projects / deliverable / linux.git / blame_incremental
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (non-incremental) | history | HEAD
Btrfs: allow clone of an arbitrary file range
[deliverable/linux.git] / fs / btrfs / extent-tree.c
... / ...
CommitLineData
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
36struct 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
47static int finish_current_insert(struct btrfs_trans_handle *trans, struct
48 btrfs_root *extent_root, int all);
49static int del_pending_extents(struct btrfs_trans_handle *trans, struct
50 btrfs_root *extent_root, int all);
51static 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
56static 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 */
65int 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 */
101static struct btrfs_block_group_cache *
102block_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 */
143static 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
180static 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 }
259next:
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;
272err:
273 btrfs_free_path(path);
274 return ret;
275}
276
277/*
278 * return the block group that starts at or after bytenr
279 */
280struct 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 */
294struct 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
305static 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
319static 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
328static 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 }
376again:
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 }
409found:
410 return found_group;
411}
412
413struct 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 */
425int 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
521static 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;
558out:
559 return ret;
560}
561
562static 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]);
616out:
617 btrfs_release_path(root, path);
618 return ret;
619}
620
621static 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
645static 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);
716out:
717 btrfs_free_path(path);
718 return ret;
719}
720
721int 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
738static 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
798int 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
814int 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
822int 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);
850out:
851 btrfs_free_path(path);
852 return 0;
853}
854
855int 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;
928out:
929 btrfs_free_path(path);
930 return ret;
931}
932
933int 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 }
1010out:
1011 return ret;
1012}
1013
1014int 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 }
1096out:
1097 if (nr_extents) {
1098 if (level == 0)
1099 *nr_extents = nr_file_extents;
1100 else
1101 *nr_extents = nritems;
1102 }
1103 return 0;
1104fail:
1105 WARN_ON(1);
1106 return ret;
1107}
1108
1109int 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;
1177fail:
1178 WARN_ON(1);
1179 return -1;
1180}
1181
1182static 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);
1203fail:
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
1214int 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
1264static 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
1299static 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
1315static 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
1343static 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) {
1402printk("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);
1410out_unlock:
1411 mutex_unlock(&extent_root->fs_info->chunk_mutex);
1412out:
1413 return ret;
1414}
1415
1416static 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
1466static 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
1477int 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
1520static 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
1550int 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
1571int 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
1601static 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
1708static 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);
1743pinit:
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 */
1753static 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 */
1915static 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);
1963free_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 */
2015static 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
2078int 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
2092static 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 */
2107static 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 (empty_size)
2178 extra_loop = 1;
2179
2180 if (!block_group)
2181 goto new_group_no_lock;
2182
2183 mutex_lock(&block_group->alloc_mutex);
2184 if (unlikely(!block_group_bits(block_group, data)))
2185 goto new_group;
2186
2187 ret = cache_block_group(root, block_group);
2188 if (ret) {
2189 mutex_unlock(&block_group->alloc_mutex);
2190 break;
2191 }
2192
2193 if (block_group->ro)
2194 goto new_group;
2195
2196 free_space = btrfs_find_free_space(block_group, search_start,
2197 total_needed);
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 empty_size += empty_cluster;
2216 last_wanted = 0;
2217 /*
2218 * if search_start is still in this block group
2219 * then we just re-search this block group
2220 */
2221 if (search_start >= start &&
2222 search_start < end) {
2223 mutex_unlock(&block_group->alloc_mutex);
2224 continue;
2225 }
2226
2227 /* else we go to the next block group */
2228 goto new_group;
2229 }
2230
2231 if (exclude_nr > 0 &&
2232 (search_start + num_bytes > exclude_start &&
2233 search_start < exclude_start + exclude_nr)) {
2234 search_start = exclude_start + exclude_nr;
2235 /*
2236 * if search_start is still in this block group
2237 * then we just re-search this block group
2238 */
2239 if (search_start >= start &&
2240 search_start < end) {
2241 mutex_unlock(&block_group->alloc_mutex);
2242 last_wanted = 0;
2243 continue;
2244 }
2245
2246 /* else we go to the next block group */
2247 goto new_group;
2248 }
2249
2250 ins->objectid = search_start;
2251 ins->offset = num_bytes;
2252
2253 btrfs_remove_free_space_lock(block_group, search_start,
2254 num_bytes);
2255 /* we are all good, lets return */
2256 mutex_unlock(&block_group->alloc_mutex);
2257 break;
2258 }
2259new_group:
2260 mutex_unlock(&block_group->alloc_mutex);
2261new_group_no_lock:
2262 /* don't try to compare new allocations against the
2263 * last allocation any more
2264 */
2265 last_wanted = 0;
2266
2267 /*
2268 * Here's how this works.
2269 * loop == 0: we were searching a block group via a hint
2270 * and didn't find anything, so we start at
2271 * the head of the block groups and keep searching
2272 * loop == 1: we're searching through all of the block groups
2273 * if we hit the head again we have searched
2274 * all of the block groups for this space and we
2275 * need to try and allocate, if we cant error out.
2276 * loop == 2: we allocated more space and are looping through
2277 * all of the block groups again.
2278 */
2279 if (loop == 0) {
2280 head = &space_info->block_groups;
2281 cur = head->next;
2282 loop++;
2283 } else if (loop == 1 && cur == head) {
2284 int keep_going;
2285
2286 /* at this point we give up on the empty_size
2287 * allocations and just try to allocate the min
2288 * space.
2289 *
2290 * The extra_loop field was set if an empty_size
2291 * allocation was attempted above, and if this
2292 * is try we need to try the loop again without
2293 * the additional empty_size.
2294 */
2295 total_needed -= empty_size;
2296 empty_size = 0;
2297 keep_going = extra_loop;
2298 loop++;
2299
2300 if (allowed_chunk_alloc && !chunk_alloc_done) {
2301 up_read(&space_info->groups_sem);
2302 ret = do_chunk_alloc(trans, root, num_bytes +
2303 2 * 1024 * 1024, data, 1);
2304 down_read(&space_info->groups_sem);
2305 if (ret < 0)
2306 goto loop_check;
2307 head = &space_info->block_groups;
2308 /*
2309 * we've allocated a new chunk, keep
2310 * trying
2311 */
2312 keep_going = 1;
2313 chunk_alloc_done = 1;
2314 } else if (!allowed_chunk_alloc) {
2315 space_info->force_alloc = 1;
2316 }
2317loop_check:
2318 if (keep_going) {
2319 cur = head->next;
2320 extra_loop = 0;
2321 } else {
2322 break;
2323 }
2324 } else if (cur == head) {
2325 break;
2326 }
2327
2328 block_group = list_entry(cur, struct btrfs_block_group_cache,
2329 list);
2330 search_start = block_group->key.objectid;
2331 cur = cur->next;
2332 }
2333
2334 /* we found what we needed */
2335 if (ins->objectid) {
2336 if (!(data & BTRFS_BLOCK_GROUP_DATA))
2337 trans->block_group = block_group;
2338
2339 if (last_ptr)
2340 *last_ptr = ins->objectid + ins->offset;
2341 ret = 0;
2342 } else if (!ret) {
2343 ret = -ENOSPC;
2344 }
2345
2346 up_read(&space_info->groups_sem);
2347 return ret;
2348}
2349
2350static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
2351{
2352 struct btrfs_block_group_cache *cache;
2353 struct list_head *l;
2354
2355 printk(KERN_INFO "space_info has %Lu free, is %sfull\n",
2356 info->total_bytes - info->bytes_used - info->bytes_pinned -
2357 info->bytes_reserved, (info->full) ? "" : "not ");
2358
2359 down_read(&info->groups_sem);
2360 list_for_each(l, &info->block_groups) {
2361 cache = list_entry(l, struct btrfs_block_group_cache, list);
2362 spin_lock(&cache->lock);
2363 printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used "
2364 "%Lu pinned %Lu reserved\n",
2365 cache->key.objectid, cache->key.offset,
2366 btrfs_block_group_used(&cache->item),
2367 cache->pinned, cache->reserved);
2368 btrfs_dump_free_space(cache, bytes);
2369 spin_unlock(&cache->lock);
2370 }
2371 up_read(&info->groups_sem);
2372}
2373
2374static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2375 struct btrfs_root *root,
2376 u64 num_bytes, u64 min_alloc_size,
2377 u64 empty_size, u64 hint_byte,
2378 u64 search_end, struct btrfs_key *ins,
2379 u64 data)
2380{
2381 int ret;
2382 u64 search_start = 0;
2383 u64 alloc_profile;
2384 struct btrfs_fs_info *info = root->fs_info;
2385
2386 if (data) {
2387 alloc_profile = info->avail_data_alloc_bits &
2388 info->data_alloc_profile;
2389 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2390 } else if (root == root->fs_info->chunk_root) {
2391 alloc_profile = info->avail_system_alloc_bits &
2392 info->system_alloc_profile;
2393 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2394 } else {
2395 alloc_profile = info->avail_metadata_alloc_bits &
2396 info->metadata_alloc_profile;
2397 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2398 }
2399again:
2400 data = reduce_alloc_profile(root, data);
2401 /*
2402 * the only place that sets empty_size is btrfs_realloc_node, which
2403 * is not called recursively on allocations
2404 */
2405 if (empty_size || root->ref_cows) {
2406 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
2407 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2408 2 * 1024 * 1024,
2409 BTRFS_BLOCK_GROUP_METADATA |
2410 (info->metadata_alloc_profile &
2411 info->avail_metadata_alloc_bits), 0);
2412 }
2413 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2414 num_bytes + 2 * 1024 * 1024, data, 0);
2415 }
2416
2417 WARN_ON(num_bytes < root->sectorsize);
2418 ret = find_free_extent(trans, root, num_bytes, empty_size,
2419 search_start, search_end, hint_byte, ins,
2420 trans->alloc_exclude_start,
2421 trans->alloc_exclude_nr, data);
2422
2423 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
2424 num_bytes = num_bytes >> 1;
2425 num_bytes = num_bytes & ~(root->sectorsize - 1);
2426 num_bytes = max(num_bytes, min_alloc_size);
2427 do_chunk_alloc(trans, root->fs_info->extent_root,
2428 num_bytes, data, 1);
2429 goto again;
2430 }
2431 if (ret) {
2432 struct btrfs_space_info *sinfo;
2433
2434 sinfo = __find_space_info(root->fs_info, data);
2435 printk("allocation failed flags %Lu, wanted %Lu\n",
2436 data, num_bytes);
2437 dump_space_info(sinfo, num_bytes);
2438 BUG();
2439 }
2440
2441 return ret;
2442}
2443
2444int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
2445{
2446 struct btrfs_block_group_cache *cache;
2447
2448 cache = btrfs_lookup_block_group(root->fs_info, start);
2449 if (!cache) {
2450 printk(KERN_ERR "Unable to find block group for %Lu\n", start);
2451 return -ENOSPC;
2452 }
2453 btrfs_add_free_space(cache, start, len);
2454 update_reserved_extents(root, start, len, 0);
2455 return 0;
2456}
2457
2458int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2459 struct btrfs_root *root,
2460 u64 num_bytes, u64 min_alloc_size,
