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Btrfs: async delalloc flushing under space pressure
[GitHub/mt8127/android_kernel_alcatel_ttab.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 #ifdef BIO_RW_DISCARD
1572 static void btrfs_issue_discard(struct block_device *bdev,
1573 u64 start, u64 len)
1574 {
1575 blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL);
1576 }
1577 #endif
1578
1579 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
1580 u64 num_bytes)
1581 {
1582 #ifdef BIO_RW_DISCARD
1583 int ret;
1584 u64 map_length = num_bytes;
1585 struct btrfs_multi_bio *multi = NULL;
1586
1587 /* Tell the block device(s) that the sectors can be discarded */
1588 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
1589 bytenr, &map_length, &multi, 0);
1590 if (!ret) {
1591 struct btrfs_bio_stripe *stripe = multi->stripes;
1592 int i;
1593
1594 if (map_length > num_bytes)
1595 map_length = num_bytes;
1596
1597 for (i = 0; i < multi->num_stripes; i++, stripe++) {
1598 btrfs_issue_discard(stripe->dev->bdev,
1599 stripe->physical,
1600 map_length);
1601 }
1602 kfree(multi);
1603 }
1604
1605 return ret;
1606 #else
1607 return 0;
1608 #endif
1609 }
1610
1611 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1612 struct btrfs_root *root,
1613 u64 bytenr, u64 num_bytes, u64 parent,
1614 u64 root_objectid, u64 owner, u64 offset)
1615 {
1616 int ret;
1617 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
1618 root_objectid == BTRFS_TREE_LOG_OBJECTID);
1619
1620 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1621 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
1622 parent, root_objectid, (int)owner,
1623 BTRFS_ADD_DELAYED_REF, NULL);
1624 } else {
1625 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
1626 parent, root_objectid, owner, offset,
1627 BTRFS_ADD_DELAYED_REF, NULL);
1628 }
1629 return ret;
1630 }
1631
1632 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1633 struct btrfs_root *root,
1634 u64 bytenr, u64 num_bytes,
1635 u64 parent, u64 root_objectid,
1636 u64 owner, u64 offset, int refs_to_add,
1637 struct btrfs_delayed_extent_op *extent_op)
1638 {
1639 struct btrfs_path *path;
1640 struct extent_buffer *leaf;
1641 struct btrfs_extent_item *item;
1642 u64 refs;
1643 int ret;
1644 int err = 0;
1645
1646 path = btrfs_alloc_path();
1647 if (!path)
1648 return -ENOMEM;
1649
1650 path->reada = 1;
1651 path->leave_spinning = 1;
1652 /* this will setup the path even if it fails to insert the back ref */
1653 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1654 path, bytenr, num_bytes, parent,
1655 root_objectid, owner, offset,
1656 refs_to_add, extent_op);
1657 if (ret == 0)
1658 goto out;
1659
1660 if (ret != -EAGAIN) {
1661 err = ret;
1662 goto out;
1663 }
1664
1665 leaf = path->nodes[0];
1666 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1667 refs = btrfs_extent_refs(leaf, item);
1668 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1669 if (extent_op)
1670 __run_delayed_extent_op(extent_op, leaf, item);
1671
1672 btrfs_mark_buffer_dirty(leaf);
1673 btrfs_release_path(root->fs_info->extent_root, path);
1674
1675 path->reada = 1;
1676 path->leave_spinning = 1;
1677
1678 /* now insert the actual backref */
1679 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1680 path, bytenr, parent, root_objectid,
1681 owner, offset, refs_to_add);
1682 BUG_ON(ret);
1683 out:
1684 btrfs_free_path(path);
1685 return err;
1686 }
1687
1688 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1689 struct btrfs_root *root,
1690 struct btrfs_delayed_ref_node *node,
1691 struct btrfs_delayed_extent_op *extent_op,
1692 int insert_reserved)
1693 {
1694 int ret = 0;
1695 struct btrfs_delayed_data_ref *ref;
1696 struct btrfs_key ins;
1697 u64 parent = 0;
1698 u64 ref_root = 0;
1699 u64 flags = 0;
1700
1701 ins.objectid = node->bytenr;
1702 ins.offset = node->num_bytes;
1703 ins.type = BTRFS_EXTENT_ITEM_KEY;
1704
1705 ref = btrfs_delayed_node_to_data_ref(node);
1706 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
1707 parent = ref->parent;
1708 else
1709 ref_root = ref->root;
1710
1711 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1712 if (extent_op) {
1713 BUG_ON(extent_op->update_key);
1714 flags |= extent_op->flags_to_set;
1715 }
1716 ret = alloc_reserved_file_extent(trans, root,
1717 parent, ref_root, flags,
1718 ref->objectid, ref->offset,
1719 &ins, node->ref_mod);
1720 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1721 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1722 node->num_bytes, parent,
1723 ref_root, ref->objectid,
1724 ref->offset, node->ref_mod,
1725 extent_op);
1726 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1727 ret = __btrfs_free_extent(trans, root, node->bytenr,
1728 node->num_bytes, parent,
1729 ref_root, ref->objectid,
1730 ref->offset, node->ref_mod,
1731 extent_op);
1732 } else {
1733 BUG();
1734 }
1735 return ret;
1736 }
1737
1738 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
1739 struct extent_buffer *leaf,
1740 struct btrfs_extent_item *ei)
1741 {
1742 u64 flags = btrfs_extent_flags(leaf, ei);
1743 if (extent_op->update_flags) {
1744 flags |= extent_op->flags_to_set;
1745 btrfs_set_extent_flags(leaf, ei, flags);
1746 }
1747
1748 if (extent_op->update_key) {
1749 struct btrfs_tree_block_info *bi;
1750 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
1751 bi = (struct btrfs_tree_block_info *)(ei + 1);
1752 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
1753 }
1754 }
1755
1756 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
1757 struct btrfs_root *root,
1758 struct btrfs_delayed_ref_node *node,
1759 struct btrfs_delayed_extent_op *extent_op)
1760 {
1761 struct btrfs_key key;
1762 struct btrfs_path *path;
1763 struct btrfs_extent_item *ei;
1764 struct extent_buffer *leaf;
1765 u32 item_size;
1766 int ret;
1767 int err = 0;
1768
1769 path = btrfs_alloc_path();
1770 if (!path)
1771 return -ENOMEM;
1772
1773 key.objectid = node->bytenr;
1774 key.type = BTRFS_EXTENT_ITEM_KEY;
1775 key.offset = node->num_bytes;
1776
1777 path->reada = 1;
1778 path->leave_spinning = 1;
1779 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
1780 path, 0, 1);
1781 if (ret < 0) {
1782 err = ret;
1783 goto out;
1784 }
1785 if (ret > 0) {
1786 err = -EIO;
1787 goto out;
1788 }
1789
1790 leaf = path->nodes[0];
1791 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1792 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1793 if (item_size < sizeof(*ei)) {
1794 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1795 path, (u64)-1, 0);
1796 if (ret < 0) {
1797 err = ret;
1798 goto out;
1799 }
1800 leaf = path->nodes[0];
1801 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1802 }
1803 #endif
1804 BUG_ON(item_size < sizeof(*ei));
1805 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1806 __run_delayed_extent_op(extent_op, leaf, ei);
1807
1808 btrfs_mark_buffer_dirty(leaf);
1809 out:
1810 btrfs_free_path(path);
1811 return err;
1812 }
1813
1814 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
1815 struct btrfs_root *root,
1816 struct btrfs_delayed_ref_node *node,
1817 struct btrfs_delayed_extent_op *extent_op,
1818 int insert_reserved)
1819 {
1820 int ret = 0;
1821 struct btrfs_delayed_tree_ref *ref;
1822 struct btrfs_key ins;
1823 u64 parent = 0;
1824 u64 ref_root = 0;
1825
1826 ins.objectid = node->bytenr;
1827 ins.offset = node->num_bytes;
1828 ins.type = BTRFS_EXTENT_ITEM_KEY;
1829
1830 ref = btrfs_delayed_node_to_tree_ref(node);
1831 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1832 parent = ref->parent;
1833 else
1834 ref_root = ref->root;
1835
1836 BUG_ON(node->ref_mod != 1);
1837 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1838 BUG_ON(!extent_op || !extent_op->update_flags ||
1839 !extent_op->update_key);
1840 ret = alloc_reserved_tree_block(trans, root,
1841 parent, ref_root,
1842 extent_op->flags_to_set,
1843 &extent_op->key,
1844 ref->level, &ins);
1845 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1846 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1847 node->num_bytes, parent, ref_root,
1848 ref->level, 0, 1, extent_op);
1849 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1850 ret = __btrfs_free_extent(trans, root, node->bytenr,
1851 node->num_bytes, parent, ref_root,
1852 ref->level, 0, 1, extent_op);
1853 } else {
1854 BUG();
1855 }
1856 return ret;
1857 }
1858
1859
1860 /* helper function to actually process a single delayed ref entry */
1861 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
1862 struct btrfs_root *root,
1863 struct btrfs_delayed_ref_node *node,
1864 struct btrfs_delayed_extent_op *extent_op,
1865 int insert_reserved)
1866 {
1867 int ret;
1868 if (btrfs_delayed_ref_is_head(node)) {
1869 struct btrfs_delayed_ref_head *head;
1870 /*
1871 * we've hit the end of the chain and we were supposed
1872 * to insert this extent into the tree. But, it got
1873 * deleted before we ever needed to insert it, so all
1874 * we have to do is clean up the accounting
1875 */
1876 BUG_ON(extent_op);
1877 head = btrfs_delayed_node_to_head(node);
1878 if (insert_reserved) {
1879 int mark_free = 0;
1880 struct extent_buffer *must_clean = NULL;
1881
1882 ret = pin_down_bytes(trans, root, NULL,
1883 node->bytenr, node->num_bytes,
1884 head->is_data, 1, &must_clean);
1885 if (ret > 0)
1886 mark_free = 1;
1887
1888 if (must_clean) {
1889 clean_tree_block(NULL, root, must_clean);
1890 btrfs_tree_unlock(must_clean);
1891 free_extent_buffer(must_clean);
1892 }
1893 if (head->is_data) {
1894 ret = btrfs_del_csums(trans, root,
1895 node->bytenr,
1896 node->num_bytes);
1897 BUG_ON(ret);
1898 }
1899 if (mark_free) {
1900 ret = btrfs_free_reserved_extent(root,
1901 node->bytenr,
1902 node->num_bytes);
1903 BUG_ON(ret);
1904 }
1905 }
1906 mutex_unlock(&head->mutex);
1907 return 0;
1908 }
1909
1910 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1911 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1912 ret = run_delayed_tree_ref(trans, root, node, extent_op,
1913 insert_reserved);
1914 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1915 node->type == BTRFS_SHARED_DATA_REF_KEY)
1916 ret = run_delayed_data_ref(trans, root, node, extent_op,
1917 insert_reserved);
1918 else
1919 BUG();
1920 return ret;
1921 }
1922
1923 static noinline struct btrfs_delayed_ref_node *
1924 select_delayed_ref(struct btrfs_delayed_ref_head *head)
1925 {
1926 struct rb_node *node;
1927 struct btrfs_delayed_ref_node *ref;
1928 int action = BTRFS_ADD_DELAYED_REF;
1929 again:
1930 /*
1931 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
1932 * this prevents ref count from going down to zero when
1933 * there still are pending delayed ref.
1934 */
1935 node = rb_prev(&head->node.rb_node);
1936 while (1) {
1937 if (!node)
1938 break;
1939 ref = rb_entry(node, struct btrfs_delayed_ref_node,
1940 rb_node);
1941 if (ref->bytenr != head->node.bytenr)
1942 break;
1943 if (ref->action == action)
1944 return ref;
1945 node = rb_prev(node);
1946 }
1947 if (action == BTRFS_ADD_DELAYED_REF) {
1948 action = BTRFS_DROP_DELAYED_REF;
1949 goto again;
1950 }
1951 return NULL;
1952 }
1953
1954 static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
1955 struct btrfs_root *root,
1956 struct list_head *cluster)
1957 {
1958 struct btrfs_delayed_ref_root *delayed_refs;
1959 struct btrfs_delayed_ref_node *ref;
1960 struct btrfs_delayed_ref_head *locked_ref = NULL;
1961 struct btrfs_delayed_extent_op *extent_op;
1962 int ret;
1963 int count = 0;
1964 int must_insert_reserved = 0;
1965
1966 delayed_refs = &trans->transaction->delayed_refs;
1967 while (1) {
1968 if (!locked_ref) {
1969 /* pick a new head ref from the cluster list */
1970 if (list_empty(cluster))
1971 break;
1972
1973 locked_ref = list_entry(cluster->next,
1974 struct btrfs_delayed_ref_head, cluster);
1975
1976 /* grab the lock that says we are going to process
1977 * all the refs for this head */
1978 ret = btrfs_delayed_ref_lock(trans, locked_ref);
1979
1980 /*
1981 * we may have dropped the spin lock to get the head
1982 * mutex lock, and that might have given someone else
1983 * time to free the head. If that's true, it has been
1984 * removed from our list and we can move on.
1985 */
1986 if (ret == -EAGAIN) {
1987 locked_ref = NULL;
1988 count++;
1989 continue;
1990 }
1991 }
1992
1993 /*
1994 * record the must insert reserved flag before we
1995 * drop the spin lock.
1996 */
1997 must_insert_reserved = locked_ref->must_insert_reserved;
1998 locked_ref->must_insert_reserved = 0;
1999
2000 extent_op = locked_ref->extent_op;
2001 locked_ref->extent_op = NULL;
2002
2003 /*
2004 * locked_ref is the head node, so we have to go one
2005 * node back for any delayed ref updates
2006 */
2007 ref = select_delayed_ref(locked_ref);
2008 if (!ref) {
2009 /* All delayed refs have been processed, Go ahead
2010 * and send the head node to run_one_delayed_ref,
2011 * so that any accounting fixes can happen
2012 */
2013 ref = &locked_ref->node;
2014
2015 if (extent_op && must_insert_reserved) {
2016 kfree(extent_op);
2017 extent_op = NULL;
2018 }
2019
2020 if (extent_op) {
2021 spin_unlock(&delayed_refs->lock);
2022
2023 ret = run_delayed_extent_op(trans, root,
2024 ref, extent_op);
2025 BUG_ON(ret);
2026 kfree(extent_op);
2027
2028 cond_resched();
2029 spin_lock(&delayed_refs->lock);
2030 continue;
2031 }
2032
2033 list_del_init(&locked_ref->cluster);
2034 locked_ref = NULL;
2035 }
2036
2037 ref->in_tree = 0;
2038 rb_erase(&ref->rb_node, &delayed_refs->root);
2039 delayed_refs->num_entries--;
2040
2041 spin_unlock(&delayed_refs->lock);
2042
2043 ret = run_one_delayed_ref(trans, root, ref, extent_op,
2044 must_insert_reserved);
2045 BUG_ON(ret);
2046
2047 btrfs_put_delayed_ref(ref);
2048 kfree(extent_op);
2049 count++;
2050
2051 cond_resched();
2052 spin_lock(&delayed_refs->lock);
2053 }
2054 return count;
2055 }
2056
2057 /*
2058 * this starts processing the delayed reference count updates and
2059 * extent insertions we have queued up so far. count can be
2060 * 0, which means to process everything in the tree at the start
2061 * of the run (but not newly added entries), or it can be some target
2062 * number you'd like to process.
2063 */
2064 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
2065 struct btrfs_root *root, unsigned long count)
2066 {
2067 struct rb_node *node;
2068 struct btrfs_delayed_ref_root *delayed_refs;
2069 struct btrfs_delayed_ref_node *ref;
2070 struct list_head cluster;
2071 int ret;
2072 int run_all = count == (unsigned long)-1;
2073 int run_most = 0;
2074
2075 if (root == root->fs_info->extent_root)
2076 root = root->fs_info->tree_root;
2077
2078 delayed_refs = &trans->transaction->delayed_refs;
2079 INIT_LIST_HEAD(&cluster);
2080 again:
2081 spin_lock(&delayed_refs->lock);
2082 if (count == 0) {
2083 count = delayed_refs->num_entries * 2;
2084 run_most = 1;
2085 }
2086 while (1) {
2087 if (!(run_all || run_most) &&
2088 delayed_refs->num_heads_ready < 64)
2089 break;
2090
2091 /*
2092 * go find something we can process in the rbtree. We start at
2093 * the beginning of the tree, and then build a cluster
2094 * of refs to process starting at the first one we are able to
2095 * lock
2096 */
2097 ret = btrfs_find_ref_cluster(trans, &cluster,
2098 delayed_refs->run_delayed_start);
2099 if (ret)
2100 break;
2101
2102 ret = run_clustered_refs(trans, root, &cluster);
2103 BUG_ON(ret < 0);
2104
2105 count -= min_t(unsigned long, ret, count);
2106
2107 if (count == 0)
2108 break;
2109 }
2110
2111 if (run_all) {
2112 node = rb_first(&delayed_refs->root);
2113 if (!node)
2114 goto out;
2115 count = (unsigned long)-1;
2116
2117 while (node) {
2118 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2119 rb_node);
2120 if (btrfs_delayed_ref_is_head(ref)) {
2121 struct btrfs_delayed_ref_head *head;
2122
2123 head = btrfs_delayed_node_to_head(ref);
2124 atomic_inc(&ref->refs);
2125
2126 spin_unlock(&delayed_refs->lock);
2127 mutex_lock(&head->mutex);
2128 mutex_unlock(&head->mutex);
2129
2130 btrfs_put_delayed_ref(ref);
2131 cond_resched();
2132 goto again;
2133 }
2134 node = rb_next(node);
2135 }
2136 spin_unlock(&delayed_refs->lock);
2137 schedule_timeout(1);
2138 goto again;
2139 }
2140 out:
2141 spin_unlock(&delayed_refs->lock);
2142 return 0;
2143 }
2144
2145 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2146 struct btrfs_root *root,
2147 u64 bytenr, u64 num_bytes, u64 flags,
2148 int is_data)
2149 {
2150 struct btrfs_delayed_extent_op *extent_op;
2151 int ret;
2152
2153 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2154 if (!extent_op)
2155 return -ENOMEM;
2156
2157 extent_op->flags_to_set = flags;
2158 extent_op->update_flags = 1;
2159 extent_op->update_key = 0;
2160 extent_op->is_data = is_data ? 1 : 0;
2161
2162 ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
2163 if (ret)
2164 kfree(extent_op);
2165 return ret;
2166 }
2167
2168 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
2169 struct btrfs_root *root,
2170 struct btrfs_path *path,
2171 u64 objectid, u64 offset, u64 bytenr)
2172 {
2173 struct btrfs_delayed_ref_head *head;
2174 struct btrfs_delayed_ref_node *ref;
2175 struct btrfs_delayed_data_ref *data_ref;
2176 struct btrfs_delayed_ref_root *delayed_refs;
2177 struct rb_node *node;
2178 int ret = 0;
2179
2180 ret = -ENOENT;
2181 delayed_refs = &trans->transaction->delayed_refs;
2182 spin_lock(&delayed_refs->lock);
2183 head = btrfs_find_delayed_ref_head(trans, bytenr);
2184 if (!head)
2185 goto out;
2186
2187 if (!mutex_trylock(&head->mutex)) {
2188 atomic_inc(&head->node.refs);
2189 spin_unlock(&delayed_refs->lock);
2190
2191 btrfs_release_path(root->fs_info->extent_root, path);
2192
2193 mutex_lock(&head->mutex);
2194 mutex_unlock(&head->mutex);
2195 btrfs_put_delayed_ref(&head->node);
2196 return -EAGAIN;
2197 }
2198
2199 node = rb_prev(&head->node.rb_node);
2200 if (!node)
2201 goto out_unlock;
2202
2203 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2204
2205 if (ref->bytenr != bytenr)
2206 goto out_unlock;
2207
2208 ret = 1;
2209 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
2210 goto out_unlock;
2211
2212 data_ref = btrfs_delayed_node_to_data_ref(ref);
2213
2214 node = rb_prev(node);
2215 if (node) {
2216 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2217 if (ref->bytenr == bytenr)
2218 goto out_unlock;
2219 }
2220
2221 if (data_ref->root != root->root_key.objectid ||
2222 data_ref->objectid != objectid || data_ref->offset != offset)
2223 goto out_unlock;
2224
2225 ret = 0;
2226 out_unlock:
2227 mutex_unlock(&head->mutex);
2228 out:
2229 spin_unlock(&delayed_refs->lock);
2230 return ret;
2231 }
2232
2233 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
2234 struct btrfs_root *root,
2235 struct btrfs_path *path,
2236 u64 objectid, u64 offset, u64 bytenr)
2237 {
2238 struct btrfs_root *extent_root = root->fs_info->extent_root;
2239 struct extent_buffer *leaf;
2240 struct btrfs_extent_data_ref *ref;
2241 struct btrfs_extent_inline_ref *iref;
2242 struct btrfs_extent_item *ei;
2243 struct btrfs_key key;
2244 u32 item_size;
2245 int ret;
2246
2247 key.objectid = bytenr;
2248 key.offset = (u64)-1;
2249 key.type = BTRFS_EXTENT_ITEM_KEY;
2250
2251 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2252 if (ret < 0)
2253 goto out;
2254 BUG_ON(ret == 0);
2255
2256 ret = -ENOENT;
2257 if (path->slots[0] == 0)
2258 goto out;
2259
2260 path->slots[0]--;
2261 leaf = path->nodes[0];
2262 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2263
2264 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2265 goto out;
2266
2267 ret = 1;
2268 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2269 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2270 if (item_size < sizeof(*ei)) {
2271 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
2272 goto out;
2273 }
2274 #endif
2275 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2276
2277 if (item_size != sizeof(*ei) +
2278 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2279 goto out;
2280
2281 if (btrfs_extent_generation(leaf, ei) <=
2282 btrfs_root_last_snapshot(&root->root_item))
2283 goto out;
2284
2285 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2286 if (btrfs_extent_inline_ref_type(leaf, iref) !=
2287 BTRFS_EXTENT_DATA_REF_KEY)
2288 goto out;
2289
2290 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2291 if (btrfs_extent_refs(leaf, ei) !=
2292 btrfs_extent_data_ref_count(leaf, ref) ||
2293 btrfs_extent_data_ref_root(leaf, ref) !=
2294 root->root_key.objectid ||
2295 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2296 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2297 goto out;
2298
2299 ret = 0;
2300 out:
2301 return ret;
2302 }
2303
2304 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
2305 struct btrfs_root *root,
2306 u64 objectid, u64 offset, u64 bytenr)
2307 {
2308 struct btrfs_path *path;
2309 int ret;
2310 int ret2;
2311
2312 path = btrfs_alloc_path();
2313 if (!path)
2314 return -ENOENT;
2315
2316 do {
2317 ret = check_committed_ref(trans, root, path, objectid,
2318 offset, bytenr);
2319 if (ret && ret != -ENOENT)
2320 goto out;
2321
2322 ret2 = check_delayed_ref(trans, root, path, objectid,
2323 offset, bytenr);
2324 } while (ret2 == -EAGAIN);
2325
2326 if (ret2 && ret2 != -ENOENT) {
2327 ret = ret2;
2328 goto out;
2329 }
2330
2331 if (ret != -ENOENT || ret2 != -ENOENT)
2332 ret = 0;
2333 out:
2334 btrfs_free_path(path);
2335 return ret;
2336 }
2337
2338 #if 0
2339 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2340 struct extent_buffer *buf, u32 nr_extents)
2341 {
2342 struct btrfs_key key;
2343 struct btrfs_file_extent_item *fi;
2344 u64 root_gen;
2345 u32 nritems;
2346 int i;
2347 int level;
2348 int ret = 0;
2349 int shared = 0;
2350
2351 if (!root->ref_cows)
2352 return 0;
2353
2354 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
2355 shared = 0;
2356 root_gen = root->root_key.offset;
2357 } else {
2358 shared = 1;
2359 root_gen = trans->transid - 1;
2360 }
2361
2362 level = btrfs_header_level(buf);
2363 nritems = btrfs_header_nritems(buf);
2364
2365 if (level == 0) {
2366 struct btrfs_leaf_ref *ref;
2367 struct btrfs_extent_info *info;
2368
2369 ref = btrfs_alloc_leaf_ref(root, nr_extents);
2370 if (!ref) {
2371 ret = -ENOMEM;
2372 goto out;
2373 }
2374
2375 ref->root_gen = root_gen;
2376 ref->bytenr = buf->start;
2377 ref->owner = btrfs_header_owner(buf);
2378 ref->generation = btrfs_header_generation(buf);
2379 ref->nritems = nr_extents;
2380 info = ref->extents;
2381
2382 for (i = 0; nr_extents > 0 && i < nritems; i++) {
2383 u64 disk_bytenr;
2384 btrfs_item_key_to_cpu(buf, &key, i);
2385 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2386 continue;
2387 fi = btrfs_item_ptr(buf, i,
2388 struct btrfs_file_extent_item);
2389 if (btrfs_file_extent_type(buf, fi) ==
2390 BTRFS_FILE_EXTENT_INLINE)
2391 continue;
2392 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2393 if (disk_bytenr == 0)
2394 continue;
2395
2396 info->bytenr = disk_bytenr;
2397 info->num_bytes =
2398 btrfs_file_extent_disk_num_bytes(buf, fi);
2399 info->objectid = key.objectid;
2400 info->offset = key.offset;
2401 info++;
2402 }
2403
2404 ret = btrfs_add_leaf_ref(root, ref, shared);
2405 if (ret == -EEXIST && shared) {
2406 struct btrfs_leaf_ref *old;
2407 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
2408 BUG_ON(!old);
2409 btrfs_remove_leaf_ref(root, old);
2410 btrfs_free_leaf_ref(root, old);
2411 ret = btrfs_add_leaf_ref(root, ref, shared);
2412 }
2413 WARN_ON(ret);
2414 btrfs_free_leaf_ref(root, ref);
2415 }
2416 out:
2417 return ret;
2418 }
2419
2420 /* when a block goes through cow, we update the reference counts of
2421 * everything that block points to. The internal pointers of the block
2422 * can be in just about any order, and it is likely to have clusters of
2423 * things that are close together and clusters of things that are not.
