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Btrfs: fix multi-device code to use raid policies set by mkfs
[linux-2.6/mini2440.git] / fs / btrfs / extent-tree.c
blob677d5e774fad74c203e0b0a6d1c857948756f45d
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 * - offset in the file corresponding to the key holding the reference
529 * - number of references holding by parent node (alway 1 for tree blocks)
530 *
531 * Btree leaf may hold multiple references to a file extent. In most cases,
532 * these references are from same file and the corresponding offsets inside
533 * the file are close together. So inode objectid and offset in file are
534 * just hints, they provide hints about where in the btree the references
535 * can be found and when we can stop searching.
536 *
537 * When a file extent is allocated the fields are filled in:
538 * (root_key.objectid, trans->transid, inode objectid, offset in file, 1)
539 *
540 * When a leaf is cow'd new references are added for every file extent found
541 * in the leaf. It looks similar to the create case, but trans->transid will
542 * be different when the block is cow'd.
543 *
544 * (root_key.objectid, trans->transid, inode objectid, offset in file,
545 * number of references in the leaf)
546 *
547 * Because inode objectid and offset in file are just hints, they are not
548 * used when backrefs are deleted. When a file extent is removed either
549 * during snapshot deletion or file truncation, we find the corresponding
550 * back back reference and check the following fields.
551 *
552 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf))
553 *
554 * Btree extents can be referenced by:
555 *
556 * - Different subvolumes
557 * - Different generations of the same subvolume
558 *
559 * When a tree block is created, back references are inserted:
560 *
561 * (root->root_key.objectid, trans->transid, level, 0, 1)
562 *
563 * When a tree block is cow'd, new back references are added for all the
564 * blocks it points to. If the tree block isn't in reference counted root,
565 * the old back references are removed. These new back references are of
566 * the form (trans->transid will have increased since creation):
567 *
568 * (root->root_key.objectid, trans->transid, level, 0, 1)
569 *
570 * When a backref is in deleting, the following fields are checked:
571 *
572 * if backref was for a tree root:
573 * (btrfs_header_owner(itself), btrfs_header_generation(itself))
574 * else
575 * (btrfs_header_owner(parent), btrfs_header_generation(parent))
576 *
577 * Back Reference Key composing:
578 *
579 * The key objectid corresponds to the first byte in the extent, the key
580 * type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first
581 * byte of parent extent. If a extent is tree root, the key offset is set
582 * to the key objectid.
583 */
584
585 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
586 struct btrfs_root *root,
587 struct btrfs_path *path, u64 bytenr,
588 u64 parent, u64 ref_root,
589 u64 ref_generation, int del)
590 {
591 struct btrfs_key key;
592 struct btrfs_extent_ref *ref;
593 struct extent_buffer *leaf;
594 int ret;
595
596 key.objectid = bytenr;
597 key.type = BTRFS_EXTENT_REF_KEY;
598 key.offset = parent;
599
600 ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1);
601 if (ret < 0)
602 goto out;
603 if (ret > 0) {
604 ret = -ENOENT;
605 goto out;
606 }
607
608 leaf = path->nodes[0];
609 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
610 if (btrfs_ref_root(leaf, ref) != ref_root ||
611 btrfs_ref_generation(leaf, ref) != ref_generation) {
612 ret = -EIO;
613 WARN_ON(1);
614 goto out;
615 }
616 ret = 0;
617 out:
618 return ret;
619 }
620
621 static int noinline insert_extent_backref(struct btrfs_trans_handle *trans,
622 struct btrfs_root *root,
623 struct btrfs_path *path,
624 u64 bytenr, u64 parent,
625 u64 ref_root, u64 ref_generation,
626 u64 owner_objectid, u64 owner_offset)
627 {
628 struct btrfs_key key;
629 struct extent_buffer *leaf;
630 struct btrfs_extent_ref *ref;
631 u32 num_refs;
632 int ret;
633
634 key.objectid = bytenr;
635 key.type = BTRFS_EXTENT_REF_KEY;
636 key.offset = parent;
637
638 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref));
639 if (ret == 0) {
640 leaf = path->nodes[0];
641 ref = btrfs_item_ptr(leaf, path->slots[0],
642 struct btrfs_extent_ref);
643 btrfs_set_ref_root(leaf, ref, ref_root);
644 btrfs_set_ref_generation(leaf, ref, ref_generation);
645 btrfs_set_ref_objectid(leaf, ref, owner_objectid);
646 btrfs_set_ref_offset(leaf, ref, owner_offset);
647 btrfs_set_ref_num_refs(leaf, ref, 1);
648 } else if (ret == -EEXIST) {
649 u64 existing_owner;
650 BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID);
651 leaf = path->nodes[0];
652 ref = btrfs_item_ptr(leaf, path->slots[0],
653 struct btrfs_extent_ref);
654 if (btrfs_ref_root(leaf, ref) != ref_root ||
655 btrfs_ref_generation(leaf, ref) != ref_generation) {
656 ret = -EIO;
657 WARN_ON(1);
658 goto out;
659 }
660
661 num_refs = btrfs_ref_num_refs(leaf, ref);
662 BUG_ON(num_refs == 0);
663 btrfs_set_ref_num_refs(leaf, ref, num_refs + 1);
664
665 existing_owner = btrfs_ref_objectid(leaf, ref);
666 if (existing_owner == owner_objectid &&
667 btrfs_ref_offset(leaf, ref) > owner_offset) {
668 btrfs_set_ref_offset(leaf, ref, owner_offset);
669 } else if (existing_owner != owner_objectid &&
670 existing_owner != BTRFS_MULTIPLE_OBJECTIDS) {
671 btrfs_set_ref_objectid(leaf, ref,
672 BTRFS_MULTIPLE_OBJECTIDS);
673 btrfs_set_ref_offset(leaf, ref, 0);
674 }
675 ret = 0;
676 } else {
677 goto out;
678 }
679 btrfs_mark_buffer_dirty(path->nodes[0]);
680 out:
681 btrfs_release_path(root, path);
682 return ret;
683 }
684
685 static int noinline remove_extent_backref(struct btrfs_trans_handle *trans,
686 struct btrfs_root *root,
687 struct btrfs_path *path)
688 {
689 struct extent_buffer *leaf;
690 struct btrfs_extent_ref *ref;
691 u32 num_refs;
692 int ret = 0;
693
694 leaf = path->nodes[0];
695 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
696 num_refs = btrfs_ref_num_refs(leaf, ref);
697 BUG_ON(num_refs == 0);
698 num_refs -= 1;
699 if (num_refs == 0) {
700 ret = btrfs_del_item(trans, root, path);
701 } else {
702 btrfs_set_ref_num_refs(leaf, ref, num_refs);
703 btrfs_mark_buffer_dirty(leaf);
704 }
705 btrfs_release_path(root, path);
706 return ret;
707 }
708
709 static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
710 struct btrfs_root *root, u64 bytenr,
711 u64 orig_parent, u64 parent,
712 u64 orig_root, u64 ref_root,
713 u64 orig_generation, u64 ref_generation,
714 u64 owner_objectid, u64 owner_offset)
715 {
716 int ret;
717 struct btrfs_root *extent_root = root->fs_info->extent_root;
718 struct btrfs_path *path;
719
720 if (root == root->fs_info->extent_root) {
721 struct pending_extent_op *extent_op;
722 u64 num_bytes;
723
724 BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL);
725 num_bytes = btrfs_level_size(root, (int)owner_objectid);
726 if (test_range_bit(&root->fs_info->extent_ins, bytenr,
727 bytenr + num_bytes - 1, EXTENT_LOCKED, 0)) {
728 u64 priv;
729 ret = get_state_private(&root->fs_info->extent_ins,
730 bytenr, &priv);
731 BUG_ON(ret);
732 extent_op = (struct pending_extent_op *)
733 (unsigned long)priv;
734 BUG_ON(extent_op->parent != orig_parent);
735 BUG_ON(extent_op->generation != orig_generation);
736 extent_op->parent = parent;
737 extent_op->generation = ref_generation;
738 } else {
739 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
740 BUG_ON(!extent_op);
741
742 extent_op->type = PENDING_BACKREF_UPDATE;
743 extent_op->bytenr = bytenr;
744 extent_op->num_bytes = num_bytes;
745 extent_op->parent = parent;
746 extent_op->orig_parent = orig_parent;
747 extent_op->generation = ref_generation;
748 extent_op->orig_generation = orig_generation;
749 extent_op->level = (int)owner_objectid;
750
751 set_extent_bits(&root->fs_info->extent_ins,
752 bytenr, bytenr + num_bytes - 1,
753 EXTENT_LOCKED, GFP_NOFS);
754 set_state_private(&root->fs_info->extent_ins,
755 bytenr, (unsigned long)extent_op);
756 }
757 return 0;
758 }
759
760 path = btrfs_alloc_path();
761 if (!path)
762 return -ENOMEM;
763 ret = lookup_extent_backref(trans, extent_root, path,
764 bytenr, orig_parent, orig_root,
765 orig_generation, 1);
766 if (ret)
767 goto out;
768 ret = remove_extent_backref(trans, extent_root, path);
769 if (ret)
770 goto out;
771 ret = insert_extent_backref(trans, extent_root, path, bytenr,
772 parent, ref_root, ref_generation,
773 owner_objectid, owner_offset);
774 BUG_ON(ret);
775 finish_current_insert(trans, extent_root);
776 del_pending_extents(trans, extent_root);
777 out:
778 btrfs_free_path(path);
779 return ret;
780 }
781
782 int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
783 struct btrfs_root *root, u64 bytenr,
784 u64 orig_parent, u64 parent,
785 u64 ref_root, u64 ref_generation,
786 u64 owner_objectid, u64 owner_offset)
787 {
788 int ret;
789 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
790 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
791 return 0;
792 maybe_lock_mutex(root);
793 ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent,
794 parent, ref_root, ref_root,
795 ref_generation, ref_generation,
796 owner_objectid, owner_offset);
797 maybe_unlock_mutex(root);
798 return ret;
799 }
800
801 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
802 struct btrfs_root *root, u64 bytenr,
803 u64 orig_parent, u64 parent,
804 u64 orig_root, u64 ref_root,
805 u64 orig_generation, u64 ref_generation,
806 u64 owner_objectid, u64 owner_offset)
807 {
808 struct btrfs_path *path;
809 int ret;
810 struct btrfs_key key;
811 struct extent_buffer *l;
812 struct btrfs_extent_item *item;
813 u32 refs;
814
815 path = btrfs_alloc_path();
816 if (!path)
817 return -ENOMEM;
818
819 path->reada = 1;
820 key.objectid = bytenr;
821 key.type = BTRFS_EXTENT_ITEM_KEY;
822 key.offset = (u64)-1;
823
824 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
825 0, 1);
826 if (ret < 0)
827 return ret;
828 BUG_ON(ret == 0 || path->slots[0] == 0);
829
830 path->slots[0]--;
831 l = path->nodes[0];
832
833 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
834 BUG_ON(key.objectid != bytenr);
835 BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY);
836
837 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
838 refs = btrfs_extent_refs(l, item);
839 btrfs_set_extent_refs(l, item, refs + 1);
840 btrfs_mark_buffer_dirty(path->nodes[0]);
841
842 btrfs_release_path(root->fs_info->extent_root, path);
843
844 path->reada = 1;
845 ret = insert_extent_backref(trans, root->fs_info->extent_root,
846 path, bytenr, parent,
847 ref_root, ref_generation,
848 owner_objectid, owner_offset);
849 BUG_ON(ret);
850 finish_current_insert(trans, root->fs_info->extent_root);
851 del_pending_extents(trans, root->fs_info->extent_root);
852
853 btrfs_free_path(path);
854 return 0;
855 }
856
857 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
858 struct btrfs_root *root,
859 u64 bytenr, u64 num_bytes, u64 parent,
860 u64 ref_root, u64 ref_generation,
861 u64 owner_objectid, u64 owner_offset)
862 {
863 int ret;
864 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
865 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
866 return 0;
867 maybe_lock_mutex(root);
868 ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent,
869 0, ref_root, 0, ref_generation,
870 owner_objectid, owner_offset);
871 maybe_unlock_mutex(root);
872 return ret;
873 }
874
875 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
876 struct btrfs_root *root)
877 {
878 finish_current_insert(trans, root->fs_info->extent_root);
879 del_pending_extents(trans, root->fs_info->extent_root);
880 return 0;
881 }
882
883 int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
884 struct btrfs_root *root, u64 bytenr,
885 u64 num_bytes, u32 *refs)
886 {
887 struct btrfs_path *path;
888 int ret;
889 struct btrfs_key key;
890 struct extent_buffer *l;
891 struct btrfs_extent_item *item;
892
893 WARN_ON(num_bytes < root->sectorsize);
894 path = btrfs_alloc_path();
895 path->reada = 1;
896 key.objectid = bytenr;
897 key.offset = num_bytes;
898 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
899 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
900 0, 0);
901 if (ret < 0)
902 goto out;
903 if (ret != 0) {
904 btrfs_print_leaf(root, path->nodes[0]);
905 printk("failed to find block number %Lu\n", bytenr);
906 BUG();
907 }
908 l = path->nodes[0];
909 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
910 *refs = btrfs_extent_refs(l, item);
911 out:
912 btrfs_free_path(path);
913 return 0;
914 }
915
916 static int get_reference_status(struct btrfs_root *root, u64 bytenr,
917 u64 parent_gen, u64 ref_objectid,
918 u64 *min_generation, u32 *ref_count)
919 {
920 struct btrfs_root *extent_root = root->fs_info->extent_root;
921 struct btrfs_path *path;
922 struct extent_buffer *leaf;
923 struct btrfs_extent_ref *ref_item;
924 struct btrfs_key key;
925 struct btrfs_key found_key;
926 u64 root_objectid = root->root_key.objectid;
927 u64 ref_generation;
928 u32 nritems;
929 int ret;
930
931 key.objectid = bytenr;
932 key.offset = (u64)-1;
933 key.type = BTRFS_EXTENT_ITEM_KEY;
934
935 path = btrfs_alloc_path();
936 mutex_lock(&root->fs_info->alloc_mutex);
937 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
938 if (ret < 0)
939 goto out;
940 BUG_ON(ret == 0);
941 if (ret < 0 || path->slots[0] == 0)
942 goto out;
943
944 path->slots[0]--;
945 leaf = path->nodes[0];
946 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
947
948 if (found_key.objectid != bytenr ||
949 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
950 ret = 1;
951 goto out;
952 }
953
954 *ref_count = 0;
955 *min_generation = (u64)-1;
956
957 while (1) {
958 leaf = path->nodes[0];
959 nritems = btrfs_header_nritems(leaf);
960 if (path->slots[0] >= nritems) {
961 ret = btrfs_next_leaf(extent_root, path);
962 if (ret < 0)
963 goto out;
964 if (ret == 0)
965 continue;
966 break;
967 }
968 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
969 if (found_key.objectid != bytenr)
970 break;
971
972 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
973 path->slots[0]++;
974 continue;
975 }
976
977 ref_item = btrfs_item_ptr(leaf, path->slots[0],
978 struct btrfs_extent_ref);
979 ref_generation = btrfs_ref_generation(leaf, ref_item);
980 /*
981 * For (parent_gen > 0 && parent_gen > ref_generation):
982 *
983 * we reach here through the oldest root, therefore
984 * all other reference from same snapshot should have
985 * a larger generation.
