Btrfs: account for space used by the super mirrors
[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
72 static noinline int
73 block_group_cache_done(struct btrfs_block_group_cache *cache)
74 {
75 smp_mb();
76 return cache->cached == BTRFS_CACHE_FINISHED;
77 }
78
79 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
80 {
81 return (cache->flags & bits) == bits;
82 }
83
84 /*
85 * this adds the block group to the fs_info rb tree for the block group
86 * cache
87 */
88 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
89 struct btrfs_block_group_cache *block_group)
90 {
91 struct rb_node **p;
92 struct rb_node *parent = NULL;
93 struct btrfs_block_group_cache *cache;
94
95 spin_lock(&info->block_group_cache_lock);
96 p = &info->block_group_cache_tree.rb_node;
97
98 while (*p) {
99 parent = *p;
100 cache = rb_entry(parent, struct btrfs_block_group_cache,
101 cache_node);
102 if (block_group->key.objectid < cache->key.objectid) {
103 p = &(*p)->rb_left;
104 } else if (block_group->key.objectid > cache->key.objectid) {
105 p = &(*p)->rb_right;
106 } else {
107 spin_unlock(&info->block_group_cache_lock);
108 return -EEXIST;
109 }
110 }
111
112 rb_link_node(&block_group->cache_node, parent, p);
113 rb_insert_color(&block_group->cache_node,
114 &info->block_group_cache_tree);
115 spin_unlock(&info->block_group_cache_lock);
116
117 return 0;
118 }
119
120 /*
121 * This will return the block group at or after bytenr if contains is 0, else
122 * it will return the block group that contains the bytenr
123 */
124 static struct btrfs_block_group_cache *
125 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
126 int contains)
127 {
128 struct btrfs_block_group_cache *cache, *ret = NULL;
129 struct rb_node *n;
130 u64 end, start;
131
132 spin_lock(&info->block_group_cache_lock);
133 n = info->block_group_cache_tree.rb_node;
134
135 while (n) {
136 cache = rb_entry(n, struct btrfs_block_group_cache,
137 cache_node);
138 end = cache->key.objectid + cache->key.offset - 1;
139 start = cache->key.objectid;
140
141 if (bytenr < start) {
142 if (!contains && (!ret || start < ret->key.objectid))
143 ret = cache;
144 n = n->rb_left;
145 } else if (bytenr > start) {
146 if (contains && bytenr <= end) {
147 ret = cache;
148 break;
149 }
150 n = n->rb_right;
151 } else {
152 ret = cache;
153 break;
154 }
155 }
156 if (ret)
157 atomic_inc(&ret->count);
158 spin_unlock(&info->block_group_cache_lock);
159
160 return ret;
161 }
162
163 static int add_excluded_extent(struct btrfs_root *root,
164 u64 start, u64 num_bytes)
165 {
166 u64 end = start + num_bytes - 1;
167 set_extent_bits(&root->fs_info->freed_extents[0],
168 start, end, EXTENT_UPTODATE, GFP_NOFS);
169 set_extent_bits(&root->fs_info->freed_extents[1],
170 start, end, EXTENT_UPTODATE, GFP_NOFS);
171 return 0;
172 }
173
174 static void free_excluded_extents(struct btrfs_root *root,
175 struct btrfs_block_group_cache *cache)
176 {
177 u64 start, end;
178
179 start = cache->key.objectid;
180 end = start + cache->key.offset - 1;
181
182 clear_extent_bits(&root->fs_info->freed_extents[0],
183 start, end, EXTENT_UPTODATE, GFP_NOFS);
184 clear_extent_bits(&root->fs_info->freed_extents[1],
185 start, end, EXTENT_UPTODATE, GFP_NOFS);
186 }
187
188 static int exclude_super_stripes(struct btrfs_root *root,
189 struct btrfs_block_group_cache *cache)
190 {
191 u64 bytenr;
192 u64 *logical;
193 int stripe_len;
194 int i, nr, ret;
195
196 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
197 bytenr = btrfs_sb_offset(i);
198 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
199 cache->key.objectid, bytenr,
200 0, &logical, &nr, &stripe_len);
201 BUG_ON(ret);
202
203 while (nr--) {
204 cache->bytes_super += stripe_len;
205 ret = add_excluded_extent(root, logical[nr],
206 stripe_len);
207 BUG_ON(ret);
208 }
209
210 kfree(logical);
211 }
212 return 0;
213 }
214
215 static struct btrfs_caching_control *
216 get_caching_control(struct btrfs_block_group_cache *cache)
217 {
218 struct btrfs_caching_control *ctl;
219
220 spin_lock(&cache->lock);
221 if (cache->cached != BTRFS_CACHE_STARTED) {
222 spin_unlock(&cache->lock);
223 return NULL;
224 }
225
226 ctl = cache->caching_ctl;
227 atomic_inc(&ctl->count);
228 spin_unlock(&cache->lock);
229 return ctl;
230 }
231
232 static void put_caching_control(struct btrfs_caching_control *ctl)
233 {
234 if (atomic_dec_and_test(&ctl->count))
235 kfree(ctl);
236 }
237
238 /*
239 * this is only called by cache_block_group, since we could have freed extents
240 * we need to check the pinned_extents for any extents that can't be used yet
241 * since their free space will be released as soon as the transaction commits.
242 */
243 static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
244 struct btrfs_fs_info *info, u64 start, u64 end)
245 {
246 u64 extent_start, extent_end, size, total_added = 0;
247 int ret;
248
249 while (start < end) {
250 ret = find_first_extent_bit(info->pinned_extents, start,
251 &extent_start, &extent_end,
252 EXTENT_DIRTY | EXTENT_UPTODATE);
253 if (ret)
254 break;
255
256 if (extent_start == start) {
257 start = extent_end + 1;
258 } else if (extent_start > start && extent_start < end) {
259 size = extent_start - start;
260 total_added += size;
261 ret = btrfs_add_free_space(block_group, start,
262 size);
263 BUG_ON(ret);
264 start = extent_end + 1;
265 } else {
266 break;
267 }
268 }
269
270 if (start < end) {
271 size = end - start;
272 total_added += size;
273 ret = btrfs_add_free_space(block_group, start, size);
274 BUG_ON(ret);
275 }
276
277 return total_added;
278 }
279
280 static int caching_kthread(void *data)
281 {
282 struct btrfs_block_group_cache *block_group = data;
283 struct btrfs_fs_info *fs_info = block_group->fs_info;
284 struct btrfs_caching_control *caching_ctl = block_group->caching_ctl;
285 struct btrfs_root *extent_root = fs_info->extent_root;
286 struct btrfs_path *path;
287 struct extent_buffer *leaf;
288 struct btrfs_key key;
289 u64 total_found = 0;
290 u64 last = 0;
291 u32 nritems;
292 int ret = 0;
293
294 path = btrfs_alloc_path();
295 if (!path)
296 return -ENOMEM;
297
298 exclude_super_stripes(extent_root, block_group);
299 spin_lock(&block_group->space_info->lock);
300 block_group->space_info->bytes_super += block_group->bytes_super;
301 spin_unlock(&block_group->space_info->lock);
302
303 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
304
305 /*
306 * We don't want to deadlock with somebody trying to allocate a new
307 * extent for the extent root while also trying to search the extent
308 * root to add free space. So we skip locking and search the commit
309 * root, since its read-only
310 */
311 path->skip_locking = 1;
312 path->search_commit_root = 1;
313 path->reada = 2;
314
315 key.objectid = last;
316 key.offset = 0;
317 key.type = BTRFS_EXTENT_ITEM_KEY;
318 again:
319 mutex_lock(&caching_ctl->mutex);
320 /* need to make sure the commit_root doesn't disappear */
321 down_read(&fs_info->extent_commit_sem);
322
323 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
324 if (ret < 0)
325 goto err;
326
327 leaf = path->nodes[0];
328 nritems = btrfs_header_nritems(leaf);
329
330 while (1) {
331 smp_mb();
332 if (fs_info->closing > 1) {
333 last = (u64)-1;
334 break;
335 }
336
337 if (path->slots[0] < nritems) {
338 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
339 } else {
340 ret = find_next_key(path, 0, &key);
341 if (ret)
342 break;
343
344 caching_ctl->progress = last;
345 btrfs_release_path(extent_root, path);
346 up_read(&fs_info->extent_commit_sem);
347 mutex_unlock(&caching_ctl->mutex);
348 if (btrfs_transaction_in_commit(fs_info))
349 schedule_timeout(1);
350 else
351 cond_resched();
352 goto again;
353 }
354
355 if (key.objectid < block_group->key.objectid) {
356 path->slots[0]++;
357 continue;
358 }
359
360 if (key.objectid >= block_group->key.objectid +
361 block_group->key.offset)
362 break;
363
364 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
365 total_found += add_new_free_space(block_group,
366 fs_info, last,
367 key.objectid);
368 last = key.objectid + key.offset;
369
370 if (total_found > (1024 * 1024 * 2)) {
371 total_found = 0;
372 wake_up(&caching_ctl->wait);
373 }
374 }
375 path->slots[0]++;
376 }
377 ret = 0;
378
379 total_found += add_new_free_space(block_group, fs_info, last,
380 block_group->key.objectid +
381 block_group->key.offset);
382 caching_ctl->progress = (u64)-1;
383
384 spin_lock(&block_group->lock);
385 block_group->caching_ctl = NULL;
386 block_group->cached = BTRFS_CACHE_FINISHED;
387 spin_unlock(&block_group->lock);
388
389 err:
390 btrfs_free_path(path);
391 up_read(&fs_info->extent_commit_sem);
392
393 free_excluded_extents(extent_root, block_group);
394
395 mutex_unlock(&caching_ctl->mutex);
396 wake_up(&caching_ctl->wait);
397
398 put_caching_control(caching_ctl);
399 atomic_dec(&block_group->space_info->caching_threads);
400 return 0;
401 }
402
403 static int cache_block_group(struct btrfs_block_group_cache *cache)
404 {
405 struct btrfs_fs_info *fs_info = cache->fs_info;
406 struct btrfs_caching_control *caching_ctl;
407 struct task_struct *tsk;
408 int ret = 0;
409
410 smp_mb();
411 if (cache->cached != BTRFS_CACHE_NO)
412 return 0;
413
414 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_KERNEL);
415 BUG_ON(!caching_ctl);
416
417 INIT_LIST_HEAD(&caching_ctl->list);
418 mutex_init(&caching_ctl->mutex);
419 init_waitqueue_head(&caching_ctl->wait);
420 caching_ctl->block_group = cache;
421 caching_ctl->progress = cache->key.objectid;
422 /* one for caching kthread, one for caching block group list */
423 atomic_set(&caching_ctl->count, 2);
424
425 spin_lock(&cache->lock);
426 if (cache->cached != BTRFS_CACHE_NO) {
427 spin_unlock(&cache->lock);
428 kfree(caching_ctl);
429 return 0;
430 }
431 cache->caching_ctl = caching_ctl;
432 cache->cached = BTRFS_CACHE_STARTED;
433 spin_unlock(&cache->lock);
434
435 down_write(&fs_info->extent_commit_sem);
436 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
437 up_write(&fs_info->extent_commit_sem);
438
439 atomic_inc(&cache->space_info->caching_threads);
440
441 tsk = kthread_run(caching_kthread, cache, "btrfs-cache-%llu\n",
442 cache->key.objectid);
443 if (IS_ERR(tsk)) {
444 ret = PTR_ERR(tsk);
445 printk(KERN_ERR "error running thread %d\n", ret);
446 BUG();
447 }
448
449 return ret;
450 }
451
452 /*
453 * return the block group that starts at or after bytenr
454 */
455 static struct btrfs_block_group_cache *
456 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
457 {
458 struct btrfs_block_group_cache *cache;
459
460 cache = block_group_cache_tree_search(info, bytenr, 0);
461
462 return cache;
463 }
464
465 /*
466 * return the block group that contains the given bytenr
467 */
468 struct btrfs_block_group_cache *btrfs_lookup_block_group(
469 struct btrfs_fs_info *info,
470 u64 bytenr)
471 {
472 struct btrfs_block_group_cache *cache;
473
474 cache = block_group_cache_tree_search(info, bytenr, 1);
475
476 return cache;
477 }
478
479 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
480 {
481 if (atomic_dec_and_test(&cache->count))
482 kfree(cache);
483 }
484
485 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
486 u64 flags)
487 {
488 struct list_head *head = &info->space_info;
489 struct btrfs_space_info *found;
490
491 rcu_read_lock();
492 list_for_each_entry_rcu(found, head, list) {
493 if (found->flags == flags) {
494 rcu_read_unlock();
495 return found;
496 }
497 }
498 rcu_read_unlock();
499 return NULL;
500 }
501
502 /*
503 * after adding space to the filesystem, we need to clear the full flags
504 * on all the space infos.
505 */
506 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
507 {
508 struct list_head *head = &info->space_info;
509 struct btrfs_space_info *found;
510
511 rcu_read_lock();
512 list_for_each_entry_rcu(found, head, list)
513 found->full = 0;
514 rcu_read_unlock();
515 }
516
517 static u64 div_factor(u64 num, int factor)
518 {
519 if (factor == 10)
520 return num;
521 num *= factor;
522 do_div(num, 10);
523 return num;
524 }
525
526 u64 btrfs_find_block_group(struct btrfs_root *root,
527 u64 search_start, u64 search_hint, int owner)
528 {
529 struct btrfs_block_group_cache *cache;
530 u64 used;
531 u64 last = max(search_hint, search_start);
532 u64 group_start = 0;
533 int full_search = 0;
534 int factor = 9;
535 int wrapped = 0;
536 again:
537 while (1) {
538 cache = btrfs_lookup_first_block_group(root->fs_info, last);
539 if (!cache)
540 break;
541
542 spin_lock(&cache->lock);
543 last = cache->key.objectid + cache->key.offset;
544 used = btrfs_block_group_used(&cache->item);
545
546 if ((full_search || !cache->ro) &&
547 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
548 if (used + cache->pinned + cache->reserved <
549 div_factor(cache->key.offset, factor)) {
550 group_start = cache->key.objectid;
551 spin_unlock(&cache->lock);
552 btrfs_put_block_group(cache);
553 goto found;
554 }
555 }
556 spin_unlock(&cache->lock);
557 btrfs_put_block_group(cache);
558 cond_resched();
559 }
560 if (!wrapped) {
561 last = search_start;
562 wrapped = 1;
563 goto again;
564 }
565 if (!full_search && factor < 10) {
566 last = search_start;
567 full_search = 1;
568 factor = 10;
569 goto again;
570 }
571 found:
572 return group_start;
573 }
574
575 /* simple helper to search for an existing extent at a given offset */
576 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
577 {
578 int ret;
579 struct btrfs_key key;
580 struct btrfs_path *path;
581
582 path = btrfs_alloc_path();
583 BUG_ON(!path);
584 key.objectid = start;
585 key.offset = len;
586 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
587 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
588 0, 0);
589 btrfs_free_path(path);
590 return ret;
591 }
592
593 /*
594 * Back reference rules. Back refs have three main goals:
595 *
596 * 1) differentiate between all holders of references to an extent so that
597 * when a reference is dropped we can make sure it was a valid reference
598 * before freeing the extent.
599 *
600 * 2) Provide enough information to quickly find the holders of an extent
601 * if we notice a given block is corrupted or bad.
602 *
603 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
604 * maintenance. This is actually the same as #2, but with a slightly
605 * different use case.
606 *
607 * There are two kinds of back refs. The implicit back refs is optimized
608 * for pointers in non-shared tree blocks. For a given pointer in a block,
609 * back refs of this kind provide information about the block's owner tree
610 * and the pointer's key. These information allow us to find the block by
611 * b-tree searching. The full back refs is for pointers in tree blocks not
612 * referenced by their owner trees. The location of tree block is recorded
613 * in the back refs. Actually the full back refs is generic, and can be
614 * used in all cases the implicit back refs is used. The major shortcoming
615 * of the full back refs is its overhead. Every time a tree block gets
616 * COWed, we have to update back refs entry for all pointers in it.
617 *
618 * For a newly allocated tree block, we use implicit back refs for
619 * pointers in it. This means most tree related operations only involve
620 * implicit back refs. For a tree block created in old transaction, the
621 * only way to drop a reference to it is COW it. So we can detect the
622 * event that tree block loses its owner tree's reference and do the
623 * back refs conversion.
624 *
625 * When a tree block is COW'd through a tree, there are four cases:
626 *
627 * The reference count of the block is one and the tree is the block's
628 * owner tree. Nothing to do in this case.
629 *
630 * The reference count of the block is one and the tree is not the
631 * block's owner tree. In this case, full back refs is used for pointers
632 * in the block. Remove these full back refs, add implicit back refs for
633 * every pointers in the new block.
634 *
635 * The reference count of the block is greater than one and the tree is
636 * the block's owner tree. In this case, implicit back refs is used for
637 * pointers in the block. Add full back refs for every pointers in the
638 * block, increase lower level extents' reference counts. The original
639 * implicit back refs are entailed to the new block.
640 *
641 * The reference count of the block is greater than one and the tree is
642 * not the block's owner tree. Add implicit back refs for every pointer in
643 * the new block, increase lower level extents' reference count.
644 *
645 * Back Reference Key composing:
646 *
647 * The key objectid corresponds to the first byte in the extent,
648 * The key type is used to differentiate between types of back refs.
649 * There are different meanings of the key offset for different types
650 * of back refs.
651 *
652 * File extents can be referenced by:
653 *
654 * - multiple snapshots, subvolumes, or different generations in one subvol
655 * - different files inside a single subvolume
656 * - different offsets inside a file (bookend extents in file.c)
657 *
658 * The extent ref structure for the implicit back refs has fields for:
659 *
660 * - Objectid of the subvolume root
661 * - objectid of the file holding the reference
662 * - original offset in the file
663 * - how many bookend extents
664 *
665 * The key offset for the implicit back refs is hash of the first
666 * three fields.
667 *
668 * The extent ref structure for the full back refs has field for:
669 *
670 * - number of pointers in the tree leaf
671 *
672 * The key offset for the implicit back refs is the first byte of
673 * the tree leaf
674 *
675 * When a file extent is allocated, The implicit back refs is used.
676 * the fields are filled in:
677 *
678 * (root_key.objectid, inode objectid, offset in file, 1)
679 *
680 * When a file extent is removed file truncation, we find the
681 * corresponding implicit back refs and check the following fields:
682 *
683 * (btrfs_header_owner(leaf), inode objectid, offset in file)
684 *
685 * Btree extents can be referenced by:
686 *
687 * - Different subvolumes
688 *
689 * Both the implicit back refs and the full back refs for tree blocks
690 * only consist of key. The key offset for the implicit back refs is
691 * objectid of block's owner tree. The key offset for the full back refs
692 * is the first byte of parent block.
693 *
694 * When implicit back refs is used, information about the lowest key and
695 * level of the tree block are required. These information are stored in
696 * tree block info structure.
697 */
698
699 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
700 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
701 struct btrfs_root *root,
702 struct btrfs_path *path,
703 u64 owner, u32 extra_size)
704 {
705 struct btrfs_extent_item *item;
706 struct btrfs_extent_item_v0 *ei0;
707 struct btrfs_extent_ref_v0 *ref0;
708 struct btrfs_tree_block_info *bi;
709 struct extent_buffer *leaf;
710 struct btrfs_key key;
711 struct btrfs_key found_key;
712 u32 new_size = sizeof(*item);
713 u64 refs;
714 int ret;
715
716 leaf = path->nodes[0];
717 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
718
719 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
720 ei0 = btrfs_item_ptr(leaf, path->slots[0],
721 struct btrfs_extent_item_v0);
722 refs = btrfs_extent_refs_v0(leaf, ei0);
723
724 if (owner == (u64)-1) {
725 while (1) {
726 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
727 ret = btrfs_next_leaf(root, path);
728 if (ret < 0)
729 return ret;
730 BUG_ON(ret > 0);
731 leaf = path->nodes[0];
732 }
733 btrfs_item_key_to_cpu(leaf, &found_key,
734 path->slots[0]);
735 BUG_ON(key.objectid != found_key.objectid);
736 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
737 path->slots[0]++;
738 continue;
739 }
740 ref0 = btrfs_item_ptr(leaf, path->slots[0],
741 struct btrfs_extent_ref_v0);
742 owner = btrfs_ref_objectid_v0(leaf, ref0);
743 break;
744 }
745 }
746 btrfs_release_path(root, path);
747
748 if (owner < BTRFS_FIRST_FREE_OBJECTID)
749 new_size += sizeof(*bi);
750
751 new_size -= sizeof(*ei0);
752 ret = btrfs_search_slot(trans, root, &key, path,
753 new_size + extra_size, 1);
754 if (ret < 0)
755 return ret;
756 BUG_ON(ret);
757
758 ret = btrfs_extend_item(trans, root, path, new_size);
759 BUG_ON(ret);
760
761 leaf = path->nodes[0];
762 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
763 btrfs_set_extent_refs(leaf, item, refs);
764 /* FIXME: get real generation */
765 btrfs_set_extent_generation(leaf, item, 0);
766 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
767 btrfs_set_extent_flags(leaf, item,
768 BTRFS_EXTENT_FLAG_TREE_BLOCK |
769 BTRFS_BLOCK_FLAG_FULL_BACKREF);
770 bi = (struct btrfs_tree_block_info *)(item + 1);
771 /* FIXME: get first key of the block */
772 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
773 btrfs_set_tree_block_level(leaf, bi, (int)owner);
774 } else {
775 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
776 }
777 btrfs_mark_buffer_dirty(leaf);
778 return 0;
779 }
780 #endif
781
782 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
783 {
784 u32 high_crc = ~(u32)0;
785 u32 low_crc = ~(u32)0;
786 __le64 lenum;
787
788 lenum = cpu_to_le64(root_objectid);
789 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
790 lenum = cpu_to_le64(owner);
791 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
792 lenum = cpu_to_le64(offset);
793 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
794
795 return ((u64)high_crc << 31) ^ (u64)low_crc;
796 }
797
798 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
799 struct btrfs_extent_data_ref *ref)
800 {
801 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
802 btrfs_extent_data_ref_objectid(leaf, ref),
803 btrfs_extent_data_ref_offset(leaf, ref));
804 }
805
806 static int match_extent_data_ref(struct extent_buffer *leaf,
807 struct btrfs_extent_data_ref *ref,
808 u64 root_objectid, u64 owner, u64 offset)
809 {
810 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
811 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
812 btrfs_extent_data_ref_offset(leaf, ref) != offset)
813 return 0;
814 return 1;
815 }
816
817 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
818 struct btrfs_root *root,
819 struct btrfs_path *path,
820 u64 bytenr, u64 parent,
821 u64 root_objectid,
822 u64 owner, u64 offset)
823 {
824 struct btrfs_key key;
825 struct btrfs_extent_data_ref *ref;
826 struct extent_buffer *leaf;
827 u32 nritems;
828 int ret;
829 int recow;
830 int err = -ENOENT;
831
832 key.objectid = bytenr;
833 if (parent) {
834 key.type = BTRFS_SHARED_DATA_REF_KEY;
835 key.offset = parent;
836 } else {
837 key.type = BTRFS_EXTENT_DATA_REF_KEY;
838 key.offset = hash_extent_data_ref(root_objectid,
839 owner, offset);
840 }
841 again:
842 recow = 0;
843 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
844 if (ret < 0) {
845 err = ret;
846 goto fail;
847 }
848
849 if (parent) {
850 if (!ret)
851 return 0;
852 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
853 key.type = BTRFS_EXTENT_REF_V0_KEY;
854 btrfs_release_path(root, path);
855 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
856 if (ret < 0) {
857 err = ret;
858 goto fail;
859 }
860 if (!ret)
861 return 0;
862 #endif
863 goto fail;
864 }
865
866 leaf = path->nodes[0];
867 nritems = btrfs_header_nritems(leaf);
868 while (1) {
869 if (path->slots[0] >= nritems) {
870 ret = btrfs_next_leaf(root, path);
871 if (ret < 0)
872 err = ret;
873 if (ret)
874 goto fail;
875
876 leaf = path->nodes[0];
877 nritems = btrfs_header_nritems(leaf);
878 recow = 1;
879 }
880
881 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
882 if (key.objectid != bytenr ||
883 key.type != BTRFS_EXTENT_DATA_REF_KEY)
884 goto fail;
885
886 ref = btrfs_item_ptr(leaf, path->slots[0],
887 struct btrfs_extent_data_ref);
888
889 if (match_extent_data_ref(leaf, ref, root_objectid,
890 owner, offset)) {
891 if (recow) {
892 btrfs_release_path(root, path);
893 goto again;
894 }
895 err = 0;
896 break;
897 }
898 path->slots[0]++;
899 }
900 fail:
901 return err;
902 }
903
904 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
905 struct btrfs_root *root,
906 struct btrfs_path *path,
907 u64 bytenr, u64 parent,
908 u64 root_objectid, u64 owner,
909 u64 offset, int refs_to_add)
910 {
911 struct btrfs_key key;
912 struct extent_buffer *leaf;
913 u32 size;
914 u32 num_refs;
915 int ret;
916
917 key.objectid = bytenr;
918 if (parent) {
919 key.type = BTRFS_SHARED_DATA_REF_KEY;
920 key.offset = parent;
921 size = sizeof(struct btrfs_shared_data_ref);
922 } else {
923 key.type = BTRFS_EXTENT_DATA_REF_KEY;
924 key.offset = hash_extent_data_ref(root_objectid,
925 owner, offset);
926 size = sizeof(struct btrfs_extent_data_ref);
927 }
928
929 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
930 if (ret && ret != -EEXIST)
931 goto fail;
932
933 leaf = path->nodes[0];
934 if (parent) {
935 struct btrfs_shared_data_ref *ref;
936 ref = btrfs_item_ptr(leaf, path->slots[0],
937 struct btrfs_shared_data_ref);
938 if (ret == 0) {
939 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
940 } else {
941 num_refs = btrfs_shared_data_ref_count(leaf, ref);
942 num_refs += refs_to_add;
943 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
944 }
945 } else {
946 struct btrfs_extent_data_ref *ref;
947 while (ret == -EEXIST) {
948 ref = btrfs_item_ptr(leaf, path->slots[0],
949 struct btrfs_extent_data_ref);
950 if (match_extent_data_ref(leaf, ref, root_objectid,
951 owner, offset))
952 break;
953 btrfs_release_path(root, path);
954 key.offset++;
955 ret = btrfs_insert_empty_item(trans, root, path, &key,
956 size);
957 if (ret && ret != -EEXIST)
958 goto fail;
959
960 leaf = path->nodes[0];
961 }
962 ref = btrfs_item_ptr(leaf, path->slots[0],
963 struct btrfs_extent_data_ref);
964 if (ret == 0) {
965 btrfs_set_extent_data_ref_root(leaf, ref,
966 root_objectid);
967 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
968 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
969 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
970 } else {
971 num_refs = btrfs_extent_data_ref_count(leaf, ref);
972 num_refs += refs_to_add;
973 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
974 }
975 }
976 btrfs_mark_buffer_dirty(leaf);
977 ret = 0;
978 fail:
979 btrfs_release_path(root, path);
980 return ret;
981 }
982
983 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
984 struct btrfs_root *root,
985 struct btrfs_path *path,
986 int refs_to_drop)
987 {
988 struct btrfs_key key;
989 struct btrfs_extent_data_ref *ref1 = NULL;
990 struct btrfs_shared_data_ref *ref2 = NULL;
991 struct extent_buffer *leaf;
992 u32 num_refs = 0;
993 int ret = 0;
994
995 leaf = path->nodes[0];
996 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
997
998 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
999 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1000 struct btrfs_extent_data_ref);
1001 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1002 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1003 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1004 struct btrfs_shared_data_ref);
1005 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1006 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1007 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1008 struct btrfs_extent_ref_v0 *ref0;
1009 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1010 struct btrfs_extent_ref_v0);
1011 num_refs = btrfs_ref_count_v0(leaf, ref0);
1012 #endif
1013 } else {
1014 BUG();
1015 }
1016
1017 BUG_ON(num_refs < refs_to_drop);
1018 num_refs -= refs_to_drop;
1019
1020 if (num_refs == 0) {
1021 ret = btrfs_del_item(trans, root, path);
1022 } else {
1023 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
1024 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
1025 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
1026 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
1027 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1028 else {
1029 struct btrfs_extent_ref_v0 *ref0;
1030 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1031 struct btrfs_extent_ref_v0);
1032 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
1033 }
1034 #endif
1035 btrfs_mark_buffer_dirty(leaf);
1036 }
1037 return ret;
1038 }
1039
1040 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
1041 struct btrfs_path *path,
1042 struct btrfs_extent_inline_ref *iref)
1043 {
1044 struct btrfs_key key;
1045 struct extent_buffer *leaf;
1046 struct btrfs_extent_data_ref *ref1;
1047 struct btrfs_shared_data_ref *ref2;
1048 u32 num_refs = 0;
1049
1050 leaf = path->nodes[0];
1051 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1052 if (iref) {
1053 if (btrfs_extent_inline_ref_type(leaf, iref) ==
1054 BTRFS_EXTENT_DATA_REF_KEY) {
1055 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
1056 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1057 } else {
1058 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
1059 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1060 }
1061 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1062 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1063 struct btrfs_extent_data_ref);
1064 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1065 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1066 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1067 struct btrfs_shared_data_ref);
1068 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1069 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1070 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1071 struct btrfs_extent_ref_v0 *ref0;
1072 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1073 struct btrfs_extent_ref_v0);
1074 num_refs = btrfs_ref_count_v0(leaf, ref0);
1075 #endif
1076 } else {
1077 WARN_ON(1);
1078 }
1079 return num_refs;
1080 }
1081
1082 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
1083 struct btrfs_root *root,
1084 struct btrfs_path *path,
1085 u64 bytenr, u64 parent,
1086 u64 root_objectid)
1087 {
1088 struct btrfs_key key;
1089 int ret;
1090
1091 key.objectid = bytenr;
1092 if (parent) {
1093 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1094 key.offset = parent;
1095 } else {
1096 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1097 key.offset = root_objectid;
1098 }
1099
1100 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1101 if (ret > 0)
1102 ret = -ENOENT;
1103 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1104 if (ret == -ENOENT && parent) {
1105 btrfs_release_path(root, path);
1106 key.type = BTRFS_EXTENT_REF_V0_KEY;
1107 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1108 if (ret > 0)
1109 ret = -ENOENT;
1110 }
1111 #endif
1112 return ret;
1113 }
1114
1115 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
1116 struct btrfs_root *root,
1117 struct btrfs_path *path,
1118 u64 bytenr, u64 parent,
1119 u64 root_objectid)
1120 {
1121 struct btrfs_key key;
1122 int ret;
1123
1124 key.objectid = bytenr;
1125 if (parent) {
1126 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1127 key.offset = parent;
1128 } else {
1129 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1130 key.offset = root_objectid;
1131 }
1132
1133 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1134 btrfs_release_path(root, path);
1135 return ret;
1136 }
1137
1138 static inline int extent_ref_type(u64 parent, u64 owner)
1139 {
1140 int type;
1141 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1142 if (parent > 0)
1143 type = BTRFS_SHARED_BLOCK_REF_KEY;
1144 else
1145 type = BTRFS_TREE_BLOCK_REF_KEY;
1146 } else {
1147 if (parent > 0)
1148 type = BTRFS_SHARED_DATA_REF_KEY;
1149 else
1150 type = BTRFS_EXTENT_DATA_REF_KEY;
1151 }
1152 return type;
1153 }
1154
1155 static int find_next_key(struct btrfs_path *path, int level,
1156 struct btrfs_key *key)
1157
1158 {
1159 for (; level < BTRFS_MAX_LEVEL; level++) {
1160 if (!path->nodes[level])
1161 break;
1162 if (path->slots[level] + 1 >=
1163 btrfs_header_nritems(path->nodes[level]))
1164 continue;
1165 if (level == 0)
1166 btrfs_item_key_to_cpu(path->nodes[level], key,
1167 path->slots[level] + 1);
1168 else
1169 btrfs_node_key_to_cpu(path->nodes[level], key,
1170 path->slots[level] + 1);
1171 return 0;
1172 }
1173 return 1;
1174 }
1175
1176 /*
1177 * look for inline back ref. if back ref is found, *ref_ret is set
1178 * to the address of inline back ref, and 0 is returned.
