?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ftrace: add command interface for function selection
[linux-2.6/kvm.git] / fs / btrfs / extent-tree.c
blob7527523c2d2d851ce1200424dce799814ac5a1fa
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/pagemap.h>
20 #include <linux/writeback.h>
21 #include <linux/blkdev.h>
22 #include <linux/sort.h>
23 #include "compat.h"
24 #include "hash.h"
25 #include "crc32c.h"
26 #include "ctree.h"
27 #include "disk-io.h"
28 #include "print-tree.h"
29 #include "transaction.h"
30 #include "volumes.h"
31 #include "locking.h"
32 #include "ref-cache.h"
33
34 #define PENDING_EXTENT_INSERT 0
35 #define PENDING_EXTENT_DELETE 1
36 #define PENDING_BACKREF_UPDATE 2
37
38 struct pending_extent_op {
39 int type;
40 u64 bytenr;
41 u64 num_bytes;
42 u64 parent;
43 u64 orig_parent;
44 u64 generation;
45 u64 orig_generation;
46 int level;
47 struct list_head list;
48 int del;
49 };
50
51 static int finish_current_insert(struct btrfs_trans_handle *trans,
52 struct btrfs_root *extent_root, int all);
53 static int del_pending_extents(struct btrfs_trans_handle *trans,
54 struct btrfs_root *extent_root, int all);
55 static int pin_down_bytes(struct btrfs_trans_handle *trans,
56 struct btrfs_root *root,
57 u64 bytenr, u64 num_bytes, int is_data);
58 static int update_block_group(struct btrfs_trans_handle *trans,
59 struct btrfs_root *root,
60 u64 bytenr, u64 num_bytes, int alloc,
61 int mark_free);
62
63 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
64 {
65 return (cache->flags & bits) == bits;
66 }
67
68 /*
69 * this adds the block group to the fs_info rb tree for the block group
70 * cache
71 */
72 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
73 struct btrfs_block_group_cache *block_group)
74 {
75 struct rb_node **p;
76 struct rb_node *parent = NULL;
77 struct btrfs_block_group_cache *cache;
78
79 spin_lock(&info->block_group_cache_lock);
80 p = &info->block_group_cache_tree.rb_node;
81
82 while (*p) {
83 parent = *p;
84 cache = rb_entry(parent, struct btrfs_block_group_cache,
85 cache_node);
86 if (block_group->key.objectid < cache->key.objectid) {
87 p = &(*p)->rb_left;
88 } else if (block_group->key.objectid > cache->key.objectid) {
89 p = &(*p)->rb_right;
90 } else {
91 spin_unlock(&info->block_group_cache_lock);
92 return -EEXIST;
93 }
94 }
95
96 rb_link_node(&block_group->cache_node, parent, p);
97 rb_insert_color(&block_group->cache_node,
98 &info->block_group_cache_tree);
99 spin_unlock(&info->block_group_cache_lock);
100
101 return 0;
102 }
103
104 /*
105 * This will return the block group at or after bytenr if contains is 0, else
106 * it will return the block group that contains the bytenr
107 */
108 static struct btrfs_block_group_cache *
109 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
110 int contains)
111 {
112 struct btrfs_block_group_cache *cache, *ret = NULL;
113 struct rb_node *n;
114 u64 end, start;
115
116 spin_lock(&info->block_group_cache_lock);
117 n = info->block_group_cache_tree.rb_node;
118
119 while (n) {
120 cache = rb_entry(n, struct btrfs_block_group_cache,
121 cache_node);
122 end = cache->key.objectid + cache->key.offset - 1;
123 start = cache->key.objectid;
124
125 if (bytenr < start) {
126 if (!contains && (!ret || start < ret->key.objectid))
127 ret = cache;
128 n = n->rb_left;
129 } else if (bytenr > start) {
130 if (contains && bytenr <= end) {
131 ret = cache;
132 break;
133 }
134 n = n->rb_right;
135 } else {
136 ret = cache;
137 break;
138 }
139 }
140 if (ret)
141 atomic_inc(&ret->count);
142 spin_unlock(&info->block_group_cache_lock);
143
144 return ret;
145 }
146
147 /*
148 * this is only called by cache_block_group, since we could have freed extents
149 * we need to check the pinned_extents for any extents that can't be used yet
150 * since their free space will be released as soon as the transaction commits.
151 */
152 static int add_new_free_space(struct btrfs_block_group_cache *block_group,
153 struct btrfs_fs_info *info, u64 start, u64 end)
154 {
155 u64 extent_start, extent_end, size;
156 int ret;
157
158 mutex_lock(&info->pinned_mutex);
159 while (start < end) {
160 ret = find_first_extent_bit(&info->pinned_extents, start,
161 &extent_start, &extent_end,
162 EXTENT_DIRTY);
163 if (ret)
164 break;
165
166 if (extent_start == start) {
167 start = extent_end + 1;
168 } else if (extent_start > start && extent_start < end) {
169 size = extent_start - start;
170 ret = btrfs_add_free_space(block_group, start,
171 size);
172 BUG_ON(ret);
173 start = extent_end + 1;
174 } else {
175 break;
176 }
177 }
178
179 if (start < end) {
180 size = end - start;
181 ret = btrfs_add_free_space(block_group, start, size);
182 BUG_ON(ret);
183 }
184 mutex_unlock(&info->pinned_mutex);
185
186 return 0;
187 }
188
189 static int remove_sb_from_cache(struct btrfs_root *root,
190 struct btrfs_block_group_cache *cache)
191 {
192 u64 bytenr;
193 u64 *logical;
194 int stripe_len;
195 int i, nr, ret;
196
197 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
198 bytenr = btrfs_sb_offset(i);
199 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
200 cache->key.objectid, bytenr, 0,
201 &logical, &nr, &stripe_len);
202 BUG_ON(ret);
203 while (nr--) {
204 btrfs_remove_free_space(cache, logical[nr],
205 stripe_len);
206 }
207 kfree(logical);
208 }
209 return 0;
210 }
211
212 static int cache_block_group(struct btrfs_root *root,
213 struct btrfs_block_group_cache *block_group)
214 {
215 struct btrfs_path *path;
216 int ret = 0;
217 struct btrfs_key key;
218 struct extent_buffer *leaf;
219 int slot;
220 u64 last;
221
222 if (!block_group)
223 return 0;
224
225 root = root->fs_info->extent_root;
226
227 if (block_group->cached)
228 return 0;
229
230 path = btrfs_alloc_path();
231 if (!path)
232 return -ENOMEM;
233
234 path->reada = 2;
235 /*
236 * we get into deadlocks with paths held by callers of this function.
237 * since the alloc_mutex is protecting things right now, just
238 * skip the locking here
239 */
240 path->skip_locking = 1;
241 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
242 key.objectid = last;
243 key.offset = 0;
244 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
245 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
246 if (ret < 0)
247 goto err;
248
249 while (1) {
250 leaf = path->nodes[0];
251 slot = path->slots[0];
252 if (slot >= btrfs_header_nritems(leaf)) {
253 ret = btrfs_next_leaf(root, path);
254 if (ret < 0)
255 goto err;
256 if (ret == 0)
257 continue;
258 else
259 break;
260 }
261 btrfs_item_key_to_cpu(leaf, &key, slot);
262 if (key.objectid < block_group->key.objectid)
263 goto next;
264
265 if (key.objectid >= block_group->key.objectid +
266 block_group->key.offset)
267 break;
268
269 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
270 add_new_free_space(block_group, root->fs_info, last,
271 key.objectid);
272
273 last = key.objectid + key.offset;
274 }
275 next:
276 path->slots[0]++;
277 }
278
279 add_new_free_space(block_group, root->fs_info, last,
280 block_group->key.objectid +
281 block_group->key.offset);
282
283 remove_sb_from_cache(root, block_group);
284 block_group->cached = 1;
285 ret = 0;
286 err:
287 btrfs_free_path(path);
288 return ret;
289 }
290
291 /*
292 * return the block group that starts at or after bytenr
293 */
294 static struct btrfs_block_group_cache *
295 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
296 {
297 struct btrfs_block_group_cache *cache;
298
299 cache = block_group_cache_tree_search(info, bytenr, 0);
300
301 return cache;
302 }
303
304 /*
305 * return the block group that contains teh given bytenr
306 */
307 struct btrfs_block_group_cache *btrfs_lookup_block_group(
308 struct btrfs_fs_info *info,
309 u64 bytenr)
310 {
311 struct btrfs_block_group_cache *cache;
312
313 cache = block_group_cache_tree_search(info, bytenr, 1);
314
315 return cache;
316 }
317
318 static inline void put_block_group(struct btrfs_block_group_cache *cache)
319 {
320 if (atomic_dec_and_test(&cache->count))
321 kfree(cache);
322 }
323
324 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
325 u64 flags)
326 {
327 struct list_head *head = &info->space_info;
328 struct btrfs_space_info *found;
329 list_for_each_entry(found, head, list) {
330 if (found->flags == flags)
331 return found;
332 }
333 return NULL;
334 }
335
336 static u64 div_factor(u64 num, int factor)
337 {
338 if (factor == 10)
339 return num;
340 num *= factor;
341 do_div(num, 10);
342 return num;
343 }
344
345 u64 btrfs_find_block_group(struct btrfs_root *root,
346 u64 search_start, u64 search_hint, int owner)
347 {
348 struct btrfs_block_group_cache *cache;
349 u64 used;
350 u64 last = max(search_hint, search_start);
351 u64 group_start = 0;
352 int full_search = 0;
353 int factor = 9;
354 int wrapped = 0;
355 again:
356 while (1) {
357 cache = btrfs_lookup_first_block_group(root->fs_info, last);
358 if (!cache)
359 break;
360
361 spin_lock(&cache->lock);
362 last = cache->key.objectid + cache->key.offset;
363 used = btrfs_block_group_used(&cache->item);
364
365 if ((full_search || !cache->ro) &&
366 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
367 if (used + cache->pinned + cache->reserved <
368 div_factor(cache->key.offset, factor)) {
369 group_start = cache->key.objectid;
370 spin_unlock(&cache->lock);
371 put_block_group(cache);
372 goto found;
373 }
374 }
375 spin_unlock(&cache->lock);
376 put_block_group(cache);
377 cond_resched();
378 }
379 if (!wrapped) {
380 last = search_start;
381 wrapped = 1;
382 goto again;
383 }
384 if (!full_search && factor < 10) {
385 last = search_start;
386 full_search = 1;
387 factor = 10;
388 goto again;
389 }
390 found:
391 return group_start;
392 }
393
394 /* simple helper to search for an existing extent at a given offset */
395 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
396 {
397 int ret;
398 struct btrfs_key key;
399 struct btrfs_path *path;
400
401 path = btrfs_alloc_path();
402 BUG_ON(!path);
403 key.objectid = start;
404 key.offset = len;
405 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
406 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
407 0, 0);
408 btrfs_free_path(path);
409 return ret;
410 }
411
412 /*
413 * Back reference rules. Back refs have three main goals:
414 *
415 * 1) differentiate between all holders of references to an extent so that
416 * when a reference is dropped we can make sure it was a valid reference
417 * before freeing the extent.