986 */
987 if ((root_objectid != btrfs_ref_root(leaf, ref_item)) ||
988 (parent_gen > 0 && parent_gen > ref_generation) ||
989 (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
990 ref_objectid != btrfs_ref_objectid(leaf, ref_item))) {
991 *ref_count = 2;
992 break;
993 }
994
995 *ref_count = 1;
996 if (*min_generation > ref_generation)
997 *min_generation = ref_generation;
998
999 path->slots[0]++;
1000 }
1001 ret = 0;
1002 out:
1003 mutex_unlock(&root->fs_info->alloc_mutex);
1004 btrfs_free_path(path);
1005 return ret;
1006 }
1007
1008 int btrfs_cross_ref_exists(struct btrfs_trans_handle *trans,
1009 struct btrfs_root *root,
1010 struct btrfs_key *key, u64 bytenr)
1011 {
1012 struct btrfs_root *old_root;
1013 struct btrfs_path *path = NULL;
1014 struct extent_buffer *eb;
1015 struct btrfs_file_extent_item *item;
1016 u64 ref_generation;
1017 u64 min_generation;
1018 u64 extent_start;
1019 u32 ref_count;
1020 int level;
1021 int ret;
1022
1023 BUG_ON(trans == NULL);
1024 BUG_ON(key->type != BTRFS_EXTENT_DATA_KEY);
1025 ret = get_reference_status(root, bytenr, 0, key->objectid,
1026 &min_generation, &ref_count);
1027 if (ret)
1028 return ret;
1029
1030 if (ref_count != 1)
1031 return 1;
1032
1033 old_root = root->dirty_root->root;
1034 ref_generation = old_root->root_key.offset;
1035
1036 /* all references are created in running transaction */
1037 if (min_generation > ref_generation) {
1038 ret = 0;
1039 goto out;
1040 }
1041
1042 path = btrfs_alloc_path();
1043 if (!path) {
1044 ret = -ENOMEM;
1045 goto out;
1046 }
1047
1048 path->skip_locking = 1;
1049 /* if no item found, the extent is referenced by other snapshot */
1050 ret = btrfs_search_slot(NULL, old_root, key, path, 0, 0);
1051 if (ret)
1052 goto out;
1053
1054 eb = path->nodes[0];
1055 item = btrfs_item_ptr(eb, path->slots[0],
1056 struct btrfs_file_extent_item);
1057 if (btrfs_file_extent_type(eb, item) != BTRFS_FILE_EXTENT_REG ||
1058 btrfs_file_extent_disk_bytenr(eb, item) != bytenr) {
1059 ret = 1;
1060 goto out;
1061 }
1062
1063 for (level = BTRFS_MAX_LEVEL - 1; level >= -1; level--) {
1064 if (level >= 0) {
1065 eb = path->nodes[level];
1066 if (!eb)
1067 continue;
1068 extent_start = eb->start;
1069 } else
1070 extent_start = bytenr;
1071
1072 ret = get_reference_status(root, extent_start, ref_generation,
1073 0, &min_generation, &ref_count);
1074 if (ret)
1075 goto out;
1076
1077 if (ref_count != 1) {
1078 ret = 1;
1079 goto out;
1080 }
1081 if (level >= 0)
1082 ref_generation = btrfs_header_generation(eb);
1083 }
1084 ret = 0;
1085 out:
1086 if (path)
1087 btrfs_free_path(path);
1088 return ret;
1089 }
1090
1091 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1092 struct extent_buffer *buf, u32 nr_extents)
1093 {
1094 struct btrfs_key key;
1095 struct btrfs_file_extent_item *fi;
1096 u64 root_gen;
1097 u32 nritems;
1098 int i;
1099 int level;
1100 int ret = 0;
1101 int shared = 0;
1102
1103 if (!root->ref_cows)
1104 return 0;
1105
1106 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1107 shared = 0;
1108 root_gen = root->root_key.offset;
1109 } else {
1110 shared = 1;
1111 root_gen = trans->transid - 1;
1112 }
1113
1114 level = btrfs_header_level(buf);
1115 nritems = btrfs_header_nritems(buf);
1116
1117 if (level == 0) {
1118 struct btrfs_leaf_ref *ref;
1119 struct btrfs_extent_info *info;
1120
1121 ref = btrfs_alloc_leaf_ref(root, nr_extents);
1122 if (!ref) {
1123 ret = -ENOMEM;
1124 goto out;
1125 }
1126
1127 ref->root_gen = root_gen;
1128 ref->bytenr = buf->start;
1129 ref->owner = btrfs_header_owner(buf);
1130 ref->generation = btrfs_header_generation(buf);
1131 ref->nritems = nr_extents;
1132 info = ref->extents;
1133
1134 for (i = 0; nr_extents > 0 && i < nritems; i++) {
1135 u64 disk_bytenr;
1136 btrfs_item_key_to_cpu(buf, &key, i);
1137 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1138 continue;
1139 fi = btrfs_item_ptr(buf, i,
1140 struct btrfs_file_extent_item);
1141 if (btrfs_file_extent_type(buf, fi) ==
1142 BTRFS_FILE_EXTENT_INLINE)
1143 continue;
1144 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1145 if (disk_bytenr == 0)
1146 continue;
1147
1148 info->bytenr = disk_bytenr;
1149 info->num_bytes =
1150 btrfs_file_extent_disk_num_bytes(buf, fi);
1151 info->objectid = key.objectid;
1152 info->offset = key.offset;
1153 info++;
1154 }
1155
1156 ret = btrfs_add_leaf_ref(root, ref, shared);
1157 WARN_ON(ret);
1158 btrfs_free_leaf_ref(root, ref);
1159 }
1160 out:
1161 return ret;
1162 }
1163
1164 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1165 struct extent_buffer *orig_buf, struct extent_buffer *buf,
1166 u32 *nr_extents)
1167 {
1168 u64 bytenr;
1169 u64 ref_root;
1170 u64 orig_root;
1171 u64 ref_generation;
1172 u64 orig_generation;
1173 u32 nritems;
1174 u32 nr_file_extents = 0;
1175 struct btrfs_key key;
1176 struct btrfs_file_extent_item *fi;
1177 int i;
1178 int level;
1179 int ret = 0;
1180 int faili = 0;
1181 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
1182 u64, u64, u64, u64, u64, u64, u64, u64, u64);
1183
1184 ref_root = btrfs_header_owner(buf);
1185 ref_generation = btrfs_header_generation(buf);
1186 orig_root = btrfs_header_owner(orig_buf);
1187 orig_generation = btrfs_header_generation(orig_buf);
1188
1189 nritems = btrfs_header_nritems(buf);
1190 level = btrfs_header_level(buf);
1191
1192 if (root->ref_cows) {
1193 process_func = __btrfs_inc_extent_ref;
1194 } else {
1195 if (level == 0 &&
1196 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1197 goto out;
1198 if (level != 0 &&
1199 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1200 goto out;
1201 process_func = __btrfs_update_extent_ref;
1202 }
1203
1204 for (i = 0; i < nritems; i++) {
1205 cond_resched();
1206 if (level == 0) {
1207 btrfs_item_key_to_cpu(buf, &key, i);
1208 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1209 continue;
1210 fi = btrfs_item_ptr(buf, i,
1211 struct btrfs_file_extent_item);
1212 if (btrfs_file_extent_type(buf, fi) ==
1213 BTRFS_FILE_EXTENT_INLINE)
1214 continue;
1215 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1216 if (bytenr == 0)
1217 continue;
1218
1219 nr_file_extents++;
1220
1221 maybe_lock_mutex(root);
1222 ret = process_func(trans, root, bytenr,
1223 orig_buf->start, buf->start,
1224 orig_root, ref_root,
1225 orig_generation, ref_generation,
1226 key.objectid, key.offset);
1227 maybe_unlock_mutex(root);
1228
1229 if (ret) {
1230 faili = i;
1231 WARN_ON(1);
1232 goto fail;
1233 }
1234 } else {
1235 bytenr = btrfs_node_blockptr(buf, i);
1236 maybe_lock_mutex(root);
1237 ret = process_func(trans, root, bytenr,
1238 orig_buf->start, buf->start,
1239 orig_root, ref_root,
1240 orig_generation, ref_generation,
1241 level - 1, 0);
1242 maybe_unlock_mutex(root);
1243 if (ret) {
1244 faili = i;
1245 WARN_ON(1);
1246 goto fail;
1247 }
1248 }
1249 }
1250 out:
1251 if (nr_extents) {
1252 if (level == 0)
1253 *nr_extents = nr_file_extents;
1254 else
1255 *nr_extents = nritems;
1256 }
1257 return 0;
1258 fail:
1259 WARN_ON(1);
1260 return ret;
1261 }
1262
1263 int btrfs_update_ref(struct btrfs_trans_handle *trans,
1264 struct btrfs_root *root, struct extent_buffer *orig_buf,
1265 struct extent_buffer *buf, int start_slot, int nr)
1266
1267 {
1268 u64 bytenr;
1269 u64 ref_root;
1270 u64 orig_root;
1271 u64 ref_generation;
1272 u64 orig_generation;
1273 struct btrfs_key key;
1274 struct btrfs_file_extent_item *fi;
1275 int i;
1276 int ret;
1277 int slot;
1278 int level;
1279
1280 BUG_ON(start_slot < 0);
1281 BUG_ON(start_slot + nr > btrfs_header_nritems(buf));
1282
1283 ref_root = btrfs_header_owner(buf);
1284 ref_generation = btrfs_header_generation(buf);
1285 orig_root = btrfs_header_owner(orig_buf);
1286 orig_generation = btrfs_header_generation(orig_buf);
1287 level = btrfs_header_level(buf);
1288
1289 if (!root->ref_cows) {
1290 if (level == 0 &&
1291 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1292 return 0;
1293 if (level != 0 &&
1294 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1295 return 0;
1296 }
1297
1298 for (i = 0, slot = start_slot; i < nr; i++, slot++) {
1299 cond_resched();
1300 if (level == 0) {
1301 btrfs_item_key_to_cpu(buf, &key, slot);
1302 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1303 continue;
1304 fi = btrfs_item_ptr(buf, slot,
1305 struct btrfs_file_extent_item);
1306 if (btrfs_file_extent_type(buf, fi) ==
1307 BTRFS_FILE_EXTENT_INLINE)
1308 continue;
1309 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1310 if (bytenr == 0)
1311 continue;
1312 maybe_lock_mutex(root);
1313 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1314 orig_buf->start, buf->start,
1315 orig_root, ref_root,
1316 orig_generation, ref_generation,
1317 key.objectid, key.offset);
1318 maybe_unlock_mutex(root);
1319 if (ret)
1320 goto fail;
1321 } else {
1322 bytenr = btrfs_node_blockptr(buf, slot);
1323 maybe_lock_mutex(root);
1324 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1325 orig_buf->start, buf->start,
1326 orig_root, ref_root,
1327 orig_generation, ref_generation,
1328 level - 1, 0);
1329 maybe_unlock_mutex(root);
1330 if (ret)
1331 goto fail;
1332 }
1333 }
1334 return 0;
1335 fail:
1336 WARN_ON(1);
1337 return -1;
1338 }
1339
1340 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1341 struct btrfs_root *root,
1342 struct btrfs_path *path,
1343 struct btrfs_block_group_cache *cache)
1344 {
1345 int ret;
1346 int pending_ret;
1347 struct btrfs_root *extent_root = root->fs_info->extent_root;
1348 unsigned long bi;
1349 struct extent_buffer *leaf;
1350
1351 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1352 if (ret < 0)
1353 goto fail;
1354 BUG_ON(ret);
1355
1356 leaf = path->nodes[0];
1357 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1358 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1359 btrfs_mark_buffer_dirty(leaf);
1360 btrfs_release_path(extent_root, path);
1361 fail:
1362 finish_current_insert(trans, extent_root);
1363 pending_ret = del_pending_extents(trans, extent_root);
1364 if (ret)
1365 return ret;
1366 if (pending_ret)
1367 return pending_ret;
1368 return 0;
1369
1370 }
1371
1372 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1373 struct btrfs_root *root)
1374 {
1375 struct btrfs_block_group_cache *cache, *entry;
1376 struct rb_node *n;
1377 int err = 0;
1378 int werr = 0;
1379 struct btrfs_path *path;
1380 u64 last = 0;
1381
1382 path = btrfs_alloc_path();
1383 if (!path)
1384 return -ENOMEM;
1385
1386 mutex_lock(&root->fs_info->alloc_mutex);
1387 while(1) {
1388 cache = NULL;
1389 spin_lock(&root->fs_info->block_group_cache_lock);
1390 for (n = rb_first(&root->fs_info->block_group_cache_tree);
1391 n; n = rb_next(n)) {
1392 entry = rb_entry(n, struct btrfs_block_group_cache,
1393 cache_node);
1394 if (entry->dirty) {
1395 cache = entry;
1396 break;
1397 }
1398 }
1399 spin_unlock(&root->fs_info->block_group_cache_lock);
1400
1401 if (!cache)
1402 break;
1403
1404 cache->dirty = 0;
1405 last += cache->key.offset;
1406
1407 err = write_one_cache_group(trans, root,
1408 path, cache);
1409 /*
1410 * if we fail to write the cache group, we want
1411 * to keep it marked dirty in hopes that a later
1412 * write will work
1413 */
1414 if (err) {
1415 werr = err;
1416 continue;
1417 }
1418 }
1419 btrfs_free_path(path);
1420 mutex_unlock(&root->fs_info->alloc_mutex);
1421 return werr;
1422 }
1423
1424 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1425 u64 total_bytes, u64 bytes_used,
1426 struct btrfs_space_info **space_info)
1427 {
1428 struct btrfs_space_info *found;
1429
1430 found = __find_space_info(info, flags);
1431 if (found) {
1432 found->total_bytes += total_bytes;
1433 found->bytes_used += bytes_used;
1434 found->full = 0;
1435 *space_info = found;
1436 return 0;
1437 }
1438 found = kmalloc(sizeof(*found), GFP_NOFS);
1439 if (!found)
1440 return -ENOMEM;
1441
1442 list_add(&found->list, &info->space_info);
1443 INIT_LIST_HEAD(&found->block_groups);
1444 spin_lock_init(&found->lock);
1445 found->flags = flags;
1446 found->total_bytes = total_bytes;
1447 found->bytes_used = bytes_used;
1448 found->bytes_pinned = 0;
1449 found->bytes_reserved = 0;
1450 found->full = 0;
1451 found->force_alloc = 0;
1452 *space_info = found;
1453 return 0;
1454 }
1455
1456 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1457 {
1458 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1459 BTRFS_BLOCK_GROUP_RAID1 |
1460 BTRFS_BLOCK_GROUP_RAID10 |
1461 BTRFS_BLOCK_GROUP_DUP);
1462 if (extra_flags) {
1463 if (flags & BTRFS_BLOCK_GROUP_DATA)
1464 fs_info->avail_data_alloc_bits |= extra_flags;
1465 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1466 fs_info->avail_metadata_alloc_bits |= extra_flags;
1467 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1468 fs_info->avail_system_alloc_bits |= extra_flags;
1469 }
1470 }
1471
1472 static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags)
1473 {
1474 u64 num_devices = root->fs_info->fs_devices->num_devices;
1475
1476 if (num_devices == 1)
1477 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
1478 if (num_devices < 4)
1479 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
1480
1481 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
1482 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
1483 BTRFS_BLOCK_GROUP_RAID10))) {
1484 flags &= ~BTRFS_BLOCK_GROUP_DUP;
1485 }
1486
1487 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
1488 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
1489 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
1490 }
1491
1492 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
1493 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
1494 (flags & BTRFS_BLOCK_GROUP_RAID10) |
1495 (flags & BTRFS_BLOCK_GROUP_DUP)))
1496 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
1497 return flags;
1498 }
1499
1500 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1501 struct btrfs_root *extent_root, u64 alloc_bytes,
1502 u64 flags, int force)
1503 {
1504 struct btrfs_space_info *space_info;
1505 u64 thresh;
1506 u64 start;
1507 u64 num_bytes;
1508 int ret = 0;
1509
1510 flags = reduce_alloc_profile(extent_root, flags);
1511
1512 space_info = __find_space_info(extent_root->fs_info, flags);
1513 if (!space_info) {
1514 ret = update_space_info(extent_root->fs_info, flags,
1515 0, 0, &space_info);
1516 BUG_ON(ret);
1517 }
1518 BUG_ON(!space_info);
1519
1520 if (space_info->force_alloc) {
1521 force = 1;
1522 space_info->force_alloc = 0;
1523 }
1524 if (space_info->full)
1525 goto out;
1526
1527 thresh = div_factor(space_info->total_bytes, 6);
1528 if (!force &&
1529 (space_info->bytes_used + space_info->bytes_pinned +
1530 space_info->bytes_reserved + alloc_bytes) < thresh)
1531 goto out;
1532
1533 mutex_lock(&extent_root->fs_info->chunk_mutex);
1534 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1535 if (ret == -ENOSPC) {
1536 printk("space info full %Lu\n", flags);
1537 space_info->full = 1;
1538 goto out_unlock;
1539 }
1540 BUG_ON(ret);
1541
1542 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1543 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1544 BUG_ON(ret);
1545
1546 out_unlock:
1547 mutex_unlock(&extent_root->fs_info->chunk_mutex);
1548 out:
1549 return ret;
1550 }
1551
1552 static int update_block_group(struct btrfs_trans_handle *trans,
1553 struct btrfs_root *root,
1554 u64 bytenr, u64 num_bytes, int alloc,
1555 int mark_free)
1556 {
1557 struct btrfs_block_group_cache *cache;
1558 struct btrfs_fs_info *info = root->fs_info;
1559 u64 total = num_bytes;
1560 u64 old_val;
1561 u64 byte_in_group;
1562
1563 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1564 while(total) {
1565 cache = btrfs_lookup_block_group(info, bytenr);
1566 if (!cache) {
1567 return -1;
1568 }
1569 byte_in_group = bytenr - cache->key.objectid;
1570 WARN_ON(byte_in_group > cache->key.offset);
1571
1572 spin_lock(&cache->lock);
1573 cache->dirty = 1;
1574 old_val = btrfs_block_group_used(&cache->item);
1575 num_bytes = min(total, cache->key.offset - byte_in_group);
1576 if (alloc) {
1577 old_val += num_bytes;
1578 cache->space_info->bytes_used += num_bytes;
1579 btrfs_set_block_group_used(&cache->item, old_val);
1580 spin_unlock(&cache->lock);
1581 } else {
1582 old_val -= num_bytes;
1583 cache->space_info->bytes_used -= num_bytes;
1584 btrfs_set_block_group_used(&cache->item, old_val);
1585 spin_unlock(&cache->lock);
1586 if (mark_free) {
1587 int ret;
1588 ret = btrfs_add_free_space(cache, bytenr,
1589 num_bytes);
1590 if (ret)
1591 return -1;
1592 }
1593 }
1594 total -= num_bytes;
1595 bytenr += num_bytes;
1596 }
1597 return 0;
1598 }
1599
1600 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
1601 {
1602 struct btrfs_block_group_cache *cache;
1603
1604 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
1605 if (!cache)
1606 return 0;
1607
1608 return cache->key.objectid;
1609 }
1610
1611 int btrfs_update_pinned_extents(struct btrfs_root *root,
1612 u64 bytenr, u64 num, int pin)
1613 {
1614 u64 len;
1615 struct btrfs_block_group_cache *cache;
1616 struct btrfs_fs_info *fs_info = root->fs_info;
1617
1618 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1619 if (pin) {
1620 set_extent_dirty(&fs_info->pinned_extents,
1621 bytenr, bytenr + num - 1, GFP_NOFS);
1622 } else {
1623 clear_extent_dirty(&fs_info->pinned_extents,
1624 bytenr, bytenr + num - 1, GFP_NOFS);
1625 }
1626 while (num > 0) {
1627 cache = btrfs_lookup_block_group(fs_info, bytenr);
1628 BUG_ON(!cache);
1629 len = min(num, cache->key.offset -
1630 (bytenr - cache->key.objectid));
1631 if (pin) {
1632 spin_lock(&cache->lock);
1633 cache->pinned += len;
1634 cache->space_info->bytes_pinned += len;
1635 spin_unlock(&cache->lock);
1636 fs_info->total_pinned += len;
1637 } else {
1638 spin_lock(&cache->lock);
1639 cache->pinned -= len;
1640 cache->space_info->bytes_pinned -= len;
1641 spin_unlock(&cache->lock);
1642 fs_info->total_pinned -= len;
1643 }
1644 bytenr += len;
1645 num -= len;
1646 }
1647 return 0;
1648 }
1649
1650 static int update_reserved_extents(struct btrfs_root *root,
1651 u64 bytenr, u64 num, int reserve)
1652 {
1653 u64 len;
1654 struct btrfs_block_group_cache *cache;
1655 struct btrfs_fs_info *fs_info = root->fs_info;
1656
1657 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1658 while (num > 0) {
1659 cache = btrfs_lookup_block_group(fs_info, bytenr);
1660 BUG_ON(!cache);
1661 len = min(num, cache->key.offset -
1662 (bytenr - cache->key.objectid));
1663 if (reserve) {
1664 spin_lock(&cache->lock);
1665 cache->reserved += len;
1666 cache->space_info->bytes_reserved += len;
1667 spin_unlock(&cache->lock);
1668 } else {
1669 spin_lock(&cache->lock);
1670 cache->reserved -= len;
1671 cache->space_info->bytes_reserved -= len;
1672 spin_unlock(&cache->lock);
1673 }
1674 bytenr += len;
1675 num -= len;
1676 }
1677 return 0;
1678 }
1679
1680 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1681 {
1682 u64 last = 0;
1683 u64 start;
1684 u64 end;
1685 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1686 int ret;
1687
1688 while(1) {
1689 ret = find_first_extent_bit(pinned_extents, last,
1690 &start, &end, EXTENT_DIRTY);
1691 if (ret)
1692 break;
1693 set_extent_dirty(copy, start, end, GFP_NOFS);
1694 last = end + 1;
1695 }
1696 return 0;
1697 }
1698
1699 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1700 struct btrfs_root *root,
1701 struct extent_io_tree *unpin)
1702 {
1703 u64 start;
1704 u64 end;
1705 int ret;
1706 struct btrfs_block_group_cache *cache;
1707
1708 mutex_lock(&root->fs_info->alloc_mutex);
1709 while(1) {
1710 ret = find_first_extent_bit(unpin, 0, &start, &end,
1711 EXTENT_DIRTY);
1712 if (ret)
1713 break;
1714 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
1715 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1716 cache = btrfs_lookup_block_group(root->fs_info, start);
1717 if (cache->cached)
1718 btrfs_add_free_space(cache, start, end - start + 1);
1719 if (need_resched()) {
1720 mutex_unlock(&root->fs_info->alloc_mutex);
1721 cond_resched();
1722 mutex_lock(&root->fs_info->alloc_mutex);
1723 }
1724 }
1725 mutex_unlock(&root->fs_info->alloc_mutex);
1726 return 0;
1727 }
1728
1729 static int finish_current_insert(struct btrfs_trans_handle *trans,
1730 struct btrfs_root *extent_root)
1731 {
1732 u64 start;
1733 u64 end;
1734 u64 priv;
1735 struct btrfs_fs_info *info = extent_root->fs_info;
1736 struct btrfs_path *path;
1737 struct btrfs_extent_ref *ref;
1738 struct pending_extent_op *extent_op;
1739 struct btrfs_key key;
1740 struct btrfs_extent_item extent_item;
1741 int ret;
1742 int err = 0;
1743
1744 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
1745 btrfs_set_stack_extent_refs(&extent_item, 1);
1746 path = btrfs_alloc_path();
1747
1748 while(1) {
1749 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1750 &end, EXTENT_LOCKED);
1751 if (ret)
1752 break;
1753
1754 ret = get_state_private(&info->extent_ins, start, &priv);
1755 BUG_ON(ret);
1756 extent_op = (struct pending_extent_op *)(unsigned long)priv;
1757
1758 if (extent_op->type == PENDING_EXTENT_INSERT) {
1759 key.objectid = start;
1760 key.offset = end + 1 - start;
1761 key.type = BTRFS_EXTENT_ITEM_KEY;
1762 err = btrfs_insert_item(trans, extent_root, &key,
1763 &extent_item, sizeof(extent_item));
1764 BUG_ON(err);
1765
1766 clear_extent_bits(&info->extent_ins, start, end,
1767 EXTENT_LOCKED, GFP_NOFS);
1768
1769 err = insert_extent_backref(trans, extent_root, path,
1770 start, extent_op->parent,
1771 extent_root->root_key.objectid,
1772 extent_op->generation,
1773 extent_op->level, 0);
1774 BUG_ON(err);
1775 } else if (extent_op->type == PENDING_BACKREF_UPDATE) {
1776 err = lookup_extent_backref(trans, extent_root, path,
1777 start, extent_op->orig_parent,
1778 extent_root->root_key.objectid,
1779 extent_op->orig_generation, 0);
1780 BUG_ON(err);
1781
1782 clear_extent_bits(&info->extent_ins, start, end,
1783 EXTENT_LOCKED, GFP_NOFS);
1784
1785 key.objectid = start;
1786 key.offset = extent_op->parent;
1787 key.type = BTRFS_EXTENT_REF_KEY;
1788 err = btrfs_set_item_key_safe(trans, extent_root, path,
1789 &key);
1790 BUG_ON(err);
1791 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1792 struct btrfs_extent_ref);
1793 btrfs_set_ref_generation(path->nodes[0], ref,
1794 extent_op->generation);
1795 btrfs_mark_buffer_dirty(path->nodes[0]);
1796 btrfs_release_path(extent_root, path);
1797 } else {
1798 BUG_ON(1);
1799 }
1800 kfree(extent_op);
1801
1802 if (need_resched()) {
1803 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1804 cond_resched();
1805 mutex_lock(&extent_root->fs_info->alloc_mutex);
1806 }
1807 }
1808 btrfs_free_path(path);
1809 return 0;
1810 }
1811
1812 static int pin_down_bytes(struct btrfs_trans_handle *trans,
1813 struct btrfs_root *root,
1814 u64 bytenr, u64 num_bytes, int is_data)
1815 {
1816 int err = 0;
1817 struct extent_buffer *buf;
1818
1819 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1820 if (is_data)
1821 goto pinit;
1822
1823 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1824 if (!buf)
1825 goto pinit;
1826
1827 /* we can reuse a block if it hasn't been written
1828 * and it is from this transaction. We can't
1829 * reuse anything from the tree log root because
1830 * it has tiny sub-transactions.