2461 u64 empty_size, u64 hint_byte,
2462 u64 search_end, struct btrfs_key *ins,
2463 u64 data)
2464{
2465 int ret;
2466 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
2467 empty_size, hint_byte, search_end, ins,
2468 data);
2469 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2470 return ret;
2471}
2472
2473static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2474 struct btrfs_root *root, u64 parent,
2475 u64 root_objectid, u64 ref_generation,
2476 u64 owner, struct btrfs_key *ins)
2477{
2478 int ret;
2479 int pending_ret;
2480 u64 super_used;
2481 u64 root_used;
2482 u64 num_bytes = ins->offset;
2483 u32 sizes[2];
2484 struct btrfs_fs_info *info = root->fs_info;
2485 struct btrfs_root *extent_root = info->extent_root;
2486 struct btrfs_extent_item *extent_item;
2487 struct btrfs_extent_ref *ref;
2488 struct btrfs_path *path;
2489 struct btrfs_key keys[2];
2490
2491 if (parent == 0)
2492 parent = ins->objectid;
2493
2494 /* block accounting for super block */
2495 spin_lock_irq(&info->delalloc_lock);
2496 super_used = btrfs_super_bytes_used(&info->super_copy);
2497 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
2498 spin_unlock_irq(&info->delalloc_lock);
2499
2500 /* block accounting for root item */
2501 root_used = btrfs_root_used(&root->root_item);
2502 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
2503
2504 if (root == extent_root) {
2505 struct pending_extent_op *extent_op;
2506
2507 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2508 BUG_ON(!extent_op);
2509
2510 extent_op->type = PENDING_EXTENT_INSERT;
2511 extent_op->bytenr = ins->objectid;
2512 extent_op->num_bytes = ins->offset;
2513 extent_op->parent = parent;
2514 extent_op->orig_parent = 0;
2515 extent_op->generation = ref_generation;
2516 extent_op->orig_generation = 0;
2517 extent_op->level = (int)owner;
2518
2519 mutex_lock(&root->fs_info->extent_ins_mutex);
2520 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2521 ins->objectid + ins->offset - 1,
2522 EXTENT_WRITEBACK, GFP_NOFS);
2523 set_state_private(&root->fs_info->extent_ins,
2524 ins->objectid, (unsigned long)extent_op);
2525 mutex_unlock(&root->fs_info->extent_ins_mutex);
2526 goto update_block;
2527 }
2528
2529 memcpy(&keys[0], ins, sizeof(*ins));
2530 keys[1].objectid = ins->objectid;
2531 keys[1].type = BTRFS_EXTENT_REF_KEY;
2532 keys[1].offset = parent;
2533 sizes[0] = sizeof(*extent_item);
2534 sizes[1] = sizeof(*ref);
2535
2536 path = btrfs_alloc_path();
2537 BUG_ON(!path);
2538
2539 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
2540 sizes, 2);
2541 BUG_ON(ret);
2542
2543 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2544 struct btrfs_extent_item);
2545 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
2546 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
2547 struct btrfs_extent_ref);
2548
2549 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
2550 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
2551 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
2552 btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
2553
2554 btrfs_mark_buffer_dirty(path->nodes[0]);
2555
2556 trans->alloc_exclude_start = 0;
2557 trans->alloc_exclude_nr = 0;
2558 btrfs_free_path(path);
2559 finish_current_insert(trans, extent_root, 0);
2560 pending_ret = del_pending_extents(trans, extent_root, 0);
2561
2562 if (ret)
2563 goto out;
2564 if (pending_ret) {
2565 ret = pending_ret;
2566 goto out;
2567 }
2568
2569update_block:
2570 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
2571 if (ret) {
2572 printk("update block group failed for %Lu %Lu\n",
2573 ins->objectid, ins->offset);
2574 BUG();
2575 }
2576out:
2577 return ret;
2578}
2579
2580int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2581 struct btrfs_root *root, u64 parent,
2582 u64 root_objectid, u64 ref_generation,
2583 u64 owner, struct btrfs_key *ins)
2584{
2585 int ret;
2586
2587 if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
2588 return 0;
2589 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
2590 ref_generation, owner, ins);
2591 update_reserved_extents(root, ins->objectid, ins->offset, 0);
2592 return ret;
2593}
2594
2595/*
2596 * this is used by the tree logging recovery code. It records that
2597 * an extent has been allocated and makes sure to clear the free
2598 * space cache bits as well
2599 */
2600int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
2601 struct btrfs_root *root, u64 parent,
2602 u64 root_objectid, u64 ref_generation,
2603 u64 owner, struct btrfs_key *ins)
2604{
2605 int ret;
2606 struct btrfs_block_group_cache *block_group;
2607
2608 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2609 mutex_lock(&block_group->alloc_mutex);
2610 cache_block_group(root, block_group);
2611
2612 ret = btrfs_remove_free_space_lock(block_group, ins->objectid,
2613 ins->offset);
2614 mutex_unlock(&block_group->alloc_mutex);
2615 BUG_ON(ret);
2616 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
2617 ref_generation, owner, ins);
2618 return ret;
2619}
2620
2621/*
2622 * finds a free extent and does all the dirty work required for allocation
2623 * returns the key for the extent through ins, and a tree buffer for
2624 * the first block of the extent through buf.
2625 *
2626 * returns 0 if everything worked, non-zero otherwise.
2627 */
2628int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
2629 struct btrfs_root *root,
2630 u64 num_bytes, u64 parent, u64 min_alloc_size,
2631 u64 root_objectid, u64 ref_generation,
2632 u64 owner_objectid, u64 empty_size, u64 hint_byte,
2633 u64 search_end, struct btrfs_key *ins, u64 data)
2634{
2635 int ret;
2636
2637 ret = __btrfs_reserve_extent(trans, root, num_bytes,
2638 min_alloc_size, empty_size, hint_byte,
2639 search_end, ins, data);
2640 BUG_ON(ret);
2641 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
2642 ret = __btrfs_alloc_reserved_extent(trans, root, parent,
2643 root_objectid, ref_generation,
2644 owner_objectid, ins);
2645 BUG_ON(ret);
2646
2647 } else {
2648 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2649 }
2650 return ret;
2651}
2652
2653struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
2654 struct btrfs_root *root,
2655 u64 bytenr, u32 blocksize)
2656{
2657 struct extent_buffer *buf;
2658
2659 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
2660 if (!buf)
2661 return ERR_PTR(-ENOMEM);
2662 btrfs_set_header_generation(buf, trans->transid);
2663 btrfs_tree_lock(buf);
2664 clean_tree_block(trans, root, buf);
2665 btrfs_set_buffer_uptodate(buf);
2666 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2667 set_extent_dirty(&root->dirty_log_pages, buf->start,
2668 buf->start + buf->len - 1, GFP_NOFS);
2669 } else {
2670 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
2671 buf->start + buf->len - 1, GFP_NOFS);
2672 }
2673 trans->blocks_used++;
2674 return buf;
2675}
2676
2677/*
2678 * helper function to allocate a block for a given tree
2679 * returns the tree buffer or NULL.
2680 */
2681struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2682 struct btrfs_root *root,
2683 u32 blocksize, u64 parent,
2684 u64 root_objectid,
2685 u64 ref_generation,
2686 int level,
2687 u64 hint,
2688 u64 empty_size)
2689{
2690 struct btrfs_key ins;
2691 int ret;
2692 struct extent_buffer *buf;
2693
2694 ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
2695 root_objectid, ref_generation, level,
2696 empty_size, hint, (u64)-1, &ins, 0);
2697 if (ret) {
2698 BUG_ON(ret > 0);
2699 return ERR_PTR(ret);
2700 }
2701
2702 buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
2703 return buf;
2704}
2705
2706int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
2707 struct btrfs_root *root, struct extent_buffer *leaf)
2708{
2709 u64 leaf_owner;
2710 u64 leaf_generation;
2711 struct btrfs_key key;
2712 struct btrfs_file_extent_item *fi;
2713 int i;
2714 int nritems;
2715 int ret;
2716
2717 BUG_ON(!btrfs_is_leaf(leaf));
2718 nritems = btrfs_header_nritems(leaf);
2719 leaf_owner = btrfs_header_owner(leaf);
2720 leaf_generation = btrfs_header_generation(leaf);
2721
2722 for (i = 0; i < nritems; i++) {
2723 u64 disk_bytenr;
2724 cond_resched();
2725
2726 btrfs_item_key_to_cpu(leaf, &key, i);
2727 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2728 continue;
2729 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2730 if (btrfs_file_extent_type(leaf, fi) ==
2731 BTRFS_FILE_EXTENT_INLINE)
2732 continue;
2733 /*
2734 * FIXME make sure to insert a trans record that
2735 * repeats the snapshot del on crash
2736 */
2737 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2738 if (disk_bytenr == 0)
2739 continue;
2740
2741 ret = __btrfs_free_extent(trans, root, disk_bytenr,
2742 btrfs_file_extent_disk_num_bytes(leaf, fi),
2743 leaf->start, leaf_owner, leaf_generation,
2744 key.objectid, 0);
2745 BUG_ON(ret);
2746
2747 atomic_inc(&root->fs_info->throttle_gen);
2748 wake_up(&root->fs_info->transaction_throttle);
2749 cond_resched();
2750 }
2751 return 0;
2752}
2753
2754static int noinline cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
2755 struct btrfs_root *root,
2756 struct btrfs_leaf_ref *ref)
2757{
2758 int i;
2759 int ret;
2760 struct btrfs_extent_info *info = ref->extents;
2761
2762 for (i = 0; i < ref->nritems; i++) {
2763 ret = __btrfs_free_extent(trans, root, info->bytenr,
2764 info->num_bytes, ref->bytenr,
2765 ref->owner, ref->generation,
2766 info->objectid, 0);
2767
2768 atomic_inc(&root->fs_info->throttle_gen);
2769 wake_up(&root->fs_info->transaction_throttle);
2770 cond_resched();
2771
2772 BUG_ON(ret);
2773 info++;
2774 }
2775
2776 return 0;
2777}
2778
2779int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len,
2780 u32 *refs)
2781{
2782 int ret;
2783
2784 ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
2785 BUG_ON(ret);
2786
2787#if 0 // some debugging code in case we see problems here
2788 /* if the refs count is one, it won't get increased again. But
2789 * if the ref count is > 1, someone may be decreasing it at
2790 * the same time we are.
2791 */
2792 if (*refs != 1) {
2793 struct extent_buffer *eb = NULL;
2794 eb = btrfs_find_create_tree_block(root, start, len);
2795 if (eb)
2796 btrfs_tree_lock(eb);
2797
2798 mutex_lock(&root->fs_info->alloc_mutex);
2799 ret = lookup_extent_ref(NULL, root, start, len, refs);
2800 BUG_ON(ret);
2801 mutex_unlock(&root->fs_info->alloc_mutex);
2802
2803 if (eb) {
2804 btrfs_tree_unlock(eb);
2805 free_extent_buffer(eb);
2806 }
2807 if (*refs == 1) {
2808 printk("block %llu went down to one during drop_snap\n",
2809 (unsigned long long)start);
2810 }
2811
2812 }
2813#endif
2814
2815 cond_resched();
2816 return ret;
2817}
2818
2819/*
2820 * helper function for drop_snapshot, this walks down the tree dropping ref
2821 * counts as it goes.
2822 */
2823static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2824 struct btrfs_root *root,
2825 struct btrfs_path *path, int *level)
2826{
2827 u64 root_owner;
2828 u64 root_gen;
2829 u64 bytenr;
2830 u64 ptr_gen;
2831 struct extent_buffer *next;
2832 struct extent_buffer *cur;
2833 struct extent_buffer *parent;
2834 struct btrfs_leaf_ref *ref;
2835 u32 blocksize;
2836 int ret;
2837 u32 refs;
2838
2839 WARN_ON(*level < 0);
2840 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2841 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
2842 path->nodes[*level]->len, &refs);
2843 BUG_ON(ret);
2844 if (refs > 1)
2845 goto out;
2846
2847 /*
2848 * walk down to the last node level and free all the leaves
2849 */
2850 while(*level >= 0) {
2851 WARN_ON(*level < 0);
2852 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2853 cur = path->nodes[*level];
2854
2855 if (btrfs_header_level(cur) != *level)
2856 WARN_ON(1);
2857
2858 if (path->slots[*level] >=
2859 btrfs_header_nritems(cur))
2860 break;
2861 if (*level == 0) {
2862 ret = btrfs_drop_leaf_ref(trans, root, cur);
2863 BUG_ON(ret);
2864 break;
2865 }
2866 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2867 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2868 blocksize = btrfs_level_size(root, *level - 1);
2869
2870 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
2871 BUG_ON(ret);
2872 if (refs != 1) {
2873 parent = path->nodes[*level];
2874 root_owner = btrfs_header_owner(parent);
2875 root_gen = btrfs_header_generation(parent);
2876 path->slots[*level]++;
2877
2878 ret = __btrfs_free_extent(trans, root, bytenr,
2879 blocksize, parent->start,
2880 root_owner, root_gen,
2881 *level - 1, 1);
2882 BUG_ON(ret);
2883
2884 atomic_inc(&root->fs_info->throttle_gen);
2885 wake_up(&root->fs_info->transaction_throttle);
2886 cond_resched();
2887
2888 continue;
2889 }
2890 /*
2891 * at this point, we have a single ref, and since the
2892 * only place referencing this extent is a dead root
2893 * the reference count should never go higher.