418 *
419 * 2) Provide enough information to quickly find the holders of an extent
420 * if we notice a given block is corrupted or bad.
421 *
422 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
423 * maintenance. This is actually the same as #2, but with a slightly
424 * different use case.
425 *
426 * File extents can be referenced by:
427 *
428 * - multiple snapshots, subvolumes, or different generations in one subvol
429 * - different files inside a single subvolume
430 * - different offsets inside a file (bookend extents in file.c)
431 *
432 * The extent ref structure has fields for:
433 *
434 * - Objectid of the subvolume root
435 * - Generation number of the tree holding the reference
436 * - objectid of the file holding the reference
437 * - number of references holding by parent node (alway 1 for tree blocks)
438 *
439 * Btree leaf may hold multiple references to a file extent. In most cases,
440 * these references are from same file and the corresponding offsets inside
441 * the file are close together.
442 *
443 * When a file extent is allocated the fields are filled in:
444 * (root_key.objectid, trans->transid, inode objectid, 1)
445 *
446 * When a leaf is cow'd new references are added for every file extent found
447 * in the leaf. It looks similar to the create case, but trans->transid will
448 * be different when the block is cow'd.
449 *
450 * (root_key.objectid, trans->transid, inode objectid,
451 * number of references in the leaf)
452 *
453 * When a file extent is removed either during snapshot deletion or
454 * file truncation, we find the corresponding back reference and check
455 * the following fields:
456 *
457 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
458 * inode objectid)
459 *
460 * Btree extents can be referenced by:
461 *
462 * - Different subvolumes
463 * - Different generations of the same subvolume
464 *
465 * When a tree block is created, back references are inserted:
466 *
467 * (root->root_key.objectid, trans->transid, level, 1)
468 *
469 * When a tree block is cow'd, new back references are added for all the
470 * blocks it points to. If the tree block isn't in reference counted root,
471 * the old back references are removed. These new back references are of
472 * the form (trans->transid will have increased since creation):
473 *
474 * (root->root_key.objectid, trans->transid, level, 1)
475 *
476 * When a backref is in deleting, the following fields are checked:
477 *
478 * if backref was for a tree root:
479 * (btrfs_header_owner(itself), btrfs_header_generation(itself), level)
480 * else
481 * (btrfs_header_owner(parent), btrfs_header_generation(parent), level)
482 *
483 * Back Reference Key composing:
484 *
485 * The key objectid corresponds to the first byte in the extent, the key
486 * type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first
487 * byte of parent extent. If a extent is tree root, the key offset is set
488 * to the key objectid.
489 */
490
491 static noinline int lookup_extent_backref(struct btrfs_trans_handle *trans,
492 struct btrfs_root *root,
493 struct btrfs_path *path,
494 u64 bytenr, u64 parent,
495 u64 ref_root, u64 ref_generation,
496 u64 owner_objectid, int del)
497 {
498 struct btrfs_key key;
499 struct btrfs_extent_ref *ref;
500 struct extent_buffer *leaf;
501 u64 ref_objectid;
502 int ret;
503
504 key.objectid = bytenr;
505 key.type = BTRFS_EXTENT_REF_KEY;
506 key.offset = parent;
507
508 ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1);
509 if (ret < 0)
510 goto out;
511 if (ret > 0) {
512 ret = -ENOENT;
513 goto out;
514 }
515
516 leaf = path->nodes[0];
517 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
518 ref_objectid = btrfs_ref_objectid(leaf, ref);
519 if (btrfs_ref_root(leaf, ref) != ref_root ||
520 btrfs_ref_generation(leaf, ref) != ref_generation ||
521 (ref_objectid != owner_objectid &&
522 ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
523 ret = -EIO;
524 WARN_ON(1);
525 goto out;
526 }
527 ret = 0;
528 out:
529 return ret;
530 }
531
532 /*
533 * updates all the backrefs that are pending on update_list for the
534 * extent_root
535 */
536 static noinline int update_backrefs(struct btrfs_trans_handle *trans,
537 struct btrfs_root *extent_root,
538 struct btrfs_path *path,
539 struct list_head *update_list)
540 {
541 struct btrfs_key key;
542 struct btrfs_extent_ref *ref;
543 struct btrfs_fs_info *info = extent_root->fs_info;
544 struct pending_extent_op *op;
545 struct extent_buffer *leaf;
546 int ret = 0;
547 struct list_head *cur = update_list->next;
548 u64 ref_objectid;
549 u64 ref_root = extent_root->root_key.objectid;
550
551 op = list_entry(cur, struct pending_extent_op, list);
552
553 search:
554 key.objectid = op->bytenr;
555 key.type = BTRFS_EXTENT_REF_KEY;
556 key.offset = op->orig_parent;
557
558 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 1);
559 BUG_ON(ret);
560
561 leaf = path->nodes[0];
562
563 loop:
564 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
565
566 ref_objectid = btrfs_ref_objectid(leaf, ref);
567
568 if (btrfs_ref_root(leaf, ref) != ref_root ||
569 btrfs_ref_generation(leaf, ref) != op->orig_generation ||
570 (ref_objectid != op->level &&
571 ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
572 printk(KERN_ERR "btrfs couldn't find %llu, parent %llu, "
573 "root %llu, owner %u\n",
574 (unsigned long long)op->bytenr,
575 (unsigned long long)op->orig_parent,
576 (unsigned long long)ref_root, op->level);
577 btrfs_print_leaf(extent_root, leaf);
578 BUG();
579 }
580
581 key.objectid = op->bytenr;
582 key.offset = op->parent;
583 key.type = BTRFS_EXTENT_REF_KEY;
584 ret = btrfs_set_item_key_safe(trans, extent_root, path, &key);
585 BUG_ON(ret);
586 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
587 btrfs_set_ref_generation(leaf, ref, op->generation);
588
589 cur = cur->next;
590
591 list_del_init(&op->list);
592 unlock_extent(&info->extent_ins, op->bytenr,
593 op->bytenr + op->num_bytes - 1, GFP_NOFS);
594 kfree(op);
595
596 if (cur == update_list) {
597 btrfs_mark_buffer_dirty(path->nodes[0]);
598 btrfs_release_path(extent_root, path);
599 goto out;
600 }
601
602 op = list_entry(cur, struct pending_extent_op, list);
603
604 path->slots[0]++;
605 while (path->slots[0] < btrfs_header_nritems(leaf)) {
606 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
607 if (key.objectid == op->bytenr &&
608 key.type == BTRFS_EXTENT_REF_KEY)
609 goto loop;
610 path->slots[0]++;
611 }
612
613 btrfs_mark_buffer_dirty(path->nodes[0]);
614 btrfs_release_path(extent_root, path);
615 goto search;
616
617 out:
618 return 0;
619 }
620
621 static noinline int insert_extents(struct btrfs_trans_handle *trans,
622 struct btrfs_root *extent_root,
623 struct btrfs_path *path,
624 struct list_head *insert_list, int nr)
625 {
626 struct btrfs_key *keys;
627 u32 *data_size;
628 struct pending_extent_op *op;
629 struct extent_buffer *leaf;
630 struct list_head *cur = insert_list->next;
631 struct btrfs_fs_info *info = extent_root->fs_info;
632 u64 ref_root = extent_root->root_key.objectid;
633 int i = 0, last = 0, ret;
634 int total = nr * 2;
635
636 if (!nr)
637 return 0;
638
639 keys = kzalloc(total * sizeof(struct btrfs_key), GFP_NOFS);
640 if (!keys)
641 return -ENOMEM;
642
643 data_size = kzalloc(total * sizeof(u32), GFP_NOFS);
644 if (!data_size) {
645 kfree(keys);
646 return -ENOMEM;
647 }
648
649 list_for_each_entry(op, insert_list, list) {
650 keys[i].objectid = op->bytenr;
651 keys[i].offset = op->num_bytes;
652 keys[i].type = BTRFS_EXTENT_ITEM_KEY;
653 data_size[i] = sizeof(struct btrfs_extent_item);
654 i++;
655
656 keys[i].objectid = op->bytenr;
657 keys[i].offset = op->parent;
658 keys[i].type = BTRFS_EXTENT_REF_KEY;
659 data_size[i] = sizeof(struct btrfs_extent_ref);
660 i++;
661 }
662
663 op = list_entry(cur, struct pending_extent_op, list);
664 i = 0;
665 while (i < total) {
666 int c;
667 ret = btrfs_insert_some_items(trans, extent_root, path,
668 keys+i, data_size+i, total-i);
669 BUG_ON(ret < 0);
670
671 if (last && ret > 1)
672 BUG();
673
674 leaf = path->nodes[0];
675 for (c = 0; c < ret; c++) {
676 int ref_first = keys[i].type == BTRFS_EXTENT_REF_KEY;
677
678 /*
679 * if the first item we inserted was a backref, then
680 * the EXTENT_ITEM will be the odd c's, else it will
681 * be the even c's
682 */
683 if ((ref_first && (c % 2)) ||
684 (!ref_first && !(c % 2))) {
685 struct btrfs_extent_item *itm;
686
687 itm = btrfs_item_ptr(leaf, path->slots[0] + c,
688 struct btrfs_extent_item);
689 btrfs_set_extent_refs(path->nodes[0], itm, 1);
690 op->del++;
691 } else {
692 struct btrfs_extent_ref *ref;
693
694 ref = btrfs_item_ptr(leaf, path->slots[0] + c,
695 struct btrfs_extent_ref);
696 btrfs_set_ref_root(leaf, ref, ref_root);
697 btrfs_set_ref_generation(leaf, ref,
698 op->generation);
699 btrfs_set_ref_objectid(leaf, ref, op->level);
700 btrfs_set_ref_num_refs(leaf, ref, 1);
701 op->del++;
702 }
703
704 /*
705 * using del to see when its ok to free up the
706 * pending_extent_op. In the case where we insert the
707 * last item on the list in order to help do batching
708 * we need to not free the extent op until we actually
709 * insert the extent_item
710 */
711 if (op->del == 2) {
712 unlock_extent(&info->extent_ins, op->bytenr,
713 op->bytenr + op->num_bytes - 1,
714 GFP_NOFS);
715 cur = cur->next;
716 list_del_init(&op->list);
717 kfree(op);
718 if (cur != insert_list)
719 op = list_entry(cur,
720 struct pending_extent_op,
721 list);
722 }
723 }
724 btrfs_mark_buffer_dirty(leaf);
725 btrfs_release_path(extent_root, path);
726
727 /*
728 * Ok backref's and items usually go right next to eachother,
729 * but if we could only insert 1 item that means that we
730 * inserted on the end of a leaf, and we have no idea what may
731 * be on the next leaf so we just play it safe. In order to
732 * try and help this case we insert the last thing on our
733 * insert list so hopefully it will end up being the last
734 * thing on the leaf and everything else will be before it,
735 * which will let us insert a whole bunch of items at the same
736 * time.