1831 */
1832 if (btrfs_buffer_uptodate(buf, 0) &&
1833 btrfs_try_tree_lock(buf)) {
1834 u64 header_owner = btrfs_header_owner(buf);
1835 u64 header_transid = btrfs_header_generation(buf);
1836 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
1837 header_owner != BTRFS_TREE_RELOC_OBJECTID &&
1838 header_transid == trans->transid &&
1839 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
1840 clean_tree_block(NULL, root, buf);
1841 btrfs_tree_unlock(buf);
1842 free_extent_buffer(buf);
1843 return 1;
1844 }
1845 btrfs_tree_unlock(buf);
1846 }
1847 free_extent_buffer(buf);
1848 pinit:
1849 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
1850
1851 BUG_ON(err < 0);
1852 return 0;
1853 }
1854
1855 /*
1856 * remove an extent from the root, returns 0 on success
1857 */
1858 static int __free_extent(struct btrfs_trans_handle *trans,
1859 struct btrfs_root *root,
1860 u64 bytenr, u64 num_bytes, u64 parent,
1861 u64 root_objectid, u64 ref_generation,
1862 u64 owner_objectid, u64 owner_offset,
1863 int pin, int mark_free)
1864 {
1865 struct btrfs_path *path;
1866 struct btrfs_key key;
1867 struct btrfs_fs_info *info = root->fs_info;
1868 struct btrfs_root *extent_root = info->extent_root;
1869 struct extent_buffer *leaf;
1870 int ret;
1871 int extent_slot = 0;
1872 int found_extent = 0;
1873 int num_to_del = 1;
1874 struct btrfs_extent_item *ei;
1875 u32 refs;
1876
1877 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1878 key.objectid = bytenr;
1879 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1880 key.offset = num_bytes;
1881 path = btrfs_alloc_path();
1882 if (!path)
1883 return -ENOMEM;
1884
1885 path->reada = 1;
1886 ret = lookup_extent_backref(trans, extent_root, path, bytenr, parent,
1887 root_objectid, ref_generation, 1);
1888 if (ret == 0) {
1889 struct btrfs_key found_key;
1890 extent_slot = path->slots[0];
1891 while(extent_slot > 0) {
1892 extent_slot--;
1893 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1894 extent_slot);
1895 if (found_key.objectid != bytenr)
1896 break;
1897 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1898 found_key.offset == num_bytes) {
1899 found_extent = 1;
1900 break;
1901 }
1902 if (path->slots[0] - extent_slot > 5)
1903 break;
1904 }
1905 if (!found_extent) {
1906 ret = remove_extent_backref(trans, extent_root, path);
1907 BUG_ON(ret);
1908 btrfs_release_path(extent_root, path);
1909 ret = btrfs_search_slot(trans, extent_root,
1910 &key, path, -1, 1);
1911 BUG_ON(ret);
1912 extent_slot = path->slots[0];
1913 }
1914 } else {
1915 btrfs_print_leaf(extent_root, path->nodes[0]);
1916 WARN_ON(1);
1917 printk("Unable to find ref byte nr %Lu root %Lu "
1918 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1919 root_objectid, ref_generation, owner_objectid,
1920 owner_offset);
1921 }
1922
1923 leaf = path->nodes[0];
1924 ei = btrfs_item_ptr(leaf, extent_slot,
1925 struct btrfs_extent_item);
1926 refs = btrfs_extent_refs(leaf, ei);
1927 BUG_ON(refs == 0);
1928 refs -= 1;
1929 btrfs_set_extent_refs(leaf, ei, refs);
1930
1931 btrfs_mark_buffer_dirty(leaf);
1932
1933 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1934 struct btrfs_extent_ref *ref;
1935 ref = btrfs_item_ptr(leaf, path->slots[0],
1936 struct btrfs_extent_ref);
1937 BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1);
1938 /* if the back ref and the extent are next to each other
1939 * they get deleted below in one shot
1940 */
1941 path->slots[0] = extent_slot;
1942 num_to_del = 2;
1943 } else if (found_extent) {
1944 /* otherwise delete the extent back ref */
1945 ret = remove_extent_backref(trans, extent_root, path);
1946 BUG_ON(ret);
1947 /* if refs are 0, we need to setup the path for deletion */
1948 if (refs == 0) {
1949 btrfs_release_path(extent_root, path);
1950 ret = btrfs_search_slot(trans, extent_root, &key, path,
1951 -1, 1);
1952 BUG_ON(ret);
1953 }
1954 }
1955
1956 if (refs == 0) {
1957 u64 super_used;
1958 u64 root_used;
1959 #ifdef BIO_RW_DISCARD
1960 u64 map_length = num_bytes;
1961 struct btrfs_multi_bio *multi = NULL;
1962 #endif
1963
1964 if (pin) {
1965 ret = pin_down_bytes(trans, root, bytenr, num_bytes,
1966 owner_objectid >= BTRFS_FIRST_FREE_OBJECTID);
1967 if (ret > 0)
1968 mark_free = 1;
1969 BUG_ON(ret < 0);
1970 }
1971
1972 /* block accounting for super block */
1973 spin_lock_irq(&info->delalloc_lock);
1974 super_used = btrfs_super_bytes_used(&info->super_copy);
1975 btrfs_set_super_bytes_used(&info->super_copy,
1976 super_used - num_bytes);
1977 spin_unlock_irq(&info->delalloc_lock);
1978
1979 /* block accounting for root item */
1980 root_used = btrfs_root_used(&root->root_item);
1981 btrfs_set_root_used(&root->root_item,
1982 root_used - num_bytes);
1983 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1984 num_to_del);
1985 BUG_ON(ret);
1986 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1987 mark_free);
1988 BUG_ON(ret);
1989
1990 #ifdef BIO_RW_DISCARD
1991 /* Tell the block device(s) that the sectors can be discarded */
1992 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
1993 bytenr, &map_length, &multi, 0);
1994 if (!ret) {
1995 struct btrfs_bio_stripe *stripe = multi->stripes;
1996 int i;
1997
1998 if (map_length > num_bytes)
1999 map_length = num_bytes;
2000
2001 for (i = 0; i < multi->num_stripes; i++, stripe++) {
2002 blkdev_issue_discard(stripe->dev->bdev,
2003 stripe->physical >> 9,
2004 map_length >> 9);
2005 }
2006 kfree(multi);
2007 }
2008 #endif
2009 }
2010 btrfs_free_path(path);
2011 finish_current_insert(trans, extent_root);
2012 return ret;
2013 }
2014
2015 /*
2016 * find all the blocks marked as pending in the radix tree and remove
2017 * them from the extent map
2018 */
2019 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
2020 btrfs_root *extent_root)
2021 {
2022 int ret;
2023 int err = 0;
2024 int mark_free = 0;
2025 u64 start;
2026 u64 end;
2027 u64 priv;
2028 struct extent_io_tree *pending_del;
2029 struct extent_io_tree *extent_ins;
2030 struct pending_extent_op *extent_op;
2031
2032 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
2033 extent_ins = &extent_root->fs_info->extent_ins;
2034 pending_del = &extent_root->fs_info->pending_del;
2035
2036 while(1) {
2037 ret = find_first_extent_bit(pending_del, 0, &start, &end,
2038 EXTENT_LOCKED);
2039 if (ret)
2040 break;
2041
2042 ret = get_state_private(pending_del, start, &priv);
2043 BUG_ON(ret);
2044 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2045
2046 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
2047 GFP_NOFS);
2048
2049 ret = pin_down_bytes(trans, extent_root, start,
2050 end + 1 - start, 0);
2051 mark_free = ret > 0;
2052 if (!test_range_bit(extent_ins, start, end,
2053 EXTENT_LOCKED, 0)) {
2054 free_extent:
2055 ret = __free_extent(trans, extent_root,
2056 start, end + 1 - start,
2057 extent_op->orig_parent,
2058 extent_root->root_key.objectid,
2059 extent_op->orig_generation,
2060 extent_op->level, 0, 0, mark_free);
2061 kfree(extent_op);
2062 } else {
2063 kfree(extent_op);
2064 ret = get_state_private(extent_ins, start, &priv);
2065 BUG_ON(ret);
2066 extent_op = (struct pending_extent_op *)
2067 (unsigned long)priv;
2068
2069 clear_extent_bits(extent_ins, start, end,
2070 EXTENT_LOCKED, GFP_NOFS);
2071
2072 if (extent_op->type == PENDING_BACKREF_UPDATE)
2073 goto free_extent;
2074
2075 ret = update_block_group(trans, extent_root, start,
2076 end + 1 - start, 0, mark_free);
2077 BUG_ON(ret);
2078 kfree(extent_op);
2079 }
2080 if (ret)
2081 err = ret;
2082
2083 if (need_resched()) {
2084 mutex_unlock(&extent_root->fs_info->alloc_mutex);
2085 cond_resched();
2086 mutex_lock(&extent_root->fs_info->alloc_mutex);
2087 }
2088 }
2089 return err;
2090 }
2091
2092 /*
2093 * remove an extent from the root, returns 0 on success
2094 */
2095 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
2096 struct btrfs_root *root,
2097 u64 bytenr, u64 num_bytes, u64 parent,
2098 u64 root_objectid, u64 ref_generation,
2099 u64 owner_objectid, u64 owner_offset, int pin)
2100 {
2101 struct btrfs_root *extent_root = root->fs_info->extent_root;
2102 int pending_ret;
2103 int ret;
2104
2105 WARN_ON(num_bytes < root->sectorsize);
2106 if (root == extent_root) {
2107 struct pending_extent_op *extent_op;
2108
2109 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2110 BUG_ON(!extent_op);
2111
2112 extent_op->type = PENDING_EXTENT_DELETE;
2113 extent_op->bytenr = bytenr;
2114 extent_op->num_bytes = num_bytes;
2115 extent_op->parent = parent;
2116 extent_op->orig_parent = parent;
2117 extent_op->generation = ref_generation;
2118 extent_op->orig_generation = ref_generation;
2119 extent_op->level = (int)owner_objectid;
2120
2121 set_extent_bits(&root->fs_info->pending_del,
2122 bytenr, bytenr + num_bytes - 1,
2123 EXTENT_LOCKED, GFP_NOFS);
2124 set_state_private(&root->fs_info->pending_del,
2125 bytenr, (unsigned long)extent_op);
2126 return 0;
2127 }
2128 /* if metadata always pin */
2129 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
2130 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2131 struct btrfs_block_group_cache *cache;
2132
2133 /* btrfs_free_reserved_extent */
2134 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
2135 BUG_ON(!cache);
2136 btrfs_add_free_space(cache, bytenr, num_bytes);
2137 update_reserved_extents(root, bytenr, num_bytes, 0);
2138 return 0;
2139 }
2140 pin = 1;
2141 }
2142
2143 /* if data pin when any transaction has committed this */
2144 if (ref_generation != trans->transid)
2145 pin = 1;
2146
2147 ret = __free_extent(trans, root, bytenr, num_bytes, parent,
2148 root_objectid, ref_generation, owner_objectid,
2149 owner_offset, pin, pin == 0);
2150
2151 finish_current_insert(trans, root->fs_info->extent_root);
2152 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
2153 return ret ? ret : pending_ret;
2154 }
2155
2156 int btrfs_free_extent(struct btrfs_trans_handle *trans,
2157 struct btrfs_root *root,
2158 u64 bytenr, u64 num_bytes, u64 parent,
2159 u64 root_objectid, u64 ref_generation,
2160 u64 owner_objectid, u64 owner_offset, int pin)
2161 {
2162 int ret;
2163
2164 maybe_lock_mutex(root);
2165 ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent,
2166 root_objectid, ref_generation,
2167 owner_objectid, owner_offset, pin);
2168 maybe_unlock_mutex(root);
2169 return ret;
2170 }
2171
2172 static u64 stripe_align(struct btrfs_root *root, u64 val)
2173 {
2174 u64 mask = ((u64)root->stripesize - 1);
2175 u64 ret = (val + mask) & ~mask;
2176 return ret;
2177 }
2178
2179 /*
2180 * walks the btree of allocated extents and find a hole of a given size.
2181 * The key ins is changed to record the hole:
2182 * ins->objectid == block start
2183 * ins->flags = BTRFS_EXTENT_ITEM_KEY
2184 * ins->offset == number of blocks
2185 * Any available blocks before search_start are skipped.
2186 */
2187 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
2188 struct btrfs_root *orig_root,
2189 u64 num_bytes, u64 empty_size,
2190 u64 search_start, u64 search_end,
2191 u64 hint_byte, struct btrfs_key *ins,
2192 u64 exclude_start, u64 exclude_nr,
2193 int data)
2194 {
2195 int ret;
2196 u64 orig_search_start;
2197 struct btrfs_root * root = orig_root->fs_info->extent_root;
2198 struct btrfs_fs_info *info = root->fs_info;
2199 u64 total_needed = num_bytes;
2200 u64 *last_ptr = NULL;
2201 struct btrfs_block_group_cache *block_group;
2202 int chunk_alloc_done = 0;
2203 int empty_cluster = 2 * 1024 * 1024;
2204 int allowed_chunk_alloc = 0;
2205
2206 WARN_ON(num_bytes < root->sectorsize);
2207 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
2208
2209 if (orig_root->ref_cows || empty_size)
2210 allowed_chunk_alloc = 1;
2211
2212 if (data & BTRFS_BLOCK_GROUP_METADATA) {
2213 last_ptr = &root->fs_info->last_alloc;
2214 empty_cluster = 256 * 1024;
2215 }
2216
2217 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
2218 last_ptr = &root->fs_info->last_data_alloc;
2219
2220 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2221 last_ptr = &root->fs_info->last_log_alloc;
2222 if (!last_ptr == 0 && root->fs_info->last_alloc) {
2223 *last_ptr = root->fs_info->last_alloc + empty_cluster;
2224 }
2225 }
2226
2227 if (last_ptr) {
2228 if (*last_ptr)
2229 hint_byte = *last_ptr;
2230 else
2231 empty_size += empty_cluster;
2232 }
2233
2234 search_start = max(search_start, first_logical_byte(root, 0));
2235 orig_search_start = search_start;
2236
2237 search_start = max(search_start, hint_byte);
2238 total_needed += empty_size;
2239
2240 new_group:
2241 block_group = btrfs_lookup_block_group(info, search_start);
2242 if (!block_group)
2243 block_group = btrfs_lookup_first_block_group(info,
2244 search_start);
2245
2246 /*
2247 * Ok this looks a little tricky, buts its really simple. First if we
2248 * didn't find a block group obviously we want to start over.
2249 * Secondly, if the block group we found does not match the type we
2250 * need, and we have a last_ptr and its not 0, chances are the last
2251 * allocation we made was at the end of the block group, so lets go
2252 * ahead and skip the looking through the rest of the block groups and
2253 * start at the beginning. This helps with metadata allocations,
2254 * since you are likely to have a bunch of data block groups to search
2255 * through first before you realize that you need to start over, so go
2256 * ahead and start over and save the time.
2257 */
2258 if (!block_group || (!block_group_bits(block_group, data) &&
2259 last_ptr && *last_ptr)) {
2260 if (search_start != orig_search_start) {
2261 if (last_ptr && *last_ptr) {
2262 total_needed += empty_cluster;
2263 *last_ptr = 0;
2264 }
2265 search_start = orig_search_start;
2266 goto new_group;
2267 } else if (!chunk_alloc_done && allowed_chunk_alloc) {
2268 ret = do_chunk_alloc(trans, root,
2269 num_bytes + 2 * 1024 * 1024,
2270 data, 1);
2271 if (ret < 0)
2272 goto error;
2273 BUG_ON(ret);
2274 chunk_alloc_done = 1;
2275 search_start = orig_search_start;
2276 goto new_group;
2277 } else {
2278 ret = -ENOSPC;
2279 goto error;
2280 }
2281 }
2282
2283 /*
2284 * this is going to seach through all of the existing block groups it
2285 * can find, so if we don't find something we need to see if we can
2286 * allocate what we need.