1179 *
1180 * if back ref isn't found, *ref_ret is set to the address where it
1181 * should be inserted, and -ENOENT is returned.
1182 *
1183 * if insert is true and there are too many inline back refs, the path
1184 * points to the extent item, and -EAGAIN is returned.
1185 *
1186 * NOTE: inline back refs are ordered in the same way that back ref
1187 * items in the tree are ordered.
1188 */
1189 static noinline_for_stack
1190 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1191 struct btrfs_root *root,
1192 struct btrfs_path *path,
1193 struct btrfs_extent_inline_ref **ref_ret,
1194 u64 bytenr, u64 num_bytes,
1195 u64 parent, u64 root_objectid,
1196 u64 owner, u64 offset, int insert)
1197 {
1198 struct btrfs_key key;
1199 struct extent_buffer *leaf;
1200 struct btrfs_extent_item *ei;
1201 struct btrfs_extent_inline_ref *iref;
1202 u64 flags;
1203 u64 item_size;
1204 unsigned long ptr;
1205 unsigned long end;
1206 int extra_size;
1207 int type;
1208 int want;
1209 int ret;
1210 int err = 0;
1211
1212 key.objectid = bytenr;
1213 key.type = BTRFS_EXTENT_ITEM_KEY;
1214 key.offset = num_bytes;
1215
1216 want = extent_ref_type(parent, owner);
1217 if (insert) {
1218 extra_size = btrfs_extent_inline_ref_size(want);
1219 path->keep_locks = 1;
1220 } else
1221 extra_size = -1;
1222 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1223 if (ret < 0) {
1224 err = ret;
1225 goto out;
1226 }
1227 BUG_ON(ret);
1228
1229 leaf = path->nodes[0];
1230 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1231 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1232 if (item_size < sizeof(*ei)) {
1233 if (!insert) {
1234 err = -ENOENT;
1235 goto out;
1236 }
1237 ret = convert_extent_item_v0(trans, root, path, owner,
1238 extra_size);
1239 if (ret < 0) {
1240 err = ret;
1241 goto out;
1242 }
1243 leaf = path->nodes[0];
1244 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1245 }
1246 #endif
1247 BUG_ON(item_size < sizeof(*ei));
1248
1249 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1250 flags = btrfs_extent_flags(leaf, ei);
1251
1252 ptr = (unsigned long)(ei + 1);
1253 end = (unsigned long)ei + item_size;
1254
1255 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1256 ptr += sizeof(struct btrfs_tree_block_info);
1257 BUG_ON(ptr > end);
1258 } else {
1259 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
1260 }
1261
1262 err = -ENOENT;
1263 while (1) {
1264 if (ptr >= end) {
1265 WARN_ON(ptr > end);
1266 break;
1267 }
1268 iref = (struct btrfs_extent_inline_ref *)ptr;
1269 type = btrfs_extent_inline_ref_type(leaf, iref);
1270 if (want < type)
1271 break;
1272 if (want > type) {
1273 ptr += btrfs_extent_inline_ref_size(type);
1274 continue;
1275 }
1276
1277 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1278 struct btrfs_extent_data_ref *dref;
1279 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1280 if (match_extent_data_ref(leaf, dref, root_objectid,
1281 owner, offset)) {
1282 err = 0;
1283 break;
1284 }
1285 if (hash_extent_data_ref_item(leaf, dref) <
1286 hash_extent_data_ref(root_objectid, owner, offset))
1287 break;
1288 } else {
1289 u64 ref_offset;
1290 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1291 if (parent > 0) {
1292 if (parent == ref_offset) {
1293 err = 0;
1294 break;
1295 }
1296 if (ref_offset < parent)
1297 break;
1298 } else {
1299 if (root_objectid == ref_offset) {
1300 err = 0;
1301 break;
1302 }
1303 if (ref_offset < root_objectid)
1304 break;
1305 }
1306 }
1307 ptr += btrfs_extent_inline_ref_size(type);
1308 }
1309 if (err == -ENOENT && insert) {
1310 if (item_size + extra_size >=
1311 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1312 err = -EAGAIN;
1313 goto out;
1314 }
1315 /*
1316 * To add new inline back ref, we have to make sure
1317 * there is no corresponding back ref item.
1318 * For simplicity, we just do not add new inline back
1319 * ref if there is any kind of item for this block
1320 */
1321 if (find_next_key(path, 0, &key) == 0 &&
1322 key.objectid == bytenr &&
1323 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1324 err = -EAGAIN;
1325 goto out;
1326 }
1327 }
1328 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1329 out:
1330 if (insert) {
1331 path->keep_locks = 0;
1332 btrfs_unlock_up_safe(path, 1);
1333 }
1334 return err;
1335 }
1336
1337 /*
1338 * helper to add new inline back ref
1339 */
1340 static noinline_for_stack
1341 int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
1342 struct btrfs_root *root,
1343 struct btrfs_path *path,
1344 struct btrfs_extent_inline_ref *iref,
1345 u64 parent, u64 root_objectid,
1346 u64 owner, u64 offset, int refs_to_add,
1347 struct btrfs_delayed_extent_op *extent_op)
1348 {
1349 struct extent_buffer *leaf;
1350 struct btrfs_extent_item *ei;
1351 unsigned long ptr;
1352 unsigned long end;
1353 unsigned long item_offset;
1354 u64 refs;
1355 int size;
1356 int type;
1357 int ret;
1358
1359 leaf = path->nodes[0];
1360 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1361 item_offset = (unsigned long)iref - (unsigned long)ei;
1362
1363 type = extent_ref_type(parent, owner);
1364 size = btrfs_extent_inline_ref_size(type);
1365
1366 ret = btrfs_extend_item(trans, root, path, size);
1367 BUG_ON(ret);
1368
1369 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1370 refs = btrfs_extent_refs(leaf, ei);
1371 refs += refs_to_add;
1372 btrfs_set_extent_refs(leaf, ei, refs);
1373 if (extent_op)
1374 __run_delayed_extent_op(extent_op, leaf, ei);
1375
1376 ptr = (unsigned long)ei + item_offset;
1377 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1378 if (ptr < end - size)
1379 memmove_extent_buffer(leaf, ptr + size, ptr,
1380 end - size - ptr);
1381
1382 iref = (struct btrfs_extent_inline_ref *)ptr;
1383 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1384 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1385 struct btrfs_extent_data_ref *dref;
1386 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1387 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1388 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1389 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1390 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1391 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1392 struct btrfs_shared_data_ref *sref;
1393 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1394 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1395 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1396 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1397 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1398 } else {
1399 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1400 }
1401 btrfs_mark_buffer_dirty(leaf);
1402 return 0;
1403 }
1404
1405 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1406 struct btrfs_root *root,
1407 struct btrfs_path *path,
1408 struct btrfs_extent_inline_ref **ref_ret,
1409 u64 bytenr, u64 num_bytes, u64 parent,
1410 u64 root_objectid, u64 owner, u64 offset)
1411 {
1412 int ret;
1413
1414 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1415 bytenr, num_bytes, parent,
1416 root_objectid, owner, offset, 0);
1417 if (ret != -ENOENT)
1418 return ret;
1419
1420 btrfs_release_path(root, path);
1421 *ref_ret = NULL;
1422
1423 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1424 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1425 root_objectid);
1426 } else {
1427 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1428 root_objectid, owner, offset);
1429 }
1430 return ret;
1431 }
1432
1433 /*
1434 * helper to update/remove inline back ref
1435 */
1436 static noinline_for_stack
1437 int update_inline_extent_backref(struct btrfs_trans_handle *trans,
1438 struct btrfs_root *root,
1439 struct btrfs_path *path,
1440 struct btrfs_extent_inline_ref *iref,
1441 int refs_to_mod,
1442 struct btrfs_delayed_extent_op *extent_op)
1443 {
1444 struct extent_buffer *leaf;
1445 struct btrfs_extent_item *ei;
1446 struct btrfs_extent_data_ref *dref = NULL;
1447 struct btrfs_shared_data_ref *sref = NULL;
1448 unsigned long ptr;
1449 unsigned long end;
1450 u32 item_size;
1451 int size;
1452 int type;
1453 int ret;
1454 u64 refs;
1455
1456 leaf = path->nodes[0];
1457 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1458 refs = btrfs_extent_refs(leaf, ei);
1459 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1460 refs += refs_to_mod;
1461 btrfs_set_extent_refs(leaf, ei, refs);
1462 if (extent_op)
1463 __run_delayed_extent_op(extent_op, leaf, ei);
1464
1465 type = btrfs_extent_inline_ref_type(leaf, iref);
1466
1467 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1468 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1469 refs = btrfs_extent_data_ref_count(leaf, dref);
1470 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1471 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1472 refs = btrfs_shared_data_ref_count(leaf, sref);
1473 } else {
1474 refs = 1;
1475 BUG_ON(refs_to_mod != -1);
1476 }
1477
1478 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1479 refs += refs_to_mod;
1480
1481 if (refs > 0) {
1482 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1483 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1484 else
1485 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1486 } else {
1487 size = btrfs_extent_inline_ref_size(type);
1488 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1489 ptr = (unsigned long)iref;
1490 end = (unsigned long)ei + item_size;
1491 if (ptr + size < end)
1492 memmove_extent_buffer(leaf, ptr, ptr + size,
1493 end - ptr - size);
1494 item_size -= size;
1495 ret = btrfs_truncate_item(trans, root, path, item_size, 1);
1496 BUG_ON(ret);
1497 }
1498 btrfs_mark_buffer_dirty(leaf);
1499 return 0;
1500 }
1501
1502 static noinline_for_stack
1503 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1504 struct btrfs_root *root,
1505 struct btrfs_path *path,
1506 u64 bytenr, u64 num_bytes, u64 parent,
1507 u64 root_objectid, u64 owner,
1508 u64 offset, int refs_to_add,
1509 struct btrfs_delayed_extent_op *extent_op)
1510 {
1511 struct btrfs_extent_inline_ref *iref;
1512 int ret;
1513
1514 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1515 bytenr, num_bytes, parent,
1516 root_objectid, owner, offset, 1);
1517 if (ret == 0) {
1518 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1519 ret = update_inline_extent_backref(trans, root, path, iref,
1520 refs_to_add, extent_op);
1521 } else if (ret == -ENOENT) {
1522 ret = setup_inline_extent_backref(trans, root, path, iref,
1523 parent, root_objectid,
1524 owner, offset, refs_to_add,
1525 extent_op);
1526 }
1527 return ret;
1528 }
1529
1530 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1531 struct btrfs_root *root,
1532 struct btrfs_path *path,
1533 u64 bytenr, u64 parent, u64 root_objectid,
1534 u64 owner, u64 offset, int refs_to_add)
1535 {
1536 int ret;
1537 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1538 BUG_ON(refs_to_add != 1);
1539 ret = insert_tree_block_ref(trans, root, path, bytenr,
1540 parent, root_objectid);
1541 } else {
1542 ret = insert_extent_data_ref(trans, root, path, bytenr,
1543 parent, root_objectid,
1544 owner, offset, refs_to_add);
1545 }
1546 return ret;
1547 }
1548
1549 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1550 struct btrfs_root *root,
1551 struct btrfs_path *path,
1552 struct btrfs_extent_inline_ref *iref,
1553 int refs_to_drop, int is_data)
1554 {
1555 int ret;
1556
1557 BUG_ON(!is_data && refs_to_drop != 1);
1558 if (iref) {
1559 ret = update_inline_extent_backref(trans, root, path, iref,
1560 -refs_to_drop, NULL);
1561 } else if (is_data) {
1562 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1563 } else {
1564 ret = btrfs_del_item(trans, root, path);
1565 }
1566 return ret;
1567 }
1568
1569 #ifdef BIO_RW_DISCARD
1570 static void btrfs_issue_discard(struct block_device *bdev,
1571 u64 start, u64 len)
1572 {
1573 blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL);
1574 }
1575 #endif
1576
1577 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
1578 u64 num_bytes)
1579 {
1580 #ifdef BIO_RW_DISCARD
1581 int ret;
1582 u64 map_length = num_bytes;
1583 struct btrfs_multi_bio *multi = NULL;
1584
1585 /* Tell the block device(s) that the sectors can be discarded */
1586 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
1587 bytenr, &map_length, &multi, 0);
1588 if (!ret) {
1589 struct btrfs_bio_stripe *stripe = multi->stripes;
1590 int i;
1591
1592 if (map_length > num_bytes)
1593 map_length = num_bytes;
1594
1595 for (i = 0; i < multi->num_stripes; i++, stripe++) {
1596 btrfs_issue_discard(stripe->dev->bdev,
1597 stripe->physical,
1598 map_length);
1599 }
1600 kfree(multi);
1601 }
1602
1603 return ret;
1604 #else
1605 return 0;
1606 #endif
1607 }
1608
1609 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1610 struct btrfs_root *root,
1611 u64 bytenr, u64 num_bytes, u64 parent,
1612 u64 root_objectid, u64 owner, u64 offset)
1613 {
1614 int ret;
1615 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
1616 root_objectid == BTRFS_TREE_LOG_OBJECTID);
1617
1618 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1619 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
1620 parent, root_objectid, (int)owner,
1621 BTRFS_ADD_DELAYED_REF, NULL);
1622 } else {
1623 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
1624 parent, root_objectid, owner, offset,
1625 BTRFS_ADD_DELAYED_REF, NULL);
1626 }
1627 return ret;
1628 }
1629
1630 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1631 struct btrfs_root *root,
1632 u64 bytenr, u64 num_bytes,
1633 u64 parent, u64 root_objectid,
1634 u64 owner, u64 offset, int refs_to_add,
1635 struct btrfs_delayed_extent_op *extent_op)
1636 {
1637 struct btrfs_path *path;
1638 struct extent_buffer *leaf;
1639 struct btrfs_extent_item *item;
1640 u64 refs;
1641 int ret;
1642 int err = 0;
1643
1644 path = btrfs_alloc_path();
1645 if (!path)
1646 return -ENOMEM;
1647
1648 path->reada = 1;
1649 path->leave_spinning = 1;
1650 /* this will setup the path even if it fails to insert the back ref */
1651 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1652 path, bytenr, num_bytes, parent,
1653 root_objectid, owner, offset,
1654 refs_to_add, extent_op);
1655 if (ret == 0)
1656 goto out;
1657
1658 if (ret != -EAGAIN) {
1659 err = ret;
1660 goto out;
1661 }
1662
1663 leaf = path->nodes[0];
1664 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1665 refs = btrfs_extent_refs(leaf, item);
1666 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1667 if (extent_op)
1668 __run_delayed_extent_op(extent_op, leaf, item);
1669
1670 btrfs_mark_buffer_dirty(leaf);
1671 btrfs_release_path(root->fs_info->extent_root, path);
1672
1673 path->reada = 1;
1674 path->leave_spinning = 1;
1675
1676 /* now insert the actual backref */
1677 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1678 path, bytenr, parent, root_objectid,
1679 owner, offset, refs_to_add);
1680 BUG_ON(ret);
1681 out:
1682 btrfs_free_path(path);
1683 return err;
1684 }
1685
1686 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1687 struct btrfs_root *root,
1688 struct btrfs_delayed_ref_node *node,
1689 struct btrfs_delayed_extent_op *extent_op,
1690 int insert_reserved)
1691 {
1692 int ret = 0;
1693 struct btrfs_delayed_data_ref *ref;
1694 struct btrfs_key ins;
1695 u64 parent = 0;
1696 u64 ref_root = 0;
1697 u64 flags = 0;
1698
1699 ins.objectid = node->bytenr;
1700 ins.offset = node->num_bytes;
1701 ins.type = BTRFS_EXTENT_ITEM_KEY;
1702
1703 ref = btrfs_delayed_node_to_data_ref(node);
1704 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
1705 parent = ref->parent;
1706 else
1707 ref_root = ref->root;
1708
1709 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1710 if (extent_op) {
1711 BUG_ON(extent_op->update_key);
1712 flags |= extent_op->flags_to_set;
1713 }
1714 ret = alloc_reserved_file_extent(trans, root,
1715 parent, ref_root, flags,
1716 ref->objectid, ref->offset,
1717 &ins, node->ref_mod);
1718 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1719 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1720 node->num_bytes, parent,
1721 ref_root, ref->objectid,
1722 ref->offset, node->ref_mod,
1723 extent_op);
1724 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1725 ret = __btrfs_free_extent(trans, root, node->bytenr,
1726 node->num_bytes, parent,
1727 ref_root, ref->objectid,
1728 ref->offset, node->ref_mod,
1729 extent_op);
1730 } else {
1731 BUG();
1732 }
1733 return ret;
1734 }
1735
1736 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
1737 struct extent_buffer *leaf,
1738 struct btrfs_extent_item *ei)
1739 {
1740 u64 flags = btrfs_extent_flags(leaf, ei);
1741 if (extent_op->update_flags) {
1742 flags |= extent_op->flags_to_set;
1743 btrfs_set_extent_flags(leaf, ei, flags);
1744 }
1745
1746 if (extent_op->update_key) {
1747 struct btrfs_tree_block_info *bi;
1748 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
1749 bi = (struct btrfs_tree_block_info *)(ei + 1);
1750 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
1751 }
1752 }
1753
1754 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
1755 struct btrfs_root *root,
1756 struct btrfs_delayed_ref_node *node,
1757 struct btrfs_delayed_extent_op *extent_op)
1758 {
1759 struct btrfs_key key;
1760 struct btrfs_path *path;
1761 struct btrfs_extent_item *ei;
1762 struct extent_buffer *leaf;
1763 u32 item_size;
1764 int ret;
1765 int err = 0;
1766
1767 path = btrfs_alloc_path();
1768 if (!path)
1769 return -ENOMEM;
1770
1771 key.objectid = node->bytenr;
1772 key.type = BTRFS_EXTENT_ITEM_KEY;
1773 key.offset = node->num_bytes;
1774
1775 path->reada = 1;
1776 path->leave_spinning = 1;
1777 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
1778 path, 0, 1);
1779 if (ret < 0) {
1780 err = ret;
1781 goto out;
1782 }
1783 if (ret > 0) {
1784 err = -EIO;
1785 goto out;
1786 }
1787
1788 leaf = path->nodes[0];
1789 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1790 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1791 if (item_size < sizeof(*ei)) {
1792 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1793 path, (u64)-1, 0);
1794 if (ret < 0) {
1795 err = ret;
1796 goto out;
1797 }
1798 leaf = path->nodes[0];
1799 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1800 }
1801 #endif
1802 BUG_ON(item_size < sizeof(*ei));
1803 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1804 __run_delayed_extent_op(extent_op, leaf, ei);
1805
1806 btrfs_mark_buffer_dirty(leaf);
1807 out:
1808 btrfs_free_path(path);
1809 return err;
1810 }
1811
1812 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
1813 struct btrfs_root *root,
1814 struct btrfs_delayed_ref_node *node,
1815 struct btrfs_delayed_extent_op *extent_op,
1816 int insert_reserved)
1817 {
1818 int ret = 0;
1819 struct btrfs_delayed_tree_ref *ref;
1820 struct btrfs_key ins;
1821 u64 parent = 0;
1822 u64 ref_root = 0;
1823
1824 ins.objectid = node->bytenr;
1825 ins.offset = node->num_bytes;
1826 ins.type = BTRFS_EXTENT_ITEM_KEY;
1827
1828 ref = btrfs_delayed_node_to_tree_ref(node);
1829 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1830 parent = ref->parent;
1831 else
1832 ref_root = ref->root;
1833
1834 BUG_ON(node->ref_mod != 1);
1835 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1836 BUG_ON(!extent_op || !extent_op->update_flags ||
1837 !extent_op->update_key);
1838 ret = alloc_reserved_tree_block(trans, root,
1839 parent, ref_root,
1840 extent_op->flags_to_set,
1841 &extent_op->key,
1842 ref->level, &ins);
1843 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1844 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1845 node->num_bytes, parent, ref_root,
1846 ref->level, 0, 1, extent_op);
1847 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1848 ret = __btrfs_free_extent(trans, root, node->bytenr,
1849 node->num_bytes, parent, ref_root,
1850 ref->level, 0, 1, extent_op);
1851 } else {
1852 BUG();
1853 }
1854 return ret;
1855 }
1856
1857
1858 /* helper function to actually process a single delayed ref entry */
1859 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
1860 struct btrfs_root *root,
1861 struct btrfs_delayed_ref_node *node,
1862 struct btrfs_delayed_extent_op *extent_op,
1863 int insert_reserved)
1864 {
1865 int ret;
1866 if (btrfs_delayed_ref_is_head(node)) {
1867 struct btrfs_delayed_ref_head *head;
1868 /*
1869 * we've hit the end of the chain and we were supposed
1870 * to insert this extent into the tree. But, it got
1871 * deleted before we ever needed to insert it, so all
1872 * we have to do is clean up the accounting
1873 */
1874 BUG_ON(extent_op);
1875 head = btrfs_delayed_node_to_head(node);
1876 if (insert_reserved) {
1877 int mark_free = 0;
1878 struct extent_buffer *must_clean = NULL;
1879
1880 ret = pin_down_bytes(trans, root, NULL,
1881 node->bytenr, node->num_bytes,
1882 head->is_data, 1, &must_clean);
1883 if (ret > 0)
1884 mark_free = 1;
1885
1886 if (must_clean) {
1887 clean_tree_block(NULL, root, must_clean);
1888 btrfs_tree_unlock(must_clean);
1889 free_extent_buffer(must_clean);
1890 }
1891 if (head->is_data) {
1892 ret = btrfs_del_csums(trans, root,
1893 node->bytenr,
1894 node->num_bytes);
1895 BUG_ON(ret);
1896 }
1897 if (mark_free) {
1898 ret = btrfs_free_reserved_extent(root,
1899 node->bytenr,
1900 node->num_bytes);
1901 BUG_ON(ret);
1902 }
1903 }
1904 mutex_unlock(&head->mutex);
1905 return 0;
1906 }
1907
1908 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1909 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1910 ret = run_delayed_tree_ref(trans, root, node, extent_op,
1911 insert_reserved);
1912 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1913 node->type == BTRFS_SHARED_DATA_REF_KEY)
1914 ret = run_delayed_data_ref(trans, root, node, extent_op,
1915 insert_reserved);
1916 else
1917 BUG();
1918 return ret;
1919 }
1920
1921 static noinline struct btrfs_delayed_ref_node *
1922 select_delayed_ref(struct btrfs_delayed_ref_head *head)
1923 {
1924 struct rb_node *node;
1925 struct btrfs_delayed_ref_node *ref;
1926 int action = BTRFS_ADD_DELAYED_REF;
1927 again:
1928 /*
1929 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
1930 * this prevents ref count from going down to zero when
1931 * there still are pending delayed ref.
