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Btrfs: tune btrfs unplug functions for a small number of devices
[deliverable/linux.git] / fs / btrfs / extent-tree.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/pagemap.h>
20 #include <linux/writeback.h>
21 #include <linux/blkdev.h>
22 #include "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, int all);
49 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
50 btrfs_root *extent_root, int all);
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 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
57 {
58 return (cache->flags & bits) == bits;
59 }
60
61 /*
62 * this adds the block group to the fs_info rb tree for the block group
63 * cache
64 */
65 int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
66 struct btrfs_block_group_cache *block_group)
67 {
68 struct rb_node **p;
69 struct rb_node *parent = NULL;
70 struct btrfs_block_group_cache *cache;
71
72 spin_lock(&info->block_group_cache_lock);
73 p = &info->block_group_cache_tree.rb_node;
74
75 while (*p) {
76 parent = *p;
77 cache = rb_entry(parent, struct btrfs_block_group_cache,
78 cache_node);
79 if (block_group->key.objectid < cache->key.objectid) {
80 p = &(*p)->rb_left;
81 } else if (block_group->key.objectid > cache->key.objectid) {
82 p = &(*p)->rb_right;
83 } else {
84 spin_unlock(&info->block_group_cache_lock);
85 return -EEXIST;
86 }
87 }
88
89 rb_link_node(&block_group->cache_node, parent, p);
90 rb_insert_color(&block_group->cache_node,
91 &info->block_group_cache_tree);
92 spin_unlock(&info->block_group_cache_lock);
93
94 return 0;
95 }
96
97 /*
98 * This will return the block group at or after bytenr if contains is 0, else
99 * it will return the block group that contains the bytenr
100 */
101 static struct btrfs_block_group_cache *
102 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
103 int contains)
104 {
105 struct btrfs_block_group_cache *cache, *ret = NULL;
106 struct rb_node *n;
107 u64 end, start;
108
109 spin_lock(&info->block_group_cache_lock);
110 n = info->block_group_cache_tree.rb_node;
111
112 while (n) {
113 cache = rb_entry(n, struct btrfs_block_group_cache,
114 cache_node);
115 end = cache->key.objectid + cache->key.offset - 1;
116 start = cache->key.objectid;
117
118 if (bytenr < start) {
119 if (!contains && (!ret || start < ret->key.objectid))
120 ret = cache;
121 n = n->rb_left;
122 } else if (bytenr > start) {
123 if (contains && bytenr <= end) {
124 ret = cache;
125 break;
126 }
127 n = n->rb_right;
128 } else {
129 ret = cache;
130 break;
131 }
132 }
133 spin_unlock(&info->block_group_cache_lock);
134
135 return ret;
136 }
137
138 /*
139 * this is only called by cache_block_group, since we could have freed extents
140 * we need to check the pinned_extents for any extents that can't be used yet
141 * since their free space will be released as soon as the transaction commits.
142 */
143 static int add_new_free_space(struct btrfs_block_group_cache *block_group,
144 struct btrfs_fs_info *info, u64 start, u64 end)
145 {
146 u64 extent_start, extent_end, size;
147 int ret;
148
149 mutex_lock(&info->pinned_mutex);
150 while (start < end) {
151 ret = find_first_extent_bit(&info->pinned_extents, start,
152 &extent_start, &extent_end,
153 EXTENT_DIRTY);
154 if (ret)
155 break;
156
157 if (extent_start == start) {
158 start = extent_end + 1;
159 } else if (extent_start > start && extent_start < end) {
160 size = extent_start - start;
161 ret = btrfs_add_free_space_lock(block_group, start,
162 size);
163 BUG_ON(ret);
164 start = extent_end + 1;
165 } else {
166 break;
167 }
168 }
169
170 if (start < end) {
171 size = end - start;
172 ret = btrfs_add_free_space_lock(block_group, start, size);
173 BUG_ON(ret);
174 }
175 mutex_unlock(&info->pinned_mutex);
176
177 return 0;
178 }
179
180 static int cache_block_group(struct btrfs_root *root,
181 struct btrfs_block_group_cache *block_group)
182 {
183 struct btrfs_path *path;
184 int ret = 0;
185 struct btrfs_key key;
186 struct extent_buffer *leaf;
187 int slot;
188 u64 last = 0;
189 u64 first_free;
190 int found = 0;
191
192 if (!block_group)
193 return 0;
194
195 root = root->fs_info->extent_root;
196
197 if (block_group->cached)
198 return 0;
199
200 path = btrfs_alloc_path();
201 if (!path)
202 return -ENOMEM;
203
204 path->reada = 2;
205 /*
206 * we get into deadlocks with paths held by callers of this function.
207 * since the alloc_mutex is protecting things right now, just
208 * skip the locking here
209 */
210 path->skip_locking = 1;
211 first_free = max_t(u64, block_group->key.objectid,
212 BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
213 key.objectid = block_group->key.objectid;
214 key.offset = 0;
215 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
216 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
217 if (ret < 0)
218 goto err;
219 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
220 if (ret < 0)
221 goto err;
222 if (ret == 0) {
223 leaf = path->nodes[0];
224 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
225 if (key.objectid + key.offset > first_free)
226 first_free = key.objectid + key.offset;
227 }
228 while(1) {
229 leaf = path->nodes[0];
230 slot = path->slots[0];
231 if (slot >= btrfs_header_nritems(leaf)) {
232 ret = btrfs_next_leaf(root, path);
233 if (ret < 0)
234 goto err;
235 if (ret == 0)
236 continue;
237 else
238 break;
239 }
240 btrfs_item_key_to_cpu(leaf, &key, slot);
241 if (key.objectid < block_group->key.objectid)
242 goto next;
243
244 if (key.objectid >= block_group->key.objectid +
245 block_group->key.offset)
246 break;
247
248 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
249 if (!found) {
250 last = first_free;
251 found = 1;
252 }
253
254 add_new_free_space(block_group, root->fs_info, last,
255 key.objectid);
256
257 last = key.objectid + key.offset;
258 }
259 next:
260 path->slots[0]++;
261 }
262
263 if (!found)
264 last = first_free;
265
266 add_new_free_space(block_group, root->fs_info, last,
267 block_group->key.objectid +
268 block_group->key.offset);
269
270 block_group->cached = 1;
271 ret = 0;
272 err:
273 btrfs_free_path(path);
274 return ret;
275 }
276
277 /*
278 * return the block group that starts at or after bytenr
279 */
280 struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
281 btrfs_fs_info *info,
282 u64 bytenr)
283 {
284 struct btrfs_block_group_cache *cache;
285
286 cache = block_group_cache_tree_search(info, bytenr, 0);
287
288 return cache;
289 }
290
291 /*
292 * return the block group that contains teh given bytenr
293 */
294 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
295 btrfs_fs_info *info,
296 u64 bytenr)
297 {
298 struct btrfs_block_group_cache *cache;
299
300 cache = block_group_cache_tree_search(info, bytenr, 1);
301
302 return cache;
303 }
304
305 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
306 u64 flags)
307 {
308 struct list_head *head = &info->space_info;
309 struct list_head *cur;
310 struct btrfs_space_info *found;
311 list_for_each(cur, head) {
312 found = list_entry(cur, struct btrfs_space_info, list);
313 if (found->flags == flags)
314 return found;
315 }
316 return NULL;
317 }
318
319 static u64 div_factor(u64 num, int factor)
320 {
321 if (factor == 10)
322 return num;
323 num *= factor;
324 do_div(num, 10);
325 return num;
326 }
327
328 static struct btrfs_block_group_cache *
329 __btrfs_find_block_group(struct btrfs_root *root,
330 struct btrfs_block_group_cache *hint,
331 u64 search_start, int data, int owner)
332 {
333 struct btrfs_block_group_cache *cache;
334 struct btrfs_block_group_cache *found_group = NULL;
335 struct btrfs_fs_info *info = root->fs_info;
336 u64 used;
337 u64 last = 0;
338 u64 free_check;
339 int full_search = 0;
340 int factor = 10;
341 int wrapped = 0;
342
343 if (data & BTRFS_BLOCK_GROUP_METADATA)
344 factor = 9;
345
346 if (search_start) {
347 struct btrfs_block_group_cache *shint;
348 shint = btrfs_lookup_first_block_group(info, search_start);
349 if (shint && block_group_bits(shint, data) && !shint->ro) {
350 spin_lock(&shint->lock);
351 used = btrfs_block_group_used(&shint->item);
352 if (used + shint->pinned + shint->reserved <
353 div_factor(shint->key.offset, factor)) {
354 spin_unlock(&shint->lock);
355 return shint;
356 }
357 spin_unlock(&shint->lock);
358 }
359 }
360 if (hint && !hint->ro && block_group_bits(hint, data)) {
361 spin_lock(&hint->lock);
362 used = btrfs_block_group_used(&hint->item);
363 if (used + hint->pinned + hint->reserved <
364 div_factor(hint->key.offset, factor)) {
365 spin_unlock(&hint->lock);
366 return hint;
367 }
368 spin_unlock(&hint->lock);
369 last = hint->key.objectid + hint->key.offset;
370 } else {
371 if (hint)
372 last = max(hint->key.objectid, search_start);
373 else
374 last = search_start;
375 }
376 again:
377 while (1) {
378 cache = btrfs_lookup_first_block_group(root->fs_info, last);
379 if (!cache)
380 break;
381
382 spin_lock(&cache->lock);
383 last = cache->key.objectid + cache->key.offset;
384 used = btrfs_block_group_used(&cache->item);
385
386 if (!cache->ro && block_group_bits(cache, data)) {
387 free_check = div_factor(cache->key.offset, factor);
388 if (used + cache->pinned + cache->reserved <
389 free_check) {
390 found_group = cache;
391 spin_unlock(&cache->lock);
392 goto found;
393 }
394 }
395 spin_unlock(&cache->lock);
396 cond_resched();
397 }
398 if (!wrapped) {
399 last = search_start;
400 wrapped = 1;
401 goto again;
402 }
403 if (!full_search && factor < 10) {
404 last = search_start;
405 full_search = 1;
406 factor = 10;
407 goto again;
408 }
409 found:
410 return found_group;
411 }
412
413 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
414 struct btrfs_block_group_cache
415 *hint, u64 search_start,
416 int data, int owner)
417 {
418
419 struct btrfs_block_group_cache *ret;
420 ret = __btrfs_find_block_group(root, hint, search_start, data, owner);
421 return ret;
422 }
423
424 /* simple helper to search for an existing extent at a given offset */
425 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
426 {
427 int ret;
428 struct btrfs_key key;
429 struct btrfs_path *path;
430
431 path = btrfs_alloc_path();
432 BUG_ON(!path);
433 key.objectid = start;
434 key.offset = len;
435 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
436 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
437 0, 0);
438 btrfs_free_path(path);
439 return ret;
440 }
441
442 /*
443 * Back reference rules. Back refs have three main goals:
444 *
445 * 1) differentiate between all holders of references to an extent so that
446 * when a reference is dropped we can make sure it was a valid reference
447 * before freeing the extent.
448 *
449 * 2) Provide enough information to quickly find the holders of an extent
450 * if we notice a given block is corrupted or bad.
451 *
452 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
453 * maintenance. This is actually the same as #2, but with a slightly
454 * different use case.
455 *
456 * File extents can be referenced by:
457 *
458 * - multiple snapshots, subvolumes, or different generations in one subvol
459 * - different files inside a single subvolume
460 * - different offsets inside a file (bookend extents in file.c)
461 *
462 * The extent ref structure has fields for:
463 *
464 * - Objectid of the subvolume root
465 * - Generation number of the tree holding the reference
466 * - objectid of the file holding the reference
467 * - number of references holding by parent node (alway 1 for tree blocks)
468 *
469 * Btree leaf may hold multiple references to a file extent. In most cases,
470 * these references are from same file and the corresponding offsets inside
471 * the file are close together.
472 *
473 * When a file extent is allocated the fields are filled in:
474 * (root_key.objectid, trans->transid, inode objectid, 1)
475 *
476 * When a leaf is cow'd new references are added for every file extent found
477 * in the leaf. It looks similar to the create case, but trans->transid will
478 * be different when the block is cow'd.
479 *
480 * (root_key.objectid, trans->transid, inode objectid,
481 * number of references in the leaf)
482 *
483 * When a file extent is removed either during snapshot deletion or
484 * file truncation, we find the corresponding back reference and check
485 * the following fields:
486 *
487 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
488 * inode objectid)
489 *
490 * Btree extents can be referenced by:
491 *
492 * - Different subvolumes
493 * - Different generations of the same subvolume
494 *
495 * When a tree block is created, back references are inserted:
496 *
497 * (root->root_key.objectid, trans->transid, level, 1)
498 *
499 * When a tree block is cow'd, new back references are added for all the
500 * blocks it points to. If the tree block isn't in reference counted root,
501 * the old back references are removed. These new back references are of
502 * the form (trans->transid will have increased since creation):
503 *
504 * (root->root_key.objectid, trans->transid, level, 1)
505 *
506 * When a backref is in deleting, the following fields are checked:
507 *
508 * if backref was for a tree root:
509 * (btrfs_header_owner(itself), btrfs_header_generation(itself), level)
510 * else
511 * (btrfs_header_owner(parent), btrfs_header_generation(parent), level)
512 *
513 * Back Reference Key composing:
514 *
515 * The key objectid corresponds to the first byte in the extent, the key
516 * type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first
517 * byte of parent extent. If a extent is tree root, the key offset is set
518 * to the key objectid.
519 */
520
521 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
522 struct btrfs_root *root,
523 struct btrfs_path *path,
524 u64 bytenr, u64 parent,
525 u64 ref_root, u64 ref_generation,
526 u64 owner_objectid, int del)
527 {
528 struct btrfs_key key;
529 struct btrfs_extent_ref *ref;
530 struct extent_buffer *leaf;
531 u64 ref_objectid;
532 int ret;
533
534 key.objectid = bytenr;
535 key.type = BTRFS_EXTENT_REF_KEY;
536 key.offset = parent;
537
538 ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1);
539 if (ret < 0)
540 goto out;
541 if (ret > 0) {
542 ret = -ENOENT;
543 goto out;
544 }
545
546 leaf = path->nodes[0];
547 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
548 ref_objectid = btrfs_ref_objectid(leaf, ref);
549 if (btrfs_ref_root(leaf, ref) != ref_root ||
550 btrfs_ref_generation(leaf, ref) != ref_generation ||
551 (ref_objectid != owner_objectid &&
552 ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
553 ret = -EIO;
554 WARN_ON(1);
555 goto out;
556 }
557 ret = 0;
558 out:
559 return ret;
560 }
561
562 static int noinline insert_extent_backref(struct btrfs_trans_handle *trans,
563 struct btrfs_root *root,
564 struct btrfs_path *path,
565 u64 bytenr, u64 parent,
566 u64 ref_root, u64 ref_generation,
567 u64 owner_objectid)
568 {
569 struct btrfs_key key;
570 struct extent_buffer *leaf;
571 struct btrfs_extent_ref *ref;
572 u32 num_refs;
573 int ret;
574
575 key.objectid = bytenr;
576 key.type = BTRFS_EXTENT_REF_KEY;
577 key.offset = parent;
578
579 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref));
580 if (ret == 0) {
581 leaf = path->nodes[0];
582 ref = btrfs_item_ptr(leaf, path->slots[0],
583 struct btrfs_extent_ref);
584 btrfs_set_ref_root(leaf, ref, ref_root);
585 btrfs_set_ref_generation(leaf, ref, ref_generation);
586 btrfs_set_ref_objectid(leaf, ref, owner_objectid);
587 btrfs_set_ref_num_refs(leaf, ref, 1);
588 } else if (ret == -EEXIST) {
589 u64 existing_owner;
590 BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID);
591 leaf = path->nodes[0];
592 ref = btrfs_item_ptr(leaf, path->slots[0],
593 struct btrfs_extent_ref);
594 if (btrfs_ref_root(leaf, ref) != ref_root ||
595 btrfs_ref_generation(leaf, ref) != ref_generation) {
596 ret = -EIO;
597 WARN_ON(1);
598 goto out;
599 }
600
601 num_refs = btrfs_ref_num_refs(leaf, ref);
602 BUG_ON(num_refs == 0);
603 btrfs_set_ref_num_refs(leaf, ref, num_refs + 1);
604
605 existing_owner = btrfs_ref_objectid(leaf, ref);
606 if (existing_owner != owner_objectid &&
607 existing_owner != BTRFS_MULTIPLE_OBJECTIDS) {
608 btrfs_set_ref_objectid(leaf, ref,
609 BTRFS_MULTIPLE_OBJECTIDS);
610 }
611 ret = 0;
612 } else {
613 goto out;
614 }
615 btrfs_mark_buffer_dirty(path->nodes[0]);
616 out:
617 btrfs_release_path(root, path);
618 return ret;
619 }
620
621 static int noinline remove_extent_backref(struct btrfs_trans_handle *trans,
622 struct btrfs_root *root,
623 struct btrfs_path *path)
624 {
625 struct extent_buffer *leaf;
626 struct btrfs_extent_ref *ref;
627 u32 num_refs;
628 int ret = 0;
629
630 leaf = path->nodes[0];
631 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
632 num_refs = btrfs_ref_num_refs(leaf, ref);
633 BUG_ON(num_refs == 0);
634 num_refs -= 1;
635 if (num_refs == 0) {
636 ret = btrfs_del_item(trans, root, path);
637 } else {
638 btrfs_set_ref_num_refs(leaf, ref, num_refs);
639 btrfs_mark_buffer_dirty(leaf);
640 }
641 btrfs_release_path(root, path);
642 return ret;
643 }
644
645 static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
646 struct btrfs_root *root, u64 bytenr,
647 u64 orig_parent, u64 parent,
648 u64 orig_root, u64 ref_root,
649 u64 orig_generation, u64 ref_generation,
650 u64 owner_objectid)
651 {
652 int ret;
653 struct btrfs_root *extent_root = root->fs_info->extent_root;
654 struct btrfs_path *path;
655
656 if (root == root->fs_info->extent_root) {
657 struct pending_extent_op *extent_op;
658 u64 num_bytes;
659
660 BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL);
661 num_bytes = btrfs_level_size(root, (int)owner_objectid);
662 mutex_lock(&root->fs_info->extent_ins_mutex);
663 if (test_range_bit(&root->fs_info->extent_ins, bytenr,
664 bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
665 u64 priv;
666 ret = get_state_private(&root->fs_info->extent_ins,
667 bytenr, &priv);
668 BUG_ON(ret);
669 extent_op = (struct pending_extent_op *)
670 (unsigned long)priv;
671 BUG_ON(extent_op->parent != orig_parent);
672 BUG_ON(extent_op->generation != orig_generation);
673
674 extent_op->parent = parent;
675 extent_op->generation = ref_generation;
676 } else {
677 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
678 BUG_ON(!extent_op);
679
680 extent_op->type = PENDING_BACKREF_UPDATE;
681 extent_op->bytenr = bytenr;
682 extent_op->num_bytes = num_bytes;
683 extent_op->parent = parent;
684 extent_op->orig_parent = orig_parent;
685 extent_op->generation = ref_generation;
686 extent_op->orig_generation = orig_generation;
687 extent_op->level = (int)owner_objectid;
688
689 set_extent_bits(&root->fs_info->extent_ins,
690 bytenr, bytenr + num_bytes - 1,
691 EXTENT_WRITEBACK, GFP_NOFS);
692 set_state_private(&root->fs_info->extent_ins,
693 bytenr, (unsigned long)extent_op);
694 }
695 mutex_unlock(&root->fs_info->extent_ins_mutex);
696 return 0;
697 }
698
699 path = btrfs_alloc_path();
700 if (!path)
701 return -ENOMEM;
702 ret = lookup_extent_backref(trans, extent_root, path,
703 bytenr, orig_parent, orig_root,
704 orig_generation, owner_objectid, 1);
705 if (ret)
706 goto out;
707 ret = remove_extent_backref(trans, extent_root, path);
708 if (ret)
709 goto out;
710 ret = insert_extent_backref(trans, extent_root, path, bytenr,
711 parent, ref_root, ref_generation,
712 owner_objectid);
713 BUG_ON(ret);
714 finish_current_insert(trans, extent_root, 0);
715 del_pending_extents(trans, extent_root, 0);