2424 *
2425 * To help reduce the seeks that come with updating all of these reference
2426 * counts, sort them by byte number before actual updates are done.
2427 *
2428 * struct refsort is used to match byte number to slot in the btree block.
2429 * we sort based on the byte number and then use the slot to actually
2430 * find the item.
2431 *
2432 * struct refsort is smaller than strcut btrfs_item and smaller than
2433 * struct btrfs_key_ptr. Since we're currently limited to the page size
2434 * for a btree block, there's no way for a kmalloc of refsorts for a
2435 * single node to be bigger than a page.
2436 */
2437 struct refsort {
2438 u64 bytenr;
2439 u32 slot;
2440 };
2441
2442 /*
2443 * for passing into sort()
2444 */
2445 static int refsort_cmp(const void *a_void, const void *b_void)
2446 {
2447 const struct refsort *a = a_void;
2448 const struct refsort *b = b_void;
2449
2450 if (a->bytenr < b->bytenr)
2451 return -1;
2452 if (a->bytenr > b->bytenr)
2453 return 1;
2454 return 0;
2455 }
2456 #endif
2457
2458 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2459 struct btrfs_root *root,
2460 struct extent_buffer *buf,
2461 int full_backref, int inc)
2462 {
2463 u64 bytenr;
2464 u64 num_bytes;
2465 u64 parent;
2466 u64 ref_root;
2467 u32 nritems;
2468 struct btrfs_key key;
2469 struct btrfs_file_extent_item *fi;
2470 int i;
2471 int level;
2472 int ret = 0;
2473 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
2474 u64, u64, u64, u64, u64, u64);
2475
2476 ref_root = btrfs_header_owner(buf);
2477 nritems = btrfs_header_nritems(buf);
2478 level = btrfs_header_level(buf);
2479
2480 if (!root->ref_cows && level == 0)
2481 return 0;
2482
2483 if (inc)
2484 process_func = btrfs_inc_extent_ref;
2485 else
2486 process_func = btrfs_free_extent;
2487
2488 if (full_backref)
2489 parent = buf->start;
2490 else
2491 parent = 0;
2492
2493 for (i = 0; i < nritems; i++) {
2494 if (level == 0) {
2495 btrfs_item_key_to_cpu(buf, &key, i);
2496 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2497 continue;
2498 fi = btrfs_item_ptr(buf, i,
2499 struct btrfs_file_extent_item);
2500 if (btrfs_file_extent_type(buf, fi) ==
2501 BTRFS_FILE_EXTENT_INLINE)
2502 continue;
2503 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2504 if (bytenr == 0)
2505 continue;
2506
2507 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
2508 key.offset -= btrfs_file_extent_offset(buf, fi);
2509 ret = process_func(trans, root, bytenr, num_bytes,
2510 parent, ref_root, key.objectid,
2511 key.offset);
2512 if (ret)
2513 goto fail;
2514 } else {
2515 bytenr = btrfs_node_blockptr(buf, i);
2516 num_bytes = btrfs_level_size(root, level - 1);
2517 ret = process_func(trans, root, bytenr, num_bytes,
2518 parent, ref_root, level - 1, 0);
2519 if (ret)
2520 goto fail;
2521 }
2522 }
2523 return 0;
2524 fail:
2525 BUG();
2526 return ret;
2527 }
2528
2529 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2530 struct extent_buffer *buf, int full_backref)
2531 {
2532 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
2533 }
2534
2535 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2536 struct extent_buffer *buf, int full_backref)
2537 {
2538 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
2539 }
2540
2541 static int write_one_cache_group(struct btrfs_trans_handle *trans,
2542 struct btrfs_root *root,
2543 struct btrfs_path *path,
2544 struct btrfs_block_group_cache *cache)
2545 {
2546 int ret;
2547 struct btrfs_root *extent_root = root->fs_info->extent_root;
2548 unsigned long bi;
2549 struct extent_buffer *leaf;
2550
2551 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
2552 if (ret < 0)
2553 goto fail;
2554 BUG_ON(ret);
2555
2556 leaf = path->nodes[0];
2557 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
2558 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
2559 btrfs_mark_buffer_dirty(leaf);
2560 btrfs_release_path(extent_root, path);
2561 fail:
2562 if (ret)
2563 return ret;
2564 return 0;
2565
2566 }
2567
2568 static struct btrfs_block_group_cache *
2569 next_block_group(struct btrfs_root *root,
2570 struct btrfs_block_group_cache *cache)
2571 {
2572 struct rb_node *node;
2573 spin_lock(&root->fs_info->block_group_cache_lock);
2574 node = rb_next(&cache->cache_node);
2575 btrfs_put_block_group(cache);
2576 if (node) {
2577 cache = rb_entry(node, struct btrfs_block_group_cache,
2578 cache_node);
2579 atomic_inc(&cache->count);
2580 } else
2581 cache = NULL;
2582 spin_unlock(&root->fs_info->block_group_cache_lock);
2583 return cache;
2584 }
2585
2586 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
2587 struct btrfs_root *root)
2588 {
2589 struct btrfs_block_group_cache *cache;
2590 int err = 0;
2591 struct btrfs_path *path;
2592 u64 last = 0;
2593
2594 path = btrfs_alloc_path();
2595 if (!path)
2596 return -ENOMEM;
2597
2598 while (1) {
2599 if (last == 0) {
2600 err = btrfs_run_delayed_refs(trans, root,
2601 (unsigned long)-1);
2602 BUG_ON(err);
2603 }
2604
2605 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2606 while (cache) {
2607 if (cache->dirty)
2608 break;
2609 cache = next_block_group(root, cache);
2610 }
2611 if (!cache) {
2612 if (last == 0)
2613 break;
2614 last = 0;
2615 continue;
2616 }
2617
2618 cache->dirty = 0;
2619 last = cache->key.objectid + cache->key.offset;
2620
2621 err = write_one_cache_group(trans, root, path, cache);
2622 BUG_ON(err);
2623 btrfs_put_block_group(cache);
2624 }
2625
2626 btrfs_free_path(path);
2627 return 0;
2628 }
2629
2630 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
2631 {
2632 struct btrfs_block_group_cache *block_group;
2633 int readonly = 0;
2634
2635 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
2636 if (!block_group || block_group->ro)
2637 readonly = 1;
2638 if (block_group)
2639 btrfs_put_block_group(block_group);
2640 return readonly;
2641 }
2642
2643 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
2644 u64 total_bytes, u64 bytes_used,
2645 struct btrfs_space_info **space_info)
2646 {
2647 struct btrfs_space_info *found;
2648
2649 found = __find_space_info(info, flags);
2650 if (found) {
2651 spin_lock(&found->lock);
2652 found->total_bytes += total_bytes;
2653 found->bytes_used += bytes_used;
2654 found->full = 0;
2655 spin_unlock(&found->lock);
2656 *space_info = found;
2657 return 0;
2658 }
2659 found = kzalloc(sizeof(*found), GFP_NOFS);
2660 if (!found)
2661 return -ENOMEM;
2662
2663 INIT_LIST_HEAD(&found->block_groups);
2664 init_rwsem(&found->groups_sem);
2665 spin_lock_init(&found->lock);
2666 found->flags = flags;
2667 found->total_bytes = total_bytes;
2668 found->bytes_used = bytes_used;
2669 found->bytes_pinned = 0;
2670 found->bytes_reserved = 0;
2671 found->bytes_readonly = 0;
2672 found->bytes_delalloc = 0;
2673 found->full = 0;
2674 found->force_alloc = 0;
2675 *space_info = found;
2676 list_add_rcu(&found->list, &info->space_info);
2677 atomic_set(&found->caching_threads, 0);
2678 return 0;
2679 }
2680
2681 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
2682 {
2683 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
2684 BTRFS_BLOCK_GROUP_RAID1 |
2685 BTRFS_BLOCK_GROUP_RAID10 |
2686 BTRFS_BLOCK_GROUP_DUP);
2687 if (extra_flags) {
2688 if (flags & BTRFS_BLOCK_GROUP_DATA)
2689 fs_info->avail_data_alloc_bits |= extra_flags;
2690 if (flags & BTRFS_BLOCK_GROUP_METADATA)
2691 fs_info->avail_metadata_alloc_bits |= extra_flags;
2692 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
2693 fs_info->avail_system_alloc_bits |= extra_flags;
2694 }
2695 }
2696
2697 static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
2698 {
2699 spin_lock(&cache->space_info->lock);
2700 spin_lock(&cache->lock);
2701 if (!cache->ro) {
2702 cache->space_info->bytes_readonly += cache->key.offset -
2703 btrfs_block_group_used(&cache->item);
2704 cache->ro = 1;
2705 }
2706 spin_unlock(&cache->lock);
2707 spin_unlock(&cache->space_info->lock);
2708 }
2709
2710 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
2711 {
2712 u64 num_devices = root->fs_info->fs_devices->rw_devices;
2713
2714 if (num_devices == 1)
2715 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
2716 if (num_devices < 4)
2717 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
2718
2719 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
2720 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
2721 BTRFS_BLOCK_GROUP_RAID10))) {
2722 flags &= ~BTRFS_BLOCK_GROUP_DUP;
2723 }
2724
2725 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
2726 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
2727 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
2728 }
2729
2730 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
2731 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
2732 (flags & BTRFS_BLOCK_GROUP_RAID10) |
2733 (flags & BTRFS_BLOCK_GROUP_DUP)))
2734 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
2735 return flags;
2736 }
2737
2738 static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data)
2739 {
2740 struct btrfs_fs_info *info = root->fs_info;
2741 u64 alloc_profile;
2742
2743 if (data) {
2744 alloc_profile = info->avail_data_alloc_bits &
2745 info->data_alloc_profile;
2746 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2747 } else if (root == root->fs_info->chunk_root) {
2748 alloc_profile = info->avail_system_alloc_bits &
2749 info->system_alloc_profile;
2750 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2751 } else {
2752 alloc_profile = info->avail_metadata_alloc_bits &
2753 info->metadata_alloc_profile;
2754 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2755 }
2756
2757 return btrfs_reduce_alloc_profile(root, data);
2758 }
2759
2760 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
2761 {
2762 u64 alloc_target;
2763
2764 alloc_target = btrfs_get_alloc_profile(root, 1);
2765 BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
2766 alloc_target);
2767 }
2768
2769 static u64 calculate_bytes_needed(struct btrfs_root *root, int num_items)
2770 {
2771 u64 num_bytes;
2772 int level;
2773
2774 level = BTRFS_MAX_LEVEL - 2;
2775 /*
2776 * NOTE: these calculations are absolutely the worst possible case.
2777 * This assumes that _every_ item we insert will require a new leaf, and
2778 * that the tree has grown to its maximum level size.
2779 */
2780
2781 /*
2782 * for every item we insert we could insert both an extent item and a
2783 * extent ref item. Then for ever item we insert, we will need to cow
2784 * both the original leaf, plus the leaf to the left and right of it.
2785 *
2786 * Unless we are talking about the extent root, then we just want the
2787 * number of items * 2, since we just need the extent item plus its ref.
2788 */
2789 if (root == root->fs_info->extent_root)
2790 num_bytes = num_items * 2;
2791 else
2792 num_bytes = (num_items + (2 * num_items)) * 3;
2793
2794 /*
2795 * num_bytes is total number of leaves we could need times the leaf
2796 * size, and then for every leaf we could end up cow'ing 2 nodes per
2797 * level, down to the leaf level.
2798 */
2799 num_bytes = (num_bytes * root->leafsize) +
2800 (num_bytes * (level * 2)) * root->nodesize;
2801
2802 return num_bytes;
2803 }
2804
2805 /*
2806 * Unreserve metadata space for delalloc. If we have less reserved credits than
2807 * we have extents, this function does nothing.
2808 */
2809 int btrfs_unreserve_metadata_for_delalloc(struct btrfs_root *root,
2810 struct inode *inode, int num_items)
2811 {
2812 struct btrfs_fs_info *info = root->fs_info;
2813 struct btrfs_space_info *meta_sinfo;
2814 u64 num_bytes;
2815 u64 alloc_target;
2816 bool bug = false;
2817
2818 /* get the space info for where the metadata will live */
2819 alloc_target = btrfs_get_alloc_profile(root, 0);
2820 meta_sinfo = __find_space_info(info, alloc_target);
2821
2822 num_bytes = calculate_bytes_needed(root->fs_info->extent_root,
2823 num_items);
2824
2825 spin_lock(&meta_sinfo->lock);
2826 spin_lock(&BTRFS_I(inode)->accounting_lock);
2827 if (BTRFS_I(inode)->reserved_extents <=
2828 BTRFS_I(inode)->outstanding_extents) {
2829 spin_unlock(&BTRFS_I(inode)->accounting_lock);
2830 spin_unlock(&meta_sinfo->lock);
2831 return 0;
2832 }
2833 spin_unlock(&BTRFS_I(inode)->accounting_lock);
2834
2835 BTRFS_I(inode)->reserved_extents--;
2836 BUG_ON(BTRFS_I(inode)->reserved_extents < 0);
2837
2838 if (meta_sinfo->bytes_delalloc < num_bytes) {
2839 bug = true;
2840 meta_sinfo->bytes_delalloc = 0;
2841 } else {
2842 meta_sinfo->bytes_delalloc -= num_bytes;
2843 }
2844 spin_unlock(&meta_sinfo->lock);
2845
2846 BUG_ON(bug);
2847
2848 return 0;
2849 }
2850
2851 static void check_force_delalloc(struct btrfs_space_info *meta_sinfo)
2852 {
2853 u64 thresh;
2854
2855 thresh = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
2856 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
2857 meta_sinfo->bytes_super + meta_sinfo->bytes_root +
2858 meta_sinfo->bytes_may_use;
2859
2860 thresh = meta_sinfo->total_bytes - thresh;
2861 thresh *= 80;
2862 do_div(thresh, 100);
2863 if (thresh <= meta_sinfo->bytes_delalloc)
2864 meta_sinfo->force_delalloc = 1;
2865 else
2866 meta_sinfo->force_delalloc = 0;
2867 }
2868
2869 struct async_flush {
2870 struct btrfs_root *root;
2871 struct btrfs_space_info *info;
2872 struct btrfs_work work;
2873 };
2874
2875 static noinline void flush_delalloc_async(struct btrfs_work *work)
2876 {
2877 struct async_flush *async;
2878 struct btrfs_root *root;
2879 struct btrfs_space_info *info;
2880
2881 async = container_of(work, struct async_flush, work);
2882 root = async->root;
2883 info = async->info;
2884
2885 btrfs_start_delalloc_inodes(root);
2886 wake_up(&info->flush_wait);
2887 btrfs_wait_ordered_extents(root, 0);
2888
2889 spin_lock(&info->lock);
2890 info->flushing = 0;
2891 spin_unlock(&info->lock);
2892 wake_up(&info->flush_wait);
2893
2894 kfree(async);
2895 }
2896
2897 static void wait_on_flush(struct btrfs_space_info *info)
2898 {
2899 DEFINE_WAIT(wait);
2900 u64 used;
2901
2902 while (1) {
2903 prepare_to_wait(&info->flush_wait, &wait,
2904 TASK_UNINTERRUPTIBLE);
2905 spin_lock(&info->lock);
2906 if (!info->flushing) {
2907 spin_unlock(&info->lock);
2908 break;
2909 }
2910
2911 used = info->bytes_used + info->bytes_reserved +
2912 info->bytes_pinned + info->bytes_readonly +
2913 info->bytes_super + info->bytes_root +
2914 info->bytes_may_use + info->bytes_delalloc;
2915 if (used < info->total_bytes) {
2916 spin_unlock(&info->lock);
2917 break;
2918 }
2919 spin_unlock(&info->lock);
2920 schedule();
2921 }
2922 finish_wait(&info->flush_wait, &wait);
2923 }
2924
2925 static void flush_delalloc(struct btrfs_root *root,
2926 struct btrfs_space_info *info)
2927 {
2928 struct async_flush *async;
2929 bool wait = false;
2930
2931 spin_lock(&info->lock);
2932
2933 if (!info->flushing) {
2934 info->flushing = 1;
2935 init_waitqueue_head(&info->flush_wait);
2936 } else {
2937 wait = true;
2938 }
2939
2940 spin_unlock(&info->lock);
2941
2942 if (wait) {
2943 wait_on_flush(info);
2944 return;
2945 }
2946
2947 async = kzalloc(sizeof(*async), GFP_NOFS);
2948 if (!async)
2949 goto flush;
2950
2951 async->root = root;
2952 async->info = info;
2953 async->work.func = flush_delalloc_async;
2954
2955 btrfs_queue_worker(&root->fs_info->enospc_workers,
2956 &async->work);
2957 wait_on_flush(info);
2958 return;
2959
2960 flush:
2961 btrfs_start_delalloc_inodes(root);
2962 btrfs_wait_ordered_extents(root, 0);
2963
2964 spin_lock(&info->lock);
2965 info->flushing = 0;
2966 spin_unlock(&info->lock);
2967 wake_up(&info->flush_wait);
2968 }
2969
2970 static int maybe_allocate_chunk(struct btrfs_root *root,
2971 struct btrfs_space_info *info)
2972 {
2973 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
2974 struct btrfs_trans_handle *trans;
2975 bool wait = false;
2976 int ret = 0;
2977 u64 min_metadata;
2978 u64 free_space;
2979
2980 free_space = btrfs_super_total_bytes(disk_super);
2981 /*
2982 * we allow the metadata to grow to a max of either 5gb or 5% of the
2983 * space in the volume.
2984 */
2985 min_metadata = min((u64)5 * 1024 * 1024 * 1024,
2986 div64_u64(free_space * 5, 100));
2987 if (info->total_bytes >= min_metadata) {
2988 spin_unlock(&info->lock);
2989 return 0;
2990 }
2991
2992 if (info->full) {
2993 spin_unlock(&info->lock);
2994 return 0;
2995 }
2996
2997 if (!info->allocating_chunk) {
2998 info->force_alloc = 1;
2999 info->allocating_chunk = 1;
3000 init_waitqueue_head(&info->allocate_wait);
3001 } else {
3002 wait = true;
3003 }
3004
3005 spin_unlock(&info->lock);
3006
3007 if (wait) {
3008 wait_event(info->allocate_wait,
3009 !info->allocating_chunk);
3010 return 1;
3011 }
3012
3013 trans = btrfs_start_transaction(root, 1);
3014 if (!trans) {
3015 ret = -ENOMEM;
3016 goto out;
3017 }
3018
3019 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3020 4096 + 2 * 1024 * 1024,
3021 info->flags, 0);
3022 btrfs_end_transaction(trans, root);
3023 if (ret)
3024 goto out;
3025 out:
3026 spin_lock(&info->lock);
3027 info->allocating_chunk = 0;
3028 spin_unlock(&info->lock);
3029 wake_up(&info->allocate_wait);
3030
3031 if (ret)
3032 return 0;
3033 return 1;
3034 }
3035
3036 /*
3037 * Reserve metadata space for delalloc.
3038 */
3039 int btrfs_reserve_metadata_for_delalloc(struct btrfs_root *root,
3040 struct inode *inode, int num_items)
3041 {
3042 struct btrfs_fs_info *info = root->fs_info;
3043 struct btrfs_space_info *meta_sinfo;
3044 u64 num_bytes;
3045 u64 used;
3046 u64 alloc_target;
3047 int flushed = 0;
3048 int force_delalloc;
3049
3050 /* get the space info for where the metadata will live */
3051 alloc_target = btrfs_get_alloc_profile(root, 0);
3052 meta_sinfo = __find_space_info(info, alloc_target);
3053
3054 num_bytes = calculate_bytes_needed(root->fs_info->extent_root,
3055 num_items);
3056 again:
3057 spin_lock(&meta_sinfo->lock);
3058
3059 force_delalloc = meta_sinfo->force_delalloc;
3060
3061 if (unlikely(!meta_sinfo->bytes_root))
3062 meta_sinfo->bytes_root = calculate_bytes_needed(root, 6);
3063
3064 if (!flushed)
3065 meta_sinfo->bytes_delalloc += num_bytes;
3066
3067 used = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
3068 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
3069 meta_sinfo->bytes_super + meta_sinfo->bytes_root +
3070 meta_sinfo->bytes_may_use + meta_sinfo->bytes_delalloc;
3071
3072 if (used > meta_sinfo->total_bytes) {
3073 flushed++;
3074
3075 if (flushed == 1) {
3076 if (maybe_allocate_chunk(root, meta_sinfo))
3077 goto again;
3078 flushed++;
3079 } else {
3080 spin_unlock(&meta_sinfo->lock);
3081 }
3082
3083 if (flushed == 2) {
3084 filemap_flush(inode->i_mapping);
3085 goto again;
3086 } else if (flushed == 3) {
3087 flush_delalloc(root, meta_sinfo);
3088 goto again;
3089 }
3090 spin_lock(&meta_sinfo->lock);
3091 meta_sinfo->bytes_delalloc -= num_bytes;
3092 spin_unlock(&meta_sinfo->lock);
3093 printk(KERN_ERR "enospc, has %d, reserved %d\n",
3094 BTRFS_I(inode)->outstanding_extents,
3095 BTRFS_I(inode)->reserved_extents);
3096 dump_space_info(meta_sinfo, 0, 0);
3097 return -ENOSPC;
3098 }
3099
3100 BTRFS_I(inode)->reserved_extents++;
3101 check_force_delalloc(meta_sinfo);
3102 spin_unlock(&meta_sinfo->lock);
3103
3104 if (!flushed && force_delalloc)
3105 filemap_flush(inode->i_mapping);
3106
3107 return 0;
3108 }
3109
3110 /*
3111 * unreserve num_items number of items worth of metadata space. This needs to
3112 * be paired with btrfs_reserve_metadata_space.
3113 *
3114 * NOTE: if you have the option, run this _AFTER_ you do a
3115 * btrfs_end_transaction, since btrfs_end_transaction will run delayed ref
3116 * oprations which will result in more used metadata, so we want to make sure we
3117 * can do that without issue.
