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Btrfs: Fix leaf reference cache miss
[linux-2.6/mini2440.git] / fs / btrfs / extent-tree.c
blob280ac1aa9b6d7d39816a24283836cdaa6de60cf4
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 "hash.h"
23 #include "crc32c.h"
24 #include "ctree.h"
25 #include "disk-io.h"
26 #include "print-tree.h"
27 #include "transaction.h"
28 #include "volumes.h"
29 #include "locking.h"
30 #include "ref-cache.h"
31
32 #define PENDING_EXTENT_INSERT 0
33 #define PENDING_EXTENT_DELETE 1
34 #define PENDING_BACKREF_UPDATE 2
35
36 struct pending_extent_op {
37 int type;
38 u64 bytenr;
39 u64 num_bytes;
40 u64 parent;
41 u64 orig_parent;
42 u64 generation;
43 u64 orig_generation;
44 int level;
45 };
46
47 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
48 btrfs_root *extent_root);
49 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
50 btrfs_root *extent_root);
51 static struct btrfs_block_group_cache *
52 __btrfs_find_block_group(struct btrfs_root *root,
53 struct btrfs_block_group_cache *hint,
54 u64 search_start, int data, int owner);
55
56 void maybe_lock_mutex(struct btrfs_root *root)
57 {
58 if (root != root->fs_info->extent_root &&
59 root != root->fs_info->chunk_root &&
60 root != root->fs_info->dev_root) {
61 mutex_lock(&root->fs_info->alloc_mutex);
62 }
63 }
64
65 void maybe_unlock_mutex(struct btrfs_root *root)
66 {
67 if (root != root->fs_info->extent_root &&
68 root != root->fs_info->chunk_root &&
69 root != root->fs_info->dev_root) {
70 mutex_unlock(&root->fs_info->alloc_mutex);
71 }
72 }
73
74 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
75 {
76 return (cache->flags & bits) == bits;
77 }
78
79 /*
80 * this adds the block group to the fs_info rb tree for the block group
81 * cache
82 */
83 int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
84 struct btrfs_block_group_cache *block_group)
85 {
86 struct rb_node **p;
87 struct rb_node *parent = NULL;
88 struct btrfs_block_group_cache *cache;
89
90 spin_lock(&info->block_group_cache_lock);
91 p = &info->block_group_cache_tree.rb_node;
92
93 while (*p) {
94 parent = *p;
95 cache = rb_entry(parent, struct btrfs_block_group_cache,
96 cache_node);
97 if (block_group->key.objectid < cache->key.objectid) {
98 p = &(*p)->rb_left;
99 } else if (block_group->key.objectid > cache->key.objectid) {
100 p = &(*p)->rb_right;
101 } else {
102 spin_unlock(&info->block_group_cache_lock);
103 return -EEXIST;
104 }
105 }
106
107 rb_link_node(&block_group->cache_node, parent, p);
108 rb_insert_color(&block_group->cache_node,
109 &info->block_group_cache_tree);
110 spin_unlock(&info->block_group_cache_lock);
111
112 return 0;
113 }
114
115 /*
116 * This will return the block group at or after bytenr if contains is 0, else
117 * it will return the block group that contains the bytenr
118 */
119 static struct btrfs_block_group_cache *
120 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
121 int contains)
122 {
123 struct btrfs_block_group_cache *cache, *ret = NULL;
124 struct rb_node *n;
125 u64 end, start;
126
127 spin_lock(&info->block_group_cache_lock);
128 n = info->block_group_cache_tree.rb_node;
129
130 while (n) {
131 cache = rb_entry(n, struct btrfs_block_group_cache,
132 cache_node);
133 end = cache->key.objectid + cache->key.offset - 1;
134 start = cache->key.objectid;
135
136 if (bytenr < start) {
137 if (!contains && (!ret || start < ret->key.objectid))
138 ret = cache;
139 n = n->rb_left;
140 } else if (bytenr > start) {
141 if (contains && bytenr <= end) {
142 ret = cache;
143 break;
144 }
145 n = n->rb_right;
146 } else {
147 ret = cache;
148 break;
149 }
150 }
151 spin_unlock(&info->block_group_cache_lock);
152
153 return ret;
154 }
155
156 /*
157 * this is only called by cache_block_group, since we could have freed extents
158 * we need to check the pinned_extents for any extents that can't be used yet
159 * since their free space will be released as soon as the transaction commits.
160 */
161 static int add_new_free_space(struct btrfs_block_group_cache *block_group,
162 struct btrfs_fs_info *info, u64 start, u64 end)
163 {
164 u64 extent_start, extent_end, size;
165 int ret;
166
167 while (start < end) {
168 ret = find_first_extent_bit(&info->pinned_extents, start,
169 &extent_start, &extent_end,
170 EXTENT_DIRTY);
171 if (ret)
172 break;
173
174 if (extent_start == start) {
175 start = extent_end + 1;
176 } else if (extent_start > start && extent_start < end) {
177 size = extent_start - start;
178 ret = btrfs_add_free_space(block_group, start, size);
179 BUG_ON(ret);
180 start = extent_end + 1;
181 } else {
182 break;
183 }
184 }
185
186 if (start < end) {
187 size = end - start;
188 ret = btrfs_add_free_space(block_group, start, size);
189 BUG_ON(ret);
190 }
191
192 return 0;
193 }
194
195 static int cache_block_group(struct btrfs_root *root,
196 struct btrfs_block_group_cache *block_group)
197 {
198 struct btrfs_path *path;
199 int ret = 0;
200 struct btrfs_key key;
201 struct extent_buffer *leaf;
202 int slot;
203 u64 last = 0;
204 u64 first_free;
205 int found = 0;
206
207 if (!block_group)
208 return 0;
209
210 root = root->fs_info->extent_root;
211
212 if (block_group->cached)
213 return 0;
214
215 path = btrfs_alloc_path();
216 if (!path)
217 return -ENOMEM;
218
219 path->reada = 2;
220 /*
221 * we get into deadlocks with paths held by callers of this function.
222 * since the alloc_mutex is protecting things right now, just
223 * skip the locking here
224 */
225 path->skip_locking = 1;
226 first_free = max_t(u64, block_group->key.objectid,
227 BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
228 key.objectid = block_group->key.objectid;
229 key.offset = 0;
230 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
231 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
232 if (ret < 0)
233 goto err;
234 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
235 if (ret < 0)
236 goto err;
237 if (ret == 0) {
238 leaf = path->nodes[0];
239 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
240 if (key.objectid + key.offset > first_free)
241 first_free = key.objectid + key.offset;
242 }
243 while(1) {
244 leaf = path->nodes[0];
245 slot = path->slots[0];
246 if (slot >= btrfs_header_nritems(leaf)) {
247 ret = btrfs_next_leaf(root, path);
248 if (ret < 0)
249 goto err;
250 if (ret == 0)
251 continue;
252 else
253 break;
254 }
255 btrfs_item_key_to_cpu(leaf, &key, slot);
256 if (key.objectid < block_group->key.objectid)
257 goto next;
258
259 if (key.objectid >= block_group->key.objectid +
260 block_group->key.offset)
261 break;
262
263 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
264 if (!found) {
265 last = first_free;
266 found = 1;
267 }
268
269 add_new_free_space(block_group, root->fs_info, last,
270 key.objectid);
271
272 last = key.objectid + key.offset;
273 }
274 next:
275 path->slots[0]++;
276 }
277
278 if (!found)
279 last = first_free;
280
281 add_new_free_space(block_group, root->fs_info, last,
282 block_group->key.objectid +
283 block_group->key.offset);
284
285 block_group->cached = 1;
286 ret = 0;
287 err:
288 btrfs_free_path(path);
289 return ret;
290 }
291
292 /*
293 * return the block group that starts at or after bytenr
294 */
295 struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
296 btrfs_fs_info *info,
297 u64 bytenr)
298 {
299 struct btrfs_block_group_cache *cache;
300
301 cache = block_group_cache_tree_search(info, bytenr, 0);
302
303 return cache;
304 }
305
306 /*
307 * return the block group that contains teh given bytenr
308 */
309 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
310 btrfs_fs_info *info,
311 u64 bytenr)
312 {
313 struct btrfs_block_group_cache *cache;
314
315 cache = block_group_cache_tree_search(info, bytenr, 1);
316
317 return cache;
318 }
319
320 static int noinline find_free_space(struct btrfs_root *root,
321 struct btrfs_block_group_cache **cache_ret,
322 u64 *start_ret, u64 num, int data)
323 {
324 int ret;
325 struct btrfs_block_group_cache *cache = *cache_ret;
326 struct btrfs_free_space *info = NULL;
327 u64 last;
328 u64 search_start = *start_ret;
329
330 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
331 if (!cache)
332 goto out;
333
334 last = max(search_start, cache->key.objectid);
335
336 again:
337 ret = cache_block_group(root, cache);
338 if (ret)
339 goto out;
340
341 if (cache->ro || !block_group_bits(cache, data))
342 goto new_group;
343
344 info = btrfs_find_free_space(cache, last, num);
345 if (info) {
346 *start_ret = info->offset;
347 return 0;
348 }
349
350 new_group:
351 last = cache->key.objectid + cache->key.offset;
352
353 cache = btrfs_lookup_first_block_group(root->fs_info, last);
354 if (!cache)
355 goto out;
356
357 *cache_ret = cache;
358 goto again;
359
360 out:
361 return -ENOSPC;
362 }
363
364 static u64 div_factor(u64 num, int factor)
365 {
366 if (factor == 10)
367 return num;
368 num *= factor;
369 do_div(num, 10);
370 return num;
371 }
372
373 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
374 u64 flags)
375 {
376 struct list_head *head = &info->space_info;
377 struct list_head *cur;
378 struct btrfs_space_info *found;
379 list_for_each(cur, head) {
380 found = list_entry(cur, struct btrfs_space_info, list);
381 if (found->flags == flags)
382 return found;
383 }
384 return NULL;
385 }
386
387 static struct btrfs_block_group_cache *
388 __btrfs_find_block_group(struct btrfs_root *root,
389 struct btrfs_block_group_cache *hint,
390 u64 search_start, int data, int owner)
391 {
392 struct btrfs_block_group_cache *cache;
393 struct btrfs_block_group_cache *found_group = NULL;
394 struct btrfs_fs_info *info = root->fs_info;
395 u64 used;
396 u64 last = 0;
397 u64 free_check;
398 int full_search = 0;
399 int factor = 10;
400 int wrapped = 0;
401
402 if (data & BTRFS_BLOCK_GROUP_METADATA)
403 factor = 9;
404
405 if (search_start) {
406 struct btrfs_block_group_cache *shint;
407 shint = btrfs_lookup_first_block_group(info, search_start);
408 if (shint && block_group_bits(shint, data) && !shint->ro) {
409 spin_lock(&shint->lock);
410 used = btrfs_block_group_used(&shint->item);
411 if (used + shint->pinned + shint->reserved <
412 div_factor(shint->key.offset, factor)) {
413 spin_unlock(&shint->lock);
414 return shint;
415 }
416 spin_unlock(&shint->lock);
417 }
418 }
419 if (hint && !hint->ro && block_group_bits(hint, data)) {
420 spin_lock(&hint->lock);
421 used = btrfs_block_group_used(&hint->item);
422 if (used + hint->pinned + hint->reserved <
423 div_factor(hint->key.offset, factor)) {
424 spin_unlock(&hint->lock);
425 return hint;
426 }
427 spin_unlock(&hint->lock);
428 last = hint->key.objectid + hint->key.offset;
429 } else {
430 if (hint)
431 last = max(hint->key.objectid, search_start);
432 else
433 last = search_start;
434 }
435 again:
436 while (1) {
437 cache = btrfs_lookup_first_block_group(root->fs_info, last);
438 if (!cache)
439 break;
440
441 spin_lock(&cache->lock);
442 last = cache->key.objectid + cache->key.offset;
443 used = btrfs_block_group_used(&cache->item);
444
445 if (!cache->ro && block_group_bits(cache, data)) {
446 free_check = div_factor(cache->key.offset, factor);
447 if (used + cache->pinned + cache->reserved <
448 free_check) {
449 found_group = cache;
450 spin_unlock(&cache->lock);
451 goto found;
452 }
453 }
454 spin_unlock(&cache->lock);
455 cond_resched();
456 }
457 if (!wrapped) {
458 last = search_start;
459 wrapped = 1;
460 goto again;
461 }
462 if (!full_search && factor < 10) {
463 last = search_start;
464 full_search = 1;
465 factor = 10;
466 goto again;
467 }
468 found:
469 return found_group;
470 }
471
472 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
473 struct btrfs_block_group_cache
474 *hint, u64 search_start,
475 int data, int owner)
476 {
477
478 struct btrfs_block_group_cache *ret;
479 ret = __btrfs_find_block_group(root, hint, search_start, data, owner);
480 return ret;
481 }
482
483 /* simple helper to search for an existing extent at a given offset */
484 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
485 {
486 int ret;
487 struct btrfs_key key;
488 struct btrfs_path *path;
489
490 path = btrfs_alloc_path();
491 BUG_ON(!path);
492 maybe_lock_mutex(root);
493 key.objectid = start;
494 key.offset = len;
495 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
496 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
497 0, 0);
498 maybe_unlock_mutex(root);
499 btrfs_free_path(path);
500 return ret;
501 }
502
503 /*
504 * Back reference rules. Back refs have three main goals:
505 *
506 * 1) differentiate between all holders of references to an extent so that
507 * when a reference is dropped we can make sure it was a valid reference
508 * before freeing the extent.
509 *
510 * 2) Provide enough information to quickly find the holders of an extent
511 * if we notice a given block is corrupted or bad.
512 *
513 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
514 * maintenance. This is actually the same as #2, but with a slightly
515 * different use case.
516 *
517 * File extents can be referenced by:
518 *
519 * - multiple snapshots, subvolumes, or different generations in one subvol
520 * - different files inside a single subvolume
521 * - different offsets inside a file (bookend extents in file.c)
522 *
523 * The extent ref structure has fields for:
524 *
525 * - Objectid of the subvolume root
526 * - Generation number of the tree holding the reference
527 * - objectid of the file holding the reference
528 * - number of references holding by parent node (alway 1 for tree blocks)
529 *
530 * Btree leaf may hold multiple references to a file extent. In most cases,
531 * these references are from same file and the corresponding offsets inside
532 * the file are close together.
533 *
534 * When a file extent is allocated the fields are filled in:
535 * (root_key.objectid, trans->transid, inode objectid, 1)
536 *
537 * When a leaf is cow'd new references are added for every file extent found
538 * in the leaf. It looks similar to the create case, but trans->transid will
539 * be different when the block is cow'd.
540 *
541 * (root_key.objectid, trans->transid, inode objectid,
542 * number of references in the leaf)
543 *
544 * When a file extent is removed either during snapshot deletion or
545 * file truncation, we find the corresponding back reference and check
546 * the following fields:
547 *
548 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
549 * inode objectid)
550 *
551 * Btree extents can be referenced by:
552 *
553 * - Different subvolumes
554 * - Different generations of the same subvolume
555 *
556 * When a tree block is created, back references are inserted:
557 *
558 * (root->root_key.objectid, trans->transid, level, 1)
559 *
560 * When a tree block is cow'd, new back references are added for all the
561 * blocks it points to. If the tree block isn't in reference counted root,
562 * the old back references are removed. These new back references are of
563 * the form (trans->transid will have increased since creation):
564 *
565 * (root->root_key.objectid, trans->transid, level, 1)
566 *
567 * When a backref is in deleting, the following fields are checked:
568 *
569 * if backref was for a tree root:
570 * (btrfs_header_owner(itself), btrfs_header_generation(itself), level)
571 * else
572 * (btrfs_header_owner(parent), btrfs_header_generation(parent), level)
573 *
574 * Back Reference Key composing:
575 *
576 * The key objectid corresponds to the first byte in the extent, the key
577 * type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first
578 * byte of parent extent. If a extent is tree root, the key offset is set
579 * to the key objectid.
