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mm-only debug patch...
[mmotm.git] / fs / btrfs / extent-tree.c
blobd0c4d584efadd9cf92050bf0da946e364da2dc8a
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/pagemap.h>
20 #include <linux/writeback.h>
21 #include <linux/blkdev.h>
22 #include <linux/sort.h>
23 #include <linux/rcupdate.h>
24 #include <linux/kthread.h>
25 #include "compat.h"
26 #include "hash.h"
27 #include "ctree.h"
28 #include "disk-io.h"
29 #include "print-tree.h"
30 #include "transaction.h"
31 #include "volumes.h"
32 #include "locking.h"
33 #include "free-space-cache.h"
34
35 static int update_block_group(struct btrfs_trans_handle *trans,
36 struct btrfs_root *root,
37 u64 bytenr, u64 num_bytes, int alloc,
38 int mark_free);
39 static int update_reserved_extents(struct btrfs_block_group_cache *cache,
40 u64 num_bytes, int reserve);
41 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
42 struct btrfs_root *root,
43 u64 bytenr, u64 num_bytes, u64 parent,
44 u64 root_objectid, u64 owner_objectid,
45 u64 owner_offset, int refs_to_drop,
46 struct btrfs_delayed_extent_op *extra_op);
47 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
48 struct extent_buffer *leaf,
49 struct btrfs_extent_item *ei);
50 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
51 struct btrfs_root *root,
52 u64 parent, u64 root_objectid,
53 u64 flags, u64 owner, u64 offset,
54 struct btrfs_key *ins, int ref_mod);
55 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
56 struct btrfs_root *root,
57 u64 parent, u64 root_objectid,
58 u64 flags, struct btrfs_disk_key *key,
59 int level, struct btrfs_key *ins);
60 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
61 struct btrfs_root *extent_root, u64 alloc_bytes,
62 u64 flags, int force);
63 static int pin_down_bytes(struct btrfs_trans_handle *trans,
64 struct btrfs_root *root,
65 struct btrfs_path *path,
66 u64 bytenr, u64 num_bytes,
67 int is_data, int reserved,
68 struct extent_buffer **must_clean);
69 static int find_next_key(struct btrfs_path *path, int level,
70 struct btrfs_key *key);
71 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
72 int dump_block_groups);
73
74 static noinline int
75 block_group_cache_done(struct btrfs_block_group_cache *cache)
76 {
77 smp_mb();
78 return cache->cached == BTRFS_CACHE_FINISHED;
79 }
80
81 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
82 {
83 return (cache->flags & bits) == bits;
84 }
85
86 /*
87 * this adds the block group to the fs_info rb tree for the block group
88 * cache
89 */
90 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
91 struct btrfs_block_group_cache *block_group)
92 {
93 struct rb_node **p;
94 struct rb_node *parent = NULL;
95 struct btrfs_block_group_cache *cache;
96
97 spin_lock(&info->block_group_cache_lock);
98 p = &info->block_group_cache_tree.rb_node;
99
100 while (*p) {
101 parent = *p;
102 cache = rb_entry(parent, struct btrfs_block_group_cache,
103 cache_node);
104 if (block_group->key.objectid < cache->key.objectid) {
105 p = &(*p)->rb_left;
106 } else if (block_group->key.objectid > cache->key.objectid) {
107 p = &(*p)->rb_right;
108 } else {
109 spin_unlock(&info->block_group_cache_lock);
110 return -EEXIST;
111 }
112 }
113
114 rb_link_node(&block_group->cache_node, parent, p);
115 rb_insert_color(&block_group->cache_node,
116 &info->block_group_cache_tree);
117 spin_unlock(&info->block_group_cache_lock);
118
119 return 0;
120 }
121
122 /*
123 * This will return the block group at or after bytenr if contains is 0, else
124 * it will return the block group that contains the bytenr
125 */
126 static struct btrfs_block_group_cache *
127 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
128 int contains)
129 {
130 struct btrfs_block_group_cache *cache, *ret = NULL;
131 struct rb_node *n;
132 u64 end, start;
133
134 spin_lock(&info->block_group_cache_lock);
135 n = info->block_group_cache_tree.rb_node;
136
137 while (n) {
138 cache = rb_entry(n, struct btrfs_block_group_cache,
139 cache_node);
140 end = cache->key.objectid + cache->key.offset - 1;
141 start = cache->key.objectid;
142
143 if (bytenr < start) {
144 if (!contains && (!ret || start < ret->key.objectid))
145 ret = cache;
146 n = n->rb_left;
147 } else if (bytenr > start) {
148 if (contains && bytenr <= end) {
149 ret = cache;
150 break;
151 }
152 n = n->rb_right;
153 } else {
154 ret = cache;
155 break;
156 }
157 }
158 if (ret)
159 atomic_inc(&ret->count);
160 spin_unlock(&info->block_group_cache_lock);
161
162 return ret;
163 }
164
165 static int add_excluded_extent(struct btrfs_root *root,
166 u64 start, u64 num_bytes)
167 {
168 u64 end = start + num_bytes - 1;
169 set_extent_bits(&root->fs_info->freed_extents[0],
170 start, end, EXTENT_UPTODATE, GFP_NOFS);
171 set_extent_bits(&root->fs_info->freed_extents[1],
172 start, end, EXTENT_UPTODATE, GFP_NOFS);
173 return 0;
174 }
175
176 static void free_excluded_extents(struct btrfs_root *root,
177 struct btrfs_block_group_cache *cache)
178 {
179 u64 start, end;
180
181 start = cache->key.objectid;
182 end = start + cache->key.offset - 1;
183
184 clear_extent_bits(&root->fs_info->freed_extents[0],
185 start, end, EXTENT_UPTODATE, GFP_NOFS);
186 clear_extent_bits(&root->fs_info->freed_extents[1],
187 start, end, EXTENT_UPTODATE, GFP_NOFS);
188 }
189
190 static int exclude_super_stripes(struct btrfs_root *root,
191 struct btrfs_block_group_cache *cache)
192 {
193 u64 bytenr;
194 u64 *logical;
195 int stripe_len;
196 int i, nr, ret;
197
198 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
199 bytenr = btrfs_sb_offset(i);
200 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
201 cache->key.objectid, bytenr,
202 0, &logical, &nr, &stripe_len);
203 BUG_ON(ret);
204
205 while (nr--) {
206 cache->bytes_super += stripe_len;
207 ret = add_excluded_extent(root, logical[nr],
208 stripe_len);
209 BUG_ON(ret);
210 }
211
212 kfree(logical);
213 }
214 return 0;
215 }
216
217 static struct btrfs_caching_control *
218 get_caching_control(struct btrfs_block_group_cache *cache)
219 {
220 struct btrfs_caching_control *ctl;
221
222 spin_lock(&cache->lock);
223 if (cache->cached != BTRFS_CACHE_STARTED) {
224 spin_unlock(&cache->lock);
225 return NULL;
226 }
227
228 ctl = cache->caching_ctl;
229 atomic_inc(&ctl->count);
230 spin_unlock(&cache->lock);
231 return ctl;
232 }
233
234 static void put_caching_control(struct btrfs_caching_control *ctl)
235 {
236 if (atomic_dec_and_test(&ctl->count))
237 kfree(ctl);
238 }
239
240 /*
241 * this is only called by cache_block_group, since we could have freed extents
242 * we need to check the pinned_extents for any extents that can't be used yet
243 * since their free space will be released as soon as the transaction commits.
244 */
245 static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
246 struct btrfs_fs_info *info, u64 start, u64 end)
247 {
248 u64 extent_start, extent_end, size, total_added = 0;
249 int ret;
250
251 while (start < end) {
252 ret = find_first_extent_bit(info->pinned_extents, start,
253 &extent_start, &extent_end,
254 EXTENT_DIRTY | EXTENT_UPTODATE);
255 if (ret)
256 break;
257
258 if (extent_start == start) {
259 start = extent_end + 1;
260 } else if (extent_start > start && extent_start < end) {
261 size = extent_start - start;
262 total_added += size;
263 ret = btrfs_add_free_space(block_group, start,
264 size);
265 BUG_ON(ret);
266 start = extent_end + 1;
267 } else {
268 break;
269 }
270 }
271
272 if (start < end) {
273 size = end - start;
274 total_added += size;
275 ret = btrfs_add_free_space(block_group, start, size);
276 BUG_ON(ret);
277 }
278
279 return total_added;
280 }
281
282 static int caching_kthread(void *data)
283 {
284 struct btrfs_block_group_cache *block_group = data;
285 struct btrfs_fs_info *fs_info = block_group->fs_info;
286 struct btrfs_caching_control *caching_ctl = block_group->caching_ctl;
287 struct btrfs_root *extent_root = fs_info->extent_root;
288 struct btrfs_path *path;
289 struct extent_buffer *leaf;
290 struct btrfs_key key;
291 u64 total_found = 0;
292 u64 last = 0;
293 u32 nritems;
294 int ret = 0;
295
296 path = btrfs_alloc_path();
297 if (!path)
298 return -ENOMEM;
299
300 exclude_super_stripes(extent_root, block_group);
301 spin_lock(&block_group->space_info->lock);
302 block_group->space_info->bytes_super += block_group->bytes_super;
303 spin_unlock(&block_group->space_info->lock);
304
305 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
306
307 /*
308 * We don't want to deadlock with somebody trying to allocate a new
309 * extent for the extent root while also trying to search the extent
310 * root to add free space. So we skip locking and search the commit
311 * root, since its read-only
312 */
313 path->skip_locking = 1;
314 path->search_commit_root = 1;
315 path->reada = 2;
316
317 key.objectid = last;
318 key.offset = 0;
319 key.type = BTRFS_EXTENT_ITEM_KEY;
320 again:
321 mutex_lock(&caching_ctl->mutex);
322 /* need to make sure the commit_root doesn't disappear */
323 down_read(&fs_info->extent_commit_sem);
324
325 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
326 if (ret < 0)
327 goto err;
328
329 leaf = path->nodes[0];
330 nritems = btrfs_header_nritems(leaf);
331
332 while (1) {
333 smp_mb();
334 if (fs_info->closing > 1) {
335 last = (u64)-1;
336 break;
337 }
338
339 if (path->slots[0] < nritems) {
340 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
341 } else {
342 ret = find_next_key(path, 0, &key);
343 if (ret)
344 break;
345
346 caching_ctl->progress = last;
347 btrfs_release_path(extent_root, path);
348 up_read(&fs_info->extent_commit_sem);
349 mutex_unlock(&caching_ctl->mutex);
350 if (btrfs_transaction_in_commit(fs_info))
351 schedule_timeout(1);
352 else
353 cond_resched();
354 goto again;
355 }
356
357 if (key.objectid < block_group->key.objectid) {
358 path->slots[0]++;
359 continue;
360 }
361
362 if (key.objectid >= block_group->key.objectid +
363 block_group->key.offset)
364 break;
365
366 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
367 total_found += add_new_free_space(block_group,
368 fs_info, last,
369 key.objectid);
370 last = key.objectid + key.offset;
371
372 if (total_found > (1024 * 1024 * 2)) {
373 total_found = 0;
374 wake_up(&caching_ctl->wait);
375 }
376 }
377 path->slots[0]++;
378 }
379 ret = 0;
380
381 total_found += add_new_free_space(block_group, fs_info, last,
382 block_group->key.objectid +
383 block_group->key.offset);
384 caching_ctl->progress = (u64)-1;
385
386 spin_lock(&block_group->lock);
387 block_group->caching_ctl = NULL;
388 block_group->cached = BTRFS_CACHE_FINISHED;
389 spin_unlock(&block_group->lock);
390
391 err:
392 btrfs_free_path(path);
393 up_read(&fs_info->extent_commit_sem);
394
395 free_excluded_extents(extent_root, block_group);
396
397 mutex_unlock(&caching_ctl->mutex);
398 wake_up(&caching_ctl->wait);
399
400 put_caching_control(caching_ctl);
401 atomic_dec(&block_group->space_info->caching_threads);
402 return 0;
403 }
404
405 static int cache_block_group(struct btrfs_block_group_cache *cache)
406 {
407 struct btrfs_fs_info *fs_info = cache->fs_info;
408 struct btrfs_caching_control *caching_ctl;
409 struct task_struct *tsk;
410 int ret = 0;
411
412 smp_mb();
413 if (cache->cached != BTRFS_CACHE_NO)
414 return 0;
415
416 caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_KERNEL);
417 BUG_ON(!caching_ctl);
418
419 INIT_LIST_HEAD(&caching_ctl->list);
420 mutex_init(&caching_ctl->mutex);
421 init_waitqueue_head(&caching_ctl->wait);
422 caching_ctl->block_group = cache;
423 caching_ctl->progress = cache->key.objectid;
424 /* one for caching kthread, one for caching block group list */
425 atomic_set(&caching_ctl->count, 2);
426
427 spin_lock(&cache->lock);
428 if (cache->cached != BTRFS_CACHE_NO) {
429 spin_unlock(&cache->lock);
430 kfree(caching_ctl);
431 return 0;
432 }
433 cache->caching_ctl = caching_ctl;
434 cache->cached = BTRFS_CACHE_STARTED;
435 spin_unlock(&cache->lock);
436
437 down_write(&fs_info->extent_commit_sem);
438 list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
439 up_write(&fs_info->extent_commit_sem);
440
441 atomic_inc(&cache->space_info->caching_threads);
442
443 tsk = kthread_run(caching_kthread, cache, "btrfs-cache-%llu\n",
444 cache->key.objectid);
445 if (IS_ERR(tsk)) {
446 ret = PTR_ERR(tsk);
447 printk(KERN_ERR "error running thread %d\n", ret);
448 BUG();
449 }
450
451 return ret;
452 }
453
454 /*
455 * return the block group that starts at or after bytenr
456 */
457 static struct btrfs_block_group_cache *
458 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
459 {
460 struct btrfs_block_group_cache *cache;
461
462 cache = block_group_cache_tree_search(info, bytenr, 0);
463
464 return cache;
465 }
466
467 /*
468 * return the block group that contains the given bytenr
469 */
470 struct btrfs_block_group_cache *btrfs_lookup_block_group(
471 struct btrfs_fs_info *info,
472 u64 bytenr)
473 {
474 struct btrfs_block_group_cache *cache;
475
476 cache = block_group_cache_tree_search(info, bytenr, 1);
477
478 return cache;
479 }
480
481 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
482 {
483 if (atomic_dec_and_test(&cache->count))
484 kfree(cache);
485 }
486
487 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
488 u64 flags)
489 {
490 struct list_head *head = &info->space_info;
491 struct btrfs_space_info *found;
492
493 rcu_read_lock();
494 list_for_each_entry_rcu(found, head, list) {
495 if (found->flags == flags) {
496 rcu_read_unlock();
497 return found;
498 }
499 }
500 rcu_read_unlock();
501 return NULL;
502 }
503
504 /*
505 * after adding space to the filesystem, we need to clear the full flags
506 * on all the space infos.
507 */
508 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
509 {
510 struct list_head *head = &info->space_info;
511 struct btrfs_space_info *found;
512
513 rcu_read_lock();
514 list_for_each_entry_rcu(found, head, list)
515 found->full = 0;
516 rcu_read_unlock();
517 }
518
519 static u64 div_factor(u64 num, int factor)
520 {
521 if (factor == 10)
522 return num;
523 num *= factor;
524 do_div(num, 10);
525 return num;
526 }
527
528 u64 btrfs_find_block_group(struct btrfs_root *root,
529 u64 search_start, u64 search_hint, int owner)
530 {
531 struct btrfs_block_group_cache *cache;
532 u64 used;
533 u64 last = max(search_hint, search_start);
534 u64 group_start = 0;
535 int full_search = 0;
536 int factor = 9;
537 int wrapped = 0;
538 again:
539 while (1) {
540 cache = btrfs_lookup_first_block_group(root->fs_info, last);
541 if (!cache)
542 break;
543
544 spin_lock(&cache->lock);
545 last = cache->key.objectid + cache->key.offset;
546 used = btrfs_block_group_used(&cache->item);
547
548 if ((full_search || !cache->ro) &&
549 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
550 if (used + cache->pinned + cache->reserved <
551 div_factor(cache->key.offset, factor)) {
552 group_start = cache->key.objectid;
553 spin_unlock(&cache->lock);
554 btrfs_put_block_group(cache);
555 goto found;
556 }
557 }
558 spin_unlock(&cache->lock);
559 btrfs_put_block_group(cache);
560 cond_resched();
561 }
562 if (!wrapped) {
563 last = search_start;
564 wrapped = 1;
565 goto again;
566 }
567 if (!full_search && factor < 10) {
568 last = search_start;
569 full_search = 1;
570 factor = 10;
571 goto again;
572 }
573 found:
574 return group_start;
575 }
576
577 /* simple helper to search for an existing extent at a given offset */
578 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
579 {
580 int ret;
581 struct btrfs_key key;
582 struct btrfs_path *path;
583
584 path = btrfs_alloc_path();
585 BUG_ON(!path);
586 key.objectid = start;
587 key.offset = len;
588 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
589 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
590 0, 0);
591 btrfs_free_path(path);
592 return ret;
593 }
594
595 /*
596 * Back reference rules. Back refs have three main goals:
597 *
598 * 1) differentiate between all holders of references to an extent so that
599 * when a reference is dropped we can make sure it was a valid reference
600 * before freeing the extent.
601 *
602 * 2) Provide enough information to quickly find the holders of an extent
603 * if we notice a given block is corrupted or bad.
604 *
605 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
606 * maintenance. This is actually the same as #2, but with a slightly
607 * different use case.
608 *
609 * There are two kinds of back refs. The implicit back refs is optimized
610 * for pointers in non-shared tree blocks. For a given pointer in a block,
611 * back refs of this kind provide information about the block's owner tree
612 * and the pointer's key. These information allow us to find the block by
613 * b-tree searching. The full back refs is for pointers in tree blocks not
614 * referenced by their owner trees. The location of tree block is recorded
615 * in the back refs. Actually the full back refs is generic, and can be
616 * used in all cases the implicit back refs is used. The major shortcoming
617 * of the full back refs is its overhead. Every time a tree block gets
618 * COWed, we have to update back refs entry for all pointers in it.
619 *
620 * For a newly allocated tree block, we use implicit back refs for
621 * pointers in it. This means most tree related operations only involve
622 * implicit back refs. For a tree block created in old transaction, the
623 * only way to drop a reference to it is COW it. So we can detect the
624 * event that tree block loses its owner tree's reference and do the
625 * back refs conversion.
626 *
627 * When a tree block is COW'd through a tree, there are four cases:
628 *
629 * The reference count of the block is one and the tree is the block's
630 * owner tree. Nothing to do in this case.
631 *
632 * The reference count of the block is one and the tree is not the
633 * block's owner tree. In this case, full back refs is used for pointers
634 * in the block. Remove these full back refs, add implicit back refs for
635 * every pointers in the new block.
636 *
637 * The reference count of the block is greater than one and the tree is
638 * the block's owner tree. In this case, implicit back refs is used for
639 * pointers in the block. Add full back refs for every pointers in the
640 * block, increase lower level extents' reference counts. The original
641 * implicit back refs are entailed to the new block.
642 *
643 * The reference count of the block is greater than one and the tree is
644 * not the block's owner tree. Add implicit back refs for every pointer in
645 * the new block, increase lower level extents' reference count.
646 *
647 * Back Reference Key composing:
648 *
649 * The key objectid corresponds to the first byte in the extent,
650 * The key type is used to differentiate between types of back refs.
651 * There are different meanings of the key offset for different types
652 * of back refs.
653 *
654 * File extents can be referenced by:
655 *
656 * - multiple snapshots, subvolumes, or different generations in one subvol
657 * - different files inside a single subvolume
658 * - different offsets inside a file (bookend extents in file.c)
659 *
660 * The extent ref structure for the implicit back refs has fields for:
661 *
662 * - Objectid of the subvolume root
663 * - objectid of the file holding the reference
664 * - original offset in the file
665 * - how many bookend extents
666 *
667 * The key offset for the implicit back refs is hash of the first
668 * three fields.
669 *
670 * The extent ref structure for the full back refs has field for:
671 *
672 * - number of pointers in the tree leaf
673 *
674 * The key offset for the implicit back refs is the first byte of
675 * the tree leaf
676 *
677 * When a file extent is allocated, The implicit back refs is used.
678 * the fields are filled in:
679 *
680 * (root_key.objectid, inode objectid, offset in file, 1)
681 *
682 * When a file extent is removed file truncation, we find the
683 * corresponding implicit back refs and check the following fields:
684 *
685 * (btrfs_header_owner(leaf), inode objectid, offset in file)
686 *
687 * Btree extents can be referenced by:
688 *
689 * - Different subvolumes
690 *
691 * Both the implicit back refs and the full back refs for tree blocks
692 * only consist of key. The key offset for the implicit back refs is
693 * objectid of block's owner tree. The key offset for the full back refs
694 * is the first byte of parent block.
695 *
696 * When implicit back refs is used, information about the lowest key and
697 * level of the tree block are required. These information are stored in
698 * tree block info structure.
699 */
700
701 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
702 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
703 struct btrfs_root *root,
704 struct btrfs_path *path,
705 u64 owner, u32 extra_size)
706 {
707 struct btrfs_extent_item *item;
708 struct btrfs_extent_item_v0 *ei0;
709 struct btrfs_extent_ref_v0 *ref0;
710 struct btrfs_tree_block_info *bi;
711 struct extent_buffer *leaf;
712 struct btrfs_key key;
713 struct btrfs_key found_key;
714 u32 new_size = sizeof(*item);
715 u64 refs;
716 int ret;
717
718 leaf = path->nodes[0];
719 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
720
721 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
722 ei0 = btrfs_item_ptr(leaf, path->slots[0],
723 struct btrfs_extent_item_v0);
724 refs = btrfs_extent_refs_v0(leaf, ei0);
725
726 if (owner == (u64)-1) {
727 while (1) {
728 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
729 ret = btrfs_next_leaf(root, path);
730 if (ret < 0)
731 return ret;
732 BUG_ON(ret > 0);
733 leaf = path->nodes[0];
734 }
735 btrfs_item_key_to_cpu(leaf, &found_key,
736 path->slots[0]);
737 BUG_ON(key.objectid != found_key.objectid);
738 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
739 path->slots[0]++;
740 continue;
741 }
742 ref0 = btrfs_item_ptr(leaf, path->slots[0],
743 struct btrfs_extent_ref_v0);
744 owner = btrfs_ref_objectid_v0(leaf, ref0);
745 break;
746 }
747 }
748 btrfs_release_path(root, path);
749
750 if (owner < BTRFS_FIRST_FREE_OBJECTID)
751 new_size += sizeof(*bi);
752
753 new_size -= sizeof(*ei0);
754 ret = btrfs_search_slot(trans, root, &key, path,
755 new_size + extra_size, 1);
756 if (ret < 0)
757 return ret;
758 BUG_ON(ret);
759
760 ret = btrfs_extend_item(trans, root, path, new_size);
761 BUG_ON(ret);
762
763 leaf = path->nodes[0];
764 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
765 btrfs_set_extent_refs(leaf, item, refs);
766 /* FIXME: get real generation */
767 btrfs_set_extent_generation(leaf, item, 0);
768 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
769 btrfs_set_extent_flags(leaf, item,
770 BTRFS_EXTENT_FLAG_TREE_BLOCK |
771 BTRFS_BLOCK_FLAG_FULL_BACKREF);
772 bi = (struct btrfs_tree_block_info *)(item + 1);
773 /* FIXME: get first key of the block */
774 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
775 btrfs_set_tree_block_level(leaf, bi, (int)owner);
776 } else {
777 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
778 }
779 btrfs_mark_buffer_dirty(leaf);
780 return 0;
781 }
782 #endif
783
784 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
785 {
786 u32 high_crc = ~(u32)0;
787 u32 low_crc = ~(u32)0;
788 __le64 lenum;
789
790 lenum = cpu_to_le64(root_objectid);
791 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
792 lenum = cpu_to_le64(owner);
793 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
794 lenum = cpu_to_le64(offset);
795 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
796
797 return ((u64)high_crc << 31) ^ (u64)low_crc;
798 }
799
800 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
801 struct btrfs_extent_data_ref *ref)
802 {
803 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
804 btrfs_extent_data_ref_objectid(leaf, ref),
805 btrfs_extent_data_ref_offset(leaf, ref));
806 }
807
808 static int match_extent_data_ref(struct extent_buffer *leaf,
809 struct btrfs_extent_data_ref *ref,
810 u64 root_objectid, u64 owner, u64 offset)
811 {
812 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
813 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
814 btrfs_extent_data_ref_offset(leaf, ref) != offset)
815 return 0;
816 return 1;
817 }
818
819 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
820 struct btrfs_root *root,
821 struct btrfs_path *path,
822 u64 bytenr, u64 parent,
823 u64 root_objectid,
824 u64 owner, u64 offset)
825 {
826 struct btrfs_key key;
827 struct btrfs_extent_data_ref *ref;
828 struct extent_buffer *leaf;
829 u32 nritems;
830 int ret;
831 int recow;
832 int err = -ENOENT;
833
834 key.objectid = bytenr;
835 if (parent) {
836 key.type = BTRFS_SHARED_DATA_REF_KEY;
837 key.offset = parent;
838 } else {
839 key.type = BTRFS_EXTENT_DATA_REF_KEY;
840 key.offset = hash_extent_data_ref(root_objectid,
841 owner, offset);
842 }
843 again:
844 recow = 0;
845 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
846 if (ret < 0) {
847 err = ret;
848 goto fail;
849 }
850
851 if (parent) {
852 if (!ret)
853 return 0;
854 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
855 key.type = BTRFS_EXTENT_REF_V0_KEY;
856 btrfs_release_path(root, path);
857 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
858 if (ret < 0) {
859 err = ret;
860 goto fail;
861 }
862 if (!ret)
863 return 0;
864 #endif
865 goto fail;
866 }
867
868 leaf = path->nodes[0];
869 nritems = btrfs_header_nritems(leaf);
870 while (1) {
871 if (path->slots[0] >= nritems) {
872 ret = btrfs_next_leaf(root, path);
873 if (ret < 0)
874 err = ret;
875 if (ret)
876 goto fail;
877
878 leaf = path->nodes[0];
879 nritems = btrfs_header_nritems(leaf);
880 recow = 1;
881 }
882
883 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
884 if (key.objectid != bytenr ||
885 key.type != BTRFS_EXTENT_DATA_REF_KEY)
886 goto fail;
887
888 ref = btrfs_item_ptr(leaf, path->slots[0],
889 struct btrfs_extent_data_ref);
890
891 if (match_extent_data_ref(leaf, ref, root_objectid,
892 owner, offset)) {
893 if (recow) {
894 btrfs_release_path(root, path);
895 goto again;
896 }
897 err = 0;
898 break;
899 }
900 path->slots[0]++;
901 }
902 fail:
903 return err;
904 }
905
906 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
907 struct btrfs_root *root,
908 struct btrfs_path *path,
909 u64 bytenr, u64 parent,
910 u64 root_objectid, u64 owner,
911 u64 offset, int refs_to_add)
912 {
913 struct btrfs_key key;
914 struct extent_buffer *leaf;
915 u32 size;
916 u32 num_refs;
917 int ret;
918
919 key.objectid = bytenr;
920 if (parent) {
921 key.type = BTRFS_SHARED_DATA_REF_KEY;
922 key.offset = parent;
923 size = sizeof(struct btrfs_shared_data_ref);
924 } else {
925 key.type = BTRFS_EXTENT_DATA_REF_KEY;
926 key.offset = hash_extent_data_ref(root_objectid,
927 owner, offset);
928 size = sizeof(struct btrfs_extent_data_ref);
929 }
930
931 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
932 if (ret && ret != -EEXIST)
933 goto fail;
934
935 leaf = path->nodes[0];
936 if (parent) {
937 struct btrfs_shared_data_ref *ref;
938 ref = btrfs_item_ptr(leaf, path->slots[0],
939 struct btrfs_shared_data_ref);
940 if (ret == 0) {
941 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
942 } else {
943 num_refs = btrfs_shared_data_ref_count(leaf, ref);
944 num_refs += refs_to_add;
945 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
946 }
947 } else {
948 struct btrfs_extent_data_ref *ref;
949 while (ret == -EEXIST) {
950 ref = btrfs_item_ptr(leaf, path->slots[0],
951 struct btrfs_extent_data_ref);
952 if (match_extent_data_ref(leaf, ref, root_objectid,
953 owner, offset))
954 break;
955 btrfs_release_path(root, path);
956 key.offset++;
957 ret = btrfs_insert_empty_item(trans, root, path, &key,
958 size);
959 if (ret && ret != -EEXIST)
960 goto fail;
961
962 leaf = path->nodes[0];
963 }
964 ref = btrfs_item_ptr(leaf, path->slots[0],
965 struct btrfs_extent_data_ref);
966 if (ret == 0) {
967 btrfs_set_extent_data_ref_root(leaf, ref,
968 root_objectid);
969 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
970 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
971 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
972 } else {
973 num_refs = btrfs_extent_data_ref_count(leaf, ref);
974 num_refs += refs_to_add;
975 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
976 }
977 }
978 btrfs_mark_buffer_dirty(leaf);
979 ret = 0;
980 fail:
981 btrfs_release_path(root, path);
982 return ret;
983 }
984
985 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
986 struct btrfs_root *root,
987 struct btrfs_path *path,
988 int refs_to_drop)
989 {
990 struct btrfs_key key;
991 struct btrfs_extent_data_ref *ref1 = NULL;
992 struct btrfs_shared_data_ref *ref2 = NULL;
993 struct extent_buffer *leaf;
994 u32 num_refs = 0;
995 int ret = 0;
996
997 leaf = path->nodes[0];
998 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
999
1000 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1001 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1002 struct btrfs_extent_data_ref);
1003 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1004 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1005 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1006 struct btrfs_shared_data_ref);
1007 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1008 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1009 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1010 struct btrfs_extent_ref_v0 *ref0;
1011 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1012 struct btrfs_extent_ref_v0);
1013 num_refs = btrfs_ref_count_v0(leaf, ref0);
1014 #endif
1015 } else {
1016 BUG();
1017 }
1018
1019 BUG_ON(num_refs < refs_to_drop);
1020 num_refs -= refs_to_drop;
1021
1022 if (num_refs == 0) {
1023 ret = btrfs_del_item(trans, root, path);
1024 } else {
1025 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
1026 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
1027 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
1028 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
1029 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1030 else {
1031 struct btrfs_extent_ref_v0 *ref0;
1032 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1033 struct btrfs_extent_ref_v0);
1034 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
1035 }
1036 #endif
1037 btrfs_mark_buffer_dirty(leaf);
1038 }
1039 return ret;
1040 }
1041
1042 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
1043 struct btrfs_path *path,
1044 struct btrfs_extent_inline_ref *iref)
1045 {
1046 struct btrfs_key key;
1047 struct extent_buffer *leaf;
1048 struct btrfs_extent_data_ref *ref1;
1049 struct btrfs_shared_data_ref *ref2;
1050 u32 num_refs = 0;
1051
1052 leaf = path->nodes[0];
1053 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1054 if (iref) {
1055 if (btrfs_extent_inline_ref_type(leaf, iref) ==
1056 BTRFS_EXTENT_DATA_REF_KEY) {
1057 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
1058 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1059 } else {
1060 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
1061 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1062 }
1063 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1064 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1065 struct btrfs_extent_data_ref);
1066 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1067 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1068 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1069 struct btrfs_shared_data_ref);
1070 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1071 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1072 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1073 struct btrfs_extent_ref_v0 *ref0;
1074 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1075 struct btrfs_extent_ref_v0);
1076 num_refs = btrfs_ref_count_v0(leaf, ref0);
1077 #endif
1078 } else {
1079 WARN_ON(1);
1080 }
1081 return num_refs;
1082 }
1083
1084 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
1085 struct btrfs_root *root,
1086 struct btrfs_path *path,
1087 u64 bytenr, u64 parent,
1088 u64 root_objectid)
1089 {
1090 struct btrfs_key key;
1091 int ret;
1092
1093 key.objectid = bytenr;
1094 if (parent) {
1095 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1096 key.offset = parent;
1097 } else {
1098 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1099 key.offset = root_objectid;
1100 }
1101
1102 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1103 if (ret > 0)
1104 ret = -ENOENT;
1105 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1106 if (ret == -ENOENT && parent) {
1107 btrfs_release_path(root, path);
1108 key.type = BTRFS_EXTENT_REF_V0_KEY;
1109 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1110 if (ret > 0)
1111 ret = -ENOENT;
1112 }
1113 #endif
1114 return ret;
1115 }
1116
1117 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
1118 struct btrfs_root *root,
1119 struct btrfs_path *path,
1120 u64 bytenr, u64 parent,
1121 u64 root_objectid)
1122 {
1123 struct btrfs_key key;
1124 int ret;
1125
1126 key.objectid = bytenr;
1127 if (parent) {
1128 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1129 key.offset = parent;
1130 } else {
1131 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1132 key.offset = root_objectid;
1133 }
1134
1135 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1136 btrfs_release_path(root, path);
1137 return ret;
1138 }
1139
1140 static inline int extent_ref_type(u64 parent, u64 owner)
1141 {
1142 int type;
1143 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1144 if (parent > 0)
1145 type = BTRFS_SHARED_BLOCK_REF_KEY;
1146 else
1147 type = BTRFS_TREE_BLOCK_REF_KEY;
1148 } else {
1149 if (parent > 0)
1150 type = BTRFS_SHARED_DATA_REF_KEY;
1151 else
1152 type = BTRFS_EXTENT_DATA_REF_KEY;
1153 }
1154 return type;
1155 }
1156
1157 static int find_next_key(struct btrfs_path *path, int level,
1158 struct btrfs_key *key)
1159
1160 {
1161 for (; level < BTRFS_MAX_LEVEL; level++) {
1162 if (!path->nodes[level])
1163 break;
1164 if (path->slots[level] + 1 >=
1165 btrfs_header_nritems(path->nodes[level]))
1166 continue;
1167 if (level == 0)
1168 btrfs_item_key_to_cpu(path->nodes[level], key,
1169 path->slots[level] + 1);
1170 else
1171 btrfs_node_key_to_cpu(path->nodes[level], key,
1172 path->slots[level] + 1);
1173 return 0;
1174 }
1175 return 1;
1176 }
1177
1178 /*
1179 * look for inline back ref. if back ref is found, *ref_ret is set
1180 * to the address of inline back ref, and 0 is returned.
