
335
336 key.objectid = last;
337 key.offset = 0;
338 key.type = BTRFS_EXTENT_ITEM_KEY;
339 again:
340 mutex_lock(&caching_ctl->mutex);
341 /* need to make sure the commit_root doesn't disappear */
342 down_read(&fs_info->extent_commit_sem);
343
344 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
345 if (ret < 0)
346 goto err;
347
348 leaf = path->nodes[0];
349 nritems = btrfs_header_nritems(leaf);
350
351 while (1) {
352 smp_mb();
353 if (fs_info->closing > 1) {
354 last = (u64)-1;
355 break;
356 }
357
358 if (path->slots[0] < nritems) {
359 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
360 } else {
361 ret = find_next_key(path, 0, &key);
362 if (ret)
363 break;
364
365 caching_ctl->progress = last;
366 btrfs_release_path(extent_root, path);
367 up_read(&fs_info->extent_commit_sem);
368 mutex_unlock(&caching_ctl->mutex);
369 if (btrfs_transaction_in_commit(fs_info))
370 schedule_timeout(1);
371 else
372 cond_resched();
373 goto again;
374 }
375
376 if (key.objectid < block_group->key.objectid) {
377 path->slots[0]++;
378 continue;
379 }
380
381 if (key.objectid >= block_group->key.objectid +
382 block_group->key.offset)
383 break;
384
385 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
386 total_found += add_new_free_space(block_group,
387 fs_info, last,
388 key.objectid);
389 last = key.objectid + key.offset;
390
391 if (total_found > (1024 * 1024 * 2)) {
392 total_found = 0;
393 wake_up(&caching_ctl->wait);
394 }
395 }
396 path->slots[0]++;
397 }
398 ret = 0;
399
400 total_found += add_new_free_space(block_group, fs_info, last,
401 block_group->key.objectid +
402 block_group->key.offset);
403 caching_ctl->progress = (u64)-1;
404
405 spin_lock(&block_group->lock);
406 block_group->caching_ctl = NULL;
407 block_group->cached = BTRFS_CACHE_FINISHED;
408 spin_unlock(&block_group->lock);
409
410 err:
411 btrfs_free_path(path);
412 up_read(&fs_info->extent_commit_sem);
413
414 free_excluded_extents(extent_root, block_group);
415
416 mutex_unlock(&caching_ctl->mutex);
417 wake_up(&caching_ctl->wait);
418
419 put_caching_control(caching_ctl);
420 atomic_dec(&block_group->space_info->caching_threads);
421 btrfs_put_block_group(block_group);
422
423 return 0;
424 }
425
426 static int cache_block_group(struct btrfs_block_group_cache *cache)
427 {
428 struct btrfs_fs_info *fs_info = cache->fs_info;
429 struct btrfs_caching_control *caching_ctl;
430 struct task_struct *tsk;
431 int ret = 0;
432
433 smp_mb();
434 if (cache->cached != BTRFS_CACHE_NO)
435 return 0;
436
437 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_KERNEL);
438 BUG_ON(!caching_ctl);
439
440 INIT_LIST_HEAD(&caching_ctl->list);
441 mutex_init(&caching_ctl->mutex);
442 init_waitqueue_head(&caching_ctl->wait);
443 caching_ctl->block_group = cache;
444 caching_ctl->progress = cache->key.objectid;
445 /* one for caching kthread, one for caching block group list */
446 atomic_set(&caching_ctl->count, 2);
447
448 spin_lock(&cache->lock);
449 if (cache->cached != BTRFS_CACHE_NO) {
450 spin_unlock(&cache->lock);
451 kfree(caching_ctl);
452 return 0;
453 }
454 cache->caching_ctl = caching_ctl;
455 cache->cached = BTRFS_CACHE_STARTED;
456 spin_unlock(&cache->lock);
457
458 down_write(&fs_info->extent_commit_sem);
459 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
460 up_write(&fs_info->extent_commit_sem);
461
462 atomic_inc(&cache->space_info->caching_threads);
463 btrfs_get_block_group(cache);
464
465 tsk = kthread_run(caching_kthread, cache, "btrfs-cache-%llu\n",
466 cache->key.objectid);
467 if (IS_ERR(tsk)) {
468 ret = PTR_ERR(tsk);
469 printk(KERN_ERR "error running thread %d\n", ret);
470 BUG();
471 }
472
473 return ret;
474 }
475
476 /*
477 * return the block group that starts at or after bytenr
478 */
479 static struct btrfs_block_group_cache *
480 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
481 {
482 struct btrfs_block_group_cache *cache;
483
484 cache = block_group_cache_tree_search(info, bytenr, 0);
485
486 return cache;
487 }
488
489 /*
490 * return the block group that contains the given bytenr
491 */
492 struct btrfs_block_group_cache *btrfs_lookup_block_group(
493 struct btrfs_fs_info *info,
494 u64 bytenr)
495 {
496 struct btrfs_block_group_cache *cache;
497
498 cache = block_group_cache_tree_search(info, bytenr, 1);
499
500 return cache;
501 }
502
503 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
504 u64 flags)
505 {
506 struct list_head *head = &info->space_info;
507 struct btrfs_space_info *found;
508
509 rcu_read_lock();
510 list_for_each_entry_rcu(found, head, list) {
511 if (found->flags == flags) {
512 rcu_read_unlock();
513 return found;
514 }
515 }
516 rcu_read_unlock();
517 return NULL;
518 }
519
520 /*
521 * after adding space to the filesystem, we need to clear the full flags
522 * on all the space infos.
523 */
524 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
525 {
526 struct list_head *head = &info->space_info;
527 struct btrfs_space_info *found;
528
529 rcu_read_lock();
530 list_for_each_entry_rcu(found, head, list)
531 found->full = 0;
532 rcu_read_unlock();
533 }
534
535 static u64 div_factor(u64 num, int factor)
536 {
537 if (factor == 10)
538 return num;
539 num *= factor;
540 do_div(num, 10);
541 return num;
542 }
543
544 u64 btrfs_find_block_group(struct btrfs_root *root,
545 u64 search_start, u64 search_hint, int owner)
546 {
547 struct btrfs_block_group_cache *cache;
548 u64 used;
549 u64 last = max(search_hint, search_start);
550 u64 group_start = 0;
551 int full_search = 0;
552 int factor = 9;
553 int wrapped = 0;
554 again:
555 while (1) {
556 cache = btrfs_lookup_first_block_group(root->fs_info, last);
557 if (!cache)
558 break;
559
560 spin_lock(&cache->lock);
561 last = cache->key.objectid + cache->key.offset;
562 used = btrfs_block_group_used(&cache->item);
563
564 if ((full_search || !cache->ro) &&
565 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
566 if (used + cache->pinned + cache->reserved <
567 div_factor(cache->key.offset, factor)) {
568 group_start = cache->key.objectid;
569 spin_unlock(&cache->lock);
570 btrfs_put_block_group(cache);
571 goto found;
572 }
573 }
574 spin_unlock(&cache->lock);
575 btrfs_put_block_group(cache);
576 cond_resched();
577 }
578 if (!wrapped) {
579 last = search_start;
580 wrapped = 1;
581 goto again;
582 }
583 if (!full_search && factor < 10) {
584 last = search_start;
585 full_search = 1;
586 factor = 10;
587 goto again;
588 }
589 found:
590 return group_start;
591 }
592
593 /* simple helper to search for an existing extent at a given offset */
594 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
595 {
596 int ret;
597 struct btrfs_key key;
598 struct btrfs_path *path;
599
600 path = btrfs_alloc_path();
601 BUG_ON(!path);
602 key.objectid = start;
603 key.offset = len;
604 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
605 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
606 0, 0);
607 btrfs_free_path(path);
608 return ret;
609 }
610
611 /*
612 * Back reference rules. Back refs have three main goals:
613 *
614 * 1) differentiate between all holders of references to an extent so that
615 * when a reference is dropped we can make sure it was a valid reference
616 * before freeing the extent.
617 *
618 * 2) Provide enough information to quickly find the holders of an extent
619 * if we notice a given block is corrupted or bad.
620 *
621 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
622 * maintenance. This is actually the same as #2, but with a slightly
623 * different use case.
624 *
625 * There are two kinds of back refs. The implicit back refs is optimized
626 * for pointers in non-shared tree blocks. For a given pointer in a block,
627 * back refs of this kind provide information about the block's owner tree
628 * and the pointer's key. These information allow us to find the block by
629 * b-tree searching. The full back refs is for pointers in tree blocks not
630 * referenced by their owner trees. The location of tree block is recorded
631 * in the back refs. Actually the full back refs is generic, and can be
632 * used in all cases the implicit back refs is used. The major shortcoming
633 * of the full back refs is its overhead. Every time a tree block gets
634 * COWed, we have to update back refs entry for all pointers in it.
635 *
636 * For a newly allocated tree block, we use implicit back refs for
637 * pointers in it. This means most tree related operations only involve
638 * implicit back refs. For a tree block created in old transaction, the
639 * only way to drop a reference to it is COW it. So we can detect the
640 * event that tree block loses its owner tree's reference and do the
641 * back refs conversion.
642 *
643 * When a tree block is COW'd through a tree, there are four cases:
644 *
645 * The reference count of the block is one and the tree is the block's
646 * owner tree. Nothing to do in this case.
647 *
648 * The reference count of the block is one and the tree is not the
649 * block's owner tree. In this case, full back refs is used for pointers
650 * in the block. Remove these full back refs, add implicit back refs for
651 * every pointers in the new block.
652 *
653 * The reference count of the block is greater than one and the tree is
654 * the block's owner tree. In this case, implicit back refs is used for
655 * pointers in the block. Add full back refs for every pointers in the
656 * block, increase lower level extents' reference counts. The original
657 * implicit back refs are entailed to the new block.
658 *
659 * The reference count of the block is greater than one and the tree is
660 * not the block's owner tree. Add implicit back refs for every pointer in
661 * the new block, increase lower level extents' reference count.
662 *
663 * Back Reference Key composing:
664 *
665 * The key objectid corresponds to the first byte in the extent,
666 * The key type is used to differentiate between types of back refs.
667 * There are different meanings of the key offset for different types
668 * of back refs.
669 *
670 * File extents can be referenced by:
671 *
672 * - multiple snapshots, subvolumes, or different generations in one subvol
673 * - different files inside a single subvolume
674 * - different offsets inside a file (bookend extents in file.c)
675 *
676 * The extent ref structure for the implicit back refs has fields for:
677 *
678 * - Objectid of the subvolume root
679 * - objectid of the file holding the reference
680 * - original offset in the file
681 * - how many bookend extents
682 *
683 * The key offset for the implicit back refs is hash of the first
684 * three fields.
685 *
686 * The extent ref structure for the full back refs has field for:
687 *
688 * - number of pointers in the tree leaf
689 *
690 * The key offset for the implicit back refs is the first byte of
691 * the tree leaf
692 *
693 * When a file extent is allocated, The implicit back refs is used.
694 * the fields are filled in:
695 *
696 * (root_key.objectid, inode objectid, offset in file, 1)
697 *
698 * When a file extent is removed file truncation, we find the
699 * corresponding implicit back refs and check the following fields:
700 *
701 * (btrfs_header_owner(leaf), inode objectid, offset in file)
702 *
703 * Btree extents can be referenced by:
704 *
705 * - Different subvolumes
706 *
707 * Both the implicit back refs and the full back refs for tree blocks
708 * only consist of key. The key offset for the implicit back refs is
709 * objectid of block's owner tree. The key offset for the full back refs
710 * is the first byte of parent block.
711 *
712 * When implicit back refs is used, information about the lowest key and
713 * level of the tree block are required. These information are stored in
714 * tree block info structure.
715 */
716
717 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
718 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
719 struct btrfs_root *root,
720 struct btrfs_path *path,
721 u64 owner, u32 extra_size)
722 {
723 struct btrfs_extent_item *item;
724 struct btrfs_extent_item_v0 *ei0;
725 struct btrfs_extent_ref_v0 *ref0;
726 struct btrfs_tree_block_info *bi;
727 struct extent_buffer *leaf;
728 struct btrfs_key key;
729 struct btrfs_key found_key;
730 u32 new_size = sizeof(*item);
731 u64 refs;
732 int ret;
733
734 leaf = path->nodes[0];
735 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
736
737 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
738 ei0 = btrfs_item_ptr(leaf, path->slots[0],
739 struct btrfs_extent_item_v0);
740 refs = btrfs_extent_refs_v0(leaf, ei0);
741
742 if (owner == (u64)-1) {
743 while (1) {
744 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
745 ret = btrfs_next_leaf(root, path);
746 if (ret < 0)
747 return ret;
748 BUG_ON(ret > 0);
749 leaf = path->nodes[0];
750 }
751 btrfs_item_key_to_cpu(leaf, &found_key,
752 path->slots[0]);
753 BUG_ON(key.objectid != found_key.objectid);
754 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
755 path->slots[0]++;
756 continue;
757 }
758 ref0 = btrfs_item_ptr(leaf, path->slots[0],
759 struct btrfs_extent_ref_v0);
760 owner = btrfs_ref_objectid_v0(leaf, ref0);
761 break;
762 }
763 }
764 btrfs_release_path(root, path);
765
766 if (owner < BTRFS_FIRST_FREE_OBJECTID)
767 new_size += sizeof(*bi);
768
769 new_size -= sizeof(*ei0);
770 ret = btrfs_search_slot(trans, root, &key, path,
771 new_size + extra_size, 1);
772 if (ret < 0)
773 return ret;
774 BUG_ON(ret);
775
776 ret = btrfs_extend_item(trans, root, path, new_size);
777 BUG_ON(ret);
778
779 leaf = path->nodes[0];
780 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
781 btrfs_set_extent_refs(leaf, item, refs);
782 /* FIXME: get real generation */
783 btrfs_set_extent_generation(leaf, item, 0);
784 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
785 btrfs_set_extent_flags(leaf, item,
786 BTRFS_EXTENT_FLAG_TREE_BLOCK |
787 BTRFS_BLOCK_FLAG_FULL_BACKREF);
788 bi = (struct btrfs_tree_block_info *)(item + 1);
789 /* FIXME: get first key of the block */
790 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
791 btrfs_set_tree_block_level(leaf, bi, (int)owner);
792 } else {
793 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
794 }
795 btrfs_mark_buffer_dirty(leaf);
796 return 0;
797 }
798 #endif
799
800 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
801 {
802 u32 high_crc = ~(u32)0;
803 u32 low_crc = ~(u32)0;
804 __le64 lenum;
805
806 lenum = cpu_to_le64(root_objectid);
807 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
808 lenum = cpu_to_le64(owner);
809 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
810 lenum = cpu_to_le64(offset);
811 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
812
813 return ((u64)high_crc << 31) ^ (u64)low_crc;
814 }
815
816 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
817 struct btrfs_extent_data_ref *ref)
818 {
819 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
820 btrfs_extent_data_ref_objectid(leaf, ref),
821 btrfs_extent_data_ref_offset(leaf, ref));
822 }
823
824 static int match_extent_data_ref(struct extent_buffer *leaf,
825 struct btrfs_extent_data_ref *ref,
826 u64 root_objectid, u64 owner, u64 offset)
827 {
828 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
829 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
830 btrfs_extent_data_ref_offset(leaf, ref) != offset)
831 return 0;
832 return 1;
833 }
834
835 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
836 struct btrfs_root *root,
837 struct btrfs_path *path,
838 u64 bytenr, u64 parent,
839 u64 root_objectid,
840 u64 owner, u64 offset)
841 {
842 struct btrfs_key key;
843 struct btrfs_extent_data_ref *ref;
844 struct extent_buffer *leaf;
845 u32 nritems;
846 int ret;
847 int recow;
848 int err = -ENOENT;
849
850 key.objectid = bytenr;
851 if (parent) {
852 key.type = BTRFS_SHARED_DATA_REF_KEY;
853 key.offset = parent;
854 } else {
855 key.type = BTRFS_EXTENT_DATA_REF_KEY;
856 key.offset = hash_extent_data_ref(root_objectid,
857 owner, offset);
858 }
859 again:
860 recow = 0;
861 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
862 if (ret < 0) {
863 err = ret;
864 goto fail;
865 }
866
867 if (parent) {
868 if (!ret)
869 return 0;
870 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
871 key.type = BTRFS_EXTENT_REF_V0_KEY;
872 btrfs_release_path(root, path);
873 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
874 if (ret < 0) {
875 err = ret;
876 goto fail;
877 }
878 if (!ret)
879 return 0;
880 #endif
881 goto fail;
882 }
883
884 leaf = path->nodes[0];
885 nritems = btrfs_header_nritems(leaf);
886 while (1) {
887 if (path->slots[0] >= nritems) {
888 ret = btrfs_next_leaf(root, path);
889 if (ret < 0)
890 err = ret;
891 if (ret)
892 goto fail;
893
894 leaf = path->nodes[0];
895 nritems = btrfs_header_nritems(leaf);
896 recow = 1;
897 }
898
899 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
900 if (key.objectid != bytenr ||
901 key.type != BTRFS_EXTENT_DATA_REF_KEY)
902 goto fail;
903
904 ref = btrfs_item_ptr(leaf, path->slots[0],
905 struct btrfs_extent_data_ref);
906
907 if (match_extent_data_ref(leaf, ref, root_objectid,
908 owner, offset)) {
909 if (recow) {
910 btrfs_release_path(root, path);
911 goto again;
912 }
913 err = 0;
914 break;
915 }
916 path->slots[0]++;
917 }
918 fail:
919 return err;
920 }
921
922 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
923 struct btrfs_root *root,
924 struct btrfs_path *path,
925 u64 bytenr, u64 parent,
926 u64 root_objectid, u64 owner,
927 u64 offset, int refs_to_add)
928 {
929 struct btrfs_key key;
930 struct extent_buffer *leaf;
931 u32 size;
932 u32 num_refs;
933 int ret;
934
935 key.objectid = bytenr;
936 if (parent) {
937 key.type = BTRFS_SHARED_DATA_REF_KEY;
938 key.offset = parent;
939 size = sizeof(struct btrfs_shared_data_ref);
940 } else {
941 key.type = BTRFS_EXTENT_DATA_REF_KEY;
942 key.offset = hash_extent_data_ref(root_objectid,
943 owner, offset);
944 size = sizeof(struct btrfs_extent_data_ref);
945 }
946
947 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
948 if (ret && ret != -EEXIST)
949 goto fail;
950
951 leaf = path->nodes[0];
952 if (parent) {
953 struct btrfs_shared_data_ref *ref;
954 ref = btrfs_item_ptr(leaf, path->slots[0],
955 struct btrfs_shared_data_ref);
956 if (ret == 0) {
957 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
958 } else {
959 num_refs = btrfs_shared_data_ref_count(leaf, ref);
960 num_refs += refs_to_add;
961 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
962 }
963 } else {
964 struct btrfs_extent_data_ref *ref;
965 while (ret == -EEXIST) {
966 ref = btrfs_item_ptr(leaf, path->slots[0],
967 struct btrfs_extent_data_ref);
968 if (match_extent_data_ref(leaf, ref, root_objectid,
969 owner, offset))
970 break;
971 btrfs_release_path(root, path);
972 key.offset++;
973 ret = btrfs_insert_empty_item(trans, root, path, &key,
974 size);
975 if (ret && ret != -EEXIST)
976 goto fail;
977
978 leaf = path->nodes[0];
979 }
980 ref = btrfs_item_ptr(leaf, path->slots[0],
981 struct btrfs_extent_data_ref);
982 if (ret == 0) {
983 btrfs_set_extent_data_ref_root(leaf, ref,
984 root_objectid);
985 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
986 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
987 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
988 } else {
989 num_refs = btrfs_extent_data_ref_count(leaf, ref);
990 num_refs += refs_to_add;
991 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
992 }
993 }
994 btrfs_mark_buffer_dirty(leaf);
995 ret = 0;
996 fail:
997 btrfs_release_path(root, path);
998 return ret;
999 }
1000
1001 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
1002 struct btrfs_root *root,
1003 struct btrfs_path *path,
1004 int refs_to_drop)
1005 {
1006 struct btrfs_key key;
1007 struct btrfs_extent_data_ref *ref1 = NULL;
1008 struct btrfs_shared_data_ref *ref2 = NULL;
1009 struct extent_buffer *leaf;
1010 u32 num_refs = 0;
1011 int ret = 0;
1012
1013 leaf = path->nodes[0];
1014 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1015
1016 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1017 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1018 struct btrfs_extent_data_ref);
1019 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1020 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1021 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1022 struct btrfs_shared_data_ref);
1023 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1024 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1025 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1026 struct btrfs_extent_ref_v0 *ref0;
1027 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1028 struct btrfs_extent_ref_v0);
1029 num_refs = btrfs_ref_count_v0(leaf, ref0);
1030 #endif
1031 } else {
1032 BUG();
1033 }
1034
1035 BUG_ON(num_refs < refs_to_drop);
1036 num_refs -= refs_to_drop;
1037
1038 if (num_refs == 0) {
1039 ret = btrfs_del_item(trans, root, path);
1040 } else {
1041 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
1042 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
1043 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
1044 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
1045 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1046 else {
1047 struct btrfs_extent_ref_v0 *ref0;
1048 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1049 struct btrfs_extent_ref_v0);
1050 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
1051 }
1052 #endif
1053 btrfs_mark_buffer_dirty(leaf);
1054 }
1055 return ret;
1056 }
1057
1058 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
1059 struct btrfs_path *path,
1060 struct btrfs_extent_inline_ref *iref)
1061 {
1062 struct btrfs_key key;
1063 struct extent_buffer *leaf;
1064 struct btrfs_extent_data_ref *ref1;
1065 struct btrfs_shared_data_ref *ref2;
1066 u32 num_refs = 0;
1067
1068 leaf = path->nodes[0];
1069 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1070 if (iref) {
1071 if (btrfs_extent_inline_ref_type(leaf, iref) ==
1072 BTRFS_EXTENT_DATA_REF_KEY) {
1073 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
1074 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1075 } else {
1076 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
1077 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1078 }
1079 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1080 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1081 struct btrfs_extent_data_ref);
1082 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1083 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1084 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1085 struct btrfs_shared_data_ref);
1086 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1087 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1088 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1089 struct btrfs_extent_ref_v0 *ref0;
1090 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1091 struct btrfs_extent_ref_v0);
1092 num_refs = btrfs_ref_count_v0(leaf, ref0);
1093 #endif
1094 } else {
1095 WARN_ON(1);
1096 }
1097 return num_refs;
1098 }
1099
1100 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
1101 struct btrfs_root *root,
1102 struct btrfs_path *path,
1103 u64 bytenr, u64 parent,
1104 u64 root_objectid)
1105 {
1106 struct btrfs_key key;
1107 int ret;
1108
1109 key.objectid = bytenr;
1110 if (parent) {
1111 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1112 key.offset = parent;
1113 } else {
1114 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1115 key.offset = root_objectid;
1116 }
1117
1118 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1119 if (ret > 0)
1120 ret = -ENOENT;
1121 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1122 if (ret == -ENOENT && parent) {
1123 btrfs_release_path(root, path);
1124 key.type = BTRFS_EXTENT_REF_V0_KEY;
1125 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1126 if (ret > 0)
1127 ret = -ENOENT;
1128 }
1129 #endif
1130 return ret;
1131 }
1132
1133 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
1134 struct btrfs_root *root,
1135 struct btrfs_path *path,
1136 u64 bytenr, u64 parent,
1137 u64 root_objectid)
1138 {
1139 struct btrfs_key key;
1140 int ret;
1141
1142 key.objectid = bytenr;
1143 if (parent) {
1144 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1145 key.offset = parent;
1146 } else {
1147 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1148 key.offset = root_objectid;
1149 }
1150
1151 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1152 btrfs_release_path(root, path);
1153 return ret;
1154 }
1155
1156 static inline int extent_ref_type(u64 parent, u64 owner)
1157 {
1158 int type;
1159 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1160 if (parent > 0)
1161 type = BTRFS_SHARED_BLOCK_REF_KEY;
1162 else
1163 type = BTRFS_TREE_BLOCK_REF_KEY;
1164 } else {
1165 if (parent > 0)
1166 type = BTRFS_SHARED_DATA_REF_KEY;
1167 else
1168 type = BTRFS_EXTENT_DATA_REF_KEY;
1169 }
1170 return type;
1171 }
1172
1173 static int find_next_key(struct btrfs_path *path, int level,
1174 struct btrfs_key *key)
1175
1176 {
1177 for (; level < BTRFS_MAX_LEVEL; level++) {
1178 if (!path->nodes[level])
1179 break;
1180 if (path->slots[level] + 1 >=
1181 btrfs_header_nritems(path->nodes[level]))
1182 continue;
1183 if (level == 0)
1184 btrfs_item_key_to_cpu(path->nodes[level], key,
1185 path->slots[level] + 1);
1186 else
1187 btrfs_node_key_to_cpu(path->nodes[level], key,
1188 path->slots[level] + 1);
1189 return 0;
1190 }
1191 return 1;
1192 }
1193
1194 /*
1195 * look for inline back ref. if back ref is found, *ref_ret is set
1196 * to the address of inline back ref, and 0 is returned.
1197 *
1198 * if back ref isn't found, *ref_ret is set to the address where it
1199 * should be inserted, and -ENOENT is returned.
1200 *
1201 * if insert is true and there are too many inline back refs, the path
1202 * points to the extent item, and -EAGAIN is returned.
1203 *
1204 * NOTE: inline back refs are ordered in the same way that back ref
1205 * items in the tree are ordered.
1206 */
1207 static noinline_for_stack
1208 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1209 struct btrfs_root *root,
1210 struct btrfs_path *path,
1211 struct btrfs_extent_inline_ref **ref_ret,
1212 u64 bytenr, u64 num_bytes,
1213 u64 parent, u64 root_objectid,
1214 u64 owner, u64 offset, int insert)
1215 {
1216 struct btrfs_key key;
1217 struct extent_buffer *leaf;
1218 struct btrfs_extent_item *ei;
1219 struct btrfs_extent_inline_ref *iref;
1220 u64 flags;
1221 u64 item_size;
1222 unsigned long ptr;
1223 unsigned long end;
1224 int extra_size;
1225 int type;
1226 int want;
1227 int ret;
1228 int err = 0;
1229
1230 key.objectid = bytenr;
1231 key.type = BTRFS_EXTENT_ITEM_KEY;
1232 key.offset = num_bytes;
1233
1234 want = extent_ref_type(parent, owner);
1235 if (insert) {
1236 extra_size = btrfs_extent_inline_ref_size(want);
1237 path->keep_locks = 1;
1238 } else
1239 extra_size = -1;
1240 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1241 if (ret < 0) {
1242 err = ret;
1243 goto out;
1244 }
1245 BUG_ON(ret);
1246
1247 leaf = path->nodes[0];
1248 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1249 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1250 if (item_size < sizeof(*ei)) {
1251 if (!insert) {
1252 err = -ENOENT;
1253 goto out;
1254 }
1255 ret = convert_extent_item_v0(trans, root, path, owner,
1256 extra_size);
1257 if (ret < 0) {
1258 err = ret;
1259 goto out;
1260 }
1261 leaf = path->nodes[0];
1262 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1263 }
1264 #endif
1265 BUG_ON(item_size < sizeof(*ei));
1266
1267 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1268 flags = btrfs_extent_flags(leaf, ei);
1269
1270 ptr = (unsigned long)(ei + 1);
1271 end = (unsigned long)ei + item_size;
1272
1273 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1274 ptr += sizeof(struct btrfs_tree_block_info);
1275 BUG_ON(ptr > end);
1276 } else {
1277 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
1278 }
1279
1280 err = -ENOENT;
1281 while (1) {
1282 if (ptr >= end) {
1283 WARN_ON(ptr > end);
1284 break;
1285 }
1286 iref = (struct btrfs_extent_inline_ref *)ptr;
1287 type = btrfs_extent_inline_ref_type(leaf, iref);
1288 if (want < type)
1289 break;
1290 if (want > type) {
1291 ptr += btrfs_extent_inline_ref_size(type);
1292 continue;
1293 }
1294
1295 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1296 struct btrfs_extent_data_ref *dref;
1297 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1298 if (match_extent_data_ref(leaf, dref, root_objectid,
1299 owner, offset)) {
1300 err = 0;
1301 break;
1302 }
1303 if (hash_extent_data_ref_item(leaf, dref) <
1304 hash_extent_data_ref(root_objectid, owner, offset))
1305 break;
1306 } else {
1307 u64 ref_offset;
1308 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1309 if (parent > 0) {
1310 if (parent == ref_offset) {
1311 err = 0;
1312 break;
1313 }
1314 if (ref_offset < parent)
1315 break;
1316 } else {
1317 if (root_objectid == ref_offset) {
1318 err = 0;
1319 break;
1320 }
1321 if (ref_offset < root_objectid)
1322 break;
1323 }
1324 }
1325 ptr += btrfs_extent_inline_ref_size(type);
1326 }
1327 if (err == -ENOENT && insert) {
1328 if (item_size + extra_size >=
1329 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1330 err = -EAGAIN;
1331 goto out;
1332 }
1333 /*
1334 * To add new inline back ref, we have to make sure
1335 * there is no corresponding back ref item.