580 */
581
582 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
583 struct btrfs_root *root,
584 struct btrfs_path *path,
585 u64 bytenr, u64 parent,
586 u64 ref_root, u64 ref_generation,
587 u64 owner_objectid, int del)
588 {
589 struct btrfs_key key;
590 struct btrfs_extent_ref *ref;
591 struct extent_buffer *leaf;
592 u64 ref_objectid;
593 int ret;
594
595 key.objectid = bytenr;
596 key.type = BTRFS_EXTENT_REF_KEY;
597 key.offset = parent;
598
599 ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1);
600 if (ret < 0)
601 goto out;
602 if (ret > 0) {
603 ret = -ENOENT;
604 goto out;
605 }
606
607 leaf = path->nodes[0];
608 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
609 ref_objectid = btrfs_ref_objectid(leaf, ref);
610 if (btrfs_ref_root(leaf, ref) != ref_root ||
611 btrfs_ref_generation(leaf, ref) != ref_generation ||
612 (ref_objectid != owner_objectid &&
613 ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
614 ret = -EIO;
615 WARN_ON(1);
616 goto out;
617 }
618 ret = 0;
619 out:
620 return ret;
621 }
622
623 static int noinline insert_extent_backref(struct btrfs_trans_handle *trans,
624 struct btrfs_root *root,
625 struct btrfs_path *path,
626 u64 bytenr, u64 parent,
627 u64 ref_root, u64 ref_generation,
628 u64 owner_objectid)
629 {
630 struct btrfs_key key;
631 struct extent_buffer *leaf;
632 struct btrfs_extent_ref *ref;
633 u32 num_refs;
634 int ret;
635
636 key.objectid = bytenr;
637 key.type = BTRFS_EXTENT_REF_KEY;
638 key.offset = parent;
639
640 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref));
641 if (ret == 0) {
642 leaf = path->nodes[0];
643 ref = btrfs_item_ptr(leaf, path->slots[0],
644 struct btrfs_extent_ref);
645 btrfs_set_ref_root(leaf, ref, ref_root);
646 btrfs_set_ref_generation(leaf, ref, ref_generation);
647 btrfs_set_ref_objectid(leaf, ref, owner_objectid);
648 btrfs_set_ref_num_refs(leaf, ref, 1);
649 } else if (ret == -EEXIST) {
650 u64 existing_owner;
651 BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID);
652 leaf = path->nodes[0];
653 ref = btrfs_item_ptr(leaf, path->slots[0],
654 struct btrfs_extent_ref);
655 if (btrfs_ref_root(leaf, ref) != ref_root ||
656 btrfs_ref_generation(leaf, ref) != ref_generation) {
657 ret = -EIO;
658 WARN_ON(1);
659 goto out;
660 }
661
662 num_refs = btrfs_ref_num_refs(leaf, ref);
663 BUG_ON(num_refs == 0);
664 btrfs_set_ref_num_refs(leaf, ref, num_refs + 1);
665
666 existing_owner = btrfs_ref_objectid(leaf, ref);
667 if (existing_owner != owner_objectid &&
668 existing_owner != BTRFS_MULTIPLE_OBJECTIDS) {
669 btrfs_set_ref_objectid(leaf, ref,
670 BTRFS_MULTIPLE_OBJECTIDS);
671 }
672 ret = 0;
673 } else {
674 goto out;
675 }
676 btrfs_mark_buffer_dirty(path->nodes[0]);
677 out:
678 btrfs_release_path(root, path);
679 return ret;
680 }
681
682 static int noinline remove_extent_backref(struct btrfs_trans_handle *trans,
683 struct btrfs_root *root,
684 struct btrfs_path *path)
685 {
686 struct extent_buffer *leaf;
687 struct btrfs_extent_ref *ref;
688 u32 num_refs;
689 int ret = 0;
690
691 leaf = path->nodes[0];
692 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
693 num_refs = btrfs_ref_num_refs(leaf, ref);
694 BUG_ON(num_refs == 0);
695 num_refs -= 1;
696 if (num_refs == 0) {
697 ret = btrfs_del_item(trans, root, path);
698 } else {
699 btrfs_set_ref_num_refs(leaf, ref, num_refs);
700 btrfs_mark_buffer_dirty(leaf);
701 }
702 btrfs_release_path(root, path);
703 return ret;
704 }
705
706 static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
707 struct btrfs_root *root, u64 bytenr,
708 u64 orig_parent, u64 parent,
709 u64 orig_root, u64 ref_root,
710 u64 orig_generation, u64 ref_generation,
711 u64 owner_objectid)
712 {
713 int ret;
714 struct btrfs_root *extent_root = root->fs_info->extent_root;
715 struct btrfs_path *path;
716
717 if (root == root->fs_info->extent_root) {
718 struct pending_extent_op *extent_op;
719 u64 num_bytes;
720
721 BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL);
722 num_bytes = btrfs_level_size(root, (int)owner_objectid);
723 if (test_range_bit(&root->fs_info->extent_ins, bytenr,
724 bytenr + num_bytes - 1, EXTENT_LOCKED, 0)) {
725 u64 priv;
726 ret = get_state_private(&root->fs_info->extent_ins,
727 bytenr, &priv);
728 BUG_ON(ret);
729 extent_op = (struct pending_extent_op *)
730 (unsigned long)priv;
731 BUG_ON(extent_op->parent != orig_parent);
732 BUG_ON(extent_op->generation != orig_generation);
733 extent_op->parent = parent;
734 extent_op->generation = ref_generation;
735 } else {
736 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
737 BUG_ON(!extent_op);
738
739 extent_op->type = PENDING_BACKREF_UPDATE;
740 extent_op->bytenr = bytenr;
741 extent_op->num_bytes = num_bytes;
742 extent_op->parent = parent;
743 extent_op->orig_parent = orig_parent;
744 extent_op->generation = ref_generation;
745 extent_op->orig_generation = orig_generation;
746 extent_op->level = (int)owner_objectid;
747
748 set_extent_bits(&root->fs_info->extent_ins,
749 bytenr, bytenr + num_bytes - 1,
750 EXTENT_LOCKED, GFP_NOFS);
751 set_state_private(&root->fs_info->extent_ins,
752 bytenr, (unsigned long)extent_op);
753 }
754 return 0;
755 }
756
757 path = btrfs_alloc_path();
758 if (!path)
759 return -ENOMEM;
760 ret = lookup_extent_backref(trans, extent_root, path,
761 bytenr, orig_parent, orig_root,
762 orig_generation, owner_objectid, 1);
763 if (ret)
764 goto out;
765 ret = remove_extent_backref(trans, extent_root, path);
766 if (ret)
767 goto out;
768 ret = insert_extent_backref(trans, extent_root, path, bytenr,
769 parent, ref_root, ref_generation,
770 owner_objectid);
771 BUG_ON(ret);
772 finish_current_insert(trans, extent_root);
773 del_pending_extents(trans, extent_root);
774 out:
775 btrfs_free_path(path);
776 return ret;
777 }
778
779 int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
780 struct btrfs_root *root, u64 bytenr,
781 u64 orig_parent, u64 parent,
782 u64 ref_root, u64 ref_generation,
783 u64 owner_objectid)
784 {
785 int ret;
786 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
787 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
788 return 0;
789 maybe_lock_mutex(root);
790 ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent,
791 parent, ref_root, ref_root,
792 ref_generation, ref_generation,
793 owner_objectid);
794 maybe_unlock_mutex(root);
795 return ret;
796 }
797
798 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
799 struct btrfs_root *root, u64 bytenr,
800 u64 orig_parent, u64 parent,
801 u64 orig_root, u64 ref_root,
802 u64 orig_generation, u64 ref_generation,
803 u64 owner_objectid)
804 {
805 struct btrfs_path *path;
806 int ret;
807 struct btrfs_key key;
808 struct extent_buffer *l;
809 struct btrfs_extent_item *item;
810 u32 refs;
811
812 path = btrfs_alloc_path();
813 if (!path)
814 return -ENOMEM;
815
816 path->reada = 1;
817 key.objectid = bytenr;
818 key.type = BTRFS_EXTENT_ITEM_KEY;
819 key.offset = (u64)-1;
820
821 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
822 0, 1);
823 if (ret < 0)
824 return ret;
825 BUG_ON(ret == 0 || path->slots[0] == 0);
826
827 path->slots[0]--;
828 l = path->nodes[0];
829
830 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
831 BUG_ON(key.objectid != bytenr);
832 BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY);
833
834 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
835 refs = btrfs_extent_refs(l, item);
836 btrfs_set_extent_refs(l, item, refs + 1);
837 btrfs_mark_buffer_dirty(path->nodes[0]);
838
839 btrfs_release_path(root->fs_info->extent_root, path);
840
841 path->reada = 1;
842 ret = insert_extent_backref(trans, root->fs_info->extent_root,
843 path, bytenr, parent,
844 ref_root, ref_generation,
845 owner_objectid);
846 BUG_ON(ret);
847 finish_current_insert(trans, root->fs_info->extent_root);
848 del_pending_extents(trans, root->fs_info->extent_root);
849
850 btrfs_free_path(path);
851 return 0;
852 }
853
854 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
855 struct btrfs_root *root,
856 u64 bytenr, u64 num_bytes, u64 parent,
857 u64 ref_root, u64 ref_generation,
858 u64 owner_objectid)
859 {
860 int ret;
861 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
862 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
863 return 0;
864 maybe_lock_mutex(root);
865 ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent,
866 0, ref_root, 0, ref_generation,
867 owner_objectid);
868 maybe_unlock_mutex(root);
869 return ret;
870 }
871
872 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
873 struct btrfs_root *root)
874 {
875 finish_current_insert(trans, root->fs_info->extent_root);
876 del_pending_extents(trans, root->fs_info->extent_root);
877 return 0;
878 }
879
880 int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
881 struct btrfs_root *root, u64 bytenr,
882 u64 num_bytes, u32 *refs)
883 {
884 struct btrfs_path *path;
885 int ret;
886 struct btrfs_key key;
887 struct extent_buffer *l;
888 struct btrfs_extent_item *item;
889
890 WARN_ON(num_bytes < root->sectorsize);
891 path = btrfs_alloc_path();
892 path->reada = 1;
893 key.objectid = bytenr;
894 key.offset = num_bytes;
895 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
896 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
897 0, 0);
898 if (ret < 0)
899 goto out;
900 if (ret != 0) {
901 btrfs_print_leaf(root, path->nodes[0]);
902 printk("failed to find block number %Lu\n", bytenr);
903 BUG();
904 }
905 l = path->nodes[0];
906 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
907 *refs = btrfs_extent_refs(l, item);
908 out:
909 btrfs_free_path(path);
910 return 0;
911 }
912
913 static int get_reference_status(struct btrfs_root *root, u64 bytenr,
914 u64 parent_gen, u64 ref_objectid,
915 u64 *min_generation, u32 *ref_count)
916 {
917 struct btrfs_root *extent_root = root->fs_info->extent_root;
918 struct btrfs_path *path;
919 struct extent_buffer *leaf;
920 struct btrfs_extent_ref *ref_item;
921 struct btrfs_key key;
922 struct btrfs_key found_key;
923 u64 root_objectid = root->root_key.objectid;
924 u64 ref_generation;
925 u32 nritems;
926 int ret;
927
928 key.objectid = bytenr;
929 key.offset = (u64)-1;
930 key.type = BTRFS_EXTENT_ITEM_KEY;
931
932 path = btrfs_alloc_path();
933 mutex_lock(&root->fs_info->alloc_mutex);
934 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
935 if (ret < 0)
936 goto out;
937 BUG_ON(ret == 0);
938 if (ret < 0 || path->slots[0] == 0)
939 goto out;
940
941 path->slots[0]--;
942 leaf = path->nodes[0];
943 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
944
945 if (found_key.objectid != bytenr ||
946 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
947 ret = 1;
948 goto out;
949 }
950
951 *ref_count = 0;
952 *min_generation = (u64)-1;
953
954 while (1) {
955 leaf = path->nodes[0];
956 nritems = btrfs_header_nritems(leaf);
957 if (path->slots[0] >= nritems) {
958 ret = btrfs_next_leaf(extent_root, path);
959 if (ret < 0)
960 goto out;
961 if (ret == 0)
962 continue;
963 break;
964 }
965 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
966 if (found_key.objectid != bytenr)
967 break;
968
969 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
970 path->slots[0]++;
971 continue;
972 }
973
974 ref_item = btrfs_item_ptr(leaf, path->slots[0],
975 struct btrfs_extent_ref);
976 ref_generation = btrfs_ref_generation(leaf, ref_item);
977 /*
978 * For (parent_gen > 0 && parent_gen > ref_generation):
979 *
980 * we reach here through the oldest root, therefore
981 * all other reference from same snapshot should have
982 * a larger generation.
983 */
984 if ((root_objectid != btrfs_ref_root(leaf, ref_item)) ||
985 (parent_gen > 0 && parent_gen > ref_generation) ||
986 (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
987 ref_objectid != btrfs_ref_objectid(leaf, ref_item))) {
988 *ref_count = 2;
989 break;
990 }
991
992 *ref_count = 1;
993 if (*min_generation > ref_generation)
994 *min_generation = ref_generation;
995
996 path->slots[0]++;
997 }
998 ret = 0;
999 out:
1000 mutex_unlock(&root->fs_info->alloc_mutex);
1001 btrfs_free_path(path);
1002 return ret;
1003 }
1004
1005 int btrfs_cross_ref_exists(struct btrfs_trans_handle *trans,
1006 struct btrfs_root *root,
1007 struct btrfs_key *key, u64 bytenr)
1008 {
1009 struct btrfs_root *old_root;
1010 struct btrfs_path *path = NULL;
1011 struct extent_buffer *eb;
1012 struct btrfs_file_extent_item *item;
1013 u64 ref_generation;
1014 u64 min_generation;
1015 u64 extent_start;
1016 u32 ref_count;
1017 int level;
1018 int ret;
1019
1020 BUG_ON(trans == NULL);
1021 BUG_ON(key->type != BTRFS_EXTENT_DATA_KEY);
1022 ret = get_reference_status(root, bytenr, 0, key->objectid,
1023 &min_generation, &ref_count);
1024 if (ret)
1025 return ret;
1026
1027 if (ref_count != 1)
1028 return 1;
1029
1030 old_root = root->dirty_root->root;
1031 ref_generation = old_root->root_key.offset;
1032
1033 /* all references are created in running transaction */
1034 if (min_generation > ref_generation) {
1035 ret = 0;
1036 goto out;
1037 }
1038
1039 path = btrfs_alloc_path();
1040 if (!path) {
1041 ret = -ENOMEM;
1042 goto out;
1043 }
1044
1045 path->skip_locking = 1;
1046 /* if no item found, the extent is referenced by other snapshot */
1047 ret = btrfs_search_slot(NULL, old_root, key, path, 0, 0);
1048 if (ret)
1049 goto out;
1050
1051 eb = path->nodes[0];
1052 item = btrfs_item_ptr(eb, path->slots[0],
1053 struct btrfs_file_extent_item);
1054 if (btrfs_file_extent_type(eb, item) != BTRFS_FILE_EXTENT_REG ||
1055 btrfs_file_extent_disk_bytenr(eb, item) != bytenr) {
1056 ret = 1;
1057 goto out;
1058 }
1059
1060 for (level = BTRFS_MAX_LEVEL - 1; level >= -1; level--) {
1061 if (level >= 0) {
1062 eb = path->nodes[level];
1063 if (!eb)
1064 continue;
1065 extent_start = eb->start;
1066 } else
1067 extent_start = bytenr;
1068
1069 ret = get_reference_status(root, extent_start, ref_generation,
1070 0, &min_generation, &ref_count);
1071 if (ret)
1072 goto out;
1073
1074 if (ref_count != 1) {
1075 ret = 1;
1076 goto out;
1077 }
1078 if (level >= 0)
1079 ref_generation = btrfs_header_generation(eb);
1080 }
1081 ret = 0;
1082 out:
1083 if (path)
1084 btrfs_free_path(path);
1085 return ret;
1086 }
1087
1088 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1089 struct extent_buffer *buf, u32 nr_extents)
1090 {
1091 struct btrfs_key key;
1092 struct btrfs_file_extent_item *fi;
1093 u64 root_gen;
1094 u32 nritems;
1095 int i;
1096 int level;
1097 int ret = 0;
1098 int shared = 0;
1099
1100 if (!root->ref_cows)
1101 return 0;
1102
1103 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1104 shared = 0;
1105 root_gen = root->root_key.offset;
1106 } else {
1107 shared = 1;
1108 root_gen = trans->transid - 1;
1109 }
1110
1111 level = btrfs_header_level(buf);
1112 nritems = btrfs_header_nritems(buf);
1113
1114 if (level == 0) {
1115 struct btrfs_leaf_ref *ref;
1116 struct btrfs_extent_info *info;
1117
1118 ref = btrfs_alloc_leaf_ref(root, nr_extents);
1119 if (!ref) {
1120 ret = -ENOMEM;
1121 goto out;
1122 }
1123
1124 ref->root_gen = root_gen;
1125 ref->bytenr = buf->start;
1126 ref->owner = btrfs_header_owner(buf);
1127 ref->generation = btrfs_header_generation(buf);
1128 ref->nritems = nr_extents;
1129 info = ref->extents;
1130
1131 for (i = 0; nr_extents > 0 && i < nritems; i++) {
1132 u64 disk_bytenr;
1133 btrfs_item_key_to_cpu(buf, &key, i);
1134 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1135 continue;
1136 fi = btrfs_item_ptr(buf, i,
1137 struct btrfs_file_extent_item);
1138 if (btrfs_file_extent_type(buf, fi) ==
1139 BTRFS_FILE_EXTENT_INLINE)
1140 continue;
1141 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1142 if (disk_bytenr == 0)
1143 continue;
1144
1145 info->bytenr = disk_bytenr;
1146 info->num_bytes =
1147 btrfs_file_extent_disk_num_bytes(buf, fi);
1148 info->objectid = key.objectid;
1149 info->offset = key.offset;
1150 info++;
1151 }
1152
1153 ret = btrfs_add_leaf_ref(root, ref, shared);
1154 if (ret == -EEXIST && shared) {
1155 struct btrfs_leaf_ref *old;
1156 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
1157 BUG_ON(!old);
1158 btrfs_remove_leaf_ref(root, old);
1159 btrfs_free_leaf_ref(root, old);
1160 ret = btrfs_add_leaf_ref(root, ref, shared);
1161 }
1162 WARN_ON(ret);
1163 btrfs_free_leaf_ref(root, ref);
1164 }
1165 out:
1166 return ret;
1167 }
1168
1169 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1170 struct extent_buffer *orig_buf, struct extent_buffer *buf,
1171 u32 *nr_extents)
1172 {
1173 u64 bytenr;
1174 u64 ref_root;
1175 u64 orig_root;
1176 u64 ref_generation;
1177 u64 orig_generation;
1178 u32 nritems;
1179 u32 nr_file_extents = 0;
1180 struct btrfs_key key;
1181 struct btrfs_file_extent_item *fi;
1182 int i;
1183 int level;
1184 int ret = 0;
1185 int faili = 0;
1186 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
1187 u64, u64, u64, u64, u64, u64, u64, u64);
1188
1189 ref_root = btrfs_header_owner(buf);
1190 ref_generation = btrfs_header_generation(buf);
1191 orig_root = btrfs_header_owner(orig_buf);
1192 orig_generation = btrfs_header_generation(orig_buf);
1193
1194 nritems = btrfs_header_nritems(buf);
1195 level = btrfs_header_level(buf);
1196
1197 if (root->ref_cows) {
1198 process_func = __btrfs_inc_extent_ref;
1199 } else {
1200 if (level == 0 &&
1201 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1202 goto out;
1203 if (level != 0 &&
1204 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1205 goto out;
1206 process_func = __btrfs_update_extent_ref;
1207 }
1208
1209 for (i = 0; i < nritems; i++) {
1210 cond_resched();
1211 if (level == 0) {
1212 btrfs_item_key_to_cpu(buf, &key, i);
1213 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1214 continue;
1215 fi = btrfs_item_ptr(buf, i,
1216 struct btrfs_file_extent_item);
1217 if (btrfs_file_extent_type(buf, fi) ==
1218 BTRFS_FILE_EXTENT_INLINE)
1219 continue;
1220 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1221 if (bytenr == 0)
1222 continue;
1223
1224 nr_file_extents++;
1225
1226 maybe_lock_mutex(root);
1227 ret = process_func(trans, root, bytenr,
1228 orig_buf->start, buf->start,
1229 orig_root, ref_root,
1230 orig_generation, ref_generation,
1231 key.objectid);
1232 maybe_unlock_mutex(root);
1233
1234 if (ret) {
1235 faili = i;
1236 WARN_ON(1);
1237 goto fail;
1238 }
1239 } else {
1240 bytenr = btrfs_node_blockptr(buf, i);
1241 maybe_lock_mutex(root);
1242 ret = process_func(trans, root, bytenr,
1243 orig_buf->start, buf->start,
1244 orig_root, ref_root,
1245 orig_generation, ref_generation,
1246 level - 1);
1247 maybe_unlock_mutex(root);
1248 if (ret) {
1249 faili = i;
1250 WARN_ON(1);
1251 goto fail;
1252 }
1253 }
1254 }
1255 out:
1256 if (nr_extents) {
1257 if (level == 0)
1258 *nr_extents = nr_file_extents;
1259 else
1260 *nr_extents = nritems;
1261 }
1262 return 0;
1263 fail:
1264 WARN_ON(1);
1265 return ret;
1266 }
1267
1268 int btrfs_update_ref(struct btrfs_trans_handle *trans,
1269 struct btrfs_root *root, struct extent_buffer *orig_buf,
1270 struct extent_buffer *buf, int start_slot, int nr)
1271
1272 {
1273 u64 bytenr;
1274 u64 ref_root;
1275 u64 orig_root;
1276 u64 ref_generation;
1277 u64 orig_generation;
1278 struct btrfs_key key;
1279 struct btrfs_file_extent_item *fi;
1280 int i;
1281 int ret;
1282 int slot;
1283 int level;
1284
1285 BUG_ON(start_slot < 0);
1286 BUG_ON(start_slot + nr > btrfs_header_nritems(buf));
1287
1288 ref_root = btrfs_header_owner(buf);
1289 ref_generation = btrfs_header_generation(buf);
1290 orig_root = btrfs_header_owner(orig_buf);
1291 orig_generation = btrfs_header_generation(orig_buf);
1292 level = btrfs_header_level(buf);
1293
1294 if (!root->ref_cows) {
1295 if (level == 0 &&
1296 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1297 return 0;
1298 if (level != 0 &&
1299 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1300 return 0;
1301 }
1302
1303 for (i = 0, slot = start_slot; i < nr; i++, slot++) {
1304 cond_resched();
1305 if (level == 0) {
1306 btrfs_item_key_to_cpu(buf, &key, slot);
1307 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1308 continue;
1309 fi = btrfs_item_ptr(buf, slot,
1310 struct btrfs_file_extent_item);
1311 if (btrfs_file_extent_type(buf, fi) ==
1312 BTRFS_FILE_EXTENT_INLINE)
1313 continue;
1314 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1315 if (bytenr == 0)
1316 continue;
1317 maybe_lock_mutex(root);
1318 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1319 orig_buf->start, buf->start,
1320 orig_root, ref_root,
1321 orig_generation, ref_generation,
1322 key.objectid);
1323 maybe_unlock_mutex(root);
1324 if (ret)
1325 goto fail;
1326 } else {
1327 bytenr = btrfs_node_blockptr(buf, slot);
1328 maybe_lock_mutex(root);
1329 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1330 orig_buf->start, buf->start,
1331 orig_root, ref_root,
1332 orig_generation, ref_generation,
1333 level - 1);
1334 maybe_unlock_mutex(root);
1335 if (ret)
1336 goto fail;
1337 }
1338 }
1339 return 0;
1340 fail:
1341 WARN_ON(1);
1342 return -1;
1343 }
1344
1345 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1346 struct btrfs_root *root,
1347 struct btrfs_path *path,
1348 struct btrfs_block_group_cache *cache)
1349 {
1350 int ret;
1351 int pending_ret;
1352 struct btrfs_root *extent_root = root->fs_info->extent_root;
1353 unsigned long bi;
1354 struct extent_buffer *leaf;
1355
1356 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1357 if (ret < 0)
1358 goto fail;
1359 BUG_ON(ret);
1360
1361 leaf = path->nodes[0];
1362 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1363 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1364 btrfs_mark_buffer_dirty(leaf);
1365 btrfs_release_path(extent_root, path);
1366 fail:
1367 finish_current_insert(trans, extent_root);
1368 pending_ret = del_pending_extents(trans, extent_root);
1369 if (ret)
1370 return ret;
1371 if (pending_ret)
1372 return pending_ret;
1373 return 0;
1374
1375 }
1376
1377 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1378 struct btrfs_root *root)
1379 {
1380 struct btrfs_block_group_cache *cache, *entry;
1381 struct rb_node *n;
1382 int err = 0;
1383 int werr = 0;
1384 struct btrfs_path *path;
1385 u64 last = 0;
1386
1387 path = btrfs_alloc_path();
1388 if (!path)
1389 return -ENOMEM;
1390
1391 mutex_lock(&root->fs_info->alloc_mutex);
1392 while(1) {
1393 cache = NULL;
1394 spin_lock(&root->fs_info->block_group_cache_lock);
1395 for (n = rb_first(&root->fs_info->block_group_cache_tree);
1396 n; n = rb_next(n)) {
1397 entry = rb_entry(n, struct btrfs_block_group_cache,
1398 cache_node);
1399 if (entry->dirty) {
1400 cache = entry;
1401 break;
1402 }
1403 }
1404 spin_unlock(&root->fs_info->block_group_cache_lock);
1405
1406 if (!cache)
1407 break;
1408
1409 cache->dirty = 0;
1410 last += cache->key.offset;
1411
1412 err = write_one_cache_group(trans, root,
1413 path, cache);
1414 /*
1415 * if we fail to write the cache group, we want