737 */
738 if (ret == 1 && !last && (i + ret < total)) {
739 /*
740 * last: where we will pick up the next time around
741 * i: our current key to insert, will be total - 1
742 * cur: the current op we are screwing with
743 * op: duh
744 */
745 last = i + ret;
746 i = total - 1;
747 cur = insert_list->prev;
748 op = list_entry(cur, struct pending_extent_op, list);
749 } else if (last) {
750 /*
751 * ok we successfully inserted the last item on the
752 * list, lets reset everything
753 *
754 * i: our current key to insert, so where we left off
755 * last time
756 * last: done with this
757 * cur: the op we are messing with
758 * op: duh
759 * total: since we inserted the last key, we need to
760 * decrement total so we dont overflow
761 */
762 i = last;
763 last = 0;
764 total--;
765 if (i < total) {
766 cur = insert_list->next;
767 op = list_entry(cur, struct pending_extent_op,
768 list);
769 }
770 } else {
771 i += ret;
772 }
773
774 cond_resched();
775 }
776 ret = 0;
777 kfree(keys);
778 kfree(data_size);
779 return ret;
780 }
781
782 static noinline int insert_extent_backref(struct btrfs_trans_handle *trans,
783 struct btrfs_root *root,
784 struct btrfs_path *path,
785 u64 bytenr, u64 parent,
786 u64 ref_root, u64 ref_generation,
787 u64 owner_objectid)
788 {
789 struct btrfs_key key;
790 struct extent_buffer *leaf;
791 struct btrfs_extent_ref *ref;
792 u32 num_refs;
793 int ret;
794
795 key.objectid = bytenr;
796 key.type = BTRFS_EXTENT_REF_KEY;
797 key.offset = parent;
798
799 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref));
800 if (ret == 0) {
801 leaf = path->nodes[0];
802 ref = btrfs_item_ptr(leaf, path->slots[0],
803 struct btrfs_extent_ref);
804 btrfs_set_ref_root(leaf, ref, ref_root);
805 btrfs_set_ref_generation(leaf, ref, ref_generation);
806 btrfs_set_ref_objectid(leaf, ref, owner_objectid);
807 btrfs_set_ref_num_refs(leaf, ref, 1);
808 } else if (ret == -EEXIST) {
809 u64 existing_owner;
810 BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID);
811 leaf = path->nodes[0];
812 ref = btrfs_item_ptr(leaf, path->slots[0],
813 struct btrfs_extent_ref);
814 if (btrfs_ref_root(leaf, ref) != ref_root ||
815 btrfs_ref_generation(leaf, ref) != ref_generation) {
816 ret = -EIO;
817 WARN_ON(1);
818 goto out;
819 }
820
821 num_refs = btrfs_ref_num_refs(leaf, ref);
822 BUG_ON(num_refs == 0);
823 btrfs_set_ref_num_refs(leaf, ref, num_refs + 1);
824
825 existing_owner = btrfs_ref_objectid(leaf, ref);
826 if (existing_owner != owner_objectid &&
827 existing_owner != BTRFS_MULTIPLE_OBJECTIDS) {
828 btrfs_set_ref_objectid(leaf, ref,
829 BTRFS_MULTIPLE_OBJECTIDS);
830 }
831 ret = 0;
832 } else {
833 goto out;
834 }
835 btrfs_mark_buffer_dirty(path->nodes[0]);
836 out:
837 btrfs_release_path(root, path);
838 return ret;
839 }
840
841 static noinline int remove_extent_backref(struct btrfs_trans_handle *trans,
842 struct btrfs_root *root,
843 struct btrfs_path *path)
844 {
845 struct extent_buffer *leaf;
846 struct btrfs_extent_ref *ref;
847 u32 num_refs;
848 int ret = 0;
849
850 leaf = path->nodes[0];
851 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
852 num_refs = btrfs_ref_num_refs(leaf, ref);
853 BUG_ON(num_refs == 0);
854 num_refs -= 1;
855 if (num_refs == 0) {
856 ret = btrfs_del_item(trans, root, path);
857 } else {
858 btrfs_set_ref_num_refs(leaf, ref, num_refs);
859 btrfs_mark_buffer_dirty(leaf);
860 }
861 btrfs_release_path(root, path);
862 return ret;
863 }
864
865 #ifdef BIO_RW_DISCARD
866 static void btrfs_issue_discard(struct block_device *bdev,
867 u64 start, u64 len)
868 {
869 blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL);
870 }
871 #endif
872
873 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
874 u64 num_bytes)
875 {
876 #ifdef BIO_RW_DISCARD
877 int ret;
878 u64 map_length = num_bytes;
879 struct btrfs_multi_bio *multi = NULL;
880
881 /* Tell the block device(s) that the sectors can be discarded */
882 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
883 bytenr, &map_length, &multi, 0);
884 if (!ret) {
885 struct btrfs_bio_stripe *stripe = multi->stripes;
886 int i;
887
888 if (map_length > num_bytes)
889 map_length = num_bytes;
890
891 for (i = 0; i < multi->num_stripes; i++, stripe++) {
892 btrfs_issue_discard(stripe->dev->bdev,
893 stripe->physical,
894 map_length);
895 }
896 kfree(multi);
897 }
898
899 return ret;
900 #else
901 return 0;
902 #endif
903 }
904
905 static noinline int free_extents(struct btrfs_trans_handle *trans,
906 struct btrfs_root *extent_root,
907 struct list_head *del_list)
908 {
909 struct btrfs_fs_info *info = extent_root->fs_info;
910 struct btrfs_path *path;
911 struct btrfs_key key, found_key;
912 struct extent_buffer *leaf;
913 struct list_head *cur;
914 struct pending_extent_op *op;
915 struct btrfs_extent_item *ei;
916 int ret, num_to_del, extent_slot = 0, found_extent = 0;
917 u32 refs;
918 u64 bytes_freed = 0;
919
920 path = btrfs_alloc_path();
921 if (!path)
922 return -ENOMEM;
923 path->reada = 1;
924
925 search:
926 /* search for the backref for the current ref we want to delete */
927 cur = del_list->next;
928 op = list_entry(cur, struct pending_extent_op, list);
929 ret = lookup_extent_backref(trans, extent_root, path, op->bytenr,
930 op->orig_parent,
931 extent_root->root_key.objectid,
932 op->orig_generation, op->level, 1);
933 if (ret) {
934 printk(KERN_ERR "btrfs unable to find backref byte nr %llu "
935 "root %llu gen %llu owner %u\n",
936 (unsigned long long)op->bytenr,
937 (unsigned long long)extent_root->root_key.objectid,
938 (unsigned long long)op->orig_generation, op->level);
939 btrfs_print_leaf(extent_root, path->nodes[0]);
940 WARN_ON(1);
941 goto out;
942 }
943
944 extent_slot = path->slots[0];
945 num_to_del = 1;
946 found_extent = 0;
947
948 /*
949 * if we aren't the first item on the leaf we can move back one and see
950 * if our ref is right next to our extent item
951 */
952 if (likely(extent_slot)) {
953 extent_slot--;
954 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
955 extent_slot);
956 if (found_key.objectid == op->bytenr &&
957 found_key.type == BTRFS_EXTENT_ITEM_KEY &&
958 found_key.offset == op->num_bytes) {
959 num_to_del++;
960 found_extent = 1;
961 }
962 }
963
964 /*
965 * if we didn't find the extent we need to delete the backref and then
966 * search for the extent item key so we can update its ref count
967 */
968 if (!found_extent) {
969 key.objectid = op->bytenr;
970 key.type = BTRFS_EXTENT_ITEM_KEY;
971 key.offset = op->num_bytes;
972
973 ret = remove_extent_backref(trans, extent_root, path);
974 BUG_ON(ret);
975 btrfs_release_path(extent_root, path);
976 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
977 BUG_ON(ret);
978 extent_slot = path->slots[0];
979 }
980
981 /* this is where we update the ref count for the extent */
982 leaf = path->nodes[0];
983 ei = btrfs_item_ptr(leaf, extent_slot, struct btrfs_extent_item);
984 refs = btrfs_extent_refs(leaf, ei);
985 BUG_ON(refs == 0);
986 refs--;
987 btrfs_set_extent_refs(leaf, ei, refs);
988
989 btrfs_mark_buffer_dirty(leaf);
990
991 /*
992 * This extent needs deleting. The reason cur_slot is extent_slot +
993 * num_to_del is because extent_slot points to the slot where the extent
994 * is, and if the backref was not right next to the extent we will be
995 * deleting at least 1 item, and will want to start searching at the
996 * slot directly next to extent_slot. However if we did find the
997 * backref next to the extent item them we will be deleting at least 2
998 * items and will want to start searching directly after the ref slot
999 */
1000 if (!refs) {
1001 struct list_head *pos, *n, *end;
1002 int cur_slot = extent_slot+num_to_del;
1003 u64 super_used;
1004 u64 root_used;
1005
1006 path->slots[0] = extent_slot;
1007 bytes_freed = op->num_bytes;
1008
1009 mutex_lock(&info->pinned_mutex);
1010 ret = pin_down_bytes(trans, extent_root, op->bytenr,
1011 op->num_bytes, op->level >=
1012 BTRFS_FIRST_FREE_OBJECTID);
1013 mutex_unlock(&info->pinned_mutex);
1014 BUG_ON(ret < 0);
1015 op->del = ret;
1016
1017 /*
1018 * we need to see if we can delete multiple things at once, so
1019 * start looping through the list of extents we are wanting to
1020 * delete and see if their extent/backref's are right next to
1021 * eachother and the extents only have 1 ref
1022 */
1023 for (pos = cur->next; pos != del_list; pos = pos->next) {
1024 struct pending_extent_op *tmp;
1025
1026 tmp = list_entry(pos, struct pending_extent_op, list);
1027
1028 /* we only want to delete extent+ref at this stage */
1029 if (cur_slot >= btrfs_header_nritems(leaf) - 1)
1030 break;
1031
1032 btrfs_item_key_to_cpu(leaf, &found_key, cur_slot);
1033 if (found_key.objectid != tmp->bytenr ||
1034 found_key.type != BTRFS_EXTENT_ITEM_KEY ||
1035 found_key.offset != tmp->num_bytes)
1036 break;
1037
1038 /* check to make sure this extent only has one ref */
1039 ei = btrfs_item_ptr(leaf, cur_slot,
1040 struct btrfs_extent_item);
1041 if (btrfs_extent_refs(leaf, ei) != 1)
1042 break;
1043
1044 btrfs_item_key_to_cpu(leaf, &found_key, cur_slot+1);
1045 if (found_key.objectid != tmp->bytenr ||
1046 found_key.type != BTRFS_EXTENT_REF_KEY ||
1047 found_key.offset != tmp->orig_parent)
1048 break;
1049
1050 /*
1051 * the ref is right next to the extent, we can set the
1052 * ref count to 0 since we will delete them both now
1053 */
1054 btrfs_set_extent_refs(leaf, ei, 0);
1055
1056 /* pin down the bytes for this extent */
1057 mutex_lock(&info->pinned_mutex);
1058 ret = pin_down_bytes(trans, extent_root, tmp->bytenr,
1059 tmp->num_bytes, tmp->level >=
1060 BTRFS_FIRST_FREE_OBJECTID);
1061 mutex_unlock(&info->pinned_mutex);
1062 BUG_ON(ret < 0);
1063
1064 /*
1065 * use the del field to tell if we need to go ahead and
1066 * free up the extent when we delete the item or not.