716 out:
717 btrfs_free_path(path);
718 return ret;
719 }
720
721 int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
722 struct btrfs_root *root, u64 bytenr,
723 u64 orig_parent, u64 parent,
724 u64 ref_root, u64 ref_generation,
725 u64 owner_objectid)
726 {
727 int ret;
728 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
729 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
730 return 0;
731 ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent,
732 parent, ref_root, ref_root,
733 ref_generation, ref_generation,
734 owner_objectid);
735 return ret;
736 }
737
738 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
739 struct btrfs_root *root, u64 bytenr,
740 u64 orig_parent, u64 parent,
741 u64 orig_root, u64 ref_root,
742 u64 orig_generation, u64 ref_generation,
743 u64 owner_objectid)
744 {
745 struct btrfs_path *path;
746 int ret;
747 struct btrfs_key key;
748 struct extent_buffer *l;
749 struct btrfs_extent_item *item;
750 u32 refs;
751
752 path = btrfs_alloc_path();
753 if (!path)
754 return -ENOMEM;
755
756 path->reada = 1;
757 key.objectid = bytenr;
758 key.type = BTRFS_EXTENT_ITEM_KEY;
759 key.offset = (u64)-1;
760
761 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
762 0, 1);
763 if (ret < 0)
764 return ret;
765 BUG_ON(ret == 0 || path->slots[0] == 0);
766
767 path->slots[0]--;
768 l = path->nodes[0];
769
770 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
771 if (key.objectid != bytenr) {
772 btrfs_print_leaf(root->fs_info->extent_root, path->nodes[0]);
773 printk("wanted %Lu found %Lu\n", bytenr, key.objectid);
774 BUG();
775 }
776 BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY);
777
778 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
779 refs = btrfs_extent_refs(l, item);
780 btrfs_set_extent_refs(l, item, refs + 1);
781 btrfs_mark_buffer_dirty(path->nodes[0]);
782
783 btrfs_release_path(root->fs_info->extent_root, path);
784
785 path->reada = 1;
786 ret = insert_extent_backref(trans, root->fs_info->extent_root,
787 path, bytenr, parent,
788 ref_root, ref_generation,
789 owner_objectid);
790 BUG_ON(ret);
791 finish_current_insert(trans, root->fs_info->extent_root, 0);
792 del_pending_extents(trans, root->fs_info->extent_root, 0);
793
794 btrfs_free_path(path);
795 return 0;
796 }
797
798 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
799 struct btrfs_root *root,
800 u64 bytenr, u64 num_bytes, u64 parent,
801 u64 ref_root, u64 ref_generation,
802 u64 owner_objectid)
803 {
804 int ret;
805 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
806 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
807 return 0;
808 ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent,
809 0, ref_root, 0, ref_generation,
810 owner_objectid);
811 return ret;
812 }
813
814 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
815 struct btrfs_root *root)
816 {
817 finish_current_insert(trans, root->fs_info->extent_root, 1);
818 del_pending_extents(trans, root->fs_info->extent_root, 1);
819 return 0;
820 }
821
822 int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
823 struct btrfs_root *root, u64 bytenr,
824 u64 num_bytes, u32 *refs)
825 {
826 struct btrfs_path *path;
827 int ret;
828 struct btrfs_key key;
829 struct extent_buffer *l;
830 struct btrfs_extent_item *item;
831
832 WARN_ON(num_bytes < root->sectorsize);
833 path = btrfs_alloc_path();
834 path->reada = 1;
835 key.objectid = bytenr;
836 key.offset = num_bytes;
837 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
838 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
839 0, 0);
840 if (ret < 0)
841 goto out;
842 if (ret != 0) {
843 btrfs_print_leaf(root, path->nodes[0]);
844 printk("failed to find block number %Lu\n", bytenr);
845 BUG();
846 }
847 l = path->nodes[0];
848 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
849 *refs = btrfs_extent_refs(l, item);
850 out:
851 btrfs_free_path(path);
852 return 0;
853 }
854
855 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
856 struct btrfs_root *root, u64 bytenr)
857 {
858 struct btrfs_root *extent_root = root->fs_info->extent_root;
859 struct btrfs_path *path;
860 struct extent_buffer *leaf;
861 struct btrfs_extent_ref *ref_item;
862 struct btrfs_key key;
863 struct btrfs_key found_key;
864 u64 ref_root;
865 u64 last_snapshot;
866 u32 nritems;
867 int ret;
868
869 key.objectid = bytenr;
870 key.offset = (u64)-1;
871 key.type = BTRFS_EXTENT_ITEM_KEY;
872
873 path = btrfs_alloc_path();
874 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
875 if (ret < 0)
876 goto out;
877 BUG_ON(ret == 0);
878
879 ret = -ENOENT;
880 if (path->slots[0] == 0)
881 goto out;
882
883 path->slots[0]--;
884 leaf = path->nodes[0];
885 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
886
887 if (found_key.objectid != bytenr ||
888 found_key.type != BTRFS_EXTENT_ITEM_KEY)
889 goto out;
890
891 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
892 while (1) {
893 leaf = path->nodes[0];
894 nritems = btrfs_header_nritems(leaf);
895 if (path->slots[0] >= nritems) {
896 ret = btrfs_next_leaf(extent_root, path);
897 if (ret < 0)
898 goto out;
899 if (ret == 0)
900 continue;
901 break;
902 }
903 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
904 if (found_key.objectid != bytenr)
905 break;
906
907 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
908 path->slots[0]++;
909 continue;
910 }
911
912 ref_item = btrfs_item_ptr(leaf, path->slots[0],
913 struct btrfs_extent_ref);
914 ref_root = btrfs_ref_root(leaf, ref_item);
915 if (ref_root != root->root_key.objectid &&
916 ref_root != BTRFS_TREE_LOG_OBJECTID) {
917 ret = 1;
918 goto out;
919 }
920 if (btrfs_ref_generation(leaf, ref_item) <= last_snapshot) {
921 ret = 1;
922 goto out;
923 }
924
925 path->slots[0]++;
926 }
927 ret = 0;
928 out:
929 btrfs_free_path(path);
930 return ret;
931 }
932
933 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
934 struct extent_buffer *buf, u32 nr_extents)
935 {
936 struct btrfs_key key;
937 struct btrfs_file_extent_item *fi;
938 u64 root_gen;
939 u32 nritems;
940 int i;
941 int level;
942 int ret = 0;
943 int shared = 0;
944
945 if (!root->ref_cows)
946 return 0;
947
948 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
949 shared = 0;
950 root_gen = root->root_key.offset;
951 } else {
952 shared = 1;
953 root_gen = trans->transid - 1;
954 }
955
956 level = btrfs_header_level(buf);
957 nritems = btrfs_header_nritems(buf);
958
959 if (level == 0) {
960 struct btrfs_leaf_ref *ref;
961 struct btrfs_extent_info *info;
962
963 ref = btrfs_alloc_leaf_ref(root, nr_extents);
964 if (!ref) {
965 ret = -ENOMEM;
966 goto out;
967 }
968
969 ref->root_gen = root_gen;
970 ref->bytenr = buf->start;
971 ref->owner = btrfs_header_owner(buf);
972 ref->generation = btrfs_header_generation(buf);
973 ref->nritems = nr_extents;
974 info = ref->extents;
975
976 for (i = 0; nr_extents > 0 && i < nritems; i++) {
977 u64 disk_bytenr;
978 btrfs_item_key_to_cpu(buf, &key, i);
979 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
980 continue;
981 fi = btrfs_item_ptr(buf, i,
982 struct btrfs_file_extent_item);
983 if (btrfs_file_extent_type(buf, fi) ==
984 BTRFS_FILE_EXTENT_INLINE)
985 continue;
986 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
987 if (disk_bytenr == 0)
988 continue;
989
990 info->bytenr = disk_bytenr;
991 info->num_bytes =
992 btrfs_file_extent_disk_num_bytes(buf, fi);
993 info->objectid = key.objectid;
994 info->offset = key.offset;
995 info++;
996 }
997
998 ret = btrfs_add_leaf_ref(root, ref, shared);
999 if (ret == -EEXIST && shared) {
1000 struct btrfs_leaf_ref *old;
1001 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
1002 BUG_ON(!old);
1003 btrfs_remove_leaf_ref(root, old);
1004 btrfs_free_leaf_ref(root, old);
1005 ret = btrfs_add_leaf_ref(root, ref, shared);
1006 }
1007 WARN_ON(ret);
1008 btrfs_free_leaf_ref(root, ref);
1009 }
1010 out:
1011 return ret;
1012 }
1013
1014 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1015 struct extent_buffer *orig_buf, struct extent_buffer *buf,
1016 u32 *nr_extents)
1017 {
1018 u64 bytenr;
1019 u64 ref_root;
1020 u64 orig_root;
1021 u64 ref_generation;
1022 u64 orig_generation;
1023 u32 nritems;
1024 u32 nr_file_extents = 0;
1025 struct btrfs_key key;
1026 struct btrfs_file_extent_item *fi;
1027 int i;
1028 int level;
1029 int ret = 0;
1030 int faili = 0;
1031 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
1032 u64, u64, u64, u64, u64, u64, u64, u64);
1033
1034 ref_root = btrfs_header_owner(buf);
1035 ref_generation = btrfs_header_generation(buf);
1036 orig_root = btrfs_header_owner(orig_buf);
1037 orig_generation = btrfs_header_generation(orig_buf);
1038
1039 nritems = btrfs_header_nritems(buf);
1040 level = btrfs_header_level(buf);
1041
1042 if (root->ref_cows) {
1043 process_func = __btrfs_inc_extent_ref;
1044 } else {
1045 if (level == 0 &&
1046 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1047 goto out;
1048 if (level != 0 &&
1049 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1050 goto out;
1051 process_func = __btrfs_update_extent_ref;
1052 }
1053
1054 for (i = 0; i < nritems; i++) {
1055 cond_resched();
1056 if (level == 0) {
1057 btrfs_item_key_to_cpu(buf, &key, i);
1058 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1059 continue;
1060 fi = btrfs_item_ptr(buf, i,
1061 struct btrfs_file_extent_item);
1062 if (btrfs_file_extent_type(buf, fi) ==
1063 BTRFS_FILE_EXTENT_INLINE)
1064 continue;
1065 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1066 if (bytenr == 0)
1067 continue;
1068
1069 nr_file_extents++;
1070
1071 ret = process_func(trans, root, bytenr,
1072 orig_buf->start, buf->start,
1073 orig_root, ref_root,
1074 orig_generation, ref_generation,
1075 key.objectid);
1076
1077 if (ret) {
1078 faili = i;
1079 WARN_ON(1);
1080 goto fail;
1081 }
1082 } else {
1083 bytenr = btrfs_node_blockptr(buf, i);
1084 ret = process_func(trans, root, bytenr,
1085 orig_buf->start, buf->start,
1086 orig_root, ref_root,
1087 orig_generation, ref_generation,
1088 level - 1);
1089 if (ret) {
1090 faili = i;
1091 WARN_ON(1);
1092 goto fail;
1093 }
1094 }
1095 }
1096 out:
1097 if (nr_extents) {
1098 if (level == 0)
1099 *nr_extents = nr_file_extents;
1100 else
1101 *nr_extents = nritems;
1102 }
1103 return 0;
1104 fail:
1105 WARN_ON(1);
1106 return ret;
1107 }
1108
1109 int btrfs_update_ref(struct btrfs_trans_handle *trans,
1110 struct btrfs_root *root, struct extent_buffer *orig_buf,
1111 struct extent_buffer *buf, int start_slot, int nr)
1112
1113 {
1114 u64 bytenr;
1115 u64 ref_root;
1116 u64 orig_root;
1117 u64 ref_generation;
1118 u64 orig_generation;
1119 struct btrfs_key key;
1120 struct btrfs_file_extent_item *fi;
1121 int i;
1122 int ret;
1123 int slot;
1124 int level;
1125
1126 BUG_ON(start_slot < 0);
1127 BUG_ON(start_slot + nr > btrfs_header_nritems(buf));
1128
1129 ref_root = btrfs_header_owner(buf);
1130 ref_generation = btrfs_header_generation(buf);
1131 orig_root = btrfs_header_owner(orig_buf);
1132 orig_generation = btrfs_header_generation(orig_buf);
1133 level = btrfs_header_level(buf);
1134
1135 if (!root->ref_cows) {
1136 if (level == 0 &&
1137 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1138 return 0;
1139 if (level != 0 &&
1140 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1141 return 0;
1142 }
1143
1144 for (i = 0, slot = start_slot; i < nr; i++, slot++) {
1145 cond_resched();
1146 if (level == 0) {
1147 btrfs_item_key_to_cpu(buf, &key, slot);
1148 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1149 continue;
1150 fi = btrfs_item_ptr(buf, slot,
1151 struct btrfs_file_extent_item);
1152 if (btrfs_file_extent_type(buf, fi) ==
1153 BTRFS_FILE_EXTENT_INLINE)
1154 continue;
1155 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1156 if (bytenr == 0)
1157 continue;
1158 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1159 orig_buf->start, buf->start,
1160 orig_root, ref_root,
1161 orig_generation, ref_generation,
1162 key.objectid);
1163 if (ret)
1164 goto fail;
1165 } else {
1166 bytenr = btrfs_node_blockptr(buf, slot);
1167 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1168 orig_buf->start, buf->start,
1169 orig_root, ref_root,
1170 orig_generation, ref_generation,
1171 level - 1);
1172 if (ret)
1173 goto fail;
1174 }
1175 }
1176 return 0;
1177 fail:
1178 WARN_ON(1);
1179 return -1;
1180 }
1181
1182 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1183 struct btrfs_root *root,
1184 struct btrfs_path *path,
1185 struct btrfs_block_group_cache *cache)
1186 {
1187 int ret;
1188 int pending_ret;
1189 struct btrfs_root *extent_root = root->fs_info->extent_root;
1190 unsigned long bi;
1191 struct extent_buffer *leaf;
1192
1193 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1194 if (ret < 0)
1195 goto fail;
1196 BUG_ON(ret);
1197
1198 leaf = path->nodes[0];
1199 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1200 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1201 btrfs_mark_buffer_dirty(leaf);
1202 btrfs_release_path(extent_root, path);
1203 fail:
1204 finish_current_insert(trans, extent_root, 0);
1205 pending_ret = del_pending_extents(trans, extent_root, 0);
1206 if (ret)
1207 return ret;
1208 if (pending_ret)
1209 return pending_ret;
1210 return 0;
1211
1212 }
1213
1214 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1215 struct btrfs_root *root)
1216 {
1217 struct btrfs_block_group_cache *cache, *entry;
1218 struct rb_node *n;
1219 int err = 0;
1220 int werr = 0;
1221 struct btrfs_path *path;
1222 u64 last = 0;
1223
1224 path = btrfs_alloc_path();
1225 if (!path)
1226 return -ENOMEM;
1227
1228 while(1) {
1229 cache = NULL;
1230 spin_lock(&root->fs_info->block_group_cache_lock);
1231 for (n = rb_first(&root->fs_info->block_group_cache_tree);
1232 n; n = rb_next(n)) {
1233 entry = rb_entry(n, struct btrfs_block_group_cache,
1234 cache_node);
1235 if (entry->dirty) {
1236 cache = entry;
1237 break;
1238 }
1239 }
1240 spin_unlock(&root->fs_info->block_group_cache_lock);
1241
1242 if (!cache)
1243 break;
1244
1245 cache->dirty = 0;
1246 last += cache->key.offset;
1247
1248 err = write_one_cache_group(trans, root,
1249 path, cache);
1250 /*
1251 * if we fail to write the cache group, we want
1252 * to keep it marked dirty in hopes that a later
1253 * write will work
1254 */
1255 if (err) {
1256 werr = err;
1257 continue;
1258 }
1259 }
1260 btrfs_free_path(path);
1261 return werr;
1262 }
1263
1264 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1265 u64 total_bytes, u64 bytes_used,
1266 struct btrfs_space_info **space_info)
1267 {
1268 struct btrfs_space_info *found;
1269
1270 found = __find_space_info(info, flags);
1271 if (found) {
1272 spin_lock(&found->lock);
1273 found->total_bytes += total_bytes;
1274 found->bytes_used += bytes_used;
1275 found->full = 0;
1276 spin_unlock(&found->lock);
1277 *space_info = found;
1278 return 0;
1279 }
1280 found = kmalloc(sizeof(*found), GFP_NOFS);
1281 if (!found)
1282 return -ENOMEM;
1283
1284 list_add(&found->list, &info->space_info);
1285 INIT_LIST_HEAD(&found->block_groups);
1286 init_rwsem(&found->groups_sem);
1287 spin_lock_init(&found->lock);
1288 found->flags = flags;
1289 found->total_bytes = total_bytes;
1290 found->bytes_used = bytes_used;
1291 found->bytes_pinned = 0;
1292 found->bytes_reserved = 0;
1293 found->full = 0;
1294 found->force_alloc = 0;
1295 *space_info = found;
1296 return 0;
1297 }
1298
1299 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1300 {
1301 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1302 BTRFS_BLOCK_GROUP_RAID1 |
1303 BTRFS_BLOCK_GROUP_RAID10 |
1304 BTRFS_BLOCK_GROUP_DUP);
1305 if (extra_flags) {
1306 if (flags & BTRFS_BLOCK_GROUP_DATA)
1307 fs_info->avail_data_alloc_bits |= extra_flags;
1308 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1309 fs_info->avail_metadata_alloc_bits |= extra_flags;
1310 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1311 fs_info->avail_system_alloc_bits |= extra_flags;
1312 }
1313 }
1314
1315 static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags)
1316 {
1317 u64 num_devices = root->fs_info->fs_devices->num_devices;
1318
1319 if (num_devices == 1)
1320 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
1321 if (num_devices < 4)
1322 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
1323
1324 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
1325 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
1326 BTRFS_BLOCK_GROUP_RAID10))) {
1327 flags &= ~BTRFS_BLOCK_GROUP_DUP;
1328 }
1329
1330 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
1331 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
1332 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
1333 }
1334
1335 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
1336 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
1337 (flags & BTRFS_BLOCK_GROUP_RAID10) |
1338 (flags & BTRFS_BLOCK_GROUP_DUP)))
1339 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
1340 return flags;
1341 }
1342
1343 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1344 struct btrfs_root *extent_root, u64 alloc_bytes,
1345 u64 flags, int force)
1346 {
1347 struct btrfs_space_info *space_info;
1348 u64 thresh;
1349 u64 start;
1350 u64 num_bytes;
1351 int ret = 0, waited = 0;
1352
1353 flags = reduce_alloc_profile(extent_root, flags);
1354
1355 space_info = __find_space_info(extent_root->fs_info, flags);
1356 if (!space_info) {
1357 ret = update_space_info(extent_root->fs_info, flags,
1358 0, 0, &space_info);
1359 BUG_ON(ret);
1360 }
1361 BUG_ON(!space_info);
1362
1363 spin_lock(&space_info->lock);
1364 if (space_info->force_alloc) {
1365 force = 1;
1366 space_info->force_alloc = 0;
1367 }
1368 if (space_info->full) {
1369 spin_unlock(&space_info->lock);
1370 goto out;
1371 }
1372
1373 thresh = div_factor(space_info->total_bytes, 6);
1374 if (!force &&
1375 (space_info->bytes_used + space_info->bytes_pinned +
1376 space_info->bytes_reserved + alloc_bytes) < thresh) {
1377 spin_unlock(&space_info->lock);
1378 goto out;
1379 }
1380
1381 spin_unlock(&space_info->lock);
1382
1383 ret = mutex_trylock(&extent_root->fs_info->chunk_mutex);
1384 if (!ret && !force) {
1385 goto out;
1386 } else if (!ret) {
1387 mutex_lock(&extent_root->fs_info->chunk_mutex);
1388 waited = 1;
1389 }
1390
1391 if (waited) {
1392 spin_lock(&space_info->lock);
1393 if (space_info->full) {
1394 spin_unlock(&space_info->lock);
1395 goto out_unlock;
1396 }
1397 spin_unlock(&space_info->lock);
1398 }
1399
1400 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1401 if (ret) {
1402 printk("space info full %Lu\n", flags);
1403 space_info->full = 1;
1404 goto out_unlock;
1405 }
1406
1407 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1408 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1409 BUG_ON(ret);
1410 out_unlock:
1411 mutex_unlock(&extent_root->fs_info->chunk_mutex);
1412 out:
1413 return ret;
1414 }
1415
1416 static int update_block_group(struct btrfs_trans_handle *trans,
1417 struct btrfs_root *root,
1418 u64 bytenr, u64 num_bytes, int alloc,
1419 int mark_free)
1420 {
1421 struct btrfs_block_group_cache *cache;
1422 struct btrfs_fs_info *info = root->fs_info;
1423 u64 total = num_bytes;
1424 u64 old_val;
1425 u64 byte_in_group;
1426
1427 while(total) {
1428 cache = btrfs_lookup_block_group(info, bytenr);
1429 if (!cache) {
1430 return -1;
1431 }
1432 byte_in_group = bytenr - cache->key.objectid;
1433 WARN_ON(byte_in_group > cache->key.offset);
1434
1435 spin_lock(&cache->space_info->lock);