1416 * to keep it marked dirty in hopes that a later
1417 * write will work
1418 */
1419 if (err) {
1420 werr = err;
1421 continue;
1422 }
1423 }
1424 btrfs_free_path(path);
1425 mutex_unlock(&root->fs_info->alloc_mutex);
1426 return werr;
1427 }
1428
1429 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1430 u64 total_bytes, u64 bytes_used,
1431 struct btrfs_space_info **space_info)
1432 {
1433 struct btrfs_space_info *found;
1434
1435 found = __find_space_info(info, flags);
1436 if (found) {
1437 found->total_bytes += total_bytes;
1438 found->bytes_used += bytes_used;
1439 found->full = 0;
1440 *space_info = found;
1441 return 0;
1442 }
1443 found = kmalloc(sizeof(*found), GFP_NOFS);
1444 if (!found)
1445 return -ENOMEM;
1446
1447 list_add(&found->list, &info->space_info);
1448 INIT_LIST_HEAD(&found->block_groups);
1449 spin_lock_init(&found->lock);
1450 found->flags = flags;
1451 found->total_bytes = total_bytes;
1452 found->bytes_used = bytes_used;
1453 found->bytes_pinned = 0;
1454 found->bytes_reserved = 0;
1455 found->full = 0;
1456 found->force_alloc = 0;
1457 *space_info = found;
1458 return 0;
1459 }
1460
1461 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1462 {
1463 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1464 BTRFS_BLOCK_GROUP_RAID1 |
1465 BTRFS_BLOCK_GROUP_RAID10 |
1466 BTRFS_BLOCK_GROUP_DUP);
1467 if (extra_flags) {
1468 if (flags & BTRFS_BLOCK_GROUP_DATA)
1469 fs_info->avail_data_alloc_bits |= extra_flags;
1470 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1471 fs_info->avail_metadata_alloc_bits |= extra_flags;
1472 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1473 fs_info->avail_system_alloc_bits |= extra_flags;
1474 }
1475 }
1476
1477 static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags)
1478 {
1479 u64 num_devices = root->fs_info->fs_devices->num_devices;
1480
1481 if (num_devices == 1)
1482 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
1483 if (num_devices < 4)
1484 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
1485
1486 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
1487 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
1488 BTRFS_BLOCK_GROUP_RAID10))) {
1489 flags &= ~BTRFS_BLOCK_GROUP_DUP;
1490 }
1491
1492 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
1493 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
1494 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
1495 }
1496
1497 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
1498 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
1499 (flags & BTRFS_BLOCK_GROUP_RAID10) |
1500 (flags & BTRFS_BLOCK_GROUP_DUP)))
1501 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
1502 return flags;
1503 }
1504
1505 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1506 struct btrfs_root *extent_root, u64 alloc_bytes,
1507 u64 flags, int force)
1508 {
1509 struct btrfs_space_info *space_info;
1510 u64 thresh;
1511 u64 start;
1512 u64 num_bytes;
1513 int ret = 0, waited = 0;
1514
1515 flags = reduce_alloc_profile(extent_root, flags);
1516
1517 space_info = __find_space_info(extent_root->fs_info, flags);
1518 if (!space_info) {
1519 ret = update_space_info(extent_root->fs_info, flags,
1520 0, 0, &space_info);
1521 BUG_ON(ret);
1522 }
1523 BUG_ON(!space_info);
1524
1525 if (space_info->force_alloc) {
1526 force = 1;
1527 space_info->force_alloc = 0;
1528 }
1529 if (space_info->full)
1530 goto out;
1531
1532 thresh = div_factor(space_info->total_bytes, 6);
1533 if (!force &&
1534 (space_info->bytes_used + space_info->bytes_pinned +
1535 space_info->bytes_reserved + alloc_bytes) < thresh)
1536 goto out;
1537
1538 while (!mutex_trylock(&extent_root->fs_info->chunk_mutex)) {
1539 if (!force)
1540 goto out;
1541 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1542 cond_resched();
1543 mutex_lock(&extent_root->fs_info->alloc_mutex);
1544 waited = 1;
1545 }
1546
1547 if (waited && space_info->full)
1548 goto out_unlock;
1549
1550 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1551 if (ret == -ENOSPC) {
1552 printk("space info full %Lu\n", flags);
1553 space_info->full = 1;
1554 goto out_unlock;
1555 }
1556 BUG_ON(ret);
1557
1558 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1559 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1560 BUG_ON(ret);
1561
1562 out_unlock:
1563 mutex_unlock(&extent_root->fs_info->chunk_mutex);
1564 out:
1565 return ret;
1566 }
1567
1568 static int update_block_group(struct btrfs_trans_handle *trans,
1569 struct btrfs_root *root,
1570 u64 bytenr, u64 num_bytes, int alloc,
1571 int mark_free)
1572 {
1573 struct btrfs_block_group_cache *cache;
1574 struct btrfs_fs_info *info = root->fs_info;
1575 u64 total = num_bytes;
1576 u64 old_val;
1577 u64 byte_in_group;
1578
1579 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1580 while(total) {
1581 cache = btrfs_lookup_block_group(info, bytenr);
1582 if (!cache) {
1583 return -1;
1584 }
1585 byte_in_group = bytenr - cache->key.objectid;
1586 WARN_ON(byte_in_group > cache->key.offset);
1587
1588 spin_lock(&cache->lock);
1589 cache->dirty = 1;
1590 old_val = btrfs_block_group_used(&cache->item);
1591 num_bytes = min(total, cache->key.offset - byte_in_group);
1592 if (alloc) {
1593 old_val += num_bytes;
1594 cache->space_info->bytes_used += num_bytes;
1595 btrfs_set_block_group_used(&cache->item, old_val);
1596 spin_unlock(&cache->lock);
1597 } else {
1598 old_val -= num_bytes;
1599 cache->space_info->bytes_used -= num_bytes;
1600 btrfs_set_block_group_used(&cache->item, old_val);
1601 spin_unlock(&cache->lock);
1602 if (mark_free) {
1603 int ret;
1604 ret = btrfs_add_free_space(cache, bytenr,
1605 num_bytes);
1606 if (ret)
1607 return -1;
1608 }
1609 }
1610 total -= num_bytes;
1611 bytenr += num_bytes;
1612 }
1613 return 0;
1614 }
1615
1616 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
1617 {
1618 struct btrfs_block_group_cache *cache;
1619
1620 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
1621 if (!cache)
1622 return 0;
1623
1624 return cache->key.objectid;
1625 }
1626
1627 int btrfs_update_pinned_extents(struct btrfs_root *root,
1628 u64 bytenr, u64 num, int pin)
1629 {
1630 u64 len;
1631 struct btrfs_block_group_cache *cache;
1632 struct btrfs_fs_info *fs_info = root->fs_info;
1633
1634 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1635 if (pin) {
1636 set_extent_dirty(&fs_info->pinned_extents,
1637 bytenr, bytenr + num - 1, GFP_NOFS);
1638 } else {
1639 clear_extent_dirty(&fs_info->pinned_extents,
1640 bytenr, bytenr + num - 1, GFP_NOFS);
1641 }
1642 while (num > 0) {
1643 cache = btrfs_lookup_block_group(fs_info, bytenr);
1644 BUG_ON(!cache);
1645 len = min(num, cache->key.offset -
1646 (bytenr - cache->key.objectid));
1647 if (pin) {
1648 spin_lock(&cache->lock);
1649 cache->pinned += len;
1650 cache->space_info->bytes_pinned += len;
1651 spin_unlock(&cache->lock);
1652 fs_info->total_pinned += len;
1653 } else {
1654 spin_lock(&cache->lock);
1655 cache->pinned -= len;
1656 cache->space_info->bytes_pinned -= len;
1657 spin_unlock(&cache->lock);
1658 fs_info->total_pinned -= len;
1659 }
1660 bytenr += len;
1661 num -= len;
1662 }
1663 return 0;
1664 }
1665
1666 static int update_reserved_extents(struct btrfs_root *root,
1667 u64 bytenr, u64 num, int reserve)
1668 {
1669 u64 len;
1670 struct btrfs_block_group_cache *cache;
1671 struct btrfs_fs_info *fs_info = root->fs_info;
1672
1673 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1674 while (num > 0) {
1675 cache = btrfs_lookup_block_group(fs_info, bytenr);
1676 BUG_ON(!cache);
1677 len = min(num, cache->key.offset -
1678 (bytenr - cache->key.objectid));
1679 if (reserve) {
1680 spin_lock(&cache->lock);
1681 cache->reserved += len;
1682 cache->space_info->bytes_reserved += len;
1683 spin_unlock(&cache->lock);
1684 } else {
1685 spin_lock(&cache->lock);
1686 cache->reserved -= len;
1687 cache->space_info->bytes_reserved -= len;
1688 spin_unlock(&cache->lock);
1689 }
1690 bytenr += len;
1691 num -= len;
1692 }
1693 return 0;
1694 }
1695
1696 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1697 {
1698 u64 last = 0;
1699 u64 start;
1700 u64 end;
1701 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1702 int ret;
1703
1704 while(1) {
1705 ret = find_first_extent_bit(pinned_extents, last,
1706 &start, &end, EXTENT_DIRTY);
1707 if (ret)
1708 break;
1709 set_extent_dirty(copy, start, end, GFP_NOFS);
1710 last = end + 1;
1711 }
1712 return 0;
1713 }
1714
1715 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1716 struct btrfs_root *root,
1717 struct extent_io_tree *unpin)
1718 {
1719 u64 start;
1720 u64 end;
1721 int ret;
1722 struct btrfs_block_group_cache *cache;
1723
1724 mutex_lock(&root->fs_info->alloc_mutex);
1725 while(1) {
1726 ret = find_first_extent_bit(unpin, 0, &start, &end,
1727 EXTENT_DIRTY);
1728 if (ret)
1729 break;
1730 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
1731 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1732 cache = btrfs_lookup_block_group(root->fs_info, start);
1733 if (cache->cached)
1734 btrfs_add_free_space(cache, start, end - start + 1);
1735 if (need_resched()) {
1736 mutex_unlock(&root->fs_info->alloc_mutex);
1737 cond_resched();
1738 mutex_lock(&root->fs_info->alloc_mutex);
1739 }
1740 }
1741 mutex_unlock(&root->fs_info->alloc_mutex);
1742 return 0;
1743 }
1744
1745 static int finish_current_insert(struct btrfs_trans_handle *trans,
1746 struct btrfs_root *extent_root)
1747 {
1748 u64 start;
1749 u64 end;
1750 u64 priv;
1751 struct btrfs_fs_info *info = extent_root->fs_info;
1752 struct btrfs_path *path;
1753 struct btrfs_extent_ref *ref;
1754 struct pending_extent_op *extent_op;
1755 struct btrfs_key key;
1756 struct btrfs_extent_item extent_item;
1757 int ret;
1758 int err = 0;
1759
1760 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
1761 btrfs_set_stack_extent_refs(&extent_item, 1);
1762 path = btrfs_alloc_path();
1763
1764 while(1) {
1765 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1766 &end, EXTENT_LOCKED);
1767 if (ret)
1768 break;
1769
1770 ret = get_state_private(&info->extent_ins, start, &priv);
1771 BUG_ON(ret);
1772 extent_op = (struct pending_extent_op *)(unsigned long)priv;
1773
1774 if (extent_op->type == PENDING_EXTENT_INSERT) {
1775 key.objectid = start;
1776 key.offset = end + 1 - start;
1777 key.type = BTRFS_EXTENT_ITEM_KEY;
1778 err = btrfs_insert_item(trans, extent_root, &key,
1779 &extent_item, sizeof(extent_item));
1780 BUG_ON(err);
1781
1782 clear_extent_bits(&info->extent_ins, start, end,
1783 EXTENT_LOCKED, GFP_NOFS);
1784
1785 err = insert_extent_backref(trans, extent_root, path,
1786 start, extent_op->parent,
1787 extent_root->root_key.objectid,
1788 extent_op->generation,
1789 extent_op->level);
1790 BUG_ON(err);
1791 } else if (extent_op->type == PENDING_BACKREF_UPDATE) {
1792 err = lookup_extent_backref(trans, extent_root, path,
1793 start, extent_op->orig_parent,
1794 extent_root->root_key.objectid,
1795 extent_op->orig_generation,
1796 extent_op->level, 0);
1797 BUG_ON(err);
1798
1799 clear_extent_bits(&info->extent_ins, start, end,
1800 EXTENT_LOCKED, GFP_NOFS);
1801
1802 key.objectid = start;
1803 key.offset = extent_op->parent;
1804 key.type = BTRFS_EXTENT_REF_KEY;
1805 err = btrfs_set_item_key_safe(trans, extent_root, path,
1806 &key);
1807 BUG_ON(err);
1808 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1809 struct btrfs_extent_ref);
1810 btrfs_set_ref_generation(path->nodes[0], ref,
1811 extent_op->generation);
1812 btrfs_mark_buffer_dirty(path->nodes[0]);
1813 btrfs_release_path(extent_root, path);
1814 } else {
1815 BUG_ON(1);
1816 }
1817 kfree(extent_op);
1818
1819 if (need_resched()) {
1820 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1821 cond_resched();
1822 mutex_lock(&extent_root->fs_info->alloc_mutex);
1823 }
1824 }
1825 btrfs_free_path(path);
1826 return 0;
1827 }
1828
1829 static int pin_down_bytes(struct btrfs_trans_handle *trans,
1830 struct btrfs_root *root,
1831 u64 bytenr, u64 num_bytes, int is_data)
1832 {
1833 int err = 0;
1834 struct extent_buffer *buf;
1835
1836 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1837 if (is_data)
1838 goto pinit;
1839
1840 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1841 if (!buf)
1842 goto pinit;
1843
1844 /* we can reuse a block if it hasn't been written
1845 * and it is from this transaction. We can't
1846 * reuse anything from the tree log root because
1847 * it has tiny sub-transactions.
1848 */
1849 if (btrfs_buffer_uptodate(buf, 0) &&
1850 btrfs_try_tree_lock(buf)) {
1851 u64 header_owner = btrfs_header_owner(buf);
1852 u64 header_transid = btrfs_header_generation(buf);
1853 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
1854 header_owner != BTRFS_TREE_RELOC_OBJECTID &&
1855 header_transid == trans->transid &&
1856 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
1857 clean_tree_block(NULL, root, buf);
1858 btrfs_tree_unlock(buf);
1859 free_extent_buffer(buf);
1860 return 1;
1861 }
1862 btrfs_tree_unlock(buf);
1863 }
1864 free_extent_buffer(buf);
1865 pinit:
1866 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
1867
1868 BUG_ON(err < 0);
1869 return 0;
1870 }
1871
1872 /*
1873 * remove an extent from the root, returns 0 on success
1874 */
1875 static int __free_extent(struct btrfs_trans_handle *trans,
1876 struct btrfs_root *root,
1877 u64 bytenr, u64 num_bytes, u64 parent,
1878 u64 root_objectid, u64 ref_generation,
1879 u64 owner_objectid, int pin, int mark_free)
1880 {
1881 struct btrfs_path *path;
1882 struct btrfs_key key;
1883 struct btrfs_fs_info *info = root->fs_info;
1884 struct btrfs_root *extent_root = info->extent_root;
1885 struct extent_buffer *leaf;
1886 int ret;
1887 int extent_slot = 0;
1888 int found_extent = 0;
1889 int num_to_del = 1;
1890 struct btrfs_extent_item *ei;
1891 u32 refs;
1892
1893 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1894 key.objectid = bytenr;
1895 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1896 key.offset = num_bytes;
1897 path = btrfs_alloc_path();
1898 if (!path)
1899 return -ENOMEM;
1900
1901 path->reada = 1;
1902 ret = lookup_extent_backref(trans, extent_root, path,
1903 bytenr, parent, root_objectid,
1904 ref_generation, owner_objectid, 1);
1905 if (ret == 0) {
1906 struct btrfs_key found_key;
1907 extent_slot = path->slots[0];
1908 while(extent_slot > 0) {
1909 extent_slot--;
1910 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1911 extent_slot);
1912 if (found_key.objectid != bytenr)
1913 break;
1914 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1915 found_key.offset == num_bytes) {
1916 found_extent = 1;
1917 break;
1918 }
1919 if (path->slots[0] - extent_slot > 5)
1920 break;
1921 }
1922 if (!found_extent) {
1923 ret = remove_extent_backref(trans, extent_root, path);
1924 BUG_ON(ret);
1925 btrfs_release_path(extent_root, path);
1926 ret = btrfs_search_slot(trans, extent_root,
1927 &key, path, -1, 1);
1928 BUG_ON(ret);
1929 extent_slot = path->slots[0];
1930 }
1931 } else {
1932 btrfs_print_leaf(extent_root, path->nodes[0]);
1933 WARN_ON(1);
1934 printk("Unable to find ref byte nr %Lu root %Lu "
1935 "gen %Lu owner %Lu\n", bytenr,
1936 root_objectid, ref_generation, owner_objectid);
1937 }
1938
1939 leaf = path->nodes[0];
1940 ei = btrfs_item_ptr(leaf, extent_slot,
1941 struct btrfs_extent_item);
1942 refs = btrfs_extent_refs(leaf, ei);
1943 BUG_ON(refs == 0);
1944 refs -= 1;
1945 btrfs_set_extent_refs(leaf, ei, refs);
1946
1947 btrfs_mark_buffer_dirty(leaf);
1948
1949 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1950 struct btrfs_extent_ref *ref;
1951 ref = btrfs_item_ptr(leaf, path->slots[0],
1952 struct btrfs_extent_ref);
1953 BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1);
1954 /* if the back ref and the extent are next to each other
1955 * they get deleted below in one shot
1956 */
1957 path->slots[0] = extent_slot;
1958 num_to_del = 2;
1959 } else if (found_extent) {
1960 /* otherwise delete the extent back ref */
1961 ret = remove_extent_backref(trans, extent_root, path);
1962 BUG_ON(ret);
1963 /* if refs are 0, we need to setup the path for deletion */
1964 if (refs == 0) {
1965 btrfs_release_path(extent_root, path);
1966 ret = btrfs_search_slot(trans, extent_root, &key, path,
1967 -1, 1);
1968 BUG_ON(ret);
1969 }
1970 }
1971
1972 if (refs == 0) {
1973 u64 super_used;
1974 u64 root_used;
1975 #ifdef BIO_RW_DISCARD
1976 u64 map_length = num_bytes;
1977 struct btrfs_multi_bio *multi = NULL;
1978 #endif
1979
1980 if (pin) {
1981 ret = pin_down_bytes(trans, root, bytenr, num_bytes,
1982 owner_objectid >= BTRFS_FIRST_FREE_OBJECTID);
1983 if (ret > 0)
1984 mark_free = 1;
1985 BUG_ON(ret < 0);
1986 }
1987
1988 /* block accounting for super block */
1989 spin_lock_irq(&info->delalloc_lock);
1990 super_used = btrfs_super_bytes_used(&info->super_copy);
1991 btrfs_set_super_bytes_used(&info->super_copy,
1992 super_used - num_bytes);
1993 spin_unlock_irq(&info->delalloc_lock);
1994
1995 /* block accounting for root item */
1996 root_used = btrfs_root_used(&root->root_item);
1997 btrfs_set_root_used(&root->root_item,
1998 root_used - num_bytes);
1999 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
2000 num_to_del);
2001 BUG_ON(ret);
2002 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
2003 mark_free);
2004 BUG_ON(ret);
2005
2006 #ifdef BIO_RW_DISCARD
2007 /* Tell the block device(s) that the sectors can be discarded */
2008 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
2009 bytenr, &map_length, &multi, 0);
2010 if (!ret) {
2011 struct btrfs_bio_stripe *stripe = multi->stripes;
2012 int i;
2013
2014 if (map_length > num_bytes)
2015 map_length = num_bytes;
2016
2017 for (i = 0; i < multi->num_stripes; i++, stripe++) {
2018 blkdev_issue_discard(stripe->dev->bdev,
2019 stripe->physical >> 9,
2020 map_length >> 9);
2021 }
2022 kfree(multi);
2023 }
2024 #endif
2025 }
2026 btrfs_free_path(path);
2027 finish_current_insert(trans, extent_root);
2028 return ret;
2029 }
2030
2031 /*
2032 * find all the blocks marked as pending in the radix tree and remove
2033 * them from the extent map
2034 */
2035 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
2036 btrfs_root *extent_root)
2037 {
2038 int ret;
2039 int err = 0;
2040 int mark_free = 0;
2041 u64 start;
2042 u64 end;
2043 u64 priv;
2044 struct extent_io_tree *pending_del;
2045 struct extent_io_tree *extent_ins;
2046 struct pending_extent_op *extent_op;
2047
2048 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
2049 extent_ins = &extent_root->fs_info->extent_ins;
2050 pending_del = &extent_root->fs_info->pending_del;
2051
2052 while(1) {
2053 ret = find_first_extent_bit(pending_del, 0, &start, &end,
2054 EXTENT_LOCKED);
2055 if (ret)
2056 break;
2057
2058 ret = get_state_private(pending_del, start, &priv);
2059 BUG_ON(ret);
2060 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2061
2062 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
2063 GFP_NOFS);
2064
2065 ret = pin_down_bytes(trans, extent_root, start,
2066 end + 1 - start, 0);
2067 mark_free = ret > 0;
2068 if (!test_range_bit(extent_ins, start, end,
2069 EXTENT_LOCKED, 0)) {
2070 free_extent:
2071 ret = __free_extent(trans, extent_root,
2072 start, end + 1 - start,
2073 extent_op->orig_parent,
2074 extent_root->root_key.objectid,
2075 extent_op->orig_generation,
2076 extent_op->level, 0, mark_free);
2077 kfree(extent_op);
2078 } else {
2079 kfree(extent_op);
2080 ret = get_state_private(extent_ins, start, &priv);
2081 BUG_ON(ret);
2082 extent_op = (struct pending_extent_op *)
2083 (unsigned long)priv;
2084
2085 clear_extent_bits(extent_ins, start, end,
2086 EXTENT_LOCKED, GFP_NOFS);
2087
2088 if (extent_op->type == PENDING_BACKREF_UPDATE)
2089 goto free_extent;
2090
2091 ret = update_block_group(trans, extent_root, start,
2092 end + 1 - start, 0, mark_free);
2093 BUG_ON(ret);
2094 kfree(extent_op);
2095 }
2096 if (ret)
2097 err = ret;
2098
2099 if (need_resched()) {
2100 mutex_unlock(&extent_root->fs_info->alloc_mutex);
2101 cond_resched();
2102 mutex_lock(&extent_root->fs_info->alloc_mutex);
2103 }
2104 }
2105 return err;
2106 }
2107
2108 /*
2109 * remove an extent from the root, returns 0 on success
2110 */
2111 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
2112 struct btrfs_root *root,
2113 u64 bytenr, u64 num_bytes, u64 parent,
2114 u64 root_objectid, u64 ref_generation,
2115 u64 owner_objectid, int pin)
2116 {
2117 struct btrfs_root *extent_root = root->fs_info->extent_root;
2118 int pending_ret;
2119 int ret;
2120
2121 WARN_ON(num_bytes < root->sectorsize);
2122 if (root == extent_root) {
2123 struct pending_extent_op *extent_op;
2124
2125 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2126 BUG_ON(!extent_op);
2127
2128 extent_op->type = PENDING_EXTENT_DELETE;
2129 extent_op->bytenr = bytenr;
2130 extent_op->num_bytes = num_bytes;
2131 extent_op->parent = parent;
2132 extent_op->orig_parent = parent;
2133 extent_op->generation = ref_generation;
2134 extent_op->orig_generation = ref_generation;
2135 extent_op->level = (int)owner_objectid;
2136
2137 set_extent_bits(&root->fs_info->pending_del,
2138 bytenr, bytenr + num_bytes - 1,
2139 EXTENT_LOCKED, GFP_NOFS);
2140 set_state_private(&root->fs_info->pending_del,
2141 bytenr, (unsigned long)extent_op);
2142 return 0;
2143 }
2144 /* if metadata always pin */
2145 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
2146 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2147 struct btrfs_block_group_cache *cache;
2148
2149 /* btrfs_free_reserved_extent */
2150 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
2151 BUG_ON(!cache);
2152 btrfs_add_free_space(cache, bytenr, num_bytes);
2153 update_reserved_extents(root, bytenr, num_bytes, 0);
2154 return 0;
2155 }
2156 pin = 1;
2157 }
2158
2159 /* if data pin when any transaction has committed this */
2160 if (ref_generation != trans->transid)
2161 pin = 1;
2162
2163 ret = __free_extent(trans, root, bytenr, num_bytes, parent,
2164 root_objectid, ref_generation,
2165 owner_objectid, pin, pin == 0);
2166
2167 finish_current_insert(trans, root->fs_info->extent_root);
2168 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
2169 return ret ? ret : pending_ret;
2170 }
2171
2172 int btrfs_free_extent(struct btrfs_trans_handle *trans,
2173 struct btrfs_root *root,
2174 u64 bytenr, u64 num_bytes, u64 parent,
2175 u64 root_objectid, u64 ref_generation,
2176 u64 owner_objectid, int pin)
2177 {
2178 int ret;
2179
2180 maybe_lock_mutex(root);
2181 ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent,
2182 root_objectid, ref_generation,
2183 owner_objectid, pin);
2184 maybe_unlock_mutex(root);
2185 return ret;
2186 }
2187
2188 static u64 stripe_align(struct btrfs_root *root, u64 val)
2189 {
2190 u64 mask = ((u64)root->stripesize - 1);
2191 u64 ret = (val + mask) & ~mask;
2192 return ret;
2193 }
2194
2195 /*
2196 * walks the btree of allocated extents and find a hole of a given size.
