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PM / yenta: Split resume into early and late parts (rev. 4)
[linux/fpc-iii.git] / fs / btrfs / extent-tree.c
blob72a2b9c28e9fc7a6a7aacce09469cb6414215635
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_reserved_extents(struct btrfs_root *root,
36 u64 bytenr, u64 num, int reserve);
37 static int update_block_group(struct btrfs_trans_handle *trans,
38 struct btrfs_root *root,
39 u64 bytenr, u64 num_bytes, int alloc,
40 int mark_free);
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
61 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
62 struct btrfs_root *extent_root, u64 alloc_bytes,
63 u64 flags, int force);
64
65 static noinline int
66 block_group_cache_done(struct btrfs_block_group_cache *cache)
67 {
68 smp_mb();
69 return cache->cached == BTRFS_CACHE_FINISHED;
70 }
71
72 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
73 {
74 return (cache->flags & bits) == bits;
75 }
76
77 /*
78 * this adds the block group to the fs_info rb tree for the block group
79 * cache
80 */
81 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
82 struct btrfs_block_group_cache *block_group)
83 {
84 struct rb_node **p;
85 struct rb_node *parent = NULL;
86 struct btrfs_block_group_cache *cache;
87
88 spin_lock(&info->block_group_cache_lock);
89 p = &info->block_group_cache_tree.rb_node;
90
91 while (*p) {
92 parent = *p;
93 cache = rb_entry(parent, struct btrfs_block_group_cache,
94 cache_node);
95 if (block_group->key.objectid < cache->key.objectid) {
96 p = &(*p)->rb_left;
97 } else if (block_group->key.objectid > cache->key.objectid) {
98 p = &(*p)->rb_right;
99 } else {
100 spin_unlock(&info->block_group_cache_lock);
101 return -EEXIST;
102 }
103 }
104
105 rb_link_node(&block_group->cache_node, parent, p);
106 rb_insert_color(&block_group->cache_node,
107 &info->block_group_cache_tree);
108 spin_unlock(&info->block_group_cache_lock);
109
110 return 0;
111 }
112
113 /*
114 * This will return the block group at or after bytenr if contains is 0, else
115 * it will return the block group that contains the bytenr
116 */
117 static struct btrfs_block_group_cache *
118 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
119 int contains)
120 {
121 struct btrfs_block_group_cache *cache, *ret = NULL;
122 struct rb_node *n;
123 u64 end, start;
124
125 spin_lock(&info->block_group_cache_lock);
126 n = info->block_group_cache_tree.rb_node;
127
128 while (n) {
129 cache = rb_entry(n, struct btrfs_block_group_cache,
130 cache_node);
131 end = cache->key.objectid + cache->key.offset - 1;
132 start = cache->key.objectid;
133
134 if (bytenr < start) {
135 if (!contains && (!ret || start < ret->key.objectid))
136 ret = cache;
137 n = n->rb_left;
138 } else if (bytenr > start) {
139 if (contains && bytenr <= end) {
140 ret = cache;
141 break;
142 }
143 n = n->rb_right;
144 } else {
145 ret = cache;
146 break;
147 }
148 }
149 if (ret)
150 atomic_inc(&ret->count);
151 spin_unlock(&info->block_group_cache_lock);
152
153 return ret;
154 }
155
156 /*
157 * We always set EXTENT_LOCKED for the super mirror extents so we don't
158 * overwrite them, so those bits need to be unset. Also, if we are unmounting
159 * with pinned extents still sitting there because we had a block group caching,
160 * we need to clear those now, since we are done.
161 */
162 void btrfs_free_pinned_extents(struct btrfs_fs_info *info)
163 {
164 u64 start, end, last = 0;
165 int ret;
166
167 while (1) {
168 ret = find_first_extent_bit(&info->pinned_extents, last,
169 &start, &end,
170 EXTENT_LOCKED|EXTENT_DIRTY);
171 if (ret)
172 break;
173
174 clear_extent_bits(&info->pinned_extents, start, end,
175 EXTENT_LOCKED|EXTENT_DIRTY, GFP_NOFS);
176 last = end+1;
177 }
178 }
179
180 static int remove_sb_from_cache(struct btrfs_root *root,
181 struct btrfs_block_group_cache *cache)
182 {
183 struct btrfs_fs_info *fs_info = root->fs_info;
184 u64 bytenr;
185 u64 *logical;
186 int stripe_len;
187 int i, nr, ret;
188
189 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
190 bytenr = btrfs_sb_offset(i);
191 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
192 cache->key.objectid, bytenr,
193 0, &logical, &nr, &stripe_len);
194 BUG_ON(ret);
195 while (nr--) {
196 try_lock_extent(&fs_info->pinned_extents,
197 logical[nr],
198 logical[nr] + stripe_len - 1, GFP_NOFS);
199 }
200 kfree(logical);
201 }
202
203 return 0;
204 }
205
206 /*
207 * this is only called by cache_block_group, since we could have freed extents
208 * we need to check the pinned_extents for any extents that can't be used yet
209 * since their free space will be released as soon as the transaction commits.
210 */
211 static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
212 struct btrfs_fs_info *info, u64 start, u64 end)
213 {
214 u64 extent_start, extent_end, size, total_added = 0;
215 int ret;
216
217 while (start < end) {
218 ret = find_first_extent_bit(&info->pinned_extents, start,
219 &extent_start, &extent_end,
220 EXTENT_DIRTY|EXTENT_LOCKED);
221 if (ret)
222 break;
223
224 if (extent_start == start) {
225 start = extent_end + 1;
226 } else if (extent_start > start && extent_start < end) {
227 size = extent_start - start;
228 total_added += size;
229 ret = btrfs_add_free_space(block_group, start,
230 size);
231 BUG_ON(ret);
232 start = extent_end + 1;
233 } else {
234 break;
235 }
236 }
237
238 if (start < end) {
239 size = end - start;
240 total_added += size;
241 ret = btrfs_add_free_space(block_group, start, size);
242 BUG_ON(ret);
243 }
244
245 return total_added;
246 }
247
248 static int caching_kthread(void *data)
249 {
250 struct btrfs_block_group_cache *block_group = data;
251 struct btrfs_fs_info *fs_info = block_group->fs_info;
252 u64 last = 0;
253 struct btrfs_path *path;
254 int ret = 0;
255 struct btrfs_key key;
256 struct extent_buffer *leaf;
257 int slot;
258 u64 total_found = 0;
259
260 BUG_ON(!fs_info);
261
262 path = btrfs_alloc_path();
263 if (!path)
264 return -ENOMEM;
265
266 atomic_inc(&block_group->space_info->caching_threads);
267 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
268 /*
269 * We don't want to deadlock with somebody trying to allocate a new
270 * extent for the extent root while also trying to search the extent
271 * root to add free space. So we skip locking and search the commit
272 * root, since its read-only
273 */
274 path->skip_locking = 1;
275 path->search_commit_root = 1;
276 path->reada = 2;
277
278 key.objectid = last;
279 key.offset = 0;
280 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
281 again:
282 /* need to make sure the commit_root doesn't disappear */
283 down_read(&fs_info->extent_commit_sem);
284
285 ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
286 if (ret < 0)
287 goto err;
288
289 while (1) {
290 smp_mb();
291 if (block_group->fs_info->closing > 1) {
292 last = (u64)-1;
293 break;
294 }
295
296 leaf = path->nodes[0];
297 slot = path->slots[0];
298 if (slot >= btrfs_header_nritems(leaf)) {
299 ret = btrfs_next_leaf(fs_info->extent_root, path);
300 if (ret < 0)
301 goto err;
302 else if (ret)
303 break;
304
305 if (need_resched() ||
306 btrfs_transaction_in_commit(fs_info)) {
307 leaf = path->nodes[0];
308
309 /* this shouldn't happen, but if the
310 * leaf is empty just move on.
311 */
312 if (btrfs_header_nritems(leaf) == 0)
313 break;
314 /*
315 * we need to copy the key out so that
316 * we are sure the next search advances
317 * us forward in the btree.
318 */
319 btrfs_item_key_to_cpu(leaf, &key, 0);
320 btrfs_release_path(fs_info->extent_root, path);
321 up_read(&fs_info->extent_commit_sem);
322 schedule_timeout(1);
323 goto again;
324 }
325
326 continue;
327 }
328 btrfs_item_key_to_cpu(leaf, &key, slot);
329 if (key.objectid < block_group->key.objectid)
330 goto next;
331
332 if (key.objectid >= block_group->key.objectid +
333 block_group->key.offset)
334 break;
335
336 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
337 total_found += add_new_free_space(block_group,
338 fs_info, last,
339 key.objectid);
340 last = key.objectid + key.offset;
341 }
342
343 if (total_found > (1024 * 1024 * 2)) {
344 total_found = 0;
345 wake_up(&block_group->caching_q);
346 }
347 next:
348 path->slots[0]++;
349 }
350 ret = 0;
351
352 total_found += add_new_free_space(block_group, fs_info, last,
353 block_group->key.objectid +
354 block_group->key.offset);
355
356 spin_lock(&block_group->lock);
357 block_group->cached = BTRFS_CACHE_FINISHED;
358 spin_unlock(&block_group->lock);
359
360 err:
361 btrfs_free_path(path);
362 up_read(&fs_info->extent_commit_sem);
363 atomic_dec(&block_group->space_info->caching_threads);
364 wake_up(&block_group->caching_q);
365
366 return 0;
367 }
368
369 static int cache_block_group(struct btrfs_block_group_cache *cache)
370 {
371 struct task_struct *tsk;
372 int ret = 0;
373
374 spin_lock(&cache->lock);
375 if (cache->cached != BTRFS_CACHE_NO) {
376 spin_unlock(&cache->lock);
377 return ret;
378 }
379 cache->cached = BTRFS_CACHE_STARTED;
380 spin_unlock(&cache->lock);
381
382 tsk = kthread_run(caching_kthread, cache, "btrfs-cache-%llu\n",
383 cache->key.objectid);
384 if (IS_ERR(tsk)) {
385 ret = PTR_ERR(tsk);
386 printk(KERN_ERR "error running thread %d\n", ret);
387 BUG();
388 }
389
390 return ret;
391 }
392
393 /*
394 * return the block group that starts at or after bytenr
395 */
396 static struct btrfs_block_group_cache *
397 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
398 {
399 struct btrfs_block_group_cache *cache;
400
401 cache = block_group_cache_tree_search(info, bytenr, 0);
402
403 return cache;
404 }
405
406 /*
407 * return the block group that contains the given bytenr
408 */
409 struct btrfs_block_group_cache *btrfs_lookup_block_group(
410 struct btrfs_fs_info *info,
411 u64 bytenr)
412 {
413 struct btrfs_block_group_cache *cache;
414
415 cache = block_group_cache_tree_search(info, bytenr, 1);
416
417 return cache;
418 }
419
420 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
421 {
422 if (atomic_dec_and_test(&cache->count))
423 kfree(cache);
424 }
425
426 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
427 u64 flags)
428 {
429 struct list_head *head = &info->space_info;
430 struct btrfs_space_info *found;
431
432 rcu_read_lock();
433 list_for_each_entry_rcu(found, head, list) {
434 if (found->flags == flags) {
435 rcu_read_unlock();
436 return found;
437 }
438 }
439 rcu_read_unlock();
440 return NULL;
441 }
442
443 /*
444 * after adding space to the filesystem, we need to clear the full flags
445 * on all the space infos.
446 */
447 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
448 {
449 struct list_head *head = &info->space_info;
450 struct btrfs_space_info *found;
451
452 rcu_read_lock();
453 list_for_each_entry_rcu(found, head, list)
454 found->full = 0;
455 rcu_read_unlock();
456 }
457
458 static u64 div_factor(u64 num, int factor)
459 {
460 if (factor == 10)
461 return num;
462 num *= factor;
463 do_div(num, 10);
464 return num;
465 }
466
467 u64 btrfs_find_block_group(struct btrfs_root *root,
468 u64 search_start, u64 search_hint, int owner)
469 {
470 struct btrfs_block_group_cache *cache;
471 u64 used;
472 u64 last = max(search_hint, search_start);
473 u64 group_start = 0;
474 int full_search = 0;
475 int factor = 9;
476 int wrapped = 0;
477 again:
478 while (1) {
479 cache = btrfs_lookup_first_block_group(root->fs_info, last);
480 if (!cache)
481 break;
482
483 spin_lock(&cache->lock);
484 last = cache->key.objectid + cache->key.offset;
485 used = btrfs_block_group_used(&cache->item);
486
487 if ((full_search || !cache->ro) &&
488 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
489 if (used + cache->pinned + cache->reserved <
490 div_factor(cache->key.offset, factor)) {
491 group_start = cache->key.objectid;
492 spin_unlock(&cache->lock);
493 btrfs_put_block_group(cache);
494 goto found;
495 }
496 }
497 spin_unlock(&cache->lock);
498 btrfs_put_block_group(cache);
499 cond_resched();
500 }
501 if (!wrapped) {
502 last = search_start;
503 wrapped = 1;
504 goto again;
505 }
506 if (!full_search && factor < 10) {
507 last = search_start;
508 full_search = 1;
509 factor = 10;
510 goto again;
511 }
512 found:
513 return group_start;
514 }
515
516 /* simple helper to search for an existing extent at a given offset */
517 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
518 {
519 int ret;
520 struct btrfs_key key;
521 struct btrfs_path *path;
522
523 path = btrfs_alloc_path();
524 BUG_ON(!path);
525 key.objectid = start;
526 key.offset = len;
527 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
528 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
529 0, 0);
530 btrfs_free_path(path);
531 return ret;
532 }
533
534 /*
535 * Back reference rules. Back refs have three main goals:
536 *
537 * 1) differentiate between all holders of references to an extent so that
538 * when a reference is dropped we can make sure it was a valid reference
539 * before freeing the extent.
540 *
541 * 2) Provide enough information to quickly find the holders of an extent
542 * if we notice a given block is corrupted or bad.
543 *
544 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
545 * maintenance. This is actually the same as #2, but with a slightly
546 * different use case.
547 *
548 * There are two kinds of back refs. The implicit back refs is optimized
549 * for pointers in non-shared tree blocks. For a given pointer in a block,
550 * back refs of this kind provide information about the block's owner tree
551 * and the pointer's key. These information allow us to find the block by
552 * b-tree searching. The full back refs is for pointers in tree blocks not
553 * referenced by their owner trees. The location of tree block is recorded
554 * in the back refs. Actually the full back refs is generic, and can be
555 * used in all cases the implicit back refs is used. The major shortcoming
556 * of the full back refs is its overhead. Every time a tree block gets
557 * COWed, we have to update back refs entry for all pointers in it.
558 *
559 * For a newly allocated tree block, we use implicit back refs for
560 * pointers in it. This means most tree related operations only involve
561 * implicit back refs. For a tree block created in old transaction, the
562 * only way to drop a reference to it is COW it. So we can detect the
563 * event that tree block loses its owner tree's reference and do the
564 * back refs conversion.
565 *
566 * When a tree block is COW'd through a tree, there are four cases:
567 *
568 * The reference count of the block is one and the tree is the block's
569 * owner tree. Nothing to do in this case.
570 *
571 * The reference count of the block is one and the tree is not the
572 * block's owner tree. In this case, full back refs is used for pointers
573 * in the block. Remove these full back refs, add implicit back refs for
574 * every pointers in the new block.
575 *
576 * The reference count of the block is greater than one and the tree is
577 * the block's owner tree. In this case, implicit back refs is used for
578 * pointers in the block. Add full back refs for every pointers in the
579 * block, increase lower level extents' reference counts. The original
580 * implicit back refs are entailed to the new block.
581 *
582 * The reference count of the block is greater than one and the tree is
583 * not the block's owner tree. Add implicit back refs for every pointer in
584 * the new block, increase lower level extents' reference count.
585 *
586 * Back Reference Key composing:
587 *
588 * The key objectid corresponds to the first byte in the extent,
589 * The key type is used to differentiate between types of back refs.
590 * There are different meanings of the key offset for different types
591 * of back refs.
592 *
593 * File extents can be referenced by:
594 *
595 * - multiple snapshots, subvolumes, or different generations in one subvol
596 * - different files inside a single subvolume
597 * - different offsets inside a file (bookend extents in file.c)
598 *
599 * The extent ref structure for the implicit back refs has fields for:
600 *
601 * - Objectid of the subvolume root
602 * - objectid of the file holding the reference
603 * - original offset in the file
604 * - how many bookend extents
605 *
606 * The key offset for the implicit back refs is hash of the first
607 * three fields.
608 *
609 * The extent ref structure for the full back refs has field for:
610 *
611 * - number of pointers in the tree leaf
612 *
613 * The key offset for the implicit back refs is the first byte of
614 * the tree leaf
615 *
616 * When a file extent is allocated, The implicit back refs is used.
617 * the fields are filled in:
618 *
619 * (root_key.objectid, inode objectid, offset in file, 1)
620 *
621 * When a file extent is removed file truncation, we find the
622 * corresponding implicit back refs and check the following fields:
623 *
624 * (btrfs_header_owner(leaf), inode objectid, offset in file)
625 *
626 * Btree extents can be referenced by:
627 *
628 * - Different subvolumes
629 *
630 * Both the implicit back refs and the full back refs for tree blocks
631 * only consist of key. The key offset for the implicit back refs is
632 * objectid of block's owner tree. The key offset for the full back refs
633 * is the first byte of parent block.
634 *
635 * When implicit back refs is used, information about the lowest key and
636 * level of the tree block are required. These information are stored in
637 * tree block info structure.
638 */
639
640 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
641 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
642 struct btrfs_root *root,
643 struct btrfs_path *path,
644 u64 owner, u32 extra_size)
645 {
646 struct btrfs_extent_item *item;
647 struct btrfs_extent_item_v0 *ei0;
648 struct btrfs_extent_ref_v0 *ref0;
649 struct btrfs_tree_block_info *bi;
650 struct extent_buffer *leaf;
651 struct btrfs_key key;
652 struct btrfs_key found_key;
653 u32 new_size = sizeof(*item);
654 u64 refs;
655 int ret;
656
657 leaf = path->nodes[0];
658 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
659
660 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
661 ei0 = btrfs_item_ptr(leaf, path->slots[0],
662 struct btrfs_extent_item_v0);
663 refs = btrfs_extent_refs_v0(leaf, ei0);
664
665 if (owner == (u64)-1) {
666 while (1) {
667 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
668 ret = btrfs_next_leaf(root, path);
669 if (ret < 0)
670 return ret;
671 BUG_ON(ret > 0);
672 leaf = path->nodes[0];
673 }
674 btrfs_item_key_to_cpu(leaf, &found_key,
675 path->slots[0]);
676 BUG_ON(key.objectid != found_key.objectid);
677 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
678 path->slots[0]++;
679 continue;
680 }
681 ref0 = btrfs_item_ptr(leaf, path->slots[0],
682 struct btrfs_extent_ref_v0);
683 owner = btrfs_ref_objectid_v0(leaf, ref0);
684 break;
685 }
686 }
687 btrfs_release_path(root, path);
688
689 if (owner < BTRFS_FIRST_FREE_OBJECTID)
690 new_size += sizeof(*bi);
691
692 new_size -= sizeof(*ei0);
693 ret = btrfs_search_slot(trans, root, &key, path,
694 new_size + extra_size, 1);
695 if (ret < 0)
696 return ret;
697 BUG_ON(ret);
698
699 ret = btrfs_extend_item(trans, root, path, new_size);
700 BUG_ON(ret);
701
702 leaf = path->nodes[0];
703 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
704 btrfs_set_extent_refs(leaf, item, refs);
705 /* FIXME: get real generation */
706 btrfs_set_extent_generation(leaf, item, 0);
707 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
708 btrfs_set_extent_flags(leaf, item,
709 BTRFS_EXTENT_FLAG_TREE_BLOCK |
710 BTRFS_BLOCK_FLAG_FULL_BACKREF);
711 bi = (struct btrfs_tree_block_info *)(item + 1);
712 /* FIXME: get first key of the block */
713 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
714 btrfs_set_tree_block_level(leaf, bi, (int)owner);
715 } else {
716 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
717 }
718 btrfs_mark_buffer_dirty(leaf);
719 return 0;
720 }
721 #endif
722
723 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
724 {
725 u32 high_crc = ~(u32)0;
726 u32 low_crc = ~(u32)0;
727 __le64 lenum;
728
729 lenum = cpu_to_le64(root_objectid);
730 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
731 lenum = cpu_to_le64(owner);
732 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
733 lenum = cpu_to_le64(offset);
734 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
735
736 return ((u64)high_crc << 31) ^ (u64)low_crc;
737 }
738
739 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
740 struct btrfs_extent_data_ref *ref)
741 {
742 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
743 btrfs_extent_data_ref_objectid(leaf, ref),
744 btrfs_extent_data_ref_offset(leaf, ref));
745 }
746
747 static int match_extent_data_ref(struct extent_buffer *leaf,
748 struct btrfs_extent_data_ref *ref,
749 u64 root_objectid, u64 owner, u64 offset)
750 {
751 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
752 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
753 btrfs_extent_data_ref_offset(leaf, ref) != offset)
754 return 0;
755 return 1;
756 }
757
758 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
759 struct btrfs_root *root,
760 struct btrfs_path *path,
761 u64 bytenr, u64 parent,
762 u64 root_objectid,
763 u64 owner, u64 offset)
764 {
765 struct btrfs_key key;
766 struct btrfs_extent_data_ref *ref;
767 struct extent_buffer *leaf;
768 u32 nritems;
769 int ret;
770 int recow;
771 int err = -ENOENT;
772
773 key.objectid = bytenr;
774 if (parent) {
775 key.type = BTRFS_SHARED_DATA_REF_KEY;
776 key.offset = parent;
777 } else {
778 key.type = BTRFS_EXTENT_DATA_REF_KEY;
779 key.offset = hash_extent_data_ref(root_objectid,
780 owner, offset);
781 }
782 again:
783 recow = 0;
784 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
785 if (ret < 0) {
786 err = ret;
787 goto fail;
788 }
789
790 if (parent) {
791 if (!ret)
792 return 0;
793 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
794 key.type = BTRFS_EXTENT_REF_V0_KEY;
795 btrfs_release_path(root, path);
796 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
797 if (ret < 0) {
798 err = ret;
799 goto fail;
800 }
801 if (!ret)
802 return 0;
803 #endif
804 goto fail;
805 }
806
807 leaf = path->nodes[0];
808 nritems = btrfs_header_nritems(leaf);
809 while (1) {
810 if (path->slots[0] >= nritems) {
811 ret = btrfs_next_leaf(root, path);
812 if (ret < 0)
813 err = ret;
814 if (ret)
815 goto fail;
816
817 leaf = path->nodes[0];
818 nritems = btrfs_header_nritems(leaf);
819 recow = 1;
820 }
821
822 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
823 if (key.objectid != bytenr ||
824 key.type != BTRFS_EXTENT_DATA_REF_KEY)
825 goto fail;
826
827 ref = btrfs_item_ptr(leaf, path->slots[0],
828 struct btrfs_extent_data_ref);
829
830 if (match_extent_data_ref(leaf, ref, root_objectid,
831 owner, offset)) {
832 if (recow) {
833 btrfs_release_path(root, path);
834 goto again;
835 }
836 err = 0;
837 break;
838 }
839 path->slots[0]++;
840 }
841 fail:
842 return err;
843 }
844
845 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
846 struct btrfs_root *root,
847 struct btrfs_path *path,
848 u64 bytenr, u64 parent,
849 u64 root_objectid, u64 owner,
850 u64 offset, int refs_to_add)
851 {
852 struct btrfs_key key;
853 struct extent_buffer *leaf;
854 u32 size;
855 u32 num_refs;
856 int ret;
857
858 key.objectid = bytenr;
859 if (parent) {
860 key.type = BTRFS_SHARED_DATA_REF_KEY;
861 key.offset = parent;
862 size = sizeof(struct btrfs_shared_data_ref);
863 } else {
864 key.type = BTRFS_EXTENT_DATA_REF_KEY;
865 key.offset = hash_extent_data_ref(root_objectid,
866 owner, offset);
867 size = sizeof(struct btrfs_extent_data_ref);
868 }
869
870 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
871 if (ret && ret != -EEXIST)
872 goto fail;
873
874 leaf = path->nodes[0];
875 if (parent) {
876 struct btrfs_shared_data_ref *ref;
877 ref = btrfs_item_ptr(leaf, path->slots[0],
878 struct btrfs_shared_data_ref);
879 if (ret == 0) {
880 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
881 } else {
882 num_refs = btrfs_shared_data_ref_count(leaf, ref);
883 num_refs += refs_to_add;
884 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
885 }
886 } else {
887 struct btrfs_extent_data_ref *ref;
888 while (ret == -EEXIST) {
889 ref = btrfs_item_ptr(leaf, path->slots[0],
890 struct btrfs_extent_data_ref);
891 if (match_extent_data_ref(leaf, ref, root_objectid,
892 owner, offset))
893 break;
894 btrfs_release_path(root, path);
895 key.offset++;
896 ret = btrfs_insert_empty_item(trans, root, path, &key,
897 size);
898 if (ret && ret != -EEXIST)
899 goto fail;
900
901 leaf = path->nodes[0];
902 }
903 ref = btrfs_item_ptr(leaf, path->slots[0],
904 struct btrfs_extent_data_ref);
905 if (ret == 0) {
906 btrfs_set_extent_data_ref_root(leaf, ref,
907 root_objectid);
908 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
909 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
910 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
911 } else {
912 num_refs = btrfs_extent_data_ref_count(leaf, ref);
913 num_refs += refs_to_add;
914 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
915 }
916 }
917 btrfs_mark_buffer_dirty(leaf);
918 ret = 0;
919 fail:
920 btrfs_release_path(root, path);
921 return ret;
922 }
923
924 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
925 struct btrfs_root *root,
926 struct btrfs_path *path,
927 int refs_to_drop)
928 {
929 struct btrfs_key key;
930 struct btrfs_extent_data_ref *ref1 = NULL;
931 struct btrfs_shared_data_ref *ref2 = NULL;
932 struct extent_buffer *leaf;
933 u32 num_refs = 0;
934 int ret = 0;
935
936 leaf = path->nodes[0];
937 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
938
939 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
940 ref1 = btrfs_item_ptr(leaf, path->slots[0],
941 struct btrfs_extent_data_ref);
942 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
943 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
944 ref2 = btrfs_item_ptr(leaf, path->slots[0],
945 struct btrfs_shared_data_ref);
946 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
947 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
948 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
949 struct btrfs_extent_ref_v0 *ref0;
950 ref0 = btrfs_item_ptr(leaf, path->slots[0],
951 struct btrfs_extent_ref_v0);
952 num_refs = btrfs_ref_count_v0(leaf, ref0);
953 #endif
954 } else {
955 BUG();
956 }
957
958 BUG_ON(num_refs < refs_to_drop);
959 num_refs -= refs_to_drop;
960
961 if (num_refs == 0) {
962 ret = btrfs_del_item(trans, root, path);
963 } else {
964 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
965 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
966 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
967 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
968 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
969 else {
970 struct btrfs_extent_ref_v0 *ref0;
971 ref0 = btrfs_item_ptr(leaf, path->slots[0],
972 struct btrfs_extent_ref_v0);
973 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
974 }
975 #endif
976 btrfs_mark_buffer_dirty(leaf);
977 }
978 return ret;
979 }
980
981 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
982 struct btrfs_path *path,
983 struct btrfs_extent_inline_ref *iref)
984 {
985 struct btrfs_key key;
986 struct extent_buffer *leaf;
987 struct btrfs_extent_data_ref *ref1;
988 struct btrfs_shared_data_ref *ref2;
989 u32 num_refs = 0;
990
991 leaf = path->nodes[0];
992 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
993 if (iref) {
994 if (btrfs_extent_inline_ref_type(leaf, iref) ==
995 BTRFS_EXTENT_DATA_REF_KEY) {
996 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
997 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
998 } else {
999 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
1000 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1001 }
1002 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
1003 ref1 = btrfs_item_ptr(leaf, path->slots[0],
1004 struct btrfs_extent_data_ref);
1005 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
1006 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
1007 ref2 = btrfs_item_ptr(leaf, path->slots[0],
1008 struct btrfs_shared_data_ref);
1009 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
1010 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1011 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
1012 struct btrfs_extent_ref_v0 *ref0;
1013 ref0 = btrfs_item_ptr(leaf, path->slots[0],
1014 struct btrfs_extent_ref_v0);
1015 num_refs = btrfs_ref_count_v0(leaf, ref0);
1016 #endif
1017 } else {
1018 WARN_ON(1);
1019 }
1020 return num_refs;
1021 }
1022
1023 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
1024 struct btrfs_root *root,
1025 struct btrfs_path *path,
1026 u64 bytenr, u64 parent,
1027 u64 root_objectid)
1028 {
1029 struct btrfs_key key;
1030 int ret;
1031
1032 key.objectid = bytenr;
1033 if (parent) {
1034 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1035 key.offset = parent;
1036 } else {
1037 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1038 key.offset = root_objectid;
1039 }
1040
1041 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1042 if (ret > 0)
1043 ret = -ENOENT;
1044 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1045 if (ret == -ENOENT && parent) {
1046 btrfs_release_path(root, path);
1047 key.type = BTRFS_EXTENT_REF_V0_KEY;
1048 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1049 if (ret > 0)
1050 ret = -ENOENT;
1051 }
1052 #endif
1053 return ret;
1054 }
1055
1056 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
1057 struct btrfs_root *root,
1058 struct btrfs_path *path,
1059 u64 bytenr, u64 parent,
1060 u64 root_objectid)
1061 {
1062 struct btrfs_key key;
1063 int ret;
1064
1065 key.objectid = bytenr;
1066 if (parent) {
1067 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
1068 key.offset = parent;
1069 } else {
1070 key.type = BTRFS_TREE_BLOCK_REF_KEY;
1071 key.offset = root_objectid;
1072 }
1073
1074 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1075 btrfs_release_path(root, path);
1076 return ret;
1077 }
1078
1079 static inline int extent_ref_type(u64 parent, u64 owner)
1080 {
1081 int type;
1082 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1083 if (parent > 0)
1084 type = BTRFS_SHARED_BLOCK_REF_KEY;
1085 else
1086 type = BTRFS_TREE_BLOCK_REF_KEY;
1087 } else {
1088 if (parent > 0)
1089 type = BTRFS_SHARED_DATA_REF_KEY;
1090 else
1091 type = BTRFS_EXTENT_DATA_REF_KEY;
1092 }
1093 return type;
1094 }
1095
1096 static int find_next_key(struct btrfs_path *path, int level,
1097 struct btrfs_key *key)
1098
1099 {
1100 for (; level < BTRFS_MAX_LEVEL; level++) {
1101 if (!path->nodes[level])
1102 break;
1103 if (path->slots[level] + 1 >=
1104 btrfs_header_nritems(path->nodes[level]))
1105 continue;
1106 if (level == 0)
1107 btrfs_item_key_to_cpu(path->nodes[level], key,
1108 path->slots[level] + 1);
1109 else
1110 btrfs_node_key_to_cpu(path->nodes[level], key,
1111 path->slots[level] + 1);
1112 return 0;
1113 }
1114 return 1;
1115 }
1116
1117 /*
1118 * look for inline back ref. if back ref is found, *ref_ret is set
1119 * to the address of inline back ref, and 0 is returned.