2894 * So, we don't need to check it again
2895 */
2896 if (*level == 1) {
2897 ref = btrfs_lookup_leaf_ref(root, bytenr);
2898 if (ref && ref->generation != ptr_gen) {
2899 btrfs_free_leaf_ref(root, ref);
2900 ref = NULL;
2901 }
2902 if (ref) {
2903 ret = cache_drop_leaf_ref(trans, root, ref);
2904 BUG_ON(ret);
2905 btrfs_remove_leaf_ref(root, ref);
2906 btrfs_free_leaf_ref(root, ref);
2907 *level = 0;
2908 break;
2909 }
2910 if (printk_ratelimit()) {
2911 printk("leaf ref miss for bytenr %llu\n",
2912 (unsigned long long)bytenr);
2913 }
2914 }
2915 next = btrfs_find_tree_block(root, bytenr, blocksize);
2916 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2917 free_extent_buffer(next);
2918
2919 next = read_tree_block(root, bytenr, blocksize,
2920 ptr_gen);
2921 cond_resched();
2922#if 0
2923 /*
2924 * this is a debugging check and can go away
2925 * the ref should never go all the way down to 1
2926 * at this point
2927 */
2928 ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
2929 &refs);
2930 BUG_ON(ret);
2931 WARN_ON(refs != 1);
2932#endif
2933 }
2934 WARN_ON(*level <= 0);
2935 if (path->nodes[*level-1])
2936 free_extent_buffer(path->nodes[*level-1]);
2937 path->nodes[*level-1] = next;
2938 *level = btrfs_header_level(next);
2939 path->slots[*level] = 0;
2940 cond_resched();
2941 }
2942out:
2943 WARN_ON(*level < 0);
2944 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2945
2946 if (path->nodes[*level] == root->node) {
2947 parent = path->nodes[*level];
2948 bytenr = path->nodes[*level]->start;
2949 } else {
2950 parent = path->nodes[*level + 1];
2951 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
2952 }
2953
2954 blocksize = btrfs_level_size(root, *level);
2955 root_owner = btrfs_header_owner(parent);
2956 root_gen = btrfs_header_generation(parent);
2957
2958 ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
2959 parent->start, root_owner, root_gen,
2960 *level, 1);
2961 free_extent_buffer(path->nodes[*level]);
2962 path->nodes[*level] = NULL;
2963 *level += 1;
2964 BUG_ON(ret);
2965
2966 cond_resched();
2967 return 0;
2968}
2969
2970/*
2971 * helper function for drop_subtree, this function is similar to
2972 * walk_down_tree. The main difference is that it checks reference
2973 * counts while tree blocks are locked.
2974 */
2975static int noinline walk_down_subtree(struct btrfs_trans_handle *trans,
2976 struct btrfs_root *root,
2977 struct btrfs_path *path, int *level)
2978{
2979 struct extent_buffer *next;
2980 struct extent_buffer *cur;
2981 struct extent_buffer *parent;
2982 u64 bytenr;
2983 u64 ptr_gen;
2984 u32 blocksize;
2985 u32 refs;
2986 int ret;
2987
2988 cur = path->nodes[*level];
2989 ret = btrfs_lookup_extent_ref(trans, root, cur->start, cur->len,
2990 &refs);
2991 BUG_ON(ret);
2992 if (refs > 1)
2993 goto out;
2994
2995 while (*level >= 0) {
2996 cur = path->nodes[*level];
2997 if (*level == 0) {
2998 ret = btrfs_drop_leaf_ref(trans, root, cur);
2999 BUG_ON(ret);
3000 clean_tree_block(trans, root, cur);
3001 break;
3002 }
3003 if (path->slots[*level] >= btrfs_header_nritems(cur)) {
3004 clean_tree_block(trans, root, cur);
3005 break;
3006 }
3007
3008 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
3009 blocksize = btrfs_level_size(root, *level - 1);
3010 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
3011
3012 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
3013 btrfs_tree_lock(next);
3014
3015 ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize,
3016 &refs);
3017 BUG_ON(ret);
3018 if (refs > 1) {
3019 parent = path->nodes[*level];
3020 ret = btrfs_free_extent(trans, root, bytenr,
3021 blocksize, parent->start,
3022 btrfs_header_owner(parent),
3023 btrfs_header_generation(parent),
3024 *level - 1, 1);
3025 BUG_ON(ret);
3026 path->slots[*level]++;
3027 btrfs_tree_unlock(next);
3028 free_extent_buffer(next);
3029 continue;
3030 }
3031
3032 *level = btrfs_header_level(next);
3033 path->nodes[*level] = next;
3034 path->slots[*level] = 0;
3035 path->locks[*level] = 1;
3036 cond_resched();
3037 }
3038out:
3039 parent = path->nodes[*level + 1];
3040 bytenr = path->nodes[*level]->start;
3041 blocksize = path->nodes[*level]->len;
3042
3043 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
3044 parent->start, btrfs_header_owner(parent),
3045 btrfs_header_generation(parent), *level, 1);
3046 BUG_ON(ret);
3047
3048 if (path->locks[*level]) {
3049 btrfs_tree_unlock(path->nodes[*level]);
3050 path->locks[*level] = 0;
3051 }
3052 free_extent_buffer(path->nodes[*level]);
3053 path->nodes[*level] = NULL;
3054 *level += 1;
3055 cond_resched();
3056 return 0;
3057}
3058
3059/*
3060 * helper for dropping snapshots. This walks back up the tree in the path
3061 * to find the first node higher up where we haven't yet gone through
3062 * all the slots
3063 */
3064static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
3065 struct btrfs_root *root,
3066 struct btrfs_path *path,
3067 int *level, int max_level)
3068{
3069 u64 root_owner;
3070 u64 root_gen;
3071 struct btrfs_root_item *root_item = &root->root_item;
3072 int i;
3073 int slot;
3074 int ret;
3075
3076 for (i = *level; i < max_level && path->nodes[i]; i++) {
3077 slot = path->slots[i];
3078 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
3079 struct extent_buffer *node;
3080 struct btrfs_disk_key disk_key;
3081 node = path->nodes[i];
3082 path->slots[i]++;
3083 *level = i;
3084 WARN_ON(*level == 0);
3085 btrfs_node_key(node, &disk_key, path->slots[i]);
3086 memcpy(&root_item->drop_progress,
3087 &disk_key, sizeof(disk_key));
3088 root_item->drop_level = i;
3089 return 0;
3090 } else {
3091 struct extent_buffer *parent;
3092 if (path->nodes[*level] == root->node)
3093 parent = path->nodes[*level];
3094 else
3095 parent = path->nodes[*level + 1];
3096
3097 root_owner = btrfs_header_owner(parent);
3098 root_gen = btrfs_header_generation(parent);
3099
3100 clean_tree_block(trans, root, path->nodes[*level]);
3101 ret = btrfs_free_extent(trans, root,
3102 path->nodes[*level]->start,
3103 path->nodes[*level]->len,
3104 parent->start, root_owner,
3105 root_gen, *level, 1);
3106 BUG_ON(ret);
3107 if (path->locks[*level]) {
3108 btrfs_tree_unlock(path->nodes[*level]);
3109 path->locks[*level] = 0;
3110 }
3111 free_extent_buffer(path->nodes[*level]);
3112 path->nodes[*level] = NULL;
3113 *level = i + 1;
3114 }
3115 }
3116 return 1;
3117}
3118
3119/*
3120 * drop the reference count on the tree rooted at 'snap'. This traverses
3121 * the tree freeing any blocks that have a ref count of zero after being
3122 * decremented.
3123 */
3124int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
3125 *root)
3126{
3127 int ret = 0;
3128 int wret;
3129 int level;
3130 struct btrfs_path *path;
3131 int i;
3132 int orig_level;
3133 struct btrfs_root_item *root_item = &root->root_item;
3134
3135 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
3136 path = btrfs_alloc_path();
3137 BUG_ON(!path);
3138
3139 level = btrfs_header_level(root->node);
3140 orig_level = level;
3141 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
3142 path->nodes[level] = root->node;
3143 extent_buffer_get(root->node);
3144 path->slots[level] = 0;
3145 } else {
3146 struct btrfs_key key;
3147 struct btrfs_disk_key found_key;
3148 struct extent_buffer *node;
3149
3150 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
3151 level = root_item->drop_level;
3152 path->lowest_level = level;
3153 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3154 if (wret < 0) {
3155 ret = wret;
3156 goto out;
3157 }
3158 node = path->nodes[level];
3159 btrfs_node_key(node, &found_key, path->slots[level]);
3160 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
3161 sizeof(found_key)));
3162 /*
3163 * unlock our path, this is safe because only this
3164 * function is allowed to delete this snapshot
3165 */
3166 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
3167 if (path->nodes[i] && path->locks[i]) {
3168 path->locks[i] = 0;
3169 btrfs_tree_unlock(path->nodes[i]);
3170 }
3171 }
3172 }
3173 while(1) {
3174 wret = walk_down_tree(trans, root, path, &level);
3175 if (wret > 0)
3176 break;
3177 if (wret < 0)
3178 ret = wret;
3179
3180 wret = walk_up_tree(trans, root, path, &level,
3181 BTRFS_MAX_LEVEL);
3182 if (wret > 0)
3183 break;
3184 if (wret < 0)
3185 ret = wret;
3186 if (trans->transaction->in_commit) {
3187 ret = -EAGAIN;
3188 break;
3189 }
3190 atomic_inc(&root->fs_info->throttle_gen);
3191 wake_up(&root->fs_info->transaction_throttle);
3192 }
3193 for (i = 0; i <= orig_level; i++) {
3194 if (path->nodes[i]) {
3195 free_extent_buffer(path->nodes[i]);
3196 path->nodes[i] = NULL;
3197 }
3198 }
3199out:
3200 btrfs_free_path(path);
3201 return ret;
3202}
3203
3204int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
3205 struct btrfs_root *root,
3206 struct extent_buffer *node,
3207 struct extent_buffer *parent)
3208{
3209 struct btrfs_path *path;
3210 int level;
3211 int parent_level;
3212 int ret = 0;
3213 int wret;
3214
3215 path = btrfs_alloc_path();
3216 BUG_ON(!path);
3217
3218 BUG_ON(!btrfs_tree_locked(parent));
3219 parent_level = btrfs_header_level(parent);
3220 extent_buffer_get(parent);
3221 path->nodes[parent_level] = parent;
3222 path->slots[parent_level] = btrfs_header_nritems(parent);
3223
3224 BUG_ON(!btrfs_tree_locked(node));
3225 level = btrfs_header_level(node);
3226 extent_buffer_get(node);
3227 path->nodes[level] = node;
3228 path->slots[level] = 0;
3229
3230 while (1) {
3231 wret = walk_down_subtree(trans, root, path, &level);
3232 if (wret < 0)
3233 ret = wret;
3234 if (wret != 0)
3235 break;
3236
3237 wret = walk_up_tree(trans, root, path, &level, parent_level);
3238 if (wret < 0)
3239 ret = wret;
3240 if (wret != 0)
3241 break;
3242 }
3243
3244 btrfs_free_path(path);
3245 return ret;
3246}
3247
3248static unsigned long calc_ra(unsigned long start, unsigned long last,
3249 unsigned long nr)
3250{
3251 return min(last, start + nr - 1);
3252}
3253
3254static int noinline relocate_inode_pages(struct inode *inode, u64 start,
3255 u64 len)
3256{
3257 u64 page_start;
3258 u64 page_end;
3259 unsigned long first_index;
3260 unsigned long last_index;
3261 unsigned long i;
3262 struct page *page;
3263 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3264 struct file_ra_state *ra;
3265 struct btrfs_ordered_extent *ordered;
3266 unsigned int total_read = 0;
3267 unsigned int total_dirty = 0;
3268 int ret = 0;
3269
3270 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3271
3272 mutex_lock(&inode->i_mutex);
3273 first_index = start >> PAGE_CACHE_SHIFT;
3274 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
3275
3276 /* make sure the dirty trick played by the caller work */
3277 ret = invalidate_inode_pages2_range(inode->i_mapping,
3278 first_index, last_index);
3279 if (ret)
3280 goto out_unlock;
3281
3282 file_ra_state_init(ra, inode->i_mapping);
3283
3284 for (i = first_index ; i <= last_index; i++) {
3285 if (total_read % ra->ra_pages == 0) {
3286 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
3287 calc_ra(i, last_index, ra->ra_pages));
3288 }
3289 total_read++;
3290again:
3291 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
3292 BUG_ON(1);
3293 page = grab_cache_page(inode->i_mapping, i);
3294 if (!page) {
3295 ret = -ENOMEM;
3296 goto out_unlock;
3297 }
3298 if (!PageUptodate(page)) {
3299 btrfs_readpage(NULL, page);
3300 lock_page(page);
3301 if (!PageUptodate(page)) {
3302 unlock_page(page);
3303 page_cache_release(page);
3304 ret = -EIO;
3305 goto out_unlock;
3306 }
3307 }
3308 wait_on_page_writeback(page);
3309
3310 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
3311 page_end = page_start + PAGE_CACHE_SIZE - 1;
3312 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
3313
3314 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3315 if (ordered) {
3316 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3317 unlock_page(page);
3318 page_cache_release(page);
3319 btrfs_start_ordered_extent(inode, ordered, 1);
3320 btrfs_put_ordered_extent(ordered);
3321 goto again;
3322 }
3323 set_page_extent_mapped(page);
3324
3325 btrfs_set_extent_delalloc(inode, page_start, page_end);
3326 if (i == first_index)
3327 set_extent_bits(io_tree, page_start, page_end,
3328 EXTENT_BOUNDARY, GFP_NOFS);
3329
3330 set_page_dirty(page);
3331 total_dirty++;
3332
3333 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3334 unlock_page(page);
3335 page_cache_release(page);
3336 }
3337
3338out_unlock:
3339 kfree(ra);
3340 mutex_unlock(&inode->i_mutex);
3341 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