1436 spin_lock(&cache->lock);
1437 cache->dirty = 1;
1438 old_val = btrfs_block_group_used(&cache->item);
1439 num_bytes = min(total, cache->key.offset - byte_in_group);
1440 if (alloc) {
1441 old_val += num_bytes;
1442 cache->space_info->bytes_used += num_bytes;
1443 btrfs_set_block_group_used(&cache->item, old_val);
1444 spin_unlock(&cache->lock);
1445 spin_unlock(&cache->space_info->lock);
1446 } else {
1447 old_val -= num_bytes;
1448 cache->space_info->bytes_used -= num_bytes;
1449 btrfs_set_block_group_used(&cache->item, old_val);
1450 spin_unlock(&cache->lock);
1451 spin_unlock(&cache->space_info->lock);
1452 if (mark_free) {
1453 int ret;
1454 ret = btrfs_add_free_space(cache, bytenr,
1455 num_bytes);
1456 if (ret)
1457 return -1;
1458 }
1459 }
1460 total -= num_bytes;
1461 bytenr += num_bytes;
1462 }
1463 return 0;
1464 }
1465
1466 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
1467 {
1468 struct btrfs_block_group_cache *cache;
1469
1470 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
1471 if (!cache)
1472 return 0;
1473
1474 return cache->key.objectid;
1475 }
1476
1477 int btrfs_update_pinned_extents(struct btrfs_root *root,
1478 u64 bytenr, u64 num, int pin)
1479 {
1480 u64 len;
1481 struct btrfs_block_group_cache *cache;
1482 struct btrfs_fs_info *fs_info = root->fs_info;
1483
1484 WARN_ON(!mutex_is_locked(&root->fs_info->pinned_mutex));
1485 if (pin) {
1486 set_extent_dirty(&fs_info->pinned_extents,
1487 bytenr, bytenr + num - 1, GFP_NOFS);
1488 } else {
1489 clear_extent_dirty(&fs_info->pinned_extents,
1490 bytenr, bytenr + num - 1, GFP_NOFS);
1491 }
1492 while (num > 0) {
1493 cache = btrfs_lookup_block_group(fs_info, bytenr);
1494 BUG_ON(!cache);
1495 len = min(num, cache->key.offset -
1496 (bytenr - cache->key.objectid));
1497 if (pin) {
1498 spin_lock(&cache->space_info->lock);
1499 spin_lock(&cache->lock);
1500 cache->pinned += len;
1501 cache->space_info->bytes_pinned += len;
1502 spin_unlock(&cache->lock);
1503 spin_unlock(&cache->space_info->lock);
1504 fs_info->total_pinned += len;
1505 } else {
1506 spin_lock(&cache->space_info->lock);
1507 spin_lock(&cache->lock);
1508 cache->pinned -= len;
1509 cache->space_info->bytes_pinned -= len;
1510 spin_unlock(&cache->lock);
1511 spin_unlock(&cache->space_info->lock);
1512 fs_info->total_pinned -= len;
1513 }
1514 bytenr += len;
1515 num -= len;
1516 }
1517 return 0;
1518 }
1519
1520 static int update_reserved_extents(struct btrfs_root *root,
1521 u64 bytenr, u64 num, int reserve)
1522 {
1523 u64 len;
1524 struct btrfs_block_group_cache *cache;
1525 struct btrfs_fs_info *fs_info = root->fs_info;
1526
1527 while (num > 0) {
1528 cache = btrfs_lookup_block_group(fs_info, bytenr);
1529 BUG_ON(!cache);
1530 len = min(num, cache->key.offset -
1531 (bytenr - cache->key.objectid));
1532
1533 spin_lock(&cache->space_info->lock);
1534 spin_lock(&cache->lock);
1535 if (reserve) {
1536 cache->reserved += len;
1537 cache->space_info->bytes_reserved += len;
1538 } else {
1539 cache->reserved -= len;
1540 cache->space_info->bytes_reserved -= len;
1541 }
1542 spin_unlock(&cache->lock);
1543 spin_unlock(&cache->space_info->lock);
1544 bytenr += len;
1545 num -= len;
1546 }
1547 return 0;
1548 }
1549
1550 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1551 {
1552 u64 last = 0;
1553 u64 start;
1554 u64 end;
1555 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1556 int ret;
1557
1558 mutex_lock(&root->fs_info->pinned_mutex);
1559 while(1) {
1560 ret = find_first_extent_bit(pinned_extents, last,
1561 &start, &end, EXTENT_DIRTY);
1562 if (ret)
1563 break;
1564 set_extent_dirty(copy, start, end, GFP_NOFS);
1565 last = end + 1;
1566 }
1567 mutex_unlock(&root->fs_info->pinned_mutex);
1568 return 0;
1569 }
1570
1571 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1572 struct btrfs_root *root,
1573 struct extent_io_tree *unpin)
1574 {
1575 u64 start;
1576 u64 end;
1577 int ret;
1578 struct btrfs_block_group_cache *cache;
1579
1580 mutex_lock(&root->fs_info->pinned_mutex);
1581 while(1) {
1582 ret = find_first_extent_bit(unpin, 0, &start, &end,
1583 EXTENT_DIRTY);
1584 if (ret)
1585 break;
1586 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
1587 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1588 cache = btrfs_lookup_block_group(root->fs_info, start);
1589 if (cache->cached)
1590 btrfs_add_free_space(cache, start, end - start + 1);
1591 if (need_resched()) {
1592 mutex_unlock(&root->fs_info->pinned_mutex);
1593 cond_resched();
1594 mutex_lock(&root->fs_info->pinned_mutex);
1595 }
1596 }
1597 mutex_unlock(&root->fs_info->pinned_mutex);
1598 return 0;
1599 }
1600
1601 static int finish_current_insert(struct btrfs_trans_handle *trans,
1602 struct btrfs_root *extent_root, int all)
1603 {
1604 u64 start;
1605 u64 end;
1606 u64 priv;
1607 u64 search = 0;
1608 struct btrfs_fs_info *info = extent_root->fs_info;
1609 struct btrfs_path *path;
1610 struct btrfs_extent_ref *ref;
1611 struct pending_extent_op *extent_op;
1612 struct btrfs_key key;
1613 struct btrfs_extent_item extent_item;
1614 int ret;
1615 int err = 0;
1616
1617 btrfs_set_stack_extent_refs(&extent_item, 1);
1618 path = btrfs_alloc_path();
1619
1620 while(1) {
1621 mutex_lock(&info->extent_ins_mutex);
1622 ret = find_first_extent_bit(&info->extent_ins, search, &start,
1623 &end, EXTENT_WRITEBACK);
1624 if (ret) {
1625 mutex_unlock(&info->extent_ins_mutex);
1626 if (search && all) {
1627 search = 0;
1628 continue;
1629 }
1630 break;
1631 }
1632
1633 ret = try_lock_extent(&info->extent_ins, start, end, GFP_NOFS);
1634 if (!ret) {
1635 search = end + 1;
1636 mutex_unlock(&info->extent_ins_mutex);
1637 cond_resched();
1638 continue;
1639 }
1640 BUG_ON(ret < 0);
1641
1642 ret = get_state_private(&info->extent_ins, start, &priv);
1643 BUG_ON(ret);
1644 extent_op = (struct pending_extent_op *)(unsigned long)priv;
1645
1646 mutex_unlock(&info->extent_ins_mutex);
1647
1648 if (extent_op->type == PENDING_EXTENT_INSERT) {
1649 key.objectid = start;
1650 key.offset = end + 1 - start;
1651 key.type = BTRFS_EXTENT_ITEM_KEY;
1652 err = btrfs_insert_item(trans, extent_root, &key,
1653 &extent_item, sizeof(extent_item));
1654 BUG_ON(err);
1655
1656 mutex_lock(&info->extent_ins_mutex);
1657 clear_extent_bits(&info->extent_ins, start, end,
1658 EXTENT_WRITEBACK, GFP_NOFS);
1659 mutex_unlock(&info->extent_ins_mutex);
1660
1661 err = insert_extent_backref(trans, extent_root, path,
1662 start, extent_op->parent,
1663 extent_root->root_key.objectid,
1664 extent_op->generation,
1665 extent_op->level);
1666 BUG_ON(err);
1667 } else if (extent_op->type == PENDING_BACKREF_UPDATE) {
1668 err = lookup_extent_backref(trans, extent_root, path,
1669 start, extent_op->orig_parent,
1670 extent_root->root_key.objectid,
1671 extent_op->orig_generation,
1672 extent_op->level, 0);
1673 BUG_ON(err);
1674
1675 mutex_lock(&info->extent_ins_mutex);
1676 clear_extent_bits(&info->extent_ins, start, end,
1677 EXTENT_WRITEBACK, GFP_NOFS);
1678 mutex_unlock(&info->extent_ins_mutex);
1679
1680 key.objectid = start;
1681 key.offset = extent_op->parent;
1682 key.type = BTRFS_EXTENT_REF_KEY;
1683 err = btrfs_set_item_key_safe(trans, extent_root, path,
1684 &key);
1685 BUG_ON(err);
1686 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1687 struct btrfs_extent_ref);
1688 btrfs_set_ref_generation(path->nodes[0], ref,
1689 extent_op->generation);
1690 btrfs_mark_buffer_dirty(path->nodes[0]);
1691 btrfs_release_path(extent_root, path);
1692 } else {
1693 BUG_ON(1);
1694 }
1695 kfree(extent_op);
1696 unlock_extent(&info->extent_ins, start, end, GFP_NOFS);
1697 if (all)
1698 search = 0;
1699 else
1700 search = end + 1;
1701
1702 cond_resched();
1703 }
1704 btrfs_free_path(path);
1705 return 0;
1706 }
1707
1708 static int pin_down_bytes(struct btrfs_trans_handle *trans,
1709 struct btrfs_root *root,
1710 u64 bytenr, u64 num_bytes, int is_data)
1711 {
1712 int err = 0;
1713 struct extent_buffer *buf;
1714
1715 if (is_data)
1716 goto pinit;
1717
1718 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1719 if (!buf)
1720 goto pinit;
1721
1722 /* we can reuse a block if it hasn't been written
1723 * and it is from this transaction. We can't
1724 * reuse anything from the tree log root because
1725 * it has tiny sub-transactions.
1726 */
1727 if (btrfs_buffer_uptodate(buf, 0) &&
1728 btrfs_try_tree_lock(buf)) {
1729 u64 header_owner = btrfs_header_owner(buf);
1730 u64 header_transid = btrfs_header_generation(buf);
1731 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
1732 header_owner != BTRFS_TREE_RELOC_OBJECTID &&
1733 header_transid == trans->transid &&
1734 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
1735 clean_tree_block(NULL, root, buf);
1736 btrfs_tree_unlock(buf);
1737 free_extent_buffer(buf);
1738 return 1;
1739 }
1740 btrfs_tree_unlock(buf);
1741 }
1742 free_extent_buffer(buf);
1743 pinit:
1744 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
1745
1746 BUG_ON(err < 0);
1747 return 0;
1748 }
1749
1750 /*
1751 * remove an extent from the root, returns 0 on success
1752 */
1753 static int __free_extent(struct btrfs_trans_handle *trans,
1754 struct btrfs_root *root,
1755 u64 bytenr, u64 num_bytes, u64 parent,
1756 u64 root_objectid, u64 ref_generation,
1757 u64 owner_objectid, int pin, int mark_free)
1758 {
1759 struct btrfs_path *path;
1760 struct btrfs_key key;
1761 struct btrfs_fs_info *info = root->fs_info;
1762 struct btrfs_root *extent_root = info->extent_root;
1763 struct extent_buffer *leaf;
1764 int ret;
1765 int extent_slot = 0;
1766 int found_extent = 0;
1767 int num_to_del = 1;
1768 struct btrfs_extent_item *ei;
1769 u32 refs;
1770
1771 key.objectid = bytenr;
1772 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1773 key.offset = num_bytes;
1774 path = btrfs_alloc_path();
1775 if (!path)
1776 return -ENOMEM;
1777
1778 path->reada = 1;
1779 ret = lookup_extent_backref(trans, extent_root, path,
1780 bytenr, parent, root_objectid,
1781 ref_generation, owner_objectid, 1);
1782 if (ret == 0) {
1783 struct btrfs_key found_key;
1784 extent_slot = path->slots[0];
1785 while(extent_slot > 0) {
1786 extent_slot--;
1787 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1788 extent_slot);
1789 if (found_key.objectid != bytenr)
1790 break;
1791 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1792 found_key.offset == num_bytes) {
1793 found_extent = 1;
1794 break;
1795 }
1796 if (path->slots[0] - extent_slot > 5)
1797 break;
1798 }
1799 if (!found_extent) {
1800 ret = remove_extent_backref(trans, extent_root, path);
1801 BUG_ON(ret);
1802 btrfs_release_path(extent_root, path);
1803 ret = btrfs_search_slot(trans, extent_root,
1804 &key, path, -1, 1);
1805 BUG_ON(ret);
1806 extent_slot = path->slots[0];
1807 }
1808 } else {
1809 btrfs_print_leaf(extent_root, path->nodes[0]);
1810 WARN_ON(1);
1811 printk("Unable to find ref byte nr %Lu root %Lu "
1812 "gen %Lu owner %Lu\n", bytenr,
1813 root_objectid, ref_generation, owner_objectid);
1814 }
1815
1816 leaf = path->nodes[0];
1817 ei = btrfs_item_ptr(leaf, extent_slot,
1818 struct btrfs_extent_item);
1819 refs = btrfs_extent_refs(leaf, ei);
1820 BUG_ON(refs == 0);
1821 refs -= 1;
1822 btrfs_set_extent_refs(leaf, ei, refs);
1823
1824 btrfs_mark_buffer_dirty(leaf);
1825
1826 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1827 struct btrfs_extent_ref *ref;
1828 ref = btrfs_item_ptr(leaf, path->slots[0],
1829 struct btrfs_extent_ref);
1830 BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1);
1831 /* if the back ref and the extent are next to each other
1832 * they get deleted below in one shot
1833 */
1834 path->slots[0] = extent_slot;
1835 num_to_del = 2;
1836 } else if (found_extent) {
1837 /* otherwise delete the extent back ref */
1838 ret = remove_extent_backref(trans, extent_root, path);
1839 BUG_ON(ret);
1840 /* if refs are 0, we need to setup the path for deletion */
1841 if (refs == 0) {
1842 btrfs_release_path(extent_root, path);
1843 ret = btrfs_search_slot(trans, extent_root, &key, path,
1844 -1, 1);
1845 BUG_ON(ret);
1846 }
1847 }
1848
1849 if (refs == 0) {
1850 u64 super_used;
1851 u64 root_used;
1852 #ifdef BIO_RW_DISCARD
1853 u64 map_length = num_bytes;
1854 struct btrfs_multi_bio *multi = NULL;
1855 #endif
1856
1857 if (pin) {
1858 mutex_lock(&root->fs_info->pinned_mutex);
1859 ret = pin_down_bytes(trans, root, bytenr, num_bytes,
1860 owner_objectid >= BTRFS_FIRST_FREE_OBJECTID);
1861 mutex_unlock(&root->fs_info->pinned_mutex);
1862 if (ret > 0)
1863 mark_free = 1;
1864 BUG_ON(ret < 0);
1865 }
1866
1867 /* block accounting for super block */
1868 spin_lock_irq(&info->delalloc_lock);
1869 super_used = btrfs_super_bytes_used(&info->super_copy);
1870 btrfs_set_super_bytes_used(&info->super_copy,
1871 super_used - num_bytes);
1872 spin_unlock_irq(&info->delalloc_lock);
1873
1874 /* block accounting for root item */
1875 root_used = btrfs_root_used(&root->root_item);
1876 btrfs_set_root_used(&root->root_item,
1877 root_used - num_bytes);
1878 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1879 num_to_del);
1880 BUG_ON(ret);
1881 btrfs_release_path(extent_root, path);
1882 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1883 mark_free);
1884 BUG_ON(ret);
1885
1886 #ifdef BIO_RW_DISCARD
1887 /* Tell the block device(s) that the sectors can be discarded */
1888 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
1889 bytenr, &map_length, &multi, 0);
1890 if (!ret) {
1891 struct btrfs_bio_stripe *stripe = multi->stripes;
1892 int i;
1893
1894 if (map_length > num_bytes)
1895 map_length = num_bytes;
1896
1897 for (i = 0; i < multi->num_stripes; i++, stripe++) {
1898 blkdev_issue_discard(stripe->dev->bdev,
1899 stripe->physical >> 9,
1900 map_length >> 9);
1901 }
1902 kfree(multi);
1903 }
1904 #endif
1905 }
1906 btrfs_free_path(path);
1907 finish_current_insert(trans, extent_root, 0);
1908 return ret;
1909 }
1910
1911 /*
1912 * find all the blocks marked as pending in the radix tree and remove
1913 * them from the extent map
1914 */
1915 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1916 btrfs_root *extent_root, int all)
1917 {
1918 int ret;
1919 int err = 0;
1920 u64 start;
1921 u64 end;
1922 u64 priv;
1923 u64 search = 0;
1924 struct extent_io_tree *pending_del;
1925 struct extent_io_tree *extent_ins;
1926 struct pending_extent_op *extent_op;
1927 struct btrfs_fs_info *info = extent_root->fs_info;
1928
1929 extent_ins = &extent_root->fs_info->extent_ins;
1930 pending_del = &extent_root->fs_info->pending_del;
1931
1932 while(1) {
1933 mutex_lock(&info->extent_ins_mutex);
1934 ret = find_first_extent_bit(pending_del, search, &start, &end,
1935 EXTENT_WRITEBACK);
1936 if (ret) {
1937 mutex_unlock(&info->extent_ins_mutex);
1938 if (all && search) {
1939 search = 0;
1940 continue;
1941 }
1942 break;
1943 }
1944
1945 ret = try_lock_extent(extent_ins, start, end, GFP_NOFS);
1946 if (!ret) {
1947 search = end+1;
1948 mutex_unlock(&info->extent_ins_mutex);
1949 cond_resched();
1950 continue;
1951 }
1952 BUG_ON(ret < 0);
1953
1954 ret = get_state_private(pending_del, start, &priv);
1955 BUG_ON(ret);
1956 extent_op = (struct pending_extent_op *)(unsigned long)priv;
1957
1958 clear_extent_bits(pending_del, start, end, EXTENT_WRITEBACK,
1959 GFP_NOFS);
1960 if (!test_range_bit(extent_ins, start, end,
1961 EXTENT_WRITEBACK, 0)) {
1962 mutex_unlock(&info->extent_ins_mutex);
1963 free_extent:
1964 ret = __free_extent(trans, extent_root,
1965 start, end + 1 - start,
1966 extent_op->orig_parent,
1967 extent_root->root_key.objectid,
1968 extent_op->orig_generation,
1969 extent_op->level, 1, 0);
1970 kfree(extent_op);
1971 } else {
1972 kfree(extent_op);
1973
1974 ret = get_state_private(&info->extent_ins, start,
1975 &priv);
1976 BUG_ON(ret);
1977 extent_op = (struct pending_extent_op *)
1978 (unsigned long)priv;
1979
1980 clear_extent_bits(&info->extent_ins, start, end,
1981 EXTENT_WRITEBACK, GFP_NOFS);
1982
1983 mutex_unlock(&info->extent_ins_mutex);
1984
1985 if (extent_op->type == PENDING_BACKREF_UPDATE)
1986 goto free_extent;
1987
1988 mutex_lock(&extent_root->fs_info->pinned_mutex);
1989 ret = pin_down_bytes(trans, extent_root, start,
1990 end + 1 - start, 0);
1991 mutex_unlock(&extent_root->fs_info->pinned_mutex);
1992
1993 ret = update_block_group(trans, extent_root, start,
1994 end + 1 - start, 0, ret > 0);
1995
1996 BUG_ON(ret);
1997 kfree(extent_op);
1998 }
1999 if (ret)
2000 err = ret;
2001 unlock_extent(extent_ins, start, end, GFP_NOFS);
2002
2003 if (all)
2004 search = 0;
2005 else
2006 search = end + 1;
2007 cond_resched();
2008 }
2009 return err;
2010 }
2011
2012 /*
2013 * remove an extent from the root, returns 0 on success
2014 */
2015 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
2016 struct btrfs_root *root,
2017 u64 bytenr, u64 num_bytes, u64 parent,
2018 u64 root_objectid, u64 ref_generation,
2019 u64 owner_objectid, int pin)
2020 {
2021 struct btrfs_root *extent_root = root->fs_info->extent_root;
2022 int pending_ret;
2023 int ret;
2024
2025 WARN_ON(num_bytes < root->sectorsize);
2026 if (root == extent_root) {
2027 struct pending_extent_op *extent_op;
2028
2029 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2030 BUG_ON(!extent_op);
2031
2032 extent_op->type = PENDING_EXTENT_DELETE;
2033 extent_op->bytenr = bytenr;
2034 extent_op->num_bytes = num_bytes;
2035 extent_op->parent = parent;
2036 extent_op->orig_parent = parent;
2037 extent_op->generation = ref_generation;
2038 extent_op->orig_generation = ref_generation;
2039 extent_op->level = (int)owner_objectid;
2040
2041 mutex_lock(&root->fs_info->extent_ins_mutex);
2042 set_extent_bits(&root->fs_info->pending_del,
2043 bytenr, bytenr + num_bytes - 1,
2044 EXTENT_WRITEBACK, GFP_NOFS);
2045 set_state_private(&root->fs_info->pending_del,
2046 bytenr, (unsigned long)extent_op);
2047 mutex_unlock(&root->fs_info->extent_ins_mutex);
2048 return 0;
2049 }
2050 /* if metadata always pin */
2051 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
2052 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2053 struct btrfs_block_group_cache *cache;
2054
2055 /* btrfs_free_reserved_extent */
2056 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
2057 BUG_ON(!cache);
2058 btrfs_add_free_space(cache, bytenr, num_bytes);
2059 update_reserved_extents(root, bytenr, num_bytes, 0);
2060 return 0;
2061 }
2062 pin = 1;
2063 }
2064
2065 /* if data pin when any transaction has committed this */
2066 if (ref_generation != trans->transid)
2067 pin = 1;
2068
2069 ret = __free_extent(trans, root, bytenr, num_bytes, parent,
2070 root_objectid, ref_generation,
2071 owner_objectid, pin, pin == 0);
2072
2073 finish_current_insert(trans, root->fs_info->extent_root, 0);
2074 pending_ret = del_pending_extents(trans, root->fs_info->extent_root, 0);
2075 return ret ? ret : pending_ret;
2076 }
2077
2078 int btrfs_free_extent(struct btrfs_trans_handle *trans,
2079 struct btrfs_root *root,
2080 u64 bytenr, u64 num_bytes, u64 parent,
2081 u64 root_objectid, u64 ref_generation,
2082 u64 owner_objectid, int pin)
2083 {
2084 int ret;
2085
2086 ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent,
2087 root_objectid, ref_generation,
2088 owner_objectid, pin);
2089 return ret;
2090 }
2091
2092 static u64 stripe_align(struct btrfs_root *root, u64 val)
2093 {
2094 u64 mask = ((u64)root->stripesize - 1);
2095 u64 ret = (val + mask) & ~mask;
2096 return ret;
2097 }
2098
2099 /*
2100 * walks the btree of allocated extents and find a hole of a given size.