3118 */
3119 int btrfs_unreserve_metadata_space(struct btrfs_root *root, int num_items)
3120 {
3121 struct btrfs_fs_info *info = root->fs_info;
3122 struct btrfs_space_info *meta_sinfo;
3123 u64 num_bytes;
3124 u64 alloc_target;
3125 bool bug = false;
3126
3127 /* get the space info for where the metadata will live */
3128 alloc_target = btrfs_get_alloc_profile(root, 0);
3129 meta_sinfo = __find_space_info(info, alloc_target);
3130
3131 num_bytes = calculate_bytes_needed(root, num_items);
3132
3133 spin_lock(&meta_sinfo->lock);
3134 if (meta_sinfo->bytes_may_use < num_bytes) {
3135 bug = true;
3136 meta_sinfo->bytes_may_use = 0;
3137 } else {
3138 meta_sinfo->bytes_may_use -= num_bytes;
3139 }
3140 spin_unlock(&meta_sinfo->lock);
3141
3142 BUG_ON(bug);
3143
3144 return 0;
3145 }
3146
3147 /*
3148 * Reserve some metadata space for use. We'll calculate the worste case number
3149 * of bytes that would be needed to modify num_items number of items. If we
3150 * have space, fantastic, if not, you get -ENOSPC. Please call
3151 * btrfs_unreserve_metadata_space when you are done for the _SAME_ number of
3152 * items you reserved, since whatever metadata you needed should have already
3153 * been allocated.
3154 *
3155 * This will commit the transaction to make more space if we don't have enough
3156 * metadata space. THe only time we don't do this is if we're reserving space
3157 * inside of a transaction, then we will just return -ENOSPC and it is the
3158 * callers responsibility to handle it properly.
3159 */
3160 int btrfs_reserve_metadata_space(struct btrfs_root *root, int num_items)
3161 {
3162 struct btrfs_fs_info *info = root->fs_info;
3163 struct btrfs_space_info *meta_sinfo;
3164 u64 num_bytes;
3165 u64 used;
3166 u64 alloc_target;
3167 int retries = 0;
3168
3169 /* get the space info for where the metadata will live */
3170 alloc_target = btrfs_get_alloc_profile(root, 0);
3171 meta_sinfo = __find_space_info(info, alloc_target);
3172
3173 num_bytes = calculate_bytes_needed(root, num_items);
3174 again:
3175 spin_lock(&meta_sinfo->lock);
3176
3177 if (unlikely(!meta_sinfo->bytes_root))
3178 meta_sinfo->bytes_root = calculate_bytes_needed(root, 6);
3179
3180 if (!retries)
3181 meta_sinfo->bytes_may_use += num_bytes;
3182
3183 used = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
3184 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
3185 meta_sinfo->bytes_super + meta_sinfo->bytes_root +
3186 meta_sinfo->bytes_may_use + meta_sinfo->bytes_delalloc;
3187
3188 if (used > meta_sinfo->total_bytes) {
3189 retries++;
3190 if (retries == 1) {
3191 if (maybe_allocate_chunk(root, meta_sinfo))
3192 goto again;
3193 retries++;
3194 } else {
3195 spin_unlock(&meta_sinfo->lock);
3196 }
3197
3198 if (retries == 2) {
3199 flush_delalloc(root, meta_sinfo);
3200 goto again;
3201 }
3202 spin_lock(&meta_sinfo->lock);
3203 meta_sinfo->bytes_may_use -= num_bytes;
3204 spin_unlock(&meta_sinfo->lock);
3205
3206 dump_space_info(meta_sinfo, 0, 0);
3207 return -ENOSPC;
3208 }
3209
3210 check_force_delalloc(meta_sinfo);
3211 spin_unlock(&meta_sinfo->lock);
3212
3213 return 0;
3214 }
3215
3216 /*
3217 * This will check the space that the inode allocates from to make sure we have
3218 * enough space for bytes.
3219 */
3220 int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
3221 u64 bytes)
3222 {
3223 struct btrfs_space_info *data_sinfo;
3224 int ret = 0, committed = 0;
3225
3226 /* make sure bytes are sectorsize aligned */
3227 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
3228
3229 data_sinfo = BTRFS_I(inode)->space_info;
3230 if (!data_sinfo)
3231 goto alloc;
3232
3233 again:
3234 /* make sure we have enough space to handle the data first */
3235 spin_lock(&data_sinfo->lock);
3236 if (data_sinfo->total_bytes - data_sinfo->bytes_used -
3237 data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved -
3238 data_sinfo->bytes_pinned - data_sinfo->bytes_readonly -
3239 data_sinfo->bytes_may_use - data_sinfo->bytes_super < bytes) {
3240 struct btrfs_trans_handle *trans;
3241
3242 /*
3243 * if we don't have enough free bytes in this space then we need
3244 * to alloc a new chunk.
3245 */
3246 if (!data_sinfo->full) {
3247 u64 alloc_target;
3248
3249 data_sinfo->force_alloc = 1;
3250 spin_unlock(&data_sinfo->lock);
3251 alloc:
3252 alloc_target = btrfs_get_alloc_profile(root, 1);
3253 trans = btrfs_start_transaction(root, 1);
3254 if (!trans)
3255 return -ENOMEM;
3256
3257 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3258 bytes + 2 * 1024 * 1024,
3259 alloc_target, 0);
3260 btrfs_end_transaction(trans, root);
3261 if (ret)
3262 return ret;
3263
3264 if (!data_sinfo) {
3265 btrfs_set_inode_space_info(root, inode);
3266 data_sinfo = BTRFS_I(inode)->space_info;
3267 }
3268 goto again;
3269 }
3270 spin_unlock(&data_sinfo->lock);
3271
3272 /* commit the current transaction and try again */
3273 if (!committed && !root->fs_info->open_ioctl_trans) {
3274 committed = 1;
3275 trans = btrfs_join_transaction(root, 1);
3276 if (!trans)
3277 return -ENOMEM;
3278 ret = btrfs_commit_transaction(trans, root);
3279 if (ret)
3280 return ret;
3281 goto again;
3282 }
3283
3284 printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes"
3285 ", %llu bytes_used, %llu bytes_reserved, "
3286 "%llu bytes_pinned, %llu bytes_readonly, %llu may use "
3287 "%llu total\n", (unsigned long long)bytes,
3288 (unsigned long long)data_sinfo->bytes_delalloc,
3289 (unsigned long long)data_sinfo->bytes_used,
3290 (unsigned long long)data_sinfo->bytes_reserved,
3291 (unsigned long long)data_sinfo->bytes_pinned,
3292 (unsigned long long)data_sinfo->bytes_readonly,
3293 (unsigned long long)data_sinfo->bytes_may_use,
3294 (unsigned long long)data_sinfo->total_bytes);
3295 return -ENOSPC;
3296 }
3297 data_sinfo->bytes_may_use += bytes;
3298 BTRFS_I(inode)->reserved_bytes += bytes;
3299 spin_unlock(&data_sinfo->lock);
3300
3301 return 0;
3302 }
3303
3304 /*
3305 * if there was an error for whatever reason after calling
3306 * btrfs_check_data_free_space, call this so we can cleanup the counters.
3307 */
3308 void btrfs_free_reserved_data_space(struct btrfs_root *root,
3309 struct inode *inode, u64 bytes)
3310 {
3311 struct btrfs_space_info *data_sinfo;
3312
3313 /* make sure bytes are sectorsize aligned */
3314 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
3315
3316 data_sinfo = BTRFS_I(inode)->space_info;
3317 spin_lock(&data_sinfo->lock);
3318 data_sinfo->bytes_may_use -= bytes;
3319 BTRFS_I(inode)->reserved_bytes -= bytes;
3320 spin_unlock(&data_sinfo->lock);
3321 }
3322
3323 /* called when we are adding a delalloc extent to the inode's io_tree */
3324 void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
3325 u64 bytes)
3326 {
3327 struct btrfs_space_info *data_sinfo;
3328
3329 /* get the space info for where this inode will be storing its data */
3330 data_sinfo = BTRFS_I(inode)->space_info;
3331
3332 /* make sure we have enough space to handle the data first */
3333 spin_lock(&data_sinfo->lock);
3334 data_sinfo->bytes_delalloc += bytes;
3335
3336 /*
3337 * we are adding a delalloc extent without calling
3338 * btrfs_check_data_free_space first. This happens on a weird
3339 * writepage condition, but shouldn't hurt our accounting
3340 */
3341 if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {
3342 data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;
3343 BTRFS_I(inode)->reserved_bytes = 0;
3344 } else {
3345 data_sinfo->bytes_may_use -= bytes;
3346 BTRFS_I(inode)->reserved_bytes -= bytes;
3347 }
3348
3349 spin_unlock(&data_sinfo->lock);
3350 }
3351
3352 /* called when we are clearing an delalloc extent from the inode's io_tree */
3353 void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
3354 u64 bytes)
3355 {
3356 struct btrfs_space_info *info;
3357
3358 info = BTRFS_I(inode)->space_info;
3359
3360 spin_lock(&info->lock);
3361 info->bytes_delalloc -= bytes;
3362 spin_unlock(&info->lock);
3363 }
3364
3365 static void force_metadata_allocation(struct btrfs_fs_info *info)
3366 {
3367 struct list_head *head = &info->space_info;
3368 struct btrfs_space_info *found;
3369
3370 rcu_read_lock();
3371 list_for_each_entry_rcu(found, head, list) {
3372 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
3373 found->force_alloc = 1;
3374 }
3375 rcu_read_unlock();
3376 }
3377
3378 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
3379 struct btrfs_root *extent_root, u64 alloc_bytes,
3380 u64 flags, int force)
3381 {
3382 struct btrfs_space_info *space_info;
3383 struct btrfs_fs_info *fs_info = extent_root->fs_info;
3384 u64 thresh;
3385 int ret = 0;
3386
3387 mutex_lock(&fs_info->chunk_mutex);
3388
3389 flags = btrfs_reduce_alloc_profile(extent_root, flags);
3390
3391 space_info = __find_space_info(extent_root->fs_info, flags);
3392 if (!space_info) {
3393 ret = update_space_info(extent_root->fs_info, flags,
3394 0, 0, &space_info);
3395 BUG_ON(ret);
3396 }
3397 BUG_ON(!space_info);
3398
3399 spin_lock(&space_info->lock);
3400 if (space_info->force_alloc)
3401 force = 1;
3402 if (space_info->full) {
3403 spin_unlock(&space_info->lock);
3404 goto out;
3405 }
3406
3407 thresh = space_info->total_bytes - space_info->bytes_readonly;
3408 thresh = div_factor(thresh, 8);
3409 if (!force &&
3410 (space_info->bytes_used + space_info->bytes_pinned +
3411 space_info->bytes_reserved + alloc_bytes) < thresh) {
3412 spin_unlock(&space_info->lock);
3413 goto out;
3414 }
3415 spin_unlock(&space_info->lock);
3416
3417 /*
3418 * if we're doing a data chunk, go ahead and make sure that
3419 * we keep a reasonable number of metadata chunks allocated in the
3420 * FS as well.
3421 */
3422 if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
3423 fs_info->data_chunk_allocations++;
3424 if (!(fs_info->data_chunk_allocations %
3425 fs_info->metadata_ratio))
3426 force_metadata_allocation(fs_info);
3427 }
3428
3429 ret = btrfs_alloc_chunk(trans, extent_root, flags);
3430 spin_lock(&space_info->lock);
3431 if (ret)
3432 space_info->full = 1;
3433 space_info->force_alloc = 0;
3434 spin_unlock(&space_info->lock);
3435 out:
3436 mutex_unlock(&extent_root->fs_info->chunk_mutex);
3437 return ret;
3438 }
3439
3440 static int update_block_group(struct btrfs_trans_handle *trans,
3441 struct btrfs_root *root,
3442 u64 bytenr, u64 num_bytes, int alloc,
3443 int mark_free)
3444 {
3445 struct btrfs_block_group_cache *cache;
3446 struct btrfs_fs_info *info = root->fs_info;
3447 u64 total = num_bytes;
3448 u64 old_val;
3449 u64 byte_in_group;
3450
3451 /* block accounting for super block */
3452 spin_lock(&info->delalloc_lock);
3453 old_val = btrfs_super_bytes_used(&info->super_copy);
3454 if (alloc)
3455 old_val += num_bytes;
3456 else
3457 old_val -= num_bytes;
3458 btrfs_set_super_bytes_used(&info->super_copy, old_val);
3459
3460 /* block accounting for root item */
3461 old_val = btrfs_root_used(&root->root_item);
3462 if (alloc)
3463 old_val += num_bytes;
3464 else
3465 old_val -= num_bytes;
3466 btrfs_set_root_used(&root->root_item, old_val);
3467 spin_unlock(&info->delalloc_lock);
3468
3469 while (total) {
3470 cache = btrfs_lookup_block_group(info, bytenr);
3471 if (!cache)
3472 return -1;
3473 byte_in_group = bytenr - cache->key.objectid;
3474 WARN_ON(byte_in_group > cache->key.offset);
3475
3476 spin_lock(&cache->space_info->lock);
3477 spin_lock(&cache->lock);
3478 cache->dirty = 1;
3479 old_val = btrfs_block_group_used(&cache->item);
3480 num_bytes = min(total, cache->key.offset - byte_in_group);
3481 if (alloc) {
3482 old_val += num_bytes;
3483 btrfs_set_block_group_used(&cache->item, old_val);
3484 cache->reserved -= num_bytes;
3485 cache->space_info->bytes_used += num_bytes;
3486 cache->space_info->bytes_reserved -= num_bytes;
3487 if (cache->ro)
3488 cache->space_info->bytes_readonly -= num_bytes;
3489 spin_unlock(&cache->lock);
3490 spin_unlock(&cache->space_info->lock);
3491 } else {
3492 old_val -= num_bytes;
3493 cache->space_info->bytes_used -= num_bytes;
3494 if (cache->ro)
3495 cache->space_info->bytes_readonly += num_bytes;
3496 btrfs_set_block_group_used(&cache->item, old_val);
3497 spin_unlock(&cache->lock);
3498 spin_unlock(&cache->space_info->lock);
3499 if (mark_free) {
3500 int ret;
3501
3502 ret = btrfs_discard_extent(root, bytenr,
3503 num_bytes);
3504 WARN_ON(ret);
3505
3506 ret = btrfs_add_free_space(cache, bytenr,
3507 num_bytes);
3508 WARN_ON(ret);
3509 }
3510 }
3511 btrfs_put_block_group(cache);
3512 total -= num_bytes;
3513 bytenr += num_bytes;
3514 }
3515 return 0;
3516 }
3517
3518 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
3519 {
3520 struct btrfs_block_group_cache *cache;
3521 u64 bytenr;
3522
3523 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
3524 if (!cache)
3525 return 0;
3526
3527 bytenr = cache->key.objectid;
3528 btrfs_put_block_group(cache);
3529
3530 return bytenr;
3531 }
3532
3533 /*
3534 * this function must be called within transaction
3535 */
3536 int btrfs_pin_extent(struct btrfs_root *root,
3537 u64 bytenr, u64 num_bytes, int reserved)
3538 {
3539 struct btrfs_fs_info *fs_info = root->fs_info;
3540 struct btrfs_block_group_cache *cache;
3541
3542 cache = btrfs_lookup_block_group(fs_info, bytenr);
3543 BUG_ON(!cache);
3544
3545 spin_lock(&cache->space_info->lock);
3546 spin_lock(&cache->lock);
3547 cache->pinned += num_bytes;
3548 cache->space_info->bytes_pinned += num_bytes;
3549 if (reserved) {
3550 cache->reserved -= num_bytes;
3551 cache->space_info->bytes_reserved -= num_bytes;
3552 }
3553 spin_unlock(&cache->lock);
3554 spin_unlock(&cache->space_info->lock);
3555
3556 btrfs_put_block_group(cache);
3557
3558 set_extent_dirty(fs_info->pinned_extents,
3559 bytenr, bytenr + num_bytes - 1, GFP_NOFS);
3560 return 0;
3561 }
3562
3563 static int update_reserved_extents(struct btrfs_block_group_cache *cache,
3564 u64 num_bytes, int reserve)
3565 {
3566 spin_lock(&cache->space_info->lock);
3567 spin_lock(&cache->lock);
3568 if (reserve) {
3569 cache->reserved += num_bytes;
3570 cache->space_info->bytes_reserved += num_bytes;
3571 } else {
3572 cache->reserved -= num_bytes;
3573 cache->space_info->bytes_reserved -= num_bytes;
3574 }
3575 spin_unlock(&cache->lock);
3576 spin_unlock(&cache->space_info->lock);
3577 return 0;
3578 }
3579
3580 int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
3581 struct btrfs_root *root)
3582 {
3583 struct btrfs_fs_info *fs_info = root->fs_info;
3584 struct btrfs_caching_control *next;
3585 struct btrfs_caching_control *caching_ctl;
3586 struct btrfs_block_group_cache *cache;
3587
3588 down_write(&fs_info->extent_commit_sem);
3589
3590 list_for_each_entry_safe(caching_ctl, next,
3591 &fs_info->caching_block_groups, list) {
3592 cache = caching_ctl->block_group;
3593 if (block_group_cache_done(cache)) {
3594 cache->last_byte_to_unpin = (u64)-1;
3595 list_del_init(&caching_ctl->list);
3596 put_caching_control(caching_ctl);
3597 } else {
3598 cache->last_byte_to_unpin = caching_ctl->progress;
3599 }
3600 }
3601
3602 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
3603 fs_info->pinned_extents = &fs_info->freed_extents[1];
3604 else
3605 fs_info->pinned_extents = &fs_info->freed_extents[0];
3606
3607 up_write(&fs_info->extent_commit_sem);
3608 return 0;
3609 }
3610
3611 static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
3612 {
3613 struct btrfs_fs_info *fs_info = root->fs_info;
3614 struct btrfs_block_group_cache *cache = NULL;
3615 u64 len;
3616
3617 while (start <= end) {
3618 if (!cache ||
3619 start >= cache->key.objectid + cache->key.offset) {
3620 if (cache)
3621 btrfs_put_block_group(cache);
3622 cache = btrfs_lookup_block_group(fs_info, start);
3623 BUG_ON(!cache);
3624 }
3625
3626 len = cache->key.objectid + cache->key.offset - start;
3627 len = min(len, end + 1 - start);
3628
3629 if (start < cache->last_byte_to_unpin) {
3630 len = min(len, cache->last_byte_to_unpin - start);
3631 btrfs_add_free_space(cache, start, len);
3632 }
3633
3634 spin_lock(&cache->space_info->lock);
3635 spin_lock(&cache->lock);
3636 cache->pinned -= len;
3637 cache->space_info->bytes_pinned -= len;
3638 spin_unlock(&cache->lock);
3639 spin_unlock(&cache->space_info->lock);
3640
3641 start += len;
3642 }
3643
3644 if (cache)
3645 btrfs_put_block_group(cache);
3646 return 0;
3647 }
3648
3649 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
3650 struct btrfs_root *root)
3651 {
3652 struct btrfs_fs_info *fs_info = root->fs_info;
3653 struct extent_io_tree *unpin;
3654 u64 start;
3655 u64 end;
3656 int ret;
3657
3658 if (fs_info->pinned_extents == &fs_info->freed_extents[0])
3659 unpin = &fs_info->freed_extents[1];
3660 else
3661 unpin = &fs_info->freed_extents[0];
3662
3663 while (1) {
3664 ret = find_first_extent_bit(unpin, 0, &start, &end,
3665 EXTENT_DIRTY);
3666 if (ret)
3667 break;
3668
3669 ret = btrfs_discard_extent(root, start, end + 1 - start);
3670
3671 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3672 unpin_extent_range(root, start, end);
3673 cond_resched();
3674 }
3675
3676 return ret;
3677 }
3678
3679 static int pin_down_bytes(struct btrfs_trans_handle *trans,
3680 struct btrfs_root *root,
3681 struct btrfs_path *path,
3682 u64 bytenr, u64 num_bytes,
3683 int is_data, int reserved,
3684 struct extent_buffer **must_clean)
3685 {
3686 int err = 0;
3687 struct extent_buffer *buf;
3688
3689 if (is_data)
3690 goto pinit;
3691
3692 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
3693 if (!buf)
3694 goto pinit;
3695
3696 /* we can reuse a block if it hasn't been written
3697 * and it is from this transaction. We can't
3698 * reuse anything from the tree log root because
3699 * it has tiny sub-transactions.