1067 */
1068 tmp->del = ret;
1069 bytes_freed += tmp->num_bytes;
1070
1071 num_to_del += 2;
1072 cur_slot += 2;
1073 }
1074 end = pos;
1075
1076 /* update the free space counters */
1077 spin_lock(&info->delalloc_lock);
1078 super_used = btrfs_super_bytes_used(&info->super_copy);
1079 btrfs_set_super_bytes_used(&info->super_copy,
1080 super_used - bytes_freed);
1081
1082 root_used = btrfs_root_used(&extent_root->root_item);
1083 btrfs_set_root_used(&extent_root->root_item,
1084 root_used - bytes_freed);
1085 spin_unlock(&info->delalloc_lock);
1086
1087 /* delete the items */
1088 ret = btrfs_del_items(trans, extent_root, path,
1089 path->slots[0], num_to_del);
1090 BUG_ON(ret);
1091
1092 /*
1093 * loop through the extents we deleted and do the cleanup work
1094 * on them
1095 */
1096 for (pos = cur, n = pos->next; pos != end;
1097 pos = n, n = pos->next) {
1098 struct pending_extent_op *tmp;
1099 tmp = list_entry(pos, struct pending_extent_op, list);
1100
1101 /*
1102 * remember tmp->del tells us wether or not we pinned
1103 * down the extent
1104 */
1105 ret = update_block_group(trans, extent_root,
1106 tmp->bytenr, tmp->num_bytes, 0,
1107 tmp->del);
1108 BUG_ON(ret);
1109
1110 list_del_init(&tmp->list);
1111 unlock_extent(&info->extent_ins, tmp->bytenr,
1112 tmp->bytenr + tmp->num_bytes - 1,
1113 GFP_NOFS);
1114 kfree(tmp);
1115 }
1116 } else if (refs && found_extent) {
1117 /*
1118 * the ref and extent were right next to eachother, but the
1119 * extent still has a ref, so just free the backref and keep
1120 * going
1121 */
1122 ret = remove_extent_backref(trans, extent_root, path);
1123 BUG_ON(ret);
1124
1125 list_del_init(&op->list);
1126 unlock_extent(&info->extent_ins, op->bytenr,
1127 op->bytenr + op->num_bytes - 1, GFP_NOFS);
1128 kfree(op);
1129 } else {
1130 /*
1131 * the extent has multiple refs and the backref we were looking
1132 * for was not right next to it, so just unlock and go next,
1133 * we're good to go
1134 */
1135 list_del_init(&op->list);
1136 unlock_extent(&info->extent_ins, op->bytenr,
1137 op->bytenr + op->num_bytes - 1, GFP_NOFS);
1138 kfree(op);
1139 }
1140
1141 btrfs_release_path(extent_root, path);
1142 if (!list_empty(del_list))
1143 goto search;
1144
1145 out:
1146 btrfs_free_path(path);
1147 return ret;
1148 }
1149
1150 static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
1151 struct btrfs_root *root, u64 bytenr,
1152 u64 orig_parent, u64 parent,
1153 u64 orig_root, u64 ref_root,
1154 u64 orig_generation, u64 ref_generation,
1155 u64 owner_objectid)
1156 {
1157 int ret;
1158 struct btrfs_root *extent_root = root->fs_info->extent_root;
1159 struct btrfs_path *path;
1160
1161 if (root == root->fs_info->extent_root) {
1162 struct pending_extent_op *extent_op;
1163 u64 num_bytes;
1164
1165 BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL);
1166 num_bytes = btrfs_level_size(root, (int)owner_objectid);
1167 mutex_lock(&root->fs_info->extent_ins_mutex);
1168 if (test_range_bit(&root->fs_info->extent_ins, bytenr,
1169 bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
1170 u64 priv;
1171 ret = get_state_private(&root->fs_info->extent_ins,
1172 bytenr, &priv);
1173 BUG_ON(ret);
1174 extent_op = (struct pending_extent_op *)
1175 (unsigned long)priv;
1176 BUG_ON(extent_op->parent != orig_parent);
1177 BUG_ON(extent_op->generation != orig_generation);
1178
1179 extent_op->parent = parent;
1180 extent_op->generation = ref_generation;
1181 } else {
1182 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
1183 BUG_ON(!extent_op);
1184
1185 extent_op->type = PENDING_BACKREF_UPDATE;
1186 extent_op->bytenr = bytenr;
1187 extent_op->num_bytes = num_bytes;
1188 extent_op->parent = parent;
1189 extent_op->orig_parent = orig_parent;
1190 extent_op->generation = ref_generation;
1191 extent_op->orig_generation = orig_generation;
1192 extent_op->level = (int)owner_objectid;
1193 INIT_LIST_HEAD(&extent_op->list);
1194 extent_op->del = 0;
1195
1196 set_extent_bits(&root->fs_info->extent_ins,
1197 bytenr, bytenr + num_bytes - 1,
1198 EXTENT_WRITEBACK, GFP_NOFS);
1199 set_state_private(&root->fs_info->extent_ins,
1200 bytenr, (unsigned long)extent_op);
1201 }
1202 mutex_unlock(&root->fs_info->extent_ins_mutex);
1203 return 0;
1204 }
1205
1206 path = btrfs_alloc_path();
1207 if (!path)
1208 return -ENOMEM;
1209 ret = lookup_extent_backref(trans, extent_root, path,
1210 bytenr, orig_parent, orig_root,
1211 orig_generation, owner_objectid, 1);
1212 if (ret)
1213 goto out;
1214 ret = remove_extent_backref(trans, extent_root, path);
1215 if (ret)
1216 goto out;
1217 ret = insert_extent_backref(trans, extent_root, path, bytenr,
1218 parent, ref_root, ref_generation,
1219 owner_objectid);
1220 BUG_ON(ret);
1221 finish_current_insert(trans, extent_root, 0);
1222 del_pending_extents(trans, extent_root, 0);
1223 out:
1224 btrfs_free_path(path);
1225 return ret;
1226 }
1227
1228 int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
1229 struct btrfs_root *root, u64 bytenr,
1230 u64 orig_parent, u64 parent,
1231 u64 ref_root, u64 ref_generation,
1232 u64 owner_objectid)
1233 {
1234 int ret;
1235 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
1236 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
1237 return 0;
1238 ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent,
1239 parent, ref_root, ref_root,
1240 ref_generation, ref_generation,
1241 owner_objectid);
1242 return ret;
1243 }
1244
1245 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1246 struct btrfs_root *root, u64 bytenr,
1247 u64 orig_parent, u64 parent,
1248 u64 orig_root, u64 ref_root,
1249 u64 orig_generation, u64 ref_generation,
1250 u64 owner_objectid)
1251 {
1252 struct btrfs_path *path;
1253 int ret;
1254 struct btrfs_key key;
1255 struct extent_buffer *l;
1256 struct btrfs_extent_item *item;
1257 u32 refs;
1258
1259 path = btrfs_alloc_path();
1260 if (!path)
1261 return -ENOMEM;
1262
1263 path->reada = 1;
1264 key.objectid = bytenr;
1265 key.type = BTRFS_EXTENT_ITEM_KEY;
1266 key.offset = (u64)-1;
1267
1268 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1269 0, 1);
1270 if (ret < 0)
1271 return ret;
1272 BUG_ON(ret == 0 || path->slots[0] == 0);
1273
1274 path->slots[0]--;
1275 l = path->nodes[0];
1276
1277 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1278 if (key.objectid != bytenr) {
1279 btrfs_print_leaf(root->fs_info->extent_root, path->nodes[0]);
1280 printk(KERN_ERR "btrfs wanted %llu found %llu\n",
1281 (unsigned long long)bytenr,
1282 (unsigned long long)key.objectid);
1283 BUG();
1284 }
1285 BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY);
1286
1287 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1288 refs = btrfs_extent_refs(l, item);
1289 btrfs_set_extent_refs(l, item, refs + 1);
1290 btrfs_mark_buffer_dirty(path->nodes[0]);
1291
1292 btrfs_release_path(root->fs_info->extent_root, path);
1293
1294 path->reada = 1;
1295 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1296 path, bytenr, parent,
1297 ref_root, ref_generation,
1298 owner_objectid);
1299 BUG_ON(ret);
1300 finish_current_insert(trans, root->fs_info->extent_root, 0);
1301 del_pending_extents(trans, root->fs_info->extent_root, 0);
1302
1303 btrfs_free_path(path);
1304 return 0;
1305 }
1306
1307 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1308 struct btrfs_root *root,
1309 u64 bytenr, u64 num_bytes, u64 parent,
1310 u64 ref_root, u64 ref_generation,
1311 u64 owner_objectid)
1312 {
1313 int ret;
1314 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
1315 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
1316 return 0;
1317 ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent,
1318 0, ref_root, 0, ref_generation,
1319 owner_objectid);
1320 return ret;
1321 }
1322
1323 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
1324 struct btrfs_root *root)
1325 {
1326 finish_current_insert(trans, root->fs_info->extent_root, 1);
1327 del_pending_extents(trans, root->fs_info->extent_root, 1);
1328 return 0;
1329 }
1330
1331 int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
1332 struct btrfs_root *root, u64 bytenr,
1333 u64 num_bytes, u32 *refs)
1334 {
1335 struct btrfs_path *path;
1336 int ret;
1337 struct btrfs_key key;
1338 struct extent_buffer *l;
1339 struct btrfs_extent_item *item;
1340
1341 WARN_ON(num_bytes < root->sectorsize);
1342 path = btrfs_alloc_path();
1343 path->reada = 1;
1344 key.objectid = bytenr;
1345 key.offset = num_bytes;
1346 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1347 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1348 0, 0);
1349 if (ret < 0)
1350 goto out;
1351 if (ret != 0) {
1352 btrfs_print_leaf(root, path->nodes[0]);
1353 printk(KERN_INFO "btrfs failed to find block number %llu\n",
1354 (unsigned long long)bytenr);
1355 BUG();
1356 }
1357 l = path->nodes[0];