2197 * The key ins is changed to record the hole:
2198 * ins->objectid == block start
2199 * ins->flags = BTRFS_EXTENT_ITEM_KEY
2200 * ins->offset == number of blocks
2201 * Any available blocks before search_start are skipped.
2202 */
2203 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
2204 struct btrfs_root *orig_root,
2205 u64 num_bytes, u64 empty_size,
2206 u64 search_start, u64 search_end,
2207 u64 hint_byte, struct btrfs_key *ins,
2208 u64 exclude_start, u64 exclude_nr,
2209 int data)
2210 {
2211 int ret;
2212 u64 orig_search_start;
2213 struct btrfs_root * root = orig_root->fs_info->extent_root;
2214 struct btrfs_fs_info *info = root->fs_info;
2215 u64 total_needed = num_bytes;
2216 u64 *last_ptr = NULL;
2217 struct btrfs_block_group_cache *block_group;
2218 int chunk_alloc_done = 0;
2219 int empty_cluster = 2 * 1024 * 1024;
2220 int allowed_chunk_alloc = 0;
2221
2222 WARN_ON(num_bytes < root->sectorsize);
2223 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
2224
2225 if (orig_root->ref_cows || empty_size)
2226 allowed_chunk_alloc = 1;
2227
2228 if (data & BTRFS_BLOCK_GROUP_METADATA) {
2229 last_ptr = &root->fs_info->last_alloc;
2230 empty_cluster = 256 * 1024;
2231 }
2232
2233 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
2234 last_ptr = &root->fs_info->last_data_alloc;
2235
2236 if (last_ptr) {
2237 if (*last_ptr)
2238 hint_byte = *last_ptr;
2239 else
2240 empty_size += empty_cluster;
2241 }
2242
2243 search_start = max(search_start, first_logical_byte(root, 0));
2244 orig_search_start = search_start;
2245
2246 search_start = max(search_start, hint_byte);
2247 total_needed += empty_size;
2248
2249 new_group:
2250 block_group = btrfs_lookup_block_group(info, search_start);
2251 if (!block_group)
2252 block_group = btrfs_lookup_first_block_group(info,
2253 search_start);
2254
2255 /*
2256 * Ok this looks a little tricky, buts its really simple. First if we
2257 * didn't find a block group obviously we want to start over.
2258 * Secondly, if the block group we found does not match the type we
2259 * need, and we have a last_ptr and its not 0, chances are the last
2260 * allocation we made was at the end of the block group, so lets go
2261 * ahead and skip the looking through the rest of the block groups and
2262 * start at the beginning. This helps with metadata allocations,
2263 * since you are likely to have a bunch of data block groups to search
2264 * through first before you realize that you need to start over, so go
2265 * ahead and start over and save the time.
2266 */
2267 if (!block_group || (!block_group_bits(block_group, data) &&
2268 last_ptr && *last_ptr)) {
2269 if (search_start != orig_search_start) {
2270 if (last_ptr && *last_ptr) {
2271 total_needed += empty_cluster;
2272 *last_ptr = 0;
2273 }
2274 search_start = orig_search_start;
2275 goto new_group;
2276 } else if (!chunk_alloc_done && allowed_chunk_alloc) {
2277 ret = do_chunk_alloc(trans, root,
2278 num_bytes + 2 * 1024 * 1024,
2279 data, 1);
2280 if (ret < 0)
2281 goto error;
2282 BUG_ON(ret);
2283 chunk_alloc_done = 1;
2284 search_start = orig_search_start;
2285 goto new_group;
2286 } else {
2287 ret = -ENOSPC;
2288 goto error;
2289 }
2290 }
2291
2292 /*
2293 * this is going to seach through all of the existing block groups it
2294 * can find, so if we don't find something we need to see if we can
2295 * allocate what we need.
2296 */
2297 ret = find_free_space(root, &block_group, &search_start,
2298 total_needed, data);
2299 if (ret == -ENOSPC) {
2300 /*
2301 * instead of allocating, start at the original search start
2302 * and see if there is something to be found, if not then we
2303 * allocate
2304 */
2305 if (search_start != orig_search_start) {
2306 if (last_ptr && *last_ptr) {
2307 *last_ptr = 0;
2308 total_needed += empty_cluster;
2309 }
2310 search_start = orig_search_start;
2311 goto new_group;
2312 }
2313
2314 /*
2315 * we've already allocated, we're pretty screwed
2316 */
2317 if (chunk_alloc_done) {
2318 goto error;
2319 } else if (!allowed_chunk_alloc && block_group &&
2320 block_group_bits(block_group, data)) {
2321 block_group->space_info->force_alloc = 1;
2322 goto error;
2323 } else if (!allowed_chunk_alloc) {
2324 goto error;
2325 }
2326
2327 ret = do_chunk_alloc(trans, root, num_bytes + 2 * 1024 * 1024,
2328 data, 1);
2329 if (ret < 0)
2330 goto error;
2331
2332 BUG_ON(ret);
2333 chunk_alloc_done = 1;
2334 if (block_group)
2335 search_start = block_group->key.objectid +
2336 block_group->key.offset;
2337 else
2338 search_start = orig_search_start;
2339 goto new_group;
2340 }
2341
2342 if (ret)
2343 goto error;
2344
2345 search_start = stripe_align(root, search_start);
2346 ins->objectid = search_start;
2347 ins->offset = num_bytes;
2348
2349 if (ins->objectid + num_bytes >= search_end) {
2350 search_start = orig_search_start;
2351 if (chunk_alloc_done) {
2352 ret = -ENOSPC;
2353 goto error;
2354 }
2355 goto new_group;
2356 }
2357
2358 if (ins->objectid + num_bytes >
2359 block_group->key.objectid + block_group->key.offset) {
2360 if (search_start == orig_search_start && chunk_alloc_done) {
2361 ret = -ENOSPC;
2362 goto error;
2363 }
2364 search_start = block_group->key.objectid +
2365 block_group->key.offset;
2366 goto new_group;
2367 }
2368
2369 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
2370 ins->objectid < exclude_start + exclude_nr)) {
2371 search_start = exclude_start + exclude_nr;
2372 goto new_group;
2373 }
2374
2375 if (!(data & BTRFS_BLOCK_GROUP_DATA))
2376 trans->block_group = block_group;
2377
2378 ins->offset = num_bytes;
2379 if (last_ptr) {
2380 *last_ptr = ins->objectid + ins->offset;
2381 if (*last_ptr ==
2382 btrfs_super_total_bytes(&root->fs_info->super_copy))
2383 *last_ptr = 0;
2384 }
2385
2386 ret = 0;
2387 error:
2388 return ret;
2389 }
2390
2391 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
2392 {
2393 struct btrfs_block_group_cache *cache;
2394 struct list_head *l;
2395
2396 printk(KERN_INFO "space_info has %Lu free, is %sfull\n",
2397 info->total_bytes - info->bytes_used - info->bytes_pinned -
2398 info->bytes_reserved, (info->full) ? "" : "not ");
2399
2400 spin_lock(&info->lock);
2401 list_for_each(l, &info->block_groups) {
2402 cache = list_entry(l, struct btrfs_block_group_cache, list);
2403 spin_lock(&cache->lock);
2404 printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used "
2405 "%Lu pinned %Lu reserved\n",
2406 cache->key.objectid, cache->key.offset,
2407 btrfs_block_group_used(&cache->item),
2408 cache->pinned, cache->reserved);
2409 btrfs_dump_free_space(cache, bytes);
2410 spin_unlock(&cache->lock);
2411 }
2412 spin_unlock(&info->lock);
2413 }
2414
2415 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2416 struct btrfs_root *root,
2417 u64 num_bytes, u64 min_alloc_size,
2418 u64 empty_size, u64 hint_byte,
2419 u64 search_end, struct btrfs_key *ins,
2420 u64 data)
2421 {
2422 int ret;
2423 u64 search_start = 0;
2424 u64 alloc_profile;
2425 struct btrfs_fs_info *info = root->fs_info;
2426 struct btrfs_block_group_cache *cache;
2427
2428 if (data) {
2429 alloc_profile = info->avail_data_alloc_bits &
2430 info->data_alloc_profile;
2431 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2432 } else if (root == root->fs_info->chunk_root) {
2433 alloc_profile = info->avail_system_alloc_bits &
2434 info->system_alloc_profile;
2435 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2436 } else {
2437 alloc_profile = info->avail_metadata_alloc_bits &
2438 info->metadata_alloc_profile;
2439 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2440 }
2441 again:
2442 data = reduce_alloc_profile(root, data);
2443 /*
2444 * the only place that sets empty_size is btrfs_realloc_node, which
2445 * is not called recursively on allocations
2446 */
2447 if (empty_size || root->ref_cows) {
2448 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
2449 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2450 2 * 1024 * 1024,
2451 BTRFS_BLOCK_GROUP_METADATA |
2452 (info->metadata_alloc_profile &
2453 info->avail_metadata_alloc_bits), 0);
2454 }
2455 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2456 num_bytes + 2 * 1024 * 1024, data, 0);
2457 }
2458
2459 WARN_ON(num_bytes < root->sectorsize);
2460 ret = find_free_extent(trans, root, num_bytes, empty_size,
2461 search_start, search_end, hint_byte, ins,
2462 trans->alloc_exclude_start,
2463 trans->alloc_exclude_nr, data);
2464
2465 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
2466 num_bytes = num_bytes >> 1;
2467 num_bytes = num_bytes & ~(root->sectorsize - 1);
2468 num_bytes = max(num_bytes, min_alloc_size);
2469 do_chunk_alloc(trans, root->fs_info->extent_root,
2470 num_bytes, data, 1);
2471 goto again;
2472 }
2473 if (ret) {
2474 struct btrfs_space_info *sinfo;
2475
2476 sinfo = __find_space_info(root->fs_info, data);
2477 printk("allocation failed flags %Lu, wanted %Lu\n",
2478 data, num_bytes);
2479 dump_space_info(sinfo, num_bytes);
2480 BUG();
2481 }
2482 cache = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2483 if (!cache) {
2484 printk(KERN_ERR "Unable to find block group for %Lu\n", ins->objectid);
2485 return -ENOSPC;
2486 }
2487
2488 ret = btrfs_remove_free_space(cache, ins->objectid, ins->offset);
2489
2490 return ret;
2491 }
2492
2493 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
2494 {
2495 struct btrfs_block_group_cache *cache;
2496
2497 maybe_lock_mutex(root);
2498 cache = btrfs_lookup_block_group(root->fs_info, start);
2499 if (!cache) {
2500 printk(KERN_ERR "Unable to find block group for %Lu\n", start);
2501 maybe_unlock_mutex(root);
2502 return -ENOSPC;
2503 }
2504 btrfs_add_free_space(cache, start, len);
2505 update_reserved_extents(root, start, len, 0);
2506 maybe_unlock_mutex(root);
2507 return 0;
2508 }
2509
2510 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2511 struct btrfs_root *root,
2512 u64 num_bytes, u64 min_alloc_size,
2513 u64 empty_size, u64 hint_byte,
2514 u64 search_end, struct btrfs_key *ins,
2515 u64 data)
2516 {
2517 int ret;
2518 maybe_lock_mutex(root);
2519 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
2520 empty_size, hint_byte, search_end, ins,
2521 data);
2522 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2523 maybe_unlock_mutex(root);
2524 return ret;
2525 }
2526
2527 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2528 struct btrfs_root *root, u64 parent,
2529 u64 root_objectid, u64 ref_generation,
2530 u64 owner, struct btrfs_key *ins)
2531 {
2532 int ret;
2533 int pending_ret;
2534 u64 super_used;
2535 u64 root_used;
2536 u64 num_bytes = ins->offset;
2537 u32 sizes[2];
2538 struct btrfs_fs_info *info = root->fs_info;
2539 struct btrfs_root *extent_root = info->extent_root;
2540 struct btrfs_extent_item *extent_item;
2541 struct btrfs_extent_ref *ref;
2542 struct btrfs_path *path;
2543 struct btrfs_key keys[2];
2544
2545 if (parent == 0)
2546 parent = ins->objectid;
2547
2548 /* block accounting for super block */
2549 spin_lock_irq(&info->delalloc_lock);
2550 super_used = btrfs_super_bytes_used(&info->super_copy);
2551 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
2552 spin_unlock_irq(&info->delalloc_lock);
2553
2554 /* block accounting for root item */
2555 root_used = btrfs_root_used(&root->root_item);
2556 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
2557
2558 if (root == extent_root) {
2559 struct pending_extent_op *extent_op;
2560
2561 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2562 BUG_ON(!extent_op);
2563
2564 extent_op->type = PENDING_EXTENT_INSERT;
2565 extent_op->bytenr = ins->objectid;
2566 extent_op->num_bytes = ins->offset;
2567 extent_op->parent = parent;
2568 extent_op->orig_parent = 0;
2569 extent_op->generation = ref_generation;
2570 extent_op->orig_generation = 0;
2571 extent_op->level = (int)owner;
2572
2573 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2574 ins->objectid + ins->offset - 1,
2575 EXTENT_LOCKED, GFP_NOFS);
2576 set_state_private(&root->fs_info->extent_ins,
2577 ins->objectid, (unsigned long)extent_op);
2578 goto update_block;
2579 }
2580
2581 memcpy(&keys[0], ins, sizeof(*ins));
2582 keys[1].objectid = ins->objectid;
2583 keys[1].type = BTRFS_EXTENT_REF_KEY;
2584 keys[1].offset = parent;
2585 sizes[0] = sizeof(*extent_item);
2586 sizes[1] = sizeof(*ref);
2587
2588 path = btrfs_alloc_path();
2589 BUG_ON(!path);
2590
2591 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
2592 sizes, 2);
2593 BUG_ON(ret);
2594
2595 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2596 struct btrfs_extent_item);
2597 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
2598 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
2599 struct btrfs_extent_ref);
2600
2601 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
2602 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
2603 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
2604 btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
2605
2606 btrfs_mark_buffer_dirty(path->nodes[0]);
2607
2608 trans->alloc_exclude_start = 0;
2609 trans->alloc_exclude_nr = 0;
2610 btrfs_free_path(path);
2611 finish_current_insert(trans, extent_root);
2612 pending_ret = del_pending_extents(trans, extent_root);
2613
2614 if (ret)
2615 goto out;
2616 if (pending_ret) {
2617 ret = pending_ret;
2618 goto out;
2619 }
2620
2621 update_block:
2622 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
2623 if (ret) {
2624 printk("update block group failed for %Lu %Lu\n",
2625 ins->objectid, ins->offset);
2626 BUG();
2627 }
2628 out:
2629 return ret;
2630 }
2631
2632 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2633 struct btrfs_root *root, u64 parent,
2634 u64 root_objectid, u64 ref_generation,
2635 u64 owner, struct btrfs_key *ins)
2636 {
2637 int ret;
2638
2639 if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
2640 return 0;
2641 maybe_lock_mutex(root);
2642 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
2643 ref_generation, owner, ins);
2644 update_reserved_extents(root, ins->objectid, ins->offset, 0);
2645 maybe_unlock_mutex(root);
2646 return ret;
2647 }
2648
2649 /*
2650 * this is used by the tree logging recovery code. It records that
2651 * an extent has been allocated and makes sure to clear the free
2652 * space cache bits as well
2653 */
2654 int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
2655 struct btrfs_root *root, u64 parent,
2656 u64 root_objectid, u64 ref_generation,
2657 u64 owner, struct btrfs_key *ins)
2658 {
2659 int ret;
2660 struct btrfs_block_group_cache *block_group;
2661
2662 maybe_lock_mutex(root);
2663 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2664 cache_block_group(root, block_group);
2665
2666 ret = btrfs_remove_free_space(block_group, ins->objectid, ins->offset);
2667 BUG_ON(ret);
2668 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
2669 ref_generation, owner, ins);
2670 maybe_unlock_mutex(root);
2671 return ret;
2672 }
2673
2674 /*
2675 * finds a free extent and does all the dirty work required for allocation
2676 * returns the key for the extent through ins, and a tree buffer for
2677 * the first block of the extent through buf.