2101 * The key ins is changed to record the hole:
2102 * ins->objectid == block start
2103 * ins->flags = BTRFS_EXTENT_ITEM_KEY
2104 * ins->offset == number of blocks
2105 * Any available blocks before search_start are skipped.
2106 */
2107 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
2108 struct btrfs_root *orig_root,
2109 u64 num_bytes, u64 empty_size,
2110 u64 search_start, u64 search_end,
2111 u64 hint_byte, struct btrfs_key *ins,
2112 u64 exclude_start, u64 exclude_nr,
2113 int data)
2114 {
2115 int ret = 0;
2116 struct btrfs_root * root = orig_root->fs_info->extent_root;
2117 u64 total_needed = num_bytes;
2118 u64 *last_ptr = NULL;
2119 u64 last_wanted = 0;
2120 struct btrfs_block_group_cache *block_group = NULL;
2121 int chunk_alloc_done = 0;
2122 int empty_cluster = 2 * 1024 * 1024;
2123 int allowed_chunk_alloc = 0;
2124 struct list_head *head = NULL, *cur = NULL;
2125 int loop = 0;
2126 int extra_loop = 0;
2127 struct btrfs_space_info *space_info;
2128
2129 WARN_ON(num_bytes < root->sectorsize);
2130 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
2131 ins->objectid = 0;
2132 ins->offset = 0;
2133
2134 if (orig_root->ref_cows || empty_size)
2135 allowed_chunk_alloc = 1;
2136
2137 if (data & BTRFS_BLOCK_GROUP_METADATA) {
2138 last_ptr = &root->fs_info->last_alloc;
2139 empty_cluster = 64 * 1024;
2140 }
2141
2142 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
2143 last_ptr = &root->fs_info->last_data_alloc;
2144
2145 if (last_ptr) {
2146 if (*last_ptr) {
2147 hint_byte = *last_ptr;
2148 last_wanted = *last_ptr;
2149 } else
2150 empty_size += empty_cluster;
2151 } else {
2152 empty_cluster = 0;
2153 }
2154 search_start = max(search_start, first_logical_byte(root, 0));
2155 search_start = max(search_start, hint_byte);
2156
2157 if (last_wanted && search_start != last_wanted) {
2158 last_wanted = 0;
2159 empty_size += empty_cluster;
2160 }
2161
2162 total_needed += empty_size;
2163 block_group = btrfs_lookup_block_group(root->fs_info, search_start);
2164 if (!block_group)
2165 block_group = btrfs_lookup_first_block_group(root->fs_info,
2166 search_start);
2167 space_info = __find_space_info(root->fs_info, data);
2168
2169 down_read(&space_info->groups_sem);
2170 while (1) {
2171 struct btrfs_free_space *free_space;
2172 /*
2173 * the only way this happens if our hint points to a block
2174 * group thats not of the proper type, while looping this
2175 * should never happen
2176 */
2177 if (!block_group)
2178 goto new_group_no_lock;
2179
2180 mutex_lock(&block_group->alloc_mutex);
2181 if (unlikely(!block_group_bits(block_group, data)))
2182 goto new_group;
2183
2184 ret = cache_block_group(root, block_group);
2185 if (ret) {
2186 mutex_unlock(&block_group->alloc_mutex);
2187 break;
2188 }
2189
2190 if (block_group->ro)
2191 goto new_group;
2192
2193 free_space = btrfs_find_free_space(block_group, search_start,
2194 total_needed);
2195 if (empty_size)
2196 extra_loop = 1;
2197
2198 if (free_space) {
2199 u64 start = block_group->key.objectid;
2200 u64 end = block_group->key.objectid +
2201 block_group->key.offset;
2202
2203 search_start = stripe_align(root, free_space->offset);
2204
2205 /* move on to the next group */
2206 if (search_start + num_bytes >= search_end)
2207 goto new_group;
2208
2209 /* move on to the next group */
2210 if (search_start + num_bytes > end)
2211 goto new_group;
2212
2213 if (last_wanted && search_start != last_wanted) {
2214 total_needed += empty_cluster;
2215 last_wanted = 0;
2216 /*
2217 * if search_start is still in this block group
2218 * then we just re-search this block group
2219 */
2220 if (search_start >= start &&
2221 search_start < end) {
2222 mutex_unlock(&block_group->alloc_mutex);
2223 continue;
2224 }
2225
2226 /* else we go to the next block group */
2227 goto new_group;
2228 }
2229
2230 if (exclude_nr > 0 &&
2231 (search_start + num_bytes > exclude_start &&
2232 search_start < exclude_start + exclude_nr)) {
2233 search_start = exclude_start + exclude_nr;
2234 /*
2235 * if search_start is still in this block group
2236 * then we just re-search this block group
2237 */
2238 if (search_start >= start &&
2239 search_start < end) {
2240 mutex_unlock(&block_group->alloc_mutex);
2241 last_wanted = 0;
2242 continue;
2243 }
2244
2245 /* else we go to the next block group */
2246 goto new_group;
2247 }
2248
2249 ins->objectid = search_start;
2250 ins->offset = num_bytes;
2251
2252 btrfs_remove_free_space_lock(block_group, search_start,
2253 num_bytes);
2254 /* we are all good, lets return */
2255 mutex_unlock(&block_group->alloc_mutex);
2256 break;
2257 }
2258 new_group:
2259 mutex_unlock(&block_group->alloc_mutex);
2260 new_group_no_lock:
2261 /* don't try to compare new allocations against the
2262 * last allocation any more
2263 */
2264 last_wanted = 0;
2265
2266 /*
2267 * Here's how this works.
2268 * loop == 0: we were searching a block group via a hint
2269 * and didn't find anything, so we start at
2270 * the head of the block groups and keep searching
2271 * loop == 1: we're searching through all of the block groups
2272 * if we hit the head again we have searched
2273 * all of the block groups for this space and we
2274 * need to try and allocate, if we cant error out.
2275 * loop == 2: we allocated more space and are looping through
2276 * all of the block groups again.
2277 */
2278 if (loop == 0) {
2279 head = &space_info->block_groups;
2280 cur = head->next;
2281 loop++;
2282 } else if (loop == 1 && cur == head) {
2283 int keep_going;
2284
2285 /* at this point we give up on the empty_size
2286 * allocations and just try to allocate the min
2287 * space.
2288 *
2289 * The extra_loop field was set if an empty_size
2290 * allocation was attempted above, and if this
2291 * is try we need to try the loop again without
2292 * the additional empty_size.
2293 */
2294 total_needed -= empty_size;
2295 empty_size = 0;
2296 keep_going = extra_loop;
2297 loop++;
2298
2299 if (allowed_chunk_alloc && !chunk_alloc_done) {
2300 up_read(&space_info->groups_sem);
2301 ret = do_chunk_alloc(trans, root, num_bytes +
2302 2 * 1024 * 1024, data, 1);
2303 if (ret < 0)
2304 break;
2305 down_read(&space_info->groups_sem);
2306 head = &space_info->block_groups;
2307 /*
2308 * we've allocated a new chunk, keep
2309 * trying
2310 */
2311 keep_going = 1;
2312 chunk_alloc_done = 1;
2313 } else if (!allowed_chunk_alloc) {
2314 space_info->force_alloc = 1;
2315 }
2316 if (keep_going) {
2317 cur = head->next;
2318 extra_loop = 0;
2319 } else {
2320 break;
2321 }
2322 } else if (cur == head) {
2323 break;
2324 }
2325
2326 block_group = list_entry(cur, struct btrfs_block_group_cache,
2327 list);
2328 search_start = block_group->key.objectid;
2329 cur = cur->next;
2330 }
2331
2332 /* we found what we needed */
2333 if (ins->objectid) {
2334 if (!(data & BTRFS_BLOCK_GROUP_DATA))
2335 trans->block_group = block_group;
2336
2337 if (last_ptr)
2338 *last_ptr = ins->objectid + ins->offset;
2339 ret = 0;
2340 } else if (!ret) {
2341 ret = -ENOSPC;
2342 }
2343
2344 up_read(&space_info->groups_sem);
2345 return ret;
2346 }
2347
2348 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
2349 {
2350 struct btrfs_block_group_cache *cache;
2351 struct list_head *l;
2352
2353 printk(KERN_INFO "space_info has %Lu free, is %sfull\n",
2354 info->total_bytes - info->bytes_used - info->bytes_pinned -
2355 info->bytes_reserved, (info->full) ? "" : "not ");
2356
2357 down_read(&info->groups_sem);
2358 list_for_each(l, &info->block_groups) {
2359 cache = list_entry(l, struct btrfs_block_group_cache, list);
2360 spin_lock(&cache->lock);
2361 printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used "
2362 "%Lu pinned %Lu reserved\n",
2363 cache->key.objectid, cache->key.offset,
2364 btrfs_block_group_used(&cache->item),
2365 cache->pinned, cache->reserved);
2366 btrfs_dump_free_space(cache, bytes);
2367 spin_unlock(&cache->lock);
2368 }
2369 up_read(&info->groups_sem);
2370 }
2371
2372 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2373 struct btrfs_root *root,
2374 u64 num_bytes, u64 min_alloc_size,
2375 u64 empty_size, u64 hint_byte,
2376 u64 search_end, struct btrfs_key *ins,
2377 u64 data)
2378 {
2379 int ret;
2380 u64 search_start = 0;
2381 u64 alloc_profile;
2382 struct btrfs_fs_info *info = root->fs_info;
2383
2384 if (data) {
2385 alloc_profile = info->avail_data_alloc_bits &
2386 info->data_alloc_profile;
2387 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2388 } else if (root == root->fs_info->chunk_root) {
2389 alloc_profile = info->avail_system_alloc_bits &
2390 info->system_alloc_profile;
2391 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2392 } else {
2393 alloc_profile = info->avail_metadata_alloc_bits &
2394 info->metadata_alloc_profile;
2395 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2396 }
2397 again:
2398 data = reduce_alloc_profile(root, data);
2399 /*
2400 * the only place that sets empty_size is btrfs_realloc_node, which
2401 * is not called recursively on allocations
2402 */
2403 if (empty_size || root->ref_cows) {
2404 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
2405 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2406 2 * 1024 * 1024,
2407 BTRFS_BLOCK_GROUP_METADATA |
2408 (info->metadata_alloc_profile &
2409 info->avail_metadata_alloc_bits), 0);
2410 }
2411 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2412 num_bytes + 2 * 1024 * 1024, data, 0);
2413 }
2414
2415 WARN_ON(num_bytes < root->sectorsize);
2416 ret = find_free_extent(trans, root, num_bytes, empty_size,
2417 search_start, search_end, hint_byte, ins,
2418 trans->alloc_exclude_start,
2419 trans->alloc_exclude_nr, data);
2420
2421 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
2422 num_bytes = num_bytes >> 1;
2423 num_bytes = num_bytes & ~(root->sectorsize - 1);
2424 num_bytes = max(num_bytes, min_alloc_size);
2425 do_chunk_alloc(trans, root->fs_info->extent_root,
2426 num_bytes, data, 1);
2427 goto again;
2428 }
2429 if (ret) {
2430 struct btrfs_space_info *sinfo;
2431
2432 sinfo = __find_space_info(root->fs_info, data);
2433 printk("allocation failed flags %Lu, wanted %Lu\n",
2434 data, num_bytes);
2435 dump_space_info(sinfo, num_bytes);
2436 BUG();
2437 }
2438
2439 return ret;
2440 }
2441
2442 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
2443 {
2444 struct btrfs_block_group_cache *cache;
2445
2446 cache = btrfs_lookup_block_group(root->fs_info, start);
2447 if (!cache) {
2448 printk(KERN_ERR "Unable to find block group for %Lu\n", start);
2449 return -ENOSPC;
2450 }
2451 btrfs_add_free_space(cache, start, len);
2452 update_reserved_extents(root, start, len, 0);
2453 return 0;
2454 }
2455
2456 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2457 struct btrfs_root *root,
2458 u64 num_bytes, u64 min_alloc_size,
2459 u64 empty_size, u64 hint_byte,
2460 u64 search_end, struct btrfs_key *ins,
2461 u64 data)
2462 {
2463 int ret;
2464 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
2465 empty_size, hint_byte, search_end, ins,
2466 data);
2467 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2468 return ret;
2469 }
2470
2471 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2472 struct btrfs_root *root, u64 parent,
2473 u64 root_objectid, u64 ref_generation,
2474 u64 owner, struct btrfs_key *ins)
2475 {
2476 int ret;
2477 int pending_ret;
2478 u64 super_used;
2479 u64 root_used;
2480 u64 num_bytes = ins->offset;
2481 u32 sizes[2];
2482 struct btrfs_fs_info *info = root->fs_info;
2483 struct btrfs_root *extent_root = info->extent_root;
2484 struct btrfs_extent_item *extent_item;
2485 struct btrfs_extent_ref *ref;
2486 struct btrfs_path *path;
2487 struct btrfs_key keys[2];
2488
2489 if (parent == 0)
2490 parent = ins->objectid;
2491
2492 /* block accounting for super block */
2493 spin_lock_irq(&info->delalloc_lock);
2494 super_used = btrfs_super_bytes_used(&info->super_copy);
2495 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
2496 spin_unlock_irq(&info->delalloc_lock);
2497
2498 /* block accounting for root item */
2499 root_used = btrfs_root_used(&root->root_item);
2500 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
2501
2502 if (root == extent_root) {
2503 struct pending_extent_op *extent_op;
2504
2505 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2506 BUG_ON(!extent_op);
2507
2508 extent_op->type = PENDING_EXTENT_INSERT;
2509 extent_op->bytenr = ins->objectid;
2510 extent_op->num_bytes = ins->offset;
2511 extent_op->parent = parent;
2512 extent_op->orig_parent = 0;
2513 extent_op->generation = ref_generation;
2514 extent_op->orig_generation = 0;
2515 extent_op->level = (int)owner;
2516
2517 mutex_lock(&root->fs_info->extent_ins_mutex);
2518 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2519 ins->objectid + ins->offset - 1,
2520 EXTENT_WRITEBACK, GFP_NOFS);
2521 set_state_private(&root->fs_info->extent_ins,
2522 ins->objectid, (unsigned long)extent_op);
2523 mutex_unlock(&root->fs_info->extent_ins_mutex);
2524 goto update_block;
2525 }
2526
2527 memcpy(&keys[0], ins, sizeof(*ins));
2528 keys[1].objectid = ins->objectid;
2529 keys[1].type = BTRFS_EXTENT_REF_KEY;
2530 keys[1].offset = parent;
2531 sizes[0] = sizeof(*extent_item);
2532 sizes[1] = sizeof(*ref);
2533
2534 path = btrfs_alloc_path();
2535 BUG_ON(!path);
2536
2537 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
2538 sizes, 2);
2539 BUG_ON(ret);
2540
2541 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2542 struct btrfs_extent_item);
2543 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
2544 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
2545 struct btrfs_extent_ref);
2546
2547 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
2548 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
2549 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
2550 btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
2551
2552 btrfs_mark_buffer_dirty(path->nodes[0]);
2553
2554 trans->alloc_exclude_start = 0;
2555 trans->alloc_exclude_nr = 0;
2556 btrfs_free_path(path);
2557 finish_current_insert(trans, extent_root, 0);
2558 pending_ret = del_pending_extents(trans, extent_root, 0);
2559
2560 if (ret)
2561 goto out;
2562 if (pending_ret) {
2563 ret = pending_ret;
2564 goto out;
2565 }
2566
2567 update_block:
2568 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
2569 if (ret) {
2570 printk("update block group failed for %Lu %Lu\n",
2571 ins->objectid, ins->offset);
2572 BUG();
2573 }
2574 out:
2575 return ret;
2576 }
2577
2578 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2579 struct btrfs_root *root, u64 parent,
2580 u64 root_objectid, u64 ref_generation,
2581 u64 owner, struct btrfs_key *ins)
2582 {
2583 int ret;
2584
2585 if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
2586 return 0;
2587 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
2588 ref_generation, owner, ins);
2589 update_reserved_extents(root, ins->objectid, ins->offset, 0);
2590 return ret;
2591 }
2592
2593 /*
2594 * this is used by the tree logging recovery code. It records that
2595 * an extent has been allocated and makes sure to clear the free
2596 * space cache bits as well
2597 */
2598 int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
2599 struct btrfs_root *root, u64 parent,
2600 u64 root_objectid, u64 ref_generation,
2601 u64 owner, struct btrfs_key *ins)
2602 {
2603 int ret;
2604 struct btrfs_block_group_cache *block_group;
2605
2606 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2607 mutex_lock(&block_group->alloc_mutex);
2608 cache_block_group(root, block_group);
2609
2610 ret = btrfs_remove_free_space_lock(block_group, ins->objectid,
2611 ins->offset);
2612 mutex_unlock(&block_group->alloc_mutex);
2613 BUG_ON(ret);
2614 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
2615 ref_generation, owner, ins);
2616 return ret;
2617 }
2618
2619 /*
2620 * finds a free extent and does all the dirty work required for allocation
2621 * returns the key for the extent through ins, and a tree buffer for
2622 * the first block of the extent through buf.
2623 *
2624 * returns 0 if everything worked, non-zero otherwise.