1358 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1359 *refs = btrfs_extent_refs(l, item);
1360 out:
1361 btrfs_free_path(path);
1362 return 0;
1363 }
1364
1365 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
1366 struct btrfs_root *root, u64 objectid, u64 bytenr)
1367 {
1368 struct btrfs_root *extent_root = root->fs_info->extent_root;
1369 struct btrfs_path *path;
1370 struct extent_buffer *leaf;
1371 struct btrfs_extent_ref *ref_item;
1372 struct btrfs_key key;
1373 struct btrfs_key found_key;
1374 u64 ref_root;
1375 u64 last_snapshot;
1376 u32 nritems;
1377 int ret;
1378
1379 key.objectid = bytenr;
1380 key.offset = (u64)-1;
1381 key.type = BTRFS_EXTENT_ITEM_KEY;
1382
1383 path = btrfs_alloc_path();
1384 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
1385 if (ret < 0)
1386 goto out;
1387 BUG_ON(ret == 0);
1388
1389 ret = -ENOENT;
1390 if (path->slots[0] == 0)
1391 goto out;
1392
1393 path->slots[0]--;
1394 leaf = path->nodes[0];
1395 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1396
1397 if (found_key.objectid != bytenr ||
1398 found_key.type != BTRFS_EXTENT_ITEM_KEY)
1399 goto out;
1400
1401 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1402 while (1) {
1403 leaf = path->nodes[0];
1404 nritems = btrfs_header_nritems(leaf);
1405 if (path->slots[0] >= nritems) {
1406 ret = btrfs_next_leaf(extent_root, path);
1407 if (ret < 0)
1408 goto out;
1409 if (ret == 0)
1410 continue;
1411 break;
1412 }
1413 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1414 if (found_key.objectid != bytenr)
1415 break;
1416
1417 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
1418 path->slots[0]++;
1419 continue;
1420 }
1421
1422 ref_item = btrfs_item_ptr(leaf, path->slots[0],
1423 struct btrfs_extent_ref);
1424 ref_root = btrfs_ref_root(leaf, ref_item);
1425 if ((ref_root != root->root_key.objectid &&
1426 ref_root != BTRFS_TREE_LOG_OBJECTID) ||
1427 objectid != btrfs_ref_objectid(leaf, ref_item)) {
1428 ret = 1;
1429 goto out;
1430 }
1431 if (btrfs_ref_generation(leaf, ref_item) <= last_snapshot) {
1432 ret = 1;
1433 goto out;
1434 }
1435
1436 path->slots[0]++;
1437 }
1438 ret = 0;
1439 out:
1440 btrfs_free_path(path);
1441 return ret;
1442 }
1443
1444 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1445 struct extent_buffer *buf, u32 nr_extents)
1446 {
1447 struct btrfs_key key;
1448 struct btrfs_file_extent_item *fi;
1449 u64 root_gen;
1450 u32 nritems;
1451 int i;
1452 int level;
1453 int ret = 0;
1454 int shared = 0;
1455
1456 if (!root->ref_cows)
1457 return 0;
1458
1459 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1460 shared = 0;
1461 root_gen = root->root_key.offset;
1462 } else {
1463 shared = 1;
1464 root_gen = trans->transid - 1;
1465 }
1466
1467 level = btrfs_header_level(buf);
1468 nritems = btrfs_header_nritems(buf);
1469
1470 if (level == 0) {
1471 struct btrfs_leaf_ref *ref;
1472 struct btrfs_extent_info *info;
1473
1474 ref = btrfs_alloc_leaf_ref(root, nr_extents);
1475 if (!ref) {
1476 ret = -ENOMEM;
1477 goto out;
1478 }
1479
1480 ref->root_gen = root_gen;
1481 ref->bytenr = buf->start;
1482 ref->owner = btrfs_header_owner(buf);
1483 ref->generation = btrfs_header_generation(buf);
1484 ref->nritems = nr_extents;
1485 info = ref->extents;
1486
1487 for (i = 0; nr_extents > 0 && i < nritems; i++) {
1488 u64 disk_bytenr;
1489 btrfs_item_key_to_cpu(buf, &key, i);
1490 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1491 continue;
1492 fi = btrfs_item_ptr(buf, i,
1493 struct btrfs_file_extent_item);
1494 if (btrfs_file_extent_type(buf, fi) ==
1495 BTRFS_FILE_EXTENT_INLINE)
1496 continue;
1497 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1498 if (disk_bytenr == 0)
1499 continue;
1500
1501 info->bytenr = disk_bytenr;
1502 info->num_bytes =
1503 btrfs_file_extent_disk_num_bytes(buf, fi);
1504 info->objectid = key.objectid;
1505 info->offset = key.offset;
1506 info++;
1507 }
1508
1509 ret = btrfs_add_leaf_ref(root, ref, shared);
1510 if (ret == -EEXIST && shared) {
1511 struct btrfs_leaf_ref *old;
1512 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
1513 BUG_ON(!old);
1514 btrfs_remove_leaf_ref(root, old);
1515 btrfs_free_leaf_ref(root, old);
1516 ret = btrfs_add_leaf_ref(root, ref, shared);
1517 }
1518 WARN_ON(ret);
1519 btrfs_free_leaf_ref(root, ref);
1520 }
1521 out:
1522 return ret;
1523 }
1524
1525 /* when a block goes through cow, we update the reference counts of
1526 * everything that block points to. The internal pointers of the block
1527 * can be in just about any order, and it is likely to have clusters of
1528 * things that are close together and clusters of things that are not.
1529 *
1530 * To help reduce the seeks that come with updating all of these reference
1531 * counts, sort them by byte number before actual updates are done.
1532 *
1533 * struct refsort is used to match byte number to slot in the btree block.
1534 * we sort based on the byte number and then use the slot to actually
1535 * find the item.
1536 *
1537 * struct refsort is smaller than strcut btrfs_item and smaller than
1538 * struct btrfs_key_ptr. Since we're currently limited to the page size
1539 * for a btree block, there's no way for a kmalloc of refsorts for a
1540 * single node to be bigger than a page.
1541 */
1542 struct refsort {
1543 u64 bytenr;
1544 u32 slot;
1545 };
1546
1547 /*
1548 * for passing into sort()
1549 */
1550 static int refsort_cmp(const void *a_void, const void *b_void)
1551 {
1552 const struct refsort *a = a_void;
1553 const struct refsort *b = b_void;
1554
1555 if (a->bytenr < b->bytenr)
1556 return -1;
1557 if (a->bytenr > b->bytenr)
1558 return 1;
1559 return 0;
1560 }
1561
1562
1563 noinline int btrfs_inc_ref(struct btrfs_trans_handle *trans,
1564 struct btrfs_root *root,
1565 struct extent_buffer *orig_buf,
1566 struct extent_buffer *buf, u32 *nr_extents)
1567 {
1568 u64 bytenr;
1569 u64 ref_root;
1570 u64 orig_root;
1571 u64 ref_generation;
1572 u64 orig_generation;
1573 struct refsort *sorted;
1574 u32 nritems;
1575 u32 nr_file_extents = 0;
1576 struct btrfs_key key;
1577 struct btrfs_file_extent_item *fi;
1578 int i;
1579 int level;
1580 int ret = 0;
1581 int faili = 0;
1582 int refi = 0;
1583 int slot;
1584 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
1585 u64, u64, u64, u64, u64, u64, u64, u64);
1586
1587 ref_root = btrfs_header_owner(buf);
1588 ref_generation = btrfs_header_generation(buf);
1589 orig_root = btrfs_header_owner(orig_buf);
1590 orig_generation = btrfs_header_generation(orig_buf);
1591
1592 nritems = btrfs_header_nritems(buf);
1593 level = btrfs_header_level(buf);
1594
1595 sorted = kmalloc(sizeof(struct refsort) * nritems, GFP_NOFS);
1596 BUG_ON(!sorted);
1597
1598 if (root->ref_cows) {
1599 process_func = __btrfs_inc_extent_ref;
1600 } else {
1601 if (level == 0 &&
1602 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1603 goto out;
1604 if (level != 0 &&
1605 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1606 goto out;
1607 process_func = __btrfs_update_extent_ref;
1608 }
1609
1610 /*
1611 * we make two passes through the items. In the first pass we
1612 * only record the byte number and slot. Then we sort based on
1613 * byte number and do the actual work based on the sorted results
1614 */
1615 for (i = 0; i < nritems; i++) {
1616 cond_resched();
1617 if (level == 0) {
1618 btrfs_item_key_to_cpu(buf, &key, i);
1619 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1620 continue;
1621 fi = btrfs_item_ptr(buf, i,
1622 struct btrfs_file_extent_item);
1623 if (btrfs_file_extent_type(buf, fi) ==
1624 BTRFS_FILE_EXTENT_INLINE)
1625 continue;
1626 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1627 if (bytenr == 0)
1628 continue;
1629
1630 nr_file_extents++;
1631 sorted[refi].bytenr = bytenr;
1632 sorted[refi].slot = i;
1633 refi++;
1634 } else {
1635 bytenr = btrfs_node_blockptr(buf, i);
1636 sorted[refi].bytenr = bytenr;
1637 sorted[refi].slot = i;
1638 refi++;
1639 }
1640 }
1641 /*
1642 * if refi == 0, we didn't actually put anything into the sorted
1643 * array and we're done
1644 */
1645 if (refi == 0)
1646 goto out;
1647
1648 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
1649
1650 for (i = 0; i < refi; i++) {
1651 cond_resched();
1652 slot = sorted[i].slot;
1653 bytenr = sorted[i].bytenr;
1654
1655 if (level == 0) {
1656 btrfs_item_key_to_cpu(buf, &key, slot);
1657
1658 ret = process_func(trans, root, bytenr,
1659 orig_buf->start, buf->start,
1660 orig_root, ref_root,
1661 orig_generation, ref_generation,
1662 key.objectid);
1663
1664 if (ret) {
1665 faili = slot;
1666 WARN_ON(1);
1667 goto fail;
1668 }
1669 } else {
1670 ret = process_func(trans, root, bytenr,
1671 orig_buf->start, buf->start,
1672 orig_root, ref_root,
1673 orig_generation, ref_generation,
1674 level - 1);
1675 if (ret) {
1676 faili = slot;