2678 *
2679 * returns 0 if everything worked, non-zero otherwise.
2680 */
2681 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
2682 struct btrfs_root *root,
2683 u64 num_bytes, u64 parent, u64 min_alloc_size,
2684 u64 root_objectid, u64 ref_generation,
2685 u64 owner_objectid, u64 empty_size, u64 hint_byte,
2686 u64 search_end, struct btrfs_key *ins, u64 data)
2687 {
2688 int ret;
2689
2690 maybe_lock_mutex(root);
2691
2692 ret = __btrfs_reserve_extent(trans, root, num_bytes,
2693 min_alloc_size, empty_size, hint_byte,
2694 search_end, ins, data);
2695 BUG_ON(ret);
2696 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
2697 ret = __btrfs_alloc_reserved_extent(trans, root, parent,
2698 root_objectid, ref_generation,
2699 owner_objectid, ins);
2700 BUG_ON(ret);
2701
2702 } else {
2703 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2704 }
2705 maybe_unlock_mutex(root);
2706 return ret;
2707 }
2708
2709 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
2710 struct btrfs_root *root,
2711 u64 bytenr, u32 blocksize)
2712 {
2713 struct extent_buffer *buf;
2714
2715 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
2716 if (!buf)
2717 return ERR_PTR(-ENOMEM);
2718 btrfs_set_header_generation(buf, trans->transid);
2719 btrfs_tree_lock(buf);
2720 clean_tree_block(trans, root, buf);
2721 btrfs_set_buffer_uptodate(buf);
2722 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2723 set_extent_dirty(&root->dirty_log_pages, buf->start,
2724 buf->start + buf->len - 1, GFP_NOFS);
2725 } else {
2726 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
2727 buf->start + buf->len - 1, GFP_NOFS);
2728 }
2729 trans->blocks_used++;
2730 return buf;
2731 }
2732
2733 /*
2734 * helper function to allocate a block for a given tree
2735 * returns the tree buffer or NULL.
2736 */
2737 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2738 struct btrfs_root *root,
2739 u32 blocksize, u64 parent,
2740 u64 root_objectid,
2741 u64 ref_generation,
2742 int level,
2743 u64 hint,
2744 u64 empty_size)
2745 {
2746 struct btrfs_key ins;
2747 int ret;
2748 struct extent_buffer *buf;
2749
2750 ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
2751 root_objectid, ref_generation, level,
2752 empty_size, hint, (u64)-1, &ins, 0);
2753 if (ret) {
2754 BUG_ON(ret > 0);
2755 return ERR_PTR(ret);
2756 }
2757
2758 buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
2759 return buf;
2760 }
2761
2762 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
2763 struct btrfs_root *root, struct extent_buffer *leaf)
2764 {
2765 u64 leaf_owner;
2766 u64 leaf_generation;
2767 struct btrfs_key key;
2768 struct btrfs_file_extent_item *fi;
2769 int i;
2770 int nritems;
2771 int ret;
2772
2773 BUG_ON(!btrfs_is_leaf(leaf));
2774 nritems = btrfs_header_nritems(leaf);
2775 leaf_owner = btrfs_header_owner(leaf);
2776 leaf_generation = btrfs_header_generation(leaf);
2777
2778 for (i = 0; i < nritems; i++) {
2779 u64 disk_bytenr;
2780 cond_resched();
2781
2782 btrfs_item_key_to_cpu(leaf, &key, i);
2783 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2784 continue;
2785 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2786 if (btrfs_file_extent_type(leaf, fi) ==
2787 BTRFS_FILE_EXTENT_INLINE)
2788 continue;
2789 /*
2790 * FIXME make sure to insert a trans record that
2791 * repeats the snapshot del on crash
2792 */
2793 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2794 if (disk_bytenr == 0)
2795 continue;
2796
2797 mutex_lock(&root->fs_info->alloc_mutex);
2798 ret = __btrfs_free_extent(trans, root, disk_bytenr,
2799 btrfs_file_extent_disk_num_bytes(leaf, fi),
2800 leaf->start, leaf_owner, leaf_generation,
2801 key.objectid, 0);
2802 mutex_unlock(&root->fs_info->alloc_mutex);
2803 BUG_ON(ret);
2804
2805 atomic_inc(&root->fs_info->throttle_gen);
2806 wake_up(&root->fs_info->transaction_throttle);
2807 cond_resched();
2808 }
2809 return 0;
2810 }
2811
2812 static int noinline cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
2813 struct btrfs_root *root,
2814 struct btrfs_leaf_ref *ref)
2815 {
2816 int i;
2817 int ret;
2818 struct btrfs_extent_info *info = ref->extents;
2819
2820 for (i = 0; i < ref->nritems; i++) {
2821 mutex_lock(&root->fs_info->alloc_mutex);
2822 ret = __btrfs_free_extent(trans, root, info->bytenr,
2823 info->num_bytes, ref->bytenr,
2824 ref->owner, ref->generation,
2825 info->objectid, 0);
2826 mutex_unlock(&root->fs_info->alloc_mutex);
2827
2828 atomic_inc(&root->fs_info->throttle_gen);
2829 wake_up(&root->fs_info->transaction_throttle);
2830 cond_resched();
2831
2832 BUG_ON(ret);
2833 info++;
2834 }
2835
2836 return 0;
2837 }
2838
2839 int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len,
2840 u32 *refs)
2841 {
2842 int ret;
2843
2844 ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
2845 BUG_ON(ret);
2846
2847 #if 0 // some debugging code in case we see problems here
2848 /* if the refs count is one, it won't get increased again. But
2849 * if the ref count is > 1, someone may be decreasing it at
2850 * the same time we are.
2851 */
2852 if (*refs != 1) {
2853 struct extent_buffer *eb = NULL;
2854 eb = btrfs_find_create_tree_block(root, start, len);
2855 if (eb)
2856 btrfs_tree_lock(eb);
2857
2858 mutex_lock(&root->fs_info->alloc_mutex);
2859 ret = lookup_extent_ref(NULL, root, start, len, refs);
2860 BUG_ON(ret);
2861 mutex_unlock(&root->fs_info->alloc_mutex);
2862
2863 if (eb) {
2864 btrfs_tree_unlock(eb);
2865 free_extent_buffer(eb);
2866 }
2867 if (*refs == 1) {
2868 printk("block %llu went down to one during drop_snap\n",
2869 (unsigned long long)start);
2870 }
2871
2872 }
2873 #endif
2874
2875 cond_resched();
2876 return ret;
2877 }
2878
2879 /*
2880 * helper function for drop_snapshot, this walks down the tree dropping ref
2881 * counts as it goes.
2882 */
2883 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2884 struct btrfs_root *root,
2885 struct btrfs_path *path, int *level)
2886 {
2887 u64 root_owner;
2888 u64 root_gen;
2889 u64 bytenr;
2890 u64 ptr_gen;
2891 struct extent_buffer *next;
2892 struct extent_buffer *cur;
2893 struct extent_buffer *parent;
2894 struct btrfs_leaf_ref *ref;
2895 u32 blocksize;
2896 int ret;
2897 u32 refs;
2898
2899 WARN_ON(*level < 0);
2900 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2901 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
2902 path->nodes[*level]->len, &refs);
2903 BUG_ON(ret);
2904 if (refs > 1)
2905 goto out;
2906
2907 /*
2908 * walk down to the last node level and free all the leaves
2909 */
2910 while(*level >= 0) {
2911 WARN_ON(*level < 0);
2912 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2913 cur = path->nodes[*level];
2914
2915 if (btrfs_header_level(cur) != *level)
2916 WARN_ON(1);
2917
2918 if (path->slots[*level] >=
2919 btrfs_header_nritems(cur))
2920 break;
2921 if (*level == 0) {
2922 ret = btrfs_drop_leaf_ref(trans, root, cur);
2923 BUG_ON(ret);
2924 break;
2925 }
2926 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2927 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2928 blocksize = btrfs_level_size(root, *level - 1);
2929
2930 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
2931 BUG_ON(ret);
2932 if (refs != 1) {
2933 parent = path->nodes[*level];
2934 root_owner = btrfs_header_owner(parent);
2935 root_gen = btrfs_header_generation(parent);
2936 path->slots[*level]++;
2937
2938 mutex_lock(&root->fs_info->alloc_mutex);
2939 ret = __btrfs_free_extent(trans, root, bytenr,
2940 blocksize, parent->start,
2941 root_owner, root_gen,
2942 *level - 1, 1);
2943 BUG_ON(ret);
2944 mutex_unlock(&root->fs_info->alloc_mutex);
2945
2946 atomic_inc(&root->fs_info->throttle_gen);
2947 wake_up(&root->fs_info->transaction_throttle);
2948 cond_resched();
2949
2950 continue;
2951 }
2952 /*
2953 * at this point, we have a single ref, and since the
2954 * only place referencing this extent is a dead root
2955 * the reference count should never go higher.
2956 * So, we don't need to check it again
2957 */
2958 if (*level == 1) {
2959 ref = btrfs_lookup_leaf_ref(root, bytenr);
2960 if (ref && ref->generation != ptr_gen) {
2961 btrfs_free_leaf_ref(root, ref);
2962 ref = NULL;
2963 }
2964 if (ref) {
2965 ret = cache_drop_leaf_ref(trans, root, ref);
2966 BUG_ON(ret);
2967 btrfs_remove_leaf_ref(root, ref);
2968 btrfs_free_leaf_ref(root, ref);
2969 *level = 0;
2970 break;
2971 }
2972 if (printk_ratelimit()) {
2973 printk("leaf ref miss for bytenr %llu\n",
2974 (unsigned long long)bytenr);
2975 }
2976 }
2977 next = btrfs_find_tree_block(root, bytenr, blocksize);
2978 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2979 free_extent_buffer(next);
2980
2981 next = read_tree_block(root, bytenr, blocksize,
2982 ptr_gen);
2983 cond_resched();
2984 #if 0
2985 /*
2986 * this is a debugging check and can go away
2987 * the ref should never go all the way down to 1
2988 * at this point
2989 */
2990 ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
2991 &refs);
2992 BUG_ON(ret);
2993 WARN_ON(refs != 1);
2994 #endif
2995 }
2996 WARN_ON(*level <= 0);
2997 if (path->nodes[*level-1])
2998 free_extent_buffer(path->nodes[*level-1]);
2999 path->nodes[*level-1] = next;
3000 *level = btrfs_header_level(next);
3001 path->slots[*level] = 0;
3002 cond_resched();
3003 }
3004 out:
3005 WARN_ON(*level < 0);
3006 WARN_ON(*level >= BTRFS_MAX_LEVEL);
3007
3008 if (path->nodes[*level] == root->node) {
3009 parent = path->nodes[*level];
3010 bytenr = path->nodes[*level]->start;
3011 } else {
3012 parent = path->nodes[*level + 1];
3013 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
3014 }
3015
3016 blocksize = btrfs_level_size(root, *level);
3017 root_owner = btrfs_header_owner(parent);
3018 root_gen = btrfs_header_generation(parent);
3019
3020 mutex_lock(&root->fs_info->alloc_mutex);
3021 ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
3022 parent->start, root_owner, root_gen,
3023 *level, 1);
3024 mutex_unlock(&root->fs_info->alloc_mutex);
3025 free_extent_buffer(path->nodes[*level]);
3026 path->nodes[*level] = NULL;
3027 *level += 1;
3028 BUG_ON(ret);
3029
3030 cond_resched();
3031 return 0;
3032 }
3033
3034 /*
3035 * helper for dropping snapshots. This walks back up the tree in the path
3036 * to find the first node higher up where we haven't yet gone through
3037 * all the slots
3038 */
3039 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
3040 struct btrfs_root *root,
3041 struct btrfs_path *path, int *level)
3042 {
3043 u64 root_owner;
3044 u64 root_gen;
3045 struct btrfs_root_item *root_item = &root->root_item;
3046 int i;
3047 int slot;
3048 int ret;
3049
3050 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
3051 slot = path->slots[i];
3052 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
3053 struct extent_buffer *node;
3054 struct btrfs_disk_key disk_key;
3055 node = path->nodes[i];
3056 path->slots[i]++;
3057 *level = i;
3058 WARN_ON(*level == 0);
3059 btrfs_node_key(node, &disk_key, path->slots[i]);
3060 memcpy(&root_item->drop_progress,
3061 &disk_key, sizeof(disk_key));
3062 root_item->drop_level = i;
3063 return 0;
3064 } else {
3065 struct extent_buffer *parent;
3066 if (path->nodes[*level] == root->node)
3067 parent = path->nodes[*level];
3068 else
3069 parent = path->nodes[*level + 1];
3070
3071 root_owner = btrfs_header_owner(parent);
3072 root_gen = btrfs_header_generation(parent);
3073 ret = btrfs_free_extent(trans, root,
3074 path->nodes[*level]->start,
3075 path->nodes[*level]->len,
3076 parent->start, root_owner,
3077 root_gen, *level, 1);
3078 BUG_ON(ret);
3079 free_extent_buffer(path->nodes[*level]);
3080 path->nodes[*level] = NULL;
3081 *level = i + 1;
3082 }
3083 }
3084 return 1;
3085 }
3086
3087 /*
3088 * drop the reference count on the tree rooted at 'snap'. This traverses
3089 * the tree freeing any blocks that have a ref count of zero after being
3090 * decremented.
3091 */
3092 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
3093 *root)
3094 {
3095 int ret = 0;
3096 int wret;
3097 int level;
3098 struct btrfs_path *path;
3099 int i;
3100 int orig_level;
3101 struct btrfs_root_item *root_item = &root->root_item;
3102
3103 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
3104 path = btrfs_alloc_path();
3105 BUG_ON(!path);
3106
3107 level = btrfs_header_level(root->node);
3108 orig_level = level;
3109 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
3110 path->nodes[level] = root->node;
3111 extent_buffer_get(root->node);
3112 path->slots[level] = 0;
3113 } else {
3114 struct btrfs_key key;
3115 struct btrfs_disk_key found_key;
3116 struct extent_buffer *node;
3117
3118 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
3119 level = root_item->drop_level;
3120 path->lowest_level = level;
3121 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3122 if (wret < 0) {
3123 ret = wret;
3124 goto out;
3125 }
3126 node = path->nodes[level];
3127 btrfs_node_key(node, &found_key, path->slots[level]);
3128 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
3129 sizeof(found_key)));
3130 /*
3131 * unlock our path, this is safe because only this
3132 * function is allowed to delete this snapshot
3133 */
3134 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
3135 if (path->nodes[i] && path->locks[i]) {
3136 path->locks[i] = 0;
3137 btrfs_tree_unlock(path->nodes[i]);
3138 }
3139 }
3140 }
3141 while(1) {
3142 wret = walk_down_tree(trans, root, path, &level);
3143 if (wret > 0)
3144 break;
3145 if (wret < 0)
3146 ret = wret;
3147
3148 wret = walk_up_tree(trans, root, path, &level);
3149 if (wret > 0)
3150 break;
3151 if (wret < 0)
3152 ret = wret;
3153 if (trans->transaction->in_commit) {
3154 ret = -EAGAIN;
3155 break;
3156 }
3157 atomic_inc(&root->fs_info->throttle_gen);
3158 wake_up(&root->fs_info->transaction_throttle);
3159 }
3160 for (i = 0; i <= orig_level; i++) {
3161 if (path->nodes[i]) {
3162 free_extent_buffer(path->nodes[i]);
3163 path->nodes[i] = NULL;
3164 }
3165 }
3166 out:
3167 btrfs_free_path(path);
3168 return ret;
3169 }
3170
3171 static unsigned long calc_ra(unsigned long start, unsigned long last,
3172 unsigned long nr)
3173 {
3174 return min(last, start + nr - 1);
3175 }
3176
3177 static int noinline relocate_inode_pages(struct inode *inode, u64 start,
3178 u64 len)
3179 {
3180 u64 page_start;
3181 u64 page_end;
3182 unsigned long first_index;
3183 unsigned long last_index;
3184 unsigned long i;
3185 struct page *page;
3186 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3187 struct file_ra_state *ra;
3188 struct btrfs_ordered_extent *ordered;
3189 unsigned int total_read = 0;
3190 unsigned int total_dirty = 0;
3191 int ret = 0;
3192
3193 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3194
3195 mutex_lock(&inode->i_mutex);
3196 first_index = start >> PAGE_CACHE_SHIFT;
3197 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
3198
3199 /* make sure the dirty trick played by the caller work */
3200 ret = invalidate_inode_pages2_range(inode->i_mapping,
3201 first_index, last_index);
3202 if (ret)
3203 goto out_unlock;
3204
3205 file_ra_state_init(ra, inode->i_mapping);
3206
3207 for (i = first_index ; i <= last_index; i++) {
3208 if (total_read % ra->ra_pages == 0) {
3209 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
3210 calc_ra(i, last_index, ra->ra_pages));
3211 }
3212 total_read++;
3213 again:
3214 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
3215 BUG_ON(1);
3216 page = grab_cache_page(inode->i_mapping, i);
3217 if (!page) {
3218 ret = -ENOMEM;
3219 goto out_unlock;
3220 }
3221 if (!PageUptodate(page)) {
3222 btrfs_readpage(NULL, page);
3223 lock_page(page);
3224 if (!PageUptodate(page)) {
3225 unlock_page(page);
3226 page_cache_release(page);
3227 ret = -EIO;
3228 goto out_unlock;
3229 }
3230 }
3231 wait_on_page_writeback(page);
3232
3233 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
3234 page_end = page_start + PAGE_CACHE_SIZE - 1;
3235 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
3236
3237 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3238 if (ordered) {
3239 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3240 unlock_page(page);
3241 page_cache_release(page);
3242 btrfs_start_ordered_extent(inode, ordered, 1);
3243 btrfs_put_ordered_extent(ordered);
3244 goto again;
3245 }
3246 set_page_extent_mapped(page);
3247
3248 btrfs_set_extent_delalloc(inode, page_start, page_end);
3249 if (i == first_index)
3250 set_extent_bits(io_tree, page_start, page_end,
3251 EXTENT_BOUNDARY, GFP_NOFS);
3252
3253 set_page_dirty(page);
3254 total_dirty++;
3255
3256 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3257 unlock_page(page);
3258 page_cache_release(page);
3259 }
3260
3261 out_unlock:
3262 kfree(ra);
3263 mutex_unlock(&inode->i_mutex);
3264 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
3265 return ret;
3266 }
3267
3268 static int noinline relocate_data_extent(struct inode *reloc_inode,
3269 struct btrfs_key *extent_key,
3270 u64 offset)
3271 {
3272 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3273 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
3274 struct extent_map *em;
3275
3276 em = alloc_extent_map(GFP_NOFS);
3277 BUG_ON(!em || IS_ERR(em));
3278
3279 em->start = extent_key->objectid - offset;
3280 em->len = extent_key->offset;
3281 em->block_start = extent_key->objectid;
3282 em->bdev = root->fs_info->fs_devices->latest_bdev;
3283 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3284
3285 /* setup extent map to cheat btrfs_readpage */
3286 mutex_lock(&BTRFS_I(reloc_inode)->extent_mutex);
3287 while (1) {
3288 int ret;
3289 spin_lock(&em_tree->lock);
3290 ret = add_extent_mapping(em_tree, em);
3291 spin_unlock(&em_tree->lock);
3292 if (ret != -EEXIST) {
3293 free_extent_map(em);
3294 break;
3295 }
3296 btrfs_drop_extent_cache(reloc_inode, em->start,
3297 em->start + em->len - 1, 0);
3298 }
3299 mutex_unlock(&BTRFS_I(reloc_inode)->extent_mutex);
3300
3301 return relocate_inode_pages(reloc_inode, extent_key->objectid - offset,
3302 extent_key->offset);
3303 }
3304
3305 struct btrfs_ref_path {
3306 u64 extent_start;
3307 u64 nodes[BTRFS_MAX_LEVEL];
3308 u64 root_objectid;
3309 u64 root_generation;
3310 u64 owner_objectid;
3311 u32 num_refs;
3312 int lowest_level;
3313 int current_level;
3314 };
3315
3316 struct disk_extent {
3317 u64 disk_bytenr;
3318 u64 disk_num_bytes;
3319 u64 offset;
3320 u64 num_bytes;
3321 };
3322
3323 static int is_cowonly_root(u64 root_objectid)
3324 {
3325 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
3326 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
3327 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
3328 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
3329 root_objectid == BTRFS_TREE_LOG_OBJECTID)
3330 return 1;
3331 return 0;
3332 }
3333
3334 static int noinline __next_ref_path(struct btrfs_trans_handle *trans,
3335 struct btrfs_root *extent_root,
3336 struct btrfs_ref_path *ref_path,
3337 int first_time)
3338 {
3339 struct extent_buffer *leaf;
3340 struct btrfs_path *path;
3341 struct btrfs_extent_ref *ref;
3342 struct btrfs_key key;
3343 struct btrfs_key found_key;
3344 u64 bytenr;
3345 u32 nritems;
3346 int level;
3347 int ret = 1;
3348
3349 path = btrfs_alloc_path();
3350 if (!path)
3351 return -ENOMEM;
3352
3353 mutex_lock(&extent_root->fs_info->alloc_mutex);
3354
3355 if (first_time) {
3356 ref_path->lowest_level = -1;
3357 ref_path->current_level = -1;
3358 goto walk_up;
3359 }
3360 walk_down:
3361 level = ref_path->current_level - 1;
3362 while (level >= -1) {
3363 u64 parent;
3364 if (level < ref_path->lowest_level)
3365 break;
3366
3367 if (level >= 0) {
3368 bytenr = ref_path->nodes[level];
3369 } else {
3370 bytenr = ref_path->extent_start;
3371 }
3372 BUG_ON(bytenr == 0);
3373
3374 parent = ref_path->nodes[level + 1];
3375 ref_path->nodes[level + 1] = 0;
3376 ref_path->current_level = level;
3377 BUG_ON(parent == 0);
3378
3379 key.objectid = bytenr;
3380 key.offset = parent + 1;
3381 key.type = BTRFS_EXTENT_REF_KEY;
3382
3383 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3384 if (ret < 0)
3385 goto out;
3386 BUG_ON(ret == 0);
3387
3388 leaf = path->nodes[0];
3389 nritems = btrfs_header_nritems(leaf);
3390 if (path->slots[0] >= nritems) {
3391 ret = btrfs_next_leaf(extent_root, path);
3392 if (ret < 0)
3393 goto out;
3394 if (ret > 0)
3395 goto next;
3396 leaf = path->nodes[0];
3397 }
3398
3399 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3400 if (found_key.objectid == bytenr &&
3401 found_key.type == BTRFS_EXTENT_REF_KEY)
3402 goto found;
3403 next:
3404 level--;
3405 btrfs_release_path(extent_root, path);
3406 if (need_resched()) {
3407 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3408 cond_resched();
3409 mutex_lock(&extent_root->fs_info->alloc_mutex);
3410 }
3411 }
3412 /* reached lowest level */
3413 ret = 1;
3414 goto out;
3415 walk_up:
3416 level = ref_path->current_level;
3417 while (level < BTRFS_MAX_LEVEL - 1) {
3418 u64 ref_objectid;
3419 if (level >= 0) {
3420 bytenr = ref_path->nodes[level];
3421 } else {
3422 bytenr = ref_path->extent_start;
3423 }
3424 BUG_ON(bytenr == 0);
3425
3426 key.objectid = bytenr;
3427 key.offset = 0;
3428 key.type = BTRFS_EXTENT_REF_KEY;
3429
3430 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3431 if (ret < 0)
3432 goto out;
3433
3434 leaf = path->nodes[0];
3435 nritems = btrfs_header_nritems(leaf);
3436 if (path->slots[0] >= nritems) {
3437 ret = btrfs_next_leaf(extent_root, path);
3438 if (ret < 0)
3439 goto out;
3440 if (ret > 0) {
3441 /* the extent was freed by someone */
3442 if (ref_path->lowest_level == level)
3443 goto out;
3444 btrfs_release_path(extent_root, path);
3445 goto walk_down;
3446 }
3447 leaf = path->nodes[0];
3448 }
3449
3450 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3451 if (found_key.objectid != bytenr ||
3452 found_key.type != BTRFS_EXTENT_REF_KEY) {
3453 /* the extent was freed by someone */
3454 if (ref_path->lowest_level == level) {
3455 ret = 1;
3456 goto out;
3457 }
3458 btrfs_release_path(extent_root, path);
3459 goto walk_down;
3460 }
3461 found:
3462 ref = btrfs_item_ptr(leaf, path->slots[0],
3463 struct btrfs_extent_ref);
3464 ref_objectid = btrfs_ref_objectid(leaf, ref);
3465 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3466 if (first_time) {
3467 level = (int)ref_objectid;
3468 BUG_ON(level >= BTRFS_MAX_LEVEL);
3469 ref_path->lowest_level = level;
3470 ref_path->current_level = level;
3471 ref_path->nodes[level] = bytenr;
3472 } else {
3473 WARN_ON(ref_objectid != level);
3474 }
3475 } else {
3476 WARN_ON(level != -1);
3477 }
3478 first_time = 0;
3479
3480 if (ref_path->lowest_level == level) {
3481 ref_path->owner_objectid = ref_objectid;
3482 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
3483 }
3484
3485 /*
3486 * the block is tree root or the block isn't in reference
3487 * counted tree.