2287 */
2288 ret = find_free_space(root, &block_group, &search_start,
2289 total_needed, data);
2290 if (ret == -ENOSPC) {
2291 /*
2292 * instead of allocating, start at the original search start
2293 * and see if there is something to be found, if not then we
2294 * allocate
2295 */
2296 if (search_start != orig_search_start) {
2297 if (last_ptr && *last_ptr) {
2298 *last_ptr = 0;
2299 total_needed += empty_cluster;
2300 }
2301 search_start = orig_search_start;
2302 goto new_group;
2303 }
2304
2305 /*
2306 * we've already allocated, we're pretty screwed
2307 */
2308 if (chunk_alloc_done) {
2309 goto error;
2310 } else if (!allowed_chunk_alloc && block_group &&
2311 block_group_bits(block_group, data)) {
2312 block_group->space_info->force_alloc = 1;
2313 goto error;
2314 } else if (!allowed_chunk_alloc) {
2315 goto error;
2316 }
2317
2318 ret = do_chunk_alloc(trans, root, num_bytes + 2 * 1024 * 1024,
2319 data, 1);
2320 if (ret < 0)
2321 goto error;
2322
2323 BUG_ON(ret);
2324 chunk_alloc_done = 1;
2325 if (block_group)
2326 search_start = block_group->key.objectid +
2327 block_group->key.offset;
2328 else
2329 search_start = orig_search_start;
2330 goto new_group;
2331 }
2332
2333 if (ret)
2334 goto error;
2335
2336 search_start = stripe_align(root, search_start);
2337 ins->objectid = search_start;
2338 ins->offset = num_bytes;
2339
2340 if (ins->objectid + num_bytes >= search_end) {
2341 search_start = orig_search_start;
2342 if (chunk_alloc_done) {
2343 ret = -ENOSPC;
2344 goto error;
2345 }
2346 goto new_group;
2347 }
2348
2349 if (ins->objectid + num_bytes >
2350 block_group->key.objectid + block_group->key.offset) {
2351 if (search_start == orig_search_start && chunk_alloc_done) {
2352 ret = -ENOSPC;
2353 goto error;
2354 }
2355 search_start = block_group->key.objectid +
2356 block_group->key.offset;
2357 goto new_group;
2358 }
2359
2360 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
2361 ins->objectid < exclude_start + exclude_nr)) {
2362 search_start = exclude_start + exclude_nr;
2363 goto new_group;
2364 }
2365
2366 if (!(data & BTRFS_BLOCK_GROUP_DATA))
2367 trans->block_group = block_group;
2368
2369 ins->offset = num_bytes;
2370 if (last_ptr) {
2371 *last_ptr = ins->objectid + ins->offset;
2372 if (*last_ptr ==
2373 btrfs_super_total_bytes(&root->fs_info->super_copy))
2374 *last_ptr = 0;
2375 }
2376
2377 ret = 0;
2378 error:
2379 return ret;
2380 }
2381
2382 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
2383 {
2384 struct btrfs_block_group_cache *cache;
2385 struct list_head *l;
2386
2387 printk(KERN_INFO "space_info has %Lu free, is %sfull\n",
2388 info->total_bytes - info->bytes_used - info->bytes_pinned -
2389 info->bytes_reserved, (info->full) ? "" : "not ");
2390
2391 spin_lock(&info->lock);
2392 list_for_each(l, &info->block_groups) {
2393 cache = list_entry(l, struct btrfs_block_group_cache, list);
2394 spin_lock(&cache->lock);
2395 printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used "
2396 "%Lu pinned %Lu reserved\n",
2397 cache->key.objectid, cache->key.offset,
2398 btrfs_block_group_used(&cache->item),
2399 cache->pinned, cache->reserved);
2400 btrfs_dump_free_space(cache, bytes);
2401 spin_unlock(&cache->lock);
2402 }
2403 spin_unlock(&info->lock);
2404 }
2405
2406 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2407 struct btrfs_root *root,
2408 u64 num_bytes, u64 min_alloc_size,
2409 u64 empty_size, u64 hint_byte,
2410 u64 search_end, struct btrfs_key *ins,
2411 u64 data)
2412 {
2413 int ret;
2414 u64 search_start = 0;
2415 u64 alloc_profile;
2416 struct btrfs_fs_info *info = root->fs_info;
2417 struct btrfs_block_group_cache *cache;
2418
2419 if (data) {
2420 alloc_profile = info->avail_data_alloc_bits &
2421 info->data_alloc_profile;
2422 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2423 } else if (root == root->fs_info->chunk_root) {
2424 alloc_profile = info->avail_system_alloc_bits &
2425 info->system_alloc_profile;
2426 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2427 } else {
2428 alloc_profile = info->avail_metadata_alloc_bits &
2429 info->metadata_alloc_profile;
2430 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2431 }
2432 again:
2433 data = reduce_alloc_profile(root, data);
2434 /*
2435 * the only place that sets empty_size is btrfs_realloc_node, which
2436 * is not called recursively on allocations
2437 */
2438 if (empty_size || root->ref_cows) {
2439 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
2440 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2441 2 * 1024 * 1024,
2442 BTRFS_BLOCK_GROUP_METADATA |
2443 (info->metadata_alloc_profile &
2444 info->avail_metadata_alloc_bits), 0);
2445 }
2446 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2447 num_bytes + 2 * 1024 * 1024, data, 0);
2448 }
2449
2450 WARN_ON(num_bytes < root->sectorsize);
2451 ret = find_free_extent(trans, root, num_bytes, empty_size,
2452 search_start, search_end, hint_byte, ins,
2453 trans->alloc_exclude_start,
2454 trans->alloc_exclude_nr, data);
2455
2456 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
2457 num_bytes = num_bytes >> 1;
2458 num_bytes = num_bytes & ~(root->sectorsize - 1);
2459 num_bytes = max(num_bytes, min_alloc_size);
2460 do_chunk_alloc(trans, root->fs_info->extent_root,
2461 num_bytes, data, 1);
2462 goto again;
2463 }
2464 if (ret) {
2465 struct btrfs_space_info *sinfo;
2466
2467 sinfo = __find_space_info(root->fs_info, data);
2468 printk("allocation failed flags %Lu, wanted %Lu\n",
2469 data, num_bytes);
2470 dump_space_info(sinfo, num_bytes);
2471 BUG();
2472 }
2473 cache = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2474 if (!cache) {
2475 printk(KERN_ERR "Unable to find block group for %Lu\n", ins->objectid);
2476 return -ENOSPC;
2477 }
2478
2479 ret = btrfs_remove_free_space(cache, ins->objectid, ins->offset);
2480
2481 return ret;
2482 }
2483
2484 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
2485 {
2486 struct btrfs_block_group_cache *cache;
2487
2488 maybe_lock_mutex(root);
2489 cache = btrfs_lookup_block_group(root->fs_info, start);
2490 if (!cache) {
2491 printk(KERN_ERR "Unable to find block group for %Lu\n", start);
2492 maybe_unlock_mutex(root);
2493 return -ENOSPC;
2494 }
2495 btrfs_add_free_space(cache, start, len);
2496 update_reserved_extents(root, start, len, 0);
2497 maybe_unlock_mutex(root);
2498 return 0;
2499 }
2500
2501 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2502 struct btrfs_root *root,
2503 u64 num_bytes, u64 min_alloc_size,
2504 u64 empty_size, u64 hint_byte,
2505 u64 search_end, struct btrfs_key *ins,
2506 u64 data)
2507 {
2508 int ret;
2509 maybe_lock_mutex(root);
2510 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
2511 empty_size, hint_byte, search_end, ins,
2512 data);
2513 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2514 maybe_unlock_mutex(root);
2515 return ret;
2516 }
2517
2518 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2519 struct btrfs_root *root, u64 parent,
2520 u64 root_objectid, u64 ref_generation,
2521 u64 owner, u64 owner_offset,
2522 struct btrfs_key *ins)
2523 {
2524 int ret;
2525 int pending_ret;
2526 u64 super_used;
2527 u64 root_used;
2528 u64 num_bytes = ins->offset;
2529 u32 sizes[2];
2530 struct btrfs_fs_info *info = root->fs_info;
2531 struct btrfs_root *extent_root = info->extent_root;
2532 struct btrfs_extent_item *extent_item;
2533 struct btrfs_extent_ref *ref;
2534 struct btrfs_path *path;
2535 struct btrfs_key keys[2];
2536
2537 if (parent == 0)
2538 parent = ins->objectid;
2539
2540 /* block accounting for super block */
2541 spin_lock_irq(&info->delalloc_lock);
2542 super_used = btrfs_super_bytes_used(&info->super_copy);
2543 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
2544 spin_unlock_irq(&info->delalloc_lock);
2545
2546 /* block accounting for root item */
2547 root_used = btrfs_root_used(&root->root_item);
2548 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
2549
2550 if (root == extent_root) {
2551 struct pending_extent_op *extent_op;
2552
2553 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2554 BUG_ON(!extent_op);
2555
2556 extent_op->type = PENDING_EXTENT_INSERT;
2557 extent_op->bytenr = ins->objectid;
2558 extent_op->num_bytes = ins->offset;
2559 extent_op->parent = parent;
2560 extent_op->orig_parent = 0;
2561 extent_op->generation = ref_generation;
2562 extent_op->orig_generation = 0;
2563 extent_op->level = (int)owner;
2564
2565 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2566 ins->objectid + ins->offset - 1,
2567 EXTENT_LOCKED, GFP_NOFS);
2568 set_state_private(&root->fs_info->extent_ins,
2569 ins->objectid, (unsigned long)extent_op);
2570 goto update_block;
2571 }
2572
2573 memcpy(&keys[0], ins, sizeof(*ins));
2574 keys[1].objectid = ins->objectid;
2575 keys[1].type = BTRFS_EXTENT_REF_KEY;
2576 keys[1].offset = parent;
2577 sizes[0] = sizeof(*extent_item);
2578 sizes[1] = sizeof(*ref);
2579
2580 path = btrfs_alloc_path();
2581 BUG_ON(!path);
2582
2583 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
2584 sizes, 2);
2585 BUG_ON(ret);
2586
2587 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2588 struct btrfs_extent_item);
2589 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
2590 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
2591 struct btrfs_extent_ref);
2592
2593 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
2594 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
2595 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
2596 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
2597 btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
2598
2599 btrfs_mark_buffer_dirty(path->nodes[0]);
2600
2601 trans->alloc_exclude_start = 0;
2602 trans->alloc_exclude_nr = 0;
2603 btrfs_free_path(path);
2604 finish_current_insert(trans, extent_root);
2605 pending_ret = del_pending_extents(trans, extent_root);
2606
2607 if (ret)
2608 goto out;
2609 if (pending_ret) {
2610 ret = pending_ret;
2611 goto out;
2612 }
2613
2614 update_block:
2615 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
2616 if (ret) {
2617 printk("update block group failed for %Lu %Lu\n",
2618 ins->objectid, ins->offset);
2619 BUG();
2620 }
2621 out:
2622 return ret;
2623 }
2624
2625 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2626 struct btrfs_root *root, u64 parent,
2627 u64 root_objectid, u64 ref_generation,
2628 u64 owner, u64 owner_offset,
2629 struct btrfs_key *ins)
2630 {
2631 int ret;
2632
2633 if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
2634 return 0;
2635 maybe_lock_mutex(root);
2636 ret = __btrfs_alloc_reserved_extent(trans, root, parent,
2637 root_objectid, ref_generation,
2638 owner, owner_offset, ins);
2639 update_reserved_extents(root, ins->objectid, ins->offset, 0);
2640 maybe_unlock_mutex(root);
2641 return ret;
2642 }
2643
2644 /*
2645 * this is used by the tree logging recovery code. It records that
2646 * an extent has been allocated and makes sure to clear the free
2647 * space cache bits as well
2648 */
2649 int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
2650 struct btrfs_root *root, u64 parent,
2651 u64 root_objectid, u64 ref_generation,
2652 u64 owner, u64 owner_offset,
2653 struct btrfs_key *ins)
2654 {
2655 int ret;
2656 struct btrfs_block_group_cache *block_group;
2657
2658 maybe_lock_mutex(root);
2659 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2660 cache_block_group(root, block_group);
2661
2662 ret = btrfs_remove_free_space(block_group, ins->objectid, ins->offset);
2663 BUG_ON(ret);
2664 ret = __btrfs_alloc_reserved_extent(trans, root, parent,
2665 root_objectid, ref_generation,
2666 owner, owner_offset, ins);
2667 maybe_unlock_mutex(root);
2668 return ret;
2669 }
2670
2671 /*
2672 * finds a free extent and does all the dirty work required for allocation
2673 * returns the key for the extent through ins, and a tree buffer for
2674 * the first block of the extent through buf.
2675 *
2676 * returns 0 if everything worked, non-zero otherwise.
2677 */
2678 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
2679 struct btrfs_root *root,
2680 u64 num_bytes, u64 parent, u64 min_alloc_size,
2681 u64 root_objectid, u64 ref_generation,
2682 u64 owner_objectid, u64 owner_offset,
2683 u64 empty_size, u64 hint_byte,
2684 u64 search_end, struct btrfs_key *ins, u64 data)
2685 {
2686 int ret;
2687
2688 maybe_lock_mutex(root);
2689
2690 ret = __btrfs_reserve_extent(trans, root, num_bytes,
2691 min_alloc_size, empty_size, hint_byte,
2692 search_end, ins, data);
2693 BUG_ON(ret);
2694 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
2695 ret = __btrfs_alloc_reserved_extent(trans, root, parent,
2696 root_objectid, ref_generation,
2697 owner_objectid, owner_offset, ins);
2698 BUG_ON(ret);
2699
2700 } else {
2701 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2702 }
2703 maybe_unlock_mutex(root);
2704 return ret;
2705 }
2706
2707 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
2708 struct btrfs_root *root,
2709 u64 bytenr, u32 blocksize)
2710 {
2711 struct extent_buffer *buf;
2712
2713 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
2714 if (!buf)
2715 return ERR_PTR(-ENOMEM);
2716 btrfs_set_header_generation(buf, trans->transid);
2717 btrfs_tree_lock(buf);
2718 clean_tree_block(trans, root, buf);
2719 btrfs_set_buffer_uptodate(buf);
2720 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2721 set_extent_dirty(&root->dirty_log_pages, buf->start,
2722 buf->start + buf->len - 1, GFP_NOFS);
2723 } else {
2724 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
2725 buf->start + buf->len - 1, GFP_NOFS);
2726 }
2727 trans->blocks_used++;
2728 return buf;
2729 }
2730
2731 /*
2732 * helper function to allocate a block for a given tree
2733 * returns the tree buffer or NULL.
2734 */
2735 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2736 struct btrfs_root *root,
2737 u32 blocksize, u64 parent,
2738 u64 root_objectid,
2739 u64 ref_generation,
2740 int level,
2741 u64 hint,
2742 u64 empty_size)
2743 {
2744 struct btrfs_key ins;
2745 int ret;
2746 struct extent_buffer *buf;
2747
2748 ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
2749 root_objectid, ref_generation, level, 0,
2750 empty_size, hint, (u64)-1, &ins, 0);
2751 if (ret) {
2752 BUG_ON(ret > 0);
2753 return ERR_PTR(ret);
2754 }
2755
2756 buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
2757 return buf;
2758 }
2759
2760 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
2761 struct btrfs_root *root, struct extent_buffer *leaf)
2762 {
2763 u64 leaf_owner;
2764 u64 leaf_generation;
2765 struct btrfs_key key;
2766 struct btrfs_file_extent_item *fi;
2767 int i;
2768 int nritems;
2769 int ret;
2770
2771 BUG_ON(!btrfs_is_leaf(leaf));
2772 nritems = btrfs_header_nritems(leaf);
2773 leaf_owner = btrfs_header_owner(leaf);
2774 leaf_generation = btrfs_header_generation(leaf);
2775
2776 for (i = 0; i < nritems; i++) {
2777 u64 disk_bytenr;
2778 cond_resched();
2779
2780 btrfs_item_key_to_cpu(leaf, &key, i);
2781 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2782 continue;
2783 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2784 if (btrfs_file_extent_type(leaf, fi) ==
2785 BTRFS_FILE_EXTENT_INLINE)
2786 continue;
2787 /*
2788 * FIXME make sure to insert a trans record that
2789 * repeats the snapshot del on crash
2790 */
2791 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2792 if (disk_bytenr == 0)
2793 continue;
2794
2795 mutex_lock(&root->fs_info->alloc_mutex);
2796 ret = __btrfs_free_extent(trans, root, disk_bytenr,
2797 btrfs_file_extent_disk_num_bytes(leaf, fi),
2798 leaf->start, leaf_owner, leaf_generation,
2799 key.objectid, key.offset, 0);
2800 mutex_unlock(&root->fs_info->alloc_mutex);
2801 BUG_ON(ret);
2802
2803 atomic_inc(&root->fs_info->throttle_gen);
2804 wake_up(&root->fs_info->transaction_throttle);
2805 cond_resched();
2806 }
2807 return 0;
2808 }
2809
2810 static int noinline cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
2811 struct btrfs_root *root,
2812 struct btrfs_leaf_ref *ref)
2813 {
2814 int i;
2815 int ret;
2816 struct btrfs_extent_info *info = ref->extents;
2817
2818 for (i = 0; i < ref->nritems; i++) {
2819 mutex_lock(&root->fs_info->alloc_mutex);
2820 ret = __btrfs_free_extent(trans, root, info->bytenr,
2821 info->num_bytes, ref->bytenr,
2822 ref->owner, ref->generation,
2823 info->objectid, info->offset, 0);
2824 mutex_unlock(&root->fs_info->alloc_mutex);
2825
2826 atomic_inc(&root->fs_info->throttle_gen);
2827 wake_up(&root->fs_info->transaction_throttle);
2828 cond_resched();
2829
2830 BUG_ON(ret);
2831 info++;
2832 }
2833
2834 return 0;
2835 }
2836
2837 int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len,
2838 u32 *refs)
2839 {
2840 int ret;
2841
2842 ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
2843 BUG_ON(ret);
2844
2845 #if 0 // some debugging code in case we see problems here
2846 /* if the refs count is one, it won't get increased again. But
2847 * if the ref count is > 1, someone may be decreasing it at
2848 * the same time we are.
2849 */
2850 if (*refs != 1) {
2851 struct extent_buffer *eb = NULL;
2852 eb = btrfs_find_create_tree_block(root, start, len);
2853 if (eb)
2854 btrfs_tree_lock(eb);
2855
2856 mutex_lock(&root->fs_info->alloc_mutex);
2857 ret = lookup_extent_ref(NULL, root, start, len, refs);
2858 BUG_ON(ret);
2859 mutex_unlock(&root->fs_info->alloc_mutex);
2860
2861 if (eb) {
2862 btrfs_tree_unlock(eb);
2863 free_extent_buffer(eb);
2864 }
2865 if (*refs == 1) {
2866 printk("block %llu went down to one during drop_snap\n",
2867 (unsigned long long)start);
2868 }
2869
2870 }
2871 #endif
2872
2873 cond_resched();
2874 return ret;
2875 }
2876
2877 /*
2878 * helper function for drop_snapshot, this walks down the tree dropping ref
2879 * counts as it goes.