1677 WARN_ON(1);
1678 goto fail;
1679 }
1680 }
1681 }
1682 out:
1683 kfree(sorted);
1684 if (nr_extents) {
1685 if (level == 0)
1686 *nr_extents = nr_file_extents;
1687 else
1688 *nr_extents = nritems;
1689 }
1690 return 0;
1691 fail:
1692 kfree(sorted);
1693 WARN_ON(1);
1694 return ret;
1695 }
1696
1697 int btrfs_update_ref(struct btrfs_trans_handle *trans,
1698 struct btrfs_root *root, struct extent_buffer *orig_buf,
1699 struct extent_buffer *buf, int start_slot, int nr)
1700
1701 {
1702 u64 bytenr;
1703 u64 ref_root;
1704 u64 orig_root;
1705 u64 ref_generation;
1706 u64 orig_generation;
1707 struct btrfs_key key;
1708 struct btrfs_file_extent_item *fi;
1709 int i;
1710 int ret;
1711 int slot;
1712 int level;
1713
1714 BUG_ON(start_slot < 0);
1715 BUG_ON(start_slot + nr > btrfs_header_nritems(buf));
1716
1717 ref_root = btrfs_header_owner(buf);
1718 ref_generation = btrfs_header_generation(buf);
1719 orig_root = btrfs_header_owner(orig_buf);
1720 orig_generation = btrfs_header_generation(orig_buf);
1721 level = btrfs_header_level(buf);
1722
1723 if (!root->ref_cows) {
1724 if (level == 0 &&
1725 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1726 return 0;
1727 if (level != 0 &&
1728 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1729 return 0;
1730 }
1731
1732 for (i = 0, slot = start_slot; i < nr; i++, slot++) {
1733 cond_resched();
1734 if (level == 0) {
1735 btrfs_item_key_to_cpu(buf, &key, slot);
1736 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1737 continue;
1738 fi = btrfs_item_ptr(buf, slot,
1739 struct btrfs_file_extent_item);
1740 if (btrfs_file_extent_type(buf, fi) ==
1741 BTRFS_FILE_EXTENT_INLINE)
1742 continue;
1743 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1744 if (bytenr == 0)
1745 continue;
1746 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1747 orig_buf->start, buf->start,
1748 orig_root, ref_root,
1749 orig_generation, ref_generation,
1750 key.objectid);
1751 if (ret)
1752 goto fail;
1753 } else {
1754 bytenr = btrfs_node_blockptr(buf, slot);
1755 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1756 orig_buf->start, buf->start,
1757 orig_root, ref_root,
1758 orig_generation, ref_generation,
1759 level - 1);
1760 if (ret)
1761 goto fail;
1762 }
1763 }
1764 return 0;
1765 fail:
1766 WARN_ON(1);
1767 return -1;
1768 }
1769
1770 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1771 struct btrfs_root *root,
1772 struct btrfs_path *path,
1773 struct btrfs_block_group_cache *cache)
1774 {
1775 int ret;
1776 int pending_ret;
1777 struct btrfs_root *extent_root = root->fs_info->extent_root;
1778 unsigned long bi;
1779 struct extent_buffer *leaf;
1780
1781 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1782 if (ret < 0)
1783 goto fail;
1784 BUG_ON(ret);
1785
1786 leaf = path->nodes[0];
1787 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1788 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1789 btrfs_mark_buffer_dirty(leaf);
1790 btrfs_release_path(extent_root, path);
1791 fail:
1792 finish_current_insert(trans, extent_root, 0);
1793 pending_ret = del_pending_extents(trans, extent_root, 0);
1794 if (ret)
1795 return ret;
1796 if (pending_ret)
1797 return pending_ret;
1798 return 0;
1799
1800 }
1801
1802 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1803 struct btrfs_root *root)
1804 {
1805 struct btrfs_block_group_cache *cache, *entry;
1806 struct rb_node *n;
1807 int err = 0;
1808 int werr = 0;
1809 struct btrfs_path *path;
1810 u64 last = 0;
1811
1812 path = btrfs_alloc_path();
1813 if (!path)
1814 return -ENOMEM;
1815
1816 while (1) {
1817 cache = NULL;
1818 spin_lock(&root->fs_info->block_group_cache_lock);
1819 for (n = rb_first(&root->fs_info->block_group_cache_tree);
1820 n; n = rb_next(n)) {
1821 entry = rb_entry(n, struct btrfs_block_group_cache,
1822 cache_node);
1823 if (entry->dirty) {
1824 cache = entry;
1825 break;
1826 }
1827 }
1828 spin_unlock(&root->fs_info->block_group_cache_lock);
1829
1830 if (!cache)
1831 break;
1832
1833 cache->dirty = 0;
1834 last += cache->key.offset;
1835
1836 err = write_one_cache_group(trans, root,
1837 path, cache);
1838 /*
1839 * if we fail to write the cache group, we want
1840 * to keep it marked dirty in hopes that a later
1841 * write will work
1842 */
1843 if (err) {
1844 werr = err;
1845 continue;
1846 }
1847 }
1848 btrfs_free_path(path);
1849 return werr;
1850 }
1851
1852 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
1853 {
1854 struct btrfs_block_group_cache *block_group;
1855 int readonly = 0;
1856
1857 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
1858 if (!block_group || block_group->ro)
1859 readonly = 1;
1860 if (block_group)
1861 put_block_group(block_group);
1862 return readonly;
1863 }
1864
1865 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1866 u64 total_bytes, u64 bytes_used,
1867 struct btrfs_space_info **space_info)
1868 {
1869 struct btrfs_space_info *found;
1870
1871 found = __find_space_info(info, flags);
1872 if (found) {
1873 spin_lock(&found->lock);
1874 found->total_bytes += total_bytes;
1875 found->bytes_used += bytes_used;
1876 found->full = 0;
1877 spin_unlock(&found->lock);
1878 *space_info = found;
1879 return 0;
1880 }
1881 found = kzalloc(sizeof(*found), GFP_NOFS);
1882 if (!found)
1883 return -ENOMEM;
1884
1885 list_add(&found->list, &info->space_info);
1886 INIT_LIST_HEAD(&found->block_groups);
1887 init_rwsem(&found->groups_sem);
1888 spin_lock_init(&found->lock);
1889 found->flags = flags;
1890 found->total_bytes = total_bytes;
1891 found->bytes_used = bytes_used;
1892 found->bytes_pinned = 0;
1893 found->bytes_reserved = 0;
1894 found->bytes_readonly = 0;
1895 found->full = 0;
1896 found->force_alloc = 0;
1897 *space_info = found;
1898 return 0;
1899 }
1900
1901 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1902 {
1903 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1904 BTRFS_BLOCK_GROUP_RAID1 |
1905 BTRFS_BLOCK_GROUP_RAID10 |
1906 BTRFS_BLOCK_GROUP_DUP);
1907 if (extra_flags) {
1908 if (flags & BTRFS_BLOCK_GROUP_DATA)
1909 fs_info->avail_data_alloc_bits |= extra_flags;
1910 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1911 fs_info->avail_metadata_alloc_bits |= extra_flags;
1912 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1913 fs_info->avail_system_alloc_bits |= extra_flags;
1914 }
1915 }
1916
1917 static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
1918 {
1919 spin_lock(&cache->space_info->lock);
1920 spin_lock(&cache->lock);
1921 if (!cache->ro) {
1922 cache->space_info->bytes_readonly += cache->key.offset -
1923 btrfs_block_group_used(&cache->item);
1924 cache->ro = 1;
1925 }
1926 spin_unlock(&cache->lock);
1927 spin_unlock(&cache->space_info->lock);
1928 }
1929
1930 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
1931 {
1932 u64 num_devices = root->fs_info->fs_devices->rw_devices;
1933
1934 if (num_devices == 1)
1935 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
1936 if (num_devices < 4)
1937 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
1938
1939 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
1940 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
1941 BTRFS_BLOCK_GROUP_RAID10))) {
1942 flags &= ~BTRFS_BLOCK_GROUP_DUP;
1943 }
1944
1945 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
1946 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
1947 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
1948 }
1949
1950 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
1951 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
1952 (flags & BTRFS_BLOCK_GROUP_RAID10) |
1953 (flags & BTRFS_BLOCK_GROUP_DUP)))
1954 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
1955 return flags;
1956 }
1957
1958 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1959 struct btrfs_root *extent_root, u64 alloc_bytes,
1960 u64 flags, int force)
1961 {
1962 struct btrfs_space_info *space_info;
1963 u64 thresh;
1964 int ret = 0;
1965
1966 mutex_lock(&extent_root->fs_info->chunk_mutex);
1967
1968 flags = btrfs_reduce_alloc_profile(extent_root, flags);
1969
1970 space_info = __find_space_info(extent_root->fs_info, flags);
1971 if (!space_info) {
1972 ret = update_space_info(extent_root->fs_info, flags,
1973 0, 0, &space_info);
1974 BUG_ON(ret);
1975 }
1976 BUG_ON(!space_info);
1977
1978 spin_lock(&space_info->lock);
1979 if (space_info->force_alloc) {
1980 force = 1;
1981 space_info->force_alloc = 0;
1982 }
1983 if (space_info->full) {
1984 spin_unlock(&space_info->lock);
1985 goto out;
1986 }
1987
1988 thresh = space_info->total_bytes - space_info->bytes_readonly;
1989 thresh = div_factor(thresh, 6);
1990 if (!force &&
1991 (space_info->bytes_used + space_info->bytes_pinned +
1992 space_info->bytes_reserved + alloc_bytes) < thresh) {
1993 spin_unlock(&space_info->lock);
1994 goto out;
1995 }