1932 */
1933 node = rb_prev(&head->node.rb_node);
1934 while (1) {
1935 if (!node)
1936 break;
1937 ref = rb_entry(node, struct btrfs_delayed_ref_node,
1938 rb_node);
1939 if (ref->bytenr != head->node.bytenr)
1940 break;
1941 if (ref->action == action)
1942 return ref;
1943 node = rb_prev(node);
1944 }
1945 if (action == BTRFS_ADD_DELAYED_REF) {
1946 action = BTRFS_DROP_DELAYED_REF;
1947 goto again;
1948 }
1949 return NULL;
1950 }
1951
1952 static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
1953 struct btrfs_root *root,
1954 struct list_head *cluster)
1955 {
1956 struct btrfs_delayed_ref_root *delayed_refs;
1957 struct btrfs_delayed_ref_node *ref;
1958 struct btrfs_delayed_ref_head *locked_ref = NULL;
1959 struct btrfs_delayed_extent_op *extent_op;
1960 int ret;
1961 int count = 0;
1962 int must_insert_reserved = 0;
1963
1964 delayed_refs = &trans->transaction->delayed_refs;
1965 while (1) {
1966 if (!locked_ref) {
1967 /* pick a new head ref from the cluster list */
1968 if (list_empty(cluster))
1969 break;
1970
1971 locked_ref = list_entry(cluster->next,
1972 struct btrfs_delayed_ref_head, cluster);
1973
1974 /* grab the lock that says we are going to process
1975 * all the refs for this head */
1976 ret = btrfs_delayed_ref_lock(trans, locked_ref);
1977
1978 /*
1979 * we may have dropped the spin lock to get the head
1980 * mutex lock, and that might have given someone else
1981 * time to free the head. If that's true, it has been
1982 * removed from our list and we can move on.
1983 */
1984 if (ret == -EAGAIN) {
1985 locked_ref = NULL;
1986 count++;
1987 continue;
1988 }
1989 }
1990
1991 /*
1992 * record the must insert reserved flag before we
1993 * drop the spin lock.
1994 */
1995 must_insert_reserved = locked_ref->must_insert_reserved;
1996 locked_ref->must_insert_reserved = 0;
1997
1998 extent_op = locked_ref->extent_op;
1999 locked_ref->extent_op = NULL;
2000
2001 /*
2002 * locked_ref is the head node, so we have to go one
2003 * node back for any delayed ref updates
2004 */
2005 ref = select_delayed_ref(locked_ref);
2006 if (!ref) {
2007 /* All delayed refs have been processed, Go ahead
2008 * and send the head node to run_one_delayed_ref,
2009 * so that any accounting fixes can happen
2010 */
2011 ref = &locked_ref->node;
2012
2013 if (extent_op && must_insert_reserved) {
2014 kfree(extent_op);
2015 extent_op = NULL;
2016 }
2017
2018 if (extent_op) {
2019 spin_unlock(&delayed_refs->lock);
2020
2021 ret = run_delayed_extent_op(trans, root,
2022 ref, extent_op);
2023 BUG_ON(ret);
2024 kfree(extent_op);
2025
2026 cond_resched();
2027 spin_lock(&delayed_refs->lock);
2028 continue;
2029 }
2030
2031 list_del_init(&locked_ref->cluster);
2032 locked_ref = NULL;
2033 }
2034
2035 ref->in_tree = 0;
2036 rb_erase(&ref->rb_node, &delayed_refs->root);
2037 delayed_refs->num_entries--;
2038
2039 spin_unlock(&delayed_refs->lock);
2040
2041 ret = run_one_delayed_ref(trans, root, ref, extent_op,
2042 must_insert_reserved);
2043 BUG_ON(ret);
2044
2045 btrfs_put_delayed_ref(ref);
2046 kfree(extent_op);
2047 count++;
2048
2049 cond_resched();
2050 spin_lock(&delayed_refs->lock);
2051 }
2052 return count;
2053 }
2054
2055 /*
2056 * this starts processing the delayed reference count updates and
2057 * extent insertions we have queued up so far. count can be
2058 * 0, which means to process everything in the tree at the start
2059 * of the run (but not newly added entries), or it can be some target
2060 * number you'd like to process.
2061 */
2062 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2063 struct btrfs_root *root, unsigned long count)
2064 {
2065 struct rb_node *node;
2066 struct btrfs_delayed_ref_root *delayed_refs;
2067 struct btrfs_delayed_ref_node *ref;
2068 struct list_head cluster;
2069 int ret;
2070 int run_all = count == (unsigned long)-1;
2071 int run_most = 0;
2072
2073 if (root == root->fs_info->extent_root)
2074 root = root->fs_info->tree_root;
2075
2076 delayed_refs = &trans->transaction->delayed_refs;
2077 INIT_LIST_HEAD(&cluster);
2078 again:
2079 spin_lock(&delayed_refs->lock);
2080 if (count == 0) {
2081 count = delayed_refs->num_entries * 2;
2082 run_most = 1;
2083 }
2084 while (1) {
2085 if (!(run_all || run_most) &&
2086 delayed_refs->num_heads_ready < 64)
2087 break;
2088
2089 /*
2090 * go find something we can process in the rbtree. We start at
2091 * the beginning of the tree, and then build a cluster
2092 * of refs to process starting at the first one we are able to
2093 * lock
2094 */
2095 ret = btrfs_find_ref_cluster(trans, &cluster,
2096 delayed_refs->run_delayed_start);
2097 if (ret)
2098 break;
2099
2100 ret = run_clustered_refs(trans, root, &cluster);
2101 BUG_ON(ret < 0);
2102
2103 count -= min_t(unsigned long, ret, count);
2104
2105 if (count == 0)
2106 break;
2107 }
2108
2109 if (run_all) {
2110 node = rb_first(&delayed_refs->root);
2111 if (!node)
2112 goto out;
2113 count = (unsigned long)-1;
2114
2115 while (node) {
2116 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2117 rb_node);
2118 if (btrfs_delayed_ref_is_head(ref)) {
2119 struct btrfs_delayed_ref_head *head;
2120
2121 head = btrfs_delayed_node_to_head(ref);
2122 atomic_inc(&ref->refs);
2123
2124 spin_unlock(&delayed_refs->lock);
2125 mutex_lock(&head->mutex);
2126 mutex_unlock(&head->mutex);
2127
2128 btrfs_put_delayed_ref(ref);
2129 cond_resched();
2130 goto again;
2131 }
2132 node = rb_next(node);
2133 }
2134 spin_unlock(&delayed_refs->lock);
2135 schedule_timeout(1);
2136 goto again;
2137 }
2138 out:
2139 spin_unlock(&delayed_refs->lock);
2140 return 0;
2141 }
2142
2143 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2144 struct btrfs_root *root,
2145 u64 bytenr, u64 num_bytes, u64 flags,
2146 int is_data)
2147 {
2148 struct btrfs_delayed_extent_op *extent_op;
2149 int ret;
2150
2151 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2152 if (!extent_op)
2153 return -ENOMEM;
2154
2155 extent_op->flags_to_set = flags;
2156 extent_op->update_flags = 1;
2157 extent_op->update_key = 0;
2158 extent_op->is_data = is_data ? 1 : 0;
2159
2160 ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
2161 if (ret)
2162 kfree(extent_op);
2163 return ret;
2164 }
2165
2166 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
2167 struct btrfs_root *root,
2168 struct btrfs_path *path,
2169 u64 objectid, u64 offset, u64 bytenr)
2170 {
2171 struct btrfs_delayed_ref_head *head;
2172 struct btrfs_delayed_ref_node *ref;
2173 struct btrfs_delayed_data_ref *data_ref;
2174 struct btrfs_delayed_ref_root *delayed_refs;
2175 struct rb_node *node;
2176 int ret = 0;
2177
2178 ret = -ENOENT;
2179 delayed_refs = &trans->transaction->delayed_refs;
2180 spin_lock(&delayed_refs->lock);
2181 head = btrfs_find_delayed_ref_head(trans, bytenr);
2182 if (!head)
2183 goto out;
2184
2185 if (!mutex_trylock(&head->mutex)) {
2186 atomic_inc(&head->node.refs);
2187 spin_unlock(&delayed_refs->lock);
2188
2189 btrfs_release_path(root->fs_info->extent_root, path);
2190
2191 mutex_lock(&head->mutex);
2192 mutex_unlock(&head->mutex);
2193 btrfs_put_delayed_ref(&head->node);
2194 return -EAGAIN;
2195 }
2196
2197 node = rb_prev(&head->node.rb_node);
2198 if (!node)
2199 goto out_unlock;
2200
2201 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2202
2203 if (ref->bytenr != bytenr)
2204 goto out_unlock;
2205
2206 ret = 1;
2207 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
2208 goto out_unlock;
2209
2210 data_ref = btrfs_delayed_node_to_data_ref(ref);
2211
2212 node = rb_prev(node);
2213 if (node) {
2214 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2215 if (ref->bytenr == bytenr)
2216 goto out_unlock;
2217 }
2218
2219 if (data_ref->root != root->root_key.objectid ||
2220 data_ref->objectid != objectid || data_ref->offset != offset)
2221 goto out_unlock;
2222
2223 ret = 0;
2224 out_unlock:
2225 mutex_unlock(&head->mutex);
2226 out:
2227 spin_unlock(&delayed_refs->lock);
2228 return ret;
2229 }
2230
2231 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
2232 struct btrfs_root *root,
2233 struct btrfs_path *path,
2234 u64 objectid, u64 offset, u64 bytenr)
2235 {
2236 struct btrfs_root *extent_root = root->fs_info->extent_root;
2237 struct extent_buffer *leaf;
2238 struct btrfs_extent_data_ref *ref;
2239 struct btrfs_extent_inline_ref *iref;
2240 struct btrfs_extent_item *ei;
2241 struct btrfs_key key;
2242 u32 item_size;
2243 int ret;
2244
2245 key.objectid = bytenr;
2246 key.offset = (u64)-1;
2247 key.type = BTRFS_EXTENT_ITEM_KEY;
2248
2249 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2250 if (ret < 0)
2251 goto out;
2252 BUG_ON(ret == 0);
2253
2254 ret = -ENOENT;
2255 if (path->slots[0] == 0)
2256 goto out;
2257
2258 path->slots[0]--;
2259 leaf = path->nodes[0];
2260 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2261
2262 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2263 goto out;
2264
2265 ret = 1;
2266 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2267 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2268 if (item_size < sizeof(*ei)) {
2269 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
2270 goto out;
2271 }
2272 #endif
2273 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2274
2275 if (item_size != sizeof(*ei) +
2276 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2277 goto out;
2278
2279 if (btrfs_extent_generation(leaf, ei) <=
2280 btrfs_root_last_snapshot(&root->root_item))
2281 goto out;
2282
2283 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2284 if (btrfs_extent_inline_ref_type(leaf, iref) !=
2285 BTRFS_EXTENT_DATA_REF_KEY)
2286 goto out;
2287
2288 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2289 if (btrfs_extent_refs(leaf, ei) !=
2290 btrfs_extent_data_ref_count(leaf, ref) ||
2291 btrfs_extent_data_ref_root(leaf, ref) !=
2292 root->root_key.objectid ||
2293 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2294 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2295 goto out;
2296
2297 ret = 0;
2298 out:
2299 return ret;
2300 }
2301
2302 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
2303 struct btrfs_root *root,
2304 u64 objectid, u64 offset, u64 bytenr)
2305 {
2306 struct btrfs_path *path;
2307 int ret;
2308 int ret2;
2309
2310 path = btrfs_alloc_path();
2311 if (!path)
2312 return -ENOENT;
2313
2314 do {
2315 ret = check_committed_ref(trans, root, path, objectid,
2316 offset, bytenr);
2317 if (ret && ret != -ENOENT)
2318 goto out;
2319
2320 ret2 = check_delayed_ref(trans, root, path, objectid,
2321 offset, bytenr);
2322 } while (ret2 == -EAGAIN);
2323
2324 if (ret2 && ret2 != -ENOENT) {
2325 ret = ret2;
2326 goto out;
2327 }
2328
2329 if (ret != -ENOENT || ret2 != -ENOENT)
2330 ret = 0;
2331 out:
2332 btrfs_free_path(path);
2333 return ret;
2334 }
2335
2336 #if 0
2337 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2338 struct extent_buffer *buf, u32 nr_extents)
2339 {
2340 struct btrfs_key key;
2341 struct btrfs_file_extent_item *fi;
2342 u64 root_gen;
2343 u32 nritems;
2344 int i;
2345 int level;
2346 int ret = 0;
2347 int shared = 0;
2348
2349 if (!root->ref_cows)
2350 return 0;
2351
2352 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
2353 shared = 0;
2354 root_gen = root->root_key.offset;
2355 } else {
2356 shared = 1;
2357 root_gen = trans->transid - 1;
2358 }
2359
2360 level = btrfs_header_level(buf);
2361 nritems = btrfs_header_nritems(buf);
2362
2363 if (level == 0) {
2364 struct btrfs_leaf_ref *ref;
2365 struct btrfs_extent_info *info;
2366
2367 ref = btrfs_alloc_leaf_ref(root, nr_extents);
2368 if (!ref) {
2369 ret = -ENOMEM;
2370 goto out;
2371 }
2372
2373 ref->root_gen = root_gen;
2374 ref->bytenr = buf->start;
2375 ref->owner = btrfs_header_owner(buf);
2376 ref->generation = btrfs_header_generation(buf);
2377 ref->nritems = nr_extents;
2378 info = ref->extents;
2379
2380 for (i = 0; nr_extents > 0 && i < nritems; i++) {
2381 u64 disk_bytenr;
2382 btrfs_item_key_to_cpu(buf, &key, i);
2383 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2384 continue;
2385 fi = btrfs_item_ptr(buf, i,
2386 struct btrfs_file_extent_item);
2387 if (btrfs_file_extent_type(buf, fi) ==
2388 BTRFS_FILE_EXTENT_INLINE)
2389 continue;
2390 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2391 if (disk_bytenr == 0)
2392 continue;
2393
2394 info->bytenr = disk_bytenr;
2395 info->num_bytes =
2396 btrfs_file_extent_disk_num_bytes(buf, fi);
2397 info->objectid = key.objectid;
2398 info->offset = key.offset;
2399 info++;
2400 }
2401
2402 ret = btrfs_add_leaf_ref(root, ref, shared);
2403 if (ret == -EEXIST && shared) {
2404 struct btrfs_leaf_ref *old;
2405 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
2406 BUG_ON(!old);
2407 btrfs_remove_leaf_ref(root, old);
2408 btrfs_free_leaf_ref(root, old);
2409 ret = btrfs_add_leaf_ref(root, ref, shared);
2410 }
2411 WARN_ON(ret);
2412 btrfs_free_leaf_ref(root, ref);
2413 }
2414 out:
2415 return ret;
2416 }
2417
2418 /* when a block goes through cow, we update the reference counts of
2419 * everything that block points to. The internal pointers of the block
2420 * can be in just about any order, and it is likely to have clusters of
2421 * things that are close together and clusters of things that are not.
2422 *
2423 * To help reduce the seeks that come with updating all of these reference
2424 * counts, sort them by byte number before actual updates are done.
2425 *
2426 * struct refsort is used to match byte number to slot in the btree block.
2427 * we sort based on the byte number and then use the slot to actually
2428 * find the item.
2429 *
2430 * struct refsort is smaller than strcut btrfs_item and smaller than
2431 * struct btrfs_key_ptr. Since we're currently limited to the page size
2432 * for a btree block, there's no way for a kmalloc of refsorts for a
2433 * single node to be bigger than a page.
2434 */
2435 struct refsort {
2436 u64 bytenr;
2437 u32 slot;
2438 };
2439
2440 /*
2441 * for passing into sort()
2442 */
2443 static int refsort_cmp(const void *a_void, const void *b_void)
2444 {
2445 const struct refsort *a = a_void;
2446 const struct refsort *b = b_void;
2447
2448 if (a->bytenr < b->bytenr)
2449 return -1;
2450 if (a->bytenr > b->bytenr)
2451 return 1;
2452 return 0;
2453 }
2454 #endif
2455
2456 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2457 struct btrfs_root *root,
2458 struct extent_buffer *buf,
2459 int full_backref, int inc)
2460 {
2461 u64 bytenr;
2462 u64 num_bytes;
2463 u64 parent;
2464 u64 ref_root;
2465 u32 nritems;
2466 struct btrfs_key key;
2467 struct btrfs_file_extent_item *fi;
2468 int i;
2469 int level;
2470 int ret = 0;
2471 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
2472 u64, u64, u64, u64, u64, u64);
2473
2474 ref_root = btrfs_header_owner(buf);
2475 nritems = btrfs_header_nritems(buf);
2476 level = btrfs_header_level(buf);
2477
2478 if (!root->ref_cows && level == 0)
2479 return 0;
2480
2481 if (inc)
2482 process_func = btrfs_inc_extent_ref;
2483 else
2484 process_func = btrfs_free_extent;
2485
2486 if (full_backref)
2487 parent = buf->start;
2488 else
2489 parent = 0;
2490
2491 for (i = 0; i < nritems; i++) {
2492 if (level == 0) {
2493 btrfs_item_key_to_cpu(buf, &key, i);
2494 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2495 continue;
2496 fi = btrfs_item_ptr(buf, i,
2497 struct btrfs_file_extent_item);
2498 if (btrfs_file_extent_type(buf, fi) ==
2499 BTRFS_FILE_EXTENT_INLINE)
2500 continue;
2501 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2502 if (bytenr == 0)
2503 continue;
2504
2505 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
2506 key.offset -= btrfs_file_extent_offset(buf, fi);
2507 ret = process_func(trans, root, bytenr, num_bytes,
2508 parent, ref_root, key.objectid,
2509 key.offset);
2510 if (ret)
2511 goto fail;
2512 } else {
2513 bytenr = btrfs_node_blockptr(buf, i);
2514 num_bytes = btrfs_level_size(root, level - 1);
2515 ret = process_func(trans, root, bytenr, num_bytes,
2516 parent, ref_root, level - 1, 0);
2517 if (ret)
2518 goto fail;
2519 }
2520 }
2521 return 0;
2522 fail:
2523 BUG();
2524 return ret;
2525 }
2526
2527 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2528 struct extent_buffer *buf, int full_backref)
2529 {
2530 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
2531 }
2532
2533 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2534 struct extent_buffer *buf, int full_backref)
2535 {
2536 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
2537 }
2538
2539 static int write_one_cache_group(struct btrfs_trans_handle *trans,
2540 struct btrfs_root *root,
2541 struct btrfs_path *path,
2542 struct btrfs_block_group_cache *cache)
2543 {
2544 int ret;
2545 struct btrfs_root *extent_root = root->fs_info->extent_root;
2546 unsigned long bi;
2547 struct extent_buffer *leaf;
2548
2549 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
2550 if (ret < 0)
2551 goto fail;
2552 BUG_ON(ret);
2553
2554 leaf = path->nodes[0];
2555 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
2556 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
2557 btrfs_mark_buffer_dirty(leaf);
2558 btrfs_release_path(extent_root, path);
2559 fail:
2560 if (ret)
2561 return ret;
2562 return 0;
2563
2564 }
2565
2566 static struct btrfs_block_group_cache *
2567 next_block_group(struct btrfs_root *root,
2568 struct btrfs_block_group_cache *cache)
2569 {
2570 struct rb_node *node;
2571 spin_lock(&root->fs_info->block_group_cache_lock);
2572 node = rb_next(&cache->cache_node);
2573 btrfs_put_block_group(cache);
2574 if (node) {
2575 cache = rb_entry(node, struct btrfs_block_group_cache,
2576 cache_node);
2577 atomic_inc(&cache->count);
2578 } else
2579 cache = NULL;
2580 spin_unlock(&root->fs_info->block_group_cache_lock);
2581 return cache;
2582 }
2583
2584 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
2585 struct btrfs_root *root)
2586 {
2587 struct btrfs_block_group_cache *cache;
2588 int err = 0;
2589 struct btrfs_path *path;
2590 u64 last = 0;
2591
2592 path = btrfs_alloc_path();
2593 if (!path)
2594 return -ENOMEM;
2595
2596 while (1) {
2597 if (last == 0) {
2598 err = btrfs_run_delayed_refs(trans, root,
2599 (unsigned long)-1);
2600 BUG_ON(err);
2601 }
2602
2603 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2604 while (cache) {
2605 if (cache->dirty)
2606 break;
2607 cache = next_block_group(root, cache);
2608 }
2609 if (!cache) {
2610 if (last == 0)
2611 break;
2612 last = 0;
2613 continue;
2614 }
2615
2616 cache->dirty = 0;
2617 last = cache->key.objectid + cache->key.offset;
2618
2619 err = write_one_cache_group(trans, root, path, cache);
2620 BUG_ON(err);
2621 btrfs_put_block_group(cache);
2622 }
2623
2624 btrfs_free_path(path);
2625 return 0;
2626 }
2627
2628 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
2629 {
2630 struct btrfs_block_group_cache *block_group;
2631 int readonly = 0;
2632
2633 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
2634 if (!block_group || block_group->ro)
2635 readonly = 1;
2636 if (block_group)
2637 btrfs_put_block_group(block_group);
2638 return readonly;
2639 }
2640
2641 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
2642 u64 total_bytes, u64 bytes_used,
2643 struct btrfs_space_info **space_info)
2644 {
2645 struct btrfs_space_info *found;
2646
2647 found = __find_space_info(info, flags);
2648 if (found) {
2649 spin_lock(&found->lock);
2650 found->total_bytes += total_bytes;
2651 found->bytes_used += bytes_used;
2652 found->full = 0;
2653 spin_unlock(&found->lock);
2654 *space_info = found;
2655 return 0;
2656 }
2657 found = kzalloc(sizeof(*found), GFP_NOFS);
2658 if (!found)
2659 return -ENOMEM;
2660
2661 INIT_LIST_HEAD(&found->block_groups);
2662 init_rwsem(&found->groups_sem);
2663 spin_lock_init(&found->lock);
2664 found->flags = flags;
2665 found->total_bytes = total_bytes;
2666 found->bytes_used = bytes_used;
2667 found->bytes_pinned = 0;
2668 found->bytes_reserved = 0;
2669 found->bytes_readonly = 0;
2670 found->bytes_delalloc = 0;
2671 found->full = 0;
2672 found->force_alloc = 0;
2673 *space_info = found;
2674 list_add_rcu(&found->list, &info->space_info);
2675 atomic_set(&found->caching_threads, 0);
2676 return 0;
2677 }
2678
2679 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
2680 {
2681 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
2682 BTRFS_BLOCK_GROUP_RAID1 |
2683 BTRFS_BLOCK_GROUP_RAID10 |
2684 BTRFS_BLOCK_GROUP_DUP);
2685 if (extra_flags) {
2686 if (flags & BTRFS_BLOCK_GROUP_DATA)
2687 fs_info->avail_data_alloc_bits |= extra_flags;
2688 if (flags & BTRFS_BLOCK_GROUP_METADATA)
2689 fs_info->avail_metadata_alloc_bits |= extra_flags;
2690 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
2691 fs_info->avail_system_alloc_bits |= extra_flags;
2692 }
2693 }
2694
2695 static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
2696 {
2697 spin_lock(&cache->space_info->lock);
2698 spin_lock(&cache->lock);
2699 if (!cache->ro) {
2700 cache->space_info->bytes_readonly += cache->key.offset -
2701 btrfs_block_group_used(&cache->item);
2702 cache->ro = 1;
2703 }
2704 spin_unlock(&cache->lock);
2705 spin_unlock(&cache->space_info->lock);
2706 }
2707
2708 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
2709 {
2710 u64 num_devices = root->fs_info->fs_devices->rw_devices;
2711
2712 if (num_devices == 1)
2713 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
2714 if (num_devices < 4)
2715 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
2716
2717 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
2718 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
2719 BTRFS_BLOCK_GROUP_RAID10))) {
2720 flags &= ~BTRFS_BLOCK_GROUP_DUP;
2721 }
2722
2723 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
2724 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
2725 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
2726 }
2727
2728 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
2729 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
2730 (flags & BTRFS_BLOCK_GROUP_RAID10) |
2731 (flags & BTRFS_BLOCK_GROUP_DUP)))
2732 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
2733 return flags;
2734 }
2735
2736 static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data)
2737 {
2738 struct btrfs_fs_info *info = root->fs_info;
2739 u64 alloc_profile;
2740
2741 if (data) {
2742 alloc_profile = info->avail_data_alloc_bits &
2743 info->data_alloc_profile;
2744 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2745 } else if (root == root->fs_info->chunk_root) {
2746 alloc_profile = info->avail_system_alloc_bits &
2747 info->system_alloc_profile;
2748 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2749 } else {
2750 alloc_profile = info->avail_metadata_alloc_bits &
2751 info->metadata_alloc_profile;
2752 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2753 }
2754
2755 return btrfs_reduce_alloc_profile(root, data);
2756 }
2757
2758 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
2759 {
2760 u64 alloc_target;
2761
2762 alloc_target = btrfs_get_alloc_profile(root, 1);
2763 BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
2764 alloc_target);
2765 }
2766
2767 /*
2768 * for now this just makes sure we have at least 5% of our metadata space free
2769 * for use.
2770 */
2771 int btrfs_check_metadata_free_space(struct btrfs_root *root)
2772 {
2773 struct btrfs_fs_info *info = root->fs_info;
2774 struct btrfs_space_info *meta_sinfo;
2775 u64 alloc_target, thresh;
2776 int committed = 0, ret;
2777
2778 /* get the space info for where the metadata will live */
2779 alloc_target = btrfs_get_alloc_profile(root, 0);
2780 meta_sinfo = __find_space_info(info, alloc_target);
2781
2782 again:
2783 spin_lock(&meta_sinfo->lock);
2784 if (!meta_sinfo->full)
2785 thresh = meta_sinfo->total_bytes * 80;
2786 else
2787 thresh = meta_sinfo->total_bytes * 95;
2788
2789 do_div(thresh, 100);
2790
2791 if (meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
2792 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
2793 meta_sinfo->bytes_super > thresh) {
2794 struct btrfs_trans_handle *trans;
2795 if (!meta_sinfo->full) {
2796 meta_sinfo->force_alloc = 1;
2797 spin_unlock(&meta_sinfo->lock);
2798
2799 trans = btrfs_start_transaction(root, 1);
2800 if (!trans)
2801 return -ENOMEM;
2802
2803 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2804 2 * 1024 * 1024, alloc_target, 0);
2805 btrfs_end_transaction(trans, root);
2806 goto again;
2807 }
2808 spin_unlock(&meta_sinfo->lock);
2809
2810 if (!committed) {
2811 committed = 1;
2812 trans = btrfs_join_transaction(root, 1);
2813 if (!trans)
2814 return -ENOMEM;
2815 ret = btrfs_commit_transaction(trans, root);
2816 if (ret)
2817 return ret;
2818 goto again;
2819 }
2820 return -ENOSPC;
2821 }
2822 spin_unlock(&meta_sinfo->lock);
2823
2824 return 0;
2825 }
2826
2827 /*
2828 * This will check the space that the inode allocates from to make sure we have
2829 * enough space for bytes.
2830 */
2831 int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
2832 u64 bytes)
2833 {
2834 struct btrfs_space_info *data_sinfo;
2835 int ret = 0, committed = 0;
2836
2837 /* make sure bytes are sectorsize aligned */
2838 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
2839
2840 data_sinfo = BTRFS_I(inode)->space_info;
2841 again:
2842 /* make sure we have enough space to handle the data first */
2843 spin_lock(&data_sinfo->lock);
2844 if (data_sinfo->total_bytes - data_sinfo->bytes_used -
2845 data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved -
2846 data_sinfo->bytes_pinned - data_sinfo->bytes_readonly -
2847 data_sinfo->bytes_may_use - data_sinfo->bytes_super < bytes) {
2848 struct btrfs_trans_handle *trans;
2849
2850 /*
2851 * if we don't have enough free bytes in this space then we need
2852 * to alloc a new chunk.