1336 * For simplicity, we just do not add new inline back
1337 * ref if there is any kind of item for this block
1338 */
1339 if (find_next_key(path, 0, &key) == 0 &&
1340 key.objectid == bytenr &&
1341 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1342 err = -EAGAIN;
1343 goto out;
1344 }
1345 }
1346 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1347 out:
1348 if (insert) {
1349 path->keep_locks = 0;
1350 btrfs_unlock_up_safe(path, 1);
1351 }
1352 return err;
1353 }
1354
1355 /*
1356 * helper to add new inline back ref
1357 */
1358 static noinline_for_stack
1359 int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
1360 struct btrfs_root *root,
1361 struct btrfs_path *path,
1362 struct btrfs_extent_inline_ref *iref,
1363 u64 parent, u64 root_objectid,
1364 u64 owner, u64 offset, int refs_to_add,
1365 struct btrfs_delayed_extent_op *extent_op)
1366 {
1367 struct extent_buffer *leaf;
1368 struct btrfs_extent_item *ei;
1369 unsigned long ptr;
1370 unsigned long end;
1371 unsigned long item_offset;
1372 u64 refs;
1373 int size;
1374 int type;
1375 int ret;
1376
1377 leaf = path->nodes[0];
1378 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1379 item_offset = (unsigned long)iref - (unsigned long)ei;
1380
1381 type = extent_ref_type(parent, owner);
1382 size = btrfs_extent_inline_ref_size(type);
1383
1384 ret = btrfs_extend_item(trans, root, path, size);
1385 BUG_ON(ret);
1386
1387 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1388 refs = btrfs_extent_refs(leaf, ei);
1389 refs += refs_to_add;
1390 btrfs_set_extent_refs(leaf, ei, refs);
1391 if (extent_op)
1392 __run_delayed_extent_op(extent_op, leaf, ei);
1393
1394 ptr = (unsigned long)ei + item_offset;
1395 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1396 if (ptr < end - size)
1397 memmove_extent_buffer(leaf, ptr + size, ptr,
1398 end - size - ptr);
1399
1400 iref = (struct btrfs_extent_inline_ref *)ptr;
1401 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1402 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1403 struct btrfs_extent_data_ref *dref;
1404 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1405 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1406 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1407 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1408 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1409 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1410 struct btrfs_shared_data_ref *sref;
1411 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1412 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1413 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1414 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1415 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1416 } else {
1417 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1418 }
1419 btrfs_mark_buffer_dirty(leaf);
1420 return 0;
1421 }
1422
1423 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1424 struct btrfs_root *root,
1425 struct btrfs_path *path,
1426 struct btrfs_extent_inline_ref **ref_ret,
1427 u64 bytenr, u64 num_bytes, u64 parent,
1428 u64 root_objectid, u64 owner, u64 offset)
1429 {
1430 int ret;
1431
1432 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1433 bytenr, num_bytes, parent,
1434 root_objectid, owner, offset, 0);
1435 if (ret != -ENOENT)
1436 return ret;
1437
1438 btrfs_release_path(root, path);
1439 *ref_ret = NULL;
1440
1441 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1442 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1443 root_objectid);
1444 } else {
1445 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1446 root_objectid, owner, offset);
1447 }
1448 return ret;
1449 }
1450
1451 /*
1452 * helper to update/remove inline back ref
1453 */
1454 static noinline_for_stack
1455 int update_inline_extent_backref(struct btrfs_trans_handle *trans,
1456 struct btrfs_root *root,
1457 struct btrfs_path *path,
1458 struct btrfs_extent_inline_ref *iref,
1459 int refs_to_mod,
1460 struct btrfs_delayed_extent_op *extent_op)
1461 {
1462 struct extent_buffer *leaf;
1463 struct btrfs_extent_item *ei;
1464 struct btrfs_extent_data_ref *dref = NULL;
1465 struct btrfs_shared_data_ref *sref = NULL;
1466 unsigned long ptr;
1467 unsigned long end;
1468 u32 item_size;
1469 int size;
1470 int type;
1471 int ret;
1472 u64 refs;
1473
1474 leaf = path->nodes[0];
1475 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1476 refs = btrfs_extent_refs(leaf, ei);
1477 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1478 refs += refs_to_mod;
1479 btrfs_set_extent_refs(leaf, ei, refs);
1480 if (extent_op)
1481 __run_delayed_extent_op(extent_op, leaf, ei);
1482
1483 type = btrfs_extent_inline_ref_type(leaf, iref);
1484
1485 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1486 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1487 refs = btrfs_extent_data_ref_count(leaf, dref);
1488 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1489 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1490 refs = btrfs_shared_data_ref_count(leaf, sref);
1491 } else {
1492 refs = 1;
1493 BUG_ON(refs_to_mod != -1);
1494 }
1495
1496 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1497 refs += refs_to_mod;
1498
1499 if (refs > 0) {
1500 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1501 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1502 else
1503 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1504 } else {
1505 size = btrfs_extent_inline_ref_size(type);
1506 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1507 ptr = (unsigned long)iref;
1508 end = (unsigned long)ei + item_size;
1509 if (ptr + size < end)
1510 memmove_extent_buffer(leaf, ptr, ptr + size,
1511 end - ptr - size);
1512 item_size -= size;
1513 ret = btrfs_truncate_item(trans, root, path, item_size, 1);
1514 BUG_ON(ret);
1515 }
1516 btrfs_mark_buffer_dirty(leaf);
1517 return 0;
1518 }
1519
1520 static noinline_for_stack
1521 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1522 struct btrfs_root *root,
1523 struct btrfs_path *path,
1524 u64 bytenr, u64 num_bytes, u64 parent,
1525 u64 root_objectid, u64 owner,
1526 u64 offset, int refs_to_add,
1527 struct btrfs_delayed_extent_op *extent_op)
1528 {
1529 struct btrfs_extent_inline_ref *iref;
1530 int ret;
1531
1532 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1533 bytenr, num_bytes, parent,
1534 root_objectid, owner, offset, 1);
1535 if (ret == 0) {
1536 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1537 ret = update_inline_extent_backref(trans, root, path, iref,
1538 refs_to_add, extent_op);
1539 } else if (ret == -ENOENT) {
1540 ret = setup_inline_extent_backref(trans, root, path, iref,
1541 parent, root_objectid,
1542 owner, offset, refs_to_add,
1543 extent_op);
1544 }
1545 return ret;
1546 }
1547
1548 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1549 struct btrfs_root *root,
1550 struct btrfs_path *path,
1551 u64 bytenr, u64 parent, u64 root_objectid,
1552 u64 owner, u64 offset, int refs_to_add)
1553 {
1554 int ret;
1555 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1556 BUG_ON(refs_to_add != 1);
1557 ret = insert_tree_block_ref(trans, root, path, bytenr,
1558 parent, root_objectid);
1559 } else {
1560 ret = insert_extent_data_ref(trans, root, path, bytenr,
1561 parent, root_objectid,
1562 owner, offset, refs_to_add);
1563 }
1564 return ret;
1565 }
1566
1567 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1568 struct btrfs_root *root,
1569 struct btrfs_path *path,
1570 struct btrfs_extent_inline_ref *iref,
1571 int refs_to_drop, int is_data)
1572 {
1573 int ret;
1574
1575 BUG_ON(!is_data && refs_to_drop != 1);
1576 if (iref) {
1577 ret = update_inline_extent_backref(trans, root, path, iref,
1578 -refs_to_drop, NULL);
1579 } else if (is_data) {
1580 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1581 } else {
1582 ret = btrfs_del_item(trans, root, path);
1583 }
1584 return ret;
1585 }
1586
1587 static void btrfs_issue_discard(struct block_device *bdev,
1588 u64 start, u64 len)
1589 {
1590 blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL,
1591 DISCARD_FL_BARRIER);
1592 }
1593
1594 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
1595 u64 num_bytes)
1596 {
1597 int ret;
1598 u64 map_length = num_bytes;
1599 struct btrfs_multi_bio *multi = NULL;
1600
1601 if (!btrfs_test_opt(root, DISCARD))
1602 return 0;
1603
1604 /* Tell the block device(s) that the sectors can be discarded */
1605 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
1606 bytenr, &map_length, &multi, 0);
1607 if (!ret) {
1608 struct btrfs_bio_stripe *stripe = multi->stripes;
1609 int i;
1610
1611 if (map_length > num_bytes)
1612 map_length = num_bytes;
1613
1614 for (i = 0; i < multi->num_stripes; i++, stripe++) {
1615 btrfs_issue_discard(stripe->dev->bdev,
1616 stripe->physical,
1617 map_length);
1618 }
1619 kfree(multi);
1620 }
1621
1622 return ret;
1623 }
1624
1625 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1626 struct btrfs_root *root,
1627 u64 bytenr, u64 num_bytes, u64 parent,
1628 u64 root_objectid, u64 owner, u64 offset)
1629 {
1630 int ret;
1631 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
1632 root_objectid == BTRFS_TREE_LOG_OBJECTID);
1633
1634 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1635 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
1636 parent, root_objectid, (int)owner,
1637 BTRFS_ADD_DELAYED_REF, NULL);
1638 } else {
1639 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
1640 parent, root_objectid, owner, offset,
1641 BTRFS_ADD_DELAYED_REF, NULL);
1642 }
1643 return ret;
1644 }
1645
1646 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1647 struct btrfs_root *root,
1648 u64 bytenr, u64 num_bytes,
1649 u64 parent, u64 root_objectid,
1650 u64 owner, u64 offset, int refs_to_add,
1651 struct btrfs_delayed_extent_op *extent_op)
1652 {
1653 struct btrfs_path *path;
1654 struct extent_buffer *leaf;
1655 struct btrfs_extent_item *item;
1656 u64 refs;
1657 int ret;
1658 int err = 0;
1659
1660 path = btrfs_alloc_path();
1661 if (!path)
1662 return -ENOMEM;
1663
1664 path->reada = 1;
1665 path->leave_spinning = 1;
1666 /* this will setup the path even if it fails to insert the back ref */
1667 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1668 path, bytenr, num_bytes, parent,
1669 root_objectid, owner, offset,
1670 refs_to_add, extent_op);
1671 if (ret == 0)
1672 goto out;
1673
1674 if (ret != -EAGAIN) {
1675 err = ret;
1676 goto out;
1677 }
1678
1679 leaf = path->nodes[0];
1680 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1681 refs = btrfs_extent_refs(leaf, item);
1682 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1683 if (extent_op)
1684 __run_delayed_extent_op(extent_op, leaf, item);
1685
1686 btrfs_mark_buffer_dirty(leaf);
1687 btrfs_release_path(root->fs_info->extent_root, path);
1688
1689 path->reada = 1;
1690 path->leave_spinning = 1;
1691
1692 /* now insert the actual backref */
1693 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1694 path, bytenr, parent, root_objectid,
1695 owner, offset, refs_to_add);
1696 BUG_ON(ret);
1697 out:
1698 btrfs_free_path(path);
1699 return err;
1700 }
1701
1702 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1703 struct btrfs_root *root,
1704 struct btrfs_delayed_ref_node *node,
1705 struct btrfs_delayed_extent_op *extent_op,
1706 int insert_reserved)
1707 {
1708 int ret = 0;
1709 struct btrfs_delayed_data_ref *ref;
1710 struct btrfs_key ins;
1711 u64 parent = 0;
1712 u64 ref_root = 0;
1713 u64 flags = 0;
1714
1715 ins.objectid = node->bytenr;
1716 ins.offset = node->num_bytes;
1717 ins.type = BTRFS_EXTENT_ITEM_KEY;
1718
1719 ref = btrfs_delayed_node_to_data_ref(node);
1720 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
1721 parent = ref->parent;
1722 else
1723 ref_root = ref->root;
1724
1725 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1726 if (extent_op) {
1727 BUG_ON(extent_op->update_key);
1728 flags |= extent_op->flags_to_set;
1729 }
1730 ret = alloc_reserved_file_extent(trans, root,
1731 parent, ref_root, flags,
1732 ref->objectid, ref->offset,
1733 &ins, node->ref_mod);
1734 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1735 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1736 node->num_bytes, parent,
1737 ref_root, ref->objectid,
1738 ref->offset, node->ref_mod,
1739 extent_op);
1740 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1741 ret = __btrfs_free_extent(trans, root, node->bytenr,
1742 node->num_bytes, parent,
1743 ref_root, ref->objectid,
1744 ref->offset, node->ref_mod,
1745 extent_op);
1746 } else {
1747 BUG();
1748 }
1749 return ret;
1750 }
1751
1752 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
1753 struct extent_buffer *leaf,
1754 struct btrfs_extent_item *ei)
1755 {
1756 u64 flags = btrfs_extent_flags(leaf, ei);
1757 if (extent_op->update_flags) {
1758 flags |= extent_op->flags_to_set;
1759 btrfs_set_extent_flags(leaf, ei, flags);
1760 }
1761
1762 if (extent_op->update_key) {
1763 struct btrfs_tree_block_info *bi;
1764 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
1765 bi = (struct btrfs_tree_block_info *)(ei + 1);
1766 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
1767 }
1768 }
1769
1770 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
1771 struct btrfs_root *root,
1772 struct btrfs_delayed_ref_node *node,
1773 struct btrfs_delayed_extent_op *extent_op)
1774 {
1775 struct btrfs_key key;
1776 struct btrfs_path *path;
1777 struct btrfs_extent_item *ei;
1778 struct extent_buffer *leaf;
1779 u32 item_size;
1780 int ret;
1781 int err = 0;
1782
1783 path = btrfs_alloc_path();
1784 if (!path)
1785 return -ENOMEM;
1786
1787 key.objectid = node->bytenr;
1788 key.type = BTRFS_EXTENT_ITEM_KEY;
1789 key.offset = node->num_bytes;
1790
1791 path->reada = 1;
1792 path->leave_spinning = 1;
1793 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
1794 path, 0, 1);
1795 if (ret < 0) {
1796 err = ret;
1797 goto out;
1798 }
1799 if (ret > 0) {
1800 err = -EIO;
1801 goto out;
1802 }
1803
1804 leaf = path->nodes[0];
1805 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1806 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1807 if (item_size < sizeof(*ei)) {
1808 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1809 path, (u64)-1, 0);
1810 if (ret < 0) {
1811 err = ret;
1812 goto out;
1813 }
1814 leaf = path->nodes[0];
1815 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1816 }
1817 #endif
1818 BUG_ON(item_size < sizeof(*ei));
1819 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1820 __run_delayed_extent_op(extent_op, leaf, ei);
1821
1822 btrfs_mark_buffer_dirty(leaf);
1823 out:
1824 btrfs_free_path(path);
1825 return err;
1826 }
1827
1828 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
1829 struct btrfs_root *root,
1830 struct btrfs_delayed_ref_node *node,
1831 struct btrfs_delayed_extent_op *extent_op,
1832 int insert_reserved)
1833 {
1834 int ret = 0;
1835 struct btrfs_delayed_tree_ref *ref;
1836 struct btrfs_key ins;
1837 u64 parent = 0;
1838 u64 ref_root = 0;
1839
1840 ins.objectid = node->bytenr;
1841 ins.offset = node->num_bytes;
1842 ins.type = BTRFS_EXTENT_ITEM_KEY;
1843
1844 ref = btrfs_delayed_node_to_tree_ref(node);
1845 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1846 parent = ref->parent;
1847 else
1848 ref_root = ref->root;
1849
1850 BUG_ON(node->ref_mod != 1);
1851 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1852 BUG_ON(!extent_op || !extent_op->update_flags ||
1853 !extent_op->update_key);
1854 ret = alloc_reserved_tree_block(trans, root,
1855 parent, ref_root,
1856 extent_op->flags_to_set,
1857 &extent_op->key,
1858 ref->level, &ins);
1859 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1860 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1861 node->num_bytes, parent, ref_root,
1862 ref->level, 0, 1, extent_op);
1863 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1864 ret = __btrfs_free_extent(trans, root, node->bytenr,
1865 node->num_bytes, parent, ref_root,
1866 ref->level, 0, 1, extent_op);
1867 } else {
1868 BUG();
1869 }
1870 return ret;
1871 }
1872
1873
1874 /* helper function to actually process a single delayed ref entry */
1875 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
1876 struct btrfs_root *root,
1877 struct btrfs_delayed_ref_node *node,
1878 struct btrfs_delayed_extent_op *extent_op,
1879 int insert_reserved)
1880 {
1881 int ret;
1882 if (btrfs_delayed_ref_is_head(node)) {
1883 struct btrfs_delayed_ref_head *head;
1884 /*
1885 * we've hit the end of the chain and we were supposed
1886 * to insert this extent into the tree. But, it got
1887 * deleted before we ever needed to insert it, so all
1888 * we have to do is clean up the accounting
1889 */
1890 BUG_ON(extent_op);
1891 head = btrfs_delayed_node_to_head(node);
1892 if (insert_reserved) {
1893 int mark_free = 0;
1894 struct extent_buffer *must_clean = NULL;
1895
1896 ret = pin_down_bytes(trans, root, NULL,
1897 node->bytenr, node->num_bytes,
1898 head->is_data, 1, &must_clean);
1899 if (ret > 0)
1900 mark_free = 1;
1901
1902 if (must_clean) {
1903 clean_tree_block(NULL, root, must_clean);
1904 btrfs_tree_unlock(must_clean);
1905 free_extent_buffer(must_clean);
1906 }
1907 if (head->is_data) {
1908 ret = btrfs_del_csums(trans, root,
1909 node->bytenr,
1910 node->num_bytes);
1911 BUG_ON(ret);
1912 }
1913 if (mark_free) {
1914 ret = btrfs_free_reserved_extent(root,
1915 node->bytenr,
1916 node->num_bytes);
1917 BUG_ON(ret);
1918 }
1919 }
1920 mutex_unlock(&head->mutex);
1921 return 0;
1922 }
1923
1924 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1925 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1926 ret = run_delayed_tree_ref(trans, root, node, extent_op,
1927 insert_reserved);
1928 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1929 node->type == BTRFS_SHARED_DATA_REF_KEY)
1930 ret = run_delayed_data_ref(trans, root, node, extent_op,
1931 insert_reserved);
1932 else
1933 BUG();
1934 return ret;
1935 }
1936
1937 static noinline struct btrfs_delayed_ref_node *
1938 select_delayed_ref(struct btrfs_delayed_ref_head *head)
1939 {
1940 struct rb_node *node;
1941 struct btrfs_delayed_ref_node *ref;
1942 int action = BTRFS_ADD_DELAYED_REF;
1943 again:
1944 /*
1945 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
1946 * this prevents ref count from going down to zero when
1947 * there still are pending delayed ref.
1948 */
1949 node = rb_prev(&head->node.rb_node);
1950 while (1) {
1951 if (!node)
1952 break;
1953 ref = rb_entry(node, struct btrfs_delayed_ref_node,
1954 rb_node);
1955 if (ref->bytenr != head->node.bytenr)
1956 break;
1957 if (ref->action == action)
1958 return ref;
1959 node = rb_prev(node);
1960 }
1961 if (action == BTRFS_ADD_DELAYED_REF) {
1962 action = BTRFS_DROP_DELAYED_REF;
1963 goto again;
1964 }
1965 return NULL;
1966 }
1967
1968 static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
1969 struct btrfs_root *root,
1970 struct list_head *cluster)
1971 {
1972 struct btrfs_delayed_ref_root *delayed_refs;
1973 struct btrfs_delayed_ref_node *ref;
1974 struct btrfs_delayed_ref_head *locked_ref = NULL;
1975 struct btrfs_delayed_extent_op *extent_op;
1976 int ret;
1977 int count = 0;
1978 int must_insert_reserved = 0;
1979
1980 delayed_refs = &trans->transaction->delayed_refs;
1981 while (1) {
1982 if (!locked_ref) {
1983 /* pick a new head ref from the cluster list */
1984 if (list_empty(cluster))
1985 break;
1986
1987 locked_ref = list_entry(cluster->next,
1988 struct btrfs_delayed_ref_head, cluster);
1989
1990 /* grab the lock that says we are going to process
1991 * all the refs for this head */
1992 ret = btrfs_delayed_ref_lock(trans, locked_ref);
1993
1994 /*
1995 * we may have dropped the spin lock to get the head
1996 * mutex lock, and that might have given someone else
1997 * time to free the head. If that's true, it has been
1998 * removed from our list and we can move on.
1999 */
2000 if (ret == -EAGAIN) {
2001 locked_ref = NULL;
2002 count++;
2003 continue;
2004 }
2005 }
2006
2007 /*
2008 * record the must insert reserved flag before we
2009 * drop the spin lock.
2010 */
2011 must_insert_reserved = locked_ref->must_insert_reserved;
2012 locked_ref->must_insert_reserved = 0;
2013
2014 extent_op = locked_ref->extent_op;
2015 locked_ref->extent_op = NULL;
2016
2017 /*
2018 * locked_ref is the head node, so we have to go one
2019 * node back for any delayed ref updates
2020 */
2021 ref = select_delayed_ref(locked_ref);
2022 if (!ref) {
2023 /* All delayed refs have been processed, Go ahead
2024 * and send the head node to run_one_delayed_ref,
2025 * so that any accounting fixes can happen
2026 */
2027 ref = &locked_ref->node;
2028
2029 if (extent_op && must_insert_reserved) {
2030 kfree(extent_op);
2031 extent_op = NULL;
2032 }
2033
2034 if (extent_op) {
2035 spin_unlock(&delayed_refs->lock);
2036
2037 ret = run_delayed_extent_op(trans, root,
2038 ref, extent_op);
2039 BUG_ON(ret);
2040 kfree(extent_op);
2041
2042 cond_resched();
2043 spin_lock(&delayed_refs->lock);
2044 continue;
2045 }
2046
2047 list_del_init(&locked_ref->cluster);
2048 locked_ref = NULL;
2049 }
2050
2051 ref->in_tree = 0;
2052 rb_erase(&ref->rb_node, &delayed_refs->root);
2053 delayed_refs->num_entries--;
2054
2055 spin_unlock(&delayed_refs->lock);
2056
2057 ret = run_one_delayed_ref(trans, root, ref, extent_op,
2058 must_insert_reserved);
2059 BUG_ON(ret);
2060
2061 btrfs_put_delayed_ref(ref);
2062 kfree(extent_op);
2063 count++;
2064
2065 cond_resched();
2066 spin_lock(&delayed_refs->lock);
2067 }
2068 return count;
2069 }
2070
2071 /*
2072 * this starts processing the delayed reference count updates and
2073 * extent insertions we have queued up so far. count can be
2074 * 0, which means to process everything in the tree at the start
2075 * of the run (but not newly added entries), or it can be some target
2076 * number you'd like to process.
2077 */
2078 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2079 struct btrfs_root *root, unsigned long count)
2080 {
2081 struct rb_node *node;
2082 struct btrfs_delayed_ref_root *delayed_refs;
2083 struct btrfs_delayed_ref_node *ref;
2084 struct list_head cluster;
2085 int ret;
2086 int run_all = count == (unsigned long)-1;
2087 int run_most = 0;
2088
2089 if (root == root->fs_info->extent_root)
2090 root = root->fs_info->tree_root;
2091
2092 delayed_refs = &trans->transaction->delayed_refs;
2093 INIT_LIST_HEAD(&cluster);
2094 again:
2095 spin_lock(&delayed_refs->lock);
2096 if (count == 0) {
2097 count = delayed_refs->num_entries * 2;
2098 run_most = 1;
2099 }
2100 while (1) {
2101 if (!(run_all || run_most) &&
2102 delayed_refs->num_heads_ready < 64)
2103 break;
2104
2105 /*
2106 * go find something we can process in the rbtree. We start at
2107 * the beginning of the tree, and then build a cluster
2108 * of refs to process starting at the first one we are able to
2109 * lock
2110 */
2111 ret = btrfs_find_ref_cluster(trans, &cluster,
2112 delayed_refs->run_delayed_start);
2113 if (ret)
2114 break;
2115
2116 ret = run_clustered_refs(trans, root, &cluster);
2117 BUG_ON(ret < 0);
2118
2119 count -= min_t(unsigned long, ret, count);
2120
2121 if (count == 0)
2122 break;
2123 }
2124
2125 if (run_all) {
2126 node = rb_first(&delayed_refs->root);
2127 if (!node)
2128 goto out;
2129 count = (unsigned long)-1;
2130
2131 while (node) {
2132 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2133 rb_node);
2134 if (btrfs_delayed_ref_is_head(ref)) {
2135 struct btrfs_delayed_ref_head *head;
2136
2137 head = btrfs_delayed_node_to_head(ref);
2138 atomic_inc(&ref->refs);
2139
2140 spin_unlock(&delayed_refs->lock);
2141 mutex_lock(&head->mutex);
2142 mutex_unlock(&head->mutex);
2143
2144 btrfs_put_delayed_ref(ref);
2145 cond_resched();
2146 goto again;
2147 }
2148 node = rb_next(node);
2149 }
2150 spin_unlock(&delayed_refs->lock);
2151 schedule_timeout(1);
2152 goto again;
2153 }
2154 out:
2155 spin_unlock(&delayed_refs->lock);
2156 return 0;
2157 }
2158
2159 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2160 struct btrfs_root *root,
2161 u64 bytenr, u64 num_bytes, u64 flags,
2162 int is_data)
2163 {
2164 struct btrfs_delayed_extent_op *extent_op;
2165 int ret;
2166
2167 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2168 if (!extent_op)
2169 return -ENOMEM;
2170
2171 extent_op->flags_to_set = flags;
2172 extent_op->update_flags = 1;
2173 extent_op->update_key = 0;
2174 extent_op->is_data = is_data ? 1 : 0;
2175
2176 ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
2177 if (ret)
2178 kfree(extent_op);
2179 return ret;
2180 }
2181
2182 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
2183 struct btrfs_root *root,
2184 struct btrfs_path *path,
2185 u64 objectid, u64 offset, u64 bytenr)
2186 {
2187 struct btrfs_delayed_ref_head *head;
2188 struct btrfs_delayed_ref_node *ref;
2189 struct btrfs_delayed_data_ref *data_ref;
2190 struct btrfs_delayed_ref_root *delayed_refs;
2191 struct rb_node *node;
2192 int ret = 0;
2193
2194 ret = -ENOENT;
2195 delayed_refs = &trans->transaction->delayed_refs;
2196 spin_lock(&delayed_refs->lock);
2197 head = btrfs_find_delayed_ref_head(trans, bytenr);
2198 if (!head)
2199 goto out;
2200
2201 if (!mutex_trylock(&head->mutex)) {
2202 atomic_inc(&head->node.refs);
2203 spin_unlock(&delayed_refs->lock);
2204
2205 btrfs_release_path(root->fs_info->extent_root, path);
2206
2207 mutex_lock(&head->mutex);
2208 mutex_unlock(&head->mutex);
2209 btrfs_put_delayed_ref(&head->node);
2210 return -EAGAIN;
2211 }
2212
2213 node = rb_prev(&head->node.rb_node);
2214 if (!node)
2215 goto out_unlock;
2216
2217 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2218
2219 if (ref->bytenr != bytenr)
2220 goto out_unlock;
2221
2222 ret = 1;
2223 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
2224 goto out_unlock;
2225
2226 data_ref = btrfs_delayed_node_to_data_ref(ref);
2227
2228 node = rb_prev(node);
2229 if (node) {
2230 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2231 if (ref->bytenr == bytenr)
2232 goto out_unlock;
2233 }
2234
2235 if (data_ref->root != root->root_key.objectid ||
2236 data_ref->objectid != objectid || data_ref->offset != offset)
2237 goto out_unlock;
2238
2239 ret = 0;
2240 out_unlock:
2241 mutex_unlock(&head->mutex);
2242 out:
2243 spin_unlock(&delayed_refs->lock);
2244 return ret;
2245 }
2246
2247 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
2248 struct btrfs_root *root,
2249 struct btrfs_path *path,
2250 u64 objectid, u64 offset, u64 bytenr)
2251 {
2252 struct btrfs_root *extent_root = root->fs_info->extent_root;
2253 struct extent_buffer *leaf;
2254 struct btrfs_extent_data_ref *ref;
2255 struct btrfs_extent_inline_ref *iref;
2256 struct btrfs_extent_item *ei;
2257 struct btrfs_key key;
2258 u32 item_size;
2259 int ret;
2260
2261 key.objectid = bytenr;
2262 key.offset = (u64)-1;
2263 key.type = BTRFS_EXTENT_ITEM_KEY;
2264
2265 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2266 if (ret < 0)
2267 goto out;
2268 BUG_ON(ret == 0);
2269
2270 ret = -ENOENT;
2271 if (path->slots[0] == 0)
2272 goto out;
2273
2274 path->slots[0]--;
2275 leaf = path->nodes[0];
2276 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2277
2278 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2279 goto out;
2280
2281 ret = 1;
2282 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2283 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2284 if (item_size < sizeof(*ei)) {
2285 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
2286 goto out;
2287 }
2288 #endif
2289 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2290
2291 if (item_size != sizeof(*ei) +
2292 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2293 goto out;
2294
2295 if (btrfs_extent_generation(leaf, ei) <=
2296 btrfs_root_last_snapshot(&root->root_item))
2297 goto out;
2298
2299 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2300 if (btrfs_extent_inline_ref_type(leaf, iref) !=
2301 BTRFS_EXTENT_DATA_REF_KEY)
2302 goto out;
2303
2304 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2305 if (btrfs_extent_refs(leaf, ei) !=
2306 btrfs_extent_data_ref_count(leaf, ref) ||
2307 btrfs_extent_data_ref_root(leaf, ref) !=
2308 root->root_key.objectid ||
2309 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2310 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2311 goto out;
2312
2313 ret = 0;
2314 out:
2315 return ret;
2316 }
2317
2318 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
2319 struct btrfs_root *root,
2320 u64 objectid, u64 offset, u64 bytenr)
2321 {
2322 struct btrfs_path *path;
2323 int ret;
2324 int ret2;
2325
2326 path = btrfs_alloc_path();
2327 if (!path)
2328 return -ENOENT;
2329
2330 do {
2331 ret = check_committed_ref(trans, root, path, objectid,
2332 offset, bytenr);
2333 if (ret && ret != -ENOENT)
2334 goto out;
2335
2336 ret2 = check_delayed_ref(trans, root, path, objectid,
2337 offset, bytenr);
2338 } while (ret2 == -EAGAIN);
2339
2340 if (ret2 && ret2 != -ENOENT) {
2341 ret = ret2;
2342 goto out;
2343 }
2344
2345 if (ret != -ENOENT || ret2 != -ENOENT)
2346 ret = 0;
2347 out:
2348 btrfs_free_path(path);
2349 return ret;
2350 }
2351
2352 #if 0
2353 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2354 struct extent_buffer *buf, u32 nr_extents)
2355 {
2356 struct btrfs_key key;
2357 struct btrfs_file_extent_item *fi;
2358 u64 root_gen;
2359 u32 nritems;
2360 int i;
2361 int level;
2362 int ret = 0;
2363 int shared = 0;
2364
2365 if (!root->ref_cows)
2366 return 0;
2367
2368 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
2369 shared = 0;
2370 root_gen = root->root_key.offset;
2371 } else {
2372 shared = 1;
2373 root_gen = trans->transid - 1;
2374 }
2375
2376 level = btrfs_header_level(buf);
2377 nritems = btrfs_header_nritems(buf);
2378
2379 if (level == 0) {
2380 struct btrfs_leaf_ref *ref;
2381 struct btrfs_extent_info *info;
2382
2383 ref = btrfs_alloc_leaf_ref(root, nr_extents);
2384 if (!ref) {
2385 ret = -ENOMEM;
2386 goto out;
2387 }
2388
2389 ref->root_gen = root_gen;
2390 ref->bytenr = buf->start;
2391 ref->owner = btrfs_header_owner(buf);
2392 ref->generation = btrfs_header_generation(buf);
2393 ref->nritems = nr_extents;
2394 info = ref->extents;
2395
2396 for (i = 0; nr_extents > 0 && i < nritems; i++) {
2397 u64 disk_bytenr;
2398 btrfs_item_key_to_cpu(buf, &key, i);
2399 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2400 continue;
2401 fi = btrfs_item_ptr(buf, i,
2402 struct btrfs_file_extent_item);
2403 if (btrfs_file_extent_type(buf, fi) ==
2404 BTRFS_FILE_EXTENT_INLINE)
2405 continue;
2406 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2407 if (disk_bytenr == 0)
2408 continue;
2409
2410 info->bytenr = disk_bytenr;
2411 info->num_bytes =
2412 btrfs_file_extent_disk_num_bytes(buf, fi);
2413 info->objectid = key.objectid;
2414 info->offset = key.offset;
2415 info++;
2416 }
2417
2418 ret = btrfs_add_leaf_ref(root, ref, shared);
2419 if (ret == -EEXIST && shared) {
2420 struct btrfs_leaf_ref *old;
2421 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
2422 BUG_ON(!old);
2423 btrfs_remove_leaf_ref(root, old);
2424 btrfs_free_leaf_ref(root, old);
2425 ret = btrfs_add_leaf_ref(root, ref, shared);
2426 }
2427 WARN_ON(ret);
2428 btrfs_free_leaf_ref(root, ref);
2429 }
2430 out:
2431 return ret;
2432 }
2433
2434 /* when a block goes through cow, we update the reference counts of
2435 * everything that block points to. The internal pointers of the block
2436 * can be in just about any order, and it is likely to have clusters of
2437 * things that are close together and clusters of things that are not.