3700 */
3701 if (btrfs_buffer_uptodate(buf, 0) &&
3702 btrfs_try_tree_lock(buf)) {
3703 u64 header_owner = btrfs_header_owner(buf);
3704 u64 header_transid = btrfs_header_generation(buf);
3705 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
3706 header_transid == trans->transid &&
3707 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
3708 *must_clean = buf;
3709 return 1;
3710 }
3711 btrfs_tree_unlock(buf);
3712 }
3713 free_extent_buffer(buf);
3714 pinit:
3715 if (path)
3716 btrfs_set_path_blocking(path);
3717 /* unlocks the pinned mutex */
3718 btrfs_pin_extent(root, bytenr, num_bytes, reserved);
3719
3720 BUG_ON(err < 0);
3721 return 0;
3722 }
3723
3724 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
3725 struct btrfs_root *root,
3726 u64 bytenr, u64 num_bytes, u64 parent,
3727 u64 root_objectid, u64 owner_objectid,
3728 u64 owner_offset, int refs_to_drop,
3729 struct btrfs_delayed_extent_op *extent_op)
3730 {
3731 struct btrfs_key key;
3732 struct btrfs_path *path;
3733 struct btrfs_fs_info *info = root->fs_info;
3734 struct btrfs_root *extent_root = info->extent_root;
3735 struct extent_buffer *leaf;
3736 struct btrfs_extent_item *ei;
3737 struct btrfs_extent_inline_ref *iref;
3738 int ret;
3739 int is_data;
3740 int extent_slot = 0;
3741 int found_extent = 0;
3742 int num_to_del = 1;
3743 u32 item_size;
3744 u64 refs;
3745
3746 path = btrfs_alloc_path();
3747 if (!path)
3748 return -ENOMEM;
3749
3750 path->reada = 1;
3751 path->leave_spinning = 1;
3752
3753 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
3754 BUG_ON(!is_data && refs_to_drop != 1);
3755
3756 ret = lookup_extent_backref(trans, extent_root, path, &iref,
3757 bytenr, num_bytes, parent,
3758 root_objectid, owner_objectid,
3759 owner_offset);
3760 if (ret == 0) {
3761 extent_slot = path->slots[0];
3762 while (extent_slot >= 0) {
3763 btrfs_item_key_to_cpu(path->nodes[0], &key,
3764 extent_slot);
3765 if (key.objectid != bytenr)
3766 break;
3767 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3768 key.offset == num_bytes) {
3769 found_extent = 1;
3770 break;
3771 }
3772 if (path->slots[0] - extent_slot > 5)
3773 break;
3774 extent_slot--;
3775 }
3776 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3777 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
3778 if (found_extent && item_size < sizeof(*ei))
3779 found_extent = 0;
3780 #endif
3781 if (!found_extent) {
3782 BUG_ON(iref);
3783 ret = remove_extent_backref(trans, extent_root, path,
3784 NULL, refs_to_drop,
3785 is_data);
3786 BUG_ON(ret);
3787 btrfs_release_path(extent_root, path);
3788 path->leave_spinning = 1;
3789
3790 key.objectid = bytenr;
3791 key.type = BTRFS_EXTENT_ITEM_KEY;
3792 key.offset = num_bytes;
3793
3794 ret = btrfs_search_slot(trans, extent_root,
3795 &key, path, -1, 1);
3796 if (ret) {
3797 printk(KERN_ERR "umm, got %d back from search"
3798 ", was looking for %llu\n", ret,
3799 (unsigned long long)bytenr);
3800 btrfs_print_leaf(extent_root, path->nodes[0]);
3801 }
3802 BUG_ON(ret);
3803 extent_slot = path->slots[0];
3804 }
3805 } else {
3806 btrfs_print_leaf(extent_root, path->nodes[0]);
3807 WARN_ON(1);
3808 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
3809 "parent %llu root %llu owner %llu offset %llu\n",
3810 (unsigned long long)bytenr,
3811 (unsigned long long)parent,
3812 (unsigned long long)root_objectid,
3813 (unsigned long long)owner_objectid,
3814 (unsigned long long)owner_offset);
3815 }
3816
3817 leaf = path->nodes[0];
3818 item_size = btrfs_item_size_nr(leaf, extent_slot);
3819 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3820 if (item_size < sizeof(*ei)) {
3821 BUG_ON(found_extent || extent_slot != path->slots[0]);
3822 ret = convert_extent_item_v0(trans, extent_root, path,
3823 owner_objectid, 0);
3824 BUG_ON(ret < 0);
3825
3826 btrfs_release_path(extent_root, path);
3827 path->leave_spinning = 1;
3828
3829 key.objectid = bytenr;
3830 key.type = BTRFS_EXTENT_ITEM_KEY;
3831 key.offset = num_bytes;
3832
3833 ret = btrfs_search_slot(trans, extent_root, &key, path,
3834 -1, 1);
3835 if (ret) {
3836 printk(KERN_ERR "umm, got %d back from search"
3837 ", was looking for %llu\n", ret,
3838 (unsigned long long)bytenr);
3839 btrfs_print_leaf(extent_root, path->nodes[0]);
3840 }
3841 BUG_ON(ret);
3842 extent_slot = path->slots[0];
3843 leaf = path->nodes[0];
3844 item_size = btrfs_item_size_nr(leaf, extent_slot);
3845 }
3846 #endif
3847 BUG_ON(item_size < sizeof(*ei));
3848 ei = btrfs_item_ptr(leaf, extent_slot,
3849 struct btrfs_extent_item);
3850 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3851 struct btrfs_tree_block_info *bi;
3852 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
3853 bi = (struct btrfs_tree_block_info *)(ei + 1);
3854 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
3855 }
3856
3857 refs = btrfs_extent_refs(leaf, ei);
3858 BUG_ON(refs < refs_to_drop);
3859 refs -= refs_to_drop;
3860
3861 if (refs > 0) {
3862 if (extent_op)
3863 __run_delayed_extent_op(extent_op, leaf, ei);
3864 /*
3865 * In the case of inline back ref, reference count will
3866 * be updated by remove_extent_backref
3867 */
3868 if (iref) {
3869 BUG_ON(!found_extent);
3870 } else {
3871 btrfs_set_extent_refs(leaf, ei, refs);
3872 btrfs_mark_buffer_dirty(leaf);
3873 }
3874 if (found_extent) {
3875 ret = remove_extent_backref(trans, extent_root, path,
3876 iref, refs_to_drop,
3877 is_data);
3878 BUG_ON(ret);
3879 }
3880 } else {
3881 int mark_free = 0;
3882 struct extent_buffer *must_clean = NULL;
3883
3884 if (found_extent) {
3885 BUG_ON(is_data && refs_to_drop !=
3886 extent_data_ref_count(root, path, iref));
3887 if (iref) {
3888 BUG_ON(path->slots[0] != extent_slot);
3889 } else {
3890 BUG_ON(path->slots[0] != extent_slot + 1);
3891 path->slots[0] = extent_slot;
3892 num_to_del = 2;
3893 }
3894 }
3895
3896 ret = pin_down_bytes(trans, root, path, bytenr,
3897 num_bytes, is_data, 0, &must_clean);
3898 if (ret > 0)
3899 mark_free = 1;
3900 BUG_ON(ret < 0);
3901 /*
3902 * it is going to be very rare for someone to be waiting
3903 * on the block we're freeing. del_items might need to
3904 * schedule, so rather than get fancy, just force it
3905 * to blocking here
3906 */
3907 if (must_clean)
3908 btrfs_set_lock_blocking(must_clean);
3909
3910 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
3911 num_to_del);
3912 BUG_ON(ret);
3913 btrfs_release_path(extent_root, path);
3914
3915 if (must_clean) {
3916 clean_tree_block(NULL, root, must_clean);
3917 btrfs_tree_unlock(must_clean);
3918 free_extent_buffer(must_clean);
3919 }
3920
3921 if (is_data) {
3922 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
3923 BUG_ON(ret);
3924 } else {
3925 invalidate_mapping_pages(info->btree_inode->i_mapping,
3926 bytenr >> PAGE_CACHE_SHIFT,
3927 (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
3928 }
3929
3930 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
3931 mark_free);
3932 BUG_ON(ret);
3933 }
3934 btrfs_free_path(path);
3935 return ret;
3936 }
3937
3938 /*
3939 * when we free an extent, it is possible (and likely) that we free the last
3940 * delayed ref for that extent as well. This searches the delayed ref tree for
3941 * a given extent, and if there are no other delayed refs to be processed, it
3942 * removes it from the tree.
3943 */
3944 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
3945 struct btrfs_root *root, u64 bytenr)
3946 {
3947 struct btrfs_delayed_ref_head *head;
3948 struct btrfs_delayed_ref_root *delayed_refs;
3949 struct btrfs_delayed_ref_node *ref;
3950 struct rb_node *node;
3951 int ret;
3952
3953 delayed_refs = &trans->transaction->delayed_refs;
3954 spin_lock(&delayed_refs->lock);
3955 head = btrfs_find_delayed_ref_head(trans, bytenr);
3956 if (!head)
3957 goto out;
3958
3959 node = rb_prev(&head->node.rb_node);
3960 if (!node)
3961 goto out;
3962
3963 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3964
3965 /* there are still entries for this ref, we can't drop it */
3966 if (ref->bytenr == bytenr)
3967 goto out;
3968
3969 if (head->extent_op) {
3970 if (!head->must_insert_reserved)
3971 goto out;
3972 kfree(head->extent_op);
3973 head->extent_op = NULL;
3974 }
3975
3976 /*
3977 * waiting for the lock here would deadlock. If someone else has it
3978 * locked they are already in the process of dropping it anyway
3979 */
3980 if (!mutex_trylock(&head->mutex))
3981 goto out;
3982
3983 /*
3984 * at this point we have a head with no other entries. Go
3985 * ahead and process it.
3986 */
3987 head->node.in_tree = 0;
3988 rb_erase(&head->node.rb_node, &delayed_refs->root);
3989
3990 delayed_refs->num_entries--;
3991
3992 /*
3993 * we don't take a ref on the node because we're removing it from the
3994 * tree, so we just steal the ref the tree was holding.
3995 */
3996 delayed_refs->num_heads--;
3997 if (list_empty(&head->cluster))
3998 delayed_refs->num_heads_ready--;
3999
4000 list_del_init(&head->cluster);
4001 spin_unlock(&delayed_refs->lock);
4002
4003 ret = run_one_delayed_ref(trans, root->fs_info->tree_root,
4004 &head->node, head->extent_op,
4005 head->must_insert_reserved);
4006 BUG_ON(ret);
4007 btrfs_put_delayed_ref(&head->node);
4008 return 0;
4009 out:
4010 spin_unlock(&delayed_refs->lock);
4011 return 0;
4012 }
4013
4014 int btrfs_free_extent(struct btrfs_trans_handle *trans,
4015 struct btrfs_root *root,
4016 u64 bytenr, u64 num_bytes, u64 parent,
4017 u64 root_objectid, u64 owner, u64 offset)
4018 {
4019 int ret;
4020
4021 /*
4022 * tree log blocks never actually go into the extent allocation
4023 * tree, just update pinning info and exit early.
4024 */
4025 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
4026 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
4027 /* unlocks the pinned mutex */
4028 btrfs_pin_extent(root, bytenr, num_bytes, 1);
4029 ret = 0;
4030 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
4031 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
4032 parent, root_objectid, (int)owner,
4033 BTRFS_DROP_DELAYED_REF, NULL);
4034 BUG_ON(ret);
4035 ret = check_ref_cleanup(trans, root, bytenr);
4036 BUG_ON(ret);
4037 } else {
4038 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
4039 parent, root_objectid, owner,
4040 offset, BTRFS_DROP_DELAYED_REF, NULL);
4041 BUG_ON(ret);
4042 }
4043 return ret;
4044 }
4045
4046 static u64 stripe_align(struct btrfs_root *root, u64 val)
4047 {
4048 u64 mask = ((u64)root->stripesize - 1);
4049 u64 ret = (val + mask) & ~mask;
4050 return ret;
4051 }
4052
4053 /*
4054 * when we wait for progress in the block group caching, its because
4055 * our allocation attempt failed at least once. So, we must sleep
4056 * and let some progress happen before we try again.
4057 *
4058 * This function will sleep at least once waiting for new free space to
4059 * show up, and then it will check the block group free space numbers
4060 * for our min num_bytes. Another option is to have it go ahead
4061 * and look in the rbtree for a free extent of a given size, but this
4062 * is a good start.
4063 */
4064 static noinline int
4065 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
4066 u64 num_bytes)
4067 {
4068 struct btrfs_caching_control *caching_ctl;
4069 DEFINE_WAIT(wait);
4070
4071 caching_ctl = get_caching_control(cache);
4072 if (!caching_ctl)
4073 return 0;
4074
4075 wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
4076 (cache->free_space >= num_bytes));
4077
4078 put_caching_control(caching_ctl);
4079 return 0;
4080 }
4081
4082 static noinline int
4083 wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
4084 {
4085 struct btrfs_caching_control *caching_ctl;
4086 DEFINE_WAIT(wait);
4087
4088 caching_ctl = get_caching_control(cache);
4089 if (!caching_ctl)
4090 return 0;
4091
4092 wait_event(caching_ctl->wait, block_group_cache_done(cache));
4093
4094 put_caching_control(caching_ctl);
4095 return 0;
4096 }
4097
4098 enum btrfs_loop_type {
4099 LOOP_CACHED_ONLY = 0,
4100 LOOP_CACHING_NOWAIT = 1,
4101 LOOP_CACHING_WAIT = 2,
4102 LOOP_ALLOC_CHUNK = 3,
4103 LOOP_NO_EMPTY_SIZE = 4,
4104 };
4105
4106 /*
4107 * walks the btree of allocated extents and find a hole of a given size.
4108 * The key ins is changed to record the hole:
4109 * ins->objectid == block start
4110 * ins->flags = BTRFS_EXTENT_ITEM_KEY
4111 * ins->offset == number of blocks
4112 * Any available blocks before search_start are skipped.
4113 */
4114 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
4115 struct btrfs_root *orig_root,
4116 u64 num_bytes, u64 empty_size,
4117 u64 search_start, u64 search_end,
4118 u64 hint_byte, struct btrfs_key *ins,
4119 u64 exclude_start, u64 exclude_nr,
4120 int data)
4121 {
4122 int ret = 0;
4123 struct btrfs_root *root = orig_root->fs_info->extent_root;
4124 struct btrfs_free_cluster *last_ptr = NULL;
4125 struct btrfs_block_group_cache *block_group = NULL;
4126 int empty_cluster = 2 * 1024 * 1024;
4127 int allowed_chunk_alloc = 0;
4128 struct btrfs_space_info *space_info;
4129 int last_ptr_loop = 0;
4130 int loop = 0;
4131 bool found_uncached_bg = false;
4132 bool failed_cluster_refill = false;
4133 bool failed_alloc = false;
4134
4135 WARN_ON(num_bytes < root->sectorsize);
4136 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
4137 ins->objectid = 0;
4138 ins->offset = 0;
4139
4140 space_info = __find_space_info(root->fs_info, data);
4141
4142 if (orig_root->ref_cows || empty_size)
4143 allowed_chunk_alloc = 1;
4144
4145 if (data & BTRFS_BLOCK_GROUP_METADATA) {
4146 last_ptr = &root->fs_info->meta_alloc_cluster;
4147 if (!btrfs_test_opt(root, SSD))
4148 empty_cluster = 64 * 1024;
4149 }
4150
4151 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
4152 last_ptr = &root->fs_info->data_alloc_cluster;
4153 }
4154
4155 if (last_ptr) {
4156 spin_lock(&last_ptr->lock);
4157 if (last_ptr->block_group)
4158 hint_byte = last_ptr->window_start;
4159 spin_unlock(&last_ptr->lock);
4160 }
4161
4162 search_start = max(search_start, first_logical_byte(root, 0));
4163 search_start = max(search_start, hint_byte);
4164
4165 if (!last_ptr)
4166 empty_cluster = 0;
4167
4168 if (search_start == hint_byte) {
4169 block_group = btrfs_lookup_block_group(root->fs_info,
4170 search_start);
4171 /*
4172 * we don't want to use the block group if it doesn't match our
4173 * allocation bits, or if its not cached.
4174 */
4175 if (block_group && block_group_bits(block_group, data) &&
4176 block_group_cache_done(block_group)) {
4177 down_read(&space_info->groups_sem);
4178 if (list_empty(&block_group->list) ||
4179 block_group->ro) {
4180 /*
4181 * someone is removing this block group,
4182 * we can't jump into the have_block_group
4183 * target because our list pointers are not
4184 * valid
4185 */
4186 btrfs_put_block_group(block_group);
4187 up_read(&space_info->groups_sem);
4188 } else
4189 goto have_block_group;
4190 } else if (block_group) {
4191 btrfs_put_block_group(block_group);
4192 }
4193 }
4194
4195 search:
4196 down_read(&space_info->groups_sem);
4197 list_for_each_entry(block_group, &space_info->block_groups, list) {
4198 u64 offset;
4199 int cached;
4200
4201 atomic_inc(&block_group->count);
4202 search_start = block_group->key.objectid;
4203
4204 have_block_group:
4205 if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
4206 /*
4207 * we want to start caching kthreads, but not too many
4208 * right off the bat so we don't overwhelm the system,
4209 * so only start them if there are less than 2 and we're
4210 * in the initial allocation phase.
4211 */
4212 if (loop > LOOP_CACHING_NOWAIT ||
4213 atomic_read(&space_info->caching_threads) < 2) {
4214 ret = cache_block_group(block_group);
4215 BUG_ON(ret);
4216 }
4217 }
4218
4219 cached = block_group_cache_done(block_group);
4220 if (unlikely(!cached)) {
4221 found_uncached_bg = true;
4222
4223 /* if we only want cached bgs, loop */
4224 if (loop == LOOP_CACHED_ONLY)
4225 goto loop;
4226 }
4227
4228 if (unlikely(block_group->ro))
4229 goto loop;
4230
4231 /*
4232 * Ok we want to try and use the cluster allocator, so lets look
4233 * there, unless we are on LOOP_NO_EMPTY_SIZE, since we will
4234 * have tried the cluster allocator plenty of times at this
4235 * point and not have found anything, so we are likely way too
4236 * fragmented for the clustering stuff to find anything, so lets
4237 * just skip it and let the allocator find whatever block it can
4238 * find
4239 */
4240 if (last_ptr && loop < LOOP_NO_EMPTY_SIZE) {
4241 /*
4242 * the refill lock keeps out other
4243 * people trying to start a new cluster
4244 */
4245 spin_lock(&last_ptr->refill_lock);
4246 if (last_ptr->block_group &&
4247 (last_ptr->block_group->ro ||
4248 !block_group_bits(last_ptr->block_group, data))) {
4249 offset = 0;
4250 goto refill_cluster;
4251 }
4252
4253 offset = btrfs_alloc_from_cluster(block_group, last_ptr,
4254 num_bytes, search_start);
4255 if (offset) {
4256 /* we have a block, we're done */
4257 spin_unlock(&last_ptr->refill_lock);
4258 goto checks;
4259 }
4260
4261 spin_lock(&last_ptr->lock);
4262 /*
4263 * whoops, this cluster doesn't actually point to
4264 * this block group. Get a ref on the block
4265 * group is does point to and try again
4266 */
4267 if (!last_ptr_loop && last_ptr->block_group &&
4268 last_ptr->block_group != block_group) {
4269
4270 btrfs_put_block_group(block_group);
4271 block_group = last_ptr->block_group;
4272 atomic_inc(&block_group->count);
4273 spin_unlock(&last_ptr->lock);
4274 spin_unlock(&last_ptr->refill_lock);
4275
4276 last_ptr_loop = 1;
4277 search_start = block_group->key.objectid;
4278 /*
4279 * we know this block group is properly
4280 * in the list because
4281 * btrfs_remove_block_group, drops the
4282 * cluster before it removes the block
4283 * group from the list
4284 */
4285 goto have_block_group;
4286 }
4287 spin_unlock(&last_ptr->lock);
4288 refill_cluster:
4289 /*
4290 * this cluster didn't work out, free it and
4291 * start over
4292 */
4293 btrfs_return_cluster_to_free_space(NULL, last_ptr);
4294
4295 last_ptr_loop = 0;
4296
4297 /* allocate a cluster in this block group */
4298 ret = btrfs_find_space_cluster(trans, root,
4299 block_group, last_ptr,
4300 offset, num_bytes,
4301 empty_cluster + empty_size);
4302 if (ret == 0) {
4303 /*
4304 * now pull our allocation out of this
4305 * cluster
4306 */
4307 offset = btrfs_alloc_from_cluster(block_group,
4308 last_ptr, num_bytes,
4309 search_start);
4310 if (offset) {
4311 /* we found one, proceed */
4312 spin_unlock(&last_ptr->refill_lock);
4313 goto checks;
4314 }
4315 } else if (!cached && loop > LOOP_CACHING_NOWAIT
4316 && !failed_cluster_refill) {
4317 spin_unlock(&last_ptr->refill_lock);
4318
4319 failed_cluster_refill = true;
4320 wait_block_group_cache_progress(block_group,
4321 num_bytes + empty_cluster + empty_size);
4322 goto have_block_group;
4323 }
4324
4325 /*
4326 * at this point we either didn't find a cluster
4327 * or we weren't able to allocate a block from our
4328 * cluster. Free the cluster we've been trying
4329 * to use, and go to the next block group
4330 */
4331 btrfs_return_cluster_to_free_space(NULL, last_ptr);
4332 spin_unlock(&last_ptr->refill_lock);
4333 goto loop;
4334 }
4335
4336 offset = btrfs_find_space_for_alloc(block_group, search_start,
4337 num_bytes, empty_size);
4338 /*
4339 * If we didn't find a chunk, and we haven't failed on this
4340 * block group before, and this block group is in the middle of
4341 * caching and we are ok with waiting, then go ahead and wait
4342 * for progress to be made, and set failed_alloc to true.
4343 *
4344 * If failed_alloc is true then we've already waited on this
4345 * block group once and should move on to the next block group.