3342 return ret;
3343}
3344
3345static int noinline relocate_data_extent(struct inode *reloc_inode,
3346 struct btrfs_key *extent_key,
3347 u64 offset)
3348{
3349 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3350 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
3351 struct extent_map *em;
3352 u64 start = extent_key->objectid - offset;
3353 u64 end = start + extent_key->offset - 1;
3354
3355 em = alloc_extent_map(GFP_NOFS);
3356 BUG_ON(!em || IS_ERR(em));
3357
3358 em->start = start;
3359 em->len = extent_key->offset;
3360 em->block_len = extent_key->offset;
3361 em->block_start = extent_key->objectid;
3362 em->bdev = root->fs_info->fs_devices->latest_bdev;
3363 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3364
3365 /* setup extent map to cheat btrfs_readpage */
3366 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
3367 while (1) {
3368 int ret;
3369 spin_lock(&em_tree->lock);
3370 ret = add_extent_mapping(em_tree, em);
3371 spin_unlock(&em_tree->lock);
3372 if (ret != -EEXIST) {
3373 free_extent_map(em);
3374 break;
3375 }
3376 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
3377 }
3378 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
3379
3380 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
3381}
3382
3383struct btrfs_ref_path {
3384 u64 extent_start;
3385 u64 nodes[BTRFS_MAX_LEVEL];
3386 u64 root_objectid;
3387 u64 root_generation;
3388 u64 owner_objectid;
3389 u32 num_refs;
3390 int lowest_level;
3391 int current_level;
3392 int shared_level;
3393
3394 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
3395 u64 new_nodes[BTRFS_MAX_LEVEL];
3396};
3397
3398struct disk_extent {
3399 u64 ram_bytes;
3400 u64 disk_bytenr;
3401 u64 disk_num_bytes;
3402 u64 offset;
3403 u64 num_bytes;
3404 u8 compression;
3405 u8 encryption;
3406 u16 other_encoding;
3407};
3408
3409static int is_cowonly_root(u64 root_objectid)
3410{
3411 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
3412 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
3413 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
3414 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
3415 root_objectid == BTRFS_TREE_LOG_OBJECTID)
3416 return 1;
3417 return 0;
3418}
3419
3420static int noinline __next_ref_path(struct btrfs_trans_handle *trans,
3421 struct btrfs_root *extent_root,
3422 struct btrfs_ref_path *ref_path,
3423 int first_time)
3424{
3425 struct extent_buffer *leaf;
3426 struct btrfs_path *path;
3427 struct btrfs_extent_ref *ref;
3428 struct btrfs_key key;
3429 struct btrfs_key found_key;
3430 u64 bytenr;
3431 u32 nritems;
3432 int level;
3433 int ret = 1;
3434
3435 path = btrfs_alloc_path();
3436 if (!path)
3437 return -ENOMEM;
3438
3439 if (first_time) {
3440 ref_path->lowest_level = -1;
3441 ref_path->current_level = -1;
3442 ref_path->shared_level = -1;
3443 goto walk_up;
3444 }
3445walk_down:
3446 level = ref_path->current_level - 1;
3447 while (level >= -1) {
3448 u64 parent;
3449 if (level < ref_path->lowest_level)
3450 break;
3451
3452 if (level >= 0) {
3453 bytenr = ref_path->nodes[level];
3454 } else {
3455 bytenr = ref_path->extent_start;
3456 }
3457 BUG_ON(bytenr == 0);
3458
3459 parent = ref_path->nodes[level + 1];
3460 ref_path->nodes[level + 1] = 0;
3461 ref_path->current_level = level;
3462 BUG_ON(parent == 0);
3463
3464 key.objectid = bytenr;
3465 key.offset = parent + 1;
3466 key.type = BTRFS_EXTENT_REF_KEY;
3467
3468 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3469 if (ret < 0)
3470 goto out;
3471 BUG_ON(ret == 0);
3472
3473 leaf = path->nodes[0];
3474 nritems = btrfs_header_nritems(leaf);
3475 if (path->slots[0] >= nritems) {
3476 ret = btrfs_next_leaf(extent_root, path);
3477 if (ret < 0)
3478 goto out;
3479 if (ret > 0)
3480 goto next;
3481 leaf = path->nodes[0];
3482 }
3483
3484 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3485 if (found_key.objectid == bytenr &&
3486 found_key.type == BTRFS_EXTENT_REF_KEY) {
3487 if (level < ref_path->shared_level)
3488 ref_path->shared_level = level;
3489 goto found;
3490 }
3491next:
3492 level--;
3493 btrfs_release_path(extent_root, path);
3494 cond_resched();
3495 }
3496 /* reached lowest level */
3497 ret = 1;
3498 goto out;
3499walk_up:
3500 level = ref_path->current_level;
3501 while (level < BTRFS_MAX_LEVEL - 1) {
3502 u64 ref_objectid;
3503 if (level >= 0) {
3504 bytenr = ref_path->nodes[level];
3505 } else {
3506 bytenr = ref_path->extent_start;
3507 }
3508 BUG_ON(bytenr == 0);
3509
3510 key.objectid = bytenr;
3511 key.offset = 0;
3512 key.type = BTRFS_EXTENT_REF_KEY;
3513
3514 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3515 if (ret < 0)
3516 goto out;
3517
3518 leaf = path->nodes[0];
3519 nritems = btrfs_header_nritems(leaf);
3520 if (path->slots[0] >= nritems) {
3521 ret = btrfs_next_leaf(extent_root, path);
3522 if (ret < 0)
3523 goto out;
3524 if (ret > 0) {
3525 /* the extent was freed by someone */
3526 if (ref_path->lowest_level == level)
3527 goto out;
3528 btrfs_release_path(extent_root, path);
3529 goto walk_down;
3530 }
3531 leaf = path->nodes[0];
3532 }
3533
3534 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3535 if (found_key.objectid != bytenr ||
3536 found_key.type != BTRFS_EXTENT_REF_KEY) {
3537 /* the extent was freed by someone */
3538 if (ref_path->lowest_level == level) {
3539 ret = 1;
3540 goto out;
3541 }
3542 btrfs_release_path(extent_root, path);
3543 goto walk_down;
3544 }
3545found:
3546 ref = btrfs_item_ptr(leaf, path->slots[0],
3547 struct btrfs_extent_ref);
3548 ref_objectid = btrfs_ref_objectid(leaf, ref);
3549 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3550 if (first_time) {
3551 level = (int)ref_objectid;
3552 BUG_ON(level >= BTRFS_MAX_LEVEL);
3553 ref_path->lowest_level = level;
3554 ref_path->current_level = level;
3555 ref_path->nodes[level] = bytenr;
3556 } else {
3557 WARN_ON(ref_objectid != level);
3558 }
3559 } else {
3560 WARN_ON(level != -1);
3561 }
3562 first_time = 0;
3563
3564 if (ref_path->lowest_level == level) {
3565 ref_path->owner_objectid = ref_objectid;
3566 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
3567 }
3568
3569 /*
3570 * the block is tree root or the block isn't in reference
3571 * counted tree.
3572 */
3573 if (found_key.objectid == found_key.offset ||
3574 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
3575 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3576 ref_path->root_generation =
3577 btrfs_ref_generation(leaf, ref);
3578 if (level < 0) {
3579 /* special reference from the tree log */
3580 ref_path->nodes[0] = found_key.offset;
3581 ref_path->current_level = 0;
3582 }
3583 ret = 0;
3584 goto out;
3585 }
3586
3587 level++;
3588 BUG_ON(ref_path->nodes[level] != 0);
3589 ref_path->nodes[level] = found_key.offset;
3590 ref_path->current_level = level;
3591
3592 /*
3593 * the reference was created in the running transaction,
3594 * no need to continue walking up.
3595 */
3596 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
3597 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3598 ref_path->root_generation =
3599 btrfs_ref_generation(leaf, ref);
3600 ret = 0;
3601 goto out;
3602 }
3603
3604 btrfs_release_path(extent_root, path);
3605 cond_resched();
3606 }
3607 /* reached max tree level, but no tree root found. */
3608 BUG();
3609out:
3610 btrfs_free_path(path);
3611 return ret;
3612}
3613
3614static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
3615 struct btrfs_root *extent_root,
3616 struct btrfs_ref_path *ref_path,
3617 u64 extent_start)
3618{
3619 memset(ref_path, 0, sizeof(*ref_path));
3620 ref_path->extent_start = extent_start;
3621
3622 return __next_ref_path(trans, extent_root, ref_path, 1);
3623}
3624
3625static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
3626 struct btrfs_root *extent_root,
3627 struct btrfs_ref_path *ref_path)
3628{
3629 return __next_ref_path(trans, extent_root, ref_path, 0);
3630}
3631
3632static int noinline get_new_locations(struct inode *reloc_inode,
3633 struct btrfs_key *extent_key,
3634 u64 offset, int no_fragment,
3635 struct disk_extent **extents,
3636 int *nr_extents)
3637{
3638 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3639 struct btrfs_path *path;
3640 struct btrfs_file_extent_item *fi;
3641 struct extent_buffer *leaf;
3642 struct disk_extent *exts = *extents;
3643 struct btrfs_key found_key;
3644 u64 cur_pos;
3645 u64 last_byte;
3646 u32 nritems;
3647 int nr = 0;
3648 int max = *nr_extents;
3649 int ret;
3650
3651 WARN_ON(!no_fragment && *extents);
3652 if (!exts) {
3653 max = 1;
3654 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
3655 if (!exts)
3656 return -ENOMEM;
3657 }
3658
3659 path = btrfs_alloc_path();
3660 BUG_ON(!path);
3661
3662 cur_pos = extent_key->objectid - offset;
3663 last_byte = extent_key->objectid + extent_key->offset;
3664 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
3665 cur_pos, 0);
3666 if (ret < 0)
3667 goto out;
3668 if (ret > 0) {
3669 ret = -ENOENT;
3670 goto out;
3671 }
3672
3673 while (1) {
3674 leaf = path->nodes[0];
3675 nritems = btrfs_header_nritems(leaf);
3676 if (path->slots[0] >= nritems) {
3677 ret = btrfs_next_leaf(root, path);
3678 if (ret < 0)
3679 goto out;
3680 if (ret > 0)
3681 break;
3682 leaf = path->nodes[0];
3683 }
3684
3685 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3686 if (found_key.offset != cur_pos ||
3687 found_key.type != BTRFS_EXTENT_DATA_KEY ||
3688 found_key.objectid != reloc_inode->i_ino)
3689 break;
3690
3691 fi = btrfs_item_ptr(leaf, path->slots[0],
3692 struct btrfs_file_extent_item);
3693 if (btrfs_file_extent_type(leaf, fi) !=
3694 BTRFS_FILE_EXTENT_REG ||
3695 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
3696 break;
3697
3698 if (nr == max) {
3699 struct disk_extent *old = exts;
3700 max *= 2;
3701 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
3702 memcpy(exts, old, sizeof(*exts) * nr);
3703 if (old != *extents)
3704 kfree(old);
3705 }
3706
3707 exts[nr].disk_bytenr =
3708 btrfs_file_extent_disk_bytenr(leaf, fi);
3709 exts[nr].disk_num_bytes =
3710 btrfs_file_extent_disk_num_bytes(leaf, fi);
3711 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
3712 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3713 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
3714 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
3715 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
3716 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
3717 fi);
3718 BUG_ON(exts[nr].offset > 0);
3719 BUG_ON(exts[nr].compression || exts[nr].encryption);
3720 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
3721
3722 cur_pos += exts[nr].num_bytes;
3723 nr++;
3724
3725 if (cur_pos + offset >= last_byte)
3726 break;
3727
3728 if (no_fragment) {
3729 ret = 1;
3730 goto out;
3731 }
3732 path->slots[0]++;
3733 }
3734
3735 WARN_ON(cur_pos + offset > last_byte);
3736 if (cur_pos + offset < last_byte) {
3737 ret = -ENOENT;
3738 goto out;
3739 }
3740 ret = 0;
3741out:
3742 btrfs_free_path(path);
3743 if (ret) {
3744 if (exts != *extents)
3745 kfree(exts);
3746 } else {
3747 *extents = exts;
3748 *nr_extents = nr;
3749 }
3750 return ret;
3751}
3752
3753static int noinline replace_one_extent(struct btrfs_trans_handle *trans,
3754 struct btrfs_root *root,
3755 struct btrfs_path *path,
3756 struct btrfs_key *extent_key,
3757 struct btrfs_key *leaf_key,
3758 struct btrfs_ref_path *ref_path,
3759 struct disk_extent *new_extents,
3760 int nr_extents)
3761{
3762 struct extent_buffer *leaf;
3763 struct btrfs_file_extent_item *fi;
3764 struct inode *inode = NULL;
3765 struct btrfs_key key;
3766 u64 lock_start = 0;
3767 u64 lock_end = 0;
3768 u64 num_bytes;
3769 u64 ext_offset;
3770 u64 first_pos;
3771 u32 nritems;
3772 int nr_scaned = 0;
3773 int extent_locked = 0;
3774 int extent_type;
3775 int ret;
3776
3777 memcpy(&key, leaf_key, sizeof(key));
3778 first_pos = INT_LIMIT(loff_t) - extent_key->offset;
3779 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3780 if (key.objectid < ref_path->owner_objectid ||
3781 (key.objectid == ref_path->owner_objectid &&
3782 key.type < BTRFS_EXTENT_DATA_KEY)) {
3783 key.objectid = ref_path->owner_objectid;
3784 key.type = BTRFS_EXTENT_DATA_KEY;
3785 key.offset = 0;
3786 }
3787 }
3788
3789 while (1) {
3790 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
3791 if (ret < 0)
3792 goto out;
3793
3794 leaf = path->nodes[0];
3795 nritems = btrfs_header_nritems(leaf);
3796next:
3797 if (extent_locked && ret > 0) {
3798 /*
3799 * the file extent item was modified by someone
3800 * before the extent got locked.