1120 *
1121 * if back ref isn't found, *ref_ret is set to the address where it
1122 * should be inserted, and -ENOENT is returned.
1123 *
1124 * if insert is true and there are too many inline back refs, the path
1125 * points to the extent item, and -EAGAIN is returned.
1126 *
1127 * NOTE: inline back refs are ordered in the same way that back ref
1128 * items in the tree are ordered.
1129 */
1130 static noinline_for_stack
1131 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1132 struct btrfs_root *root,
1133 struct btrfs_path *path,
1134 struct btrfs_extent_inline_ref **ref_ret,
1135 u64 bytenr, u64 num_bytes,
1136 u64 parent, u64 root_objectid,
1137 u64 owner, u64 offset, int insert)
1138 {
1139 struct btrfs_key key;
1140 struct extent_buffer *leaf;
1141 struct btrfs_extent_item *ei;
1142 struct btrfs_extent_inline_ref *iref;
1143 u64 flags;
1144 u64 item_size;
1145 unsigned long ptr;
1146 unsigned long end;
1147 int extra_size;
1148 int type;
1149 int want;
1150 int ret;
1151 int err = 0;
1152
1153 key.objectid = bytenr;
1154 key.type = BTRFS_EXTENT_ITEM_KEY;
1155 key.offset = num_bytes;
1156
1157 want = extent_ref_type(parent, owner);
1158 if (insert) {
1159 extra_size = btrfs_extent_inline_ref_size(want);
1160 path->keep_locks = 1;
1161 } else
1162 extra_size = -1;
1163 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1164 if (ret < 0) {
1165 err = ret;
1166 goto out;
1167 }
1168 BUG_ON(ret);
1169
1170 leaf = path->nodes[0];
1171 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1172 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1173 if (item_size < sizeof(*ei)) {
1174 if (!insert) {
1175 err = -ENOENT;
1176 goto out;
1177 }
1178 ret = convert_extent_item_v0(trans, root, path, owner,
1179 extra_size);
1180 if (ret < 0) {
1181 err = ret;
1182 goto out;
1183 }
1184 leaf = path->nodes[0];
1185 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1186 }
1187 #endif
1188 BUG_ON(item_size < sizeof(*ei));
1189
1190 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1191 flags = btrfs_extent_flags(leaf, ei);
1192
1193 ptr = (unsigned long)(ei + 1);
1194 end = (unsigned long)ei + item_size;
1195
1196 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1197 ptr += sizeof(struct btrfs_tree_block_info);
1198 BUG_ON(ptr > end);
1199 } else {
1200 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
1201 }
1202
1203 err = -ENOENT;
1204 while (1) {
1205 if (ptr >= end) {
1206 WARN_ON(ptr > end);
1207 break;
1208 }
1209 iref = (struct btrfs_extent_inline_ref *)ptr;
1210 type = btrfs_extent_inline_ref_type(leaf, iref);
1211 if (want < type)
1212 break;
1213 if (want > type) {
1214 ptr += btrfs_extent_inline_ref_size(type);
1215 continue;
1216 }
1217
1218 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1219 struct btrfs_extent_data_ref *dref;
1220 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1221 if (match_extent_data_ref(leaf, dref, root_objectid,
1222 owner, offset)) {
1223 err = 0;
1224 break;
1225 }
1226 if (hash_extent_data_ref_item(leaf, dref) <
1227 hash_extent_data_ref(root_objectid, owner, offset))
1228 break;
1229 } else {
1230 u64 ref_offset;
1231 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1232 if (parent > 0) {
1233 if (parent == ref_offset) {
1234 err = 0;
1235 break;
1236 }
1237 if (ref_offset < parent)
1238 break;
1239 } else {
1240 if (root_objectid == ref_offset) {
1241 err = 0;
1242 break;
1243 }
1244 if (ref_offset < root_objectid)
1245 break;
1246 }
1247 }
1248 ptr += btrfs_extent_inline_ref_size(type);
1249 }
1250 if (err == -ENOENT && insert) {
1251 if (item_size + extra_size >=
1252 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1253 err = -EAGAIN;
1254 goto out;
1255 }
1256 /*
1257 * To add new inline back ref, we have to make sure
1258 * there is no corresponding back ref item.
1259 * For simplicity, we just do not add new inline back
1260 * ref if there is any kind of item for this block
1261 */
1262 if (find_next_key(path, 0, &key) == 0 &&
1263 key.objectid == bytenr &&
1264 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1265 err = -EAGAIN;
1266 goto out;
1267 }
1268 }
1269 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1270 out:
1271 if (insert) {
1272 path->keep_locks = 0;
1273 btrfs_unlock_up_safe(path, 1);
1274 }
1275 return err;
1276 }
1277
1278 /*
1279 * helper to add new inline back ref
1280 */
1281 static noinline_for_stack
1282 int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
1283 struct btrfs_root *root,
1284 struct btrfs_path *path,
1285 struct btrfs_extent_inline_ref *iref,
1286 u64 parent, u64 root_objectid,
1287 u64 owner, u64 offset, int refs_to_add,
1288 struct btrfs_delayed_extent_op *extent_op)
1289 {
1290 struct extent_buffer *leaf;
1291 struct btrfs_extent_item *ei;
1292 unsigned long ptr;
1293 unsigned long end;
1294 unsigned long item_offset;
1295 u64 refs;
1296 int size;
1297 int type;
1298 int ret;
1299
1300 leaf = path->nodes[0];
1301 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1302 item_offset = (unsigned long)iref - (unsigned long)ei;
1303
1304 type = extent_ref_type(parent, owner);
1305 size = btrfs_extent_inline_ref_size(type);
1306
1307 ret = btrfs_extend_item(trans, root, path, size);
1308 BUG_ON(ret);
1309
1310 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1311 refs = btrfs_extent_refs(leaf, ei);
1312 refs += refs_to_add;
1313 btrfs_set_extent_refs(leaf, ei, refs);
1314 if (extent_op)
1315 __run_delayed_extent_op(extent_op, leaf, ei);
1316
1317 ptr = (unsigned long)ei + item_offset;
1318 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1319 if (ptr < end - size)
1320 memmove_extent_buffer(leaf, ptr + size, ptr,
1321 end - size - ptr);
1322
1323 iref = (struct btrfs_extent_inline_ref *)ptr;
1324 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1325 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1326 struct btrfs_extent_data_ref *dref;
1327 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1328 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1329 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1330 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1331 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1332 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1333 struct btrfs_shared_data_ref *sref;
1334 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1335 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1336 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1337 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1338 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1339 } else {
1340 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1341 }
1342 btrfs_mark_buffer_dirty(leaf);
1343 return 0;
1344 }
1345
1346 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1347 struct btrfs_root *root,
1348 struct btrfs_path *path,
1349 struct btrfs_extent_inline_ref **ref_ret,
1350 u64 bytenr, u64 num_bytes, u64 parent,
1351 u64 root_objectid, u64 owner, u64 offset)
1352 {
1353 int ret;
1354
1355 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1356 bytenr, num_bytes, parent,
1357 root_objectid, owner, offset, 0);
1358 if (ret != -ENOENT)
1359 return ret;
1360
1361 btrfs_release_path(root, path);
1362 *ref_ret = NULL;
1363
1364 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1365 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1366 root_objectid);
1367 } else {
1368 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1369 root_objectid, owner, offset);
1370 }
1371 return ret;
1372 }
1373
1374 /*
1375 * helper to update/remove inline back ref
1376 */
1377 static noinline_for_stack
1378 int update_inline_extent_backref(struct btrfs_trans_handle *trans,
1379 struct btrfs_root *root,
1380 struct btrfs_path *path,
1381 struct btrfs_extent_inline_ref *iref,
1382 int refs_to_mod,
1383 struct btrfs_delayed_extent_op *extent_op)
1384 {
1385 struct extent_buffer *leaf;
1386 struct btrfs_extent_item *ei;
1387 struct btrfs_extent_data_ref *dref = NULL;
1388 struct btrfs_shared_data_ref *sref = NULL;
1389 unsigned long ptr;
1390 unsigned long end;
1391 u32 item_size;
1392 int size;
1393 int type;
1394 int ret;
1395 u64 refs;
1396
1397 leaf = path->nodes[0];
1398 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1399 refs = btrfs_extent_refs(leaf, ei);
1400 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1401 refs += refs_to_mod;
1402 btrfs_set_extent_refs(leaf, ei, refs);
1403 if (extent_op)
1404 __run_delayed_extent_op(extent_op, leaf, ei);
1405
1406 type = btrfs_extent_inline_ref_type(leaf, iref);
1407
1408 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1409 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1410 refs = btrfs_extent_data_ref_count(leaf, dref);
1411 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1412 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1413 refs = btrfs_shared_data_ref_count(leaf, sref);
1414 } else {
1415 refs = 1;
1416 BUG_ON(refs_to_mod != -1);
1417 }
1418
1419 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1420 refs += refs_to_mod;
1421
1422 if (refs > 0) {
1423 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1424 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1425 else
1426 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1427 } else {
1428 size = btrfs_extent_inline_ref_size(type);
1429 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1430 ptr = (unsigned long)iref;
1431 end = (unsigned long)ei + item_size;
1432 if (ptr + size < end)
1433 memmove_extent_buffer(leaf, ptr, ptr + size,
1434 end - ptr - size);
1435 item_size -= size;
1436 ret = btrfs_truncate_item(trans, root, path, item_size, 1);
1437 BUG_ON(ret);
1438 }
1439 btrfs_mark_buffer_dirty(leaf);
1440 return 0;
1441 }
1442
1443 static noinline_for_stack
1444 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1445 struct btrfs_root *root,
1446 struct btrfs_path *path,
1447 u64 bytenr, u64 num_bytes, u64 parent,
1448 u64 root_objectid, u64 owner,
1449 u64 offset, int refs_to_add,
1450 struct btrfs_delayed_extent_op *extent_op)
1451 {
1452 struct btrfs_extent_inline_ref *iref;
1453 int ret;
1454
1455 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1456 bytenr, num_bytes, parent,
1457 root_objectid, owner, offset, 1);
1458 if (ret == 0) {
1459 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1460 ret = update_inline_extent_backref(trans, root, path, iref,
1461 refs_to_add, extent_op);
1462 } else if (ret == -ENOENT) {
1463 ret = setup_inline_extent_backref(trans, root, path, iref,
1464 parent, root_objectid,
1465 owner, offset, refs_to_add,
1466 extent_op);
1467 }
1468 return ret;
1469 }
1470
1471 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1472 struct btrfs_root *root,
1473 struct btrfs_path *path,
1474 u64 bytenr, u64 parent, u64 root_objectid,
1475 u64 owner, u64 offset, int refs_to_add)
1476 {
1477 int ret;
1478 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1479 BUG_ON(refs_to_add != 1);
1480 ret = insert_tree_block_ref(trans, root, path, bytenr,
1481 parent, root_objectid);
1482 } else {
1483 ret = insert_extent_data_ref(trans, root, path, bytenr,
1484 parent, root_objectid,
1485 owner, offset, refs_to_add);
1486 }
1487 return ret;
1488 }
1489
1490 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1491 struct btrfs_root *root,
1492 struct btrfs_path *path,
1493 struct btrfs_extent_inline_ref *iref,
1494 int refs_to_drop, int is_data)
1495 {
1496 int ret;
1497
1498 BUG_ON(!is_data && refs_to_drop != 1);
1499 if (iref) {
1500 ret = update_inline_extent_backref(trans, root, path, iref,
1501 -refs_to_drop, NULL);
1502 } else if (is_data) {
1503 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1504 } else {
1505 ret = btrfs_del_item(trans, root, path);
1506 }
1507 return ret;
1508 }
1509
1510 #ifdef BIO_RW_DISCARD
1511 static void btrfs_issue_discard(struct block_device *bdev,
1512 u64 start, u64 len)
1513 {
1514 blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL);
1515 }
1516 #endif
1517
1518 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
1519 u64 num_bytes)
1520 {
1521 #ifdef BIO_RW_DISCARD
1522 int ret;
1523 u64 map_length = num_bytes;
1524 struct btrfs_multi_bio *multi = NULL;
1525
1526 /* Tell the block device(s) that the sectors can be discarded */
1527 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
1528 bytenr, &map_length, &multi, 0);
1529 if (!ret) {
1530 struct btrfs_bio_stripe *stripe = multi->stripes;
1531 int i;
1532
1533 if (map_length > num_bytes)
1534 map_length = num_bytes;
1535
1536 for (i = 0; i < multi->num_stripes; i++, stripe++) {
1537 btrfs_issue_discard(stripe->dev->bdev,
1538 stripe->physical,
1539 map_length);
1540 }
1541 kfree(multi);
1542 }
1543
1544 return ret;
1545 #else
1546 return 0;
1547 #endif
1548 }
1549
1550 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1551 struct btrfs_root *root,
1552 u64 bytenr, u64 num_bytes, u64 parent,
1553 u64 root_objectid, u64 owner, u64 offset)
1554 {
1555 int ret;
1556 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
1557 root_objectid == BTRFS_TREE_LOG_OBJECTID);
1558
1559 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1560 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
1561 parent, root_objectid, (int)owner,
1562 BTRFS_ADD_DELAYED_REF, NULL);
1563 } else {
1564 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
1565 parent, root_objectid, owner, offset,
1566 BTRFS_ADD_DELAYED_REF, NULL);
1567 }
1568 return ret;
1569 }
1570
1571 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1572 struct btrfs_root *root,
1573 u64 bytenr, u64 num_bytes,
1574 u64 parent, u64 root_objectid,
1575 u64 owner, u64 offset, int refs_to_add,
1576 struct btrfs_delayed_extent_op *extent_op)
1577 {
1578 struct btrfs_path *path;
1579 struct extent_buffer *leaf;
1580 struct btrfs_extent_item *item;
1581 u64 refs;
1582 int ret;
1583 int err = 0;
1584
1585 path = btrfs_alloc_path();
1586 if (!path)
1587 return -ENOMEM;
1588
1589 path->reada = 1;
1590 path->leave_spinning = 1;
1591 /* this will setup the path even if it fails to insert the back ref */
1592 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1593 path, bytenr, num_bytes, parent,
1594 root_objectid, owner, offset,
1595 refs_to_add, extent_op);
1596 if (ret == 0)
1597 goto out;
1598
1599 if (ret != -EAGAIN) {
1600 err = ret;
1601 goto out;
1602 }
1603
1604 leaf = path->nodes[0];
1605 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1606 refs = btrfs_extent_refs(leaf, item);
1607 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1608 if (extent_op)
1609 __run_delayed_extent_op(extent_op, leaf, item);
1610
1611 btrfs_mark_buffer_dirty(leaf);
1612 btrfs_release_path(root->fs_info->extent_root, path);
1613
1614 path->reada = 1;
1615 path->leave_spinning = 1;
1616
1617 /* now insert the actual backref */
1618 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1619 path, bytenr, parent, root_objectid,
1620 owner, offset, refs_to_add);
1621 BUG_ON(ret);
1622 out:
1623 btrfs_free_path(path);
1624 return err;
1625 }
1626
1627 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1628 struct btrfs_root *root,
1629 struct btrfs_delayed_ref_node *node,
1630 struct btrfs_delayed_extent_op *extent_op,
1631 int insert_reserved)
1632 {
1633 int ret = 0;
1634 struct btrfs_delayed_data_ref *ref;
1635 struct btrfs_key ins;
1636 u64 parent = 0;
1637 u64 ref_root = 0;
1638 u64 flags = 0;
1639
1640 ins.objectid = node->bytenr;
1641 ins.offset = node->num_bytes;
1642 ins.type = BTRFS_EXTENT_ITEM_KEY;
1643
1644 ref = btrfs_delayed_node_to_data_ref(node);
1645 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
1646 parent = ref->parent;
1647 else
1648 ref_root = ref->root;
1649
1650 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1651 if (extent_op) {
1652 BUG_ON(extent_op->update_key);
1653 flags |= extent_op->flags_to_set;
1654 }
1655 ret = alloc_reserved_file_extent(trans, root,
1656 parent, ref_root, flags,
1657 ref->objectid, ref->offset,
1658 &ins, node->ref_mod);
1659 update_reserved_extents(root, ins.objectid, ins.offset, 0);
1660 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1661 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1662 node->num_bytes, parent,
1663 ref_root, ref->objectid,
1664 ref->offset, node->ref_mod,
1665 extent_op);
1666 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1667 ret = __btrfs_free_extent(trans, root, node->bytenr,
1668 node->num_bytes, parent,
1669 ref_root, ref->objectid,
1670 ref->offset, node->ref_mod,
1671 extent_op);
1672 } else {
1673 BUG();
1674 }
1675 return ret;
1676 }
1677
1678 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
1679 struct extent_buffer *leaf,
1680 struct btrfs_extent_item *ei)
1681 {
1682 u64 flags = btrfs_extent_flags(leaf, ei);
1683 if (extent_op->update_flags) {
1684 flags |= extent_op->flags_to_set;
1685 btrfs_set_extent_flags(leaf, ei, flags);
1686 }
1687
1688 if (extent_op->update_key) {
1689 struct btrfs_tree_block_info *bi;
1690 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
1691 bi = (struct btrfs_tree_block_info *)(ei + 1);
1692 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
1693 }
1694 }
1695
1696 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
1697 struct btrfs_root *root,
1698 struct btrfs_delayed_ref_node *node,
1699 struct btrfs_delayed_extent_op *extent_op)
1700 {
1701 struct btrfs_key key;
1702 struct btrfs_path *path;
1703 struct btrfs_extent_item *ei;
1704 struct extent_buffer *leaf;
1705 u32 item_size;
1706 int ret;
1707 int err = 0;
1708
1709 path = btrfs_alloc_path();
1710 if (!path)
1711 return -ENOMEM;
1712
1713 key.objectid = node->bytenr;
1714 key.type = BTRFS_EXTENT_ITEM_KEY;
1715 key.offset = node->num_bytes;
1716
1717 path->reada = 1;
1718 path->leave_spinning = 1;
1719 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
1720 path, 0, 1);
1721 if (ret < 0) {
1722 err = ret;
1723 goto out;
1724 }
1725 if (ret > 0) {
1726 err = -EIO;
1727 goto out;
1728 }
1729
1730 leaf = path->nodes[0];
1731 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1732 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1733 if (item_size < sizeof(*ei)) {
1734 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1735 path, (u64)-1, 0);
1736 if (ret < 0) {
1737 err = ret;
1738 goto out;
1739 }
1740 leaf = path->nodes[0];
1741 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1742 }
1743 #endif
1744 BUG_ON(item_size < sizeof(*ei));
1745 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1746 __run_delayed_extent_op(extent_op, leaf, ei);
1747
1748 btrfs_mark_buffer_dirty(leaf);
1749 out:
1750 btrfs_free_path(path);
1751 return err;
1752 }
1753
1754 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
1755 struct btrfs_root *root,
1756 struct btrfs_delayed_ref_node *node,
1757 struct btrfs_delayed_extent_op *extent_op,
1758 int insert_reserved)
1759 {
1760 int ret = 0;
1761 struct btrfs_delayed_tree_ref *ref;
1762 struct btrfs_key ins;
1763 u64 parent = 0;
1764 u64 ref_root = 0;
1765
1766 ins.objectid = node->bytenr;
1767 ins.offset = node->num_bytes;
1768 ins.type = BTRFS_EXTENT_ITEM_KEY;
1769
1770 ref = btrfs_delayed_node_to_tree_ref(node);
1771 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1772 parent = ref->parent;
1773 else
1774 ref_root = ref->root;
1775
1776 BUG_ON(node->ref_mod != 1);
1777 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1778 BUG_ON(!extent_op || !extent_op->update_flags ||
1779 !extent_op->update_key);
1780 ret = alloc_reserved_tree_block(trans, root,
1781 parent, ref_root,
1782 extent_op->flags_to_set,
1783 &extent_op->key,
1784 ref->level, &ins);
1785 update_reserved_extents(root, ins.objectid, ins.offset, 0);
1786 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1787 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1788 node->num_bytes, parent, ref_root,
1789 ref->level, 0, 1, extent_op);
1790 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1791 ret = __btrfs_free_extent(trans, root, node->bytenr,
1792 node->num_bytes, parent, ref_root,
1793 ref->level, 0, 1, extent_op);
1794 } else {
1795 BUG();
1796 }
1797 return ret;
1798 }
1799
1800
1801 /* helper function to actually process a single delayed ref entry */
1802 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
1803 struct btrfs_root *root,
1804 struct btrfs_delayed_ref_node *node,
1805 struct btrfs_delayed_extent_op *extent_op,
1806 int insert_reserved)
1807 {
1808 int ret;
1809 if (btrfs_delayed_ref_is_head(node)) {
1810 struct btrfs_delayed_ref_head *head;
1811 /*
1812 * we've hit the end of the chain and we were supposed
1813 * to insert this extent into the tree. But, it got
1814 * deleted before we ever needed to insert it, so all
1815 * we have to do is clean up the accounting
1816 */
1817 BUG_ON(extent_op);
1818 head = btrfs_delayed_node_to_head(node);
1819 if (insert_reserved) {
1820 if (head->is_data) {
1821 ret = btrfs_del_csums(trans, root,
1822 node->bytenr,
1823 node->num_bytes);
1824 BUG_ON(ret);
1825 }
1826 btrfs_update_pinned_extents(root, node->bytenr,
1827 node->num_bytes, 1);
1828 update_reserved_extents(root, node->bytenr,
1829 node->num_bytes, 0);
1830 }
1831 mutex_unlock(&head->mutex);
1832 return 0;
1833 }
1834
1835 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1836 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1837 ret = run_delayed_tree_ref(trans, root, node, extent_op,
1838 insert_reserved);
1839 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1840 node->type == BTRFS_SHARED_DATA_REF_KEY)
1841 ret = run_delayed_data_ref(trans, root, node, extent_op,
1842 insert_reserved);
1843 else
1844 BUG();
1845 return ret;
1846 }
1847
1848 static noinline struct btrfs_delayed_ref_node *
1849 select_delayed_ref(struct btrfs_delayed_ref_head *head)
1850 {
1851 struct rb_node *node;
1852 struct btrfs_delayed_ref_node *ref;
1853 int action = BTRFS_ADD_DELAYED_REF;
1854 again:
1855 /*
1856 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
1857 * this prevents ref count from going down to zero when
1858 * there still are pending delayed ref.
1859 */
1860 node = rb_prev(&head->node.rb_node);
1861 while (1) {
1862 if (!node)
1863 break;
1864 ref = rb_entry(node, struct btrfs_delayed_ref_node,
1865 rb_node);
1866 if (ref->bytenr != head->node.bytenr)
1867 break;
1868 if (ref->action == action)
1869 return ref;
1870 node = rb_prev(node);
1871 }
1872 if (action == BTRFS_ADD_DELAYED_REF) {
1873 action = BTRFS_DROP_DELAYED_REF;
1874 goto again;
1875 }
1876 return NULL;
1877 }
1878
1879 static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
1880 struct btrfs_root *root,
1881 struct list_head *cluster)
1882 {
1883 struct btrfs_delayed_ref_root *delayed_refs;
1884 struct btrfs_delayed_ref_node *ref;
1885 struct btrfs_delayed_ref_head *locked_ref = NULL;
1886 struct btrfs_delayed_extent_op *extent_op;
1887 int ret;
1888 int count = 0;
1889 int must_insert_reserved = 0;
1890
1891 delayed_refs = &trans->transaction->delayed_refs;
1892 while (1) {
1893 if (!locked_ref) {
1894 /* pick a new head ref from the cluster list */
1895 if (list_empty(cluster))
1896 break;
1897
1898 locked_ref = list_entry(cluster->next,
1899 struct btrfs_delayed_ref_head, cluster);
1900
1901 /* grab the lock that says we are going to process
1902 * all the refs for this head */
1903 ret = btrfs_delayed_ref_lock(trans, locked_ref);
1904
1905 /*
1906 * we may have dropped the spin lock to get the head
1907 * mutex lock, and that might have given someone else
1908 * time to free the head. If that's true, it has been
1909 * removed from our list and we can move on.
1910 */
1911 if (ret == -EAGAIN) {
1912 locked_ref = NULL;
1913 count++;
1914 continue;
1915 }
1916 }
1917
1918 /*
1919 * record the must insert reserved flag before we
1920 * drop the spin lock.
1921 */
1922 must_insert_reserved = locked_ref->must_insert_reserved;
1923 locked_ref->must_insert_reserved = 0;
1924
1925 extent_op = locked_ref->extent_op;
1926 locked_ref->extent_op = NULL;
1927
1928 /*
1929 * locked_ref is the head node, so we have to go one
1930 * node back for any delayed ref updates
1931 */
1932 ref = select_delayed_ref(locked_ref);
1933 if (!ref) {
1934 /* All delayed refs have been processed, Go ahead
1935 * and send the head node to run_one_delayed_ref,
1936 * so that any accounting fixes can happen
1937 */
1938 ref = &locked_ref->node;
1939
1940 if (extent_op && must_insert_reserved) {
1941 kfree(extent_op);
1942 extent_op = NULL;
1943 }
1944
1945 if (extent_op) {
1946 spin_unlock(&delayed_refs->lock);
1947
1948 ret = run_delayed_extent_op(trans, root,
1949 ref, extent_op);
1950 BUG_ON(ret);
1951 kfree(extent_op);
1952
1953 cond_resched();
1954 spin_lock(&delayed_refs->lock);
1955 continue;
1956 }
1957
1958 list_del_init(&locked_ref->cluster);
1959 locked_ref = NULL;
1960 }
1961
1962 ref->in_tree = 0;
1963 rb_erase(&ref->rb_node, &delayed_refs->root);
1964 delayed_refs->num_entries--;
1965
1966 spin_unlock(&delayed_refs->lock);
1967
1968 ret = run_one_delayed_ref(trans, root, ref, extent_op,
1969 must_insert_reserved);
1970 BUG_ON(ret);
1971
1972 btrfs_put_delayed_ref(ref);
1973 kfree(extent_op);
1974 count++;
1975
1976 cond_resched();
1977 spin_lock(&delayed_refs->lock);
1978 }
1979 return count;
1980 }
1981
1982 /*
1983 * this starts processing the delayed reference count updates and
1984 * extent insertions we have queued up so far. count can be
1985 * 0, which means to process everything in the tree at the start
1986 * of the run (but not newly added entries), or it can be some target
1987 * number you'd like to process.