1996 spin_unlock(&space_info->lock);
1997
1998 ret = btrfs_alloc_chunk(trans, extent_root, flags);
1999 if (ret)
2000 space_info->full = 1;
2001 out:
2002 mutex_unlock(&extent_root->fs_info->chunk_mutex);
2003 return ret;
2004 }
2005
2006 static int update_block_group(struct btrfs_trans_handle *trans,
2007 struct btrfs_root *root,
2008 u64 bytenr, u64 num_bytes, int alloc,
2009 int mark_free)
2010 {
2011 struct btrfs_block_group_cache *cache;
2012 struct btrfs_fs_info *info = root->fs_info;
2013 u64 total = num_bytes;
2014 u64 old_val;
2015 u64 byte_in_group;
2016
2017 while (total) {
2018 cache = btrfs_lookup_block_group(info, bytenr);
2019 if (!cache)
2020 return -1;
2021 byte_in_group = bytenr - cache->key.objectid;
2022 WARN_ON(byte_in_group > cache->key.offset);
2023
2024 spin_lock(&cache->space_info->lock);
2025 spin_lock(&cache->lock);
2026 cache->dirty = 1;
2027 old_val = btrfs_block_group_used(&cache->item);
2028 num_bytes = min(total, cache->key.offset - byte_in_group);
2029 if (alloc) {
2030 old_val += num_bytes;
2031 cache->space_info->bytes_used += num_bytes;
2032 if (cache->ro)
2033 cache->space_info->bytes_readonly -= num_bytes;
2034 btrfs_set_block_group_used(&cache->item, old_val);
2035 spin_unlock(&cache->lock);
2036 spin_unlock(&cache->space_info->lock);
2037 } else {
2038 old_val -= num_bytes;
2039 cache->space_info->bytes_used -= num_bytes;
2040 if (cache->ro)
2041 cache->space_info->bytes_readonly += num_bytes;
2042 btrfs_set_block_group_used(&cache->item, old_val);
2043 spin_unlock(&cache->lock);
2044 spin_unlock(&cache->space_info->lock);
2045 if (mark_free) {
2046 int ret;
2047
2048 ret = btrfs_discard_extent(root, bytenr,
2049 num_bytes);
2050 WARN_ON(ret);
2051
2052 ret = btrfs_add_free_space(cache, bytenr,
2053 num_bytes);
2054 WARN_ON(ret);
2055 }
2056 }
2057 put_block_group(cache);
2058 total -= num_bytes;
2059 bytenr += num_bytes;
2060 }
2061 return 0;
2062 }
2063
2064 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
2065 {
2066 struct btrfs_block_group_cache *cache;
2067 u64 bytenr;
2068
2069 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
2070 if (!cache)
2071 return 0;
2072
2073 bytenr = cache->key.objectid;
2074 put_block_group(cache);
2075
2076 return bytenr;
2077 }
2078
2079 int btrfs_update_pinned_extents(struct btrfs_root *root,
2080 u64 bytenr, u64 num, int pin)
2081 {
2082 u64 len;
2083 struct btrfs_block_group_cache *cache;
2084 struct btrfs_fs_info *fs_info = root->fs_info;
2085
2086 WARN_ON(!mutex_is_locked(&root->fs_info->pinned_mutex));
2087 if (pin) {
2088 set_extent_dirty(&fs_info->pinned_extents,
2089 bytenr, bytenr + num - 1, GFP_NOFS);
2090 } else {
2091 clear_extent_dirty(&fs_info->pinned_extents,
2092 bytenr, bytenr + num - 1, GFP_NOFS);
2093 }
2094 while (num > 0) {
2095 cache = btrfs_lookup_block_group(fs_info, bytenr);
2096 BUG_ON(!cache);
2097 len = min(num, cache->key.offset -
2098 (bytenr - cache->key.objectid));
2099 if (pin) {
2100 spin_lock(&cache->space_info->lock);
2101 spin_lock(&cache->lock);
2102 cache->pinned += len;
2103 cache->space_info->bytes_pinned += len;
2104 spin_unlock(&cache->lock);
2105 spin_unlock(&cache->space_info->lock);
2106 fs_info->total_pinned += len;
2107 } else {
2108 spin_lock(&cache->space_info->lock);
2109 spin_lock(&cache->lock);
2110 cache->pinned -= len;
2111 cache->space_info->bytes_pinned -= len;
2112 spin_unlock(&cache->lock);
2113 spin_unlock(&cache->space_info->lock);
2114 fs_info->total_pinned -= len;
2115 if (cache->cached)
2116 btrfs_add_free_space(cache, bytenr, len);
2117 }
2118 put_block_group(cache);
2119 bytenr += len;
2120 num -= len;
2121 }
2122 return 0;
2123 }
2124
2125 static int update_reserved_extents(struct btrfs_root *root,
2126 u64 bytenr, u64 num, int reserve)
2127 {
2128 u64 len;
2129 struct btrfs_block_group_cache *cache;
2130 struct btrfs_fs_info *fs_info = root->fs_info;
2131
2132 while (num > 0) {
2133 cache = btrfs_lookup_block_group(fs_info, bytenr);
2134 BUG_ON(!cache);
2135 len = min(num, cache->key.offset -
2136 (bytenr - cache->key.objectid));
2137
2138 spin_lock(&cache->space_info->lock);
2139 spin_lock(&cache->lock);
2140 if (reserve) {
2141 cache->reserved += len;
2142 cache->space_info->bytes_reserved += len;
2143 } else {
2144 cache->reserved -= len;
2145 cache->space_info->bytes_reserved -= len;
2146 }
2147 spin_unlock(&cache->lock);
2148 spin_unlock(&cache->space_info->lock);
2149 put_block_group(cache);
2150 bytenr += len;
2151 num -= len;
2152 }
2153 return 0;
2154 }
2155
2156 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
2157 {
2158 u64 last = 0;
2159 u64 start;
2160 u64 end;
2161 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
2162 int ret;
2163
2164 mutex_lock(&root->fs_info->pinned_mutex);
2165 while (1) {
2166 ret = find_first_extent_bit(pinned_extents, last,
2167 &start, &end, EXTENT_DIRTY);
2168 if (ret)
2169 break;
2170 set_extent_dirty(copy, start, end, GFP_NOFS);
2171 last = end + 1;
2172 }
2173 mutex_unlock(&root->fs_info->pinned_mutex);
2174 return 0;
2175 }
2176
2177 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
2178 struct btrfs_root *root,
2179 struct extent_io_tree *unpin)
2180 {
2181 u64 start;
2182 u64 end;
2183 int ret;
2184
2185 mutex_lock(&root->fs_info->pinned_mutex);
2186 while (1) {
2187 ret = find_first_extent_bit(unpin, 0, &start, &end,
2188 EXTENT_DIRTY);
2189 if (ret)
2190 break;
2191
2192 ret = btrfs_discard_extent(root, start, end + 1 - start);
2193
2194 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
2195 clear_extent_dirty(unpin, start, end, GFP_NOFS);
2196
2197 if (need_resched()) {
2198 mutex_unlock(&root->fs_info->pinned_mutex);
2199 cond_resched();
2200 mutex_lock(&root->fs_info->pinned_mutex);
2201 }
2202 }
2203 mutex_unlock(&root->fs_info->pinned_mutex);
2204 return ret;
2205 }
2206
2207 static int finish_current_insert(struct btrfs_trans_handle *trans,
2208 struct btrfs_root *extent_root, int all)
2209 {
2210 u64 start;
2211 u64 end;
2212 u64 priv;
2213 u64 search = 0;
2214 u64 skipped = 0;
2215 struct btrfs_fs_info *info = extent_root->fs_info;
2216 struct btrfs_path *path;
2217 struct pending_extent_op *extent_op, *tmp;
2218 struct list_head insert_list, update_list;
2219 int ret;
2220 int num_inserts = 0, max_inserts;
2221
2222 path = btrfs_alloc_path();
2223 INIT_LIST_HEAD(&insert_list);
2224 INIT_LIST_HEAD(&update_list);
2225
2226 max_inserts = extent_root->leafsize /
2227 (2 * sizeof(struct btrfs_key) + 2 * sizeof(struct btrfs_item) +
2228 sizeof(struct btrfs_extent_ref) +
2229 sizeof(struct btrfs_extent_item));
2230 again:
2231 mutex_lock(&info->extent_ins_mutex);
2232 while (1) {
2233 ret = find_first_extent_bit(&info->extent_ins, search, &start,
2234 &end, EXTENT_WRITEBACK);
2235 if (ret) {
2236 if (skipped && all && !num_inserts &&
2237 list_empty(&update_list)) {
2238 skipped = 0;
2239 search = 0;
2240 continue;
2241 }
2242 mutex_unlock(&info->extent_ins_mutex);
2243 break;
2244 }
2245
2246 ret = try_lock_extent(&info->extent_ins, start, end, GFP_NOFS);
2247 if (!ret) {
2248 skipped = 1;
2249 search = end + 1;
2250 if (need_resched()) {
2251 mutex_unlock(&info->extent_ins_mutex);
2252 cond_resched();
2253 mutex_lock(&info->extent_ins_mutex);
2254 }
2255 continue;
2256 }
2257
2258 ret = get_state_private(&info->extent_ins, start, &priv);
2259 BUG_ON(ret);
2260 extent_op = (struct pending_extent_op *)(unsigned long) priv;
2261
2262 if (extent_op->type == PENDING_EXTENT_INSERT) {
2263 num_inserts++;
2264 list_add_tail(&extent_op->list, &insert_list);
2265 search = end + 1;
2266 if (num_inserts == max_inserts) {
2267 mutex_unlock(&info->extent_ins_mutex);
2268 break;
2269 }
2270 } else if (extent_op->type == PENDING_BACKREF_UPDATE) {
2271 list_add_tail(&extent_op->list, &update_list);
2272 search = end + 1;
2273 } else {
2274 BUG();
2275 }
2276 }
2277
2278 /*
2279 * process the update list, clear the writeback bit for it, and if
2280 * somebody marked this thing for deletion then just unlock it and be
2281 * done, the free_extents will handle it
2282 */
2283 mutex_lock(&info->extent_ins_mutex);
2284 list_for_each_entry_safe(extent_op, tmp, &update_list, list) {
2285 clear_extent_bits(&info->extent_ins, extent_op->bytenr,
2286 extent_op->bytenr + extent_op->num_bytes - 1,
2287 EXTENT_WRITEBACK, GFP_NOFS);
2288 if (extent_op->del) {
2289 list_del_init(&extent_op->list);
2290 unlock_extent(&info->extent_ins, extent_op->bytenr,
2291 extent_op->bytenr + extent_op->num_bytes
2292 - 1, GFP_NOFS);
2293 kfree(extent_op);
2294 }
2295 }
2296 mutex_unlock(&info->extent_ins_mutex);
2297
2298 /*
2299 * still have things left on the update list, go ahead an update
2300 * everything
2301 */
2302 if (!list_empty(&update_list)) {
2303 ret = update_backrefs(trans, extent_root, path, &update_list);
2304 BUG_ON(ret);
2305 }
2306
2307 /*