2438 *
2439 * To help reduce the seeks that come with updating all of these reference
2440 * counts, sort them by byte number before actual updates are done.
2441 *
2442 * struct refsort is used to match byte number to slot in the btree block.
2443 * we sort based on the byte number and then use the slot to actually
2444 * find the item.
2445 *
2446 * struct refsort is smaller than strcut btrfs_item and smaller than
2447 * struct btrfs_key_ptr. Since we're currently limited to the page size
2448 * for a btree block, there's no way for a kmalloc of refsorts for a
2449 * single node to be bigger than a page.
2450 */
2451 struct refsort {
2452 u64 bytenr;
2453 u32 slot;
2454 };
2455
2456 /*
2457 * for passing into sort()
2458 */
2459 static int refsort_cmp(const void *a_void, const void *b_void)
2460 {
2461 const struct refsort *a = a_void;
2462 const struct refsort *b = b_void;
2463
2464 if (a->bytenr < b->bytenr)
2465 return -1;
2466 if (a->bytenr > b->bytenr)
2467 return 1;
2468 return 0;
2469 }
2470 #endif
2471
2472 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2473 struct btrfs_root *root,
2474 struct extent_buffer *buf,
2475 int full_backref, int inc)
2476 {
2477 u64 bytenr;
2478 u64 num_bytes;
2479 u64 parent;
2480 u64 ref_root;
2481 u32 nritems;
2482 struct btrfs_key key;
2483 struct btrfs_file_extent_item *fi;
2484 int i;
2485 int level;
2486 int ret = 0;
2487 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
2488 u64, u64, u64, u64, u64, u64);
2489
2490 ref_root = btrfs_header_owner(buf);
2491 nritems = btrfs_header_nritems(buf);
2492 level = btrfs_header_level(buf);
2493
2494 if (!root->ref_cows && level == 0)
2495 return 0;
2496
2497 if (inc)
2498 process_func = btrfs_inc_extent_ref;
2499 else
2500 process_func = btrfs_free_extent;
2501
2502 if (full_backref)
2503 parent = buf->start;
2504 else
2505 parent = 0;
2506
2507 for (i = 0; i < nritems; i++) {
2508 if (level == 0) {
2509 btrfs_item_key_to_cpu(buf, &key, i);
2510 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2511 continue;
2512 fi = btrfs_item_ptr(buf, i,
2513 struct btrfs_file_extent_item);
2514 if (btrfs_file_extent_type(buf, fi) ==
2515 BTRFS_FILE_EXTENT_INLINE)
2516 continue;
2517 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2518 if (bytenr == 0)
2519 continue;
2520
2521 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
2522 key.offset -= btrfs_file_extent_offset(buf, fi);
2523 ret = process_func(trans, root, bytenr, num_bytes,
2524 parent, ref_root, key.objectid,
2525 key.offset);
2526 if (ret)
2527 goto fail;
2528 } else {
2529 bytenr = btrfs_node_blockptr(buf, i);
2530 num_bytes = btrfs_level_size(root, level - 1);
2531 ret = process_func(trans, root, bytenr, num_bytes,
2532 parent, ref_root, level - 1, 0);
2533 if (ret)
2534 goto fail;
2535 }
2536 }
2537 return 0;
2538 fail:
2539 BUG();
2540 return ret;
2541 }
2542
2543 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2544 struct extent_buffer *buf, int full_backref)
2545 {
2546 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
2547 }
2548
2549 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2550 struct extent_buffer *buf, int full_backref)
2551 {
2552 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
2553 }
2554
2555 static int write_one_cache_group(struct btrfs_trans_handle *trans,
2556 struct btrfs_root *root,
2557 struct btrfs_path *path,
2558 struct btrfs_block_group_cache *cache)
2559 {
2560 int ret;
2561 struct btrfs_root *extent_root = root->fs_info->extent_root;
2562 unsigned long bi;
2563 struct extent_buffer *leaf;
2564
2565 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
2566 if (ret < 0)
2567 goto fail;
2568 BUG_ON(ret);
2569
2570 leaf = path->nodes[0];
2571 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
2572 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
2573 btrfs_mark_buffer_dirty(leaf);
2574 btrfs_release_path(extent_root, path);
2575 fail:
2576 if (ret)
2577 return ret;
2578 return 0;
2579
2580 }
2581
2582 static struct btrfs_block_group_cache *
2583 next_block_group(struct btrfs_root *root,
2584 struct btrfs_block_group_cache *cache)
2585 {
2586 struct rb_node *node;
2587 spin_lock(&root->fs_info->block_group_cache_lock);
2588 node = rb_next(&cache->cache_node);
2589 btrfs_put_block_group(cache);
2590 if (node) {
2591 cache = rb_entry(node, struct btrfs_block_group_cache,
2592 cache_node);
2593 btrfs_get_block_group(cache);
2594 } else
2595 cache = NULL;
2596 spin_unlock(&root->fs_info->block_group_cache_lock);
2597 return cache;
2598 }
2599
2600 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
2601 struct btrfs_root *root)
2602 {
2603 struct btrfs_block_group_cache *cache;
2604 int err = 0;
2605 struct btrfs_path *path;
2606 u64 last = 0;
2607
2608 path = btrfs_alloc_path();
2609 if (!path)
2610 return -ENOMEM;
2611
2612 while (1) {
2613 if (last == 0) {
2614 err = btrfs_run_delayed_refs(trans, root,
2615 (unsigned long)-1);
2616 BUG_ON(err);
2617 }
2618
2619 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2620 while (cache) {
2621 if (cache->dirty)
2622 break;
2623 cache = next_block_group(root, cache);
2624 }
2625 if (!cache) {
2626 if (last == 0)
2627 break;
2628 last = 0;
2629 continue;
2630 }
2631
2632 cache->dirty = 0;
2633 last = cache->key.objectid + cache->key.offset;
2634
2635 err = write_one_cache_group(trans, root, path, cache);
2636 BUG_ON(err);
2637 btrfs_put_block_group(cache);
2638 }
2639
2640 btrfs_free_path(path);
2641 return 0;
2642 }
2643
2644 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
2645 {
2646 struct btrfs_block_group_cache *block_group;
2647 int readonly = 0;
2648
2649 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
2650 if (!block_group || block_group->ro)
2651 readonly = 1;
2652 if (block_group)
2653 btrfs_put_block_group(block_group);
2654 return readonly;
2655 }
2656
2657 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
2658 u64 total_bytes, u64 bytes_used,
2659 struct btrfs_space_info **space_info)
2660 {
2661 struct btrfs_space_info *found;
2662
2663 found = __find_space_info(info, flags);
2664 if (found) {
2665 spin_lock(&found->lock);
2666 found->total_bytes += total_bytes;
2667 found->bytes_used += bytes_used;
2668 found->full = 0;
2669 spin_unlock(&found->lock);
2670 *space_info = found;
2671 return 0;
2672 }
2673 found = kzalloc(sizeof(*found), GFP_NOFS);
2674 if (!found)
2675 return -ENOMEM;
2676
2677 INIT_LIST_HEAD(&found->block_groups);
2678 init_rwsem(&found->groups_sem);
2679 spin_lock_init(&found->lock);
2680 found->flags = flags;
2681 found->total_bytes = total_bytes;
2682 found->bytes_used = bytes_used;
2683 found->bytes_pinned = 0;
2684 found->bytes_reserved = 0;
2685 found->bytes_readonly = 0;
2686 found->bytes_delalloc = 0;
2687 found->full = 0;
2688 found->force_alloc = 0;
2689 *space_info = found;
2690 list_add_rcu(&found->list, &info->space_info);
2691 atomic_set(&found->caching_threads, 0);
2692 return 0;
2693 }
2694
2695 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
2696 {
2697 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
2698 BTRFS_BLOCK_GROUP_RAID1 |
2699 BTRFS_BLOCK_GROUP_RAID10 |
2700 BTRFS_BLOCK_GROUP_DUP);
2701 if (extra_flags) {
2702 if (flags & BTRFS_BLOCK_GROUP_DATA)
2703 fs_info->avail_data_alloc_bits |= extra_flags;
2704 if (flags & BTRFS_BLOCK_GROUP_METADATA)
2705 fs_info->avail_metadata_alloc_bits |= extra_flags;
2706 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
2707 fs_info->avail_system_alloc_bits |= extra_flags;
2708 }
2709 }
2710
2711 static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
2712 {
2713 spin_lock(&cache->space_info->lock);
2714 spin_lock(&cache->lock);
2715 if (!cache->ro) {
2716 cache->space_info->bytes_readonly += cache->key.offset -
2717 btrfs_block_group_used(&cache->item);
2718 cache->ro = 1;
2719 }
2720 spin_unlock(&cache->lock);
2721 spin_unlock(&cache->space_info->lock);
2722 }
2723
2724 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
2725 {
2726 u64 num_devices = root->fs_info->fs_devices->rw_devices;
2727
2728 if (num_devices == 1)
2729 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
2730 if (num_devices < 4)
2731 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
2732
2733 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
2734 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
2735 BTRFS_BLOCK_GROUP_RAID10))) {
2736 flags &= ~BTRFS_BLOCK_GROUP_DUP;
2737 }
2738
2739 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
2740 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
2741 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
2742 }
2743
2744 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
2745 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
2746 (flags & BTRFS_BLOCK_GROUP_RAID10) |
2747 (flags & BTRFS_BLOCK_GROUP_DUP)))
2748 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
2749 return flags;
2750 }
2751
2752 static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data)
2753 {
2754 struct btrfs_fs_info *info = root->fs_info;
2755 u64 alloc_profile;
2756
2757 if (data) {
2758 alloc_profile = info->avail_data_alloc_bits &
2759 info->data_alloc_profile;
2760 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2761 } else if (root == root->fs_info->chunk_root) {
2762 alloc_profile = info->avail_system_alloc_bits &
2763 info->system_alloc_profile;
2764 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2765 } else {
2766 alloc_profile = info->avail_metadata_alloc_bits &
2767 info->metadata_alloc_profile;
2768 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2769 }
2770
2771 return btrfs_reduce_alloc_profile(root, data);
2772 }
2773
2774 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
2775 {
2776 u64 alloc_target;
2777
2778 alloc_target = btrfs_get_alloc_profile(root, 1);
2779 BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
2780 alloc_target);
2781 }
2782
2783 static u64 calculate_bytes_needed(struct btrfs_root *root, int num_items)
2784 {
2785 u64 num_bytes;
2786 int level;
2787
2788 level = BTRFS_MAX_LEVEL - 2;
2789 /*
2790 * NOTE: these calculations are absolutely the worst possible case.
2791 * This assumes that _every_ item we insert will require a new leaf, and
2792 * that the tree has grown to its maximum level size.
2793 */
2794
2795 /*
2796 * for every item we insert we could insert both an extent item and a
2797 * extent ref item. Then for ever item we insert, we will need to cow
2798 * both the original leaf, plus the leaf to the left and right of it.
2799 *
2800 * Unless we are talking about the extent root, then we just want the
2801 * number of items * 2, since we just need the extent item plus its ref.
2802 */
2803 if (root == root->fs_info->extent_root)
2804 num_bytes = num_items * 2;
2805 else
2806 num_bytes = (num_items + (2 * num_items)) * 3;
2807
2808 /*
2809 * num_bytes is total number of leaves we could need times the leaf
2810 * size, and then for every leaf we could end up cow'ing 2 nodes per
2811 * level, down to the leaf level.
2812 */
2813 num_bytes = (num_bytes * root->leafsize) +
2814 (num_bytes * (level * 2)) * root->nodesize;
2815
2816 return num_bytes;
2817 }
2818
2819 /*
2820 * Unreserve metadata space for delalloc. If we have less reserved credits than
2821 * we have extents, this function does nothing.
2822 */
2823 int btrfs_unreserve_metadata_for_delalloc(struct btrfs_root *root,
2824 struct inode *inode, int num_items)
2825 {
2826 struct btrfs_fs_info *info = root->fs_info;
2827 struct btrfs_space_info *meta_sinfo;
2828 u64 num_bytes;
2829 u64 alloc_target;
2830 bool bug = false;
2831
2832 /* get the space info for where the metadata will live */
2833 alloc_target = btrfs_get_alloc_profile(root, 0);
2834 meta_sinfo = __find_space_info(info, alloc_target);
2835
2836 num_bytes = calculate_bytes_needed(root->fs_info->extent_root,
2837 num_items);
2838
2839 spin_lock(&meta_sinfo->lock);
2840 spin_lock(&BTRFS_I(inode)->accounting_lock);
2841 if (BTRFS_I(inode)->reserved_extents <=
2842 BTRFS_I(inode)->outstanding_extents) {
2843 spin_unlock(&BTRFS_I(inode)->accounting_lock);
2844 spin_unlock(&meta_sinfo->lock);
2845 return 0;
2846 }
2847 spin_unlock(&BTRFS_I(inode)->accounting_lock);
2848
2849 BTRFS_I(inode)->reserved_extents--;
2850 BUG_ON(BTRFS_I(inode)->reserved_extents < 0);
2851
2852 if (meta_sinfo->bytes_delalloc < num_bytes) {
2853 bug = true;
2854 meta_sinfo->bytes_delalloc = 0;
2855 } else {
2856 meta_sinfo->bytes_delalloc -= num_bytes;
2857 }
2858 spin_unlock(&meta_sinfo->lock);
2859
2860 BUG_ON(bug);
2861
2862 return 0;
2863 }
2864
2865 static void check_force_delalloc(struct btrfs_space_info *meta_sinfo)
2866 {
2867 u64 thresh;
2868
2869 thresh = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
2870 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
2871 meta_sinfo->bytes_super + meta_sinfo->bytes_root +
2872 meta_sinfo->bytes_may_use;
2873
2874 thresh = meta_sinfo->total_bytes - thresh;
2875 thresh *= 80;
2876 do_div(thresh, 100);
2877 if (thresh <= meta_sinfo->bytes_delalloc)
2878 meta_sinfo->force_delalloc = 1;
2879 else
2880 meta_sinfo->force_delalloc = 0;
2881 }
2882
2883 struct async_flush {
2884 struct btrfs_root *root;
2885 struct btrfs_space_info *info;
2886 struct btrfs_work work;
2887 };
2888
2889 static noinline void flush_delalloc_async(struct btrfs_work *work)
2890 {
2891 struct async_flush *async;
2892 struct btrfs_root *root;
2893 struct btrfs_space_info *info;
2894
2895 async = container_of(work, struct async_flush, work);
2896 root = async->root;
2897 info = async->info;
2898
2899 btrfs_start_delalloc_inodes(root, 0);
2900 wake_up(&info->flush_wait);
2901 btrfs_wait_ordered_extents(root, 0, 0);
2902
2903 spin_lock(&info->lock);
2904 info->flushing = 0;
2905 spin_unlock(&info->lock);
2906 wake_up(&info->flush_wait);
2907
2908 kfree(async);
2909 }
2910
2911 static void wait_on_flush(struct btrfs_space_info *info)
2912 {
2913 DEFINE_WAIT(wait);
2914 u64 used;
2915
2916 while (1) {
2917 prepare_to_wait(&info->flush_wait, &wait,
2918 TASK_UNINTERRUPTIBLE);
2919 spin_lock(&info->lock);
2920 if (!info->flushing) {
2921 spin_unlock(&info->lock);
2922 break;
2923 }
2924
2925 used = info->bytes_used + info->bytes_reserved +
2926 info->bytes_pinned + info->bytes_readonly +
2927 info->bytes_super + info->bytes_root +
2928 info->bytes_may_use + info->bytes_delalloc;
2929 if (used < info->total_bytes) {
2930 spin_unlock(&info->lock);
2931 break;
2932 }
2933 spin_unlock(&info->lock);
2934 schedule();
2935 }
2936 finish_wait(&info->flush_wait, &wait);
2937 }
2938
2939 static void flush_delalloc(struct btrfs_root *root,
2940 struct btrfs_space_info *info)
2941 {
2942 struct async_flush *async;
2943 bool wait = false;
2944
2945 spin_lock(&info->lock);
2946
2947 if (!info->flushing) {
2948 info->flushing = 1;
2949 init_waitqueue_head(&info->flush_wait);
2950 } else {
2951 wait = true;
2952 }
2953
2954 spin_unlock(&info->lock);
2955
2956 if (wait) {
2957 wait_on_flush(info);
2958 return;
2959 }
2960
2961 async = kzalloc(sizeof(*async), GFP_NOFS);
2962 if (!async)
2963 goto flush;
2964
2965 async->root = root;
2966 async->info = info;
2967 async->work.func = flush_delalloc_async;
2968
2969 btrfs_queue_worker(&root->fs_info->enospc_workers,
2970 &async->work);
2971 wait_on_flush(info);
2972 return;
2973
2974 flush:
2975 btrfs_start_delalloc_inodes(root, 0);
2976 btrfs_wait_ordered_extents(root, 0, 0);
2977
2978 spin_lock(&info->lock);
2979 info->flushing = 0;
2980 spin_unlock(&info->lock);
2981 wake_up(&info->flush_wait);
2982 }
2983
2984 static int maybe_allocate_chunk(struct btrfs_root *root,
2985 struct btrfs_space_info *info)
2986 {
2987 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
2988 struct btrfs_trans_handle *trans;
2989 bool wait = false;
2990 int ret = 0;
2991 u64 min_metadata;
2992 u64 free_space;
2993
2994 free_space = btrfs_super_total_bytes(disk_super);
2995 /*
2996 * we allow the metadata to grow to a max of either 10gb or 5% of the
2997 * space in the volume.
2998 */
2999 min_metadata = min((u64)10 * 1024 * 1024 * 1024,
3000 div64_u64(free_space * 5, 100));
3001 if (info->total_bytes >= min_metadata) {
3002 spin_unlock(&info->lock);
3003 return 0;
3004 }
3005
3006 if (info->full) {
3007 spin_unlock(&info->lock);
3008 return 0;
3009 }
3010
3011 if (!info->allocating_chunk) {
3012 info->force_alloc = 1;
3013 info->allocating_chunk = 1;
3014 init_waitqueue_head(&info->allocate_wait);
3015 } else {
3016 wait = true;
3017 }
3018
3019 spin_unlock(&info->lock);
3020
3021 if (wait) {
3022 wait_event(info->allocate_wait,
3023 !info->allocating_chunk);
3024 return 1;
3025 }
3026
3027 trans = btrfs_start_transaction(root, 1);
3028 if (!trans) {
3029 ret = -ENOMEM;
3030 goto out;
3031 }
3032
3033 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3034 4096 + 2 * 1024 * 1024,
3035 info->flags, 0);
3036 btrfs_end_transaction(trans, root);
3037 if (ret)
3038 goto out;
3039 out:
3040 spin_lock(&info->lock);
3041 info->allocating_chunk = 0;
3042 spin_unlock(&info->lock);
3043 wake_up(&info->allocate_wait);
3044
3045 if (ret)
3046 return 0;
3047 return 1;
3048 }
3049
3050 /*
3051 * Reserve metadata space for delalloc.
3052 */
3053 int btrfs_reserve_metadata_for_delalloc(struct btrfs_root *root,
3054 struct inode *inode, int num_items)
3055 {
3056 struct btrfs_fs_info *info = root->fs_info;
3057 struct btrfs_space_info *meta_sinfo;
3058 u64 num_bytes;
3059 u64 used;
3060 u64 alloc_target;
3061 int flushed = 0;
3062 int force_delalloc;
3063
3064 /* get the space info for where the metadata will live */
3065 alloc_target = btrfs_get_alloc_profile(root, 0);
3066 meta_sinfo = __find_space_info(info, alloc_target);
3067
3068 num_bytes = calculate_bytes_needed(root->fs_info->extent_root,
3069 num_items);
3070 again:
3071 spin_lock(&meta_sinfo->lock);
3072
3073 force_delalloc = meta_sinfo->force_delalloc;
3074
3075 if (unlikely(!meta_sinfo->bytes_root))
3076 meta_sinfo->bytes_root = calculate_bytes_needed(root, 6);
3077
3078 if (!flushed)
3079 meta_sinfo->bytes_delalloc += num_bytes;
3080
3081 used = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
3082 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
3083 meta_sinfo->bytes_super + meta_sinfo->bytes_root +
3084 meta_sinfo->bytes_may_use + meta_sinfo->bytes_delalloc;
3085
3086 if (used > meta_sinfo->total_bytes) {
3087 flushed++;
3088
3089 if (flushed == 1) {
3090 if (maybe_allocate_chunk(root, meta_sinfo))
3091 goto again;
3092 flushed++;
3093 } else {
3094 spin_unlock(&meta_sinfo->lock);
3095 }
3096
3097 if (flushed == 2) {
3098 filemap_flush(inode->i_mapping);
3099 goto again;
3100 } else if (flushed == 3) {
3101 flush_delalloc(root, meta_sinfo);
3102 goto again;
3103 }
3104 spin_lock(&meta_sinfo->lock);
3105 meta_sinfo->bytes_delalloc -= num_bytes;
3106 spin_unlock(&meta_sinfo->lock);
3107 printk(KERN_ERR "enospc, has %d, reserved %d\n",
3108 BTRFS_I(inode)->outstanding_extents,
3109 BTRFS_I(inode)->reserved_extents);
3110 dump_space_info(meta_sinfo, 0, 0);
3111 return -ENOSPC;
3112 }
3113
3114 BTRFS_I(inode)->reserved_extents++;
3115 check_force_delalloc(meta_sinfo);
3116 spin_unlock(&meta_sinfo->lock);
3117
3118 if (!flushed && force_delalloc)
3119 filemap_flush(inode->i_mapping);
3120
3121 return 0;
3122 }
3123
3124 /*
3125 * unreserve num_items number of items worth of metadata space. This needs to
3126 * be paired with btrfs_reserve_metadata_space.
3127 *
3128 * NOTE: if you have the option, run this _AFTER_ you do a
3129 * btrfs_end_transaction, since btrfs_end_transaction will run delayed ref
3130 * oprations which will result in more used metadata, so we want to make sure we
3131 * can do that without issue.
3132 */
3133 int btrfs_unreserve_metadata_space(struct btrfs_root *root, int num_items)
3134 {
3135 struct btrfs_fs_info *info = root->fs_info;
3136 struct btrfs_space_info *meta_sinfo;
3137 u64 num_bytes;
3138 u64 alloc_target;
3139 bool bug = false;
3140
3141 /* get the space info for where the metadata will live */
3142 alloc_target = btrfs_get_alloc_profile(root, 0);
3143 meta_sinfo = __find_space_info(info, alloc_target);
3144
3145 num_bytes = calculate_bytes_needed(root, num_items);
3146
3147 spin_lock(&meta_sinfo->lock);
3148 if (meta_sinfo->bytes_may_use < num_bytes) {
3149 bug = true;
3150 meta_sinfo->bytes_may_use = 0;
3151 } else {
3152 meta_sinfo->bytes_may_use -= num_bytes;
3153 }
3154 spin_unlock(&meta_sinfo->lock);
3155
3156 BUG_ON(bug);
3157
3158 return 0;
3159 }
3160
3161 /*
3162 * Reserve some metadata space for use. We'll calculate the worste case number
3163 * of bytes that would be needed to modify num_items number of items. If we
3164 * have space, fantastic, if not, you get -ENOSPC. Please call
3165 * btrfs_unreserve_metadata_space when you are done for the _SAME_ number of
3166 * items you reserved, since whatever metadata you needed should have already
3167 * been allocated.
3168 *
3169 * This will commit the transaction to make more space if we don't have enough
3170 * metadata space. THe only time we don't do this is if we're reserving space
3171 * inside of a transaction, then we will just return -ENOSPC and it is the
3172 * callers responsibility to handle it properly.
3173 */
3174 int btrfs_reserve_metadata_space(struct btrfs_root *root, int num_items)
3175 {
3176 struct btrfs_fs_info *info = root->fs_info;
3177 struct btrfs_space_info *meta_sinfo;
3178 u64 num_bytes;
3179 u64 used;
3180 u64 alloc_target;
3181 int retries = 0;
3182
3183 /* get the space info for where the metadata will live */
3184 alloc_target = btrfs_get_alloc_profile(root, 0);
3185 meta_sinfo = __find_space_info(info, alloc_target);
3186
3187 num_bytes = calculate_bytes_needed(root, num_items);
3188 again:
3189 spin_lock(&meta_sinfo->lock);
3190
3191 if (unlikely(!meta_sinfo->bytes_root))
3192 meta_sinfo->bytes_root = calculate_bytes_needed(root, 6);
3193
3194 if (!retries)
3195 meta_sinfo->bytes_may_use += num_bytes;
3196
3197 used = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
3198 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
3199 meta_sinfo->bytes_super + meta_sinfo->bytes_root +
3200 meta_sinfo->bytes_may_use + meta_sinfo->bytes_delalloc;
3201
3202 if (used > meta_sinfo->total_bytes) {
3203 retries++;
3204 if (retries == 1) {
3205 if (maybe_allocate_chunk(root, meta_sinfo))
3206 goto again;
3207 retries++;
3208 } else {
3209 spin_unlock(&meta_sinfo->lock);
3210 }
3211
3212 if (retries == 2) {
3213 flush_delalloc(root, meta_sinfo);
3214 goto again;
3215 }
3216 spin_lock(&meta_sinfo->lock);
3217 meta_sinfo->bytes_may_use -= num_bytes;
3218 spin_unlock(&meta_sinfo->lock);
3219
3220 dump_space_info(meta_sinfo, 0, 0);
3221 return -ENOSPC;
3222 }
3223
3224 check_force_delalloc(meta_sinfo);
3225 spin_unlock(&meta_sinfo->lock);
3226
3227 return 0;
3228 }
3229
3230 /*
3231 * This will check the space that the inode allocates from to make sure we have
3232 * enough space for bytes.