4346 */
4347 if (!offset && !failed_alloc && !cached &&
4348 loop > LOOP_CACHING_NOWAIT) {
4349 wait_block_group_cache_progress(block_group,
4350 num_bytes + empty_size);
4351 failed_alloc = true;
4352 goto have_block_group;
4353 } else if (!offset) {
4354 goto loop;
4355 }
4356 checks:
4357 search_start = stripe_align(root, offset);
4358 /* move on to the next group */
4359 if (search_start + num_bytes >= search_end) {
4360 btrfs_add_free_space(block_group, offset, num_bytes);
4361 goto loop;
4362 }
4363
4364 /* move on to the next group */
4365 if (search_start + num_bytes >
4366 block_group->key.objectid + block_group->key.offset) {
4367 btrfs_add_free_space(block_group, offset, num_bytes);
4368 goto loop;
4369 }
4370
4371 if (exclude_nr > 0 &&
4372 (search_start + num_bytes > exclude_start &&
4373 search_start < exclude_start + exclude_nr)) {
4374 search_start = exclude_start + exclude_nr;
4375
4376 btrfs_add_free_space(block_group, offset, num_bytes);
4377 /*
4378 * if search_start is still in this block group
4379 * then we just re-search this block group
4380 */
4381 if (search_start >= block_group->key.objectid &&
4382 search_start < (block_group->key.objectid +
4383 block_group->key.offset))
4384 goto have_block_group;
4385 goto loop;
4386 }
4387
4388 ins->objectid = search_start;
4389 ins->offset = num_bytes;
4390
4391 if (offset < search_start)
4392 btrfs_add_free_space(block_group, offset,
4393 search_start - offset);
4394 BUG_ON(offset > search_start);
4395
4396 update_reserved_extents(block_group, num_bytes, 1);
4397
4398 /* we are all good, lets return */
4399 break;
4400 loop:
4401 failed_cluster_refill = false;
4402 failed_alloc = false;
4403 btrfs_put_block_group(block_group);
4404 }
4405 up_read(&space_info->groups_sem);
4406
4407 /* LOOP_CACHED_ONLY, only search fully cached block groups
4408 * LOOP_CACHING_NOWAIT, search partially cached block groups, but
4409 * dont wait foR them to finish caching
4410 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
4411 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
4412 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
4413 * again
4414 */
4415 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE &&
4416 (found_uncached_bg || empty_size || empty_cluster ||
4417 allowed_chunk_alloc)) {
4418 if (found_uncached_bg) {
4419 found_uncached_bg = false;
4420 if (loop < LOOP_CACHING_WAIT) {
4421 loop++;
4422 goto search;
4423 }
4424 }
4425
4426 if (loop == LOOP_ALLOC_CHUNK) {
4427 empty_size = 0;
4428 empty_cluster = 0;
4429 }
4430
4431 if (allowed_chunk_alloc) {
4432 ret = do_chunk_alloc(trans, root, num_bytes +
4433 2 * 1024 * 1024, data, 1);
4434 allowed_chunk_alloc = 0;
4435 } else {
4436 space_info->force_alloc = 1;
4437 }
4438
4439 if (loop < LOOP_NO_EMPTY_SIZE) {
4440 loop++;
4441 goto search;
4442 }
4443 ret = -ENOSPC;
4444 } else if (!ins->objectid) {
4445 ret = -ENOSPC;
4446 }
4447
4448 /* we found what we needed */
4449 if (ins->objectid) {
4450 if (!(data & BTRFS_BLOCK_GROUP_DATA))
4451 trans->block_group = block_group->key.objectid;
4452
4453 btrfs_put_block_group(block_group);
4454 ret = 0;
4455 }
4456
4457 return ret;
4458 }
4459
4460 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
4461 int dump_block_groups)
4462 {
4463 struct btrfs_block_group_cache *cache;
4464
4465 spin_lock(&info->lock);
4466 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
4467 (unsigned long long)(info->total_bytes - info->bytes_used -
4468 info->bytes_pinned - info->bytes_reserved -
4469 info->bytes_super),
4470 (info->full) ? "" : "not ");
4471 printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu,"
4472 " may_use=%llu, used=%llu, root=%llu, super=%llu, reserved=%llu"
4473 "\n",
4474 (unsigned long long)info->total_bytes,
4475 (unsigned long long)info->bytes_pinned,
4476 (unsigned long long)info->bytes_delalloc,
4477 (unsigned long long)info->bytes_may_use,
4478 (unsigned long long)info->bytes_used,
4479 (unsigned long long)info->bytes_root,
4480 (unsigned long long)info->bytes_super,
4481 (unsigned long long)info->bytes_reserved);
4482 spin_unlock(&info->lock);
4483
4484 if (!dump_block_groups)
4485 return;
4486
4487 down_read(&info->groups_sem);
4488 list_for_each_entry(cache, &info->block_groups, list) {
4489 spin_lock(&cache->lock);
4490 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
4491 "%llu pinned %llu reserved\n",
4492 (unsigned long long)cache->key.objectid,
4493 (unsigned long long)cache->key.offset,
4494 (unsigned long long)btrfs_block_group_used(&cache->item),
4495 (unsigned long long)cache->pinned,
4496 (unsigned long long)cache->reserved);
4497 btrfs_dump_free_space(cache, bytes);
4498 spin_unlock(&cache->lock);
4499 }
4500 up_read(&info->groups_sem);
4501 }
4502
4503 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
4504 struct btrfs_root *root,
4505 u64 num_bytes, u64 min_alloc_size,
4506 u64 empty_size, u64 hint_byte,
4507 u64 search_end, struct btrfs_key *ins,
4508 u64 data)
4509 {
4510 int ret;
4511 u64 search_start = 0;
4512 struct btrfs_fs_info *info = root->fs_info;
4513
4514 data = btrfs_get_alloc_profile(root, data);
4515 again:
4516 /*
4517 * the only place that sets empty_size is btrfs_realloc_node, which
4518 * is not called recursively on allocations
4519 */
4520 if (empty_size || root->ref_cows) {
4521 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
4522 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4523 2 * 1024 * 1024,
4524 BTRFS_BLOCK_GROUP_METADATA |
4525 (info->metadata_alloc_profile &
4526 info->avail_metadata_alloc_bits), 0);
4527 }
4528 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4529 num_bytes + 2 * 1024 * 1024, data, 0);
4530 }
4531
4532 WARN_ON(num_bytes < root->sectorsize);
4533 ret = find_free_extent(trans, root, num_bytes, empty_size,
4534 search_start, search_end, hint_byte, ins,
4535 trans->alloc_exclude_start,
4536 trans->alloc_exclude_nr, data);
4537
4538 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
4539 num_bytes = num_bytes >> 1;
4540 num_bytes = num_bytes & ~(root->sectorsize - 1);
4541 num_bytes = max(num_bytes, min_alloc_size);
4542 do_chunk_alloc(trans, root->fs_info->extent_root,
4543 num_bytes, data, 1);
4544 goto again;
4545 }
4546 if (ret == -ENOSPC) {
4547 struct btrfs_space_info *sinfo;
4548
4549 sinfo = __find_space_info(root->fs_info, data);
4550 printk(KERN_ERR "btrfs allocation failed flags %llu, "
4551 "wanted %llu\n", (unsigned long long)data,
4552 (unsigned long long)num_bytes);
4553 dump_space_info(sinfo, num_bytes, 1);
4554 }
4555
4556 return ret;
4557 }
4558
4559 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
4560 {
4561 struct btrfs_block_group_cache *cache;
4562 int ret = 0;
4563
4564 cache = btrfs_lookup_block_group(root->fs_info, start);
4565 if (!cache) {
4566 printk(KERN_ERR "Unable to find block group for %llu\n",
4567 (unsigned long long)start);
4568 return -ENOSPC;
4569 }
4570
4571 ret = btrfs_discard_extent(root, start, len);
4572
4573 btrfs_add_free_space(cache, start, len);
4574 update_reserved_extents(cache, len, 0);
4575 btrfs_put_block_group(cache);
4576
4577 return ret;
4578 }
4579
4580 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4581 struct btrfs_root *root,
4582 u64 parent, u64 root_objectid,
4583 u64 flags, u64 owner, u64 offset,
4584 struct btrfs_key *ins, int ref_mod)
4585 {
4586 int ret;
4587 struct btrfs_fs_info *fs_info = root->fs_info;
4588 struct btrfs_extent_item *extent_item;
4589 struct btrfs_extent_inline_ref *iref;
4590 struct btrfs_path *path;
4591 struct extent_buffer *leaf;
4592 int type;
4593 u32 size;
4594
4595 if (parent > 0)
4596 type = BTRFS_SHARED_DATA_REF_KEY;
4597 else
4598 type = BTRFS_EXTENT_DATA_REF_KEY;
4599
4600 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
4601
4602 path = btrfs_alloc_path();
4603 BUG_ON(!path);
4604
4605 path->leave_spinning = 1;
4606 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4607 ins, size);
4608 BUG_ON(ret);
4609
4610 leaf = path->nodes[0];
4611 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4612 struct btrfs_extent_item);
4613 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
4614 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4615 btrfs_set_extent_flags(leaf, extent_item,
4616 flags | BTRFS_EXTENT_FLAG_DATA);
4617
4618 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
4619 btrfs_set_extent_inline_ref_type(leaf, iref, type);
4620 if (parent > 0) {
4621 struct btrfs_shared_data_ref *ref;
4622 ref = (struct btrfs_shared_data_ref *)(iref + 1);
4623 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4624 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
4625 } else {
4626 struct btrfs_extent_data_ref *ref;
4627 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
4628 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
4629 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
4630 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
4631 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
4632 }
4633
4634 btrfs_mark_buffer_dirty(path->nodes[0]);
4635 btrfs_free_path(path);
4636
4637 ret = update_block_group(trans, root, ins->objectid, ins->offset,
4638 1, 0);
4639 if (ret) {
4640 printk(KERN_ERR "btrfs update block group failed for %llu "
4641 "%llu\n", (unsigned long long)ins->objectid,
4642 (unsigned long long)ins->offset);
4643 BUG();
4644 }
4645 return ret;
4646 }
4647
4648 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
4649 struct btrfs_root *root,
4650 u64 parent, u64 root_objectid,
4651 u64 flags, struct btrfs_disk_key *key,
4652 int level, struct btrfs_key *ins)
4653 {
4654 int ret;
4655 struct btrfs_fs_info *fs_info = root->fs_info;
4656 struct btrfs_extent_item *extent_item;
4657 struct btrfs_tree_block_info *block_info;
4658 struct btrfs_extent_inline_ref *iref;
4659 struct btrfs_path *path;
4660 struct extent_buffer *leaf;
4661 u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
4662
4663 path = btrfs_alloc_path();
4664 BUG_ON(!path);
4665
4666 path->leave_spinning = 1;
4667 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4668 ins, size);
4669 BUG_ON(ret);
4670
4671 leaf = path->nodes[0];
4672 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4673 struct btrfs_extent_item);
4674 btrfs_set_extent_refs(leaf, extent_item, 1);
4675 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4676 btrfs_set_extent_flags(leaf, extent_item,
4677 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
4678 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
4679
4680 btrfs_set_tree_block_key(leaf, block_info, key);
4681 btrfs_set_tree_block_level(leaf, block_info, level);
4682
4683 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
4684 if (parent > 0) {
4685 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
4686 btrfs_set_extent_inline_ref_type(leaf, iref,
4687 BTRFS_SHARED_BLOCK_REF_KEY);
4688 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4689 } else {
4690 btrfs_set_extent_inline_ref_type(leaf, iref,
4691 BTRFS_TREE_BLOCK_REF_KEY);
4692 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
4693 }
4694
4695 btrfs_mark_buffer_dirty(leaf);
4696 btrfs_free_path(path);
4697
4698 ret = update_block_group(trans, root, ins->objectid, ins->offset,
4699 1, 0);
4700 if (ret) {
4701 printk(KERN_ERR "btrfs update block group failed for %llu "
4702 "%llu\n", (unsigned long long)ins->objectid,
4703 (unsigned long long)ins->offset);
4704 BUG();
4705 }
4706 return ret;
4707 }
4708
4709 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4710 struct btrfs_root *root,
4711 u64 root_objectid, u64 owner,
4712 u64 offset, struct btrfs_key *ins)
4713 {
4714 int ret;
4715
4716 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
4717
4718 ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
4719 0, root_objectid, owner, offset,
4720 BTRFS_ADD_DELAYED_EXTENT, NULL);
4721 return ret;
4722 }
4723
4724 /*
4725 * this is used by the tree logging recovery code. It records that
4726 * an extent has been allocated and makes sure to clear the free
4727 * space cache bits as well
4728 */
4729 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
4730 struct btrfs_root *root,
4731 u64 root_objectid, u64 owner, u64 offset,
4732 struct btrfs_key *ins)
4733 {
4734 int ret;
4735 struct btrfs_block_group_cache *block_group;
4736 struct btrfs_caching_control *caching_ctl;
4737 u64 start = ins->objectid;
4738 u64 num_bytes = ins->offset;
4739
4740 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
4741 cache_block_group(block_group);
4742 caching_ctl = get_caching_control(block_group);
4743
4744 if (!caching_ctl) {
4745 BUG_ON(!block_group_cache_done(block_group));
4746 ret = btrfs_remove_free_space(block_group, start, num_bytes);
4747 BUG_ON(ret);
4748 } else {
4749 mutex_lock(&caching_ctl->mutex);
4750
4751 if (start >= caching_ctl->progress) {
4752 ret = add_excluded_extent(root, start, num_bytes);
4753 BUG_ON(ret);
4754 } else if (start + num_bytes <= caching_ctl->progress) {
4755 ret = btrfs_remove_free_space(block_group,
4756 start, num_bytes);
4757 BUG_ON(ret);
4758 } else {
4759 num_bytes = caching_ctl->progress - start;
4760 ret = btrfs_remove_free_space(block_group,
4761 start, num_bytes);
4762 BUG_ON(ret);
4763
4764 start = caching_ctl->progress;
4765 num_bytes = ins->objectid + ins->offset -
4766 caching_ctl->progress;
4767 ret = add_excluded_extent(root, start, num_bytes);
4768 BUG_ON(ret);
4769 }
4770
4771 mutex_unlock(&caching_ctl->mutex);
4772 put_caching_control(caching_ctl);
4773 }
4774
4775 update_reserved_extents(block_group, ins->offset, 1);
4776 btrfs_put_block_group(block_group);
4777 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
4778 0, owner, offset, ins, 1);
4779 return ret;
4780 }
4781
4782 /*
4783 * finds a free extent and does all the dirty work required for allocation
4784 * returns the key for the extent through ins, and a tree buffer for
4785 * the first block of the extent through buf.
4786 *
4787 * returns 0 if everything worked, non-zero otherwise.
4788 */
4789 static int alloc_tree_block(struct btrfs_trans_handle *trans,
4790 struct btrfs_root *root,
4791 u64 num_bytes, u64 parent, u64 root_objectid,
4792 struct btrfs_disk_key *key, int level,
4793 u64 empty_size, u64 hint_byte, u64 search_end,
4794 struct btrfs_key *ins)
4795 {
4796 int ret;
4797 u64 flags = 0;
4798
4799 ret = btrfs_reserve_extent(trans, root, num_bytes, num_bytes,
4800 empty_size, hint_byte, search_end,
4801 ins, 0);
4802 if (ret)
4803 return ret;
4804
4805 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
4806 if (parent == 0)
4807 parent = ins->objectid;
4808 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
4809 } else
4810 BUG_ON(parent > 0);
4811
4812 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
4813 struct btrfs_delayed_extent_op *extent_op;
4814 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
4815 BUG_ON(!extent_op);
4816 if (key)
4817 memcpy(&extent_op->key, key, sizeof(extent_op->key));
4818 else
4819 memset(&extent_op->key, 0, sizeof(extent_op->key));
4820 extent_op->flags_to_set = flags;
4821 extent_op->update_key = 1;
4822 extent_op->update_flags = 1;
4823 extent_op->is_data = 0;
4824
4825 ret = btrfs_add_delayed_tree_ref(trans, ins->objectid,
4826 ins->offset, parent, root_objectid,
4827 level, BTRFS_ADD_DELAYED_EXTENT,
4828 extent_op);
4829 BUG_ON(ret);
4830 }
4831 return ret;
4832 }
4833
4834 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
4835 struct btrfs_root *root,
4836 u64 bytenr, u32 blocksize,
4837 int level)
4838 {
4839 struct extent_buffer *buf;
4840
4841 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
4842 if (!buf)
4843 return ERR_PTR(-ENOMEM);
4844 btrfs_set_header_generation(buf, trans->transid);
4845 btrfs_set_buffer_lockdep_class(buf, level);
4846 btrfs_tree_lock(buf);
4847 clean_tree_block(trans, root, buf);
4848
4849 btrfs_set_lock_blocking(buf);
4850 btrfs_set_buffer_uptodate(buf);
4851
4852 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
4853 set_extent_dirty(&root->dirty_log_pages, buf->start,
4854 buf->start + buf->len - 1, GFP_NOFS);
4855 } else {
4856 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
4857 buf->start + buf->len - 1, GFP_NOFS);
4858 }
4859 trans->blocks_used++;
4860 /* this returns a buffer locked for blocking */
4861 return buf;
4862 }
4863
4864 /*
4865 * helper function to allocate a block for a given tree
4866 * returns the tree buffer or NULL.
4867 */
4868 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
4869 struct btrfs_root *root, u32 blocksize,
4870 u64 parent, u64 root_objectid,
4871 struct btrfs_disk_key *key, int level,
4872 u64 hint, u64 empty_size)
4873 {
4874 struct btrfs_key ins;
4875 int ret;
4876 struct extent_buffer *buf;
4877
4878 ret = alloc_tree_block(trans, root, blocksize, parent, root_objectid,
4879 key, level, empty_size, hint, (u64)-1, &ins);
4880 if (ret) {
4881 BUG_ON(ret > 0);
4882 return ERR_PTR(ret);
4883 }
4884
4885 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
4886 blocksize, level);
4887 return buf;
4888 }
4889
4890 struct walk_control {
4891 u64 refs[BTRFS_MAX_LEVEL];
4892 u64 flags[BTRFS_MAX_LEVEL];
4893 struct btrfs_key update_progress;
4894 int stage;
4895 int level;
4896 int shared_level;
4897 int update_ref;
4898 int keep_locks;
4899 int reada_slot;
4900 int reada_count;
4901 };
4902
4903 #define DROP_REFERENCE 1
4904 #define UPDATE_BACKREF 2
4905
4906 static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
4907 struct btrfs_root *root,
4908 struct walk_control *wc,
4909 struct btrfs_path *path)
4910 {
4911 u64 bytenr;
4912 u64 generation;
4913 u64 refs;
4914 u64 last = 0;
4915 u32 nritems;
4916 u32 blocksize;
4917 struct btrfs_key key;
4918 struct extent_buffer *eb;
4919 int ret;
4920 int slot;
4921 int nread = 0;
4922
4923 if (path->slots[wc->level] < wc->reada_slot) {
4924 wc->reada_count = wc->reada_count * 2 / 3;
4925 wc->reada_count = max(wc->reada_count, 2);
4926 } else {
4927 wc->reada_count = wc->reada_count * 3 / 2;
4928 wc->reada_count = min_t(int, wc->reada_count,
4929 BTRFS_NODEPTRS_PER_BLOCK(root));
4930 }
4931
4932 eb = path->nodes[wc->level];
4933 nritems = btrfs_header_nritems(eb);
4934 blocksize = btrfs_level_size(root, wc->level - 1);
4935
4936 for (slot = path->slots[wc->level]; slot < nritems; slot++) {
4937 if (nread >= wc->reada_count)
4938 break;
4939
4940 cond_resched();
4941 bytenr = btrfs_node_blockptr(eb, slot);
4942 generation = btrfs_node_ptr_generation(eb, slot);
4943
4944 if (slot == path->slots[wc->level])
4945 goto reada;
4946
4947 if (wc->stage == UPDATE_BACKREF &&
4948 generation <= root->root_key.offset)
4949 continue;
4950
4951 if (wc->stage == DROP_REFERENCE) {
4952 ret = btrfs_lookup_extent_info(trans, root,
4953 bytenr, blocksize,
4954 &refs, NULL);
4955 BUG_ON(ret);
4956 BUG_ON(refs == 0);
4957 if (refs == 1)
4958 goto reada;
4959
4960 if (!wc->update_ref ||
4961 generation <= root->root_key.offset)
4962 continue;
4963 btrfs_node_key_to_cpu(eb, &key, slot);
4964 ret = btrfs_comp_cpu_keys(&key,
4965 &wc->update_progress);
4966 if (ret < 0)
4967 continue;
4968 }
4969 reada:
4970 ret = readahead_tree_block(root, bytenr, blocksize,
4971 generation);
4972 if (ret)
4973 break;
4974 last = bytenr + blocksize;
4975 nread++;
4976 }
4977 wc->reada_slot = slot;
4978 }
4979
4980 /*
4981 * hepler to process tree block while walking down the tree.
4982 *
4983 * when wc->stage == UPDATE_BACKREF, this function updates
4984 * back refs for pointers in the block.
4985 *
4986 * NOTE: return value 1 means we should stop walking down.
4987 */
4988 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
4989 struct btrfs_root *root,
4990 struct btrfs_path *path,
4991 struct walk_control *wc)
4992 {
4993 int level = wc->level;
4994 struct extent_buffer *eb = path->nodes[level];
4995 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
4996 int ret;
4997
4998 if (wc->stage == UPDATE_BACKREF &&
4999 btrfs_header_owner(eb) != root->root_key.objectid)
5000 return 1;
5001
5002 /*
5003 * when reference count of tree block is 1, it won't increase
5004 * again. once full backref flag is set, we never clear it.
5005 */
5006 if ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
5007 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag))) {
5008 BUG_ON(!path->locks[level]);
5009 ret = btrfs_lookup_extent_info(trans, root,
5010 eb->start, eb->len,
5011 &wc->refs[level],
5012 &wc->flags[level]);
5013 BUG_ON(ret);
5014 BUG_ON(wc->refs[level] == 0);
5015 }
5016
5017 if (wc->stage == DROP_REFERENCE) {
5018 if (wc->refs[level] > 1)
5019 return 1;
5020
5021 if (path->locks[level] && !wc->keep_locks) {
5022 btrfs_tree_unlock(eb);
5023 path->locks[level] = 0;
5024 }
5025 return 0;
5026 }
5027
5028 /* wc->stage == UPDATE_BACKREF */
5029 if (!(wc->flags[level] & flag)) {
5030 BUG_ON(!path->locks[level]);
5031 ret = btrfs_inc_ref(trans, root, eb, 1);
5032 BUG_ON(ret);
5033 ret = btrfs_dec_ref(trans, root, eb, 0);
5034 BUG_ON(ret);
5035 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
5036 eb->len, flag, 0);
5037 BUG_ON(ret);
5038 wc->flags[level] |= flag;
5039 }
5040
5041 /*
5042 * the block is shared by multiple trees, so it's not good to
5043 * keep the tree lock
5044 */
5045 if (path->locks[level] && level > 0) {
5046 btrfs_tree_unlock(eb);
5047 path->locks[level] = 0;
5048 }
5049 return 0;
5050 }
5051
5052 /*
5053 * hepler to process tree block pointer.
5054 *
5055 * when wc->stage == DROP_REFERENCE, this function checks
5056 * reference count of the block pointed to. if the block
5057 * is shared and we need update back refs for the subtree
5058 * rooted at the block, this function changes wc->stage to
5059 * UPDATE_BACKREF. if the block is shared and there is no
5060 * need to update back, this function drops the reference
5061 * to the block.
5062 *
5063 * NOTE: return value 1 means we should stop walking down.
5064 */
5065 static noinline int do_walk_down(struct btrfs_trans_handle *trans,
5066 struct btrfs_root *root,
5067 struct btrfs_path *path,
5068 struct walk_control *wc)
5069 {
5070 u64 bytenr;
5071 u64 generation;
5072 u64 parent;
5073 u32 blocksize;
5074 struct btrfs_key key;
5075 struct extent_buffer *next;
5076 int level = wc->level;
5077 int reada = 0;
5078 int ret = 0;
5079
5080 generation = btrfs_node_ptr_generation(path->nodes[level],
5081 path->slots[level]);
5082 /*
5083 * if the lower level block was created before the snapshot
5084 * was created, we know there is no need to update back refs
5085 * for the subtree
5086 */
5087 if (wc->stage == UPDATE_BACKREF &&
5088 generation <= root->root_key.offset)
5089 return 1;
5090
5091 bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
5092 blocksize = btrfs_level_size(root, level - 1);
5093
5094 next = btrfs_find_tree_block(root, bytenr, blocksize);
5095 if (!next) {
5096 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
5097 reada = 1;
5098 }
5099 btrfs_tree_lock(next);
5100 btrfs_set_lock_blocking(next);
5101
5102 if (wc->stage == DROP_REFERENCE) {
5103 ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
5104 &wc->refs[level - 1],
5105 &wc->flags[level - 1]);
5106 BUG_ON(ret);
5107 BUG_ON(wc->refs[level - 1] == 0);
5108
5109 if (wc->refs[level - 1] > 1) {
5110 if (!wc->update_ref ||
5111 generation <= root->root_key.offset)
5112 goto skip;
5113
5114 btrfs_node_key_to_cpu(path->nodes[level], &key,
5115 path->slots[level]);
5116 ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
5117 if (ret < 0)
5118 goto skip;
5119
5120 wc->stage = UPDATE_BACKREF;
5121 wc->shared_level = level - 1;
5122 }
5123 }
5124
5125 if (!btrfs_buffer_uptodate(next, generation)) {
5126 btrfs_tree_unlock(next);
5127 free_extent_buffer(next);
5128 next = NULL;
5129 }
5130
5131 if (!next) {
5132 if (reada && level == 1)
5133 reada_walk_down(trans, root, wc, path);
5134 next = read_tree_block(root, bytenr, blocksize, generation);
5135 btrfs_tree_lock(next);
5136 btrfs_set_lock_blocking(next);
5137 }
5138
5139 level--;
5140 BUG_ON(level != btrfs_header_level(next));
5141 path->nodes[level] = next;
5142 path->slots[level] = 0;
5143 path->locks[level] = 1;
5144 wc->level = level;
5145 if (wc->level == 1)
5146 wc->reada_slot = 0;
5147 return 0;
5148 skip:
5149 wc->refs[level - 1] = 0;
5150 wc->flags[level - 1] = 0;
5151
5152 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
5153 parent = path->nodes[level]->start;
5154 } else {
5155 BUG_ON(root->root_key.objectid !=
5156 btrfs_header_owner(path->nodes[level]));
5157 parent = 0;
5158 }
5159
5160 ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
5161 root->root_key.objectid, level - 1, 0);
5162 BUG_ON(ret);
5163
5164 btrfs_tree_unlock(next);
5165 free_extent_buffer(next);
5166 return 1;
5167 }
5168
5169 /*
5170 * hepler to process tree block while walking up the tree.
5171 *
5172 * when wc->stage == DROP_REFERENCE, this function drops
5173 * reference count on the block.
5174 *
5175 * when wc->stage == UPDATE_BACKREF, this function changes
5176 * wc->stage back to DROP_REFERENCE if we changed wc->stage
5177 * to UPDATE_BACKREF previously while processing the block.
5178 *
5179 * NOTE: return value 1 means we should stop walking up.
5180 */
5181 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
5182 struct btrfs_root *root,
5183 struct btrfs_path *path,
5184 struct walk_control *wc)
5185 {
5186 int ret = 0;
5187 int level = wc->level;
5188 struct extent_buffer *eb = path->nodes[level];
5189 u64 parent = 0;
5190
5191 if (wc->stage == UPDATE_BACKREF) {
5192 BUG_ON(wc->shared_level < level);
5193 if (level < wc->shared_level)
5194 goto out;
5195
5196 ret = find_next_key(path, level + 1, &wc->update_progress);
5197 if (ret > 0)
5198 wc->update_ref = 0;
5199
5200 wc->stage = DROP_REFERENCE;
5201 wc->shared_level = -1;
5202 path->slots[level] = 0;
5203
5204 /*
5205 * check reference count again if the block isn't locked.
5206 * we should start walking down the tree again if reference
5207 * count is one.
5208 */
5209 if (!path->locks[level]) {
5210 BUG_ON(level == 0);
5211 btrfs_tree_lock(eb);
5212 btrfs_set_lock_blocking(eb);
5213 path->locks[level] = 1;
5214
5215 ret = btrfs_lookup_extent_info(trans, root,
5216 eb->start, eb->len,
5217 &wc->refs[level],
5218 &wc->flags[level]);
5219 BUG_ON(ret);
5220 BUG_ON(wc->refs[level] == 0);
5221 if (wc->refs[level] == 1) {
5222 btrfs_tree_unlock(eb);
5223 path->locks[level] = 0;
5224 return 1;
5225 }
5226 }
5227 }
5228
5229 /* wc->stage == DROP_REFERENCE */
5230 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
5231
5232 if (wc->refs[level] == 1) {
5233 if (level == 0) {
5234 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5235 ret = btrfs_dec_ref(trans, root, eb, 1);
5236 else
5237 ret = btrfs_dec_ref(trans, root, eb, 0);
5238 BUG_ON(ret);
5239 }
5240 /* make block locked assertion in clean_tree_block happy */
5241 if (!path->locks[level] &&
5242 btrfs_header_generation(eb) == trans->transid) {
5243 btrfs_tree_lock(eb);
5244 btrfs_set_lock_blocking(eb);
5245 path->locks[level] = 1;
5246 }
5247 clean_tree_block(trans, root, eb);
5248 }
5249
5250 if (eb == root->node) {
5251 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5252 parent = eb->start;
5253 else
5254 BUG_ON(root->root_key.objectid !=
5255 btrfs_header_owner(eb));
5256 } else {
5257 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
5258 parent = path->nodes[level + 1]->start;
5259 else
5260 BUG_ON(root->root_key.objectid !=
5261 btrfs_header_owner(path->nodes[level + 1]));
5262 }
5263
5264 ret = btrfs_free_extent(trans, root, eb->start, eb->len, parent,
5265 root->root_key.objectid, level, 0);
5266 BUG_ON(ret);
5267 out:
5268 wc->refs[level] = 0;
5269 wc->flags[level] = 0;
5270 return ret;
5271 }
5272
5273 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
5274 struct btrfs_root *root,
5275 struct btrfs_path *path,
5276 struct walk_control *wc)
5277 {
5278 int level = wc->level;
5279 int ret;
5280
5281 while (level >= 0) {
5282 if (path->slots[level] >=
5283 btrfs_header_nritems(path->nodes[level]))
5284 break;
5285
5286 ret = walk_down_proc(trans, root, path, wc);
5287 if (ret > 0)
5288 break;
5289
5290 if (level == 0)
5291 break;
5292
5293 ret = do_walk_down(trans, root, path, wc);
5294 if (ret > 0) {
5295 path->slots[level]++;
5296 continue;
5297 }
5298 level = wc->level;
5299 }
5300 return 0;
5301 }
5302
5303 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
5304 struct btrfs_root *root,
5305 struct btrfs_path *path,
5306 struct walk_control *wc, int max_level)
5307 {
5308 int level = wc->level;
5309 int ret;
5310
5311 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
5312 while (level < max_level && path->nodes[level]) {
5313 wc->level = level;
5314 if (path->slots[level] + 1 <
5315 btrfs_header_nritems(path->nodes[level])) {
5316 path->slots[level]++;
5317 return 0;
5318 } else {
5319 ret = walk_up_proc(trans, root, path, wc);
5320 if (ret > 0)
5321 return 0;
5322
5323 if (path->locks[level]) {
5324 btrfs_tree_unlock(path->nodes[level]);
5325 path->locks[level] = 0;
5326 }
5327 free_extent_buffer(path->nodes[level]);
5328 path->nodes[level] = NULL;
5329 level++;
5330 }
5331 }
5332 return 1;
5333 }
5334
5335 /*
5336 * drop a subvolume tree.