1181 *
1182 * if back ref isn't found, *ref_ret is set to the address where it
1183 * should be inserted, and -ENOENT is returned.
1184 *
1185 * if insert is true and there are too many inline back refs, the path
1186 * points to the extent item, and -EAGAIN is returned.
1187 *
1188 * NOTE: inline back refs are ordered in the same way that back ref
1189 * items in the tree are ordered.
1190 */
1191 static noinline_for_stack
1192 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1193 struct btrfs_root *root,
1194 struct btrfs_path *path,
1195 struct btrfs_extent_inline_ref **ref_ret,
1196 u64 bytenr, u64 num_bytes,
1197 u64 parent, u64 root_objectid,
1198 u64 owner, u64 offset, int insert)
1199 {
1200 struct btrfs_key key;
1201 struct extent_buffer *leaf;
1202 struct btrfs_extent_item *ei;
1203 struct btrfs_extent_inline_ref *iref;
1204 u64 flags;
1205 u64 item_size;
1206 unsigned long ptr;
1207 unsigned long end;
1208 int extra_size;
1209 int type;
1210 int want;
1211 int ret;
1212 int err = 0;
1213
1214 key.objectid = bytenr;
1215 key.type = BTRFS_EXTENT_ITEM_KEY;
1216 key.offset = num_bytes;
1217
1218 want = extent_ref_type(parent, owner);
1219 if (insert) {
1220 extra_size = btrfs_extent_inline_ref_size(want);
1221 path->keep_locks = 1;
1222 } else
1223 extra_size = -1;
1224 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1225 if (ret < 0) {
1226 err = ret;
1227 goto out;
1228 }
1229 BUG_ON(ret);
1230
1231 leaf = path->nodes[0];
1232 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1233 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1234 if (item_size < sizeof(*ei)) {
1235 if (!insert) {
1236 err = -ENOENT;
1237 goto out;
1238 }
1239 ret = convert_extent_item_v0(trans, root, path, owner,
1240 extra_size);
1241 if (ret < 0) {
1242 err = ret;
1243 goto out;
1244 }
1245 leaf = path->nodes[0];
1246 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1247 }
1248 #endif
1249 BUG_ON(item_size < sizeof(*ei));
1250
1251 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1252 flags = btrfs_extent_flags(leaf, ei);
1253
1254 ptr = (unsigned long)(ei + 1);
1255 end = (unsigned long)ei + item_size;
1256
1257 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1258 ptr += sizeof(struct btrfs_tree_block_info);
1259 BUG_ON(ptr > end);
1260 } else {
1261 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
1262 }
1263
1264 err = -ENOENT;
1265 while (1) {
1266 if (ptr >= end) {
1267 WARN_ON(ptr > end);
1268 break;
1269 }
1270 iref = (struct btrfs_extent_inline_ref *)ptr;
1271 type = btrfs_extent_inline_ref_type(leaf, iref);
1272 if (want < type)
1273 break;
1274 if (want > type) {
1275 ptr += btrfs_extent_inline_ref_size(type);
1276 continue;
1277 }
1278
1279 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1280 struct btrfs_extent_data_ref *dref;
1281 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1282 if (match_extent_data_ref(leaf, dref, root_objectid,
1283 owner, offset)) {
1284 err = 0;
1285 break;
1286 }
1287 if (hash_extent_data_ref_item(leaf, dref) <
1288 hash_extent_data_ref(root_objectid, owner, offset))
1289 break;
1290 } else {
1291 u64 ref_offset;
1292 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1293 if (parent > 0) {
1294 if (parent == ref_offset) {
1295 err = 0;
1296 break;
1297 }
1298 if (ref_offset < parent)
1299 break;
1300 } else {
1301 if (root_objectid == ref_offset) {
1302 err = 0;
1303 break;
1304 }
1305 if (ref_offset < root_objectid)
1306 break;
1307 }
1308 }
1309 ptr += btrfs_extent_inline_ref_size(type);
1310 }
1311 if (err == -ENOENT && insert) {
1312 if (item_size + extra_size >=
1313 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1314 err = -EAGAIN;
1315 goto out;
1316 }
1317 /*
1318 * To add new inline back ref, we have to make sure
1319 * there is no corresponding back ref item.
1320 * For simplicity, we just do not add new inline back
1321 * ref if there is any kind of item for this block
1322 */
1323 if (find_next_key(path, 0, &key) == 0 &&
1324 key.objectid == bytenr &&
1325 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1326 err = -EAGAIN;
1327 goto out;
1328 }
1329 }
1330 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1331 out:
1332 if (insert) {
1333 path->keep_locks = 0;
1334 btrfs_unlock_up_safe(path, 1);
1335 }
1336 return err;
1337 }
1338
1339 /*
1340 * helper to add new inline back ref
1341 */
1342 static noinline_for_stack
1343 int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
1344 struct btrfs_root *root,
1345 struct btrfs_path *path,
1346 struct btrfs_extent_inline_ref *iref,
1347 u64 parent, u64 root_objectid,
1348 u64 owner, u64 offset, int refs_to_add,
1349 struct btrfs_delayed_extent_op *extent_op)
1350 {
1351 struct extent_buffer *leaf;
1352 struct btrfs_extent_item *ei;
1353 unsigned long ptr;
1354 unsigned long end;
1355 unsigned long item_offset;
1356 u64 refs;
1357 int size;
1358 int type;
1359 int ret;
1360
1361 leaf = path->nodes[0];
1362 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1363 item_offset = (unsigned long)iref - (unsigned long)ei;
1364
1365 type = extent_ref_type(parent, owner);
1366 size = btrfs_extent_inline_ref_size(type);
1367
1368 ret = btrfs_extend_item(trans, root, path, size);
1369 BUG_ON(ret);
1370
1371 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1372 refs = btrfs_extent_refs(leaf, ei);
1373 refs += refs_to_add;
1374 btrfs_set_extent_refs(leaf, ei, refs);
1375 if (extent_op)
1376 __run_delayed_extent_op(extent_op, leaf, ei);
1377
1378 ptr = (unsigned long)ei + item_offset;
1379 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1380 if (ptr < end - size)
1381 memmove_extent_buffer(leaf, ptr + size, ptr,
1382 end - size - ptr);
1383
1384 iref = (struct btrfs_extent_inline_ref *)ptr;
1385 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1386 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1387 struct btrfs_extent_data_ref *dref;
1388 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1389 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1390 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1391 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1392 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1393 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1394 struct btrfs_shared_data_ref *sref;
1395 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1396 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1397 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1398 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1399 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1400 } else {
1401 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1402 }
1403 btrfs_mark_buffer_dirty(leaf);
1404 return 0;
1405 }
1406
1407 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1408 struct btrfs_root *root,
1409 struct btrfs_path *path,
1410 struct btrfs_extent_inline_ref **ref_ret,
1411 u64 bytenr, u64 num_bytes, u64 parent,
1412 u64 root_objectid, u64 owner, u64 offset)
1413 {
1414 int ret;
1415
1416 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1417 bytenr, num_bytes, parent,
1418 root_objectid, owner, offset, 0);
1419 if (ret != -ENOENT)
1420 return ret;
1421
1422 btrfs_release_path(root, path);
1423 *ref_ret = NULL;
1424
1425 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1426 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1427 root_objectid);
1428 } else {
1429 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1430 root_objectid, owner, offset);
1431 }
1432 return ret;
1433 }
1434
1435 /*
1436 * helper to update/remove inline back ref
1437 */
1438 static noinline_for_stack
1439 int update_inline_extent_backref(struct btrfs_trans_handle *trans,
1440 struct btrfs_root *root,
1441 struct btrfs_path *path,
1442 struct btrfs_extent_inline_ref *iref,
1443 int refs_to_mod,
1444 struct btrfs_delayed_extent_op *extent_op)
1445 {
1446 struct extent_buffer *leaf;
1447 struct btrfs_extent_item *ei;
1448 struct btrfs_extent_data_ref *dref = NULL;
1449 struct btrfs_shared_data_ref *sref = NULL;
1450 unsigned long ptr;
1451 unsigned long end;
1452 u32 item_size;
1453 int size;
1454 int type;
1455 int ret;
1456 u64 refs;
1457
1458 leaf = path->nodes[0];
1459 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1460 refs = btrfs_extent_refs(leaf, ei);
1461 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1462 refs += refs_to_mod;
1463 btrfs_set_extent_refs(leaf, ei, refs);
1464 if (extent_op)
1465 __run_delayed_extent_op(extent_op, leaf, ei);
1466
1467 type = btrfs_extent_inline_ref_type(leaf, iref);
1468
1469 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1470 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1471 refs = btrfs_extent_data_ref_count(leaf, dref);
1472 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1473 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1474 refs = btrfs_shared_data_ref_count(leaf, sref);
1475 } else {
1476 refs = 1;
1477 BUG_ON(refs_to_mod != -1);
1478 }
1479
1480 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1481 refs += refs_to_mod;
1482
1483 if (refs > 0) {
1484 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1485 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1486 else
1487 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1488 } else {
1489 size = btrfs_extent_inline_ref_size(type);
1490 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1491 ptr = (unsigned long)iref;
1492 end = (unsigned long)ei + item_size;
1493 if (ptr + size < end)
1494 memmove_extent_buffer(leaf, ptr, ptr + size,
1495 end - ptr - size);
1496 item_size -= size;
1497 ret = btrfs_truncate_item(trans, root, path, item_size, 1);
1498 BUG_ON(ret);
1499 }
1500 btrfs_mark_buffer_dirty(leaf);
1501 return 0;
1502 }
1503
1504 static noinline_for_stack
1505 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1506 struct btrfs_root *root,
1507 struct btrfs_path *path,
1508 u64 bytenr, u64 num_bytes, u64 parent,
1509 u64 root_objectid, u64 owner,
1510 u64 offset, int refs_to_add,
1511 struct btrfs_delayed_extent_op *extent_op)
1512 {
1513 struct btrfs_extent_inline_ref *iref;
1514 int ret;
1515
1516 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1517 bytenr, num_bytes, parent,
1518 root_objectid, owner, offset, 1);
1519 if (ret == 0) {
1520 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1521 ret = update_inline_extent_backref(trans, root, path, iref,
1522 refs_to_add, extent_op);
1523 } else if (ret == -ENOENT) {
1524 ret = setup_inline_extent_backref(trans, root, path, iref,
1525 parent, root_objectid,
1526 owner, offset, refs_to_add,
1527 extent_op);
1528 }
1529 return ret;
1530 }
1531
1532 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1533 struct btrfs_root *root,
1534 struct btrfs_path *path,
1535 u64 bytenr, u64 parent, u64 root_objectid,
1536 u64 owner, u64 offset, int refs_to_add)
1537 {
1538 int ret;
1539 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1540 BUG_ON(refs_to_add != 1);
1541 ret = insert_tree_block_ref(trans, root, path, bytenr,
1542 parent, root_objectid);
1543 } else {
1544 ret = insert_extent_data_ref(trans, root, path, bytenr,
1545 parent, root_objectid,
1546 owner, offset, refs_to_add);
1547 }
1548 return ret;
1549 }
1550
1551 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1552 struct btrfs_root *root,
1553 struct btrfs_path *path,
1554 struct btrfs_extent_inline_ref *iref,
1555 int refs_to_drop, int is_data)
1556 {
1557 int ret;
1558
1559 BUG_ON(!is_data && refs_to_drop != 1);
1560 if (iref) {
1561 ret = update_inline_extent_backref(trans, root, path, iref,
1562 -refs_to_drop, NULL);
1563 } else if (is_data) {
1564 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1565 } else {
1566 ret = btrfs_del_item(trans, root, path);
1567 }
1568 return ret;
1569 }
1570
1571 #ifdef BIO_RW_DISCARD
1572 static void btrfs_issue_discard(struct block_device *bdev,
1573 u64 start, u64 len)
1574 {
1575 blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL,
1576 DISCARD_FL_BARRIER);
1577 }
1578 #endif
1579
1580 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
1581 u64 num_bytes)
1582 {
1583 #ifdef BIO_RW_DISCARD
1584 int ret;
1585 u64 map_length = num_bytes;
1586 struct btrfs_multi_bio *multi = NULL;
1587
1588 /* Tell the block device(s) that the sectors can be discarded */
1589 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
1590 bytenr, &map_length, &multi, 0);
1591 if (!ret) {
1592 struct btrfs_bio_stripe *stripe = multi->stripes;
1593 int i;
1594
1595 if (map_length > num_bytes)
1596 map_length = num_bytes;
1597
1598 for (i = 0; i < multi->num_stripes; i++, stripe++) {
1599 btrfs_issue_discard(stripe->dev->bdev,
1600 stripe->physical,
1601 map_length);
1602 }
1603 kfree(multi);
1604 }
1605
1606 return ret;
1607 #else
1608 return 0;
1609 #endif
1610 }
1611
1612 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1613 struct btrfs_root *root,
1614 u64 bytenr, u64 num_bytes, u64 parent,
1615 u64 root_objectid, u64 owner, u64 offset)
1616 {
1617 int ret;
1618 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
1619 root_objectid == BTRFS_TREE_LOG_OBJECTID);
1620
1621 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1622 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
1623 parent, root_objectid, (int)owner,
1624 BTRFS_ADD_DELAYED_REF, NULL);
1625 } else {
1626 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
1627 parent, root_objectid, owner, offset,
1628 BTRFS_ADD_DELAYED_REF, NULL);
1629 }
1630 return ret;
1631 }
1632
1633 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1634 struct btrfs_root *root,
1635 u64 bytenr, u64 num_bytes,
1636 u64 parent, u64 root_objectid,
1637 u64 owner, u64 offset, int refs_to_add,
1638 struct btrfs_delayed_extent_op *extent_op)
1639 {
1640 struct btrfs_path *path;
1641 struct extent_buffer *leaf;
1642 struct btrfs_extent_item *item;
1643 u64 refs;
1644 int ret;
1645 int err = 0;
1646
1647 path = btrfs_alloc_path();
1648 if (!path)
1649 return -ENOMEM;
1650
1651 path->reada = 1;
1652 path->leave_spinning = 1;
1653 /* this will setup the path even if it fails to insert the back ref */
1654 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1655 path, bytenr, num_bytes, parent,
1656 root_objectid, owner, offset,
1657 refs_to_add, extent_op);
1658 if (ret == 0)
1659 goto out;
1660
1661 if (ret != -EAGAIN) {
1662 err = ret;
1663 goto out;
1664 }
1665
1666 leaf = path->nodes[0];
1667 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1668 refs = btrfs_extent_refs(leaf, item);
1669 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1670 if (extent_op)
1671 __run_delayed_extent_op(extent_op, leaf, item);
1672
1673 btrfs_mark_buffer_dirty(leaf);
1674 btrfs_release_path(root->fs_info->extent_root, path);
1675
1676 path->reada = 1;
1677 path->leave_spinning = 1;
1678
1679 /* now insert the actual backref */
1680 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1681 path, bytenr, parent, root_objectid,
1682 owner, offset, refs_to_add);
1683 BUG_ON(ret);
1684 out:
1685 btrfs_free_path(path);
1686 return err;
1687 }
1688
1689 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1690 struct btrfs_root *root,
1691 struct btrfs_delayed_ref_node *node,
1692 struct btrfs_delayed_extent_op *extent_op,
1693 int insert_reserved)
1694 {
1695 int ret = 0;
1696 struct btrfs_delayed_data_ref *ref;
1697 struct btrfs_key ins;
1698 u64 parent = 0;
1699 u64 ref_root = 0;
1700 u64 flags = 0;
1701
1702 ins.objectid = node->bytenr;
1703 ins.offset = node->num_bytes;
1704 ins.type = BTRFS_EXTENT_ITEM_KEY;
1705
1706 ref = btrfs_delayed_node_to_data_ref(node);
1707 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
1708 parent = ref->parent;
1709 else
1710 ref_root = ref->root;
1711
1712 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1713 if (extent_op) {
1714 BUG_ON(extent_op->update_key);
1715 flags |= extent_op->flags_to_set;
1716 }
1717 ret = alloc_reserved_file_extent(trans, root,
1718 parent, ref_root, flags,
1719 ref->objectid, ref->offset,
1720 &ins, node->ref_mod);
1721 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1722 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1723 node->num_bytes, parent,
1724 ref_root, ref->objectid,
1725 ref->offset, node->ref_mod,
1726 extent_op);
1727 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1728 ret = __btrfs_free_extent(trans, root, node->bytenr,
1729 node->num_bytes, parent,
1730 ref_root, ref->objectid,
1731 ref->offset, node->ref_mod,
1732 extent_op);
1733 } else {
1734 BUG();
1735 }
1736 return ret;
1737 }
1738
1739 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
1740 struct extent_buffer *leaf,
1741 struct btrfs_extent_item *ei)
1742 {
1743 u64 flags = btrfs_extent_flags(leaf, ei);
1744 if (extent_op->update_flags) {
1745 flags |= extent_op->flags_to_set;
1746 btrfs_set_extent_flags(leaf, ei, flags);
1747 }
1748
1749 if (extent_op->update_key) {
1750 struct btrfs_tree_block_info *bi;
1751 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
1752 bi = (struct btrfs_tree_block_info *)(ei + 1);
1753 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
1754 }
1755 }
1756
1757 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
1758 struct btrfs_root *root,
1759 struct btrfs_delayed_ref_node *node,
1760 struct btrfs_delayed_extent_op *extent_op)
1761 {
1762 struct btrfs_key key;
1763 struct btrfs_path *path;
1764 struct btrfs_extent_item *ei;
1765 struct extent_buffer *leaf;
1766 u32 item_size;
1767 int ret;
1768 int err = 0;
1769
1770 path = btrfs_alloc_path();
1771 if (!path)
1772 return -ENOMEM;
1773
1774 key.objectid = node->bytenr;
1775 key.type = BTRFS_EXTENT_ITEM_KEY;
1776 key.offset = node->num_bytes;
1777
1778 path->reada = 1;
1779 path->leave_spinning = 1;
1780 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
1781 path, 0, 1);
1782 if (ret < 0) {
1783 err = ret;
1784 goto out;
1785 }
1786 if (ret > 0) {
1787 err = -EIO;
1788 goto out;
1789 }
1790
1791 leaf = path->nodes[0];
1792 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1793 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1794 if (item_size < sizeof(*ei)) {
1795 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1796 path, (u64)-1, 0);
1797 if (ret < 0) {
1798 err = ret;
1799 goto out;
1800 }
1801 leaf = path->nodes[0];
1802 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1803 }
1804 #endif
1805 BUG_ON(item_size < sizeof(*ei));
1806 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1807 __run_delayed_extent_op(extent_op, leaf, ei);
1808
1809 btrfs_mark_buffer_dirty(leaf);
1810 out:
1811 btrfs_free_path(path);
1812 return err;
1813 }
1814
1815 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
1816 struct btrfs_root *root,
1817 struct btrfs_delayed_ref_node *node,
1818 struct btrfs_delayed_extent_op *extent_op,
1819 int insert_reserved)
1820 {
1821 int ret = 0;
1822 struct btrfs_delayed_tree_ref *ref;
1823 struct btrfs_key ins;
1824 u64 parent = 0;
1825 u64 ref_root = 0;
1826
1827 ins.objectid = node->bytenr;
1828 ins.offset = node->num_bytes;
1829 ins.type = BTRFS_EXTENT_ITEM_KEY;
1830
1831 ref = btrfs_delayed_node_to_tree_ref(node);
1832 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1833 parent = ref->parent;
1834 else
1835 ref_root = ref->root;
1836
1837 BUG_ON(node->ref_mod != 1);
1838 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1839 BUG_ON(!extent_op || !extent_op->update_flags ||
1840 !extent_op->update_key);
1841 ret = alloc_reserved_tree_block(trans, root,
1842 parent, ref_root,
1843 extent_op->flags_to_set,
1844 &extent_op->key,
1845 ref->level, &ins);
1846 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1847 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1848 node->num_bytes, parent, ref_root,
1849 ref->level, 0, 1, extent_op);
1850 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1851 ret = __btrfs_free_extent(trans, root, node->bytenr,
1852 node->num_bytes, parent, ref_root,
1853 ref->level, 0, 1, extent_op);
1854 } else {
1855 BUG();
1856 }
1857 return ret;
1858 }
1859
1860
1861 /* helper function to actually process a single delayed ref entry */
1862 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
1863 struct btrfs_root *root,
1864 struct btrfs_delayed_ref_node *node,
1865 struct btrfs_delayed_extent_op *extent_op,
1866 int insert_reserved)
1867 {
1868 int ret;
1869 if (btrfs_delayed_ref_is_head(node)) {
1870 struct btrfs_delayed_ref_head *head;
1871 /*
1872 * we've hit the end of the chain and we were supposed
1873 * to insert this extent into the tree. But, it got
1874 * deleted before we ever needed to insert it, so all
1875 * we have to do is clean up the accounting
1876 */
1877 BUG_ON(extent_op);
1878 head = btrfs_delayed_node_to_head(node);
1879 if (insert_reserved) {
1880 int mark_free = 0;
1881 struct extent_buffer *must_clean = NULL;
1882
1883 ret = pin_down_bytes(trans, root, NULL,
1884 node->bytenr, node->num_bytes,
1885 head->is_data, 1, &must_clean);
1886 if (ret > 0)
1887 mark_free = 1;
1888
1889 if (must_clean) {
1890 clean_tree_block(NULL, root, must_clean);
1891 btrfs_tree_unlock(must_clean);
1892 free_extent_buffer(must_clean);
1893 }
1894 if (head->is_data) {
1895 ret = btrfs_del_csums(trans, root,
1896 node->bytenr,
1897 node->num_bytes);
1898 BUG_ON(ret);
1899 }
1900 if (mark_free) {
1901 ret = btrfs_free_reserved_extent(root,
1902 node->bytenr,
1903 node->num_bytes);
1904 BUG_ON(ret);
1905 }
1906 }
1907 mutex_unlock(&head->mutex);
1908 return 0;
1909 }
1910
1911 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1912 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1913 ret = run_delayed_tree_ref(trans, root, node, extent_op,
1914 insert_reserved);
1915 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1916 node->type == BTRFS_SHARED_DATA_REF_KEY)
1917 ret = run_delayed_data_ref(trans, root, node, extent_op,
1918 insert_reserved);
1919 else
1920 BUG();
1921 return ret;
1922 }
1923
1924 static noinline struct btrfs_delayed_ref_node *
1925 select_delayed_ref(struct btrfs_delayed_ref_head *head)
1926 {
1927 struct rb_node *node;
1928 struct btrfs_delayed_ref_node *ref;
1929 int action = BTRFS_ADD_DELAYED_REF;
1930 again:
1931 /*
1932 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
1933 * this prevents ref count from going down to zero when
1934 * there still are pending delayed ref.
1935 */
1936 node = rb_prev(&head->node.rb_node);
1937 while (1) {
1938 if (!node)
1939 break;
1940 ref = rb_entry(node, struct btrfs_delayed_ref_node,
1941 rb_node);
1942 if (ref->bytenr != head->node.bytenr)
1943 break;
1944 if (ref->action == action)
1945 return ref;
1946 node = rb_prev(node);
1947 }
1948 if (action == BTRFS_ADD_DELAYED_REF) {
1949 action = BTRFS_DROP_DELAYED_REF;
1950 goto again;
1951 }
1952 return NULL;
1953 }
1954
1955 static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
1956 struct btrfs_root *root,
1957 struct list_head *cluster)
1958 {
1959 struct btrfs_delayed_ref_root *delayed_refs;
1960 struct btrfs_delayed_ref_node *ref;
1961 struct btrfs_delayed_ref_head *locked_ref = NULL;
1962 struct btrfs_delayed_extent_op *extent_op;
1963 int ret;
1964 int count = 0;
1965 int must_insert_reserved = 0;
1966
1967 delayed_refs = &trans->transaction->delayed_refs;
1968 while (1) {
1969 if (!locked_ref) {
1970 /* pick a new head ref from the cluster list */
1971 if (list_empty(cluster))
1972 break;
1973
1974 locked_ref = list_entry(cluster->next,
1975 struct btrfs_delayed_ref_head, cluster);
1976
1977 /* grab the lock that says we are going to process
1978 * all the refs for this head */
1979 ret = btrfs_delayed_ref_lock(trans, locked_ref);
1980
1981 /*
1982 * we may have dropped the spin lock to get the head
1983 * mutex lock, and that might have given someone else
1984 * time to free the head. If that's true, it has been
1985 * removed from our list and we can move on.
1986 */
1987 if (ret == -EAGAIN) {
1988 locked_ref = NULL;
1989 count++;
1990 continue;
1991 }
1992 }
1993
1994 /*
1995 * record the must insert reserved flag before we
1996 * drop the spin lock.