2625 */
2626 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
2627 struct btrfs_root *root,
2628 u64 num_bytes, u64 parent, u64 min_alloc_size,
2629 u64 root_objectid, u64 ref_generation,
2630 u64 owner_objectid, u64 empty_size, u64 hint_byte,
2631 u64 search_end, struct btrfs_key *ins, u64 data)
2632 {
2633 int ret;
2634
2635 ret = __btrfs_reserve_extent(trans, root, num_bytes,
2636 min_alloc_size, empty_size, hint_byte,
2637 search_end, ins, data);
2638 BUG_ON(ret);
2639 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
2640 ret = __btrfs_alloc_reserved_extent(trans, root, parent,
2641 root_objectid, ref_generation,
2642 owner_objectid, ins);
2643 BUG_ON(ret);
2644
2645 } else {
2646 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2647 }
2648 return ret;
2649 }
2650
2651 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
2652 struct btrfs_root *root,
2653 u64 bytenr, u32 blocksize)
2654 {
2655 struct extent_buffer *buf;
2656
2657 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
2658 if (!buf)
2659 return ERR_PTR(-ENOMEM);
2660 btrfs_set_header_generation(buf, trans->transid);
2661 btrfs_tree_lock(buf);
2662 clean_tree_block(trans, root, buf);
2663 btrfs_set_buffer_uptodate(buf);
2664 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2665 set_extent_dirty(&root->dirty_log_pages, buf->start,
2666 buf->start + buf->len - 1, GFP_NOFS);
2667 } else {
2668 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
2669 buf->start + buf->len - 1, GFP_NOFS);
2670 }
2671 trans->blocks_used++;
2672 return buf;
2673 }
2674
2675 /*
2676 * helper function to allocate a block for a given tree
2677 * returns the tree buffer or NULL.
2678 */
2679 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2680 struct btrfs_root *root,
2681 u32 blocksize, u64 parent,
2682 u64 root_objectid,
2683 u64 ref_generation,
2684 int level,
2685 u64 hint,
2686 u64 empty_size)
2687 {
2688 struct btrfs_key ins;
2689 int ret;
2690 struct extent_buffer *buf;
2691
2692 ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
2693 root_objectid, ref_generation, level,
2694 empty_size, hint, (u64)-1, &ins, 0);
2695 if (ret) {
2696 BUG_ON(ret > 0);
2697 return ERR_PTR(ret);
2698 }
2699
2700 buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
2701 return buf;
2702 }
2703
2704 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
2705 struct btrfs_root *root, struct extent_buffer *leaf)
2706 {
2707 u64 leaf_owner;
2708 u64 leaf_generation;
2709 struct btrfs_key key;
2710 struct btrfs_file_extent_item *fi;
2711 int i;
2712 int nritems;
2713 int ret;
2714
2715 BUG_ON(!btrfs_is_leaf(leaf));
2716 nritems = btrfs_header_nritems(leaf);
2717 leaf_owner = btrfs_header_owner(leaf);
2718 leaf_generation = btrfs_header_generation(leaf);
2719
2720 for (i = 0; i < nritems; i++) {
2721 u64 disk_bytenr;
2722 cond_resched();
2723
2724 btrfs_item_key_to_cpu(leaf, &key, i);
2725 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2726 continue;
2727 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2728 if (btrfs_file_extent_type(leaf, fi) ==
2729 BTRFS_FILE_EXTENT_INLINE)
2730 continue;
2731 /*
2732 * FIXME make sure to insert a trans record that
2733 * repeats the snapshot del on crash
2734 */
2735 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2736 if (disk_bytenr == 0)
2737 continue;
2738
2739 ret = __btrfs_free_extent(trans, root, disk_bytenr,
2740 btrfs_file_extent_disk_num_bytes(leaf, fi),
2741 leaf->start, leaf_owner, leaf_generation,
2742 key.objectid, 0);
2743 BUG_ON(ret);
2744
2745 atomic_inc(&root->fs_info->throttle_gen);
2746 wake_up(&root->fs_info->transaction_throttle);
2747 cond_resched();
2748 }
2749 return 0;
2750 }
2751
2752 static int noinline cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
2753 struct btrfs_root *root,
2754 struct btrfs_leaf_ref *ref)
2755 {
2756 int i;
2757 int ret;
2758 struct btrfs_extent_info *info = ref->extents;
2759
2760 for (i = 0; i < ref->nritems; i++) {
2761 ret = __btrfs_free_extent(trans, root, info->bytenr,
2762 info->num_bytes, ref->bytenr,
2763 ref->owner, ref->generation,
2764 info->objectid, 0);
2765
2766 atomic_inc(&root->fs_info->throttle_gen);
2767 wake_up(&root->fs_info->transaction_throttle);
2768 cond_resched();
2769
2770 BUG_ON(ret);
2771 info++;
2772 }
2773
2774 return 0;
2775 }
2776
2777 int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len,
2778 u32 *refs)
2779 {
2780 int ret;
2781
2782 ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
2783 BUG_ON(ret);
2784
2785 #if 0 // some debugging code in case we see problems here
2786 /* if the refs count is one, it won't get increased again. But
2787 * if the ref count is > 1, someone may be decreasing it at
2788 * the same time we are.
2789 */
2790 if (*refs != 1) {
2791 struct extent_buffer *eb = NULL;
2792 eb = btrfs_find_create_tree_block(root, start, len);
2793 if (eb)
2794 btrfs_tree_lock(eb);
2795
2796 mutex_lock(&root->fs_info->alloc_mutex);
2797 ret = lookup_extent_ref(NULL, root, start, len, refs);
2798 BUG_ON(ret);
2799 mutex_unlock(&root->fs_info->alloc_mutex);
2800
2801 if (eb) {
2802 btrfs_tree_unlock(eb);
2803 free_extent_buffer(eb);
2804 }
2805 if (*refs == 1) {
2806 printk("block %llu went down to one during drop_snap\n",
2807 (unsigned long long)start);
2808 }
2809
2810 }
2811 #endif
2812
2813 cond_resched();
2814 return ret;
2815 }
2816
2817 /*
2818 * helper function for drop_snapshot, this walks down the tree dropping ref
2819 * counts as it goes.
2820 */
2821 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2822 struct btrfs_root *root,
2823 struct btrfs_path *path, int *level)
2824 {
2825 u64 root_owner;
2826 u64 root_gen;
2827 u64 bytenr;
2828 u64 ptr_gen;
2829 struct extent_buffer *next;
2830 struct extent_buffer *cur;
2831 struct extent_buffer *parent;
2832 struct btrfs_leaf_ref *ref;
2833 u32 blocksize;
2834 int ret;
2835 u32 refs;
2836
2837 WARN_ON(*level < 0);
2838 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2839 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
2840 path->nodes[*level]->len, &refs);
2841 BUG_ON(ret);
2842 if (refs > 1)
2843 goto out;
2844
2845 /*
2846 * walk down to the last node level and free all the leaves
2847 */
2848 while(*level >= 0) {
2849 WARN_ON(*level < 0);
2850 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2851 cur = path->nodes[*level];
2852
2853 if (btrfs_header_level(cur) != *level)
2854 WARN_ON(1);
2855
2856 if (path->slots[*level] >=
2857 btrfs_header_nritems(cur))
2858 break;
2859 if (*level == 0) {
2860 ret = btrfs_drop_leaf_ref(trans, root, cur);
2861 BUG_ON(ret);
2862 break;
2863 }
2864 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2865 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2866 blocksize = btrfs_level_size(root, *level - 1);
2867
2868 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
2869 BUG_ON(ret);
2870 if (refs != 1) {
2871 parent = path->nodes[*level];
2872 root_owner = btrfs_header_owner(parent);
2873 root_gen = btrfs_header_generation(parent);
2874 path->slots[*level]++;
2875
2876 ret = __btrfs_free_extent(trans, root, bytenr,
2877 blocksize, parent->start,
2878 root_owner, root_gen,
2879 *level - 1, 1);
2880 BUG_ON(ret);
2881
2882 atomic_inc(&root->fs_info->throttle_gen);
2883 wake_up(&root->fs_info->transaction_throttle);
2884 cond_resched();
2885
2886 continue;
2887 }
2888 /*
2889 * at this point, we have a single ref, and since the
2890 * only place referencing this extent is a dead root
2891 * the reference count should never go higher.
2892 * So, we don't need to check it again
2893 */
2894 if (*level == 1) {
2895 ref = btrfs_lookup_leaf_ref(root, bytenr);
2896 if (ref && ref->generation != ptr_gen) {
2897 btrfs_free_leaf_ref(root, ref);
2898 ref = NULL;
2899 }
2900 if (ref) {
2901 ret = cache_drop_leaf_ref(trans, root, ref);
2902 BUG_ON(ret);
2903 btrfs_remove_leaf_ref(root, ref);
2904 btrfs_free_leaf_ref(root, ref);
2905 *level = 0;
2906 break;
2907 }
2908 if (printk_ratelimit()) {
2909 printk("leaf ref miss for bytenr %llu\n",
2910 (unsigned long long)bytenr);
2911 }
2912 }
2913 next = btrfs_find_tree_block(root, bytenr, blocksize);
2914 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2915 free_extent_buffer(next);
2916
2917 next = read_tree_block(root, bytenr, blocksize,
2918 ptr_gen);
2919 cond_resched();
2920 #if 0
2921 /*
2922 * this is a debugging check and can go away
2923 * the ref should never go all the way down to 1
2924 * at this point
2925 */
2926 ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
2927 &refs);
2928 BUG_ON(ret);
2929 WARN_ON(refs != 1);
2930 #endif
2931 }
2932 WARN_ON(*level <= 0);
2933 if (path->nodes[*level-1])
2934 free_extent_buffer(path->nodes[*level-1]);
2935 path->nodes[*level-1] = next;
2936 *level = btrfs_header_level(next);
2937 path->slots[*level] = 0;
2938 cond_resched();
2939 }
2940 out:
2941 WARN_ON(*level < 0);
2942 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2943
2944 if (path->nodes[*level] == root->node) {
2945 parent = path->nodes[*level];
2946 bytenr = path->nodes[*level]->start;
2947 } else {
2948 parent = path->nodes[*level + 1];
2949 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
2950 }
2951
2952 blocksize = btrfs_level_size(root, *level);
2953 root_owner = btrfs_header_owner(parent);
2954 root_gen = btrfs_header_generation(parent);
2955
2956 ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
2957 parent->start, root_owner, root_gen,
2958 *level, 1);
2959 free_extent_buffer(path->nodes[*level]);
2960 path->nodes[*level] = NULL;
2961 *level += 1;
2962 BUG_ON(ret);
2963
2964 cond_resched();
2965 return 0;
2966 }
2967
2968 /*
2969 * helper function for drop_subtree, this function is similar to
2970 * walk_down_tree. The main difference is that it checks reference
2971 * counts while tree blocks are locked.
2972 */
2973 static int noinline walk_down_subtree(struct btrfs_trans_handle *trans,
2974 struct btrfs_root *root,
2975 struct btrfs_path *path, int *level)
2976 {
2977 struct extent_buffer *next;
2978 struct extent_buffer *cur;
2979 struct extent_buffer *parent;
2980 u64 bytenr;
2981 u64 ptr_gen;
2982 u32 blocksize;
2983 u32 refs;
2984 int ret;
2985
2986 cur = path->nodes[*level];
2987 ret = btrfs_lookup_extent_ref(trans, root, cur->start, cur->len,
2988 &refs);
2989 BUG_ON(ret);
2990 if (refs > 1)
2991 goto out;
2992
2993 while (*level >= 0) {
2994 cur = path->nodes[*level];
2995 if (*level == 0) {
2996 ret = btrfs_drop_leaf_ref(trans, root, cur);
2997 BUG_ON(ret);
2998 clean_tree_block(trans, root, cur);
2999 break;
3000 }
3001 if (path->slots[*level] >= btrfs_header_nritems(cur)) {
3002 clean_tree_block(trans, root, cur);
3003 break;
3004 }
3005
3006 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
3007 blocksize = btrfs_level_size(root, *level - 1);
3008 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
3009
3010 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
3011 btrfs_tree_lock(next);
3012
3013 ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize,
3014 &refs);
3015 BUG_ON(ret);
3016 if (refs > 1) {
3017 parent = path->nodes[*level];
3018 ret = btrfs_free_extent(trans, root, bytenr,
3019 blocksize, parent->start,
3020 btrfs_header_owner(parent),
3021 btrfs_header_generation(parent),
3022 *level - 1, 1);
3023 BUG_ON(ret);
3024 path->slots[*level]++;
3025 btrfs_tree_unlock(next);
3026 free_extent_buffer(next);
3027 continue;
3028 }
3029
3030 *level = btrfs_header_level(next);
3031 path->nodes[*level] = next;
3032 path->slots[*level] = 0;
3033 path->locks[*level] = 1;
3034 cond_resched();
3035 }
3036 out:
3037 parent = path->nodes[*level + 1];
3038 bytenr = path->nodes[*level]->start;
3039 blocksize = path->nodes[*level]->len;
3040
3041 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
3042 parent->start, btrfs_header_owner(parent),
3043 btrfs_header_generation(parent), *level, 1);
3044 BUG_ON(ret);
3045
3046 if (path->locks[*level]) {
3047 btrfs_tree_unlock(path->nodes[*level]);
3048 path->locks[*level] = 0;
3049 }
3050 free_extent_buffer(path->nodes[*level]);
3051 path->nodes[*level] = NULL;
3052 *level += 1;
3053 cond_resched();
3054 return 0;
3055 }
3056
3057 /*
3058 * helper for dropping snapshots. This walks back up the tree in the path
3059 * to find the first node higher up where we haven't yet gone through
3060 * all the slots
3061 */
3062 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
3063 struct btrfs_root *root,
3064 struct btrfs_path *path,
3065 int *level, int max_level)
3066 {
3067 u64 root_owner;
3068 u64 root_gen;
3069 struct btrfs_root_item *root_item = &root->root_item;
3070 int i;
3071 int slot;
3072 int ret;
3073
3074 for (i = *level; i < max_level && path->nodes[i]; i++) {
3075 slot = path->slots[i];
3076 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
3077 struct extent_buffer *node;
3078 struct btrfs_disk_key disk_key;
3079 node = path->nodes[i];
3080 path->slots[i]++;
3081 *level = i;
3082 WARN_ON(*level == 0);
3083 btrfs_node_key(node, &disk_key, path->slots[i]);
3084 memcpy(&root_item->drop_progress,
3085 &disk_key, sizeof(disk_key));
3086 root_item->drop_level = i;
3087 return 0;
3088 } else {
3089 struct extent_buffer *parent;
3090 if (path->nodes[*level] == root->node)
3091 parent = path->nodes[*level];
3092 else
3093 parent = path->nodes[*level + 1];
3094
3095 root_owner = btrfs_header_owner(parent);
3096 root_gen = btrfs_header_generation(parent);
3097
3098 clean_tree_block(trans, root, path->nodes[*level]);
3099 ret = btrfs_free_extent(trans, root,
3100 path->nodes[*level]->start,
3101 path->nodes[*level]->len,
3102 parent->start, root_owner,
3103 root_gen, *level, 1);
3104 BUG_ON(ret);
3105 if (path->locks[*level]) {
3106 btrfs_tree_unlock(path->nodes[*level]);
3107 path->locks[*level] = 0;
3108 }
3109 free_extent_buffer(path->nodes[*level]);
3110 path->nodes[*level] = NULL;
3111 *level = i + 1;
3112 }
3113 }
3114 return 1;
3115 }
3116
3117 /*
3118 * drop the reference count on the tree rooted at 'snap'. This traverses
3119 * the tree freeing any blocks that have a ref count of zero after being
3120 * decremented.