1988 */
1989 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
1990 struct btrfs_root *root, unsigned long count)
1991 {
1992 struct rb_node *node;
1993 struct btrfs_delayed_ref_root *delayed_refs;
1994 struct btrfs_delayed_ref_node *ref;
1995 struct list_head cluster;
1996 int ret;
1997 int run_all = count == (unsigned long)-1;
1998 int run_most = 0;
1999
2000 if (root == root->fs_info->extent_root)
2001 root = root->fs_info->tree_root;
2002
2003 delayed_refs = &trans->transaction->delayed_refs;
2004 INIT_LIST_HEAD(&cluster);
2005 again:
2006 spin_lock(&delayed_refs->lock);
2007 if (count == 0) {
2008 count = delayed_refs->num_entries * 2;
2009 run_most = 1;
2010 }
2011 while (1) {
2012 if (!(run_all || run_most) &&
2013 delayed_refs->num_heads_ready < 64)
2014 break;
2015
2016 /*
2017 * go find something we can process in the rbtree. We start at
2018 * the beginning of the tree, and then build a cluster
2019 * of refs to process starting at the first one we are able to
2020 * lock
2021 */
2022 ret = btrfs_find_ref_cluster(trans, &cluster,
2023 delayed_refs->run_delayed_start);
2024 if (ret)
2025 break;
2026
2027 ret = run_clustered_refs(trans, root, &cluster);
2028 BUG_ON(ret < 0);
2029
2030 count -= min_t(unsigned long, ret, count);
2031
2032 if (count == 0)
2033 break;
2034 }
2035
2036 if (run_all) {
2037 node = rb_first(&delayed_refs->root);
2038 if (!node)
2039 goto out;
2040 count = (unsigned long)-1;
2041
2042 while (node) {
2043 ref = rb_entry(node, struct btrfs_delayed_ref_node,
2044 rb_node);
2045 if (btrfs_delayed_ref_is_head(ref)) {
2046 struct btrfs_delayed_ref_head *head;
2047
2048 head = btrfs_delayed_node_to_head(ref);
2049 atomic_inc(&ref->refs);
2050
2051 spin_unlock(&delayed_refs->lock);
2052 mutex_lock(&head->mutex);
2053 mutex_unlock(&head->mutex);
2054
2055 btrfs_put_delayed_ref(ref);
2056 cond_resched();
2057 goto again;
2058 }
2059 node = rb_next(node);
2060 }
2061 spin_unlock(&delayed_refs->lock);
2062 schedule_timeout(1);
2063 goto again;
2064 }
2065 out:
2066 spin_unlock(&delayed_refs->lock);
2067 return 0;
2068 }
2069
2070 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
2071 struct btrfs_root *root,
2072 u64 bytenr, u64 num_bytes, u64 flags,
2073 int is_data)
2074 {
2075 struct btrfs_delayed_extent_op *extent_op;
2076 int ret;
2077
2078 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2079 if (!extent_op)
2080 return -ENOMEM;
2081
2082 extent_op->flags_to_set = flags;
2083 extent_op->update_flags = 1;
2084 extent_op->update_key = 0;
2085 extent_op->is_data = is_data ? 1 : 0;
2086
2087 ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
2088 if (ret)
2089 kfree(extent_op);
2090 return ret;
2091 }
2092
2093 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
2094 struct btrfs_root *root,
2095 struct btrfs_path *path,
2096 u64 objectid, u64 offset, u64 bytenr)
2097 {
2098 struct btrfs_delayed_ref_head *head;
2099 struct btrfs_delayed_ref_node *ref;
2100 struct btrfs_delayed_data_ref *data_ref;
2101 struct btrfs_delayed_ref_root *delayed_refs;
2102 struct rb_node *node;
2103 int ret = 0;
2104
2105 ret = -ENOENT;
2106 delayed_refs = &trans->transaction->delayed_refs;
2107 spin_lock(&delayed_refs->lock);
2108 head = btrfs_find_delayed_ref_head(trans, bytenr);
2109 if (!head)
2110 goto out;
2111
2112 if (!mutex_trylock(&head->mutex)) {
2113 atomic_inc(&head->node.refs);
2114 spin_unlock(&delayed_refs->lock);
2115
2116 btrfs_release_path(root->fs_info->extent_root, path);
2117
2118 mutex_lock(&head->mutex);
2119 mutex_unlock(&head->mutex);
2120 btrfs_put_delayed_ref(&head->node);
2121 return -EAGAIN;
2122 }
2123
2124 node = rb_prev(&head->node.rb_node);
2125 if (!node)
2126 goto out_unlock;
2127
2128 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2129
2130 if (ref->bytenr != bytenr)
2131 goto out_unlock;
2132
2133 ret = 1;
2134 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
2135 goto out_unlock;
2136
2137 data_ref = btrfs_delayed_node_to_data_ref(ref);
2138
2139 node = rb_prev(node);
2140 if (node) {
2141 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2142 if (ref->bytenr == bytenr)
2143 goto out_unlock;
2144 }
2145
2146 if (data_ref->root != root->root_key.objectid ||
2147 data_ref->objectid != objectid || data_ref->offset != offset)
2148 goto out_unlock;
2149
2150 ret = 0;
2151 out_unlock:
2152 mutex_unlock(&head->mutex);
2153 out:
2154 spin_unlock(&delayed_refs->lock);
2155 return ret;
2156 }
2157
2158 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
2159 struct btrfs_root *root,
2160 struct btrfs_path *path,
2161 u64 objectid, u64 offset, u64 bytenr)
2162 {
2163 struct btrfs_root *extent_root = root->fs_info->extent_root;
2164 struct extent_buffer *leaf;
2165 struct btrfs_extent_data_ref *ref;
2166 struct btrfs_extent_inline_ref *iref;
2167 struct btrfs_extent_item *ei;
2168 struct btrfs_key key;
2169 u32 item_size;
2170 int ret;
2171
2172 key.objectid = bytenr;
2173 key.offset = (u64)-1;
2174 key.type = BTRFS_EXTENT_ITEM_KEY;
2175
2176 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2177 if (ret < 0)
2178 goto out;
2179 BUG_ON(ret == 0);
2180
2181 ret = -ENOENT;
2182 if (path->slots[0] == 0)
2183 goto out;
2184
2185 path->slots[0]--;
2186 leaf = path->nodes[0];
2187 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2188
2189 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2190 goto out;
2191
2192 ret = 1;
2193 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2194 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2195 if (item_size < sizeof(*ei)) {
2196 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
2197 goto out;
2198 }
2199 #endif
2200 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2201
2202 if (item_size != sizeof(*ei) +
2203 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2204 goto out;
2205
2206 if (btrfs_extent_generation(leaf, ei) <=
2207 btrfs_root_last_snapshot(&root->root_item))
2208 goto out;
2209
2210 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2211 if (btrfs_extent_inline_ref_type(leaf, iref) !=
2212 BTRFS_EXTENT_DATA_REF_KEY)
2213 goto out;
2214
2215 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2216 if (btrfs_extent_refs(leaf, ei) !=
2217 btrfs_extent_data_ref_count(leaf, ref) ||
2218 btrfs_extent_data_ref_root(leaf, ref) !=
2219 root->root_key.objectid ||
2220 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2221 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2222 goto out;
2223
2224 ret = 0;
2225 out:
2226 return ret;
2227 }
2228
2229 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
2230 struct btrfs_root *root,
2231 u64 objectid, u64 offset, u64 bytenr)
2232 {
2233 struct btrfs_path *path;
2234 int ret;
2235 int ret2;
2236
2237 path = btrfs_alloc_path();
2238 if (!path)
2239 return -ENOENT;
2240
2241 do {
2242 ret = check_committed_ref(trans, root, path, objectid,
2243 offset, bytenr);
2244 if (ret && ret != -ENOENT)
2245 goto out;
2246
2247 ret2 = check_delayed_ref(trans, root, path, objectid,
2248 offset, bytenr);
2249 } while (ret2 == -EAGAIN);
2250
2251 if (ret2 && ret2 != -ENOENT) {
2252 ret = ret2;
2253 goto out;
2254 }
2255
2256 if (ret != -ENOENT || ret2 != -ENOENT)
2257 ret = 0;
2258 out:
2259 btrfs_free_path(path);
2260 return ret;
2261 }
2262
2263 #if 0
2264 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2265 struct extent_buffer *buf, u32 nr_extents)
2266 {
2267 struct btrfs_key key;
2268 struct btrfs_file_extent_item *fi;
2269 u64 root_gen;
2270 u32 nritems;
2271 int i;
2272 int level;
2273 int ret = 0;
2274 int shared = 0;
2275
2276 if (!root->ref_cows)
2277 return 0;
2278
2279 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
2280 shared = 0;
2281 root_gen = root->root_key.offset;
2282 } else {
2283 shared = 1;
2284 root_gen = trans->transid - 1;
2285 }
2286
2287 level = btrfs_header_level(buf);
2288 nritems = btrfs_header_nritems(buf);
2289
2290 if (level == 0) {
2291 struct btrfs_leaf_ref *ref;
2292 struct btrfs_extent_info *info;
2293
2294 ref = btrfs_alloc_leaf_ref(root, nr_extents);
2295 if (!ref) {
2296 ret = -ENOMEM;
2297 goto out;
2298 }
2299
2300 ref->root_gen = root_gen;
2301 ref->bytenr = buf->start;
2302 ref->owner = btrfs_header_owner(buf);
2303 ref->generation = btrfs_header_generation(buf);
2304 ref->nritems = nr_extents;
2305 info = ref->extents;
2306
2307 for (i = 0; nr_extents > 0 && i < nritems; i++) {
2308 u64 disk_bytenr;
2309 btrfs_item_key_to_cpu(buf, &key, i);
2310 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2311 continue;
2312 fi = btrfs_item_ptr(buf, i,
2313 struct btrfs_file_extent_item);
2314 if (btrfs_file_extent_type(buf, fi) ==
2315 BTRFS_FILE_EXTENT_INLINE)
2316 continue;
2317 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2318 if (disk_bytenr == 0)
2319 continue;
2320
2321 info->bytenr = disk_bytenr;
2322 info->num_bytes =
2323 btrfs_file_extent_disk_num_bytes(buf, fi);
2324 info->objectid = key.objectid;
2325 info->offset = key.offset;
2326 info++;
2327 }
2328
2329 ret = btrfs_add_leaf_ref(root, ref, shared);
2330 if (ret == -EEXIST && shared) {
2331 struct btrfs_leaf_ref *old;
2332 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
2333 BUG_ON(!old);
2334 btrfs_remove_leaf_ref(root, old);
2335 btrfs_free_leaf_ref(root, old);
2336 ret = btrfs_add_leaf_ref(root, ref, shared);
2337 }
2338 WARN_ON(ret);
2339 btrfs_free_leaf_ref(root, ref);
2340 }
2341 out:
2342 return ret;
2343 }
2344
2345 /* when a block goes through cow, we update the reference counts of
2346 * everything that block points to. The internal pointers of the block
2347 * can be in just about any order, and it is likely to have clusters of
2348 * things that are close together and clusters of things that are not.
2349 *
2350 * To help reduce the seeks that come with updating all of these reference
2351 * counts, sort them by byte number before actual updates are done.
2352 *
2353 * struct refsort is used to match byte number to slot in the btree block.
2354 * we sort based on the byte number and then use the slot to actually
2355 * find the item.
2356 *
2357 * struct refsort is smaller than strcut btrfs_item and smaller than
2358 * struct btrfs_key_ptr. Since we're currently limited to the page size
2359 * for a btree block, there's no way for a kmalloc of refsorts for a
2360 * single node to be bigger than a page.
2361 */
2362 struct refsort {
2363 u64 bytenr;
2364 u32 slot;
2365 };
2366
2367 /*
2368 * for passing into sort()
2369 */
2370 static int refsort_cmp(const void *a_void, const void *b_void)
2371 {
2372 const struct refsort *a = a_void;
2373 const struct refsort *b = b_void;
2374
2375 if (a->bytenr < b->bytenr)
2376 return -1;
2377 if (a->bytenr > b->bytenr)
2378 return 1;
2379 return 0;
2380 }
2381 #endif
2382
2383 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2384 struct btrfs_root *root,
2385 struct extent_buffer *buf,
2386 int full_backref, int inc)
2387 {
2388 u64 bytenr;
2389 u64 num_bytes;
2390 u64 parent;
2391 u64 ref_root;
2392 u32 nritems;
2393 struct btrfs_key key;
2394 struct btrfs_file_extent_item *fi;
2395 int i;
2396 int level;
2397 int ret = 0;
2398 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
2399 u64, u64, u64, u64, u64, u64);
2400
2401 ref_root = btrfs_header_owner(buf);
2402 nritems = btrfs_header_nritems(buf);
2403 level = btrfs_header_level(buf);
2404
2405 if (!root->ref_cows && level == 0)
2406 return 0;
2407
2408 if (inc)
2409 process_func = btrfs_inc_extent_ref;
2410 else
2411 process_func = btrfs_free_extent;
2412
2413 if (full_backref)
2414 parent = buf->start;
2415 else
2416 parent = 0;
2417
2418 for (i = 0; i < nritems; i++) {
2419 if (level == 0) {
2420 btrfs_item_key_to_cpu(buf, &key, i);
2421 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2422 continue;
2423 fi = btrfs_item_ptr(buf, i,
2424 struct btrfs_file_extent_item);
2425 if (btrfs_file_extent_type(buf, fi) ==
2426 BTRFS_FILE_EXTENT_INLINE)
2427 continue;
2428 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2429 if (bytenr == 0)
2430 continue;
2431
2432 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
2433 key.offset -= btrfs_file_extent_offset(buf, fi);
2434 ret = process_func(trans, root, bytenr, num_bytes,
2435 parent, ref_root, key.objectid,
2436 key.offset);
2437 if (ret)
2438 goto fail;
2439 } else {
2440 bytenr = btrfs_node_blockptr(buf, i);
2441 num_bytes = btrfs_level_size(root, level - 1);
2442 ret = process_func(trans, root, bytenr, num_bytes,
2443 parent, ref_root, level - 1, 0);
2444 if (ret)
2445 goto fail;
2446 }
2447 }
2448 return 0;
2449 fail:
2450 BUG();
2451 return ret;
2452 }
2453
2454 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2455 struct extent_buffer *buf, int full_backref)
2456 {
2457 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
2458 }
2459
2460 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2461 struct extent_buffer *buf, int full_backref)
2462 {
2463 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
2464 }
2465
2466 static int write_one_cache_group(struct btrfs_trans_handle *trans,
2467 struct btrfs_root *root,
2468 struct btrfs_path *path,
2469 struct btrfs_block_group_cache *cache)
2470 {
2471 int ret;
2472 struct btrfs_root *extent_root = root->fs_info->extent_root;
2473 unsigned long bi;
2474 struct extent_buffer *leaf;
2475
2476 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
2477 if (ret < 0)
2478 goto fail;
2479 BUG_ON(ret);
2480
2481 leaf = path->nodes[0];
2482 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
2483 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
2484 btrfs_mark_buffer_dirty(leaf);
2485 btrfs_release_path(extent_root, path);
2486 fail:
2487 if (ret)
2488 return ret;
2489 return 0;
2490
2491 }
2492
2493 static struct btrfs_block_group_cache *
2494 next_block_group(struct btrfs_root *root,
2495 struct btrfs_block_group_cache *cache)
2496 {
2497 struct rb_node *node;
2498 spin_lock(&root->fs_info->block_group_cache_lock);
2499 node = rb_next(&cache->cache_node);
2500 btrfs_put_block_group(cache);
2501 if (node) {
2502 cache = rb_entry(node, struct btrfs_block_group_cache,
2503 cache_node);
2504 atomic_inc(&cache->count);
2505 } else
2506 cache = NULL;
2507 spin_unlock(&root->fs_info->block_group_cache_lock);
2508 return cache;
2509 }
2510
2511 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
2512 struct btrfs_root *root)
2513 {
2514 struct btrfs_block_group_cache *cache;
2515 int err = 0;
2516 struct btrfs_path *path;
2517 u64 last = 0;
2518
2519 path = btrfs_alloc_path();
2520 if (!path)
2521 return -ENOMEM;
2522
2523 while (1) {
2524 if (last == 0) {
2525 err = btrfs_run_delayed_refs(trans, root,
2526 (unsigned long)-1);
2527 BUG_ON(err);
2528 }
2529
2530 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2531 while (cache) {
2532 if (cache->dirty)
2533 break;
2534 cache = next_block_group(root, cache);
2535 }
2536 if (!cache) {
2537 if (last == 0)
2538 break;
2539 last = 0;
2540 continue;
2541 }
2542
2543 cache->dirty = 0;
2544 last = cache->key.objectid + cache->key.offset;
2545
2546 err = write_one_cache_group(trans, root, path, cache);
2547 BUG_ON(err);
2548 btrfs_put_block_group(cache);
2549 }
2550
2551 btrfs_free_path(path);
2552 return 0;
2553 }
2554
2555 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
2556 {
2557 struct btrfs_block_group_cache *block_group;
2558 int readonly = 0;
2559
2560 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
2561 if (!block_group || block_group->ro)
2562 readonly = 1;
2563 if (block_group)
2564 btrfs_put_block_group(block_group);
2565 return readonly;
2566 }
2567
2568 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
2569 u64 total_bytes, u64 bytes_used,
2570 struct btrfs_space_info **space_info)
2571 {
2572 struct btrfs_space_info *found;
2573
2574 found = __find_space_info(info, flags);
2575 if (found) {
2576 spin_lock(&found->lock);
2577 found->total_bytes += total_bytes;
2578 found->bytes_used += bytes_used;
2579 found->full = 0;
2580 spin_unlock(&found->lock);
2581 *space_info = found;
2582 return 0;
2583 }
2584 found = kzalloc(sizeof(*found), GFP_NOFS);
2585 if (!found)
2586 return -ENOMEM;
2587
2588 INIT_LIST_HEAD(&found->block_groups);
2589 init_rwsem(&found->groups_sem);
2590 spin_lock_init(&found->lock);
2591 found->flags = flags;
2592 found->total_bytes = total_bytes;
2593 found->bytes_used = bytes_used;
2594 found->bytes_pinned = 0;
2595 found->bytes_reserved = 0;
2596 found->bytes_readonly = 0;
2597 found->bytes_delalloc = 0;
2598 found->full = 0;
2599 found->force_alloc = 0;
2600 *space_info = found;
2601 list_add_rcu(&found->list, &info->space_info);
2602 atomic_set(&found->caching_threads, 0);
2603 return 0;
2604 }
2605
2606 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
2607 {
2608 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
2609 BTRFS_BLOCK_GROUP_RAID1 |
2610 BTRFS_BLOCK_GROUP_RAID10 |
2611 BTRFS_BLOCK_GROUP_DUP);
2612 if (extra_flags) {
2613 if (flags & BTRFS_BLOCK_GROUP_DATA)
2614 fs_info->avail_data_alloc_bits |= extra_flags;
2615 if (flags & BTRFS_BLOCK_GROUP_METADATA)
2616 fs_info->avail_metadata_alloc_bits |= extra_flags;
2617 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
2618 fs_info->avail_system_alloc_bits |= extra_flags;
2619 }
2620 }
2621
2622 static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
2623 {
2624 spin_lock(&cache->space_info->lock);
2625 spin_lock(&cache->lock);
2626 if (!cache->ro) {
2627 cache->space_info->bytes_readonly += cache->key.offset -
2628 btrfs_block_group_used(&cache->item);
2629 cache->ro = 1;
2630 }
2631 spin_unlock(&cache->lock);
2632 spin_unlock(&cache->space_info->lock);
2633 }
2634
2635 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
2636 {
2637 u64 num_devices = root->fs_info->fs_devices->rw_devices;
2638
2639 if (num_devices == 1)
2640 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
2641 if (num_devices < 4)
2642 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
2643
2644 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
2645 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
2646 BTRFS_BLOCK_GROUP_RAID10))) {
2647 flags &= ~BTRFS_BLOCK_GROUP_DUP;
2648 }
2649
2650 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
2651 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
2652 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
2653 }
2654
2655 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
2656 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
2657 (flags & BTRFS_BLOCK_GROUP_RAID10) |
2658 (flags & BTRFS_BLOCK_GROUP_DUP)))
2659 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
2660 return flags;
2661 }
2662
2663 static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data)
2664 {
2665 struct btrfs_fs_info *info = root->fs_info;
2666 u64 alloc_profile;
2667
2668 if (data) {
2669 alloc_profile = info->avail_data_alloc_bits &
2670 info->data_alloc_profile;
2671 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2672 } else if (root == root->fs_info->chunk_root) {
2673 alloc_profile = info->avail_system_alloc_bits &
2674 info->system_alloc_profile;
2675 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2676 } else {
2677 alloc_profile = info->avail_metadata_alloc_bits &
2678 info->metadata_alloc_profile;
2679 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2680 }
2681
2682 return btrfs_reduce_alloc_profile(root, data);
2683 }
2684
2685 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
2686 {
2687 u64 alloc_target;
2688
2689 alloc_target = btrfs_get_alloc_profile(root, 1);
2690 BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
2691 alloc_target);
2692 }
2693
2694 /*
2695 * for now this just makes sure we have at least 5% of our metadata space free
2696 * for use.
2697 */
2698 int btrfs_check_metadata_free_space(struct btrfs_root *root)
2699 {
2700 struct btrfs_fs_info *info = root->fs_info;
2701 struct btrfs_space_info *meta_sinfo;
2702 u64 alloc_target, thresh;
2703 int committed = 0, ret;
2704
2705 /* get the space info for where the metadata will live */
2706 alloc_target = btrfs_get_alloc_profile(root, 0);
2707 meta_sinfo = __find_space_info(info, alloc_target);
2708
2709 again:
2710 spin_lock(&meta_sinfo->lock);
2711 if (!meta_sinfo->full)
2712 thresh = meta_sinfo->total_bytes * 80;
2713 else
2714 thresh = meta_sinfo->total_bytes * 95;
2715
2716 do_div(thresh, 100);
2717
2718 if (meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
2719 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly > thresh) {
2720 struct btrfs_trans_handle *trans;
2721 if (!meta_sinfo->full) {
2722 meta_sinfo->force_alloc = 1;
2723 spin_unlock(&meta_sinfo->lock);
2724
2725 trans = btrfs_start_transaction(root, 1);
2726 if (!trans)
2727 return -ENOMEM;
2728
2729 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2730 2 * 1024 * 1024, alloc_target, 0);
2731 btrfs_end_transaction(trans, root);
2732 goto again;
2733 }
2734 spin_unlock(&meta_sinfo->lock);
2735
2736 if (!committed) {
2737 committed = 1;
2738 trans = btrfs_join_transaction(root, 1);
2739 if (!trans)
2740 return -ENOMEM;
2741 ret = btrfs_commit_transaction(trans, root);
2742 if (ret)
2743 return ret;
2744 goto again;
2745 }
2746 return -ENOSPC;
2747 }
2748 spin_unlock(&meta_sinfo->lock);
2749
2750 return 0;
2751 }
2752
2753 /*
2754 * This will check the space that the inode allocates from to make sure we have
2755 * enough space for bytes.
2756 */
2757 int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
2758 u64 bytes)
2759 {
2760 struct btrfs_space_info *data_sinfo;
2761 int ret = 0, committed = 0;
2762
2763 /* make sure bytes are sectorsize aligned */
2764 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
2765
2766 data_sinfo = BTRFS_I(inode)->space_info;
2767 again:
2768 /* make sure we have enough space to handle the data first */
2769 spin_lock(&data_sinfo->lock);
2770 if (data_sinfo->total_bytes - data_sinfo->bytes_used -
2771 data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved -
2772 data_sinfo->bytes_pinned - data_sinfo->bytes_readonly -
2773 data_sinfo->bytes_may_use < bytes) {
2774 struct btrfs_trans_handle *trans;
2775
2776 /*
2777 * if we don't have enough free bytes in this space then we need
2778 * to alloc a new chunk.
2779 */
2780 if (!data_sinfo->full) {
2781 u64 alloc_target;
2782
2783 data_sinfo->force_alloc = 1;
2784 spin_unlock(&data_sinfo->lock);
2785
2786 alloc_target = btrfs_get_alloc_profile(root, 1);
2787 trans = btrfs_start_transaction(root, 1);
2788 if (!trans)
2789 return -ENOMEM;
2790
2791 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2792 bytes + 2 * 1024 * 1024,
2793 alloc_target, 0);
2794 btrfs_end_transaction(trans, root);
2795 if (ret)
2796 return ret;
2797 goto again;
2798 }
2799 spin_unlock(&data_sinfo->lock);
2800
2801 /* commit the current transaction and try again */
2802 if (!committed) {
2803 committed = 1;
2804 trans = btrfs_join_transaction(root, 1);
2805 if (!trans)
2806 return -ENOMEM;
2807 ret = btrfs_commit_transaction(trans, root);
2808 if (ret)
2809 return ret;
2810 goto again;
2811 }
2812
2813 printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes"
2814 ", %llu bytes_used, %llu bytes_reserved, "
2815 "%llu bytes_pinned, %llu bytes_readonly, %llu may use "
2816 "%llu total\n", (unsigned long long)bytes,
2817 (unsigned long long)data_sinfo->bytes_delalloc,
2818 (unsigned long long)data_sinfo->bytes_used,
2819 (unsigned long long)data_sinfo->bytes_reserved,
2820 (unsigned long long)data_sinfo->bytes_pinned,
2821 (unsigned long long)data_sinfo->bytes_readonly,
2822 (unsigned long long)data_sinfo->bytes_may_use,
2823 (unsigned long long)data_sinfo->total_bytes);
2824 return -ENOSPC;
2825 }
2826 data_sinfo->bytes_may_use += bytes;
2827 BTRFS_I(inode)->reserved_bytes += bytes;
2828 spin_unlock(&data_sinfo->lock);
2829
2830 return btrfs_check_metadata_free_space(root);
2831 }
2832
2833 /*
2834 * if there was an error for whatever reason after calling
2835 * btrfs_check_data_free_space, call this so we can cleanup the counters.
2836 */
2837 void btrfs_free_reserved_data_space(struct btrfs_root *root,
2838 struct inode *inode, u64 bytes)
2839 {
2840 struct btrfs_space_info *data_sinfo;
2841
2842 /* make sure bytes are sectorsize aligned */
2843 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
2844
2845 data_sinfo = BTRFS_I(inode)->space_info;
2846 spin_lock(&data_sinfo->lock);
2847 data_sinfo->bytes_may_use -= bytes;
2848 BTRFS_I(inode)->reserved_bytes -= bytes;
2849 spin_unlock(&data_sinfo->lock);
2850 }
2851
2852 /* called when we are adding a delalloc extent to the inode's io_tree */
2853 void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
2854 u64 bytes)
2855 {
2856 struct btrfs_space_info *data_sinfo;
2857
2858 /* get the space info for where this inode will be storing its data */
2859 data_sinfo = BTRFS_I(inode)->space_info;
2860
2861 /* make sure we have enough space to handle the data first */
2862 spin_lock(&data_sinfo->lock);
2863 data_sinfo->bytes_delalloc += bytes;
2864
2865 /*
2866 * we are adding a delalloc extent without calling
2867 * btrfs_check_data_free_space first. This happens on a weird
2868 * writepage condition, but shouldn't hurt our accounting
2869 */
2870 if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {
2871 data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;
2872 BTRFS_I(inode)->reserved_bytes = 0;
2873 } else {
2874 data_sinfo->bytes_may_use -= bytes;
2875 BTRFS_I(inode)->reserved_bytes -= bytes;
2876 }
2877
2878 spin_unlock(&data_sinfo->lock);
2879 }
2880
2881 /* called when we are clearing an delalloc extent from the inode's io_tree */
2882 void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
2883 u64 bytes)
2884 {
2885 struct btrfs_space_info *info;
2886
2887 info = BTRFS_I(inode)->space_info;
2888
2889 spin_lock(&info->lock);
2890 info->bytes_delalloc -= bytes;
2891 spin_unlock(&info->lock);
2892 }
2893
2894 static void force_metadata_allocation(struct btrfs_fs_info *info)
2895 {
2896 struct list_head *head = &info->space_info;
2897 struct btrfs_space_info *found;
2898
2899 rcu_read_lock();
2900 list_for_each_entry_rcu(found, head, list) {
2901 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
2902 found->force_alloc = 1;
2903 }
2904 rcu_read_unlock();
2905 }
2906
2907 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
2908 struct btrfs_root *extent_root, u64 alloc_bytes,
2909 u64 flags, int force)
2910 {
2911 struct btrfs_space_info *space_info;
2912 struct btrfs_fs_info *fs_info = extent_root->fs_info;
2913 u64 thresh;
2914 int ret = 0;
2915
2916 mutex_lock(&fs_info->chunk_mutex);
2917
2918 flags = btrfs_reduce_alloc_profile(extent_root, flags);
2919
2920 space_info = __find_space_info(extent_root->fs_info, flags);
2921 if (!space_info) {
2922 ret = update_space_info(extent_root->fs_info, flags,
2923 0, 0, &space_info);
2924 BUG_ON(ret);
2925 }
2926 BUG_ON(!space_info);
2927
2928 spin_lock(&space_info->lock);
2929 if (space_info->force_alloc) {
2930 force = 1;
2931 space_info->force_alloc = 0;
2932 }
2933 if (space_info->full) {
2934 spin_unlock(&space_info->lock);
2935 goto out;
2936 }
2937
2938 thresh = space_info->total_bytes - space_info->bytes_readonly;
2939 thresh = div_factor(thresh, 6);
2940 if (!force &&
2941 (space_info->bytes_used + space_info->bytes_pinned +
2942 space_info->bytes_reserved + alloc_bytes) < thresh) {
2943 spin_unlock(&space_info->lock);
2944 goto out;
2945 }
2946 spin_unlock(&space_info->lock);
2947
2948 /*
2949 * if we're doing a data chunk, go ahead and make sure that
2950 * we keep a reasonable number of metadata chunks allocated in the
2951 * FS as well.