1997 */
1998 must_insert_reserved = locked_ref->must_insert_reserved;
1999 locked_ref->must_insert_reserved = 0;
2000
2001 extent_op = locked_ref->extent_op;
2002 locked_ref->extent_op = NULL;
2003
2004 /*
2005 * locked_ref is the head node, so we have to go one
2006 * node back for any delayed ref updates
2007 */
2008 ref = select_delayed_ref(locked_ref);
2009 if (!ref) {
2010 /* All delayed refs have been processed, Go ahead
2011 * and send the head node to run_one_delayed_ref,
2012 * so that any accounting fixes can happen
2013 */
2014 ref = &locked_ref->node;
2015
2016 if (extent_op && must_insert_reserved) {
2017 kfree(extent_op);
2018 extent_op = NULL;
2019 }
2020
2021 if (extent_op) {
2022 spin_unlock(&delayed_refs->lock);
2023
2024 ret = run_delayed_extent_op(trans, root,
2025 ref, extent_op);
2026 BUG_ON(ret);
2027 kfree(extent_op);
2028
2029 cond_resched();
2030 spin_lock(&delayed_refs->lock);
2031 continue;
2032 }
2033
2034 list_del_init(&locked_ref->cluster);
2035 locked_ref = NULL;
2036 }
2037
2038 ref->in_tree = 0;
2039 rb_erase(&ref->rb_node, &delayed_refs->root);
2040 delayed_refs->num_entries--;
2041
2042 spin_unlock(&delayed_refs->lock);
2043
2044 ret = run_one_delayed_ref(trans, root, ref, extent_op,
2045 must_insert_reserved);
2046 BUG_ON(ret);
2047
2048 btrfs_put_delayed_ref(ref);
2049 kfree(extent_op);
2050 count++;
2051
2052 cond_resched();
2053 spin_lock(&delayed_refs->lock);
2054 }
2055 return count;
2056 }
2057
2058 /*
2059 * this starts processing the delayed reference count updates and
2060 * extent insertions we have queued up so far. count can be
2061 * 0, which means to process everything in the tree at the start
2062 * of the run (but not newly added entries), or it can be some target
2063 * number you'd like to process.
2064 */
2065 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2066 struct btrfs_root *root, unsigned long count)
2067 {
2068 struct rb_node *node;
2069 struct btrfs_delayed_ref_root *delayed_refs;
2070 struct btrfs_delayed_ref_node *ref;
2071 struct list_head cluster;
2072 int ret;
2073 int run_all = count == (unsigned long)-1;
2074 int run_most = 0;
2075
2076 if (root == root->fs_info->extent_root)
2077 root = root->fs_info->tree_root;
2078
2079 delayed_refs = &trans->transaction->delayed_refs;
2080 INIT_LIST_HEAD(&cluster);
2081 again:
2082 spin_lock(&delayed_refs->lock);
2083 if (count == 0) {
2084 count = delayed_refs->num_entries * 2;
2085 run_most = 1;
2086 }
2087 while (1) {
2088 if (!(run_all || run_most) &&
2089 delayed_refs->num_heads_ready < 64)
2090 break;
2091
2092 /*
2093 * go find something we can process in the rbtree. We start at
2094 * the beginning of the tree, and then build a cluster
2095 * of refs to process starting at the first one we are able to
2096 * lock
2097 */
2098 ret = btrfs_find_ref_cluster(trans, &cluster,
2099 delayed_refs->run_delayed_start);
2100 if (ret)
2101 break;
2102
2103 ret = run_clustered_refs(trans, root, &cluster);
2104 BUG_ON(ret < 0);
2105
2106 count -= min_t(unsigned long, ret, count);
2107
2108 if (count == 0)
2109 break;
2110 }
2111
2112 if (run_all) {
2113 node = rb_first(&delayed_refs->root);
2114 if (!node)
2115 goto out;
2116 count = (unsigned long)-1;
2117
2118 while (node) {
2119 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2120 rb_node);
2121 if (btrfs_delayed_ref_is_head(ref)) {
2122 struct btrfs_delayed_ref_head *head;
2123
2124 head = btrfs_delayed_node_to_head(ref);
2125 atomic_inc(&ref->refs);
2126
2127 spin_unlock(&delayed_refs->lock);
2128 mutex_lock(&head->mutex);
2129 mutex_unlock(&head->mutex);
2130
2131 btrfs_put_delayed_ref(ref);
2132 cond_resched();
2133 goto again;
2134 }
2135 node = rb_next(node);
2136 }
2137 spin_unlock(&delayed_refs->lock);
2138 schedule_timeout(1);
2139 goto again;
2140 }
2141 out:
2142 spin_unlock(&delayed_refs->lock);
2143 return 0;
2144 }
2145
2146 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2147 struct btrfs_root *root,
2148 u64 bytenr, u64 num_bytes, u64 flags,
2149 int is_data)
2150 {
2151 struct btrfs_delayed_extent_op *extent_op;
2152 int ret;
2153
2154 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2155 if (!extent_op)
2156 return -ENOMEM;
2157
2158 extent_op->flags_to_set = flags;
2159 extent_op->update_flags = 1;
2160 extent_op->update_key = 0;
2161 extent_op->is_data = is_data ? 1 : 0;
2162
2163 ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
2164 if (ret)
2165 kfree(extent_op);
2166 return ret;
2167 }
2168
2169 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
2170 struct btrfs_root *root,
2171 struct btrfs_path *path,
2172 u64 objectid, u64 offset, u64 bytenr)
2173 {
2174 struct btrfs_delayed_ref_head *head;
2175 struct btrfs_delayed_ref_node *ref;
2176 struct btrfs_delayed_data_ref *data_ref;
2177 struct btrfs_delayed_ref_root *delayed_refs;
2178 struct rb_node *node;
2179 int ret = 0;
2180
2181 ret = -ENOENT;
2182 delayed_refs = &trans->transaction->delayed_refs;
2183 spin_lock(&delayed_refs->lock);
2184 head = btrfs_find_delayed_ref_head(trans, bytenr);
2185 if (!head)
2186 goto out;
2187
2188 if (!mutex_trylock(&head->mutex)) {
2189 atomic_inc(&head->node.refs);
2190 spin_unlock(&delayed_refs->lock);
2191
2192 btrfs_release_path(root->fs_info->extent_root, path);
2193
2194 mutex_lock(&head->mutex);
2195 mutex_unlock(&head->mutex);
2196 btrfs_put_delayed_ref(&head->node);
2197 return -EAGAIN;
2198 }
2199
2200 node = rb_prev(&head->node.rb_node);
2201 if (!node)
2202 goto out_unlock;
2203
2204 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2205
2206 if (ref->bytenr != bytenr)
2207 goto out_unlock;
2208
2209 ret = 1;
2210 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
2211 goto out_unlock;
2212
2213 data_ref = btrfs_delayed_node_to_data_ref(ref);
2214
2215 node = rb_prev(node);
2216 if (node) {
2217 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2218 if (ref->bytenr == bytenr)
2219 goto out_unlock;
2220 }
2221
2222 if (data_ref->root != root->root_key.objectid ||
2223 data_ref->objectid != objectid || data_ref->offset != offset)
2224 goto out_unlock;
2225
2226 ret = 0;
2227 out_unlock:
2228 mutex_unlock(&head->mutex);
2229 out:
2230 spin_unlock(&delayed_refs->lock);
2231 return ret;
2232 }
2233
2234 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
2235 struct btrfs_root *root,
2236 struct btrfs_path *path,
2237 u64 objectid, u64 offset, u64 bytenr)
2238 {
2239 struct btrfs_root *extent_root = root->fs_info->extent_root;
2240 struct extent_buffer *leaf;
2241 struct btrfs_extent_data_ref *ref;
2242 struct btrfs_extent_inline_ref *iref;
2243 struct btrfs_extent_item *ei;
2244 struct btrfs_key key;
2245 u32 item_size;
2246 int ret;
2247
2248 key.objectid = bytenr;
2249 key.offset = (u64)-1;
2250 key.type = BTRFS_EXTENT_ITEM_KEY;
2251
2252 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2253 if (ret < 0)
2254 goto out;
2255 BUG_ON(ret == 0);
2256
2257 ret = -ENOENT;
2258 if (path->slots[0] == 0)
2259 goto out;
2260
2261 path->slots[0]--;
2262 leaf = path->nodes[0];
2263 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2264
2265 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2266 goto out;
2267
2268 ret = 1;
2269 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2270 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2271 if (item_size < sizeof(*ei)) {
2272 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
2273 goto out;
2274 }
2275 #endif
2276 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2277
2278 if (item_size != sizeof(*ei) +
2279 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2280 goto out;
2281
2282 if (btrfs_extent_generation(leaf, ei) <=
2283 btrfs_root_last_snapshot(&root->root_item))
2284 goto out;
2285
2286 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2287 if (btrfs_extent_inline_ref_type(leaf, iref) !=
2288 BTRFS_EXTENT_DATA_REF_KEY)
2289 goto out;
2290
2291 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2292 if (btrfs_extent_refs(leaf, ei) !=
2293 btrfs_extent_data_ref_count(leaf, ref) ||
2294 btrfs_extent_data_ref_root(leaf, ref) !=
2295 root->root_key.objectid ||
2296 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2297 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2298 goto out;
2299
2300 ret = 0;
2301 out:
2302 return ret;
2303 }
2304
2305 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
2306 struct btrfs_root *root,
2307 u64 objectid, u64 offset, u64 bytenr)
2308 {
2309 struct btrfs_path *path;
2310 int ret;
2311 int ret2;
2312
2313 path = btrfs_alloc_path();
2314 if (!path)
2315 return -ENOENT;
2316
2317 do {
2318 ret = check_committed_ref(trans, root, path, objectid,
2319 offset, bytenr);
2320 if (ret && ret != -ENOENT)
2321 goto out;
2322
2323 ret2 = check_delayed_ref(trans, root, path, objectid,
2324 offset, bytenr);
2325 } while (ret2 == -EAGAIN);
2326
2327 if (ret2 && ret2 != -ENOENT) {
2328 ret = ret2;
2329 goto out;
2330 }
2331
2332 if (ret != -ENOENT || ret2 != -ENOENT)
2333 ret = 0;
2334 out:
2335 btrfs_free_path(path);
2336 return ret;
2337 }
2338
2339 #if 0
2340 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2341 struct extent_buffer *buf, u32 nr_extents)
2342 {
2343 struct btrfs_key key;
2344 struct btrfs_file_extent_item *fi;
2345 u64 root_gen;
2346 u32 nritems;
2347 int i;
2348 int level;
2349 int ret = 0;
2350 int shared = 0;
2351
2352 if (!root->ref_cows)
2353 return 0;
2354
2355 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
2356 shared = 0;
2357 root_gen = root->root_key.offset;
2358 } else {
2359 shared = 1;
2360 root_gen = trans->transid - 1;
2361 }
2362
2363 level = btrfs_header_level(buf);
2364 nritems = btrfs_header_nritems(buf);
2365
2366 if (level == 0) {
2367 struct btrfs_leaf_ref *ref;
2368 struct btrfs_extent_info *info;
2369
2370 ref = btrfs_alloc_leaf_ref(root, nr_extents);
2371 if (!ref) {
2372 ret = -ENOMEM;
2373 goto out;
2374 }
2375
2376 ref->root_gen = root_gen;
2377 ref->bytenr = buf->start;
2378 ref->owner = btrfs_header_owner(buf);
2379 ref->generation = btrfs_header_generation(buf);
2380 ref->nritems = nr_extents;
2381 info = ref->extents;
2382
2383 for (i = 0; nr_extents > 0 && i < nritems; i++) {
2384 u64 disk_bytenr;
2385 btrfs_item_key_to_cpu(buf, &key, i);
2386 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2387 continue;
2388 fi = btrfs_item_ptr(buf, i,
2389 struct btrfs_file_extent_item);
2390 if (btrfs_file_extent_type(buf, fi) ==
2391 BTRFS_FILE_EXTENT_INLINE)
2392 continue;
2393 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2394 if (disk_bytenr == 0)
2395 continue;
2396
2397 info->bytenr = disk_bytenr;
2398 info->num_bytes =
2399 btrfs_file_extent_disk_num_bytes(buf, fi);
2400 info->objectid = key.objectid;
2401 info->offset = key.offset;
2402 info++;
2403 }
2404
2405 ret = btrfs_add_leaf_ref(root, ref, shared);
2406 if (ret == -EEXIST && shared) {
2407 struct btrfs_leaf_ref *old;
2408 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
2409 BUG_ON(!old);
2410 btrfs_remove_leaf_ref(root, old);
2411 btrfs_free_leaf_ref(root, old);
2412 ret = btrfs_add_leaf_ref(root, ref, shared);
2413 }
2414 WARN_ON(ret);
2415 btrfs_free_leaf_ref(root, ref);
2416 }
2417 out:
2418 return ret;
2419 }
2420
2421 /* when a block goes through cow, we update the reference counts of
2422 * everything that block points to. The internal pointers of the block
2423 * can be in just about any order, and it is likely to have clusters of
2424 * things that are close together and clusters of things that are not.
2425 *
2426 * To help reduce the seeks that come with updating all of these reference
2427 * counts, sort them by byte number before actual updates are done.
2428 *
2429 * struct refsort is used to match byte number to slot in the btree block.
2430 * we sort based on the byte number and then use the slot to actually
2431 * find the item.
2432 *
2433 * struct refsort is smaller than strcut btrfs_item and smaller than
2434 * struct btrfs_key_ptr. Since we're currently limited to the page size
2435 * for a btree block, there's no way for a kmalloc of refsorts for a
2436 * single node to be bigger than a page.
2437 */
2438 struct refsort {
2439 u64 bytenr;
2440 u32 slot;
2441 };
2442
2443 /*
2444 * for passing into sort()
2445 */
2446 static int refsort_cmp(const void *a_void, const void *b_void)
2447 {
2448 const struct refsort *a = a_void;
2449 const struct refsort *b = b_void;
2450
2451 if (a->bytenr < b->bytenr)
2452 return -1;
2453 if (a->bytenr > b->bytenr)
2454 return 1;
2455 return 0;
2456 }
2457 #endif
2458
2459 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2460 struct btrfs_root *root,
2461 struct extent_buffer *buf,
2462 int full_backref, int inc)
2463 {
2464 u64 bytenr;
2465 u64 num_bytes;
2466 u64 parent;
2467 u64 ref_root;
2468 u32 nritems;
2469 struct btrfs_key key;
2470 struct btrfs_file_extent_item *fi;
2471 int i;
2472 int level;
2473 int ret = 0;
2474 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
2475 u64, u64, u64, u64, u64, u64);
2476
2477 ref_root = btrfs_header_owner(buf);
2478 nritems = btrfs_header_nritems(buf);
2479 level = btrfs_header_level(buf);
2480
2481 if (!root->ref_cows && level == 0)
2482 return 0;
2483
2484 if (inc)
2485 process_func = btrfs_inc_extent_ref;
2486 else
2487 process_func = btrfs_free_extent;
2488
2489 if (full_backref)
2490 parent = buf->start;
2491 else
2492 parent = 0;
2493
2494 for (i = 0; i < nritems; i++) {
2495 if (level == 0) {
2496 btrfs_item_key_to_cpu(buf, &key, i);
2497 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2498 continue;
2499 fi = btrfs_item_ptr(buf, i,
2500 struct btrfs_file_extent_item);
2501 if (btrfs_file_extent_type(buf, fi) ==
2502 BTRFS_FILE_EXTENT_INLINE)
2503 continue;
2504 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2505 if (bytenr == 0)
2506 continue;
2507
2508 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
2509 key.offset -= btrfs_file_extent_offset(buf, fi);
2510 ret = process_func(trans, root, bytenr, num_bytes,
2511 parent, ref_root, key.objectid,
2512 key.offset);
2513 if (ret)
2514 goto fail;
2515 } else {
2516 bytenr = btrfs_node_blockptr(buf, i);
2517 num_bytes = btrfs_level_size(root, level - 1);
2518 ret = process_func(trans, root, bytenr, num_bytes,
2519 parent, ref_root, level - 1, 0);
2520 if (ret)
2521 goto fail;
2522 }
2523 }
2524 return 0;
2525 fail:
2526 BUG();
2527 return ret;
2528 }
2529
2530 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2531 struct extent_buffer *buf, int full_backref)
2532 {
2533 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
2534 }
2535
2536 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2537 struct extent_buffer *buf, int full_backref)
2538 {
2539 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
2540 }
2541
2542 static int write_one_cache_group(struct btrfs_trans_handle *trans,
2543 struct btrfs_root *root,
2544 struct btrfs_path *path,
2545 struct btrfs_block_group_cache *cache)
2546 {
2547 int ret;
2548 struct btrfs_root *extent_root = root->fs_info->extent_root;
2549 unsigned long bi;
2550 struct extent_buffer *leaf;
2551
2552 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
2553 if (ret < 0)
2554 goto fail;
2555 BUG_ON(ret);
2556
2557 leaf = path->nodes[0];
2558 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
2559 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
2560 btrfs_mark_buffer_dirty(leaf);
2561 btrfs_release_path(extent_root, path);
2562 fail:
2563 if (ret)
2564 return ret;
2565 return 0;
2566
2567 }
2568
2569 static struct btrfs_block_group_cache *
2570 next_block_group(struct btrfs_root *root,
2571 struct btrfs_block_group_cache *cache)
2572 {
2573 struct rb_node *node;
2574 spin_lock(&root->fs_info->block_group_cache_lock);
2575 node = rb_next(&cache->cache_node);
2576 btrfs_put_block_group(cache);
2577 if (node) {
2578 cache = rb_entry(node, struct btrfs_block_group_cache,
2579 cache_node);
2580 atomic_inc(&cache->count);
2581 } else
2582 cache = NULL;
2583 spin_unlock(&root->fs_info->block_group_cache_lock);
2584 return cache;
2585 }
2586
2587 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
2588 struct btrfs_root *root)
2589 {
2590 struct btrfs_block_group_cache *cache;
2591 int err = 0;
2592 struct btrfs_path *path;
2593 u64 last = 0;
2594
2595 path = btrfs_alloc_path();
2596 if (!path)
2597 return -ENOMEM;
2598
2599 while (1) {
2600 if (last == 0) {
2601 err = btrfs_run_delayed_refs(trans, root,
2602 (unsigned long)-1);
2603 BUG_ON(err);
2604 }
2605
2606 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2607 while (cache) {
2608 if (cache->dirty)
2609 break;
2610 cache = next_block_group(root, cache);
2611 }
2612 if (!cache) {
2613 if (last == 0)
2614 break;
2615 last = 0;
2616 continue;
2617 }
2618
2619 cache->dirty = 0;
2620 last = cache->key.objectid + cache->key.offset;
2621
2622 err = write_one_cache_group(trans, root, path, cache);
2623 BUG_ON(err);
2624 btrfs_put_block_group(cache);
2625 }
2626
2627 btrfs_free_path(path);
2628 return 0;
2629 }
2630
2631 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
2632 {
2633 struct btrfs_block_group_cache *block_group;
2634 int readonly = 0;
2635
2636 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
2637 if (!block_group || block_group->ro)
2638 readonly = 1;
2639 if (block_group)
2640 btrfs_put_block_group(block_group);
2641 return readonly;
2642 }
2643
2644 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
2645 u64 total_bytes, u64 bytes_used,
2646 struct btrfs_space_info **space_info)
2647 {
2648 struct btrfs_space_info *found;
2649
2650 found = __find_space_info(info, flags);
2651 if (found) {
2652 spin_lock(&found->lock);
2653 found->total_bytes += total_bytes;
2654 found->bytes_used += bytes_used;
2655 found->full = 0;
2656 spin_unlock(&found->lock);
2657 *space_info = found;
2658 return 0;
2659 }
2660 found = kzalloc(sizeof(*found), GFP_NOFS);
2661 if (!found)
2662 return -ENOMEM;
2663
2664 INIT_LIST_HEAD(&found->block_groups);
2665 init_rwsem(&found->groups_sem);
2666 spin_lock_init(&found->lock);
2667 found->flags = flags;
2668 found->total_bytes = total_bytes;
2669 found->bytes_used = bytes_used;
2670 found->bytes_pinned = 0;
2671 found->bytes_reserved = 0;
2672 found->bytes_readonly = 0;
2673 found->bytes_delalloc = 0;
2674 found->full = 0;
2675 found->force_alloc = 0;
2676 *space_info = found;
2677 list_add_rcu(&found->list, &info->space_info);
2678 atomic_set(&found->caching_threads, 0);
2679 return 0;
2680 }
2681
2682 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
2683 {
2684 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
2685 BTRFS_BLOCK_GROUP_RAID1 |
2686 BTRFS_BLOCK_GROUP_RAID10 |
2687 BTRFS_BLOCK_GROUP_DUP);
2688 if (extra_flags) {
2689 if (flags & BTRFS_BLOCK_GROUP_DATA)
2690 fs_info->avail_data_alloc_bits |= extra_flags;
2691 if (flags & BTRFS_BLOCK_GROUP_METADATA)
2692 fs_info->avail_metadata_alloc_bits |= extra_flags;
2693 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
2694 fs_info->avail_system_alloc_bits |= extra_flags;
2695 }
2696 }
2697
2698 static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
2699 {
2700 spin_lock(&cache->space_info->lock);
2701 spin_lock(&cache->lock);
2702 if (!cache->ro) {
2703 cache->space_info->bytes_readonly += cache->key.offset -
2704 btrfs_block_group_used(&cache->item);
2705 cache->ro = 1;
2706 }
2707 spin_unlock(&cache->lock);
2708 spin_unlock(&cache->space_info->lock);
2709 }
2710
2711 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
2712 {
2713 u64 num_devices = root->fs_info->fs_devices->rw_devices;
2714
2715 if (num_devices == 1)
2716 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
2717 if (num_devices < 4)
2718 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
2719
2720 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
2721 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
2722 BTRFS_BLOCK_GROUP_RAID10))) {
2723 flags &= ~BTRFS_BLOCK_GROUP_DUP;
2724 }
2725
2726 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
2727 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
2728 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
2729 }
2730
2731 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
2732 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
2733 (flags & BTRFS_BLOCK_GROUP_RAID10) |
2734 (flags & BTRFS_BLOCK_GROUP_DUP)))
2735 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
2736 return flags;
2737 }
2738
2739 static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data)
2740 {
2741 struct btrfs_fs_info *info = root->fs_info;
2742 u64 alloc_profile;
2743
2744 if (data) {
2745 alloc_profile = info->avail_data_alloc_bits &
2746 info->data_alloc_profile;
2747 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2748 } else if (root == root->fs_info->chunk_root) {
2749 alloc_profile = info->avail_system_alloc_bits &
2750 info->system_alloc_profile;
2751 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2752 } else {
2753 alloc_profile = info->avail_metadata_alloc_bits &
2754 info->metadata_alloc_profile;
2755 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2756 }
2757
2758 return btrfs_reduce_alloc_profile(root, data);
2759 }
2760
2761 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
2762 {
2763 u64 alloc_target;
2764
2765 alloc_target = btrfs_get_alloc_profile(root, 1);
2766 BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
2767 alloc_target);
2768 }
2769
2770 static u64 calculate_bytes_needed(struct btrfs_root *root, int num_items)
2771 {
2772 u64 num_bytes;
2773 int level;
2774
2775 level = BTRFS_MAX_LEVEL - 2;
2776 /*
2777 * NOTE: these calculations are absolutely the worst possible case.
2778 * This assumes that _every_ item we insert will require a new leaf, and
2779 * that the tree has grown to its maximum level size.
2780 */
2781
2782 /*
2783 * for every item we insert we could insert both an extent item and a
2784 * extent ref item. Then for ever item we insert, we will need to cow
2785 * both the original leaf, plus the leaf to the left and right of it.
2786 *
2787 * Unless we are talking about the extent root, then we just want the
2788 * number of items * 2, since we just need the extent item plus its ref.
2789 */
2790 if (root == root->fs_info->extent_root)
2791 num_bytes = num_items * 2;
2792 else
2793 num_bytes = (num_items + (2 * num_items)) * 3;
2794
2795 /*
2796 * num_bytes is total number of leaves we could need times the leaf
2797 * size, and then for every leaf we could end up cow'ing 2 nodes per
2798 * level, down to the leaf level.
2799 */
2800 num_bytes = (num_bytes * root->leafsize) +
2801 (num_bytes * (level * 2)) * root->nodesize;
2802
2803 return num_bytes;
2804 }
2805
2806 /*
2807 * Unreserve metadata space for delalloc. If we have less reserved credits than
2808 * we have extents, this function does nothing.
2809 */
2810 int btrfs_unreserve_metadata_for_delalloc(struct btrfs_root *root,
2811 struct inode *inode, int num_items)
2812 {
2813 struct btrfs_fs_info *info = root->fs_info;
2814 struct btrfs_space_info *meta_sinfo;
2815 u64 num_bytes;
2816 u64 alloc_target;
2817 bool bug = false;
2818
2819 /* get the space info for where the metadata will live */
2820 alloc_target = btrfs_get_alloc_profile(root, 0);
2821 meta_sinfo = __find_space_info(info, alloc_target);
2822
2823 num_bytes = calculate_bytes_needed(root->fs_info->extent_root,
2824 num_items);
2825
2826 spin_lock(&meta_sinfo->lock);
2827 spin_lock(&BTRFS_I(inode)->accounting_lock);
2828 if (BTRFS_I(inode)->reserved_extents <=
2829 BTRFS_I(inode)->outstanding_extents) {
2830 spin_unlock(&BTRFS_I(inode)->accounting_lock);
2831 spin_unlock(&meta_sinfo->lock);
2832 return 0;
2833 }
2834 spin_unlock(&BTRFS_I(inode)->accounting_lock);
2835
2836 BTRFS_I(inode)->reserved_extents--;
2837 BUG_ON(BTRFS_I(inode)->reserved_extents < 0);
2838
2839 if (meta_sinfo->bytes_delalloc < num_bytes) {
2840 bug = true;
2841 meta_sinfo->bytes_delalloc = 0;
2842 } else {
2843 meta_sinfo->bytes_delalloc -= num_bytes;
2844 }
2845 spin_unlock(&meta_sinfo->lock);
2846
2847 BUG_ON(bug);
2848
2849 return 0;
2850 }
2851
2852 static void check_force_delalloc(struct btrfs_space_info *meta_sinfo)
2853 {
2854 u64 thresh;
2855
2856 thresh = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
2857 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
2858 meta_sinfo->bytes_super + meta_sinfo->bytes_root +
2859 meta_sinfo->bytes_may_use;
2860
2861 thresh = meta_sinfo->total_bytes - thresh;
2862 thresh *= 80;
2863 do_div(thresh, 100);
2864 if (thresh <= meta_sinfo->bytes_delalloc)
2865 meta_sinfo->force_delalloc = 1;
2866 else
2867 meta_sinfo->force_delalloc = 0;
2868 }
2869
2870 struct async_flush {
2871 struct btrfs_root *root;
2872 struct btrfs_space_info *info;
2873 struct btrfs_work work;
2874 };
2875
2876 static noinline void flush_delalloc_async(struct btrfs_work *work)
2877 {
2878 struct async_flush *async;
2879 struct btrfs_root *root;
2880 struct btrfs_space_info *info;
2881
2882 async = container_of(work, struct async_flush, work);
2883 root = async->root;
2884 info = async->info;
2885
2886 btrfs_start_delalloc_inodes(root);
2887 wake_up(&info->flush_wait);
2888 btrfs_wait_ordered_extents(root, 0);
2889
2890 spin_lock(&info->lock);
2891 info->flushing = 0;
2892 spin_unlock(&info->lock);
2893 wake_up(&info->flush_wait);
2894
2895 kfree(async);
2896 }
2897
2898 static void wait_on_flush(struct btrfs_space_info *info)
2899 {
2900 DEFINE_WAIT(wait);
2901 u64 used;
2902
2903 while (1) {
2904 prepare_to_wait(&info->flush_wait, &wait,
2905 TASK_UNINTERRUPTIBLE);
2906 spin_lock(&info->lock);
2907 if (!info->flushing) {
2908 spin_unlock(&info->lock);
2909 break;
2910 }
2911
2912 used = info->bytes_used + info->bytes_reserved +
2913 info->bytes_pinned + info->bytes_readonly +
2914 info->bytes_super + info->bytes_root +
2915 info->bytes_may_use + info->bytes_delalloc;
2916 if (used < info->total_bytes) {
2917 spin_unlock(&info->lock);
2918 break;
2919 }
2920 spin_unlock(&info->lock);
2921 schedule();
2922 }
2923 finish_wait(&info->flush_wait, &wait);
2924 }
2925
2926 static void flush_delalloc(struct btrfs_root *root,
2927 struct btrfs_space_info *info)
2928 {
2929 struct async_flush *async;
2930 bool wait = false;
2931
2932 spin_lock(&info->lock);
2933
2934 if (!info->flushing) {
2935 info->flushing = 1;
2936 init_waitqueue_head(&info->flush_wait);
2937 } else {
2938 wait = true;
2939 }
2940
2941 spin_unlock(&info->lock);
2942
2943 if (wait) {
2944 wait_on_flush(info);
2945 return;
2946 }
2947
2948 async = kzalloc(sizeof(*async), GFP_NOFS);
2949 if (!async)
2950 goto flush;
2951
2952 async->root = root;
2953 async->info = info;
2954 async->work.func = flush_delalloc_async;
2955
2956 btrfs_queue_worker(&root->fs_info->enospc_workers,
2957 &async->work);
2958 wait_on_flush(info);
2959 return;
2960
2961 flush:
2962 btrfs_start_delalloc_inodes(root);
2963 btrfs_wait_ordered_extents(root, 0);
2964
2965 spin_lock(&info->lock);
2966 info->flushing = 0;
2967 spin_unlock(&info->lock);
2968 wake_up(&info->flush_wait);
2969 }
2970
2971 static int maybe_allocate_chunk(struct btrfs_root *root,
2972 struct btrfs_space_info *info)
2973 {
2974 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
2975 struct btrfs_trans_handle *trans;
2976 bool wait = false;
2977 int ret = 0;
2978 u64 min_metadata;
2979 u64 free_space;
2980
2981 free_space = btrfs_super_total_bytes(disk_super);
2982 /*
2983 * we allow the metadata to grow to a max of either 5gb or 5% of the
2984 * space in the volume.