3801 */
3802 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3803 lock_end, GFP_NOFS);
3804 extent_locked = 0;
3805 }
3806
3807 if (path->slots[0] >= nritems) {
3808 if (++nr_scaned > 2)
3809 break;
3810
3811 BUG_ON(extent_locked);
3812 ret = btrfs_next_leaf(root, path);
3813 if (ret < 0)
3814 goto out;
3815 if (ret > 0)
3816 break;
3817 leaf = path->nodes[0];
3818 nritems = btrfs_header_nritems(leaf);
3819 }
3820
3821 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3822
3823 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3824 if ((key.objectid > ref_path->owner_objectid) ||
3825 (key.objectid == ref_path->owner_objectid &&
3826 key.type > BTRFS_EXTENT_DATA_KEY) ||
3827 (key.offset >= first_pos + extent_key->offset))
3828 break;
3829 }
3830
3831 if (inode && key.objectid != inode->i_ino) {
3832 BUG_ON(extent_locked);
3833 btrfs_release_path(root, path);
3834 mutex_unlock(&inode->i_mutex);
3835 iput(inode);
3836 inode = NULL;
3837 continue;
3838 }
3839
3840 if (key.type != BTRFS_EXTENT_DATA_KEY) {
3841 path->slots[0]++;
3842 ret = 1;
3843 goto next;
3844 }
3845 fi = btrfs_item_ptr(leaf, path->slots[0],
3846 struct btrfs_file_extent_item);
3847 extent_type = btrfs_file_extent_type(leaf, fi);
3848 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
3849 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
3850 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3851 extent_key->objectid)) {
3852 path->slots[0]++;
3853 ret = 1;
3854 goto next;
3855 }
3856
3857 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3858 ext_offset = btrfs_file_extent_offset(leaf, fi);
3859
3860 if (first_pos > key.offset - ext_offset)
3861 first_pos = key.offset - ext_offset;
3862
3863 if (!extent_locked) {
3864 lock_start = key.offset;
3865 lock_end = lock_start + num_bytes - 1;
3866 } else {
3867 if (lock_start > key.offset ||
3868 lock_end + 1 < key.offset + num_bytes) {
3869 unlock_extent(&BTRFS_I(inode)->io_tree,
3870 lock_start, lock_end, GFP_NOFS);
3871 extent_locked = 0;
3872 }
3873 }
3874
3875 if (!inode) {
3876 btrfs_release_path(root, path);
3877
3878 inode = btrfs_iget_locked(root->fs_info->sb,
3879 key.objectid, root);
3880 if (inode->i_state & I_NEW) {
3881 BTRFS_I(inode)->root = root;
3882 BTRFS_I(inode)->location.objectid =
3883 key.objectid;
3884 BTRFS_I(inode)->location.type =
3885 BTRFS_INODE_ITEM_KEY;
3886 BTRFS_I(inode)->location.offset = 0;
3887 btrfs_read_locked_inode(inode);
3888 unlock_new_inode(inode);
3889 }
3890 /*
3891 * some code call btrfs_commit_transaction while
3892 * holding the i_mutex, so we can't use mutex_lock
3893 * here.
3894 */
3895 if (is_bad_inode(inode) ||
3896 !mutex_trylock(&inode->i_mutex)) {
3897 iput(inode);
3898 inode = NULL;
3899 key.offset = (u64)-1;
3900 goto skip;
3901 }
3902 }
3903
3904 if (!extent_locked) {
3905 struct btrfs_ordered_extent *ordered;
3906
3907 btrfs_release_path(root, path);
3908
3909 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3910 lock_end, GFP_NOFS);
3911 ordered = btrfs_lookup_first_ordered_extent(inode,
3912 lock_end);
3913 if (ordered &&
3914 ordered->file_offset <= lock_end &&
3915 ordered->file_offset + ordered->len > lock_start) {
3916 unlock_extent(&BTRFS_I(inode)->io_tree,
3917 lock_start, lock_end, GFP_NOFS);
3918 btrfs_start_ordered_extent(inode, ordered, 1);
3919 btrfs_put_ordered_extent(ordered);
3920 key.offset += num_bytes;
3921 goto skip;
3922 }
3923 if (ordered)
3924 btrfs_put_ordered_extent(ordered);
3925
3926 extent_locked = 1;
3927 continue;
3928 }
3929
3930 if (nr_extents == 1) {
3931 /* update extent pointer in place */
3932 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3933 new_extents[0].disk_bytenr);
3934 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
3935 new_extents[0].disk_num_bytes);
3936 btrfs_mark_buffer_dirty(leaf);
3937
3938 btrfs_drop_extent_cache(inode, key.offset,
3939 key.offset + num_bytes - 1, 0);
3940
3941 ret = btrfs_inc_extent_ref(trans, root,
3942 new_extents[0].disk_bytenr,
3943 new_extents[0].disk_num_bytes,
3944 leaf->start,
3945 root->root_key.objectid,
3946 trans->transid,
3947 key.objectid);
3948 BUG_ON(ret);
3949
3950 ret = btrfs_free_extent(trans, root,
3951 extent_key->objectid,
3952 extent_key->offset,
3953 leaf->start,
3954 btrfs_header_owner(leaf),
3955 btrfs_header_generation(leaf),
3956 key.objectid, 0);
3957 BUG_ON(ret);
3958
3959 btrfs_release_path(root, path);
3960 key.offset += num_bytes;
3961 } else {
3962 BUG_ON(1);
3963#if 0
3964 u64 alloc_hint;
3965 u64 extent_len;
3966 int i;
3967 /*
3968 * drop old extent pointer at first, then insert the
3969 * new pointers one bye one
3970 */
3971 btrfs_release_path(root, path);
3972 ret = btrfs_drop_extents(trans, root, inode, key.offset,
3973 key.offset + num_bytes,
3974 key.offset, &alloc_hint);
3975 BUG_ON(ret);
3976
3977 for (i = 0; i < nr_extents; i++) {
3978 if (ext_offset >= new_extents[i].num_bytes) {
3979 ext_offset -= new_extents[i].num_bytes;
3980 continue;
3981 }
3982 extent_len = min(new_extents[i].num_bytes -
3983 ext_offset, num_bytes);
3984
3985 ret = btrfs_insert_empty_item(trans, root,
3986 path, &key,
3987 sizeof(*fi));
3988 BUG_ON(ret);
3989
3990 leaf = path->nodes[0];
3991 fi = btrfs_item_ptr(leaf, path->slots[0],
3992 struct btrfs_file_extent_item);
3993 btrfs_set_file_extent_generation(leaf, fi,
3994 trans->transid);
3995 btrfs_set_file_extent_type(leaf, fi,
3996 BTRFS_FILE_EXTENT_REG);
3997 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3998 new_extents[i].disk_bytenr);
3999 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4000 new_extents[i].disk_num_bytes);
4001 btrfs_set_file_extent_ram_bytes(leaf, fi,
4002 new_extents[i].ram_bytes);
4003
4004 btrfs_set_file_extent_compression(leaf, fi,
4005 new_extents[i].compression);
4006 btrfs_set_file_extent_encryption(leaf, fi,
4007 new_extents[i].encryption);
4008 btrfs_set_file_extent_other_encoding(leaf, fi,
4009 new_extents[i].other_encoding);
4010
4011 btrfs_set_file_extent_num_bytes(leaf, fi,
4012 extent_len);
4013 ext_offset += new_extents[i].offset;
4014 btrfs_set_file_extent_offset(leaf, fi,
4015 ext_offset);
4016 btrfs_mark_buffer_dirty(leaf);
4017
4018 btrfs_drop_extent_cache(inode, key.offset,
4019 key.offset + extent_len - 1, 0);
4020
4021 ret = btrfs_inc_extent_ref(trans, root,
4022 new_extents[i].disk_bytenr,
4023 new_extents[i].disk_num_bytes,
4024 leaf->start,
4025 root->root_key.objectid,
4026 trans->transid, key.objectid);
4027 BUG_ON(ret);
4028 btrfs_release_path(root, path);
4029
4030 inode_add_bytes(inode, extent_len);
4031
4032 ext_offset = 0;
4033 num_bytes -= extent_len;
4034 key.offset += extent_len;
4035
4036 if (num_bytes == 0)
4037 break;
4038 }
4039 BUG_ON(i >= nr_extents);
4040#endif
4041 }
4042
4043 if (extent_locked) {
4044 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
4045 lock_end, GFP_NOFS);
4046 extent_locked = 0;
4047 }
4048skip:
4049 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
4050 key.offset >= first_pos + extent_key->offset)
4051 break;
4052
4053 cond_resched();
4054 }
4055 ret = 0;
4056out:
4057 btrfs_release_path(root, path);
4058 if (inode) {
4059 mutex_unlock(&inode->i_mutex);
4060 if (extent_locked) {
4061 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
4062 lock_end, GFP_NOFS);
4063 }
4064 iput(inode);
4065 }
4066 return ret;
4067}
4068
4069int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
4070 struct btrfs_root *root,
4071 struct extent_buffer *buf, u64 orig_start)
4072{
4073 int level;
4074 int ret;
4075
4076 BUG_ON(btrfs_header_generation(buf) != trans->transid);
4077 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
4078
4079 level = btrfs_header_level(buf);
4080 if (level == 0) {
4081 struct btrfs_leaf_ref *ref;
4082 struct btrfs_leaf_ref *orig_ref;
4083
4084 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
4085 if (!orig_ref)
4086 return -ENOENT;
4087
4088 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
4089 if (!ref) {
4090 btrfs_free_leaf_ref(root, orig_ref);
4091 return -ENOMEM;
4092 }
4093
4094 ref->nritems = orig_ref->nritems;
4095 memcpy(ref->extents, orig_ref->extents,
4096 sizeof(ref->extents[0]) * ref->nritems);
4097
4098 btrfs_free_leaf_ref(root, orig_ref);
4099
4100 ref->root_gen = trans->transid;
4101 ref->bytenr = buf->start;
4102 ref->owner = btrfs_header_owner(buf);
4103 ref->generation = btrfs_header_generation(buf);
4104 ret = btrfs_add_leaf_ref(root, ref, 0);
4105 WARN_ON(ret);
4106 btrfs_free_leaf_ref(root, ref);
4107 }
4108 return 0;
4109}
4110
4111static int noinline invalidate_extent_cache(struct btrfs_root *root,
4112 struct extent_buffer *leaf,
4113 struct btrfs_block_group_cache *group,
4114 struct btrfs_root *target_root)
4115{
4116 struct btrfs_key key;
4117 struct inode *inode = NULL;
4118 struct btrfs_file_extent_item *fi;
4119 u64 num_bytes;
4120 u64 skip_objectid = 0;
4121 u32 nritems;
4122 u32 i;
4123
4124 nritems = btrfs_header_nritems(leaf);
4125 for (i = 0; i < nritems; i++) {
4126 btrfs_item_key_to_cpu(leaf, &key, i);
4127 if (key.objectid == skip_objectid ||
4128 key.type != BTRFS_EXTENT_DATA_KEY)
4129 continue;
4130 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4131 if (btrfs_file_extent_type(leaf, fi) ==
4132 BTRFS_FILE_EXTENT_INLINE)
4133 continue;
4134 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