3488 */
3489 if (found_key.objectid == found_key.offset ||
3490 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
3491 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3492 ref_path->root_generation =
3493 btrfs_ref_generation(leaf, ref);
3494 if (level < 0) {
3495 /* special reference from the tree log */
3496 ref_path->nodes[0] = found_key.offset;
3497 ref_path->current_level = 0;
3498 }
3499 ret = 0;
3500 goto out;
3501 }
3502
3503 level++;
3504 BUG_ON(ref_path->nodes[level] != 0);
3505 ref_path->nodes[level] = found_key.offset;
3506 ref_path->current_level = level;
3507
3508 /*
3509 * the reference was created in the running transaction,
3510 * no need to continue walking up.
3511 */
3512 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
3513 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3514 ref_path->root_generation =
3515 btrfs_ref_generation(leaf, ref);
3516 ret = 0;
3517 goto out;
3518 }
3519
3520 btrfs_release_path(extent_root, path);
3521 if (need_resched()) {
3522 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3523 cond_resched();
3524 mutex_lock(&extent_root->fs_info->alloc_mutex);
3525 }
3526 }
3527 /* reached max tree level, but no tree root found. */
3528 BUG();
3529 out:
3530 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3531 btrfs_free_path(path);
3532 return ret;
3533 }
3534
3535 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
3536 struct btrfs_root *extent_root,
3537 struct btrfs_ref_path *ref_path,
3538 u64 extent_start)
3539 {
3540 memset(ref_path, 0, sizeof(*ref_path));
3541 ref_path->extent_start = extent_start;
3542
3543 return __next_ref_path(trans, extent_root, ref_path, 1);
3544 }
3545
3546 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
3547 struct btrfs_root *extent_root,
3548 struct btrfs_ref_path *ref_path)
3549 {
3550 return __next_ref_path(trans, extent_root, ref_path, 0);
3551 }
3552
3553 static int noinline get_new_locations(struct inode *reloc_inode,
3554 struct btrfs_key *extent_key,
3555 u64 offset, int no_fragment,
3556 struct disk_extent **extents,
3557 int *nr_extents)
3558 {
3559 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3560 struct btrfs_path *path;
3561 struct btrfs_file_extent_item *fi;
3562 struct extent_buffer *leaf;
3563 struct disk_extent *exts = *extents;
3564 struct btrfs_key found_key;
3565 u64 cur_pos;
3566 u64 last_byte;
3567 u32 nritems;
3568 int nr = 0;
3569 int max = *nr_extents;
3570 int ret;
3571
3572 WARN_ON(!no_fragment && *extents);
3573 if (!exts) {
3574 max = 1;
3575 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
3576 if (!exts)
3577 return -ENOMEM;
3578 }
3579
3580 path = btrfs_alloc_path();
3581 BUG_ON(!path);
3582
3583 cur_pos = extent_key->objectid - offset;
3584 last_byte = extent_key->objectid + extent_key->offset;
3585 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
3586 cur_pos, 0);
3587 if (ret < 0)
3588 goto out;
3589 if (ret > 0) {
3590 ret = -ENOENT;
3591 goto out;
3592 }
3593
3594 while (1) {
3595 leaf = path->nodes[0];
3596 nritems = btrfs_header_nritems(leaf);
3597 if (path->slots[0] >= nritems) {
3598 ret = btrfs_next_leaf(root, path);
3599 if (ret < 0)
3600 goto out;
3601 if (ret > 0)
3602 break;
3603 leaf = path->nodes[0];
3604 }
3605
3606 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3607 if (found_key.offset != cur_pos ||
3608 found_key.type != BTRFS_EXTENT_DATA_KEY ||
3609 found_key.objectid != reloc_inode->i_ino)
3610 break;
3611
3612 fi = btrfs_item_ptr(leaf, path->slots[0],
3613 struct btrfs_file_extent_item);
3614 if (btrfs_file_extent_type(leaf, fi) !=
3615 BTRFS_FILE_EXTENT_REG ||
3616 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
3617 break;
3618
3619 if (nr == max) {
3620 struct disk_extent *old = exts;
3621 max *= 2;
3622 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
3623 memcpy(exts, old, sizeof(*exts) * nr);
3624 if (old != *extents)
3625 kfree(old);
3626 }
3627
3628 exts[nr].disk_bytenr =
3629 btrfs_file_extent_disk_bytenr(leaf, fi);
3630 exts[nr].disk_num_bytes =
3631 btrfs_file_extent_disk_num_bytes(leaf, fi);
3632 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
3633 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3634 WARN_ON(exts[nr].offset > 0);
3635 WARN_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
3636
3637 cur_pos += exts[nr].num_bytes;
3638 nr++;
3639
3640 if (cur_pos + offset >= last_byte)
3641 break;
3642
3643 if (no_fragment) {
3644 ret = 1;
3645 goto out;
3646 }
3647 path->slots[0]++;
3648 }
3649
3650 WARN_ON(cur_pos + offset > last_byte);
3651 if (cur_pos + offset < last_byte) {
3652 ret = -ENOENT;
3653 goto out;
3654 }
3655 ret = 0;
3656 out:
3657 btrfs_free_path(path);
3658 if (ret) {
3659 if (exts != *extents)
3660 kfree(exts);
3661 } else {
3662 *extents = exts;
3663 *nr_extents = nr;
3664 }
3665 return ret;
3666 }
3667
3668 static int noinline replace_one_extent(struct btrfs_trans_handle *trans,
3669 struct btrfs_root *root,
3670 struct btrfs_path *path,
3671 struct btrfs_key *extent_key,
3672 struct btrfs_key *leaf_key,
3673 struct btrfs_ref_path *ref_path,
3674 struct disk_extent *new_extents,
3675 int nr_extents)
3676 {
3677 struct extent_buffer *leaf;
3678 struct btrfs_file_extent_item *fi;
3679 struct inode *inode = NULL;
3680 struct btrfs_key key;
3681 u64 lock_start = 0;
3682 u64 lock_end = 0;
3683 u64 num_bytes;
3684 u64 ext_offset;
3685 u64 first_pos;
3686 u32 nritems;
3687 int nr_scaned = 0;
3688 int extent_locked = 0;
3689 int ret;
3690
3691 memcpy(&key, leaf_key, sizeof(key));
3692 first_pos = INT_LIMIT(loff_t) - extent_key->offset;
3693 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3694 if (key.objectid < ref_path->owner_objectid ||
3695 (key.objectid == ref_path->owner_objectid &&
3696 key.type < BTRFS_EXTENT_DATA_KEY)) {
3697 key.objectid = ref_path->owner_objectid;
3698 key.type = BTRFS_EXTENT_DATA_KEY;
3699 key.offset = 0;
3700 }
3701 }
3702
3703 while (1) {
3704 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
3705 if (ret < 0)
3706 goto out;
3707
3708 leaf = path->nodes[0];
3709 nritems = btrfs_header_nritems(leaf);
3710 next:
3711 if (extent_locked && ret > 0) {
3712 /*
3713 * the file extent item was modified by someone
3714 * before the extent got locked.
3715 */
3716 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3717 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3718 lock_end, GFP_NOFS);
3719 extent_locked = 0;
3720 }
3721
3722 if (path->slots[0] >= nritems) {
3723 if (++nr_scaned > 2)
3724 break;
3725
3726 BUG_ON(extent_locked);
3727 ret = btrfs_next_leaf(root, path);
3728 if (ret < 0)
3729 goto out;
3730 if (ret > 0)
3731 break;
3732 leaf = path->nodes[0];
3733 nritems = btrfs_header_nritems(leaf);
3734 }
3735
3736 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3737
3738 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3739 if ((key.objectid > ref_path->owner_objectid) ||
3740 (key.objectid == ref_path->owner_objectid &&
3741 key.type > BTRFS_EXTENT_DATA_KEY) ||
3742 (key.offset >= first_pos + extent_key->offset))
3743 break;
3744 }
3745
3746 if (inode && key.objectid != inode->i_ino) {
3747 BUG_ON(extent_locked);
3748 btrfs_release_path(root, path);
3749 mutex_unlock(&inode->i_mutex);
3750 iput(inode);
3751 inode = NULL;
3752 continue;
3753 }
3754
3755 if (key.type != BTRFS_EXTENT_DATA_KEY) {
3756 path->slots[0]++;
3757 ret = 1;
3758 goto next;
3759 }
3760 fi = btrfs_item_ptr(leaf, path->slots[0],
3761 struct btrfs_file_extent_item);
3762 if ((btrfs_file_extent_type(leaf, fi) !=
3763 BTRFS_FILE_EXTENT_REG) ||
3764 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3765 extent_key->objectid)) {
3766 path->slots[0]++;
3767 ret = 1;
3768 goto next;
3769 }
3770
3771 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3772 ext_offset = btrfs_file_extent_offset(leaf, fi);
3773
3774 if (first_pos > key.offset - ext_offset)
3775 first_pos = key.offset - ext_offset;
3776
3777 if (!extent_locked) {
3778 lock_start = key.offset;
3779 lock_end = lock_start + num_bytes - 1;
3780 } else {
3781 BUG_ON(lock_start != key.offset);
3782 BUG_ON(lock_end - lock_start + 1 < num_bytes);
3783 }
3784
3785 if (!inode) {
3786 btrfs_release_path(root, path);
3787
3788 inode = btrfs_iget_locked(root->fs_info->sb,
3789 key.objectid, root);
3790 if (inode->i_state & I_NEW) {
3791 BTRFS_I(inode)->root = root;
3792 BTRFS_I(inode)->location.objectid =
3793 key.objectid;
3794 BTRFS_I(inode)->location.type =
3795 BTRFS_INODE_ITEM_KEY;
3796 BTRFS_I(inode)->location.offset = 0;
3797 btrfs_read_locked_inode(inode);
3798 unlock_new_inode(inode);
3799 }
3800 /*
3801 * some code call btrfs_commit_transaction while
3802 * holding the i_mutex, so we can't use mutex_lock
3803 * here.