2985 */
2986 min_metadata = min((u64)5 * 1024 * 1024 * 1024,
2987 div64_u64(free_space * 5, 100));
2988 if (info->total_bytes >= min_metadata) {
2989 spin_unlock(&info->lock);
2990 return 0;
2991 }
2992
2993 if (info->full) {
2994 spin_unlock(&info->lock);
2995 return 0;
2996 }
2997
2998 if (!info->allocating_chunk) {
2999 info->force_alloc = 1;
3000 info->allocating_chunk = 1;
3001 init_waitqueue_head(&info->allocate_wait);
3002 } else {
3003 wait = true;
3004 }
3005
3006 spin_unlock(&info->lock);
3007
3008 if (wait) {
3009 wait_event(info->allocate_wait,
3010 !info->allocating_chunk);
3011 return 1;
3012 }
3013
3014 trans = btrfs_start_transaction(root, 1);
3015 if (!trans) {
3016 ret = -ENOMEM;
3017 goto out;
3018 }
3019
3020 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3021 4096 + 2 * 1024 * 1024,
3022 info->flags, 0);
3023 btrfs_end_transaction(trans, root);
3024 if (ret)
3025 goto out;
3026 out:
3027 spin_lock(&info->lock);
3028 info->allocating_chunk = 0;
3029 spin_unlock(&info->lock);
3030 wake_up(&info->allocate_wait);
3031
3032 if (ret)
3033 return 0;
3034 return 1;
3035 }
3036
3037 /*
3038 * Reserve metadata space for delalloc.
3039 */
3040 int btrfs_reserve_metadata_for_delalloc(struct btrfs_root *root,
3041 struct inode *inode, int num_items)
3042 {
3043 struct btrfs_fs_info *info = root->fs_info;
3044 struct btrfs_space_info *meta_sinfo;
3045 u64 num_bytes;
3046 u64 used;
3047 u64 alloc_target;
3048 int flushed = 0;
3049 int force_delalloc;
3050
3051 /* get the space info for where the metadata will live */
3052 alloc_target = btrfs_get_alloc_profile(root, 0);
3053 meta_sinfo = __find_space_info(info, alloc_target);
3054
3055 num_bytes = calculate_bytes_needed(root->fs_info->extent_root,
3056 num_items);
3057 again:
3058 spin_lock(&meta_sinfo->lock);
3059
3060 force_delalloc = meta_sinfo->force_delalloc;
3061
3062 if (unlikely(!meta_sinfo->bytes_root))
3063 meta_sinfo->bytes_root = calculate_bytes_needed(root, 6);
3064
3065 if (!flushed)
3066 meta_sinfo->bytes_delalloc += num_bytes;
3067
3068 used = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
3069 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
3070 meta_sinfo->bytes_super + meta_sinfo->bytes_root +
3071 meta_sinfo->bytes_may_use + meta_sinfo->bytes_delalloc;
3072
3073 if (used > meta_sinfo->total_bytes) {
3074 flushed++;
3075
3076 if (flushed == 1) {
3077 if (maybe_allocate_chunk(root, meta_sinfo))
3078 goto again;
3079 flushed++;
3080 } else {
3081 spin_unlock(&meta_sinfo->lock);
3082 }
3083
3084 if (flushed == 2) {
3085 filemap_flush(inode->i_mapping);
3086 goto again;
3087 } else if (flushed == 3) {
3088 flush_delalloc(root, meta_sinfo);
3089 goto again;
3090 }
3091 spin_lock(&meta_sinfo->lock);
3092 meta_sinfo->bytes_delalloc -= num_bytes;
3093 spin_unlock(&meta_sinfo->lock);
3094 printk(KERN_ERR "enospc, has %d, reserved %d\n",
3095 BTRFS_I(inode)->outstanding_extents,
3096 BTRFS_I(inode)->reserved_extents);
3097 dump_space_info(meta_sinfo, 0, 0);
3098 return -ENOSPC;
3099 }
3100
3101 BTRFS_I(inode)->reserved_extents++;
3102 check_force_delalloc(meta_sinfo);
3103 spin_unlock(&meta_sinfo->lock);
3104
3105 if (!flushed && force_delalloc)
3106 filemap_flush(inode->i_mapping);
3107
3108 return 0;
3109 }
3110
3111 /*
3112 * unreserve num_items number of items worth of metadata space. This needs to
3113 * be paired with btrfs_reserve_metadata_space.
3114 *
3115 * NOTE: if you have the option, run this _AFTER_ you do a
3116 * btrfs_end_transaction, since btrfs_end_transaction will run delayed ref
3117 * oprations which will result in more used metadata, so we want to make sure we
3118 * can do that without issue.
3119 */
3120 int btrfs_unreserve_metadata_space(struct btrfs_root *root, int num_items)
3121 {
3122 struct btrfs_fs_info *info = root->fs_info;
3123 struct btrfs_space_info *meta_sinfo;
3124 u64 num_bytes;
3125 u64 alloc_target;
3126 bool bug = false;
3127
3128 /* get the space info for where the metadata will live */
3129 alloc_target = btrfs_get_alloc_profile(root, 0);
3130 meta_sinfo = __find_space_info(info, alloc_target);
3131
3132 num_bytes = calculate_bytes_needed(root, num_items);
3133
3134 spin_lock(&meta_sinfo->lock);
3135 if (meta_sinfo->bytes_may_use < num_bytes) {
3136 bug = true;
3137 meta_sinfo->bytes_may_use = 0;
3138 } else {
3139 meta_sinfo->bytes_may_use -= num_bytes;
3140 }
3141 spin_unlock(&meta_sinfo->lock);
3142
3143 BUG_ON(bug);
3144
3145 return 0;
3146 }
3147
3148 /*
3149 * Reserve some metadata space for use. We'll calculate the worste case number
3150 * of bytes that would be needed to modify num_items number of items. If we
3151 * have space, fantastic, if not, you get -ENOSPC. Please call
3152 * btrfs_unreserve_metadata_space when you are done for the _SAME_ number of
3153 * items you reserved, since whatever metadata you needed should have already
3154 * been allocated.
3155 *
3156 * This will commit the transaction to make more space if we don't have enough
3157 * metadata space. THe only time we don't do this is if we're reserving space
3158 * inside of a transaction, then we will just return -ENOSPC and it is the
3159 * callers responsibility to handle it properly.
3160 */
3161 int btrfs_reserve_metadata_space(struct btrfs_root *root, int num_items)
3162 {
3163 struct btrfs_fs_info *info = root->fs_info;
3164 struct btrfs_space_info *meta_sinfo;
3165 u64 num_bytes;
3166 u64 used;
3167 u64 alloc_target;
3168 int retries = 0;
3169
3170 /* get the space info for where the metadata will live */
3171 alloc_target = btrfs_get_alloc_profile(root, 0);
3172 meta_sinfo = __find_space_info(info, alloc_target);
3173
3174 num_bytes = calculate_bytes_needed(root, num_items);
3175 again:
3176 spin_lock(&meta_sinfo->lock);
3177
3178 if (unlikely(!meta_sinfo->bytes_root))
3179 meta_sinfo->bytes_root = calculate_bytes_needed(root, 6);
3180
3181 if (!retries)
3182 meta_sinfo->bytes_may_use += num_bytes;
3183
3184 used = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
3185 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
3186 meta_sinfo->bytes_super + meta_sinfo->bytes_root +
3187 meta_sinfo->bytes_may_use + meta_sinfo->bytes_delalloc;
3188
3189 if (used > meta_sinfo->total_bytes) {
3190 retries++;
3191 if (retries == 1) {
3192 if (maybe_allocate_chunk(root, meta_sinfo))
3193 goto again;
3194 retries++;
3195 } else {
3196 spin_unlock(&meta_sinfo->lock);
3197 }
3198
3199 if (retries == 2) {
3200 flush_delalloc(root, meta_sinfo);
3201 goto again;
3202 }
3203 spin_lock(&meta_sinfo->lock);
3204 meta_sinfo->bytes_may_use -= num_bytes;
3205 spin_unlock(&meta_sinfo->lock);
3206
3207 dump_space_info(meta_sinfo, 0, 0);
3208 return -ENOSPC;
3209 }
3210
3211 check_force_delalloc(meta_sinfo);
3212 spin_unlock(&meta_sinfo->lock);
3213
3214 return 0;
3215 }
3216
3217 /*
3218 * This will check the space that the inode allocates from to make sure we have
3219 * enough space for bytes.
3220 */
3221 int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
3222 u64 bytes)
3223 {
3224 struct btrfs_space_info *data_sinfo;
3225 int ret = 0, committed = 0;
3226
3227 /* make sure bytes are sectorsize aligned */
3228 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
3229
3230 data_sinfo = BTRFS_I(inode)->space_info;
3231 if (!data_sinfo)
3232 goto alloc;
3233
3234 again:
3235 /* make sure we have enough space to handle the data first */
3236 spin_lock(&data_sinfo->lock);
3237 if (data_sinfo->total_bytes - data_sinfo->bytes_used -
3238 data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved -
3239 data_sinfo->bytes_pinned - data_sinfo->bytes_readonly -
3240 data_sinfo->bytes_may_use - data_sinfo->bytes_super < bytes) {
3241 struct btrfs_trans_handle *trans;
3242
3243 /*
3244 * if we don't have enough free bytes in this space then we need
3245 * to alloc a new chunk.
3246 */
3247 if (!data_sinfo->full) {
3248 u64 alloc_target;
3249
3250 data_sinfo->force_alloc = 1;
3251 spin_unlock(&data_sinfo->lock);
3252 alloc:
3253 alloc_target = btrfs_get_alloc_profile(root, 1);
3254 trans = btrfs_start_transaction(root, 1);
3255 if (!trans)
3256 return -ENOMEM;
3257
3258 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3259 bytes + 2 * 1024 * 1024,
3260 alloc_target, 0);
3261 btrfs_end_transaction(trans, root);
3262 if (ret)
3263 return ret;
3264
3265 if (!data_sinfo) {
3266 btrfs_set_inode_space_info(root, inode);
3267 data_sinfo = BTRFS_I(inode)->space_info;
3268 }
3269 goto again;
3270 }
3271 spin_unlock(&data_sinfo->lock);
3272
3273 /* commit the current transaction and try again */
3274 if (!committed && !root->fs_info->open_ioctl_trans) {
3275 committed = 1;
3276 trans = btrfs_join_transaction(root, 1);
3277 if (!trans)
3278 return -ENOMEM;
3279 ret = btrfs_commit_transaction(trans, root);
3280 if (ret)
3281 return ret;
3282 goto again;
3283 }
3284
3285 printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes"
3286 ", %llu bytes_used, %llu bytes_reserved, "
3287 "%llu bytes_pinned, %llu bytes_readonly, %llu may use "
3288 "%llu total\n", (unsigned long long)bytes,
3289 (unsigned long long)data_sinfo->bytes_delalloc,
3290 (unsigned long long)data_sinfo->bytes_used,
3291 (unsigned long long)data_sinfo->bytes_reserved,
3292 (unsigned long long)data_sinfo->bytes_pinned,
3293 (unsigned long long)data_sinfo->bytes_readonly,
3294 (unsigned long long)data_sinfo->bytes_may_use,
3295 (unsigned long long)data_sinfo->total_bytes);
3296 return -ENOSPC;
3297 }
3298 data_sinfo->bytes_may_use += bytes;
3299 BTRFS_I(inode)->reserved_bytes += bytes;
3300 spin_unlock(&data_sinfo->lock);
3301
3302 return 0;
3303 }
3304
3305 /*
3306 * if there was an error for whatever reason after calling
3307 * btrfs_check_data_free_space, call this so we can cleanup the counters.
3308 */
3309 void btrfs_free_reserved_data_space(struct btrfs_root *root,
3310 struct inode *inode, u64 bytes)
3311 {
3312 struct btrfs_space_info *data_sinfo;
3313
3314 /* make sure bytes are sectorsize aligned */
3315 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
3316
3317 data_sinfo = BTRFS_I(inode)->space_info;
3318 spin_lock(&data_sinfo->lock);
3319 data_sinfo->bytes_may_use -= bytes;
3320 BTRFS_I(inode)->reserved_bytes -= bytes;
3321 spin_unlock(&data_sinfo->lock);
3322 }
3323
3324 /* called when we are adding a delalloc extent to the inode's io_tree */
3325 void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
3326 u64 bytes)
3327 {
3328 struct btrfs_space_info *data_sinfo;
3329
3330 /* get the space info for where this inode will be storing its data */
3331 data_sinfo = BTRFS_I(inode)->space_info;
3332
3333 /* make sure we have enough space to handle the data first */
3334 spin_lock(&data_sinfo->lock);
3335 data_sinfo->bytes_delalloc += bytes;
3336
3337 /*
3338 * we are adding a delalloc extent without calling
3339 * btrfs_check_data_free_space first. This happens on a weird
3340 * writepage condition, but shouldn't hurt our accounting
3341 */
3342 if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {
3343 data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;
3344 BTRFS_I(inode)->reserved_bytes = 0;
3345 } else {
3346 data_sinfo->bytes_may_use -= bytes;
3347 BTRFS_I(inode)->reserved_bytes -= bytes;
3348 }
3349
3350 spin_unlock(&data_sinfo->lock);
3351 }
3352
3353 /* called when we are clearing an delalloc extent from the inode's io_tree */
3354 void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
3355 u64 bytes)
3356 {
3357 struct btrfs_space_info *info;
3358
3359 info = BTRFS_I(inode)->space_info;
3360
3361 spin_lock(&info->lock);
3362 info->bytes_delalloc -= bytes;
3363 spin_unlock(&info->lock);
3364 }
3365
3366 static void force_metadata_allocation(struct btrfs_fs_info *info)
3367 {
3368 struct list_head *head = &info->space_info;
3369 struct btrfs_space_info *found;
3370
3371 rcu_read_lock();
3372 list_for_each_entry_rcu(found, head, list) {
3373 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
3374 found->force_alloc = 1;
3375 }
3376 rcu_read_unlock();
3377 }
3378
3379 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
3380 struct btrfs_root *extent_root, u64 alloc_bytes,
3381 u64 flags, int force)
3382 {
3383 struct btrfs_space_info *space_info;
3384 struct btrfs_fs_info *fs_info = extent_root->fs_info;
3385 u64 thresh;
3386 int ret = 0;
3387
3388 mutex_lock(&fs_info->chunk_mutex);
3389
3390 flags = btrfs_reduce_alloc_profile(extent_root, flags);
3391
3392 space_info = __find_space_info(extent_root->fs_info, flags);
3393 if (!space_info) {
3394 ret = update_space_info(extent_root->fs_info, flags,
3395 0, 0, &space_info);
3396 BUG_ON(ret);
3397 }
3398 BUG_ON(!space_info);
3399
3400 spin_lock(&space_info->lock);
3401 if (space_info->force_alloc)
3402 force = 1;
3403 if (space_info->full) {
3404 spin_unlock(&space_info->lock);
3405 goto out;
3406 }
3407
3408 thresh = space_info->total_bytes - space_info->bytes_readonly;
3409 thresh = div_factor(thresh, 8);
3410 if (!force &&
3411 (space_info->bytes_used + space_info->bytes_pinned +
3412 space_info->bytes_reserved + alloc_bytes) < thresh) {
3413 spin_unlock(&space_info->lock);
3414 goto out;
3415 }
3416 spin_unlock(&space_info->lock);
3417
3418 /*
3419 * if we're doing a data chunk, go ahead and make sure that
3420 * we keep a reasonable number of metadata chunks allocated in the
3421 * FS as well.
3422 */
3423 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
3424 fs_info->data_chunk_allocations++;
3425 if (!(fs_info->data_chunk_allocations %
3426 fs_info->metadata_ratio))
3427 force_metadata_allocation(fs_info);
3428 }
3429
3430 ret = btrfs_alloc_chunk(trans, extent_root, flags);
3431 spin_lock(&space_info->lock);
3432 if (ret)
3433 space_info->full = 1;
3434 space_info->force_alloc = 0;
3435 spin_unlock(&space_info->lock);
3436 out:
3437 mutex_unlock(&extent_root->fs_info->chunk_mutex);
3438 return ret;
3439 }
3440
3441 static int update_block_group(struct btrfs_trans_handle *trans,
3442 struct btrfs_root *root,
3443 u64 bytenr, u64 num_bytes, int alloc,
3444 int mark_free)
3445 {
3446 struct btrfs_block_group_cache *cache;
3447 struct btrfs_fs_info *info = root->fs_info;
3448 u64 total = num_bytes;
3449 u64 old_val;
3450 u64 byte_in_group;
3451
3452 /* block accounting for super block */
3453 spin_lock(&info->delalloc_lock);
3454 old_val = btrfs_super_bytes_used(&info->super_copy);
3455 if (alloc)
3456 old_val += num_bytes;
3457 else
3458 old_val -= num_bytes;
3459 btrfs_set_super_bytes_used(&info->super_copy, old_val);
3460
3461 /* block accounting for root item */
3462 old_val = btrfs_root_used(&root->root_item);
3463 if (alloc)
3464 old_val += num_bytes;
3465 else
3466 old_val -= num_bytes;
3467 btrfs_set_root_used(&root->root_item, old_val);
3468 spin_unlock(&info->delalloc_lock);
3469
3470 while (total) {
3471 cache = btrfs_lookup_block_group(info, bytenr);
3472 if (!cache)
3473 return -1;
3474 byte_in_group = bytenr - cache->key.objectid;
3475 WARN_ON(byte_in_group > cache->key.offset);
3476
3477 spin_lock(&cache->space_info->lock);
3478 spin_lock(&cache->lock);
3479 cache->dirty = 1;
3480 old_val = btrfs_block_group_used(&cache->item);
3481 num_bytes = min(total, cache->key.offset - byte_in_group);
3482 if (alloc) {
3483 old_val += num_bytes;
3484 btrfs_set_block_group_used(&cache->item, old_val);
3485 cache->reserved -= num_bytes;
3486 cache->space_info->bytes_used += num_bytes;
3487 cache->space_info->bytes_reserved -= num_bytes;
3488 if (cache->ro)
3489 cache->space_info->bytes_readonly -= num_bytes;
3490 spin_unlock(&cache->lock);
3491 spin_unlock(&cache->space_info->lock);
3492 } else {
3493 old_val -= num_bytes;
3494 cache->space_info->bytes_used -= num_bytes;
3495 if (cache->ro)
3496 cache->space_info->bytes_readonly += num_bytes;
3497 btrfs_set_block_group_used(&cache->item, old_val);
3498 spin_unlock(&cache->lock);
3499 spin_unlock(&cache->space_info->lock);
3500 if (mark_free) {
3501 int ret;
3502
3503 ret = btrfs_discard_extent(root, bytenr,
3504 num_bytes);
3505 WARN_ON(ret);
3506
3507 ret = btrfs_add_free_space(cache, bytenr,
3508 num_bytes);
3509 WARN_ON(ret);
3510 }
3511 }
3512 btrfs_put_block_group(cache);
3513 total -= num_bytes;
3514 bytenr += num_bytes;
3515 }
3516 return 0;
3517 }
3518
3519 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
3520 {
3521 struct btrfs_block_group_cache *cache;
3522 u64 bytenr;
3523
3524 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
3525 if (!cache)
3526 return 0;
3527
3528 bytenr = cache->key.objectid;
3529 btrfs_put_block_group(cache);
3530
3531 return bytenr;
3532 }
3533
3534 /*
3535 * this function must be called within transaction
3536 */
3537 int btrfs_pin_extent(struct btrfs_root *root,
3538 u64 bytenr, u64 num_bytes, int reserved)
3539 {
3540 struct btrfs_fs_info *fs_info = root->fs_info;
3541 struct btrfs_block_group_cache *cache;
3542
3543 cache = btrfs_lookup_block_group(fs_info, bytenr);
3544 BUG_ON(!cache);
3545
3546 spin_lock(&cache->space_info->lock);
3547 spin_lock(&cache->lock);
3548 cache->pinned += num_bytes;
3549 cache->space_info->bytes_pinned += num_bytes;
3550 if (reserved) {
3551 cache->reserved -= num_bytes;
3552 cache->space_info->bytes_reserved -= num_bytes;
3553 }
3554 spin_unlock(&cache->lock);
3555 spin_unlock(&cache->space_info->lock);
3556
3557 btrfs_put_block_group(cache);
3558
3559 set_extent_dirty(fs_info->pinned_extents,
3560 bytenr, bytenr + num_bytes - 1, GFP_NOFS);
3561 return 0;
3562 }
3563
3564 static int update_reserved_extents(struct btrfs_block_group_cache *cache,
3565 u64 num_bytes, int reserve)
3566 {
3567 spin_lock(&cache->space_info->lock);
3568 spin_lock(&cache->lock);
3569 if (reserve) {
3570 cache->reserved += num_bytes;
3571 cache->space_info->bytes_reserved += num_bytes;
3572 } else {
3573 cache->reserved -= num_bytes;
3574 cache->space_info->bytes_reserved -= num_bytes;
3575 }
3576 spin_unlock(&cache->lock);
3577 spin_unlock(&cache->space_info->lock);
3578 return 0;
3579 }
3580
3581 int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
3582 struct btrfs_root *root)
3583 {
3584 struct btrfs_fs_info *fs_info = root->fs_info;
3585 struct btrfs_caching_control *next;
3586 struct btrfs_caching_control *caching_ctl;
3587 struct btrfs_block_group_cache *cache;
3588
3589 down_write(&fs_info->extent_commit_sem);
3590
3591 list_for_each_entry_safe(caching_ctl, next,
3592 &fs_info->caching_block_groups, list) {
3593 cache = caching_ctl->block_group;
3594 if (block_group_cache_done(cache)) {
3595 cache->last_byte_to_unpin = (u64)-1;
3596 list_del_init(&caching_ctl->list);
3597 put_caching_control(caching_ctl);
3598 } else {
3599 cache->last_byte_to_unpin = caching_ctl->progress;
3600 }
3601 }
3602
3603 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
3604 fs_info->pinned_extents = &fs_info->freed_extents[1];
3605 else
3606 fs_info->pinned_extents = &fs_info->freed_extents[0];
3607
3608 up_write(&fs_info->extent_commit_sem);
3609 return 0;
3610 }
3611
3612 static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
3613 {
3614 struct btrfs_fs_info *fs_info = root->fs_info;
3615 struct btrfs_block_group_cache *cache = NULL;
3616 u64 len;
3617
3618 while (start <= end) {
3619 if (!cache ||
3620 start >= cache->key.objectid + cache->key.offset) {
3621 if (cache)
3622 btrfs_put_block_group(cache);
3623 cache = btrfs_lookup_block_group(fs_info, start);
3624 BUG_ON(!cache);
3625 }
3626
3627 len = cache->key.objectid + cache->key.offset - start;
3628 len = min(len, end + 1 - start);
3629
3630 if (start < cache->last_byte_to_unpin) {
3631 len = min(len, cache->last_byte_to_unpin - start);
3632 btrfs_add_free_space(cache, start, len);
3633 }
3634
3635 spin_lock(&cache->space_info->lock);
3636 spin_lock(&cache->lock);
3637 cache->pinned -= len;
3638 cache->space_info->bytes_pinned -= len;
3639 spin_unlock(&cache->lock);
3640 spin_unlock(&cache->space_info->lock);
3641
3642 start += len;
3643 }
3644
3645 if (cache)
3646 btrfs_put_block_group(cache);
3647 return 0;
3648 }
3649
3650 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
3651 struct btrfs_root *root)
3652 {
3653 struct btrfs_fs_info *fs_info = root->fs_info;
3654 struct extent_io_tree *unpin;
3655 u64 start;
3656 u64 end;
3657 int ret;
3658
3659 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
3660 unpin = &fs_info->freed_extents[1];
3661 else
3662 unpin = &fs_info->freed_extents[0];
3663
3664 while (1) {
3665 ret = find_first_extent_bit(unpin, 0, &start, &end,
3666 EXTENT_DIRTY);
3667 if (ret)
3668 break;
3669
3670 ret = btrfs_discard_extent(root, start, end + 1 - start);
3671
3672 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3673 unpin_extent_range(root, start, end);
3674 cond_resched();
3675 }
3676
3677 return ret;
3678 }
3679
3680 static int pin_down_bytes(struct btrfs_trans_handle *trans,
3681 struct btrfs_root *root,
3682 struct btrfs_path *path,
3683 u64 bytenr, u64 num_bytes,
3684 int is_data, int reserved,
3685 struct extent_buffer **must_clean)
3686 {
3687 int err = 0;
3688 struct extent_buffer *buf;
3689
3690 if (is_data)
3691 goto pinit;
3692
3693 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
3694 if (!buf)
3695 goto pinit;
3696
3697 /* we can reuse a block if it hasn't been written
3698 * and it is from this transaction. We can't
3699 * reuse anything from the tree log root because
3700 * it has tiny sub-transactions.
3701 */
3702 if (btrfs_buffer_uptodate(buf, 0) &&
3703 btrfs_try_tree_lock(buf)) {
3704 u64 header_owner = btrfs_header_owner(buf);
3705 u64 header_transid = btrfs_header_generation(buf);
3706 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
3707 header_transid == trans->transid &&
3708 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
3709 *must_clean = buf;
3710 return 1;
3711 }
3712 btrfs_tree_unlock(buf);
3713 }
3714 free_extent_buffer(buf);
3715 pinit:
3716 if (path)
3717 btrfs_set_path_blocking(path);
3718 /* unlocks the pinned mutex */
3719 btrfs_pin_extent(root, bytenr, num_bytes, reserved);
3720
3721 BUG_ON(err < 0);
3722 return 0;
3723 }
3724
3725 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
3726 struct btrfs_root *root,
3727 u64 bytenr, u64 num_bytes, u64 parent,
3728 u64 root_objectid, u64 owner_objectid,
3729 u64 owner_offset, int refs_to_drop,
3730 struct btrfs_delayed_extent_op *extent_op)
3731 {
3732 struct btrfs_key key;
3733 struct btrfs_path *path;
3734 struct btrfs_fs_info *info = root->fs_info;
3735 struct btrfs_root *extent_root = info->extent_root;
3736 struct extent_buffer *leaf;
3737 struct btrfs_extent_item *ei;
3738 struct btrfs_extent_inline_ref *iref;
3739 int ret;
3740 int is_data;
3741 int extent_slot = 0;
3742 int found_extent = 0;
3743 int num_to_del = 1;
3744 u32 item_size;
3745 u64 refs;
3746
3747 path = btrfs_alloc_path();
3748 if (!path)
3749 return -ENOMEM;
3750
3751 path->reada = 1;
3752 path->leave_spinning = 1;
3753
3754 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
3755 BUG_ON(!is_data && refs_to_drop != 1);
3756
3757 ret = lookup_extent_backref(trans, extent_root, path, &iref,
3758 bytenr, num_bytes, parent,
3759 root_objectid, owner_objectid,
3760 owner_offset);
3761 if (ret == 0) {
3762 extent_slot = path->slots[0];
3763 while (extent_slot >= 0) {
3764 btrfs_item_key_to_cpu(path->nodes[0], &key,
3765 extent_slot);
3766 if (key.objectid != bytenr)
3767 break;
3768 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3769 key.offset == num_bytes) {
3770 found_extent = 1;
3771 break;
3772 }
3773 if (path->slots[0] - extent_slot > 5)
3774 break;
3775 extent_slot--;
3776 }
3777 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3778 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
3779 if (found_extent && item_size < sizeof(*ei))
3780 found_extent = 0;
3781 #endif
3782 if (!found_extent) {
3783 BUG_ON(iref);
3784 ret = remove_extent_backref(trans, extent_root, path,
3785 NULL, refs_to_drop,
3786 is_data);
3787 BUG_ON(ret);
3788 btrfs_release_path(extent_root, path);
3789 path->leave_spinning = 1;
3790
3791 key.objectid = bytenr;
3792 key.type = BTRFS_EXTENT_ITEM_KEY;
3793 key.offset = num_bytes;
3794
3795 ret = btrfs_search_slot(trans, extent_root,
3796 &key, path, -1, 1);
3797 if (ret) {
3798 printk(KERN_ERR "umm, got %d back from search"
3799 ", was looking for %llu\n", ret,
3800 (unsigned long long)bytenr);
3801 btrfs_print_leaf(extent_root, path->nodes[0]);
3802 }
3803 BUG_ON(ret);
3804 extent_slot = path->slots[0];
3805 }
3806 } else {
3807 btrfs_print_leaf(extent_root, path->nodes[0]);
3808 WARN_ON(1);
3809 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
3810 "parent %llu root %llu owner %llu offset %llu\n",
3811 (unsigned long long)bytenr,
3812 (unsigned long long)parent,
3813 (unsigned long long)root_objectid,
3814 (unsigned long long)owner_objectid,
3815 (unsigned long long)owner_offset);
3816 }
3817
3818 leaf = path->nodes[0];
3819 item_size = btrfs_item_size_nr(leaf, extent_slot);
3820 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3821 if (item_size < sizeof(*ei)) {
3822 BUG_ON(found_extent || extent_slot != path->slots[0]);
3823 ret = convert_extent_item_v0(trans, extent_root, path,
3824 owner_objectid, 0);
3825 BUG_ON(ret < 0);
3826
3827 btrfs_release_path(extent_root, path);
3828 path->leave_spinning = 1;
3829
3830 key.objectid = bytenr;
3831 key.type = BTRFS_EXTENT_ITEM_KEY;
3832 key.offset = num_bytes;
3833
3834 ret = btrfs_search_slot(trans, extent_root, &key, path,
3835 -1, 1);
3836 if (ret) {
3837 printk(KERN_ERR "umm, got %d back from search"
3838 ", was looking for %llu\n", ret,
3839 (unsigned long long)bytenr);
3840 btrfs_print_leaf(extent_root, path->nodes[0]);
3841 }
3842 BUG_ON(ret);
3843 extent_slot = path->slots[0];
3844 leaf = path->nodes[0];
3845 item_size = btrfs_item_size_nr(leaf, extent_slot);
3846 }
3847 #endif
3848 BUG_ON(item_size < sizeof(*ei));
3849 ei = btrfs_item_ptr(leaf, extent_slot,
3850 struct btrfs_extent_item);
3851 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3852 struct btrfs_tree_block_info *bi;
3853 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
3854 bi = (struct btrfs_tree_block_info *)(ei + 1);
3855 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
3856 }
3857
3858 refs = btrfs_extent_refs(leaf, ei);
3859 BUG_ON(refs < refs_to_drop);
3860 refs -= refs_to_drop;
3861
3862 if (refs > 0) {
3863 if (extent_op)
3864 __run_delayed_extent_op(extent_op, leaf, ei);
3865 /*
3866 * In the case of inline back ref, reference count will
3867 * be updated by remove_extent_backref
3868 */
3869 if (iref) {
3870 BUG_ON(!found_extent);
3871 } else {
3872 btrfs_set_extent_refs(leaf, ei, refs);
3873 btrfs_mark_buffer_dirty(leaf);
3874 }
3875 if (found_extent) {
3876 ret = remove_extent_backref(trans, extent_root, path,
3877 iref, refs_to_drop,
3878 is_data);
3879 BUG_ON(ret);
3880 }
3881 } else {
3882 int mark_free = 0;
3883 struct extent_buffer *must_clean = NULL;
3884
3885 if (found_extent) {
3886 BUG_ON(is_data && refs_to_drop !=
3887 extent_data_ref_count(root, path, iref));
3888 if (iref) {
3889 BUG_ON(path->slots[0] != extent_slot);
3890 } else {
3891 BUG_ON(path->slots[0] != extent_slot + 1);
3892 path->slots[0] = extent_slot;
3893 num_to_del = 2;
3894 }
3895 }
3896
3897 ret = pin_down_bytes(trans, root, path, bytenr,
3898 num_bytes, is_data, 0, &must_clean);
3899 if (ret > 0)
3900 mark_free = 1;
3901 BUG_ON(ret < 0);
3902 /*
3903 * it is going to be very rare for someone to be waiting
3904 * on the block we're freeing. del_items might need to
3905 * schedule, so rather than get fancy, just force it
3906 * to blocking here
3907 */
3908 if (must_clean)
3909 btrfs_set_lock_blocking(must_clean);
3910
3911 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
3912 num_to_del);
3913 BUG_ON(ret);
3914 btrfs_release_path(extent_root, path);
3915
3916 if (must_clean) {
3917 clean_tree_block(NULL, root, must_clean);
3918 btrfs_tree_unlock(must_clean);
3919 free_extent_buffer(must_clean);
3920 }
3921
3922 if (is_data) {
3923 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
3924 BUG_ON(ret);
3925 } else {
3926 invalidate_mapping_pages(info->btree_inode->i_mapping,
3927 bytenr >> PAGE_CACHE_SHIFT,
3928 (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
3929 }
3930
3931 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
3932 mark_free);
3933 BUG_ON(ret);
3934 }
3935 btrfs_free_path(path);
3936 return ret;
3937 }
3938
3939 /*
3940 * when we free an extent, it is possible (and likely) that we free the last
3941 * delayed ref for that extent as well. This searches the delayed ref tree for
3942 * a given extent, and if there are no other delayed refs to be processed, it
3943 * removes it from the tree.