2952 */
2953 if (flags & BTRFS_BLOCK_GROUP_DATA) {
2954 fs_info->data_chunk_allocations++;
2955 if (!(fs_info->data_chunk_allocations %
2956 fs_info->metadata_ratio))
2957 force_metadata_allocation(fs_info);
2958 }
2959
2960 ret = btrfs_alloc_chunk(trans, extent_root, flags);
2961 if (ret)
2962 space_info->full = 1;
2963 out:
2964 mutex_unlock(&extent_root->fs_info->chunk_mutex);
2965 return ret;
2966 }
2967
2968 static int update_block_group(struct btrfs_trans_handle *trans,
2969 struct btrfs_root *root,
2970 u64 bytenr, u64 num_bytes, int alloc,
2971 int mark_free)
2972 {
2973 struct btrfs_block_group_cache *cache;
2974 struct btrfs_fs_info *info = root->fs_info;
2975 u64 total = num_bytes;
2976 u64 old_val;
2977 u64 byte_in_group;
2978
2979 /* block accounting for super block */
2980 spin_lock(&info->delalloc_lock);
2981 old_val = btrfs_super_bytes_used(&info->super_copy);
2982 if (alloc)
2983 old_val += num_bytes;
2984 else
2985 old_val -= num_bytes;
2986 btrfs_set_super_bytes_used(&info->super_copy, old_val);
2987
2988 /* block accounting for root item */
2989 old_val = btrfs_root_used(&root->root_item);
2990 if (alloc)
2991 old_val += num_bytes;
2992 else
2993 old_val -= num_bytes;
2994 btrfs_set_root_used(&root->root_item, old_val);
2995 spin_unlock(&info->delalloc_lock);
2996
2997 while (total) {
2998 cache = btrfs_lookup_block_group(info, bytenr);
2999 if (!cache)
3000 return -1;
3001 byte_in_group = bytenr - cache->key.objectid;
3002 WARN_ON(byte_in_group > cache->key.offset);
3003
3004 spin_lock(&cache->space_info->lock);
3005 spin_lock(&cache->lock);
3006 cache->dirty = 1;
3007 old_val = btrfs_block_group_used(&cache->item);
3008 num_bytes = min(total, cache->key.offset - byte_in_group);
3009 if (alloc) {
3010 old_val += num_bytes;
3011 cache->space_info->bytes_used += num_bytes;
3012 if (cache->ro)
3013 cache->space_info->bytes_readonly -= num_bytes;
3014 btrfs_set_block_group_used(&cache->item, old_val);
3015 spin_unlock(&cache->lock);
3016 spin_unlock(&cache->space_info->lock);
3017 } else {
3018 old_val -= num_bytes;
3019 cache->space_info->bytes_used -= num_bytes;
3020 if (cache->ro)
3021 cache->space_info->bytes_readonly += num_bytes;
3022 btrfs_set_block_group_used(&cache->item, old_val);
3023 spin_unlock(&cache->lock);
3024 spin_unlock(&cache->space_info->lock);
3025 if (mark_free) {
3026 int ret;
3027
3028 ret = btrfs_discard_extent(root, bytenr,
3029 num_bytes);
3030 WARN_ON(ret);
3031
3032 ret = btrfs_add_free_space(cache, bytenr,
3033 num_bytes);
3034 WARN_ON(ret);
3035 }
3036 }
3037 btrfs_put_block_group(cache);
3038 total -= num_bytes;
3039 bytenr += num_bytes;
3040 }
3041 return 0;
3042 }
3043
3044 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
3045 {
3046 struct btrfs_block_group_cache *cache;
3047 u64 bytenr;
3048
3049 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
3050 if (!cache)
3051 return 0;
3052
3053 bytenr = cache->key.objectid;
3054 btrfs_put_block_group(cache);
3055
3056 return bytenr;
3057 }
3058
3059 int btrfs_update_pinned_extents(struct btrfs_root *root,
3060 u64 bytenr, u64 num, int pin)
3061 {
3062 u64 len;
3063 struct btrfs_block_group_cache *cache;
3064 struct btrfs_fs_info *fs_info = root->fs_info;
3065
3066 if (pin)
3067 set_extent_dirty(&fs_info->pinned_extents,
3068 bytenr, bytenr + num - 1, GFP_NOFS);
3069
3070 while (num > 0) {
3071 cache = btrfs_lookup_block_group(fs_info, bytenr);
3072 BUG_ON(!cache);
3073 len = min(num, cache->key.offset -
3074 (bytenr - cache->key.objectid));
3075 if (pin) {
3076 spin_lock(&cache->space_info->lock);
3077 spin_lock(&cache->lock);
3078 cache->pinned += len;
3079 cache->space_info->bytes_pinned += len;
3080 spin_unlock(&cache->lock);
3081 spin_unlock(&cache->space_info->lock);
3082 fs_info->total_pinned += len;
3083 } else {
3084 int unpin = 0;
3085
3086 /*
3087 * in order to not race with the block group caching, we
3088 * only want to unpin the extent if we are cached. If
3089 * we aren't cached, we want to start async caching this
3090 * block group so we can free the extent the next time
3091 * around.
3092 */
3093 spin_lock(&cache->space_info->lock);
3094 spin_lock(&cache->lock);
3095 unpin = (cache->cached == BTRFS_CACHE_FINISHED);
3096 if (likely(unpin)) {
3097 cache->pinned -= len;
3098 cache->space_info->bytes_pinned -= len;
3099 fs_info->total_pinned -= len;
3100 }
3101 spin_unlock(&cache->lock);
3102 spin_unlock(&cache->space_info->lock);
3103
3104 if (likely(unpin))
3105 clear_extent_dirty(&fs_info->pinned_extents,
3106 bytenr, bytenr + len -1,
3107 GFP_NOFS);
3108 else
3109 cache_block_group(cache);
3110
3111 if (unpin)
3112 btrfs_add_free_space(cache, bytenr, len);
3113 }
3114 btrfs_put_block_group(cache);
3115 bytenr += len;
3116 num -= len;
3117 }
3118 return 0;
3119 }
3120
3121 static int update_reserved_extents(struct btrfs_root *root,
3122 u64 bytenr, u64 num, int reserve)
3123 {
3124 u64 len;
3125 struct btrfs_block_group_cache *cache;
3126 struct btrfs_fs_info *fs_info = root->fs_info;
3127
3128 while (num > 0) {
3129 cache = btrfs_lookup_block_group(fs_info, bytenr);
3130 BUG_ON(!cache);
3131 len = min(num, cache->key.offset -
3132 (bytenr - cache->key.objectid));
3133
3134 spin_lock(&cache->space_info->lock);
3135 spin_lock(&cache->lock);
3136 if (reserve) {
3137 cache->reserved += len;
3138 cache->space_info->bytes_reserved += len;
3139 } else {
3140 cache->reserved -= len;
3141 cache->space_info->bytes_reserved -= len;
3142 }
3143 spin_unlock(&cache->lock);
3144 spin_unlock(&cache->space_info->lock);
3145 btrfs_put_block_group(cache);
3146 bytenr += len;
3147 num -= len;
3148 }
3149 return 0;
3150 }
3151
3152 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
3153 {
3154 u64 last = 0;
3155 u64 start;
3156 u64 end;
3157 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
3158 int ret;
3159
3160 while (1) {
3161 ret = find_first_extent_bit(pinned_extents, last,
3162 &start, &end, EXTENT_DIRTY);
3163 if (ret)
3164 break;
3165
3166 set_extent_dirty(copy, start, end, GFP_NOFS);
3167 last = end + 1;
3168 }
3169 return 0;
3170 }
3171
3172 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
3173 struct btrfs_root *root,
3174 struct extent_io_tree *unpin)
3175 {
3176 u64 start;
3177 u64 end;
3178 int ret;
3179
3180 while (1) {
3181 ret = find_first_extent_bit(unpin, 0, &start, &end,
3182 EXTENT_DIRTY);
3183 if (ret)
3184 break;
3185
3186 ret = btrfs_discard_extent(root, start, end + 1 - start);
3187
3188 /* unlocks the pinned mutex */
3189 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
3190 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3191
3192 cond_resched();
3193 }
3194
3195 return ret;
3196 }
3197
3198 static int pin_down_bytes(struct btrfs_trans_handle *trans,
3199 struct btrfs_root *root,
3200 struct btrfs_path *path,
3201 u64 bytenr, u64 num_bytes, int is_data,
3202 struct extent_buffer **must_clean)
3203 {
3204 int err = 0;
3205 struct extent_buffer *buf;
3206
3207 if (is_data)
3208 goto pinit;
3209
3210 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
3211 if (!buf)
3212 goto pinit;
3213
3214 /* we can reuse a block if it hasn't been written
3215 * and it is from this transaction. We can't
3216 * reuse anything from the tree log root because
3217 * it has tiny sub-transactions.
3218 */
3219 if (btrfs_buffer_uptodate(buf, 0) &&
3220 btrfs_try_tree_lock(buf)) {
3221 u64 header_owner = btrfs_header_owner(buf);
3222 u64 header_transid = btrfs_header_generation(buf);
3223 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
3224 header_transid == trans->transid &&
3225 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
3226 *must_clean = buf;
3227 return 1;
3228 }
3229 btrfs_tree_unlock(buf);
3230 }
3231 free_extent_buffer(buf);
3232 pinit:
3233 btrfs_set_path_blocking(path);
3234 /* unlocks the pinned mutex */
3235 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
3236
3237 BUG_ON(err < 0);
3238 return 0;
3239 }
3240
3241
3242 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
3243 struct btrfs_root *root,
3244 u64 bytenr, u64 num_bytes, u64 parent,
3245 u64 root_objectid, u64 owner_objectid,
3246 u64 owner_offset, int refs_to_drop,
3247 struct btrfs_delayed_extent_op *extent_op)
3248 {
3249 struct btrfs_key key;
3250 struct btrfs_path *path;
3251 struct btrfs_fs_info *info = root->fs_info;
3252 struct btrfs_root *extent_root = info->extent_root;
3253 struct extent_buffer *leaf;
3254 struct btrfs_extent_item *ei;
3255 struct btrfs_extent_inline_ref *iref;
3256 int ret;
3257 int is_data;
3258 int extent_slot = 0;
3259 int found_extent = 0;
3260 int num_to_del = 1;
3261 u32 item_size;
3262 u64 refs;
3263
3264 path = btrfs_alloc_path();
3265 if (!path)
3266 return -ENOMEM;
3267
3268 path->reada = 1;
3269 path->leave_spinning = 1;
3270
3271 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
3272 BUG_ON(!is_data && refs_to_drop != 1);
3273
3274 ret = lookup_extent_backref(trans, extent_root, path, &iref,
3275 bytenr, num_bytes, parent,
3276 root_objectid, owner_objectid,
3277 owner_offset);
3278 if (ret == 0) {
3279 extent_slot = path->slots[0];
3280 while (extent_slot >= 0) {
3281 btrfs_item_key_to_cpu(path->nodes[0], &key,
3282 extent_slot);
3283 if (key.objectid != bytenr)
3284 break;
3285 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3286 key.offset == num_bytes) {
3287 found_extent = 1;
3288 break;
3289 }
3290 if (path->slots[0] - extent_slot > 5)
3291 break;
3292 extent_slot--;
3293 }
3294 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3295 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
3296 if (found_extent && item_size < sizeof(*ei))
3297 found_extent = 0;
3298 #endif
3299 if (!found_extent) {
3300 BUG_ON(iref);
3301 ret = remove_extent_backref(trans, extent_root, path,
3302 NULL, refs_to_drop,
3303 is_data);
3304 BUG_ON(ret);
3305 btrfs_release_path(extent_root, path);
3306 path->leave_spinning = 1;
3307
3308 key.objectid = bytenr;
3309 key.type = BTRFS_EXTENT_ITEM_KEY;
3310 key.offset = num_bytes;
3311
3312 ret = btrfs_search_slot(trans, extent_root,
3313 &key, path, -1, 1);
3314 if (ret) {
3315 printk(KERN_ERR "umm, got %d back from search"
3316 ", was looking for %llu\n", ret,
3317 (unsigned long long)bytenr);
3318 btrfs_print_leaf(extent_root, path->nodes[0]);
3319 }
3320 BUG_ON(ret);
3321 extent_slot = path->slots[0];
3322 }
3323 } else {
3324 btrfs_print_leaf(extent_root, path->nodes[0]);
3325 WARN_ON(1);
3326 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
3327 "parent %llu root %llu owner %llu offset %llu\n",
3328 (unsigned long long)bytenr,
3329 (unsigned long long)parent,
3330 (unsigned long long)root_objectid,
3331 (unsigned long long)owner_objectid,
3332 (unsigned long long)owner_offset);
3333 }
3334
3335 leaf = path->nodes[0];
3336 item_size = btrfs_item_size_nr(leaf, extent_slot);
3337 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3338 if (item_size < sizeof(*ei)) {
3339 BUG_ON(found_extent || extent_slot != path->slots[0]);
3340 ret = convert_extent_item_v0(trans, extent_root, path,
3341 owner_objectid, 0);
3342 BUG_ON(ret < 0);
3343
3344 btrfs_release_path(extent_root, path);
3345 path->leave_spinning = 1;
3346
3347 key.objectid = bytenr;
3348 key.type = BTRFS_EXTENT_ITEM_KEY;
3349 key.offset = num_bytes;
3350
3351 ret = btrfs_search_slot(trans, extent_root, &key, path,
3352 -1, 1);
3353 if (ret) {
3354 printk(KERN_ERR "umm, got %d back from search"
3355 ", was looking for %llu\n", ret,
3356 (unsigned long long)bytenr);
3357 btrfs_print_leaf(extent_root, path->nodes[0]);
3358 }
3359 BUG_ON(ret);
3360 extent_slot = path->slots[0];
3361 leaf = path->nodes[0];
3362 item_size = btrfs_item_size_nr(leaf, extent_slot);
3363 }
3364 #endif
3365 BUG_ON(item_size < sizeof(*ei));
3366 ei = btrfs_item_ptr(leaf, extent_slot,
3367 struct btrfs_extent_item);
3368 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3369 struct btrfs_tree_block_info *bi;
3370 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
3371 bi = (struct btrfs_tree_block_info *)(ei + 1);
3372 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
3373 }
3374
3375 refs = btrfs_extent_refs(leaf, ei);
3376 BUG_ON(refs < refs_to_drop);
3377 refs -= refs_to_drop;
3378
3379 if (refs > 0) {
3380 if (extent_op)
3381 __run_delayed_extent_op(extent_op, leaf, ei);
3382 /*
3383 * In the case of inline back ref, reference count will
3384 * be updated by remove_extent_backref
3385 */
3386 if (iref) {
3387 BUG_ON(!found_extent);
3388 } else {
3389 btrfs_set_extent_refs(leaf, ei, refs);
3390 btrfs_mark_buffer_dirty(leaf);
3391 }
3392 if (found_extent) {
3393 ret = remove_extent_backref(trans, extent_root, path,
3394 iref, refs_to_drop,
3395 is_data);
3396 BUG_ON(ret);
3397 }
3398 } else {
3399 int mark_free = 0;
3400 struct extent_buffer *must_clean = NULL;
3401
3402 if (found_extent) {
3403 BUG_ON(is_data && refs_to_drop !=
3404 extent_data_ref_count(root, path, iref));
3405 if (iref) {
3406 BUG_ON(path->slots[0] != extent_slot);
3407 } else {
3408 BUG_ON(path->slots[0] != extent_slot + 1);
3409 path->slots[0] = extent_slot;
3410 num_to_del = 2;
3411 }
3412 }
3413
3414 ret = pin_down_bytes(trans, root, path, bytenr,
3415 num_bytes, is_data, &must_clean);
3416 if (ret > 0)
3417 mark_free = 1;
3418 BUG_ON(ret < 0);
3419 /*
3420 * it is going to be very rare for someone to be waiting
3421 * on the block we're freeing. del_items might need to
3422 * schedule, so rather than get fancy, just force it
3423 * to blocking here
3424 */
3425 if (must_clean)
3426 btrfs_set_lock_blocking(must_clean);
3427
3428 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
3429 num_to_del);
3430 BUG_ON(ret);
3431 btrfs_release_path(extent_root, path);
3432
3433 if (must_clean) {
3434 clean_tree_block(NULL, root, must_clean);
3435 btrfs_tree_unlock(must_clean);
3436 free_extent_buffer(must_clean);
3437 }
3438
3439 if (is_data) {
3440 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
3441 BUG_ON(ret);
3442 } else {
3443 invalidate_mapping_pages(info->btree_inode->i_mapping,
3444 bytenr >> PAGE_CACHE_SHIFT,
3445 (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
3446 }
3447
3448 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
3449 mark_free);
3450 BUG_ON(ret);
3451 }
3452 btrfs_free_path(path);
3453 return ret;
3454 }
3455
3456 /*
3457 * when we free an extent, it is possible (and likely) that we free the last
3458 * delayed ref for that extent as well. This searches the delayed ref tree for
3459 * a given extent, and if there are no other delayed refs to be processed, it
3460 * removes it from the tree.
3461 */
3462 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
3463 struct btrfs_root *root, u64 bytenr)
3464 {
3465 struct btrfs_delayed_ref_head *head;
3466 struct btrfs_delayed_ref_root *delayed_refs;
3467 struct btrfs_delayed_ref_node *ref;
3468 struct rb_node *node;
3469 int ret;
3470
3471 delayed_refs = &trans->transaction->delayed_refs;
3472 spin_lock(&delayed_refs->lock);
3473 head = btrfs_find_delayed_ref_head(trans, bytenr);
3474 if (!head)
3475 goto out;
3476
3477 node = rb_prev(&head->node.rb_node);
3478 if (!node)
3479 goto out;
3480
3481 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3482
3483 /* there are still entries for this ref, we can't drop it */
3484 if (ref->bytenr == bytenr)
3485 goto out;
3486
3487 if (head->extent_op) {
3488 if (!head->must_insert_reserved)
3489 goto out;
3490 kfree(head->extent_op);
3491 head->extent_op = NULL;
3492 }
3493
3494 /*
3495 * waiting for the lock here would deadlock. If someone else has it
3496 * locked they are already in the process of dropping it anyway
3497 */
3498 if (!mutex_trylock(&head->mutex))
3499 goto out;
3500
3501 /*
3502 * at this point we have a head with no other entries. Go
3503 * ahead and process it.
3504 */
3505 head->node.in_tree = 0;
3506 rb_erase(&head->node.rb_node, &delayed_refs->root);
3507
3508 delayed_refs->num_entries--;
3509
3510 /*
3511 * we don't take a ref on the node because we're removing it from the
3512 * tree, so we just steal the ref the tree was holding.
3513 */
3514 delayed_refs->num_heads--;
3515 if (list_empty(&head->cluster))
3516 delayed_refs->num_heads_ready--;
3517
3518 list_del_init(&head->cluster);
3519 spin_unlock(&delayed_refs->lock);
3520
3521 ret = run_one_delayed_ref(trans, root->fs_info->tree_root,
3522 &head->node, head->extent_op,
3523 head->must_insert_reserved);
3524 BUG_ON(ret);
3525 btrfs_put_delayed_ref(&head->node);
3526 return 0;
3527 out:
3528 spin_unlock(&delayed_refs->lock);
3529 return 0;
3530 }
3531
3532 int btrfs_free_extent(struct btrfs_trans_handle *trans,
3533 struct btrfs_root *root,
3534 u64 bytenr, u64 num_bytes, u64 parent,
3535 u64 root_objectid, u64 owner, u64 offset)
3536 {
3537 int ret;
3538
3539 /*
3540 * tree log blocks never actually go into the extent allocation
3541 * tree, just update pinning info and exit early.
3542 */
3543 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
3544 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
3545 /* unlocks the pinned mutex */
3546 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
3547 update_reserved_extents(root, bytenr, num_bytes, 0);
3548 ret = 0;
3549 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
3550 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
3551 parent, root_objectid, (int)owner,
3552 BTRFS_DROP_DELAYED_REF, NULL);
3553 BUG_ON(ret);
3554 ret = check_ref_cleanup(trans, root, bytenr);
3555 BUG_ON(ret);
3556 } else {
3557 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
3558 parent, root_objectid, owner,
3559 offset, BTRFS_DROP_DELAYED_REF, NULL);
3560 BUG_ON(ret);
3561 }
3562 return ret;
3563 }
3564
3565 static u64 stripe_align(struct btrfs_root *root, u64 val)
3566 {
3567 u64 mask = ((u64)root->stripesize - 1);
3568 u64 ret = (val + mask) & ~mask;
3569 return ret;
3570 }
3571
3572 /*
3573 * when we wait for progress in the block group caching, its because
3574 * our allocation attempt failed at least once. So, we must sleep
3575 * and let some progress happen before we try again.
3576 *
3577 * This function will sleep at least once waiting for new free space to
3578 * show up, and then it will check the block group free space numbers
3579 * for our min num_bytes. Another option is to have it go ahead
3580 * and look in the rbtree for a free extent of a given size, but this
3581 * is a good start.
3582 */
3583 static noinline int
3584 wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
3585 u64 num_bytes)
3586 {
3587 DEFINE_WAIT(wait);
3588
3589 prepare_to_wait(&cache->caching_q, &wait, TASK_UNINTERRUPTIBLE);
3590
3591 if (block_group_cache_done(cache)) {
3592 finish_wait(&cache->caching_q, &wait);
3593 return 0;
3594 }
3595 schedule();
3596 finish_wait(&cache->caching_q, &wait);
3597
3598 wait_event(cache->caching_q, block_group_cache_done(cache) ||
3599 (cache->free_space >= num_bytes));
3600 return 0;
3601 }
3602
3603 enum btrfs_loop_type {
3604 LOOP_CACHED_ONLY = 0,
3605 LOOP_CACHING_NOWAIT = 1,
3606 LOOP_CACHING_WAIT = 2,
3607 LOOP_ALLOC_CHUNK = 3,
3608 LOOP_NO_EMPTY_SIZE = 4,
3609 };
3610
3611 /*
3612 * walks the btree of allocated extents and find a hole of a given size.
3613 * The key ins is changed to record the hole:
3614 * ins->objectid == block start
3615 * ins->flags = BTRFS_EXTENT_ITEM_KEY
3616 * ins->offset == number of blocks
3617 * Any available blocks before search_start are skipped.
3618 */
3619 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
3620 struct btrfs_root *orig_root,
3621 u64 num_bytes, u64 empty_size,
3622 u64 search_start, u64 search_end,
3623 u64 hint_byte, struct btrfs_key *ins,
3624 u64 exclude_start, u64 exclude_nr,
3625 int data)
3626 {
3627 int ret = 0;
3628 struct btrfs_root *root = orig_root->fs_info->extent_root;
3629 struct btrfs_free_cluster *last_ptr = NULL;
3630 struct btrfs_block_group_cache *block_group = NULL;
3631 int empty_cluster = 2 * 1024 * 1024;
3632 int allowed_chunk_alloc = 0;
3633 struct btrfs_space_info *space_info;
3634 int last_ptr_loop = 0;
3635 int loop = 0;
3636 bool found_uncached_bg = false;
3637
3638 WARN_ON(num_bytes < root->sectorsize);
3639 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
3640 ins->objectid = 0;
3641 ins->offset = 0;
3642
3643 space_info = __find_space_info(root->fs_info, data);
3644
3645 if (orig_root->ref_cows || empty_size)
3646 allowed_chunk_alloc = 1;
3647
3648 if (data & BTRFS_BLOCK_GROUP_METADATA) {
3649 last_ptr = &root->fs_info->meta_alloc_cluster;
3650 if (!btrfs_test_opt(root, SSD))
3651 empty_cluster = 64 * 1024;
3652 }
3653
3654 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
3655 last_ptr = &root->fs_info->data_alloc_cluster;
3656 }
3657
3658 if (last_ptr) {
3659 spin_lock(&last_ptr->lock);
3660 if (last_ptr->block_group)
3661 hint_byte = last_ptr->window_start;
3662 spin_unlock(&last_ptr->lock);
3663 }
3664
3665 search_start = max(search_start, first_logical_byte(root, 0));
3666 search_start = max(search_start, hint_byte);
3667
3668 if (!last_ptr)
3669 empty_cluster = 0;
3670
3671 if (search_start == hint_byte) {
3672 block_group = btrfs_lookup_block_group(root->fs_info,
3673 search_start);
3674 /*
3675 * we don't want to use the block group if it doesn't match our
3676 * allocation bits, or if its not cached.
3677 */
3678 if (block_group && block_group_bits(block_group, data) &&
3679 block_group_cache_done(block_group)) {
3680 down_read(&space_info->groups_sem);
3681 if (list_empty(&block_group->list) ||
3682 block_group->ro) {
3683 /*
3684 * someone is removing this block group,
3685 * we can't jump into the have_block_group
3686 * target because our list pointers are not
3687 * valid
3688 */
3689 btrfs_put_block_group(block_group);
3690 up_read(&space_info->groups_sem);
3691 } else
3692 goto have_block_group;
3693 } else if (block_group) {
3694 btrfs_put_block_group(block_group);
3695 }
3696 }
3697
3698 search:
3699 down_read(&space_info->groups_sem);
3700 list_for_each_entry(block_group, &space_info->block_groups, list) {
3701 u64 offset;
3702 int cached;
3703
3704 atomic_inc(&block_group->count);
3705 search_start = block_group->key.objectid;
3706
3707 have_block_group:
3708 if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
3709 /*
3710 * we want to start caching kthreads, but not too many
3711 * right off the bat so we don't overwhelm the system,
3712 * so only start them if there are less than 2 and we're
3713 * in the initial allocation phase.