3121 */
3122 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
3123 *root)
3124 {
3125 int ret = 0;
3126 int wret;
3127 int level;
3128 struct btrfs_path *path;
3129 int i;
3130 int orig_level;
3131 struct btrfs_root_item *root_item = &root->root_item;
3132
3133 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
3134 path = btrfs_alloc_path();
3135 BUG_ON(!path);
3136
3137 level = btrfs_header_level(root->node);
3138 orig_level = level;
3139 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
3140 path->nodes[level] = root->node;
3141 extent_buffer_get(root->node);
3142 path->slots[level] = 0;
3143 } else {
3144 struct btrfs_key key;
3145 struct btrfs_disk_key found_key;
3146 struct extent_buffer *node;
3147
3148 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
3149 level = root_item->drop_level;
3150 path->lowest_level = level;
3151 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3152 if (wret < 0) {
3153 ret = wret;
3154 goto out;
3155 }
3156 node = path->nodes[level];
3157 btrfs_node_key(node, &found_key, path->slots[level]);
3158 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
3159 sizeof(found_key)));
3160 /*
3161 * unlock our path, this is safe because only this
3162 * function is allowed to delete this snapshot
3163 */
3164 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
3165 if (path->nodes[i] && path->locks[i]) {
3166 path->locks[i] = 0;
3167 btrfs_tree_unlock(path->nodes[i]);
3168 }
3169 }
3170 }
3171 while(1) {
3172 wret = walk_down_tree(trans, root, path, &level);
3173 if (wret > 0)
3174 break;
3175 if (wret < 0)
3176 ret = wret;
3177
3178 wret = walk_up_tree(trans, root, path, &level,
3179 BTRFS_MAX_LEVEL);
3180 if (wret > 0)
3181 break;
3182 if (wret < 0)
3183 ret = wret;
3184 if (trans->transaction->in_commit) {
3185 ret = -EAGAIN;
3186 break;
3187 }
3188 atomic_inc(&root->fs_info->throttle_gen);
3189 wake_up(&root->fs_info->transaction_throttle);
3190 }
3191 for (i = 0; i <= orig_level; i++) {
3192 if (path->nodes[i]) {
3193 free_extent_buffer(path->nodes[i]);
3194 path->nodes[i] = NULL;
3195 }
3196 }
3197 out:
3198 btrfs_free_path(path);
3199 return ret;
3200 }
3201
3202 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
3203 struct btrfs_root *root,
3204 struct extent_buffer *node,
3205 struct extent_buffer *parent)
3206 {
3207 struct btrfs_path *path;
3208 int level;
3209 int parent_level;
3210 int ret = 0;
3211 int wret;
3212
3213 path = btrfs_alloc_path();
3214 BUG_ON(!path);
3215
3216 BUG_ON(!btrfs_tree_locked(parent));
3217 parent_level = btrfs_header_level(parent);
3218 extent_buffer_get(parent);
3219 path->nodes[parent_level] = parent;
3220 path->slots[parent_level] = btrfs_header_nritems(parent);
3221
3222 BUG_ON(!btrfs_tree_locked(node));
3223 level = btrfs_header_level(node);
3224 extent_buffer_get(node);
3225 path->nodes[level] = node;
3226 path->slots[level] = 0;
3227
3228 while (1) {
3229 wret = walk_down_subtree(trans, root, path, &level);
3230 if (wret < 0)
3231 ret = wret;
3232 if (wret != 0)
3233 break;
3234
3235 wret = walk_up_tree(trans, root, path, &level, parent_level);
3236 if (wret < 0)
3237 ret = wret;
3238 if (wret != 0)
3239 break;
3240 }
3241
3242 btrfs_free_path(path);
3243 return ret;
3244 }
3245
3246 static unsigned long calc_ra(unsigned long start, unsigned long last,
3247 unsigned long nr)
3248 {
3249 return min(last, start + nr - 1);
3250 }
3251
3252 static int noinline relocate_inode_pages(struct inode *inode, u64 start,
3253 u64 len)
3254 {
3255 u64 page_start;
3256 u64 page_end;
3257 unsigned long first_index;
3258 unsigned long last_index;
3259 unsigned long i;
3260 struct page *page;
3261 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3262 struct file_ra_state *ra;
3263 struct btrfs_ordered_extent *ordered;
3264 unsigned int total_read = 0;
3265 unsigned int total_dirty = 0;
3266 int ret = 0;
3267
3268 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3269
3270 mutex_lock(&inode->i_mutex);
3271 first_index = start >> PAGE_CACHE_SHIFT;
3272 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
3273
3274 /* make sure the dirty trick played by the caller work */
3275 ret = invalidate_inode_pages2_range(inode->i_mapping,
3276 first_index, last_index);
3277 if (ret)
3278 goto out_unlock;
3279
3280 file_ra_state_init(ra, inode->i_mapping);
3281
3282 for (i = first_index ; i <= last_index; i++) {
3283 if (total_read % ra->ra_pages == 0) {
3284 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
3285 calc_ra(i, last_index, ra->ra_pages));
3286 }
3287 total_read++;
3288 again:
3289 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
3290 BUG_ON(1);
3291 page = grab_cache_page(inode->i_mapping, i);
3292 if (!page) {
3293 ret = -ENOMEM;
3294 goto out_unlock;
3295 }
3296 if (!PageUptodate(page)) {
3297 btrfs_readpage(NULL, page);
3298 lock_page(page);
3299 if (!PageUptodate(page)) {
3300 unlock_page(page);
3301 page_cache_release(page);
3302 ret = -EIO;
3303 goto out_unlock;
3304 }
3305 }
3306 wait_on_page_writeback(page);
3307
3308 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
3309 page_end = page_start + PAGE_CACHE_SIZE - 1;
3310 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
3311
3312 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3313 if (ordered) {
3314 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3315 unlock_page(page);
3316 page_cache_release(page);
3317 btrfs_start_ordered_extent(inode, ordered, 1);
3318 btrfs_put_ordered_extent(ordered);
3319 goto again;
3320 }
3321 set_page_extent_mapped(page);
3322
3323 btrfs_set_extent_delalloc(inode, page_start, page_end);
3324 if (i == first_index)
3325 set_extent_bits(io_tree, page_start, page_end,
3326 EXTENT_BOUNDARY, GFP_NOFS);
3327
3328 set_page_dirty(page);
3329 total_dirty++;
3330
3331 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3332 unlock_page(page);
3333 page_cache_release(page);
3334 }
3335
3336 out_unlock:
3337 kfree(ra);
3338 mutex_unlock(&inode->i_mutex);
3339 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
3340 return ret;
3341 }
3342
3343 static int noinline relocate_data_extent(struct inode *reloc_inode,
3344 struct btrfs_key *extent_key,
3345 u64 offset)
3346 {
3347 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3348 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
3349 struct extent_map *em;
3350 u64 start = extent_key->objectid - offset;
3351 u64 end = start + extent_key->offset - 1;
3352
3353 em = alloc_extent_map(GFP_NOFS);
3354 BUG_ON(!em || IS_ERR(em));
3355
3356 em->start = start;
3357 em->len = extent_key->offset;
3358 em->block_len = extent_key->offset;
3359 em->block_start = extent_key->objectid;
3360 em->bdev = root->fs_info->fs_devices->latest_bdev;
3361 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3362
3363 /* setup extent map to cheat btrfs_readpage */
3364 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
3365 while (1) {
3366 int ret;
3367 spin_lock(&em_tree->lock);
3368 ret = add_extent_mapping(em_tree, em);
3369 spin_unlock(&em_tree->lock);
3370 if (ret != -EEXIST) {
3371 free_extent_map(em);
3372 break;
3373 }
3374 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
3375 }
3376 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
3377
3378 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
3379 }
3380
3381 struct btrfs_ref_path {
3382 u64 extent_start;
3383 u64 nodes[BTRFS_MAX_LEVEL];
3384 u64 root_objectid;
3385 u64 root_generation;
3386 u64 owner_objectid;
3387 u32 num_refs;
3388 int lowest_level;
3389 int current_level;
3390 int shared_level;
3391
3392 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
3393 u64 new_nodes[BTRFS_MAX_LEVEL];
3394 };
3395
3396 struct disk_extent {
3397 u64 ram_bytes;
3398 u64 disk_bytenr;
3399 u64 disk_num_bytes;
3400 u64 offset;
3401 u64 num_bytes;
3402 u8 compression;
3403 u8 encryption;
3404 u16 other_encoding;
3405 };
3406
3407 static int is_cowonly_root(u64 root_objectid)
3408 {
3409 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
3410 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
3411 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
3412 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
3413 root_objectid == BTRFS_TREE_LOG_OBJECTID)
3414 return 1;
3415 return 0;
3416 }
3417
3418 static int noinline __next_ref_path(struct btrfs_trans_handle *trans,
3419 struct btrfs_root *extent_root,
3420 struct btrfs_ref_path *ref_path,
3421 int first_time)
3422 {
3423 struct extent_buffer *leaf;
3424 struct btrfs_path *path;
3425 struct btrfs_extent_ref *ref;
3426 struct btrfs_key key;
3427 struct btrfs_key found_key;
3428 u64 bytenr;
3429 u32 nritems;
3430 int level;
3431 int ret = 1;
3432
3433 path = btrfs_alloc_path();
3434 if (!path)
3435 return -ENOMEM;
3436
3437 if (first_time) {
3438 ref_path->lowest_level = -1;
3439 ref_path->current_level = -1;
3440 ref_path->shared_level = -1;
3441 goto walk_up;
3442 }
3443 walk_down:
3444 level = ref_path->current_level - 1;
3445 while (level >= -1) {
3446 u64 parent;
3447 if (level < ref_path->lowest_level)
3448 break;
3449
3450 if (level >= 0) {
3451 bytenr = ref_path->nodes[level];
3452 } else {
3453 bytenr = ref_path->extent_start;
3454 }
3455 BUG_ON(bytenr == 0);
3456
3457 parent = ref_path->nodes[level + 1];
3458 ref_path->nodes[level + 1] = 0;
3459 ref_path->current_level = level;
3460 BUG_ON(parent == 0);
3461
3462 key.objectid = bytenr;
3463 key.offset = parent + 1;
3464 key.type = BTRFS_EXTENT_REF_KEY;
3465
3466 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3467 if (ret < 0)
3468 goto out;
3469 BUG_ON(ret == 0);
3470
3471 leaf = path->nodes[0];
3472 nritems = btrfs_header_nritems(leaf);
3473 if (path->slots[0] >= nritems) {
3474 ret = btrfs_next_leaf(extent_root, path);
3475 if (ret < 0)
3476 goto out;
3477 if (ret > 0)
3478 goto next;
3479 leaf = path->nodes[0];
3480 }
3481
3482 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3483 if (found_key.objectid == bytenr &&
3484 found_key.type == BTRFS_EXTENT_REF_KEY) {
3485 if (level < ref_path->shared_level)
3486 ref_path->shared_level = level;
3487 goto found;
3488 }
3489 next:
3490 level--;
3491 btrfs_release_path(extent_root, path);
3492 cond_resched();
3493 }
3494 /* reached lowest level */
3495 ret = 1;
3496 goto out;
3497 walk_up:
3498 level = ref_path->current_level;
3499 while (level < BTRFS_MAX_LEVEL - 1) {
3500 u64 ref_objectid;
3501 if (level >= 0) {
3502 bytenr = ref_path->nodes[level];
3503 } else {
3504 bytenr = ref_path->extent_start;
3505 }
3506 BUG_ON(bytenr == 0);
3507
3508 key.objectid = bytenr;
3509 key.offset = 0;
3510 key.type = BTRFS_EXTENT_REF_KEY;
3511
3512 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3513 if (ret < 0)
3514 goto out;
3515
3516 leaf = path->nodes[0];
3517 nritems = btrfs_header_nritems(leaf);
3518 if (path->slots[0] >= nritems) {
3519 ret = btrfs_next_leaf(extent_root, path);
3520 if (ret < 0)
3521 goto out;
3522 if (ret > 0) {
3523 /* the extent was freed by someone */
3524 if (ref_path->lowest_level == level)
3525 goto out;
3526 btrfs_release_path(extent_root, path);
3527 goto walk_down;
3528 }
3529 leaf = path->nodes[0];
3530 }
3531
3532 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3533 if (found_key.objectid != bytenr ||
3534 found_key.type != BTRFS_EXTENT_REF_KEY) {
3535 /* the extent was freed by someone */
3536 if (ref_path->lowest_level == level) {
3537 ret = 1;
3538 goto out;
3539 }
3540 btrfs_release_path(extent_root, path);
3541 goto walk_down;
3542 }
3543 found:
3544 ref = btrfs_item_ptr(leaf, path->slots[0],
3545 struct btrfs_extent_ref);
3546 ref_objectid = btrfs_ref_objectid(leaf, ref);
3547 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3548 if (first_time) {
3549 level = (int)ref_objectid;
3550 BUG_ON(level >= BTRFS_MAX_LEVEL);
3551 ref_path->lowest_level = level;
3552 ref_path->current_level = level;
3553 ref_path->nodes[level] = bytenr;
3554 } else {
3555 WARN_ON(ref_objectid != level);
3556 }
3557 } else {
3558 WARN_ON(level != -1);
3559 }
3560 first_time = 0;
3561
3562 if (ref_path->lowest_level == level) {
3563 ref_path->owner_objectid = ref_objectid;
3564 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
3565 }
3566
3567 /*
3568 * the block is tree root or the block isn't in reference
3569 * counted tree.
3570 */
3571 if (found_key.objectid == found_key.offset ||
3572 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
3573 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3574 ref_path->root_generation =
3575 btrfs_ref_generation(leaf, ref);
3576 if (level < 0) {
3577 /* special reference from the tree log */
3578 ref_path->nodes[0] = found_key.offset;
3579 ref_path->current_level = 0;
3580 }
3581 ret = 0;
3582 goto out;
3583 }
3584
3585 level++;
3586 BUG_ON(ref_path->nodes[level] != 0);
3587 ref_path->nodes[level] = found_key.offset;
3588 ref_path->current_level = level;
3589
3590 /*
3591 * the reference was created in the running transaction,
3592 * no need to continue walking up.
3593 */
3594 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
3595 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3596 ref_path->root_generation =
3597 btrfs_ref_generation(leaf, ref);
3598 ret = 0;
3599 goto out;
3600 }
3601
3602 btrfs_release_path(extent_root, path);
3603 cond_resched();
3604 }
3605 /* reached max tree level, but no tree root found. */
3606 BUG();
3607 out:
3608 btrfs_free_path(path);
3609 return ret;
3610 }
3611
3612 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
3613 struct btrfs_root *extent_root,
3614 struct btrfs_ref_path *ref_path,
3615 u64 extent_start)
3616 {
3617 memset(ref_path, 0, sizeof(*ref_path));
3618 ref_path->extent_start = extent_start;
3619
3620 return __next_ref_path(trans, extent_root, ref_path, 1);
3621 }
3622
3623 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
3624 struct btrfs_root *extent_root,
3625 struct btrfs_ref_path *ref_path)
3626 {
3627 return __next_ref_path(trans, extent_root, ref_path, 0);
3628 }
3629
3630 static int noinline get_new_locations(struct inode *reloc_inode,
3631 struct btrfs_key *extent_key,
3632 u64 offset, int no_fragment,
3633 struct disk_extent **extents,
3634 int *nr_extents)
3635 {
3636 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3637 struct btrfs_path *path;
3638 struct btrfs_file_extent_item *fi;
3639 struct extent_buffer *leaf;
3640 struct disk_extent *exts = *extents;
3641 struct btrfs_key found_key;
3642 u64 cur_pos;
3643 u64 last_byte;
3644 u32 nritems;
3645 int nr = 0;
3646 int max = *nr_extents;
3647 int ret;
3648
3649 WARN_ON(!no_fragment && *extents);
3650 if (!exts) {
3651 max = 1;
3652 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
3653 if (!exts)
3654 return -ENOMEM;
3655 }
3656
3657 path = btrfs_alloc_path();
3658 BUG_ON(!path);
3659
3660 cur_pos = extent_key->objectid - offset;
3661 last_byte = extent_key->objectid + extent_key->offset;
3662 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
3663 cur_pos, 0);
3664 if (ret < 0)
3665 goto out;
3666 if (ret > 0) {
3667 ret = -ENOENT;
3668 goto out;
3669 }
3670
3671 while (1) {
3672 leaf = path->nodes[0];
3673 nritems = btrfs_header_nritems(leaf);
3674 if (path->slots[0] >= nritems) {
3675 ret = btrfs_next_leaf(root, path);
3676 if (ret < 0)
3677 goto out;
3678 if (ret > 0)
3679 break;
3680 leaf = path->nodes[0];
3681 }
3682
3683 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3684 if (found_key.offset != cur_pos ||
3685 found_key.type != BTRFS_EXTENT_DATA_KEY ||
3686 found_key.objectid != reloc_inode->i_ino)
3687 break;
3688
3689 fi = btrfs_item_ptr(leaf, path->slots[0],
3690 struct btrfs_file_extent_item);
3691 if (btrfs_file_extent_type(leaf, fi) !=
3692 BTRFS_FILE_EXTENT_REG ||
3693 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
3694 break;
3695
3696 if (nr == max) {
3697 struct disk_extent *old = exts;
3698 max *= 2;
3699 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
3700 memcpy(exts, old, sizeof(*exts) * nr);
3701 if (old != *extents)
3702 kfree(old);
3703 }
3704
3705 exts[nr].disk_bytenr =
3706 btrfs_file_extent_disk_bytenr(leaf, fi);
3707 exts[nr].disk_num_bytes =
3708 btrfs_file_extent_disk_num_bytes(leaf, fi);
3709 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
3710 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3711 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
3712 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
3713 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
3714 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
3715 fi);
3716 BUG_ON(exts[nr].offset > 0);
3717 BUG_ON(exts[nr].compression || exts[nr].encryption);
3718 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
3719
3720 cur_pos += exts[nr].num_bytes;
3721 nr++;
3722
3723 if (cur_pos + offset >= last_byte)
3724 break;
3725
3726 if (no_fragment) {
3727 ret = 1;
3728 goto out;
3729 }
3730 path->slots[0]++;
3731 }
3732
3733 WARN_ON(cur_pos + offset > last_byte);
3734 if (cur_pos + offset < last_byte) {
3735 ret = -ENOENT;
3736 goto out;
3737 }
3738 ret = 0;
3739 out:
3740 btrfs_free_path(path);
3741 if (ret) {
3742 if (exts != *extents)
3743 kfree(exts);
3744 } else {
3745 *extents = exts;
3746 *nr_extents = nr;
3747 }
3748 return ret;
3749 }
3750
3751 static int noinline replace_one_extent(struct btrfs_trans_handle *trans,
3752 struct btrfs_root *root,
3753 struct btrfs_path *path,
3754 struct btrfs_key *extent_key,
3755 struct btrfs_key *leaf_key,
3756 struct btrfs_ref_path *ref_path,
3757 struct disk_extent *new_extents,
3758 int nr_extents)
3759 {
3760 struct extent_buffer *leaf;
3761 struct btrfs_file_extent_item *fi;
3762 struct inode *inode = NULL;
3763 struct btrfs_key key;
3764 u64 lock_start = 0;
3765 u64 lock_end = 0;
3766 u64 num_bytes;
3767 u64 ext_offset;
3768 u64 first_pos;
3769 u32 nritems;
3770 int nr_scaned = 0;
3771 int extent_locked = 0;
3772 int extent_type;
3773 int ret;
3774
3775 memcpy(&key, leaf_key, sizeof(key));
3776 first_pos = INT_LIMIT(loff_t) - extent_key->offset;
3777 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3778 if (key.objectid < ref_path->owner_objectid ||
3779 (key.objectid == ref_path->owner_objectid &&
3780 key.type < BTRFS_EXTENT_DATA_KEY)) {
3781 key.objectid = ref_path->owner_objectid;
3782 key.type = BTRFS_EXTENT_DATA_KEY;
3783 key.offset = 0;
3784 }
3785 }
3786
3787 while (1) {
3788 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
3789 if (ret < 0)
3790 goto out;
3791
3792 leaf = path->nodes[0];
3793 nritems = btrfs_header_nritems(leaf);
3794 next:
3795 if (extent_locked && ret > 0) {
3796 /*
3797 * the file extent item was modified by someone
3798 * before the extent got locked.
3799 */
3800 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3801 lock_end, GFP_NOFS);
3802 extent_locked = 0;
3803 }
3804
3805 if (path->slots[0] >= nritems) {
3806 if (++nr_scaned > 2)
3807 break;
3808
3809 BUG_ON(extent_locked);
3810 ret = btrfs_next_leaf(root, path);
3811 if (ret < 0)
3812 goto out;
3813 if (ret > 0)
3814 break;
3815 leaf = path->nodes[0];
3816 nritems = btrfs_header_nritems(leaf);
3817 }
3818
3819 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3820
3821 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3822 if ((key.objectid > ref_path->owner_objectid) ||
3823 (key.objectid == ref_path->owner_objectid &&
3824 key.type > BTRFS_EXTENT_DATA_KEY) ||
3825 (key.offset >= first_pos + extent_key->offset))
3826 break;
3827 }
3828
3829 if (inode && key.objectid != inode->i_ino) {
3830 BUG_ON(extent_locked);
3831 btrfs_release_path(root, path);
3832 mutex_unlock(&inode->i_mutex);
3833 iput(inode);
3834 inode = NULL;
3835 continue;
3836 }
3837
3838 if (key.type != BTRFS_EXTENT_DATA_KEY) {
3839 path->slots[0]++;
3840 ret = 1;
3841 goto next;
3842 }
3843 fi = btrfs_item_ptr(leaf, path->slots[0],
3844 struct btrfs_file_extent_item);
3845 extent_type = btrfs_file_extent_type(leaf, fi);
3846 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
3847 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
3848 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3849 extent_key->objectid)) {
3850 path->slots[0]++;
3851 ret = 1;
3852 goto next;
3853 }
3854
3855 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3856 ext_offset = btrfs_file_extent_offset(leaf, fi);
3857
3858 if (first_pos > key.offset - ext_offset)
3859 first_pos = key.offset - ext_offset;
3860
3861 if (!extent_locked) {
3862 lock_start = key.offset;
3863 lock_end = lock_start + num_bytes - 1;
3864 } else {
3865 if (lock_start > key.offset ||
3866 lock_end + 1 < key.offset + num_bytes) {
3867 unlock_extent(&BTRFS_I(inode)->io_tree,
3868 lock_start, lock_end, GFP_NOFS);
3869 extent_locked = 0;
3870 }
3871 }
3872
3873 if (!inode) {
3874 btrfs_release_path(root, path);
3875
3876 inode = btrfs_iget_locked(root->fs_info->sb,
3877 key.objectid, root);
3878 if (inode->i_state & I_NEW) {
3879 BTRFS_I(inode)->root = root;
3880 BTRFS_I(inode)->location.objectid =
3881 key.objectid;
3882 BTRFS_I(inode)->location.type =
3883 BTRFS_INODE_ITEM_KEY;
3884 BTRFS_I(inode)->location.offset = 0;
3885 btrfs_read_locked_inode(inode);
3886 unlock_new_inode(inode);
3887 }
3888 /*
3889 * some code call btrfs_commit_transaction while
3890 * holding the i_mutex, so we can't use mutex_lock
3891 * here.