2880 */
2881 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2882 struct btrfs_root *root,
2883 struct btrfs_path *path, int *level)
2884 {
2885 u64 root_owner;
2886 u64 root_gen;
2887 u64 bytenr;
2888 u64 ptr_gen;
2889 struct extent_buffer *next;
2890 struct extent_buffer *cur;
2891 struct extent_buffer *parent;
2892 struct btrfs_leaf_ref *ref;
2893 u32 blocksize;
2894 int ret;
2895 u32 refs;
2896
2897 WARN_ON(*level < 0);
2898 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2899 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
2900 path->nodes[*level]->len, &refs);
2901 BUG_ON(ret);
2902 if (refs > 1)
2903 goto out;
2904
2905 /*
2906 * walk down to the last node level and free all the leaves
2907 */
2908 while(*level >= 0) {
2909 WARN_ON(*level < 0);
2910 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2911 cur = path->nodes[*level];
2912
2913 if (btrfs_header_level(cur) != *level)
2914 WARN_ON(1);
2915
2916 if (path->slots[*level] >=
2917 btrfs_header_nritems(cur))
2918 break;
2919 if (*level == 0) {
2920 ret = btrfs_drop_leaf_ref(trans, root, cur);
2921 BUG_ON(ret);
2922 break;
2923 }
2924 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2925 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2926 blocksize = btrfs_level_size(root, *level - 1);
2927
2928 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
2929 BUG_ON(ret);
2930 if (refs != 1) {
2931 parent = path->nodes[*level];
2932 root_owner = btrfs_header_owner(parent);
2933 root_gen = btrfs_header_generation(parent);
2934 path->slots[*level]++;
2935
2936 mutex_lock(&root->fs_info->alloc_mutex);
2937 ret = __btrfs_free_extent(trans, root, bytenr,
2938 blocksize, parent->start,
2939 root_owner, root_gen, 0, 0, 1);
2940 BUG_ON(ret);
2941 mutex_unlock(&root->fs_info->alloc_mutex);
2942
2943 atomic_inc(&root->fs_info->throttle_gen);
2944 wake_up(&root->fs_info->transaction_throttle);
2945 cond_resched();
2946
2947 continue;
2948 }
2949 /*
2950 * at this point, we have a single ref, and since the
2951 * only place referencing this extent is a dead root
2952 * the reference count should never go higher.
2953 * So, we don't need to check it again
2954 */
2955 if (*level == 1) {
2956 ref = btrfs_lookup_leaf_ref(root, bytenr);
2957 if (ref && ref->generation != ptr_gen) {
2958 btrfs_free_leaf_ref(root, ref);
2959 ref = NULL;
2960 }
2961 if (ref) {
2962 ret = cache_drop_leaf_ref(trans, root, ref);
2963 BUG_ON(ret);
2964 btrfs_remove_leaf_ref(root, ref);
2965 btrfs_free_leaf_ref(root, ref);
2966 *level = 0;
2967 break;
2968 }
2969 if (printk_ratelimit())
2970 printk("leaf ref miss for bytenr %llu\n",
2971 (unsigned long long)bytenr);
2972 }
2973 next = btrfs_find_tree_block(root, bytenr, blocksize);
2974 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2975 free_extent_buffer(next);
2976
2977 next = read_tree_block(root, bytenr, blocksize,
2978 ptr_gen);
2979 cond_resched();
2980 #if 0
2981 /*
2982 * this is a debugging check and can go away
2983 * the ref should never go all the way down to 1
2984 * at this point
2985 */
2986 ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
2987 &refs);
2988 BUG_ON(ret);
2989 WARN_ON(refs != 1);
2990 #endif
2991 }
2992 WARN_ON(*level <= 0);
2993 if (path->nodes[*level-1])
2994 free_extent_buffer(path->nodes[*level-1]);
2995 path->nodes[*level-1] = next;
2996 *level = btrfs_header_level(next);
2997 path->slots[*level] = 0;
2998 cond_resched();
2999 }
3000 out:
3001 WARN_ON(*level < 0);
3002 WARN_ON(*level >= BTRFS_MAX_LEVEL);
3003
3004 if (path->nodes[*level] == root->node) {
3005 parent = path->nodes[*level];
3006 bytenr = path->nodes[*level]->start;
3007 } else {
3008 parent = path->nodes[*level + 1];
3009 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
3010 }
3011
3012 blocksize = btrfs_level_size(root, *level);
3013 root_owner = btrfs_header_owner(parent);
3014 root_gen = btrfs_header_generation(parent);
3015
3016 mutex_lock(&root->fs_info->alloc_mutex);
3017 ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
3018 parent->start, root_owner, root_gen,
3019 0, 0, 1);
3020 mutex_unlock(&root->fs_info->alloc_mutex);
3021 free_extent_buffer(path->nodes[*level]);
3022 path->nodes[*level] = NULL;
3023 *level += 1;
3024 BUG_ON(ret);
3025
3026 cond_resched();
3027 return 0;
3028 }
3029
3030 /*
3031 * helper for dropping snapshots. This walks back up the tree in the path
3032 * to find the first node higher up where we haven't yet gone through
3033 * all the slots
3034 */
3035 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
3036 struct btrfs_root *root,
3037 struct btrfs_path *path, int *level)
3038 {
3039 u64 root_owner;
3040 u64 root_gen;
3041 struct btrfs_root_item *root_item = &root->root_item;
3042 int i;
3043 int slot;
3044 int ret;
3045
3046 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
3047 slot = path->slots[i];
3048 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
3049 struct extent_buffer *node;
3050 struct btrfs_disk_key disk_key;
3051 node = path->nodes[i];
3052 path->slots[i]++;
3053 *level = i;
3054 WARN_ON(*level == 0);
3055 btrfs_node_key(node, &disk_key, path->slots[i]);
3056 memcpy(&root_item->drop_progress,
3057 &disk_key, sizeof(disk_key));
3058 root_item->drop_level = i;
3059 return 0;
3060 } else {
3061 struct extent_buffer *parent;
3062 if (path->nodes[*level] == root->node)
3063 parent = path->nodes[*level];
3064 else
3065 parent = path->nodes[*level + 1];
3066
3067 root_owner = btrfs_header_owner(parent);
3068 root_gen = btrfs_header_generation(parent);
3069 ret = btrfs_free_extent(trans, root,
3070 path->nodes[*level]->start,
3071 path->nodes[*level]->len,
3072 parent->start,
3073 root_owner, root_gen, 0, 0, 1);
3074 BUG_ON(ret);
3075 free_extent_buffer(path->nodes[*level]);
3076 path->nodes[*level] = NULL;
3077 *level = i + 1;
3078 }
3079 }
3080 return 1;
3081 }
3082
3083 /*
3084 * drop the reference count on the tree rooted at 'snap'. This traverses
3085 * the tree freeing any blocks that have a ref count of zero after being
3086 * decremented.
3087 */
3088 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
3089 *root)
3090 {
3091 int ret = 0;
3092 int wret;
3093 int level;
3094 struct btrfs_path *path;
3095 int i;
3096 int orig_level;
3097 struct btrfs_root_item *root_item = &root->root_item;
3098
3099 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
3100 path = btrfs_alloc_path();
3101 BUG_ON(!path);
3102
3103 level = btrfs_header_level(root->node);
3104 orig_level = level;
3105 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
3106 path->nodes[level] = root->node;
3107 extent_buffer_get(root->node);
3108 path->slots[level] = 0;
3109 } else {
3110 struct btrfs_key key;
3111 struct btrfs_disk_key found_key;
3112 struct extent_buffer *node;
3113
3114 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
3115 level = root_item->drop_level;
3116 path->lowest_level = level;
3117 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3118 if (wret < 0) {
3119 ret = wret;
3120 goto out;
3121 }
3122 node = path->nodes[level];
3123 btrfs_node_key(node, &found_key, path->slots[level]);
3124 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
3125 sizeof(found_key)));
3126 /*
3127 * unlock our path, this is safe because only this
3128 * function is allowed to delete this snapshot
3129 */
3130 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
3131 if (path->nodes[i] && path->locks[i]) {
3132 path->locks[i] = 0;
3133 btrfs_tree_unlock(path->nodes[i]);
3134 }
3135 }
3136 }
3137 while(1) {
3138 wret = walk_down_tree(trans, root, path, &level);
3139 if (wret > 0)
3140 break;
3141 if (wret < 0)
3142 ret = wret;
3143
3144 wret = walk_up_tree(trans, root, path, &level);
3145 if (wret > 0)
3146 break;
3147 if (wret < 0)
3148 ret = wret;
3149 if (trans->transaction->in_commit) {
3150 ret = -EAGAIN;
3151 break;
3152 }
3153 atomic_inc(&root->fs_info->throttle_gen);
3154 wake_up(&root->fs_info->transaction_throttle);
3155 }
3156 for (i = 0; i <= orig_level; i++) {
3157 if (path->nodes[i]) {
3158 free_extent_buffer(path->nodes[i]);
3159 path->nodes[i] = NULL;
3160 }
3161 }
3162 out:
3163 btrfs_free_path(path);
3164 return ret;
3165 }
3166
3167 static unsigned long calc_ra(unsigned long start, unsigned long last,
3168 unsigned long nr)
3169 {
3170 return min(last, start + nr - 1);
3171 }
3172
3173 static int noinline relocate_inode_pages(struct inode *inode, u64 start,
3174 u64 len)
3175 {
3176 u64 page_start;
3177 u64 page_end;
3178 unsigned long first_index;
3179 unsigned long last_index;
3180 unsigned long i;
3181 struct page *page;
3182 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3183 struct file_ra_state *ra;
3184 struct btrfs_ordered_extent *ordered;
3185 unsigned int total_read = 0;
3186 unsigned int total_dirty = 0;
3187 int ret = 0;
3188
3189 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3190
3191 mutex_lock(&inode->i_mutex);
3192 first_index = start >> PAGE_CACHE_SHIFT;
3193 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
3194
3195 /* make sure the dirty trick played by the caller work */
3196 ret = invalidate_inode_pages2_range(inode->i_mapping,
3197 first_index, last_index);
3198 if (ret)
3199 goto out_unlock;
3200
3201 file_ra_state_init(ra, inode->i_mapping);
3202
3203 for (i = first_index ; i <= last_index; i++) {
3204 if (total_read % ra->ra_pages == 0) {
3205 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
3206 calc_ra(i, last_index, ra->ra_pages));
3207 }
3208 total_read++;
3209 again:
3210 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
3211 BUG_ON(1);
3212 page = grab_cache_page(inode->i_mapping, i);
3213 if (!page) {
3214 ret = -ENOMEM;
3215 goto out_unlock;
3216 }
3217 if (!PageUptodate(page)) {
3218 btrfs_readpage(NULL, page);
3219 lock_page(page);
3220 if (!PageUptodate(page)) {
3221 unlock_page(page);
3222 page_cache_release(page);
3223 ret = -EIO;
3224 goto out_unlock;
3225 }
3226 }
3227 wait_on_page_writeback(page);
3228
3229 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
3230 page_end = page_start + PAGE_CACHE_SIZE - 1;
3231 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
3232
3233 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3234 if (ordered) {
3235 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3236 unlock_page(page);
3237 page_cache_release(page);
3238 btrfs_start_ordered_extent(inode, ordered, 1);
3239 btrfs_put_ordered_extent(ordered);
3240 goto again;
3241 }
3242 set_page_extent_mapped(page);
3243
3244 btrfs_set_extent_delalloc(inode, page_start, page_end);
3245 if (i == first_index)
3246 set_extent_bits(io_tree, page_start, page_end,
3247 EXTENT_BOUNDARY, GFP_NOFS);
3248
3249 set_page_dirty(page);
3250 total_dirty++;
3251
3252 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3253 unlock_page(page);
3254 page_cache_release(page);
3255 }
3256
3257 out_unlock:
3258 kfree(ra);
3259 mutex_unlock(&inode->i_mutex);
3260 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
3261 return ret;
3262 }
3263
3264 static int noinline relocate_data_extent(struct inode *reloc_inode,
3265 struct btrfs_key *extent_key,
3266 u64 offset)
3267 {
3268 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3269 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
3270 struct extent_map *em;
3271
3272 em = alloc_extent_map(GFP_NOFS);
3273 BUG_ON(!em || IS_ERR(em));
3274
3275 em->start = extent_key->objectid - offset;
3276 em->len = extent_key->offset;
3277 em->block_start = extent_key->objectid;
3278 em->bdev = root->fs_info->fs_devices->latest_bdev;
3279 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3280
3281 /* setup extent map to cheat btrfs_readpage */
3282 mutex_lock(&BTRFS_I(reloc_inode)->extent_mutex);
3283 while (1) {
3284 int ret;
3285 spin_lock(&em_tree->lock);
3286 ret = add_extent_mapping(em_tree, em);
3287 spin_unlock(&em_tree->lock);
3288 if (ret != -EEXIST) {
3289 free_extent_map(em);
3290 break;
3291 }
3292 btrfs_drop_extent_cache(reloc_inode, em->start,
3293 em->start + em->len - 1, 0);
3294 }
3295 mutex_unlock(&BTRFS_I(reloc_inode)->extent_mutex);
3296
3297 return relocate_inode_pages(reloc_inode, extent_key->objectid - offset,
3298 extent_key->offset);
3299 }
3300
3301 struct btrfs_ref_path {
3302 u64 extent_start;
3303 u64 nodes[BTRFS_MAX_LEVEL];
3304 u64 root_objectid;
3305 u64 root_generation;
3306 u64 owner_objectid;
3307 u64 owner_offset;
3308 u32 num_refs;
3309 int lowest_level;
3310 int current_level;
3311 };
3312
3313 struct disk_extent {
3314 u64 disk_bytenr;
3315 u64 disk_num_bytes;
3316 u64 offset;
3317 u64 num_bytes;
3318 };
3319
3320 static int is_cowonly_root(u64 root_objectid)
3321 {
3322 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
3323 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
3324 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
3325 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
3326 root_objectid == BTRFS_TREE_LOG_OBJECTID)
3327 return 1;
3328 return 0;
3329 }
3330
3331 static int noinline __next_ref_path(struct btrfs_trans_handle *trans,
3332 struct btrfs_root *extent_root,
3333 struct btrfs_ref_path *ref_path,
3334 int first_time)
3335 {
3336 struct extent_buffer *leaf;
3337 struct btrfs_path *path;
3338 struct btrfs_extent_ref *ref;
3339 struct btrfs_key key;
3340 struct btrfs_key found_key;
3341 u64 bytenr;
3342 u32 nritems;
3343 int level;
3344 int ret = 1;
3345
3346 path = btrfs_alloc_path();
3347 if (!path)
3348 return -ENOMEM;
3349
3350 mutex_lock(&extent_root->fs_info->alloc_mutex);
3351
3352 if (first_time) {
3353 ref_path->lowest_level = -1;
3354 ref_path->current_level = -1;
3355 goto walk_up;
3356 }
3357 walk_down:
3358 level = ref_path->current_level - 1;
3359 while (level >= -1) {
3360 u64 parent;
3361 if (level < ref_path->lowest_level)
3362 break;
3363
3364 if (level >= 0) {
3365 bytenr = ref_path->nodes[level];
3366 } else {
3367 bytenr = ref_path->extent_start;
3368 }
3369 BUG_ON(bytenr == 0);
3370
3371 parent = ref_path->nodes[level + 1];
3372 ref_path->nodes[level + 1] = 0;
3373 ref_path->current_level = level;
3374 BUG_ON(parent == 0);
3375
3376 key.objectid = bytenr;
3377 key.offset = parent + 1;
3378 key.type = BTRFS_EXTENT_REF_KEY;
3379
3380 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3381 if (ret < 0)
3382 goto out;
3383 BUG_ON(ret == 0);
3384
3385 leaf = path->nodes[0];
3386 nritems = btrfs_header_nritems(leaf);
3387 if (path->slots[0] >= nritems) {
3388 ret = btrfs_next_leaf(extent_root, path);
3389 if (ret < 0)
3390 goto out;
3391 if (ret > 0)
3392 goto next;
3393 leaf = path->nodes[0];
3394 }
3395
3396 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3397 if (found_key.objectid == bytenr &&
3398 found_key.type == BTRFS_EXTENT_REF_KEY)
3399 goto found;
3400 next:
3401 level--;
3402 btrfs_release_path(extent_root, path);
3403 if (need_resched()) {
3404 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3405 cond_resched();
3406 mutex_lock(&extent_root->fs_info->alloc_mutex);
3407 }
3408 }
3409 /* reached lowest level */
3410 ret = 1;
3411 goto out;
3412 walk_up:
3413 level = ref_path->current_level;
3414 while (level < BTRFS_MAX_LEVEL - 1) {
3415 u64 ref_objectid;
3416 if (level >= 0) {
3417 bytenr = ref_path->nodes[level];
3418 } else {
3419 bytenr = ref_path->extent_start;
3420 }
3421 BUG_ON(bytenr == 0);
3422
3423 key.objectid = bytenr;
3424 key.offset = 0;
3425 key.type = BTRFS_EXTENT_REF_KEY;
3426
3427 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3428 if (ret < 0)
3429 goto out;
3430
3431 leaf = path->nodes[0];
3432 nritems = btrfs_header_nritems(leaf);
3433 if (path->slots[0] >= nritems) {
3434 ret = btrfs_next_leaf(extent_root, path);
3435 if (ret < 0)
3436 goto out;
3437 if (ret > 0) {
3438 /* the extent was freed by someone */
3439 if (ref_path->lowest_level == level)
3440 goto out;
3441 btrfs_release_path(extent_root, path);
3442 goto walk_down;
3443 }
3444 leaf = path->nodes[0];
3445 }
3446
3447 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3448 if (found_key.objectid != bytenr ||
3449 found_key.type != BTRFS_EXTENT_REF_KEY) {
3450 /* the extent was freed by someone */
3451 if (ref_path->lowest_level == level) {
3452 ret = 1;
3453 goto out;
3454 }
3455 btrfs_release_path(extent_root, path);
3456 goto walk_down;
3457 }
3458 found:
3459 ref = btrfs_item_ptr(leaf, path->slots[0],
3460 struct btrfs_extent_ref);
3461 ref_objectid = btrfs_ref_objectid(leaf, ref);
3462 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3463 if (first_time) {
3464 level = (int)ref_objectid;
3465 BUG_ON(level >= BTRFS_MAX_LEVEL);
3466 ref_path->lowest_level = level;
3467 ref_path->current_level = level;
3468 ref_path->nodes[level] = bytenr;
3469 } else {
3470 WARN_ON(ref_objectid != level);
3471 }
3472 } else {
3473 WARN_ON(level != -1);
3474 }
3475 first_time = 0;
3476
3477 if (ref_path->lowest_level == level) {
3478 ref_path->owner_objectid = ref_objectid;
3479 ref_path->owner_offset = btrfs_ref_offset(leaf, ref);
3480 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
3481 }
3482
3483 /*
3484 * the block is tree root or the block isn't in reference
3485 * counted tree.