2853 */
2854 if (!data_sinfo->full) {
2855 u64 alloc_target;
2856
2857 data_sinfo->force_alloc = 1;
2858 spin_unlock(&data_sinfo->lock);
2859
2860 alloc_target = btrfs_get_alloc_profile(root, 1);
2861 trans = btrfs_start_transaction(root, 1);
2862 if (!trans)
2863 return -ENOMEM;
2864
2865 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2866 bytes + 2 * 1024 * 1024,
2867 alloc_target, 0);
2868 btrfs_end_transaction(trans, root);
2869 if (ret)
2870 return ret;
2871 goto again;
2872 }
2873 spin_unlock(&data_sinfo->lock);
2874
2875 /* commit the current transaction and try again */
2876 if (!committed) {
2877 committed = 1;
2878 trans = btrfs_join_transaction(root, 1);
2879 if (!trans)
2880 return -ENOMEM;
2881 ret = btrfs_commit_transaction(trans, root);
2882 if (ret)
2883 return ret;
2884 goto again;
2885 }
2886
2887 printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes"
2888 ", %llu bytes_used, %llu bytes_reserved, "
2889 "%llu bytes_pinned, %llu bytes_readonly, %llu may use "
2890 "%llu total\n", (unsigned long long)bytes,
2891 (unsigned long long)data_sinfo->bytes_delalloc,
2892 (unsigned long long)data_sinfo->bytes_used,
2893 (unsigned long long)data_sinfo->bytes_reserved,
2894 (unsigned long long)data_sinfo->bytes_pinned,
2895 (unsigned long long)data_sinfo->bytes_readonly,
2896 (unsigned long long)data_sinfo->bytes_may_use,
2897 (unsigned long long)data_sinfo->total_bytes);
2898 return -ENOSPC;
2899 }
2900 data_sinfo->bytes_may_use += bytes;
2901 BTRFS_I(inode)->reserved_bytes += bytes;
2902 spin_unlock(&data_sinfo->lock);
2903
2904 return btrfs_check_metadata_free_space(root);
2905 }
2906
2907 /*
2908 * if there was an error for whatever reason after calling
2909 * btrfs_check_data_free_space, call this so we can cleanup the counters.
2910 */
2911 void btrfs_free_reserved_data_space(struct btrfs_root *root,
2912 struct inode *inode, u64 bytes)
2913 {
2914 struct btrfs_space_info *data_sinfo;
2915
2916 /* make sure bytes are sectorsize aligned */
2917 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
2918
2919 data_sinfo = BTRFS_I(inode)->space_info;
2920 spin_lock(&data_sinfo->lock);
2921 data_sinfo->bytes_may_use -= bytes;
2922 BTRFS_I(inode)->reserved_bytes -= bytes;
2923 spin_unlock(&data_sinfo->lock);
2924 }
2925
2926 /* called when we are adding a delalloc extent to the inode's io_tree */
2927 void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
2928 u64 bytes)
2929 {
2930 struct btrfs_space_info *data_sinfo;
2931
2932 /* get the space info for where this inode will be storing its data */
2933 data_sinfo = BTRFS_I(inode)->space_info;
2934
2935 /* make sure we have enough space to handle the data first */
2936 spin_lock(&data_sinfo->lock);
2937 data_sinfo->bytes_delalloc += bytes;
2938
2939 /*
2940 * we are adding a delalloc extent without calling
2941 * btrfs_check_data_free_space first. This happens on a weird
2942 * writepage condition, but shouldn't hurt our accounting
2943 */
2944 if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {
2945 data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;
2946 BTRFS_I(inode)->reserved_bytes = 0;
2947 } else {
2948 data_sinfo->bytes_may_use -= bytes;
2949 BTRFS_I(inode)->reserved_bytes -= bytes;
2950 }
2951
2952 spin_unlock(&data_sinfo->lock);
2953 }
2954
2955 /* called when we are clearing an delalloc extent from the inode's io_tree */
2956 void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
2957 u64 bytes)
2958 {
2959 struct btrfs_space_info *info;
2960
2961 info = BTRFS_I(inode)->space_info;
2962
2963 spin_lock(&info->lock);
2964 info->bytes_delalloc -= bytes;
2965 spin_unlock(&info->lock);
2966 }
2967
2968 static void force_metadata_allocation(struct btrfs_fs_info *info)
2969 {
2970 struct list_head *head = &info->space_info;
2971 struct btrfs_space_info *found;
2972
2973 rcu_read_lock();
2974 list_for_each_entry_rcu(found, head, list) {
2975 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
2976 found->force_alloc = 1;
2977 }
2978 rcu_read_unlock();
2979 }
2980
2981 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
2982 struct btrfs_root *extent_root, u64 alloc_bytes,
2983 u64 flags, int force)
2984 {
2985 struct btrfs_space_info *space_info;
2986 struct btrfs_fs_info *fs_info = extent_root->fs_info;
2987 u64 thresh;
2988 int ret = 0;
2989
2990 mutex_lock(&fs_info->chunk_mutex);
2991
2992 flags = btrfs_reduce_alloc_profile(extent_root, flags);
2993
2994 space_info = __find_space_info(extent_root->fs_info, flags);
2995 if (!space_info) {
2996 ret = update_space_info(extent_root->fs_info, flags,
2997 0, 0, &space_info);
2998 BUG_ON(ret);
2999 }
3000 BUG_ON(!space_info);
3001
3002 spin_lock(&space_info->lock);
3003 if (space_info->force_alloc) {
3004 force = 1;
3005 space_info->force_alloc = 0;
3006 }
3007 if (space_info->full) {
3008 spin_unlock(&space_info->lock);
3009 goto out;
3010 }
3011
3012 thresh = space_info->total_bytes - space_info->bytes_readonly;
3013 thresh = div_factor(thresh, 6);
3014 if (!force &&
3015 (space_info->bytes_used + space_info->bytes_pinned +
3016 space_info->bytes_reserved + alloc_bytes) < thresh) {
3017 spin_unlock(&space_info->lock);
3018 goto out;
3019 }
3020 spin_unlock(&space_info->lock);
3021
3022 /*
3023 * if we're doing a data chunk, go ahead and make sure that
3024 * we keep a reasonable number of metadata chunks allocated in the
3025 * FS as well.
3026 */
3027 if (flags & BTRFS_BLOCK_GROUP_DATA) {
3028 fs_info->data_chunk_allocations++;
3029 if (!(fs_info->data_chunk_allocations %
3030 fs_info->metadata_ratio))
3031 force_metadata_allocation(fs_info);
3032 }
3033
3034 ret = btrfs_alloc_chunk(trans, extent_root, flags);
3035 if (ret)
3036 space_info->full = 1;
3037 out:
3038 mutex_unlock(&extent_root->fs_info->chunk_mutex);
3039 return ret;
3040 }
3041
3042 static int update_block_group(struct btrfs_trans_handle *trans,
3043 struct btrfs_root *root,
3044 u64 bytenr, u64 num_bytes, int alloc,
3045 int mark_free)
3046 {
3047 struct btrfs_block_group_cache *cache;
3048 struct btrfs_fs_info *info = root->fs_info;
3049 u64 total = num_bytes;
3050 u64 old_val;
3051 u64 byte_in_group;
3052
3053 /* block accounting for super block */
3054 spin_lock(&info->delalloc_lock);
3055 old_val = btrfs_super_bytes_used(&info->super_copy);
3056 if (alloc)
3057 old_val += num_bytes;
3058 else
3059 old_val -= num_bytes;
3060 btrfs_set_super_bytes_used(&info->super_copy, old_val);
3061
3062 /* block accounting for root item */
3063 old_val = btrfs_root_used(&root->root_item);
3064 if (alloc)
3065 old_val += num_bytes;
3066 else
3067 old_val -= num_bytes;
3068 btrfs_set_root_used(&root->root_item, old_val);
3069 spin_unlock(&info->delalloc_lock);
3070
3071 while (total) {
3072 cache = btrfs_lookup_block_group(info, bytenr);
3073 if (!cache)
3074 return -1;
3075 byte_in_group = bytenr - cache->key.objectid;
3076 WARN_ON(byte_in_group > cache->key.offset);
3077
3078 spin_lock(&cache->space_info->lock);
3079 spin_lock(&cache->lock);
3080 cache->dirty = 1;
3081 old_val = btrfs_block_group_used(&cache->item);
3082 num_bytes = min(total, cache->key.offset - byte_in_group);
3083 if (alloc) {
3084 old_val += num_bytes;
3085 btrfs_set_block_group_used(&cache->item, old_val);
3086 cache->reserved -= num_bytes;
3087 cache->space_info->bytes_used += num_bytes;
3088 cache->space_info->bytes_reserved -= num_bytes;
3089 if (cache->ro)
3090 cache->space_info->bytes_readonly -= num_bytes;
3091 spin_unlock(&cache->lock);
3092 spin_unlock(&cache->space_info->lock);
3093 } else {
3094 old_val -= num_bytes;
3095 cache->space_info->bytes_used -= num_bytes;
3096 if (cache->ro)
3097 cache->space_info->bytes_readonly += num_bytes;
3098 btrfs_set_block_group_used(&cache->item, old_val);
3099 spin_unlock(&cache->lock);
3100 spin_unlock(&cache->space_info->lock);
3101 if (mark_free) {
3102 int ret;
3103
3104 ret = btrfs_discard_extent(root, bytenr,
3105 num_bytes);
3106 WARN_ON(ret);
3107
3108 ret = btrfs_add_free_space(cache, bytenr,
3109 num_bytes);
3110 WARN_ON(ret);
3111 }
3112 }
3113 btrfs_put_block_group(cache);
3114 total -= num_bytes;
3115 bytenr += num_bytes;
3116 }
3117 return 0;
3118 }
3119
3120 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
3121 {
3122 struct btrfs_block_group_cache *cache;
3123 u64 bytenr;
3124
3125 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
3126 if (!cache)
3127 return 0;
3128
3129 bytenr = cache->key.objectid;
3130 btrfs_put_block_group(cache);
3131
3132 return bytenr;
3133 }
3134
3135 /*
3136 * this function must be called within transaction
3137 */
3138 int btrfs_pin_extent(struct btrfs_root *root,
3139 u64 bytenr, u64 num_bytes, int reserved)
3140 {
3141 struct btrfs_fs_info *fs_info = root->fs_info;
3142 struct btrfs_block_group_cache *cache;
3143
3144 cache = btrfs_lookup_block_group(fs_info, bytenr);
3145 BUG_ON(!cache);
3146
3147 spin_lock(&cache->space_info->lock);
3148 spin_lock(&cache->lock);
3149 cache->pinned += num_bytes;
3150 cache->space_info->bytes_pinned += num_bytes;
3151 if (reserved) {
3152 cache->reserved -= num_bytes;
3153 cache->space_info->bytes_reserved -= num_bytes;
3154 }
3155 spin_unlock(&cache->lock);
3156 spin_unlock(&cache->space_info->lock);
3157
3158 btrfs_put_block_group(cache);
3159
3160 set_extent_dirty(fs_info->pinned_extents,
3161 bytenr, bytenr + num_bytes - 1, GFP_NOFS);
3162 return 0;
3163 }
3164
3165 static int update_reserved_extents(struct btrfs_block_group_cache *cache,
3166 u64 num_bytes, int reserve)
3167 {
3168 spin_lock(&cache->space_info->lock);
3169 spin_lock(&cache->lock);
3170 if (reserve) {
3171 cache->reserved += num_bytes;
3172 cache->space_info->bytes_reserved += num_bytes;
3173 } else {
3174 cache->reserved -= num_bytes;
3175 cache->space_info->bytes_reserved -= num_bytes;
3176 }
3177 spin_unlock(&cache->lock);
3178 spin_unlock(&cache->space_info->lock);
3179 return 0;
3180 }
3181
3182 int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
3183 struct btrfs_root *root)
3184 {
3185 struct btrfs_fs_info *fs_info = root->fs_info;
3186 struct btrfs_caching_control *next;
3187 struct btrfs_caching_control *caching_ctl;
3188 struct btrfs_block_group_cache *cache;
3189
3190 down_write(&fs_info->extent_commit_sem);
3191
3192 list_for_each_entry_safe(caching_ctl, next,
3193 &fs_info->caching_block_groups, list) {
3194 cache = caching_ctl->block_group;
3195 if (block_group_cache_done(cache)) {
3196 cache->last_byte_to_unpin = (u64)-1;
3197 list_del_init(&caching_ctl->list);
3198 put_caching_control(caching_ctl);
3199 } else {
3200 cache->last_byte_to_unpin = caching_ctl->progress;
3201 }
3202 }
3203
3204 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
3205 fs_info->pinned_extents = &fs_info->freed_extents[1];
3206 else
3207 fs_info->pinned_extents = &fs_info->freed_extents[0];
3208
3209 up_write(&fs_info->extent_commit_sem);
3210 return 0;
3211 }
3212
3213 static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
3214 {
3215 struct btrfs_fs_info *fs_info = root->fs_info;
3216 struct btrfs_block_group_cache *cache = NULL;
3217 u64 len;
3218
3219 while (start <= end) {
3220 if (!cache ||
3221 start >= cache->key.objectid + cache->key.offset) {
3222 if (cache)
3223 btrfs_put_block_group(cache);
3224 cache = btrfs_lookup_block_group(fs_info, start);
3225 BUG_ON(!cache);
3226 }
3227
3228 len = cache->key.objectid + cache->key.offset - start;
3229 len = min(len, end + 1 - start);
3230
3231 if (start < cache->last_byte_to_unpin) {
3232 len = min(len, cache->last_byte_to_unpin - start);
3233 btrfs_add_free_space(cache, start, len);
3234 }
3235
3236 spin_lock(&cache->space_info->lock);
3237 spin_lock(&cache->lock);
3238 cache->pinned -= len;
3239 cache->space_info->bytes_pinned -= len;
3240 spin_unlock(&cache->lock);
3241 spin_unlock(&cache->space_info->lock);
3242
3243 start += len;
3244 }
3245
3246 if (cache)
3247 btrfs_put_block_group(cache);
3248 return 0;
3249 }
3250
3251 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
3252 struct btrfs_root *root)
3253 {
3254 struct btrfs_fs_info *fs_info = root->fs_info;
3255 struct extent_io_tree *unpin;
3256 u64 start;
3257 u64 end;
3258 int ret;
3259
3260 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
3261 unpin = &fs_info->freed_extents[1];
3262 else
3263 unpin = &fs_info->freed_extents[0];
3264
3265 while (1) {
3266 ret = find_first_extent_bit(unpin, 0, &start, &end,
3267 EXTENT_DIRTY);
3268 if (ret)
3269 break;
3270
3271 ret = btrfs_discard_extent(root, start, end + 1 - start);
3272
3273 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3274 unpin_extent_range(root, start, end);
3275 cond_resched();
3276 }
3277
3278 return ret;
3279 }
3280
3281 static int pin_down_bytes(struct btrfs_trans_handle *trans,
3282 struct btrfs_root *root,
3283 struct btrfs_path *path,
3284 u64 bytenr, u64 num_bytes,
3285 int is_data, int reserved,
3286 struct extent_buffer **must_clean)
3287 {
3288 int err = 0;
3289 struct extent_buffer *buf;
3290
3291 if (is_data)
3292 goto pinit;
3293
3294 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
3295 if (!buf)
3296 goto pinit;
3297
3298 /* we can reuse a block if it hasn't been written
3299 * and it is from this transaction. We can't
3300 * reuse anything from the tree log root because
3301 * it has tiny sub-transactions.
3302 */
3303 if (btrfs_buffer_uptodate(buf, 0) &&
3304 btrfs_try_tree_lock(buf)) {
3305 u64 header_owner = btrfs_header_owner(buf);
3306 u64 header_transid = btrfs_header_generation(buf);
3307 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
3308 header_transid == trans->transid &&
3309 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
3310 *must_clean = buf;
3311 return 1;
3312 }
3313 btrfs_tree_unlock(buf);
3314 }
3315 free_extent_buffer(buf);
3316 pinit:
3317 if (path)
3318 btrfs_set_path_blocking(path);
3319 /* unlocks the pinned mutex */
3320 btrfs_pin_extent(root, bytenr, num_bytes, reserved);
3321
3322 BUG_ON(err < 0);
3323 return 0;
3324 }
3325
3326 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
3327 struct btrfs_root *root,
3328 u64 bytenr, u64 num_bytes, u64 parent,
3329 u64 root_objectid, u64 owner_objectid,
3330 u64 owner_offset, int refs_to_drop,
3331 struct btrfs_delayed_extent_op *extent_op)
3332 {
3333 struct btrfs_key key;
3334 struct btrfs_path *path;
3335 struct btrfs_fs_info *info = root->fs_info;
3336 struct btrfs_root *extent_root = info->extent_root;
3337 struct extent_buffer *leaf;
3338 struct btrfs_extent_item *ei;
3339 struct btrfs_extent_inline_ref *iref;
3340 int ret;
3341 int is_data;
3342 int extent_slot = 0;
3343 int found_extent = 0;
3344 int num_to_del = 1;
3345 u32 item_size;
3346 u64 refs;
3347
3348 path = btrfs_alloc_path();
3349 if (!path)
3350 return -ENOMEM;
3351
3352 path->reada = 1;
3353 path->leave_spinning = 1;
3354
3355 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
3356 BUG_ON(!is_data && refs_to_drop != 1);
3357
3358 ret = lookup_extent_backref(trans, extent_root, path, &iref,
3359 bytenr, num_bytes, parent,
3360 root_objectid, owner_objectid,
3361 owner_offset);
3362 if (ret == 0) {
3363 extent_slot = path->slots[0];
3364 while (extent_slot >= 0) {
3365 btrfs_item_key_to_cpu(path->nodes[0], &key,
3366 extent_slot);
3367 if (key.objectid != bytenr)
3368 break;
3369 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3370 key.offset == num_bytes) {
3371 found_extent = 1;
3372 break;
3373 }
3374 if (path->slots[0] - extent_slot > 5)
3375 break;
3376 extent_slot--;
3377 }
3378 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3379 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
3380 if (found_extent && item_size < sizeof(*ei))
3381 found_extent = 0;
3382 #endif
3383 if (!found_extent) {
3384 BUG_ON(iref);
3385 ret = remove_extent_backref(trans, extent_root, path,
3386 NULL, refs_to_drop,
3387 is_data);
3388 BUG_ON(ret);
3389 btrfs_release_path(extent_root, path);
3390 path->leave_spinning = 1;
3391
3392 key.objectid = bytenr;
3393 key.type = BTRFS_EXTENT_ITEM_KEY;
3394 key.offset = num_bytes;
3395
3396 ret = btrfs_search_slot(trans, extent_root,
3397 &key, path, -1, 1);
3398 if (ret) {
3399 printk(KERN_ERR "umm, got %d back from search"
3400 ", was looking for %llu\n", ret,
3401 (unsigned long long)bytenr);
3402 btrfs_print_leaf(extent_root, path->nodes[0]);
3403 }
3404 BUG_ON(ret);
3405 extent_slot = path->slots[0];
3406 }
3407 } else {
3408 btrfs_print_leaf(extent_root, path->nodes[0]);
3409 WARN_ON(1);
3410 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
3411 "parent %llu root %llu owner %llu offset %llu\n",
3412 (unsigned long long)bytenr,
3413 (unsigned long long)parent,
3414 (unsigned long long)root_objectid,
3415 (unsigned long long)owner_objectid,
3416 (unsigned long long)owner_offset);
3417 }
3418
3419 leaf = path->nodes[0];
3420 item_size = btrfs_item_size_nr(leaf, extent_slot);
3421 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3422 if (item_size < sizeof(*ei)) {
3423 BUG_ON(found_extent || extent_slot != path->slots[0]);
3424 ret = convert_extent_item_v0(trans, extent_root, path,
3425 owner_objectid, 0);
3426 BUG_ON(ret < 0);
3427
3428 btrfs_release_path(extent_root, path);
3429 path->leave_spinning = 1;
3430
3431 key.objectid = bytenr;
3432 key.type = BTRFS_EXTENT_ITEM_KEY;
3433 key.offset = num_bytes;
3434
3435 ret = btrfs_search_slot(trans, extent_root, &key, path,
3436 -1, 1);
3437 if (ret) {
3438 printk(KERN_ERR "umm, got %d back from search"
3439 ", was looking for %llu\n", ret,
3440 (unsigned long long)bytenr);
3441 btrfs_print_leaf(extent_root, path->nodes[0]);
3442 }
3443 BUG_ON(ret);
3444 extent_slot = path->slots[0];
3445 leaf = path->nodes[0];
3446 item_size = btrfs_item_size_nr(leaf, extent_slot);
3447 }
3448 #endif
3449 BUG_ON(item_size < sizeof(*ei));
3450 ei = btrfs_item_ptr(leaf, extent_slot,
3451 struct btrfs_extent_item);
3452 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3453 struct btrfs_tree_block_info *bi;
3454 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
3455 bi = (struct btrfs_tree_block_info *)(ei + 1);
3456 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
3457 }
3458
3459 refs = btrfs_extent_refs(leaf, ei);
3460 BUG_ON(refs < refs_to_drop);
3461 refs -= refs_to_drop;
3462
3463 if (refs > 0) {
3464 if (extent_op)
3465 __run_delayed_extent_op(extent_op, leaf, ei);
3466 /*
3467 * In the case of inline back ref, reference count will
3468 * be updated by remove_extent_backref
3469 */
3470 if (iref) {
3471 BUG_ON(!found_extent);
3472 } else {
3473 btrfs_set_extent_refs(leaf, ei, refs);
3474 btrfs_mark_buffer_dirty(leaf);
3475 }
3476 if (found_extent) {
3477 ret = remove_extent_backref(trans, extent_root, path,
3478 iref, refs_to_drop,
3479 is_data);
3480 BUG_ON(ret);
3481 }
3482 } else {
3483 int mark_free = 0;
3484 struct extent_buffer *must_clean = NULL;
3485
3486 if (found_extent) {
3487 BUG_ON(is_data && refs_to_drop !=
3488 extent_data_ref_count(root, path, iref));
3489 if (iref) {
3490 BUG_ON(path->slots[0] != extent_slot);
3491 } else {
3492 BUG_ON(path->slots[0] != extent_slot + 1);
3493 path->slots[0] = extent_slot;
3494 num_to_del = 2;
3495 }
3496 }
3497
3498 ret = pin_down_bytes(trans, root, path, bytenr,
3499 num_bytes, is_data, 0, &must_clean);
3500 if (ret > 0)
3501 mark_free = 1;
3502 BUG_ON(ret < 0);
3503 /*
3504 * it is going to be very rare for someone to be waiting
3505 * on the block we're freeing. del_items might need to
3506 * schedule, so rather than get fancy, just force it
3507 * to blocking here
3508 */
3509 if (must_clean)
3510 btrfs_set_lock_blocking(must_clean);
3511
3512 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
3513 num_to_del);
3514 BUG_ON(ret);
3515 btrfs_release_path(extent_root, path);
3516
3517 if (must_clean) {
3518 clean_tree_block(NULL, root, must_clean);
3519 btrfs_tree_unlock(must_clean);
3520 free_extent_buffer(must_clean);
3521 }
3522
3523 if (is_data) {
3524 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
3525 BUG_ON(ret);
3526 } else {
3527 invalidate_mapping_pages(info->btree_inode->i_mapping,
3528 bytenr >> PAGE_CACHE_SHIFT,
3529 (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
3530 }
3531
3532 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
3533 mark_free);
3534 BUG_ON(ret);
3535 }
3536 btrfs_free_path(path);
3537 return ret;
3538 }
3539
3540 /*
3541 * when we free an extent, it is possible (and likely) that we free the last
3542 * delayed ref for that extent as well. This searches the delayed ref tree for
3543 * a given extent, and if there are no other delayed refs to be processed, it
3544 * removes it from the tree.
3545 */
3546 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
3547 struct btrfs_root *root, u64 bytenr)
3548 {
3549 struct btrfs_delayed_ref_head *head;
3550 struct btrfs_delayed_ref_root *delayed_refs;
3551 struct btrfs_delayed_ref_node *ref;
3552 struct rb_node *node;
3553 int ret;
3554
3555 delayed_refs = &trans->transaction->delayed_refs;
3556 spin_lock(&delayed_refs->lock);
3557 head = btrfs_find_delayed_ref_head(trans, bytenr);
3558 if (!head)
3559 goto out;
3560
3561 node = rb_prev(&head->node.rb_node);
3562 if (!node)
3563 goto out;
3564
3565 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3566
3567 /* there are still entries for this ref, we can't drop it */
3568 if (ref->bytenr == bytenr)
3569 goto out;
3570
3571 if (head->extent_op) {
3572 if (!head->must_insert_reserved)
3573 goto out;
3574 kfree(head->extent_op);
3575 head->extent_op = NULL;
3576 }
3577
3578 /*
3579 * waiting for the lock here would deadlock. If someone else has it
3580 * locked they are already in the process of dropping it anyway
3581 */
3582 if (!mutex_trylock(&head->mutex))
3583 goto out;
3584
3585 /*
3586 * at this point we have a head with no other entries. Go
3587 * ahead and process it.
3588 */
3589 head->node.in_tree = 0;
3590 rb_erase(&head->node.rb_node, &delayed_refs->root);
3591
3592 delayed_refs->num_entries--;
3593
3594 /*
3595 * we don't take a ref on the node because we're removing it from the
3596 * tree, so we just steal the ref the tree was holding.
3597 */
3598 delayed_refs->num_heads--;
3599 if (list_empty(&head->cluster))
3600 delayed_refs->num_heads_ready--;
3601
3602 list_del_init(&head->cluster);
3603 spin_unlock(&delayed_refs->lock);
3604
3605 ret = run_one_delayed_ref(trans, root->fs_info->tree_root,
3606 &head->node, head->extent_op,
3607 head->must_insert_reserved);
3608 BUG_ON(ret);
3609 btrfs_put_delayed_ref(&head->node);
3610 return 0;
3611 out:
3612 spin_unlock(&delayed_refs->lock);
3613 return 0;
3614 }
3615
3616 int btrfs_free_extent(struct btrfs_trans_handle *trans,
3617 struct btrfs_root *root,
3618 u64 bytenr, u64 num_bytes, u64 parent,
3619 u64 root_objectid, u64 owner, u64 offset)
3620 {
3621 int ret;
3622
3623 /*
3624 * tree log blocks never actually go into the extent allocation
3625 * tree, just update pinning info and exit early.
3626 */
3627 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
3628 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
3629 /* unlocks the pinned mutex */
3630 btrfs_pin_extent(root, bytenr, num_bytes, 1);
3631 ret = 0;
3632 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
3633 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
3634 parent, root_objectid, (int)owner,
3635 BTRFS_DROP_DELAYED_REF, NULL);
3636 BUG_ON(ret);
3637 ret = check_ref_cleanup(trans, root, bytenr);
3638 BUG_ON(ret);
3639 } else {
3640 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
3641 parent, root_objectid, owner,
3642 offset, BTRFS_DROP_DELAYED_REF, NULL);
3643 BUG_ON(ret);
3644 }
3645 return ret;
3646 }
3647
3648 static u64 stripe_align(struct btrfs_root *root, u64 val)
3649 {
3650 u64 mask = ((u64)root->stripesize - 1);
3651 u64 ret = (val + mask) & ~mask;
3652 return ret;
3653 }
3654
3655 /*
3656 * when we wait for progress in the block group caching, its because
3657 * our allocation attempt failed at least once. So, we must sleep
3658 * and let some progress happen before we try again.
3659 *
3660 * This function will sleep at least once waiting for new free space to
3661 * show up, and then it will check the block group free space numbers
3662 * for our min num_bytes. Another option is to have it go ahead
3663 * and look in the rbtree for a free extent of a given size, but this
3664 * is a good start.