4135 continue;
4136 if (!inode || inode->i_ino != key.objectid) {
4137 iput(inode);
4138 inode = btrfs_ilookup(target_root->fs_info->sb,
4139 key.objectid, target_root, 1);
4140 }
4141 if (!inode) {
4142 skip_objectid = key.objectid;
4143 continue;
4144 }
4145 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4146
4147 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4148 key.offset + num_bytes - 1, GFP_NOFS);
4149 btrfs_drop_extent_cache(inode, key.offset,
4150 key.offset + num_bytes - 1, 1);
4151 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4152 key.offset + num_bytes - 1, GFP_NOFS);
4153 cond_resched();
4154 }
4155 iput(inode);
4156 return 0;
4157}
4158
4159static int noinline replace_extents_in_leaf(struct btrfs_trans_handle *trans,
4160 struct btrfs_root *root,
4161 struct extent_buffer *leaf,
4162 struct btrfs_block_group_cache *group,
4163 struct inode *reloc_inode)
4164{
4165 struct btrfs_key key;
4166 struct btrfs_key extent_key;
4167 struct btrfs_file_extent_item *fi;
4168 struct btrfs_leaf_ref *ref;
4169 struct disk_extent *new_extent;
4170 u64 bytenr;
4171 u64 num_bytes;
4172 u32 nritems;
4173 u32 i;
4174 int ext_index;
4175 int nr_extent;
4176 int ret;
4177
4178 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
4179 BUG_ON(!new_extent);
4180
4181 ref = btrfs_lookup_leaf_ref(root, leaf->start);
4182 BUG_ON(!ref);
4183
4184 ext_index = -1;
4185 nritems = btrfs_header_nritems(leaf);
4186 for (i = 0; i < nritems; i++) {
4187 btrfs_item_key_to_cpu(leaf, &key, i);
4188 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
4189 continue;
4190 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4191 if (btrfs_file_extent_type(leaf, fi) ==
4192 BTRFS_FILE_EXTENT_INLINE)
4193 continue;
4194 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
4195 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
4196 if (bytenr == 0)
4197 continue;
4198
4199 ext_index++;
4200 if (bytenr >= group->key.objectid + group->key.offset ||
4201 bytenr + num_bytes <= group->key.objectid)
4202 continue;
4203
4204 extent_key.objectid = bytenr;
4205 extent_key.offset = num_bytes;
4206 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
4207 nr_extent = 1;
4208 ret = get_new_locations(reloc_inode, &extent_key,
4209 group->key.objectid, 1,
4210 &new_extent, &nr_extent);
4211 if (ret > 0)
4212 continue;
4213 BUG_ON(ret < 0);
4214
4215 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
4216 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
4217 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
4218 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
4219
4220 btrfs_set_file_extent_disk_bytenr(leaf, fi,
4221 new_extent->disk_bytenr);
4222 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4223 new_extent->disk_num_bytes);
4224 btrfs_mark_buffer_dirty(leaf);
4225
4226 ret = btrfs_inc_extent_ref(trans, root,
4227 new_extent->disk_bytenr,
4228 new_extent->disk_num_bytes,
4229 leaf->start,
4230 root->root_key.objectid,
4231 trans->transid, key.objectid);
4232 BUG_ON(ret);
4233 ret = btrfs_free_extent(trans, root,
4234 bytenr, num_bytes, leaf->start,
4235 btrfs_header_owner(leaf),
4236 btrfs_header_generation(leaf),
4237 key.objectid, 0);
4238 BUG_ON(ret);
4239 cond_resched();
4240 }
4241 kfree(new_extent);
4242 BUG_ON(ext_index + 1 != ref->nritems);
4243 btrfs_free_leaf_ref(root, ref);
4244 return 0;
4245}
4246
4247int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
4248 struct btrfs_root *root)
4249{
4250 struct btrfs_root *reloc_root;
4251 int ret;
4252
4253 if (root->reloc_root) {
4254 reloc_root = root->reloc_root;
4255 root->reloc_root = NULL;
4256 list_add(&reloc_root->dead_list,
4257 &root->fs_info->dead_reloc_roots);
4258
4259 btrfs_set_root_bytenr(&reloc_root->root_item,
4260 reloc_root->node->start);
4261 btrfs_set_root_level(&root->root_item,
4262 btrfs_header_level(reloc_root->node));
4263 memset(&reloc_root->root_item.drop_progress, 0,
4264 sizeof(struct btrfs_disk_key));
4265 reloc_root->root_item.drop_level = 0;
4266
4267 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4268 &reloc_root->root_key,
4269 &reloc_root->root_item);
4270 BUG_ON(ret);
4271 }
4272 return 0;
4273}
4274
4275int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
4276{
4277 struct btrfs_trans_handle *trans;
4278 struct btrfs_root *reloc_root;
4279 struct btrfs_root *prev_root = NULL;
4280 struct list_head dead_roots;
4281 int ret;
4282 unsigned long nr;
4283
4284 INIT_LIST_HEAD(&dead_roots);
4285 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
4286
4287 while (!list_empty(&dead_roots)) {
4288 reloc_root = list_entry(dead_roots.prev,
4289 struct btrfs_root, dead_list);
4290 list_del_init(&reloc_root->dead_list);
4291
4292 BUG_ON(reloc_root->commit_root != NULL);
4293 while (1) {
4294 trans = btrfs_join_transaction(root, 1);
4295 BUG_ON(!trans);
4296
4297 mutex_lock(&root->fs_info->drop_mutex);
4298 ret = btrfs_drop_snapshot(trans, reloc_root);
4299 if (ret != -EAGAIN)
4300 break;
4301 mutex_unlock(&root->fs_info->drop_mutex);
4302
4303 nr = trans->blocks_used;
4304 ret = btrfs_end_transaction(trans, root);
4305 BUG_ON(ret);
4306 btrfs_btree_balance_dirty(root, nr);
4307 }
4308
4309 free_extent_buffer(reloc_root->node);
4310
4311 ret = btrfs_del_root(trans, root->fs_info->tree_root,
4312 &reloc_root->root_key);
4313 BUG_ON(ret);
4314 mutex_unlock(&root->fs_info->drop_mutex);
4315
4316 nr = trans->blocks_used;
4317 ret = btrfs_end_transaction(trans, root);
4318 BUG_ON(ret);
4319 btrfs_btree_balance_dirty(root, nr);
4320
4321 kfree(prev_root);
4322 prev_root = reloc_root;
4323 }
4324 if (prev_root) {
4325 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
4326 kfree(prev_root);
4327 }
4328 return 0;
4329}
4330
4331int btrfs_add_dead_reloc_root(struct btrfs_root *root)
4332{
4333 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
4334 return 0;
4335}
4336
4337int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
4338{
4339 struct btrfs_root *reloc_root;
4340 struct btrfs_trans_handle *trans;
4341 struct btrfs_key location;
4342 int found;
4343 int ret;
4344
4345 mutex_lock(&root->fs_info->tree_reloc_mutex);
4346 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
4347 BUG_ON(ret);
4348 found = !list_empty(&root->fs_info->dead_reloc_roots);
4349 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4350
4351 if (found) {
4352 trans = btrfs_start_transaction(root, 1);
4353 BUG_ON(!trans);
4354 ret = btrfs_commit_transaction(trans, root);
4355 BUG_ON(ret);
4356 }
4357
4358 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4359 location.offset = (u64)-1;
4360 location.type = BTRFS_ROOT_ITEM_KEY;
4361
4362 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
4363 BUG_ON(!reloc_root);
4364 btrfs_orphan_cleanup(reloc_root);
4365 return 0;
4366}
4367
4368static int noinline init_reloc_tree(struct btrfs_trans_handle *trans,
4369 struct btrfs_root *root)
4370{
4371 struct btrfs_root *reloc_root;
4372 struct extent_buffer *eb;
4373 struct btrfs_root_item *root_item;
4374 struct btrfs_key root_key;
4375 int ret;
4376
4377 BUG_ON(!root->ref_cows);
4378 if (root->reloc_root)
4379 return 0;
4380
4381 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
4382 BUG_ON(!root_item);
4383
4384 ret = btrfs_copy_root(trans, root, root->commit_root,
4385 &eb, BTRFS_TREE_RELOC_OBJECTID);
4386 BUG_ON(ret);
4387
4388 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4389 root_key.offset = root->root_key.objectid;
4390 root_key.type = BTRFS_ROOT_ITEM_KEY;
4391
4392 memcpy(root_item, &root->root_item, sizeof(root_item));
4393 btrfs_set_root_refs(root_item, 0);
4394 btrfs_set_root_bytenr(root_item, eb->start);
4395 btrfs_set_root_level(root_item, btrfs_header_level(eb));
4396 btrfs_set_root_generation(root_item, trans->transid);
4397
4398 btrfs_tree_unlock(eb);
4399 free_extent_buffer(eb);
4400
4401 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
4402 &root_key, root_item);
4403 BUG_ON(ret);
4404 kfree(root_item);
4405
4406 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
4407 &root_key);
4408 BUG_ON(!reloc_root);
4409 reloc_root->last_trans = trans->transid;
4410 reloc_root->commit_root = NULL;
4411 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
4412
4413 root->reloc_root = reloc_root;
4414 return 0;
4415}
4416
4417/*
4418 * Core function of space balance.
4419 *
4420 * The idea is using reloc trees to relocate tree blocks in reference
4421 * counted roots. There is one reloc tree for each subvol, and all
4422 * reloc trees share same root key objectid. Reloc trees are snapshots
4423 * of the latest committed roots of subvols (root->commit_root).
4424 *
4425 * To relocate a tree block referenced by a subvol, there are two steps.
4426 * COW the block through subvol's reloc tree, then update block pointer
4427 * in the subvol to point to the new block. Since all reloc trees share
4428 * same root key objectid, doing special handing for tree blocks owned
4429 * by them is easy. Once a tree block has been COWed in one reloc tree,
4430 * we can use the resulting new block directly when the same block is
4431 * required to COW again through other reloc trees. By this way, relocated
4432 * tree blocks are shared between reloc trees, so they are also shared
4433 * between subvols.