3233 */
3234 int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
3235 u64 bytes)
3236 {
3237 struct btrfs_space_info *data_sinfo;
3238 int ret = 0, committed = 0;
3239
3240 /* make sure bytes are sectorsize aligned */
3241 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
3242
3243 data_sinfo = BTRFS_I(inode)->space_info;
3244 if (!data_sinfo)
3245 goto alloc;
3246
3247 again:
3248 /* make sure we have enough space to handle the data first */
3249 spin_lock(&data_sinfo->lock);
3250 if (data_sinfo->total_bytes - data_sinfo->bytes_used -
3251 data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved -
3252 data_sinfo->bytes_pinned - data_sinfo->bytes_readonly -
3253 data_sinfo->bytes_may_use - data_sinfo->bytes_super < bytes) {
3254 struct btrfs_trans_handle *trans;
3255
3256 /*
3257 * if we don't have enough free bytes in this space then we need
3258 * to alloc a new chunk.
3259 */
3260 if (!data_sinfo->full) {
3261 u64 alloc_target;
3262
3263 data_sinfo->force_alloc = 1;
3264 spin_unlock(&data_sinfo->lock);
3265 alloc:
3266 alloc_target = btrfs_get_alloc_profile(root, 1);
3267 trans = btrfs_start_transaction(root, 1);
3268 if (!trans)
3269 return -ENOMEM;
3270
3271 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3272 bytes + 2 * 1024 * 1024,
3273 alloc_target, 0);
3274 btrfs_end_transaction(trans, root);
3275 if (ret)
3276 return ret;
3277
3278 if (!data_sinfo) {
3279 btrfs_set_inode_space_info(root, inode);
3280 data_sinfo = BTRFS_I(inode)->space_info;
3281 }
3282 goto again;
3283 }
3284 spin_unlock(&data_sinfo->lock);
3285
3286 /* commit the current transaction and try again */
3287 if (!committed && !root->fs_info->open_ioctl_trans) {
3288 committed = 1;
3289 trans = btrfs_join_transaction(root, 1);
3290 if (!trans)
3291 return -ENOMEM;
3292 ret = btrfs_commit_transaction(trans, root);
3293 if (ret)
3294 return ret;
3295 goto again;
3296 }
3297
3298 printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes"
3299 ", %llu bytes_used, %llu bytes_reserved, "
3300 "%llu bytes_pinned, %llu bytes_readonly, %llu may use "
3301 "%llu total\n", (unsigned long long)bytes,
3302 (unsigned long long)data_sinfo->bytes_delalloc,
3303 (unsigned long long)data_sinfo->bytes_used,
3304 (unsigned long long)data_sinfo->bytes_reserved,
3305 (unsigned long long)data_sinfo->bytes_pinned,
3306 (unsigned long long)data_sinfo->bytes_readonly,
3307 (unsigned long long)data_sinfo->bytes_may_use,
3308 (unsigned long long)data_sinfo->total_bytes);
3309 return -ENOSPC;
3310 }
3311 data_sinfo->bytes_may_use += bytes;
3312 BTRFS_I(inode)->reserved_bytes += bytes;
3313 spin_unlock(&data_sinfo->lock);
3314
3315 return 0;
3316 }
3317
3318 /*
3319 * if there was an error for whatever reason after calling
3320 * btrfs_check_data_free_space, call this so we can cleanup the counters.
3321 */
3322 void btrfs_free_reserved_data_space(struct btrfs_root *root,
3323 struct inode *inode, u64 bytes)
3324 {
3325 struct btrfs_space_info *data_sinfo;
3326
3327 /* make sure bytes are sectorsize aligned */
3328 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
3329
3330 data_sinfo = BTRFS_I(inode)->space_info;
3331 spin_lock(&data_sinfo->lock);
3332 data_sinfo->bytes_may_use -= bytes;
3333 BTRFS_I(inode)->reserved_bytes -= bytes;
3334 spin_unlock(&data_sinfo->lock);
3335 }
3336
3337 /* called when we are adding a delalloc extent to the inode's io_tree */
3338 void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
3339 u64 bytes)
3340 {
3341 struct btrfs_space_info *data_sinfo;
3342
3343 /* get the space info for where this inode will be storing its data */
3344 data_sinfo = BTRFS_I(inode)->space_info;
3345
3346 /* make sure we have enough space to handle the data first */
3347 spin_lock(&data_sinfo->lock);
3348 data_sinfo->bytes_delalloc += bytes;
3349
3350 /*
3351 * we are adding a delalloc extent without calling
3352 * btrfs_check_data_free_space first. This happens on a weird
3353 * writepage condition, but shouldn't hurt our accounting
3354 */
3355 if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {
3356 data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;
3357 BTRFS_I(inode)->reserved_bytes = 0;
3358 } else {
3359 data_sinfo->bytes_may_use -= bytes;
3360 BTRFS_I(inode)->reserved_bytes -= bytes;
3361 }
3362
3363 spin_unlock(&data_sinfo->lock);
3364 }
3365
3366 /* called when we are clearing an delalloc extent from the inode's io_tree */
3367 void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
3368 u64 bytes)
3369 {
3370 struct btrfs_space_info *info;
3371
3372 info = BTRFS_I(inode)->space_info;
3373
3374 spin_lock(&info->lock);
3375 info->bytes_delalloc -= bytes;
3376 spin_unlock(&info->lock);
3377 }
3378
3379 static void force_metadata_allocation(struct btrfs_fs_info *info)
3380 {
3381 struct list_head *head = &info->space_info;
3382 struct btrfs_space_info *found;
3383
3384 rcu_read_lock();
3385 list_for_each_entry_rcu(found, head, list) {
3386 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
3387 found->force_alloc = 1;
3388 }
3389 rcu_read_unlock();
3390 }
3391
3392 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
3393 struct btrfs_root *extent_root, u64 alloc_bytes,
3394 u64 flags, int force)
3395 {
3396 struct btrfs_space_info *space_info;
3397 struct btrfs_fs_info *fs_info = extent_root->fs_info;
3398 u64 thresh;
3399 int ret = 0;
3400
3401 mutex_lock(&fs_info->chunk_mutex);
3402
3403 flags = btrfs_reduce_alloc_profile(extent_root, flags);
3404
3405 space_info = __find_space_info(extent_root->fs_info, flags);
3406 if (!space_info) {
3407 ret = update_space_info(extent_root->fs_info, flags,
3408 0, 0, &space_info);
3409 BUG_ON(ret);
3410 }
3411 BUG_ON(!space_info);
3412
3413 spin_lock(&space_info->lock);
3414 if (space_info->force_alloc)
3415 force = 1;
3416 if (space_info->full) {
3417 spin_unlock(&space_info->lock);
3418 goto out;
3419 }
3420
3421 thresh = space_info->total_bytes - space_info->bytes_readonly;
3422 thresh = div_factor(thresh, 8);
3423 if (!force &&
3424 (space_info->bytes_used + space_info->bytes_pinned +
3425 space_info->bytes_reserved + alloc_bytes) < thresh) {
3426 spin_unlock(&space_info->lock);
3427 goto out;
3428 }
3429 spin_unlock(&space_info->lock);
3430
3431 /*
3432 * if we're doing a data chunk, go ahead and make sure that
3433 * we keep a reasonable number of metadata chunks allocated in the
3434 * FS as well.
3435 */
3436 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
3437 fs_info->data_chunk_allocations++;
3438 if (!(fs_info->data_chunk_allocations %
3439 fs_info->metadata_ratio))
3440 force_metadata_allocation(fs_info);
3441 }
3442
3443 ret = btrfs_alloc_chunk(trans, extent_root, flags);
3444 spin_lock(&space_info->lock);
3445 if (ret)
3446 space_info->full = 1;
3447 space_info->force_alloc = 0;
3448 spin_unlock(&space_info->lock);
3449 out:
3450 mutex_unlock(&extent_root->fs_info->chunk_mutex);
3451 return ret;
3452 }
3453
3454 static int update_block_group(struct btrfs_trans_handle *trans,
3455 struct btrfs_root *root,
3456 u64 bytenr, u64 num_bytes, int alloc,
3457 int mark_free)
3458 {
3459 struct btrfs_block_group_cache *cache;
3460 struct btrfs_fs_info *info = root->fs_info;
3461 u64 total = num_bytes;
3462 u64 old_val;
3463 u64 byte_in_group;
3464
3465 /* block accounting for super block */
3466 spin_lock(&info->delalloc_lock);
3467 old_val = btrfs_super_bytes_used(&info->super_copy);
3468 if (alloc)
3469 old_val += num_bytes;
3470 else
3471 old_val -= num_bytes;
3472 btrfs_set_super_bytes_used(&info->super_copy, old_val);
3473 spin_unlock(&info->delalloc_lock);
3474
3475 while (total) {
3476 cache = btrfs_lookup_block_group(info, bytenr);
3477 if (!cache)
3478 return -1;
3479 byte_in_group = bytenr - cache->key.objectid;
3480 WARN_ON(byte_in_group > cache->key.offset);
3481
3482 spin_lock(&cache->space_info->lock);
3483 spin_lock(&cache->lock);
3484 cache->dirty = 1;
3485 old_val = btrfs_block_group_used(&cache->item);
3486 num_bytes = min(total, cache->key.offset - byte_in_group);
3487 if (alloc) {
3488 old_val += num_bytes;
3489 btrfs_set_block_group_used(&cache->item, old_val);
3490 cache->reserved -= num_bytes;
3491 cache->space_info->bytes_used += num_bytes;
3492 cache->space_info->bytes_reserved -= num_bytes;
3493 if (cache->ro)
3494 cache->space_info->bytes_readonly -= num_bytes;
3495 spin_unlock(&cache->lock);
3496 spin_unlock(&cache->space_info->lock);
3497 } else {
3498 old_val -= num_bytes;
3499 cache->space_info->bytes_used -= num_bytes;
3500 if (cache->ro)
3501 cache->space_info->bytes_readonly += num_bytes;
3502 btrfs_set_block_group_used(&cache->item, old_val);
3503 spin_unlock(&cache->lock);
3504 spin_unlock(&cache->space_info->lock);
3505 if (mark_free) {
3506 int ret;
3507
3508 ret = btrfs_discard_extent(root, bytenr,
3509 num_bytes);
3510 WARN_ON(ret);
3511
3512 ret = btrfs_add_free_space(cache, bytenr,
3513 num_bytes);
3514 WARN_ON(ret);
3515 }
3516 }
3517 btrfs_put_block_group(cache);
3518 total -= num_bytes;
3519 bytenr += num_bytes;
3520 }
3521 return 0;
3522 }
3523
3524 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
3525 {
3526 struct btrfs_block_group_cache *cache;
3527 u64 bytenr;
3528
3529 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
3530 if (!cache)
3531 return 0;
3532
3533 bytenr = cache->key.objectid;
3534 btrfs_put_block_group(cache);
3535
3536 return bytenr;
3537 }
3538
3539 /*
3540 * this function must be called within transaction
3541 */
3542 int btrfs_pin_extent(struct btrfs_root *root,
3543 u64 bytenr, u64 num_bytes, int reserved)
3544 {
3545 struct btrfs_fs_info *fs_info = root->fs_info;
3546 struct btrfs_block_group_cache *cache;
3547
3548 cache = btrfs_lookup_block_group(fs_info, bytenr);
3549 BUG_ON(!cache);
3550
3551 spin_lock(&cache->space_info->lock);
3552 spin_lock(&cache->lock);
3553 cache->pinned += num_bytes;
3554 cache->space_info->bytes_pinned += num_bytes;
3555 if (reserved) {
3556 cache->reserved -= num_bytes;
3557 cache->space_info->bytes_reserved -= num_bytes;
3558 }
3559 spin_unlock(&cache->lock);
3560 spin_unlock(&cache->space_info->lock);
3561
3562 btrfs_put_block_group(cache);
3563
3564 set_extent_dirty(fs_info->pinned_extents,
3565 bytenr, bytenr + num_bytes - 1, GFP_NOFS);
3566 return 0;
3567 }
3568
3569 static int update_reserved_extents(struct btrfs_block_group_cache *cache,
3570 u64 num_bytes, int reserve)
3571 {
3572 spin_lock(&cache->space_info->lock);
3573 spin_lock(&cache->lock);
3574 if (reserve) {
3575 cache->reserved += num_bytes;
3576 cache->space_info->bytes_reserved += num_bytes;
3577 } else {
3578 cache->reserved -= num_bytes;
3579 cache->space_info->bytes_reserved -= num_bytes;
3580 }
3581 spin_unlock(&cache->lock);
3582 spin_unlock(&cache->space_info->lock);
3583 return 0;
3584 }
3585
3586 int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
3587 struct btrfs_root *root)
3588 {
3589 struct btrfs_fs_info *fs_info = root->fs_info;
3590 struct btrfs_caching_control *next;
3591 struct btrfs_caching_control *caching_ctl;
3592 struct btrfs_block_group_cache *cache;
3593
3594 down_write(&fs_info->extent_commit_sem);
3595
3596 list_for_each_entry_safe(caching_ctl, next,
3597 &fs_info->caching_block_groups, list) {
3598 cache = caching_ctl->block_group;
3599 if (block_group_cache_done(cache)) {
3600 cache->last_byte_to_unpin = (u64)-1;
3601 list_del_init(&caching_ctl->list);
3602 put_caching_control(caching_ctl);
3603 } else {
3604 cache->last_byte_to_unpin = caching_ctl->progress;
3605 }
3606 }
3607
3608 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
3609 fs_info->pinned_extents = &fs_info->freed_extents[1];
3610 else
3611 fs_info->pinned_extents = &fs_info->freed_extents[0];
3612
3613 up_write(&fs_info->extent_commit_sem);
3614 return 0;
3615 }
3616
3617 static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
3618 {
3619 struct btrfs_fs_info *fs_info = root->fs_info;
3620 struct btrfs_block_group_cache *cache = NULL;
3621 u64 len;
3622
3623 while (start <= end) {
3624 if (!cache ||
3625 start >= cache->key.objectid + cache->key.offset) {
3626 if (cache)
3627 btrfs_put_block_group(cache);
3628 cache = btrfs_lookup_block_group(fs_info, start);
3629 BUG_ON(!cache);
3630 }
3631
3632 len = cache->key.objectid + cache->key.offset - start;
3633 len = min(len, end + 1 - start);
3634
3635 if (start < cache->last_byte_to_unpin) {
3636 len = min(len, cache->last_byte_to_unpin - start);
3637 btrfs_add_free_space(cache, start, len);
3638 }
3639
3640 spin_lock(&cache->space_info->lock);
3641 spin_lock(&cache->lock);
3642 cache->pinned -= len;
3643 cache->space_info->bytes_pinned -= len;
3644 spin_unlock(&cache->lock);
3645 spin_unlock(&cache->space_info->lock);
3646
3647 start += len;
3648 }
3649
3650 if (cache)
3651 btrfs_put_block_group(cache);
3652 return 0;
3653 }
3654
3655 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
3656 struct btrfs_root *root)
3657 {
3658 struct btrfs_fs_info *fs_info = root->fs_info;
3659 struct extent_io_tree *unpin;
3660 u64 start;
3661 u64 end;
3662 int ret;
3663
3664 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
3665 unpin = &fs_info->freed_extents[1];
3666 else
3667 unpin = &fs_info->freed_extents[0];
3668
3669 while (1) {
3670 ret = find_first_extent_bit(unpin, 0, &start, &end,
3671 EXTENT_DIRTY);
3672 if (ret)
3673 break;
3674
3675 ret = btrfs_discard_extent(root, start, end + 1 - start);
3676
3677 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3678 unpin_extent_range(root, start, end);
3679 cond_resched();
3680 }
3681
3682 return ret;
3683 }
3684
3685 static int pin_down_bytes(struct btrfs_trans_handle *trans,
3686 struct btrfs_root *root,
3687 struct btrfs_path *path,
3688 u64 bytenr, u64 num_bytes,
3689 int is_data, int reserved,
3690 struct extent_buffer **must_clean)
3691 {
3692 int err = 0;
3693 struct extent_buffer *buf;
3694
3695 if (is_data)
3696 goto pinit;
3697
3698 /*
3699 * discard is sloooow, and so triggering discards on
3700 * individual btree blocks isn't a good plan. Just
3701 * pin everything in discard mode.
3702 */
3703 if (btrfs_test_opt(root, DISCARD))
3704 goto pinit;
3705
3706 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
3707 if (!buf)
3708 goto pinit;
3709
3710 /* we can reuse a block if it hasn't been written
3711 * and it is from this transaction. We can't
3712 * reuse anything from the tree log root because
3713 * it has tiny sub-transactions.
3714 */
3715 if (btrfs_buffer_uptodate(buf, 0) &&
3716 btrfs_try_tree_lock(buf)) {
3717 u64 header_owner = btrfs_header_owner(buf);
3718 u64 header_transid = btrfs_header_generation(buf);
3719 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
3720 header_transid == trans->transid &&
3721 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
3722 *must_clean = buf;
3723 return 1;
3724 }
3725 btrfs_tree_unlock(buf);
3726 }
3727 free_extent_buffer(buf);
3728 pinit:
3729 if (path)
3730 btrfs_set_path_blocking(path);
3731 /* unlocks the pinned mutex */
3732 btrfs_pin_extent(root, bytenr, num_bytes, reserved);
3733
3734 BUG_ON(err < 0);
3735 return 0;
3736 }
3737
3738 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
3739 struct btrfs_root *root,
3740 u64 bytenr, u64 num_bytes, u64 parent,
3741 u64 root_objectid, u64 owner_objectid,
3742 u64 owner_offset, int refs_to_drop,
3743 struct btrfs_delayed_extent_op *extent_op)
3744 {
3745 struct btrfs_key key;
3746 struct btrfs_path *path;
3747 struct btrfs_fs_info *info = root->fs_info;
3748 struct btrfs_root *extent_root = info->extent_root;
3749 struct extent_buffer *leaf;
3750 struct btrfs_extent_item *ei;
3751 struct btrfs_extent_inline_ref *iref;
3752 int ret;
3753 int is_data;
3754 int extent_slot = 0;
3755 int found_extent = 0;
3756 int num_to_del = 1;
3757 u32 item_size;
3758 u64 refs;
3759
3760 path = btrfs_alloc_path();
3761 if (!path)
3762 return -ENOMEM;
3763
3764 path->reada = 1;
3765 path->leave_spinning = 1;
3766
3767 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
3768 BUG_ON(!is_data && refs_to_drop != 1);
3769
3770 ret = lookup_extent_backref(trans, extent_root, path, &iref,
3771 bytenr, num_bytes, parent,
3772 root_objectid, owner_objectid,
3773 owner_offset);
3774 if (ret == 0) {
3775 extent_slot = path->slots[0];
3776 while (extent_slot >= 0) {
3777 btrfs_item_key_to_cpu(path->nodes[0], &key,
3778 extent_slot);
3779 if (key.objectid != bytenr)
3780 break;
3781 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3782 key.offset == num_bytes) {
3783 found_extent = 1;
3784 break;
3785 }
3786 if (path->slots[0] - extent_slot > 5)
3787 break;
3788 extent_slot--;
3789 }
3790 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3791 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
3792 if (found_extent && item_size < sizeof(*ei))
3793 found_extent = 0;
3794 #endif
3795 if (!found_extent) {
3796 BUG_ON(iref);
3797 ret = remove_extent_backref(trans, extent_root, path,
3798 NULL, refs_to_drop,
3799 is_data);
3800 BUG_ON(ret);
3801 btrfs_release_path(extent_root, path);
3802 path->leave_spinning = 1;
3803
3804 key.objectid = bytenr;
3805 key.type = BTRFS_EXTENT_ITEM_KEY;
3806 key.offset = num_bytes;
3807
3808 ret = btrfs_search_slot(trans, extent_root,
3809 &key, path, -1, 1);
3810 if (ret) {
3811 printk(KERN_ERR "umm, got %d back from search"
3812 ", was looking for %llu\n", ret,
3813 (unsigned long long)bytenr);
3814 btrfs_print_leaf(extent_root, path->nodes[0]);
3815 }
3816 BUG_ON(ret);
3817 extent_slot = path->slots[0];
3818 }
3819 } else {
3820 btrfs_print_leaf(extent_root, path->nodes[0]);
3821 WARN_ON(1);
3822 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
3823 "parent %llu root %llu owner %llu offset %llu\n",
3824 (unsigned long long)bytenr,
3825 (unsigned long long)parent,
3826 (unsigned long long)root_objectid,
3827 (unsigned long long)owner_objectid,
3828 (unsigned long long)owner_offset);
3829 }
3830
3831 leaf = path->nodes[0];
3832 item_size = btrfs_item_size_nr(leaf, extent_slot);
3833 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3834 if (item_size < sizeof(*ei)) {
3835 BUG_ON(found_extent || extent_slot != path->slots[0]);
3836 ret = convert_extent_item_v0(trans, extent_root, path,
3837 owner_objectid, 0);
3838 BUG_ON(ret < 0);
3839
3840 btrfs_release_path(extent_root, path);
3841 path->leave_spinning = 1;
3842
3843 key.objectid = bytenr;
3844 key.type = BTRFS_EXTENT_ITEM_KEY;
3845 key.offset = num_bytes;
3846
3847 ret = btrfs_search_slot(trans, extent_root, &key, path,
3848 -1, 1);
3849 if (ret) {
3850 printk(KERN_ERR "umm, got %d back from search"
3851 ", was looking for %llu\n", ret,
3852 (unsigned long long)bytenr);
3853 btrfs_print_leaf(extent_root, path->nodes[0]);
3854 }
3855 BUG_ON(ret);
3856 extent_slot = path->slots[0];
3857 leaf = path->nodes[0];
3858 item_size = btrfs_item_size_nr(leaf, extent_slot);
3859 }
3860 #endif
3861 BUG_ON(item_size < sizeof(*ei));
3862 ei = btrfs_item_ptr(leaf, extent_slot,
3863 struct btrfs_extent_item);
3864 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3865 struct btrfs_tree_block_info *bi;
3866 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
3867 bi = (struct btrfs_tree_block_info *)(ei + 1);
3868 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
3869 }
3870
3871 refs = btrfs_extent_refs(leaf, ei);
3872 BUG_ON(refs < refs_to_drop);
3873 refs -= refs_to_drop;
3874
3875 if (refs > 0) {
3876 if (extent_op)
3877 __run_delayed_extent_op(extent_op, leaf, ei);
3878 /*
3879 * In the case of inline back ref, reference count will
3880 * be updated by remove_extent_backref
3881 */
3882 if (iref) {
3883 BUG_ON(!found_extent);
3884 } else {
3885 btrfs_set_extent_refs(leaf, ei, refs);
3886 btrfs_mark_buffer_dirty(leaf);
3887 }
3888 if (found_extent) {
3889 ret = remove_extent_backref(trans, extent_root, path,
3890 iref, refs_to_drop,
3891 is_data);
3892 BUG_ON(ret);
3893 }
3894 } else {
3895 int mark_free = 0;
3896 struct extent_buffer *must_clean = NULL;
3897
3898 if (found_extent) {
3899 BUG_ON(is_data && refs_to_drop !=
3900 extent_data_ref_count(root, path, iref));
3901 if (iref) {
3902 BUG_ON(path->slots[0] != extent_slot);
3903 } else {
3904 BUG_ON(path->slots[0] != extent_slot + 1);
3905 path->slots[0] = extent_slot;
3906 num_to_del = 2;
3907 }
3908 }
3909
3910 ret = pin_down_bytes(trans, root, path, bytenr,
3911 num_bytes, is_data, 0, &must_clean);
3912 if (ret > 0)
3913 mark_free = 1;
3914 BUG_ON(ret < 0);
3915 /*
3916 * it is going to be very rare for someone to be waiting
3917 * on the block we're freeing. del_items might need to
3918 * schedule, so rather than get fancy, just force it
3919 * to blocking here
3920 */
3921 if (must_clean)
3922 btrfs_set_lock_blocking(must_clean);
3923
3924 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
3925 num_to_del);
3926 BUG_ON(ret);
3927 btrfs_release_path(extent_root, path);
3928
3929 if (must_clean) {
3930 clean_tree_block(NULL, root, must_clean);
3931 btrfs_tree_unlock(must_clean);
3932 free_extent_buffer(must_clean);
3933 }
3934
3935 if (is_data) {
3936 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
3937 BUG_ON(ret);
3938 } else {
3939 invalidate_mapping_pages(info->btree_inode->i_mapping,
3940 bytenr >> PAGE_CACHE_SHIFT,
3941 (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
3942 }
3943
3944 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
3945 mark_free);
3946 BUG_ON(ret);
3947 }
3948 btrfs_free_path(path);
3949 return ret;
3950 }
3951
3952 /*
3953 * when we free an extent, it is possible (and likely) that we free the last
3954 * delayed ref for that extent as well. This searches the delayed ref tree for
3955 * a given extent, and if there are no other delayed refs to be processed, it
3956 * removes it from the tree.
3957 */
3958 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
3959 struct btrfs_root *root, u64 bytenr)
3960 {
3961 struct btrfs_delayed_ref_head *head;
3962 struct btrfs_delayed_ref_root *delayed_refs;
3963 struct btrfs_delayed_ref_node *ref;
3964 struct rb_node *node;
3965 int ret;
3966
3967 delayed_refs = &trans->transaction->delayed_refs;
3968 spin_lock(&delayed_refs->lock);
3969 head = btrfs_find_delayed_ref_head(trans, bytenr);
3970 if (!head)
3971 goto out;
3972
3973 node = rb_prev(&head->node.rb_node);
3974 if (!node)
3975 goto out;
3976
3977 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3978
3979 /* there are still entries for this ref, we can't drop it */
3980 if (ref->bytenr == bytenr)
3981 goto out;
3982
3983 if (head->extent_op) {
3984 if (!head->must_insert_reserved)
3985 goto out;
3986 kfree(head->extent_op);
3987 head->extent_op = NULL;
3988 }
3989
3990 /*
3991 * waiting for the lock here would deadlock. If someone else has it
3992 * locked they are already in the process of dropping it anyway
3993 */
3994 if (!mutex_trylock(&head->mutex))
3995 goto out;
3996
3997 /*
3998 * at this point we have a head with no other entries. Go
3999 * ahead and process it.
4000 */
4001 head->node.in_tree = 0;
4002 rb_erase(&head->node.rb_node, &delayed_refs->root);
4003
4004 delayed_refs->num_entries--;
4005
4006 /*
4007 * we don't take a ref on the node because we're removing it from the
4008 * tree, so we just steal the ref the tree was holding.
4009 */
4010 delayed_refs->num_heads--;
4011 if (list_empty(&head->cluster))
4012 delayed_refs->num_heads_ready--;
4013
4014 list_del_init(&head->cluster);
4015 spin_unlock(&delayed_refs->lock);
4016
4017 ret = run_one_delayed_ref(trans, root->fs_info->tree_root,
4018 &head->node, head->extent_op,
4019 head->must_insert_reserved);
4020 BUG_ON(ret);
4021 btrfs_put_delayed_ref(&head->node);
4022 return 0;
4023 out:
4024 spin_unlock(&delayed_refs->lock);
4025 return 0;
4026 }
4027
4028 int btrfs_free_extent(struct btrfs_trans_handle *trans,
4029 struct btrfs_root *root,
4030 u64 bytenr, u64 num_bytes, u64 parent,
4031 u64 root_objectid, u64 owner, u64 offset)
4032 {
4033 int ret;
4034
4035 /*
4036 * tree log blocks never actually go into the extent allocation
4037 * tree, just update pinning info and exit early.
4038 */
4039 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
4040 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
4041 /* unlocks the pinned mutex */
4042 btrfs_pin_extent(root, bytenr, num_bytes, 1);
4043 ret = 0;
4044 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
4045 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
4046 parent, root_objectid, (int)owner,
4047 BTRFS_DROP_DELAYED_REF, NULL);
4048 BUG_ON(ret);
4049 ret = check_ref_cleanup(trans, root, bytenr);
4050 BUG_ON(ret);
4051 } else {
4052 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
4053 parent, root_objectid, owner,
4054 offset, BTRFS_DROP_DELAYED_REF, NULL);
4055 BUG_ON(ret);
4056 }
4057 return ret;
4058 }
4059
4060 int btrfs_free_tree_block(struct btrfs_trans_handle *trans,
4061 struct btrfs_root *root,
4062 u64 bytenr, u32 blocksize,
4063 u64 parent, u64 root_objectid, int level)
4064 {
4065 u64 used;
4066 spin_lock(&root->node_lock);
4067 used = btrfs_root_used(&root->root_item) - blocksize;
4068 btrfs_set_root_used(&root->root_item, used);
4069 spin_unlock(&root->node_lock);
4070
4071 return btrfs_free_extent(trans, root, bytenr, blocksize,
4072 parent, root_objectid, level, 0);
4073 }
4074
4075 static u64 stripe_align(struct btrfs_root *root, u64 val)
4076 {
4077 u64 mask = ((u64)root->stripesize - 1);
4078 u64 ret = (val + mask) & ~mask;
4079 return ret;
4080 }
4081
4082 /*
4083 * when we wait for progress in the block group caching, its because
4084 * our allocation attempt failed at least once. So, we must sleep
4085 * and let some progress happen before we try again.