3665 */
3666 static noinline int
3667 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
3668 u64 num_bytes)
3669 {
3670 struct btrfs_caching_control *caching_ctl;
3671 DEFINE_WAIT(wait);
3672
3673 caching_ctl = get_caching_control(cache);
3674 if (!caching_ctl)
3675 return 0;
3676
3677 wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
3678 (cache->free_space >= num_bytes));
3679
3680 put_caching_control(caching_ctl);
3681 return 0;
3682 }
3683
3684 static noinline int
3685 wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
3686 {
3687 struct btrfs_caching_control *caching_ctl;
3688 DEFINE_WAIT(wait);
3689
3690 caching_ctl = get_caching_control(cache);
3691 if (!caching_ctl)
3692 return 0;
3693
3694 wait_event(caching_ctl->wait, block_group_cache_done(cache));
3695
3696 put_caching_control(caching_ctl);
3697 return 0;
3698 }
3699
3700 enum btrfs_loop_type {
3701 LOOP_CACHED_ONLY = 0,
3702 LOOP_CACHING_NOWAIT = 1,
3703 LOOP_CACHING_WAIT = 2,
3704 LOOP_ALLOC_CHUNK = 3,
3705 LOOP_NO_EMPTY_SIZE = 4,
3706 };
3707
3708 /*
3709 * walks the btree of allocated extents and find a hole of a given size.
3710 * The key ins is changed to record the hole:
3711 * ins->objectid == block start
3712 * ins->flags = BTRFS_EXTENT_ITEM_KEY
3713 * ins->offset == number of blocks
3714 * Any available blocks before search_start are skipped.
3715 */
3716 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
3717 struct btrfs_root *orig_root,
3718 u64 num_bytes, u64 empty_size,
3719 u64 search_start, u64 search_end,
3720 u64 hint_byte, struct btrfs_key *ins,
3721 u64 exclude_start, u64 exclude_nr,
3722 int data)
3723 {
3724 int ret = 0;
3725 struct btrfs_root *root = orig_root->fs_info->extent_root;
3726 struct btrfs_free_cluster *last_ptr = NULL;
3727 struct btrfs_block_group_cache *block_group = NULL;
3728 int empty_cluster = 2 * 1024 * 1024;
3729 int allowed_chunk_alloc = 0;
3730 struct btrfs_space_info *space_info;
3731 int last_ptr_loop = 0;
3732 int loop = 0;
3733 bool found_uncached_bg = false;
3734 bool failed_cluster_refill = false;
3735
3736 WARN_ON(num_bytes < root->sectorsize);
3737 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
3738 ins->objectid = 0;
3739 ins->offset = 0;
3740
3741 space_info = __find_space_info(root->fs_info, data);
3742
3743 if (orig_root->ref_cows || empty_size)
3744 allowed_chunk_alloc = 1;
3745
3746 if (data & BTRFS_BLOCK_GROUP_METADATA) {
3747 last_ptr = &root->fs_info->meta_alloc_cluster;
3748 if (!btrfs_test_opt(root, SSD))
3749 empty_cluster = 64 * 1024;
3750 }
3751
3752 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
3753 last_ptr = &root->fs_info->data_alloc_cluster;
3754 }
3755
3756 if (last_ptr) {
3757 spin_lock(&last_ptr->lock);
3758 if (last_ptr->block_group)
3759 hint_byte = last_ptr->window_start;
3760 spin_unlock(&last_ptr->lock);
3761 }
3762
3763 search_start = max(search_start, first_logical_byte(root, 0));
3764 search_start = max(search_start, hint_byte);
3765
3766 if (!last_ptr)
3767 empty_cluster = 0;
3768
3769 if (search_start == hint_byte) {
3770 block_group = btrfs_lookup_block_group(root->fs_info,
3771 search_start);
3772 /*
3773 * we don't want to use the block group if it doesn't match our
3774 * allocation bits, or if its not cached.
3775 */
3776 if (block_group && block_group_bits(block_group, data) &&
3777 block_group_cache_done(block_group)) {
3778 down_read(&space_info->groups_sem);
3779 if (list_empty(&block_group->list) ||
3780 block_group->ro) {
3781 /*
3782 * someone is removing this block group,
3783 * we can't jump into the have_block_group
3784 * target because our list pointers are not
3785 * valid
3786 */
3787 btrfs_put_block_group(block_group);
3788 up_read(&space_info->groups_sem);
3789 } else
3790 goto have_block_group;
3791 } else if (block_group) {
3792 btrfs_put_block_group(block_group);
3793 }
3794 }
3795
3796 search:
3797 down_read(&space_info->groups_sem);
3798 list_for_each_entry(block_group, &space_info->block_groups, list) {
3799 u64 offset;
3800 int cached;
3801
3802 atomic_inc(&block_group->count);
3803 search_start = block_group->key.objectid;
3804
3805 have_block_group:
3806 if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
3807 /*
3808 * we want to start caching kthreads, but not too many
3809 * right off the bat so we don't overwhelm the system,
3810 * so only start them if there are less than 2 and we're
3811 * in the initial allocation phase.
3812 */
3813 if (loop > LOOP_CACHING_NOWAIT ||
3814 atomic_read(&space_info->caching_threads) < 2) {
3815 ret = cache_block_group(block_group);
3816 BUG_ON(ret);
3817 }
3818 }
3819
3820 cached = block_group_cache_done(block_group);
3821 if (unlikely(!cached)) {
3822 found_uncached_bg = true;
3823
3824 /* if we only want cached bgs, loop */
3825 if (loop == LOOP_CACHED_ONLY)
3826 goto loop;
3827 }
3828
3829 if (unlikely(block_group->ro))
3830 goto loop;
3831
3832 /*
3833 * Ok we want to try and use the cluster allocator, so lets look
3834 * there, unless we are on LOOP_NO_EMPTY_SIZE, since we will
3835 * have tried the cluster allocator plenty of times at this
3836 * point and not have found anything, so we are likely way too
3837 * fragmented for the clustering stuff to find anything, so lets
3838 * just skip it and let the allocator find whatever block it can
3839 * find
3840 */
3841 if (last_ptr && loop < LOOP_NO_EMPTY_SIZE) {
3842 /*
3843 * the refill lock keeps out other
3844 * people trying to start a new cluster
3845 */
3846 spin_lock(&last_ptr->refill_lock);
3847 if (last_ptr->block_group &&
3848 (last_ptr->block_group->ro ||
3849 !block_group_bits(last_ptr->block_group, data))) {
3850 offset = 0;
3851 goto refill_cluster;
3852 }
3853
3854 offset = btrfs_alloc_from_cluster(block_group, last_ptr,
3855 num_bytes, search_start);
3856 if (offset) {
3857 /* we have a block, we're done */
3858 spin_unlock(&last_ptr->refill_lock);
3859 goto checks;
3860 }
3861
3862 spin_lock(&last_ptr->lock);
3863 /*
3864 * whoops, this cluster doesn't actually point to
3865 * this block group. Get a ref on the block
3866 * group is does point to and try again
3867 */
3868 if (!last_ptr_loop && last_ptr->block_group &&
3869 last_ptr->block_group != block_group) {
3870
3871 btrfs_put_block_group(block_group);
3872 block_group = last_ptr->block_group;
3873 atomic_inc(&block_group->count);
3874 spin_unlock(&last_ptr->lock);
3875 spin_unlock(&last_ptr->refill_lock);
3876
3877 last_ptr_loop = 1;
3878 search_start = block_group->key.objectid;
3879 /*
3880 * we know this block group is properly
3881 * in the list because
3882 * btrfs_remove_block_group, drops the
3883 * cluster before it removes the block
3884 * group from the list
3885 */
3886 goto have_block_group;
3887 }
3888 spin_unlock(&last_ptr->lock);
3889 refill_cluster:
3890 /*
3891 * this cluster didn't work out, free it and
3892 * start over
3893 */
3894 btrfs_return_cluster_to_free_space(NULL, last_ptr);
3895
3896 last_ptr_loop = 0;
3897
3898 /* allocate a cluster in this block group */
3899 ret = btrfs_find_space_cluster(trans, root,
3900 block_group, last_ptr,
3901 offset, num_bytes,
3902 empty_cluster + empty_size);
3903 if (ret == 0) {
3904 /*
3905 * now pull our allocation out of this
3906 * cluster
3907 */
3908 offset = btrfs_alloc_from_cluster(block_group,
3909 last_ptr, num_bytes,
3910 search_start);
3911 if (offset) {
3912 /* we found one, proceed */
3913 spin_unlock(&last_ptr->refill_lock);
3914 goto checks;
3915 }
3916 } else if (!cached && loop > LOOP_CACHING_NOWAIT
3917 && !failed_cluster_refill) {
3918 spin_unlock(&last_ptr->refill_lock);
3919
3920 failed_cluster_refill = true;
3921 wait_block_group_cache_progress(block_group,
3922 num_bytes + empty_cluster + empty_size);
3923 goto have_block_group;
3924 }
3925
3926 /*
3927 * at this point we either didn't find a cluster
3928 * or we weren't able to allocate a block from our
3929 * cluster. Free the cluster we've been trying
3930 * to use, and go to the next block group
3931 */
3932 btrfs_return_cluster_to_free_space(NULL, last_ptr);
3933 spin_unlock(&last_ptr->refill_lock);
3934 goto loop;
3935 }
3936
3937 offset = btrfs_find_space_for_alloc(block_group, search_start,
3938 num_bytes, empty_size);
3939 if (!offset && (cached || (!cached &&
3940 loop == LOOP_CACHING_NOWAIT))) {
3941 goto loop;
3942 } else if (!offset && (!cached &&
3943 loop > LOOP_CACHING_NOWAIT)) {
3944 wait_block_group_cache_progress(block_group,
3945 num_bytes + empty_size);
3946 goto have_block_group;
3947 }
3948 checks:
3949 search_start = stripe_align(root, offset);
3950 /* move on to the next group */
3951 if (search_start + num_bytes >= search_end) {
3952 btrfs_add_free_space(block_group, offset, num_bytes);
3953 goto loop;
3954 }
3955
3956 /* move on to the next group */
3957 if (search_start + num_bytes >
3958 block_group->key.objectid + block_group->key.offset) {
3959 btrfs_add_free_space(block_group, offset, num_bytes);
3960 goto loop;
3961 }
3962
3963 if (exclude_nr > 0 &&
3964 (search_start + num_bytes > exclude_start &&
3965 search_start < exclude_start + exclude_nr)) {
3966 search_start = exclude_start + exclude_nr;
3967
3968 btrfs_add_free_space(block_group, offset, num_bytes);
3969 /*
3970 * if search_start is still in this block group
3971 * then we just re-search this block group
3972 */
3973 if (search_start >= block_group->key.objectid &&
3974 search_start < (block_group->key.objectid +
3975 block_group->key.offset))
3976 goto have_block_group;
3977 goto loop;
3978 }
3979
3980 ins->objectid = search_start;
3981 ins->offset = num_bytes;
3982
3983 if (offset < search_start)
3984 btrfs_add_free_space(block_group, offset,
3985 search_start - offset);
3986 BUG_ON(offset > search_start);
3987
3988 update_reserved_extents(block_group, num_bytes, 1);
3989
3990 /* we are all good, lets return */
3991 break;
3992 loop:
3993 failed_cluster_refill = false;
3994 btrfs_put_block_group(block_group);
3995 }
3996 up_read(&space_info->groups_sem);
3997
3998 /* LOOP_CACHED_ONLY, only search fully cached block groups
3999 * LOOP_CACHING_NOWAIT, search partially cached block groups, but
4000 * dont wait foR them to finish caching
4001 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
4002 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
4003 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
4004 * again
4005 */
4006 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE &&
4007 (found_uncached_bg || empty_size || empty_cluster ||
4008 allowed_chunk_alloc)) {
4009 if (found_uncached_bg) {
4010 found_uncached_bg = false;
4011 if (loop < LOOP_CACHING_WAIT) {
4012 loop++;
4013 goto search;
4014 }
4015 }
4016
4017 if (loop == LOOP_ALLOC_CHUNK) {
4018 empty_size = 0;
4019 empty_cluster = 0;
4020 }
4021
4022 if (allowed_chunk_alloc) {
4023 ret = do_chunk_alloc(trans, root, num_bytes +
4024 2 * 1024 * 1024, data, 1);
4025 allowed_chunk_alloc = 0;
4026 } else {
4027 space_info->force_alloc = 1;
4028 }
4029
4030 if (loop < LOOP_NO_EMPTY_SIZE) {
4031 loop++;
4032 goto search;
4033 }
4034 ret = -ENOSPC;
4035 } else if (!ins->objectid) {
4036 ret = -ENOSPC;
4037 }
4038
4039 /* we found what we needed */
4040 if (ins->objectid) {
4041 if (!(data & BTRFS_BLOCK_GROUP_DATA))
4042 trans->block_group = block_group->key.objectid;
4043
4044 btrfs_put_block_group(block_group);
4045 ret = 0;
4046 }
4047
4048 return ret;
4049 }
4050
4051 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
4052 {
4053 struct btrfs_block_group_cache *cache;
4054
4055 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
4056 (unsigned long long)(info->total_bytes - info->bytes_used -
4057 info->bytes_pinned - info->bytes_reserved),
4058 (info->full) ? "" : "not ");
4059 printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu,"
4060 " may_use=%llu, used=%llu\n",
4061 (unsigned long long)info->total_bytes,
4062 (unsigned long long)info->bytes_pinned,
4063 (unsigned long long)info->bytes_delalloc,
4064 (unsigned long long)info->bytes_may_use,
4065 (unsigned long long)info->bytes_used);
4066
4067 down_read(&info->groups_sem);
4068 list_for_each_entry(cache, &info->block_groups, list) {
4069 spin_lock(&cache->lock);
4070 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
4071 "%llu pinned %llu reserved\n",
4072 (unsigned long long)cache->key.objectid,
4073 (unsigned long long)cache->key.offset,
4074 (unsigned long long)btrfs_block_group_used(&cache->item),
4075 (unsigned long long)cache->pinned,
4076 (unsigned long long)cache->reserved);
4077 btrfs_dump_free_space(cache, bytes);
4078 spin_unlock(&cache->lock);
4079 }
4080 up_read(&info->groups_sem);
4081 }
4082
4083 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
4084 struct btrfs_root *root,
4085 u64 num_bytes, u64 min_alloc_size,
4086 u64 empty_size, u64 hint_byte,
4087 u64 search_end, struct btrfs_key *ins,
4088 u64 data)
4089 {
4090 int ret;
4091 u64 search_start = 0;
4092 struct btrfs_fs_info *info = root->fs_info;
4093
4094 data = btrfs_get_alloc_profile(root, data);
4095 again:
4096 /*
4097 * the only place that sets empty_size is btrfs_realloc_node, which
4098 * is not called recursively on allocations
4099 */
4100 if (empty_size || root->ref_cows) {
4101 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
4102 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4103 2 * 1024 * 1024,
4104 BTRFS_BLOCK_GROUP_METADATA |
4105 (info->metadata_alloc_profile &
4106 info->avail_metadata_alloc_bits), 0);
4107 }
4108 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4109 num_bytes + 2 * 1024 * 1024, data, 0);
4110 }
4111
4112 WARN_ON(num_bytes < root->sectorsize);
4113 ret = find_free_extent(trans, root, num_bytes, empty_size,
4114 search_start, search_end, hint_byte, ins,
4115 trans->alloc_exclude_start,
4116 trans->alloc_exclude_nr, data);
4117
4118 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
4119 num_bytes = num_bytes >> 1;
4120 num_bytes = num_bytes & ~(root->sectorsize - 1);
4121 num_bytes = max(num_bytes, min_alloc_size);
4122 do_chunk_alloc(trans, root->fs_info->extent_root,
4123 num_bytes, data, 1);
4124 goto again;
4125 }
4126 if (ret == -ENOSPC) {
4127 struct btrfs_space_info *sinfo;
4128
4129 sinfo = __find_space_info(root->fs_info, data);
4130 printk(KERN_ERR "btrfs allocation failed flags %llu, "
4131 "wanted %llu\n", (unsigned long long)data,
4132 (unsigned long long)num_bytes);
4133 dump_space_info(sinfo, num_bytes);
4134 }
4135
4136 return ret;
4137 }
4138
4139 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
4140 {
4141 struct btrfs_block_group_cache *cache;
4142 int ret = 0;
4143
4144 cache = btrfs_lookup_block_group(root->fs_info, start);
4145 if (!cache) {
4146 printk(KERN_ERR "Unable to find block group for %llu\n",
4147 (unsigned long long)start);
4148 return -ENOSPC;
4149 }
4150
4151 ret = btrfs_discard_extent(root, start, len);
4152
4153 btrfs_add_free_space(cache, start, len);
4154 update_reserved_extents(cache, len, 0);
4155 btrfs_put_block_group(cache);
4156
4157 return ret;
4158 }
4159
4160 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4161 struct btrfs_root *root,
4162 u64 parent, u64 root_objectid,
4163 u64 flags, u64 owner, u64 offset,
4164 struct btrfs_key *ins, int ref_mod)
4165 {
4166 int ret;
4167 struct btrfs_fs_info *fs_info = root->fs_info;
4168 struct btrfs_extent_item *extent_item;
4169 struct btrfs_extent_inline_ref *iref;
4170 struct btrfs_path *path;
4171 struct extent_buffer *leaf;
4172 int type;
4173 u32 size;
4174
4175 if (parent > 0)
4176 type = BTRFS_SHARED_DATA_REF_KEY;
4177 else
4178 type = BTRFS_EXTENT_DATA_REF_KEY;
4179
4180 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
4181
4182 path = btrfs_alloc_path();
4183 BUG_ON(!path);
4184
4185 path->leave_spinning = 1;
4186 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4187 ins, size);
4188 BUG_ON(ret);
4189
4190 leaf = path->nodes[0];
4191 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4192 struct btrfs_extent_item);
4193 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
4194 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4195 btrfs_set_extent_flags(leaf, extent_item,
4196 flags | BTRFS_EXTENT_FLAG_DATA);
4197
4198 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
4199 btrfs_set_extent_inline_ref_type(leaf, iref, type);
4200 if (parent > 0) {
4201 struct btrfs_shared_data_ref *ref;
4202 ref = (struct btrfs_shared_data_ref *)(iref + 1);
4203 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4204 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
4205 } else {
4206 struct btrfs_extent_data_ref *ref;
4207 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
4208 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
4209 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
4210 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
4211 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
4212 }
4213
4214 btrfs_mark_buffer_dirty(path->nodes[0]);
4215 btrfs_free_path(path);
4216
4217 ret = update_block_group(trans, root, ins->objectid, ins->offset,
4218 1, 0);
4219 if (ret) {
4220 printk(KERN_ERR "btrfs update block group failed for %llu "
4221 "%llu\n", (unsigned long long)ins->objectid,
4222 (unsigned long long)ins->offset);
4223 BUG();
4224 }
4225 return ret;
4226 }
4227
4228 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
4229 struct btrfs_root *root,
4230 u64 parent, u64 root_objectid,
4231 u64 flags, struct btrfs_disk_key *key,
4232 int level, struct btrfs_key *ins)
4233 {
4234 int ret;
4235 struct btrfs_fs_info *fs_info = root->fs_info;
4236 struct btrfs_extent_item *extent_item;
4237 struct btrfs_tree_block_info *block_info;
4238 struct btrfs_extent_inline_ref *iref;
4239 struct btrfs_path *path;
4240 struct extent_buffer *leaf;
4241 u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
4242
4243 path = btrfs_alloc_path();
4244 BUG_ON(!path);
4245
4246 path->leave_spinning = 1;
4247 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4248 ins, size);
4249 BUG_ON(ret);
4250
4251 leaf = path->nodes[0];
4252 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4253 struct btrfs_extent_item);
4254 btrfs_set_extent_refs(leaf, extent_item, 1);
4255 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4256 btrfs_set_extent_flags(leaf, extent_item,
4257 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
4258 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
4259
4260 btrfs_set_tree_block_key(leaf, block_info, key);
4261 btrfs_set_tree_block_level(leaf, block_info, level);
4262
4263 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
4264 if (parent > 0) {
4265 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
4266 btrfs_set_extent_inline_ref_type(leaf, iref,
4267 BTRFS_SHARED_BLOCK_REF_KEY);
4268 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4269 } else {
4270 btrfs_set_extent_inline_ref_type(leaf, iref,
4271 BTRFS_TREE_BLOCK_REF_KEY);
4272 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
4273 }
4274
4275 btrfs_mark_buffer_dirty(leaf);
4276 btrfs_free_path(path);
4277
4278 ret = update_block_group(trans, root, ins->objectid, ins->offset,
4279 1, 0);
4280 if (ret) {
4281 printk(KERN_ERR "btrfs update block group failed for %llu "
4282 "%llu\n", (unsigned long long)ins->objectid,
4283 (unsigned long long)ins->offset);
4284 BUG();
4285 }
4286 return ret;
4287 }
4288
4289 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4290 struct btrfs_root *root,
4291 u64 root_objectid, u64 owner,
4292 u64 offset, struct btrfs_key *ins)
4293 {
4294 int ret;
4295
4296 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
4297
4298 ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
4299 0, root_objectid, owner, offset,
4300 BTRFS_ADD_DELAYED_EXTENT, NULL);
4301 return ret;
4302 }
4303
4304 /*
4305 * this is used by the tree logging recovery code. It records that
4306 * an extent has been allocated and makes sure to clear the free
4307 * space cache bits as well
4308 */
4309 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
4310 struct btrfs_root *root,
4311 u64 root_objectid, u64 owner, u64 offset,
4312 struct btrfs_key *ins)
4313 {
4314 int ret;
4315 struct btrfs_block_group_cache *block_group;
4316 struct btrfs_caching_control *caching_ctl;
4317 u64 start = ins->objectid;
4318 u64 num_bytes = ins->offset;
4319
4320 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
4321 cache_block_group(block_group);
4322 caching_ctl = get_caching_control(block_group);
4323
4324 if (!caching_ctl) {
4325 BUG_ON(!block_group_cache_done(block_group));
4326 ret = btrfs_remove_free_space(block_group, start, num_bytes);
4327 BUG_ON(ret);
4328 } else {
4329 mutex_lock(&caching_ctl->mutex);
4330
4331 if (start >= caching_ctl->progress) {
4332 ret = add_excluded_extent(root, start, num_bytes);
4333 BUG_ON(ret);
4334 } else if (start + num_bytes <= caching_ctl->progress) {
4335 ret = btrfs_remove_free_space(block_group,
4336 start, num_bytes);
4337 BUG_ON(ret);
4338 } else {
4339 num_bytes = caching_ctl->progress - start;
4340 ret = btrfs_remove_free_space(block_group,
4341 start, num_bytes);
4342 BUG_ON(ret);
4343
4344 start = caching_ctl->progress;
4345 num_bytes = ins->objectid + ins->offset -
4346 caching_ctl->progress;
4347 ret = add_excluded_extent(root, start, num_bytes);
4348 BUG_ON(ret);
4349 }
4350
4351 mutex_unlock(&caching_ctl->mutex);
4352 put_caching_control(caching_ctl);
4353 }
4354
4355 update_reserved_extents(block_group, ins->offset, 1);
4356 btrfs_put_block_group(block_group);
4357 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
4358 0, owner, offset, ins, 1);
4359 return ret;
4360 }
4361
4362 /*
4363 * finds a free extent and does all the dirty work required for allocation
4364 * returns the key for the extent through ins, and a tree buffer for
4365 * the first block of the extent through buf.
4366 *
4367 * returns 0 if everything worked, non-zero otherwise.
4368 */
4369 static int alloc_tree_block(struct btrfs_trans_handle *trans,
4370 struct btrfs_root *root,
4371 u64 num_bytes, u64 parent, u64 root_objectid,
4372 struct btrfs_disk_key *key, int level,
4373 u64 empty_size, u64 hint_byte, u64 search_end,
4374 struct btrfs_key *ins)
4375 {
4376 int ret;
4377 u64 flags = 0;
4378
4379 ret = btrfs_reserve_extent(trans, root, num_bytes, num_bytes,
4380 empty_size, hint_byte, search_end,
4381 ins, 0);
4382 if (ret)
4383 return ret;
4384
4385 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
4386 if (parent == 0)
4387 parent = ins->objectid;
4388 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
4389 } else
4390 BUG_ON(parent > 0);
4391
4392 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
4393 struct btrfs_delayed_extent_op *extent_op;
4394 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
4395 BUG_ON(!extent_op);
4396 if (key)
4397 memcpy(&extent_op->key, key, sizeof(extent_op->key));
4398 else
4399 memset(&extent_op->key, 0, sizeof(extent_op->key));
4400 extent_op->flags_to_set = flags;
4401 extent_op->update_key = 1;
4402 extent_op->update_flags = 1;
4403 extent_op->is_data = 0;
4404
4405 ret = btrfs_add_delayed_tree_ref(trans, ins->objectid,
4406 ins->offset, parent, root_objectid,
4407 level, BTRFS_ADD_DELAYED_EXTENT,
4408 extent_op);
4409 BUG_ON(ret);
4410 }
4411 return ret;
4412 }
4413
4414 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
4415 struct btrfs_root *root,
4416 u64 bytenr, u32 blocksize,
4417 int level)
4418 {
4419 struct extent_buffer *buf;
4420
4421 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
4422 if (!buf)
4423 return ERR_PTR(-ENOMEM);
4424 btrfs_set_header_generation(buf, trans->transid);
4425 btrfs_set_buffer_lockdep_class(buf, level);
4426 btrfs_tree_lock(buf);
4427 clean_tree_block(trans, root, buf);
4428
4429 btrfs_set_lock_blocking(buf);
4430 btrfs_set_buffer_uptodate(buf);
4431
4432 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
4433 set_extent_dirty(&root->dirty_log_pages, buf->start,
4434 buf->start + buf->len - 1, GFP_NOFS);
4435 } else {
4436 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
4437 buf->start + buf->len - 1, GFP_NOFS);
4438 }
4439 trans->blocks_used++;
4440 /* this returns a buffer locked for blocking */
4441 return buf;
4442 }
4443
4444 /*
4445 * helper function to allocate a block for a given tree
4446 * returns the tree buffer or NULL.
4447 */
4448 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
4449 struct btrfs_root *root, u32 blocksize,
4450 u64 parent, u64 root_objectid,
4451 struct btrfs_disk_key *key, int level,
4452 u64 hint, u64 empty_size)
4453 {
4454 struct btrfs_key ins;
4455 int ret;
4456 struct extent_buffer *buf;
4457
4458 ret = alloc_tree_block(trans, root, blocksize, parent, root_objectid,
4459 key, level, empty_size, hint, (u64)-1, &ins);
4460 if (ret) {
4461 BUG_ON(ret > 0);
4462 return ERR_PTR(ret);
4463 }
4464
4465 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
4466 blocksize, level);
4467 return buf;
4468 }
4469
4470 struct walk_control {
4471 u64 refs[BTRFS_MAX_LEVEL];
4472 u64 flags[BTRFS_MAX_LEVEL];
4473 struct btrfs_key update_progress;
4474 int stage;
4475 int level;
4476 int shared_level;
4477 int update_ref;
4478 int keep_locks;
4479 int reada_slot;
4480 int reada_count;
4481 };
4482
4483 #define DROP_REFERENCE 1
4484 #define UPDATE_BACKREF 2
4485
4486 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
4487 struct btrfs_root *root,
4488 struct walk_control *wc,
4489 struct btrfs_path *path)
4490 {
4491 u64 bytenr;
4492 u64 generation;
4493 u64 refs;
4494 u64 last = 0;
4495 u32 nritems;
4496 u32 blocksize;
4497 struct btrfs_key key;
4498 struct extent_buffer *eb;
4499 int ret;
4500 int slot;
4501 int nread = 0;
4502
4503 if (path->slots[wc->level] < wc->reada_slot) {
4504 wc->reada_count = wc->reada_count * 2 / 3;
4505 wc->reada_count = max(wc->reada_count, 2);
4506 } else {
4507 wc->reada_count = wc->reada_count * 3 / 2;
4508 wc->reada_count = min_t(int, wc->reada_count,
4509 BTRFS_NODEPTRS_PER_BLOCK(root));
4510 }
4511
4512 eb = path->nodes[wc->level];
4513 nritems = btrfs_header_nritems(eb);
4514 blocksize = btrfs_level_size(root, wc->level - 1);
4515
4516 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
4517 if (nread >= wc->reada_count)
4518 break;
4519
4520 cond_resched();
4521 bytenr = btrfs_node_blockptr(eb, slot);
4522 generation = btrfs_node_ptr_generation(eb, slot);
4523
4524 if (slot == path->slots[wc->level])
4525 goto reada;
4526
4527 if (wc->stage == UPDATE_BACKREF &&
4528 generation <= root->root_key.offset)
4529 continue;
4530
4531 if (wc->stage == DROP_REFERENCE) {
4532 ret = btrfs_lookup_extent_info(trans, root,
4533 bytenr, blocksize,
4534 &refs, NULL);
4535 BUG_ON(ret);
4536 BUG_ON(refs == 0);
4537 if (refs == 1)
4538 goto reada;
4539
4540 if (!wc->update_ref ||
4541 generation <= root->root_key.offset)
4542 continue;
4543 btrfs_node_key_to_cpu(eb, &key, slot);
4544 ret = btrfs_comp_cpu_keys(&key,
4545 &wc->update_progress);
4546 if (ret < 0)
4547 continue;
4548 }
4549 reada:
4550 ret = readahead_tree_block(root, bytenr, blocksize,
4551 generation);
4552 if (ret)
4553 break;
4554 last = bytenr + blocksize;
4555 nread++;
4556 }
4557 wc->reada_slot = slot;
4558 }
4559
4560 /*
4561 * hepler to process tree block while walking down the tree.