3804 */
3805 if (is_bad_inode(inode) ||
3806 !mutex_trylock(&inode->i_mutex)) {
3807 iput(inode);
3808 inode = NULL;
3809 key.offset = (u64)-1;
3810 goto skip;
3811 }
3812 }
3813
3814 if (!extent_locked) {
3815 struct btrfs_ordered_extent *ordered;
3816
3817 btrfs_release_path(root, path);
3818
3819 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3820 lock_end, GFP_NOFS);
3821 ordered = btrfs_lookup_first_ordered_extent(inode,
3822 lock_end);
3823 if (ordered &&
3824 ordered->file_offset <= lock_end &&
3825 ordered->file_offset + ordered->len > lock_start) {
3826 unlock_extent(&BTRFS_I(inode)->io_tree,
3827 lock_start, lock_end, GFP_NOFS);
3828 btrfs_start_ordered_extent(inode, ordered, 1);
3829 btrfs_put_ordered_extent(ordered);
3830 key.offset += num_bytes;
3831 goto skip;
3832 }
3833 if (ordered)
3834 btrfs_put_ordered_extent(ordered);
3835
3836 mutex_lock(&BTRFS_I(inode)->extent_mutex);
3837 extent_locked = 1;
3838 continue;
3839 }
3840
3841 if (nr_extents == 1) {
3842 /* update extent pointer in place */
3843 btrfs_set_file_extent_generation(leaf, fi,
3844 trans->transid);
3845 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3846 new_extents[0].disk_bytenr);
3847 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
3848 new_extents[0].disk_num_bytes);
3849 ext_offset += new_extents[0].offset;
3850 btrfs_set_file_extent_offset(leaf, fi, ext_offset);
3851 btrfs_mark_buffer_dirty(leaf);
3852
3853 btrfs_drop_extent_cache(inode, key.offset,
3854 key.offset + num_bytes - 1, 0);
3855
3856 ret = btrfs_inc_extent_ref(trans, root,
3857 new_extents[0].disk_bytenr,
3858 new_extents[0].disk_num_bytes,
3859 leaf->start,
3860 root->root_key.objectid,
3861 trans->transid,
3862 key.objectid);
3863 BUG_ON(ret);
3864
3865 ret = btrfs_free_extent(trans, root,
3866 extent_key->objectid,
3867 extent_key->offset,
3868 leaf->start,
3869 btrfs_header_owner(leaf),
3870 btrfs_header_generation(leaf),
3871 key.objectid, 0);
3872 BUG_ON(ret);
3873
3874 btrfs_release_path(root, path);
3875 key.offset += num_bytes;
3876 } else {
3877 u64 alloc_hint;
3878 u64 extent_len;
3879 int i;
3880 /*
3881 * drop old extent pointer at first, then insert the
3882 * new pointers one bye one
3883 */
3884 btrfs_release_path(root, path);
3885 ret = btrfs_drop_extents(trans, root, inode, key.offset,
3886 key.offset + num_bytes,
3887 key.offset, &alloc_hint);
3888 BUG_ON(ret);
3889
3890 for (i = 0; i < nr_extents; i++) {
3891 if (ext_offset >= new_extents[i].num_bytes) {
3892 ext_offset -= new_extents[i].num_bytes;
3893 continue;
3894 }
3895 extent_len = min(new_extents[i].num_bytes -
3896 ext_offset, num_bytes);
3897
3898 ret = btrfs_insert_empty_item(trans, root,
3899 path, &key,
3900 sizeof(*fi));
3901 BUG_ON(ret);
3902
3903 leaf = path->nodes[0];
3904 fi = btrfs_item_ptr(leaf, path->slots[0],
3905 struct btrfs_file_extent_item);
3906 btrfs_set_file_extent_generation(leaf, fi,
3907 trans->transid);
3908 btrfs_set_file_extent_type(leaf, fi,
3909 BTRFS_FILE_EXTENT_REG);
3910 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3911 new_extents[i].disk_bytenr);
3912 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
3913 new_extents[i].disk_num_bytes);
3914 btrfs_set_file_extent_num_bytes(leaf, fi,
3915 extent_len);
3916 ext_offset += new_extents[i].offset;
3917 btrfs_set_file_extent_offset(leaf, fi,
3918 ext_offset);
3919 btrfs_mark_buffer_dirty(leaf);
3920
3921 btrfs_drop_extent_cache(inode, key.offset,
3922 key.offset + extent_len - 1, 0);
3923
3924 ret = btrfs_inc_extent_ref(trans, root,
3925 new_extents[i].disk_bytenr,
3926 new_extents[i].disk_num_bytes,
3927 leaf->start,
3928 root->root_key.objectid,
3929 trans->transid, key.objectid);
3930 BUG_ON(ret);
3931 btrfs_release_path(root, path);
3932
3933 inode_add_bytes(inode, extent_len);
3934
3935 ext_offset = 0;
3936 num_bytes -= extent_len;
3937 key.offset += extent_len;
3938
3939 if (num_bytes == 0)
3940 break;
3941 }
3942 BUG_ON(i >= nr_extents);
3943 }
3944
3945 if (extent_locked) {
3946 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3947 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3948 lock_end, GFP_NOFS);
3949 extent_locked = 0;
3950 }
3951 skip:
3952 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
3953 key.offset >= first_pos + extent_key->offset)
3954 break;
3955
3956 cond_resched();
3957 }
3958 ret = 0;
3959 out:
3960 btrfs_release_path(root, path);
3961 if (inode) {
3962 mutex_unlock(&inode->i_mutex);
3963 if (extent_locked) {
3964 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3965 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3966 lock_end, GFP_NOFS);
3967 }
3968 iput(inode);
3969 }
3970 return ret;
3971 }
3972
3973 int btrfs_add_reloc_mapping(struct btrfs_root *root, u64 orig_bytenr,
3974 u64 num_bytes, u64 new_bytenr)
3975 {
3976 set_extent_bits(&root->fs_info->reloc_mapping_tree,
3977 orig_bytenr, orig_bytenr + num_bytes - 1,
3978 EXTENT_LOCKED, GFP_NOFS);
3979 set_state_private(&root->fs_info->reloc_mapping_tree,
3980 orig_bytenr, new_bytenr);
3981 return 0;
3982 }
3983
3984 int btrfs_get_reloc_mapping(struct btrfs_root *root, u64 orig_bytenr,
3985 u64 num_bytes, u64 *new_bytenr)
3986 {
3987 u64 bytenr;
3988 u64 cur_bytenr = orig_bytenr;
3989 u64 prev_bytenr = orig_bytenr;
3990 int ret;
3991
3992 while (1) {
3993 ret = get_state_private(&root->fs_info->reloc_mapping_tree,
3994 cur_bytenr, &bytenr);
3995 if (ret)
3996 break;
3997 prev_bytenr = cur_bytenr;
3998 cur_bytenr = bytenr;
3999 }
4000
4001 if (orig_bytenr == cur_bytenr)
4002 return -ENOENT;
4003
4004 if (prev_bytenr != orig_bytenr) {
4005 set_state_private(&root->fs_info->reloc_mapping_tree,
4006 orig_bytenr, cur_bytenr);
4007 }
4008 *new_bytenr = cur_bytenr;
4009 return 0;
4010 }
4011
4012 void btrfs_free_reloc_mappings(struct btrfs_root *root)
4013 {
4014 clear_extent_bits(&root->fs_info->reloc_mapping_tree,
4015 0, (u64)-1, -1, GFP_NOFS);
4016 }
4017
4018 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
4019 struct btrfs_root *root,
4020 struct extent_buffer *buf, u64 orig_start)
4021 {
4022 int level;
4023 int ret;
4024
4025 BUG_ON(btrfs_header_generation(buf) != trans->transid);
4026 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
4027
4028 level = btrfs_header_level(buf);
4029 if (level == 0) {
4030 struct btrfs_leaf_ref *ref;
4031 struct btrfs_leaf_ref *orig_ref;
4032
4033 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
4034 if (!orig_ref)
4035 return -ENOENT;
4036
4037 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
4038 if (!ref) {
4039 btrfs_free_leaf_ref(root, orig_ref);
4040 return -ENOMEM;
4041 }
4042
4043 ref->nritems = orig_ref->nritems;
4044 memcpy(ref->extents, orig_ref->extents,
4045 sizeof(ref->extents[0]) * ref->nritems);
4046
4047 btrfs_free_leaf_ref(root, orig_ref);
4048
4049 ref->root_gen = trans->transid;
4050 ref->bytenr = buf->start;
4051 ref->owner = btrfs_header_owner(buf);
4052 ref->generation = btrfs_header_generation(buf);
4053 ret = btrfs_add_leaf_ref(root, ref, 0);
4054 WARN_ON(ret);
4055 btrfs_free_leaf_ref(root, ref);
4056 }
4057 return 0;
4058 }
4059
4060 static int noinline invalidate_extent_cache(struct btrfs_root *root,
4061 struct extent_buffer *leaf,
4062 struct btrfs_block_group_cache *group,
4063 struct btrfs_root *target_root)
4064 {
4065 struct btrfs_key key;
4066 struct inode *inode = NULL;
4067 struct btrfs_file_extent_item *fi;
4068 u64 num_bytes;
4069 u64 skip_objectid = 0;
4070 u32 nritems;
4071 u32 i;
4072
4073 nritems = btrfs_header_nritems(leaf);
4074 for (i = 0; i < nritems; i++) {
4075 btrfs_item_key_to_cpu(leaf, &key, i);
4076 if (key.objectid == skip_objectid ||
4077 key.type != BTRFS_EXTENT_DATA_KEY)
4078 continue;
4079 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4080 if (btrfs_file_extent_type(leaf, fi) ==
4081 BTRFS_FILE_EXTENT_INLINE)
4082 continue;
4083 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
4084 continue;
4085 if (!inode || inode->i_ino != key.objectid) {
4086 iput(inode);
4087 inode = btrfs_ilookup(target_root->fs_info->sb,
4088 key.objectid, target_root, 1);
4089 }
4090 if (!inode) {
4091 skip_objectid = key.objectid;
4092 continue;
4093 }
4094 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4095
4096 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4097 key.offset + num_bytes - 1, GFP_NOFS);
4098 mutex_lock(&BTRFS_I(inode)->extent_mutex);
4099 btrfs_drop_extent_cache(inode, key.offset,
4100 key.offset + num_bytes - 1, 1);
4101 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
4102 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4103 key.offset + num_bytes - 1, GFP_NOFS);
4104 cond_resched();
4105 }
4106 iput(inode);
4107 return 0;
4108 }
4109
4110 static int noinline replace_extents_in_leaf(struct btrfs_trans_handle *trans,
4111 struct btrfs_root *root,
4112 struct extent_buffer *leaf,
4113 struct btrfs_block_group_cache *group,
4114 struct inode *reloc_inode)
4115 {
4116 struct btrfs_key key;
4117 struct btrfs_key extent_key;
4118 struct btrfs_file_extent_item *fi;
4119 struct btrfs_leaf_ref *ref;
4120 struct disk_extent *new_extent;
4121 u64 bytenr;
4122 u64 num_bytes;
4123 u32 nritems;
4124 u32 i;
4125 int ext_index;
4126 int nr_extent;
4127 int ret;
4128
4129 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
4130 BUG_ON(!new_extent);
4131
4132 ref = btrfs_lookup_leaf_ref(root, leaf->start);
4133 BUG_ON(!ref);
4134
4135 ext_index = -1;
4136 nritems = btrfs_header_nritems(leaf);
4137 for (i = 0; i < nritems; i++) {
4138 btrfs_item_key_to_cpu(leaf, &key, i);
4139 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
4140 continue;
4141 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4142 if (btrfs_file_extent_type(leaf, fi) ==
4143 BTRFS_FILE_EXTENT_INLINE)
4144 continue;
4145 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
4146 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
4147 if (bytenr == 0)
4148 continue;
4149
4150 ext_index++;
4151 if (bytenr >= group->key.objectid + group->key.offset ||
4152 bytenr + num_bytes <= group->key.objectid)
4153 continue;
4154
4155 extent_key.objectid = bytenr;
4156 extent_key.offset = num_bytes;
4157 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
4158 nr_extent = 1;
4159 ret = get_new_locations(reloc_inode, &extent_key,
4160 group->key.objectid, 1,
4161 &new_extent, &nr_extent);
4162 if (ret > 0)
4163 continue;
4164 BUG_ON(ret < 0);
4165
4166 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
4167 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
4168 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
4169 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
4170
4171 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
4172 btrfs_set_file_extent_disk_bytenr(leaf, fi,
4173 new_extent->disk_bytenr);
4174 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4175 new_extent->disk_num_bytes);
4176 new_extent->offset += btrfs_file_extent_offset(leaf, fi);
4177 btrfs_set_file_extent_offset(leaf, fi, new_extent->offset);
4178 btrfs_mark_buffer_dirty(leaf);
4179
4180 ret = btrfs_inc_extent_ref(trans, root,
4181 new_extent->disk_bytenr,
4182 new_extent->disk_num_bytes,
4183 leaf->start,
4184 root->root_key.objectid,
4185 trans->transid, key.objectid);
4186 BUG_ON(ret);
4187 ret = btrfs_free_extent(trans, root,
4188 bytenr, num_bytes, leaf->start,
4189 btrfs_header_owner(leaf),
4190 btrfs_header_generation(leaf),
4191 key.objectid, 0);
4192 BUG_ON(ret);
4193 cond_resched();
4194 }
4195 kfree(new_extent);
4196 BUG_ON(ext_index + 1 != ref->nritems);
4197 btrfs_free_leaf_ref(root, ref);
4198 return 0;
4199 }
4200
4201 int btrfs_free_reloc_root(struct btrfs_root *root)
4202 {
4203 struct btrfs_root *reloc_root;
4204
4205 if (root->reloc_root) {
4206 reloc_root = root->reloc_root;
4207 root->reloc_root = NULL;
4208 list_add(&reloc_root->dead_list,
4209 &root->fs_info->dead_reloc_roots);
4210 }
4211 return 0;
4212 }
4213
4214 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
4215 {
4216 struct btrfs_trans_handle *trans;
4217 struct btrfs_root *reloc_root;
4218 struct btrfs_root *prev_root = NULL;
4219 struct list_head dead_roots;
4220 int ret;
4221 unsigned long nr;
4222
4223 INIT_LIST_HEAD(&dead_roots);
4224 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
4225
4226 while (!list_empty(&dead_roots)) {
4227 reloc_root = list_entry(dead_roots.prev,
4228 struct btrfs_root, dead_list);
4229 list_del_init(&reloc_root->dead_list);
4230
4231 BUG_ON(reloc_root->commit_root != NULL);
4232 while (1) {
4233 trans = btrfs_join_transaction(root, 1);
4234 BUG_ON(!trans);
4235
4236 mutex_lock(&root->fs_info->drop_mutex);
4237 ret = btrfs_drop_snapshot(trans, reloc_root);
4238 if (ret != -EAGAIN)
4239 break;
4240 mutex_unlock(&root->fs_info->drop_mutex);
4241
4242 nr = trans->blocks_used;
4243 ret = btrfs_end_transaction(trans, root);
4244 BUG_ON(ret);
4245 btrfs_btree_balance_dirty(root, nr);
4246 }
4247
4248 free_extent_buffer(reloc_root->node);
4249
4250 ret = btrfs_del_root(trans, root->fs_info->tree_root,
4251 &reloc_root->root_key);
4252 BUG_ON(ret);
4253 mutex_unlock(&root->fs_info->drop_mutex);
4254
4255 nr = trans->blocks_used;
4256 ret = btrfs_end_transaction(trans, root);
4257 BUG_ON(ret);
4258 btrfs_btree_balance_dirty(root, nr);
4259
4260 kfree(prev_root);
4261 prev_root = reloc_root;
4262 }
4263 if (prev_root) {
4264 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
4265 kfree(prev_root);
4266 }
4267 return 0;
4268 }
4269
4270 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
4271 {
4272 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
4273 return 0;
4274 }
4275
4276 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
4277 {
4278 struct btrfs_root *reloc_root;
4279 struct btrfs_trans_handle *trans;
4280 struct btrfs_key location;
4281 int found;
4282 int ret;
4283
4284 mutex_lock(&root->fs_info->tree_reloc_mutex);
4285 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
4286 BUG_ON(ret);
4287 found = !list_empty(&root->fs_info->dead_reloc_roots);
4288 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4289
4290 if (found) {
4291 trans = btrfs_start_transaction(root, 1);
4292 BUG_ON(!trans);
4293 ret = btrfs_commit_transaction(trans, root);
4294 BUG_ON(ret);
4295 }
4296
4297 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4298 location.offset = (u64)-1;
4299 location.type = BTRFS_ROOT_ITEM_KEY;
4300
4301 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
4302 BUG_ON(!reloc_root);
4303 btrfs_orphan_cleanup(reloc_root);
4304 return 0;
4305 }
4306
4307 static int noinline init_reloc_tree(struct btrfs_trans_handle *trans,
4308 struct btrfs_root *root)
4309 {
4310 struct btrfs_root *reloc_root;
4311 struct extent_buffer *eb;
4312 struct btrfs_root_item *root_item;
4313 struct btrfs_key root_key;
4314 int ret;
4315
4316 BUG_ON(!root->ref_cows);
4317 if (root->reloc_root)
4318 return 0;
4319
4320 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
4321 BUG_ON(!root_item);
4322
4323 ret = btrfs_copy_root(trans, root, root->commit_root,
4324 &eb, BTRFS_TREE_RELOC_OBJECTID);
4325 BUG_ON(ret);
4326
4327 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4328 root_key.offset = root->root_key.objectid;
4329 root_key.type = BTRFS_ROOT_ITEM_KEY;
4330
4331 memcpy(root_item, &root->root_item, sizeof(root_item));
4332 btrfs_set_root_refs(root_item, 0);
4333 btrfs_set_root_bytenr(root_item, eb->start);
4334 btrfs_set_root_level(root_item, btrfs_header_level(eb));
4335 memset(&root_item->drop_progress, 0, sizeof(root_item->drop_progress));
4336 root_item->drop_level = 0;
4337
4338 btrfs_tree_unlock(eb);
4339 free_extent_buffer(eb);
4340
4341 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
4342 &root_key, root_item);
4343 BUG_ON(ret);
4344 kfree(root_item);
4345
4346 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
4347 &root_key);
4348 BUG_ON(!reloc_root);
4349 reloc_root->last_trans = trans->transid;
4350 reloc_root->commit_root = NULL;
4351 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
4352
4353 root->reloc_root = reloc_root;
4354 return 0;
4355 }
4356
4357 /*
4358 * Core function of space balance.
4359 *
4360 * The idea is using reloc trees to relocate tree blocks in reference
4361 * counted roots. There is one reloc tree for each subvol, all reloc
4362 * trees share same key objectid. Reloc trees are snapshots of the
4363 * latest committed roots (subvol root->commit_root). To relocate a tree
4364 * block referenced by a subvol, the code COW the block through the reloc
4365 * tree, then update pointer in the subvol to point to the new block.
4366 * Since all reloc trees share same key objectid, we can easily do special
4367 * handing to share tree blocks between reloc trees. Once a tree block has
4368 * been COWed in one reloc tree, we can use the result when the same block
4369 * is COWed again through other reloc trees.
4370 */
4371 static int noinline relocate_one_path(struct btrfs_trans_handle *trans,
4372 struct btrfs_root *root,
4373 struct btrfs_path *path,
4374 struct btrfs_key *first_key,
4375 struct btrfs_ref_path *ref_path,
4376 struct btrfs_block_group_cache *group,
4377 struct inode *reloc_inode)
4378 {
4379 struct btrfs_root *reloc_root;
4380 struct extent_buffer *eb = NULL;
4381 struct btrfs_key *keys;
4382 u64 *nodes;
4383 int level;
4384 int lowest_merge;
4385 int lowest_level = 0;
4386 int update_refs;
4387 int ret;
4388
4389 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
4390 lowest_level = ref_path->owner_objectid;
4391
4392 if (is_cowonly_root(ref_path->root_objectid)) {
4393 path->lowest_level = lowest_level;
4394 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
4395 BUG_ON(ret < 0);
4396 path->lowest_level = 0;
4397 btrfs_release_path(root, path);
4398 return 0;
4399 }
4400
4401 keys = kzalloc(sizeof(*keys) * BTRFS_MAX_LEVEL, GFP_NOFS);
4402 BUG_ON(!keys);
4403 nodes = kzalloc(sizeof(*nodes) * BTRFS_MAX_LEVEL, GFP_NOFS);
4404 BUG_ON(!nodes);
4405
4406 mutex_lock(&root->fs_info->tree_reloc_mutex);
4407 ret = init_reloc_tree(trans, root);
4408 BUG_ON(ret);
4409 reloc_root = root->reloc_root;
4410
4411 path->lowest_level = lowest_level;
4412 ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 0);
4413 BUG_ON(ret);
4414 /*
4415 * get relocation mapping for tree blocks in the path
4416 */
4417 lowest_merge = BTRFS_MAX_LEVEL;
4418 for (level = BTRFS_MAX_LEVEL - 1; level >= lowest_level; level--) {
4419 u64 new_bytenr;
4420 eb = path->nodes[level];
4421 if (!eb || eb == reloc_root->node)
4422 continue;
4423 ret = btrfs_get_reloc_mapping(reloc_root, eb->start, eb->len,
4424 &new_bytenr);
4425 if (ret)
4426 continue;
4427 if (level == 0)
4428 btrfs_item_key_to_cpu(eb, &keys[level], 0);
4429 else
4430 btrfs_node_key_to_cpu(eb, &keys[level], 0);
4431 nodes[level] = new_bytenr;
4432 lowest_merge = level;
4433 }
4434
4435 update_refs = 0;
4436 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4437 eb = path->nodes[0];
4438 if (btrfs_header_generation(eb) < trans->transid)
4439 update_refs = 1;
4440 }
4441
4442 btrfs_release_path(reloc_root, path);
4443 /*
4444 * merge tree blocks that already relocated in other reloc trees
4445 */
4446 if (lowest_merge != BTRFS_MAX_LEVEL) {
4447 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
4448 lowest_merge);
4449 BUG_ON(ret < 0);
4450 }
4451 /*
4452 * cow any tree blocks that still haven't been relocated
4453 */
4454 ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 1);
4455 BUG_ON(ret);
4456 /*
4457 * if we are relocating data block group, update extent pointers
4458 * in the newly created tree leaf.
4459 */
4460 eb = path->nodes[0];
4461 if (update_refs && nodes[0] != eb->start) {
4462 ret = replace_extents_in_leaf(trans, reloc_root, eb, group,
4463 reloc_inode);
4464 BUG_ON(ret);
4465 }
4466
4467 memset(keys, 0, sizeof(*keys) * BTRFS_MAX_LEVEL);
4468 memset(nodes, 0, sizeof(*nodes) * BTRFS_MAX_LEVEL);
4469 for (level = BTRFS_MAX_LEVEL - 1; level >= lowest_level; level--) {
4470 eb = path->nodes[level];
4471 if (!eb || eb == reloc_root->node)
4472 continue;
4473 BUG_ON(btrfs_header_owner(eb) != BTRFS_TREE_RELOC_OBJECTID);
4474 nodes[level] = eb->start;
4475 if (level == 0)
4476 btrfs_item_key_to_cpu(eb, &keys[level], 0);
4477 else
4478 btrfs_node_key_to_cpu(eb, &keys[level], 0);
4479 }
4480
4481 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4482 eb = path->nodes[0];
4483 extent_buffer_get(eb);
4484 }
4485 btrfs_release_path(reloc_root, path);
4486 /*
4487 * replace tree blocks in the fs tree with tree blocks in
4488 * the reloc tree.
4489 */
4490 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
4491 BUG_ON(ret < 0);
4492
4493 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4494 ret = invalidate_extent_cache(reloc_root, eb, group, root);
4495 BUG_ON(ret);
4496 free_extent_buffer(eb);
4497 }
4498 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4499
4500 path->lowest_level = 0;
4501 kfree(nodes);
4502 kfree(keys);
4503 return 0;
4504 }
4505
4506 static int noinline relocate_tree_block(struct btrfs_trans_handle *trans,
4507 struct btrfs_root *root,
4508 struct btrfs_path *path,
4509 struct btrfs_key *first_key,
4510 struct btrfs_ref_path *ref_path)
4511 {
4512 int ret;
4513 int needs_lock = 0;
4514
4515 if (root == root->fs_info->extent_root ||
4516 root == root->fs_info->chunk_root ||
4517 root == root->fs_info->dev_root) {
4518 needs_lock = 1;
4519 mutex_lock(&root->fs_info->alloc_mutex);
4520 }
4521
4522 ret = relocate_one_path(trans, root, path, first_key,
4523 ref_path, NULL, NULL);
4524 BUG_ON(ret);
4525
4526 if (root == root->fs_info->extent_root)
4527 btrfs_extent_post_op(trans, root);
4528 if (needs_lock)
4529 mutex_unlock(&root->fs_info->alloc_mutex);
4530
4531 return 0;
4532 }
4533
4534 static int noinline del_extent_zero(struct btrfs_trans_handle *trans,
4535 struct btrfs_root *extent_root,
4536 struct btrfs_path *path,
4537 struct btrfs_key *extent_key)
4538 {
4539 int ret;
4540
4541 mutex_lock(&extent_root->fs_info->alloc_mutex);
4542 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
4543 if (ret)
4544 goto out;
4545 ret = btrfs_del_item(trans, extent_root, path);
4546 out:
4547 btrfs_release_path(extent_root, path);
4548 mutex_unlock(&extent_root->fs_info->alloc_mutex);
4549 return ret;
4550 }
4551
4552 static struct btrfs_root noinline *read_ref_root(struct btrfs_fs_info *fs_info,
4553 struct btrfs_ref_path *ref_path)
4554 {
4555 struct btrfs_key root_key;
4556
4557 root_key.objectid = ref_path->root_objectid;
4558 root_key.type = BTRFS_ROOT_ITEM_KEY;
4559 if (is_cowonly_root(ref_path->root_objectid))
4560 root_key.offset = 0;
4561 else
4562 root_key.offset = (u64)-1;
4563
4564 return btrfs_read_fs_root_no_name(fs_info, &root_key);
4565 }
4566
4567 static int noinline relocate_one_extent(struct btrfs_root *extent_root,
4568 struct btrfs_path *path,
4569 struct btrfs_key *extent_key,
4570 struct btrfs_block_group_cache *group,
4571 struct inode *reloc_inode, int pass)
4572 {
4573 struct btrfs_trans_handle *trans;
4574 struct btrfs_root *found_root;
4575 struct btrfs_ref_path *ref_path = NULL;
4576 struct disk_extent *new_extents = NULL;
4577 int nr_extents = 0;
4578 int loops;
4579 int ret;
4580 int level;
4581 struct btrfs_key first_key;
4582 u64 prev_block = 0;
4583
4584 mutex_unlock(&extent_root->fs_info->alloc_mutex);
4585
4586 trans = btrfs_start_transaction(extent_root, 1);
4587 BUG_ON(!trans);
4588
4589 if (extent_key->objectid == 0) {
4590 ret = del_extent_zero(trans, extent_root, path, extent_key);
4591 goto out;
4592 }
4593
4594 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
4595 if (!ref_path) {
4596 ret = -ENOMEM;
4597 goto out;
4598 }
4599
4600 for (loops = 0; ; loops++) {
4601 if (loops == 0) {
4602 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
4603 extent_key->objectid);
4604 } else {
4605 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
4606 }
4607 if (ret < 0)
4608 goto out;
4609 if (ret > 0)
4610 break;
4611
4612 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
4613 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
4614 continue;
4615
4616 found_root = read_ref_root(extent_root->fs_info, ref_path);
4617 BUG_ON(!found_root);
4618 /*
4619 * for reference counted tree, only process reference paths
4620 * rooted at the latest committed root.