3714 */
3715 if (loop > LOOP_CACHING_NOWAIT ||
3716 atomic_read(&space_info->caching_threads) < 2) {
3717 ret = cache_block_group(block_group);
3718 BUG_ON(ret);
3719 }
3720 }
3721
3722 cached = block_group_cache_done(block_group);
3723 if (unlikely(!cached)) {
3724 found_uncached_bg = true;
3725
3726 /* if we only want cached bgs, loop */
3727 if (loop == LOOP_CACHED_ONLY)
3728 goto loop;
3729 }
3730
3731 if (unlikely(block_group->ro))
3732 goto loop;
3733
3734 if (last_ptr) {
3735 /*
3736 * the refill lock keeps out other
3737 * people trying to start a new cluster
3738 */
3739 spin_lock(&last_ptr->refill_lock);
3740 if (last_ptr->block_group &&
3741 (last_ptr->block_group->ro ||
3742 !block_group_bits(last_ptr->block_group, data))) {
3743 offset = 0;
3744 goto refill_cluster;
3745 }
3746
3747 offset = btrfs_alloc_from_cluster(block_group, last_ptr,
3748 num_bytes, search_start);
3749 if (offset) {
3750 /* we have a block, we're done */
3751 spin_unlock(&last_ptr->refill_lock);
3752 goto checks;
3753 }
3754
3755 spin_lock(&last_ptr->lock);
3756 /*
3757 * whoops, this cluster doesn't actually point to
3758 * this block group. Get a ref on the block
3759 * group is does point to and try again
3760 */
3761 if (!last_ptr_loop && last_ptr->block_group &&
3762 last_ptr->block_group != block_group) {
3763
3764 btrfs_put_block_group(block_group);
3765 block_group = last_ptr->block_group;
3766 atomic_inc(&block_group->count);
3767 spin_unlock(&last_ptr->lock);
3768 spin_unlock(&last_ptr->refill_lock);
3769
3770 last_ptr_loop = 1;
3771 search_start = block_group->key.objectid;
3772 /*
3773 * we know this block group is properly
3774 * in the list because
3775 * btrfs_remove_block_group, drops the
3776 * cluster before it removes the block
3777 * group from the list
3778 */
3779 goto have_block_group;
3780 }
3781 spin_unlock(&last_ptr->lock);
3782 refill_cluster:
3783 /*
3784 * this cluster didn't work out, free it and
3785 * start over
3786 */
3787 btrfs_return_cluster_to_free_space(NULL, last_ptr);
3788
3789 last_ptr_loop = 0;
3790
3791 /* allocate a cluster in this block group */
3792 ret = btrfs_find_space_cluster(trans, root,
3793 block_group, last_ptr,
3794 offset, num_bytes,
3795 empty_cluster + empty_size);
3796 if (ret == 0) {
3797 /*
3798 * now pull our allocation out of this
3799 * cluster
3800 */
3801 offset = btrfs_alloc_from_cluster(block_group,
3802 last_ptr, num_bytes,
3803 search_start);
3804 if (offset) {
3805 /* we found one, proceed */
3806 spin_unlock(&last_ptr->refill_lock);
3807 goto checks;
3808 }
3809 } else if (!cached && loop > LOOP_CACHING_NOWAIT) {
3810 spin_unlock(&last_ptr->refill_lock);
3811
3812 wait_block_group_cache_progress(block_group,
3813 num_bytes + empty_cluster + empty_size);
3814 goto have_block_group;
3815 }
3816
3817 /*
3818 * at this point we either didn't find a cluster
3819 * or we weren't able to allocate a block from our
3820 * cluster. Free the cluster we've been trying
3821 * to use, and go to the next block group
3822 */
3823 if (loop < LOOP_NO_EMPTY_SIZE) {
3824 btrfs_return_cluster_to_free_space(NULL,
3825 last_ptr);
3826 spin_unlock(&last_ptr->refill_lock);
3827 goto loop;
3828 }
3829 spin_unlock(&last_ptr->refill_lock);
3830 }
3831
3832 offset = btrfs_find_space_for_alloc(block_group, search_start,
3833 num_bytes, empty_size);
3834 if (!offset && (cached || (!cached &&
3835 loop == LOOP_CACHING_NOWAIT))) {
3836 goto loop;
3837 } else if (!offset && (!cached &&
3838 loop > LOOP_CACHING_NOWAIT)) {
3839 wait_block_group_cache_progress(block_group,
3840 num_bytes + empty_size);
3841 goto have_block_group;
3842 }
3843 checks:
3844 search_start = stripe_align(root, offset);
3845 /* move on to the next group */
3846 if (search_start + num_bytes >= search_end) {
3847 btrfs_add_free_space(block_group, offset, num_bytes);
3848 goto loop;
3849 }
3850
3851 /* move on to the next group */
3852 if (search_start + num_bytes >
3853 block_group->key.objectid + block_group->key.offset) {
3854 btrfs_add_free_space(block_group, offset, num_bytes);
3855 goto loop;
3856 }
3857
3858 if (exclude_nr > 0 &&
3859 (search_start + num_bytes > exclude_start &&
3860 search_start < exclude_start + exclude_nr)) {
3861 search_start = exclude_start + exclude_nr;
3862
3863 btrfs_add_free_space(block_group, offset, num_bytes);
3864 /*
3865 * if search_start is still in this block group
3866 * then we just re-search this block group
3867 */
3868 if (search_start >= block_group->key.objectid &&
3869 search_start < (block_group->key.objectid +
3870 block_group->key.offset))
3871 goto have_block_group;
3872 goto loop;
3873 }
3874
3875 ins->objectid = search_start;
3876 ins->offset = num_bytes;
3877
3878 if (offset < search_start)
3879 btrfs_add_free_space(block_group, offset,
3880 search_start - offset);
3881 BUG_ON(offset > search_start);
3882
3883 /* we are all good, lets return */
3884 break;
3885 loop:
3886 btrfs_put_block_group(block_group);
3887 }
3888 up_read(&space_info->groups_sem);
3889
3890 /* LOOP_CACHED_ONLY, only search fully cached block groups
3891 * LOOP_CACHING_NOWAIT, search partially cached block groups, but
3892 * dont wait foR them to finish caching
3893 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
3894 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
3895 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
3896 * again
3897 */
3898 if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE &&
3899 (found_uncached_bg || empty_size || empty_cluster ||
3900 allowed_chunk_alloc)) {
3901 if (found_uncached_bg) {
3902 found_uncached_bg = false;
3903 if (loop < LOOP_CACHING_WAIT) {
3904 loop++;
3905 goto search;
3906 }
3907 }
3908
3909 if (loop == LOOP_ALLOC_CHUNK) {
3910 empty_size = 0;
3911 empty_cluster = 0;
3912 }
3913
3914 if (allowed_chunk_alloc) {
3915 ret = do_chunk_alloc(trans, root, num_bytes +
3916 2 * 1024 * 1024, data, 1);
3917 allowed_chunk_alloc = 0;
3918 } else {
3919 space_info->force_alloc = 1;
3920 }
3921
3922 if (loop < LOOP_NO_EMPTY_SIZE) {
3923 loop++;
3924 goto search;
3925 }
3926 ret = -ENOSPC;
3927 } else if (!ins->objectid) {
3928 ret = -ENOSPC;
3929 }
3930
3931 /* we found what we needed */
3932 if (ins->objectid) {
3933 if (!(data & BTRFS_BLOCK_GROUP_DATA))
3934 trans->block_group = block_group->key.objectid;
3935
3936 btrfs_put_block_group(block_group);
3937 ret = 0;
3938 }
3939
3940 return ret;
3941 }
3942
3943 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
3944 {
3945 struct btrfs_block_group_cache *cache;
3946
3947 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
3948 (unsigned long long)(info->total_bytes - info->bytes_used -
3949 info->bytes_pinned - info->bytes_reserved),
3950 (info->full) ? "" : "not ");
3951 printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu,"
3952 " may_use=%llu, used=%llu\n",
3953 (unsigned long long)info->total_bytes,
3954 (unsigned long long)info->bytes_pinned,
3955 (unsigned long long)info->bytes_delalloc,
3956 (unsigned long long)info->bytes_may_use,
3957 (unsigned long long)info->bytes_used);
3958
3959 down_read(&info->groups_sem);
3960 list_for_each_entry(cache, &info->block_groups, list) {
3961 spin_lock(&cache->lock);
3962 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
3963 "%llu pinned %llu reserved\n",
3964 (unsigned long long)cache->key.objectid,
3965 (unsigned long long)cache->key.offset,
3966 (unsigned long long)btrfs_block_group_used(&cache->item),
3967 (unsigned long long)cache->pinned,
3968 (unsigned long long)cache->reserved);
3969 btrfs_dump_free_space(cache, bytes);
3970 spin_unlock(&cache->lock);
3971 }
3972 up_read(&info->groups_sem);
3973 }
3974
3975 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
3976 struct btrfs_root *root,
3977 u64 num_bytes, u64 min_alloc_size,
3978 u64 empty_size, u64 hint_byte,
3979 u64 search_end, struct btrfs_key *ins,
3980 u64 data)
3981 {
3982 int ret;
3983 u64 search_start = 0;
3984 struct btrfs_fs_info *info = root->fs_info;
3985
3986 data = btrfs_get_alloc_profile(root, data);
3987 again:
3988 /*
3989 * the only place that sets empty_size is btrfs_realloc_node, which
3990 * is not called recursively on allocations
3991 */
3992 if (empty_size || root->ref_cows) {
3993 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
3994 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3995 2 * 1024 * 1024,
3996 BTRFS_BLOCK_GROUP_METADATA |
3997 (info->metadata_alloc_profile &
3998 info->avail_metadata_alloc_bits), 0);
3999 }
4000 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
4001 num_bytes + 2 * 1024 * 1024, data, 0);
4002 }
4003
4004 WARN_ON(num_bytes < root->sectorsize);
4005 ret = find_free_extent(trans, root, num_bytes, empty_size,
4006 search_start, search_end, hint_byte, ins,
4007 trans->alloc_exclude_start,
4008 trans->alloc_exclude_nr, data);
4009
4010 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
4011 num_bytes = num_bytes >> 1;
4012 num_bytes = num_bytes & ~(root->sectorsize - 1);
4013 num_bytes = max(num_bytes, min_alloc_size);
4014 do_chunk_alloc(trans, root->fs_info->extent_root,
4015 num_bytes, data, 1);
4016 goto again;
4017 }
4018 if (ret == -ENOSPC) {
4019 struct btrfs_space_info *sinfo;
4020
4021 sinfo = __find_space_info(root->fs_info, data);
4022 printk(KERN_ERR "btrfs allocation failed flags %llu, "
4023 "wanted %llu\n", (unsigned long long)data,
4024 (unsigned long long)num_bytes);
4025 dump_space_info(sinfo, num_bytes);
4026 }
4027
4028 return ret;
4029 }
4030
4031 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
4032 {
4033 struct btrfs_block_group_cache *cache;
4034 int ret = 0;
4035
4036 cache = btrfs_lookup_block_group(root->fs_info, start);
4037 if (!cache) {
4038 printk(KERN_ERR "Unable to find block group for %llu\n",
4039 (unsigned long long)start);
4040 return -ENOSPC;
4041 }
4042
4043 ret = btrfs_discard_extent(root, start, len);
4044
4045 btrfs_add_free_space(cache, start, len);
4046 btrfs_put_block_group(cache);
4047 update_reserved_extents(root, start, len, 0);
4048
4049 return ret;
4050 }
4051
4052 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
4053 struct btrfs_root *root,
4054 u64 num_bytes, u64 min_alloc_size,
4055 u64 empty_size, u64 hint_byte,
4056 u64 search_end, struct btrfs_key *ins,
4057 u64 data)
4058 {
4059 int ret;
4060 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
4061 empty_size, hint_byte, search_end, ins,
4062 data);
4063 if (!ret)
4064 update_reserved_extents(root, ins->objectid, ins->offset, 1);
4065
4066 return ret;
4067 }
4068
4069 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4070 struct btrfs_root *root,
4071 u64 parent, u64 root_objectid,
4072 u64 flags, u64 owner, u64 offset,
4073 struct btrfs_key *ins, int ref_mod)
4074 {
4075 int ret;
4076 struct btrfs_fs_info *fs_info = root->fs_info;
4077 struct btrfs_extent_item *extent_item;
4078 struct btrfs_extent_inline_ref *iref;
4079 struct btrfs_path *path;
4080 struct extent_buffer *leaf;
4081 int type;
4082 u32 size;
4083
4084 if (parent > 0)
4085 type = BTRFS_SHARED_DATA_REF_KEY;
4086 else
4087 type = BTRFS_EXTENT_DATA_REF_KEY;
4088
4089 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
4090
4091 path = btrfs_alloc_path();
4092 BUG_ON(!path);
4093
4094 path->leave_spinning = 1;
4095 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4096 ins, size);
4097 BUG_ON(ret);
4098
4099 leaf = path->nodes[0];
4100 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4101 struct btrfs_extent_item);
4102 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
4103 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4104 btrfs_set_extent_flags(leaf, extent_item,
4105 flags | BTRFS_EXTENT_FLAG_DATA);
4106
4107 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
4108 btrfs_set_extent_inline_ref_type(leaf, iref, type);
4109 if (parent > 0) {
4110 struct btrfs_shared_data_ref *ref;
4111 ref = (struct btrfs_shared_data_ref *)(iref + 1);
4112 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4113 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
4114 } else {
4115 struct btrfs_extent_data_ref *ref;
4116 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
4117 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
4118 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
4119 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
4120 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
4121 }
4122
4123 btrfs_mark_buffer_dirty(path->nodes[0]);
4124 btrfs_free_path(path);
4125
4126 ret = update_block_group(trans, root, ins->objectid, ins->offset,
4127 1, 0);
4128 if (ret) {
4129 printk(KERN_ERR "btrfs update block group failed for %llu "
4130 "%llu\n", (unsigned long long)ins->objectid,
4131 (unsigned long long)ins->offset);
4132 BUG();
4133 }
4134 return ret;
4135 }
4136
4137 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
4138 struct btrfs_root *root,
4139 u64 parent, u64 root_objectid,
4140 u64 flags, struct btrfs_disk_key *key,
4141 int level, struct btrfs_key *ins)
4142 {
4143 int ret;
4144 struct btrfs_fs_info *fs_info = root->fs_info;
4145 struct btrfs_extent_item *extent_item;
4146 struct btrfs_tree_block_info *block_info;
4147 struct btrfs_extent_inline_ref *iref;
4148 struct btrfs_path *path;
4149 struct extent_buffer *leaf;
4150 u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
4151
4152 path = btrfs_alloc_path();
4153 BUG_ON(!path);
4154
4155 path->leave_spinning = 1;
4156 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
4157 ins, size);
4158 BUG_ON(ret);
4159
4160 leaf = path->nodes[0];
4161 extent_item = btrfs_item_ptr(leaf, path->slots[0],
4162 struct btrfs_extent_item);
4163 btrfs_set_extent_refs(leaf, extent_item, 1);
4164 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
4165 btrfs_set_extent_flags(leaf, extent_item,
4166 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
4167 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
4168
4169 btrfs_set_tree_block_key(leaf, block_info, key);
4170 btrfs_set_tree_block_level(leaf, block_info, level);
4171
4172 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
4173 if (parent > 0) {
4174 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
4175 btrfs_set_extent_inline_ref_type(leaf, iref,
4176 BTRFS_SHARED_BLOCK_REF_KEY);
4177 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
4178 } else {
4179 btrfs_set_extent_inline_ref_type(leaf, iref,
4180 BTRFS_TREE_BLOCK_REF_KEY);
4181 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
4182 }
4183
4184 btrfs_mark_buffer_dirty(leaf);
4185 btrfs_free_path(path);
4186
4187 ret = update_block_group(trans, root, ins->objectid, ins->offset,
4188 1, 0);
4189 if (ret) {
4190 printk(KERN_ERR "btrfs update block group failed for %llu "
4191 "%llu\n", (unsigned long long)ins->objectid,
4192 (unsigned long long)ins->offset);
4193 BUG();
4194 }
4195 return ret;
4196 }
4197
4198 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
4199 struct btrfs_root *root,
4200 u64 root_objectid, u64 owner,
4201 u64 offset, struct btrfs_key *ins)
4202 {
4203 int ret;
4204
4205 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
4206
4207 ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
4208 0, root_objectid, owner, offset,
4209 BTRFS_ADD_DELAYED_EXTENT, NULL);
4210 return ret;
4211 }
4212
4213 /*
4214 * this is used by the tree logging recovery code. It records that
4215 * an extent has been allocated and makes sure to clear the free
4216 * space cache bits as well
4217 */
4218 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
4219 struct btrfs_root *root,
4220 u64 root_objectid, u64 owner, u64 offset,
4221 struct btrfs_key *ins)
4222 {
4223 int ret;
4224 struct btrfs_block_group_cache *block_group;
4225
4226 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
4227 cache_block_group(block_group);
4228 wait_event(block_group->caching_q,
4229 block_group_cache_done(block_group));
4230
4231 ret = btrfs_remove_free_space(block_group, ins->objectid,
4232 ins->offset);
4233 BUG_ON(ret);
4234 btrfs_put_block_group(block_group);
4235 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
4236 0, owner, offset, ins, 1);
4237 return ret;
4238 }
4239
4240 /*
4241 * finds a free extent and does all the dirty work required for allocation
4242 * returns the key for the extent through ins, and a tree buffer for
4243 * the first block of the extent through buf.
4244 *
4245 * returns 0 if everything worked, non-zero otherwise.
4246 */
4247 static int alloc_tree_block(struct btrfs_trans_handle *trans,
4248 struct btrfs_root *root,
4249 u64 num_bytes, u64 parent, u64 root_objectid,
4250 struct btrfs_disk_key *key, int level,
4251 u64 empty_size, u64 hint_byte, u64 search_end,
4252 struct btrfs_key *ins)
4253 {
4254 int ret;
4255 u64 flags = 0;
4256
4257 ret = __btrfs_reserve_extent(trans, root, num_bytes, num_bytes,
4258 empty_size, hint_byte, search_end,
4259 ins, 0);
4260 if (ret)
4261 return ret;
4262
4263 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
4264 if (parent == 0)
4265 parent = ins->objectid;
4266 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
4267 } else
4268 BUG_ON(parent > 0);
4269
4270 update_reserved_extents(root, ins->objectid, ins->offset, 1);
4271 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
4272 struct btrfs_delayed_extent_op *extent_op;
4273 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
4274 BUG_ON(!extent_op);
4275 if (key)
4276 memcpy(&extent_op->key, key, sizeof(extent_op->key));
4277 else
4278 memset(&extent_op->key, 0, sizeof(extent_op->key));
4279 extent_op->flags_to_set = flags;
4280 extent_op->update_key = 1;
4281 extent_op->update_flags = 1;
4282 extent_op->is_data = 0;
4283
4284 ret = btrfs_add_delayed_tree_ref(trans, ins->objectid,
4285 ins->offset, parent, root_objectid,
4286 level, BTRFS_ADD_DELAYED_EXTENT,
4287 extent_op);
4288 BUG_ON(ret);
4289 }
4290 return ret;
4291 }
4292
4293 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
4294 struct btrfs_root *root,
4295 u64 bytenr, u32 blocksize,
4296 int level)
4297 {
4298 struct extent_buffer *buf;
4299
4300 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
4301 if (!buf)
4302 return ERR_PTR(-ENOMEM);
4303 btrfs_set_header_generation(buf, trans->transid);
4304 btrfs_set_buffer_lockdep_class(buf, level);
4305 btrfs_tree_lock(buf);
4306 clean_tree_block(trans, root, buf);
4307
4308 btrfs_set_lock_blocking(buf);
4309 btrfs_set_buffer_uptodate(buf);
4310
4311 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
4312 set_extent_dirty(&root->dirty_log_pages, buf->start,
4313 buf->start + buf->len - 1, GFP_NOFS);
4314 } else {
4315 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
4316 buf->start + buf->len - 1, GFP_NOFS);
4317 }
4318 trans->blocks_used++;
4319 /* this returns a buffer locked for blocking */
4320 return buf;
4321 }
4322
4323 /*
4324 * helper function to allocate a block for a given tree
4325 * returns the tree buffer or NULL.
4326 */
4327 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
4328 struct btrfs_root *root, u32 blocksize,
4329 u64 parent, u64 root_objectid,
4330 struct btrfs_disk_key *key, int level,
4331 u64 hint, u64 empty_size)
4332 {
4333 struct btrfs_key ins;
4334 int ret;
4335 struct extent_buffer *buf;
4336
4337 ret = alloc_tree_block(trans, root, blocksize, parent, root_objectid,
4338 key, level, empty_size, hint, (u64)-1, &ins);
4339 if (ret) {
4340 BUG_ON(ret > 0);
4341 return ERR_PTR(ret);
4342 }
4343
4344 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
4345 blocksize, level);
4346 return buf;
4347 }
4348
4349 #if 0
4350 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
4351 struct btrfs_root *root, struct extent_buffer *leaf)
4352 {
4353 u64 disk_bytenr;
4354 u64 num_bytes;
4355 struct btrfs_key key;
4356 struct btrfs_file_extent_item *fi;
4357 u32 nritems;
4358 int i;
4359 int ret;
4360
4361 BUG_ON(!btrfs_is_leaf(leaf));
4362 nritems = btrfs_header_nritems(leaf);
4363
4364 for (i = 0; i < nritems; i++) {
4365 cond_resched();
4366 btrfs_item_key_to_cpu(leaf, &key, i);
4367
4368 /* only extents have references, skip everything else */
4369 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
4370 continue;
4371
4372 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4373
4374 /* inline extents live in the btree, they don't have refs */
4375 if (btrfs_file_extent_type(leaf, fi) ==
4376 BTRFS_FILE_EXTENT_INLINE)
4377 continue;
4378
4379 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
4380
4381 /* holes don't have refs */
4382 if (disk_bytenr == 0)
4383 continue;
4384
4385 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
4386 ret = btrfs_free_extent(trans, root, disk_bytenr, num_bytes,
4387 leaf->start, 0, key.objectid, 0);
4388 BUG_ON(ret);
4389 }
4390 return 0;
4391 }
4392
4393 static noinline int cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
4394 struct btrfs_root *root,
4395 struct btrfs_leaf_ref *ref)
4396 {
4397 int i;
4398 int ret;
4399 struct btrfs_extent_info *info;
4400 struct refsort *sorted;
4401
4402 if (ref->nritems == 0)
4403 return 0;
4404
4405 sorted = kmalloc(sizeof(*sorted) * ref->nritems, GFP_NOFS);
4406 for (i = 0; i < ref->nritems; i++) {
4407 sorted[i].bytenr = ref->extents[i].bytenr;
4408 sorted[i].slot = i;
4409 }
4410 sort(sorted, ref->nritems, sizeof(struct refsort), refsort_cmp, NULL);
4411
4412 /*
4413 * the items in the ref were sorted when the ref was inserted
4414 * into the ref cache, so this is already in order
4415 */
4416 for (i = 0; i < ref->nritems; i++) {
4417 info = ref->extents + sorted[i].slot;
4418 ret = btrfs_free_extent(trans, root, info->bytenr,
4419 info->num_bytes, ref->bytenr,
4420 ref->owner, ref->generation,
4421 info->objectid, 0);
4422
4423 atomic_inc(&root->fs_info->throttle_gen);
4424 wake_up(&root->fs_info->transaction_throttle);
4425 cond_resched();
4426
4427 BUG_ON(ret);
4428 info++;
4429 }
4430
4431 kfree(sorted);
4432 return 0;
4433 }
4434
4435
4436 static int drop_snap_lookup_refcount(struct btrfs_trans_handle *trans,
4437 struct btrfs_root *root, u64 start,
4438 u64 len, u32 *refs)
4439 {
4440 int ret;
4441
4442 ret = btrfs_lookup_extent_refs(trans, root, start, len, refs);
4443 BUG_ON(ret);
4444
4445 #if 0 /* some debugging code in case we see problems here */
4446 /* if the refs count is one, it won't get increased again. But
4447 * if the ref count is > 1, someone may be decreasing it at
4448 * the same time we are.
4449 */
4450 if (*refs != 1) {
4451 struct extent_buffer *eb = NULL;
4452 eb = btrfs_find_create_tree_block(root, start, len);
4453 if (eb)
4454 btrfs_tree_lock(eb);
4455
4456 mutex_lock(&root->fs_info->alloc_mutex);
4457 ret = lookup_extent_ref(NULL, root, start, len, refs);
4458 BUG_ON(ret);
4459 mutex_unlock(&root->fs_info->alloc_mutex);
4460
4461 if (eb) {
4462 btrfs_tree_unlock(eb);
4463 free_extent_buffer(eb);
4464 }
4465 if (*refs == 1) {
4466 printk(KERN_ERR "btrfs block %llu went down to one "
4467 "during drop_snap\n", (unsigned long long)start);
4468 }
4469
4470 }
4471 #endif
4472
4473 cond_resched();
4474 return ret;
4475 }
4476
4477
4478 /*
4479 * this is used while deleting old snapshots, and it drops the refs
4480 * on a whole subtree starting from a level 1 node.
4481 *
4482 * The idea is to sort all the leaf pointers, and then drop the
4483 * ref on all the leaves in order. Most of the time the leaves
4484 * will have ref cache entries, so no leaf IOs will be required to
4485 * find the extents they have references on.
4486 *
4487 * For each leaf, any references it has are also dropped in order
4488 *
4489 * This ends up dropping the references in something close to optimal
4490 * order for reading and modifying the extent allocation tree.
4491 */
4492 static noinline int drop_level_one_refs(struct btrfs_trans_handle *trans,
4493 struct btrfs_root *root,
4494 struct btrfs_path *path)
4495 {
4496 u64 bytenr;
4497 u64 root_owner;
4498 u64 root_gen;
4499 struct extent_buffer *eb = path->nodes[1];
4500 struct extent_buffer *leaf;
4501 struct btrfs_leaf_ref *ref;
4502 struct refsort *sorted = NULL;
4503 int nritems = btrfs_header_nritems(eb);
4504 int ret;
4505 int i;
4506 int refi = 0;
4507 int slot = path->slots[1];
4508 u32 blocksize = btrfs_level_size(root, 0);
4509 u32 refs;
4510
4511 if (nritems == 0)
4512 goto out;
4513
4514 root_owner = btrfs_header_owner(eb);
4515 root_gen = btrfs_header_generation(eb);
4516 sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
4517
4518 /*
4519 * step one, sort all the leaf pointers so we don't scribble
4520 * randomly into the extent allocation tree
4521 */
4522 for (i = slot; i < nritems; i++) {
4523 sorted[refi].bytenr = btrfs_node_blockptr(eb, i);
4524 sorted[refi].slot = i;
4525 refi++;
4526 }
4527
4528 /*
4529 * nritems won't be zero, but if we're picking up drop_snapshot
4530 * after a crash, slot might be > 0, so double check things
4531 * just in case.
4532 */
4533 if (refi == 0)
4534 goto out;
4535
4536 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
4537
4538 /*
4539 * the first loop frees everything the leaves point to
4540 */
4541 for (i = 0; i < refi; i++) {
4542 u64 ptr_gen;
4543
4544 bytenr = sorted[i].bytenr;
4545
4546 /*
4547 * check the reference count on this leaf. If it is > 1
4548 * we just decrement it below and don't update any
4549 * of the refs the leaf points to.
4550 */
4551 ret = drop_snap_lookup_refcount(trans, root, bytenr,
4552 blocksize, &refs);
4553 BUG_ON(ret);
4554 if (refs != 1)
4555 continue;
4556
4557 ptr_gen = btrfs_node_ptr_generation(eb, sorted[i].slot);
4558
4559 /*
4560 * the leaf only had one reference, which means the
4561 * only thing pointing to this leaf is the snapshot
4562 * we're deleting. It isn't possible for the reference
4563 * count to increase again later
4564 *
4565 * The reference cache is checked for the leaf,
4566 * and if found we'll be able to drop any refs held by
4567 * the leaf without needing to read it in.
4568 */
4569 ref = btrfs_lookup_leaf_ref(root, bytenr);
4570 if (ref && ref->generation != ptr_gen) {
4571 btrfs_free_leaf_ref(root, ref);
4572 ref = NULL;
4573 }
4574 if (ref) {
4575 ret = cache_drop_leaf_ref(trans, root, ref);
4576 BUG_ON(ret);
4577 btrfs_remove_leaf_ref(root, ref);
4578 btrfs_free_leaf_ref(root, ref);
4579 } else {
4580 /*
4581 * the leaf wasn't in the reference cache, so
4582 * we have to read it.
4583 */
4584 leaf = read_tree_block(root, bytenr, blocksize,
4585 ptr_gen);
4586 ret = btrfs_drop_leaf_ref(trans, root, leaf);
4587 BUG_ON(ret);
4588 free_extent_buffer(leaf);
4589 }
4590 atomic_inc(&root->fs_info->throttle_gen);
4591 wake_up(&root->fs_info->transaction_throttle);
4592 cond_resched();
4593 }
4594
4595 /*
4596 * run through the loop again to free the refs on the leaves.
4597 * This is faster than doing it in the loop above because
4598 * the leaves are likely to be clustered together. We end up
4599 * working in nice chunks on the extent allocation tree.
4600 */
4601 for (i = 0; i < refi; i++) {
4602 bytenr = sorted[i].bytenr;
4603 ret = btrfs_free_extent(trans, root, bytenr,
4604 blocksize, eb->start,
4605 root_owner, root_gen, 0, 1);
4606 BUG_ON(ret);
4607
4608 atomic_inc(&root->fs_info->throttle_gen);
4609 wake_up(&root->fs_info->transaction_throttle);
4610 cond_resched();
4611 }
4612 out:
4613 kfree(sorted);
4614
4615 /*
4616 * update the path to show we've processed the entire level 1
4617 * node. This will get saved into the root's drop_snapshot_progress
4618 * field so these drops are not repeated again if this transaction
4619 * commits.
4620 */
4621 path->slots[1] = nritems;
4622 return 0;
4623 }
4624
4625 /*
4626 * helper function for drop_snapshot, this walks down the tree dropping ref
4627 * counts as it goes.
4628 */
4629 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
4630 struct btrfs_root *root,
4631 struct btrfs_path *path, int *level)
4632 {
4633 u64 root_owner;
4634 u64 root_gen;
4635 u64 bytenr;
4636 u64 ptr_gen;
4637 struct extent_buffer *next;
4638 struct extent_buffer *cur;
4639 struct extent_buffer *parent;
4640 u32 blocksize;
4641 int ret;
4642 u32 refs;
4643
4644 WARN_ON(*level < 0);
4645 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4646 ret = drop_snap_lookup_refcount(trans, root, path->nodes[*level]->start,
4647 path->nodes[*level]->len, &refs);
4648 BUG_ON(ret);
4649 if (refs > 1)
4650 goto out;
4651
4652 /*
4653 * walk down to the last node level and free all the leaves
4654 */
4655 while (*level >= 0) {
4656 WARN_ON(*level < 0);
4657 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4658 cur = path->nodes[*level];
4659
4660 if (btrfs_header_level(cur) != *level)
4661 WARN_ON(1);
4662
4663 if (path->slots[*level] >=
4664 btrfs_header_nritems(cur))
4665 break;
4666
4667 /* the new code goes down to level 1 and does all the
4668 * leaves pointed to that node in bulk. So, this check
4669 * for level 0 will always be false.
4670 *
4671 * But, the disk format allows the drop_snapshot_progress
4672 * field in the root to leave things in a state where
4673 * a leaf will need cleaning up here. If someone crashes
4674 * with the old code and then boots with the new code,
4675 * we might find a leaf here.
4676 */
4677 if (*level == 0) {
4678 ret = btrfs_drop_leaf_ref(trans, root, cur);
4679 BUG_ON(ret);
4680 break;
4681 }
4682
4683 /*
4684 * once we get to level one, process the whole node
4685 * at once, including everything below it.