5337 *
5338 * this function traverses the tree freeing any blocks that only
5339 * referenced by the tree.
5340 *
5341 * when a shared tree block is found. this function decreases its
5342 * reference count by one. if update_ref is true, this function
5343 * also make sure backrefs for the shared block and all lower level
5344 * blocks are properly updated.
5345 */
5346 int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref)
5347 {
5348 struct btrfs_path *path;
5349 struct btrfs_trans_handle *trans;
5350 struct btrfs_root *tree_root = root->fs_info->tree_root;
5351 struct btrfs_root_item *root_item = &root->root_item;
5352 struct walk_control *wc;
5353 struct btrfs_key key;
5354 int err = 0;
5355 int ret;
5356 int level;
5357
5358 path = btrfs_alloc_path();
5359 BUG_ON(!path);
5360
5361 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5362 BUG_ON(!wc);
5363
5364 trans = btrfs_start_transaction(tree_root, 1);
5365
5366 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
5367 level = btrfs_header_level(root->node);
5368 path->nodes[level] = btrfs_lock_root_node(root);
5369 btrfs_set_lock_blocking(path->nodes[level]);
5370 path->slots[level] = 0;
5371 path->locks[level] = 1;
5372 memset(&wc->update_progress, 0,
5373 sizeof(wc->update_progress));
5374 } else {
5375 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
5376 memcpy(&wc->update_progress, &key,
5377 sizeof(wc->update_progress));
5378
5379 level = root_item->drop_level;
5380 BUG_ON(level == 0);
5381 path->lowest_level = level;
5382 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5383 path->lowest_level = 0;
5384 if (ret < 0) {
5385 err = ret;
5386 goto out;
5387 }
5388 WARN_ON(ret > 0);
5389
5390 /*
5391 * unlock our path, this is safe because only this
5392 * function is allowed to delete this snapshot
5393 */
5394 btrfs_unlock_up_safe(path, 0);
5395
5396 level = btrfs_header_level(root->node);
5397 while (1) {
5398 btrfs_tree_lock(path->nodes[level]);
5399 btrfs_set_lock_blocking(path->nodes[level]);
5400
5401 ret = btrfs_lookup_extent_info(trans, root,
5402 path->nodes[level]->start,
5403 path->nodes[level]->len,
5404 &wc->refs[level],
5405 &wc->flags[level]);
5406 BUG_ON(ret);
5407 BUG_ON(wc->refs[level] == 0);
5408
5409 if (level == root_item->drop_level)
5410 break;
5411
5412 btrfs_tree_unlock(path->nodes[level]);
5413 WARN_ON(wc->refs[level] != 1);
5414 level--;
5415 }
5416 }
5417
5418 wc->level = level;
5419 wc->shared_level = -1;
5420 wc->stage = DROP_REFERENCE;
5421 wc->update_ref = update_ref;
5422 wc->keep_locks = 0;
5423 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
5424
5425 while (1) {
5426 ret = walk_down_tree(trans, root, path, wc);
5427 if (ret < 0) {
5428 err = ret;
5429 break;
5430 }
5431
5432 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
5433 if (ret < 0) {
5434 err = ret;
5435 break;
5436 }
5437
5438 if (ret > 0) {
5439 BUG_ON(wc->stage != DROP_REFERENCE);
5440 break;
5441 }
5442
5443 if (wc->stage == DROP_REFERENCE) {
5444 level = wc->level;
5445 btrfs_node_key(path->nodes[level],
5446 &root_item->drop_progress,
5447 path->slots[level]);
5448 root_item->drop_level = level;
5449 }
5450
5451 BUG_ON(wc->level == 0);
5452 if (trans->transaction->in_commit ||
5453 trans->transaction->delayed_refs.flushing) {
5454 ret = btrfs_update_root(trans, tree_root,
5455 &root->root_key,
5456 root_item);
5457 BUG_ON(ret);
5458
5459 btrfs_end_transaction(trans, tree_root);
5460 trans = btrfs_start_transaction(tree_root, 1);
5461 } else {
5462 unsigned long update;
5463 update = trans->delayed_ref_updates;
5464 trans->delayed_ref_updates = 0;
5465 if (update)
5466 btrfs_run_delayed_refs(trans, tree_root,
5467 update);
5468 }
5469 }
5470 btrfs_release_path(root, path);
5471 BUG_ON(err);
5472
5473 ret = btrfs_del_root(trans, tree_root, &root->root_key);
5474 BUG_ON(ret);
5475
5476 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
5477 ret = btrfs_find_last_root(tree_root, root->root_key.objectid,
5478 NULL, NULL);
5479 BUG_ON(ret < 0);
5480 if (ret > 0) {
5481 ret = btrfs_del_orphan_item(trans, tree_root,
5482 root->root_key.objectid);
5483 BUG_ON(ret);
5484 }
5485 }
5486
5487 if (root->in_radix) {
5488 btrfs_free_fs_root(tree_root->fs_info, root);
5489 } else {
5490 free_extent_buffer(root->node);
5491 free_extent_buffer(root->commit_root);
5492 kfree(root);
5493 }
5494 out:
5495 btrfs_end_transaction(trans, tree_root);
5496 kfree(wc);
5497 btrfs_free_path(path);
5498 return err;
5499 }
5500
5501 /*
5502 * drop subtree rooted at tree block 'node'.
5503 *
5504 * NOTE: this function will unlock and release tree block 'node'
5505 */
5506 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
5507 struct btrfs_root *root,
5508 struct extent_buffer *node,
5509 struct extent_buffer *parent)
5510 {
5511 struct btrfs_path *path;
5512 struct walk_control *wc;
5513 int level;
5514 int parent_level;
5515 int ret = 0;
5516 int wret;
5517
5518 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5519
5520 path = btrfs_alloc_path();
5521 BUG_ON(!path);
5522
5523 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5524 BUG_ON(!wc);
5525
5526 btrfs_assert_tree_locked(parent);
5527 parent_level = btrfs_header_level(parent);
5528 extent_buffer_get(parent);
5529 path->nodes[parent_level] = parent;
5530 path->slots[parent_level] = btrfs_header_nritems(parent);
5531
5532 btrfs_assert_tree_locked(node);
5533 level = btrfs_header_level(node);
5534 path->nodes[level] = node;
5535 path->slots[level] = 0;
5536 path->locks[level] = 1;
5537
5538 wc->refs[parent_level] = 1;
5539 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5540 wc->level = level;
5541 wc->shared_level = -1;
5542 wc->stage = DROP_REFERENCE;
5543 wc->update_ref = 0;
5544 wc->keep_locks = 1;
5545 wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
5546
5547 while (1) {
5548 wret = walk_down_tree(trans, root, path, wc);
5549 if (wret < 0) {
5550 ret = wret;
5551 break;
5552 }
5553
5554 wret = walk_up_tree(trans, root, path, wc, parent_level);
5555 if (wret < 0)
5556 ret = wret;
5557 if (wret != 0)
5558 break;
5559 }
5560
5561 kfree(wc);
5562 btrfs_free_path(path);
5563 return ret;
5564 }
5565
5566 #if 0
5567 static unsigned long calc_ra(unsigned long start, unsigned long last,
5568 unsigned long nr)
5569 {
5570 return min(last, start + nr - 1);
5571 }
5572
5573 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
5574 u64 len)
5575 {
5576 u64 page_start;
5577 u64 page_end;
5578 unsigned long first_index;
5579 unsigned long last_index;
5580 unsigned long i;
5581 struct page *page;
5582 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5583 struct file_ra_state *ra;
5584 struct btrfs_ordered_extent *ordered;
5585 unsigned int total_read = 0;
5586 unsigned int total_dirty = 0;
5587 int ret = 0;
5588
5589 ra = kzalloc(sizeof(*ra), GFP_NOFS);
5590
5591 mutex_lock(&inode->i_mutex);
5592 first_index = start >> PAGE_CACHE_SHIFT;
5593 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
5594
5595 /* make sure the dirty trick played by the caller work */
5596 ret = invalidate_inode_pages2_range(inode->i_mapping,
5597 first_index, last_index);
5598 if (ret)
5599 goto out_unlock;
5600
5601 file_ra_state_init(ra, inode->i_mapping);
5602
5603 for (i = first_index ; i <= last_index; i++) {
5604 if (total_read % ra->ra_pages == 0) {
5605 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
5606 calc_ra(i, last_index, ra->ra_pages));
5607 }
5608 total_read++;
5609 again:
5610 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
5611 BUG_ON(1);
5612 page = grab_cache_page(inode->i_mapping, i);
5613 if (!page) {
5614 ret = -ENOMEM;
5615 goto out_unlock;
5616 }
5617 if (!PageUptodate(page)) {
5618 btrfs_readpage(NULL, page);
5619 lock_page(page);
5620 if (!PageUptodate(page)) {
5621 unlock_page(page);
5622 page_cache_release(page);
5623 ret = -EIO;
5624 goto out_unlock;
5625 }
5626 }
5627 wait_on_page_writeback(page);
5628
5629 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
5630 page_end = page_start + PAGE_CACHE_SIZE - 1;
5631 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
5632
5633 ordered = btrfs_lookup_ordered_extent(inode, page_start);
5634 if (ordered) {
5635 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5636 unlock_page(page);
5637 page_cache_release(page);
5638 btrfs_start_ordered_extent(inode, ordered, 1);
5639 btrfs_put_ordered_extent(ordered);
5640 goto again;
5641 }
5642 set_page_extent_mapped(page);
5643
5644 if (i == first_index)
5645 set_extent_bits(io_tree, page_start, page_end,
5646 EXTENT_BOUNDARY, GFP_NOFS);
5647 btrfs_set_extent_delalloc(inode, page_start, page_end);
5648
5649 set_page_dirty(page);
5650 total_dirty++;
5651
5652 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5653 unlock_page(page);
5654 page_cache_release(page);
5655 }
5656
5657 out_unlock:
5658 kfree(ra);
5659 mutex_unlock(&inode->i_mutex);
5660 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
5661 return ret;
5662 }
5663
5664 static noinline int relocate_data_extent(struct inode *reloc_inode,
5665 struct btrfs_key *extent_key,
5666 u64 offset)
5667 {
5668 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5669 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
5670 struct extent_map *em;
5671 u64 start = extent_key->objectid - offset;
5672 u64 end = start + extent_key->offset - 1;
5673
5674 em = alloc_extent_map(GFP_NOFS);
5675 BUG_ON(!em || IS_ERR(em));
5676
5677 em->start = start;
5678 em->len = extent_key->offset;
5679 em->block_len = extent_key->offset;
5680 em->block_start = extent_key->objectid;
5681 em->bdev = root->fs_info->fs_devices->latest_bdev;
5682 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5683
5684 /* setup extent map to cheat btrfs_readpage */
5685 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5686 while (1) {
5687 int ret;
5688 write_lock(&em_tree->lock);
5689 ret = add_extent_mapping(em_tree, em);
5690 write_unlock(&em_tree->lock);
5691 if (ret != -EEXIST) {
5692 free_extent_map(em);
5693 break;
5694 }
5695 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
5696 }
5697 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5698
5699 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
5700 }
5701
5702 struct btrfs_ref_path {
5703 u64 extent_start;
5704 u64 nodes[BTRFS_MAX_LEVEL];
5705 u64 root_objectid;
5706 u64 root_generation;
5707 u64 owner_objectid;
5708 u32 num_refs;
5709 int lowest_level;
5710 int current_level;
5711 int shared_level;
5712
5713 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
5714 u64 new_nodes[BTRFS_MAX_LEVEL];
5715 };
5716
5717 struct disk_extent {
5718 u64 ram_bytes;
5719 u64 disk_bytenr;
5720 u64 disk_num_bytes;
5721 u64 offset;
5722 u64 num_bytes;
5723 u8 compression;
5724 u8 encryption;
5725 u16 other_encoding;
5726 };
5727
5728 static int is_cowonly_root(u64 root_objectid)
5729 {
5730 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
5731 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
5732 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
5733 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
5734 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
5735 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
5736 return 1;
5737 return 0;
5738 }
5739
5740 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
5741 struct btrfs_root *extent_root,
5742 struct btrfs_ref_path *ref_path,
5743 int first_time)
5744 {
5745 struct extent_buffer *leaf;
5746 struct btrfs_path *path;
5747 struct btrfs_extent_ref *ref;
5748 struct btrfs_key key;
5749 struct btrfs_key found_key;
5750 u64 bytenr;
5751 u32 nritems;
5752 int level;
5753 int ret = 1;
5754
5755 path = btrfs_alloc_path();
5756 if (!path)
5757 return -ENOMEM;
5758
5759 if (first_time) {
5760 ref_path->lowest_level = -1;
5761 ref_path->current_level = -1;
5762 ref_path->shared_level = -1;
5763 goto walk_up;
5764 }
5765 walk_down:
5766 level = ref_path->current_level - 1;
5767 while (level >= -1) {
5768 u64 parent;
5769 if (level < ref_path->lowest_level)
5770 break;
5771
5772 if (level >= 0)
5773 bytenr = ref_path->nodes[level];
5774 else
5775 bytenr = ref_path->extent_start;
5776 BUG_ON(bytenr == 0);
5777
5778 parent = ref_path->nodes[level + 1];
5779 ref_path->nodes[level + 1] = 0;
5780 ref_path->current_level = level;
5781 BUG_ON(parent == 0);
5782
5783 key.objectid = bytenr;
5784 key.offset = parent + 1;
5785 key.type = BTRFS_EXTENT_REF_KEY;
5786
5787 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5788 if (ret < 0)
5789 goto out;
5790 BUG_ON(ret == 0);
5791
5792 leaf = path->nodes[0];
5793 nritems = btrfs_header_nritems(leaf);
5794 if (path->slots[0] >= nritems) {
5795 ret = btrfs_next_leaf(extent_root, path);
5796 if (ret < 0)
5797 goto out;
5798 if (ret > 0)
5799 goto next;
5800 leaf = path->nodes[0];
5801 }
5802
5803 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5804 if (found_key.objectid == bytenr &&
5805 found_key.type == BTRFS_EXTENT_REF_KEY) {
5806 if (level < ref_path->shared_level)
5807 ref_path->shared_level = level;
5808 goto found;
5809 }
5810 next:
5811 level--;
5812 btrfs_release_path(extent_root, path);
5813 cond_resched();
5814 }
5815 /* reached lowest level */
5816 ret = 1;
5817 goto out;
5818 walk_up:
5819 level = ref_path->current_level;
5820 while (level < BTRFS_MAX_LEVEL - 1) {
5821 u64 ref_objectid;
5822
5823 if (level >= 0)
5824 bytenr = ref_path->nodes[level];
5825 else
5826 bytenr = ref_path->extent_start;
5827
5828 BUG_ON(bytenr == 0);
5829
5830 key.objectid = bytenr;
5831 key.offset = 0;
5832 key.type = BTRFS_EXTENT_REF_KEY;
5833
5834 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5835 if (ret < 0)
5836 goto out;
5837
5838 leaf = path->nodes[0];
5839 nritems = btrfs_header_nritems(leaf);
5840 if (path->slots[0] >= nritems) {
5841 ret = btrfs_next_leaf(extent_root, path);
5842 if (ret < 0)
5843 goto out;
5844 if (ret > 0) {
5845 /* the extent was freed by someone */
5846 if (ref_path->lowest_level == level)
5847 goto out;
5848 btrfs_release_path(extent_root, path);
5849 goto walk_down;
5850 }
5851 leaf = path->nodes[0];
5852 }
5853
5854 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5855 if (found_key.objectid != bytenr ||
5856 found_key.type != BTRFS_EXTENT_REF_KEY) {
5857 /* the extent was freed by someone */
5858 if (ref_path->lowest_level == level) {
5859 ret = 1;
5860 goto out;
5861 }
5862 btrfs_release_path(extent_root, path);
5863 goto walk_down;
5864 }
5865 found:
5866 ref = btrfs_item_ptr(leaf, path->slots[0],
5867 struct btrfs_extent_ref);
5868 ref_objectid = btrfs_ref_objectid(leaf, ref);
5869 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
5870 if (first_time) {
5871 level = (int)ref_objectid;
5872 BUG_ON(level >= BTRFS_MAX_LEVEL);
5873 ref_path->lowest_level = level;
5874 ref_path->current_level = level;
5875 ref_path->nodes[level] = bytenr;
5876 } else {
5877 WARN_ON(ref_objectid != level);
5878 }
5879 } else {
5880 WARN_ON(level != -1);
5881 }
5882 first_time = 0;
5883
5884 if (ref_path->lowest_level == level) {
5885 ref_path->owner_objectid = ref_objectid;
5886 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
5887 }
5888
5889 /*
5890 * the block is tree root or the block isn't in reference
5891 * counted tree.
5892 */
5893 if (found_key.objectid == found_key.offset ||
5894 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
5895 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5896 ref_path->root_generation =
5897 btrfs_ref_generation(leaf, ref);
5898 if (level < 0) {
5899 /* special reference from the tree log */
5900 ref_path->nodes[0] = found_key.offset;
5901 ref_path->current_level = 0;
5902 }
5903 ret = 0;
5904 goto out;
5905 }
5906
5907 level++;
5908 BUG_ON(ref_path->nodes[level] != 0);
5909 ref_path->nodes[level] = found_key.offset;
5910 ref_path->current_level = level;
5911
5912 /*
5913 * the reference was created in the running transaction,
5914 * no need to continue walking up.
5915 */
5916 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
5917 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5918 ref_path->root_generation =
5919 btrfs_ref_generation(leaf, ref);
5920 ret = 0;
5921 goto out;
5922 }
5923
5924 btrfs_release_path(extent_root, path);
5925 cond_resched();
5926 }
5927 /* reached max tree level, but no tree root found. */
5928 BUG();
5929 out:
5930 btrfs_free_path(path);
5931 return ret;
5932 }
5933
5934 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
5935 struct btrfs_root *extent_root,
5936 struct btrfs_ref_path *ref_path,
5937 u64 extent_start)
5938 {
5939 memset(ref_path, 0, sizeof(*ref_path));
5940 ref_path->extent_start = extent_start;
5941
5942 return __next_ref_path(trans, extent_root, ref_path, 1);
5943 }
5944
5945 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
5946 struct btrfs_root *extent_root,
5947 struct btrfs_ref_path *ref_path)
5948 {
5949 return __next_ref_path(trans, extent_root, ref_path, 0);
5950 }
5951
5952 static noinline int get_new_locations(struct inode *reloc_inode,
5953 struct btrfs_key *extent_key,
5954 u64 offset, int no_fragment,
5955 struct disk_extent **extents,
5956 int *nr_extents)
5957 {
5958 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5959 struct btrfs_path *path;
5960 struct btrfs_file_extent_item *fi;
5961 struct extent_buffer *leaf;
5962 struct disk_extent *exts = *extents;
5963 struct btrfs_key found_key;
5964 u64 cur_pos;
5965 u64 last_byte;
5966 u32 nritems;
5967 int nr = 0;
5968 int max = *nr_extents;
5969 int ret;
5970
5971 WARN_ON(!no_fragment && *extents);
5972 if (!exts) {
5973 max = 1;
5974 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
5975 if (!exts)
5976 return -ENOMEM;
5977 }
5978
5979 path = btrfs_alloc_path();
5980 BUG_ON(!path);
5981
5982 cur_pos = extent_key->objectid - offset;
5983 last_byte = extent_key->objectid + extent_key->offset;
5984 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
5985 cur_pos, 0);
5986 if (ret < 0)
5987 goto out;
5988 if (ret > 0) {
5989 ret = -ENOENT;
5990 goto out;
5991 }
5992
5993 while (1) {
5994 leaf = path->nodes[0];
5995 nritems = btrfs_header_nritems(leaf);
5996 if (path->slots[0] >= nritems) {
5997 ret = btrfs_next_leaf(root, path);
5998 if (ret < 0)
5999 goto out;
6000 if (ret > 0)
6001 break;
6002 leaf = path->nodes[0];
6003 }
6004
6005 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6006 if (found_key.offset != cur_pos ||
6007 found_key.type != BTRFS_EXTENT_DATA_KEY ||
6008 found_key.objectid != reloc_inode->i_ino)
6009 break;
6010
6011 fi = btrfs_item_ptr(leaf, path->slots[0],
6012 struct btrfs_file_extent_item);
6013 if (btrfs_file_extent_type(leaf, fi) !=
6014 BTRFS_FILE_EXTENT_REG ||
6015 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
6016 break;
6017
6018 if (nr == max) {
6019 struct disk_extent *old = exts;
6020 max *= 2;
6021 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
6022 memcpy(exts, old, sizeof(*exts) * nr);
6023 if (old != *extents)
6024 kfree(old);
6025 }
6026
6027 exts[nr].disk_bytenr =
6028 btrfs_file_extent_disk_bytenr(leaf, fi);
6029 exts[nr].disk_num_bytes =
6030 btrfs_file_extent_disk_num_bytes(leaf, fi);
6031 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
6032 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6033 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6034 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
6035 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
6036 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
6037 fi);
6038 BUG_ON(exts[nr].offset > 0);
6039 BUG_ON(exts[nr].compression || exts[nr].encryption);
6040 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
6041
6042 cur_pos += exts[nr].num_bytes;
6043 nr++;
6044
6045 if (cur_pos + offset >= last_byte)
6046 break;
6047
6048 if (no_fragment) {
6049 ret = 1;
6050 goto out;
6051 }
6052 path->slots[0]++;
6053 }
6054
6055 BUG_ON(cur_pos + offset > last_byte);
6056 if (cur_pos + offset < last_byte) {
6057 ret = -ENOENT;
6058 goto out;
6059 }
6060 ret = 0;
6061 out:
6062 btrfs_free_path(path);
6063 if (ret) {
6064 if (exts != *extents)
6065 kfree(exts);
6066 } else {
6067 *extents = exts;
6068 *nr_extents = nr;
6069 }
6070 return ret;
6071 }
6072
6073 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
6074 struct btrfs_root *root,
6075 struct btrfs_path *path,
6076 struct btrfs_key *extent_key,
6077 struct btrfs_key *leaf_key,
6078 struct btrfs_ref_path *ref_path,
6079 struct disk_extent *new_extents,
6080 int nr_extents)
6081 {
6082 struct extent_buffer *leaf;
6083 struct btrfs_file_extent_item *fi;
6084 struct inode *inode = NULL;
6085 struct btrfs_key key;
6086 u64 lock_start = 0;
6087 u64 lock_end = 0;
6088 u64 num_bytes;
6089 u64 ext_offset;
6090 u64 search_end = (u64)-1;
6091 u32 nritems;
6092 int nr_scaned = 0;
6093 int extent_locked = 0;
6094 int extent_type;
6095 int ret;
6096
6097 memcpy(&key, leaf_key, sizeof(key));
6098 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
6099 if (key.objectid < ref_path->owner_objectid ||
6100 (key.objectid == ref_path->owner_objectid &&
6101 key.type < BTRFS_EXTENT_DATA_KEY)) {
6102 key.objectid = ref_path->owner_objectid;
6103 key.type = BTRFS_EXTENT_DATA_KEY;
6104 key.offset = 0;
6105 }
6106 }
6107
6108 while (1) {
6109 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
6110 if (ret < 0)
6111 goto out;
6112
6113 leaf = path->nodes[0];
6114 nritems = btrfs_header_nritems(leaf);
6115 next:
6116 if (extent_locked && ret > 0) {
6117 /*
6118 * the file extent item was modified by someone
6119 * before the extent got locked.