4562 *
4563 * when wc->stage == UPDATE_BACKREF, this function updates
4564 * back refs for pointers in the block.
4565 *
4566 * NOTE: return value 1 means we should stop walking down.
4567 */
4568 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
4569 struct btrfs_root *root,
4570 struct btrfs_path *path,
4571 struct walk_control *wc)
4572 {
4573 int level = wc->level;
4574 struct extent_buffer *eb = path->nodes[level];
4575 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
4576 int ret;
4577
4578 if (wc->stage == UPDATE_BACKREF &&
4579 btrfs_header_owner(eb) != root->root_key.objectid)
4580 return 1;
4581
4582 /*
4583 * when reference count of tree block is 1, it won't increase
4584 * again. once full backref flag is set, we never clear it.
4585 */
4586 if ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
4587 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag))) {
4588 BUG_ON(!path->locks[level]);
4589 ret = btrfs_lookup_extent_info(trans, root,
4590 eb->start, eb->len,
4591 &wc->refs[level],
4592 &wc->flags[level]);
4593 BUG_ON(ret);
4594 BUG_ON(wc->refs[level] == 0);
4595 }
4596
4597 if (wc->stage == DROP_REFERENCE) {
4598 if (wc->refs[level] > 1)
4599 return 1;
4600
4601 if (path->locks[level] && !wc->keep_locks) {
4602 btrfs_tree_unlock(eb);
4603 path->locks[level] = 0;
4604 }
4605 return 0;
4606 }
4607
4608 /* wc->stage == UPDATE_BACKREF */
4609 if (!(wc->flags[level] & flag)) {
4610 BUG_ON(!path->locks[level]);
4611 ret = btrfs_inc_ref(trans, root, eb, 1);
4612 BUG_ON(ret);
4613 ret = btrfs_dec_ref(trans, root, eb, 0);
4614 BUG_ON(ret);
4615 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
4616 eb->len, flag, 0);
4617 BUG_ON(ret);
4618 wc->flags[level] |= flag;
4619 }
4620
4621 /*
4622 * the block is shared by multiple trees, so it's not good to
4623 * keep the tree lock
4624 */
4625 if (path->locks[level] && level > 0) {
4626 btrfs_tree_unlock(eb);
4627 path->locks[level] = 0;
4628 }
4629 return 0;
4630 }
4631
4632 /*
4633 * hepler to process tree block pointer.
4634 *
4635 * when wc->stage == DROP_REFERENCE, this function checks
4636 * reference count of the block pointed to. if the block
4637 * is shared and we need update back refs for the subtree
4638 * rooted at the block, this function changes wc->stage to
4639 * UPDATE_BACKREF. if the block is shared and there is no
4640 * need to update back, this function drops the reference
4641 * to the block.
4642 *
4643 * NOTE: return value 1 means we should stop walking down.
4644 */
4645 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
4646 struct btrfs_root *root,
4647 struct btrfs_path *path,
4648 struct walk_control *wc)
4649 {
4650 u64 bytenr;
4651 u64 generation;
4652 u64 parent;
4653 u32 blocksize;
4654 struct btrfs_key key;
4655 struct extent_buffer *next;
4656 int level = wc->level;
4657 int reada = 0;
4658 int ret = 0;
4659
4660 generation = btrfs_node_ptr_generation(path->nodes[level],
4661 path->slots[level]);
4662 /*
4663 * if the lower level block was created before the snapshot
4664 * was created, we know there is no need to update back refs
4665 * for the subtree
4666 */
4667 if (wc->stage == UPDATE_BACKREF &&
4668 generation <= root->root_key.offset)
4669 return 1;
4670
4671 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
4672 blocksize = btrfs_level_size(root, level - 1);
4673
4674 next = btrfs_find_tree_block(root, bytenr, blocksize);
4675 if (!next) {
4676 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
4677 reada = 1;
4678 }
4679 btrfs_tree_lock(next);
4680 btrfs_set_lock_blocking(next);
4681
4682 if (wc->stage == DROP_REFERENCE) {
4683 ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
4684 &wc->refs[level - 1],
4685 &wc->flags[level - 1]);
4686 BUG_ON(ret);
4687 BUG_ON(wc->refs[level - 1] == 0);
4688
4689 if (wc->refs[level - 1] > 1) {
4690 if (!wc->update_ref ||
4691 generation <= root->root_key.offset)
4692 goto skip;
4693
4694 btrfs_node_key_to_cpu(path->nodes[level], &key,
4695 path->slots[level]);
4696 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
4697 if (ret < 0)
4698 goto skip;
4699
4700 wc->stage = UPDATE_BACKREF;
4701 wc->shared_level = level - 1;
4702 }
4703 }
4704
4705 if (!btrfs_buffer_uptodate(next, generation)) {
4706 btrfs_tree_unlock(next);
4707 free_extent_buffer(next);
4708 next = NULL;
4709 }
4710
4711 if (!next) {
4712 if (reada && level == 1)
4713 reada_walk_down(trans, root, wc, path);
4714 next = read_tree_block(root, bytenr, blocksize, generation);
4715 btrfs_tree_lock(next);
4716 btrfs_set_lock_blocking(next);
4717 }
4718
4719 level--;
4720 BUG_ON(level != btrfs_header_level(next));
4721 path->nodes[level] = next;
4722 path->slots[level] = 0;
4723 path->locks[level] = 1;
4724 wc->level = level;
4725 if (wc->level == 1)
4726 wc->reada_slot = 0;
4727 return 0;
4728 skip:
4729 wc->refs[level - 1] = 0;
4730 wc->flags[level - 1] = 0;
4731
4732 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
4733 parent = path->nodes[level]->start;
4734 } else {
4735 BUG_ON(root->root_key.objectid !=
4736 btrfs_header_owner(path->nodes[level]));
4737 parent = 0;
4738 }
4739
4740 ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
4741 root->root_key.objectid, level - 1, 0);
4742 BUG_ON(ret);
4743
4744 btrfs_tree_unlock(next);
4745 free_extent_buffer(next);
4746 return 1;
4747 }
4748
4749 /*
4750 * hepler to process tree block while walking up the tree.
4751 *
4752 * when wc->stage == DROP_REFERENCE, this function drops
4753 * reference count on the block.
4754 *
4755 * when wc->stage == UPDATE_BACKREF, this function changes
4756 * wc->stage back to DROP_REFERENCE if we changed wc->stage
4757 * to UPDATE_BACKREF previously while processing the block.
4758 *
4759 * NOTE: return value 1 means we should stop walking up.
4760 */
4761 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
4762 struct btrfs_root *root,
4763 struct btrfs_path *path,
4764 struct walk_control *wc)
4765 {
4766 int ret = 0;
4767 int level = wc->level;
4768 struct extent_buffer *eb = path->nodes[level];
4769 u64 parent = 0;
4770
4771 if (wc->stage == UPDATE_BACKREF) {
4772 BUG_ON(wc->shared_level < level);
4773 if (level < wc->shared_level)
4774 goto out;
4775
4776 ret = find_next_key(path, level + 1, &wc->update_progress);
4777 if (ret > 0)
4778 wc->update_ref = 0;
4779
4780 wc->stage = DROP_REFERENCE;
4781 wc->shared_level = -1;
4782 path->slots[level] = 0;
4783
4784 /*
4785 * check reference count again if the block isn't locked.
4786 * we should start walking down the tree again if reference
4787 * count is one.
4788 */
4789 if (!path->locks[level]) {
4790 BUG_ON(level == 0);
4791 btrfs_tree_lock(eb);
4792 btrfs_set_lock_blocking(eb);
4793 path->locks[level] = 1;
4794
4795 ret = btrfs_lookup_extent_info(trans, root,
4796 eb->start, eb->len,
4797 &wc->refs[level],
4798 &wc->flags[level]);
4799 BUG_ON(ret);
4800 BUG_ON(wc->refs[level] == 0);
4801 if (wc->refs[level] == 1) {
4802 btrfs_tree_unlock(eb);
4803 path->locks[level] = 0;
4804 return 1;
4805 }
4806 }
4807 }
4808
4809 /* wc->stage == DROP_REFERENCE */
4810 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
4811
4812 if (wc->refs[level] == 1) {
4813 if (level == 0) {
4814 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4815 ret = btrfs_dec_ref(trans, root, eb, 1);
4816 else
4817 ret = btrfs_dec_ref(trans, root, eb, 0);
4818 BUG_ON(ret);
4819 }
4820 /* make block locked assertion in clean_tree_block happy */
4821 if (!path->locks[level] &&
4822 btrfs_header_generation(eb) == trans->transid) {
4823 btrfs_tree_lock(eb);
4824 btrfs_set_lock_blocking(eb);
4825 path->locks[level] = 1;
4826 }
4827 clean_tree_block(trans, root, eb);
4828 }
4829
4830 if (eb == root->node) {
4831 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4832 parent = eb->start;
4833 else
4834 BUG_ON(root->root_key.objectid !=
4835 btrfs_header_owner(eb));
4836 } else {
4837 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4838 parent = path->nodes[level + 1]->start;
4839 else
4840 BUG_ON(root->root_key.objectid !=
4841 btrfs_header_owner(path->nodes[level + 1]));
4842 }
4843
4844 ret = btrfs_free_extent(trans, root, eb->start, eb->len, parent,
4845 root->root_key.objectid, level, 0);
4846 BUG_ON(ret);
4847 out:
4848 wc->refs[level] = 0;
4849 wc->flags[level] = 0;
4850 return ret;
4851 }
4852
4853 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
4854 struct btrfs_root *root,
4855 struct btrfs_path *path,
4856 struct walk_control *wc)
4857 {
4858 int level = wc->level;
4859 int ret;
4860
4861 while (level >= 0) {
4862 if (path->slots[level] >=
4863 btrfs_header_nritems(path->nodes[level]))
4864 break;
4865
4866 ret = walk_down_proc(trans, root, path, wc);
4867 if (ret > 0)
4868 break;
4869
4870 if (level == 0)
4871 break;
4872
4873 ret = do_walk_down(trans, root, path, wc);
4874 if (ret > 0) {
4875 path->slots[level]++;
4876 continue;
4877 }
4878 level = wc->level;
4879 }
4880 return 0;
4881 }
4882
4883 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
4884 struct btrfs_root *root,
4885 struct btrfs_path *path,
4886 struct walk_control *wc, int max_level)
4887 {
4888 int level = wc->level;
4889 int ret;
4890
4891 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
4892 while (level < max_level && path->nodes[level]) {
4893 wc->level = level;
4894 if (path->slots[level] + 1 <
4895 btrfs_header_nritems(path->nodes[level])) {
4896 path->slots[level]++;
4897 return 0;
4898 } else {
4899 ret = walk_up_proc(trans, root, path, wc);
4900 if (ret > 0)
4901 return 0;
4902
4903 if (path->locks[level]) {
4904 btrfs_tree_unlock(path->nodes[level]);
4905 path->locks[level] = 0;
4906 }
4907 free_extent_buffer(path->nodes[level]);
4908 path->nodes[level] = NULL;
4909 level++;
4910 }
4911 }
4912 return 1;
4913 }
4914
4915 /*
4916 * drop a subvolume tree.
4917 *
4918 * this function traverses the tree freeing any blocks that only
4919 * referenced by the tree.
4920 *
4921 * when a shared tree block is found. this function decreases its
4922 * reference count by one. if update_ref is true, this function
4923 * also make sure backrefs for the shared block and all lower level
4924 * blocks are properly updated.
4925 */
4926 int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref)
4927 {
4928 struct btrfs_path *path;
4929 struct btrfs_trans_handle *trans;
4930 struct btrfs_root *tree_root = root->fs_info->tree_root;
4931 struct btrfs_root_item *root_item = &root->root_item;
4932 struct walk_control *wc;
4933 struct btrfs_key key;
4934 int err = 0;
4935 int ret;
4936 int level;
4937
4938 path = btrfs_alloc_path();
4939 BUG_ON(!path);
4940
4941 wc = kzalloc(sizeof(*wc), GFP_NOFS);
4942 BUG_ON(!wc);
4943
4944 trans = btrfs_start_transaction(tree_root, 1);
4945
4946 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
4947 level = btrfs_header_level(root->node);
4948 path->nodes[level] = btrfs_lock_root_node(root);
4949 btrfs_set_lock_blocking(path->nodes[level]);
4950 path->slots[level] = 0;
4951 path->locks[level] = 1;
4952 memset(&wc->update_progress, 0,
4953 sizeof(wc->update_progress));
4954 } else {
4955 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
4956 memcpy(&wc->update_progress, &key,
4957 sizeof(wc->update_progress));
4958
4959 level = root_item->drop_level;
4960 BUG_ON(level == 0);
4961 path->lowest_level = level;
4962 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4963 path->lowest_level = 0;
4964 if (ret < 0) {
4965 err = ret;
4966 goto out;
4967 }
4968 WARN_ON(ret > 0);
4969
4970 /*
4971 * unlock our path, this is safe because only this
4972 * function is allowed to delete this snapshot
4973 */
4974 btrfs_unlock_up_safe(path, 0);
4975
4976 level = btrfs_header_level(root->node);
4977 while (1) {
4978 btrfs_tree_lock(path->nodes[level]);
4979 btrfs_set_lock_blocking(path->nodes[level]);
4980
4981 ret = btrfs_lookup_extent_info(trans, root,
4982 path->nodes[level]->start,
4983 path->nodes[level]->len,
4984 &wc->refs[level],
4985 &wc->flags[level]);
4986 BUG_ON(ret);
4987 BUG_ON(wc->refs[level] == 0);
4988
4989 if (level == root_item->drop_level)
4990 break;
4991
4992 btrfs_tree_unlock(path->nodes[level]);
4993 WARN_ON(wc->refs[level] != 1);
4994 level--;
4995 }
4996 }
4997
4998 wc->level = level;
4999 wc->shared_level = -1;
5000 wc->stage = DROP_REFERENCE;
5001 wc->update_ref = update_ref;
5002 wc->keep_locks = 0;
5003 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
5004
5005 while (1) {
5006 ret = walk_down_tree(trans, root, path, wc);
5007 if (ret < 0) {
5008 err = ret;
5009 break;
5010 }
5011
5012 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
5013 if (ret < 0) {
5014 err = ret;
5015 break;
5016 }
5017
5018 if (ret > 0) {
5019 BUG_ON(wc->stage != DROP_REFERENCE);
5020 break;
5021 }
5022
5023 if (wc->stage == DROP_REFERENCE) {
5024 level = wc->level;
5025 btrfs_node_key(path->nodes[level],
5026 &root_item->drop_progress,
5027 path->slots[level]);
5028 root_item->drop_level = level;
5029 }
5030
5031 BUG_ON(wc->level == 0);
5032 if (trans->transaction->in_commit ||
5033 trans->transaction->delayed_refs.flushing) {
5034 ret = btrfs_update_root(trans, tree_root,
5035 &root->root_key,
5036 root_item);
5037 BUG_ON(ret);
5038
5039 btrfs_end_transaction(trans, tree_root);
5040 trans = btrfs_start_transaction(tree_root, 1);
5041 } else {
5042 unsigned long update;
5043 update = trans->delayed_ref_updates;
5044 trans->delayed_ref_updates = 0;
5045 if (update)
5046 btrfs_run_delayed_refs(trans, tree_root,
5047 update);
5048 }
5049 }
5050 btrfs_release_path(root, path);
5051 BUG_ON(err);
5052
5053 ret = btrfs_del_root(trans, tree_root, &root->root_key);
5054 BUG_ON(ret);
5055
5056 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
5057 ret = btrfs_find_last_root(tree_root, root->root_key.objectid,
5058 NULL, NULL);
5059 BUG_ON(ret < 0);
5060 if (ret > 0) {
5061 ret = btrfs_del_orphan_item(trans, tree_root,
5062 root->root_key.objectid);
5063 BUG_ON(ret);
5064 }
5065 }
5066
5067 if (root->in_radix) {
5068 btrfs_free_fs_root(tree_root->fs_info, root);
5069 } else {
5070 free_extent_buffer(root->node);
5071 free_extent_buffer(root->commit_root);
5072 kfree(root);
5073 }
5074 out:
5075 btrfs_end_transaction(trans, tree_root);
5076 kfree(wc);
5077 btrfs_free_path(path);
5078 return err;
5079 }
5080
5081 /*
5082 * drop subtree rooted at tree block 'node'.
5083 *
5084 * NOTE: this function will unlock and release tree block 'node'
5085 */
5086 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
5087 struct btrfs_root *root,
5088 struct extent_buffer *node,
5089 struct extent_buffer *parent)
5090 {
5091 struct btrfs_path *path;
5092 struct walk_control *wc;
5093 int level;
5094 int parent_level;
5095 int ret = 0;
5096 int wret;
5097
5098 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5099
5100 path = btrfs_alloc_path();
5101 BUG_ON(!path);
5102
5103 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5104 BUG_ON(!wc);
5105
5106 btrfs_assert_tree_locked(parent);
5107 parent_level = btrfs_header_level(parent);
5108 extent_buffer_get(parent);
5109 path->nodes[parent_level] = parent;
5110 path->slots[parent_level] = btrfs_header_nritems(parent);
5111
5112 btrfs_assert_tree_locked(node);
5113 level = btrfs_header_level(node);
5114 path->nodes[level] = node;
5115 path->slots[level] = 0;
5116 path->locks[level] = 1;
5117
5118 wc->refs[parent_level] = 1;
5119 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5120 wc->level = level;
5121 wc->shared_level = -1;
5122 wc->stage = DROP_REFERENCE;
5123 wc->update_ref = 0;
5124 wc->keep_locks = 1;
5125 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
5126
5127 while (1) {
5128 wret = walk_down_tree(trans, root, path, wc);
5129 if (wret < 0) {
5130 ret = wret;
5131 break;
5132 }
5133
5134 wret = walk_up_tree(trans, root, path, wc, parent_level);
5135 if (wret < 0)
5136 ret = wret;
5137 if (wret != 0)
5138 break;
5139 }
5140
5141 kfree(wc);
5142 btrfs_free_path(path);
5143 return ret;
5144 }
5145
5146 #if 0
5147 static unsigned long calc_ra(unsigned long start, unsigned long last,
5148 unsigned long nr)
5149 {
5150 return min(last, start + nr - 1);
5151 }
5152
5153 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
5154 u64 len)
5155 {
5156 u64 page_start;
5157 u64 page_end;
5158 unsigned long first_index;
5159 unsigned long last_index;
5160 unsigned long i;
5161 struct page *page;
5162 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5163 struct file_ra_state *ra;
5164 struct btrfs_ordered_extent *ordered;
5165 unsigned int total_read = 0;
5166 unsigned int total_dirty = 0;
5167 int ret = 0;
5168
5169 ra = kzalloc(sizeof(*ra), GFP_NOFS);
5170
5171 mutex_lock(&inode->i_mutex);
5172 first_index = start >> PAGE_CACHE_SHIFT;
5173 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
5174
5175 /* make sure the dirty trick played by the caller work */
5176 ret = invalidate_inode_pages2_range(inode->i_mapping,
5177 first_index, last_index);
5178 if (ret)
5179 goto out_unlock;
5180
5181 file_ra_state_init(ra, inode->i_mapping);
5182
5183 for (i = first_index ; i <= last_index; i++) {
5184 if (total_read % ra->ra_pages == 0) {
5185 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
5186 calc_ra(i, last_index, ra->ra_pages));
5187 }
5188 total_read++;
5189 again:
5190 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
5191 BUG_ON(1);
5192 page = grab_cache_page(inode->i_mapping, i);
5193 if (!page) {
5194 ret = -ENOMEM;
5195 goto out_unlock;
5196 }
5197 if (!PageUptodate(page)) {
5198 btrfs_readpage(NULL, page);
5199 lock_page(page);
5200 if (!PageUptodate(page)) {
5201 unlock_page(page);
5202 page_cache_release(page);
5203 ret = -EIO;
5204 goto out_unlock;
5205 }
5206 }
5207 wait_on_page_writeback(page);
5208
5209 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
5210 page_end = page_start + PAGE_CACHE_SIZE - 1;
5211 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
5212
5213 ordered = btrfs_lookup_ordered_extent(inode, page_start);
5214 if (ordered) {
5215 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5216 unlock_page(page);
5217 page_cache_release(page);
5218 btrfs_start_ordered_extent(inode, ordered, 1);
5219 btrfs_put_ordered_extent(ordered);
5220 goto again;
5221 }
5222 set_page_extent_mapped(page);
5223
5224 if (i == first_index)
5225 set_extent_bits(io_tree, page_start, page_end,
5226 EXTENT_BOUNDARY, GFP_NOFS);
5227 btrfs_set_extent_delalloc(inode, page_start, page_end);
5228
5229 set_page_dirty(page);
5230 total_dirty++;
5231
5232 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5233 unlock_page(page);
5234 page_cache_release(page);
5235 }
5236
5237 out_unlock:
5238 kfree(ra);
5239 mutex_unlock(&inode->i_mutex);
5240 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
5241 return ret;
5242 }
5243
5244 static noinline int relocate_data_extent(struct inode *reloc_inode,
5245 struct btrfs_key *extent_key,
5246 u64 offset)
5247 {
5248 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5249 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
5250 struct extent_map *em;
5251 u64 start = extent_key->objectid - offset;
5252 u64 end = start + extent_key->offset - 1;
5253
5254 em = alloc_extent_map(GFP_NOFS);
5255 BUG_ON(!em || IS_ERR(em));
5256
5257 em->start = start;
5258 em->len = extent_key->offset;
5259 em->block_len = extent_key->offset;
5260 em->block_start = extent_key->objectid;
5261 em->bdev = root->fs_info->fs_devices->latest_bdev;
5262 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5263
5264 /* setup extent map to cheat btrfs_readpage */
5265 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5266 while (1) {
5267 int ret;
5268 write_lock(&em_tree->lock);
5269 ret = add_extent_mapping(em_tree, em);
5270 write_unlock(&em_tree->lock);
5271 if (ret != -EEXIST) {
5272 free_extent_map(em);
5273 break;
5274 }
5275 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
5276 }
5277 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5278
5279 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
5280 }
5281
5282 struct btrfs_ref_path {
5283 u64 extent_start;
5284 u64 nodes[BTRFS_MAX_LEVEL];
5285 u64 root_objectid;
5286 u64 root_generation;
5287 u64 owner_objectid;
5288 u32 num_refs;
5289 int lowest_level;
5290 int current_level;
5291 int shared_level;
5292
5293 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
5294 u64 new_nodes[BTRFS_MAX_LEVEL];
5295 };
5296
5297 struct disk_extent {
5298 u64 ram_bytes;
5299 u64 disk_bytenr;
5300 u64 disk_num_bytes;
5301 u64 offset;
5302 u64 num_bytes;
5303 u8 compression;
5304 u8 encryption;
5305 u16 other_encoding;
5306 };
5307
5308 static int is_cowonly_root(u64 root_objectid)
5309 {
5310 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
5311 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
5312 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
5313 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
5314 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
5315 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
5316 return 1;
5317 return 0;
5318 }
5319
5320 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
5321 struct btrfs_root *extent_root,
5322 struct btrfs_ref_path *ref_path,
5323 int first_time)
5324 {
5325 struct extent_buffer *leaf;
5326 struct btrfs_path *path;
5327 struct btrfs_extent_ref *ref;
5328 struct btrfs_key key;
5329 struct btrfs_key found_key;
5330 u64 bytenr;
5331 u32 nritems;
5332 int level;
5333 int ret = 1;
5334
5335 path = btrfs_alloc_path();
5336 if (!path)
5337 return -ENOMEM;
5338
5339 if (first_time) {
5340 ref_path->lowest_level = -1;
5341 ref_path->current_level = -1;
5342 ref_path->shared_level = -1;
5343 goto walk_up;
5344 }
5345 walk_down:
5346 level = ref_path->current_level - 1;
5347 while (level >= -1) {
5348 u64 parent;
5349 if (level < ref_path->lowest_level)
5350 break;
5351
5352 if (level >= 0)
5353 bytenr = ref_path->nodes[level];
5354 else
5355 bytenr = ref_path->extent_start;
5356 BUG_ON(bytenr == 0);
5357
5358 parent = ref_path->nodes[level + 1];
5359 ref_path->nodes[level + 1] = 0;
5360 ref_path->current_level = level;
5361 BUG_ON(parent == 0);
5362
5363 key.objectid = bytenr;
5364 key.offset = parent + 1;
5365 key.type = BTRFS_EXTENT_REF_KEY;
5366
5367 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5368 if (ret < 0)
5369 goto out;
5370 BUG_ON(ret == 0);
5371
5372 leaf = path->nodes[0];
5373 nritems = btrfs_header_nritems(leaf);
5374 if (path->slots[0] >= nritems) {
5375 ret = btrfs_next_leaf(extent_root, path);
5376 if (ret < 0)
5377 goto out;
5378 if (ret > 0)
5379 goto next;
5380 leaf = path->nodes[0];
5381 }
5382
5383 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5384 if (found_key.objectid == bytenr &&
5385 found_key.type == BTRFS_EXTENT_REF_KEY) {
5386 if (level < ref_path->shared_level)
5387 ref_path->shared_level = level;
5388 goto found;
5389 }
5390 next:
5391 level--;
5392 btrfs_release_path(extent_root, path);
5393 cond_resched();
5394 }
5395 /* reached lowest level */
5396 ret = 1;
5397 goto out;
5398 walk_up:
5399 level = ref_path->current_level;
5400 while (level < BTRFS_MAX_LEVEL - 1) {
5401 u64 ref_objectid;
5402
5403 if (level >= 0)
5404 bytenr = ref_path->nodes[level];
5405 else
5406 bytenr = ref_path->extent_start;
5407
5408 BUG_ON(bytenr == 0);
5409
5410 key.objectid = bytenr;
5411 key.offset = 0;
5412 key.type = BTRFS_EXTENT_REF_KEY;
5413
5414 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5415 if (ret < 0)
5416 goto out;
5417
5418 leaf = path->nodes[0];
5419 nritems = btrfs_header_nritems(leaf);
5420 if (path->slots[0] >= nritems) {
5421 ret = btrfs_next_leaf(extent_root, path);
5422 if (ret < 0)
5423 goto out;
5424 if (ret > 0) {
5425 /* the extent was freed by someone */
5426 if (ref_path->lowest_level == level)
5427 goto out;
5428 btrfs_release_path(extent_root, path);
5429 goto walk_down;
5430 }
5431 leaf = path->nodes[0];
5432 }
5433
5434 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5435 if (found_key.objectid != bytenr ||
5436 found_key.type != BTRFS_EXTENT_REF_KEY) {
5437 /* the extent was freed by someone */
5438 if (ref_path->lowest_level == level) {
5439 ret = 1;
5440 goto out;
5441 }
5442 btrfs_release_path(extent_root, path);
5443 goto walk_down;
5444 }
5445 found:
5446 ref = btrfs_item_ptr(leaf, path->slots[0],
5447 struct btrfs_extent_ref);
5448 ref_objectid = btrfs_ref_objectid(leaf, ref);
5449 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
5450 if (first_time) {
5451 level = (int)ref_objectid;
5452 BUG_ON(level >= BTRFS_MAX_LEVEL);
5453 ref_path->lowest_level = level;
5454 ref_path->current_level = level;
5455 ref_path->nodes[level] = bytenr;
5456 } else {
5457 WARN_ON(ref_objectid != level);
5458 }
5459 } else {
5460 WARN_ON(level != -1);
5461 }
5462 first_time = 0;
5463
5464 if (ref_path->lowest_level == level) {
5465 ref_path->owner_objectid = ref_objectid;
5466 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
5467 }
5468
5469 /*
5470 * the block is tree root or the block isn't in reference
5471 * counted tree.