3944 */
3945 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
3946 struct btrfs_root *root, u64 bytenr)
3947 {
3948 struct btrfs_delayed_ref_head *head;
3949 struct btrfs_delayed_ref_root *delayed_refs;
3950 struct btrfs_delayed_ref_node *ref;
3951 struct rb_node *node;
3952 int ret;
3953
3954 delayed_refs = &trans->transaction->delayed_refs;
3955 spin_lock(&delayed_refs->lock);
3956 head = btrfs_find_delayed_ref_head(trans, bytenr);
3957 if (!head)
3958 goto out;
3959
3960 node = rb_prev(&head->node.rb_node);
3961 if (!node)
3962 goto out;
3963
3964 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3965
3966 /* there are still entries for this ref, we can't drop it */
3967 if (ref->bytenr == bytenr)
3968 goto out;
3969
3970 if (head->extent_op) {
3971 if (!head->must_insert_reserved)
3972 goto out;
3973 kfree(head->extent_op);
3974 head->extent_op = NULL;
3975 }
3976
3977 /*
3978 * waiting for the lock here would deadlock. If someone else has it
3979 * locked they are already in the process of dropping it anyway
3980 */
3981 if (!mutex_trylock(&head->mutex))
3982 goto out;
3983
3984 /*
3985 * at this point we have a head with no other entries. Go
3986 * ahead and process it.
3987 */
3988 head->node.in_tree = 0;
3989 rb_erase(&head->node.rb_node, &delayed_refs->root);
3990
3991 delayed_refs->num_entries--;
3992
3993 /*
3994 * we don't take a ref on the node because we're removing it from the
3995 * tree, so we just steal the ref the tree was holding.
3996 */
3997 delayed_refs->num_heads--;
3998 if (list_empty(&head->cluster))
3999 delayed_refs->num_heads_ready--;
4000
4001 list_del_init(&head->cluster);
4002 spin_unlock(&delayed_refs->lock);
4003
4004 ret = run_one_delayed_ref(trans, root->fs_info->tree_root,
4005 &head->node, head->extent_op,
4006 head->must_insert_reserved);
4007 BUG_ON(ret);
4008 btrfs_put_delayed_ref(&head->node);
4009 return 0;
4010 out:
4011 spin_unlock(&delayed_refs->lock);
4012 return 0;
4013 }
4014
4015 int btrfs_free_extent(struct btrfs_trans_handle *trans,
4016 struct btrfs_root *root,
4017 u64 bytenr, u64 num_bytes, u64 parent,
4018 u64 root_objectid, u64 owner, u64 offset)
4019 {
4020 int ret;
4021
4022 /*
4023 * tree log blocks never actually go into the extent allocation
4024 * tree, just update pinning info and exit early.
4025 */
4026 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
4027 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
4028 /* unlocks the pinned mutex */
4029 btrfs_pin_extent(root, bytenr, num_bytes, 1);
4030 ret = 0;
4031 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
4032 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
4033 parent, root_objectid, (int)owner,
4034 BTRFS_DROP_DELAYED_REF, NULL);
4035 BUG_ON(ret);
4036 ret = check_ref_cleanup(trans, root, bytenr);
4037 BUG_ON(ret);
4038 } else {
4039 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
4040 parent, root_objectid, owner,
4041 offset, BTRFS_DROP_DELAYED_REF, NULL);
4042 BUG_ON(ret);
4043 }
4044 return ret;
4045 }
4046
4047 static u64 stripe_align(struct btrfs_root *root, u64 val)
4048 {
4049 u64 mask = ((u64)root->stripesize - 1);
4050 u64 ret = (val + mask) & ~mask;
4051 return ret;
4052 }
4053
4054 /*
4055 * when we wait for progress in the block group caching, its because
4056 * our allocation attempt failed at least once. So, we must sleep
4057 * and let some progress happen before we try again.
4058 *
4059 * This function will sleep at least once waiting for new free space to
4060 * show up, and then it will check the block group free space numbers
4061 * for our min num_bytes. Another option is to have it go ahead
4062 * and look in the rbtree for a free extent of a given size, but this
4063 * is a good start.
4064 */
4065 static noinline int
4066 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
4067 u64 num_bytes)
4068 {
4069 struct btrfs_caching_control *caching_ctl;
4070 DEFINE_WAIT(wait);
4071
4072 caching_ctl = get_caching_control(cache);
4073 if (!caching_ctl)
4074 return 0;
4075
4076 wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
4077 (cache->free_space >= num_bytes));
4078
4079 put_caching_control(caching_ctl);
4080 return 0;
4081 }
4082
4083 static noinline int
4084 wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
4085 {
4086 struct btrfs_caching_control *caching_ctl;
4087 DEFINE_WAIT(wait);
4088
4089 caching_ctl = get_caching_control(cache);
4090 if (!caching_ctl)
4091 return 0;
4092
4093 wait_event(caching_ctl->wait, block_group_cache_done(cache));
4094
4095 put_caching_control(caching_ctl);
4096 return 0;
4097 }
4098
4099 enum btrfs_loop_type {
4100 LOOP_CACHED_ONLY = 0,
4101 LOOP_CACHING_NOWAIT = 1,
4102 LOOP_CACHING_WAIT = 2,
4103 LOOP_ALLOC_CHUNK = 3,
4104 LOOP_NO_EMPTY_SIZE = 4,
4105 };
4106
4107 /*
4108 * walks the btree of allocated extents and find a hole of a given size.
4109 * The key ins is changed to record the hole:
4110 * ins->objectid == block start
4111 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4112 * ins->offset == number of blocks
4113 * Any available blocks before search_start are skipped.
4114 */
4115 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
4116 struct btrfs_root *orig_root,
4117 u64 num_bytes, u64 empty_size,
4118 u64 search_start, u64 search_end,
4119 u64 hint_byte, struct btrfs_key *ins,
4120 u64 exclude_start, u64 exclude_nr,
4121 int data)
4122 {
4123 int ret = 0;
4124 struct btrfs_root *root = orig_root->fs_info->extent_root;
4125 struct btrfs_free_cluster *last_ptr = NULL;
4126 struct btrfs_block_group_cache *block_group = NULL;
4127 int empty_cluster = 2 * 1024 * 1024;
4128 int allowed_chunk_alloc = 0;
4129 struct btrfs_space_info *space_info;
4130 int last_ptr_loop = 0;
4131 int loop = 0;
4132 bool found_uncached_bg = false;
4133 bool failed_cluster_refill = false;
4134 bool failed_alloc = false;
4135
4136 WARN_ON(num_bytes < root->sectorsize);
4137 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
4138 ins->objectid = 0;
4139 ins->offset = 0;
4140
4141 space_info = __find_space_info(root->fs_info, data);
4142
4143 if (orig_root->ref_cows || empty_size)
4144 allowed_chunk_alloc = 1;
4145
4146 if (data & BTRFS_BLOCK_GROUP_METADATA) {
4147 last_ptr = &root->fs_info->meta_alloc_cluster;
4148 if (!btrfs_test_opt(root, SSD))
4149 empty_cluster = 64 * 1024;
4150 }
4151
4152 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
4153 last_ptr = &root->fs_info->data_alloc_cluster;
4154 }
4155
4156 if (last_ptr) {
4157 spin_lock(&last_ptr->lock);
4158 if (last_ptr->block_group)
4159 hint_byte = last_ptr->window_start;
4160 spin_unlock(&last_ptr->lock);
4161 }
4162
4163 search_start = max(search_start, first_logical_byte(root, 0));
4164 search_start = max(search_start, hint_byte);
4165
4166 if (!last_ptr)
4167 empty_cluster = 0;
4168
4169 if (search_start == hint_byte) {
4170 block_group = btrfs_lookup_block_group(root->fs_info,
4171 search_start);
4172 /*
4173 * we don't want to use the block group if it doesn't match our
4174 * allocation bits, or if its not cached.
4175 */
4176 if (block_group && block_group_bits(block_group, data) &&
4177 block_group_cache_done(block_group)) {
4178 down_read(&space_info->groups_sem);
4179 if (list_empty(&block_group->list) ||
4180 block_group->ro) {
4181 /*
4182 * someone is removing this block group,
4183 * we can't jump into the have_block_group
4184 * target because our list pointers are not
4185 * valid
4186 */
4187 btrfs_put_block_group(block_group);
4188 up_read(&space_info->groups_sem);
4189 } else
4190 goto have_block_group;
4191 } else if (block_group) {
4192 btrfs_put_block_group(block_group);
4193 }
4194 }
4195
4196 search:
4197 down_read(&space_info->groups_sem);
4198 list_for_each_entry(block_group, &space_info->block_groups, list) {
4199 u64 offset;
4200 int cached;
4201
4202 atomic_inc(&block_group->count);
4203 search_start = block_group->key.objectid;
4204
4205 have_block_group:
4206 if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
4207 /*
4208 * we want to start caching kthreads, but not too many
4209 * right off the bat so we don't overwhelm the system,
4210 * so only start them if there are less than 2 and we're
4211 * in the initial allocation phase.
4212 */
4213 if (loop > LOOP_CACHING_NOWAIT ||
4214 atomic_read(&space_info->caching_threads) < 2) {
4215 ret = cache_block_group(block_group);
4216 BUG_ON(ret);
4217 }
4218 }
4219
4220 cached = block_group_cache_done(block_group);
4221 if (unlikely(!cached)) {
4222 found_uncached_bg = true;
4223
4224 /* if we only want cached bgs, loop */
4225 if (loop == LOOP_CACHED_ONLY)
4226 goto loop;
4227 }
4228
4229 if (unlikely(block_group->ro))
4230 goto loop;
4231
4232 /*
4233 * Ok we want to try and use the cluster allocator, so lets look
4234 * there, unless we are on LOOP_NO_EMPTY_SIZE, since we will
4235 * have tried the cluster allocator plenty of times at this
4236 * point and not have found anything, so we are likely way too
4237 * fragmented for the clustering stuff to find anything, so lets
4238 * just skip it and let the allocator find whatever block it can
4239 * find
4240 */
4241 if (last_ptr && loop < LOOP_NO_EMPTY_SIZE) {
4242 /*
4243 * the refill lock keeps out other
4244 * people trying to start a new cluster
4245 */
4246 spin_lock(&last_ptr->refill_lock);
4247 if (last_ptr->block_group &&
4248 (last_ptr->block_group->ro ||
4249 !block_group_bits(last_ptr->block_group, data))) {
4250 offset = 0;
4251 goto refill_cluster;
4252 }
4253
4254 offset = btrfs_alloc_from_cluster(block_group, last_ptr,
4255 num_bytes, search_start);
4256 if (offset) {
4257 /* we have a block, we're done */
4258 spin_unlock(&last_ptr->refill_lock);
4259 goto checks;
4260 }
4261
4262 spin_lock(&last_ptr->lock);
4263 /*
4264 * whoops, this cluster doesn't actually point to
4265 * this block group. Get a ref on the block
4266 * group is does point to and try again
4267 */
4268 if (!last_ptr_loop && last_ptr->block_group &&
4269 last_ptr->block_group != block_group) {
4270
4271 btrfs_put_block_group(block_group);
4272 block_group = last_ptr->block_group;
4273 atomic_inc(&block_group->count);
4274 spin_unlock(&last_ptr->lock);
4275 spin_unlock(&last_ptr->refill_lock);
4276
4277 last_ptr_loop = 1;
4278 search_start = block_group->key.objectid;
4279 /*
4280 * we know this block group is properly
4281 * in the list because
4282 * btrfs_remove_block_group, drops the
4283 * cluster before it removes the block
4284 * group from the list
4285 */
4286 goto have_block_group;
4287 }
4288 spin_unlock(&last_ptr->lock);
4289 refill_cluster:
4290 /*
4291 * this cluster didn't work out, free it and
4292 * start over
4293 */
4294 btrfs_return_cluster_to_free_space(NULL, last_ptr);
4295
4296 last_ptr_loop = 0;
4297
4298 /* allocate a cluster in this block group */
4299 ret = btrfs_find_space_cluster(trans, root,
4300 block_group, last_ptr,
4301 offset, num_bytes,
4302 empty_cluster + empty_size);
4303 if (ret == 0) {
4304 /*
4305 * now pull our allocation out of this
4306 * cluster
4307 */
4308 offset = btrfs_alloc_from_cluster(block_group,
4309 last_ptr, num_bytes,
4310 search_start);
4311 if (offset) {
4312 /* we found one, proceed */
4313 spin_unlock(&last_ptr->refill_lock);
4314 goto checks;
4315 }
4316 } else if (!cached && loop > LOOP_CACHING_NOWAIT
4317 && !failed_cluster_refill) {
4318 spin_unlock(&last_ptr->refill_lock);
4319
4320 failed_cluster_refill = true;
4321 wait_block_group_cache_progress(block_group,
4322 num_bytes + empty_cluster + empty_size);
4323 goto have_block_group;
4324 }
4325
4326 /*
4327 * at this point we either didn't find a cluster
4328 * or we weren't able to allocate a block from our
4329 * cluster. Free the cluster we've been trying
4330 * to use, and go to the next block group
4331 */
4332 btrfs_return_cluster_to_free_space(NULL, last_ptr);
4333 spin_unlock(&last_ptr->refill_lock);
4334 goto loop;
4335 }
4336
4337 offset = btrfs_find_space_for_alloc(block_group, search_start,
4338 num_bytes, empty_size);
4339 /*
4340 * If we didn't find a chunk, and we haven't failed on this
4341 * block group before, and this block group is in the middle of
4342 * caching and we are ok with waiting, then go ahead and wait
4343 * for progress to be made, and set failed_alloc to true.
4344 *
4345 * If failed_alloc is true then we've already waited on this
4346 * block group once and should move on to the next block group.
4347 */
4348 if (!offset && !failed_alloc && !cached &&
4349 loop > LOOP_CACHING_NOWAIT) {
4350 wait_block_group_cache_progress(block_group,
4351 num_bytes + empty_size);
4352 failed_alloc = true;
4353 goto have_block_group;
4354 } else if (!offset) {
4355 goto loop;
4356 }
4357 checks:
4358 search_start = stripe_align(root, offset);
4359 /* move on to the next group */
4360 if (search_start + num_bytes >= search_end) {
4361 btrfs_add_free_space(block_group, offset, num_bytes);
4362 goto loop;
4363 }
4364
4365 /* move on to the next group */
4366 if (search_start + num_bytes >
4367 block_group->key.objectid + block_group->key.offset) {
4368 btrfs_add_free_space(block_group, offset, num_bytes);
4369 goto loop;
4370 }
4371
4372 if (exclude_nr > 0 &&
4373 (search_start + num_bytes > exclude_start &&
4374 search_start < exclude_start + exclude_nr)) {
4375 search_start = exclude_start + exclude_nr;
4376
4377 btrfs_add_free_space(block_group, offset, num_bytes);
4378 /*
4379 * if search_start is still in this block group
4380 * then we just re-search this block group
4381 */
4382 if (search_start >= block_group->key.objectid &&
4383 search_start < (block_group->key.objectid +
4384 block_group->key.offset))
4385 goto have_block_group;
4386 goto loop;
4387 }
4388
4389 ins->objectid = search_start;
4390 ins->offset = num_bytes;
4391
4392 if (offset < search_start)
4393 btrfs_add_free_space(block_group, offset,
4394 search_start - offset);
4395 BUG_ON(offset > search_start);
4396
4397 update_reserved_extents(block_group, num_bytes, 1);
4398
4399 /* we are all good, lets return */
4400 break;
4401 loop:
4402 failed_cluster_refill = false;
4403 failed_alloc = false;
4404 btrfs_put_block_group(block_group);
4405 }
4406 up_read(&space_info->groups_sem);
4407
4408 /* LOOP_CACHED_ONLY, only search fully cached block groups
4409 * LOOP_CACHING_NOWAIT, search partially cached block groups, but
4410 * dont wait foR them to finish caching
4411 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
4412 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
4413 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
4414 * again
4415 */
4416 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE &&
4417 (found_uncached_bg || empty_size || empty_cluster ||
4418 allowed_chunk_alloc)) {
4419 if (found_uncached_bg) {
4420 found_uncached_bg = false;
4421 if (loop < LOOP_CACHING_WAIT) {
4422 loop++;
4423 goto search;
4424 }
4425 }
4426
4427 if (loop == LOOP_ALLOC_CHUNK) {
4428 empty_size = 0;
4429 empty_cluster = 0;
4430 }
4431
4432 if (allowed_chunk_alloc) {
4433 ret = do_chunk_alloc(trans, root, num_bytes +
4434 2 * 1024 * 1024, data, 1);
4435 allowed_chunk_alloc = 0;
4436 } else {
4437 space_info->force_alloc = 1;
4438 }
4439
4440 if (loop < LOOP_NO_EMPTY_SIZE) {
4441 loop++;
4442 goto search;
4443 }
4444 ret = -ENOSPC;
4445 } else if (!ins->objectid) {
4446 ret = -ENOSPC;
4447 }
4448
4449 /* we found what we needed */
4450 if (ins->objectid) {
4451 if (!(data & BTRFS_BLOCK_GROUP_DATA))
4452 trans->block_group = block_group->key.objectid;
4453
4454 btrfs_put_block_group(block_group);
4455 ret = 0;
4456 }
4457
4458 return ret;
4459 }
4460
4461 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
4462 int dump_block_groups)
4463 {
4464 struct btrfs_block_group_cache *cache;
4465
4466 spin_lock(&info->lock);
4467 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
4468 (unsigned long long)(info->total_bytes - info->bytes_used -
4469 info->bytes_pinned - info->bytes_reserved -
4470 info->bytes_super),
4471 (info->full) ? "" : "not ");
4472 printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu,"
4473 " may_use=%llu, used=%llu, root=%llu, super=%llu, reserved=%llu"
4474 "\n",
4475 (unsigned long long)info->total_bytes,
4476 (unsigned long long)info->bytes_pinned,
4477 (unsigned long long)info->bytes_delalloc,
4478 (unsigned long long)info->bytes_may_use,
4479 (unsigned long long)info->bytes_used,
4480 (unsigned long long)info->bytes_root,
4481 (unsigned long long)info->bytes_super,
4482 (unsigned long long)info->bytes_reserved);
4483 spin_unlock(&info->lock);
4484
4485 if (!dump_block_groups)
4486 return;
4487
4488 down_read(&info->groups_sem);
4489 list_for_each_entry(cache, &info->block_groups, list) {
4490 spin_lock(&cache->lock);
4491 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
4492 "%llu pinned %llu reserved\n",
4493 (unsigned long long)cache->key.objectid,
4494 (unsigned long long)cache->key.offset,
4495 (unsigned long long)btrfs_block_group_used(&cache->item),
4496 (unsigned long long)cache->pinned,
4497 (unsigned long long)cache->reserved);
4498 btrfs_dump_free_space(cache, bytes);
4499 spin_unlock(&cache->lock);
4500 }
4501 up_read(&info->groups_sem);
4502 }
4503
4504 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
4505 struct btrfs_root *root,
4506 u64 num_bytes, u64 min_alloc_size,
4507 u64 empty_size, u64 hint_byte,
4508 u64 search_end, struct btrfs_key *ins,
4509 u64 data)
4510 {
4511 int ret;
4512 u64 search_start = 0;
4513 struct btrfs_fs_info *info = root->fs_info;
4514
4515 data = btrfs_get_alloc_profile(root, data);
4516 again:
4517 /*
4518 * the only place that sets empty_size is btrfs_realloc_node, which
4519 * is not called recursively on allocations
4520 */
4521 if (empty_size || root->ref_cows) {
4522 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
4523 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4524 2 * 1024 * 1024,
4525 BTRFS_BLOCK_GROUP_METADATA |
4526 (info->metadata_alloc_profile &
4527 info->avail_metadata_alloc_bits), 0);
4528 }
4529 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4530 num_bytes + 2 * 1024 * 1024, data, 0);
4531 }
4532
4533 WARN_ON(num_bytes < root->sectorsize);
4534 ret = find_free_extent(trans, root, num_bytes, empty_size,
4535 search_start, search_end, hint_byte, ins,
4536 trans->alloc_exclude_start,
4537 trans->alloc_exclude_nr, data);
4538
4539 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
4540 num_bytes = num_bytes >> 1;
4541 num_bytes = num_bytes & ~(root->sectorsize - 1);
4542 num_bytes = max(num_bytes, min_alloc_size);
4543 do_chunk_alloc(trans, root->fs_info->extent_root,
4544 num_bytes, data, 1);
4545 goto again;
4546 }
4547 if (ret == -ENOSPC) {
4548 struct btrfs_space_info *sinfo;
4549
4550 sinfo = __find_space_info(root->fs_info, data);
4551 printk(KERN_ERR "btrfs allocation failed flags %llu, "
4552 "wanted %llu\n", (unsigned long long)data,
4553 (unsigned long long)num_bytes);
4554 dump_space_info(sinfo, num_bytes, 1);
4555 }
4556
4557 return ret;
4558 }
4559
4560 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
4561 {
4562 struct btrfs_block_group_cache *cache;
4563 int ret = 0;
4564
4565 cache = btrfs_lookup_block_group(root->fs_info, start);
4566 if (!cache) {
4567 printk(KERN_ERR "Unable to find block group for %llu\n",
4568 (unsigned long long)start);
4569 return -ENOSPC;
4570 }
4571
4572 ret = btrfs_discard_extent(root, start, len);
4573
4574 btrfs_add_free_space(cache, start, len);
4575 update_reserved_extents(cache, len, 0);
4576 btrfs_put_block_group(cache);
4577
4578 return ret;
4579 }
4580
4581 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4582 struct btrfs_root *root,
4583 u64 parent, u64 root_objectid,
4584 u64 flags, u64 owner, u64 offset,
4585 struct btrfs_key *ins, int ref_mod)
4586 {
4587 int ret;
4588 struct btrfs_fs_info *fs_info = root->fs_info;
4589 struct btrfs_extent_item *extent_item;
4590 struct btrfs_extent_inline_ref *iref;
4591 struct btrfs_path *path;
4592 struct extent_buffer *leaf;
4593 int type;
4594 u32 size;
4595
4596 if (parent > 0)
4597 type = BTRFS_SHARED_DATA_REF_KEY;
4598 else
4599 type = BTRFS_EXTENT_DATA_REF_KEY;
4600
4601 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
4602
4603 path = btrfs_alloc_path();
4604 BUG_ON(!path);
4605
4606 path->leave_spinning = 1;
4607 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4608 ins, size);
4609 BUG_ON(ret);
4610
4611 leaf = path->nodes[0];
4612 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4613 struct btrfs_extent_item);
4614 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
4615 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4616 btrfs_set_extent_flags(leaf, extent_item,
4617 flags | BTRFS_EXTENT_FLAG_DATA);
4618
4619 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
4620 btrfs_set_extent_inline_ref_type(leaf, iref, type);
4621 if (parent > 0) {
4622 struct btrfs_shared_data_ref *ref;
4623 ref = (struct btrfs_shared_data_ref *)(iref + 1);
4624 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4625 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
4626 } else {
4627 struct btrfs_extent_data_ref *ref;
4628 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
4629 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
4630 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
4631 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
4632 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
4633 }
4634
4635 btrfs_mark_buffer_dirty(path->nodes[0]);
4636 btrfs_free_path(path);
4637
4638 ret = update_block_group(trans, root, ins->objectid, ins->offset,
4639 1, 0);
4640 if (ret) {
4641 printk(KERN_ERR "btrfs update block group failed for %llu "
4642 "%llu\n", (unsigned long long)ins->objectid,
4643 (unsigned long long)ins->offset);
4644 BUG();
4645 }
4646 return ret;
4647 }
4648
4649 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
4650 struct btrfs_root *root,
4651 u64 parent, u64 root_objectid,
4652 u64 flags, struct btrfs_disk_key *key,
4653 int level, struct btrfs_key *ins)
4654 {
4655 int ret;
4656 struct btrfs_fs_info *fs_info = root->fs_info;
4657 struct btrfs_extent_item *extent_item;
4658 struct btrfs_tree_block_info *block_info;
4659 struct btrfs_extent_inline_ref *iref;
4660 struct btrfs_path *path;
4661 struct extent_buffer *leaf;
4662 u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
4663
4664 path = btrfs_alloc_path();
4665 BUG_ON(!path);
4666
4667 path->leave_spinning = 1;
4668 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4669 ins, size);
4670 BUG_ON(ret);
4671
4672 leaf = path->nodes[0];
4673 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4674 struct btrfs_extent_item);
4675 btrfs_set_extent_refs(leaf, extent_item, 1);
4676 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4677 btrfs_set_extent_flags(leaf, extent_item,
4678 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
4679 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
4680
4681 btrfs_set_tree_block_key(leaf, block_info, key);
4682 btrfs_set_tree_block_level(leaf, block_info, level);
4683
4684 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
4685 if (parent > 0) {
4686 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
4687 btrfs_set_extent_inline_ref_type(leaf, iref,
4688 BTRFS_SHARED_BLOCK_REF_KEY);
4689 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4690 } else {
4691 btrfs_set_extent_inline_ref_type(leaf, iref,
4692 BTRFS_TREE_BLOCK_REF_KEY);
4693 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
4694 }
4695
4696 btrfs_mark_buffer_dirty(leaf);
4697 btrfs_free_path(path);
4698
4699 ret = update_block_group(trans, root, ins->objectid, ins->offset,
4700 1, 0);
4701 if (ret) {
4702 printk(KERN_ERR "btrfs update block group failed for %llu "
4703 "%llu\n", (unsigned long long)ins->objectid,
4704 (unsigned long long)ins->offset);
4705 BUG();
4706 }
4707 return ret;
4708 }
4709
4710 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4711 struct btrfs_root *root,
4712 u64 root_objectid, u64 owner,
4713 u64 offset, struct btrfs_key *ins)
4714 {
4715 int ret;
4716
4717 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
4718
4719 ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
4720 0, root_objectid, owner, offset,
4721 BTRFS_ADD_DELAYED_EXTENT, NULL);
4722 return ret;
4723 }
4724
4725 /*
4726 * this is used by the tree logging recovery code. It records that
4727 * an extent has been allocated and makes sure to clear the free
4728 * space cache bits as well
4729 */
4730 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
4731 struct btrfs_root *root,
4732 u64 root_objectid, u64 owner, u64 offset,
4733 struct btrfs_key *ins)
4734 {
4735 int ret;
4736 struct btrfs_block_group_cache *block_group;
4737 struct btrfs_caching_control *caching_ctl;
4738 u64 start = ins->objectid;
4739 u64 num_bytes = ins->offset;
4740
4741 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
4742 cache_block_group(block_group);
4743 caching_ctl = get_caching_control(block_group);
4744
4745 if (!caching_ctl) {
4746 BUG_ON(!block_group_cache_done(block_group));
4747 ret = btrfs_remove_free_space(block_group, start, num_bytes);
4748 BUG_ON(ret);
4749 } else {
4750 mutex_lock(&caching_ctl->mutex);
4751
4752 if (start >= caching_ctl->progress) {
4753 ret = add_excluded_extent(root, start, num_bytes);
4754 BUG_ON(ret);
4755 } else if (start + num_bytes <= caching_ctl->progress) {
4756 ret = btrfs_remove_free_space(block_group,
4757 start, num_bytes);
4758 BUG_ON(ret);
4759 } else {
4760 num_bytes = caching_ctl->progress - start;
4761 ret = btrfs_remove_free_space(block_group,
4762 start, num_bytes);
4763 BUG_ON(ret);
4764
4765 start = caching_ctl->progress;
4766 num_bytes = ins->objectid + ins->offset -
4767 caching_ctl->progress;
4768 ret = add_excluded_extent(root, start, num_bytes);
4769 BUG_ON(ret);
4770 }
4771
4772 mutex_unlock(&caching_ctl->mutex);
4773 put_caching_control(caching_ctl);
4774 }
4775
4776 update_reserved_extents(block_group, ins->offset, 1);
4777 btrfs_put_block_group(block_group);
4778 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
4779 0, owner, offset, ins, 1);
4780 return ret;
4781 }
4782
4783 /*
4784 * finds a free extent and does all the dirty work required for allocation
4785 * returns the key for the extent through ins, and a tree buffer for
4786 * the first block of the extent through buf.