4086 *
4087 * This function will sleep at least once waiting for new free space to
4088 * show up, and then it will check the block group free space numbers
4089 * for our min num_bytes. Another option is to have it go ahead
4090 * and look in the rbtree for a free extent of a given size, but this
4091 * is a good start.
4092 */
4093 static noinline int
4094 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
4095 u64 num_bytes)
4096 {
4097 struct btrfs_caching_control *caching_ctl;
4098 DEFINE_WAIT(wait);
4099
4100 caching_ctl = get_caching_control(cache);
4101 if (!caching_ctl)
4102 return 0;
4103
4104 wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
4105 (cache->free_space >= num_bytes));
4106
4107 put_caching_control(caching_ctl);
4108 return 0;
4109 }
4110
4111 static noinline int
4112 wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
4113 {
4114 struct btrfs_caching_control *caching_ctl;
4115 DEFINE_WAIT(wait);
4116
4117 caching_ctl = get_caching_control(cache);
4118 if (!caching_ctl)
4119 return 0;
4120
4121 wait_event(caching_ctl->wait, block_group_cache_done(cache));
4122
4123 put_caching_control(caching_ctl);
4124 return 0;
4125 }
4126
4127 enum btrfs_loop_type {
4128 LOOP_FIND_IDEAL = 0,
4129 LOOP_CACHING_NOWAIT = 1,
4130 LOOP_CACHING_WAIT = 2,
4131 LOOP_ALLOC_CHUNK = 3,
4132 LOOP_NO_EMPTY_SIZE = 4,
4133 };
4134
4135 /*
4136 * walks the btree of allocated extents and find a hole of a given size.
4137 * The key ins is changed to record the hole:
4138 * ins->objectid == block start
4139 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4140 * ins->offset == number of blocks
4141 * Any available blocks before search_start are skipped.
4142 */
4143 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
4144 struct btrfs_root *orig_root,
4145 u64 num_bytes, u64 empty_size,
4146 u64 search_start, u64 search_end,
4147 u64 hint_byte, struct btrfs_key *ins,
4148 u64 exclude_start, u64 exclude_nr,
4149 int data)
4150 {
4151 int ret = 0;
4152 struct btrfs_root *root = orig_root->fs_info->extent_root;
4153 struct btrfs_free_cluster *last_ptr = NULL;
4154 struct btrfs_block_group_cache *block_group = NULL;
4155 int empty_cluster = 2 * 1024 * 1024;
4156 int allowed_chunk_alloc = 0;
4157 int done_chunk_alloc = 0;
4158 struct btrfs_space_info *space_info;
4159 int last_ptr_loop = 0;
4160 int loop = 0;
4161 bool found_uncached_bg = false;
4162 bool failed_cluster_refill = false;
4163 bool failed_alloc = false;
4164 u64 ideal_cache_percent = 0;
4165 u64 ideal_cache_offset = 0;
4166
4167 WARN_ON(num_bytes < root->sectorsize);
4168 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
4169 ins->objectid = 0;
4170 ins->offset = 0;
4171
4172 space_info = __find_space_info(root->fs_info, data);
4173 if (!space_info) {
4174 printk(KERN_ERR "No space info for %d\n", data);
4175 return -ENOSPC;
4176 }
4177
4178 if (orig_root->ref_cows || empty_size)
4179 allowed_chunk_alloc = 1;
4180
4181 if (data & BTRFS_BLOCK_GROUP_METADATA) {
4182 last_ptr = &root->fs_info->meta_alloc_cluster;
4183 if (!btrfs_test_opt(root, SSD))
4184 empty_cluster = 64 * 1024;
4185 }
4186
4187 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
4188 last_ptr = &root->fs_info->data_alloc_cluster;
4189 }
4190
4191 if (last_ptr) {
4192 spin_lock(&last_ptr->lock);
4193 if (last_ptr->block_group)
4194 hint_byte = last_ptr->window_start;
4195 spin_unlock(&last_ptr->lock);
4196 }
4197
4198 search_start = max(search_start, first_logical_byte(root, 0));
4199 search_start = max(search_start, hint_byte);
4200
4201 if (!last_ptr)
4202 empty_cluster = 0;
4203
4204 if (search_start == hint_byte) {
4205 ideal_cache:
4206 block_group = btrfs_lookup_block_group(root->fs_info,
4207 search_start);
4208 /*
4209 * we don't want to use the block group if it doesn't match our
4210 * allocation bits, or if its not cached.
4211 *
4212 * However if we are re-searching with an ideal block group
4213 * picked out then we don't care that the block group is cached.
4214 */
4215 if (block_group && block_group_bits(block_group, data) &&
4216 (block_group->cached != BTRFS_CACHE_NO ||
4217 search_start == ideal_cache_offset)) {
4218 down_read(&space_info->groups_sem);
4219 if (list_empty(&block_group->list) ||
4220 block_group->ro) {
4221 /*
4222 * someone is removing this block group,
4223 * we can't jump into the have_block_group
4224 * target because our list pointers are not
4225 * valid
4226 */
4227 btrfs_put_block_group(block_group);
4228 up_read(&space_info->groups_sem);
4229 } else {
4230 goto have_block_group;
4231 }
4232 } else if (block_group) {
4233 btrfs_put_block_group(block_group);
4234 }
4235 }
4236 search:
4237 down_read(&space_info->groups_sem);
4238 list_for_each_entry(block_group, &space_info->block_groups, list) {
4239 u64 offset;
4240 int cached;
4241
4242 btrfs_get_block_group(block_group);
4243 search_start = block_group->key.objectid;
4244
4245 have_block_group:
4246 if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
4247 u64 free_percent;
4248
4249 free_percent = btrfs_block_group_used(&block_group->item);
4250 free_percent *= 100;
4251 free_percent = div64_u64(free_percent,
4252 block_group->key.offset);
4253 free_percent = 100 - free_percent;
4254 if (free_percent > ideal_cache_percent &&
4255 likely(!block_group->ro)) {
4256 ideal_cache_offset = block_group->key.objectid;
4257 ideal_cache_percent = free_percent;
4258 }
4259
4260 /*
4261 * We only want to start kthread caching if we are at
4262 * the point where we will wait for caching to make
4263 * progress, or if our ideal search is over and we've
4264 * found somebody to start caching.
4265 */
4266 if (loop > LOOP_CACHING_NOWAIT ||
4267 (loop > LOOP_FIND_IDEAL &&
4268 atomic_read(&space_info->caching_threads) < 2)) {
4269 ret = cache_block_group(block_group);
4270 BUG_ON(ret);
4271 }
4272 found_uncached_bg = true;
4273
4274 /*
4275 * If loop is set for cached only, try the next block
4276 * group.
4277 */
4278 if (loop == LOOP_FIND_IDEAL)
4279 goto loop;
4280 }
4281
4282 cached = block_group_cache_done(block_group);
4283 if (unlikely(!cached))
4284 found_uncached_bg = true;
4285
4286 if (unlikely(block_group->ro))
4287 goto loop;
4288
4289 /*
4290 * Ok we want to try and use the cluster allocator, so lets look
4291 * there, unless we are on LOOP_NO_EMPTY_SIZE, since we will
4292 * have tried the cluster allocator plenty of times at this
4293 * point and not have found anything, so we are likely way too
4294 * fragmented for the clustering stuff to find anything, so lets
4295 * just skip it and let the allocator find whatever block it can
4296 * find
4297 */
4298 if (last_ptr && loop < LOOP_NO_EMPTY_SIZE) {
4299 /*
4300 * the refill lock keeps out other
4301 * people trying to start a new cluster
4302 */
4303 spin_lock(&last_ptr->refill_lock);
4304 if (last_ptr->block_group &&
4305 (last_ptr->block_group->ro ||
4306 !block_group_bits(last_ptr->block_group, data))) {
4307 offset = 0;
4308 goto refill_cluster;
4309 }
4310
4311 offset = btrfs_alloc_from_cluster(block_group, last_ptr,
4312 num_bytes, search_start);
4313 if (offset) {
4314 /* we have a block, we're done */
4315 spin_unlock(&last_ptr->refill_lock);
4316 goto checks;
4317 }
4318
4319 spin_lock(&last_ptr->lock);
4320 /*
4321 * whoops, this cluster doesn't actually point to
4322 * this block group. Get a ref on the block
4323 * group is does point to and try again
4324 */
4325 if (!last_ptr_loop && last_ptr->block_group &&
4326 last_ptr->block_group != block_group) {
4327
4328 btrfs_put_block_group(block_group);
4329 block_group = last_ptr->block_group;
4330 btrfs_get_block_group(block_group);
4331 spin_unlock(&last_ptr->lock);
4332 spin_unlock(&last_ptr->refill_lock);
4333
4334 last_ptr_loop = 1;
4335 search_start = block_group->key.objectid;
4336 /*
4337 * we know this block group is properly
4338 * in the list because
4339 * btrfs_remove_block_group, drops the
4340 * cluster before it removes the block
4341 * group from the list
4342 */
4343 goto have_block_group;
4344 }
4345 spin_unlock(&last_ptr->lock);
4346 refill_cluster:
4347 /*
4348 * this cluster didn't work out, free it and
4349 * start over
4350 */
4351 btrfs_return_cluster_to_free_space(NULL, last_ptr);
4352
4353 last_ptr_loop = 0;
4354
4355 /* allocate a cluster in this block group */
4356 ret = btrfs_find_space_cluster(trans, root,
4357 block_group, last_ptr,
4358 offset, num_bytes,
4359 empty_cluster + empty_size);
4360 if (ret == 0) {
4361 /*
4362 * now pull our allocation out of this
4363 * cluster
4364 */
4365 offset = btrfs_alloc_from_cluster(block_group,
4366 last_ptr, num_bytes,
4367 search_start);
4368 if (offset) {
4369 /* we found one, proceed */
4370 spin_unlock(&last_ptr->refill_lock);
4371 goto checks;
4372 }
4373 } else if (!cached && loop > LOOP_CACHING_NOWAIT
4374 && !failed_cluster_refill) {
4375 spin_unlock(&last_ptr->refill_lock);
4376
4377 failed_cluster_refill = true;
4378 wait_block_group_cache_progress(block_group,
4379 num_bytes + empty_cluster + empty_size);
4380 goto have_block_group;
4381 }
4382
4383 /*
4384 * at this point we either didn't find a cluster
4385 * or we weren't able to allocate a block from our
4386 * cluster. Free the cluster we've been trying
4387 * to use, and go to the next block group
4388 */
4389 btrfs_return_cluster_to_free_space(NULL, last_ptr);
4390 spin_unlock(&last_ptr->refill_lock);
4391 goto loop;
4392 }
4393
4394 offset = btrfs_find_space_for_alloc(block_group, search_start,
4395 num_bytes, empty_size);
4396 /*
4397 * If we didn't find a chunk, and we haven't failed on this
4398 * block group before, and this block group is in the middle of
4399 * caching and we are ok with waiting, then go ahead and wait
4400 * for progress to be made, and set failed_alloc to true.
4401 *
4402 * If failed_alloc is true then we've already waited on this
4403 * block group once and should move on to the next block group.
4404 */
4405 if (!offset && !failed_alloc && !cached &&
4406 loop > LOOP_CACHING_NOWAIT) {
4407 wait_block_group_cache_progress(block_group,
4408 num_bytes + empty_size);
4409 failed_alloc = true;
4410 goto have_block_group;
4411 } else if (!offset) {
4412 goto loop;
4413 }
4414 checks:
4415 search_start = stripe_align(root, offset);
4416 /* move on to the next group */
4417 if (search_start + num_bytes >= search_end) {
4418 btrfs_add_free_space(block_group, offset, num_bytes);
4419 goto loop;
4420 }
4421
4422 /* move on to the next group */
4423 if (search_start + num_bytes >
4424 block_group->key.objectid + block_group->key.offset) {
4425 btrfs_add_free_space(block_group, offset, num_bytes);
4426 goto loop;
4427 }
4428
4429 if (exclude_nr > 0 &&
4430 (search_start + num_bytes > exclude_start &&
4431 search_start < exclude_start + exclude_nr)) {
4432 search_start = exclude_start + exclude_nr;
4433
4434 btrfs_add_free_space(block_group, offset, num_bytes);
4435 /*
4436 * if search_start is still in this block group
4437 * then we just re-search this block group
4438 */
4439 if (search_start >= block_group->key.objectid &&
4440 search_start < (block_group->key.objectid +
4441 block_group->key.offset))
4442 goto have_block_group;
4443 goto loop;
4444 }
4445
4446 ins->objectid = search_start;
4447 ins->offset = num_bytes;
4448
4449 if (offset < search_start)
4450 btrfs_add_free_space(block_group, offset,
4451 search_start - offset);
4452 BUG_ON(offset > search_start);
4453
4454 update_reserved_extents(block_group, num_bytes, 1);
4455
4456 /* we are all good, lets return */
4457 break;
4458 loop:
4459 failed_cluster_refill = false;
4460 failed_alloc = false;
4461 btrfs_put_block_group(block_group);
4462 }
4463 up_read(&space_info->groups_sem);
4464
4465 /* LOOP_FIND_IDEAL, only search caching/cached bg's, and don't wait for
4466 * for them to make caching progress. Also
4467 * determine the best possible bg to cache
4468 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
4469 * caching kthreads as we move along
4470 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
4471 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
4472 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
4473 * again
4474 */
4475 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE &&
4476 (found_uncached_bg || empty_size || empty_cluster ||
4477 allowed_chunk_alloc)) {
4478 if (loop == LOOP_FIND_IDEAL && found_uncached_bg) {
4479 found_uncached_bg = false;
4480 loop++;
4481 if (!ideal_cache_percent &&
4482 atomic_read(&space_info->caching_threads))
4483 goto search;
4484
4485 /*
4486 * 1 of the following 2 things have happened so far
4487 *
4488 * 1) We found an ideal block group for caching that
4489 * is mostly full and will cache quickly, so we might
4490 * as well wait for it.
4491 *
4492 * 2) We searched for cached only and we didn't find
4493 * anything, and we didn't start any caching kthreads
4494 * either, so chances are we will loop through and
4495 * start a couple caching kthreads, and then come back
4496 * around and just wait for them. This will be slower
4497 * because we will have 2 caching kthreads reading at
4498 * the same time when we could have just started one
4499 * and waited for it to get far enough to give us an
4500 * allocation, so go ahead and go to the wait caching
4501 * loop.
4502 */
4503 loop = LOOP_CACHING_WAIT;
4504 search_start = ideal_cache_offset;
4505 ideal_cache_percent = 0;
4506 goto ideal_cache;
4507 } else if (loop == LOOP_FIND_IDEAL) {
4508 /*
4509 * Didn't find a uncached bg, wait on anything we find
4510 * next.
4511 */
4512 loop = LOOP_CACHING_WAIT;
4513 goto search;
4514 }
4515
4516 if (loop < LOOP_CACHING_WAIT) {
4517 loop++;
4518 goto search;
4519 }
4520
4521 if (loop == LOOP_ALLOC_CHUNK) {
4522 empty_size = 0;
4523 empty_cluster = 0;
4524 }
4525
4526 if (allowed_chunk_alloc) {
4527 ret = do_chunk_alloc(trans, root, num_bytes +
4528 2 * 1024 * 1024, data, 1);
4529 allowed_chunk_alloc = 0;
4530 done_chunk_alloc = 1;
4531 } else if (!done_chunk_alloc) {
4532 space_info->force_alloc = 1;
4533 }
4534
4535 if (loop < LOOP_NO_EMPTY_SIZE) {
4536 loop++;
4537 goto search;
4538 }
4539 ret = -ENOSPC;
4540 } else if (!ins->objectid) {
4541 ret = -ENOSPC;
4542 }
4543
4544 /* we found what we needed */
4545 if (ins->objectid) {
4546 if (!(data & BTRFS_BLOCK_GROUP_DATA))
4547 trans->block_group = block_group->key.objectid;
4548
4549 btrfs_put_block_group(block_group);
4550 ret = 0;
4551 }
4552
4553 return ret;
4554 }
4555
4556 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
4557 int dump_block_groups)
4558 {
4559 struct btrfs_block_group_cache *cache;
4560
4561 spin_lock(&info->lock);
4562 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
4563 (unsigned long long)(info->total_bytes - info->bytes_used -
4564 info->bytes_pinned - info->bytes_reserved -
4565 info->bytes_super),
4566 (info->full) ? "" : "not ");
4567 printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu,"
4568 " may_use=%llu, used=%llu, root=%llu, super=%llu, reserved=%llu"
4569 "\n",
4570 (unsigned long long)info->total_bytes,
4571 (unsigned long long)info->bytes_pinned,
4572 (unsigned long long)info->bytes_delalloc,
4573 (unsigned long long)info->bytes_may_use,
4574 (unsigned long long)info->bytes_used,
4575 (unsigned long long)info->bytes_root,
4576 (unsigned long long)info->bytes_super,
4577 (unsigned long long)info->bytes_reserved);
4578 spin_unlock(&info->lock);
4579
4580 if (!dump_block_groups)
4581 return;
4582
4583 down_read(&info->groups_sem);
4584 list_for_each_entry(cache, &info->block_groups, list) {
4585 spin_lock(&cache->lock);
4586 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
4587 "%llu pinned %llu reserved\n",
4588 (unsigned long long)cache->key.objectid,
4589 (unsigned long long)cache->key.offset,
4590 (unsigned long long)btrfs_block_group_used(&cache->item),
4591 (unsigned long long)cache->pinned,
4592 (unsigned long long)cache->reserved);
4593 btrfs_dump_free_space(cache, bytes);
4594 spin_unlock(&cache->lock);
4595 }
4596 up_read(&info->groups_sem);
4597 }
4598
4599 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
4600 struct btrfs_root *root,
4601 u64 num_bytes, u64 min_alloc_size,
4602 u64 empty_size, u64 hint_byte,
4603 u64 search_end, struct btrfs_key *ins,
4604 u64 data)
4605 {
4606 int ret;
4607 u64 search_start = 0;
4608
4609 data = btrfs_get_alloc_profile(root, data);
4610 again:
4611 /*
4612 * the only place that sets empty_size is btrfs_realloc_node, which
4613 * is not called recursively on allocations
4614 */
4615 if (empty_size || root->ref_cows)
4616 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4617 num_bytes + 2 * 1024 * 1024, data, 0);
4618
4619 WARN_ON(num_bytes < root->sectorsize);
4620 ret = find_free_extent(trans, root, num_bytes, empty_size,
4621 search_start, search_end, hint_byte, ins,
4622 trans->alloc_exclude_start,
4623 trans->alloc_exclude_nr, data);
4624
4625 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
4626 num_bytes = num_bytes >> 1;
4627 num_bytes = num_bytes & ~(root->sectorsize - 1);
4628 num_bytes = max(num_bytes, min_alloc_size);
4629 do_chunk_alloc(trans, root->fs_info->extent_root,
4630 num_bytes, data, 1);
4631 goto again;
4632 }
4633 if (ret == -ENOSPC) {
4634 struct btrfs_space_info *sinfo;
4635
4636 sinfo = __find_space_info(root->fs_info, data);
4637 printk(KERN_ERR "btrfs allocation failed flags %llu, "
4638 "wanted %llu\n", (unsigned long long)data,
4639 (unsigned long long)num_bytes);
4640 dump_space_info(sinfo, num_bytes, 1);
4641 }
4642
4643 return ret;
4644 }
4645
4646 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
4647 {
4648 struct btrfs_block_group_cache *cache;
4649 int ret = 0;
4650
4651 cache = btrfs_lookup_block_group(root->fs_info, start);
4652 if (!cache) {
4653 printk(KERN_ERR "Unable to find block group for %llu\n",
4654 (unsigned long long)start);
4655 return -ENOSPC;
4656 }
4657
4658 ret = btrfs_discard_extent(root, start, len);
4659
4660 btrfs_add_free_space(cache, start, len);
4661 update_reserved_extents(cache, len, 0);
4662 btrfs_put_block_group(cache);
4663
4664 return ret;
4665 }
4666
4667 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4668 struct btrfs_root *root,
4669 u64 parent, u64 root_objectid,
4670 u64 flags, u64 owner, u64 offset,
4671 struct btrfs_key *ins, int ref_mod)
4672 {
4673 int ret;
4674 struct btrfs_fs_info *fs_info = root->fs_info;
4675 struct btrfs_extent_item *extent_item;
4676 struct btrfs_extent_inline_ref *iref;
4677 struct btrfs_path *path;
4678 struct extent_buffer *leaf;
4679 int type;
4680 u32 size;
4681
4682 if (parent > 0)
4683 type = BTRFS_SHARED_DATA_REF_KEY;
4684 else
4685 type = BTRFS_EXTENT_DATA_REF_KEY;
4686
4687 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
4688
4689 path = btrfs_alloc_path();
4690 BUG_ON(!path);
4691
4692 path->leave_spinning = 1;
4693 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4694 ins, size);
4695 BUG_ON(ret);
4696
4697 leaf = path->nodes[0];
4698 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4699 struct btrfs_extent_item);
4700 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
4701 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4702 btrfs_set_extent_flags(leaf, extent_item,
4703 flags | BTRFS_EXTENT_FLAG_DATA);
4704
4705 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
4706 btrfs_set_extent_inline_ref_type(leaf, iref, type);
4707 if (parent > 0) {
4708 struct btrfs_shared_data_ref *ref;
4709 ref = (struct btrfs_shared_data_ref *)(iref + 1);
4710 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4711 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
4712 } else {
4713 struct btrfs_extent_data_ref *ref;
4714 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
4715 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
4716 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
4717 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
4718 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
4719 }
4720
4721 btrfs_mark_buffer_dirty(path->nodes[0]);
4722 btrfs_free_path(path);
4723
4724 ret = update_block_group(trans, root, ins->objectid, ins->offset,
4725 1, 0);
4726 if (ret) {
4727 printk(KERN_ERR "btrfs update block group failed for %llu "
4728 "%llu\n", (unsigned long long)ins->objectid,
4729 (unsigned long long)ins->offset);
4730 BUG();
4731 }
4732 return ret;
4733 }
4734
4735 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
4736 struct btrfs_root *root,
4737 u64 parent, u64 root_objectid,
4738 u64 flags, struct btrfs_disk_key *key,
4739 int level, struct btrfs_key *ins)
4740 {
4741 int ret;
4742 struct btrfs_fs_info *fs_info = root->fs_info;
4743 struct btrfs_extent_item *extent_item;
4744 struct btrfs_tree_block_info *block_info;
4745 struct btrfs_extent_inline_ref *iref;
4746 struct btrfs_path *path;
4747 struct extent_buffer *leaf;
4748 u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
4749
4750 path = btrfs_alloc_path();
4751 BUG_ON(!path);
4752
4753 path->leave_spinning = 1;
4754 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4755 ins, size);
4756 BUG_ON(ret);
4757
4758 leaf = path->nodes[0];
4759 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4760 struct btrfs_extent_item);
4761 btrfs_set_extent_refs(leaf, extent_item, 1);
4762 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4763 btrfs_set_extent_flags(leaf, extent_item,
4764 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
4765 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
4766
4767 btrfs_set_tree_block_key(leaf, block_info, key);
4768 btrfs_set_tree_block_level(leaf, block_info, level);
4769
4770 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
4771 if (parent > 0) {
4772 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
4773 btrfs_set_extent_inline_ref_type(leaf, iref,
4774 BTRFS_SHARED_BLOCK_REF_KEY);
4775 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4776 } else {
4777 btrfs_set_extent_inline_ref_type(leaf, iref,
4778 BTRFS_TREE_BLOCK_REF_KEY);
4779 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
4780 }
4781
4782 btrfs_mark_buffer_dirty(leaf);
4783 btrfs_free_path(path);
4784
4785 ret = update_block_group(trans, root, ins->objectid, ins->offset,
4786 1, 0);
4787 if (ret) {
4788 printk(KERN_ERR "btrfs update block group failed for %llu "
4789 "%llu\n", (unsigned long long)ins->objectid,
4790 (unsigned long long)ins->offset);
4791 BUG();
4792 }
4793 return ret;
4794 }
4795
4796 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4797 struct btrfs_root *root,
4798 u64 root_objectid, u64 owner,
4799 u64 offset, struct btrfs_key *ins)
4800 {
4801 int ret;
4802
4803 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
4804
4805 ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
4806 0, root_objectid, owner, offset,
4807 BTRFS_ADD_DELAYED_EXTENT, NULL);
4808 return ret;
4809 }
4810
4811 /*
4812 * this is used by the tree logging recovery code. It records that
4813 * an extent has been allocated and makes sure to clear the free
4814 * space cache bits as well
4815 */
4816 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
4817 struct btrfs_root *root,
4818 u64 root_objectid, u64 owner, u64 offset,
4819 struct btrfs_key *ins)
4820 {
4821 int ret;
4822 struct btrfs_block_group_cache *block_group;
4823 struct btrfs_caching_control *caching_ctl;
4824 u64 start = ins->objectid;
4825 u64 num_bytes = ins->offset;
4826
4827 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
4828 cache_block_group(block_group);
4829 caching_ctl = get_caching_control(block_group);
4830
4831 if (!caching_ctl) {
4832 BUG_ON(!block_group_cache_done(block_group));
4833 ret = btrfs_remove_free_space(block_group, start, num_bytes);
4834 BUG_ON(ret);
4835 } else {
4836 mutex_lock(&caching_ctl->mutex);
4837
4838 if (start >= caching_ctl->progress) {
4839 ret = add_excluded_extent(root, start, num_bytes);
4840 BUG_ON(ret);
4841 } else if (start + num_bytes <= caching_ctl->progress) {
4842 ret = btrfs_remove_free_space(block_group,
4843 start, num_bytes);
4844 BUG_ON(ret);
4845 } else {
4846 num_bytes = caching_ctl->progress - start;
4847 ret = btrfs_remove_free_space(block_group,
4848 start, num_bytes);
4849 BUG_ON(ret);
4850
4851 start = caching_ctl->progress;
4852 num_bytes = ins->objectid + ins->offset -
4853 caching_ctl->progress;
4854 ret = add_excluded_extent(root, start, num_bytes);
4855 BUG_ON(ret);
4856 }
4857
4858 mutex_unlock(&caching_ctl->mutex);
4859 put_caching_control(caching_ctl);
4860 }
4861
4862 update_reserved_extents(block_group, ins->offset, 1);
4863 btrfs_put_block_group(block_group);
4864 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
4865 0, owner, offset, ins, 1);
4866 return ret;
4867 }
4868
4869 /*
4870 * finds a free extent and does all the dirty work required for allocation
4871 * returns the key for the extent through ins, and a tree buffer for
4872 * the first block of the extent through buf.
4873 *
4874 * returns 0 if everything worked, non-zero otherwise.
4875 */
4876 static int alloc_tree_block(struct btrfs_trans_handle *trans,
4877 struct btrfs_root *root,
4878 u64 num_bytes, u64 parent, u64 root_objectid,
4879 struct btrfs_disk_key *key, int level,
4880 u64 empty_size, u64 hint_byte, u64 search_end,
4881 struct btrfs_key *ins)
4882 {
4883 int ret;
4884 u64 flags = 0;
4885
4886 ret = btrfs_reserve_extent(trans, root, num_bytes, num_bytes,
4887 empty_size, hint_byte, search_end,
4888 ins, 0);
4889 if (ret)
4890 return ret;
4891
4892 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
4893 if (parent == 0)
4894 parent = ins->objectid;
4895 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
4896 } else
4897 BUG_ON(parent > 0);
4898
4899 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
4900 struct btrfs_delayed_extent_op *extent_op;
4901 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
4902 BUG_ON(!extent_op);
4903 if (key)
4904 memcpy(&extent_op->key, key, sizeof(extent_op->key));
4905 else
4906 memset(&extent_op->key, 0, sizeof(extent_op->key));
4907 extent_op->flags_to_set = flags;
4908 extent_op->update_key = 1;
4909 extent_op->update_flags = 1;
4910 extent_op->is_data = 0;
4911
4912 ret = btrfs_add_delayed_tree_ref(trans, ins->objectid,
4913 ins->offset, parent, root_objectid,
4914 level, BTRFS_ADD_DELAYED_EXTENT,
4915 extent_op);
4916 BUG_ON(ret);
4917 }
4918
4919 if (root_objectid == root->root_key.objectid) {
4920 u64 used;
4921 spin_lock(&root->node_lock);
4922 used = btrfs_root_used(&root->root_item) + num_bytes;
4923 btrfs_set_root_used(&root->root_item, used);
4924 spin_unlock(&root->node_lock);
4925 }
4926 return ret;
4927 }
4928
4929 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
4930 struct btrfs_root *root,
4931 u64 bytenr, u32 blocksize,
4932 int level)
4933 {
4934 struct extent_buffer *buf;
4935
4936 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
4937 if (!buf)
4938 return ERR_PTR(-ENOMEM);
4939 btrfs_set_header_generation(buf, trans->transid);
4940 btrfs_set_buffer_lockdep_class(buf, level);
4941 btrfs_tree_lock(buf);
4942 clean_tree_block(trans, root, buf);
4943
4944 btrfs_set_lock_blocking(buf);
4945 btrfs_set_buffer_uptodate(buf);
4946
4947 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
4948 /*
4949 * we allow two log transactions at a time, use different
4950 * EXENT bit to differentiate dirty pages.