3892 */
3893 if (is_bad_inode(inode) ||
3894 !mutex_trylock(&inode->i_mutex)) {
3895 iput(inode);
3896 inode = NULL;
3897 key.offset = (u64)-1;
3898 goto skip;
3899 }
3900 }
3901
3902 if (!extent_locked) {
3903 struct btrfs_ordered_extent *ordered;
3904
3905 btrfs_release_path(root, path);
3906
3907 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3908 lock_end, GFP_NOFS);
3909 ordered = btrfs_lookup_first_ordered_extent(inode,
3910 lock_end);
3911 if (ordered &&
3912 ordered->file_offset <= lock_end &&
3913 ordered->file_offset + ordered->len > lock_start) {
3914 unlock_extent(&BTRFS_I(inode)->io_tree,
3915 lock_start, lock_end, GFP_NOFS);
3916 btrfs_start_ordered_extent(inode, ordered, 1);
3917 btrfs_put_ordered_extent(ordered);
3918 key.offset += num_bytes;
3919 goto skip;
3920 }
3921 if (ordered)
3922 btrfs_put_ordered_extent(ordered);
3923
3924 extent_locked = 1;
3925 continue;
3926 }
3927
3928 if (nr_extents == 1) {
3929 /* update extent pointer in place */
3930 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3931 new_extents[0].disk_bytenr);
3932 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
3933 new_extents[0].disk_num_bytes);
3934 btrfs_mark_buffer_dirty(leaf);
3935
3936 btrfs_drop_extent_cache(inode, key.offset,
3937 key.offset + num_bytes - 1, 0);
3938
3939 ret = btrfs_inc_extent_ref(trans, root,
3940 new_extents[0].disk_bytenr,
3941 new_extents[0].disk_num_bytes,
3942 leaf->start,
3943 root->root_key.objectid,
3944 trans->transid,
3945 key.objectid);
3946 BUG_ON(ret);
3947
3948 ret = btrfs_free_extent(trans, root,
3949 extent_key->objectid,
3950 extent_key->offset,
3951 leaf->start,
3952 btrfs_header_owner(leaf),
3953 btrfs_header_generation(leaf),
3954 key.objectid, 0);
3955 BUG_ON(ret);
3956
3957 btrfs_release_path(root, path);
3958 key.offset += num_bytes;
3959 } else {
3960 BUG_ON(1);
3961 #if 0
3962 u64 alloc_hint;
3963 u64 extent_len;
3964 int i;
3965 /*
3966 * drop old extent pointer at first, then insert the
3967 * new pointers one bye one
3968 */
3969 btrfs_release_path(root, path);
3970 ret = btrfs_drop_extents(trans, root, inode, key.offset,
3971 key.offset + num_bytes,
3972 key.offset, &alloc_hint);
3973 BUG_ON(ret);
3974
3975 for (i = 0; i < nr_extents; i++) {
3976 if (ext_offset >= new_extents[i].num_bytes) {
3977 ext_offset -= new_extents[i].num_bytes;
3978 continue;
3979 }
3980 extent_len = min(new_extents[i].num_bytes -
3981 ext_offset, num_bytes);
3982
3983 ret = btrfs_insert_empty_item(trans, root,
3984 path, &key,
3985 sizeof(*fi));
3986 BUG_ON(ret);
3987
3988 leaf = path->nodes[0];
3989 fi = btrfs_item_ptr(leaf, path->slots[0],
3990 struct btrfs_file_extent_item);
3991 btrfs_set_file_extent_generation(leaf, fi,
3992 trans->transid);
3993 btrfs_set_file_extent_type(leaf, fi,
3994 BTRFS_FILE_EXTENT_REG);
3995 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3996 new_extents[i].disk_bytenr);
3997 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
3998 new_extents[i].disk_num_bytes);
3999 btrfs_set_file_extent_ram_bytes(leaf, fi,
4000 new_extents[i].ram_bytes);
4001
4002 btrfs_set_file_extent_compression(leaf, fi,
4003 new_extents[i].compression);
4004 btrfs_set_file_extent_encryption(leaf, fi,
4005 new_extents[i].encryption);
4006 btrfs_set_file_extent_other_encoding(leaf, fi,
4007 new_extents[i].other_encoding);
4008
4009 btrfs_set_file_extent_num_bytes(leaf, fi,
4010 extent_len);
4011 ext_offset += new_extents[i].offset;
4012 btrfs_set_file_extent_offset(leaf, fi,
4013 ext_offset);
4014 btrfs_mark_buffer_dirty(leaf);
4015
4016 btrfs_drop_extent_cache(inode, key.offset,
4017 key.offset + extent_len - 1, 0);
4018
4019 ret = btrfs_inc_extent_ref(trans, root,
4020 new_extents[i].disk_bytenr,
4021 new_extents[i].disk_num_bytes,
4022 leaf->start,
4023 root->root_key.objectid,
4024 trans->transid, key.objectid);
4025 BUG_ON(ret);
4026 btrfs_release_path(root, path);
4027
4028 inode_add_bytes(inode, extent_len);
4029
4030 ext_offset = 0;
4031 num_bytes -= extent_len;
4032 key.offset += extent_len;
4033
4034 if (num_bytes == 0)
4035 break;
4036 }
4037 BUG_ON(i >= nr_extents);
4038 #endif
4039 }
4040
4041 if (extent_locked) {
4042 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
4043 lock_end, GFP_NOFS);
4044 extent_locked = 0;
4045 }
4046 skip:
4047 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
4048 key.offset >= first_pos + extent_key->offset)
4049 break;
4050
4051 cond_resched();
4052 }
4053 ret = 0;
4054 out:
4055 btrfs_release_path(root, path);
4056 if (inode) {
4057 mutex_unlock(&inode->i_mutex);
4058 if (extent_locked) {
4059 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
4060 lock_end, GFP_NOFS);
4061 }
4062 iput(inode);
4063 }
4064 return ret;
4065 }
4066
4067 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
4068 struct btrfs_root *root,
4069 struct extent_buffer *buf, u64 orig_start)
4070 {
4071 int level;
4072 int ret;
4073
4074 BUG_ON(btrfs_header_generation(buf) != trans->transid);
4075 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
4076
4077 level = btrfs_header_level(buf);
4078 if (level == 0) {
4079 struct btrfs_leaf_ref *ref;
4080 struct btrfs_leaf_ref *orig_ref;
4081
4082 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
4083 if (!orig_ref)
4084 return -ENOENT;
4085
4086 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
4087 if (!ref) {
4088 btrfs_free_leaf_ref(root, orig_ref);
4089 return -ENOMEM;
4090 }
4091
4092 ref->nritems = orig_ref->nritems;
4093 memcpy(ref->extents, orig_ref->extents,
4094 sizeof(ref->extents[0]) * ref->nritems);
4095
4096 btrfs_free_leaf_ref(root, orig_ref);
4097
4098 ref->root_gen = trans->transid;
4099 ref->bytenr = buf->start;
4100 ref->owner = btrfs_header_owner(buf);
4101 ref->generation = btrfs_header_generation(buf);
4102 ret = btrfs_add_leaf_ref(root, ref, 0);
4103 WARN_ON(ret);
4104 btrfs_free_leaf_ref(root, ref);
4105 }
4106 return 0;
4107 }
4108
4109 static int noinline invalidate_extent_cache(struct btrfs_root *root,
4110 struct extent_buffer *leaf,
4111 struct btrfs_block_group_cache *group,
4112 struct btrfs_root *target_root)
4113 {
4114 struct btrfs_key key;
4115 struct inode *inode = NULL;
4116 struct btrfs_file_extent_item *fi;
4117 u64 num_bytes;
4118 u64 skip_objectid = 0;
4119 u32 nritems;
4120 u32 i;
4121
4122 nritems = btrfs_header_nritems(leaf);
4123 for (i = 0; i < nritems; i++) {
4124 btrfs_item_key_to_cpu(leaf, &key, i);
4125 if (key.objectid == skip_objectid ||
4126 key.type != BTRFS_EXTENT_DATA_KEY)
4127 continue;
4128 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4129 if (btrfs_file_extent_type(leaf, fi) ==
4130 BTRFS_FILE_EXTENT_INLINE)
4131 continue;
4132 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
4133 continue;
4134 if (!inode || inode->i_ino != key.objectid) {
4135 iput(inode);
4136 inode = btrfs_ilookup(target_root->fs_info->sb,
4137 key.objectid, target_root, 1);
4138 }
4139 if (!inode) {
4140 skip_objectid = key.objectid;
4141 continue;
4142 }
4143 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4144
4145 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4146 key.offset + num_bytes - 1, GFP_NOFS);
4147 btrfs_drop_extent_cache(inode, key.offset,
4148 key.offset + num_bytes - 1, 1);
4149 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4150 key.offset + num_bytes - 1, GFP_NOFS);
4151 cond_resched();
4152 }
4153 iput(inode);
4154 return 0;
4155 }
4156
4157 static int noinline replace_extents_in_leaf(struct btrfs_trans_handle *trans,
4158 struct btrfs_root *root,
4159 struct extent_buffer *leaf,
4160 struct btrfs_block_group_cache *group,
4161 struct inode *reloc_inode)
4162 {
4163 struct btrfs_key key;
4164 struct btrfs_key extent_key;
4165 struct btrfs_file_extent_item *fi;
4166 struct btrfs_leaf_ref *ref;
4167 struct disk_extent *new_extent;
4168 u64 bytenr;
4169 u64 num_bytes;
4170 u32 nritems;
4171 u32 i;
4172 int ext_index;
4173 int nr_extent;
4174 int ret;
4175
4176 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
4177 BUG_ON(!new_extent);
4178
4179 ref = btrfs_lookup_leaf_ref(root, leaf->start);
4180 BUG_ON(!ref);
4181
4182 ext_index = -1;
4183 nritems = btrfs_header_nritems(leaf);
4184 for (i = 0; i < nritems; i++) {
4185 btrfs_item_key_to_cpu(leaf, &key, i);
4186 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
4187 continue;
4188 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4189 if (btrfs_file_extent_type(leaf, fi) ==
4190 BTRFS_FILE_EXTENT_INLINE)
4191 continue;
4192 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
4193 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
4194 if (bytenr == 0)
4195 continue;
4196
4197 ext_index++;
4198 if (bytenr >= group->key.objectid + group->key.offset ||
4199 bytenr + num_bytes <= group->key.objectid)
4200 continue;
4201
4202 extent_key.objectid = bytenr;
4203 extent_key.offset = num_bytes;
4204 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
4205 nr_extent = 1;
4206 ret = get_new_locations(reloc_inode, &extent_key,
4207 group->key.objectid, 1,
4208 &new_extent, &nr_extent);
4209 if (ret > 0)
4210 continue;
4211 BUG_ON(ret < 0);
4212
4213 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
4214 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
4215 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
4216 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
4217
4218 btrfs_set_file_extent_disk_bytenr(leaf, fi,
4219 new_extent->disk_bytenr);
4220 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4221 new_extent->disk_num_bytes);
4222 btrfs_mark_buffer_dirty(leaf);
4223
4224 ret = btrfs_inc_extent_ref(trans, root,
4225 new_extent->disk_bytenr,
4226 new_extent->disk_num_bytes,
4227 leaf->start,
4228 root->root_key.objectid,
4229 trans->transid, key.objectid);
4230 BUG_ON(ret);
4231 ret = btrfs_free_extent(trans, root,
4232 bytenr, num_bytes, leaf->start,
4233 btrfs_header_owner(leaf),
4234 btrfs_header_generation(leaf),
4235 key.objectid, 0);
4236 BUG_ON(ret);
4237 cond_resched();
4238 }
4239 kfree(new_extent);
4240 BUG_ON(ext_index + 1 != ref->nritems);
4241 btrfs_free_leaf_ref(root, ref);
4242 return 0;
4243 }
4244
4245 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
4246 struct btrfs_root *root)
4247 {
4248 struct btrfs_root *reloc_root;
4249 int ret;
4250
4251 if (root->reloc_root) {
4252 reloc_root = root->reloc_root;
4253 root->reloc_root = NULL;
4254 list_add(&reloc_root->dead_list,
4255 &root->fs_info->dead_reloc_roots);
4256
4257 btrfs_set_root_bytenr(&reloc_root->root_item,
4258 reloc_root->node->start);
4259 btrfs_set_root_level(&root->root_item,
4260 btrfs_header_level(reloc_root->node));
4261 memset(&reloc_root->root_item.drop_progress, 0,
4262 sizeof(struct btrfs_disk_key));
4263 reloc_root->root_item.drop_level = 0;
4264
4265 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4266 &reloc_root->root_key,
4267 &reloc_root->root_item);
4268 BUG_ON(ret);
4269 }
4270 return 0;
4271 }
4272
4273 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
4274 {
4275 struct btrfs_trans_handle *trans;
4276 struct btrfs_root *reloc_root;
4277 struct btrfs_root *prev_root = NULL;
4278 struct list_head dead_roots;
4279 int ret;
4280 unsigned long nr;
4281
4282 INIT_LIST_HEAD(&dead_roots);
4283 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
4284
4285 while (!list_empty(&dead_roots)) {
4286 reloc_root = list_entry(dead_roots.prev,
4287 struct btrfs_root, dead_list);
4288 list_del_init(&reloc_root->dead_list);
4289
4290 BUG_ON(reloc_root->commit_root != NULL);
4291 while (1) {
4292 trans = btrfs_join_transaction(root, 1);
4293 BUG_ON(!trans);
4294
4295 mutex_lock(&root->fs_info->drop_mutex);
4296 ret = btrfs_drop_snapshot(trans, reloc_root);
4297 if (ret != -EAGAIN)
4298 break;
4299 mutex_unlock(&root->fs_info->drop_mutex);
4300
4301 nr = trans->blocks_used;
4302 ret = btrfs_end_transaction(trans, root);
4303 BUG_ON(ret);
4304 btrfs_btree_balance_dirty(root, nr);
4305 }
4306
4307 free_extent_buffer(reloc_root->node);
4308
4309 ret = btrfs_del_root(trans, root->fs_info->tree_root,
4310 &reloc_root->root_key);
4311 BUG_ON(ret);
4312 mutex_unlock(&root->fs_info->drop_mutex);
4313
4314 nr = trans->blocks_used;
4315 ret = btrfs_end_transaction(trans, root);
4316 BUG_ON(ret);
4317 btrfs_btree_balance_dirty(root, nr);
4318
4319 kfree(prev_root);
4320 prev_root = reloc_root;
4321 }
4322 if (prev_root) {
4323 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
4324 kfree(prev_root);
4325 }
4326 return 0;
4327 }
4328
4329 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
4330 {
4331 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
4332 return 0;
4333 }
4334
4335 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
4336 {
4337 struct btrfs_root *reloc_root;
4338 struct btrfs_trans_handle *trans;
4339 struct btrfs_key location;
4340 int found;
4341 int ret;
4342
4343 mutex_lock(&root->fs_info->tree_reloc_mutex);
4344 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
4345 BUG_ON(ret);
4346 found = !list_empty(&root->fs_info->dead_reloc_roots);
4347 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4348
4349 if (found) {
4350 trans = btrfs_start_transaction(root, 1);
4351 BUG_ON(!trans);
4352 ret = btrfs_commit_transaction(trans, root);
4353 BUG_ON(ret);
4354 }
4355
4356 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4357 location.offset = (u64)-1;
4358 location.type = BTRFS_ROOT_ITEM_KEY;
4359
4360 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
4361 BUG_ON(!reloc_root);
4362 btrfs_orphan_cleanup(reloc_root);
4363 return 0;
4364 }
4365
4366 static int noinline init_reloc_tree(struct btrfs_trans_handle *trans,
4367 struct btrfs_root *root)
4368 {
4369 struct btrfs_root *reloc_root;
4370 struct extent_buffer *eb;
4371 struct btrfs_root_item *root_item;
4372 struct btrfs_key root_key;
4373 int ret;
4374
4375 BUG_ON(!root->ref_cows);
4376 if (root->reloc_root)
4377 return 0;
4378
4379 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
4380 BUG_ON(!root_item);
4381
4382 ret = btrfs_copy_root(trans, root, root->commit_root,
4383 &eb, BTRFS_TREE_RELOC_OBJECTID);
4384 BUG_ON(ret);
4385
4386 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4387 root_key.offset = root->root_key.objectid;
4388 root_key.type = BTRFS_ROOT_ITEM_KEY;
4389
4390 memcpy(root_item, &root->root_item, sizeof(root_item));
4391 btrfs_set_root_refs(root_item, 0);
4392 btrfs_set_root_bytenr(root_item, eb->start);
4393 btrfs_set_root_level(root_item, btrfs_header_level(eb));
4394 btrfs_set_root_generation(root_item, trans->transid);
4395
4396 btrfs_tree_unlock(eb);
4397 free_extent_buffer(eb);
4398
4399 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
4400 &root_key, root_item);
4401 BUG_ON(ret);
4402 kfree(root_item);
4403
4404 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
4405 &root_key);
4406 BUG_ON(!reloc_root);
4407 reloc_root->last_trans = trans->transid;
4408 reloc_root->commit_root = NULL;
4409 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
4410
4411 root->reloc_root = reloc_root;
4412 return 0;
4413 }
4414
4415 /*
4416 * Core function of space balance.
4417 *
4418 * The idea is using reloc trees to relocate tree blocks in reference
4419 * counted roots. There is one reloc tree for each subvol, and all
4420 * reloc trees share same root key objectid. Reloc trees are snapshots
4421 * of the latest committed roots of subvols (root->commit_root).
4422 *
4423 * To relocate a tree block referenced by a subvol, there are two steps.
4424 * COW the block through subvol's reloc tree, then update block pointer
4425 * in the subvol to point to the new block. Since all reloc trees share
4426 * same root key objectid, doing special handing for tree blocks owned
4427 * by them is easy. Once a tree block has been COWed in one reloc tree,
4428 * we can use the resulting new block directly when the same block is
4429 * required to COW again through other reloc trees. By this way, relocated
4430 * tree blocks are shared between reloc trees, so they are also shared
4431 * between subvols.
4432 */
4433 static int noinline relocate_one_path(struct btrfs_trans_handle *trans,
4434 struct btrfs_root *root,
4435 struct btrfs_path *path,
4436 struct btrfs_key *first_key,
4437 struct btrfs_ref_path *ref_path,
4438 struct btrfs_block_group_cache *group,
4439 struct inode *reloc_inode)
4440 {
4441 struct btrfs_root *reloc_root;
4442 struct extent_buffer *eb = NULL;
4443 struct btrfs_key *keys;
4444 u64 *nodes;
4445 int level;
4446 int shared_level;
4447 int lowest_level = 0;
4448 int ret;
4449
4450 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
4451 lowest_level = ref_path->owner_objectid;
4452
4453 if (!root->ref_cows) {
4454 path->lowest_level = lowest_level;
4455 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
4456 BUG_ON(ret < 0);
4457 path->lowest_level = 0;
4458 btrfs_release_path(root, path);
4459 return 0;
4460 }
4461
4462 mutex_lock(&root->fs_info->tree_reloc_mutex);
4463 ret = init_reloc_tree(trans, root);
4464 BUG_ON(ret);
4465 reloc_root = root->reloc_root;
4466
4467 shared_level = ref_path->shared_level;
4468 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
4469
4470 keys = ref_path->node_keys;
4471 nodes = ref_path->new_nodes;
4472 memset(&keys[shared_level + 1], 0,
4473 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
4474 memset(&nodes[shared_level + 1], 0,
4475 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
4476
4477 if (nodes[lowest_level] == 0) {
4478 path->lowest_level = lowest_level;
4479 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
4480 0, 1);
4481 BUG_ON(ret);
4482 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
4483 eb = path->nodes[level];
4484 if (!eb || eb == reloc_root->node)
4485 break;
4486 nodes[level] = eb->start;
4487 if (level == 0)
4488 btrfs_item_key_to_cpu(eb, &keys[level], 0);
4489 else
4490 btrfs_node_key_to_cpu(eb, &keys[level], 0);
4491 }
4492 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4493 eb = path->nodes[0];
4494 ret = replace_extents_in_leaf(trans, reloc_root, eb,
4495 group, reloc_inode);
4496 BUG_ON(ret);
4497 }
4498 btrfs_release_path(reloc_root, path);
4499 } else {
4500 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
4501 lowest_level);
4502 BUG_ON(ret);
4503 }
4504
4505 /*
4506 * replace tree blocks in the fs tree with tree blocks in
4507 * the reloc tree.
4508 */
4509 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
4510 BUG_ON(ret < 0);
4511
4512 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4513 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
4514 0, 0);
4515 BUG_ON(ret);
4516 extent_buffer_get(path->nodes[0]);
4517 eb = path->nodes[0];
4518 btrfs_release_path(reloc_root, path);
4519 ret = invalidate_extent_cache(reloc_root, eb, group, root);
4520 BUG_ON(ret);
4521 free_extent_buffer(eb);
4522 }
4523
4524 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4525 path->lowest_level = 0;
4526 return 0;
4527 }
4528
4529 static int noinline relocate_tree_block(struct btrfs_trans_handle *trans,
4530 struct btrfs_root *root,
4531 struct btrfs_path *path,
4532 struct btrfs_key *first_key,
4533 struct btrfs_ref_path *ref_path)
4534 {
4535 int ret;
4536
4537 ret = relocate_one_path(trans, root, path, first_key,
4538 ref_path, NULL, NULL);
4539 BUG_ON(ret);
4540
4541 if (root == root->fs_info->extent_root)
4542 btrfs_extent_post_op(trans, root);
4543
4544 return 0;
4545 }
4546
4547 static int noinline del_extent_zero(struct btrfs_trans_handle *trans,
4548 struct btrfs_root *extent_root,
4549 struct btrfs_path *path,
4550 struct btrfs_key *extent_key)
4551 {
4552 int ret;
4553
4554 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
4555 if (ret)
4556 goto out;
4557 ret = btrfs_del_item(trans, extent_root, path);
4558 out:
4559 btrfs_release_path(extent_root, path);
4560 return ret;
4561 }
4562
4563 static struct btrfs_root noinline *read_ref_root(struct btrfs_fs_info *fs_info,
4564 struct btrfs_ref_path *ref_path)
4565 {
4566 struct btrfs_key root_key;
4567
4568 root_key.objectid = ref_path->root_objectid;
4569 root_key.type = BTRFS_ROOT_ITEM_KEY;
4570 if (is_cowonly_root(ref_path->root_objectid))
4571 root_key.offset = 0;
4572 else
4573 root_key.offset = (u64)-1;
4574
4575 return btrfs_read_fs_root_no_name(fs_info, &root_key);
4576 }
4577
4578 static int noinline relocate_one_extent(struct btrfs_root *extent_root,
4579 struct btrfs_path *path,
4580 struct btrfs_key *extent_key,
4581 struct btrfs_block_group_cache *group,
4582 struct inode *reloc_inode, int pass)
4583 {
4584 struct btrfs_trans_handle *trans;
4585 struct btrfs_root *found_root;
4586 struct btrfs_ref_path *ref_path = NULL;
4587 struct disk_extent *new_extents = NULL;
4588 int nr_extents = 0;
4589 int loops;
4590 int ret;
4591 int level;
4592 struct btrfs_key first_key;
4593 u64 prev_block = 0;
4594
4595
4596 trans = btrfs_start_transaction(extent_root, 1);
4597 BUG_ON(!trans);
4598
4599 if (extent_key->objectid == 0) {
4600 ret = del_extent_zero(trans, extent_root, path, extent_key);
4601 goto out;
4602 }
4603
4604 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
4605 if (!ref_path) {
4606 ret = -ENOMEM;
4607 goto out;
4608 }
4609
4610 for (loops = 0; ; loops++) {
4611 if (loops == 0) {
4612 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
4613 extent_key->objectid);
4614 } else {
4615 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
4616 }
4617 if (ret < 0)
4618 goto out;
4619 if (ret > 0)
4620 break;
4621
4622 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
4623 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
4624 continue;
4625
4626 found_root = read_ref_root(extent_root->fs_info, ref_path);
4627 BUG_ON(!found_root);
4628 /*
4629 * for reference counted tree, only process reference paths
4630 * rooted at the latest committed root.