4787 *
4788 * returns 0 if everything worked, non-zero otherwise.
4789 */
4790 static int alloc_tree_block(struct btrfs_trans_handle *trans,
4791 struct btrfs_root *root,
4792 u64 num_bytes, u64 parent, u64 root_objectid,
4793 struct btrfs_disk_key *key, int level,
4794 u64 empty_size, u64 hint_byte, u64 search_end,
4795 struct btrfs_key *ins)
4796 {
4797 int ret;
4798 u64 flags = 0;
4799
4800 ret = btrfs_reserve_extent(trans, root, num_bytes, num_bytes,
4801 empty_size, hint_byte, search_end,
4802 ins, 0);
4803 if (ret)
4804 return ret;
4805
4806 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
4807 if (parent == 0)
4808 parent = ins->objectid;
4809 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
4810 } else
4811 BUG_ON(parent > 0);
4812
4813 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
4814 struct btrfs_delayed_extent_op *extent_op;
4815 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
4816 BUG_ON(!extent_op);
4817 if (key)
4818 memcpy(&extent_op->key, key, sizeof(extent_op->key));
4819 else
4820 memset(&extent_op->key, 0, sizeof(extent_op->key));
4821 extent_op->flags_to_set = flags;
4822 extent_op->update_key = 1;
4823 extent_op->update_flags = 1;
4824 extent_op->is_data = 0;
4825
4826 ret = btrfs_add_delayed_tree_ref(trans, ins->objectid,
4827 ins->offset, parent, root_objectid,
4828 level, BTRFS_ADD_DELAYED_EXTENT,
4829 extent_op);
4830 BUG_ON(ret);
4831 }
4832 return ret;
4833 }
4834
4835 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
4836 struct btrfs_root *root,
4837 u64 bytenr, u32 blocksize,
4838 int level)
4839 {
4840 struct extent_buffer *buf;
4841
4842 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
4843 if (!buf)
4844 return ERR_PTR(-ENOMEM);
4845 btrfs_set_header_generation(buf, trans->transid);
4846 btrfs_set_buffer_lockdep_class(buf, level);
4847 btrfs_tree_lock(buf);
4848 clean_tree_block(trans, root, buf);
4849
4850 btrfs_set_lock_blocking(buf);
4851 btrfs_set_buffer_uptodate(buf);
4852
4853 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
4854 set_extent_dirty(&root->dirty_log_pages, buf->start,
4855 buf->start + buf->len - 1, GFP_NOFS);
4856 } else {
4857 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
4858 buf->start + buf->len - 1, GFP_NOFS);
4859 }
4860 trans->blocks_used++;
4861 /* this returns a buffer locked for blocking */
4862 return buf;
4863 }
4864
4865 /*
4866 * helper function to allocate a block for a given tree
4867 * returns the tree buffer or NULL.
4868 */
4869 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
4870 struct btrfs_root *root, u32 blocksize,
4871 u64 parent, u64 root_objectid,
4872 struct btrfs_disk_key *key, int level,
4873 u64 hint, u64 empty_size)
4874 {
4875 struct btrfs_key ins;
4876 int ret;
4877 struct extent_buffer *buf;
4878
4879 ret = alloc_tree_block(trans, root, blocksize, parent, root_objectid,
4880 key, level, empty_size, hint, (u64)-1, &ins);
4881 if (ret) {
4882 BUG_ON(ret > 0);
4883 return ERR_PTR(ret);
4884 }
4885
4886 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
4887 blocksize, level);
4888 return buf;
4889 }
4890
4891 struct walk_control {
4892 u64 refs[BTRFS_MAX_LEVEL];
4893 u64 flags[BTRFS_MAX_LEVEL];
4894 struct btrfs_key update_progress;
4895 int stage;
4896 int level;
4897 int shared_level;
4898 int update_ref;
4899 int keep_locks;
4900 int reada_slot;
4901 int reada_count;
4902 };
4903
4904 #define DROP_REFERENCE 1
4905 #define UPDATE_BACKREF 2
4906
4907 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
4908 struct btrfs_root *root,
4909 struct walk_control *wc,
4910 struct btrfs_path *path)
4911 {
4912 u64 bytenr;
4913 u64 generation;
4914 u64 refs;
4915 u64 flags;
4916 u64 last = 0;
4917 u32 nritems;
4918 u32 blocksize;
4919 struct btrfs_key key;
4920 struct extent_buffer *eb;
4921 int ret;
4922 int slot;
4923 int nread = 0;
4924
4925 if (path->slots[wc->level] < wc->reada_slot) {
4926 wc->reada_count = wc->reada_count * 2 / 3;
4927 wc->reada_count = max(wc->reada_count, 2);
4928 } else {
4929 wc->reada_count = wc->reada_count * 3 / 2;
4930 wc->reada_count = min_t(int, wc->reada_count,
4931 BTRFS_NODEPTRS_PER_BLOCK(root));
4932 }
4933
4934 eb = path->nodes[wc->level];
4935 nritems = btrfs_header_nritems(eb);
4936 blocksize = btrfs_level_size(root, wc->level - 1);
4937
4938 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
4939 if (nread >= wc->reada_count)
4940 break;
4941
4942 cond_resched();
4943 bytenr = btrfs_node_blockptr(eb, slot);
4944 generation = btrfs_node_ptr_generation(eb, slot);
4945
4946 if (slot == path->slots[wc->level])
4947 goto reada;
4948
4949 if (wc->stage == UPDATE_BACKREF &&
4950 generation <= root->root_key.offset)
4951 continue;
4952
4953 /* We don't lock the tree block, it's OK to be racy here */
4954 ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
4955 &refs, &flags);
4956 BUG_ON(ret);
4957 BUG_ON(refs == 0);
4958
4959 if (wc->stage == DROP_REFERENCE) {
4960 if (refs == 1)
4961 goto reada;
4962
4963 if (wc->level == 1 &&
4964 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
4965 continue;
4966 if (!wc->update_ref ||
4967 generation <= root->root_key.offset)
4968 continue;
4969 btrfs_node_key_to_cpu(eb, &key, slot);
4970 ret = btrfs_comp_cpu_keys(&key,
4971 &wc->update_progress);
4972 if (ret < 0)
4973 continue;
4974 } else {
4975 if (wc->level == 1 &&
4976 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
4977 continue;
4978 }
4979 reada:
4980 ret = readahead_tree_block(root, bytenr, blocksize,
4981 generation);
4982 if (ret)
4983 break;
4984 last = bytenr + blocksize;
4985 nread++;
4986 }
4987 wc->reada_slot = slot;
4988 }
4989
4990 /*
4991 * hepler to process tree block while walking down the tree.
4992 *
4993 * when wc->stage == UPDATE_BACKREF, this function updates
4994 * back refs for pointers in the block.
4995 *
4996 * NOTE: return value 1 means we should stop walking down.
4997 */
4998 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
4999 struct btrfs_root *root,
5000 struct btrfs_path *path,
5001 struct walk_control *wc, int lookup_info)
5002 {
5003 int level = wc->level;
5004 struct extent_buffer *eb = path->nodes[level];
5005 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5006 int ret;
5007
5008 if (wc->stage == UPDATE_BACKREF &&
5009 btrfs_header_owner(eb) != root->root_key.objectid)
5010 return 1;
5011
5012 /*
5013 * when reference count of tree block is 1, it won't increase
5014 * again. once full backref flag is set, we never clear it.
5015 */
5016 if (lookup_info &&
5017 ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
5018 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
5019 BUG_ON(!path->locks[level]);
5020 ret = btrfs_lookup_extent_info(trans, root,
5021 eb->start, eb->len,
5022 &wc->refs[level],
5023 &wc->flags[level]);
5024 BUG_ON(ret);
5025 BUG_ON(wc->refs[level] == 0);
5026 }
5027
5028 if (wc->stage == DROP_REFERENCE) {
5029 if (wc->refs[level] > 1)
5030 return 1;
5031
5032 if (path->locks[level] && !wc->keep_locks) {
5033 btrfs_tree_unlock(eb);
5034 path->locks[level] = 0;
5035 }
5036 return 0;
5037 }
5038
5039 /* wc->stage == UPDATE_BACKREF */
5040 if (!(wc->flags[level] & flag)) {
5041 BUG_ON(!path->locks[level]);
5042 ret = btrfs_inc_ref(trans, root, eb, 1);
5043 BUG_ON(ret);
5044 ret = btrfs_dec_ref(trans, root, eb, 0);
5045 BUG_ON(ret);
5046 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
5047 eb->len, flag, 0);
5048 BUG_ON(ret);
5049 wc->flags[level] |= flag;
5050 }
5051
5052 /*
5053 * the block is shared by multiple trees, so it's not good to
5054 * keep the tree lock
5055 */
5056 if (path->locks[level] && level > 0) {
5057 btrfs_tree_unlock(eb);
5058 path->locks[level] = 0;
5059 }
5060 return 0;
5061 }
5062
5063 /*
5064 * hepler to process tree block pointer.
5065 *
5066 * when wc->stage == DROP_REFERENCE, this function checks
5067 * reference count of the block pointed to. if the block
5068 * is shared and we need update back refs for the subtree
5069 * rooted at the block, this function changes wc->stage to
5070 * UPDATE_BACKREF. if the block is shared and there is no
5071 * need to update back, this function drops the reference
5072 * to the block.
5073 *
5074 * NOTE: return value 1 means we should stop walking down.
5075 */
5076 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
5077 struct btrfs_root *root,
5078 struct btrfs_path *path,
5079 struct walk_control *wc, int *lookup_info)
5080 {
5081 u64 bytenr;
5082 u64 generation;
5083 u64 parent;
5084 u32 blocksize;
5085 struct btrfs_key key;
5086 struct extent_buffer *next;
5087 int level = wc->level;
5088 int reada = 0;
5089 int ret = 0;
5090
5091 generation = btrfs_node_ptr_generation(path->nodes[level],
5092 path->slots[level]);
5093 /*
5094 * if the lower level block was created before the snapshot
5095 * was created, we know there is no need to update back refs
5096 * for the subtree
5097 */
5098 if (wc->stage == UPDATE_BACKREF &&
5099 generation <= root->root_key.offset) {
5100 *lookup_info = 1;
5101 return 1;
5102 }
5103
5104 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
5105 blocksize = btrfs_level_size(root, level - 1);
5106
5107 next = btrfs_find_tree_block(root, bytenr, blocksize);
5108 if (!next) {
5109 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
5110 reada = 1;
5111 }
5112 btrfs_tree_lock(next);
5113 btrfs_set_lock_blocking(next);
5114
5115 ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
5116 &wc->refs[level - 1],
5117 &wc->flags[level - 1]);
5118 BUG_ON(ret);
5119 BUG_ON(wc->refs[level - 1] == 0);
5120 *lookup_info = 0;
5121
5122 if (wc->stage == DROP_REFERENCE) {
5123 if (wc->refs[level - 1] > 1) {
5124 if (level == 1 &&
5125 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5126 goto skip;
5127
5128 if (!wc->update_ref ||
5129 generation <= root->root_key.offset)
5130 goto skip;
5131
5132 btrfs_node_key_to_cpu(path->nodes[level], &key,
5133 path->slots[level]);
5134 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
5135 if (ret < 0)
5136 goto skip;
5137
5138 wc->stage = UPDATE_BACKREF;
5139 wc->shared_level = level - 1;
5140 }
5141 } else {
5142 if (level == 1 &&
5143 (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
5144 goto skip;
5145 }
5146
5147 if (!btrfs_buffer_uptodate(next, generation)) {
5148 btrfs_tree_unlock(next);
5149 free_extent_buffer(next);
5150 next = NULL;
5151 *lookup_info = 1;
5152 }
5153
5154 if (!next) {
5155 if (reada && level == 1)
5156 reada_walk_down(trans, root, wc, path);
5157 next = read_tree_block(root, bytenr, blocksize, generation);
5158 btrfs_tree_lock(next);
5159 btrfs_set_lock_blocking(next);
5160 }
5161
5162 level--;
5163 BUG_ON(level != btrfs_header_level(next));
5164 path->nodes[level] = next;
5165 path->slots[level] = 0;
5166 path->locks[level] = 1;
5167 wc->level = level;
5168 if (wc->level == 1)
5169 wc->reada_slot = 0;
5170 return 0;
5171 skip:
5172 wc->refs[level - 1] = 0;
5173 wc->flags[level - 1] = 0;
5174 if (wc->stage == DROP_REFERENCE) {
5175 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
5176 parent = path->nodes[level]->start;
5177 } else {
5178 BUG_ON(root->root_key.objectid !=
5179 btrfs_header_owner(path->nodes[level]));
5180 parent = 0;
5181 }
5182
5183 ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
5184 root->root_key.objectid, level - 1, 0);
5185 BUG_ON(ret);
5186 }
5187 btrfs_tree_unlock(next);
5188 free_extent_buffer(next);
5189 *lookup_info = 1;
5190 return 1;
5191 }
5192
5193 /*
5194 * hepler to process tree block while walking up the tree.
5195 *
5196 * when wc->stage == DROP_REFERENCE, this function drops
5197 * reference count on the block.
5198 *
5199 * when wc->stage == UPDATE_BACKREF, this function changes
5200 * wc->stage back to DROP_REFERENCE if we changed wc->stage
5201 * to UPDATE_BACKREF previously while processing the block.
5202 *
5203 * NOTE: return value 1 means we should stop walking up.
5204 */
5205 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
5206 struct btrfs_root *root,
5207 struct btrfs_path *path,
5208 struct walk_control *wc)
5209 {
5210 int ret = 0;
5211 int level = wc->level;
5212 struct extent_buffer *eb = path->nodes[level];
5213 u64 parent = 0;
5214
5215 if (wc->stage == UPDATE_BACKREF) {
5216 BUG_ON(wc->shared_level < level);
5217 if (level < wc->shared_level)
5218 goto out;
5219
5220 ret = find_next_key(path, level + 1, &wc->update_progress);
5221 if (ret > 0)
5222 wc->update_ref = 0;
5223
5224 wc->stage = DROP_REFERENCE;
5225 wc->shared_level = -1;
5226 path->slots[level] = 0;
5227
5228 /*
5229 * check reference count again if the block isn't locked.
5230 * we should start walking down the tree again if reference
5231 * count is one.
5232 */
5233 if (!path->locks[level]) {
5234 BUG_ON(level == 0);
5235 btrfs_tree_lock(eb);
5236 btrfs_set_lock_blocking(eb);
5237 path->locks[level] = 1;
5238
5239 ret = btrfs_lookup_extent_info(trans, root,
5240 eb->start, eb->len,
5241 &wc->refs[level],
5242 &wc->flags[level]);
5243 BUG_ON(ret);
5244 BUG_ON(wc->refs[level] == 0);
5245 if (wc->refs[level] == 1) {
5246 btrfs_tree_unlock(eb);
5247 path->locks[level] = 0;
5248 return 1;
5249 }
5250 }
5251 }
5252
5253 /* wc->stage == DROP_REFERENCE */
5254 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
5255
5256 if (wc->refs[level] == 1) {
5257 if (level == 0) {
5258 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5259 ret = btrfs_dec_ref(trans, root, eb, 1);
5260 else
5261 ret = btrfs_dec_ref(trans, root, eb, 0);
5262 BUG_ON(ret);
5263 }
5264 /* make block locked assertion in clean_tree_block happy */
5265 if (!path->locks[level] &&
5266 btrfs_header_generation(eb) == trans->transid) {
5267 btrfs_tree_lock(eb);
5268 btrfs_set_lock_blocking(eb);
5269 path->locks[level] = 1;
5270 }
5271 clean_tree_block(trans, root, eb);
5272 }
5273
5274 if (eb == root->node) {
5275 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5276 parent = eb->start;
5277 else
5278 BUG_ON(root->root_key.objectid !=
5279 btrfs_header_owner(eb));
5280 } else {
5281 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5282 parent = path->nodes[level + 1]->start;
5283 else
5284 BUG_ON(root->root_key.objectid !=
5285 btrfs_header_owner(path->nodes[level + 1]));
5286 }
5287
5288 ret = btrfs_free_extent(trans, root, eb->start, eb->len, parent,
5289 root->root_key.objectid, level, 0);
5290 BUG_ON(ret);
5291 out:
5292 wc->refs[level] = 0;
5293 wc->flags[level] = 0;
5294 return ret;
5295 }
5296
5297 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
5298 struct btrfs_root *root,
5299 struct btrfs_path *path,
5300 struct walk_control *wc)
5301 {
5302 int level = wc->level;
5303 int lookup_info = 1;
5304 int ret;
5305
5306 while (level >= 0) {
5307 if (path->slots[level] >=
5308 btrfs_header_nritems(path->nodes[level]))
5309 break;
5310
5311 ret = walk_down_proc(trans, root, path, wc, lookup_info);
5312 if (ret > 0)
5313 break;
5314
5315 if (level == 0)
5316 break;
5317
5318 ret = do_walk_down(trans, root, path, wc, &lookup_info);
5319 if (ret > 0) {
5320 path->slots[level]++;
5321 continue;
5322 }
5323 level = wc->level;
5324 }
5325 return 0;
5326 }
5327
5328 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
5329 struct btrfs_root *root,
5330 struct btrfs_path *path,
5331 struct walk_control *wc, int max_level)
5332 {
5333 int level = wc->level;
5334 int ret;
5335
5336 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
5337 while (level < max_level && path->nodes[level]) {
5338 wc->level = level;
5339 if (path->slots[level] + 1 <
5340 btrfs_header_nritems(path->nodes[level])) {
5341 path->slots[level]++;
5342 return 0;
5343 } else {
5344 ret = walk_up_proc(trans, root, path, wc);
5345 if (ret > 0)
5346 return 0;
5347
5348 if (path->locks[level]) {
5349 btrfs_tree_unlock(path->nodes[level]);
5350 path->locks[level] = 0;
5351 }
5352 free_extent_buffer(path->nodes[level]);
5353 path->nodes[level] = NULL;
5354 level++;
5355 }
5356 }
5357 return 1;
5358 }
5359
5360 /*
5361 * drop a subvolume tree.
5362 *
5363 * this function traverses the tree freeing any blocks that only
5364 * referenced by the tree.
5365 *
5366 * when a shared tree block is found. this function decreases its
5367 * reference count by one. if update_ref is true, this function
5368 * also make sure backrefs for the shared block and all lower level
5369 * blocks are properly updated.
5370 */
5371 int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref)
5372 {
5373 struct btrfs_path *path;
5374 struct btrfs_trans_handle *trans;
5375 struct btrfs_root *tree_root = root->fs_info->tree_root;
5376 struct btrfs_root_item *root_item = &root->root_item;
5377 struct walk_control *wc;
5378 struct btrfs_key key;
5379 int err = 0;
5380 int ret;
5381 int level;
5382
5383 path = btrfs_alloc_path();
5384 BUG_ON(!path);
5385
5386 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5387 BUG_ON(!wc);
5388
5389 trans = btrfs_start_transaction(tree_root, 1);
5390
5391 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
5392 level = btrfs_header_level(root->node);
5393 path->nodes[level] = btrfs_lock_root_node(root);
5394 btrfs_set_lock_blocking(path->nodes[level]);
5395 path->slots[level] = 0;
5396 path->locks[level] = 1;
5397 memset(&wc->update_progress, 0,
5398 sizeof(wc->update_progress));
5399 } else {
5400 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
5401 memcpy(&wc->update_progress, &key,
5402 sizeof(wc->update_progress));
5403
5404 level = root_item->drop_level;
5405 BUG_ON(level == 0);
5406 path->lowest_level = level;
5407 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5408 path->lowest_level = 0;
5409 if (ret < 0) {
5410 err = ret;
5411 goto out;
5412 }
5413 WARN_ON(ret > 0);
5414
5415 /*
5416 * unlock our path, this is safe because only this
5417 * function is allowed to delete this snapshot
5418 */
5419 btrfs_unlock_up_safe(path, 0);
5420
5421 level = btrfs_header_level(root->node);
5422 while (1) {
5423 btrfs_tree_lock(path->nodes[level]);
5424 btrfs_set_lock_blocking(path->nodes[level]);
5425
5426 ret = btrfs_lookup_extent_info(trans, root,
5427 path->nodes[level]->start,
5428 path->nodes[level]->len,
5429 &wc->refs[level],
5430 &wc->flags[level]);
5431 BUG_ON(ret);
5432 BUG_ON(wc->refs[level] == 0);
5433
5434 if (level == root_item->drop_level)
5435 break;
5436
5437 btrfs_tree_unlock(path->nodes[level]);
5438 WARN_ON(wc->refs[level] != 1);
5439 level--;
5440 }
5441 }
5442
5443 wc->level = level;
5444 wc->shared_level = -1;
5445 wc->stage = DROP_REFERENCE;
5446 wc->update_ref = update_ref;
5447 wc->keep_locks = 0;
5448 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
5449
5450 while (1) {
5451 ret = walk_down_tree(trans, root, path, wc);
5452 if (ret < 0) {
5453 err = ret;
5454 break;
5455 }
5456
5457 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
5458 if (ret < 0) {
5459 err = ret;
5460 break;
5461 }
5462
5463 if (ret > 0) {
5464 BUG_ON(wc->stage != DROP_REFERENCE);
5465 break;
5466 }
5467
5468 if (wc->stage == DROP_REFERENCE) {
5469 level = wc->level;
5470 btrfs_node_key(path->nodes[level],
5471 &root_item->drop_progress,
5472 path->slots[level]);
5473 root_item->drop_level = level;
5474 }
5475
5476 BUG_ON(wc->level == 0);
5477 if (trans->transaction->in_commit ||
5478 trans->transaction->delayed_refs.flushing) {
5479 ret = btrfs_update_root(trans, tree_root,
5480 &root->root_key,
5481 root_item);
5482 BUG_ON(ret);
5483
5484 btrfs_end_transaction(trans, tree_root);
5485 trans = btrfs_start_transaction(tree_root, 1);
5486 } else {
5487 unsigned long update;
5488 update = trans->delayed_ref_updates;
5489 trans->delayed_ref_updates = 0;
5490 if (update)
5491 btrfs_run_delayed_refs(trans, tree_root,
5492 update);
5493 }
5494 }
5495 btrfs_release_path(root, path);
5496 BUG_ON(err);
5497
5498 ret = btrfs_del_root(trans, tree_root, &root->root_key);
5499 BUG_ON(ret);
5500
5501 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
5502 ret = btrfs_find_last_root(tree_root, root->root_key.objectid,
5503 NULL, NULL);
5504 BUG_ON(ret < 0);
5505 if (ret > 0) {
5506 ret = btrfs_del_orphan_item(trans, tree_root,
5507 root->root_key.objectid);
5508 BUG_ON(ret);
5509 }
5510 }
5511
5512 if (root->in_radix) {
5513 btrfs_free_fs_root(tree_root->fs_info, root);
5514 } else {
5515 free_extent_buffer(root->node);
5516 free_extent_buffer(root->commit_root);
5517 kfree(root);
5518 }
5519 out:
5520 btrfs_end_transaction(trans, tree_root);
5521 kfree(wc);
5522 btrfs_free_path(path);
5523 return err;
5524 }
5525
5526 /*
5527 * drop subtree rooted at tree block 'node'.