4951 */
4952 if (root->log_transid % 2 == 0)
4953 set_extent_dirty(&root->dirty_log_pages, buf->start,
4954 buf->start + buf->len - 1, GFP_NOFS);
4955 else
4956 set_extent_new(&root->dirty_log_pages, buf->start,
4957 buf->start + buf->len - 1, GFP_NOFS);
4958 } else {
4959 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
4960 buf->start + buf->len - 1, GFP_NOFS);
4961 }
4962 trans->blocks_used++;
4963 /* this returns a buffer locked for blocking */
4964 return buf;
4965 }
4966
4967 /*
4968 * helper function to allocate a block for a given tree
4969 * returns the tree buffer or NULL.
4970 */
4971 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
4972 struct btrfs_root *root, u32 blocksize,
4973 u64 parent, u64 root_objectid,
4974 struct btrfs_disk_key *key, int level,
4975 u64 hint, u64 empty_size)
4976 {
4977 struct btrfs_key ins;
4978 int ret;
4979 struct extent_buffer *buf;
4980
4981 ret = alloc_tree_block(trans, root, blocksize, parent, root_objectid,
4982 key, level, empty_size, hint, (u64)-1, &ins);
4983 if (ret) {
4984 BUG_ON(ret > 0);
4985 return ERR_PTR(ret);
4986 }
4987
4988 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
4989 blocksize, level);
4990 return buf;
4991 }
4992
4993 struct walk_control {
4994 u64 refs[BTRFS_MAX_LEVEL];
4995 u64 flags[BTRFS_MAX_LEVEL];
4996 struct btrfs_key update_progress;
4997 int stage;
4998 int level;
4999 int shared_level;
5000 int update_ref;
5001 int keep_locks;
5002 int reada_slot;
5003 int reada_count;
5004 };
5005
5006 #define DROP_REFERENCE 1
5007 #define UPDATE_BACKREF 2
5008
5009 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
5010 struct btrfs_root *root,
5011 struct walk_control *wc,
5012 struct btrfs_path *path)
5013 {
5014 u64 bytenr;
5015 u64 generation;
5016 u64 refs;
5017 u64 flags;
5018 u64 last = 0;
5019 u32 nritems;
5020 u32 blocksize;
5021 struct btrfs_key key;
5022 struct extent_buffer *eb;
5023 int ret;
5024 int slot;
5025 int nread = 0;
5026
5027 if (path->slots[wc->level] < wc->reada_slot) {
5028 wc->reada_count = wc->reada_count * 2 / 3;
5029 wc->reada_count = max(wc->reada_count, 2);
5030 } else {
5031 wc->reada_count = wc->reada_count * 3 / 2;
5032 wc->reada_count = min_t(int, wc->reada_count,
5033 BTRFS_NODEPTRS_PER_BLOCK(root));
5034 }
5035
5036 eb = path->nodes[wc->level];
5037 nritems = btrfs_header_nritems(eb);
5038 blocksize = btrfs_level_size(root, wc->level - 1);
5039
5040 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
5041 if (nread >= wc->reada_count)
5042 break;
5043
5044 cond_resched();
5045 bytenr = btrfs_node_blockptr(eb, slot);
5046 generation = btrfs_node_ptr_generation(eb, slot);
5047
5048 if (slot == path->slots[wc->level])
5049 goto reada;
5050
5051 if (wc->stage == UPDATE_BACKREF &&
5052 generation <= root->root_key.offset)
5053 continue;
5054
5055 /* We don't lock the tree block, it's OK to be racy here */
5056 ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
5057 &refs, &flags);
5058 BUG_ON(ret);
5059 BUG_ON(refs == 0);
5060
5061 if (wc->stage == DROP_REFERENCE) {
5062 if (refs == 1)
5063 goto reada;
5064
5065 if (wc->level == 1 &&
5066 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5067 continue;
5068 if (!wc->update_ref ||
5069 generation <= root->root_key.offset)
5070 continue;
5071 btrfs_node_key_to_cpu(eb, &key, slot);
5072 ret = btrfs_comp_cpu_keys(&key,
5073 &wc->update_progress);
5074 if (ret < 0)
5075 continue;
5076 } else {
5077 if (wc->level == 1 &&
5078 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5079 continue;
5080 }
5081 reada:
5082 ret = readahead_tree_block(root, bytenr, blocksize,
5083 generation);
5084 if (ret)
5085 break;
5086 last = bytenr + blocksize;
5087 nread++;
5088 }
5089 wc->reada_slot = slot;
5090 }
5091
5092 /*
5093 * hepler to process tree block while walking down the tree.
5094 *
5095 * when wc->stage == UPDATE_BACKREF, this function updates
5096 * back refs for pointers in the block.
5097 *
5098 * NOTE: return value 1 means we should stop walking down.
5099 */
5100 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
5101 struct btrfs_root *root,
5102 struct btrfs_path *path,
5103 struct walk_control *wc, int lookup_info)
5104 {
5105 int level = wc->level;
5106 struct extent_buffer *eb = path->nodes[level];
5107 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5108 int ret;
5109
5110 if (wc->stage == UPDATE_BACKREF &&
5111 btrfs_header_owner(eb) != root->root_key.objectid)
5112 return 1;
5113
5114 /*
5115 * when reference count of tree block is 1, it won't increase
5116 * again. once full backref flag is set, we never clear it.
5117 */
5118 if (lookup_info &&
5119 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
5120 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
5121 BUG_ON(!path->locks[level]);
5122 ret = btrfs_lookup_extent_info(trans, root,
5123 eb->start, eb->len,
5124 &wc->refs[level],
5125 &wc->flags[level]);
5126 BUG_ON(ret);
5127 BUG_ON(wc->refs[level] == 0);
5128 }
5129
5130 if (wc->stage == DROP_REFERENCE) {
5131 if (wc->refs[level] > 1)
5132 return 1;
5133
5134 if (path->locks[level] && !wc->keep_locks) {
5135 btrfs_tree_unlock(eb);
5136 path->locks[level] = 0;
5137 }
5138 return 0;
5139 }
5140
5141 /* wc->stage == UPDATE_BACKREF */
5142 if (!(wc->flags[level] & flag)) {
5143 BUG_ON(!path->locks[level]);
5144 ret = btrfs_inc_ref(trans, root, eb, 1);
5145 BUG_ON(ret);
5146 ret = btrfs_dec_ref(trans, root, eb, 0);
5147 BUG_ON(ret);
5148 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
5149 eb->len, flag, 0);
5150 BUG_ON(ret);
5151 wc->flags[level] |= flag;
5152 }
5153
5154 /*
5155 * the block is shared by multiple trees, so it's not good to
5156 * keep the tree lock
5157 */
5158 if (path->locks[level] && level > 0) {
5159 btrfs_tree_unlock(eb);
5160 path->locks[level] = 0;
5161 }
5162 return 0;
5163 }
5164
5165 /*
5166 * hepler to process tree block pointer.
5167 *
5168 * when wc->stage == DROP_REFERENCE, this function checks
5169 * reference count of the block pointed to. if the block
5170 * is shared and we need update back refs for the subtree
5171 * rooted at the block, this function changes wc->stage to
5172 * UPDATE_BACKREF. if the block is shared and there is no
5173 * need to update back, this function drops the reference
5174 * to the block.
5175 *
5176 * NOTE: return value 1 means we should stop walking down.
5177 */
5178 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
5179 struct btrfs_root *root,
5180 struct btrfs_path *path,
5181 struct walk_control *wc, int *lookup_info)
5182 {
5183 u64 bytenr;
5184 u64 generation;
5185 u64 parent;
5186 u32 blocksize;
5187 struct btrfs_key key;
5188 struct extent_buffer *next;
5189 int level = wc->level;
5190 int reada = 0;
5191 int ret = 0;
5192
5193 generation = btrfs_node_ptr_generation(path->nodes[level],
5194 path->slots[level]);
5195 /*
5196 * if the lower level block was created before the snapshot
5197 * was created, we know there is no need to update back refs
5198 * for the subtree
5199 */
5200 if (wc->stage == UPDATE_BACKREF &&
5201 generation <= root->root_key.offset) {
5202 *lookup_info = 1;
5203 return 1;
5204 }
5205
5206 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
5207 blocksize = btrfs_level_size(root, level - 1);
5208
5209 next = btrfs_find_tree_block(root, bytenr, blocksize);
5210 if (!next) {
5211 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
5212 if (!next)
5213 return -ENOMEM;
5214 reada = 1;
5215 }
5216 btrfs_tree_lock(next);
5217 btrfs_set_lock_blocking(next);
5218
5219 ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
5220 &wc->refs[level - 1],
5221 &wc->flags[level - 1]);
5222 BUG_ON(ret);
5223 BUG_ON(wc->refs[level - 1] == 0);
5224 *lookup_info = 0;
5225
5226 if (wc->stage == DROP_REFERENCE) {
5227 if (wc->refs[level - 1] > 1) {
5228 if (level == 1 &&
5229 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5230 goto skip;
5231
5232 if (!wc->update_ref ||
5233 generation <= root->root_key.offset)
5234 goto skip;
5235
5236 btrfs_node_key_to_cpu(path->nodes[level], &key,
5237 path->slots[level]);
5238 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
5239 if (ret < 0)
5240 goto skip;
5241
5242 wc->stage = UPDATE_BACKREF;
5243 wc->shared_level = level - 1;
5244 }
5245 } else {
5246 if (level == 1 &&
5247 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5248 goto skip;
5249 }
5250
5251 if (!btrfs_buffer_uptodate(next, generation)) {
5252 btrfs_tree_unlock(next);
5253 free_extent_buffer(next);
5254 next = NULL;
5255 *lookup_info = 1;
5256 }
5257
5258 if (!next) {
5259 if (reada && level == 1)
5260 reada_walk_down(trans, root, wc, path);
5261 next = read_tree_block(root, bytenr, blocksize, generation);
5262 btrfs_tree_lock(next);
5263 btrfs_set_lock_blocking(next);
5264 }
5265
5266 level--;
5267 BUG_ON(level != btrfs_header_level(next));
5268 path->nodes[level] = next;
5269 path->slots[level] = 0;
5270 path->locks[level] = 1;
5271 wc->level = level;
5272 if (wc->level == 1)
5273 wc->reada_slot = 0;
5274 return 0;
5275 skip:
5276 wc->refs[level - 1] = 0;
5277 wc->flags[level - 1] = 0;
5278 if (wc->stage == DROP_REFERENCE) {
5279 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
5280 parent = path->nodes[level]->start;
5281 } else {
5282 BUG_ON(root->root_key.objectid !=
5283 btrfs_header_owner(path->nodes[level]));
5284 parent = 0;
5285 }
5286
5287 ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
5288 root->root_key.objectid, level - 1, 0);
5289 BUG_ON(ret);
5290 }
5291 btrfs_tree_unlock(next);
5292 free_extent_buffer(next);
5293 *lookup_info = 1;
5294 return 1;
5295 }
5296
5297 /*
5298 * hepler to process tree block while walking up the tree.
5299 *
5300 * when wc->stage == DROP_REFERENCE, this function drops
5301 * reference count on the block.
5302 *
5303 * when wc->stage == UPDATE_BACKREF, this function changes
5304 * wc->stage back to DROP_REFERENCE if we changed wc->stage
5305 * to UPDATE_BACKREF previously while processing the block.
5306 *
5307 * NOTE: return value 1 means we should stop walking up.
5308 */
5309 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
5310 struct btrfs_root *root,
5311 struct btrfs_path *path,
5312 struct walk_control *wc)
5313 {
5314 int ret = 0;
5315 int level = wc->level;
5316 struct extent_buffer *eb = path->nodes[level];
5317 u64 parent = 0;
5318
5319 if (wc->stage == UPDATE_BACKREF) {
5320 BUG_ON(wc->shared_level < level);
5321 if (level < wc->shared_level)
5322 goto out;
5323
5324 ret = find_next_key(path, level + 1, &wc->update_progress);
5325 if (ret > 0)
5326 wc->update_ref = 0;
5327
5328 wc->stage = DROP_REFERENCE;
5329 wc->shared_level = -1;
5330 path->slots[level] = 0;
5331
5332 /*
5333 * check reference count again if the block isn't locked.
5334 * we should start walking down the tree again if reference
5335 * count is one.
5336 */
5337 if (!path->locks[level]) {
5338 BUG_ON(level == 0);
5339 btrfs_tree_lock(eb);
5340 btrfs_set_lock_blocking(eb);
5341 path->locks[level] = 1;
5342
5343 ret = btrfs_lookup_extent_info(trans, root,
5344 eb->start, eb->len,
5345 &wc->refs[level],
5346 &wc->flags[level]);
5347 BUG_ON(ret);
5348 BUG_ON(wc->refs[level] == 0);
5349 if (wc->refs[level] == 1) {
5350 btrfs_tree_unlock(eb);
5351 path->locks[level] = 0;
5352 return 1;
5353 }
5354 }
5355 }
5356
5357 /* wc->stage == DROP_REFERENCE */
5358 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
5359
5360 if (wc->refs[level] == 1) {
5361 if (level == 0) {
5362 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5363 ret = btrfs_dec_ref(trans, root, eb, 1);
5364 else
5365 ret = btrfs_dec_ref(trans, root, eb, 0);
5366 BUG_ON(ret);
5367 }
5368 /* make block locked assertion in clean_tree_block happy */
5369 if (!path->locks[level] &&
5370 btrfs_header_generation(eb) == trans->transid) {
5371 btrfs_tree_lock(eb);
5372 btrfs_set_lock_blocking(eb);
5373 path->locks[level] = 1;
5374 }
5375 clean_tree_block(trans, root, eb);
5376 }
5377
5378 if (eb == root->node) {
5379 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5380 parent = eb->start;
5381 else
5382 BUG_ON(root->root_key.objectid !=
5383 btrfs_header_owner(eb));
5384 } else {
5385 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5386 parent = path->nodes[level + 1]->start;
5387 else
5388 BUG_ON(root->root_key.objectid !=
5389 btrfs_header_owner(path->nodes[level + 1]));
5390 }
5391
5392 ret = btrfs_free_extent(trans, root, eb->start, eb->len, parent,
5393 root->root_key.objectid, level, 0);
5394 BUG_ON(ret);
5395 out:
5396 wc->refs[level] = 0;
5397 wc->flags[level] = 0;
5398 return ret;
5399 }
5400
5401 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
5402 struct btrfs_root *root,
5403 struct btrfs_path *path,
5404 struct walk_control *wc)
5405 {
5406 int level = wc->level;
5407 int lookup_info = 1;
5408 int ret;
5409
5410 while (level >= 0) {
5411 ret = walk_down_proc(trans, root, path, wc, lookup_info);
5412 if (ret > 0)
5413 break;
5414
5415 if (level == 0)
5416 break;
5417
5418 if (path->slots[level] >=
5419 btrfs_header_nritems(path->nodes[level]))
5420 break;
5421
5422 ret = do_walk_down(trans, root, path, wc, &lookup_info);
5423 if (ret > 0) {
5424 path->slots[level]++;
5425 continue;
5426 } else if (ret < 0)
5427 return ret;
5428 level = wc->level;
5429 }
5430 return 0;
5431 }
5432
5433 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
5434 struct btrfs_root *root,
5435 struct btrfs_path *path,
5436 struct walk_control *wc, int max_level)
5437 {
5438 int level = wc->level;
5439 int ret;
5440
5441 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
5442 while (level < max_level && path->nodes[level]) {
5443 wc->level = level;
5444 if (path->slots[level] + 1 <
5445 btrfs_header_nritems(path->nodes[level])) {
5446 path->slots[level]++;
5447 return 0;
5448 } else {
5449 ret = walk_up_proc(trans, root, path, wc);
5450 if (ret > 0)
5451 return 0;
5452
5453 if (path->locks[level]) {
5454 btrfs_tree_unlock(path->nodes[level]);
5455 path->locks[level] = 0;
5456 }
5457 free_extent_buffer(path->nodes[level]);
5458 path->nodes[level] = NULL;
5459 level++;
5460 }
5461 }
5462 return 1;
5463 }
5464
5465 /*
5466 * drop a subvolume tree.
5467 *
5468 * this function traverses the tree freeing any blocks that only
5469 * referenced by the tree.
5470 *
5471 * when a shared tree block is found. this function decreases its
5472 * reference count by one. if update_ref is true, this function
5473 * also make sure backrefs for the shared block and all lower level
5474 * blocks are properly updated.
5475 */
5476 int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref)
5477 {
5478 struct btrfs_path *path;
5479 struct btrfs_trans_handle *trans;
5480 struct btrfs_root *tree_root = root->fs_info->tree_root;
5481 struct btrfs_root_item *root_item = &root->root_item;
5482 struct walk_control *wc;
5483 struct btrfs_key key;
5484 int err = 0;
5485 int ret;
5486 int level;
5487
5488 path = btrfs_alloc_path();
5489 BUG_ON(!path);
5490
5491 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5492 BUG_ON(!wc);
5493
5494 trans = btrfs_start_transaction(tree_root, 1);
5495
5496 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
5497 level = btrfs_header_level(root->node);
5498 path->nodes[level] = btrfs_lock_root_node(root);
5499 btrfs_set_lock_blocking(path->nodes[level]);
5500 path->slots[level] = 0;
5501 path->locks[level] = 1;
5502 memset(&wc->update_progress, 0,
5503 sizeof(wc->update_progress));
5504 } else {
5505 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
5506 memcpy(&wc->update_progress, &key,
5507 sizeof(wc->update_progress));
5508
5509 level = root_item->drop_level;
5510 BUG_ON(level == 0);
5511 path->lowest_level = level;
5512 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5513 path->lowest_level = 0;
5514 if (ret < 0) {
5515 err = ret;
5516 goto out;
5517 }
5518 WARN_ON(ret > 0);
5519
5520 /*
5521 * unlock our path, this is safe because only this
5522 * function is allowed to delete this snapshot
5523 */
5524 btrfs_unlock_up_safe(path, 0);
5525
5526 level = btrfs_header_level(root->node);
5527 while (1) {
5528 btrfs_tree_lock(path->nodes[level]);
5529 btrfs_set_lock_blocking(path->nodes[level]);
5530
5531 ret = btrfs_lookup_extent_info(trans, root,
5532 path->nodes[level]->start,
5533 path->nodes[level]->len,
5534 &wc->refs[level],
5535 &wc->flags[level]);
5536 BUG_ON(ret);
5537 BUG_ON(wc->refs[level] == 0);
5538
5539 if (level == root_item->drop_level)
5540 break;
5541
5542 btrfs_tree_unlock(path->nodes[level]);
5543 WARN_ON(wc->refs[level] != 1);
5544 level--;
5545 }
5546 }
5547
5548 wc->level = level;
5549 wc->shared_level = -1;
5550 wc->stage = DROP_REFERENCE;
5551 wc->update_ref = update_ref;
5552 wc->keep_locks = 0;
5553 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
5554
5555 while (1) {
5556 ret = walk_down_tree(trans, root, path, wc);
5557 if (ret < 0) {
5558 err = ret;
5559 break;
5560 }
5561
5562 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
5563 if (ret < 0) {
5564 err = ret;
5565 break;
5566 }
5567
5568 if (ret > 0) {
5569 BUG_ON(wc->stage != DROP_REFERENCE);
5570 break;
5571 }
5572
5573 if (wc->stage == DROP_REFERENCE) {
5574 level = wc->level;
5575 btrfs_node_key(path->nodes[level],
5576 &root_item->drop_progress,
5577 path->slots[level]);
5578 root_item->drop_level = level;
5579 }
5580
5581 BUG_ON(wc->level == 0);
5582 if (trans->transaction->in_commit ||
5583 trans->transaction->delayed_refs.flushing) {
5584 ret = btrfs_update_root(trans, tree_root,
5585 &root->root_key,
5586 root_item);
5587 BUG_ON(ret);
5588
5589 btrfs_end_transaction(trans, tree_root);
5590 trans = btrfs_start_transaction(tree_root, 1);
5591 } else {
5592 unsigned long update;
5593 update = trans->delayed_ref_updates;
5594 trans->delayed_ref_updates = 0;
5595 if (update)
5596 btrfs_run_delayed_refs(trans, tree_root,
5597 update);
5598 }
5599 }
5600 btrfs_release_path(root, path);
5601 BUG_ON(err);
5602
5603 ret = btrfs_del_root(trans, tree_root, &root->root_key);
5604 BUG_ON(ret);
5605
5606 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
5607 ret = btrfs_find_last_root(tree_root, root->root_key.objectid,
5608 NULL, NULL);
5609 BUG_ON(ret < 0);
5610 if (ret > 0) {
5611 ret = btrfs_del_orphan_item(trans, tree_root,
5612 root->root_key.objectid);
5613 BUG_ON(ret);
5614 }
5615 }
5616
5617 if (root->in_radix) {
5618 btrfs_free_fs_root(tree_root->fs_info, root);
5619 } else {
5620 free_extent_buffer(root->node);
5621 free_extent_buffer(root->commit_root);
5622 kfree(root);
5623 }
5624 out:
5625 btrfs_end_transaction(trans, tree_root);
5626 kfree(wc);
5627 btrfs_free_path(path);
5628 return err;
5629 }
5630
5631 /*
5632 * drop subtree rooted at tree block 'node'.
5633 *
5634 * NOTE: this function will unlock and release tree block 'node'
5635 */
5636 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
5637 struct btrfs_root *root,
5638 struct extent_buffer *node,
5639 struct extent_buffer *parent)
5640 {
5641 struct btrfs_path *path;
5642 struct walk_control *wc;
5643 int level;
5644 int parent_level;
5645 int ret = 0;
5646 int wret;
5647
5648 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5649
5650 path = btrfs_alloc_path();
5651 BUG_ON(!path);
5652
5653 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5654 BUG_ON(!wc);
5655
5656 btrfs_assert_tree_locked(parent);
5657 parent_level = btrfs_header_level(parent);
5658 extent_buffer_get(parent);
5659 path->nodes[parent_level] = parent;
5660 path->slots[parent_level] = btrfs_header_nritems(parent);
5661
5662 btrfs_assert_tree_locked(node);
5663 level = btrfs_header_level(node);
5664 path->nodes[level] = node;
5665 path->slots[level] = 0;
5666 path->locks[level] = 1;
5667
5668 wc->refs[parent_level] = 1;
5669 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5670 wc->level = level;
5671 wc->shared_level = -1;
5672 wc->stage = DROP_REFERENCE;
5673 wc->update_ref = 0;
5674 wc->keep_locks = 1;
5675 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
5676
5677 while (1) {
5678 wret = walk_down_tree(trans, root, path, wc);
5679 if (wret < 0) {
5680 ret = wret;
5681 break;
5682 }
5683
5684 wret = walk_up_tree(trans, root, path, wc, parent_level);
5685 if (wret < 0)
5686 ret = wret;
5687 if (wret != 0)
5688 break;
5689 }
5690
5691 kfree(wc);
5692 btrfs_free_path(path);
5693 return ret;
5694 }
5695
5696 #if 0
5697 static unsigned long calc_ra(unsigned long start, unsigned long last,
5698 unsigned long nr)
5699 {
5700 return min(last, start + nr - 1);
5701 }
5702
5703 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
5704 u64 len)
5705 {
5706 u64 page_start;
5707 u64 page_end;
5708 unsigned long first_index;
5709 unsigned long last_index;
5710 unsigned long i;
5711 struct page *page;
5712 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5713 struct file_ra_state *ra;
5714 struct btrfs_ordered_extent *ordered;
5715 unsigned int total_read = 0;
5716 unsigned int total_dirty = 0;
5717 int ret = 0;
5718
5719 ra = kzalloc(sizeof(*ra), GFP_NOFS);
5720
5721 mutex_lock(&inode->i_mutex);
5722 first_index = start >> PAGE_CACHE_SHIFT;
5723 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
5724
5725 /* make sure the dirty trick played by the caller work */
5726 ret = invalidate_inode_pages2_range(inode->i_mapping,
5727 first_index, last_index);
5728 if (ret)
5729 goto out_unlock;
5730
5731 file_ra_state_init(ra, inode->i_mapping);
5732
5733 for (i = first_index ; i <= last_index; i++) {
5734 if (total_read % ra->ra_pages == 0) {
5735 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
5736 calc_ra(i, last_index, ra->ra_pages));
5737 }
5738 total_read++;
5739 again:
5740 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
5741 BUG_ON(1);
5742 page = grab_cache_page(inode->i_mapping, i);
5743 if (!page) {
5744 ret = -ENOMEM;
5745 goto out_unlock;
5746 }
5747 if (!PageUptodate(page)) {
5748 btrfs_readpage(NULL, page);
5749 lock_page(page);
5750 if (!PageUptodate(page)) {
5751 unlock_page(page);
5752 page_cache_release(page);
5753 ret = -EIO;
5754 goto out_unlock;
5755 }
5756 }
5757 wait_on_page_writeback(page);
5758
5759 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
5760 page_end = page_start + PAGE_CACHE_SIZE - 1;
5761 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
5762
5763 ordered = btrfs_lookup_ordered_extent(inode, page_start);
5764 if (ordered) {
5765 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5766 unlock_page(page);
5767 page_cache_release(page);
5768 btrfs_start_ordered_extent(inode, ordered, 1);
5769 btrfs_put_ordered_extent(ordered);
5770 goto again;
5771 }
5772 set_page_extent_mapped(page);
5773
5774 if (i == first_index)
5775 set_extent_bits(io_tree, page_start, page_end,
5776 EXTENT_BOUNDARY, GFP_NOFS);
5777 btrfs_set_extent_delalloc(inode, page_start, page_end);
5778
5779 set_page_dirty(page);
5780 total_dirty++;
5781
5782 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5783 unlock_page(page);
5784 page_cache_release(page);
5785 }
5786
5787 out_unlock:
5788 kfree(ra);
5789 mutex_unlock(&inode->i_mutex);
5790 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
5791 return ret;
5792 }
5793
5794 static noinline int relocate_data_extent(struct inode *reloc_inode,
5795 struct btrfs_key *extent_key,
5796 u64 offset)
5797 {
5798 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5799 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
5800 struct extent_map *em;
5801 u64 start = extent_key->objectid - offset;
5802 u64 end = start + extent_key->offset - 1;
5803
5804 em = alloc_extent_map(GFP_NOFS);
5805 BUG_ON(!em || IS_ERR(em));
5806
5807 em->start = start;
5808 em->len = extent_key->offset;
5809 em->block_len = extent_key->offset;
5810 em->block_start = extent_key->objectid;
5811 em->bdev = root->fs_info->fs_devices->latest_bdev;
5812 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5813
5814 /* setup extent map to cheat btrfs_readpage */
5815 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5816 while (1) {
5817 int ret;
5818 write_lock(&em_tree->lock);
5819 ret = add_extent_mapping(em_tree, em);
5820 write_unlock(&em_tree->lock);
5821 if (ret != -EEXIST) {
5822 free_extent_map(em);
5823 break;
5824 }
5825 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
5826 }
5827 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5828
5829 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
5830 }
5831
5832 struct btrfs_ref_path {
5833 u64 extent_start;
5834 u64 nodes[BTRFS_MAX_LEVEL];
5835 u64 root_objectid;
5836 u64 root_generation;
5837 u64 owner_objectid;
5838 u32 num_refs;
5839 int lowest_level;
5840 int current_level;
5841 int shared_level;
5842
5843 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
5844 u64 new_nodes[BTRFS_MAX_LEVEL];
5845 };
5846
5847 struct disk_extent {
5848 u64 ram_bytes;
5849 u64 disk_bytenr;
5850 u64 disk_num_bytes;
5851 u64 offset;
5852 u64 num_bytes;
5853 u8 compression;
5854 u8 encryption;
5855 u16 other_encoding;
5856 };
5857
5858 static int is_cowonly_root(u64 root_objectid)
5859 {
5860 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
5861 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
5862 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
5863 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
5864 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
5865 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
5866 return 1;
5867 return 0;
5868 }
5869
5870 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
5871 struct btrfs_root *extent_root,
5872 struct btrfs_ref_path *ref_path,
5873 int first_time)
5874 {
5875 struct extent_buffer *leaf;
5876 struct btrfs_path *path;
5877 struct btrfs_extent_ref *ref;
5878 struct btrfs_key key;
5879 struct btrfs_key found_key;
5880 u64 bytenr;
5881 u32 nritems;
5882 int level;
5883 int ret = 1;
5884
5885 path = btrfs_alloc_path();
5886 if (!path)
5887 return -ENOMEM;
5888
5889 if (first_time) {
5890 ref_path->lowest_level = -1;
5891 ref_path->current_level = -1;
5892 ref_path->shared_level = -1;
5893 goto walk_up;
5894 }
5895 walk_down:
5896 level = ref_path->current_level - 1;
5897 while (level >= -1) {
5898 u64 parent;
5899 if (level < ref_path->lowest_level)
5900 break;
5901
5902 if (level >= 0)
5903 bytenr = ref_path->nodes[level];
5904 else
5905 bytenr = ref_path->extent_start;
5906 BUG_ON(bytenr == 0);
5907
5908 parent = ref_path->nodes[level + 1];
5909 ref_path->nodes[level + 1] = 0;
5910 ref_path->current_level = level;
5911 BUG_ON(parent == 0);
5912
5913 key.objectid = bytenr;
5914 key.offset = parent + 1;
5915 key.type = BTRFS_EXTENT_REF_KEY;
5916
5917 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5918 if (ret < 0)
5919 goto out;
5920 BUG_ON(ret == 0);
5921
5922 leaf = path->nodes[0];
5923 nritems = btrfs_header_nritems(leaf);
5924 if (path->slots[0] >= nritems) {
5925 ret = btrfs_next_leaf(extent_root, path);
5926 if (ret < 0)
5927 goto out;
5928 if (ret > 0)
5929 goto next;
5930 leaf = path->nodes[0];
5931 }
5932
5933 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5934 if (found_key.objectid == bytenr &&
5935 found_key.type == BTRFS_EXTENT_REF_KEY) {
5936 if (level < ref_path->shared_level)
5937 ref_path->shared_level = level;
5938 goto found;
5939 }
5940 next:
5941 level--;
5942 btrfs_release_path(extent_root, path);
5943 cond_resched();
5944 }
5945 /* reached lowest level */
5946 ret = 1;
5947 goto out;
5948 walk_up:
5949 level = ref_path->current_level;
5950 while (level < BTRFS_MAX_LEVEL - 1) {
5951 u64 ref_objectid;
5952
5953 if (level >= 0)
5954 bytenr = ref_path->nodes[level];
5955 else
5956 bytenr = ref_path->extent_start;
5957
5958 BUG_ON(bytenr == 0);
5959
5960 key.objectid = bytenr;
5961 key.offset = 0;
5962 key.type = BTRFS_EXTENT_REF_KEY;
5963
5964 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5965 if (ret < 0)
5966 goto out;
5967
5968 leaf = path->nodes[0];
5969 nritems = btrfs_header_nritems(leaf);
5970 if (path->slots[0] >= nritems) {
5971 ret = btrfs_next_leaf(extent_root, path);
5972 if (ret < 0)
5973 goto out;
5974 if (ret > 0) {
5975 /* the extent was freed by someone */
5976 if (ref_path->lowest_level == level)
5977 goto out;
5978 btrfs_release_path(extent_root, path);
5979 goto walk_down;
5980 }
5981 leaf = path->nodes[0];
5982 }
5983
5984 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5985 if (found_key.objectid != bytenr ||
5986 found_key.type != BTRFS_EXTENT_REF_KEY) {
5987 /* the extent was freed by someone */
5988 if (ref_path->lowest_level == level) {
5989 ret = 1;
5990 goto out;
5991 }
5992 btrfs_release_path(extent_root, path);
5993 goto walk_down;
5994 }
5995 found:
5996 ref = btrfs_item_ptr(leaf, path->slots[0],
5997 struct btrfs_extent_ref);
5998 ref_objectid = btrfs_ref_objectid(leaf, ref);
5999 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
6000 if (first_time) {
6001 level = (int)ref_objectid;
6002 BUG_ON(level >= BTRFS_MAX_LEVEL);
6003 ref_path->lowest_level = level;
6004 ref_path->current_level = level;
6005 ref_path->nodes[level] = bytenr;
6006 } else {
6007 WARN_ON(ref_objectid != level);
6008 }
6009 } else {
6010 WARN_ON(level != -1);
6011 }
6012 first_time = 0;
6013
6014 if (ref_path->lowest_level == level) {
6015 ref_path->owner_objectid = ref_objectid;
6016 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
6017 }
6018
6019 /*
6020 * the block is tree root or the block isn't in reference
6021 * counted tree.