4686 */
4687 if (*level == 1) {
4688 ret = drop_level_one_refs(trans, root, path);
4689 BUG_ON(ret);
4690 break;
4691 }
4692
4693 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
4694 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
4695 blocksize = btrfs_level_size(root, *level - 1);
4696
4697 ret = drop_snap_lookup_refcount(trans, root, bytenr,
4698 blocksize, &refs);
4699 BUG_ON(ret);
4700
4701 /*
4702 * if there is more than one reference, we don't need
4703 * to read that node to drop any references it has. We
4704 * just drop the ref we hold on that node and move on to the
4705 * next slot in this level.
4706 */
4707 if (refs != 1) {
4708 parent = path->nodes[*level];
4709 root_owner = btrfs_header_owner(parent);
4710 root_gen = btrfs_header_generation(parent);
4711 path->slots[*level]++;
4712
4713 ret = btrfs_free_extent(trans, root, bytenr,
4714 blocksize, parent->start,
4715 root_owner, root_gen,
4716 *level - 1, 1);
4717 BUG_ON(ret);
4718
4719 atomic_inc(&root->fs_info->throttle_gen);
4720 wake_up(&root->fs_info->transaction_throttle);
4721 cond_resched();
4722
4723 continue;
4724 }
4725
4726 /*
4727 * we need to keep freeing things in the next level down.
4728 * read the block and loop around to process it
4729 */
4730 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
4731 WARN_ON(*level <= 0);
4732 if (path->nodes[*level-1])
4733 free_extent_buffer(path->nodes[*level-1]);
4734 path->nodes[*level-1] = next;
4735 *level = btrfs_header_level(next);
4736 path->slots[*level] = 0;
4737 cond_resched();
4738 }
4739 out:
4740 WARN_ON(*level < 0);
4741 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4742
4743 if (path->nodes[*level] == root->node) {
4744 parent = path->nodes[*level];
4745 bytenr = path->nodes[*level]->start;
4746 } else {
4747 parent = path->nodes[*level + 1];
4748 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
4749 }
4750
4751 blocksize = btrfs_level_size(root, *level);
4752 root_owner = btrfs_header_owner(parent);
4753 root_gen = btrfs_header_generation(parent);
4754
4755 /*
4756 * cleanup and free the reference on the last node
4757 * we processed
4758 */
4759 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
4760 parent->start, root_owner, root_gen,
4761 *level, 1);
4762 free_extent_buffer(path->nodes[*level]);
4763 path->nodes[*level] = NULL;
4764
4765 *level += 1;
4766 BUG_ON(ret);
4767
4768 cond_resched();
4769 return 0;
4770 }
4771 #endif
4772
4773 struct walk_control {
4774 u64 refs[BTRFS_MAX_LEVEL];
4775 u64 flags[BTRFS_MAX_LEVEL];
4776 struct btrfs_key update_progress;
4777 int stage;
4778 int level;
4779 int shared_level;
4780 int update_ref;
4781 int keep_locks;
4782 };
4783
4784 #define DROP_REFERENCE 1
4785 #define UPDATE_BACKREF 2
4786
4787 /*
4788 * hepler to process tree block while walking down the tree.
4789 *
4790 * when wc->stage == DROP_REFERENCE, this function checks
4791 * reference count of the block. if the block is shared and
4792 * we need update back refs for the subtree rooted at the
4793 * block, this function changes wc->stage to UPDATE_BACKREF
4794 *
4795 * when wc->stage == UPDATE_BACKREF, this function updates
4796 * back refs for pointers in the block.
4797 *
4798 * NOTE: return value 1 means we should stop walking down.
4799 */
4800 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
4801 struct btrfs_root *root,
4802 struct btrfs_path *path,
4803 struct walk_control *wc)
4804 {
4805 int level = wc->level;
4806 struct extent_buffer *eb = path->nodes[level];
4807 struct btrfs_key key;
4808 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
4809 int ret;
4810
4811 if (wc->stage == UPDATE_BACKREF &&
4812 btrfs_header_owner(eb) != root->root_key.objectid)
4813 return 1;
4814
4815 /*
4816 * when reference count of tree block is 1, it won't increase
4817 * again. once full backref flag is set, we never clear it.
4818 */
4819 if ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
4820 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag))) {
4821 BUG_ON(!path->locks[level]);
4822 ret = btrfs_lookup_extent_info(trans, root,
4823 eb->start, eb->len,
4824 &wc->refs[level],
4825 &wc->flags[level]);
4826 BUG_ON(ret);
4827 BUG_ON(wc->refs[level] == 0);
4828 }
4829
4830 if (wc->stage == DROP_REFERENCE &&
4831 wc->update_ref && wc->refs[level] > 1) {
4832 BUG_ON(eb == root->node);
4833 BUG_ON(path->slots[level] > 0);
4834 if (level == 0)
4835 btrfs_item_key_to_cpu(eb, &key, path->slots[level]);
4836 else
4837 btrfs_node_key_to_cpu(eb, &key, path->slots[level]);
4838 if (btrfs_header_owner(eb) == root->root_key.objectid &&
4839 btrfs_comp_cpu_keys(&key, &wc->update_progress) >= 0) {
4840 wc->stage = UPDATE_BACKREF;
4841 wc->shared_level = level;
4842 }
4843 }
4844
4845 if (wc->stage == DROP_REFERENCE) {
4846 if (wc->refs[level] > 1)
4847 return 1;
4848
4849 if (path->locks[level] && !wc->keep_locks) {
4850 btrfs_tree_unlock(eb);
4851 path->locks[level] = 0;
4852 }
4853 return 0;
4854 }
4855
4856 /* wc->stage == UPDATE_BACKREF */
4857 if (!(wc->flags[level] & flag)) {
4858 BUG_ON(!path->locks[level]);
4859 ret = btrfs_inc_ref(trans, root, eb, 1);
4860 BUG_ON(ret);
4861 ret = btrfs_dec_ref(trans, root, eb, 0);
4862 BUG_ON(ret);
4863 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
4864 eb->len, flag, 0);
4865 BUG_ON(ret);
4866 wc->flags[level] |= flag;
4867 }
4868
4869 /*
4870 * the block is shared by multiple trees, so it's not good to
4871 * keep the tree lock
4872 */
4873 if (path->locks[level] && level > 0) {
4874 btrfs_tree_unlock(eb);
4875 path->locks[level] = 0;
4876 }
4877 return 0;
4878 }
4879
4880 /*
4881 * hepler to process tree block while walking up the tree.
4882 *
4883 * when wc->stage == DROP_REFERENCE, this function drops
4884 * reference count on the block.
4885 *
4886 * when wc->stage == UPDATE_BACKREF, this function changes
4887 * wc->stage back to DROP_REFERENCE if we changed wc->stage
4888 * to UPDATE_BACKREF previously while processing the block.
4889 *
4890 * NOTE: return value 1 means we should stop walking up.
4891 */
4892 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
4893 struct btrfs_root *root,
4894 struct btrfs_path *path,
4895 struct walk_control *wc)
4896 {
4897 int ret = 0;
4898 int level = wc->level;
4899 struct extent_buffer *eb = path->nodes[level];
4900 u64 parent = 0;
4901
4902 if (wc->stage == UPDATE_BACKREF) {
4903 BUG_ON(wc->shared_level < level);
4904 if (level < wc->shared_level)
4905 goto out;
4906
4907 BUG_ON(wc->refs[level] <= 1);
4908 ret = find_next_key(path, level + 1, &wc->update_progress);
4909 if (ret > 0)
4910 wc->update_ref = 0;
4911
4912 wc->stage = DROP_REFERENCE;
4913 wc->shared_level = -1;
4914 path->slots[level] = 0;
4915
4916 /*
4917 * check reference count again if the block isn't locked.
4918 * we should start walking down the tree again if reference
4919 * count is one.
4920 */
4921 if (!path->locks[level]) {
4922 BUG_ON(level == 0);
4923 btrfs_tree_lock(eb);
4924 btrfs_set_lock_blocking(eb);
4925 path->locks[level] = 1;
4926
4927 ret = btrfs_lookup_extent_info(trans, root,
4928 eb->start, eb->len,
4929 &wc->refs[level],
4930 &wc->flags[level]);
4931 BUG_ON(ret);
4932 BUG_ON(wc->refs[level] == 0);
4933 if (wc->refs[level] == 1) {
4934 btrfs_tree_unlock(eb);
4935 path->locks[level] = 0;
4936 return 1;
4937 }
4938 } else {
4939 BUG_ON(level != 0);
4940 }
4941 }
4942
4943 /* wc->stage == DROP_REFERENCE */
4944 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
4945
4946 if (wc->refs[level] == 1) {
4947 if (level == 0) {
4948 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4949 ret = btrfs_dec_ref(trans, root, eb, 1);
4950 else
4951 ret = btrfs_dec_ref(trans, root, eb, 0);
4952 BUG_ON(ret);
4953 }
4954 /* make block locked assertion in clean_tree_block happy */
4955 if (!path->locks[level] &&
4956 btrfs_header_generation(eb) == trans->transid) {
4957 btrfs_tree_lock(eb);
4958 btrfs_set_lock_blocking(eb);
4959 path->locks[level] = 1;
4960 }
4961 clean_tree_block(trans, root, eb);
4962 }
4963
4964 if (eb == root->node) {
4965 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4966 parent = eb->start;
4967 else
4968 BUG_ON(root->root_key.objectid !=
4969 btrfs_header_owner(eb));
4970 } else {
4971 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4972 parent = path->nodes[level + 1]->start;
4973 else
4974 BUG_ON(root->root_key.objectid !=
4975 btrfs_header_owner(path->nodes[level + 1]));
4976 }
4977
4978 ret = btrfs_free_extent(trans, root, eb->start, eb->len, parent,
4979 root->root_key.objectid, level, 0);
4980 BUG_ON(ret);
4981 out:
4982 wc->refs[level] = 0;
4983 wc->flags[level] = 0;
4984 return ret;
4985 }
4986
4987 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
4988 struct btrfs_root *root,
4989 struct btrfs_path *path,
4990 struct walk_control *wc)
4991 {
4992 struct extent_buffer *next;
4993 struct extent_buffer *cur;
4994 u64 bytenr;
4995 u64 ptr_gen;
4996 u32 blocksize;
4997 int level = wc->level;
4998 int ret;
4999
5000 while (level >= 0) {
5001 cur = path->nodes[level];
5002 BUG_ON(path->slots[level] >= btrfs_header_nritems(cur));
5003
5004 ret = walk_down_proc(trans, root, path, wc);
5005 if (ret > 0)
5006 break;
5007
5008 if (level == 0)
5009 break;
5010
5011 bytenr = btrfs_node_blockptr(cur, path->slots[level]);
5012 blocksize = btrfs_level_size(root, level - 1);
5013 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[level]);
5014
5015 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
5016 btrfs_tree_lock(next);
5017 btrfs_set_lock_blocking(next);
5018
5019 level--;
5020 BUG_ON(level != btrfs_header_level(next));
5021 path->nodes[level] = next;
5022 path->slots[level] = 0;
5023 path->locks[level] = 1;
5024 wc->level = level;
5025 }
5026 return 0;
5027 }
5028
5029 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
5030 struct btrfs_root *root,
5031 struct btrfs_path *path,
5032 struct walk_control *wc, int max_level)
5033 {
5034 int level = wc->level;
5035 int ret;
5036
5037 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
5038 while (level < max_level && path->nodes[level]) {
5039 wc->level = level;
5040 if (path->slots[level] + 1 <
5041 btrfs_header_nritems(path->nodes[level])) {
5042 path->slots[level]++;
5043 return 0;
5044 } else {
5045 ret = walk_up_proc(trans, root, path, wc);
5046 if (ret > 0)
5047 return 0;
5048
5049 if (path->locks[level]) {
5050 btrfs_tree_unlock(path->nodes[level]);
5051 path->locks[level] = 0;
5052 }
5053 free_extent_buffer(path->nodes[level]);
5054 path->nodes[level] = NULL;
5055 level++;
5056 }
5057 }
5058 return 1;
5059 }
5060
5061 /*
5062 * drop a subvolume tree.
5063 *
5064 * this function traverses the tree freeing any blocks that only
5065 * referenced by the tree.
5066 *
5067 * when a shared tree block is found. this function decreases its
5068 * reference count by one. if update_ref is true, this function
5069 * also make sure backrefs for the shared block and all lower level
5070 * blocks are properly updated.
5071 */
5072 int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref)
5073 {
5074 struct btrfs_path *path;
5075 struct btrfs_trans_handle *trans;
5076 struct btrfs_root *tree_root = root->fs_info->tree_root;
5077 struct btrfs_root_item *root_item = &root->root_item;
5078 struct walk_control *wc;
5079 struct btrfs_key key;
5080 int err = 0;
5081 int ret;
5082 int level;
5083
5084 path = btrfs_alloc_path();
5085 BUG_ON(!path);
5086
5087 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5088 BUG_ON(!wc);
5089
5090 trans = btrfs_start_transaction(tree_root, 1);
5091
5092 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
5093 level = btrfs_header_level(root->node);
5094 path->nodes[level] = btrfs_lock_root_node(root);
5095 btrfs_set_lock_blocking(path->nodes[level]);
5096 path->slots[level] = 0;
5097 path->locks[level] = 1;
5098 memset(&wc->update_progress, 0,
5099 sizeof(wc->update_progress));
5100 } else {
5101 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
5102 memcpy(&wc->update_progress, &key,
5103 sizeof(wc->update_progress));
5104
5105 level = root_item->drop_level;
5106 BUG_ON(level == 0);
5107 path->lowest_level = level;
5108 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5109 path->lowest_level = 0;
5110 if (ret < 0) {
5111 err = ret;
5112 goto out;
5113 }
5114 btrfs_node_key_to_cpu(path->nodes[level], &key,
5115 path->slots[level]);
5116 WARN_ON(memcmp(&key, &wc->update_progress, sizeof(key)));
5117
5118 /*
5119 * unlock our path, this is safe because only this
5120 * function is allowed to delete this snapshot
5121 */
5122 btrfs_unlock_up_safe(path, 0);
5123
5124 level = btrfs_header_level(root->node);
5125 while (1) {
5126 btrfs_tree_lock(path->nodes[level]);
5127 btrfs_set_lock_blocking(path->nodes[level]);
5128
5129 ret = btrfs_lookup_extent_info(trans, root,
5130 path->nodes[level]->start,
5131 path->nodes[level]->len,
5132 &wc->refs[level],
5133 &wc->flags[level]);
5134 BUG_ON(ret);
5135 BUG_ON(wc->refs[level] == 0);
5136
5137 if (level == root_item->drop_level)
5138 break;
5139
5140 btrfs_tree_unlock(path->nodes[level]);
5141 WARN_ON(wc->refs[level] != 1);
5142 level--;
5143 }
5144 }
5145
5146 wc->level = level;
5147 wc->shared_level = -1;
5148 wc->stage = DROP_REFERENCE;
5149 wc->update_ref = update_ref;
5150 wc->keep_locks = 0;
5151
5152 while (1) {
5153 ret = walk_down_tree(trans, root, path, wc);
5154 if (ret < 0) {
5155 err = ret;
5156 break;
5157 }
5158
5159 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
5160 if (ret < 0) {
5161 err = ret;
5162 break;
5163 }
5164
5165 if (ret > 0) {
5166 BUG_ON(wc->stage != DROP_REFERENCE);
5167 break;
5168 }
5169
5170 if (wc->stage == DROP_REFERENCE) {
5171 level = wc->level;
5172 btrfs_node_key(path->nodes[level],
5173 &root_item->drop_progress,
5174 path->slots[level]);
5175 root_item->drop_level = level;
5176 }
5177
5178 BUG_ON(wc->level == 0);
5179 if (trans->transaction->in_commit ||
5180 trans->transaction->delayed_refs.flushing) {
5181 ret = btrfs_update_root(trans, tree_root,
5182 &root->root_key,
5183 root_item);
5184 BUG_ON(ret);
5185
5186 btrfs_end_transaction(trans, tree_root);
5187 trans = btrfs_start_transaction(tree_root, 1);
5188 } else {
5189 unsigned long update;
5190 update = trans->delayed_ref_updates;
5191 trans->delayed_ref_updates = 0;
5192 if (update)
5193 btrfs_run_delayed_refs(trans, tree_root,
5194 update);
5195 }
5196 }
5197 btrfs_release_path(root, path);
5198 BUG_ON(err);
5199
5200 ret = btrfs_del_root(trans, tree_root, &root->root_key);
5201 BUG_ON(ret);
5202
5203 free_extent_buffer(root->node);
5204 free_extent_buffer(root->commit_root);
5205 kfree(root);
5206 out:
5207 btrfs_end_transaction(trans, tree_root);
5208 kfree(wc);
5209 btrfs_free_path(path);
5210 return err;
5211 }
5212
5213 /*
5214 * drop subtree rooted at tree block 'node'.
5215 *
5216 * NOTE: this function will unlock and release tree block 'node'
5217 */
5218 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
5219 struct btrfs_root *root,
5220 struct extent_buffer *node,
5221 struct extent_buffer *parent)
5222 {
5223 struct btrfs_path *path;
5224 struct walk_control *wc;
5225 int level;
5226 int parent_level;
5227 int ret = 0;
5228 int wret;
5229
5230 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5231
5232 path = btrfs_alloc_path();
5233 BUG_ON(!path);
5234
5235 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5236 BUG_ON(!wc);
5237
5238 btrfs_assert_tree_locked(parent);
5239 parent_level = btrfs_header_level(parent);
5240 extent_buffer_get(parent);
5241 path->nodes[parent_level] = parent;
5242 path->slots[parent_level] = btrfs_header_nritems(parent);
5243
5244 btrfs_assert_tree_locked(node);
5245 level = btrfs_header_level(node);
5246 path->nodes[level] = node;
5247 path->slots[level] = 0;
5248 path->locks[level] = 1;
5249
5250 wc->refs[parent_level] = 1;
5251 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5252 wc->level = level;
5253 wc->shared_level = -1;
5254 wc->stage = DROP_REFERENCE;
5255 wc->update_ref = 0;
5256 wc->keep_locks = 1;
5257
5258 while (1) {
5259 wret = walk_down_tree(trans, root, path, wc);
5260 if (wret < 0) {
5261 ret = wret;
5262 break;
5263 }
5264
5265 wret = walk_up_tree(trans, root, path, wc, parent_level);
5266 if (wret < 0)
5267 ret = wret;
5268 if (wret != 0)
5269 break;
5270 }
5271
5272 kfree(wc);
5273 btrfs_free_path(path);
5274 return ret;
5275 }
5276
5277 #if 0
5278 static unsigned long calc_ra(unsigned long start, unsigned long last,
5279 unsigned long nr)
5280 {
5281 return min(last, start + nr - 1);
5282 }
5283
5284 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
5285 u64 len)
5286 {
5287 u64 page_start;
5288 u64 page_end;
5289 unsigned long first_index;
5290 unsigned long last_index;
5291 unsigned long i;
5292 struct page *page;
5293 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5294 struct file_ra_state *ra;
5295 struct btrfs_ordered_extent *ordered;
5296 unsigned int total_read = 0;
5297 unsigned int total_dirty = 0;
5298 int ret = 0;
5299
5300 ra = kzalloc(sizeof(*ra), GFP_NOFS);
5301
5302 mutex_lock(&inode->i_mutex);
5303 first_index = start >> PAGE_CACHE_SHIFT;
5304 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
5305
5306 /* make sure the dirty trick played by the caller work */
5307 ret = invalidate_inode_pages2_range(inode->i_mapping,
5308 first_index, last_index);
5309 if (ret)
5310 goto out_unlock;
5311
5312 file_ra_state_init(ra, inode->i_mapping);
5313
5314 for (i = first_index ; i <= last_index; i++) {
5315 if (total_read % ra->ra_pages == 0) {
5316 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
5317 calc_ra(i, last_index, ra->ra_pages));
5318 }
5319 total_read++;
5320 again:
5321 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
5322 BUG_ON(1);
5323 page = grab_cache_page(inode->i_mapping, i);
5324 if (!page) {
5325 ret = -ENOMEM;
5326 goto out_unlock;
5327 }
5328 if (!PageUptodate(page)) {
5329 btrfs_readpage(NULL, page);
5330 lock_page(page);
5331 if (!PageUptodate(page)) {
5332 unlock_page(page);
5333 page_cache_release(page);
5334 ret = -EIO;
5335 goto out_unlock;
5336 }
5337 }
5338 wait_on_page_writeback(page);
5339
5340 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
5341 page_end = page_start + PAGE_CACHE_SIZE - 1;
5342 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
5343
5344 ordered = btrfs_lookup_ordered_extent(inode, page_start);
5345 if (ordered) {
5346 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5347 unlock_page(page);
5348 page_cache_release(page);
5349 btrfs_start_ordered_extent(inode, ordered, 1);
5350 btrfs_put_ordered_extent(ordered);
5351 goto again;
5352 }
5353 set_page_extent_mapped(page);
5354
5355 if (i == first_index)
5356 set_extent_bits(io_tree, page_start, page_end,
5357 EXTENT_BOUNDARY, GFP_NOFS);
5358 btrfs_set_extent_delalloc(inode, page_start, page_end);
5359
5360 set_page_dirty(page);
5361 total_dirty++;
5362
5363 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5364 unlock_page(page);
5365 page_cache_release(page);
5366 }
5367
5368 out_unlock:
5369 kfree(ra);
5370 mutex_unlock(&inode->i_mutex);
5371 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
5372 return ret;
5373 }
5374
5375 static noinline int relocate_data_extent(struct inode *reloc_inode,
5376 struct btrfs_key *extent_key,
5377 u64 offset)
5378 {
5379 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5380 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
5381 struct extent_map *em;
5382 u64 start = extent_key->objectid - offset;
5383 u64 end = start + extent_key->offset - 1;
5384
5385 em = alloc_extent_map(GFP_NOFS);
5386 BUG_ON(!em || IS_ERR(em));
5387
5388 em->start = start;
5389 em->len = extent_key->offset;
5390 em->block_len = extent_key->offset;
5391 em->block_start = extent_key->objectid;
5392 em->bdev = root->fs_info->fs_devices->latest_bdev;
5393 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5394
5395 /* setup extent map to cheat btrfs_readpage */
5396 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5397 while (1) {
5398 int ret;
5399 spin_lock(&em_tree->lock);
5400 ret = add_extent_mapping(em_tree, em);
5401 spin_unlock(&em_tree->lock);
5402 if (ret != -EEXIST) {
5403 free_extent_map(em);
5404 break;
5405 }
5406 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
5407 }
5408 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5409
5410 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
5411 }
5412
5413 struct btrfs_ref_path {
5414 u64 extent_start;
5415 u64 nodes[BTRFS_MAX_LEVEL];
5416 u64 root_objectid;
5417 u64 root_generation;
5418 u64 owner_objectid;
5419 u32 num_refs;
5420 int lowest_level;
5421 int current_level;
5422 int shared_level;
5423
5424 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
5425 u64 new_nodes[BTRFS_MAX_LEVEL];
5426 };
5427
5428 struct disk_extent {
5429 u64 ram_bytes;
5430 u64 disk_bytenr;
5431 u64 disk_num_bytes;
5432 u64 offset;
5433 u64 num_bytes;
5434 u8 compression;
5435 u8 encryption;
5436 u16 other_encoding;
5437 };
5438
5439 static int is_cowonly_root(u64 root_objectid)
5440 {
5441 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
5442 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
5443 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
5444 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
5445 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
5446 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
5447 return 1;
5448 return 0;
5449 }
5450
5451 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
5452 struct btrfs_root *extent_root,
5453 struct btrfs_ref_path *ref_path,
5454 int first_time)
5455 {
5456 struct extent_buffer *leaf;
5457 struct btrfs_path *path;
5458 struct btrfs_extent_ref *ref;
5459 struct btrfs_key key;
5460 struct btrfs_key found_key;
5461 u64 bytenr;
5462 u32 nritems;
5463 int level;
5464 int ret = 1;
5465
5466 path = btrfs_alloc_path();
5467 if (!path)
5468 return -ENOMEM;
5469
5470 if (first_time) {
5471 ref_path->lowest_level = -1;
5472 ref_path->current_level = -1;
5473 ref_path->shared_level = -1;
5474 goto walk_up;
5475 }
5476 walk_down:
5477 level = ref_path->current_level - 1;
5478 while (level >= -1) {
5479 u64 parent;
5480 if (level < ref_path->lowest_level)
5481 break;
5482
5483 if (level >= 0)
5484 bytenr = ref_path->nodes[level];
5485 else
5486 bytenr = ref_path->extent_start;
5487 BUG_ON(bytenr == 0);
5488
5489 parent = ref_path->nodes[level + 1];
5490 ref_path->nodes[level + 1] = 0;
5491 ref_path->current_level = level;
5492 BUG_ON(parent == 0);
5493
5494 key.objectid = bytenr;
5495 key.offset = parent + 1;
5496 key.type = BTRFS_EXTENT_REF_KEY;
5497
5498 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5499 if (ret < 0)
5500 goto out;
5501 BUG_ON(ret == 0);
5502
5503 leaf = path->nodes[0];
5504 nritems = btrfs_header_nritems(leaf);
5505 if (path->slots[0] >= nritems) {
5506 ret = btrfs_next_leaf(extent_root, path);
5507 if (ret < 0)
5508 goto out;
5509 if (ret > 0)
5510 goto next;
5511 leaf = path->nodes[0];
5512 }
5513
5514 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5515 if (found_key.objectid == bytenr &&
5516 found_key.type == BTRFS_EXTENT_REF_KEY) {
5517 if (level < ref_path->shared_level)
5518 ref_path->shared_level = level;
5519 goto found;
5520 }
5521 next:
5522 level--;
5523 btrfs_release_path(extent_root, path);
5524 cond_resched();
5525 }
5526 /* reached lowest level */
5527 ret = 1;
5528 goto out;
5529 walk_up:
5530 level = ref_path->current_level;
5531 while (level < BTRFS_MAX_LEVEL - 1) {
5532 u64 ref_objectid;
5533
5534 if (level >= 0)
5535 bytenr = ref_path->nodes[level];
5536 else
5537 bytenr = ref_path->extent_start;
5538
5539 BUG_ON(bytenr == 0);
5540
5541 key.objectid = bytenr;
5542 key.offset = 0;
5543 key.type = BTRFS_EXTENT_REF_KEY;
5544
5545 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5546 if (ret < 0)
5547 goto out;
5548
5549 leaf = path->nodes[0];
5550 nritems = btrfs_header_nritems(leaf);
5551 if (path->slots[0] >= nritems) {
5552 ret = btrfs_next_leaf(extent_root, path);
5553 if (ret < 0)
5554 goto out;
5555 if (ret > 0) {
5556 /* the extent was freed by someone */
5557 if (ref_path->lowest_level == level)
5558 goto out;
5559 btrfs_release_path(extent_root, path);
5560 goto walk_down;
5561 }
5562 leaf = path->nodes[0];
5563 }
5564
5565 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5566 if (found_key.objectid != bytenr ||
5567 found_key.type != BTRFS_EXTENT_REF_KEY) {
5568 /* the extent was freed by someone */
5569 if (ref_path->lowest_level == level) {
5570 ret = 1;
5571 goto out;
5572 }
5573 btrfs_release_path(extent_root, path);
5574 goto walk_down;
5575 }
5576 found:
5577 ref = btrfs_item_ptr(leaf, path->slots[0],
5578 struct btrfs_extent_ref);
5579 ref_objectid = btrfs_ref_objectid(leaf, ref);
5580 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
5581 if (first_time) {
5582 level = (int)ref_objectid;
5583 BUG_ON(level >= BTRFS_MAX_LEVEL);
5584 ref_path->lowest_level = level;
5585 ref_path->current_level = level;
5586 ref_path->nodes[level] = bytenr;
5587 } else {
5588 WARN_ON(ref_objectid != level);
5589 }
5590 } else {
5591 WARN_ON(level != -1);
5592 }
5593 first_time = 0;
5594
5595 if (ref_path->lowest_level == level) {
5596 ref_path->owner_objectid = ref_objectid;
5597 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
5598 }
5599
5600 /*
5601 * the block is tree root or the block isn't in reference
5602 * counted tree.
5603 */
5604 if (found_key.objectid == found_key.offset ||
5605 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
5606 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5607 ref_path->root_generation =
5608 btrfs_ref_generation(leaf, ref);
5609 if (level < 0) {
5610 /* special reference from the tree log */
5611 ref_path->nodes[0] = found_key.offset;
5612 ref_path->current_level = 0;
5613 }
5614 ret = 0;
5615 goto out;
5616 }
5617
5618 level++;
5619 BUG_ON(ref_path->nodes[level] != 0);
5620 ref_path->nodes[level] = found_key.offset;
5621 ref_path->current_level = level;
5622
5623 /*
5624 * the reference was created in the running transaction,
5625 * no need to continue walking up.