5528 *
5529 * NOTE: this function will unlock and release tree block 'node'
5530 */
5531 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
5532 struct btrfs_root *root,
5533 struct extent_buffer *node,
5534 struct extent_buffer *parent)
5535 {
5536 struct btrfs_path *path;
5537 struct walk_control *wc;
5538 int level;
5539 int parent_level;
5540 int ret = 0;
5541 int wret;
5542
5543 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5544
5545 path = btrfs_alloc_path();
5546 BUG_ON(!path);
5547
5548 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5549 BUG_ON(!wc);
5550
5551 btrfs_assert_tree_locked(parent);
5552 parent_level = btrfs_header_level(parent);
5553 extent_buffer_get(parent);
5554 path->nodes[parent_level] = parent;
5555 path->slots[parent_level] = btrfs_header_nritems(parent);
5556
5557 btrfs_assert_tree_locked(node);
5558 level = btrfs_header_level(node);
5559 path->nodes[level] = node;
5560 path->slots[level] = 0;
5561 path->locks[level] = 1;
5562
5563 wc->refs[parent_level] = 1;
5564 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5565 wc->level = level;
5566 wc->shared_level = -1;
5567 wc->stage = DROP_REFERENCE;
5568 wc->update_ref = 0;
5569 wc->keep_locks = 1;
5570 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
5571
5572 while (1) {
5573 wret = walk_down_tree(trans, root, path, wc);
5574 if (wret < 0) {
5575 ret = wret;
5576 break;
5577 }
5578
5579 wret = walk_up_tree(trans, root, path, wc, parent_level);
5580 if (wret < 0)
5581 ret = wret;
5582 if (wret != 0)
5583 break;
5584 }
5585
5586 kfree(wc);
5587 btrfs_free_path(path);
5588 return ret;
5589 }
5590
5591 #if 0
5592 static unsigned long calc_ra(unsigned long start, unsigned long last,
5593 unsigned long nr)
5594 {
5595 return min(last, start + nr - 1);
5596 }
5597
5598 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
5599 u64 len)
5600 {
5601 u64 page_start;
5602 u64 page_end;
5603 unsigned long first_index;
5604 unsigned long last_index;
5605 unsigned long i;
5606 struct page *page;
5607 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5608 struct file_ra_state *ra;
5609 struct btrfs_ordered_extent *ordered;
5610 unsigned int total_read = 0;
5611 unsigned int total_dirty = 0;
5612 int ret = 0;
5613
5614 ra = kzalloc(sizeof(*ra), GFP_NOFS);
5615
5616 mutex_lock(&inode->i_mutex);
5617 first_index = start >> PAGE_CACHE_SHIFT;
5618 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
5619
5620 /* make sure the dirty trick played by the caller work */
5621 ret = invalidate_inode_pages2_range(inode->i_mapping,
5622 first_index, last_index);
5623 if (ret)
5624 goto out_unlock;
5625
5626 file_ra_state_init(ra, inode->i_mapping);
5627
5628 for (i = first_index ; i <= last_index; i++) {
5629 if (total_read % ra->ra_pages == 0) {
5630 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
5631 calc_ra(i, last_index, ra->ra_pages));
5632 }
5633 total_read++;
5634 again:
5635 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
5636 BUG_ON(1);
5637 page = grab_cache_page(inode->i_mapping, i);
5638 if (!page) {
5639 ret = -ENOMEM;
5640 goto out_unlock;
5641 }
5642 if (!PageUptodate(page)) {
5643 btrfs_readpage(NULL, page);
5644 lock_page(page);
5645 if (!PageUptodate(page)) {
5646 unlock_page(page);
5647 page_cache_release(page);
5648 ret = -EIO;
5649 goto out_unlock;
5650 }
5651 }
5652 wait_on_page_writeback(page);
5653
5654 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
5655 page_end = page_start + PAGE_CACHE_SIZE - 1;
5656 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
5657
5658 ordered = btrfs_lookup_ordered_extent(inode, page_start);
5659 if (ordered) {
5660 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5661 unlock_page(page);
5662 page_cache_release(page);
5663 btrfs_start_ordered_extent(inode, ordered, 1);
5664 btrfs_put_ordered_extent(ordered);
5665 goto again;
5666 }
5667 set_page_extent_mapped(page);
5668
5669 if (i == first_index)
5670 set_extent_bits(io_tree, page_start, page_end,
5671 EXTENT_BOUNDARY, GFP_NOFS);
5672 btrfs_set_extent_delalloc(inode, page_start, page_end);
5673
5674 set_page_dirty(page);
5675 total_dirty++;
5676
5677 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5678 unlock_page(page);
5679 page_cache_release(page);
5680 }
5681
5682 out_unlock:
5683 kfree(ra);
5684 mutex_unlock(&inode->i_mutex);
5685 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
5686 return ret;
5687 }
5688
5689 static noinline int relocate_data_extent(struct inode *reloc_inode,
5690 struct btrfs_key *extent_key,
5691 u64 offset)
5692 {
5693 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5694 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
5695 struct extent_map *em;
5696 u64 start = extent_key->objectid - offset;
5697 u64 end = start + extent_key->offset - 1;
5698
5699 em = alloc_extent_map(GFP_NOFS);
5700 BUG_ON(!em || IS_ERR(em));
5701
5702 em->start = start;
5703 em->len = extent_key->offset;
5704 em->block_len = extent_key->offset;
5705 em->block_start = extent_key->objectid;
5706 em->bdev = root->fs_info->fs_devices->latest_bdev;
5707 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5708
5709 /* setup extent map to cheat btrfs_readpage */
5710 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5711 while (1) {
5712 int ret;
5713 write_lock(&em_tree->lock);
5714 ret = add_extent_mapping(em_tree, em);
5715 write_unlock(&em_tree->lock);
5716 if (ret != -EEXIST) {
5717 free_extent_map(em);
5718 break;
5719 }
5720 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
5721 }
5722 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5723
5724 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
5725 }
5726
5727 struct btrfs_ref_path {
5728 u64 extent_start;
5729 u64 nodes[BTRFS_MAX_LEVEL];
5730 u64 root_objectid;
5731 u64 root_generation;
5732 u64 owner_objectid;
5733 u32 num_refs;
5734 int lowest_level;
5735 int current_level;
5736 int shared_level;
5737
5738 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
5739 u64 new_nodes[BTRFS_MAX_LEVEL];
5740 };
5741
5742 struct disk_extent {
5743 u64 ram_bytes;
5744 u64 disk_bytenr;
5745 u64 disk_num_bytes;
5746 u64 offset;
5747 u64 num_bytes;
5748 u8 compression;
5749 u8 encryption;
5750 u16 other_encoding;
5751 };
5752
5753 static int is_cowonly_root(u64 root_objectid)
5754 {
5755 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
5756 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
5757 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
5758 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
5759 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
5760 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
5761 return 1;
5762 return 0;
5763 }
5764
5765 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
5766 struct btrfs_root *extent_root,
5767 struct btrfs_ref_path *ref_path,
5768 int first_time)
5769 {
5770 struct extent_buffer *leaf;
5771 struct btrfs_path *path;
5772 struct btrfs_extent_ref *ref;
5773 struct btrfs_key key;
5774 struct btrfs_key found_key;
5775 u64 bytenr;
5776 u32 nritems;
5777 int level;
5778 int ret = 1;
5779
5780 path = btrfs_alloc_path();
5781 if (!path)
5782 return -ENOMEM;
5783
5784 if (first_time) {
5785 ref_path->lowest_level = -1;
5786 ref_path->current_level = -1;
5787 ref_path->shared_level = -1;
5788 goto walk_up;
5789 }
5790 walk_down:
5791 level = ref_path->current_level - 1;
5792 while (level >= -1) {
5793 u64 parent;
5794 if (level < ref_path->lowest_level)
5795 break;
5796
5797 if (level >= 0)
5798 bytenr = ref_path->nodes[level];
5799 else
5800 bytenr = ref_path->extent_start;
5801 BUG_ON(bytenr == 0);
5802
5803 parent = ref_path->nodes[level + 1];
5804 ref_path->nodes[level + 1] = 0;
5805 ref_path->current_level = level;
5806 BUG_ON(parent == 0);
5807
5808 key.objectid = bytenr;
5809 key.offset = parent + 1;
5810 key.type = BTRFS_EXTENT_REF_KEY;
5811
5812 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5813 if (ret < 0)
5814 goto out;
5815 BUG_ON(ret == 0);
5816
5817 leaf = path->nodes[0];
5818 nritems = btrfs_header_nritems(leaf);
5819 if (path->slots[0] >= nritems) {
5820 ret = btrfs_next_leaf(extent_root, path);
5821 if (ret < 0)
5822 goto out;
5823 if (ret > 0)
5824 goto next;
5825 leaf = path->nodes[0];
5826 }
5827
5828 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5829 if (found_key.objectid == bytenr &&
5830 found_key.type == BTRFS_EXTENT_REF_KEY) {
5831 if (level < ref_path->shared_level)
5832 ref_path->shared_level = level;
5833 goto found;
5834 }
5835 next:
5836 level--;
5837 btrfs_release_path(extent_root, path);
5838 cond_resched();
5839 }
5840 /* reached lowest level */
5841 ret = 1;
5842 goto out;
5843 walk_up:
5844 level = ref_path->current_level;
5845 while (level < BTRFS_MAX_LEVEL - 1) {
5846 u64 ref_objectid;
5847
5848 if (level >= 0)
5849 bytenr = ref_path->nodes[level];
5850 else
5851 bytenr = ref_path->extent_start;
5852
5853 BUG_ON(bytenr == 0);
5854
5855 key.objectid = bytenr;
5856 key.offset = 0;
5857 key.type = BTRFS_EXTENT_REF_KEY;
5858
5859 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5860 if (ret < 0)
5861 goto out;
5862
5863 leaf = path->nodes[0];
5864 nritems = btrfs_header_nritems(leaf);
5865 if (path->slots[0] >= nritems) {
5866 ret = btrfs_next_leaf(extent_root, path);
5867 if (ret < 0)
5868 goto out;
5869 if (ret > 0) {
5870 /* the extent was freed by someone */
5871 if (ref_path->lowest_level == level)
5872 goto out;
5873 btrfs_release_path(extent_root, path);
5874 goto walk_down;
5875 }
5876 leaf = path->nodes[0];
5877 }
5878
5879 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5880 if (found_key.objectid != bytenr ||
5881 found_key.type != BTRFS_EXTENT_REF_KEY) {
5882 /* the extent was freed by someone */
5883 if (ref_path->lowest_level == level) {
5884 ret = 1;
5885 goto out;
5886 }
5887 btrfs_release_path(extent_root, path);
5888 goto walk_down;
5889 }
5890 found:
5891 ref = btrfs_item_ptr(leaf, path->slots[0],
5892 struct btrfs_extent_ref);
5893 ref_objectid = btrfs_ref_objectid(leaf, ref);
5894 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
5895 if (first_time) {
5896 level = (int)ref_objectid;
5897 BUG_ON(level >= BTRFS_MAX_LEVEL);
5898 ref_path->lowest_level = level;
5899 ref_path->current_level = level;
5900 ref_path->nodes[level] = bytenr;
5901 } else {
5902 WARN_ON(ref_objectid != level);
5903 }
5904 } else {
5905 WARN_ON(level != -1);
5906 }
5907 first_time = 0;
5908
5909 if (ref_path->lowest_level == level) {
5910 ref_path->owner_objectid = ref_objectid;
5911 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
5912 }
5913
5914 /*
5915 * the block is tree root or the block isn't in reference
5916 * counted tree.
5917 */
5918 if (found_key.objectid == found_key.offset ||
5919 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
5920 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5921 ref_path->root_generation =
5922 btrfs_ref_generation(leaf, ref);
5923 if (level < 0) {
5924 /* special reference from the tree log */
5925 ref_path->nodes[0] = found_key.offset;
5926 ref_path->current_level = 0;
5927 }
5928 ret = 0;
5929 goto out;
5930 }
5931
5932 level++;
5933 BUG_ON(ref_path->nodes[level] != 0);
5934 ref_path->nodes[level] = found_key.offset;
5935 ref_path->current_level = level;
5936
5937 /*
5938 * the reference was created in the running transaction,
5939 * no need to continue walking up.
5940 */
5941 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
5942 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5943 ref_path->root_generation =
5944 btrfs_ref_generation(leaf, ref);
5945 ret = 0;
5946 goto out;
5947 }
5948
5949 btrfs_release_path(extent_root, path);
5950 cond_resched();
5951 }
5952 /* reached max tree level, but no tree root found. */
5953 BUG();
5954 out:
5955 btrfs_free_path(path);
5956 return ret;
5957 }
5958
5959 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
5960 struct btrfs_root *extent_root,
5961 struct btrfs_ref_path *ref_path,
5962 u64 extent_start)
5963 {
5964 memset(ref_path, 0, sizeof(*ref_path));
5965 ref_path->extent_start = extent_start;
5966
5967 return __next_ref_path(trans, extent_root, ref_path, 1);
5968 }
5969
5970 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
5971 struct btrfs_root *extent_root,
5972 struct btrfs_ref_path *ref_path)
5973 {
5974 return __next_ref_path(trans, extent_root, ref_path, 0);
5975 }
5976
5977 static noinline int get_new_locations(struct inode *reloc_inode,
5978 struct btrfs_key *extent_key,
5979 u64 offset, int no_fragment,
5980 struct disk_extent **extents,
5981 int *nr_extents)
5982 {
5983 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5984 struct btrfs_path *path;
5985 struct btrfs_file_extent_item *fi;
5986 struct extent_buffer *leaf;
5987 struct disk_extent *exts = *extents;
5988 struct btrfs_key found_key;
5989 u64 cur_pos;
5990 u64 last_byte;
5991 u32 nritems;
5992 int nr = 0;
5993 int max = *nr_extents;
5994 int ret;
5995
5996 WARN_ON(!no_fragment && *extents);
5997 if (!exts) {
5998 max = 1;
5999 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
6000 if (!exts)
6001 return -ENOMEM;
6002 }
6003
6004 path = btrfs_alloc_path();
6005 BUG_ON(!path);
6006
6007 cur_pos = extent_key->objectid - offset;
6008 last_byte = extent_key->objectid + extent_key->offset;
6009 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
6010 cur_pos, 0);
6011 if (ret < 0)
6012 goto out;
6013 if (ret > 0) {
6014 ret = -ENOENT;
6015 goto out;
6016 }
6017
6018 while (1) {
6019 leaf = path->nodes[0];
6020 nritems = btrfs_header_nritems(leaf);
6021 if (path->slots[0] >= nritems) {
6022 ret = btrfs_next_leaf(root, path);
6023 if (ret < 0)
6024 goto out;
6025 if (ret > 0)
6026 break;
6027 leaf = path->nodes[0];
6028 }
6029
6030 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6031 if (found_key.offset != cur_pos ||
6032 found_key.type != BTRFS_EXTENT_DATA_KEY ||
6033 found_key.objectid != reloc_inode->i_ino)
6034 break;
6035
6036 fi = btrfs_item_ptr(leaf, path->slots[0],
6037 struct btrfs_file_extent_item);
6038 if (btrfs_file_extent_type(leaf, fi) !=
6039 BTRFS_FILE_EXTENT_REG ||
6040 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
6041 break;
6042
6043 if (nr == max) {
6044 struct disk_extent *old = exts;
6045 max *= 2;
6046 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
6047 memcpy(exts, old, sizeof(*exts) * nr);
6048 if (old != *extents)
6049 kfree(old);
6050 }
6051
6052 exts[nr].disk_bytenr =
6053 btrfs_file_extent_disk_bytenr(leaf, fi);
6054 exts[nr].disk_num_bytes =
6055 btrfs_file_extent_disk_num_bytes(leaf, fi);
6056 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
6057 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6058 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6059 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
6060 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
6061 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
6062 fi);
6063 BUG_ON(exts[nr].offset > 0);
6064 BUG_ON(exts[nr].compression || exts[nr].encryption);
6065 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
6066
6067 cur_pos += exts[nr].num_bytes;
6068 nr++;
6069
6070 if (cur_pos + offset >= last_byte)
6071 break;
6072
6073 if (no_fragment) {
6074 ret = 1;
6075 goto out;
6076 }
6077 path->slots[0]++;
6078 }
6079
6080 BUG_ON(cur_pos + offset > last_byte);
6081 if (cur_pos + offset < last_byte) {
6082 ret = -ENOENT;
6083 goto out;
6084 }
6085 ret = 0;
6086 out:
6087 btrfs_free_path(path);
6088 if (ret) {
6089 if (exts != *extents)
6090 kfree(exts);
6091 } else {
6092 *extents = exts;
6093 *nr_extents = nr;
6094 }
6095 return ret;
6096 }
6097
6098 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
6099 struct btrfs_root *root,
6100 struct btrfs_path *path,
6101 struct btrfs_key *extent_key,
6102 struct btrfs_key *leaf_key,
6103 struct btrfs_ref_path *ref_path,
6104 struct disk_extent *new_extents,
6105 int nr_extents)
6106 {
6107 struct extent_buffer *leaf;
6108 struct btrfs_file_extent_item *fi;
6109 struct inode *inode = NULL;
6110 struct btrfs_key key;
6111 u64 lock_start = 0;
6112 u64 lock_end = 0;
6113 u64 num_bytes;
6114 u64 ext_offset;
6115 u64 search_end = (u64)-1;
6116 u32 nritems;
6117 int nr_scaned = 0;
6118 int extent_locked = 0;
6119 int extent_type;
6120 int ret;
6121
6122 memcpy(&key, leaf_key, sizeof(key));
6123 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
6124 if (key.objectid < ref_path->owner_objectid ||
6125 (key.objectid == ref_path->owner_objectid &&
6126 key.type < BTRFS_EXTENT_DATA_KEY)) {
6127 key.objectid = ref_path->owner_objectid;
6128 key.type = BTRFS_EXTENT_DATA_KEY;
6129 key.offset = 0;
6130 }
6131 }
6132
6133 while (1) {
6134 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
6135 if (ret < 0)
6136 goto out;
6137
6138 leaf = path->nodes[0];
6139 nritems = btrfs_header_nritems(leaf);
6140 next:
6141 if (extent_locked && ret > 0) {
6142 /*
6143 * the file extent item was modified by someone
6144 * before the extent got locked.
6145 */
6146 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6147 lock_end, GFP_NOFS);
6148 extent_locked = 0;
6149 }
6150
6151 if (path->slots[0] >= nritems) {
6152 if (++nr_scaned > 2)
6153 break;
6154
6155 BUG_ON(extent_locked);
6156 ret = btrfs_next_leaf(root, path);
6157 if (ret < 0)
6158 goto out;
6159 if (ret > 0)
6160 break;
6161 leaf = path->nodes[0];
6162 nritems = btrfs_header_nritems(leaf);
6163 }
6164
6165 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
6166
6167 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
6168 if ((key.objectid > ref_path->owner_objectid) ||
6169 (key.objectid == ref_path->owner_objectid &&
6170 key.type > BTRFS_EXTENT_DATA_KEY) ||
6171 key.offset >= search_end)
6172 break;
6173 }
6174
6175 if (inode && key.objectid != inode->i_ino) {
6176 BUG_ON(extent_locked);
6177 btrfs_release_path(root, path);
6178 mutex_unlock(&inode->i_mutex);
6179 iput(inode);
6180 inode = NULL;
6181 continue;
6182 }
6183
6184 if (key.type != BTRFS_EXTENT_DATA_KEY) {
6185 path->slots[0]++;
6186 ret = 1;
6187 goto next;
6188 }
6189 fi = btrfs_item_ptr(leaf, path->slots[0],
6190 struct btrfs_file_extent_item);
6191 extent_type = btrfs_file_extent_type(leaf, fi);
6192 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
6193 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
6194 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
6195 extent_key->objectid)) {
6196 path->slots[0]++;
6197 ret = 1;
6198 goto next;
6199 }
6200
6201 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6202 ext_offset = btrfs_file_extent_offset(leaf, fi);
6203
6204 if (search_end == (u64)-1) {
6205 search_end = key.offset - ext_offset +
6206 btrfs_file_extent_ram_bytes(leaf, fi);
6207 }
6208
6209 if (!extent_locked) {
6210 lock_start = key.offset;
6211 lock_end = lock_start + num_bytes - 1;
6212 } else {
6213 if (lock_start > key.offset ||
6214 lock_end + 1 < key.offset + num_bytes) {
6215 unlock_extent(&BTRFS_I(inode)->io_tree,
6216 lock_start, lock_end, GFP_NOFS);
6217 extent_locked = 0;
6218 }
6219 }
6220
6221 if (!inode) {
6222 btrfs_release_path(root, path);
6223
6224 inode = btrfs_iget_locked(root->fs_info->sb,
6225 key.objectid, root);
6226 if (inode->i_state & I_NEW) {
6227 BTRFS_I(inode)->root = root;
6228 BTRFS_I(inode)->location.objectid =
6229 key.objectid;
6230 BTRFS_I(inode)->location.type =
6231 BTRFS_INODE_ITEM_KEY;
6232 BTRFS_I(inode)->location.offset = 0;
6233 btrfs_read_locked_inode(inode);
6234 unlock_new_inode(inode);
6235 }
6236 /*
6237 * some code call btrfs_commit_transaction while
6238 * holding the i_mutex, so we can't use mutex_lock
6239 * here.
6240 */
6241 if (is_bad_inode(inode) ||
6242 !mutex_trylock(&inode->i_mutex)) {
6243 iput(inode);
6244 inode = NULL;
6245 key.offset = (u64)-1;
6246 goto skip;
6247 }
6248 }
6249
6250 if (!extent_locked) {
6251 struct btrfs_ordered_extent *ordered;
6252
6253 btrfs_release_path(root, path);
6254
6255 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6256 lock_end, GFP_NOFS);
6257 ordered = btrfs_lookup_first_ordered_extent(inode,
6258 lock_end);
6259 if (ordered &&
6260 ordered->file_offset <= lock_end &&
6261 ordered->file_offset + ordered->len > lock_start) {
6262 unlock_extent(&BTRFS_I(inode)->io_tree,
6263 lock_start, lock_end, GFP_NOFS);
6264 btrfs_start_ordered_extent(inode, ordered, 1);
6265 btrfs_put_ordered_extent(ordered);
6266 key.offset += num_bytes;
6267 goto skip;
6268 }
6269 if (ordered)
6270 btrfs_put_ordered_extent(ordered);
6271
6272 extent_locked = 1;
6273 continue;
6274 }
6275
6276 if (nr_extents == 1) {
6277 /* update extent pointer in place */
6278 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6279 new_extents[0].disk_bytenr);
6280 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6281 new_extents[0].disk_num_bytes);
6282 btrfs_mark_buffer_dirty(leaf);
6283
6284 btrfs_drop_extent_cache(inode, key.offset,
6285 key.offset + num_bytes - 1, 0);
6286
6287 ret = btrfs_inc_extent_ref(trans, root,
6288 new_extents[0].disk_bytenr,
6289 new_extents[0].disk_num_bytes,
6290 leaf->start,
6291 root->root_key.objectid,
6292 trans->transid,
6293 key.objectid);
6294 BUG_ON(ret);
6295
6296 ret = btrfs_free_extent(trans, root,
6297 extent_key->objectid,
6298 extent_key->offset,
6299 leaf->start,
6300 btrfs_header_owner(leaf),
6301 btrfs_header_generation(leaf),
6302 key.objectid, 0);
6303 BUG_ON(ret);
6304
6305 btrfs_release_path(root, path);
6306 key.offset += num_bytes;
6307 } else {
6308 BUG_ON(1);
6309 #if 0
6310 u64 alloc_hint;
6311 u64 extent_len;
6312 int i;
6313 /*
6314 * drop old extent pointer at first, then insert the
6315 * new pointers one bye one
6316 */
6317 btrfs_release_path(root, path);
6318 ret = btrfs_drop_extents(trans, root, inode, key.offset,
6319 key.offset + num_bytes,
6320 key.offset, &alloc_hint);
6321 BUG_ON(ret);
6322
6323 for (i = 0; i < nr_extents; i++) {
6324 if (ext_offset >= new_extents[i].num_bytes) {
6325 ext_offset -= new_extents[i].num_bytes;
6326 continue;
6327 }
6328 extent_len = min(new_extents[i].num_bytes -
6329 ext_offset, num_bytes);
6330
6331 ret = btrfs_insert_empty_item(trans, root,
6332 path, &key,
6333 sizeof(*fi));
6334 BUG_ON(ret);
6335
6336 leaf = path->nodes[0];
6337 fi = btrfs_item_ptr(leaf, path->slots[0],
6338 struct btrfs_file_extent_item);
6339 btrfs_set_file_extent_generation(leaf, fi,
6340 trans->transid);
6341 btrfs_set_file_extent_type(leaf, fi,
6342 BTRFS_FILE_EXTENT_REG);
6343 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6344 new_extents[i].disk_bytenr);
6345 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6346 new_extents[i].disk_num_bytes);
6347 btrfs_set_file_extent_ram_bytes(leaf, fi,
6348 new_extents[i].ram_bytes);
6349
6350 btrfs_set_file_extent_compression(leaf, fi,
6351 new_extents[i].compression);
6352 btrfs_set_file_extent_encryption(leaf, fi,
6353 new_extents[i].encryption);
6354 btrfs_set_file_extent_other_encoding(leaf, fi,
6355 new_extents[i].other_encoding);
6356
6357 btrfs_set_file_extent_num_bytes(leaf, fi,
6358 extent_len);
6359 ext_offset += new_extents[i].offset;
6360 btrfs_set_file_extent_offset(leaf, fi,
6361 ext_offset);
6362 btrfs_mark_buffer_dirty(leaf);
6363
6364 btrfs_drop_extent_cache(inode, key.offset,
6365 key.offset + extent_len - 1, 0);
6366
6367 ret = btrfs_inc_extent_ref(trans, root,
6368 new_extents[i].disk_bytenr,
6369 new_extents[i].disk_num_bytes,
6370 leaf->start,
6371 root->root_key.objectid,
6372 trans->transid, key.objectid);
6373 BUG_ON(ret);
6374 btrfs_release_path(root, path);
6375
6376 inode_add_bytes(inode, extent_len);
6377
6378 ext_offset = 0;
6379 num_bytes -= extent_len;
6380 key.offset += extent_len;
6381
6382 if (num_bytes == 0)
6383 break;
6384 }
6385 BUG_ON(i >= nr_extents);
6386 #endif
6387 }
6388
6389 if (extent_locked) {
6390 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6391 lock_end, GFP_NOFS);
6392 extent_locked = 0;
6393 }
6394 skip:
6395 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
6396 key.offset >= search_end)
6397 break;
6398
6399 cond_resched();
6400 }
6401 ret = 0;
6402 out:
6403 btrfs_release_path(root, path);
6404 if (inode) {
6405 mutex_unlock(&inode->i_mutex);
6406 if (extent_locked) {
6407 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6408 lock_end, GFP_NOFS);
6409 }
6410 iput(inode);
6411 }
6412 return ret;
6413 }
6414
6415 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
6416 struct btrfs_root *root,
6417 struct extent_buffer *buf, u64 orig_start)
6418 {
6419 int level;
6420 int ret;
6421
6422 BUG_ON(btrfs_header_generation(buf) != trans->transid);
6423 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
6424
6425 level = btrfs_header_level(buf);
6426 if (level == 0) {
6427 struct btrfs_leaf_ref *ref;
6428 struct btrfs_leaf_ref *orig_ref;
6429
6430 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
6431 if (!orig_ref)
6432 return -ENOENT;
6433
6434 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
6435 if (!ref) {
6436 btrfs_free_leaf_ref(root, orig_ref);
6437 return -ENOMEM;
6438 }
6439
6440 ref->nritems = orig_ref->nritems;
6441 memcpy(ref->extents, orig_ref->extents,
6442 sizeof(ref->extents[0]) * ref->nritems);
6443
6444 btrfs_free_leaf_ref(root, orig_ref);
6445
6446 ref->root_gen = trans->transid;
6447 ref->bytenr = buf->start;
6448 ref->owner = btrfs_header_owner(buf);
6449 ref->generation = btrfs_header_generation(buf);
6450
6451 ret = btrfs_add_leaf_ref(root, ref, 0);
6452 WARN_ON(ret);
6453 btrfs_free_leaf_ref(root, ref);
6454 }
6455 return 0;
6456 }
6457
6458 static noinline int invalidate_extent_cache(struct btrfs_root *root,
6459 struct extent_buffer *leaf,
6460 struct btrfs_block_group_cache *group,
6461 struct btrfs_root *target_root)
6462 {
6463 struct btrfs_key key;
6464 struct inode *inode = NULL;
6465 struct btrfs_file_extent_item *fi;
6466 u64 num_bytes;
6467 u64 skip_objectid = 0;
6468 u32 nritems;
6469 u32 i;
6470
6471 nritems = btrfs_header_nritems(leaf);
6472 for (i = 0; i < nritems; i++) {
6473 btrfs_item_key_to_cpu(leaf, &key, i);
6474 if (key.objectid == skip_objectid ||
6475 key.type != BTRFS_EXTENT_DATA_KEY)
6476 continue;
6477 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6478 if (btrfs_file_extent_type(leaf, fi) ==
6479 BTRFS_FILE_EXTENT_INLINE)
6480 continue;
6481 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
6482 continue;
6483 if (!inode || inode->i_ino != key.objectid) {
6484 iput(inode);
6485 inode = btrfs_ilookup(target_root->fs_info->sb,
6486 key.objectid, target_root, 1);
6487 }
6488 if (!inode) {
6489 skip_objectid = key.objectid;
6490 continue;
6491 }
6492 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6493
6494 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
6495 key.offset + num_bytes - 1, GFP_NOFS);
6496 btrfs_drop_extent_cache(inode, key.offset,
6497 key.offset + num_bytes - 1, 1);
6498 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
6499 key.offset + num_bytes - 1, GFP_NOFS);
6500 cond_resched();
6501 }
6502 iput(inode);
6503 return 0;
6504 }
6505
6506 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
6507 struct btrfs_root *root,
6508 struct extent_buffer *leaf,
6509 struct btrfs_block_group_cache *group,
6510 struct inode *reloc_inode)
6511 {
6512 struct btrfs_key key;
6513 struct btrfs_key extent_key;
6514 struct btrfs_file_extent_item *fi;
6515 struct btrfs_leaf_ref *ref;
6516 struct disk_extent *new_extent;
6517 u64 bytenr;
6518 u64 num_bytes;
6519 u32 nritems;
6520 u32 i;
6521 int ext_index;
6522 int nr_extent;
6523 int ret;
6524
6525 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
6526 BUG_ON(!new_extent);
6527
6528 ref = btrfs_lookup_leaf_ref(root, leaf->start);
6529 BUG_ON(!ref);
6530
6531 ext_index = -1;
6532 nritems = btrfs_header_nritems(leaf);
6533 for (i = 0; i < nritems; i++) {
6534 btrfs_item_key_to_cpu(leaf, &key, i);
6535 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
6536 continue;
6537 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6538 if (btrfs_file_extent_type(leaf, fi) ==
6539 BTRFS_FILE_EXTENT_INLINE)
6540 continue;
6541 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6542 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
6543 if (bytenr == 0)
6544 continue;
6545
6546 ext_index++;
6547 if (bytenr >= group->key.objectid + group->key.offset ||
6548 bytenr + num_bytes <= group->key.objectid)
6549 continue;
6550
6551 extent_key.objectid = bytenr;
6552 extent_key.offset = num_bytes;
6553 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
6554 nr_extent = 1;
6555 ret = get_new_locations(reloc_inode, &extent_key,
6556 group->key.objectid, 1,
6557 &new_extent, &nr_extent);
6558 if (ret > 0)
6559 continue;
6560 BUG_ON(ret < 0);
6561
6562 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
6563 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
6564 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
6565 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
6566
6567 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6568 new_extent->disk_bytenr);
6569 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6570 new_extent->disk_num_bytes);
6571 btrfs_mark_buffer_dirty(leaf);
6572
6573 ret = btrfs_inc_extent_ref(trans, root,
6574 new_extent->disk_bytenr,
6575 new_extent->disk_num_bytes,
6576 leaf->start,
6577 root->root_key.objectid,
6578 trans->transid, key.objectid);
6579 BUG_ON(ret);
6580
6581 ret = btrfs_free_extent(trans, root,
6582 bytenr, num_bytes, leaf->start,
6583 btrfs_header_owner(leaf),
6584 btrfs_header_generation(leaf),
6585 key.objectid, 0);
6586 BUG_ON(ret);
6587 cond_resched();
6588 }
6589 kfree(new_extent);
6590 BUG_ON(ext_index + 1 != ref->nritems);
6591 btrfs_free_leaf_ref(root, ref);
6592 return 0;
6593 }
6594
6595 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
6596 struct btrfs_root *root)
6597 {
6598 struct btrfs_root *reloc_root;
6599 int ret;
6600
6601 if (root->reloc_root) {
6602 reloc_root = root->reloc_root;
6603 root->reloc_root = NULL;
6604 list_add(&reloc_root->dead_list,
6605 &root->fs_info->dead_reloc_roots);
6606
6607 btrfs_set_root_bytenr(&reloc_root->root_item,
6608 reloc_root->node->start);
6609 btrfs_set_root_level(&root->root_item,
6610 btrfs_header_level(reloc_root->node));
6611 memset(&reloc_root->root_item.drop_progress, 0,
6612 sizeof(struct btrfs_disk_key));
6613 reloc_root->root_item.drop_level = 0;
6614
6615 ret = btrfs_update_root(trans, root->fs_info->tree_root,
6616 &reloc_root->root_key,
6617 &reloc_root->root_item);
6618 BUG_ON(ret);
6619 }
6620 return 0;
6621 }
6622
6623 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
6624 {
6625 struct btrfs_trans_handle *trans;
6626 struct btrfs_root *reloc_root;
6627 struct btrfs_root *prev_root = NULL;
6628 struct list_head dead_roots;
6629 int ret;
6630 unsigned long nr;
6631
6632 INIT_LIST_HEAD(&dead_roots);
6633 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
6634
6635 while (!list_empty(&dead_roots)) {
6636 reloc_root = list_entry(dead_roots.prev,
6637 struct btrfs_root, dead_list);
6638 list_del_init(&reloc_root->dead_list);
6639
6640 BUG_ON(reloc_root->commit_root != NULL);
6641 while (1) {
6642 trans = btrfs_join_transaction(root, 1);
6643 BUG_ON(!trans);
6644
6645 mutex_lock(&root->fs_info->drop_mutex);
6646 ret = btrfs_drop_snapshot(trans, reloc_root);
6647 if (ret != -EAGAIN)
6648 break;
6649 mutex_unlock(&root->fs_info->drop_mutex);
6650
6651 nr = trans->blocks_used;
6652 ret = btrfs_end_transaction(trans, root);
6653 BUG_ON(ret);
6654 btrfs_btree_balance_dirty(root, nr);
6655 }
6656
6657 free_extent_buffer(reloc_root->node);
6658
6659 ret = btrfs_del_root(trans, root->fs_info->tree_root,
6660 &reloc_root->root_key);
6661 BUG_ON(ret);
6662 mutex_unlock(&root->fs_info->drop_mutex);
6663
6664 nr = trans->blocks_used;
6665 ret = btrfs_end_transaction(trans, root);
6666 BUG_ON(ret);
6667 btrfs_btree_balance_dirty(root, nr);
6668
6669 kfree(prev_root);
6670 prev_root = reloc_root;
6671 }
6672 if (prev_root) {
6673 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
6674 kfree(prev_root);
6675 }
6676 return 0;
6677 }
6678
6679 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
6680 {
6681 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
6682 return 0;
6683 }
6684
6685 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
6686 {
6687 struct btrfs_root *reloc_root;
6688 struct btrfs_trans_handle *trans;
6689 struct btrfs_key location;
6690 int found;
6691 int ret;
6692
6693 mutex_lock(&root->fs_info->tree_reloc_mutex);
6694 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
6695 BUG_ON(ret);
6696 found = !list_empty(&root->fs_info->dead_reloc_roots);
6697 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6698
6699 if (found) {
6700 trans = btrfs_start_transaction(root, 1);
6701 BUG_ON(!trans);
6702 ret = btrfs_commit_transaction(trans, root);
6703 BUG_ON(ret);
6704 }
6705
6706 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
6707 location.offset = (u64)-1;
6708 location.type = BTRFS_ROOT_ITEM_KEY;
6709
6710 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
6711 BUG_ON(!reloc_root);
6712 btrfs_orphan_cleanup(reloc_root);
6713 return 0;
6714 }
6715
6716 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
6717 struct btrfs_root *root)
6718 {
6719 struct btrfs_root *reloc_root;
6720 struct extent_buffer *eb;
6721 struct btrfs_root_item *root_item;
6722 struct btrfs_key root_key;
6723 int ret;
6724
6725 BUG_ON(!root->ref_cows);
6726 if (root->reloc_root)
6727 return 0;
6728
6729 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
6730 BUG_ON(!root_item);
6731
6732 ret = btrfs_copy_root(trans, root, root->commit_root,
6733 &eb, BTRFS_TREE_RELOC_OBJECTID);
6734 BUG_ON(ret);
6735
6736 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
6737 root_key.offset = root->root_key.objectid;
6738 root_key.type = BTRFS_ROOT_ITEM_KEY;
6739
6740 memcpy(root_item, &root->root_item, sizeof(root_item));
6741 btrfs_set_root_refs(root_item, 0);
6742 btrfs_set_root_bytenr(root_item, eb->start);
6743 btrfs_set_root_level(root_item, btrfs_header_level(eb));
6744 btrfs_set_root_generation(root_item, trans->transid);
6745
6746 btrfs_tree_unlock(eb);
6747 free_extent_buffer(eb);
6748
6749 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
6750 &root_key, root_item);
6751 BUG_ON(ret);
6752 kfree(root_item);
6753
6754 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
6755 &root_key);
6756 BUG_ON(!reloc_root);
6757 reloc_root->last_trans = trans->transid;
6758 reloc_root->commit_root = NULL;
6759 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
6760
6761 root->reloc_root = reloc_root;
6762 return 0;
6763 }
6764
6765 /*
6766 * Core function of space balance.