4631 */
4632 if (found_root->ref_cows &&
4633 ref_path->root_generation != found_root->root_key.offset)
4634 continue;
4635
4636 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4637 if (pass == 0) {
4638 /*
4639 * copy data extents to new locations
4640 */
4641 u64 group_start = group->key.objectid;
4642 ret = relocate_data_extent(reloc_inode,
4643 extent_key,
4644 group_start);
4645 if (ret < 0)
4646 goto out;
4647 break;
4648 }
4649 level = 0;
4650 } else {
4651 level = ref_path->owner_objectid;
4652 }
4653
4654 if (prev_block != ref_path->nodes[level]) {
4655 struct extent_buffer *eb;
4656 u64 block_start = ref_path->nodes[level];
4657 u64 block_size = btrfs_level_size(found_root, level);
4658
4659 eb = read_tree_block(found_root, block_start,
4660 block_size, 0);
4661 btrfs_tree_lock(eb);
4662 BUG_ON(level != btrfs_header_level(eb));
4663
4664 if (level == 0)
4665 btrfs_item_key_to_cpu(eb, &first_key, 0);
4666 else
4667 btrfs_node_key_to_cpu(eb, &first_key, 0);
4668
4669 btrfs_tree_unlock(eb);
4670 free_extent_buffer(eb);
4671 prev_block = block_start;
4672 }
4673
4674 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
4675 pass >= 2) {
4676 /*
4677 * use fallback method to process the remaining
4678 * references.
4679 */
4680 if (!new_extents) {
4681 u64 group_start = group->key.objectid;
4682 new_extents = kmalloc(sizeof(*new_extents),
4683 GFP_NOFS);
4684 nr_extents = 1;
4685 ret = get_new_locations(reloc_inode,
4686 extent_key,
4687 group_start, 1,
4688 &new_extents,
4689 &nr_extents);
4690 if (ret)
4691 goto out;
4692 }
4693 btrfs_record_root_in_trans(found_root);
4694 ret = replace_one_extent(trans, found_root,
4695 path, extent_key,
4696 &first_key, ref_path,
4697 new_extents, nr_extents);
4698 if (ret < 0)
4699 goto out;
4700 continue;
4701 }
4702
4703 btrfs_record_root_in_trans(found_root);
4704 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
4705 ret = relocate_tree_block(trans, found_root, path,
4706 &first_key, ref_path);
4707 } else {
4708 /*
4709 * try to update data extent references while
4710 * keeping metadata shared between snapshots.
4711 */
4712 ret = relocate_one_path(trans, found_root, path,
4713 &first_key, ref_path,
4714 group, reloc_inode);
4715 }
4716 if (ret < 0)
4717 goto out;
4718 }
4719 ret = 0;
4720 out:
4721 btrfs_end_transaction(trans, extent_root);
4722 kfree(new_extents);
4723 kfree(ref_path);
4724 return ret;
4725 }
4726
4727 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
4728 {
4729 u64 num_devices;
4730 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
4731 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
4732
4733 num_devices = root->fs_info->fs_devices->num_devices;
4734 if (num_devices == 1) {
4735 stripped |= BTRFS_BLOCK_GROUP_DUP;
4736 stripped = flags & ~stripped;
4737
4738 /* turn raid0 into single device chunks */
4739 if (flags & BTRFS_BLOCK_GROUP_RAID0)
4740 return stripped;
4741
4742 /* turn mirroring into duplication */
4743 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
4744 BTRFS_BLOCK_GROUP_RAID10))
4745 return stripped | BTRFS_BLOCK_GROUP_DUP;
4746 return flags;
4747 } else {
4748 /* they already had raid on here, just return */
4749 if (flags & stripped)
4750 return flags;
4751
4752 stripped |= BTRFS_BLOCK_GROUP_DUP;
4753 stripped = flags & ~stripped;
4754
4755 /* switch duplicated blocks with raid1 */
4756 if (flags & BTRFS_BLOCK_GROUP_DUP)
4757 return stripped | BTRFS_BLOCK_GROUP_RAID1;
4758
4759 /* turn single device chunks into raid0 */
4760 return stripped | BTRFS_BLOCK_GROUP_RAID0;
4761 }
4762 return flags;
4763 }
4764
4765 int __alloc_chunk_for_shrink(struct btrfs_root *root,
4766 struct btrfs_block_group_cache *shrink_block_group,
4767 int force)
4768 {
4769 struct btrfs_trans_handle *trans;
4770 u64 new_alloc_flags;
4771 u64 calc;
4772
4773 spin_lock(&shrink_block_group->lock);
4774 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
4775 spin_unlock(&shrink_block_group->lock);
4776
4777 trans = btrfs_start_transaction(root, 1);
4778 spin_lock(&shrink_block_group->lock);
4779
4780 new_alloc_flags = update_block_group_flags(root,
4781 shrink_block_group->flags);
4782 if (new_alloc_flags != shrink_block_group->flags) {
4783 calc =
4784 btrfs_block_group_used(&shrink_block_group->item);
4785 } else {
4786 calc = shrink_block_group->key.offset;
4787 }
4788 spin_unlock(&shrink_block_group->lock);
4789
4790 do_chunk_alloc(trans, root->fs_info->extent_root,
4791 calc + 2 * 1024 * 1024, new_alloc_flags, force);
4792
4793 btrfs_end_transaction(trans, root);
4794 } else
4795 spin_unlock(&shrink_block_group->lock);
4796 return 0;
4797 }
4798
4799 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4800 struct btrfs_root *root,
4801 u64 objectid, u64 size)
4802 {
4803 struct btrfs_path *path;
4804 struct btrfs_inode_item *item;
4805 struct extent_buffer *leaf;
4806 int ret;
4807
4808 path = btrfs_alloc_path();
4809 if (!path)
4810 return -ENOMEM;
4811
4812 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4813 if (ret)
4814 goto out;
4815
4816 leaf = path->nodes[0];
4817 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4818 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4819 btrfs_set_inode_generation(leaf, item, 1);
4820 btrfs_set_inode_size(leaf, item, size);
4821 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4822 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NODATASUM |
4823 BTRFS_INODE_NOCOMPRESS);
4824 btrfs_mark_buffer_dirty(leaf);
4825 btrfs_release_path(root, path);
4826 out:
4827 btrfs_free_path(path);
4828 return ret;
4829 }
4830
4831 static struct inode noinline *create_reloc_inode(struct btrfs_fs_info *fs_info,
4832 struct btrfs_block_group_cache *group)
4833 {
4834 struct inode *inode = NULL;
4835 struct btrfs_trans_handle *trans;
4836 struct btrfs_root *root;
4837 struct btrfs_key root_key;
4838 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4839 int err = 0;
4840
4841 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4842 root_key.type = BTRFS_ROOT_ITEM_KEY;
4843 root_key.offset = (u64)-1;
4844 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
4845 if (IS_ERR(root))
4846 return ERR_CAST(root);
4847
4848 trans = btrfs_start_transaction(root, 1);
4849 BUG_ON(!trans);
4850
4851 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
4852 if (err)
4853 goto out;
4854
4855 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
4856 BUG_ON(err);
4857
4858 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
4859 group->key.offset, 0, group->key.offset,
4860 0, 0, 0);
4861 BUG_ON(err);
4862
4863 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
4864 if (inode->i_state & I_NEW) {
4865 BTRFS_I(inode)->root = root;
4866 BTRFS_I(inode)->location.objectid = objectid;
4867 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
4868 BTRFS_I(inode)->location.offset = 0;
4869 btrfs_read_locked_inode(inode);
4870 unlock_new_inode(inode);
4871 BUG_ON(is_bad_inode(inode));
4872 } else {
4873 BUG_ON(1);
4874 }
4875
4876 err = btrfs_orphan_add(trans, inode);
4877 out:
4878 btrfs_end_transaction(trans, root);
4879 if (err) {
4880 if (inode)
4881 iput(inode);
4882 inode = ERR_PTR(err);
4883 }
4884 return inode;
4885 }
4886
4887 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
4888 {
4889 struct btrfs_trans_handle *trans;
4890 struct btrfs_path *path;
4891 struct btrfs_fs_info *info = root->fs_info;
4892 struct extent_buffer *leaf;
4893 struct inode *reloc_inode;
4894 struct btrfs_block_group_cache *block_group;
4895 struct btrfs_key key;
4896 u64 skipped;
4897 u64 cur_byte;
4898 u64 total_found;
4899 u32 nritems;
4900 int ret;
4901 int progress;
4902 int pass = 0;
4903
4904 root = root->fs_info->extent_root;
4905
4906 block_group = btrfs_lookup_block_group(info, group_start);
4907 BUG_ON(!block_group);
4908
4909 printk("btrfs relocating block group %llu flags %llu\n",
4910 (unsigned long long)block_group->key.objectid,
4911 (unsigned long long)block_group->flags);
4912
4913 path = btrfs_alloc_path();
4914 BUG_ON(!path);
4915
4916 reloc_inode = create_reloc_inode(info, block_group);
4917 BUG_ON(IS_ERR(reloc_inode));
4918
4919 __alloc_chunk_for_shrink(root, block_group, 1);
4920 block_group->ro = 1;
4921 block_group->space_info->total_bytes -= block_group->key.offset;
4922
4923 btrfs_start_delalloc_inodes(info->tree_root);
4924 btrfs_wait_ordered_extents(info->tree_root, 0);
4925 again:
4926 skipped = 0;
4927 total_found = 0;
4928 progress = 0;
4929 key.objectid = block_group->key.objectid;
4930 key.offset = 0;
4931 key.type = 0;
4932 cur_byte = key.objectid;
4933
4934 trans = btrfs_start_transaction(info->tree_root, 1);
4935 btrfs_commit_transaction(trans, info->tree_root);
4936
4937 mutex_lock(&root->fs_info->cleaner_mutex);
4938 btrfs_clean_old_snapshots(info->tree_root);
4939 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
4940 mutex_unlock(&root->fs_info->cleaner_mutex);
4941
4942 while(1) {
4943 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4944 if (ret < 0)
4945 goto out;
4946 next:
4947 leaf = path->nodes[0];
4948 nritems = btrfs_header_nritems(leaf);
4949 if (path->slots[0] >= nritems) {
4950 ret = btrfs_next_leaf(root, path);
4951 if (ret < 0)
4952 goto out;
4953 if (ret == 1) {
4954 ret = 0;
4955 break;
4956 }
4957 leaf = path->nodes[0];
4958 nritems = btrfs_header_nritems(leaf);
4959 }
4960
4961 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4962
4963 if (key.objectid >= block_group->key.objectid +
4964 block_group->key.offset)
4965 break;
4966
4967 if (progress && need_resched()) {
4968 btrfs_release_path(root, path);
4969 cond_resched();
4970 progress = 0;
4971 continue;
4972 }
4973 progress = 1;
4974
4975 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
4976 key.objectid + key.offset <= cur_byte) {
4977 path->slots[0]++;
4978 goto next;
4979 }
4980
4981 total_found++;
4982 cur_byte = key.objectid + key.offset;
4983 btrfs_release_path(root, path);
4984
4985 __alloc_chunk_for_shrink(root, block_group, 0);
4986 ret = relocate_one_extent(root, path, &key, block_group,
4987 reloc_inode, pass);
4988 BUG_ON(ret < 0);
4989 if (ret > 0)
4990 skipped++;
4991
4992 key.objectid = cur_byte;
4993 key.type = 0;
4994 key.offset = 0;
4995 }
4996
4997 btrfs_release_path(root, path);
4998
4999 if (pass == 0) {
5000 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
5001 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
5002 WARN_ON(reloc_inode->i_mapping->nrpages);
5003 }
5004
5005 if (total_found > 0) {
5006 printk("btrfs found %llu extents in pass %d\n",
5007 (unsigned long long)total_found, pass);
5008 pass++;
5009 if (total_found == skipped && pass > 2) {
5010 iput(reloc_inode);
5011 reloc_inode = create_reloc_inode(info, block_group);
5012 pass = 0;
5013 }
5014 goto again;
5015 }
5016
5017 /* delete reloc_inode */
5018 iput(reloc_inode);
5019
5020 /* unpin extents in this range */
5021 trans = btrfs_start_transaction(info->tree_root, 1);
5022 btrfs_commit_transaction(trans, info->tree_root);
5023
5024 spin_lock(&block_group->lock);
5025 WARN_ON(block_group->pinned > 0);
5026 WARN_ON(block_group->reserved > 0);
5027 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
5028 spin_unlock(&block_group->lock);
5029 ret = 0;
5030 out:
5031 btrfs_free_path(path);
5032 return ret;
5033 }
5034
5035 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
5036 struct btrfs_key *key)
5037 {
5038 int ret = 0;
5039 struct btrfs_key found_key;
5040 struct extent_buffer *leaf;
5041 int slot;
5042
5043 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
5044 if (ret < 0)
5045 goto out;
5046
5047 while(1) {
5048 slot = path->slots[0];
5049 leaf = path->nodes[0];
5050 if (slot >= btrfs_header_nritems(leaf)) {
5051 ret = btrfs_next_leaf(root, path);
5052 if (ret == 0)
5053 continue;
5054 if (ret < 0)
5055 goto out;
5056 break;
5057 }
5058 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5059
5060 if (found_key.objectid >= key->objectid &&
5061 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
5062 ret = 0;
5063 goto out;
5064 }
5065 path->slots[0]++;
5066 }
5067 ret = -ENOENT;
5068 out:
5069 return ret;
5070 }
5071
5072 int btrfs_free_block_groups(struct btrfs_fs_info *info)
5073 {
5074 struct btrfs_block_group_cache *block_group;
5075 struct rb_node *n;
5076
5077 spin_lock(&info->block_group_cache_lock);
5078 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
5079 block_group = rb_entry(n, struct btrfs_block_group_cache,
5080 cache_node);
5081 rb_erase(&block_group->cache_node,
5082 &info->block_group_cache_tree);
5083 spin_unlock(&info->block_group_cache_lock);
5084
5085 btrfs_remove_free_space_cache(block_group);
5086 down_write(&block_group->space_info->groups_sem);
5087 list_del(&block_group->list);
5088 up_write(&block_group->space_info->groups_sem);
5089 kfree(block_group);
5090
5091 spin_lock(&info->block_group_cache_lock);
5092 }
5093 spin_unlock(&info->block_group_cache_lock);
5094 return 0;
5095 }
5096
5097 int btrfs_read_block_groups(struct btrfs_root *root)
5098 {
5099 struct btrfs_path *path;
5100 int ret;
5101 struct btrfs_block_group_cache *cache;
5102 struct btrfs_fs_info *info = root->fs_info;
5103 struct btrfs_space_info *space_info;
5104 struct btrfs_key key;
5105 struct btrfs_key found_key;
5106 struct extent_buffer *leaf;
5107
5108 root = info->extent_root;
5109 key.objectid = 0;
5110 key.offset = 0;
5111 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5112 path = btrfs_alloc_path();
5113 if (!path)
5114 return -ENOMEM;
5115
5116 while(1) {
5117 ret = find_first_block_group(root, path, &key);
5118 if (ret > 0) {
5119 ret = 0;
5120 goto error;
5121 }
5122 if (ret != 0)
5123 goto error;
5124
5125 leaf = path->nodes[0];
5126 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5127 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5128 if (!cache) {
5129 ret = -ENOMEM;
5130 break;
5131 }
5132
5133 spin_lock_init(&cache->lock);
5134 mutex_init(&cache->alloc_mutex);
5135 INIT_LIST_HEAD(&cache->list);
5136 read_extent_buffer(leaf, &cache->item,
5137 btrfs_item_ptr_offset(leaf, path->slots[0]),
5138 sizeof(cache->item));
5139 memcpy(&cache->key, &found_key, sizeof(found_key));
5140
5141 key.objectid = found_key.objectid + found_key.offset;
5142 btrfs_release_path(root, path);
5143 cache->flags = btrfs_block_group_flags(&cache->item);
5144
5145 ret = update_space_info(info, cache->flags, found_key.offset,
5146 btrfs_block_group_used(&cache->item),
5147 &space_info);
5148 BUG_ON(ret);
5149 cache->space_info = space_info;
5150 down_write(&space_info->groups_sem);
5151 list_add_tail(&cache->list, &space_info->block_groups);
5152 up_write(&space_info->groups_sem);
5153
5154 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5155 BUG_ON(ret);
5156
5157 set_avail_alloc_bits(root->fs_info, cache->flags);
5158 }
5159 ret = 0;
5160 error:
5161 btrfs_free_path(path);
5162 return ret;
5163 }
5164
5165 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
5166 struct btrfs_root *root, u64 bytes_used,
5167 u64 type, u64 chunk_objectid, u64 chunk_offset,
5168 u64 size)
5169 {
5170 int ret;
5171 struct btrfs_root *extent_root;
5172 struct btrfs_block_group_cache *cache;
5173
5174 extent_root = root->fs_info->extent_root;
5175
5176 root->fs_info->last_trans_new_blockgroup = trans->transid;
5177
5178 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5179 if (!cache)
5180 return -ENOMEM;
5181
5182 cache->key.objectid = chunk_offset;
5183 cache->key.offset = size;
5184 spin_lock_init(&cache->lock);
5185 mutex_init(&cache->alloc_mutex);
5186 INIT_LIST_HEAD(&cache->list);
5187 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5188
5189 btrfs_set_block_group_used(&cache->item, bytes_used);
5190 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
5191 cache->flags = type;
5192 btrfs_set_block_group_flags(&cache->item, type);
5193
5194 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
5195 &cache->space_info);
5196 BUG_ON(ret);
5197 down_write(&cache->space_info->groups_sem);
5198 list_add_tail(&cache->list, &cache->space_info->block_groups);
5199 up_write(&cache->space_info->groups_sem);
5200
5201 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5202 BUG_ON(ret);
5203
5204 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
5205 sizeof(cache->item));
5206 BUG_ON(ret);
5207
5208 finish_current_insert(trans, extent_root, 0);
5209 ret = del_pending_extents(trans, extent_root, 0);
5210 BUG_ON(ret);
5211 set_avail_alloc_bits(extent_root->fs_info, type);
5212
5213 return 0;
5214 }
5215
5216 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
5217 struct btrfs_root *root, u64 group_start)
5218 {
5219 struct btrfs_path *path;
5220 struct btrfs_block_group_cache *block_group;
5221 struct btrfs_key key;
5222 int ret;
5223
5224 root = root->fs_info->extent_root;
5225
5226 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
5227 BUG_ON(!block_group);
5228
5229 memcpy(&key, &block_group->key, sizeof(key));
5230
5231 path = btrfs_alloc_path();
5232 BUG_ON(!path);
5233
5234 btrfs_remove_free_space_cache(block_group);
5235 rb_erase(&block_group->cache_node,
5236 &root->fs_info->block_group_cache_tree);
5237 down_write(&block_group->space_info->groups_sem);
5238 list_del(&block_group->list);
5239 up_write(&block_group->space_info->groups_sem);
5240
5241 /*
5242 memset(shrink_block_group, 0, sizeof(*shrink_block_group));
5243 kfree(shrink_block_group);
5244 */
5245
5246 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
5247 if (ret > 0)
5248 ret = -EIO;
5249 if (ret < 0)
5250 goto out;
5251
5252 ret = btrfs_del_item(trans, root, path);
5253 out:
5254 btrfs_free_path(path);
5255 return ret;
5256 }
Linux kernel - Deliverables
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