6022 */
6023 if (found_key.objectid == found_key.offset ||
6024 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
6025 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
6026 ref_path->root_generation =
6027 btrfs_ref_generation(leaf, ref);
6028 if (level < 0) {
6029 /* special reference from the tree log */
6030 ref_path->nodes[0] = found_key.offset;
6031 ref_path->current_level = 0;
6032 }
6033 ret = 0;
6034 goto out;
6035 }
6036
6037 level++;
6038 BUG_ON(ref_path->nodes[level] != 0);
6039 ref_path->nodes[level] = found_key.offset;
6040 ref_path->current_level = level;
6041
6042 /*
6043 * the reference was created in the running transaction,
6044 * no need to continue walking up.
6045 */
6046 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
6047 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
6048 ref_path->root_generation =
6049 btrfs_ref_generation(leaf, ref);
6050 ret = 0;
6051 goto out;
6052 }
6053
6054 btrfs_release_path(extent_root, path);
6055 cond_resched();
6056 }
6057 /* reached max tree level, but no tree root found. */
6058 BUG();
6059 out:
6060 btrfs_free_path(path);
6061 return ret;
6062 }
6063
6064 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
6065 struct btrfs_root *extent_root,
6066 struct btrfs_ref_path *ref_path,
6067 u64 extent_start)
6068 {
6069 memset(ref_path, 0, sizeof(*ref_path));
6070 ref_path->extent_start = extent_start;
6071
6072 return __next_ref_path(trans, extent_root, ref_path, 1);
6073 }
6074
6075 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
6076 struct btrfs_root *extent_root,
6077 struct btrfs_ref_path *ref_path)
6078 {
6079 return __next_ref_path(trans, extent_root, ref_path, 0);
6080 }
6081
6082 static noinline int get_new_locations(struct inode *reloc_inode,
6083 struct btrfs_key *extent_key,
6084 u64 offset, int no_fragment,
6085 struct disk_extent **extents,
6086 int *nr_extents)
6087 {
6088 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
6089 struct btrfs_path *path;
6090 struct btrfs_file_extent_item *fi;
6091 struct extent_buffer *leaf;
6092 struct disk_extent *exts = *extents;
6093 struct btrfs_key found_key;
6094 u64 cur_pos;
6095 u64 last_byte;
6096 u32 nritems;
6097 int nr = 0;
6098 int max = *nr_extents;
6099 int ret;
6100
6101 WARN_ON(!no_fragment && *extents);
6102 if (!exts) {
6103 max = 1;
6104 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
6105 if (!exts)
6106 return -ENOMEM;
6107 }
6108
6109 path = btrfs_alloc_path();
6110 BUG_ON(!path);
6111
6112 cur_pos = extent_key->objectid - offset;
6113 last_byte = extent_key->objectid + extent_key->offset;
6114 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
6115 cur_pos, 0);
6116 if (ret < 0)
6117 goto out;
6118 if (ret > 0) {
6119 ret = -ENOENT;
6120 goto out;
6121 }
6122
6123 while (1) {
6124 leaf = path->nodes[0];
6125 nritems = btrfs_header_nritems(leaf);
6126 if (path->slots[0] >= nritems) {
6127 ret = btrfs_next_leaf(root, path);
6128 if (ret < 0)
6129 goto out;
6130 if (ret > 0)
6131 break;
6132 leaf = path->nodes[0];
6133 }
6134
6135 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6136 if (found_key.offset != cur_pos ||
6137 found_key.type != BTRFS_EXTENT_DATA_KEY ||
6138 found_key.objectid != reloc_inode->i_ino)
6139 break;
6140
6141 fi = btrfs_item_ptr(leaf, path->slots[0],
6142 struct btrfs_file_extent_item);
6143 if (btrfs_file_extent_type(leaf, fi) !=
6144 BTRFS_FILE_EXTENT_REG ||
6145 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
6146 break;
6147
6148 if (nr == max) {
6149 struct disk_extent *old = exts;
6150 max *= 2;
6151 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
6152 memcpy(exts, old, sizeof(*exts) * nr);
6153 if (old != *extents)
6154 kfree(old);
6155 }
6156
6157 exts[nr].disk_bytenr =
6158 btrfs_file_extent_disk_bytenr(leaf, fi);
6159 exts[nr].disk_num_bytes =
6160 btrfs_file_extent_disk_num_bytes(leaf, fi);
6161 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
6162 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6163 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6164 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
6165 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
6166 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
6167 fi);
6168 BUG_ON(exts[nr].offset > 0);
6169 BUG_ON(exts[nr].compression || exts[nr].encryption);
6170 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
6171
6172 cur_pos += exts[nr].num_bytes;
6173 nr++;
6174
6175 if (cur_pos + offset >= last_byte)
6176 break;
6177
6178 if (no_fragment) {
6179 ret = 1;
6180 goto out;
6181 }
6182 path->slots[0]++;
6183 }
6184
6185 BUG_ON(cur_pos + offset > last_byte);
6186 if (cur_pos + offset < last_byte) {
6187 ret = -ENOENT;
6188 goto out;
6189 }
6190 ret = 0;
6191 out:
6192 btrfs_free_path(path);
6193 if (ret) {
6194 if (exts != *extents)
6195 kfree(exts);
6196 } else {
6197 *extents = exts;
6198 *nr_extents = nr;
6199 }
6200 return ret;
6201 }
6202
6203 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
6204 struct btrfs_root *root,
6205 struct btrfs_path *path,
6206 struct btrfs_key *extent_key,
6207 struct btrfs_key *leaf_key,
6208 struct btrfs_ref_path *ref_path,
6209 struct disk_extent *new_extents,
6210 int nr_extents)
6211 {
6212 struct extent_buffer *leaf;
6213 struct btrfs_file_extent_item *fi;
6214 struct inode *inode = NULL;
6215 struct btrfs_key key;
6216 u64 lock_start = 0;
6217 u64 lock_end = 0;
6218 u64 num_bytes;
6219 u64 ext_offset;
6220 u64 search_end = (u64)-1;
6221 u32 nritems;
6222 int nr_scaned = 0;
6223 int extent_locked = 0;
6224 int extent_type;
6225 int ret;
6226
6227 memcpy(&key, leaf_key, sizeof(key));
6228 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
6229 if (key.objectid < ref_path->owner_objectid ||
6230 (key.objectid == ref_path->owner_objectid &&
6231 key.type < BTRFS_EXTENT_DATA_KEY)) {
6232 key.objectid = ref_path->owner_objectid;
6233 key.type = BTRFS_EXTENT_DATA_KEY;
6234 key.offset = 0;
6235 }
6236 }
6237
6238 while (1) {
6239 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
6240 if (ret < 0)
6241 goto out;
6242
6243 leaf = path->nodes[0];
6244 nritems = btrfs_header_nritems(leaf);
6245 next:
6246 if (extent_locked && ret > 0) {
6247 /*
6248 * the file extent item was modified by someone
6249 * before the extent got locked.
6250 */
6251 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6252 lock_end, GFP_NOFS);
6253 extent_locked = 0;
6254 }
6255
6256 if (path->slots[0] >= nritems) {
6257 if (++nr_scaned > 2)
6258 break;
6259
6260 BUG_ON(extent_locked);
6261 ret = btrfs_next_leaf(root, path);
6262 if (ret < 0)
6263 goto out;
6264 if (ret > 0)
6265 break;
6266 leaf = path->nodes[0];
6267 nritems = btrfs_header_nritems(leaf);
6268 }
6269
6270 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
6271
6272 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
6273 if ((key.objectid > ref_path->owner_objectid) ||
6274 (key.objectid == ref_path->owner_objectid &&
6275 key.type > BTRFS_EXTENT_DATA_KEY) ||
6276 key.offset >= search_end)
6277 break;
6278 }
6279
6280 if (inode && key.objectid != inode->i_ino) {
6281 BUG_ON(extent_locked);
6282 btrfs_release_path(root, path);
6283 mutex_unlock(&inode->i_mutex);
6284 iput(inode);
6285 inode = NULL;
6286 continue;
6287 }
6288
6289 if (key.type != BTRFS_EXTENT_DATA_KEY) {
6290 path->slots[0]++;
6291 ret = 1;
6292 goto next;
6293 }
6294 fi = btrfs_item_ptr(leaf, path->slots[0],
6295 struct btrfs_file_extent_item);
6296 extent_type = btrfs_file_extent_type(leaf, fi);
6297 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
6298 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
6299 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
6300 extent_key->objectid)) {
6301 path->slots[0]++;
6302 ret = 1;
6303 goto next;
6304 }
6305
6306 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6307 ext_offset = btrfs_file_extent_offset(leaf, fi);
6308
6309 if (search_end == (u64)-1) {
6310 search_end = key.offset - ext_offset +
6311 btrfs_file_extent_ram_bytes(leaf, fi);
6312 }
6313
6314 if (!extent_locked) {
6315 lock_start = key.offset;
6316 lock_end = lock_start + num_bytes - 1;
6317 } else {
6318 if (lock_start > key.offset ||
6319 lock_end + 1 < key.offset + num_bytes) {
6320 unlock_extent(&BTRFS_I(inode)->io_tree,
6321 lock_start, lock_end, GFP_NOFS);
6322 extent_locked = 0;
6323 }
6324 }
6325
6326 if (!inode) {
6327 btrfs_release_path(root, path);
6328
6329 inode = btrfs_iget_locked(root->fs_info->sb,
6330 key.objectid, root);
6331 if (inode->i_state & I_NEW) {
6332 BTRFS_I(inode)->root = root;
6333 BTRFS_I(inode)->location.objectid =
6334 key.objectid;
6335 BTRFS_I(inode)->location.type =
6336 BTRFS_INODE_ITEM_KEY;
6337 BTRFS_I(inode)->location.offset = 0;
6338 btrfs_read_locked_inode(inode);
6339 unlock_new_inode(inode);
6340 }
6341 /*
6342 * some code call btrfs_commit_transaction while
6343 * holding the i_mutex, so we can't use mutex_lock
6344 * here.
6345 */
6346 if (is_bad_inode(inode) ||
6347 !mutex_trylock(&inode->i_mutex)) {
6348 iput(inode);
6349 inode = NULL;
6350 key.offset = (u64)-1;
6351 goto skip;
6352 }
6353 }
6354
6355 if (!extent_locked) {
6356 struct btrfs_ordered_extent *ordered;
6357
6358 btrfs_release_path(root, path);
6359
6360 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6361 lock_end, GFP_NOFS);
6362 ordered = btrfs_lookup_first_ordered_extent(inode,
6363 lock_end);
6364 if (ordered &&
6365 ordered->file_offset <= lock_end &&
6366 ordered->file_offset + ordered->len > lock_start) {
6367 unlock_extent(&BTRFS_I(inode)->io_tree,
6368 lock_start, lock_end, GFP_NOFS);
6369 btrfs_start_ordered_extent(inode, ordered, 1);
6370 btrfs_put_ordered_extent(ordered);
6371 key.offset += num_bytes;
6372 goto skip;
6373 }
6374 if (ordered)
6375 btrfs_put_ordered_extent(ordered);
6376
6377 extent_locked = 1;
6378 continue;
6379 }
6380
6381 if (nr_extents == 1) {
6382 /* update extent pointer in place */
6383 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6384 new_extents[0].disk_bytenr);
6385 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6386 new_extents[0].disk_num_bytes);
6387 btrfs_mark_buffer_dirty(leaf);
6388
6389 btrfs_drop_extent_cache(inode, key.offset,
6390 key.offset + num_bytes - 1, 0);
6391
6392 ret = btrfs_inc_extent_ref(trans, root,
6393 new_extents[0].disk_bytenr,
6394 new_extents[0].disk_num_bytes,
6395 leaf->start,
6396 root->root_key.objectid,
6397 trans->transid,
6398 key.objectid);
6399 BUG_ON(ret);
6400
6401 ret = btrfs_free_extent(trans, root,
6402 extent_key->objectid,
6403 extent_key->offset,
6404 leaf->start,
6405 btrfs_header_owner(leaf),
6406 btrfs_header_generation(leaf),
6407 key.objectid, 0);
6408 BUG_ON(ret);
6409
6410 btrfs_release_path(root, path);
6411 key.offset += num_bytes;
6412 } else {
6413 BUG_ON(1);
6414 #if 0
6415 u64 alloc_hint;
6416 u64 extent_len;
6417 int i;
6418 /*
6419 * drop old extent pointer at first, then insert the
6420 * new pointers one bye one
6421 */
6422 btrfs_release_path(root, path);
6423 ret = btrfs_drop_extents(trans, root, inode, key.offset,
6424 key.offset + num_bytes,
6425 key.offset, &alloc_hint);
6426 BUG_ON(ret);
6427
6428 for (i = 0; i < nr_extents; i++) {
6429 if (ext_offset >= new_extents[i].num_bytes) {
6430 ext_offset -= new_extents[i].num_bytes;
6431 continue;
6432 }
6433 extent_len = min(new_extents[i].num_bytes -
6434 ext_offset, num_bytes);
6435
6436 ret = btrfs_insert_empty_item(trans, root,
6437 path, &key,
6438 sizeof(*fi));
6439 BUG_ON(ret);
6440
6441 leaf = path->nodes[0];
6442 fi = btrfs_item_ptr(leaf, path->slots[0],
6443 struct btrfs_file_extent_item);
6444 btrfs_set_file_extent_generation(leaf, fi,
6445 trans->transid);
6446 btrfs_set_file_extent_type(leaf, fi,
6447 BTRFS_FILE_EXTENT_REG);
6448 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6449 new_extents[i].disk_bytenr);
6450 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6451 new_extents[i].disk_num_bytes);
6452 btrfs_set_file_extent_ram_bytes(leaf, fi,
6453 new_extents[i].ram_bytes);
6454
6455 btrfs_set_file_extent_compression(leaf, fi,
6456 new_extents[i].compression);
6457 btrfs_set_file_extent_encryption(leaf, fi,
6458 new_extents[i].encryption);
6459 btrfs_set_file_extent_other_encoding(leaf, fi,
6460 new_extents[i].other_encoding);
6461
6462 btrfs_set_file_extent_num_bytes(leaf, fi,
6463 extent_len);
6464 ext_offset += new_extents[i].offset;
6465 btrfs_set_file_extent_offset(leaf, fi,
6466 ext_offset);
6467 btrfs_mark_buffer_dirty(leaf);
6468
6469 btrfs_drop_extent_cache(inode, key.offset,
6470 key.offset + extent_len - 1, 0);
6471
6472 ret = btrfs_inc_extent_ref(trans, root,
6473 new_extents[i].disk_bytenr,
6474 new_extents[i].disk_num_bytes,
6475 leaf->start,
6476 root->root_key.objectid,
6477 trans->transid, key.objectid);
6478 BUG_ON(ret);
6479 btrfs_release_path(root, path);
6480
6481 inode_add_bytes(inode, extent_len);
6482
6483 ext_offset = 0;
6484 num_bytes -= extent_len;
6485 key.offset += extent_len;
6486
6487 if (num_bytes == 0)
6488 break;
6489 }
6490 BUG_ON(i >= nr_extents);
6491 #endif
6492 }
6493
6494 if (extent_locked) {
6495 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6496 lock_end, GFP_NOFS);
6497 extent_locked = 0;
6498 }
6499 skip:
6500 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
6501 key.offset >= search_end)
6502 break;
6503
6504 cond_resched();
6505 }
6506 ret = 0;
6507 out:
6508 btrfs_release_path(root, path);
6509 if (inode) {
6510 mutex_unlock(&inode->i_mutex);
6511 if (extent_locked) {
6512 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6513 lock_end, GFP_NOFS);
6514 }
6515 iput(inode);
6516 }
6517 return ret;
6518 }
6519
6520 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
6521 struct btrfs_root *root,
6522 struct extent_buffer *buf, u64 orig_start)
6523 {
6524 int level;
6525 int ret;
6526
6527 BUG_ON(btrfs_header_generation(buf) != trans->transid);
6528 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
6529
6530 level = btrfs_header_level(buf);
6531 if (level == 0) {
6532 struct btrfs_leaf_ref *ref;
6533 struct btrfs_leaf_ref *orig_ref;
6534
6535 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
6536 if (!orig_ref)
6537 return -ENOENT;
6538
6539 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
6540 if (!ref) {
6541 btrfs_free_leaf_ref(root, orig_ref);
6542 return -ENOMEM;
6543 }
6544
6545 ref->nritems = orig_ref->nritems;
6546 memcpy(ref->extents, orig_ref->extents,
6547 sizeof(ref->extents[0]) * ref->nritems);
6548
6549 btrfs_free_leaf_ref(root, orig_ref);
6550
6551 ref->root_gen = trans->transid;
6552 ref->bytenr = buf->start;
6553 ref->owner = btrfs_header_owner(buf);
6554 ref->generation = btrfs_header_generation(buf);
6555
6556 ret = btrfs_add_leaf_ref(root, ref, 0);
6557 WARN_ON(ret);
6558 btrfs_free_leaf_ref(root, ref);
6559 }
6560 return 0;
6561 }
6562
6563 static noinline int invalidate_extent_cache(struct btrfs_root *root,
6564 struct extent_buffer *leaf,
6565 struct btrfs_block_group_cache *group,
6566 struct btrfs_root *target_root)
6567 {
6568 struct btrfs_key key;
6569 struct inode *inode = NULL;
6570 struct btrfs_file_extent_item *fi;
6571 struct extent_state *cached_state = NULL;
6572 u64 num_bytes;
6573 u64 skip_objectid = 0;
6574 u32 nritems;
6575 u32 i;
6576
6577 nritems = btrfs_header_nritems(leaf);
6578 for (i = 0; i < nritems; i++) {
6579 btrfs_item_key_to_cpu(leaf, &key, i);
6580 if (key.objectid == skip_objectid ||
6581 key.type != BTRFS_EXTENT_DATA_KEY)
6582 continue;
6583 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6584 if (btrfs_file_extent_type(leaf, fi) ==
6585 BTRFS_FILE_EXTENT_INLINE)
6586 continue;
6587 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
6588 continue;
6589 if (!inode || inode->i_ino != key.objectid) {
6590 iput(inode);
6591 inode = btrfs_ilookup(target_root->fs_info->sb,
6592 key.objectid, target_root, 1);
6593 }
6594 if (!inode) {
6595 skip_objectid = key.objectid;
6596 continue;
6597 }
6598 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6599
6600 lock_extent_bits(&BTRFS_I(inode)->io_tree, key.offset,
6601 key.offset + num_bytes - 1, 0, &cached_state,
6602 GFP_NOFS);
6603 btrfs_drop_extent_cache(inode, key.offset,
6604 key.offset + num_bytes - 1, 1);
6605 unlock_extent_cached(&BTRFS_I(inode)->io_tree, key.offset,
6606 key.offset + num_bytes - 1, &cached_state,
6607 GFP_NOFS);
6608 cond_resched();
6609 }
6610 iput(inode);
6611 return 0;
6612 }
6613
6614 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
6615 struct btrfs_root *root,
6616 struct extent_buffer *leaf,
6617 struct btrfs_block_group_cache *group,
6618 struct inode *reloc_inode)
6619 {
6620 struct btrfs_key key;
6621 struct btrfs_key extent_key;
6622 struct btrfs_file_extent_item *fi;
6623 struct btrfs_leaf_ref *ref;
6624 struct disk_extent *new_extent;
6625 u64 bytenr;
6626 u64 num_bytes;
6627 u32 nritems;
6628 u32 i;
6629 int ext_index;
6630 int nr_extent;
6631 int ret;
6632
6633 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
6634 BUG_ON(!new_extent);
6635
6636 ref = btrfs_lookup_leaf_ref(root, leaf->start);
6637 BUG_ON(!ref);
6638
6639 ext_index = -1;
6640 nritems = btrfs_header_nritems(leaf);
6641 for (i = 0; i < nritems; i++) {
6642 btrfs_item_key_to_cpu(leaf, &key, i);
6643 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
6644 continue;
6645 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6646 if (btrfs_file_extent_type(leaf, fi) ==
6647 BTRFS_FILE_EXTENT_INLINE)
6648 continue;
6649 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6650 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
6651 if (bytenr == 0)
6652 continue;
6653
6654 ext_index++;
6655 if (bytenr >= group->key.objectid + group->key.offset ||
6656 bytenr + num_bytes <= group->key.objectid)
6657 continue;
6658
6659 extent_key.objectid = bytenr;
6660 extent_key.offset = num_bytes;
6661 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
6662 nr_extent = 1;
6663 ret = get_new_locations(reloc_inode, &extent_key,
6664 group->key.objectid, 1,
6665 &new_extent, &nr_extent);
6666 if (ret > 0)
6667 continue;
6668 BUG_ON(ret < 0);
6669
6670 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
6671 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
6672 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
6673 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
6674
6675 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6676 new_extent->disk_bytenr);
6677 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6678 new_extent->disk_num_bytes);
6679 btrfs_mark_buffer_dirty(leaf);
6680
6681 ret = btrfs_inc_extent_ref(trans, root,
6682 new_extent->disk_bytenr,
6683 new_extent->disk_num_bytes,
6684 leaf->start,
6685 root->root_key.objectid,
6686 trans->transid, key.objectid);
6687 BUG_ON(ret);
6688
6689 ret = btrfs_free_extent(trans, root,
6690 bytenr, num_bytes, leaf->start,
6691 btrfs_header_owner(leaf),
6692 btrfs_header_generation(leaf),
6693 key.objectid, 0);
6694 BUG_ON(ret);
6695 cond_resched();
6696 }
6697 kfree(new_extent);
6698 BUG_ON(ext_index + 1 != ref->nritems);
6699 btrfs_free_leaf_ref(root, ref);
6700 return 0;
6701 }
6702
6703 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
6704 struct btrfs_root *root)
6705 {
6706 struct btrfs_root *reloc_root;
6707 int ret;
6708
6709 if (root->reloc_root) {
6710 reloc_root = root->reloc_root;
6711 root->reloc_root = NULL;
6712 list_add(&reloc_root->dead_list,
6713 &root->fs_info->dead_reloc_roots);
6714
6715 btrfs_set_root_bytenr(&reloc_root->root_item,
6716 reloc_root->node->start);
6717 btrfs_set_root_level(&root->root_item,
6718 btrfs_header_level(reloc_root->node));
6719 memset(&reloc_root->root_item.drop_progress, 0,
6720 sizeof(struct btrfs_disk_key));
6721 reloc_root->root_item.drop_level = 0;
6722
6723 ret = btrfs_update_root(trans, root->fs_info->tree_root,
6724 &reloc_root->root_key,
6725 &reloc_root->root_item);
6726 BUG_ON(ret);
6727 }
6728 return 0;
6729 }
6730
6731 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
6732 {
6733 struct btrfs_trans_handle *trans;
6734 struct btrfs_root *reloc_root;
6735 struct btrfs_root *prev_root = NULL;
6736 struct list_head dead_roots;
6737 int ret;
6738 unsigned long nr;
6739
6740 INIT_LIST_HEAD(&dead_roots);
6741 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
6742
6743 while (!list_empty(&dead_roots)) {
6744 reloc_root = list_entry(dead_roots.prev,
6745 struct btrfs_root, dead_list);
6746 list_del_init(&reloc_root->dead_list);
6747
6748 BUG_ON(reloc_root->commit_root != NULL);
6749 while (1) {
6750 trans = btrfs_join_transaction(root, 1);
6751 BUG_ON(!trans);
6752
6753 mutex_lock(&root->fs_info->drop_mutex);
6754 ret = btrfs_drop_snapshot(trans, reloc_root);
6755 if (ret != -EAGAIN)
6756 break;
6757 mutex_unlock(&root->fs_info->drop_mutex);
6758
6759 nr = trans->blocks_used;
6760 ret = btrfs_end_transaction(trans, root);
6761 BUG_ON(ret);
6762 btrfs_btree_balance_dirty(root, nr);
6763 }
6764
6765 free_extent_buffer(reloc_root->node);
6766
6767 ret = btrfs_del_root(trans, root->fs_info->tree_root,
6768 &reloc_root->root_key);
6769 BUG_ON(ret);
6770 mutex_unlock(&root->fs_info->drop_mutex);
6771
6772 nr = trans->blocks_used;
6773 ret = btrfs_end_transaction(trans, root);
6774 BUG_ON(ret);
6775 btrfs_btree_balance_dirty(root, nr);
6776
6777 kfree(prev_root);
6778 prev_root = reloc_root;
6779 }
6780 if (prev_root) {
6781 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
6782 kfree(prev_root);
6783 }
6784 return 0;
6785 }
6786
6787 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
6788 {
6789 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
6790 return 0;
6791 }
6792
6793 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
6794 {
6795 struct btrfs_root *reloc_root;
6796 struct btrfs_trans_handle *trans;
6797 struct btrfs_key location;
6798 int found;
6799 int ret;
6800
6801 mutex_lock(&root->fs_info->tree_reloc_mutex);
6802 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
6803 BUG_ON(ret);
6804 found = !list_empty(&root->fs_info->dead_reloc_roots);
6805 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6806
6807 if (found) {
6808 trans = btrfs_start_transaction(root, 1);
6809 BUG_ON(!trans);
6810 ret = btrfs_commit_transaction(trans, root);
6811 BUG_ON(ret);
6812 }
6813
6814 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
6815 location.offset = (u64)-1;
6816 location.type = BTRFS_ROOT_ITEM_KEY;
6817
6818 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
6819 BUG_ON(!reloc_root);
6820 btrfs_orphan_cleanup(reloc_root);
6821 return 0;
6822 }
6823
6824 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
6825 struct btrfs_root *root)
6826 {
6827 struct btrfs_root *reloc_root;
6828 struct extent_buffer *eb;
6829 struct btrfs_root_item *root_item;
6830 struct btrfs_key root_key;
6831 int ret;
6832
6833 BUG_ON(!root->ref_cows);
6834 if (root->reloc_root)
6835 return 0;
6836
6837 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
6838 BUG_ON(!root_item);
6839
6840 ret = btrfs_copy_root(trans, root, root->commit_root,
6841 &eb, BTRFS_TREE_RELOC_OBJECTID);
6842 BUG_ON(ret);
6843
6844 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
6845 root_key.offset = root->root_key.objectid;
6846 root_key.type = BTRFS_ROOT_ITEM_KEY;
6847
6848 memcpy(root_item, &root->root_item, sizeof(root_item));
6849 btrfs_set_root_refs(root_item, 0);
6850 btrfs_set_root_bytenr(root_item, eb->start);
6851 btrfs_set_root_level(root_item, btrfs_header_level(eb));
6852 btrfs_set_root_generation(root_item, trans->transid);
6853
6854 btrfs_tree_unlock(eb);
6855 free_extent_buffer(eb);
6856
6857 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
6858 &root_key, root_item);
6859 BUG_ON(ret);
6860 kfree(root_item);
6861
6862 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
6863 &root_key);
6864 BUG_ON(!reloc_root);
6865 reloc_root->last_trans = trans->transid;
6866 reloc_root->commit_root = NULL;
6867 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
6868
6869 root->reloc_root = reloc_root;
6870 return 0;
6871 }
6872
6873 /*
6874 * Core function of space balance.