3486 */
3487 if (found_key.objectid == found_key.offset ||
3488 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
3489 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3490 ref_path->root_generation =
3491 btrfs_ref_generation(leaf, ref);
3492 if (level < 0) {
3493 /* special reference from the tree log */
3494 ref_path->nodes[0] = found_key.offset;
3495 ref_path->current_level = 0;
3496 }
3497 ret = 0;
3498 goto out;
3499 }
3500
3501 level++;
3502 BUG_ON(ref_path->nodes[level] != 0);
3503 ref_path->nodes[level] = found_key.offset;
3504 ref_path->current_level = level;
3505
3506 /*
3507 * the reference was created in the running transaction,
3508 * no need to continue walking up.
3509 */
3510 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
3511 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3512 ref_path->root_generation =
3513 btrfs_ref_generation(leaf, ref);
3514 ret = 0;
3515 goto out;
3516 }
3517
3518 btrfs_release_path(extent_root, path);
3519 if (need_resched()) {
3520 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3521 cond_resched();
3522 mutex_lock(&extent_root->fs_info->alloc_mutex);
3523 }
3524 }
3525 /* reached max tree level, but no tree root found. */
3526 BUG();
3527 out:
3528 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3529 btrfs_free_path(path);
3530 return ret;
3531 }
3532
3533 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
3534 struct btrfs_root *extent_root,
3535 struct btrfs_ref_path *ref_path,
3536 u64 extent_start)
3537 {
3538 memset(ref_path, 0, sizeof(*ref_path));
3539 ref_path->extent_start = extent_start;
3540
3541 return __next_ref_path(trans, extent_root, ref_path, 1);
3542 }
3543
3544 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
3545 struct btrfs_root *extent_root,
3546 struct btrfs_ref_path *ref_path)
3547 {
3548 return __next_ref_path(trans, extent_root, ref_path, 0);
3549 }
3550
3551 static int noinline get_new_locations(struct inode *reloc_inode,
3552 struct btrfs_key *extent_key,
3553 u64 offset, int no_fragment,
3554 struct disk_extent **extents,
3555 int *nr_extents)
3556 {
3557 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3558 struct btrfs_path *path;
3559 struct btrfs_file_extent_item *fi;
3560 struct extent_buffer *leaf;
3561 struct disk_extent *exts = *extents;
3562 struct btrfs_key found_key;
3563 u64 cur_pos;
3564 u64 last_byte;
3565 u32 nritems;
3566 int nr = 0;
3567 int max = *nr_extents;
3568 int ret;
3569
3570 WARN_ON(!no_fragment && *extents);
3571 if (!exts) {
3572 max = 1;
3573 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
3574 if (!exts)
3575 return -ENOMEM;
3576 }
3577
3578 path = btrfs_alloc_path();
3579 BUG_ON(!path);
3580
3581 cur_pos = extent_key->objectid - offset;
3582 last_byte = extent_key->objectid + extent_key->offset;
3583 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
3584 cur_pos, 0);
3585 if (ret < 0)
3586 goto out;
3587 if (ret > 0) {
3588 ret = -ENOENT;
3589 goto out;
3590 }
3591
3592 while (1) {
3593 leaf = path->nodes[0];
3594 nritems = btrfs_header_nritems(leaf);
3595 if (path->slots[0] >= nritems) {
3596 ret = btrfs_next_leaf(root, path);
3597 if (ret < 0)
3598 goto out;
3599 if (ret > 0)
3600 break;
3601 leaf = path->nodes[0];
3602 }
3603
3604 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3605 if (found_key.offset != cur_pos ||
3606 found_key.type != BTRFS_EXTENT_DATA_KEY ||
3607 found_key.objectid != reloc_inode->i_ino)
3608 break;
3609
3610 fi = btrfs_item_ptr(leaf, path->slots[0],
3611 struct btrfs_file_extent_item);
3612 if (btrfs_file_extent_type(leaf, fi) !=
3613 BTRFS_FILE_EXTENT_REG ||
3614 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
3615 break;
3616
3617 if (nr == max) {
3618 struct disk_extent *old = exts;
3619 max *= 2;
3620 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
3621 memcpy(exts, old, sizeof(*exts) * nr);
3622 if (old != *extents)
3623 kfree(old);
3624 }
3625
3626 exts[nr].disk_bytenr =
3627 btrfs_file_extent_disk_bytenr(leaf, fi);
3628 exts[nr].disk_num_bytes =
3629 btrfs_file_extent_disk_num_bytes(leaf, fi);
3630 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
3631 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3632 WARN_ON(exts[nr].offset > 0);
3633 WARN_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
3634
3635 cur_pos += exts[nr].num_bytes;
3636 nr++;
3637
3638 if (cur_pos + offset >= last_byte)
3639 break;
3640
3641 if (no_fragment) {
3642 ret = 1;
3643 goto out;
3644 }
3645 path->slots[0]++;
3646 }
3647
3648 WARN_ON(cur_pos + offset > last_byte);
3649 if (cur_pos + offset < last_byte) {
3650 ret = -ENOENT;
3651 goto out;
3652 }
3653 ret = 0;
3654 out:
3655 btrfs_free_path(path);
3656 if (ret) {
3657 if (exts != *extents)
3658 kfree(exts);
3659 } else {
3660 *extents = exts;
3661 *nr_extents = nr;
3662 }
3663 return ret;
3664 }
3665
3666 static int noinline replace_one_extent(struct btrfs_trans_handle *trans,
3667 struct btrfs_root *root,
3668 struct btrfs_path *path,
3669 struct btrfs_key *extent_key,
3670 struct btrfs_key *leaf_key,
3671 struct btrfs_ref_path *ref_path,
3672 struct disk_extent *new_extents,
3673 int nr_extents)
3674 {
3675 struct extent_buffer *leaf;
3676 struct btrfs_file_extent_item *fi;
3677 struct inode *inode = NULL;
3678 struct btrfs_key key;
3679 u64 lock_start = 0;
3680 u64 lock_end = 0;
3681 u64 num_bytes;
3682 u64 ext_offset;
3683 u64 first_pos;
3684 u32 nritems;
3685 int extent_locked = 0;
3686 int ret;
3687
3688 first_pos = ref_path->owner_offset;
3689 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3690 key.objectid = ref_path->owner_objectid;
3691 key.offset = ref_path->owner_offset;
3692 key.type = BTRFS_EXTENT_DATA_KEY;
3693 } else {
3694 memcpy(&key, leaf_key, sizeof(key));
3695 }
3696
3697 while (1) {
3698 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
3699 if (ret < 0)
3700 goto out;
3701
3702 leaf = path->nodes[0];
3703 nritems = btrfs_header_nritems(leaf);
3704 next:
3705 if (extent_locked && ret > 0) {
3706 /*
3707 * the file extent item was modified by someone
3708 * before the extent got locked.
3709 */
3710 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3711 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3712 lock_end, GFP_NOFS);
3713 extent_locked = 0;
3714 }
3715
3716 if (path->slots[0] >= nritems) {
3717 if (ref_path->owner_objectid ==
3718 BTRFS_MULTIPLE_OBJECTIDS)
3719 break;
3720
3721 BUG_ON(extent_locked);
3722 ret = btrfs_next_leaf(root, path);
3723 if (ret < 0)
3724 goto out;
3725 if (ret > 0)
3726 break;
3727 leaf = path->nodes[0];
3728 nritems = btrfs_header_nritems(leaf);
3729 }
3730
3731 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3732
3733 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3734 if ((key.objectid > ref_path->owner_objectid) ||
3735 (key.objectid == ref_path->owner_objectid &&
3736 key.type > BTRFS_EXTENT_DATA_KEY) ||
3737 (key.offset >= first_pos + extent_key->offset))
3738 break;
3739 }
3740
3741 if (inode && key.objectid != inode->i_ino) {
3742 BUG_ON(extent_locked);
3743 btrfs_release_path(root, path);
3744 mutex_unlock(&inode->i_mutex);
3745 iput(inode);
3746 inode = NULL;
3747 continue;
3748 }
3749
3750 if (key.type != BTRFS_EXTENT_DATA_KEY) {
3751 path->slots[0]++;
3752 ret = 1;
3753 goto next;
3754 }
3755 fi = btrfs_item_ptr(leaf, path->slots[0],
3756 struct btrfs_file_extent_item);
3757 if ((btrfs_file_extent_type(leaf, fi) !=
3758 BTRFS_FILE_EXTENT_REG) ||
3759 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3760 extent_key->objectid)) {
3761 path->slots[0]++;
3762 ret = 1;
3763 goto next;
3764 }
3765
3766 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3767 ext_offset = btrfs_file_extent_offset(leaf, fi);
3768
3769 if (first_pos > key.offset - ext_offset)
3770 first_pos = key.offset - ext_offset;
3771
3772 if (!extent_locked) {
3773 lock_start = key.offset;
3774 lock_end = lock_start + num_bytes - 1;
3775 } else {
3776 BUG_ON(lock_start != key.offset);
3777 BUG_ON(lock_end - lock_start + 1 < num_bytes);
3778 }
3779
3780 if (!inode) {
3781 btrfs_release_path(root, path);
3782
3783 inode = btrfs_iget_locked(root->fs_info->sb,
3784 key.objectid, root);
3785 if (inode->i_state & I_NEW) {
3786 BTRFS_I(inode)->root = root;
3787 BTRFS_I(inode)->location.objectid =
3788 key.objectid;
3789 BTRFS_I(inode)->location.type =
3790 BTRFS_INODE_ITEM_KEY;
3791 BTRFS_I(inode)->location.offset = 0;
3792 btrfs_read_locked_inode(inode);
3793 unlock_new_inode(inode);
3794 }
3795 /*
3796 * some code call btrfs_commit_transaction while
3797 * holding the i_mutex, so we can't use mutex_lock
3798 * here.
3799 */
3800 if (is_bad_inode(inode) ||
3801 !mutex_trylock(&inode->i_mutex)) {
3802 iput(inode);
3803 inode = NULL;
3804 key.offset = (u64)-1;
3805 goto skip;
3806 }
3807 }
3808
3809 if (!extent_locked) {
3810 struct btrfs_ordered_extent *ordered;
3811
3812 btrfs_release_path(root, path);
3813
3814 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3815 lock_end, GFP_NOFS);
3816 ordered = btrfs_lookup_first_ordered_extent(inode,
3817 lock_end);
3818 if (ordered &&
3819 ordered->file_offset <= lock_end &&
3820 ordered->file_offset + ordered->len > lock_start) {
3821 unlock_extent(&BTRFS_I(inode)->io_tree,
3822 lock_start, lock_end, GFP_NOFS);
3823 btrfs_start_ordered_extent(inode, ordered, 1);
3824 btrfs_put_ordered_extent(ordered);
3825 key.offset += num_bytes;
3826 goto skip;
3827 }
3828 if (ordered)
3829 btrfs_put_ordered_extent(ordered);
3830
3831 mutex_lock(&BTRFS_I(inode)->extent_mutex);
3832 extent_locked = 1;
3833 continue;
3834 }
3835
3836 if (nr_extents == 1) {
3837 /* update extent pointer in place */
3838 btrfs_set_file_extent_generation(leaf, fi,
3839 trans->transid);
3840 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3841 new_extents[0].disk_bytenr);
3842 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
3843 new_extents[0].disk_num_bytes);
3844 ext_offset += new_extents[0].offset;
3845 btrfs_set_file_extent_offset(leaf, fi, ext_offset);
3846 btrfs_mark_buffer_dirty(leaf);
3847
3848 btrfs_drop_extent_cache(inode, key.offset,
3849 key.offset + num_bytes - 1, 0);
3850
3851 ret = btrfs_inc_extent_ref(trans, root,
3852 new_extents[0].disk_bytenr,
3853 new_extents[0].disk_num_bytes,
3854 leaf->start,
3855 root->root_key.objectid,
3856 trans->transid,
3857 key.objectid, key.offset);
3858 BUG_ON(ret);
3859
3860 ret = btrfs_free_extent(trans, root,
3861 extent_key->objectid,
3862 extent_key->offset,
3863 leaf->start,
3864 btrfs_header_owner(leaf),
3865 btrfs_header_generation(leaf),
3866 key.objectid, key.offset, 0);
3867 BUG_ON(ret);
3868
3869 btrfs_release_path(root, path);
3870 key.offset += num_bytes;
3871 } else {
3872 u64 alloc_hint;
3873 u64 extent_len;
3874 int i;
3875 /*
3876 * drop old extent pointer at first, then insert the
3877 * new pointers one bye one
3878 */
3879 btrfs_release_path(root, path);
3880 ret = btrfs_drop_extents(trans, root, inode, key.offset,
3881 key.offset + num_bytes,
3882 key.offset, &alloc_hint);
3883 BUG_ON(ret);
3884
3885 for (i = 0; i < nr_extents; i++) {
3886 if (ext_offset >= new_extents[i].num_bytes) {
3887 ext_offset -= new_extents[i].num_bytes;
3888 continue;
3889 }
3890 extent_len = min(new_extents[i].num_bytes -
3891 ext_offset, num_bytes);
3892
3893 ret = btrfs_insert_empty_item(trans, root,
3894 path, &key,
3895 sizeof(*fi));
3896 BUG_ON(ret);
3897
3898 leaf = path->nodes[0];
3899 fi = btrfs_item_ptr(leaf, path->slots[0],
3900 struct btrfs_file_extent_item);
3901 btrfs_set_file_extent_generation(leaf, fi,
3902 trans->transid);
3903 btrfs_set_file_extent_type(leaf, fi,
3904 BTRFS_FILE_EXTENT_REG);
3905 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3906 new_extents[i].disk_bytenr);
3907 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
3908 new_extents[i].disk_num_bytes);
3909 btrfs_set_file_extent_num_bytes(leaf, fi,
3910 extent_len);
3911 ext_offset += new_extents[i].offset;
3912 btrfs_set_file_extent_offset(leaf, fi,
3913 ext_offset);
3914 btrfs_mark_buffer_dirty(leaf);
3915
3916 btrfs_drop_extent_cache(inode, key.offset,
3917 key.offset + extent_len - 1, 0);
3918
3919 ret = btrfs_inc_extent_ref(trans, root,
3920 new_extents[i].disk_bytenr,
3921 new_extents[i].disk_num_bytes,
3922 leaf->start,
3923 root->root_key.objectid,
3924 trans->transid,
3925 key.objectid, key.offset);
3926 BUG_ON(ret);
3927 btrfs_release_path(root, path);
3928
3929 inode->i_blocks += extent_len >> 9;
3930
3931 ext_offset = 0;
3932 num_bytes -= extent_len;
3933 key.offset += extent_len;
3934
3935 if (num_bytes == 0)
3936 break;
3937 }
3938 BUG_ON(i >= nr_extents);
3939 }
3940
3941 if (extent_locked) {
3942 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3943 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3944 lock_end, GFP_NOFS);
3945 extent_locked = 0;
3946 }
3947 skip:
3948 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
3949 key.offset >= first_pos + extent_key->offset)
3950 break;
3951
3952 cond_resched();
3953 }
3954 ret = 0;
3955 out:
3956 btrfs_release_path(root, path);
3957 if (inode) {
3958 mutex_unlock(&inode->i_mutex);
3959 if (extent_locked) {
3960 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3961 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3962 lock_end, GFP_NOFS);
3963 }
3964 iput(inode);
3965 }
3966 return ret;
3967 }
3968
3969 int btrfs_add_reloc_mapping(struct btrfs_root *root, u64 orig_bytenr,
3970 u64 num_bytes, u64 new_bytenr)
3971 {
3972 set_extent_bits(&root->fs_info->reloc_mapping_tree,
3973 orig_bytenr, orig_bytenr + num_bytes - 1,
3974 EXTENT_LOCKED, GFP_NOFS);
3975 set_state_private(&root->fs_info->reloc_mapping_tree,
3976 orig_bytenr, new_bytenr);
3977 return 0;
3978 }
3979
3980 int btrfs_get_reloc_mapping(struct btrfs_root *root, u64 orig_bytenr,
3981 u64 num_bytes, u64 *new_bytenr)
3982 {
3983 u64 bytenr;
3984 u64 cur_bytenr = orig_bytenr;
3985 u64 prev_bytenr = orig_bytenr;
3986 int ret;
3987
3988 while (1) {
3989 ret = get_state_private(&root->fs_info->reloc_mapping_tree,
3990 cur_bytenr, &bytenr);
3991 if (ret)
3992 break;
3993 prev_bytenr = cur_bytenr;
3994 cur_bytenr = bytenr;
3995 }
3996
3997 if (orig_bytenr == cur_bytenr)
3998 return -ENOENT;
3999
4000 if (prev_bytenr != orig_bytenr) {
4001 set_state_private(&root->fs_info->reloc_mapping_tree,
4002 orig_bytenr, cur_bytenr);
4003 }
4004 *new_bytenr = cur_bytenr;
4005 return 0;
4006 }
4007
4008 void btrfs_free_reloc_mappings(struct btrfs_root *root)
4009 {
4010 clear_extent_bits(&root->fs_info->reloc_mapping_tree,
4011 0, (u64)-1, -1, GFP_NOFS);
4012 }
4013
4014 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
4015 struct btrfs_root *root,
4016 struct extent_buffer *buf, u64 orig_start)
4017 {
4018 int level;
4019 int ret;
4020
4021 BUG_ON(btrfs_header_generation(buf) != trans->transid);
4022 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
4023
4024 level = btrfs_header_level(buf);
4025 if (level == 0) {
4026 struct btrfs_leaf_ref *ref;
4027 struct btrfs_leaf_ref *orig_ref;
4028
4029 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
4030 if (!orig_ref)
4031 return -ENOENT;
4032
4033 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
4034 if (!ref) {
4035 btrfs_free_leaf_ref(root, orig_ref);
4036 return -ENOMEM;
4037 }
4038
4039 ref->nritems = orig_ref->nritems;
4040 memcpy(ref->extents, orig_ref->extents,
4041 sizeof(ref->extents[0]) * ref->nritems);
4042
4043 btrfs_free_leaf_ref(root, orig_ref);
4044
4045 ref->root_gen = trans->transid;
4046 ref->bytenr = buf->start;
4047 ref->owner = btrfs_header_owner(buf);
4048 ref->generation = btrfs_header_generation(buf);
4049 ret = btrfs_add_leaf_ref(root, ref, 0);
4050 WARN_ON(ret);
4051 btrfs_free_leaf_ref(root, ref);
4052 }
4053 return 0;
4054 }
4055
4056 static int noinline invalidate_extent_cache(struct btrfs_root *root,
4057 struct extent_buffer *leaf,
4058 struct btrfs_block_group_cache *group,
4059 struct btrfs_root *target_root)
4060 {
4061 struct btrfs_key key;
4062 struct inode *inode = NULL;
4063 struct btrfs_file_extent_item *fi;
4064 u64 num_bytes;
4065 u64 skip_objectid = 0;
4066 u32 nritems;
4067 u32 i;
4068
4069 nritems = btrfs_header_nritems(leaf);
4070 for (i = 0; i < nritems; i++) {
4071 btrfs_item_key_to_cpu(leaf, &key, i);
4072 if (key.objectid == skip_objectid ||
4073 key.type != BTRFS_EXTENT_DATA_KEY)
4074 continue;
4075 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4076 if (btrfs_file_extent_type(leaf, fi) ==
4077 BTRFS_FILE_EXTENT_INLINE)
4078 continue;