6767 *
6768 * The idea is using reloc trees to relocate tree blocks in reference
6769 * counted roots. There is one reloc tree for each subvol, and all
6770 * reloc trees share same root key objectid. Reloc trees are snapshots
6771 * of the latest committed roots of subvols (root->commit_root).
6772 *
6773 * To relocate a tree block referenced by a subvol, there are two steps.
6774 * COW the block through subvol's reloc tree, then update block pointer
6775 * in the subvol to point to the new block. Since all reloc trees share
6776 * same root key objectid, doing special handing for tree blocks owned
6777 * by them is easy. Once a tree block has been COWed in one reloc tree,
6778 * we can use the resulting new block directly when the same block is
6779 * required to COW again through other reloc trees. By this way, relocated
6780 * tree blocks are shared between reloc trees, so they are also shared
6781 * between subvols.
6782 */
6783 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
6784 struct btrfs_root *root,
6785 struct btrfs_path *path,
6786 struct btrfs_key *first_key,
6787 struct btrfs_ref_path *ref_path,
6788 struct btrfs_block_group_cache *group,
6789 struct inode *reloc_inode)
6790 {
6791 struct btrfs_root *reloc_root;
6792 struct extent_buffer *eb = NULL;
6793 struct btrfs_key *keys;
6794 u64 *nodes;
6795 int level;
6796 int shared_level;
6797 int lowest_level = 0;
6798 int ret;
6799
6800 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
6801 lowest_level = ref_path->owner_objectid;
6802
6803 if (!root->ref_cows) {
6804 path->lowest_level = lowest_level;
6805 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
6806 BUG_ON(ret < 0);
6807 path->lowest_level = 0;
6808 btrfs_release_path(root, path);
6809 return 0;
6810 }
6811
6812 mutex_lock(&root->fs_info->tree_reloc_mutex);
6813 ret = init_reloc_tree(trans, root);
6814 BUG_ON(ret);
6815 reloc_root = root->reloc_root;
6816
6817 shared_level = ref_path->shared_level;
6818 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
6819
6820 keys = ref_path->node_keys;
6821 nodes = ref_path->new_nodes;
6822 memset(&keys[shared_level + 1], 0,
6823 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
6824 memset(&nodes[shared_level + 1], 0,
6825 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
6826
6827 if (nodes[lowest_level] == 0) {
6828 path->lowest_level = lowest_level;
6829 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6830 0, 1);
6831 BUG_ON(ret);
6832 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
6833 eb = path->nodes[level];
6834 if (!eb || eb == reloc_root->node)
6835 break;
6836 nodes[level] = eb->start;
6837 if (level == 0)
6838 btrfs_item_key_to_cpu(eb, &keys[level], 0);
6839 else
6840 btrfs_node_key_to_cpu(eb, &keys[level], 0);
6841 }
6842 if (nodes[0] &&
6843 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6844 eb = path->nodes[0];
6845 ret = replace_extents_in_leaf(trans, reloc_root, eb,
6846 group, reloc_inode);
6847 BUG_ON(ret);
6848 }
6849 btrfs_release_path(reloc_root, path);
6850 } else {
6851 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
6852 lowest_level);
6853 BUG_ON(ret);
6854 }
6855
6856 /*
6857 * replace tree blocks in the fs tree with tree blocks in
6858 * the reloc tree.
6859 */
6860 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
6861 BUG_ON(ret < 0);
6862
6863 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6864 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6865 0, 0);
6866 BUG_ON(ret);
6867 extent_buffer_get(path->nodes[0]);
6868 eb = path->nodes[0];
6869 btrfs_release_path(reloc_root, path);
6870 ret = invalidate_extent_cache(reloc_root, eb, group, root);
6871 BUG_ON(ret);
6872 free_extent_buffer(eb);
6873 }
6874
6875 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6876 path->lowest_level = 0;
6877 return 0;
6878 }
6879
6880 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
6881 struct btrfs_root *root,
6882 struct btrfs_path *path,
6883 struct btrfs_key *first_key,
6884 struct btrfs_ref_path *ref_path)
6885 {
6886 int ret;
6887
6888 ret = relocate_one_path(trans, root, path, first_key,
6889 ref_path, NULL, NULL);
6890 BUG_ON(ret);
6891
6892 return 0;
6893 }
6894
6895 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
6896 struct btrfs_root *extent_root,
6897 struct btrfs_path *path,
6898 struct btrfs_key *extent_key)
6899 {
6900 int ret;
6901
6902 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
6903 if (ret)
6904 goto out;
6905 ret = btrfs_del_item(trans, extent_root, path);
6906 out:
6907 btrfs_release_path(extent_root, path);
6908 return ret;
6909 }
6910
6911 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
6912 struct btrfs_ref_path *ref_path)
6913 {
6914 struct btrfs_key root_key;
6915
6916 root_key.objectid = ref_path->root_objectid;
6917 root_key.type = BTRFS_ROOT_ITEM_KEY;
6918 if (is_cowonly_root(ref_path->root_objectid))
6919 root_key.offset = 0;
6920 else
6921 root_key.offset = (u64)-1;
6922
6923 return btrfs_read_fs_root_no_name(fs_info, &root_key);
6924 }
6925
6926 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
6927 struct btrfs_path *path,
6928 struct btrfs_key *extent_key,
6929 struct btrfs_block_group_cache *group,
6930 struct inode *reloc_inode, int pass)
6931 {
6932 struct btrfs_trans_handle *trans;
6933 struct btrfs_root *found_root;
6934 struct btrfs_ref_path *ref_path = NULL;
6935 struct disk_extent *new_extents = NULL;
6936 int nr_extents = 0;
6937 int loops;
6938 int ret;
6939 int level;
6940 struct btrfs_key first_key;
6941 u64 prev_block = 0;
6942
6943
6944 trans = btrfs_start_transaction(extent_root, 1);
6945 BUG_ON(!trans);
6946
6947 if (extent_key->objectid == 0) {
6948 ret = del_extent_zero(trans, extent_root, path, extent_key);
6949 goto out;
6950 }
6951
6952 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
6953 if (!ref_path) {
6954 ret = -ENOMEM;
6955 goto out;
6956 }
6957
6958 for (loops = 0; ; loops++) {
6959 if (loops == 0) {
6960 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
6961 extent_key->objectid);
6962 } else {
6963 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
6964 }
6965 if (ret < 0)
6966 goto out;
6967 if (ret > 0)
6968 break;
6969
6970 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
6971 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
6972 continue;
6973
6974 found_root = read_ref_root(extent_root->fs_info, ref_path);
6975 BUG_ON(!found_root);
6976 /*
6977 * for reference counted tree, only process reference paths
6978 * rooted at the latest committed root.
6979 */
6980 if (found_root->ref_cows &&
6981 ref_path->root_generation != found_root->root_key.offset)
6982 continue;
6983
6984 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6985 if (pass == 0) {
6986 /*
6987 * copy data extents to new locations
6988 */
6989 u64 group_start = group->key.objectid;
6990 ret = relocate_data_extent(reloc_inode,
6991 extent_key,
6992 group_start);
6993 if (ret < 0)
6994 goto out;
6995 break;
6996 }
6997 level = 0;
6998 } else {
6999 level = ref_path->owner_objectid;
7000 }
7001
7002 if (prev_block != ref_path->nodes[level]) {
7003 struct extent_buffer *eb;
7004 u64 block_start = ref_path->nodes[level];
7005 u64 block_size = btrfs_level_size(found_root, level);
7006
7007 eb = read_tree_block(found_root, block_start,
7008 block_size, 0);
7009 btrfs_tree_lock(eb);
7010 BUG_ON(level != btrfs_header_level(eb));
7011
7012 if (level == 0)
7013 btrfs_item_key_to_cpu(eb, &first_key, 0);
7014 else
7015 btrfs_node_key_to_cpu(eb, &first_key, 0);
7016
7017 btrfs_tree_unlock(eb);
7018 free_extent_buffer(eb);
7019 prev_block = block_start;
7020 }
7021
7022 mutex_lock(&extent_root->fs_info->trans_mutex);
7023 btrfs_record_root_in_trans(found_root);
7024 mutex_unlock(&extent_root->fs_info->trans_mutex);
7025 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
7026 /*
7027 * try to update data extent references while
7028 * keeping metadata shared between snapshots.
7029 */
7030 if (pass == 1) {
7031 ret = relocate_one_path(trans, found_root,
7032 path, &first_key, ref_path,
7033 group, reloc_inode);
7034 if (ret < 0)
7035 goto out;
7036 continue;
7037 }
7038 /*
7039 * use fallback method to process the remaining
7040 * references.
7041 */
7042 if (!new_extents) {
7043 u64 group_start = group->key.objectid;
7044 new_extents = kmalloc(sizeof(*new_extents),
7045 GFP_NOFS);
7046 nr_extents = 1;
7047 ret = get_new_locations(reloc_inode,
7048 extent_key,
7049 group_start, 1,
7050 &new_extents,
7051 &nr_extents);
7052 if (ret)
7053 goto out;
7054 }
7055 ret = replace_one_extent(trans, found_root,
7056 path, extent_key,
7057 &first_key, ref_path,
7058 new_extents, nr_extents);
7059 } else {
7060 ret = relocate_tree_block(trans, found_root, path,
7061 &first_key, ref_path);
7062 }
7063 if (ret < 0)
7064 goto out;
7065 }
7066 ret = 0;
7067 out:
7068 btrfs_end_transaction(trans, extent_root);
7069 kfree(new_extents);
7070 kfree(ref_path);
7071 return ret;
7072 }
7073 #endif
7074
7075 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
7076 {
7077 u64 num_devices;
7078 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
7079 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
7080
7081 num_devices = root->fs_info->fs_devices->rw_devices;
7082 if (num_devices == 1) {
7083 stripped |= BTRFS_BLOCK_GROUP_DUP;
7084 stripped = flags & ~stripped;
7085
7086 /* turn raid0 into single device chunks */
7087 if (flags & BTRFS_BLOCK_GROUP_RAID0)
7088 return stripped;
7089
7090 /* turn mirroring into duplication */
7091 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
7092 BTRFS_BLOCK_GROUP_RAID10))
7093 return stripped | BTRFS_BLOCK_GROUP_DUP;
7094 return flags;
7095 } else {
7096 /* they already had raid on here, just return */
7097 if (flags & stripped)
7098 return flags;
7099
7100 stripped |= BTRFS_BLOCK_GROUP_DUP;
7101 stripped = flags & ~stripped;
7102
7103 /* switch duplicated blocks with raid1 */
7104 if (flags & BTRFS_BLOCK_GROUP_DUP)
7105 return stripped | BTRFS_BLOCK_GROUP_RAID1;
7106
7107 /* turn single device chunks into raid0 */
7108 return stripped | BTRFS_BLOCK_GROUP_RAID0;
7109 }
7110 return flags;
7111 }
7112
7113 static int __alloc_chunk_for_shrink(struct btrfs_root *root,
7114 struct btrfs_block_group_cache *shrink_block_group,
7115 int force)
7116 {
7117 struct btrfs_trans_handle *trans;
7118 u64 new_alloc_flags;
7119 u64 calc;
7120
7121 spin_lock(&shrink_block_group->lock);
7122 if (btrfs_block_group_used(&shrink_block_group->item) +
7123 shrink_block_group->reserved > 0) {
7124 spin_unlock(&shrink_block_group->lock);
7125
7126 trans = btrfs_start_transaction(root, 1);
7127 spin_lock(&shrink_block_group->lock);
7128
7129 new_alloc_flags = update_block_group_flags(root,
7130 shrink_block_group->flags);
7131 if (new_alloc_flags != shrink_block_group->flags) {
7132 calc =
7133 btrfs_block_group_used(&shrink_block_group->item);
7134 } else {
7135 calc = shrink_block_group->key.offset;
7136 }
7137 spin_unlock(&shrink_block_group->lock);
7138
7139 do_chunk_alloc(trans, root->fs_info->extent_root,
7140 calc + 2 * 1024 * 1024, new_alloc_flags, force);
7141
7142 btrfs_end_transaction(trans, root);
7143 } else
7144 spin_unlock(&shrink_block_group->lock);
7145 return 0;
7146 }
7147
7148
7149 int btrfs_prepare_block_group_relocation(struct btrfs_root *root,
7150 struct btrfs_block_group_cache *group)
7151
7152 {
7153 __alloc_chunk_for_shrink(root, group, 1);
7154 set_block_group_readonly(group);
7155 return 0;
7156 }
7157
7158 /*
7159 * checks to see if its even possible to relocate this block group.
7160 *
7161 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
7162 * ok to go ahead and try.
7163 */
7164 int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
7165 {
7166 struct btrfs_block_group_cache *block_group;
7167 struct btrfs_space_info *space_info;
7168 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
7169 struct btrfs_device *device;
7170 int full = 0;
7171 int ret = 0;
7172
7173 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
7174
7175 /* odd, couldn't find the block group, leave it alone */
7176 if (!block_group)
7177 return -1;
7178
7179 /* no bytes used, we're good */
7180 if (!btrfs_block_group_used(&block_group->item))
7181 goto out;
7182
7183 space_info = block_group->space_info;
7184 spin_lock(&space_info->lock);
7185
7186 full = space_info->full;
7187
7188 /*
7189 * if this is the last block group we have in this space, we can't
7190 * relocate it unless we're able to allocate a new chunk below.
7191 *
7192 * Otherwise, we need to make sure we have room in the space to handle
7193 * all of the extents from this block group. If we can, we're good
7194 */
7195 if ((space_info->total_bytes != block_group->key.offset) &&
7196 (space_info->bytes_used + space_info->bytes_reserved +
7197 space_info->bytes_pinned + space_info->bytes_readonly +
7198 btrfs_block_group_used(&block_group->item) <
7199 space_info->total_bytes)) {
7200 spin_unlock(&space_info->lock);
7201 goto out;
7202 }
7203 spin_unlock(&space_info->lock);
7204
7205 /*
7206 * ok we don't have enough space, but maybe we have free space on our
7207 * devices to allocate new chunks for relocation, so loop through our
7208 * alloc devices and guess if we have enough space. However, if we
7209 * were marked as full, then we know there aren't enough chunks, and we
7210 * can just return.
7211 */
7212 ret = -1;
7213 if (full)
7214 goto out;
7215
7216 mutex_lock(&root->fs_info->chunk_mutex);
7217 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
7218 u64 min_free = btrfs_block_group_used(&block_group->item);
7219 u64 dev_offset, max_avail;
7220
7221 /*
7222 * check to make sure we can actually find a chunk with enough
7223 * space to fit our block group in.
7224 */
7225 if (device->total_bytes > device->bytes_used + min_free) {
7226 ret = find_free_dev_extent(NULL, device, min_free,
7227 &dev_offset, &max_avail);
7228 if (!ret)
7229 break;
7230 ret = -1;
7231 }
7232 }
7233 mutex_unlock(&root->fs_info->chunk_mutex);
7234 out:
7235 btrfs_put_block_group(block_group);
7236 return ret;
7237 }
7238
7239 static int find_first_block_group(struct btrfs_root *root,
7240 struct btrfs_path *path, struct btrfs_key *key)
7241 {
7242 int ret = 0;
7243 struct btrfs_key found_key;
7244 struct extent_buffer *leaf;
7245 int slot;
7246
7247 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
7248 if (ret < 0)
7249 goto out;
7250
7251 while (1) {
7252 slot = path->slots[0];
7253 leaf = path->nodes[0];
7254 if (slot >= btrfs_header_nritems(leaf)) {
7255 ret = btrfs_next_leaf(root, path);
7256 if (ret == 0)
7257 continue;
7258 if (ret < 0)
7259 goto out;
7260 break;
7261 }
7262 btrfs_item_key_to_cpu(leaf, &found_key, slot);
7263
7264 if (found_key.objectid >= key->objectid &&
7265 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
7266 ret = 0;
7267 goto out;
7268 }
7269 path->slots[0]++;
7270 }
7271 ret = -ENOENT;
7272 out:
7273 return ret;
7274 }
7275
7276 int btrfs_free_block_groups(struct btrfs_fs_info *info)
7277 {
7278 struct btrfs_block_group_cache *block_group;
7279 struct btrfs_space_info *space_info;
7280 struct btrfs_caching_control *caching_ctl;
7281 struct rb_node *n;
7282
7283 down_write(&info->extent_commit_sem);
7284 while (!list_empty(&info->caching_block_groups)) {
7285 caching_ctl = list_entry(info->caching_block_groups.next,
7286 struct btrfs_caching_control, list);
7287 list_del(&caching_ctl->list);
7288 put_caching_control(caching_ctl);
7289 }
7290 up_write(&info->extent_commit_sem);
7291
7292 spin_lock(&info->block_group_cache_lock);
7293 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
7294 block_group = rb_entry(n, struct btrfs_block_group_cache,
7295 cache_node);
7296 rb_erase(&block_group->cache_node,
7297 &info->block_group_cache_tree);
7298 spin_unlock(&info->block_group_cache_lock);
7299
7300 down_write(&block_group->space_info->groups_sem);
7301 list_del(&block_group->list);
7302 up_write(&block_group->space_info->groups_sem);
7303
7304 if (block_group->cached == BTRFS_CACHE_STARTED)
7305 wait_block_group_cache_done(block_group);
7306
7307 btrfs_remove_free_space_cache(block_group);
7308
7309 WARN_ON(atomic_read(&block_group->count) != 1);
7310 kfree(block_group);
7311
7312 spin_lock(&info->block_group_cache_lock);
7313 }
7314 spin_unlock(&info->block_group_cache_lock);
7315
7316 /* now that all the block groups are freed, go through and
7317 * free all the space_info structs. This is only called during
7318 * the final stages of unmount, and so we know nobody is
7319 * using them. We call synchronize_rcu() once before we start,
7320 * just to be on the safe side.
7321 */
7322 synchronize_rcu();
7323
7324 while(!list_empty(&info->space_info)) {
7325 space_info = list_entry(info->space_info.next,
7326 struct btrfs_space_info,
7327 list);
7328
7329 list_del(&space_info->list);
7330 kfree(space_info);
7331 }
7332 return 0;
7333 }
7334
7335 int btrfs_read_block_groups(struct btrfs_root *root)
7336 {
7337 struct btrfs_path *path;
7338 int ret;
7339 struct btrfs_block_group_cache *cache;
7340 struct btrfs_fs_info *info = root->fs_info;
7341 struct btrfs_space_info *space_info;
7342 struct btrfs_key key;
7343 struct btrfs_key found_key;
7344 struct extent_buffer *leaf;
7345
7346 root = info->extent_root;
7347 key.objectid = 0;
7348 key.offset = 0;
7349 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
7350 path = btrfs_alloc_path();
7351 if (!path)
7352 return -ENOMEM;
7353
7354 while (1) {
7355 ret = find_first_block_group(root, path, &key);
7356 if (ret > 0) {
7357 ret = 0;
7358 goto error;
7359 }
7360 if (ret != 0)
7361 goto error;
7362
7363 leaf = path->nodes[0];
7364 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7365 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7366 if (!cache) {
7367 ret = -ENOMEM;
7368 break;
7369 }
7370
7371 atomic_set(&cache->count, 1);
7372 spin_lock_init(&cache->lock);
7373 spin_lock_init(&cache->tree_lock);
7374 cache->fs_info = info;
7375 INIT_LIST_HEAD(&cache->list);
7376 INIT_LIST_HEAD(&cache->cluster_list);
7377
7378 /*
7379 * we only want to have 32k of ram per block group for keeping
7380 * track of free space, and if we pass 1/2 of that we want to
7381 * start converting things over to using bitmaps
7382 */
7383 cache->extents_thresh = ((1024 * 32) / 2) /
7384 sizeof(struct btrfs_free_space);
7385
7386 read_extent_buffer(leaf, &cache->item,
7387 btrfs_item_ptr_offset(leaf, path->slots[0]),
7388 sizeof(cache->item));
7389 memcpy(&cache->key, &found_key, sizeof(found_key));
7390
7391 key.objectid = found_key.objectid + found_key.offset;
7392 btrfs_release_path(root, path);
7393 cache->flags = btrfs_block_group_flags(&cache->item);
7394 cache->sectorsize = root->sectorsize;
7395
7396 /*
7397 * check for two cases, either we are full, and therefore
7398 * don't need to bother with the caching work since we won't
7399 * find any space, or we are empty, and we can just add all
7400 * the space in and be done with it. This saves us _alot_ of
7401 * time, particularly in the full case.
7402 */
7403 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
7404 exclude_super_stripes(root, cache);
7405 cache->last_byte_to_unpin = (u64)-1;
7406 cache->cached = BTRFS_CACHE_FINISHED;
7407 free_excluded_extents(root, cache);
7408 } else if (btrfs_block_group_used(&cache->item) == 0) {
7409 exclude_super_stripes(root, cache);
7410 cache->last_byte_to_unpin = (u64)-1;
7411 cache->cached = BTRFS_CACHE_FINISHED;
7412 add_new_free_space(cache, root->fs_info,
7413 found_key.objectid,
7414 found_key.objectid +
7415 found_key.offset);
7416 free_excluded_extents(root, cache);
7417 }
7418
7419 ret = update_space_info(info, cache->flags, found_key.offset,
7420 btrfs_block_group_used(&cache->item),
7421 &space_info);
7422 BUG_ON(ret);
7423 cache->space_info = space_info;
7424 spin_lock(&cache->space_info->lock);
7425 cache->space_info->bytes_super += cache->bytes_super;
7426 spin_unlock(&cache->space_info->lock);
7427
7428 down_write(&space_info->groups_sem);
7429 list_add_tail(&cache->list, &space_info->block_groups);
7430 up_write(&space_info->groups_sem);
7431
7432 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7433 BUG_ON(ret);
7434
7435 set_avail_alloc_bits(root->fs_info, cache->flags);
7436 if (btrfs_chunk_readonly(root, cache->key.objectid))
7437 set_block_group_readonly(cache);
7438 }
7439 ret = 0;
7440 error:
7441 btrfs_free_path(path);
7442 return ret;
7443 }
7444
7445 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
7446 struct btrfs_root *root, u64 bytes_used,
7447 u64 type, u64 chunk_objectid, u64 chunk_offset,
7448 u64 size)
7449 {
7450 int ret;
7451 struct btrfs_root *extent_root;
7452 struct btrfs_block_group_cache *cache;
7453
7454 extent_root = root->fs_info->extent_root;
7455
7456 root->fs_info->last_trans_log_full_commit = trans->transid;
7457
7458 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7459 if (!cache)
7460 return -ENOMEM;
7461
7462 cache->key.objectid = chunk_offset;
7463 cache->key.offset = size;
7464 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
7465 cache->sectorsize = root->sectorsize;
7466
7467 /*
7468 * we only want to have 32k of ram per block group for keeping track
7469 * of free space, and if we pass 1/2 of that we want to start
7470 * converting things over to using bitmaps
7471 */
7472 cache->extents_thresh = ((1024 * 32) / 2) /
7473 sizeof(struct btrfs_free_space);
7474 atomic_set(&cache->count, 1);
7475 spin_lock_init(&cache->lock);
7476 spin_lock_init(&cache->tree_lock);
7477 INIT_LIST_HEAD(&cache->list);
7478 INIT_LIST_HEAD(&cache->cluster_list);
7479
7480 btrfs_set_block_group_used(&cache->item, bytes_used);
7481 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
7482 cache->flags = type;
7483 btrfs_set_block_group_flags(&cache->item, type);
7484
7485 cache->last_byte_to_unpin = (u64)-1;
7486 cache->cached = BTRFS_CACHE_FINISHED;
7487 exclude_super_stripes(root, cache);
7488
7489 add_new_free_space(cache, root->fs_info, chunk_offset,
7490 chunk_offset + size);
7491
7492 free_excluded_extents(root, cache);
7493
7494 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
7495 &cache->space_info);
7496 BUG_ON(ret);
7497
7498 spin_lock(&cache->space_info->lock);
7499 cache->space_info->bytes_super += cache->bytes_super;
7500 spin_unlock(&cache->space_info->lock);
7501
7502 down_write(&cache->space_info->groups_sem);
7503 list_add_tail(&cache->list, &cache->space_info->block_groups);
7504 up_write(&cache->space_info->groups_sem);
7505
7506 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7507 BUG_ON(ret);
7508
7509 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
7510 sizeof(cache->item));
7511 BUG_ON(ret);
7512
7513 set_avail_alloc_bits(extent_root->fs_info, type);
7514
7515 return 0;
7516 }
7517
7518 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
7519 struct btrfs_root *root, u64 group_start)
7520 {
7521 struct btrfs_path *path;
7522 struct btrfs_block_group_cache *block_group;
7523 struct btrfs_free_cluster *cluster;
7524 struct btrfs_key key;
7525 int ret;
7526
7527 root = root->fs_info->extent_root;
7528
7529 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
7530 BUG_ON(!block_group);
7531 BUG_ON(!block_group->ro);
7532
7533 memcpy(&key, &block_group->key, sizeof(key));
7534
7535 /* make sure this block group isn't part of an allocation cluster */
7536 cluster = &root->fs_info->data_alloc_cluster;
7537 spin_lock(&cluster->refill_lock);
7538 btrfs_return_cluster_to_free_space(block_group, cluster);
7539 spin_unlock(&cluster->refill_lock);
7540
7541 /*
7542 * make sure this block group isn't part of a metadata
7543 * allocation cluster
7544 */
7545 cluster = &root->fs_info->meta_alloc_cluster;
7546 spin_lock(&cluster->refill_lock);
7547 btrfs_return_cluster_to_free_space(block_group, cluster);
7548 spin_unlock(&cluster->refill_lock);
7549
7550 path = btrfs_alloc_path();
7551 BUG_ON(!path);
7552
7553 spin_lock(&root->fs_info->block_group_cache_lock);
7554 rb_erase(&block_group->cache_node,
7555 &root->fs_info->block_group_cache_tree);
7556 spin_unlock(&root->fs_info->block_group_cache_lock);
7557
7558 down_write(&block_group->space_info->groups_sem);
7559 /*
7560 * we must use list_del_init so people can check to see if they
7561 * are still on the list after taking the semaphore
7562 */
7563 list_del_init(&block_group->list);
7564 up_write(&block_group->space_info->groups_sem);
7565
7566 if (block_group->cached == BTRFS_CACHE_STARTED)
7567 wait_block_group_cache_done(block_group);
7568
7569 btrfs_remove_free_space_cache(block_group);
7570
7571 spin_lock(&block_group->space_info->lock);
7572 block_group->space_info->total_bytes -= block_group->key.offset;
7573 block_group->space_info->bytes_readonly -= block_group->key.offset;
7574 spin_unlock(&block_group->space_info->lock);
7575
7576 btrfs_clear_space_info_full(root->fs_info);
7577
7578 btrfs_put_block_group(block_group);
7579 btrfs_put_block_group(block_group);
7580
7581 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
7582 if (ret > 0)
7583 ret = -EIO;
7584 if (ret < 0)
7585 goto out;
7586
7587 ret = btrfs_del_item(trans, root, path);
7588 out:
7589 btrfs_free_path(path);
7590 return ret;
7591 }
mm of the moment repository