4621 */
4622 if (found_root->ref_cows &&
4623 ref_path->root_generation != found_root->root_key.offset)
4624 continue;
4625
4626 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4627 if (pass == 0) {
4628 /*
4629 * copy data extents to new locations
4630 */
4631 u64 group_start = group->key.objectid;
4632 ret = relocate_data_extent(reloc_inode,
4633 extent_key,
4634 group_start);
4635 if (ret < 0)
4636 goto out;
4637 break;
4638 }
4639 level = 0;
4640 } else {
4641 level = ref_path->owner_objectid;
4642 }
4643
4644 if (prev_block != ref_path->nodes[level]) {
4645 struct extent_buffer *eb;
4646 u64 block_start = ref_path->nodes[level];
4647 u64 block_size = btrfs_level_size(found_root, level);
4648
4649 eb = read_tree_block(found_root, block_start,
4650 block_size, 0);
4651 btrfs_tree_lock(eb);
4652 BUG_ON(level != btrfs_header_level(eb));
4653
4654 if (level == 0)
4655 btrfs_item_key_to_cpu(eb, &first_key, 0);
4656 else
4657 btrfs_node_key_to_cpu(eb, &first_key, 0);
4658
4659 btrfs_tree_unlock(eb);
4660 free_extent_buffer(eb);
4661 prev_block = block_start;
4662 }
4663
4664 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
4665 pass >= 2) {
4666 /*
4667 * use fallback method to process the remaining
4668 * references.
4669 */
4670 if (!new_extents) {
4671 u64 group_start = group->key.objectid;
4672 ret = get_new_locations(reloc_inode,
4673 extent_key,
4674 group_start, 0,
4675 &new_extents,
4676 &nr_extents);
4677 if (ret < 0)
4678 goto out;
4679 }
4680 btrfs_record_root_in_trans(found_root);
4681 ret = replace_one_extent(trans, found_root,
4682 path, extent_key,
4683 &first_key, ref_path,
4684 new_extents, nr_extents);
4685 if (ret < 0)
4686 goto out;
4687 continue;
4688 }
4689
4690 btrfs_record_root_in_trans(found_root);
4691 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
4692 ret = relocate_tree_block(trans, found_root, path,
4693 &first_key, ref_path);
4694 } else {
4695 /*
4696 * try to update data extent references while
4697 * keeping metadata shared between snapshots.
4698 */
4699 ret = relocate_one_path(trans, found_root, path,
4700 &first_key, ref_path,
4701 group, reloc_inode);
4702 }
4703 if (ret < 0)
4704 goto out;
4705 }
4706 ret = 0;
4707 out:
4708 btrfs_end_transaction(trans, extent_root);
4709 kfree(new_extents);
4710 kfree(ref_path);
4711 mutex_lock(&extent_root->fs_info->alloc_mutex);
4712 return ret;
4713 }
4714
4715 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
4716 {
4717 u64 num_devices;
4718 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
4719 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
4720
4721 num_devices = root->fs_info->fs_devices->num_devices;
4722 if (num_devices == 1) {
4723 stripped |= BTRFS_BLOCK_GROUP_DUP;
4724 stripped = flags & ~stripped;
4725
4726 /* turn raid0 into single device chunks */
4727 if (flags & BTRFS_BLOCK_GROUP_RAID0)
4728 return stripped;
4729
4730 /* turn mirroring into duplication */
4731 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
4732 BTRFS_BLOCK_GROUP_RAID10))
4733 return stripped | BTRFS_BLOCK_GROUP_DUP;
4734 return flags;
4735 } else {
4736 /* they already had raid on here, just return */
4737 if (flags & stripped)
4738 return flags;
4739
4740 stripped |= BTRFS_BLOCK_GROUP_DUP;
4741 stripped = flags & ~stripped;
4742
4743 /* switch duplicated blocks with raid1 */
4744 if (flags & BTRFS_BLOCK_GROUP_DUP)
4745 return stripped | BTRFS_BLOCK_GROUP_RAID1;
4746
4747 /* turn single device chunks into raid0 */
4748 return stripped | BTRFS_BLOCK_GROUP_RAID0;
4749 }
4750 return flags;
4751 }
4752
4753 int __alloc_chunk_for_shrink(struct btrfs_root *root,
4754 struct btrfs_block_group_cache *shrink_block_group,
4755 int force)
4756 {
4757 struct btrfs_trans_handle *trans;
4758 u64 new_alloc_flags;
4759 u64 calc;
4760
4761 spin_lock(&shrink_block_group->lock);
4762 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
4763 spin_unlock(&shrink_block_group->lock);
4764 mutex_unlock(&root->fs_info->alloc_mutex);
4765
4766 trans = btrfs_start_transaction(root, 1);
4767 mutex_lock(&root->fs_info->alloc_mutex);
4768 spin_lock(&shrink_block_group->lock);
4769
4770 new_alloc_flags = update_block_group_flags(root,
4771 shrink_block_group->flags);
4772 if (new_alloc_flags != shrink_block_group->flags) {
4773 calc =
4774 btrfs_block_group_used(&shrink_block_group->item);
4775 } else {
4776 calc = shrink_block_group->key.offset;
4777 }
4778 spin_unlock(&shrink_block_group->lock);
4779
4780 do_chunk_alloc(trans, root->fs_info->extent_root,
4781 calc + 2 * 1024 * 1024, new_alloc_flags, force);
4782
4783 mutex_unlock(&root->fs_info->alloc_mutex);
4784 btrfs_end_transaction(trans, root);
4785 mutex_lock(&root->fs_info->alloc_mutex);
4786 } else
4787 spin_unlock(&shrink_block_group->lock);
4788 return 0;
4789 }
4790
4791 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4792 struct btrfs_root *root,
4793 u64 objectid, u64 size)
4794 {
4795 struct btrfs_path *path;
4796 struct btrfs_inode_item *item;
4797 struct extent_buffer *leaf;
4798 int ret;
4799
4800 path = btrfs_alloc_path();
4801 if (!path)
4802 return -ENOMEM;
4803
4804 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4805 if (ret)
4806 goto out;
4807
4808 leaf = path->nodes[0];
4809 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4810 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4811 btrfs_set_inode_generation(leaf, item, 1);
4812 btrfs_set_inode_size(leaf, item, size);
4813 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4814 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NODATASUM);
4815 btrfs_mark_buffer_dirty(leaf);
4816 btrfs_release_path(root, path);
4817 out:
4818 btrfs_free_path(path);
4819 return ret;
4820 }
4821
4822 static struct inode noinline *create_reloc_inode(struct btrfs_fs_info *fs_info,
4823 struct btrfs_block_group_cache *group)
4824 {
4825 struct inode *inode = NULL;
4826 struct btrfs_trans_handle *trans;
4827 struct btrfs_root *root;
4828 struct btrfs_key root_key;
4829 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4830 int err = 0;
4831
4832 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4833 root_key.type = BTRFS_ROOT_ITEM_KEY;
4834 root_key.offset = (u64)-1;
4835 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
4836 if (IS_ERR(root))
4837 return ERR_CAST(root);
4838
4839 trans = btrfs_start_transaction(root, 1);
4840 BUG_ON(!trans);
4841
4842 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
4843 if (err)
4844 goto out;
4845
4846 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
4847 BUG_ON(err);
4848
4849 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
4850 group->key.offset, 0);
4851 BUG_ON(err);
4852
4853 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
4854 if (inode->i_state & I_NEW) {
4855 BTRFS_I(inode)->root = root;
4856 BTRFS_I(inode)->location.objectid = objectid;
4857 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
4858 BTRFS_I(inode)->location.offset = 0;
4859 btrfs_read_locked_inode(inode);
4860 unlock_new_inode(inode);
4861 BUG_ON(is_bad_inode(inode));
4862 } else {
4863 BUG_ON(1);
4864 }
4865
4866 err = btrfs_orphan_add(trans, inode);
4867 out:
4868 btrfs_end_transaction(trans, root);
4869 if (err) {
4870 if (inode)
4871 iput(inode);
4872 inode = ERR_PTR(err);
4873 }
4874 return inode;
4875 }
4876
4877 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
4878 {
4879 struct btrfs_trans_handle *trans;
4880 struct btrfs_path *path;
4881 struct btrfs_fs_info *info = root->fs_info;
4882 struct extent_buffer *leaf;
4883 struct inode *reloc_inode;
4884 struct btrfs_block_group_cache *block_group;
4885 struct btrfs_key key;
4886 u64 cur_byte;
4887 u64 total_found;
4888 u32 nritems;
4889 int ret;
4890 int progress;
4891 int pass = 0;
4892
4893 root = root->fs_info->extent_root;
4894
4895 block_group = btrfs_lookup_block_group(info, group_start);
4896 BUG_ON(!block_group);
4897
4898 printk("btrfs relocating block group %llu flags %llu\n",
4899 (unsigned long long)block_group->key.objectid,
4900 (unsigned long long)block_group->flags);
4901
4902 path = btrfs_alloc_path();
4903 BUG_ON(!path);
4904
4905 reloc_inode = create_reloc_inode(info, block_group);
4906 BUG_ON(IS_ERR(reloc_inode));
4907
4908 mutex_lock(&root->fs_info->alloc_mutex);
4909
4910 __alloc_chunk_for_shrink(root, block_group, 1);
4911 block_group->ro = 1;
4912 block_group->space_info->total_bytes -= block_group->key.offset;
4913
4914 mutex_unlock(&root->fs_info->alloc_mutex);
4915
4916 btrfs_start_delalloc_inodes(info->tree_root);
4917 btrfs_wait_ordered_extents(info->tree_root, 0);
4918 again:
4919 total_found = 0;
4920 progress = 0;
4921 key.objectid = block_group->key.objectid;
4922 key.offset = 0;
4923 key.type = 0;
4924 cur_byte = key.objectid;
4925
4926 trans = btrfs_start_transaction(info->tree_root, 1);
4927 btrfs_commit_transaction(trans, info->tree_root);
4928
4929 mutex_lock(&root->fs_info->cleaner_mutex);
4930 btrfs_clean_old_snapshots(info->tree_root);
4931 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
4932 mutex_unlock(&root->fs_info->cleaner_mutex);
4933
4934 mutex_lock(&root->fs_info->alloc_mutex);
4935
4936 while(1) {
4937 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4938 if (ret < 0)
4939 goto out;
4940 next:
4941 leaf = path->nodes[0];
4942 nritems = btrfs_header_nritems(leaf);
4943 if (path->slots[0] >= nritems) {
4944 ret = btrfs_next_leaf(root, path);
4945 if (ret < 0)
4946 goto out;
4947 if (ret == 1) {
4948 ret = 0;
4949 break;
4950 }
4951 leaf = path->nodes[0];
4952 nritems = btrfs_header_nritems(leaf);
4953 }
4954
4955 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4956
4957 if (key.objectid >= block_group->key.objectid +
4958 block_group->key.offset)
4959 break;
4960
4961 if (progress && need_resched()) {
4962 btrfs_release_path(root, path);
4963 mutex_unlock(&root->fs_info->alloc_mutex);
4964 cond_resched();
4965 mutex_lock(&root->fs_info->alloc_mutex);
4966 progress = 0;
4967 continue;
4968 }
4969 progress = 1;
4970
4971 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
4972 key.objectid + key.offset <= cur_byte) {
4973 path->slots[0]++;
4974 goto next;
4975 }
4976
4977 total_found++;
4978 cur_byte = key.objectid + key.offset;
4979 btrfs_release_path(root, path);
4980
4981 __alloc_chunk_for_shrink(root, block_group, 0);
4982 ret = relocate_one_extent(root, path, &key, block_group,
4983 reloc_inode, pass);
4984 BUG_ON(ret < 0);
4985
4986 key.objectid = cur_byte;
4987 key.type = 0;
4988 key.offset = 0;
4989 }
4990
4991 btrfs_release_path(root, path);
4992 mutex_unlock(&root->fs_info->alloc_mutex);
4993
4994 if (pass == 0) {
4995 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
4996 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
4997 WARN_ON(reloc_inode->i_mapping->nrpages);
4998 }
4999
5000 if (total_found > 0) {
5001 printk("btrfs found %llu extents in pass %d\n",
5002 (unsigned long long)total_found, pass);
5003 pass++;
5004 goto again;
5005 }
5006
5007 /* delete reloc_inode */
5008 iput(reloc_inode);
5009
5010 /* unpin extents in this range */
5011 trans = btrfs_start_transaction(info->tree_root, 1);
5012 btrfs_commit_transaction(trans, info->tree_root);
5013
5014 mutex_lock(&root->fs_info->alloc_mutex);
5015
5016 spin_lock(&block_group->lock);
5017 WARN_ON(block_group->pinned > 0);
5018 WARN_ON(block_group->reserved > 0);
5019 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
5020 spin_unlock(&block_group->lock);
5021 ret = 0;
5022 out:
5023 mutex_unlock(&root->fs_info->alloc_mutex);
5024 btrfs_free_path(path);
5025 return ret;
5026 }
5027
5028 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
5029 struct btrfs_key *key)
5030 {
5031 int ret = 0;
5032 struct btrfs_key found_key;
5033 struct extent_buffer *leaf;
5034 int slot;
5035
5036 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
5037 if (ret < 0)
5038 goto out;
5039
5040 while(1) {
5041 slot = path->slots[0];
5042 leaf = path->nodes[0];
5043 if (slot >= btrfs_header_nritems(leaf)) {
5044 ret = btrfs_next_leaf(root, path);
5045 if (ret == 0)
5046 continue;
5047 if (ret < 0)
5048 goto out;
5049 break;
5050 }
5051 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5052
5053 if (found_key.objectid >= key->objectid &&
5054 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
5055 ret = 0;
5056 goto out;
5057 }
5058 path->slots[0]++;
5059 }
5060 ret = -ENOENT;
5061 out:
5062 return ret;
5063 }
5064
5065 int btrfs_free_block_groups(struct btrfs_fs_info *info)
5066 {
5067 struct btrfs_block_group_cache *block_group;
5068 struct rb_node *n;
5069
5070 mutex_lock(&info->alloc_mutex);
5071 spin_lock(&info->block_group_cache_lock);
5072 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
5073 block_group = rb_entry(n, struct btrfs_block_group_cache,
5074 cache_node);
5075
5076 spin_unlock(&info->block_group_cache_lock);
5077 btrfs_remove_free_space_cache(block_group);
5078 spin_lock(&info->block_group_cache_lock);
5079
5080 rb_erase(&block_group->cache_node,
5081 &info->block_group_cache_tree);
5082 spin_lock(&block_group->space_info->lock);
5083 list_del(&block_group->list);
5084 spin_unlock(&block_group->space_info->lock);
5085 kfree(block_group);
5086 }
5087 spin_unlock(&info->block_group_cache_lock);
5088 mutex_unlock(&info->alloc_mutex);
5089 return 0;
5090 }
5091
5092 int btrfs_read_block_groups(struct btrfs_root *root)
5093 {
5094 struct btrfs_path *path;
5095 int ret;
5096 struct btrfs_block_group_cache *cache;
5097 struct btrfs_fs_info *info = root->fs_info;
5098 struct btrfs_space_info *space_info;
5099 struct btrfs_key key;
5100 struct btrfs_key found_key;
5101 struct extent_buffer *leaf;
5102
5103 root = info->extent_root;
5104 key.objectid = 0;
5105 key.offset = 0;
5106 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5107 path = btrfs_alloc_path();
5108 if (!path)
5109 return -ENOMEM;
5110
5111 mutex_lock(&root->fs_info->alloc_mutex);
5112 while(1) {
5113 ret = find_first_block_group(root, path, &key);
5114 if (ret > 0) {
5115 ret = 0;
5116 goto error;
5117 }
5118 if (ret != 0)
5119 goto error;
5120
5121 leaf = path->nodes[0];
5122 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5123 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5124 if (!cache) {
5125 ret = -ENOMEM;
5126 break;
5127 }
5128
5129 spin_lock_init(&cache->lock);
5130 INIT_LIST_HEAD(&cache->list);
5131 read_extent_buffer(leaf, &cache->item,
5132 btrfs_item_ptr_offset(leaf, path->slots[0]),
5133 sizeof(cache->item));
5134 memcpy(&cache->key, &found_key, sizeof(found_key));
5135
5136 key.objectid = found_key.objectid + found_key.offset;
5137 btrfs_release_path(root, path);
5138 cache->flags = btrfs_block_group_flags(&cache->item);
5139
5140 ret = update_space_info(info, cache->flags, found_key.offset,
5141 btrfs_block_group_used(&cache->item),
5142 &space_info);
5143 BUG_ON(ret);
5144 cache->space_info = space_info;
5145 spin_lock(&space_info->lock);
5146 list_add(&cache->list, &space_info->block_groups);
5147 spin_unlock(&space_info->lock);
5148
5149 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5150 BUG_ON(ret);
5151
5152 set_avail_alloc_bits(root->fs_info, cache->flags);
5153 }
5154 ret = 0;
5155 error:
5156 btrfs_free_path(path);
5157 mutex_unlock(&root->fs_info->alloc_mutex);
5158 return ret;
5159 }
5160
5161 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
5162 struct btrfs_root *root, u64 bytes_used,
5163 u64 type, u64 chunk_objectid, u64 chunk_offset,
5164 u64 size)
5165 {
5166 int ret;
5167 struct btrfs_root *extent_root;
5168 struct btrfs_block_group_cache *cache;
5169
5170 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
5171 extent_root = root->fs_info->extent_root;
5172
5173 root->fs_info->last_trans_new_blockgroup = trans->transid;
5174
5175 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5176 if (!cache)
5177 return -ENOMEM;
5178
5179 cache->key.objectid = chunk_offset;
5180 cache->key.offset = size;
5181 spin_lock_init(&cache->lock);
5182 INIT_LIST_HEAD(&cache->list);
5183 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5184
5185 btrfs_set_block_group_used(&cache->item, bytes_used);
5186 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
5187 cache->flags = type;
5188 btrfs_set_block_group_flags(&cache->item, type);
5189
5190 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
5191 &cache->space_info);
5192 BUG_ON(ret);
5193 spin_lock(&cache->space_info->lock);
5194 list_add(&cache->list, &cache->space_info->block_groups);
5195 spin_unlock(&cache->space_info->lock);
5196
5197 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5198 BUG_ON(ret);
5199
5200 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
5201 sizeof(cache->item));
5202 BUG_ON(ret);
5203
5204 finish_current_insert(trans, extent_root);
5205 ret = del_pending_extents(trans, extent_root);
5206 BUG_ON(ret);
5207 set_avail_alloc_bits(extent_root->fs_info, type);
5208
5209 return 0;
5210 }
5211
5212 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
5213 struct btrfs_root *root, u64 group_start)
5214 {
5215 struct btrfs_path *path;
5216 struct btrfs_block_group_cache *block_group;
5217 struct btrfs_key key;
5218 int ret;
5219
5220 BUG_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
5221 root = root->fs_info->extent_root;
5222
5223 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
5224 BUG_ON(!block_group);
5225
5226 memcpy(&key, &block_group->key, sizeof(key));
5227
5228 path = btrfs_alloc_path();
5229 BUG_ON(!path);
5230
5231 btrfs_remove_free_space_cache(block_group);
5232 rb_erase(&block_group->cache_node,
5233 &root->fs_info->block_group_cache_tree);
5234 spin_lock(&block_group->space_info->lock);
5235 list_del(&block_group->list);
5236 spin_unlock(&block_group->space_info->lock);
5237
5238 /*
5239 memset(shrink_block_group, 0, sizeof(*shrink_block_group));
5240 kfree(shrink_block_group);
5241 */
5242
5243 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
5244 if (ret > 0)
5245 ret = -EIO;
5246 if (ret < 0)
5247 goto out;
5248
5249 ret = btrfs_del_item(trans, root, path);
5250 out:
5251 btrfs_free_path(path);
5252 return ret;
5253 }
Support for the Chinese Samsung S3C2440 based development boards