5472 */
5473 if (found_key.objectid == found_key.offset ||
5474 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
5475 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5476 ref_path->root_generation =
5477 btrfs_ref_generation(leaf, ref);
5478 if (level < 0) {
5479 /* special reference from the tree log */
5480 ref_path->nodes[0] = found_key.offset;
5481 ref_path->current_level = 0;
5482 }
5483 ret = 0;
5484 goto out;
5485 }
5486
5487 level++;
5488 BUG_ON(ref_path->nodes[level] != 0);
5489 ref_path->nodes[level] = found_key.offset;
5490 ref_path->current_level = level;
5491
5492 /*
5493 * the reference was created in the running transaction,
5494 * no need to continue walking up.
5495 */
5496 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
5497 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5498 ref_path->root_generation =
5499 btrfs_ref_generation(leaf, ref);
5500 ret = 0;
5501 goto out;
5502 }
5503
5504 btrfs_release_path(extent_root, path);
5505 cond_resched();
5506 }
5507 /* reached max tree level, but no tree root found. */
5508 BUG();
5509 out:
5510 btrfs_free_path(path);
5511 return ret;
5512 }
5513
5514 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
5515 struct btrfs_root *extent_root,
5516 struct btrfs_ref_path *ref_path,
5517 u64 extent_start)
5518 {
5519 memset(ref_path, 0, sizeof(*ref_path));
5520 ref_path->extent_start = extent_start;
5521
5522 return __next_ref_path(trans, extent_root, ref_path, 1);
5523 }
5524
5525 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
5526 struct btrfs_root *extent_root,
5527 struct btrfs_ref_path *ref_path)
5528 {
5529 return __next_ref_path(trans, extent_root, ref_path, 0);
5530 }
5531
5532 static noinline int get_new_locations(struct inode *reloc_inode,
5533 struct btrfs_key *extent_key,
5534 u64 offset, int no_fragment,
5535 struct disk_extent **extents,
5536 int *nr_extents)
5537 {
5538 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5539 struct btrfs_path *path;
5540 struct btrfs_file_extent_item *fi;
5541 struct extent_buffer *leaf;
5542 struct disk_extent *exts = *extents;
5543 struct btrfs_key found_key;
5544 u64 cur_pos;
5545 u64 last_byte;
5546 u32 nritems;
5547 int nr = 0;
5548 int max = *nr_extents;
5549 int ret;
5550
5551 WARN_ON(!no_fragment && *extents);
5552 if (!exts) {
5553 max = 1;
5554 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
5555 if (!exts)
5556 return -ENOMEM;
5557 }
5558
5559 path = btrfs_alloc_path();
5560 BUG_ON(!path);
5561
5562 cur_pos = extent_key->objectid - offset;
5563 last_byte = extent_key->objectid + extent_key->offset;
5564 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
5565 cur_pos, 0);
5566 if (ret < 0)
5567 goto out;
5568 if (ret > 0) {
5569 ret = -ENOENT;
5570 goto out;
5571 }
5572
5573 while (1) {
5574 leaf = path->nodes[0];
5575 nritems = btrfs_header_nritems(leaf);
5576 if (path->slots[0] >= nritems) {
5577 ret = btrfs_next_leaf(root, path);
5578 if (ret < 0)
5579 goto out;
5580 if (ret > 0)
5581 break;
5582 leaf = path->nodes[0];
5583 }
5584
5585 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5586 if (found_key.offset != cur_pos ||
5587 found_key.type != BTRFS_EXTENT_DATA_KEY ||
5588 found_key.objectid != reloc_inode->i_ino)
5589 break;
5590
5591 fi = btrfs_item_ptr(leaf, path->slots[0],
5592 struct btrfs_file_extent_item);
5593 if (btrfs_file_extent_type(leaf, fi) !=
5594 BTRFS_FILE_EXTENT_REG ||
5595 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
5596 break;
5597
5598 if (nr == max) {
5599 struct disk_extent *old = exts;
5600 max *= 2;
5601 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
5602 memcpy(exts, old, sizeof(*exts) * nr);
5603 if (old != *extents)
5604 kfree(old);
5605 }
5606
5607 exts[nr].disk_bytenr =
5608 btrfs_file_extent_disk_bytenr(leaf, fi);
5609 exts[nr].disk_num_bytes =
5610 btrfs_file_extent_disk_num_bytes(leaf, fi);
5611 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
5612 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5613 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
5614 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
5615 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
5616 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
5617 fi);
5618 BUG_ON(exts[nr].offset > 0);
5619 BUG_ON(exts[nr].compression || exts[nr].encryption);
5620 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
5621
5622 cur_pos += exts[nr].num_bytes;
5623 nr++;
5624
5625 if (cur_pos + offset >= last_byte)
5626 break;
5627
5628 if (no_fragment) {
5629 ret = 1;
5630 goto out;
5631 }
5632 path->slots[0]++;
5633 }
5634
5635 BUG_ON(cur_pos + offset > last_byte);
5636 if (cur_pos + offset < last_byte) {
5637 ret = -ENOENT;
5638 goto out;
5639 }
5640 ret = 0;
5641 out:
5642 btrfs_free_path(path);
5643 if (ret) {
5644 if (exts != *extents)
5645 kfree(exts);
5646 } else {
5647 *extents = exts;
5648 *nr_extents = nr;
5649 }
5650 return ret;
5651 }
5652
5653 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
5654 struct btrfs_root *root,
5655 struct btrfs_path *path,
5656 struct btrfs_key *extent_key,
5657 struct btrfs_key *leaf_key,
5658 struct btrfs_ref_path *ref_path,
5659 struct disk_extent *new_extents,
5660 int nr_extents)
5661 {
5662 struct extent_buffer *leaf;
5663 struct btrfs_file_extent_item *fi;
5664 struct inode *inode = NULL;
5665 struct btrfs_key key;
5666 u64 lock_start = 0;
5667 u64 lock_end = 0;
5668 u64 num_bytes;
5669 u64 ext_offset;
5670 u64 search_end = (u64)-1;
5671 u32 nritems;
5672 int nr_scaned = 0;
5673 int extent_locked = 0;
5674 int extent_type;
5675 int ret;
5676
5677 memcpy(&key, leaf_key, sizeof(key));
5678 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
5679 if (key.objectid < ref_path->owner_objectid ||
5680 (key.objectid == ref_path->owner_objectid &&
5681 key.type < BTRFS_EXTENT_DATA_KEY)) {
5682 key.objectid = ref_path->owner_objectid;
5683 key.type = BTRFS_EXTENT_DATA_KEY;
5684 key.offset = 0;
5685 }
5686 }
5687
5688 while (1) {
5689 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
5690 if (ret < 0)
5691 goto out;
5692
5693 leaf = path->nodes[0];
5694 nritems = btrfs_header_nritems(leaf);
5695 next:
5696 if (extent_locked && ret > 0) {
5697 /*
5698 * the file extent item was modified by someone
5699 * before the extent got locked.
5700 */
5701 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5702 lock_end, GFP_NOFS);
5703 extent_locked = 0;
5704 }
5705
5706 if (path->slots[0] >= nritems) {
5707 if (++nr_scaned > 2)
5708 break;
5709
5710 BUG_ON(extent_locked);
5711 ret = btrfs_next_leaf(root, path);
5712 if (ret < 0)
5713 goto out;
5714 if (ret > 0)
5715 break;
5716 leaf = path->nodes[0];
5717 nritems = btrfs_header_nritems(leaf);
5718 }
5719
5720 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
5721
5722 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
5723 if ((key.objectid > ref_path->owner_objectid) ||
5724 (key.objectid == ref_path->owner_objectid &&
5725 key.type > BTRFS_EXTENT_DATA_KEY) ||
5726 key.offset >= search_end)
5727 break;
5728 }
5729
5730 if (inode && key.objectid != inode->i_ino) {
5731 BUG_ON(extent_locked);
5732 btrfs_release_path(root, path);
5733 mutex_unlock(&inode->i_mutex);
5734 iput(inode);
5735 inode = NULL;
5736 continue;
5737 }
5738
5739 if (key.type != BTRFS_EXTENT_DATA_KEY) {
5740 path->slots[0]++;
5741 ret = 1;
5742 goto next;
5743 }
5744 fi = btrfs_item_ptr(leaf, path->slots[0],
5745 struct btrfs_file_extent_item);
5746 extent_type = btrfs_file_extent_type(leaf, fi);
5747 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
5748 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
5749 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
5750 extent_key->objectid)) {
5751 path->slots[0]++;
5752 ret = 1;
5753 goto next;
5754 }
5755
5756 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5757 ext_offset = btrfs_file_extent_offset(leaf, fi);
5758
5759 if (search_end == (u64)-1) {
5760 search_end = key.offset - ext_offset +
5761 btrfs_file_extent_ram_bytes(leaf, fi);
5762 }
5763
5764 if (!extent_locked) {
5765 lock_start = key.offset;
5766 lock_end = lock_start + num_bytes - 1;
5767 } else {
5768 if (lock_start > key.offset ||
5769 lock_end + 1 < key.offset + num_bytes) {
5770 unlock_extent(&BTRFS_I(inode)->io_tree,
5771 lock_start, lock_end, GFP_NOFS);
5772 extent_locked = 0;
5773 }
5774 }
5775
5776 if (!inode) {
5777 btrfs_release_path(root, path);
5778
5779 inode = btrfs_iget_locked(root->fs_info->sb,
5780 key.objectid, root);
5781 if (inode->i_state & I_NEW) {
5782 BTRFS_I(inode)->root = root;
5783 BTRFS_I(inode)->location.objectid =
5784 key.objectid;
5785 BTRFS_I(inode)->location.type =
5786 BTRFS_INODE_ITEM_KEY;
5787 BTRFS_I(inode)->location.offset = 0;
5788 btrfs_read_locked_inode(inode);
5789 unlock_new_inode(inode);
5790 }
5791 /*
5792 * some code call btrfs_commit_transaction while
5793 * holding the i_mutex, so we can't use mutex_lock
5794 * here.
5795 */
5796 if (is_bad_inode(inode) ||
5797 !mutex_trylock(&inode->i_mutex)) {
5798 iput(inode);
5799 inode = NULL;
5800 key.offset = (u64)-1;
5801 goto skip;
5802 }
5803 }
5804
5805 if (!extent_locked) {
5806 struct btrfs_ordered_extent *ordered;
5807
5808 btrfs_release_path(root, path);
5809
5810 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5811 lock_end, GFP_NOFS);
5812 ordered = btrfs_lookup_first_ordered_extent(inode,
5813 lock_end);
5814 if (ordered &&
5815 ordered->file_offset <= lock_end &&
5816 ordered->file_offset + ordered->len > lock_start) {
5817 unlock_extent(&BTRFS_I(inode)->io_tree,
5818 lock_start, lock_end, GFP_NOFS);
5819 btrfs_start_ordered_extent(inode, ordered, 1);
5820 btrfs_put_ordered_extent(ordered);
5821 key.offset += num_bytes;
5822 goto skip;
5823 }
5824 if (ordered)
5825 btrfs_put_ordered_extent(ordered);
5826
5827 extent_locked = 1;
5828 continue;
5829 }
5830
5831 if (nr_extents == 1) {
5832 /* update extent pointer in place */
5833 btrfs_set_file_extent_disk_bytenr(leaf, fi,
5834 new_extents[0].disk_bytenr);
5835 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
5836 new_extents[0].disk_num_bytes);
5837 btrfs_mark_buffer_dirty(leaf);
5838
5839 btrfs_drop_extent_cache(inode, key.offset,
5840 key.offset + num_bytes - 1, 0);
5841
5842 ret = btrfs_inc_extent_ref(trans, root,
5843 new_extents[0].disk_bytenr,
5844 new_extents[0].disk_num_bytes,
5845 leaf->start,
5846 root->root_key.objectid,
5847 trans->transid,
5848 key.objectid);
5849 BUG_ON(ret);
5850
5851 ret = btrfs_free_extent(trans, root,
5852 extent_key->objectid,
5853 extent_key->offset,
5854 leaf->start,
5855 btrfs_header_owner(leaf),
5856 btrfs_header_generation(leaf),
5857 key.objectid, 0);
5858 BUG_ON(ret);
5859
5860 btrfs_release_path(root, path);
5861 key.offset += num_bytes;
5862 } else {
5863 BUG_ON(1);
5864 #if 0
5865 u64 alloc_hint;
5866 u64 extent_len;
5867 int i;
5868 /*
5869 * drop old extent pointer at first, then insert the
5870 * new pointers one bye one
5871 */
5872 btrfs_release_path(root, path);
5873 ret = btrfs_drop_extents(trans, root, inode, key.offset,
5874 key.offset + num_bytes,
5875 key.offset, &alloc_hint);
5876 BUG_ON(ret);
5877
5878 for (i = 0; i < nr_extents; i++) {
5879 if (ext_offset >= new_extents[i].num_bytes) {
5880 ext_offset -= new_extents[i].num_bytes;
5881 continue;
5882 }
5883 extent_len = min(new_extents[i].num_bytes -
5884 ext_offset, num_bytes);
5885
5886 ret = btrfs_insert_empty_item(trans, root,
5887 path, &key,
5888 sizeof(*fi));
5889 BUG_ON(ret);
5890
5891 leaf = path->nodes[0];
5892 fi = btrfs_item_ptr(leaf, path->slots[0],
5893 struct btrfs_file_extent_item);
5894 btrfs_set_file_extent_generation(leaf, fi,
5895 trans->transid);
5896 btrfs_set_file_extent_type(leaf, fi,
5897 BTRFS_FILE_EXTENT_REG);
5898 btrfs_set_file_extent_disk_bytenr(leaf, fi,
5899 new_extents[i].disk_bytenr);
5900 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
5901 new_extents[i].disk_num_bytes);
5902 btrfs_set_file_extent_ram_bytes(leaf, fi,
5903 new_extents[i].ram_bytes);
5904
5905 btrfs_set_file_extent_compression(leaf, fi,
5906 new_extents[i].compression);
5907 btrfs_set_file_extent_encryption(leaf, fi,
5908 new_extents[i].encryption);
5909 btrfs_set_file_extent_other_encoding(leaf, fi,
5910 new_extents[i].other_encoding);
5911
5912 btrfs_set_file_extent_num_bytes(leaf, fi,
5913 extent_len);
5914 ext_offset += new_extents[i].offset;
5915 btrfs_set_file_extent_offset(leaf, fi,
5916 ext_offset);
5917 btrfs_mark_buffer_dirty(leaf);
5918
5919 btrfs_drop_extent_cache(inode, key.offset,
5920 key.offset + extent_len - 1, 0);
5921
5922 ret = btrfs_inc_extent_ref(trans, root,
5923 new_extents[i].disk_bytenr,
5924 new_extents[i].disk_num_bytes,
5925 leaf->start,
5926 root->root_key.objectid,
5927 trans->transid, key.objectid);
5928 BUG_ON(ret);
5929 btrfs_release_path(root, path);
5930
5931 inode_add_bytes(inode, extent_len);
5932
5933 ext_offset = 0;
5934 num_bytes -= extent_len;
5935 key.offset += extent_len;
5936
5937 if (num_bytes == 0)
5938 break;
5939 }
5940 BUG_ON(i >= nr_extents);
5941 #endif
5942 }
5943
5944 if (extent_locked) {
5945 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5946 lock_end, GFP_NOFS);
5947 extent_locked = 0;
5948 }
5949 skip:
5950 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
5951 key.offset >= search_end)
5952 break;
5953
5954 cond_resched();
5955 }
5956 ret = 0;
5957 out:
5958 btrfs_release_path(root, path);
5959 if (inode) {
5960 mutex_unlock(&inode->i_mutex);
5961 if (extent_locked) {
5962 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5963 lock_end, GFP_NOFS);
5964 }
5965 iput(inode);
5966 }
5967 return ret;
5968 }
5969
5970 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
5971 struct btrfs_root *root,
5972 struct extent_buffer *buf, u64 orig_start)
5973 {
5974 int level;
5975 int ret;
5976
5977 BUG_ON(btrfs_header_generation(buf) != trans->transid);
5978 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5979
5980 level = btrfs_header_level(buf);
5981 if (level == 0) {
5982 struct btrfs_leaf_ref *ref;
5983 struct btrfs_leaf_ref *orig_ref;
5984
5985 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
5986 if (!orig_ref)
5987 return -ENOENT;
5988
5989 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
5990 if (!ref) {
5991 btrfs_free_leaf_ref(root, orig_ref);
5992 return -ENOMEM;
5993 }
5994
5995 ref->nritems = orig_ref->nritems;
5996 memcpy(ref->extents, orig_ref->extents,
5997 sizeof(ref->extents[0]) * ref->nritems);
5998
5999 btrfs_free_leaf_ref(root, orig_ref);
6000
6001 ref->root_gen = trans->transid;
6002 ref->bytenr = buf->start;
6003 ref->owner = btrfs_header_owner(buf);
6004 ref->generation = btrfs_header_generation(buf);
6005
6006 ret = btrfs_add_leaf_ref(root, ref, 0);
6007 WARN_ON(ret);
6008 btrfs_free_leaf_ref(root, ref);
6009 }
6010 return 0;
6011 }
6012
6013 static noinline int invalidate_extent_cache(struct btrfs_root *root,
6014 struct extent_buffer *leaf,
6015 struct btrfs_block_group_cache *group,
6016 struct btrfs_root *target_root)
6017 {
6018 struct btrfs_key key;
6019 struct inode *inode = NULL;
6020 struct btrfs_file_extent_item *fi;
6021 u64 num_bytes;
6022 u64 skip_objectid = 0;
6023 u32 nritems;
6024 u32 i;
6025
6026 nritems = btrfs_header_nritems(leaf);
6027 for (i = 0; i < nritems; i++) {
6028 btrfs_item_key_to_cpu(leaf, &key, i);
6029 if (key.objectid == skip_objectid ||
6030 key.type != BTRFS_EXTENT_DATA_KEY)
6031 continue;
6032 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6033 if (btrfs_file_extent_type(leaf, fi) ==
6034 BTRFS_FILE_EXTENT_INLINE)
6035 continue;
6036 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
6037 continue;
6038 if (!inode || inode->i_ino != key.objectid) {
6039 iput(inode);
6040 inode = btrfs_ilookup(target_root->fs_info->sb,
6041 key.objectid, target_root, 1);
6042 }
6043 if (!inode) {
6044 skip_objectid = key.objectid;
6045 continue;
6046 }
6047 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6048
6049 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
6050 key.offset + num_bytes - 1, GFP_NOFS);
6051 btrfs_drop_extent_cache(inode, key.offset,
6052 key.offset + num_bytes - 1, 1);
6053 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
6054 key.offset + num_bytes - 1, GFP_NOFS);
6055 cond_resched();
6056 }
6057 iput(inode);
6058 return 0;
6059 }
6060
6061 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
6062 struct btrfs_root *root,
6063 struct extent_buffer *leaf,
6064 struct btrfs_block_group_cache *group,
6065 struct inode *reloc_inode)
6066 {
6067 struct btrfs_key key;
6068 struct btrfs_key extent_key;
6069 struct btrfs_file_extent_item *fi;
6070 struct btrfs_leaf_ref *ref;
6071 struct disk_extent *new_extent;
6072 u64 bytenr;
6073 u64 num_bytes;
6074 u32 nritems;
6075 u32 i;
6076 int ext_index;
6077 int nr_extent;
6078 int ret;
6079
6080 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
6081 BUG_ON(!new_extent);
6082
6083 ref = btrfs_lookup_leaf_ref(root, leaf->start);
6084 BUG_ON(!ref);
6085
6086 ext_index = -1;
6087 nritems = btrfs_header_nritems(leaf);
6088 for (i = 0; i < nritems; i++) {
6089 btrfs_item_key_to_cpu(leaf, &key, i);
6090 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
6091 continue;
6092 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6093 if (btrfs_file_extent_type(leaf, fi) ==
6094 BTRFS_FILE_EXTENT_INLINE)
6095 continue;
6096 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6097 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
6098 if (bytenr == 0)
6099 continue;
6100
6101 ext_index++;
6102 if (bytenr >= group->key.objectid + group->key.offset ||
6103 bytenr + num_bytes <= group->key.objectid)
6104 continue;
6105
6106 extent_key.objectid = bytenr;
6107 extent_key.offset = num_bytes;
6108 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
6109 nr_extent = 1;
6110 ret = get_new_locations(reloc_inode, &extent_key,
6111 group->key.objectid, 1,
6112 &new_extent, &nr_extent);
6113 if (ret > 0)
6114 continue;
6115 BUG_ON(ret < 0);
6116
6117 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
6118 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
6119 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
6120 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
6121
6122 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6123 new_extent->disk_bytenr);
6124 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6125 new_extent->disk_num_bytes);
6126 btrfs_mark_buffer_dirty(leaf);
6127
6128 ret = btrfs_inc_extent_ref(trans, root,
6129 new_extent->disk_bytenr,
6130 new_extent->disk_num_bytes,
6131 leaf->start,
6132 root->root_key.objectid,
6133 trans->transid, key.objectid);
6134 BUG_ON(ret);
6135
6136 ret = btrfs_free_extent(trans, root,
6137 bytenr, num_bytes, leaf->start,
6138 btrfs_header_owner(leaf),
6139 btrfs_header_generation(leaf),
6140 key.objectid, 0);
6141 BUG_ON(ret);
6142 cond_resched();
6143 }
6144 kfree(new_extent);
6145 BUG_ON(ext_index + 1 != ref->nritems);
6146 btrfs_free_leaf_ref(root, ref);
6147 return 0;
6148 }
6149
6150 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
6151 struct btrfs_root *root)
6152 {
6153 struct btrfs_root *reloc_root;
6154 int ret;
6155
6156 if (root->reloc_root) {
6157 reloc_root = root->reloc_root;
6158 root->reloc_root = NULL;
6159 list_add(&reloc_root->dead_list,
6160 &root->fs_info->dead_reloc_roots);
6161
6162 btrfs_set_root_bytenr(&reloc_root->root_item,
6163 reloc_root->node->start);
6164 btrfs_set_root_level(&root->root_item,
6165 btrfs_header_level(reloc_root->node));
6166 memset(&reloc_root->root_item.drop_progress, 0,
6167 sizeof(struct btrfs_disk_key));
6168 reloc_root->root_item.drop_level = 0;
6169
6170 ret = btrfs_update_root(trans, root->fs_info->tree_root,
6171 &reloc_root->root_key,
6172 &reloc_root->root_item);
6173 BUG_ON(ret);
6174 }
6175 return 0;
6176 }
6177
6178 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
6179 {
6180 struct btrfs_trans_handle *trans;
6181 struct btrfs_root *reloc_root;
6182 struct btrfs_root *prev_root = NULL;
6183 struct list_head dead_roots;
6184 int ret;
6185 unsigned long nr;
6186
6187 INIT_LIST_HEAD(&dead_roots);
6188 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
6189
6190 while (!list_empty(&dead_roots)) {
6191 reloc_root = list_entry(dead_roots.prev,
6192 struct btrfs_root, dead_list);
6193 list_del_init(&reloc_root->dead_list);
6194
6195 BUG_ON(reloc_root->commit_root != NULL);
6196 while (1) {
6197 trans = btrfs_join_transaction(root, 1);
6198 BUG_ON(!trans);
6199
6200 mutex_lock(&root->fs_info->drop_mutex);
6201 ret = btrfs_drop_snapshot(trans, reloc_root);
6202 if (ret != -EAGAIN)
6203 break;
6204 mutex_unlock(&root->fs_info->drop_mutex);
6205
6206 nr = trans->blocks_used;
6207 ret = btrfs_end_transaction(trans, root);
6208 BUG_ON(ret);
6209 btrfs_btree_balance_dirty(root, nr);
6210 }
6211
6212 free_extent_buffer(reloc_root->node);
6213
6214 ret = btrfs_del_root(trans, root->fs_info->tree_root,
6215 &reloc_root->root_key);
6216 BUG_ON(ret);
6217 mutex_unlock(&root->fs_info->drop_mutex);
6218
6219 nr = trans->blocks_used;
6220 ret = btrfs_end_transaction(trans, root);
6221 BUG_ON(ret);
6222 btrfs_btree_balance_dirty(root, nr);
6223
6224 kfree(prev_root);
6225 prev_root = reloc_root;
6226 }
6227 if (prev_root) {
6228 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
6229 kfree(prev_root);
6230 }
6231 return 0;
6232 }
6233
6234 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
6235 {
6236 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
6237 return 0;
6238 }
6239
6240 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
6241 {
6242 struct btrfs_root *reloc_root;
6243 struct btrfs_trans_handle *trans;
6244 struct btrfs_key location;
6245 int found;
6246 int ret;
6247
6248 mutex_lock(&root->fs_info->tree_reloc_mutex);
6249 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
6250 BUG_ON(ret);
6251 found = !list_empty(&root->fs_info->dead_reloc_roots);
6252 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6253
6254 if (found) {
6255 trans = btrfs_start_transaction(root, 1);
6256 BUG_ON(!trans);
6257 ret = btrfs_commit_transaction(trans, root);
6258 BUG_ON(ret);
6259 }
6260
6261 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
6262 location.offset = (u64)-1;
6263 location.type = BTRFS_ROOT_ITEM_KEY;
6264
6265 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
6266 BUG_ON(!reloc_root);
6267 btrfs_orphan_cleanup(reloc_root);
6268 return 0;
6269 }
6270
6271 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
6272 struct btrfs_root *root)
6273 {
6274 struct btrfs_root *reloc_root;
6275 struct extent_buffer *eb;
6276 struct btrfs_root_item *root_item;
6277 struct btrfs_key root_key;
6278 int ret;
6279
6280 BUG_ON(!root->ref_cows);
6281 if (root->reloc_root)
6282 return 0;
6283
6284 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
6285 BUG_ON(!root_item);
6286
6287 ret = btrfs_copy_root(trans, root, root->commit_root,
6288 &eb, BTRFS_TREE_RELOC_OBJECTID);
6289 BUG_ON(ret);
6290
6291 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
6292 root_key.offset = root->root_key.objectid;
6293 root_key.type = BTRFS_ROOT_ITEM_KEY;
6294
6295 memcpy(root_item, &root->root_item, sizeof(root_item));
6296 btrfs_set_root_refs(root_item, 0);
6297 btrfs_set_root_bytenr(root_item, eb->start);
6298 btrfs_set_root_level(root_item, btrfs_header_level(eb));
6299 btrfs_set_root_generation(root_item, trans->transid);
6300
6301 btrfs_tree_unlock(eb);
6302 free_extent_buffer(eb);
6303
6304 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
6305 &root_key, root_item);
6306 BUG_ON(ret);
6307 kfree(root_item);
6308
6309 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
6310 &root_key);
6311 BUG_ON(!reloc_root);
6312 reloc_root->last_trans = trans->transid;
6313 reloc_root->commit_root = NULL;
6314 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
6315
6316 root->reloc_root = reloc_root;
6317 return 0;
6318 }
6319
6320 /*
6321 * Core function of space balance.