4434 */
4435static int noinline relocate_one_path(struct btrfs_trans_handle *trans,
4436 struct btrfs_root *root,
4437 struct btrfs_path *path,
4438 struct btrfs_key *first_key,
4439 struct btrfs_ref_path *ref_path,
4440 struct btrfs_block_group_cache *group,
4441 struct inode *reloc_inode)
4442{
4443 struct btrfs_root *reloc_root;
4444 struct extent_buffer *eb = NULL;
4445 struct btrfs_key *keys;
4446 u64 *nodes;
4447 int level;
4448 int shared_level;
4449 int lowest_level = 0;
4450 int ret;
4451
4452 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
4453 lowest_level = ref_path->owner_objectid;
4454
4455 if (!root->ref_cows) {
4456 path->lowest_level = lowest_level;
4457 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
4458 BUG_ON(ret < 0);
4459 path->lowest_level = 0;
4460 btrfs_release_path(root, path);
4461 return 0;
4462 }
4463
4464 mutex_lock(&root->fs_info->tree_reloc_mutex);
4465 ret = init_reloc_tree(trans, root);
4466 BUG_ON(ret);
4467 reloc_root = root->reloc_root;
4468
4469 shared_level = ref_path->shared_level;
4470 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
4471
4472 keys = ref_path->node_keys;
4473 nodes = ref_path->new_nodes;
4474 memset(&keys[shared_level + 1], 0,
4475 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
4476 memset(&nodes[shared_level + 1], 0,
4477 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
4478
4479 if (nodes[lowest_level] == 0) {
4480 path->lowest_level = lowest_level;
4481 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
4482 0, 1);
4483 BUG_ON(ret);
4484 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
4485 eb = path->nodes[level];
4486 if (!eb || eb == reloc_root->node)
4487 break;
4488 nodes[level] = eb->start;
4489 if (level == 0)
4490 btrfs_item_key_to_cpu(eb, &keys[level], 0);
4491 else
4492 btrfs_node_key_to_cpu(eb, &keys[level], 0);
4493 }
4494 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4495 eb = path->nodes[0];
4496 ret = replace_extents_in_leaf(trans, reloc_root, eb,
4497 group, reloc_inode);
4498 BUG_ON(ret);
4499 }
4500 btrfs_release_path(reloc_root, path);
4501 } else {
4502 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
4503 lowest_level);
4504 BUG_ON(ret);
4505 }
4506
4507 /*
4508 * replace tree blocks in the fs tree with tree blocks in
4509 * the reloc tree.
4510 */
4511 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
4512 BUG_ON(ret < 0);
4513
4514 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4515 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
4516 0, 0);
4517 BUG_ON(ret);
4518 extent_buffer_get(path->nodes[0]);
4519 eb = path->nodes[0];
4520 btrfs_release_path(reloc_root, path);
4521 ret = invalidate_extent_cache(reloc_root, eb, group, root);
4522 BUG_ON(ret);
4523 free_extent_buffer(eb);
4524 }
4525
4526 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4527 path->lowest_level = 0;
4528 return 0;
4529}
4530
4531static int noinline relocate_tree_block(struct btrfs_trans_handle *trans,
4532 struct btrfs_root *root,
4533 struct btrfs_path *path,
4534 struct btrfs_key *first_key,
4535 struct btrfs_ref_path *ref_path)
4536{
4537 int ret;
4538
4539 ret = relocate_one_path(trans, root, path, first_key,
4540 ref_path, NULL, NULL);
4541 BUG_ON(ret);
4542
4543 if (root == root->fs_info->extent_root)
4544 btrfs_extent_post_op(trans, root);
4545
4546 return 0;
4547}
4548
4549static int noinline del_extent_zero(struct btrfs_trans_handle *trans,
4550 struct btrfs_root *extent_root,
4551 struct btrfs_path *path,
4552 struct btrfs_key *extent_key)
4553{
4554 int ret;
4555
4556 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
4557 if (ret)
4558 goto out;
4559 ret = btrfs_del_item(trans, extent_root, path);
4560out:
4561 btrfs_release_path(extent_root, path);
4562 return ret;
4563}
4564
4565static struct btrfs_root noinline *read_ref_root(struct btrfs_fs_info *fs_info,
4566 struct btrfs_ref_path *ref_path)
4567{
4568 struct btrfs_key root_key;
4569
4570 root_key.objectid = ref_path->root_objectid;
4571 root_key.type = BTRFS_ROOT_ITEM_KEY;
4572 if (is_cowonly_root(ref_path->root_objectid))
4573 root_key.offset = 0;
4574 else
4575 root_key.offset = (u64)-1;
4576
4577 return btrfs_read_fs_root_no_name(fs_info, &root_key);
4578}
4579
4580static int noinline relocate_one_extent(struct btrfs_root *extent_root,
4581 struct btrfs_path *path,
4582 struct btrfs_key *extent_key,
4583 struct btrfs_block_group_cache *group,
4584 struct inode *reloc_inode, int pass)
4585{
4586 struct btrfs_trans_handle *trans;
4587 struct btrfs_root *found_root;
4588 struct btrfs_ref_path *ref_path = NULL;
4589 struct disk_extent *new_extents = NULL;
4590 int nr_extents = 0;
4591 int loops;
4592 int ret;
4593 int level;
4594 struct btrfs_key first_key;
4595 u64 prev_block = 0;
4596
4597
4598 trans = btrfs_start_transaction(extent_root, 1);
4599 BUG_ON(!trans);
4600
4601 if (extent_key->objectid == 0) {
4602 ret = del_extent_zero(trans, extent_root, path, extent_key);
4603 goto out;
4604 }
4605
4606 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
4607 if (!ref_path) {
4608 ret = -ENOMEM;
4609 goto out;
4610 }
4611
4612 for (loops = 0; ; loops++) {
4613 if (loops == 0) {
4614 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
4615 extent_key->objectid);
4616 } else {
4617 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
4618 }
4619 if (ret < 0)
4620 goto out;
4621 if (ret > 0)
4622 break;
4623
4624 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
4625 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
4626 continue;
4627
4628 found_root = read_ref_root(extent_root->fs_info, ref_path);
4629 BUG_ON(!found_root);
4630 /*
4631 * for reference counted tree, only process reference paths
4632 * rooted at the latest committed root.
4633 */
4634 if (found_root->ref_cows &&
4635 ref_path->root_generation != found_root->root_key.offset)
4636 continue;
4637
4638 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4639 if (pass == 0) {
4640 /*
4641 * copy data extents to new locations
4642 */
4643 u64 group_start = group->key.objectid;
4644 ret = relocate_data_extent(reloc_inode,
4645 extent_key,
4646 group_start);
4647 if (ret < 0)
4648 goto out;
4649 break;
4650 }
4651 level = 0;
4652 } else {
4653 level = ref_path->owner_objectid;
4654 }
4655
4656 if (prev_block != ref_path->nodes[level]) {
4657 struct extent_buffer *eb;
4658 u64 block_start = ref_path->nodes[level];
4659 u64 block_size = btrfs_level_size(found_root, level);
4660
4661 eb = read_tree_block(found_root, block_start,
4662 block_size, 0);
4663 btrfs_tree_lock(eb);
4664 BUG_ON(level != btrfs_header_level(eb));
4665
4666 if (level == 0)
4667 btrfs_item_key_to_cpu(eb, &first_key, 0);
4668 else
4669 btrfs_node_key_to_cpu(eb, &first_key, 0);
4670
4671 btrfs_tree_unlock(eb);
4672 free_extent_buffer(eb);
4673 prev_block = block_start;
4674 }
4675
4676 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
4677 pass >= 2) {
4678 /*
4679 * use fallback method to process the remaining
4680 * references.
4681 */
4682 if (!new_extents) {
4683 u64 group_start = group->key.objectid;
4684 new_extents = kmalloc(sizeof(*new_extents),
4685 GFP_NOFS);
4686 nr_extents = 1;
4687 ret = get_new_locations(reloc_inode,
4688 extent_key,
4689 group_start, 1,
4690 &new_extents,
4691 &nr_extents);
4692 if (ret)
4693 goto out;
4694 }
4695 btrfs_record_root_in_trans(found_root);
4696 ret = replace_one_extent(trans, found_root,
4697 path, extent_key,
4698 &first_key, ref_path,
4699 new_extents, nr_extents);
4700 if (ret < 0)
4701 goto out;
4702 continue;
4703 }
4704
4705 btrfs_record_root_in_trans(found_root);
4706 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
4707 ret = relocate_tree_block(trans, found_root, path,
4708 &first_key, ref_path);
4709 } else {
4710 /*
4711 * try to update data extent references while
4712 * keeping metadata shared between snapshots.
4713 */
4714 ret = relocate_one_path(trans, found_root, path,
4715 &first_key, ref_path,
4716 group, reloc_inode);
4717 }
4718 if (ret < 0)
4719 goto out;
4720 }
4721 ret = 0;
4722out:
4723 btrfs_end_transaction(trans, extent_root);
4724 kfree(new_extents);
4725 kfree(ref_path);
4726 return ret;
4727}
4728
4729static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
4730{
4731 u64 num_devices;
4732 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
4733 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
4734
4735 num_devices = root->fs_info->fs_devices->num_devices;
4736 if (num_devices == 1) {
4737 stripped |= BTRFS_BLOCK_GROUP_DUP;
4738 stripped = flags & ~stripped;
4739
4740 /* turn raid0 into single device chunks */
4741 if (flags & BTRFS_BLOCK_GROUP_RAID0)
4742 return stripped;
4743
4744 /* turn mirroring into duplication */
4745 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
4746 BTRFS_BLOCK_GROUP_RAID10))
4747 return stripped | BTRFS_BLOCK_GROUP_DUP;
4748 return flags;
4749 } else {
4750 /* they already had raid on here, just return */
4751 if (flags & stripped)
4752 return flags;
4753
4754 stripped |= BTRFS_BLOCK_GROUP_DUP;
4755 stripped = flags & ~stripped;
4756
4757 /* switch duplicated blocks with raid1 */
4758 if (flags & BTRFS_BLOCK_GROUP_DUP)
4759 return stripped | BTRFS_BLOCK_GROUP_RAID1;
4760
4761 /* turn single device chunks into raid0 */
4762 return stripped | BTRFS_BLOCK_GROUP_RAID0;
4763 }
4764 return flags;
4765}
4766
4767int __alloc_chunk_for_shrink(struct btrfs_root *root,
4768 struct btrfs_block_group_cache *shrink_block_group,
4769 int force)
4770{
4771 struct btrfs_trans_handle *trans;
4772 u64 new_alloc_flags;
4773 u64 calc;
4774
4775 spin_lock(&shrink_block_group->lock);
4776 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
4777 spin_unlock(&shrink_block_group->lock);
4778
4779 trans = btrfs_start_transaction(root, 1);
4780 spin_lock(&shrink_block_group->lock);
4781
4782 new_alloc_flags = update_block_group_flags(root,
4783 shrink_block_group->flags);
4784 if (new_alloc_flags != shrink_block_group->flags) {
4785 calc =
4786 btrfs_block_group_used(&shrink_block_group->item);
4787 } else {
4788 calc = shrink_block_group->key.offset;
4789 }
4790 spin_unlock(&shrink_block_group->lock);
4791
4792 do_chunk_alloc(trans, root->fs_info->extent_root,
4793 calc + 2 * 1024 * 1024, new_alloc_flags, force);
4794
4795 btrfs_end_transaction(trans, root);
4796 } else
4797 spin_unlock(&shrink_block_group->lock);
4798 return 0;
4799}
4800
4801static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4802 struct btrfs_root *root,
4803 u64 objectid, u64 size)
4804{
4805 struct btrfs_path *path;
4806 struct btrfs_inode_item *item;
4807 struct extent_buffer *leaf;
4808 int ret;
4809
4810 path = btrfs_alloc_path();
4811 if (!path)
4812 return -ENOMEM;
4813
4814 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4815 if (ret)
4816 goto out;
4817
4818 leaf = path->nodes[0];
4819 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4820 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4821 btrfs_set_inode_generation(leaf, item, 1);
4822 btrfs_set_inode_size(leaf, item, size);
4823 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4824 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NODATASUM |
4825 BTRFS_INODE_NOCOMPRESS);
4826 btrfs_mark_buffer_dirty(leaf);
4827 btrfs_release_path(root, path);
4828out:
4829 btrfs_free_path(path);
4830 return ret;
4831}
4832
4833static struct inode noinline *create_reloc_inode(struct btrfs_fs_info *fs_info,
4834 struct btrfs_block_group_cache *group)
4835{
4836 struct inode *inode = NULL;
4837 struct btrfs_trans_handle *trans;
4838 struct btrfs_root *root;
4839 struct btrfs_key root_key;
4840 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4841 int err = 0;
4842
4843 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4844 root_key.type = BTRFS_ROOT_ITEM_KEY;