5626 */
5627 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
5628 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5629 ref_path->root_generation =
5630 btrfs_ref_generation(leaf, ref);
5631 ret = 0;
5632 goto out;
5633 }
5634
5635 btrfs_release_path(extent_root, path);
5636 cond_resched();
5637 }
5638 /* reached max tree level, but no tree root found. */
5639 BUG();
5640 out:
5641 btrfs_free_path(path);
5642 return ret;
5643 }
5644
5645 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
5646 struct btrfs_root *extent_root,
5647 struct btrfs_ref_path *ref_path,
5648 u64 extent_start)
5649 {
5650 memset(ref_path, 0, sizeof(*ref_path));
5651 ref_path->extent_start = extent_start;
5652
5653 return __next_ref_path(trans, extent_root, ref_path, 1);
5654 }
5655
5656 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
5657 struct btrfs_root *extent_root,
5658 struct btrfs_ref_path *ref_path)
5659 {
5660 return __next_ref_path(trans, extent_root, ref_path, 0);
5661 }
5662
5663 static noinline int get_new_locations(struct inode *reloc_inode,
5664 struct btrfs_key *extent_key,
5665 u64 offset, int no_fragment,
5666 struct disk_extent **extents,
5667 int *nr_extents)
5668 {
5669 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5670 struct btrfs_path *path;
5671 struct btrfs_file_extent_item *fi;
5672 struct extent_buffer *leaf;
5673 struct disk_extent *exts = *extents;
5674 struct btrfs_key found_key;
5675 u64 cur_pos;
5676 u64 last_byte;
5677 u32 nritems;
5678 int nr = 0;
5679 int max = *nr_extents;
5680 int ret;
5681
5682 WARN_ON(!no_fragment && *extents);
5683 if (!exts) {
5684 max = 1;
5685 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
5686 if (!exts)
5687 return -ENOMEM;
5688 }
5689
5690 path = btrfs_alloc_path();
5691 BUG_ON(!path);
5692
5693 cur_pos = extent_key->objectid - offset;
5694 last_byte = extent_key->objectid + extent_key->offset;
5695 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
5696 cur_pos, 0);
5697 if (ret < 0)
5698 goto out;
5699 if (ret > 0) {
5700 ret = -ENOENT;
5701 goto out;
5702 }
5703
5704 while (1) {
5705 leaf = path->nodes[0];
5706 nritems = btrfs_header_nritems(leaf);
5707 if (path->slots[0] >= nritems) {
5708 ret = btrfs_next_leaf(root, path);
5709 if (ret < 0)
5710 goto out;
5711 if (ret > 0)
5712 break;
5713 leaf = path->nodes[0];
5714 }
5715
5716 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5717 if (found_key.offset != cur_pos ||
5718 found_key.type != BTRFS_EXTENT_DATA_KEY ||
5719 found_key.objectid != reloc_inode->i_ino)
5720 break;
5721
5722 fi = btrfs_item_ptr(leaf, path->slots[0],
5723 struct btrfs_file_extent_item);
5724 if (btrfs_file_extent_type(leaf, fi) !=
5725 BTRFS_FILE_EXTENT_REG ||
5726 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
5727 break;
5728
5729 if (nr == max) {
5730 struct disk_extent *old = exts;
5731 max *= 2;
5732 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
5733 memcpy(exts, old, sizeof(*exts) * nr);
5734 if (old != *extents)
5735 kfree(old);
5736 }
5737
5738 exts[nr].disk_bytenr =
5739 btrfs_file_extent_disk_bytenr(leaf, fi);
5740 exts[nr].disk_num_bytes =
5741 btrfs_file_extent_disk_num_bytes(leaf, fi);
5742 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
5743 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5744 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
5745 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
5746 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
5747 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
5748 fi);
5749 BUG_ON(exts[nr].offset > 0);
5750 BUG_ON(exts[nr].compression || exts[nr].encryption);
5751 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
5752
5753 cur_pos += exts[nr].num_bytes;
5754 nr++;
5755
5756 if (cur_pos + offset >= last_byte)
5757 break;
5758
5759 if (no_fragment) {
5760 ret = 1;
5761 goto out;
5762 }
5763 path->slots[0]++;
5764 }
5765
5766 BUG_ON(cur_pos + offset > last_byte);
5767 if (cur_pos + offset < last_byte) {
5768 ret = -ENOENT;
5769 goto out;
5770 }
5771 ret = 0;
5772 out:
5773 btrfs_free_path(path);
5774 if (ret) {
5775 if (exts != *extents)
5776 kfree(exts);
5777 } else {
5778 *extents = exts;
5779 *nr_extents = nr;
5780 }
5781 return ret;
5782 }
5783
5784 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
5785 struct btrfs_root *root,
5786 struct btrfs_path *path,
5787 struct btrfs_key *extent_key,
5788 struct btrfs_key *leaf_key,
5789 struct btrfs_ref_path *ref_path,
5790 struct disk_extent *new_extents,
5791 int nr_extents)
5792 {
5793 struct extent_buffer *leaf;
5794 struct btrfs_file_extent_item *fi;
5795 struct inode *inode = NULL;
5796 struct btrfs_key key;
5797 u64 lock_start = 0;
5798 u64 lock_end = 0;
5799 u64 num_bytes;
5800 u64 ext_offset;
5801 u64 search_end = (u64)-1;
5802 u32 nritems;
5803 int nr_scaned = 0;
5804 int extent_locked = 0;
5805 int extent_type;
5806 int ret;
5807
5808 memcpy(&key, leaf_key, sizeof(key));
5809 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
5810 if (key.objectid < ref_path->owner_objectid ||
5811 (key.objectid == ref_path->owner_objectid &&
5812 key.type < BTRFS_EXTENT_DATA_KEY)) {
5813 key.objectid = ref_path->owner_objectid;
5814 key.type = BTRFS_EXTENT_DATA_KEY;
5815 key.offset = 0;
5816 }
5817 }
5818
5819 while (1) {
5820 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
5821 if (ret < 0)
5822 goto out;
5823
5824 leaf = path->nodes[0];
5825 nritems = btrfs_header_nritems(leaf);
5826 next:
5827 if (extent_locked && ret > 0) {
5828 /*
5829 * the file extent item was modified by someone
5830 * before the extent got locked.
5831 */
5832 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5833 lock_end, GFP_NOFS);
5834 extent_locked = 0;
5835 }
5836
5837 if (path->slots[0] >= nritems) {
5838 if (++nr_scaned > 2)
5839 break;
5840
5841 BUG_ON(extent_locked);
5842 ret = btrfs_next_leaf(root, path);
5843 if (ret < 0)
5844 goto out;
5845 if (ret > 0)
5846 break;
5847 leaf = path->nodes[0];
5848 nritems = btrfs_header_nritems(leaf);
5849 }
5850
5851 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
5852
5853 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
5854 if ((key.objectid > ref_path->owner_objectid) ||
5855 (key.objectid == ref_path->owner_objectid &&
5856 key.type > BTRFS_EXTENT_DATA_KEY) ||
5857 key.offset >= search_end)
5858 break;
5859 }
5860
5861 if (inode && key.objectid != inode->i_ino) {
5862 BUG_ON(extent_locked);
5863 btrfs_release_path(root, path);
5864 mutex_unlock(&inode->i_mutex);
5865 iput(inode);
5866 inode = NULL;
5867 continue;
5868 }
5869
5870 if (key.type != BTRFS_EXTENT_DATA_KEY) {
5871 path->slots[0]++;
5872 ret = 1;
5873 goto next;
5874 }
5875 fi = btrfs_item_ptr(leaf, path->slots[0],
5876 struct btrfs_file_extent_item);
5877 extent_type = btrfs_file_extent_type(leaf, fi);
5878 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
5879 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
5880 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
5881 extent_key->objectid)) {
5882 path->slots[0]++;
5883 ret = 1;
5884 goto next;
5885 }
5886
5887 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5888 ext_offset = btrfs_file_extent_offset(leaf, fi);
5889
5890 if (search_end == (u64)-1) {
5891 search_end = key.offset - ext_offset +
5892 btrfs_file_extent_ram_bytes(leaf, fi);
5893 }
5894
5895 if (!extent_locked) {
5896 lock_start = key.offset;
5897 lock_end = lock_start + num_bytes - 1;
5898 } else {
5899 if (lock_start > key.offset ||
5900 lock_end + 1 < key.offset + num_bytes) {
5901 unlock_extent(&BTRFS_I(inode)->io_tree,
5902 lock_start, lock_end, GFP_NOFS);
5903 extent_locked = 0;
5904 }
5905 }
5906
5907 if (!inode) {
5908 btrfs_release_path(root, path);
5909
5910 inode = btrfs_iget_locked(root->fs_info->sb,
5911 key.objectid, root);
5912 if (inode->i_state & I_NEW) {
5913 BTRFS_I(inode)->root = root;
5914 BTRFS_I(inode)->location.objectid =
5915 key.objectid;
5916 BTRFS_I(inode)->location.type =
5917 BTRFS_INODE_ITEM_KEY;
5918 BTRFS_I(inode)->location.offset = 0;
5919 btrfs_read_locked_inode(inode);
5920 unlock_new_inode(inode);
5921 }
5922 /*
5923 * some code call btrfs_commit_transaction while
5924 * holding the i_mutex, so we can't use mutex_lock
5925 * here.
5926 */
5927 if (is_bad_inode(inode) ||
5928 !mutex_trylock(&inode->i_mutex)) {
5929 iput(inode);
5930 inode = NULL;
5931 key.offset = (u64)-1;
5932 goto skip;
5933 }
5934 }
5935
5936 if (!extent_locked) {
5937 struct btrfs_ordered_extent *ordered;
5938
5939 btrfs_release_path(root, path);
5940
5941 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5942 lock_end, GFP_NOFS);
5943 ordered = btrfs_lookup_first_ordered_extent(inode,
5944 lock_end);
5945 if (ordered &&
5946 ordered->file_offset <= lock_end &&
5947 ordered->file_offset + ordered->len > lock_start) {
5948 unlock_extent(&BTRFS_I(inode)->io_tree,
5949 lock_start, lock_end, GFP_NOFS);
5950 btrfs_start_ordered_extent(inode, ordered, 1);
5951 btrfs_put_ordered_extent(ordered);
5952 key.offset += num_bytes;
5953 goto skip;
5954 }
5955 if (ordered)
5956 btrfs_put_ordered_extent(ordered);
5957
5958 extent_locked = 1;
5959 continue;
5960 }
5961
5962 if (nr_extents == 1) {
5963 /* update extent pointer in place */
5964 btrfs_set_file_extent_disk_bytenr(leaf, fi,
5965 new_extents[0].disk_bytenr);
5966 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
5967 new_extents[0].disk_num_bytes);
5968 btrfs_mark_buffer_dirty(leaf);
5969
5970 btrfs_drop_extent_cache(inode, key.offset,
5971 key.offset + num_bytes - 1, 0);
5972
5973 ret = btrfs_inc_extent_ref(trans, root,
5974 new_extents[0].disk_bytenr,
5975 new_extents[0].disk_num_bytes,
5976 leaf->start,
5977 root->root_key.objectid,
5978 trans->transid,
5979 key.objectid);
5980 BUG_ON(ret);
5981
5982 ret = btrfs_free_extent(trans, root,
5983 extent_key->objectid,
5984 extent_key->offset,
5985 leaf->start,
5986 btrfs_header_owner(leaf),
5987 btrfs_header_generation(leaf),
5988 key.objectid, 0);
5989 BUG_ON(ret);
5990
5991 btrfs_release_path(root, path);
5992 key.offset += num_bytes;
5993 } else {
5994 BUG_ON(1);
5995 #if 0
5996 u64 alloc_hint;
5997 u64 extent_len;
5998 int i;
5999 /*
6000 * drop old extent pointer at first, then insert the
6001 * new pointers one bye one
6002 */
6003 btrfs_release_path(root, path);
6004 ret = btrfs_drop_extents(trans, root, inode, key.offset,
6005 key.offset + num_bytes,
6006 key.offset, &alloc_hint);
6007 BUG_ON(ret);
6008
6009 for (i = 0; i < nr_extents; i++) {
6010 if (ext_offset >= new_extents[i].num_bytes) {
6011 ext_offset -= new_extents[i].num_bytes;
6012 continue;
6013 }
6014 extent_len = min(new_extents[i].num_bytes -
6015 ext_offset, num_bytes);
6016
6017 ret = btrfs_insert_empty_item(trans, root,
6018 path, &key,
6019 sizeof(*fi));
6020 BUG_ON(ret);
6021
6022 leaf = path->nodes[0];
6023 fi = btrfs_item_ptr(leaf, path->slots[0],
6024 struct btrfs_file_extent_item);
6025 btrfs_set_file_extent_generation(leaf, fi,
6026 trans->transid);
6027 btrfs_set_file_extent_type(leaf, fi,
6028 BTRFS_FILE_EXTENT_REG);
6029 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6030 new_extents[i].disk_bytenr);
6031 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6032 new_extents[i].disk_num_bytes);
6033 btrfs_set_file_extent_ram_bytes(leaf, fi,
6034 new_extents[i].ram_bytes);
6035
6036 btrfs_set_file_extent_compression(leaf, fi,
6037 new_extents[i].compression);
6038 btrfs_set_file_extent_encryption(leaf, fi,
6039 new_extents[i].encryption);
6040 btrfs_set_file_extent_other_encoding(leaf, fi,
6041 new_extents[i].other_encoding);
6042
6043 btrfs_set_file_extent_num_bytes(leaf, fi,
6044 extent_len);
6045 ext_offset += new_extents[i].offset;
6046 btrfs_set_file_extent_offset(leaf, fi,
6047 ext_offset);
6048 btrfs_mark_buffer_dirty(leaf);
6049
6050 btrfs_drop_extent_cache(inode, key.offset,
6051 key.offset + extent_len - 1, 0);
6052
6053 ret = btrfs_inc_extent_ref(trans, root,
6054 new_extents[i].disk_bytenr,
6055 new_extents[i].disk_num_bytes,
6056 leaf->start,
6057 root->root_key.objectid,
6058 trans->transid, key.objectid);
6059 BUG_ON(ret);
6060 btrfs_release_path(root, path);
6061
6062 inode_add_bytes(inode, extent_len);
6063
6064 ext_offset = 0;
6065 num_bytes -= extent_len;
6066 key.offset += extent_len;
6067
6068 if (num_bytes == 0)
6069 break;
6070 }
6071 BUG_ON(i >= nr_extents);
6072 #endif
6073 }
6074
6075 if (extent_locked) {
6076 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6077 lock_end, GFP_NOFS);
6078 extent_locked = 0;
6079 }
6080 skip:
6081 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
6082 key.offset >= search_end)
6083 break;
6084
6085 cond_resched();
6086 }
6087 ret = 0;
6088 out:
6089 btrfs_release_path(root, path);
6090 if (inode) {
6091 mutex_unlock(&inode->i_mutex);
6092 if (extent_locked) {
6093 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
6094 lock_end, GFP_NOFS);
6095 }
6096 iput(inode);
6097 }
6098 return ret;
6099 }
6100
6101 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
6102 struct btrfs_root *root,
6103 struct extent_buffer *buf, u64 orig_start)
6104 {
6105 int level;
6106 int ret;
6107
6108 BUG_ON(btrfs_header_generation(buf) != trans->transid);
6109 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
6110
6111 level = btrfs_header_level(buf);
6112 if (level == 0) {
6113 struct btrfs_leaf_ref *ref;
6114 struct btrfs_leaf_ref *orig_ref;
6115
6116 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
6117 if (!orig_ref)
6118 return -ENOENT;
6119
6120 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
6121 if (!ref) {
6122 btrfs_free_leaf_ref(root, orig_ref);
6123 return -ENOMEM;
6124 }
6125
6126 ref->nritems = orig_ref->nritems;
6127 memcpy(ref->extents, orig_ref->extents,
6128 sizeof(ref->extents[0]) * ref->nritems);
6129
6130 btrfs_free_leaf_ref(root, orig_ref);
6131
6132 ref->root_gen = trans->transid;
6133 ref->bytenr = buf->start;
6134 ref->owner = btrfs_header_owner(buf);
6135 ref->generation = btrfs_header_generation(buf);
6136
6137 ret = btrfs_add_leaf_ref(root, ref, 0);
6138 WARN_ON(ret);
6139 btrfs_free_leaf_ref(root, ref);
6140 }
6141 return 0;
6142 }
6143
6144 static noinline int invalidate_extent_cache(struct btrfs_root *root,
6145 struct extent_buffer *leaf,
6146 struct btrfs_block_group_cache *group,
6147 struct btrfs_root *target_root)
6148 {
6149 struct btrfs_key key;
6150 struct inode *inode = NULL;
6151 struct btrfs_file_extent_item *fi;
6152 u64 num_bytes;
6153 u64 skip_objectid = 0;
6154 u32 nritems;
6155 u32 i;
6156
6157 nritems = btrfs_header_nritems(leaf);
6158 for (i = 0; i < nritems; i++) {
6159 btrfs_item_key_to_cpu(leaf, &key, i);
6160 if (key.objectid == skip_objectid ||
6161 key.type != BTRFS_EXTENT_DATA_KEY)
6162 continue;
6163 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6164 if (btrfs_file_extent_type(leaf, fi) ==
6165 BTRFS_FILE_EXTENT_INLINE)
6166 continue;
6167 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
6168 continue;
6169 if (!inode || inode->i_ino != key.objectid) {
6170 iput(inode);
6171 inode = btrfs_ilookup(target_root->fs_info->sb,
6172 key.objectid, target_root, 1);
6173 }
6174 if (!inode) {
6175 skip_objectid = key.objectid;
6176 continue;
6177 }
6178 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
6179
6180 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
6181 key.offset + num_bytes - 1, GFP_NOFS);
6182 btrfs_drop_extent_cache(inode, key.offset,
6183 key.offset + num_bytes - 1, 1);
6184 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
6185 key.offset + num_bytes - 1, GFP_NOFS);
6186 cond_resched();
6187 }
6188 iput(inode);
6189 return 0;
6190 }
6191
6192 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
6193 struct btrfs_root *root,
6194 struct extent_buffer *leaf,
6195 struct btrfs_block_group_cache *group,
6196 struct inode *reloc_inode)
6197 {
6198 struct btrfs_key key;
6199 struct btrfs_key extent_key;
6200 struct btrfs_file_extent_item *fi;
6201 struct btrfs_leaf_ref *ref;
6202 struct disk_extent *new_extent;
6203 u64 bytenr;
6204 u64 num_bytes;
6205 u32 nritems;
6206 u32 i;
6207 int ext_index;
6208 int nr_extent;
6209 int ret;
6210
6211 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
6212 BUG_ON(!new_extent);
6213
6214 ref = btrfs_lookup_leaf_ref(root, leaf->start);
6215 BUG_ON(!ref);
6216
6217 ext_index = -1;
6218 nritems = btrfs_header_nritems(leaf);
6219 for (i = 0; i < nritems; i++) {
6220 btrfs_item_key_to_cpu(leaf, &key, i);
6221 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
6222 continue;
6223 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6224 if (btrfs_file_extent_type(leaf, fi) ==
6225 BTRFS_FILE_EXTENT_INLINE)
6226 continue;
6227 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6228 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
6229 if (bytenr == 0)
6230 continue;
6231
6232 ext_index++;
6233 if (bytenr >= group->key.objectid + group->key.offset ||
6234 bytenr + num_bytes <= group->key.objectid)
6235 continue;
6236
6237 extent_key.objectid = bytenr;
6238 extent_key.offset = num_bytes;
6239 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
6240 nr_extent = 1;
6241 ret = get_new_locations(reloc_inode, &extent_key,
6242 group->key.objectid, 1,
6243 &new_extent, &nr_extent);
6244 if (ret > 0)
6245 continue;
6246 BUG_ON(ret < 0);
6247
6248 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
6249 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
6250 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
6251 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
6252
6253 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6254 new_extent->disk_bytenr);
6255 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6256 new_extent->disk_num_bytes);
6257 btrfs_mark_buffer_dirty(leaf);
6258
6259 ret = btrfs_inc_extent_ref(trans, root,
6260 new_extent->disk_bytenr,
6261 new_extent->disk_num_bytes,
6262 leaf->start,
6263 root->root_key.objectid,
6264 trans->transid, key.objectid);
6265 BUG_ON(ret);
6266
6267 ret = btrfs_free_extent(trans, root,
6268 bytenr, num_bytes, leaf->start,
6269 btrfs_header_owner(leaf),
6270 btrfs_header_generation(leaf),
6271 key.objectid, 0);
6272 BUG_ON(ret);
6273 cond_resched();
6274 }
6275 kfree(new_extent);
6276 BUG_ON(ext_index + 1 != ref->nritems);
6277 btrfs_free_leaf_ref(root, ref);
6278 return 0;
6279 }
6280
6281 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
6282 struct btrfs_root *root)
6283 {
6284 struct btrfs_root *reloc_root;
6285 int ret;
6286
6287 if (root->reloc_root) {
6288 reloc_root = root->reloc_root;
6289 root->reloc_root = NULL;
6290 list_add(&reloc_root->dead_list,
6291 &root->fs_info->dead_reloc_roots);
6292
6293 btrfs_set_root_bytenr(&reloc_root->root_item,
6294 reloc_root->node->start);
6295 btrfs_set_root_level(&root->root_item,
6296 btrfs_header_level(reloc_root->node));
6297 memset(&reloc_root->root_item.drop_progress, 0,
6298 sizeof(struct btrfs_disk_key));
6299 reloc_root->root_item.drop_level = 0;
6300
6301 ret = btrfs_update_root(trans, root->fs_info->tree_root,
6302 &reloc_root->root_key,
6303 &reloc_root->root_item);
6304 BUG_ON(ret);
6305 }
6306 return 0;
6307 }
6308
6309 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
6310 {
6311 struct btrfs_trans_handle *trans;
6312 struct btrfs_root *reloc_root;
6313 struct btrfs_root *prev_root = NULL;
6314 struct list_head dead_roots;
6315 int ret;
6316 unsigned long nr;
6317
6318 INIT_LIST_HEAD(&dead_roots);
6319 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
6320
6321 while (!list_empty(&dead_roots)) {
6322 reloc_root = list_entry(dead_roots.prev,
6323 struct btrfs_root, dead_list);
6324 list_del_init(&reloc_root->dead_list);
6325
6326 BUG_ON(reloc_root->commit_root != NULL);
6327 while (1) {
6328 trans = btrfs_join_transaction(root, 1);
6329 BUG_ON(!trans);
6330
6331 mutex_lock(&root->fs_info->drop_mutex);
6332 ret = btrfs_drop_snapshot(trans, reloc_root);
6333 if (ret != -EAGAIN)
6334 break;
6335 mutex_unlock(&root->fs_info->drop_mutex);
6336
6337 nr = trans->blocks_used;
6338 ret = btrfs_end_transaction(trans, root);
6339 BUG_ON(ret);
6340 btrfs_btree_balance_dirty(root, nr);
6341 }
6342
6343 free_extent_buffer(reloc_root->node);
6344
6345 ret = btrfs_del_root(trans, root->fs_info->tree_root,
6346 &reloc_root->root_key);
6347 BUG_ON(ret);
6348 mutex_unlock(&root->fs_info->drop_mutex);
6349
6350 nr = trans->blocks_used;
6351 ret = btrfs_end_transaction(trans, root);
6352 BUG_ON(ret);
6353 btrfs_btree_balance_dirty(root, nr);
6354
6355 kfree(prev_root);
6356 prev_root = reloc_root;
6357 }
6358 if (prev_root) {
6359 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
6360 kfree(prev_root);
6361 }
6362 return 0;
6363 }
6364
6365 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
6366 {
6367 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
6368 return 0;
6369 }
6370
6371 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
6372 {
6373 struct btrfs_root *reloc_root;
6374 struct btrfs_trans_handle *trans;
6375 struct btrfs_key location;
6376 int found;
6377 int ret;
6378
6379 mutex_lock(&root->fs_info->tree_reloc_mutex);
6380 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
6381 BUG_ON(ret);
6382 found = !list_empty(&root->fs_info->dead_reloc_roots);
6383 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6384
6385 if (found) {
6386 trans = btrfs_start_transaction(root, 1);
6387 BUG_ON(!trans);
6388 ret = btrfs_commit_transaction(trans, root);
6389 BUG_ON(ret);
6390 }
6391
6392 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
6393 location.offset = (u64)-1;
6394 location.type = BTRFS_ROOT_ITEM_KEY;
6395
6396 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
6397 BUG_ON(!reloc_root);
6398 btrfs_orphan_cleanup(reloc_root);
6399 return 0;
6400 }
6401
6402 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
6403 struct btrfs_root *root)
6404 {
6405 struct btrfs_root *reloc_root;
6406 struct extent_buffer *eb;
6407 struct btrfs_root_item *root_item;
6408 struct btrfs_key root_key;
6409 int ret;
6410
6411 BUG_ON(!root->ref_cows);
6412 if (root->reloc_root)
6413 return 0;
6414
6415 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
6416 BUG_ON(!root_item);
6417
6418 ret = btrfs_copy_root(trans, root, root->commit_root,
6419 &eb, BTRFS_TREE_RELOC_OBJECTID);
6420 BUG_ON(ret);
6421
6422 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
6423 root_key.offset = root->root_key.objectid;
6424 root_key.type = BTRFS_ROOT_ITEM_KEY;
6425
6426 memcpy(root_item, &root->root_item, sizeof(root_item));
6427 btrfs_set_root_refs(root_item, 0);
6428 btrfs_set_root_bytenr(root_item, eb->start);
6429 btrfs_set_root_level(root_item, btrfs_header_level(eb));
6430 btrfs_set_root_generation(root_item, trans->transid);
6431
6432 btrfs_tree_unlock(eb);
6433 free_extent_buffer(eb);
6434
6435 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
6436 &root_key, root_item);
6437 BUG_ON(ret);
6438 kfree(root_item);
6439
6440 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
6441 &root_key);
6442 BUG_ON(!reloc_root);
6443 reloc_root->last_trans = trans->transid;
6444 reloc_root->commit_root = NULL;
6445 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
6446
6447 root->reloc_root = reloc_root;
6448 return 0;
6449 }
6450
6451 /*
6452 * Core function of space balance.
6453 *
6454 * The idea is using reloc trees to relocate tree blocks in reference
6455 * counted roots. There is one reloc tree for each subvol, and all
6456 * reloc trees share same root key objectid. Reloc trees are snapshots
6457 * of the latest committed roots of subvols (root->commit_root).
6458 *
6459 * To relocate a tree block referenced by a subvol, there are two steps.
6460 * COW the block through subvol's reloc tree, then update block pointer
6461 * in the subvol to point to the new block. Since all reloc trees share
6462 * same root key objectid, doing special handing for tree blocks owned
6463 * by them is easy. Once a tree block has been COWed in one reloc tree,
6464 * we can use the resulting new block directly when the same block is
6465 * required to COW again through other reloc trees. By this way, relocated
6466 * tree blocks are shared between reloc trees, so they are also shared
6467 * between subvols.
6468 */
6469 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
6470 struct btrfs_root *root,
6471 struct btrfs_path *path,
6472 struct btrfs_key *first_key,
6473 struct btrfs_ref_path *ref_path,
6474 struct btrfs_block_group_cache *group,
6475 struct inode *reloc_inode)
6476 {
6477 struct btrfs_root *reloc_root;
6478 struct extent_buffer *eb = NULL;
6479 struct btrfs_key *keys;
6480 u64 *nodes;
6481 int level;
6482 int shared_level;
6483 int lowest_level = 0;
6484 int ret;
6485
6486 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
6487 lowest_level = ref_path->owner_objectid;
6488
6489 if (!root->ref_cows) {
6490 path->lowest_level = lowest_level;
6491 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
6492 BUG_ON(ret < 0);
6493 path->lowest_level = 0;
6494 btrfs_release_path(root, path);
6495 return 0;
6496 }
6497
6498 mutex_lock(&root->fs_info->tree_reloc_mutex);
6499 ret = init_reloc_tree(trans, root);
6500 BUG_ON(ret);
6501 reloc_root = root->reloc_root;
6502
6503 shared_level = ref_path->shared_level;
6504 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
6505
6506 keys = ref_path->node_keys;
6507 nodes = ref_path->new_nodes;
6508 memset(&keys[shared_level + 1], 0,
6509 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
6510 memset(&nodes[shared_level + 1], 0,
6511 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
6512
6513 if (nodes[lowest_level] == 0) {
6514 path->lowest_level = lowest_level;
6515 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6516 0, 1);
6517 BUG_ON(ret);
6518 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
6519 eb = path->nodes[level];
6520 if (!eb || eb == reloc_root->node)
6521 break;
6522 nodes[level] = eb->start;
6523 if (level == 0)
6524 btrfs_item_key_to_cpu(eb, &keys[level], 0);
6525 else
6526 btrfs_node_key_to_cpu(eb, &keys[level], 0);
6527 }
6528 if (nodes[0] &&
6529 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6530 eb = path->nodes[0];
6531 ret = replace_extents_in_leaf(trans, reloc_root, eb,
6532 group, reloc_inode);
6533 BUG_ON(ret);
6534 }
6535 btrfs_release_path(reloc_root, path);
6536 } else {
6537 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
6538 lowest_level);
6539 BUG_ON(ret);
6540 }
6541
6542 /*
6543 * replace tree blocks in the fs tree with tree blocks in
6544 * the reloc tree.