6322 *
6323 * The idea is using reloc trees to relocate tree blocks in reference
6324 * counted roots. There is one reloc tree for each subvol, and all
6325 * reloc trees share same root key objectid. Reloc trees are snapshots
6326 * of the latest committed roots of subvols (root->commit_root).
6327 *
6328 * To relocate a tree block referenced by a subvol, there are two steps.
6329 * COW the block through subvol's reloc tree, then update block pointer
6330 * in the subvol to point to the new block. Since all reloc trees share
6331 * same root key objectid, doing special handing for tree blocks owned
6332 * by them is easy. Once a tree block has been COWed in one reloc tree,
6333 * we can use the resulting new block directly when the same block is
6334 * required to COW again through other reloc trees. By this way, relocated
6335 * tree blocks are shared between reloc trees, so they are also shared
6336 * between subvols.
6337 */
6338 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
6339 struct btrfs_root *root,
6340 struct btrfs_path *path,
6341 struct btrfs_key *first_key,
6342 struct btrfs_ref_path *ref_path,
6343 struct btrfs_block_group_cache *group,
6344 struct inode *reloc_inode)
6345 {
6346 struct btrfs_root *reloc_root;
6347 struct extent_buffer *eb = NULL;
6348 struct btrfs_key *keys;
6349 u64 *nodes;
6350 int level;
6351 int shared_level;
6352 int lowest_level = 0;
6353 int ret;
6354
6355 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
6356 lowest_level = ref_path->owner_objectid;
6357
6358 if (!root->ref_cows) {
6359 path->lowest_level = lowest_level;
6360 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
6361 BUG_ON(ret < 0);
6362 path->lowest_level = 0;
6363 btrfs_release_path(root, path);
6364 return 0;
6365 }
6366
6367 mutex_lock(&root->fs_info->tree_reloc_mutex);
6368 ret = init_reloc_tree(trans, root);
6369 BUG_ON(ret);
6370 reloc_root = root->reloc_root;
6371
6372 shared_level = ref_path->shared_level;
6373 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
6374
6375 keys = ref_path->node_keys;
6376 nodes = ref_path->new_nodes;
6377 memset(&keys[shared_level + 1], 0,
6378 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
6379 memset(&nodes[shared_level + 1], 0,
6380 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
6381
6382 if (nodes[lowest_level] == 0) {
6383 path->lowest_level = lowest_level;
6384 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6385 0, 1);
6386 BUG_ON(ret);
6387 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
6388 eb = path->nodes[level];
6389 if (!eb || eb == reloc_root->node)
6390 break;
6391 nodes[level] = eb->start;
6392 if (level == 0)
6393 btrfs_item_key_to_cpu(eb, &keys[level], 0);
6394 else
6395 btrfs_node_key_to_cpu(eb, &keys[level], 0);
6396 }
6397 if (nodes[0] &&
6398 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6399 eb = path->nodes[0];
6400 ret = replace_extents_in_leaf(trans, reloc_root, eb,
6401 group, reloc_inode);
6402 BUG_ON(ret);
6403 }
6404 btrfs_release_path(reloc_root, path);
6405 } else {
6406 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
6407 lowest_level);
6408 BUG_ON(ret);
6409 }
6410
6411 /*
6412 * replace tree blocks in the fs tree with tree blocks in
6413 * the reloc tree.
6414 */
6415 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
6416 BUG_ON(ret < 0);
6417
6418 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6419 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6420 0, 0);
6421 BUG_ON(ret);
6422 extent_buffer_get(path->nodes[0]);
6423 eb = path->nodes[0];
6424 btrfs_release_path(reloc_root, path);
6425 ret = invalidate_extent_cache(reloc_root, eb, group, root);
6426 BUG_ON(ret);
6427 free_extent_buffer(eb);
6428 }
6429
6430 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6431 path->lowest_level = 0;
6432 return 0;
6433 }
6434
6435 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
6436 struct btrfs_root *root,
6437 struct btrfs_path *path,
6438 struct btrfs_key *first_key,
6439 struct btrfs_ref_path *ref_path)
6440 {
6441 int ret;
6442
6443 ret = relocate_one_path(trans, root, path, first_key,
6444 ref_path, NULL, NULL);
6445 BUG_ON(ret);
6446
6447 return 0;
6448 }
6449
6450 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
6451 struct btrfs_root *extent_root,
6452 struct btrfs_path *path,
6453 struct btrfs_key *extent_key)
6454 {
6455 int ret;
6456
6457 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
6458 if (ret)
6459 goto out;
6460 ret = btrfs_del_item(trans, extent_root, path);
6461 out:
6462 btrfs_release_path(extent_root, path);
6463 return ret;
6464 }
6465
6466 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
6467 struct btrfs_ref_path *ref_path)
6468 {
6469 struct btrfs_key root_key;
6470
6471 root_key.objectid = ref_path->root_objectid;
6472 root_key.type = BTRFS_ROOT_ITEM_KEY;
6473 if (is_cowonly_root(ref_path->root_objectid))
6474 root_key.offset = 0;
6475 else
6476 root_key.offset = (u64)-1;
6477
6478 return btrfs_read_fs_root_no_name(fs_info, &root_key);
6479 }
6480
6481 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
6482 struct btrfs_path *path,
6483 struct btrfs_key *extent_key,
6484 struct btrfs_block_group_cache *group,
6485 struct inode *reloc_inode, int pass)
6486 {
6487 struct btrfs_trans_handle *trans;
6488 struct btrfs_root *found_root;
6489 struct btrfs_ref_path *ref_path = NULL;
6490 struct disk_extent *new_extents = NULL;
6491 int nr_extents = 0;
6492 int loops;
6493 int ret;
6494 int level;
6495 struct btrfs_key first_key;
6496 u64 prev_block = 0;
6497
6498
6499 trans = btrfs_start_transaction(extent_root, 1);
6500 BUG_ON(!trans);
6501
6502 if (extent_key->objectid == 0) {
6503 ret = del_extent_zero(trans, extent_root, path, extent_key);
6504 goto out;
6505 }
6506
6507 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
6508 if (!ref_path) {
6509 ret = -ENOMEM;
6510 goto out;
6511 }
6512
6513 for (loops = 0; ; loops++) {
6514 if (loops == 0) {
6515 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
6516 extent_key->objectid);
6517 } else {
6518 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
6519 }
6520 if (ret < 0)
6521 goto out;
6522 if (ret > 0)
6523 break;
6524
6525 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
6526 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
6527 continue;
6528
6529 found_root = read_ref_root(extent_root->fs_info, ref_path);
6530 BUG_ON(!found_root);
6531 /*
6532 * for reference counted tree, only process reference paths
6533 * rooted at the latest committed root.
6534 */
6535 if (found_root->ref_cows &&
6536 ref_path->root_generation != found_root->root_key.offset)
6537 continue;
6538
6539 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6540 if (pass == 0) {
6541 /*
6542 * copy data extents to new locations
6543 */
6544 u64 group_start = group->key.objectid;
6545 ret = relocate_data_extent(reloc_inode,
6546 extent_key,
6547 group_start);
6548 if (ret < 0)
6549 goto out;
6550 break;
6551 }
6552 level = 0;
6553 } else {
6554 level = ref_path->owner_objectid;
6555 }
6556
6557 if (prev_block != ref_path->nodes[level]) {
6558 struct extent_buffer *eb;
6559 u64 block_start = ref_path->nodes[level];
6560 u64 block_size = btrfs_level_size(found_root, level);
6561
6562 eb = read_tree_block(found_root, block_start,
6563 block_size, 0);
6564 btrfs_tree_lock(eb);
6565 BUG_ON(level != btrfs_header_level(eb));
6566
6567 if (level == 0)
6568 btrfs_item_key_to_cpu(eb, &first_key, 0);
6569 else
6570 btrfs_node_key_to_cpu(eb, &first_key, 0);
6571
6572 btrfs_tree_unlock(eb);
6573 free_extent_buffer(eb);
6574 prev_block = block_start;
6575 }
6576
6577 mutex_lock(&extent_root->fs_info->trans_mutex);
6578 btrfs_record_root_in_trans(found_root);
6579 mutex_unlock(&extent_root->fs_info->trans_mutex);
6580 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6581 /*
6582 * try to update data extent references while
6583 * keeping metadata shared between snapshots.
6584 */
6585 if (pass == 1) {
6586 ret = relocate_one_path(trans, found_root,
6587 path, &first_key, ref_path,
6588 group, reloc_inode);
6589 if (ret < 0)
6590 goto out;
6591 continue;
6592 }
6593 /*
6594 * use fallback method to process the remaining
6595 * references.
6596 */
6597 if (!new_extents) {
6598 u64 group_start = group->key.objectid;
6599 new_extents = kmalloc(sizeof(*new_extents),
6600 GFP_NOFS);
6601 nr_extents = 1;
6602 ret = get_new_locations(reloc_inode,
6603 extent_key,
6604 group_start, 1,
6605 &new_extents,
6606 &nr_extents);
6607 if (ret)
6608 goto out;
6609 }
6610 ret = replace_one_extent(trans, found_root,
6611 path, extent_key,
6612 &first_key, ref_path,
6613 new_extents, nr_extents);
6614 } else {
6615 ret = relocate_tree_block(trans, found_root, path,
6616 &first_key, ref_path);
6617 }
6618 if (ret < 0)
6619 goto out;
6620 }
6621 ret = 0;
6622 out:
6623 btrfs_end_transaction(trans, extent_root);
6624 kfree(new_extents);
6625 kfree(ref_path);
6626 return ret;
6627 }
6628 #endif
6629
6630 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
6631 {
6632 u64 num_devices;
6633 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
6634 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
6635
6636 num_devices = root->fs_info->fs_devices->rw_devices;
6637 if (num_devices == 1) {
6638 stripped |= BTRFS_BLOCK_GROUP_DUP;
6639 stripped = flags & ~stripped;
6640
6641 /* turn raid0 into single device chunks */
6642 if (flags & BTRFS_BLOCK_GROUP_RAID0)
6643 return stripped;
6644
6645 /* turn mirroring into duplication */
6646 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
6647 BTRFS_BLOCK_GROUP_RAID10))
6648 return stripped | BTRFS_BLOCK_GROUP_DUP;
6649 return flags;
6650 } else {
6651 /* they already had raid on here, just return */
6652 if (flags & stripped)
6653 return flags;
6654
6655 stripped |= BTRFS_BLOCK_GROUP_DUP;
6656 stripped = flags & ~stripped;
6657
6658 /* switch duplicated blocks with raid1 */
6659 if (flags & BTRFS_BLOCK_GROUP_DUP)
6660 return stripped | BTRFS_BLOCK_GROUP_RAID1;
6661
6662 /* turn single device chunks into raid0 */
6663 return stripped | BTRFS_BLOCK_GROUP_RAID0;
6664 }
6665 return flags;
6666 }
6667
6668 static int __alloc_chunk_for_shrink(struct btrfs_root *root,
6669 struct btrfs_block_group_cache *shrink_block_group,
6670 int force)
6671 {
6672 struct btrfs_trans_handle *trans;
6673 u64 new_alloc_flags;
6674 u64 calc;
6675
6676 spin_lock(&shrink_block_group->lock);
6677 if (btrfs_block_group_used(&shrink_block_group->item) +
6678 shrink_block_group->reserved > 0) {
6679 spin_unlock(&shrink_block_group->lock);
6680
6681 trans = btrfs_start_transaction(root, 1);
6682 spin_lock(&shrink_block_group->lock);
6683
6684 new_alloc_flags = update_block_group_flags(root,
6685 shrink_block_group->flags);
6686 if (new_alloc_flags != shrink_block_group->flags) {
6687 calc =
6688 btrfs_block_group_used(&shrink_block_group->item);
6689 } else {
6690 calc = shrink_block_group->key.offset;
6691 }
6692 spin_unlock(&shrink_block_group->lock);
6693
6694 do_chunk_alloc(trans, root->fs_info->extent_root,
6695 calc + 2 * 1024 * 1024, new_alloc_flags, force);
6696
6697 btrfs_end_transaction(trans, root);
6698 } else
6699 spin_unlock(&shrink_block_group->lock);
6700 return 0;
6701 }
6702
6703
6704 int btrfs_prepare_block_group_relocation(struct btrfs_root *root,
6705 struct btrfs_block_group_cache *group)
6706
6707 {
6708 __alloc_chunk_for_shrink(root, group, 1);
6709 set_block_group_readonly(group);
6710 return 0;
6711 }
6712
6713 /*
6714 * checks to see if its even possible to relocate this block group.
6715 *
6716 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
6717 * ok to go ahead and try.
6718 */
6719 int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
6720 {
6721 struct btrfs_block_group_cache *block_group;
6722 struct btrfs_space_info *space_info;
6723 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
6724 struct btrfs_device *device;
6725 int full = 0;
6726 int ret = 0;
6727
6728 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
6729
6730 /* odd, couldn't find the block group, leave it alone */
6731 if (!block_group)
6732 return -1;
6733
6734 /* no bytes used, we're good */
6735 if (!btrfs_block_group_used(&block_group->item))
6736 goto out;
6737
6738 space_info = block_group->space_info;
6739 spin_lock(&space_info->lock);
6740
6741 full = space_info->full;
6742
6743 /*
6744 * if this is the last block group we have in this space, we can't
6745 * relocate it.
6746 */
6747 if (space_info->total_bytes == block_group->key.offset) {
6748 ret = -1;
6749 spin_unlock(&space_info->lock);
6750 goto out;
6751 }
6752
6753 /*
6754 * need to make sure we have room in the space to handle all of the
6755 * extents from this block group. If we can, we're good
6756 */
6757 if (space_info->bytes_used + space_info->bytes_reserved +
6758 space_info->bytes_pinned + space_info->bytes_readonly +
6759 btrfs_block_group_used(&block_group->item) <
6760 space_info->total_bytes) {
6761 spin_unlock(&space_info->lock);
6762 goto out;
6763 }
6764 spin_unlock(&space_info->lock);
6765
6766 /*
6767 * ok we don't have enough space, but maybe we have free space on our
6768 * devices to allocate new chunks for relocation, so loop through our
6769 * alloc devices and guess if we have enough space. However, if we
6770 * were marked as full, then we know there aren't enough chunks, and we
6771 * can just return.
6772 */
6773 ret = -1;
6774 if (full)
6775 goto out;
6776
6777 mutex_lock(&root->fs_info->chunk_mutex);
6778 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
6779 u64 min_free = btrfs_block_group_used(&block_group->item);
6780 u64 dev_offset, max_avail;
6781
6782 /*
6783 * check to make sure we can actually find a chunk with enough
6784 * space to fit our block group in.
6785 */
6786 if (device->total_bytes > device->bytes_used + min_free) {
6787 ret = find_free_dev_extent(NULL, device, min_free,
6788 &dev_offset, &max_avail);
6789 if (!ret)
6790 break;
6791 ret = -1;
6792 }
6793 }
6794 mutex_unlock(&root->fs_info->chunk_mutex);
6795 out:
6796 btrfs_put_block_group(block_group);
6797 return ret;
6798 }
6799
6800 static int find_first_block_group(struct btrfs_root *root,
6801 struct btrfs_path *path, struct btrfs_key *key)
6802 {
6803 int ret = 0;
6804 struct btrfs_key found_key;
6805 struct extent_buffer *leaf;
6806 int slot;
6807
6808 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
6809 if (ret < 0)
6810 goto out;
6811
6812 while (1) {
6813 slot = path->slots[0];
6814 leaf = path->nodes[0];
6815 if (slot >= btrfs_header_nritems(leaf)) {
6816 ret = btrfs_next_leaf(root, path);
6817 if (ret == 0)
6818 continue;
6819 if (ret < 0)
6820 goto out;
6821 break;
6822 }
6823 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6824
6825 if (found_key.objectid >= key->objectid &&
6826 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
6827 ret = 0;
6828 goto out;
6829 }
6830 path->slots[0]++;
6831 }
6832 ret = -ENOENT;
6833 out:
6834 return ret;
6835 }
6836
6837 int btrfs_free_block_groups(struct btrfs_fs_info *info)
6838 {
6839 struct btrfs_block_group_cache *block_group;
6840 struct btrfs_space_info *space_info;
6841 struct btrfs_caching_control *caching_ctl;
6842 struct rb_node *n;
6843
6844 down_write(&info->extent_commit_sem);
6845 while (!list_empty(&info->caching_block_groups)) {
6846 caching_ctl = list_entry(info->caching_block_groups.next,
6847 struct btrfs_caching_control, list);
6848 list_del(&caching_ctl->list);
6849 put_caching_control(caching_ctl);
6850 }
6851 up_write(&info->extent_commit_sem);
6852
6853 spin_lock(&info->block_group_cache_lock);
6854 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
6855 block_group = rb_entry(n, struct btrfs_block_group_cache,
6856 cache_node);
6857 rb_erase(&block_group->cache_node,
6858 &info->block_group_cache_tree);
6859 spin_unlock(&info->block_group_cache_lock);
6860
6861 down_write(&block_group->space_info->groups_sem);
6862 list_del(&block_group->list);
6863 up_write(&block_group->space_info->groups_sem);
6864
6865 if (block_group->cached == BTRFS_CACHE_STARTED)
6866 wait_block_group_cache_done(block_group);
6867
6868 btrfs_remove_free_space_cache(block_group);
6869
6870 WARN_ON(atomic_read(&block_group->count) != 1);
6871 kfree(block_group);
6872
6873 spin_lock(&info->block_group_cache_lock);
6874 }
6875 spin_unlock(&info->block_group_cache_lock);
6876
6877 /* now that all the block groups are freed, go through and
6878 * free all the space_info structs. This is only called during
6879 * the final stages of unmount, and so we know nobody is
6880 * using them. We call synchronize_rcu() once before we start,
6881 * just to be on the safe side.
6882 */
6883 synchronize_rcu();
6884
6885 while(!list_empty(&info->space_info)) {
6886 space_info = list_entry(info->space_info.next,
6887 struct btrfs_space_info,
6888 list);
6889
6890 list_del(&space_info->list);
6891 kfree(space_info);
6892 }
6893 return 0;
6894 }
6895
6896 int btrfs_read_block_groups(struct btrfs_root *root)
6897 {
6898 struct btrfs_path *path;
6899 int ret;
6900 struct btrfs_block_group_cache *cache;
6901 struct btrfs_fs_info *info = root->fs_info;
6902 struct btrfs_space_info *space_info;
6903 struct btrfs_key key;
6904 struct btrfs_key found_key;
6905 struct extent_buffer *leaf;
6906
6907 root = info->extent_root;
6908 key.objectid = 0;
6909 key.offset = 0;
6910 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
6911 path = btrfs_alloc_path();
6912 if (!path)
6913 return -ENOMEM;
6914
6915 while (1) {
6916 ret = find_first_block_group(root, path, &key);
6917 if (ret > 0) {
6918 ret = 0;
6919 goto error;
6920 }
6921 if (ret != 0)
6922 goto error;
6923
6924 leaf = path->nodes[0];
6925 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6926 cache = kzalloc(sizeof(*cache), GFP_NOFS);
6927 if (!cache) {
6928 ret = -ENOMEM;
6929 break;
6930 }
6931
6932 atomic_set(&cache->count, 1);
6933 spin_lock_init(&cache->lock);
6934 spin_lock_init(&cache->tree_lock);
6935 cache->fs_info = info;
6936 INIT_LIST_HEAD(&cache->list);
6937 INIT_LIST_HEAD(&cache->cluster_list);
6938
6939 /*
6940 * we only want to have 32k of ram per block group for keeping
6941 * track of free space, and if we pass 1/2 of that we want to
6942 * start converting things over to using bitmaps
6943 */
6944 cache->extents_thresh = ((1024 * 32) / 2) /
6945 sizeof(struct btrfs_free_space);
6946
6947 read_extent_buffer(leaf, &cache->item,
6948 btrfs_item_ptr_offset(leaf, path->slots[0]),
6949 sizeof(cache->item));
6950 memcpy(&cache->key, &found_key, sizeof(found_key));
6951
6952 key.objectid = found_key.objectid + found_key.offset;
6953 btrfs_release_path(root, path);
6954 cache->flags = btrfs_block_group_flags(&cache->item);
6955 cache->sectorsize = root->sectorsize;
6956
6957 /*
6958 * check for two cases, either we are full, and therefore
6959 * don't need to bother with the caching work since we won't
6960 * find any space, or we are empty, and we can just add all
6961 * the space in and be done with it. This saves us _alot_ of
6962 * time, particularly in the full case.
6963 */
6964 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
6965 exclude_super_stripes(root, cache);
6966 cache->last_byte_to_unpin = (u64)-1;
6967 cache->cached = BTRFS_CACHE_FINISHED;
6968 free_excluded_extents(root, cache);
6969 } else if (btrfs_block_group_used(&cache->item) == 0) {
6970 exclude_super_stripes(root, cache);
6971 cache->last_byte_to_unpin = (u64)-1;
6972 cache->cached = BTRFS_CACHE_FINISHED;
6973 add_new_free_space(cache, root->fs_info,
6974 found_key.objectid,
6975 found_key.objectid +
6976 found_key.offset);
6977 free_excluded_extents(root, cache);
6978 }
6979
6980 ret = update_space_info(info, cache->flags, found_key.offset,
6981 btrfs_block_group_used(&cache->item),
6982 &space_info);
6983 BUG_ON(ret);
6984 cache->space_info = space_info;
6985 spin_lock(&cache->space_info->lock);
6986 cache->space_info->bytes_super += cache->bytes_super;
6987 spin_unlock(&cache->space_info->lock);
6988
6989 down_write(&space_info->groups_sem);
6990 list_add_tail(&cache->list, &space_info->block_groups);
6991 up_write(&space_info->groups_sem);
6992
6993 ret = btrfs_add_block_group_cache(root->fs_info, cache);
6994 BUG_ON(ret);
6995
6996 set_avail_alloc_bits(root->fs_info, cache->flags);
6997 if (btrfs_chunk_readonly(root, cache->key.objectid))
6998 set_block_group_readonly(cache);
6999 }
7000 ret = 0;
7001 error:
7002 btrfs_free_path(path);
7003 return ret;
7004 }
7005
7006 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
7007 struct btrfs_root *root, u64 bytes_used,
7008 u64 type, u64 chunk_objectid, u64 chunk_offset,
7009 u64 size)
7010 {
7011 int ret;
7012 struct btrfs_root *extent_root;
7013 struct btrfs_block_group_cache *cache;
7014
7015 extent_root = root->fs_info->extent_root;
7016
7017 root->fs_info->last_trans_log_full_commit = trans->transid;
7018
7019 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7020 if (!cache)
7021 return -ENOMEM;
7022
7023 cache->key.objectid = chunk_offset;
7024 cache->key.offset = size;
7025 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
7026 cache->sectorsize = root->sectorsize;
7027
7028 /*
7029 * we only want to have 32k of ram per block group for keeping track
7030 * of free space, and if we pass 1/2 of that we want to start
7031 * converting things over to using bitmaps
7032 */
7033 cache->extents_thresh = ((1024 * 32) / 2) /
7034 sizeof(struct btrfs_free_space);
7035 atomic_set(&cache->count, 1);
7036 spin_lock_init(&cache->lock);
7037 spin_lock_init(&cache->tree_lock);
7038 INIT_LIST_HEAD(&cache->list);
7039 INIT_LIST_HEAD(&cache->cluster_list);
7040
7041 btrfs_set_block_group_used(&cache->item, bytes_used);
7042 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
7043 cache->flags = type;
7044 btrfs_set_block_group_flags(&cache->item, type);
7045
7046 cache->last_byte_to_unpin = (u64)-1;
7047 cache->cached = BTRFS_CACHE_FINISHED;
7048 exclude_super_stripes(root, cache);
7049
7050 add_new_free_space(cache, root->fs_info, chunk_offset,
7051 chunk_offset + size);
7052
7053 free_excluded_extents(root, cache);
7054
7055 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
7056 &cache->space_info);
7057 BUG_ON(ret);
7058
7059 spin_lock(&cache->space_info->lock);
7060 cache->space_info->bytes_super += cache->bytes_super;
7061 spin_unlock(&cache->space_info->lock);
7062
7063 down_write(&cache->space_info->groups_sem);
7064 list_add_tail(&cache->list, &cache->space_info->block_groups);
7065 up_write(&cache->space_info->groups_sem);
7066
7067 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7068 BUG_ON(ret);
7069
7070 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
7071 sizeof(cache->item));
7072 BUG_ON(ret);
7073
7074 set_avail_alloc_bits(extent_root->fs_info, type);
7075
7076 return 0;
7077 }
7078
7079 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
7080 struct btrfs_root *root, u64 group_start)
7081 {
7082 struct btrfs_path *path;
7083 struct btrfs_block_group_cache *block_group;
7084 struct btrfs_free_cluster *cluster;
7085 struct btrfs_key key;
7086 int ret;
7087
7088 root = root->fs_info->extent_root;
7089
7090 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
7091 BUG_ON(!block_group);
7092 BUG_ON(!block_group->ro);
7093
7094 memcpy(&key, &block_group->key, sizeof(key));
7095
7096 /* make sure this block group isn't part of an allocation cluster */
7097 cluster = &root->fs_info->data_alloc_cluster;
7098 spin_lock(&cluster->refill_lock);
7099 btrfs_return_cluster_to_free_space(block_group, cluster);
7100 spin_unlock(&cluster->refill_lock);
7101
7102 /*
7103 * make sure this block group isn't part of a metadata
7104 * allocation cluster
7105 */
7106 cluster = &root->fs_info->meta_alloc_cluster;
7107 spin_lock(&cluster->refill_lock);
7108 btrfs_return_cluster_to_free_space(block_group, cluster);
7109 spin_unlock(&cluster->refill_lock);
7110
7111 path = btrfs_alloc_path();
7112 BUG_ON(!path);
7113
7114 spin_lock(&root->fs_info->block_group_cache_lock);
7115 rb_erase(&block_group->cache_node,
7116 &root->fs_info->block_group_cache_tree);
7117 spin_unlock(&root->fs_info->block_group_cache_lock);
7118
7119 down_write(&block_group->space_info->groups_sem);
7120 /*
7121 * we must use list_del_init so people can check to see if they
7122 * are still on the list after taking the semaphore
7123 */
7124 list_del_init(&block_group->list);
7125 up_write(&block_group->space_info->groups_sem);
7126
7127 if (block_group->cached == BTRFS_CACHE_STARTED)
7128 wait_block_group_cache_done(block_group);
7129
7130 btrfs_remove_free_space_cache(block_group);
7131
7132 spin_lock(&block_group->space_info->lock);
7133 block_group->space_info->total_bytes -= block_group->key.offset;
7134 block_group->space_info->bytes_readonly -= block_group->key.offset;
7135 spin_unlock(&block_group->space_info->lock);
7136
7137 btrfs_clear_space_info_full(root->fs_info);
7138
7139 btrfs_put_block_group(block_group);
7140 btrfs_put_block_group(block_group);
7141
7142 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
7143 if (ret > 0)
7144 ret = -EIO;
7145 if (ret < 0)
7146 goto out;
7147
7148 ret = btrfs_del_item(trans, root, path);
7149 out:
7150 btrfs_free_path(path);
7151 return ret;
7152 }
This page took 0.434346 seconds and 6 git commands to generate.