6120 */
6121 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6122 lock_end, GFP_NOFS);
6123 extent_locked = 0;
6124 }
6125
6126 if (path->slots[0] >= nritems) {
6127 if (++nr_scaned > 2)
6128 break;
6129
6130 BUG_ON(extent_locked);
6131 ret = btrfs_next_leaf(root, path);
6132 if (ret < 0)
6133 goto out;
6134 if (ret > 0)
6135 break;
6136 leaf = path->nodes[0];
6137 nritems = btrfs_header_nritems(leaf);
6138 }
6139
6140 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
6141
6142 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
6143 if ((key.objectid > ref_path->owner_objectid) ||
6144 (key.objectid == ref_path->owner_objectid &&
6145 key.type > BTRFS_EXTENT_DATA_KEY) ||
6146 key.offset >= search_end)
6147 break;
6148 }
6149
6150 if (inode && key.objectid != inode->i_ino) {
6151 BUG_ON(extent_locked);
6152 btrfs_release_path(root, path);
6153 mutex_unlock(&inode->i_mutex);
6154 iput(inode);
6155 inode = NULL;
6156 continue;
6157 }
6158
6159 if (key.type != BTRFS_EXTENT_DATA_KEY) {
6160 path->slots[0]++;
6161 ret = 1;
6162 goto next;
6163 }
6164 fi = btrfs_item_ptr(leaf, path->slots[0],
6165 struct btrfs_file_extent_item);
6166 extent_type = btrfs_file_extent_type(leaf, fi);
6167 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
6168 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
6169 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
6170 extent_key->objectid)) {
6171 path->slots[0]++;
6172 ret = 1;
6173 goto next;
6174 }
6175
6176 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6177 ext_offset = btrfs_file_extent_offset(leaf, fi);
6178
6179 if (search_end == (u64)-1) {
6180 search_end = key.offset - ext_offset +
6181 btrfs_file_extent_ram_bytes(leaf, fi);
6182 }
6183
6184 if (!extent_locked) {
6185 lock_start = key.offset;
6186 lock_end = lock_start + num_bytes - 1;
6187 } else {
6188 if (lock_start > key.offset ||
6189 lock_end + 1 < key.offset + num_bytes) {
6190 unlock_extent(&BTRFS_I(inode)->io_tree,
6191 lock_start, lock_end, GFP_NOFS);
6192 extent_locked = 0;
6193 }
6194 }
6195
6196 if (!inode) {
6197 btrfs_release_path(root, path);
6198
6199 inode = btrfs_iget_locked(root->fs_info->sb,
6200 key.objectid, root);
6201 if (inode->i_state & I_NEW) {
6202 BTRFS_I(inode)->root = root;
6203 BTRFS_I(inode)->location.objectid =
6204 key.objectid;
6205 BTRFS_I(inode)->location.type =
6206 BTRFS_INODE_ITEM_KEY;
6207 BTRFS_I(inode)->location.offset = 0;
6208 btrfs_read_locked_inode(inode);
6209 unlock_new_inode(inode);
6210 }
6211 /*
6212 * some code call btrfs_commit_transaction while
6213 * holding the i_mutex, so we can't use mutex_lock
6214 * here.
6215 */
6216 if (is_bad_inode(inode) ||
6217 !mutex_trylock(&inode->i_mutex)) {
6218 iput(inode);
6219 inode = NULL;
6220 key.offset = (u64)-1;
6221 goto skip;
6222 }
6223 }
6224
6225 if (!extent_locked) {
6226 struct btrfs_ordered_extent *ordered;
6227
6228 btrfs_release_path(root, path);
6229
6230 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6231 lock_end, GFP_NOFS);
6232 ordered = btrfs_lookup_first_ordered_extent(inode,
6233 lock_end);
6234 if (ordered &&
6235 ordered->file_offset <= lock_end &&
6236 ordered->file_offset + ordered->len > lock_start) {
6237 unlock_extent(&BTRFS_I(inode)->io_tree,
6238 lock_start, lock_end, GFP_NOFS);
6239 btrfs_start_ordered_extent(inode, ordered, 1);
6240 btrfs_put_ordered_extent(ordered);
6241 key.offset += num_bytes;
6242 goto skip;
6243 }
6244 if (ordered)
6245 btrfs_put_ordered_extent(ordered);
6246
6247 extent_locked = 1;
6248 continue;
6249 }
6250
6251 if (nr_extents == 1) {
6252 /* update extent pointer in place */
6253 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6254 new_extents[0].disk_bytenr);
6255 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6256 new_extents[0].disk_num_bytes);
6257 btrfs_mark_buffer_dirty(leaf);
6258
6259 btrfs_drop_extent_cache(inode, key.offset,
6260 key.offset + num_bytes - 1, 0);
6261
6262 ret = btrfs_inc_extent_ref(trans, root,
6263 new_extents[0].disk_bytenr,
6264 new_extents[0].disk_num_bytes,
6265 leaf->start,
6266 root->root_key.objectid,
6267 trans->transid,
6268 key.objectid);
6269 BUG_ON(ret);
6270
6271 ret = btrfs_free_extent(trans, root,
6272 extent_key->objectid,
6273 extent_key->offset,
6274 leaf->start,
6275 btrfs_header_owner(leaf),
6276 btrfs_header_generation(leaf),
6277 key.objectid, 0);
6278 BUG_ON(ret);
6279
6280 btrfs_release_path(root, path);
6281 key.offset += num_bytes;
6282 } else {
6283 BUG_ON(1);
6284 #if 0
6285 u64 alloc_hint;
6286 u64 extent_len;
6287 int i;
6288 /*
6289 * drop old extent pointer at first, then insert the
6290 * new pointers one bye one
6291 */
6292 btrfs_release_path(root, path);
6293 ret = btrfs_drop_extents(trans, root, inode, key.offset,
6294 key.offset + num_bytes,
6295 key.offset, &alloc_hint);
6296 BUG_ON(ret);
6297
6298 for (i = 0; i < nr_extents; i++) {
6299 if (ext_offset >= new_extents[i].num_bytes) {
6300 ext_offset -= new_extents[i].num_bytes;
6301 continue;
6302 }
6303 extent_len = min(new_extents[i].num_bytes -
6304 ext_offset, num_bytes);
6305
6306 ret = btrfs_insert_empty_item(trans, root,
6307 path, &key,
6308 sizeof(*fi));
6309 BUG_ON(ret);
6310
6311 leaf = path->nodes[0];
6312 fi = btrfs_item_ptr(leaf, path->slots[0],
6313 struct btrfs_file_extent_item);
6314 btrfs_set_file_extent_generation(leaf, fi,
6315 trans->transid);
6316 btrfs_set_file_extent_type(leaf, fi,
6317 BTRFS_FILE_EXTENT_REG);
6318 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6319 new_extents[i].disk_bytenr);
6320 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6321 new_extents[i].disk_num_bytes);
6322 btrfs_set_file_extent_ram_bytes(leaf, fi,
6323 new_extents[i].ram_bytes);
6324
6325 btrfs_set_file_extent_compression(leaf, fi,
6326 new_extents[i].compression);
6327 btrfs_set_file_extent_encryption(leaf, fi,
6328 new_extents[i].encryption);
6329 btrfs_set_file_extent_other_encoding(leaf, fi,
6330 new_extents[i].other_encoding);
6331
6332 btrfs_set_file_extent_num_bytes(leaf, fi,
6333 extent_len);
6334 ext_offset += new_extents[i].offset;
6335 btrfs_set_file_extent_offset(leaf, fi,
6336 ext_offset);
6337 btrfs_mark_buffer_dirty(leaf);
6338
6339 btrfs_drop_extent_cache(inode, key.offset,
6340 key.offset + extent_len - 1, 0);
6341
6342 ret = btrfs_inc_extent_ref(trans, root,
6343 new_extents[i].disk_bytenr,
6344 new_extents[i].disk_num_bytes,
6345 leaf->start,
6346 root->root_key.objectid,
6347 trans->transid, key.objectid);
6348 BUG_ON(ret);
6349 btrfs_release_path(root, path);
6350
6351 inode_add_bytes(inode, extent_len);
6352
6353 ext_offset = 0;
6354 num_bytes -= extent_len;
6355 key.offset += extent_len;
6356
6357 if (num_bytes == 0)
6358 break;
6359 }
6360 BUG_ON(i >= nr_extents);
6361 #endif
6362 }
6363
6364 if (extent_locked) {
6365 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6366 lock_end, GFP_NOFS);
6367 extent_locked = 0;
6368 }
6369 skip:
6370 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
6371 key.offset >= search_end)
6372 break;
6373
6374 cond_resched();
6375 }
6376 ret = 0;
6377 out:
6378 btrfs_release_path(root, path);
6379 if (inode) {
6380 mutex_unlock(&inode->i_mutex);
6381 if (extent_locked) {
6382 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6383 lock_end, GFP_NOFS);
6384 }
6385 iput(inode);
6386 }
6387 return ret;
6388 }
6389
6390 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
6391 struct btrfs_root *root,
6392 struct extent_buffer *buf, u64 orig_start)
6393 {
6394 int level;
6395 int ret;
6396
6397 BUG_ON(btrfs_header_generation(buf) != trans->transid);
6398 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
6399
6400 level = btrfs_header_level(buf);
6401 if (level == 0) {
6402 struct btrfs_leaf_ref *ref;
6403 struct btrfs_leaf_ref *orig_ref;
6404
6405 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
6406 if (!orig_ref)
6407 return -ENOENT;
6408
6409 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
6410 if (!ref) {
6411 btrfs_free_leaf_ref(root, orig_ref);
6412 return -ENOMEM;
6413 }
6414
6415 ref->nritems = orig_ref->nritems;
6416 memcpy(ref->extents, orig_ref->extents,
6417 sizeof(ref->extents[0]) * ref->nritems);
6418
6419 btrfs_free_leaf_ref(root, orig_ref);
6420
6421 ref->root_gen = trans->transid;
6422 ref->bytenr = buf->start;
6423 ref->owner = btrfs_header_owner(buf);
6424 ref->generation = btrfs_header_generation(buf);
6425
6426 ret = btrfs_add_leaf_ref(root, ref, 0);
6427 WARN_ON(ret);
6428 btrfs_free_leaf_ref(root, ref);
6429 }
6430 return 0;
6431 }
6432
6433 static noinline int invalidate_extent_cache(struct btrfs_root *root,
6434 struct extent_buffer *leaf,
6435 struct btrfs_block_group_cache *group,
6436 struct btrfs_root *target_root)
6437 {
6438 struct btrfs_key key;
6439 struct inode *inode = NULL;
6440 struct btrfs_file_extent_item *fi;
6441 u64 num_bytes;
6442 u64 skip_objectid = 0;
6443 u32 nritems;
6444 u32 i;
6445
6446 nritems = btrfs_header_nritems(leaf);
6447 for (i = 0; i < nritems; i++) {
6448 btrfs_item_key_to_cpu(leaf, &key, i);
6449 if (key.objectid == skip_objectid ||
6450 key.type != BTRFS_EXTENT_DATA_KEY)
6451 continue;
6452 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6453 if (btrfs_file_extent_type(leaf, fi) ==
6454 BTRFS_FILE_EXTENT_INLINE)
6455 continue;
6456 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
6457 continue;
6458 if (!inode || inode->i_ino != key.objectid) {
6459 iput(inode);
6460 inode = btrfs_ilookup(target_root->fs_info->sb,
6461 key.objectid, target_root, 1);
6462 }
6463 if (!inode) {
6464 skip_objectid = key.objectid;
6465 continue;
6466 }
6467 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6468
6469 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
6470 key.offset + num_bytes - 1, GFP_NOFS);
6471 btrfs_drop_extent_cache(inode, key.offset,
6472 key.offset + num_bytes - 1, 1);
6473 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
6474 key.offset + num_bytes - 1, GFP_NOFS);
6475 cond_resched();
6476 }
6477 iput(inode);
6478 return 0;
6479 }
6480
6481 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
6482 struct btrfs_root *root,
6483 struct extent_buffer *leaf,
6484 struct btrfs_block_group_cache *group,
6485 struct inode *reloc_inode)
6486 {
6487 struct btrfs_key key;
6488 struct btrfs_key extent_key;
6489 struct btrfs_file_extent_item *fi;
6490 struct btrfs_leaf_ref *ref;
6491 struct disk_extent *new_extent;
6492 u64 bytenr;
6493 u64 num_bytes;
6494 u32 nritems;
6495 u32 i;
6496 int ext_index;
6497 int nr_extent;
6498 int ret;
6499
6500 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
6501 BUG_ON(!new_extent);
6502
6503 ref = btrfs_lookup_leaf_ref(root, leaf->start);
6504 BUG_ON(!ref);
6505
6506 ext_index = -1;
6507 nritems = btrfs_header_nritems(leaf);
6508 for (i = 0; i < nritems; i++) {
6509 btrfs_item_key_to_cpu(leaf, &key, i);
6510 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
6511 continue;
6512 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6513 if (btrfs_file_extent_type(leaf, fi) ==
6514 BTRFS_FILE_EXTENT_INLINE)
6515 continue;
6516 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6517 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
6518 if (bytenr == 0)
6519 continue;
6520
6521 ext_index++;
6522 if (bytenr >= group->key.objectid + group->key.offset ||
6523 bytenr + num_bytes <= group->key.objectid)
6524 continue;
6525
6526 extent_key.objectid = bytenr;
6527 extent_key.offset = num_bytes;
6528 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
6529 nr_extent = 1;
6530 ret = get_new_locations(reloc_inode, &extent_key,
6531 group->key.objectid, 1,
6532 &new_extent, &nr_extent);
6533 if (ret > 0)
6534 continue;
6535 BUG_ON(ret < 0);
6536
6537 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
6538 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
6539 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
6540 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
6541
6542 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6543 new_extent->disk_bytenr);
6544 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6545 new_extent->disk_num_bytes);
6546 btrfs_mark_buffer_dirty(leaf);
6547
6548 ret = btrfs_inc_extent_ref(trans, root,
6549 new_extent->disk_bytenr,
6550 new_extent->disk_num_bytes,
6551 leaf->start,
6552 root->root_key.objectid,
6553 trans->transid, key.objectid);
6554 BUG_ON(ret);
6555
6556 ret = btrfs_free_extent(trans, root,
6557 bytenr, num_bytes, leaf->start,
6558 btrfs_header_owner(leaf),
6559 btrfs_header_generation(leaf),
6560 key.objectid, 0);
6561 BUG_ON(ret);
6562 cond_resched();
6563 }
6564 kfree(new_extent);
6565 BUG_ON(ext_index + 1 != ref->nritems);
6566 btrfs_free_leaf_ref(root, ref);
6567 return 0;
6568 }
6569
6570 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
6571 struct btrfs_root *root)
6572 {
6573 struct btrfs_root *reloc_root;
6574 int ret;
6575
6576 if (root->reloc_root) {
6577 reloc_root = root->reloc_root;
6578 root->reloc_root = NULL;
6579 list_add(&reloc_root->dead_list,
6580 &root->fs_info->dead_reloc_roots);
6581
6582 btrfs_set_root_bytenr(&reloc_root->root_item,
6583 reloc_root->node->start);
6584 btrfs_set_root_level(&root->root_item,
6585 btrfs_header_level(reloc_root->node));
6586 memset(&reloc_root->root_item.drop_progress, 0,
6587 sizeof(struct btrfs_disk_key));
6588 reloc_root->root_item.drop_level = 0;
6589
6590 ret = btrfs_update_root(trans, root->fs_info->tree_root,
6591 &reloc_root->root_key,
6592 &reloc_root->root_item);
6593 BUG_ON(ret);
6594 }
6595 return 0;
6596 }
6597
6598 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
6599 {
6600 struct btrfs_trans_handle *trans;
6601 struct btrfs_root *reloc_root;
6602 struct btrfs_root *prev_root = NULL;
6603 struct list_head dead_roots;
6604 int ret;
6605 unsigned long nr;
6606
6607 INIT_LIST_HEAD(&dead_roots);
6608 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
6609
6610 while (!list_empty(&dead_roots)) {
6611 reloc_root = list_entry(dead_roots.prev,
6612 struct btrfs_root, dead_list);
6613 list_del_init(&reloc_root->dead_list);
6614
6615 BUG_ON(reloc_root->commit_root != NULL);
6616 while (1) {
6617 trans = btrfs_join_transaction(root, 1);
6618 BUG_ON(!trans);
6619
6620 mutex_lock(&root->fs_info->drop_mutex);
6621 ret = btrfs_drop_snapshot(trans, reloc_root);
6622 if (ret != -EAGAIN)
6623 break;
6624 mutex_unlock(&root->fs_info->drop_mutex);
6625
6626 nr = trans->blocks_used;
6627 ret = btrfs_end_transaction(trans, root);
6628 BUG_ON(ret);
6629 btrfs_btree_balance_dirty(root, nr);
6630 }
6631
6632 free_extent_buffer(reloc_root->node);
6633
6634 ret = btrfs_del_root(trans, root->fs_info->tree_root,
6635 &reloc_root->root_key);
6636 BUG_ON(ret);
6637 mutex_unlock(&root->fs_info->drop_mutex);
6638
6639 nr = trans->blocks_used;
6640 ret = btrfs_end_transaction(trans, root);
6641 BUG_ON(ret);
6642 btrfs_btree_balance_dirty(root, nr);
6643
6644 kfree(prev_root);
6645 prev_root = reloc_root;
6646 }
6647 if (prev_root) {
6648 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
6649 kfree(prev_root);
6650 }
6651 return 0;
6652 }
6653
6654 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
6655 {
6656 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
6657 return 0;
6658 }
6659
6660 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
6661 {
6662 struct btrfs_root *reloc_root;
6663 struct btrfs_trans_handle *trans;
6664 struct btrfs_key location;
6665 int found;
6666 int ret;
6667
6668 mutex_lock(&root->fs_info->tree_reloc_mutex);
6669 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
6670 BUG_ON(ret);
6671 found = !list_empty(&root->fs_info->dead_reloc_roots);
6672 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6673
6674 if (found) {
6675 trans = btrfs_start_transaction(root, 1);
6676 BUG_ON(!trans);
6677 ret = btrfs_commit_transaction(trans, root);
6678 BUG_ON(ret);
6679 }
6680
6681 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
6682 location.offset = (u64)-1;
6683 location.type = BTRFS_ROOT_ITEM_KEY;
6684
6685 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
6686 BUG_ON(!reloc_root);
6687 btrfs_orphan_cleanup(reloc_root);
6688 return 0;
6689 }
6690
6691 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
6692 struct btrfs_root *root)
6693 {
6694 struct btrfs_root *reloc_root;
6695 struct extent_buffer *eb;
6696 struct btrfs_root_item *root_item;
6697 struct btrfs_key root_key;
6698 int ret;
6699
6700 BUG_ON(!root->ref_cows);
6701 if (root->reloc_root)
6702 return 0;
6703
6704 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
6705 BUG_ON(!root_item);
6706
6707 ret = btrfs_copy_root(trans, root, root->commit_root,
6708 &eb, BTRFS_TREE_RELOC_OBJECTID);
6709 BUG_ON(ret);
6710
6711 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
6712 root_key.offset = root->root_key.objectid;
6713 root_key.type = BTRFS_ROOT_ITEM_KEY;
6714
6715 memcpy(root_item, &root->root_item, sizeof(root_item));
6716 btrfs_set_root_refs(root_item, 0);
6717 btrfs_set_root_bytenr(root_item, eb->start);
6718 btrfs_set_root_level(root_item, btrfs_header_level(eb));
6719 btrfs_set_root_generation(root_item, trans->transid);
6720
6721 btrfs_tree_unlock(eb);
6722 free_extent_buffer(eb);
6723
6724 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
6725 &root_key, root_item);
6726 BUG_ON(ret);
6727 kfree(root_item);
6728
6729 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
6730 &root_key);
6731 BUG_ON(!reloc_root);
6732 reloc_root->last_trans = trans->transid;
6733 reloc_root->commit_root = NULL;
6734 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
6735
6736 root->reloc_root = reloc_root;
6737 return 0;
6738 }
6739
6740 /*
6741 * Core function of space balance.
6742 *
6743 * The idea is using reloc trees to relocate tree blocks in reference
6744 * counted roots. There is one reloc tree for each subvol, and all
6745 * reloc trees share same root key objectid. Reloc trees are snapshots
6746 * of the latest committed roots of subvols (root->commit_root).
6747 *
6748 * To relocate a tree block referenced by a subvol, there are two steps.
6749 * COW the block through subvol's reloc tree, then update block pointer
6750 * in the subvol to point to the new block. Since all reloc trees share
6751 * same root key objectid, doing special handing for tree blocks owned
6752 * by them is easy. Once a tree block has been COWed in one reloc tree,
6753 * we can use the resulting new block directly when the same block is
6754 * required to COW again through other reloc trees. By this way, relocated
6755 * tree blocks are shared between reloc trees, so they are also shared
6756 * between subvols.
6757 */
6758 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
6759 struct btrfs_root *root,
6760 struct btrfs_path *path,
6761 struct btrfs_key *first_key,
6762 struct btrfs_ref_path *ref_path,
6763 struct btrfs_block_group_cache *group,
6764 struct inode *reloc_inode)
6765 {
6766 struct btrfs_root *reloc_root;
6767 struct extent_buffer *eb = NULL;
6768 struct btrfs_key *keys;
6769 u64 *nodes;
6770 int level;
6771 int shared_level;
6772 int lowest_level = 0;
6773 int ret;
6774
6775 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
6776 lowest_level = ref_path->owner_objectid;
6777
6778 if (!root->ref_cows) {
6779 path->lowest_level = lowest_level;
6780 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
6781 BUG_ON(ret < 0);
6782 path->lowest_level = 0;
6783 btrfs_release_path(root, path);
6784 return 0;
6785 }
6786
6787 mutex_lock(&root->fs_info->tree_reloc_mutex);
6788 ret = init_reloc_tree(trans, root);
6789 BUG_ON(ret);
6790 reloc_root = root->reloc_root;
6791
6792 shared_level = ref_path->shared_level;
6793 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
6794
6795 keys = ref_path->node_keys;
6796 nodes = ref_path->new_nodes;
6797 memset(&keys[shared_level + 1], 0,
6798 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
6799 memset(&nodes[shared_level + 1], 0,
6800 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
6801
6802 if (nodes[lowest_level] == 0) {
6803 path->lowest_level = lowest_level;
6804 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6805 0, 1);
6806 BUG_ON(ret);
6807 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
6808 eb = path->nodes[level];
6809 if (!eb || eb == reloc_root->node)
6810 break;
6811 nodes[level] = eb->start;
6812 if (level == 0)
6813 btrfs_item_key_to_cpu(eb, &keys[level], 0);
6814 else
6815 btrfs_node_key_to_cpu(eb, &keys[level], 0);
6816 }
6817 if (nodes[0] &&
6818 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6819 eb = path->nodes[0];
6820 ret = replace_extents_in_leaf(trans, reloc_root, eb,
6821 group, reloc_inode);
6822 BUG_ON(ret);
6823 }
6824 btrfs_release_path(reloc_root, path);
6825 } else {
6826 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
6827 lowest_level);
6828 BUG_ON(ret);
6829 }
6830
6831 /*
6832 * replace tree blocks in the fs tree with tree blocks in
6833 * the reloc tree.