6875 *
6876 * The idea is using reloc trees to relocate tree blocks in reference
6877 * counted roots. There is one reloc tree for each subvol, and all
6878 * reloc trees share same root key objectid. Reloc trees are snapshots
6879 * of the latest committed roots of subvols (root->commit_root).
6880 *
6881 * To relocate a tree block referenced by a subvol, there are two steps.
6882 * COW the block through subvol's reloc tree, then update block pointer
6883 * in the subvol to point to the new block. Since all reloc trees share
6884 * same root key objectid, doing special handing for tree blocks owned
6885 * by them is easy. Once a tree block has been COWed in one reloc tree,
6886 * we can use the resulting new block directly when the same block is
6887 * required to COW again through other reloc trees. By this way, relocated
6888 * tree blocks are shared between reloc trees, so they are also shared
6889 * between subvols.
6890 */
6891 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
6892 struct btrfs_root *root,
6893 struct btrfs_path *path,
6894 struct btrfs_key *first_key,
6895 struct btrfs_ref_path *ref_path,
6896 struct btrfs_block_group_cache *group,
6897 struct inode *reloc_inode)
6898 {
6899 struct btrfs_root *reloc_root;
6900 struct extent_buffer *eb = NULL;
6901 struct btrfs_key *keys;
6902 u64 *nodes;
6903 int level;
6904 int shared_level;
6905 int lowest_level = 0;
6906 int ret;
6907
6908 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
6909 lowest_level = ref_path->owner_objectid;
6910
6911 if (!root->ref_cows) {
6912 path->lowest_level = lowest_level;
6913 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
6914 BUG_ON(ret < 0);
6915 path->lowest_level = 0;
6916 btrfs_release_path(root, path);
6917 return 0;
6918 }
6919
6920 mutex_lock(&root->fs_info->tree_reloc_mutex);
6921 ret = init_reloc_tree(trans, root);
6922 BUG_ON(ret);
6923 reloc_root = root->reloc_root;
6924
6925 shared_level = ref_path->shared_level;
6926 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
6927
6928 keys = ref_path->node_keys;
6929 nodes = ref_path->new_nodes;
6930 memset(&keys[shared_level + 1], 0,
6931 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
6932 memset(&nodes[shared_level + 1], 0,
6933 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
6934
6935 if (nodes[lowest_level] == 0) {
6936 path->lowest_level = lowest_level;
6937 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6938 0, 1);
6939 BUG_ON(ret);
6940 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
6941 eb = path->nodes[level];
6942 if (!eb || eb == reloc_root->node)
6943 break;
6944 nodes[level] = eb->start;
6945 if (level == 0)
6946 btrfs_item_key_to_cpu(eb, &keys[level], 0);
6947 else
6948 btrfs_node_key_to_cpu(eb, &keys[level], 0);
6949 }
6950 if (nodes[0] &&
6951 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6952 eb = path->nodes[0];
6953 ret = replace_extents_in_leaf(trans, reloc_root, eb,
6954 group, reloc_inode);
6955 BUG_ON(ret);
6956 }
6957 btrfs_release_path(reloc_root, path);
6958 } else {
6959 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
6960 lowest_level);
6961 BUG_ON(ret);
6962 }
6963
6964 /*
6965 * replace tree blocks in the fs tree with tree blocks in
6966 * the reloc tree.
6967 */
6968 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
6969 BUG_ON(ret < 0);
6970
6971 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6972 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6973 0, 0);
6974 BUG_ON(ret);
6975 extent_buffer_get(path->nodes[0]);
6976 eb = path->nodes[0];
6977 btrfs_release_path(reloc_root, path);
6978 ret = invalidate_extent_cache(reloc_root, eb, group, root);
6979 BUG_ON(ret);
6980 free_extent_buffer(eb);
6981 }
6982
6983 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6984 path->lowest_level = 0;
6985 return 0;
6986 }
6987
6988 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
6989 struct btrfs_root *root,
6990 struct btrfs_path *path,
6991 struct btrfs_key *first_key,
6992 struct btrfs_ref_path *ref_path)
6993 {
6994 int ret;
6995
6996 ret = relocate_one_path(trans, root, path, first_key,
6997 ref_path, NULL, NULL);
6998 BUG_ON(ret);
6999
7000 return 0;
7001 }
7002
7003 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
7004 struct btrfs_root *extent_root,
7005 struct btrfs_path *path,
7006 struct btrfs_key *extent_key)
7007 {
7008 int ret;
7009
7010 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
7011 if (ret)
7012 goto out;
7013 ret = btrfs_del_item(trans, extent_root, path);
7014 out:
7015 btrfs_release_path(extent_root, path);
7016 return ret;
7017 }
7018
7019 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
7020 struct btrfs_ref_path *ref_path)
7021 {
7022 struct btrfs_key root_key;
7023
7024 root_key.objectid = ref_path->root_objectid;
7025 root_key.type = BTRFS_ROOT_ITEM_KEY;
7026 if (is_cowonly_root(ref_path->root_objectid))
7027 root_key.offset = 0;
7028 else
7029 root_key.offset = (u64)-1;
7030
7031 return btrfs_read_fs_root_no_name(fs_info, &root_key);
7032 }
7033
7034 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
7035 struct btrfs_path *path,
7036 struct btrfs_key *extent_key,
7037 struct btrfs_block_group_cache *group,
7038 struct inode *reloc_inode, int pass)
7039 {
7040 struct btrfs_trans_handle *trans;
7041 struct btrfs_root *found_root;
7042 struct btrfs_ref_path *ref_path = NULL;
7043 struct disk_extent *new_extents = NULL;
7044 int nr_extents = 0;
7045 int loops;
7046 int ret;
7047 int level;
7048 struct btrfs_key first_key;
7049 u64 prev_block = 0;
7050
7051
7052 trans = btrfs_start_transaction(extent_root, 1);
7053 BUG_ON(!trans);
7054
7055 if (extent_key->objectid == 0) {
7056 ret = del_extent_zero(trans, extent_root, path, extent_key);
7057 goto out;
7058 }
7059
7060 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
7061 if (!ref_path) {
7062 ret = -ENOMEM;
7063 goto out;
7064 }
7065
7066 for (loops = 0; ; loops++) {
7067 if (loops == 0) {
7068 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
7069 extent_key->objectid);
7070 } else {
7071 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
7072 }
7073 if (ret < 0)
7074 goto out;
7075 if (ret > 0)
7076 break;
7077
7078 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
7079 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
7080 continue;
7081
7082 found_root = read_ref_root(extent_root->fs_info, ref_path);
7083 BUG_ON(!found_root);
7084 /*
7085 * for reference counted tree, only process reference paths
7086 * rooted at the latest committed root.
7087 */
7088 if (found_root->ref_cows &&
7089 ref_path->root_generation != found_root->root_key.offset)
7090 continue;
7091
7092 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
7093 if (pass == 0) {
7094 /*
7095 * copy data extents to new locations
7096 */
7097 u64 group_start = group->key.objectid;
7098 ret = relocate_data_extent(reloc_inode,
7099 extent_key,
7100 group_start);
7101 if (ret < 0)
7102 goto out;
7103 break;
7104 }
7105 level = 0;
7106 } else {
7107 level = ref_path->owner_objectid;
7108 }
7109
7110 if (prev_block != ref_path->nodes[level]) {
7111 struct extent_buffer *eb;
7112 u64 block_start = ref_path->nodes[level];
7113 u64 block_size = btrfs_level_size(found_root, level);
7114
7115 eb = read_tree_block(found_root, block_start,
7116 block_size, 0);
7117 btrfs_tree_lock(eb);
7118 BUG_ON(level != btrfs_header_level(eb));
7119
7120 if (level == 0)
7121 btrfs_item_key_to_cpu(eb, &first_key, 0);
7122 else
7123 btrfs_node_key_to_cpu(eb, &first_key, 0);
7124
7125 btrfs_tree_unlock(eb);
7126 free_extent_buffer(eb);
7127 prev_block = block_start;
7128 }
7129
7130 mutex_lock(&extent_root->fs_info->trans_mutex);
7131 btrfs_record_root_in_trans(found_root);
7132 mutex_unlock(&extent_root->fs_info->trans_mutex);
7133 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
7134 /*
7135 * try to update data extent references while
7136 * keeping metadata shared between snapshots.
7137 */
7138 if (pass == 1) {
7139 ret = relocate_one_path(trans, found_root,
7140 path, &first_key, ref_path,
7141 group, reloc_inode);
7142 if (ret < 0)
7143 goto out;
7144 continue;
7145 }
7146 /*
7147 * use fallback method to process the remaining
7148 * references.
7149 */
7150 if (!new_extents) {
7151 u64 group_start = group->key.objectid;
7152 new_extents = kmalloc(sizeof(*new_extents),
7153 GFP_NOFS);
7154 nr_extents = 1;
7155 ret = get_new_locations(reloc_inode,
7156 extent_key,
7157 group_start, 1,
7158 &new_extents,
7159 &nr_extents);
7160 if (ret)
7161 goto out;
7162 }
7163 ret = replace_one_extent(trans, found_root,
7164 path, extent_key,
7165 &first_key, ref_path,
7166 new_extents, nr_extents);
7167 } else {
7168 ret = relocate_tree_block(trans, found_root, path,
7169 &first_key, ref_path);
7170 }
7171 if (ret < 0)
7172 goto out;
7173 }
7174 ret = 0;
7175 out:
7176 btrfs_end_transaction(trans, extent_root);
7177 kfree(new_extents);
7178 kfree(ref_path);
7179 return ret;
7180 }
7181 #endif
7182
7183 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
7184 {
7185 u64 num_devices;
7186 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
7187 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
7188
7189 num_devices = root->fs_info->fs_devices->rw_devices;
7190 if (num_devices == 1) {
7191 stripped |= BTRFS_BLOCK_GROUP_DUP;
7192 stripped = flags & ~stripped;
7193
7194 /* turn raid0 into single device chunks */
7195 if (flags & BTRFS_BLOCK_GROUP_RAID0)
7196 return stripped;
7197
7198 /* turn mirroring into duplication */
7199 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
7200 BTRFS_BLOCK_GROUP_RAID10))
7201 return stripped | BTRFS_BLOCK_GROUP_DUP;
7202 return flags;
7203 } else {
7204 /* they already had raid on here, just return */
7205 if (flags & stripped)
7206 return flags;
7207
7208 stripped |= BTRFS_BLOCK_GROUP_DUP;
7209 stripped = flags & ~stripped;
7210
7211 /* switch duplicated blocks with raid1 */
7212 if (flags & BTRFS_BLOCK_GROUP_DUP)
7213 return stripped | BTRFS_BLOCK_GROUP_RAID1;
7214
7215 /* turn single device chunks into raid0 */
7216 return stripped | BTRFS_BLOCK_GROUP_RAID0;
7217 }
7218 return flags;
7219 }
7220
7221 static int __alloc_chunk_for_shrink(struct btrfs_root *root,
7222 struct btrfs_block_group_cache *shrink_block_group,
7223 int force)
7224 {
7225 struct btrfs_trans_handle *trans;
7226 u64 new_alloc_flags;
7227 u64 calc;
7228
7229 spin_lock(&shrink_block_group->lock);
7230 if (btrfs_block_group_used(&shrink_block_group->item) +
7231 shrink_block_group->reserved > 0) {
7232 spin_unlock(&shrink_block_group->lock);
7233
7234 trans = btrfs_start_transaction(root, 1);
7235 spin_lock(&shrink_block_group->lock);
7236
7237 new_alloc_flags = update_block_group_flags(root,
7238 shrink_block_group->flags);
7239 if (new_alloc_flags != shrink_block_group->flags) {
7240 calc =
7241 btrfs_block_group_used(&shrink_block_group->item);
7242 } else {
7243 calc = shrink_block_group->key.offset;
7244 }
7245 spin_unlock(&shrink_block_group->lock);
7246
7247 do_chunk_alloc(trans, root->fs_info->extent_root,
7248 calc + 2 * 1024 * 1024, new_alloc_flags, force);
7249
7250 btrfs_end_transaction(trans, root);
7251 } else
7252 spin_unlock(&shrink_block_group->lock);
7253 return 0;
7254 }
7255
7256
7257 int btrfs_prepare_block_group_relocation(struct btrfs_root *root,
7258 struct btrfs_block_group_cache *group)
7259
7260 {
7261 __alloc_chunk_for_shrink(root, group, 1);
7262 set_block_group_readonly(group);
7263 return 0;
7264 }
7265
7266 /*
7267 * checks to see if its even possible to relocate this block group.
7268 *
7269 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
7270 * ok to go ahead and try.
7271 */
7272 int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
7273 {
7274 struct btrfs_block_group_cache *block_group;
7275 struct btrfs_space_info *space_info;
7276 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
7277 struct btrfs_device *device;
7278 int full = 0;
7279 int ret = 0;
7280
7281 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
7282
7283 /* odd, couldn't find the block group, leave it alone */
7284 if (!block_group)
7285 return -1;
7286
7287 /* no bytes used, we're good */
7288 if (!btrfs_block_group_used(&block_group->item))
7289 goto out;
7290
7291 space_info = block_group->space_info;
7292 spin_lock(&space_info->lock);
7293
7294 full = space_info->full;
7295
7296 /*
7297 * if this is the last block group we have in this space, we can't
7298 * relocate it unless we're able to allocate a new chunk below.
7299 *
7300 * Otherwise, we need to make sure we have room in the space to handle
7301 * all of the extents from this block group. If we can, we're good
7302 */
7303 if ((space_info->total_bytes != block_group->key.offset) &&
7304 (space_info->bytes_used + space_info->bytes_reserved +
7305 space_info->bytes_pinned + space_info->bytes_readonly +
7306 btrfs_block_group_used(&block_group->item) <
7307 space_info->total_bytes)) {
7308 spin_unlock(&space_info->lock);
7309 goto out;
7310 }
7311 spin_unlock(&space_info->lock);
7312
7313 /*
7314 * ok we don't have enough space, but maybe we have free space on our
7315 * devices to allocate new chunks for relocation, so loop through our
7316 * alloc devices and guess if we have enough space. However, if we
7317 * were marked as full, then we know there aren't enough chunks, and we
7318 * can just return.
7319 */
7320 ret = -1;
7321 if (full)
7322 goto out;
7323
7324 mutex_lock(&root->fs_info->chunk_mutex);
7325 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
7326 u64 min_free = btrfs_block_group_used(&block_group->item);
7327 u64 dev_offset, max_avail;
7328
7329 /*
7330 * check to make sure we can actually find a chunk with enough
7331 * space to fit our block group in.
7332 */
7333 if (device->total_bytes > device->bytes_used + min_free) {
7334 ret = find_free_dev_extent(NULL, device, min_free,
7335 &dev_offset, &max_avail);
7336 if (!ret)
7337 break;
7338 ret = -1;
7339 }
7340 }
7341 mutex_unlock(&root->fs_info->chunk_mutex);
7342 out:
7343 btrfs_put_block_group(block_group);
7344 return ret;
7345 }
7346
7347 static int find_first_block_group(struct btrfs_root *root,
7348 struct btrfs_path *path, struct btrfs_key *key)
7349 {
7350 int ret = 0;
7351 struct btrfs_key found_key;
7352 struct extent_buffer *leaf;
7353 int slot;
7354
7355 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
7356 if (ret < 0)
7357 goto out;
7358
7359 while (1) {
7360 slot = path->slots[0];
7361 leaf = path->nodes[0];
7362 if (slot >= btrfs_header_nritems(leaf)) {
7363 ret = btrfs_next_leaf(root, path);
7364 if (ret == 0)
7365 continue;
7366 if (ret < 0)
7367 goto out;
7368 break;
7369 }
7370 btrfs_item_key_to_cpu(leaf, &found_key, slot);
7371
7372 if (found_key.objectid >= key->objectid &&
7373 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
7374 ret = 0;
7375 goto out;
7376 }
7377 path->slots[0]++;
7378 }
7379 out:
7380 return ret;
7381 }
7382
7383 int btrfs_free_block_groups(struct btrfs_fs_info *info)
7384 {
7385 struct btrfs_block_group_cache *block_group;
7386 struct btrfs_space_info *space_info;
7387 struct btrfs_caching_control *caching_ctl;
7388 struct rb_node *n;
7389
7390 down_write(&info->extent_commit_sem);
7391 while (!list_empty(&info->caching_block_groups)) {
7392 caching_ctl = list_entry(info->caching_block_groups.next,
7393 struct btrfs_caching_control, list);
7394 list_del(&caching_ctl->list);
7395 put_caching_control(caching_ctl);
7396 }
7397 up_write(&info->extent_commit_sem);
7398
7399 spin_lock(&info->block_group_cache_lock);
7400 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
7401 block_group = rb_entry(n, struct btrfs_block_group_cache,
7402 cache_node);
7403 rb_erase(&block_group->cache_node,
7404 &info->block_group_cache_tree);
7405 spin_unlock(&info->block_group_cache_lock);
7406
7407 down_write(&block_group->space_info->groups_sem);
7408 list_del(&block_group->list);
7409 up_write(&block_group->space_info->groups_sem);
7410
7411 if (block_group->cached == BTRFS_CACHE_STARTED)
7412 wait_block_group_cache_done(block_group);
7413
7414 btrfs_remove_free_space_cache(block_group);
7415 btrfs_put_block_group(block_group);
7416
7417 spin_lock(&info->block_group_cache_lock);
7418 }
7419 spin_unlock(&info->block_group_cache_lock);
7420
7421 /* now that all the block groups are freed, go through and
7422 * free all the space_info structs. This is only called during
7423 * the final stages of unmount, and so we know nobody is
7424 * using them. We call synchronize_rcu() once before we start,
7425 * just to be on the safe side.
7426 */
7427 synchronize_rcu();
7428
7429 while(!list_empty(&info->space_info)) {
7430 space_info = list_entry(info->space_info.next,
7431 struct btrfs_space_info,
7432 list);
7433
7434 list_del(&space_info->list);
7435 kfree(space_info);
7436 }
7437 return 0;
7438 }
7439
7440 int btrfs_read_block_groups(struct btrfs_root *root)
7441 {
7442 struct btrfs_path *path;
7443 int ret;
7444 struct btrfs_block_group_cache *cache;
7445 struct btrfs_fs_info *info = root->fs_info;
7446 struct btrfs_space_info *space_info;
7447 struct btrfs_key key;
7448 struct btrfs_key found_key;
7449 struct extent_buffer *leaf;
7450
7451 root = info->extent_root;
7452 key.objectid = 0;
7453 key.offset = 0;
7454 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
7455 path = btrfs_alloc_path();
7456 if (!path)
7457 return -ENOMEM;
7458
7459 while (1) {
7460 ret = find_first_block_group(root, path, &key);
7461 if (ret > 0) {
7462 ret = 0;
7463 goto error;
7464 }
7465 if (ret != 0)
7466 goto error;
7467
7468 leaf = path->nodes[0];
7469 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7470 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7471 if (!cache) {
7472 ret = -ENOMEM;
7473 break;
7474 }
7475
7476 atomic_set(&cache->count, 1);
7477 spin_lock_init(&cache->lock);
7478 spin_lock_init(&cache->tree_lock);
7479 cache->fs_info = info;
7480 INIT_LIST_HEAD(&cache->list);
7481 INIT_LIST_HEAD(&cache->cluster_list);
7482
7483 /*
7484 * we only want to have 32k of ram per block group for keeping
7485 * track of free space, and if we pass 1/2 of that we want to
7486 * start converting things over to using bitmaps
7487 */
7488 cache->extents_thresh = ((1024 * 32) / 2) /
7489 sizeof(struct btrfs_free_space);
7490
7491 read_extent_buffer(leaf, &cache->item,
7492 btrfs_item_ptr_offset(leaf, path->slots[0]),
7493 sizeof(cache->item));
7494 memcpy(&cache->key, &found_key, sizeof(found_key));
7495
7496 key.objectid = found_key.objectid + found_key.offset;
7497 btrfs_release_path(root, path);
7498 cache->flags = btrfs_block_group_flags(&cache->item);
7499 cache->sectorsize = root->sectorsize;
7500
7501 /*
7502 * check for two cases, either we are full, and therefore
7503 * don't need to bother with the caching work since we won't
7504 * find any space, or we are empty, and we can just add all
7505 * the space in and be done with it. This saves us _alot_ of
7506 * time, particularly in the full case.
7507 */
7508 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
7509 exclude_super_stripes(root, cache);
7510 cache->last_byte_to_unpin = (u64)-1;
7511 cache->cached = BTRFS_CACHE_FINISHED;
7512 free_excluded_extents(root, cache);
7513 } else if (btrfs_block_group_used(&cache->item) == 0) {
7514 exclude_super_stripes(root, cache);
7515 cache->last_byte_to_unpin = (u64)-1;
7516 cache->cached = BTRFS_CACHE_FINISHED;
7517 add_new_free_space(cache, root->fs_info,
7518 found_key.objectid,
7519 found_key.objectid +
7520 found_key.offset);
7521 free_excluded_extents(root, cache);
7522 }
7523
7524 ret = update_space_info(info, cache->flags, found_key.offset,
7525 btrfs_block_group_used(&cache->item),
7526 &space_info);
7527 BUG_ON(ret);
7528 cache->space_info = space_info;
7529 spin_lock(&cache->space_info->lock);
7530 cache->space_info->bytes_super += cache->bytes_super;
7531 spin_unlock(&cache->space_info->lock);
7532
7533 down_write(&space_info->groups_sem);
7534 list_add_tail(&cache->list, &space_info->block_groups);
7535 up_write(&space_info->groups_sem);
7536
7537 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7538 BUG_ON(ret);
7539
7540 set_avail_alloc_bits(root->fs_info, cache->flags);
7541 if (btrfs_chunk_readonly(root, cache->key.objectid))
7542 set_block_group_readonly(cache);
7543 }
7544 ret = 0;
7545 error:
7546 btrfs_free_path(path);
7547 return ret;
7548 }
7549
7550 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
7551 struct btrfs_root *root, u64 bytes_used,
7552 u64 type, u64 chunk_objectid, u64 chunk_offset,
7553 u64 size)
7554 {
7555 int ret;
7556 struct btrfs_root *extent_root;
7557 struct btrfs_block_group_cache *cache;
7558
7559 extent_root = root->fs_info->extent_root;
7560
7561 root->fs_info->last_trans_log_full_commit = trans->transid;
7562
7563 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7564 if (!cache)
7565 return -ENOMEM;
7566
7567 cache->key.objectid = chunk_offset;
7568 cache->key.offset = size;
7569 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
7570 cache->sectorsize = root->sectorsize;
7571
7572 /*
7573 * we only want to have 32k of ram per block group for keeping track
7574 * of free space, and if we pass 1/2 of that we want to start
7575 * converting things over to using bitmaps
7576 */
7577 cache->extents_thresh = ((1024 * 32) / 2) /
7578 sizeof(struct btrfs_free_space);
7579 atomic_set(&cache->count, 1);
7580 spin_lock_init(&cache->lock);
7581 spin_lock_init(&cache->tree_lock);
7582 INIT_LIST_HEAD(&cache->list);
7583 INIT_LIST_HEAD(&cache->cluster_list);
7584
7585 btrfs_set_block_group_used(&cache->item, bytes_used);
7586 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
7587 cache->flags = type;
7588 btrfs_set_block_group_flags(&cache->item, type);
7589
7590 cache->last_byte_to_unpin = (u64)-1;
7591 cache->cached = BTRFS_CACHE_FINISHED;
7592 exclude_super_stripes(root, cache);
7593
7594 add_new_free_space(cache, root->fs_info, chunk_offset,
7595 chunk_offset + size);
7596
7597 free_excluded_extents(root, cache);
7598
7599 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
7600 &cache->space_info);
7601 BUG_ON(ret);
7602
7603 spin_lock(&cache->space_info->lock);
7604 cache->space_info->bytes_super += cache->bytes_super;
7605 spin_unlock(&cache->space_info->lock);
7606
7607 down_write(&cache->space_info->groups_sem);
7608 list_add_tail(&cache->list, &cache->space_info->block_groups);
7609 up_write(&cache->space_info->groups_sem);
7610
7611 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7612 BUG_ON(ret);
7613
7614 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
7615 sizeof(cache->item));
7616 BUG_ON(ret);
7617
7618 set_avail_alloc_bits(extent_root->fs_info, type);
7619
7620 return 0;
7621 }
7622
7623 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
7624 struct btrfs_root *root, u64 group_start)
7625 {
7626 struct btrfs_path *path;
7627 struct btrfs_block_group_cache *block_group;
7628 struct btrfs_free_cluster *cluster;
7629 struct btrfs_key key;
7630 int ret;
7631
7632 root = root->fs_info->extent_root;
7633
7634 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
7635 BUG_ON(!block_group);
7636 BUG_ON(!block_group->ro);
7637
7638 memcpy(&key, &block_group->key, sizeof(key));
7639
7640 /* make sure this block group isn't part of an allocation cluster */
7641 cluster = &root->fs_info->data_alloc_cluster;
7642 spin_lock(&cluster->refill_lock);
7643 btrfs_return_cluster_to_free_space(block_group, cluster);
7644 spin_unlock(&cluster->refill_lock);
7645
7646 /*
7647 * make sure this block group isn't part of a metadata
7648 * allocation cluster
7649 */
7650 cluster = &root->fs_info->meta_alloc_cluster;
7651 spin_lock(&cluster->refill_lock);
7652 btrfs_return_cluster_to_free_space(block_group, cluster);
7653 spin_unlock(&cluster->refill_lock);
7654
7655 path = btrfs_alloc_path();
7656 BUG_ON(!path);
7657
7658 spin_lock(&root->fs_info->block_group_cache_lock);
7659 rb_erase(&block_group->cache_node,
7660 &root->fs_info->block_group_cache_tree);
7661 spin_unlock(&root->fs_info->block_group_cache_lock);
7662
7663 down_write(&block_group->space_info->groups_sem);
7664 /*
7665 * we must use list_del_init so people can check to see if they
7666 * are still on the list after taking the semaphore
7667 */
7668 list_del_init(&block_group->list);
7669 up_write(&block_group->space_info->groups_sem);
7670
7671 if (block_group->cached == BTRFS_CACHE_STARTED)
7672 wait_block_group_cache_done(block_group);
7673
7674 btrfs_remove_free_space_cache(block_group);
7675
7676 spin_lock(&block_group->space_info->lock);
7677 block_group->space_info->total_bytes -= block_group->key.offset;
7678 block_group->space_info->bytes_readonly -= block_group->key.offset;
7679 spin_unlock(&block_group->space_info->lock);
7680
7681 btrfs_clear_space_info_full(root->fs_info);
7682
7683 btrfs_put_block_group(block_group);
7684 btrfs_put_block_group(block_group);
7685
7686 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
7687 if (ret > 0)
7688 ret = -EIO;
7689 if (ret < 0)
7690 goto out;
7691
7692 ret = btrfs_del_item(trans, root, path);
7693 out:
7694 btrfs_free_path(path);
7695 return ret;
7696 }
Linux kernel - Deliverables
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