4845 root_key.offset = (u64)-1;
4846 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
4847 if (IS_ERR(root))
4848 return ERR_CAST(root);
4849
4850 trans = btrfs_start_transaction(root, 1);
4851 BUG_ON(!trans);
4852
4853 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
4854 if (err)
4855 goto out;
4856
4857 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
4858 BUG_ON(err);
4859
4860 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
4861 group->key.offset, 0, group->key.offset,
4862 0, 0, 0);
4863 BUG_ON(err);
4864
4865 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
4866 if (inode->i_state & I_NEW) {
4867 BTRFS_I(inode)->root = root;
4868 BTRFS_I(inode)->location.objectid = objectid;
4869 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
4870 BTRFS_I(inode)->location.offset = 0;
4871 btrfs_read_locked_inode(inode);
4872 unlock_new_inode(inode);
4873 BUG_ON(is_bad_inode(inode));
4874 } else {
4875 BUG_ON(1);
4876 }
4877
4878 err = btrfs_orphan_add(trans, inode);
4879out:
4880 btrfs_end_transaction(trans, root);
4881 if (err) {
4882 if (inode)
4883 iput(inode);
4884 inode = ERR_PTR(err);
4885 }
4886 return inode;
4887}
4888
4889int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
4890{
4891 struct btrfs_trans_handle *trans;
4892 struct btrfs_path *path;
4893 struct btrfs_fs_info *info = root->fs_info;
4894 struct extent_buffer *leaf;
4895 struct inode *reloc_inode;
4896 struct btrfs_block_group_cache *block_group;
4897 struct btrfs_key key;
4898 u64 skipped;
4899 u64 cur_byte;
4900 u64 total_found;
4901 u32 nritems;
4902 int ret;
4903 int progress;
4904 int pass = 0;
4905
4906 root = root->fs_info->extent_root;
4907
4908 block_group = btrfs_lookup_block_group(info, group_start);
4909 BUG_ON(!block_group);
4910
4911 printk("btrfs relocating block group %llu flags %llu\n",
4912 (unsigned long long)block_group->key.objectid,
4913 (unsigned long long)block_group->flags);
4914
4915 path = btrfs_alloc_path();
4916 BUG_ON(!path);
4917
4918 reloc_inode = create_reloc_inode(info, block_group);
4919 BUG_ON(IS_ERR(reloc_inode));
4920
4921 __alloc_chunk_for_shrink(root, block_group, 1);
4922 block_group->ro = 1;
4923 block_group->space_info->total_bytes -= block_group->key.offset;
4924
4925 btrfs_start_delalloc_inodes(info->tree_root);
4926 btrfs_wait_ordered_extents(info->tree_root, 0);
4927again:
4928 skipped = 0;
4929 total_found = 0;
4930 progress = 0;
4931 key.objectid = block_group->key.objectid;
4932 key.offset = 0;
4933 key.type = 0;
4934 cur_byte = key.objectid;
4935
4936 trans = btrfs_start_transaction(info->tree_root, 1);
4937 btrfs_commit_transaction(trans, info->tree_root);
4938
4939 mutex_lock(&root->fs_info->cleaner_mutex);
4940 btrfs_clean_old_snapshots(info->tree_root);
4941 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
4942 mutex_unlock(&root->fs_info->cleaner_mutex);
4943
4944 while(1) {
4945 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4946 if (ret < 0)
4947 goto out;
4948next:
4949 leaf = path->nodes[0];
4950 nritems = btrfs_header_nritems(leaf);
4951 if (path->slots[0] >= nritems) {
4952 ret = btrfs_next_leaf(root, path);
4953 if (ret < 0)
4954 goto out;
4955 if (ret == 1) {
4956 ret = 0;
4957 break;
4958 }
4959 leaf = path->nodes[0];
4960 nritems = btrfs_header_nritems(leaf);
4961 }
4962
4963 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4964
4965 if (key.objectid >= block_group->key.objectid +
4966 block_group->key.offset)
4967 break;
4968
4969 if (progress && need_resched()) {
4970 btrfs_release_path(root, path);
4971 cond_resched();
4972 progress = 0;
4973 continue;
4974 }
4975 progress = 1;
4976
4977 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
4978 key.objectid + key.offset <= cur_byte) {
4979 path->slots[0]++;
4980 goto next;
4981 }
4982
4983 total_found++;
4984 cur_byte = key.objectid + key.offset;
4985 btrfs_release_path(root, path);
4986
4987 __alloc_chunk_for_shrink(root, block_group, 0);
4988 ret = relocate_one_extent(root, path, &key, block_group,
4989 reloc_inode, pass);
4990 BUG_ON(ret < 0);
4991 if (ret > 0)
4992 skipped++;
4993
4994 key.objectid = cur_byte;
4995 key.type = 0;
4996 key.offset = 0;
4997 }
4998
4999 btrfs_release_path(root, path);
5000
5001 if (pass == 0) {
5002 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
5003 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
5004 WARN_ON(reloc_inode->i_mapping->nrpages);
5005 }
5006
5007 if (total_found > 0) {
5008 printk("btrfs found %llu extents in pass %d\n",
5009 (unsigned long long)total_found, pass);
5010 pass++;
5011 if (total_found == skipped && pass > 2) {
5012 iput(reloc_inode);
5013 reloc_inode = create_reloc_inode(info, block_group);
5014 pass = 0;
5015 }
5016 goto again;
5017 }
5018
5019 /* delete reloc_inode */
5020 iput(reloc_inode);
5021
5022 /* unpin extents in this range */
5023 trans = btrfs_start_transaction(info->tree_root, 1);
5024 btrfs_commit_transaction(trans, info->tree_root);
5025
5026 spin_lock(&block_group->lock);
5027 WARN_ON(block_group->pinned > 0);
5028 WARN_ON(block_group->reserved > 0);
5029 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
5030 spin_unlock(&block_group->lock);
5031 ret = 0;
5032out:
5033 btrfs_free_path(path);
5034 return ret;
5035}
5036
5037int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
5038 struct btrfs_key *key)
5039{
5040 int ret = 0;
5041 struct btrfs_key found_key;
5042 struct extent_buffer *leaf;
5043 int slot;
5044
5045 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
5046 if (ret < 0)
5047 goto out;
5048
5049 while(1) {
5050 slot = path->slots[0];
5051 leaf = path->nodes[0];
5052 if (slot >= btrfs_header_nritems(leaf)) {
5053 ret = btrfs_next_leaf(root, path);
5054 if (ret == 0)
5055 continue;
5056 if (ret < 0)
5057 goto out;
5058 break;
5059 }
5060 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5061
5062 if (found_key.objectid >= key->objectid &&
5063 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
5064 ret = 0;
5065 goto out;
5066 }
5067 path->slots[0]++;
5068 }
5069 ret = -ENOENT;
5070out:
5071 return ret;
5072}
5073
5074int btrfs_free_block_groups(struct btrfs_fs_info *info)
5075{
5076 struct btrfs_block_group_cache *block_group;
5077 struct rb_node *n;
5078
5079 spin_lock(&info->block_group_cache_lock);
5080 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
5081 block_group = rb_entry(n, struct btrfs_block_group_cache,
5082 cache_node);
5083 rb_erase(&block_group->cache_node,
5084 &info->block_group_cache_tree);
5085 spin_unlock(&info->block_group_cache_lock);
5086
5087 btrfs_remove_free_space_cache(block_group);
5088 down_write(&block_group->space_info->groups_sem);
5089 list_del(&block_group->list);
5090 up_write(&block_group->space_info->groups_sem);
5091 kfree(block_group);
5092
5093 spin_lock(&info->block_group_cache_lock);
5094 }
5095 spin_unlock(&info->block_group_cache_lock);
5096 return 0;
5097}
5098
5099int btrfs_read_block_groups(struct btrfs_root *root)
5100{
5101 struct btrfs_path *path;
5102 int ret;
5103 struct btrfs_block_group_cache *cache;
5104 struct btrfs_fs_info *info = root->fs_info;
5105 struct btrfs_space_info *space_info;
5106 struct btrfs_key key;
5107 struct btrfs_key found_key;
5108 struct extent_buffer *leaf;
5109
5110 root = info->extent_root;
5111 key.objectid = 0;
5112 key.offset = 0;
5113 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5114 path = btrfs_alloc_path();
5115 if (!path)
5116 return -ENOMEM;
5117
5118 while(1) {
5119 ret = find_first_block_group(root, path, &key);
5120 if (ret > 0) {
5121 ret = 0;
5122 goto error;
5123 }
5124 if (ret != 0)
5125 goto error;
5126
5127 leaf = path->nodes[0];
5128 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5129 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5130 if (!cache) {
5131 ret = -ENOMEM;
5132 break;
5133 }
5134
5135 spin_lock_init(&cache->lock);
5136 mutex_init(&cache->alloc_mutex);
5137 INIT_LIST_HEAD(&cache->list);
5138 read_extent_buffer(leaf, &cache->item,
5139 btrfs_item_ptr_offset(leaf, path->slots[0]),
5140 sizeof(cache->item));
5141 memcpy(&cache->key, &found_key, sizeof(found_key));
5142
5143 key.objectid = found_key.objectid + found_key.offset;
5144 btrfs_release_path(root, path);
5145 cache->flags = btrfs_block_group_flags(&cache->item);
5146
5147 ret = update_space_info(info, cache->flags, found_key.offset,
5148 btrfs_block_group_used(&cache->item),
5149 &space_info);
5150 BUG_ON(ret);
5151 cache->space_info = space_info;
5152 down_write(&space_info->groups_sem);
5153 list_add_tail(&cache->list, &space_info->block_groups);
5154 up_write(&space_info->groups_sem);
5155
5156 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5157 BUG_ON(ret);
5158
5159 set_avail_alloc_bits(root->fs_info, cache->flags);
5160 }
5161 ret = 0;
5162error:
5163 btrfs_free_path(path);
5164 return ret;
5165}
5166
5167int btrfs_make_block_group(struct btrfs_trans_handle *trans,
5168 struct btrfs_root *root, u64 bytes_used,
5169 u64 type, u64 chunk_objectid, u64 chunk_offset,
5170 u64 size)
5171{
5172 int ret;
5173 struct btrfs_root *extent_root;
5174 struct btrfs_block_group_cache *cache;
5175
5176 extent_root = root->fs_info->extent_root;
5177
5178 root->fs_info->last_trans_new_blockgroup = trans->transid;
5179
5180 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5181 if (!cache)
5182 return -ENOMEM;
5183
5184 cache->key.objectid = chunk_offset;
5185 cache->key.offset = size;
5186 spin_lock_init(&cache->lock);
5187 mutex_init(&cache->alloc_mutex);
5188 INIT_LIST_HEAD(&cache->list);
5189 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5190
5191 btrfs_set_block_group_used(&cache->item, bytes_used);
5192 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
5193 cache->flags = type;
5194 btrfs_set_block_group_flags(&cache->item, type);
5195
5196 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
5197 &cache->space_info);
5198 BUG_ON(ret);
5199 down_write(&cache->space_info->groups_sem);
5200 list_add_tail(&cache->list, &cache->space_info->block_groups);
5201 up_write(&cache->space_info->groups_sem);
5202
5203 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5204 BUG_ON(ret);
5205
5206 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
5207 sizeof(cache->item));
5208 BUG_ON(ret);
5209
5210 finish_current_insert(trans, extent_root, 0);
5211 ret = del_pending_extents(trans, extent_root, 0);
5212 BUG_ON(ret);
5213 set_avail_alloc_bits(extent_root->fs_info, type);
5214
5215 return 0;
5216}
5217
5218int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
5219 struct btrfs_root *root, u64 group_start)
5220{
5221 struct btrfs_path *path;
5222 struct btrfs_block_group_cache *block_group;
5223 struct btrfs_key key;
5224 int ret;
5225
5226 root = root->fs_info->extent_root;
5227
5228 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
5229 BUG_ON(!block_group);
5230
5231 memcpy(&key, &block_group->key, sizeof(key));
5232
5233 path = btrfs_alloc_path();
5234 BUG_ON(!path);
5235
5236 btrfs_remove_free_space_cache(block_group);
5237 rb_erase(&block_group->cache_node,
5238 &root->fs_info->block_group_cache_tree);
5239 down_write(&block_group->space_info->groups_sem);
5240 list_del(&block_group->list);
5241 up_write(&block_group->space_info->groups_sem);
5242
5243 /*
5244 memset(shrink_block_group, 0, sizeof(*shrink_block_group));
5245 kfree(shrink_block_group);
5246 */
5247
5248 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
5249 if (ret > 0)
5250 ret = -EIO;
5251 if (ret < 0)
5252 goto out;
5253
5254 ret = btrfs_del_item(trans, root, path);
5255out:
5256 btrfs_free_path(path);
5257 return ret;
5258}
Linux kernel - Deliverables
This page took 0.043873 seconds and 5 git commands to generate.