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