4079 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
4080 continue;
4081 if (!inode || inode->i_ino != key.objectid) {
4082 iput(inode);
4083 inode = btrfs_ilookup(target_root->fs_info->sb,
4084 key.objectid, target_root, 1);
4085 }
4086 if (!inode) {
4087 skip_objectid = key.objectid;
4088 continue;
4089 }
4090 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4091
4092 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4093 key.offset + num_bytes - 1, GFP_NOFS);
4094 mutex_lock(&BTRFS_I(inode)->extent_mutex);
4095 btrfs_drop_extent_cache(inode, key.offset,
4096 key.offset + num_bytes - 1, 1);
4097 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
4098 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4099 key.offset + num_bytes - 1, GFP_NOFS);
4100 cond_resched();
4101 }
4102 iput(inode);
4103 return 0;
4104 }
4105
4106 static int noinline replace_extents_in_leaf(struct btrfs_trans_handle *trans,
4107 struct btrfs_root *root,
4108 struct extent_buffer *leaf,
4109 struct btrfs_block_group_cache *group,
4110 struct inode *reloc_inode)
4111 {
4112 struct btrfs_key key;
4113 struct btrfs_key extent_key;
4114 struct btrfs_file_extent_item *fi;
4115 struct btrfs_leaf_ref *ref;
4116 struct disk_extent *new_extent;
4117 u64 bytenr;
4118 u64 num_bytes;
4119 u32 nritems;
4120 u32 i;
4121 int ext_index;
4122 int nr_extent;
4123 int ret;
4124
4125 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
4126 BUG_ON(!new_extent);
4127
4128 ref = btrfs_lookup_leaf_ref(root, leaf->start);
4129 BUG_ON(!ref);
4130
4131 ext_index = -1;
4132 nritems = btrfs_header_nritems(leaf);
4133 for (i = 0; i < nritems; i++) {
4134 btrfs_item_key_to_cpu(leaf, &key, i);
4135 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
4136 continue;
4137 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4138 if (btrfs_file_extent_type(leaf, fi) ==
4139 BTRFS_FILE_EXTENT_INLINE)
4140 continue;
4141 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
4142 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
4143 if (bytenr == 0)
4144 continue;
4145
4146 ext_index++;
4147 if (bytenr >= group->key.objectid + group->key.offset ||
4148 bytenr + num_bytes <= group->key.objectid)
4149 continue;
4150
4151 extent_key.objectid = bytenr;
4152 extent_key.offset = num_bytes;
4153 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
4154 nr_extent = 1;
4155 ret = get_new_locations(reloc_inode, &extent_key,
4156 group->key.objectid, 1,
4157 &new_extent, &nr_extent);
4158 if (ret > 0)
4159 continue;
4160 BUG_ON(ret < 0);
4161
4162 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
4163 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
4164 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
4165 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
4166
4167 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
4168 btrfs_set_file_extent_disk_bytenr(leaf, fi,
4169 new_extent->disk_bytenr);
4170 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4171 new_extent->disk_num_bytes);
4172 new_extent->offset += btrfs_file_extent_offset(leaf, fi);
4173 btrfs_set_file_extent_offset(leaf, fi, new_extent->offset);
4174 btrfs_mark_buffer_dirty(leaf);
4175
4176 ret = btrfs_inc_extent_ref(trans, root,
4177 new_extent->disk_bytenr,
4178 new_extent->disk_num_bytes,
4179 leaf->start,
4180 root->root_key.objectid,
4181 trans->transid,
4182 key.objectid, key.offset);
4183 BUG_ON(ret);
4184 ret = btrfs_free_extent(trans, root,
4185 bytenr, num_bytes, leaf->start,
4186 btrfs_header_owner(leaf),
4187 btrfs_header_generation(leaf),
4188 key.objectid, key.offset, 0);
4189 BUG_ON(ret);
4190 cond_resched();
4191 }
4192 kfree(new_extent);
4193 BUG_ON(ext_index + 1 != ref->nritems);
4194 btrfs_free_leaf_ref(root, ref);
4195 return 0;
4196 }
4197
4198 int btrfs_free_reloc_root(struct btrfs_root *root)
4199 {
4200 struct btrfs_root *reloc_root;
4201
4202 if (root->reloc_root) {
4203 reloc_root = root->reloc_root;
4204 root->reloc_root = NULL;
4205 list_add(&reloc_root->dead_list,
4206 &root->fs_info->dead_reloc_roots);
4207 }
4208 return 0;
4209 }
4210
4211 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
4212 {
4213 struct btrfs_trans_handle *trans;
4214 struct btrfs_root *reloc_root;
4215 struct btrfs_root *prev_root = NULL;
4216 struct list_head dead_roots;
4217 int ret;
4218 unsigned long nr;
4219
4220 INIT_LIST_HEAD(&dead_roots);
4221 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
4222
4223 while (!list_empty(&dead_roots)) {
4224 reloc_root = list_entry(dead_roots.prev,
4225 struct btrfs_root, dead_list);
4226 list_del_init(&reloc_root->dead_list);
4227
4228 BUG_ON(reloc_root->commit_root != NULL);
4229 while (1) {
4230 trans = btrfs_join_transaction(root, 1);
4231 BUG_ON(!trans);
4232
4233 mutex_lock(&root->fs_info->drop_mutex);
4234 ret = btrfs_drop_snapshot(trans, reloc_root);
4235 if (ret != -EAGAIN)
4236 break;
4237 mutex_unlock(&root->fs_info->drop_mutex);
4238
4239 nr = trans->blocks_used;
4240 ret = btrfs_end_transaction(trans, root);
4241 BUG_ON(ret);
4242 btrfs_btree_balance_dirty(root, nr);
4243 }
4244
4245 free_extent_buffer(reloc_root->node);
4246
4247 ret = btrfs_del_root(trans, root->fs_info->tree_root,
4248 &reloc_root->root_key);
4249 BUG_ON(ret);
4250 mutex_unlock(&root->fs_info->drop_mutex);
4251
4252 nr = trans->blocks_used;
4253 ret = btrfs_end_transaction(trans, root);
4254 BUG_ON(ret);
4255 btrfs_btree_balance_dirty(root, nr);
4256
4257 kfree(prev_root);
4258 prev_root = reloc_root;
4259 }
4260 if (prev_root) {
4261 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
4262 kfree(prev_root);
4263 }
4264 return 0;
4265 }
4266
4267 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
4268 {
4269 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
4270 return 0;
4271 }
4272
4273 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
4274 {
4275 struct btrfs_root *reloc_root;
4276 struct btrfs_trans_handle *trans;
4277 struct btrfs_key location;
4278 int found;
4279 int ret;
4280
4281 mutex_lock(&root->fs_info->tree_reloc_mutex);
4282 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
4283 BUG_ON(ret);
4284 found = !list_empty(&root->fs_info->dead_reloc_roots);
4285 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4286
4287 if (found) {
4288 trans = btrfs_start_transaction(root, 1);
4289 BUG_ON(!trans);
4290 ret = btrfs_commit_transaction(trans, root);
4291 BUG_ON(ret);
4292 }
4293
4294 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4295 location.offset = (u64)-1;
4296 location.type = BTRFS_ROOT_ITEM_KEY;
4297
4298 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
4299 BUG_ON(!reloc_root);
4300 btrfs_orphan_cleanup(reloc_root);
4301 return 0;
4302 }
4303
4304 static int noinline init_reloc_tree(struct btrfs_trans_handle *trans,
4305 struct btrfs_root *root)
4306 {
4307 struct btrfs_root *reloc_root;
4308 struct extent_buffer *eb;
4309 struct btrfs_root_item *root_item;
4310 struct btrfs_key root_key;
4311 int ret;
4312
4313 BUG_ON(!root->ref_cows);
4314 if (root->reloc_root)
4315 return 0;
4316
4317 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
4318 BUG_ON(!root_item);
4319
4320 ret = btrfs_copy_root(trans, root, root->commit_root,
4321 &eb, BTRFS_TREE_RELOC_OBJECTID);
4322 BUG_ON(ret);
4323
4324 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4325 root_key.offset = root->root_key.objectid;
4326 root_key.type = BTRFS_ROOT_ITEM_KEY;
4327
4328 memcpy(root_item, &root->root_item, sizeof(root_item));
4329 btrfs_set_root_refs(root_item, 0);
4330 btrfs_set_root_bytenr(root_item, eb->start);
4331 btrfs_set_root_level(root_item, btrfs_header_level(eb));
4332 memset(&root_item->drop_progress, 0, sizeof(root_item->drop_progress));
4333 root_item->drop_level = 0;
4334
4335 btrfs_tree_unlock(eb);
4336 free_extent_buffer(eb);
4337
4338 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
4339 &root_key, root_item);
4340 BUG_ON(ret);
4341 kfree(root_item);
4342
4343 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
4344 &root_key);
4345 BUG_ON(!reloc_root);
4346 reloc_root->last_trans = trans->transid;
4347 reloc_root->commit_root = NULL;
4348 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
4349
4350 root->reloc_root = reloc_root;
4351 return 0;
4352 }
4353
4354 /*
4355 * Core function of space balance.
4356 *
4357 * The idea is using reloc trees to relocate tree blocks in reference
4358 * counted roots. There is one reloc tree for each subvol, all reloc
4359 * trees share same key objectid. Reloc trees are snapshots of the
4360 * latest committed roots (subvol root->commit_root). To relocate a tree
4361 * block referenced by a subvol, the code COW the block through the reloc
4362 * tree, then update pointer in the subvol to point to the new block.
4363 * Since all reloc trees share same key objectid, we can easily do special
4364 * handing to share tree blocks between reloc trees. Once a tree block has
4365 * been COWed in one reloc tree, we can use the result when the same block
4366 * is COWed again through other reloc trees.
4367 */
4368 static int noinline relocate_one_path(struct btrfs_trans_handle *trans,
4369 struct btrfs_root *root,
4370 struct btrfs_path *path,
4371 struct btrfs_key *first_key,
4372 struct btrfs_ref_path *ref_path,
4373 struct btrfs_block_group_cache *group,
4374 struct inode *reloc_inode)
4375 {
4376 struct btrfs_root *reloc_root;
4377 struct extent_buffer *eb = NULL;
4378 struct btrfs_key *keys;
4379 u64 *nodes;
4380 int level;
4381 int lowest_merge;
4382 int lowest_level = 0;
4383 int update_refs;
4384 int ret;
4385
4386 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
4387 lowest_level = ref_path->owner_objectid;
4388
4389 if (is_cowonly_root(ref_path->root_objectid)) {
4390 path->lowest_level = lowest_level;
4391 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
4392 BUG_ON(ret < 0);
4393 path->lowest_level = 0;
4394 btrfs_release_path(root, path);
4395 return 0;
4396 }
4397
4398 keys = kzalloc(sizeof(*keys) * BTRFS_MAX_LEVEL, GFP_NOFS);
4399 BUG_ON(!keys);
4400 nodes = kzalloc(sizeof(*nodes) * BTRFS_MAX_LEVEL, GFP_NOFS);
4401 BUG_ON(!nodes);
4402
4403 mutex_lock(&root->fs_info->tree_reloc_mutex);
4404 ret = init_reloc_tree(trans, root);
4405 BUG_ON(ret);
4406 reloc_root = root->reloc_root;
4407
4408 path->lowest_level = lowest_level;
4409 ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 0);
4410 BUG_ON(ret);
4411 /*
4412 * get relocation mapping for tree blocks in the path
4413 */
4414 lowest_merge = BTRFS_MAX_LEVEL;
4415 for (level = BTRFS_MAX_LEVEL - 1; level >= lowest_level; level--) {
4416 u64 new_bytenr;
4417 eb = path->nodes[level];
4418 if (!eb || eb == reloc_root->node)
4419 continue;
4420 ret = btrfs_get_reloc_mapping(reloc_root, eb->start, eb->len,
4421 &new_bytenr);
4422 if (ret)
4423 continue;
4424 if (level == 0)
4425 btrfs_item_key_to_cpu(eb, &keys[level], 0);
4426 else
4427 btrfs_node_key_to_cpu(eb, &keys[level], 0);
4428 nodes[level] = new_bytenr;
4429 lowest_merge = level;
4430 }
4431
4432 update_refs = 0;
4433 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4434 eb = path->nodes[0];
4435 if (btrfs_header_generation(eb) < trans->transid)
4436 update_refs = 1;
4437 }
4438
4439 btrfs_release_path(reloc_root, path);
4440 /*
4441 * merge tree blocks that already relocated in other reloc trees
4442 */
4443 if (lowest_merge != BTRFS_MAX_LEVEL) {
4444 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
4445 lowest_merge);
4446 BUG_ON(ret < 0);
4447 }
4448 /*
4449 * cow any tree blocks that still haven't been relocated
4450 */
4451 ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 1);
4452 BUG_ON(ret);
4453 /*
4454 * if we are relocating data block group, update extent pointers
4455 * in the newly created tree leaf.
4456 */
4457 eb = path->nodes[0];
4458 if (update_refs && nodes[0] != eb->start) {
4459 ret = replace_extents_in_leaf(trans, reloc_root, eb, group,
4460 reloc_inode);
4461 BUG_ON(ret);
4462 }
4463
4464 memset(keys, 0, sizeof(*keys) * BTRFS_MAX_LEVEL);
4465 memset(nodes, 0, sizeof(*nodes) * BTRFS_MAX_LEVEL);
4466 for (level = BTRFS_MAX_LEVEL - 1; level >= lowest_level; level--) {
4467 eb = path->nodes[level];
4468 if (!eb || eb == reloc_root->node)
4469 continue;
4470 BUG_ON(btrfs_header_owner(eb) != BTRFS_TREE_RELOC_OBJECTID);
4471 nodes[level] = eb->start;
4472 if (level == 0)
4473 btrfs_item_key_to_cpu(eb, &keys[level], 0);
4474 else
4475 btrfs_node_key_to_cpu(eb, &keys[level], 0);
4476 }
4477
4478 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4479 eb = path->nodes[0];
4480 extent_buffer_get(eb);
4481 }
4482 btrfs_release_path(reloc_root, path);
4483 /*
4484 * replace tree blocks in the fs tree with tree blocks in
4485 * the reloc tree.
4486 */
4487 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
4488 BUG_ON(ret < 0);
4489
4490 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4491 ret = invalidate_extent_cache(reloc_root, eb, group, root);
4492 BUG_ON(ret);
4493 free_extent_buffer(eb);
4494 }
4495 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4496
4497 path->lowest_level = 0;
4498 kfree(nodes);
4499 kfree(keys);
4500 return 0;
4501 }
4502
4503 static int noinline relocate_tree_block(struct btrfs_trans_handle *trans,
4504 struct btrfs_root *root,
4505 struct btrfs_path *path,
4506 struct btrfs_key *first_key,
4507 struct btrfs_ref_path *ref_path)
4508 {
4509 int ret;
4510 int needs_lock = 0;
4511
4512 if (root == root->fs_info->extent_root ||
4513 root == root->fs_info->chunk_root ||
4514 root == root->fs_info->dev_root) {
4515 needs_lock = 1;
4516 mutex_lock(&root->fs_info->alloc_mutex);
4517 }
4518
4519 ret = relocate_one_path(trans, root, path, first_key,
4520 ref_path, NULL, NULL);
4521 BUG_ON(ret);
4522
4523 if (root == root->fs_info->extent_root)
4524 btrfs_extent_post_op(trans, root);
4525 if (needs_lock)
4526 mutex_unlock(&root->fs_info->alloc_mutex);
4527
4528 return 0;
4529 }
4530
4531 static int noinline del_extent_zero(struct btrfs_trans_handle *trans,
4532 struct btrfs_root *extent_root,
4533 struct btrfs_path *path,
4534 struct btrfs_key *extent_key)
4535 {
4536 int ret;
4537
4538 mutex_lock(&extent_root->fs_info->alloc_mutex);
4539 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
4540 if (ret)
4541 goto out;
4542 ret = btrfs_del_item(trans, extent_root, path);
4543 out:
4544 btrfs_release_path(extent_root, path);
4545 mutex_unlock(&extent_root->fs_info->alloc_mutex);
4546 return ret;
4547 }
4548
4549 static struct btrfs_root noinline *read_ref_root(struct btrfs_fs_info *fs_info,
4550 struct btrfs_ref_path *ref_path)
4551 {
4552 struct btrfs_key root_key;
4553
4554 root_key.objectid = ref_path->root_objectid;
4555 root_key.type = BTRFS_ROOT_ITEM_KEY;
4556 if (is_cowonly_root(ref_path->root_objectid))
4557 root_key.offset = 0;
4558 else
4559 root_key.offset = (u64)-1;
4560
4561 return btrfs_read_fs_root_no_name(fs_info, &root_key);
4562 }
4563
4564 static int noinline relocate_one_extent(struct btrfs_root *extent_root,
4565 struct btrfs_path *path,
4566 struct btrfs_key *extent_key,
4567 struct btrfs_block_group_cache *group,
4568 struct inode *reloc_inode, int pass)
4569 {
4570 struct btrfs_trans_handle *trans;
4571 struct btrfs_root *found_root;
4572 struct btrfs_ref_path *ref_path = NULL;
4573 struct disk_extent *new_extents = NULL;
4574 int nr_extents = 0;
4575 int loops;
4576 int ret;
4577 int level;
4578 struct btrfs_key first_key;
4579 u64 prev_block = 0;
4580
4581 mutex_unlock(&extent_root->fs_info->alloc_mutex);
4582
4583 trans = btrfs_start_transaction(extent_root, 1);
4584 BUG_ON(!trans);
4585
4586 if (extent_key->objectid == 0) {
4587 ret = del_extent_zero(trans, extent_root, path, extent_key);
4588 goto out;
4589 }
4590
4591 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
4592 if (!ref_path) {
4593 ret = -ENOMEM;
4594 goto out;
4595 }
4596
4597 for (loops = 0; ; loops++) {
4598 if (loops == 0) {
4599 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
4600 extent_key->objectid);
4601 } else {
4602 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
4603 }
4604 if (ret < 0)
4605 goto out;
4606 if (ret > 0)
4607 break;
4608
4609 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
4610 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
4611 continue;
4612
4613 found_root = read_ref_root(extent_root->fs_info, ref_path);
4614 BUG_ON(!found_root);
4615 /*
4616 * for reference counted tree, only process reference paths
4617 * rooted at the latest committed root.