6834 */
6835 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
6836 BUG_ON(ret < 0);
6837
6838 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6839 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6840 0, 0);
6841 BUG_ON(ret);
6842 extent_buffer_get(path->nodes[0]);
6843 eb = path->nodes[0];
6844 btrfs_release_path(reloc_root, path);
6845 ret = invalidate_extent_cache(reloc_root, eb, group, root);
6846 BUG_ON(ret);
6847 free_extent_buffer(eb);
6848 }
6849
6850 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6851 path->lowest_level = 0;
6852 return 0;
6853 }
6854
6855 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
6856 struct btrfs_root *root,
6857 struct btrfs_path *path,
6858 struct btrfs_key *first_key,
6859 struct btrfs_ref_path *ref_path)
6860 {
6861 int ret;
6862
6863 ret = relocate_one_path(trans, root, path, first_key,
6864 ref_path, NULL, NULL);
6865 BUG_ON(ret);
6866
6867 return 0;
6868 }
6869
6870 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
6871 struct btrfs_root *extent_root,
6872 struct btrfs_path *path,
6873 struct btrfs_key *extent_key)
6874 {
6875 int ret;
6876
6877 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
6878 if (ret)
6879 goto out;
6880 ret = btrfs_del_item(trans, extent_root, path);
6881 out:
6882 btrfs_release_path(extent_root, path);
6883 return ret;
6884 }
6885
6886 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
6887 struct btrfs_ref_path *ref_path)
6888 {
6889 struct btrfs_key root_key;
6890
6891 root_key.objectid = ref_path->root_objectid;
6892 root_key.type = BTRFS_ROOT_ITEM_KEY;
6893 if (is_cowonly_root(ref_path->root_objectid))
6894 root_key.offset = 0;
6895 else
6896 root_key.offset = (u64)-1;
6897
6898 return btrfs_read_fs_root_no_name(fs_info, &root_key);
6899 }
6900
6901 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
6902 struct btrfs_path *path,
6903 struct btrfs_key *extent_key,
6904 struct btrfs_block_group_cache *group,
6905 struct inode *reloc_inode, int pass)
6906 {
6907 struct btrfs_trans_handle *trans;
6908 struct btrfs_root *found_root;
6909 struct btrfs_ref_path *ref_path = NULL;
6910 struct disk_extent *new_extents = NULL;
6911 int nr_extents = 0;
6912 int loops;
6913 int ret;
6914 int level;
6915 struct btrfs_key first_key;
6916 u64 prev_block = 0;
6917
6918
6919 trans = btrfs_start_transaction(extent_root, 1);
6920 BUG_ON(!trans);
6921
6922 if (extent_key->objectid == 0) {
6923 ret = del_extent_zero(trans, extent_root, path, extent_key);
6924 goto out;
6925 }
6926
6927 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
6928 if (!ref_path) {
6929 ret = -ENOMEM;
6930 goto out;
6931 }
6932
6933 for (loops = 0; ; loops++) {
6934 if (loops == 0) {
6935 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
6936 extent_key->objectid);
6937 } else {
6938 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
6939 }
6940 if (ret < 0)
6941 goto out;
6942 if (ret > 0)
6943 break;
6944
6945 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
6946 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
6947 continue;
6948
6949 found_root = read_ref_root(extent_root->fs_info, ref_path);
6950 BUG_ON(!found_root);
6951 /*
6952 * for reference counted tree, only process reference paths
6953 * rooted at the latest committed root.
6954 */
6955 if (found_root->ref_cows &&
6956 ref_path->root_generation != found_root->root_key.offset)
6957 continue;
6958
6959 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6960 if (pass == 0) {
6961 /*
6962 * copy data extents to new locations
6963 */
6964 u64 group_start = group->key.objectid;
6965 ret = relocate_data_extent(reloc_inode,
6966 extent_key,
6967 group_start);
6968 if (ret < 0)
6969 goto out;
6970 break;
6971 }
6972 level = 0;
6973 } else {
6974 level = ref_path->owner_objectid;
6975 }
6976
6977 if (prev_block != ref_path->nodes[level]) {
6978 struct extent_buffer *eb;
6979 u64 block_start = ref_path->nodes[level];
6980 u64 block_size = btrfs_level_size(found_root, level);
6981
6982 eb = read_tree_block(found_root, block_start,
6983 block_size, 0);
6984 btrfs_tree_lock(eb);
6985 BUG_ON(level != btrfs_header_level(eb));
6986
6987 if (level == 0)
6988 btrfs_item_key_to_cpu(eb, &first_key, 0);
6989 else
6990 btrfs_node_key_to_cpu(eb, &first_key, 0);
6991
6992 btrfs_tree_unlock(eb);
6993 free_extent_buffer(eb);
6994 prev_block = block_start;
6995 }
6996
6997 mutex_lock(&extent_root->fs_info->trans_mutex);
6998 btrfs_record_root_in_trans(found_root);
6999 mutex_unlock(&extent_root->fs_info->trans_mutex);
7000 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
7001 /*
7002 * try to update data extent references while
7003 * keeping metadata shared between snapshots.
7004 */
7005 if (pass == 1) {
7006 ret = relocate_one_path(trans, found_root,
7007 path, &first_key, ref_path,
7008 group, reloc_inode);
7009 if (ret < 0)
7010 goto out;
7011 continue;
7012 }
7013 /*
7014 * use fallback method to process the remaining
7015 * references.
7016 */
7017 if (!new_extents) {
7018 u64 group_start = group->key.objectid;
7019 new_extents = kmalloc(sizeof(*new_extents),
7020 GFP_NOFS);
7021 nr_extents = 1;
7022 ret = get_new_locations(reloc_inode,
7023 extent_key,
7024 group_start, 1,
7025 &new_extents,
7026 &nr_extents);
7027 if (ret)
7028 goto out;
7029 }
7030 ret = replace_one_extent(trans, found_root,
7031 path, extent_key,
7032 &first_key, ref_path,
7033 new_extents, nr_extents);
7034 } else {
7035 ret = relocate_tree_block(trans, found_root, path,
7036 &first_key, ref_path);
7037 }
7038 if (ret < 0)
7039 goto out;
7040 }
7041 ret = 0;
7042 out:
7043 btrfs_end_transaction(trans, extent_root);
7044 kfree(new_extents);
7045 kfree(ref_path);
7046 return ret;
7047 }
7048 #endif
7049
7050 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
7051 {
7052 u64 num_devices;
7053 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
7054 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
7055
7056 num_devices = root->fs_info->fs_devices->rw_devices;
7057 if (num_devices == 1) {
7058 stripped |= BTRFS_BLOCK_GROUP_DUP;
7059 stripped = flags & ~stripped;
7060
7061 /* turn raid0 into single device chunks */
7062 if (flags & BTRFS_BLOCK_GROUP_RAID0)
7063 return stripped;
7064
7065 /* turn mirroring into duplication */
7066 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
7067 BTRFS_BLOCK_GROUP_RAID10))
7068 return stripped | BTRFS_BLOCK_GROUP_DUP;
7069 return flags;
7070 } else {
7071 /* they already had raid on here, just return */
7072 if (flags & stripped)
7073 return flags;
7074
7075 stripped |= BTRFS_BLOCK_GROUP_DUP;
7076 stripped = flags & ~stripped;
7077
7078 /* switch duplicated blocks with raid1 */
7079 if (flags & BTRFS_BLOCK_GROUP_DUP)
7080 return stripped | BTRFS_BLOCK_GROUP_RAID1;
7081
7082 /* turn single device chunks into raid0 */
7083 return stripped | BTRFS_BLOCK_GROUP_RAID0;
7084 }
7085 return flags;
7086 }
7087
7088 static int __alloc_chunk_for_shrink(struct btrfs_root *root,
7089 struct btrfs_block_group_cache *shrink_block_group,
7090 int force)
7091 {
7092 struct btrfs_trans_handle *trans;
7093 u64 new_alloc_flags;
7094 u64 calc;
7095
7096 spin_lock(&shrink_block_group->lock);
7097 if (btrfs_block_group_used(&shrink_block_group->item) +
7098 shrink_block_group->reserved > 0) {
7099 spin_unlock(&shrink_block_group->lock);
7100
7101 trans = btrfs_start_transaction(root, 1);
7102 spin_lock(&shrink_block_group->lock);
7103
7104 new_alloc_flags = update_block_group_flags(root,
7105 shrink_block_group->flags);
7106 if (new_alloc_flags != shrink_block_group->flags) {
7107 calc =
7108 btrfs_block_group_used(&shrink_block_group->item);
7109 } else {
7110 calc = shrink_block_group->key.offset;
7111 }
7112 spin_unlock(&shrink_block_group->lock);
7113
7114 do_chunk_alloc(trans, root->fs_info->extent_root,
7115 calc + 2 * 1024 * 1024, new_alloc_flags, force);
7116
7117 btrfs_end_transaction(trans, root);
7118 } else
7119 spin_unlock(&shrink_block_group->lock);
7120 return 0;
7121 }
7122
7123
7124 int btrfs_prepare_block_group_relocation(struct btrfs_root *root,
7125 struct btrfs_block_group_cache *group)
7126
7127 {
7128 __alloc_chunk_for_shrink(root, group, 1);
7129 set_block_group_readonly(group);
7130 return 0;
7131 }
7132
7133 /*
7134 * checks to see if its even possible to relocate this block group.
7135 *
7136 * @return - -1 if it's not a good idea to relocate this block group, 0 if its
7137 * ok to go ahead and try.
7138 */
7139 int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
7140 {
7141 struct btrfs_block_group_cache *block_group;
7142 struct btrfs_space_info *space_info;
7143 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
7144 struct btrfs_device *device;
7145 int full = 0;
7146 int ret = 0;
7147
7148 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
7149
7150 /* odd, couldn't find the block group, leave it alone */
7151 if (!block_group)
7152 return -1;
7153
7154 /* no bytes used, we're good */
7155 if (!btrfs_block_group_used(&block_group->item))
7156 goto out;
7157
7158 space_info = block_group->space_info;
7159 spin_lock(&space_info->lock);
7160
7161 full = space_info->full;
7162
7163 /*
7164 * if this is the last block group we have in this space, we can't
7165 * relocate it unless we're able to allocate a new chunk below.
7166 *
7167 * Otherwise, we need to make sure we have room in the space to handle
7168 * all of the extents from this block group. If we can, we're good
7169 */
7170 if ((space_info->total_bytes != block_group->key.offset) &&
7171 (space_info->bytes_used + space_info->bytes_reserved +
7172 space_info->bytes_pinned + space_info->bytes_readonly +
7173 btrfs_block_group_used(&block_group->item) <
7174 space_info->total_bytes)) {
7175 spin_unlock(&space_info->lock);
7176 goto out;
7177 }
7178 spin_unlock(&space_info->lock);
7179
7180 /*
7181 * ok we don't have enough space, but maybe we have free space on our
7182 * devices to allocate new chunks for relocation, so loop through our
7183 * alloc devices and guess if we have enough space. However, if we
7184 * were marked as full, then we know there aren't enough chunks, and we
7185 * can just return.
7186 */
7187 ret = -1;
7188 if (full)
7189 goto out;
7190
7191 mutex_lock(&root->fs_info->chunk_mutex);
7192 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
7193 u64 min_free = btrfs_block_group_used(&block_group->item);
7194 u64 dev_offset, max_avail;
7195
7196 /*
7197 * check to make sure we can actually find a chunk with enough
7198 * space to fit our block group in.
7199 */
7200 if (device->total_bytes > device->bytes_used + min_free) {
7201 ret = find_free_dev_extent(NULL, device, min_free,
7202 &dev_offset, &max_avail);
7203 if (!ret)
7204 break;
7205 ret = -1;
7206 }
7207 }
7208 mutex_unlock(&root->fs_info->chunk_mutex);
7209 out:
7210 btrfs_put_block_group(block_group);
7211 return ret;
7212 }
7213
7214 static int find_first_block_group(struct btrfs_root *root,
7215 struct btrfs_path *path, struct btrfs_key *key)
7216 {
7217 int ret = 0;
7218 struct btrfs_key found_key;
7219 struct extent_buffer *leaf;
7220 int slot;
7221
7222 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
7223 if (ret < 0)
7224 goto out;
7225
7226 while (1) {
7227 slot = path->slots[0];
7228 leaf = path->nodes[0];
7229 if (slot >= btrfs_header_nritems(leaf)) {
7230 ret = btrfs_next_leaf(root, path);
7231 if (ret == 0)
7232 continue;
7233 if (ret < 0)
7234 goto out;
7235 break;
7236 }
7237 btrfs_item_key_to_cpu(leaf, &found_key, slot);
7238
7239 if (found_key.objectid >= key->objectid &&
7240 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
7241 ret = 0;
7242 goto out;
7243 }
7244 path->slots[0]++;
7245 }
7246 ret = -ENOENT;
7247 out:
7248 return ret;
7249 }
7250
7251 int btrfs_free_block_groups(struct btrfs_fs_info *info)
7252 {
7253 struct btrfs_block_group_cache *block_group;
7254 struct btrfs_space_info *space_info;
7255 struct btrfs_caching_control *caching_ctl;
7256 struct rb_node *n;
7257
7258 down_write(&info->extent_commit_sem);
7259 while (!list_empty(&info->caching_block_groups)) {
7260 caching_ctl = list_entry(info->caching_block_groups.next,
7261 struct btrfs_caching_control, list);
7262 list_del(&caching_ctl->list);
7263 put_caching_control(caching_ctl);
7264 }
7265 up_write(&info->extent_commit_sem);
7266
7267 spin_lock(&info->block_group_cache_lock);
7268 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
7269 block_group = rb_entry(n, struct btrfs_block_group_cache,
7270 cache_node);
7271 rb_erase(&block_group->cache_node,
7272 &info->block_group_cache_tree);
7273 spin_unlock(&info->block_group_cache_lock);
7274
7275 down_write(&block_group->space_info->groups_sem);
7276 list_del(&block_group->list);
7277 up_write(&block_group->space_info->groups_sem);
7278
7279 if (block_group->cached == BTRFS_CACHE_STARTED)
7280 wait_block_group_cache_done(block_group);
7281
7282 btrfs_remove_free_space_cache(block_group);
7283
7284 WARN_ON(atomic_read(&block_group->count) != 1);
7285 kfree(block_group);
7286
7287 spin_lock(&info->block_group_cache_lock);
7288 }
7289 spin_unlock(&info->block_group_cache_lock);
7290
7291 /* now that all the block groups are freed, go through and
7292 * free all the space_info structs. This is only called during
7293 * the final stages of unmount, and so we know nobody is
7294 * using them. We call synchronize_rcu() once before we start,
7295 * just to be on the safe side.
7296 */
7297 synchronize_rcu();
7298
7299 while(!list_empty(&info->space_info)) {
7300 space_info = list_entry(info->space_info.next,
7301 struct btrfs_space_info,
7302 list);
7303
7304 list_del(&space_info->list);
7305 kfree(space_info);
7306 }
7307 return 0;
7308 }
7309
7310 int btrfs_read_block_groups(struct btrfs_root *root)
7311 {
7312 struct btrfs_path *path;
7313 int ret;
7314 struct btrfs_block_group_cache *cache;
7315 struct btrfs_fs_info *info = root->fs_info;
7316 struct btrfs_space_info *space_info;
7317 struct btrfs_key key;
7318 struct btrfs_key found_key;
7319 struct extent_buffer *leaf;
7320
7321 root = info->extent_root;
7322 key.objectid = 0;
7323 key.offset = 0;
7324 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
7325 path = btrfs_alloc_path();
7326 if (!path)
7327 return -ENOMEM;
7328
7329 while (1) {
7330 ret = find_first_block_group(root, path, &key);
7331 if (ret > 0) {
7332 ret = 0;
7333 goto error;
7334 }
7335 if (ret != 0)
7336 goto error;
7337
7338 leaf = path->nodes[0];
7339 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7340 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7341 if (!cache) {
7342 ret = -ENOMEM;
7343 break;
7344 }
7345
7346 atomic_set(&cache->count, 1);
7347 spin_lock_init(&cache->lock);
7348 spin_lock_init(&cache->tree_lock);
7349 cache->fs_info = info;
7350 INIT_LIST_HEAD(&cache->list);
7351 INIT_LIST_HEAD(&cache->cluster_list);
7352
7353 /*
7354 * we only want to have 32k of ram per block group for keeping
7355 * track of free space, and if we pass 1/2 of that we want to
7356 * start converting things over to using bitmaps
7357 */
7358 cache->extents_thresh = ((1024 * 32) / 2) /
7359 sizeof(struct btrfs_free_space);
7360
7361 read_extent_buffer(leaf, &cache->item,
7362 btrfs_item_ptr_offset(leaf, path->slots[0]),
7363 sizeof(cache->item));
7364 memcpy(&cache->key, &found_key, sizeof(found_key));
7365
7366 key.objectid = found_key.objectid + found_key.offset;
7367 btrfs_release_path(root, path);
7368 cache->flags = btrfs_block_group_flags(&cache->item);
7369 cache->sectorsize = root->sectorsize;
7370
7371 /*
7372 * check for two cases, either we are full, and therefore
7373 * don't need to bother with the caching work since we won't
7374 * find any space, or we are empty, and we can just add all
7375 * the space in and be done with it. This saves us _alot_ of
7376 * time, particularly in the full case.
7377 */
7378 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
7379 exclude_super_stripes(root, cache);
7380 cache->last_byte_to_unpin = (u64)-1;
7381 cache->cached = BTRFS_CACHE_FINISHED;
7382 free_excluded_extents(root, cache);
7383 } else if (btrfs_block_group_used(&cache->item) == 0) {
7384 exclude_super_stripes(root, cache);
7385 cache->last_byte_to_unpin = (u64)-1;
7386 cache->cached = BTRFS_CACHE_FINISHED;
7387 add_new_free_space(cache, root->fs_info,
7388 found_key.objectid,
7389 found_key.objectid +
7390 found_key.offset);
7391 free_excluded_extents(root, cache);
7392 }
7393
7394 ret = update_space_info(info, cache->flags, found_key.offset,
7395 btrfs_block_group_used(&cache->item),
7396 &space_info);
7397 BUG_ON(ret);
7398 cache->space_info = space_info;
7399 spin_lock(&cache->space_info->lock);
7400 cache->space_info->bytes_super += cache->bytes_super;
7401 spin_unlock(&cache->space_info->lock);
7402
7403 down_write(&space_info->groups_sem);
7404 list_add_tail(&cache->list, &space_info->block_groups);
7405 up_write(&space_info->groups_sem);
7406
7407 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7408 BUG_ON(ret);
7409
7410 set_avail_alloc_bits(root->fs_info, cache->flags);
7411 if (btrfs_chunk_readonly(root, cache->key.objectid))
7412 set_block_group_readonly(cache);
7413 }
7414 ret = 0;
7415 error:
7416 btrfs_free_path(path);
7417 return ret;
7418 }
7419
7420 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
7421 struct btrfs_root *root, u64 bytes_used,
7422 u64 type, u64 chunk_objectid, u64 chunk_offset,
7423 u64 size)
7424 {
7425 int ret;
7426 struct btrfs_root *extent_root;
7427 struct btrfs_block_group_cache *cache;
7428
7429 extent_root = root->fs_info->extent_root;
7430
7431 root->fs_info->last_trans_log_full_commit = trans->transid;
7432
7433 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7434 if (!cache)
7435 return -ENOMEM;
7436
7437 cache->key.objectid = chunk_offset;
7438 cache->key.offset = size;
7439 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
7440 cache->sectorsize = root->sectorsize;
7441
7442 /*
7443 * we only want to have 32k of ram per block group for keeping track
7444 * of free space, and if we pass 1/2 of that we want to start
7445 * converting things over to using bitmaps
7446 */
7447 cache->extents_thresh = ((1024 * 32) / 2) /
7448 sizeof(struct btrfs_free_space);
7449 atomic_set(&cache->count, 1);
7450 spin_lock_init(&cache->lock);
7451 spin_lock_init(&cache->tree_lock);
7452 INIT_LIST_HEAD(&cache->list);
7453 INIT_LIST_HEAD(&cache->cluster_list);
7454
7455 btrfs_set_block_group_used(&cache->item, bytes_used);
7456 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
7457 cache->flags = type;
7458 btrfs_set_block_group_flags(&cache->item, type);
7459
7460 cache->last_byte_to_unpin = (u64)-1;
7461 cache->cached = BTRFS_CACHE_FINISHED;
7462 exclude_super_stripes(root, cache);
7463
7464 add_new_free_space(cache, root->fs_info, chunk_offset,
7465 chunk_offset + size);
7466
7467 free_excluded_extents(root, cache);
7468
7469 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
7470 &cache->space_info);
7471 BUG_ON(ret);
7472
7473 spin_lock(&cache->space_info->lock);
7474 cache->space_info->bytes_super += cache->bytes_super;
7475 spin_unlock(&cache->space_info->lock);
7476
7477 down_write(&cache->space_info->groups_sem);
7478 list_add_tail(&cache->list, &cache->space_info->block_groups);
7479 up_write(&cache->space_info->groups_sem);
7480
7481 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7482 BUG_ON(ret);
7483
7484 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
7485 sizeof(cache->item));
7486 BUG_ON(ret);
7487
7488 set_avail_alloc_bits(extent_root->fs_info, type);
7489
7490 return 0;
7491 }
7492
7493 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
7494 struct btrfs_root *root, u64 group_start)
7495 {
7496 struct btrfs_path *path;
7497 struct btrfs_block_group_cache *block_group;
7498 struct btrfs_free_cluster *cluster;
7499 struct btrfs_key key;
7500 int ret;
7501
7502 root = root->fs_info->extent_root;
7503
7504 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
7505 BUG_ON(!block_group);
7506 BUG_ON(!block_group->ro);
7507
7508 memcpy(&key, &block_group->key, sizeof(key));
7509
7510 /* make sure this block group isn't part of an allocation cluster */
7511 cluster = &root->fs_info->data_alloc_cluster;
7512 spin_lock(&cluster->refill_lock);
7513 btrfs_return_cluster_to_free_space(block_group, cluster);
7514 spin_unlock(&cluster->refill_lock);
7515
7516 /*
7517 * make sure this block group isn't part of a metadata
7518 * allocation cluster
7519 */
7520 cluster = &root->fs_info->meta_alloc_cluster;
7521 spin_lock(&cluster->refill_lock);
7522 btrfs_return_cluster_to_free_space(block_group, cluster);
7523 spin_unlock(&cluster->refill_lock);
7524
7525 path = btrfs_alloc_path();
7526 BUG_ON(!path);
7527
7528 spin_lock(&root->fs_info->block_group_cache_lock);
7529 rb_erase(&block_group->cache_node,
7530 &root->fs_info->block_group_cache_tree);
7531 spin_unlock(&root->fs_info->block_group_cache_lock);
7532
7533 down_write(&block_group->space_info->groups_sem);
7534 /*
7535 * we must use list_del_init so people can check to see if they
7536 * are still on the list after taking the semaphore
7537 */
7538 list_del_init(&block_group->list);
7539 up_write(&block_group->space_info->groups_sem);
7540
7541 if (block_group->cached == BTRFS_CACHE_STARTED)
7542 wait_block_group_cache_done(block_group);
7543
7544 btrfs_remove_free_space_cache(block_group);
7545
7546 spin_lock(&block_group->space_info->lock);
7547 block_group->space_info->total_bytes -= block_group->key.offset;
7548 block_group->space_info->bytes_readonly -= block_group->key.offset;
7549 spin_unlock(&block_group->space_info->lock);
7550
7551 btrfs_clear_space_info_full(root->fs_info);
7552
7553 btrfs_put_block_group(block_group);
7554 btrfs_put_block_group(block_group);
7555
7556 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
7557 if (ret > 0)
7558 ret = -EIO;
7559 if (ret < 0)
7560 goto out;
7561
7562 ret = btrfs_del_item(trans, root, path);
7563 out:
7564 btrfs_free_path(path);
7565 return ret;
7566 }
kernel source for telekom puls (alcatel/mediatek)