6545 */
6546 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
6547 BUG_ON(ret < 0);
6548
6549 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6550 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6551 0, 0);
6552 BUG_ON(ret);
6553 extent_buffer_get(path->nodes[0]);
6554 eb = path->nodes[0];
6555 btrfs_release_path(reloc_root, path);
6556 ret = invalidate_extent_cache(reloc_root, eb, group, root);
6557 BUG_ON(ret);
6558 free_extent_buffer(eb);
6559 }
6560
6561 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6562 path->lowest_level = 0;
6563 return 0;
6564 }
6565
6566 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
6567 struct btrfs_root *root,
6568 struct btrfs_path *path,
6569 struct btrfs_key *first_key,
6570 struct btrfs_ref_path *ref_path)
6571 {
6572 int ret;
6573
6574 ret = relocate_one_path(trans, root, path, first_key,
6575 ref_path, NULL, NULL);
6576 BUG_ON(ret);
6577
6578 return 0;
6579 }
6580
6581 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
6582 struct btrfs_root *extent_root,
6583 struct btrfs_path *path,
6584 struct btrfs_key *extent_key)
6585 {
6586 int ret;
6587
6588 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
6589 if (ret)
6590 goto out;
6591 ret = btrfs_del_item(trans, extent_root, path);
6592 out:
6593 btrfs_release_path(extent_root, path);
6594 return ret;
6595 }
6596
6597 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
6598 struct btrfs_ref_path *ref_path)
6599 {
6600 struct btrfs_key root_key;
6601
6602 root_key.objectid = ref_path->root_objectid;
6603 root_key.type = BTRFS_ROOT_ITEM_KEY;
6604 if (is_cowonly_root(ref_path->root_objectid))
6605 root_key.offset = 0;
6606 else
6607 root_key.offset = (u64)-1;
6608
6609 return btrfs_read_fs_root_no_name(fs_info, &root_key);
6610 }
6611
6612 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
6613 struct btrfs_path *path,
6614 struct btrfs_key *extent_key,
6615 struct btrfs_block_group_cache *group,
6616 struct inode *reloc_inode, int pass)
6617 {
6618 struct btrfs_trans_handle *trans;
6619 struct btrfs_root *found_root;
6620 struct btrfs_ref_path *ref_path = NULL;
6621 struct disk_extent *new_extents = NULL;
6622 int nr_extents = 0;
6623 int loops;
6624 int ret;
6625 int level;
6626 struct btrfs_key first_key;
6627 u64 prev_block = 0;
6628
6629
6630 trans = btrfs_start_transaction(extent_root, 1);
6631 BUG_ON(!trans);
6632
6633 if (extent_key->objectid == 0) {
6634 ret = del_extent_zero(trans, extent_root, path, extent_key);
6635 goto out;
6636 }
6637
6638 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
6639 if (!ref_path) {
6640 ret = -ENOMEM;
6641 goto out;
6642 }
6643
6644 for (loops = 0; ; loops++) {
6645 if (loops == 0) {
6646 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
6647 extent_key->objectid);
6648 } else {
6649 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
6650 }
6651 if (ret < 0)
6652 goto out;
6653 if (ret > 0)
6654 break;
6655
6656 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
6657 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
6658 continue;
6659
6660 found_root = read_ref_root(extent_root->fs_info, ref_path);
6661 BUG_ON(!found_root);
6662 /*
6663 * for reference counted tree, only process reference paths
6664 * rooted at the latest committed root.
6665 */
6666 if (found_root->ref_cows &&
6667 ref_path->root_generation != found_root->root_key.offset)
6668 continue;
6669
6670 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6671 if (pass == 0) {
6672 /*
6673 * copy data extents to new locations
6674 */
6675 u64 group_start = group->key.objectid;
6676 ret = relocate_data_extent(reloc_inode,
6677 extent_key,
6678 group_start);
6679 if (ret < 0)
6680 goto out;
6681 break;
6682 }
6683 level = 0;
6684 } else {
6685 level = ref_path->owner_objectid;
6686 }
6687
6688 if (prev_block != ref_path->nodes[level]) {
6689 struct extent_buffer *eb;
6690 u64 block_start = ref_path->nodes[level];
6691 u64 block_size = btrfs_level_size(found_root, level);
6692
6693 eb = read_tree_block(found_root, block_start,
6694 block_size, 0);
6695 btrfs_tree_lock(eb);
6696 BUG_ON(level != btrfs_header_level(eb));
6697
6698 if (level == 0)
6699 btrfs_item_key_to_cpu(eb, &first_key, 0);
6700 else
6701 btrfs_node_key_to_cpu(eb, &first_key, 0);
6702
6703 btrfs_tree_unlock(eb);
6704 free_extent_buffer(eb);
6705 prev_block = block_start;
6706 }
6707
6708 mutex_lock(&extent_root->fs_info->trans_mutex);
6709 btrfs_record_root_in_trans(found_root);
6710 mutex_unlock(&extent_root->fs_info->trans_mutex);
6711 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6712 /*
6713 * try to update data extent references while
6714 * keeping metadata shared between snapshots.
6715 */
6716 if (pass == 1) {
6717 ret = relocate_one_path(trans, found_root,
6718 path, &first_key, ref_path,
6719 group, reloc_inode);
6720 if (ret < 0)
6721 goto out;
6722 continue;
6723 }
6724 /*
6725 * use fallback method to process the remaining
6726 * references.
6727 */
6728 if (!new_extents) {
6729 u64 group_start = group->key.objectid;
6730 new_extents = kmalloc(sizeof(*new_extents),
6731 GFP_NOFS);
6732 nr_extents = 1;
6733 ret = get_new_locations(reloc_inode,
6734 extent_key,
6735 group_start, 1,
6736 &new_extents,
6737 &nr_extents);
6738 if (ret)
6739 goto out;
6740 }
6741 ret = replace_one_extent(trans, found_root,
6742 path, extent_key,
6743 &first_key, ref_path,
6744 new_extents, nr_extents);
6745 } else {
6746 ret = relocate_tree_block(trans, found_root, path,
6747 &first_key, ref_path);
6748 }
6749 if (ret < 0)
6750 goto out;
6751 }
6752 ret = 0;
6753 out:
6754 btrfs_end_transaction(trans, extent_root);
6755 kfree(new_extents);
6756 kfree(ref_path);
6757 return ret;
6758 }
6759 #endif
6760
6761 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
6762 {
6763 u64 num_devices;
6764 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
6765 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
6766
6767 num_devices = root->fs_info->fs_devices->rw_devices;
6768 if (num_devices == 1) {
6769 stripped |= BTRFS_BLOCK_GROUP_DUP;
6770 stripped = flags & ~stripped;
6771
6772 /* turn raid0 into single device chunks */
6773 if (flags & BTRFS_BLOCK_GROUP_RAID0)
6774 return stripped;
6775
6776 /* turn mirroring into duplication */
6777 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
6778 BTRFS_BLOCK_GROUP_RAID10))
6779 return stripped | BTRFS_BLOCK_GROUP_DUP;
6780 return flags;
6781 } else {
6782 /* they already had raid on here, just return */
6783 if (flags & stripped)
6784 return flags;
6785
6786 stripped |= BTRFS_BLOCK_GROUP_DUP;
6787 stripped = flags & ~stripped;
6788
6789 /* switch duplicated blocks with raid1 */
6790 if (flags & BTRFS_BLOCK_GROUP_DUP)
6791 return stripped | BTRFS_BLOCK_GROUP_RAID1;
6792
6793 /* turn single device chunks into raid0 */
6794 return stripped | BTRFS_BLOCK_GROUP_RAID0;
6795 }
6796 return flags;
6797 }
6798
6799 static int __alloc_chunk_for_shrink(struct btrfs_root *root,
6800 struct btrfs_block_group_cache *shrink_block_group,
6801 int force)
6802 {
6803 struct btrfs_trans_handle *trans;
6804 u64 new_alloc_flags;
6805 u64 calc;
6806
6807 spin_lock(&shrink_block_group->lock);
6808 if (btrfs_block_group_used(&shrink_block_group->item) +
6809 shrink_block_group->reserved > 0) {
6810 spin_unlock(&shrink_block_group->lock);
6811
6812 trans = btrfs_start_transaction(root, 1);
6813 spin_lock(&shrink_block_group->lock);
6814
6815 new_alloc_flags = update_block_group_flags(root,
6816 shrink_block_group->flags);
6817 if (new_alloc_flags != shrink_block_group->flags) {
6818 calc =
6819 btrfs_block_group_used(&shrink_block_group->item);
6820 } else {
6821 calc = shrink_block_group->key.offset;
6822 }
6823 spin_unlock(&shrink_block_group->lock);
6824
6825 do_chunk_alloc(trans, root->fs_info->extent_root,
6826 calc + 2 * 1024 * 1024, new_alloc_flags, force);
6827
6828 btrfs_end_transaction(trans, root);
6829 } else
6830 spin_unlock(&shrink_block_group->lock);
6831 return 0;
6832 }
6833
6834
6835 int btrfs_prepare_block_group_relocation(struct btrfs_root *root,
6836 struct btrfs_block_group_cache *group)
6837
6838 {
6839 __alloc_chunk_for_shrink(root, group, 1);
6840 set_block_group_readonly(group);
6841 return 0;
6842 }
6843
6844 #if 0
6845 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
6846 struct btrfs_root *root,
6847 u64 objectid, u64 size)
6848 {
6849 struct btrfs_path *path;
6850 struct btrfs_inode_item *item;
6851 struct extent_buffer *leaf;
6852 int ret;
6853
6854 path = btrfs_alloc_path();
6855 if (!path)
6856 return -ENOMEM;
6857
6858 path->leave_spinning = 1;
6859 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
6860 if (ret)
6861 goto out;
6862
6863 leaf = path->nodes[0];
6864 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
6865 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
6866 btrfs_set_inode_generation(leaf, item, 1);
6867 btrfs_set_inode_size(leaf, item, size);
6868 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
6869 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS);
6870 btrfs_mark_buffer_dirty(leaf);
6871 btrfs_release_path(root, path);
6872 out:
6873 btrfs_free_path(path);
6874 return ret;
6875 }
6876
6877 static noinline struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
6878 struct btrfs_block_group_cache *group)
6879 {
6880 struct inode *inode = NULL;
6881 struct btrfs_trans_handle *trans;
6882 struct btrfs_root *root;
6883 struct btrfs_key root_key;
6884 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
6885 int err = 0;
6886
6887 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
6888 root_key.type = BTRFS_ROOT_ITEM_KEY;
6889 root_key.offset = (u64)-1;
6890 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
6891 if (IS_ERR(root))
6892 return ERR_CAST(root);
6893
6894 trans = btrfs_start_transaction(root, 1);
6895 BUG_ON(!trans);
6896
6897 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
6898 if (err)
6899 goto out;
6900
6901 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
6902 BUG_ON(err);
6903
6904 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
6905 group->key.offset, 0, group->key.offset,
6906 0, 0, 0);
6907 BUG_ON(err);
6908
6909 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
6910 if (inode->i_state & I_NEW) {
6911 BTRFS_I(inode)->root = root;
6912 BTRFS_I(inode)->location.objectid = objectid;
6913 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
6914 BTRFS_I(inode)->location.offset = 0;
6915 btrfs_read_locked_inode(inode);
6916 unlock_new_inode(inode);
6917 BUG_ON(is_bad_inode(inode));
6918 } else {
6919 BUG_ON(1);
6920 }
6921 BTRFS_I(inode)->index_cnt = group->key.objectid;
6922
6923 err = btrfs_orphan_add(trans, inode);
6924 out:
6925 btrfs_end_transaction(trans, root);
6926 if (err) {
6927 if (inode)
6928 iput(inode);
6929 inode = ERR_PTR(err);
6930 }
6931 return inode;
6932 }
6933
6934 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
6935 {
6936
6937 struct btrfs_ordered_sum *sums;
6938 struct btrfs_sector_sum *sector_sum;
6939 struct btrfs_ordered_extent *ordered;
6940 struct btrfs_root *root = BTRFS_I(inode)->root;
6941 struct list_head list;
6942 size_t offset;
6943 int ret;
6944 u64 disk_bytenr;
6945
6946 INIT_LIST_HEAD(&list);
6947
6948 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
6949 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
6950
6951 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
6952 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
6953 disk_bytenr + len - 1, &list);
6954
6955 while (!list_empty(&list)) {
6956 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
6957 list_del_init(&sums->list);
6958
6959 sector_sum = sums->sums;
6960 sums->bytenr = ordered->start;
6961
6962 offset = 0;
6963 while (offset < sums->len) {
6964 sector_sum->bytenr += ordered->start - disk_bytenr;
6965 sector_sum++;
6966 offset += root->sectorsize;
6967 }
6968
6969 btrfs_add_ordered_sum(inode, ordered, sums);
6970 }
6971 btrfs_put_ordered_extent(ordered);
6972 return 0;
6973 }
6974
6975 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
6976 {
6977 struct btrfs_trans_handle *trans;
6978 struct btrfs_path *path;
6979 struct btrfs_fs_info *info = root->fs_info;
6980 struct extent_buffer *leaf;
6981 struct inode *reloc_inode;
6982 struct btrfs_block_group_cache *block_group;
6983 struct btrfs_key key;
6984 u64 skipped;
6985 u64 cur_byte;
6986 u64 total_found;
6987 u32 nritems;
6988 int ret;
6989 int progress;
6990 int pass = 0;
6991
6992 root = root->fs_info->extent_root;
6993
6994 block_group = btrfs_lookup_block_group(info, group_start);
6995 BUG_ON(!block_group);
6996
6997 printk(KERN_INFO "btrfs relocating block group %llu flags %llu\n",
6998 (unsigned long long)block_group->key.objectid,
6999 (unsigned long long)block_group->flags);
7000
7001 path = btrfs_alloc_path();
7002 BUG_ON(!path);
7003
7004 reloc_inode = create_reloc_inode(info, block_group);
7005 BUG_ON(IS_ERR(reloc_inode));
7006
7007 __alloc_chunk_for_shrink(root, block_group, 1);
7008 set_block_group_readonly(block_group);
7009
7010 btrfs_start_delalloc_inodes(info->tree_root);
7011 btrfs_wait_ordered_extents(info->tree_root, 0);
7012 again:
7013 skipped = 0;
7014 total_found = 0;
7015 progress = 0;
7016 key.objectid = block_group->key.objectid;
7017 key.offset = 0;
7018 key.type = 0;
7019 cur_byte = key.objectid;
7020
7021 trans = btrfs_start_transaction(info->tree_root, 1);
7022 btrfs_commit_transaction(trans, info->tree_root);
7023
7024 mutex_lock(&root->fs_info->cleaner_mutex);
7025 btrfs_clean_old_snapshots(info->tree_root);
7026 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
7027 mutex_unlock(&root->fs_info->cleaner_mutex);
7028
7029 trans = btrfs_start_transaction(info->tree_root, 1);
7030 btrfs_commit_transaction(trans, info->tree_root);
7031
7032 while (1) {
7033 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
7034 if (ret < 0)
7035 goto out;
7036 next:
7037 leaf = path->nodes[0];
7038 nritems = btrfs_header_nritems(leaf);
7039 if (path->slots[0] >= nritems) {
7040 ret = btrfs_next_leaf(root, path);
7041 if (ret < 0)
7042 goto out;
7043 if (ret == 1) {
7044 ret = 0;
7045 break;
7046 }
7047 leaf = path->nodes[0];
7048 nritems = btrfs_header_nritems(leaf);
7049 }
7050
7051 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
7052
7053 if (key.objectid >= block_group->key.objectid +
7054 block_group->key.offset)
7055 break;
7056
7057 if (progress && need_resched()) {
7058 btrfs_release_path(root, path);
7059 cond_resched();
7060 progress = 0;
7061 continue;
7062 }
7063 progress = 1;
7064
7065 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
7066 key.objectid + key.offset <= cur_byte) {
7067 path->slots[0]++;
7068 goto next;
7069 }
7070
7071 total_found++;
7072 cur_byte = key.objectid + key.offset;
7073 btrfs_release_path(root, path);
7074
7075 __alloc_chunk_for_shrink(root, block_group, 0);
7076 ret = relocate_one_extent(root, path, &key, block_group,
7077 reloc_inode, pass);
7078 BUG_ON(ret < 0);
7079 if (ret > 0)
7080 skipped++;
7081
7082 key.objectid = cur_byte;
7083 key.type = 0;
7084 key.offset = 0;
7085 }
7086
7087 btrfs_release_path(root, path);
7088
7089 if (pass == 0) {
7090 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
7091 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
7092 }
7093
7094 if (total_found > 0) {
7095 printk(KERN_INFO "btrfs found %llu extents in pass %d\n",
7096 (unsigned long long)total_found, pass);
7097 pass++;
7098 if (total_found == skipped && pass > 2) {
7099 iput(reloc_inode);
7100 reloc_inode = create_reloc_inode(info, block_group);
7101 pass = 0;
7102 }
7103 goto again;
7104 }
7105
7106 /* delete reloc_inode */
7107 iput(reloc_inode);
7108
7109 /* unpin extents in this range */
7110 trans = btrfs_start_transaction(info->tree_root, 1);
7111 btrfs_commit_transaction(trans, info->tree_root);
7112
7113 spin_lock(&block_group->lock);
7114 WARN_ON(block_group->pinned > 0);
7115 WARN_ON(block_group->reserved > 0);
7116 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
7117 spin_unlock(&block_group->lock);
7118 btrfs_put_block_group(block_group);
7119 ret = 0;
7120 out:
7121 btrfs_free_path(path);
7122 return ret;
7123 }
7124 #endif
7125
7126 static int find_first_block_group(struct btrfs_root *root,
7127 struct btrfs_path *path, struct btrfs_key *key)
7128 {
7129 int ret = 0;
7130 struct btrfs_key found_key;
7131 struct extent_buffer *leaf;
7132 int slot;
7133
7134 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
7135 if (ret < 0)
7136 goto out;
7137
7138 while (1) {
7139 slot = path->slots[0];
7140 leaf = path->nodes[0];
7141 if (slot >= btrfs_header_nritems(leaf)) {
7142 ret = btrfs_next_leaf(root, path);
7143 if (ret == 0)
7144 continue;
7145 if (ret < 0)
7146 goto out;
7147 break;
7148 }
7149 btrfs_item_key_to_cpu(leaf, &found_key, slot);
7150
7151 if (found_key.objectid >= key->objectid &&
7152 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
7153 ret = 0;
7154 goto out;
7155 }
7156 path->slots[0]++;
7157 }
7158 ret = -ENOENT;
7159 out:
7160 return ret;
7161 }
7162
7163 int btrfs_free_block_groups(struct btrfs_fs_info *info)
7164 {
7165 struct btrfs_block_group_cache *block_group;
7166 struct btrfs_space_info *space_info;
7167 struct rb_node *n;
7168
7169 spin_lock(&info->block_group_cache_lock);
7170 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
7171 block_group = rb_entry(n, struct btrfs_block_group_cache,
7172 cache_node);
7173 rb_erase(&block_group->cache_node,
7174 &info->block_group_cache_tree);
7175 spin_unlock(&info->block_group_cache_lock);
7176
7177 down_write(&block_group->space_info->groups_sem);
7178 list_del(&block_group->list);
7179 up_write(&block_group->space_info->groups_sem);
7180
7181 if (block_group->cached == BTRFS_CACHE_STARTED)
7182 wait_event(block_group->caching_q,
7183 block_group_cache_done(block_group));
7184
7185 btrfs_remove_free_space_cache(block_group);
7186
7187 WARN_ON(atomic_read(&block_group->count) != 1);
7188 kfree(block_group);
7189
7190 spin_lock(&info->block_group_cache_lock);
7191 }
7192 spin_unlock(&info->block_group_cache_lock);
7193
7194 /* now that all the block groups are freed, go through and
7195 * free all the space_info structs. This is only called during
7196 * the final stages of unmount, and so we know nobody is
7197 * using them. We call synchronize_rcu() once before we start,
7198 * just to be on the safe side.
7199 */
7200 synchronize_rcu();
7201
7202 while(!list_empty(&info->space_info)) {
7203 space_info = list_entry(info->space_info.next,
7204 struct btrfs_space_info,
7205 list);
7206
7207 list_del(&space_info->list);
7208 kfree(space_info);
7209 }
7210 return 0;
7211 }
7212
7213 int btrfs_read_block_groups(struct btrfs_root *root)
7214 {
7215 struct btrfs_path *path;
7216 int ret;
7217 struct btrfs_block_group_cache *cache;
7218 struct btrfs_fs_info *info = root->fs_info;
7219 struct btrfs_space_info *space_info;
7220 struct btrfs_key key;
7221 struct btrfs_key found_key;
7222 struct extent_buffer *leaf;
7223
7224 root = info->extent_root;
7225 key.objectid = 0;
7226 key.offset = 0;
7227 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
7228 path = btrfs_alloc_path();
7229 if (!path)
7230 return -ENOMEM;
7231
7232 while (1) {
7233 ret = find_first_block_group(root, path, &key);
7234 if (ret > 0) {
7235 ret = 0;
7236 goto error;
7237 }
7238 if (ret != 0)
7239 goto error;
7240
7241 leaf = path->nodes[0];
7242 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7243 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7244 if (!cache) {
7245 ret = -ENOMEM;
7246 break;
7247 }
7248
7249 atomic_set(&cache->count, 1);
7250 spin_lock_init(&cache->lock);
7251 spin_lock_init(&cache->tree_lock);
7252 cache->fs_info = info;
7253 init_waitqueue_head(&cache->caching_q);
7254 INIT_LIST_HEAD(&cache->list);
7255 INIT_LIST_HEAD(&cache->cluster_list);
7256
7257 /*
7258 * we only want to have 32k of ram per block group for keeping
7259 * track of free space, and if we pass 1/2 of that we want to
7260 * start converting things over to using bitmaps
7261 */
7262 cache->extents_thresh = ((1024 * 32) / 2) /
7263 sizeof(struct btrfs_free_space);
7264
7265 read_extent_buffer(leaf, &cache->item,
7266 btrfs_item_ptr_offset(leaf, path->slots[0]),
7267 sizeof(cache->item));
7268 memcpy(&cache->key, &found_key, sizeof(found_key));
7269
7270 key.objectid = found_key.objectid + found_key.offset;
7271 btrfs_release_path(root, path);
7272 cache->flags = btrfs_block_group_flags(&cache->item);
7273 cache->sectorsize = root->sectorsize;
7274
7275 remove_sb_from_cache(root, cache);
7276
7277 /*
7278 * check for two cases, either we are full, and therefore
7279 * don't need to bother with the caching work since we won't
7280 * find any space, or we are empty, and we can just add all
7281 * the space in and be done with it. This saves us _alot_ of
7282 * time, particularly in the full case.
7283 */
7284 if (found_key.offset == btrfs_block_group_used(&cache->item)) {
7285 cache->cached = BTRFS_CACHE_FINISHED;
7286 } else if (btrfs_block_group_used(&cache->item) == 0) {
7287 cache->cached = BTRFS_CACHE_FINISHED;
7288 add_new_free_space(cache, root->fs_info,
7289 found_key.objectid,
7290 found_key.objectid +
7291 found_key.offset);
7292 }
7293
7294 ret = update_space_info(info, cache->flags, found_key.offset,
7295 btrfs_block_group_used(&cache->item),
7296 &space_info);
7297 BUG_ON(ret);
7298 cache->space_info = space_info;
7299 down_write(&space_info->groups_sem);
7300 list_add_tail(&cache->list, &space_info->block_groups);
7301 up_write(&space_info->groups_sem);
7302
7303 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7304 BUG_ON(ret);
7305
7306 set_avail_alloc_bits(root->fs_info, cache->flags);
7307 if (btrfs_chunk_readonly(root, cache->key.objectid))
7308 set_block_group_readonly(cache);
7309 }
7310 ret = 0;
7311 error:
7312 btrfs_free_path(path);
7313 return ret;
7314 }
7315
7316 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
7317 struct btrfs_root *root, u64 bytes_used,
7318 u64 type, u64 chunk_objectid, u64 chunk_offset,
7319 u64 size)
7320 {
7321 int ret;
7322 struct btrfs_root *extent_root;
7323 struct btrfs_block_group_cache *cache;
7324
7325 extent_root = root->fs_info->extent_root;
7326
7327 root->fs_info->last_trans_log_full_commit = trans->transid;
7328
7329 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7330 if (!cache)
7331 return -ENOMEM;
7332
7333 cache->key.objectid = chunk_offset;
7334 cache->key.offset = size;
7335 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
7336 cache->sectorsize = root->sectorsize;
7337
7338 /*
7339 * we only want to have 32k of ram per block group for keeping track
7340 * of free space, and if we pass 1/2 of that we want to start
7341 * converting things over to using bitmaps
7342 */
7343 cache->extents_thresh = ((1024 * 32) / 2) /
7344 sizeof(struct btrfs_free_space);
7345 atomic_set(&cache->count, 1);
7346 spin_lock_init(&cache->lock);
7347 spin_lock_init(&cache->tree_lock);
7348 init_waitqueue_head(&cache->caching_q);
7349 INIT_LIST_HEAD(&cache->list);
7350 INIT_LIST_HEAD(&cache->cluster_list);
7351
7352 btrfs_set_block_group_used(&cache->item, bytes_used);
7353 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
7354 cache->flags = type;
7355 btrfs_set_block_group_flags(&cache->item, type);
7356
7357 cache->cached = BTRFS_CACHE_FINISHED;
7358 remove_sb_from_cache(root, cache);
7359
7360 add_new_free_space(cache, root->fs_info, chunk_offset,
7361 chunk_offset + size);
7362
7363 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
7364 &cache->space_info);
7365 BUG_ON(ret);
7366 down_write(&cache->space_info->groups_sem);
7367 list_add_tail(&cache->list, &cache->space_info->block_groups);
7368 up_write(&cache->space_info->groups_sem);
7369
7370 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7371 BUG_ON(ret);
7372
7373 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
7374 sizeof(cache->item));
7375 BUG_ON(ret);
7376
7377 set_avail_alloc_bits(extent_root->fs_info, type);
7378
7379 return 0;
7380 }
7381
7382 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
7383 struct btrfs_root *root, u64 group_start)
7384 {
7385 struct btrfs_path *path;
7386 struct btrfs_block_group_cache *block_group;
7387 struct btrfs_free_cluster *cluster;
7388 struct btrfs_key key;
7389 int ret;
7390
7391 root = root->fs_info->extent_root;
7392
7393 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
7394 BUG_ON(!block_group);
7395 BUG_ON(!block_group->ro);
7396
7397 memcpy(&key, &block_group->key, sizeof(key));
7398
7399 /* make sure this block group isn't part of an allocation cluster */
7400 cluster = &root->fs_info->data_alloc_cluster;
7401 spin_lock(&cluster->refill_lock);
7402 btrfs_return_cluster_to_free_space(block_group, cluster);
7403 spin_unlock(&cluster->refill_lock);
7404
7405 /*
7406 * make sure this block group isn't part of a metadata
7407 * allocation cluster
7408 */
7409 cluster = &root->fs_info->meta_alloc_cluster;
7410 spin_lock(&cluster->refill_lock);
7411 btrfs_return_cluster_to_free_space(block_group, cluster);
7412 spin_unlock(&cluster->refill_lock);
7413
7414 path = btrfs_alloc_path();
7415 BUG_ON(!path);
7416
7417 spin_lock(&root->fs_info->block_group_cache_lock);
7418 rb_erase(&block_group->cache_node,
7419 &root->fs_info->block_group_cache_tree);
7420 spin_unlock(&root->fs_info->block_group_cache_lock);
7421
7422 down_write(&block_group->space_info->groups_sem);
7423 /*
7424 * we must use list_del_init so people can check to see if they
7425 * are still on the list after taking the semaphore
7426 */
7427 list_del_init(&block_group->list);
7428 up_write(&block_group->space_info->groups_sem);
7429
7430 if (block_group->cached == BTRFS_CACHE_STARTED)
7431 wait_event(block_group->caching_q,
7432 block_group_cache_done(block_group));
7433
7434 btrfs_remove_free_space_cache(block_group);
7435
7436 spin_lock(&block_group->space_info->lock);
7437 block_group->space_info->total_bytes -= block_group->key.offset;
7438 block_group->space_info->bytes_readonly -= block_group->key.offset;
7439 spin_unlock(&block_group->space_info->lock);
7440
7441 btrfs_clear_space_info_full(root->fs_info);
7442
7443 btrfs_put_block_group(block_group);
7444 btrfs_put_block_group(block_group);
7445
7446 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
7447 if (ret > 0)
7448 ret = -EIO;
7449 if (ret < 0)
7450 goto out;
7451
7452 ret = btrfs_del_item(trans, root, path);
7453 out:
7454 btrfs_free_path(path);
7455 return ret;
7456 }
Linux with added FPC-III support