4618 */
4619 if (found_root->ref_cows &&
4620 ref_path->root_generation != found_root->root_key.offset)
4621 continue;
4622
4623 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4624 if (pass == 0) {
4625 /*
4626 * copy data extents to new locations
4627 */
4628 u64 group_start = group->key.objectid;
4629 ret = relocate_data_extent(reloc_inode,
4630 extent_key,
4631 group_start);
4632 if (ret < 0)
4633 goto out;
4634 break;
4635 }
4636 level = 0;
4637 } else {
4638 level = ref_path->owner_objectid;
4639 }
4640
4641 if (prev_block != ref_path->nodes[level]) {
4642 struct extent_buffer *eb;
4643 u64 block_start = ref_path->nodes[level];
4644 u64 block_size = btrfs_level_size(found_root, level);
4645
4646 eb = read_tree_block(found_root, block_start,
4647 block_size, 0);
4648 btrfs_tree_lock(eb);
4649 BUG_ON(level != btrfs_header_level(eb));
4650
4651 if (level == 0)
4652 btrfs_item_key_to_cpu(eb, &first_key, 0);
4653 else
4654 btrfs_node_key_to_cpu(eb, &first_key, 0);
4655
4656 btrfs_tree_unlock(eb);
4657 free_extent_buffer(eb);
4658 prev_block = block_start;
4659 }
4660
4661 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
4662 pass >= 2) {
4663 /*
4664 * use fallback method to process the remaining
4665 * references.
4666 */
4667 if (!new_extents) {
4668 u64 group_start = group->key.objectid;
4669 ret = get_new_locations(reloc_inode,
4670 extent_key,
4671 group_start, 0,
4672 &new_extents,
4673 &nr_extents);
4674 if (ret < 0)
4675 goto out;
4676 }
4677 btrfs_record_root_in_trans(found_root);
4678 ret = replace_one_extent(trans, found_root,
4679 path, extent_key,
4680 &first_key, ref_path,
4681 new_extents, nr_extents);
4682 if (ret < 0)
4683 goto out;
4684 continue;
4685 }
4686
4687 btrfs_record_root_in_trans(found_root);
4688 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
4689 ret = relocate_tree_block(trans, found_root, path,
4690 &first_key, ref_path);
4691 } else {
4692 /*
4693 * try to update data extent references while
4694 * keeping metadata shared between snapshots.
4695 */
4696 ret = relocate_one_path(trans, found_root, path,
4697 &first_key, ref_path,
4698 group, reloc_inode);
4699 }
4700 if (ret < 0)
4701 goto out;
4702 }
4703 ret = 0;
4704 out:
4705 btrfs_end_transaction(trans, extent_root);
4706 kfree(new_extents);
4707 kfree(ref_path);
4708 mutex_lock(&extent_root->fs_info->alloc_mutex);
4709 return ret;
4710 }
4711
4712 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
4713 {
4714 u64 num_devices;
4715 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
4716 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
4717
4718 num_devices = root->fs_info->fs_devices->num_devices;
4719 if (num_devices == 1) {
4720 stripped |= BTRFS_BLOCK_GROUP_DUP;
4721 stripped = flags & ~stripped;
4722
4723 /* turn raid0 into single device chunks */
4724 if (flags & BTRFS_BLOCK_GROUP_RAID0)
4725 return stripped;
4726
4727 /* turn mirroring into duplication */
4728 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
4729 BTRFS_BLOCK_GROUP_RAID10))
4730 return stripped | BTRFS_BLOCK_GROUP_DUP;
4731 return flags;
4732 } else {
4733 /* they already had raid on here, just return */
4734 if (flags & stripped)
4735 return flags;
4736
4737 stripped |= BTRFS_BLOCK_GROUP_DUP;
4738 stripped = flags & ~stripped;
4739
4740 /* switch duplicated blocks with raid1 */
4741 if (flags & BTRFS_BLOCK_GROUP_DUP)
4742 return stripped | BTRFS_BLOCK_GROUP_RAID1;
4743
4744 /* turn single device chunks into raid0 */
4745 return stripped | BTRFS_BLOCK_GROUP_RAID0;
4746 }
4747 return flags;
4748 }
4749
4750 int __alloc_chunk_for_shrink(struct btrfs_root *root,
4751 struct btrfs_block_group_cache *shrink_block_group,
4752 int force)
4753 {
4754 struct btrfs_trans_handle *trans;
4755 u64 new_alloc_flags;
4756 u64 calc;
4757
4758 spin_lock(&shrink_block_group->lock);
4759 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
4760 spin_unlock(&shrink_block_group->lock);
4761 mutex_unlock(&root->fs_info->alloc_mutex);
4762
4763 trans = btrfs_start_transaction(root, 1);
4764 mutex_lock(&root->fs_info->alloc_mutex);
4765 spin_lock(&shrink_block_group->lock);
4766
4767 new_alloc_flags = update_block_group_flags(root,
4768 shrink_block_group->flags);
4769 if (new_alloc_flags != shrink_block_group->flags) {
4770 calc =
4771 btrfs_block_group_used(&shrink_block_group->item);
4772 } else {
4773 calc = shrink_block_group->key.offset;
4774 }
4775 spin_unlock(&shrink_block_group->lock);
4776
4777 do_chunk_alloc(trans, root->fs_info->extent_root,
4778 calc + 2 * 1024 * 1024, new_alloc_flags, force);
4779
4780 mutex_unlock(&root->fs_info->alloc_mutex);
4781 btrfs_end_transaction(trans, root);
4782 mutex_lock(&root->fs_info->alloc_mutex);
4783 } else
4784 spin_unlock(&shrink_block_group->lock);
4785 return 0;
4786 }
4787
4788 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4789 struct btrfs_root *root,
4790 u64 objectid, u64 size)
4791 {
4792 struct btrfs_path *path;
4793 struct btrfs_inode_item *item;
4794 struct extent_buffer *leaf;
4795 int ret;
4796
4797 path = btrfs_alloc_path();
4798 if (!path)
4799 return -ENOMEM;
4800
4801 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4802 if (ret)
4803 goto out;
4804
4805 leaf = path->nodes[0];
4806 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4807 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4808 btrfs_set_inode_generation(leaf, item, 1);
4809 btrfs_set_inode_size(leaf, item, size);
4810 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4811 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NODATASUM);
4812 btrfs_mark_buffer_dirty(leaf);
4813 btrfs_release_path(root, path);
4814 out:
4815 btrfs_free_path(path);
4816 return ret;
4817 }
4818
4819 static struct inode noinline *create_reloc_inode(struct btrfs_fs_info *fs_info,
4820 struct btrfs_block_group_cache *group)
4821 {
4822 struct inode *inode = NULL;
4823 struct btrfs_trans_handle *trans;
4824 struct btrfs_root *root;
4825 struct btrfs_key root_key;
4826 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4827 int err = 0;
4828
4829 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4830 root_key.type = BTRFS_ROOT_ITEM_KEY;
4831 root_key.offset = (u64)-1;
4832 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
4833 if (IS_ERR(root))
4834 return ERR_CAST(root);
4835
4836 trans = btrfs_start_transaction(root, 1);
4837 BUG_ON(!trans);
4838
4839 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
4840 if (err)
4841 goto out;
4842
4843 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
4844 BUG_ON(err);
4845
4846 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
4847 group->key.offset, 0);
4848 BUG_ON(err);
4849
4850 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
4851 if (inode->i_state & I_NEW) {
4852 BTRFS_I(inode)->root = root;
4853 BTRFS_I(inode)->location.objectid = objectid;
4854 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
4855 BTRFS_I(inode)->location.offset = 0;
4856 btrfs_read_locked_inode(inode);
4857 unlock_new_inode(inode);
4858 BUG_ON(is_bad_inode(inode));
4859 } else {
4860 BUG_ON(1);
4861 }
4862
4863 err = btrfs_orphan_add(trans, inode);
4864 out:
4865 btrfs_end_transaction(trans, root);
4866 if (err) {
4867 if (inode)
4868 iput(inode);
4869 inode = ERR_PTR(err);
4870 }
4871 return inode;
4872 }
4873
4874 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
4875 {
4876 struct btrfs_trans_handle *trans;
4877 struct btrfs_path *path;
4878 struct btrfs_fs_info *info = root->fs_info;
4879 struct extent_buffer *leaf;
4880 struct inode *reloc_inode;
4881 struct btrfs_block_group_cache *block_group;
4882 struct btrfs_key key;
4883 u64 cur_byte;
4884 u64 total_found;
4885 u32 nritems;
4886 int ret;
4887 int progress;
4888 int pass = 0;
4889
4890 root = root->fs_info->extent_root;
4891
4892 block_group = btrfs_lookup_block_group(info, group_start);
4893 BUG_ON(!block_group);
4894
4895 printk("btrfs relocating block group %llu flags %llu\n",
4896 (unsigned long long)block_group->key.objectid,
4897 (unsigned long long)block_group->flags);
4898
4899 path = btrfs_alloc_path();
4900 BUG_ON(!path);
4901
4902 reloc_inode = create_reloc_inode(info, block_group);
4903 BUG_ON(IS_ERR(reloc_inode));
4904
4905 mutex_lock(&root->fs_info->alloc_mutex);
4906
4907 __alloc_chunk_for_shrink(root, block_group, 1);
4908 block_group->ro = 1;
4909 block_group->space_info->total_bytes -= block_group->key.offset;
4910
4911 mutex_unlock(&root->fs_info->alloc_mutex);
4912
4913 btrfs_start_delalloc_inodes(info->tree_root);
4914 btrfs_wait_ordered_extents(info->tree_root, 0);
4915 again:
4916 total_found = 0;
4917 progress = 0;
4918 key.objectid = block_group->key.objectid;
4919 key.offset = 0;
4920 key.type = 0;
4921 cur_byte = key.objectid;
4922
4923 trans = btrfs_start_transaction(info->tree_root, 1);
4924 btrfs_commit_transaction(trans, info->tree_root);
4925
4926 mutex_lock(&root->fs_info->cleaner_mutex);
4927 btrfs_clean_old_snapshots(info->tree_root);
4928 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
4929 mutex_unlock(&root->fs_info->cleaner_mutex);
4930
4931 mutex_lock(&root->fs_info->alloc_mutex);
4932
4933 while(1) {
4934 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4935 if (ret < 0)
4936 goto out;
4937 next:
4938 leaf = path->nodes[0];
4939 nritems = btrfs_header_nritems(leaf);
4940 if (path->slots[0] >= nritems) {
4941 ret = btrfs_next_leaf(root, path);
4942 if (ret < 0)
4943 goto out;
4944 if (ret == 1) {
4945 ret = 0;
4946 break;
4947 }
4948 leaf = path->nodes[0];
4949 nritems = btrfs_header_nritems(leaf);
4950 }
4951
4952 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4953
4954 if (key.objectid >= block_group->key.objectid +
4955 block_group->key.offset)
4956 break;
4957
4958 if (progress && need_resched()) {
4959 btrfs_release_path(root, path);
4960 mutex_unlock(&root->fs_info->alloc_mutex);
4961 cond_resched();
4962 mutex_lock(&root->fs_info->alloc_mutex);
4963 progress = 0;
4964 continue;
4965 }
4966 progress = 1;
4967
4968 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
4969 key.objectid + key.offset <= cur_byte) {
4970 path->slots[0]++;
4971 goto next;
4972 }
4973
4974 total_found++;
4975 cur_byte = key.objectid + key.offset;
4976 btrfs_release_path(root, path);
4977
4978 __alloc_chunk_for_shrink(root, block_group, 0);
4979 ret = relocate_one_extent(root, path, &key, block_group,
4980 reloc_inode, pass);
4981 BUG_ON(ret < 0);
4982
4983 key.objectid = cur_byte;
4984 key.type = 0;
4985 key.offset = 0;
4986 }
4987
4988 btrfs_release_path(root, path);
4989 mutex_unlock(&root->fs_info->alloc_mutex);
4990
4991 if (pass == 0) {
4992 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
4993 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
4994 WARN_ON(reloc_inode->i_mapping->nrpages);
4995 }
4996
4997 if (total_found > 0) {
4998 printk("btrfs found %llu extents in pass %d\n",
4999 (unsigned long long)total_found, pass);
5000 pass++;
5001 goto again;
5002 }
5003
5004 /* delete reloc_inode */
5005 iput(reloc_inode);
5006
5007 /* unpin extents in this range */
5008 trans = btrfs_start_transaction(info->tree_root, 1);
5009 btrfs_commit_transaction(trans, info->tree_root);
5010
5011 mutex_lock(&root->fs_info->alloc_mutex);
5012
5013 spin_lock(&block_group->lock);
5014 WARN_ON(block_group->pinned > 0);
5015 WARN_ON(block_group->reserved > 0);
5016 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
5017 spin_unlock(&block_group->lock);
5018 ret = 0;
5019 out:
5020 mutex_unlock(&root->fs_info->alloc_mutex);
5021 btrfs_free_path(path);
5022 return ret;
5023 }
5024
5025 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
5026 struct btrfs_key *key)
5027 {
5028 int ret = 0;
5029 struct btrfs_key found_key;
5030 struct extent_buffer *leaf;
5031 int slot;
5032
5033 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
5034 if (ret < 0)
5035 goto out;
5036
5037 while(1) {
5038 slot = path->slots[0];
5039 leaf = path->nodes[0];
5040 if (slot >= btrfs_header_nritems(leaf)) {
5041 ret = btrfs_next_leaf(root, path);
5042 if (ret == 0)
5043 continue;
5044 if (ret < 0)
5045 goto out;
5046 break;
5047 }
5048 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5049
5050 if (found_key.objectid >= key->objectid &&
5051 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
5052 ret = 0;
5053 goto out;
5054 }
5055 path->slots[0]++;
5056 }
5057 ret = -ENOENT;
5058 out:
5059 return ret;
5060 }
5061
5062 int btrfs_free_block_groups(struct btrfs_fs_info *info)
5063 {
5064 struct btrfs_block_group_cache *block_group;
5065 struct rb_node *n;
5066
5067 mutex_lock(&info->alloc_mutex);
5068 spin_lock(&info->block_group_cache_lock);
5069 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
5070 block_group = rb_entry(n, struct btrfs_block_group_cache,
5071 cache_node);
5072
5073 spin_unlock(&info->block_group_cache_lock);
5074 btrfs_remove_free_space_cache(block_group);
5075 spin_lock(&info->block_group_cache_lock);
5076
5077 rb_erase(&block_group->cache_node,
5078 &info->block_group_cache_tree);
5079 spin_lock(&block_group->space_info->lock);
5080 list_del(&block_group->list);
5081 spin_unlock(&block_group->space_info->lock);
5082 kfree(block_group);
5083 }
5084 spin_unlock(&info->block_group_cache_lock);
5085 mutex_unlock(&info->alloc_mutex);
5086 return 0;
5087 }
5088
5089 int btrfs_read_block_groups(struct btrfs_root *root)
5090 {
5091 struct btrfs_path *path;
5092 int ret;
5093 struct btrfs_block_group_cache *cache;
5094 struct btrfs_fs_info *info = root->fs_info;
5095 struct btrfs_space_info *space_info;
5096 struct btrfs_key key;
5097 struct btrfs_key found_key;
5098 struct extent_buffer *leaf;
5099
5100 root = info->extent_root;
5101 key.objectid = 0;
5102 key.offset = 0;
5103 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5104 path = btrfs_alloc_path();
5105 if (!path)
5106 return -ENOMEM;
5107
5108 mutex_lock(&root->fs_info->alloc_mutex);
5109 while(1) {
5110 ret = find_first_block_group(root, path, &key);
5111 if (ret > 0) {
5112 ret = 0;
5113 goto error;
5114 }
5115 if (ret != 0)
5116 goto error;
5117
5118 leaf = path->nodes[0];
5119 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5120 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5121 if (!cache) {
5122 ret = -ENOMEM;
5123 break;
5124 }
5125
5126 spin_lock_init(&cache->lock);
5127 INIT_LIST_HEAD(&cache->list);
5128 read_extent_buffer(leaf, &cache->item,
5129 btrfs_item_ptr_offset(leaf, path->slots[0]),
5130 sizeof(cache->item));
5131 memcpy(&cache->key, &found_key, sizeof(found_key));
5132
5133 key.objectid = found_key.objectid + found_key.offset;
5134 btrfs_release_path(root, path);
5135 cache->flags = btrfs_block_group_flags(&cache->item);
5136
5137 ret = update_space_info(info, cache->flags, found_key.offset,
5138 btrfs_block_group_used(&cache->item),
5139 &space_info);
5140 BUG_ON(ret);
5141 cache->space_info = space_info;
5142 spin_lock(&space_info->lock);
5143 list_add(&cache->list, &space_info->block_groups);
5144 spin_unlock(&space_info->lock);
5145
5146 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5147 BUG_ON(ret);
5148
5149 set_avail_alloc_bits(root->fs_info, cache->flags);
5150 }
5151 ret = 0;
5152 error:
5153 btrfs_free_path(path);
5154 mutex_unlock(&root->fs_info->alloc_mutex);
5155 return ret;
5156 }
5157
5158 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
5159 struct btrfs_root *root, u64 bytes_used,
5160 u64 type, u64 chunk_objectid, u64 chunk_offset,
5161 u64 size)
5162 {
5163 int ret;
5164 struct btrfs_root *extent_root;
5165 struct btrfs_block_group_cache *cache;
5166
5167 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
5168 extent_root = root->fs_info->extent_root;
5169
5170 root->fs_info->last_trans_new_blockgroup = trans->transid;
5171
5172 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5173 if (!cache)
5174 return -ENOMEM;
5175
5176 cache->key.objectid = chunk_offset;
5177 cache->key.offset = size;
5178 spin_lock_init(&cache->lock);
5179 INIT_LIST_HEAD(&cache->list);
5180 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5181
5182 btrfs_set_block_group_used(&cache->item, bytes_used);
5183 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
5184 cache->flags = type;
5185 btrfs_set_block_group_flags(&cache->item, type);
5186
5187 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
5188 &cache->space_info);
5189 BUG_ON(ret);
5190 spin_lock(&cache->space_info->lock);
5191 list_add(&cache->list, &cache->space_info->block_groups);
5192 spin_unlock(&cache->space_info->lock);
5193
5194 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5195 BUG_ON(ret);
5196
5197 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
5198 sizeof(cache->item));
5199 BUG_ON(ret);
5200
5201 finish_current_insert(trans, extent_root);
5202 ret = del_pending_extents(trans, extent_root);
5203 BUG_ON(ret);
5204 set_avail_alloc_bits(extent_root->fs_info, type);
5205
5206 return 0;
5207 }
5208
5209 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
5210 struct btrfs_root *root, u64 group_start)
5211 {
5212 struct btrfs_path *path;
5213 struct btrfs_block_group_cache *block_group;
5214 struct btrfs_key key;
5215 int ret;
5216
5217 BUG_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
5218 root = root->fs_info->extent_root;
5219
5220 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
5221 BUG_ON(!block_group);
5222
5223 memcpy(&key, &block_group->key, sizeof(key));
5224
5225 path = btrfs_alloc_path();
5226 BUG_ON(!path);
5227
5228 btrfs_remove_free_space_cache(block_group);
5229 rb_erase(&block_group->cache_node,
5230 &root->fs_info->block_group_cache_tree);
5231 spin_lock(&block_group->space_info->lock);
5232 list_del(&block_group->list);
5233 spin_unlock(&block_group->space_info->lock);
5234
5235 /*
5236 memset(shrink_block_group, 0, sizeof(*shrink_block_group));
5237 kfree(shrink_block_group);
5238 */
5239
5240 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
5241 if (ret > 0)
5242 ret = -EIO;
5243 if (ret < 0)
5244 goto out;
5245
5246 ret = btrfs_del_item(trans, root, path);
5247 out:
5248 btrfs_free_path(path);
5249 return ret;
5250 }
Support for the Chinese Samsung S3C2440 based development boards