2308 * if no inserts need to be done, but we skipped some extents and we
2309 * need to make sure everything is cleaned then reset everything and
2310 * go back to the beginning
2311 */
2312 if (!num_inserts && all && skipped) {
2313 search = 0;
2314 skipped = 0;
2315 INIT_LIST_HEAD(&update_list);
2316 INIT_LIST_HEAD(&insert_list);
2317 goto again;
2318 } else if (!num_inserts) {
2319 goto out;
2320 }
2321
2322 /*
2323 * process the insert extents list. Again if we are deleting this
2324 * extent, then just unlock it, pin down the bytes if need be, and be
2325 * done with it. Saves us from having to actually insert the extent
2326 * into the tree and then subsequently come along and delete it
2327 */
2328 mutex_lock(&info->extent_ins_mutex);
2329 list_for_each_entry_safe(extent_op, tmp, &insert_list, list) {
2330 clear_extent_bits(&info->extent_ins, extent_op->bytenr,
2331 extent_op->bytenr + extent_op->num_bytes - 1,
2332 EXTENT_WRITEBACK, GFP_NOFS);
2333 if (extent_op->del) {
2334 u64 used;
2335 list_del_init(&extent_op->list);
2336 unlock_extent(&info->extent_ins, extent_op->bytenr,
2337 extent_op->bytenr + extent_op->num_bytes
2338 - 1, GFP_NOFS);
2339
2340 mutex_lock(&extent_root->fs_info->pinned_mutex);
2341 ret = pin_down_bytes(trans, extent_root,
2342 extent_op->bytenr,
2343 extent_op->num_bytes, 0);
2344 mutex_unlock(&extent_root->fs_info->pinned_mutex);
2345
2346 spin_lock(&info->delalloc_lock);
2347 used = btrfs_super_bytes_used(&info->super_copy);
2348 btrfs_set_super_bytes_used(&info->super_copy,
2349 used - extent_op->num_bytes);
2350 used = btrfs_root_used(&extent_root->root_item);
2351 btrfs_set_root_used(&extent_root->root_item,
2352 used - extent_op->num_bytes);
2353 spin_unlock(&info->delalloc_lock);
2354
2355 ret = update_block_group(trans, extent_root,
2356 extent_op->bytenr,
2357 extent_op->num_bytes,
2358 0, ret > 0);
2359 BUG_ON(ret);
2360 kfree(extent_op);
2361 num_inserts--;
2362 }
2363 }
2364 mutex_unlock(&info->extent_ins_mutex);
2365
2366 ret = insert_extents(trans, extent_root, path, &insert_list,
2367 num_inserts);
2368 BUG_ON(ret);
2369
2370 /*
2371 * if we broke out of the loop in order to insert stuff because we hit
2372 * the maximum number of inserts at a time we can handle, then loop
2373 * back and pick up where we left off
2374 */
2375 if (num_inserts == max_inserts) {
2376 INIT_LIST_HEAD(&insert_list);
2377 INIT_LIST_HEAD(&update_list);
2378 num_inserts = 0;
2379 goto again;
2380 }
2381
2382 /*
2383 * again, if we need to make absolutely sure there are no more pending
2384 * extent operations left and we know that we skipped some, go back to
2385 * the beginning and do it all again
2386 */
2387 if (all && skipped) {
2388 INIT_LIST_HEAD(&insert_list);
2389 INIT_LIST_HEAD(&update_list);
2390 search = 0;
2391 skipped = 0;
2392 num_inserts = 0;
2393 goto again;
2394 }
2395 out:
2396 btrfs_free_path(path);
2397 return 0;
2398 }
2399
2400 static int pin_down_bytes(struct btrfs_trans_handle *trans,
2401 struct btrfs_root *root,
2402 u64 bytenr, u64 num_bytes, int is_data)
2403 {
2404 int err = 0;
2405 struct extent_buffer *buf;
2406
2407 if (is_data)
2408 goto pinit;
2409
2410 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
2411 if (!buf)
2412 goto pinit;
2413
2414 /* we can reuse a block if it hasn't been written
2415 * and it is from this transaction. We can't
2416 * reuse anything from the tree log root because
2417 * it has tiny sub-transactions.
2418 */
2419 if (btrfs_buffer_uptodate(buf, 0) &&
2420 btrfs_try_tree_lock(buf)) {
2421 u64 header_owner = btrfs_header_owner(buf);
2422 u64 header_transid = btrfs_header_generation(buf);
2423 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
2424 header_owner != BTRFS_TREE_RELOC_OBJECTID &&
2425 header_transid == trans->transid &&
2426 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
2427 clean_tree_block(NULL, root, buf);
2428 btrfs_tree_unlock(buf);
2429 free_extent_buffer(buf);
2430 return 1;
2431 }
2432 btrfs_tree_unlock(buf);
2433 }
2434 free_extent_buffer(buf);
2435 pinit:
2436 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
2437
2438 BUG_ON(err < 0);
2439 return 0;
2440 }
2441
2442 /*
2443 * remove an extent from the root, returns 0 on success
2444 */
2445 static int __free_extent(struct btrfs_trans_handle *trans,
2446 struct btrfs_root *root,
2447 u64 bytenr, u64 num_bytes, u64 parent,
2448 u64 root_objectid, u64 ref_generation,
2449 u64 owner_objectid, int pin, int mark_free)
2450 {
2451 struct btrfs_path *path;
2452 struct btrfs_key key;
2453 struct btrfs_fs_info *info = root->fs_info;
2454 struct btrfs_root *extent_root = info->extent_root;
2455 struct extent_buffer *leaf;
2456 int ret;
2457 int extent_slot = 0;
2458 int found_extent = 0;
2459 int num_to_del = 1;
2460 struct btrfs_extent_item *ei;
2461 u32 refs;
2462
2463 key.objectid = bytenr;
2464 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
2465 key.offset = num_bytes;
2466 path = btrfs_alloc_path();
2467 if (!path)
2468 return -ENOMEM;
2469
2470 path->reada = 1;
2471 ret = lookup_extent_backref(trans, extent_root, path,
2472 bytenr, parent, root_objectid,
2473 ref_generation, owner_objectid, 1);
2474 if (ret == 0) {
2475 struct btrfs_key found_key;
2476 extent_slot = path->slots[0];
2477 while (extent_slot > 0) {
2478 extent_slot--;
2479 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2480 extent_slot);
2481 if (found_key.objectid != bytenr)
2482 break;
2483 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
2484 found_key.offset == num_bytes) {
2485 found_extent = 1;
2486 break;
2487 }
2488 if (path->slots[0] - extent_slot > 5)
2489 break;
2490 }
2491 if (!found_extent) {
2492 ret = remove_extent_backref(trans, extent_root, path);
2493 BUG_ON(ret);
2494 btrfs_release_path(extent_root, path);
2495 ret = btrfs_search_slot(trans, extent_root,
2496 &key, path, -1, 1);
2497 if (ret) {
2498 printk(KERN_ERR "umm, got %d back from search"
2499 ", was looking for %llu\n", ret,
2500 (unsigned long long)bytenr);
2501 btrfs_print_leaf(extent_root, path->nodes[0]);
2502 }
2503 BUG_ON(ret);
2504 extent_slot = path->slots[0];
2505 }
2506 } else {
2507 btrfs_print_leaf(extent_root, path->nodes[0]);
2508 WARN_ON(1);
2509 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
2510 "root %llu gen %llu owner %llu\n",
2511 (unsigned long long)bytenr,
2512 (unsigned long long)root_objectid,
2513 (unsigned long long)ref_generation,
2514 (unsigned long long)owner_objectid);
2515 }
2516
2517 leaf = path->nodes[0];
2518 ei = btrfs_item_ptr(leaf, extent_slot,
2519 struct btrfs_extent_item);
2520 refs = btrfs_extent_refs(leaf, ei);
2521 BUG_ON(refs == 0);
2522 refs -= 1;
2523 btrfs_set_extent_refs(leaf, ei, refs);
2524
2525 btrfs_mark_buffer_dirty(leaf);
2526
2527 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
2528 struct btrfs_extent_ref *ref;
2529 ref = btrfs_item_ptr(leaf, path->slots[0],
2530 struct btrfs_extent_ref);
2531 BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1);
2532 /* if the back ref and the extent are next to each other
2533 * they get deleted below in one shot
2534 */
2535 path->slots[0] = extent_slot;
2536 num_to_del = 2;
2537 } else if (found_extent) {
2538 /* otherwise delete the extent back ref */
2539 ret = remove_extent_backref(trans, extent_root, path);
2540 BUG_ON(ret);
2541 /* if refs are 0, we need to setup the path for deletion */
2542 if (refs == 0) {
2543 btrfs_release_path(extent_root, path);
2544 ret = btrfs_search_slot(trans, extent_root, &key, path,
2545 -1, 1);
2546 BUG_ON(ret);
2547 }
2548 }
2549
2550 if (refs == 0) {
2551 u64 super_used;
2552 u64 root_used;
2553
2554 if (pin) {
2555 mutex_lock(&root->fs_info->pinned_mutex);
2556 ret = pin_down_bytes(trans, root, bytenr, num_bytes,
2557 owner_objectid >= BTRFS_FIRST_FREE_OBJECTID);
2558 mutex_unlock(&root->fs_info->pinned_mutex);
2559 if (ret > 0)
2560 mark_free = 1;
2561 BUG_ON(ret < 0);
2562 }
2563 /* block accounting for super block */
2564 spin_lock(&info->delalloc_lock);
2565 super_used = btrfs_super_bytes_used(&info->super_copy);
2566 btrfs_set_super_bytes_used(&info->super_copy,
2567 super_used - num_bytes);
2568
2569 /* block accounting for root item */
2570 root_used = btrfs_root_used(&root->root_item);
2571 btrfs_set_root_used(&root->root_item,
2572 root_used - num_bytes);
2573 spin_unlock(&info->delalloc_lock);
2574 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
2575 num_to_del);
2576 BUG_ON(ret);
2577 btrfs_release_path(extent_root, path);
2578
2579 if (owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
2580 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
2581 BUG_ON(ret);
2582 }
2583
2584 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
2585 mark_free);
2586 BUG_ON(ret);
2587 }
2588 btrfs_free_path(path);
2589 finish_current_insert(trans, extent_root, 0);
2590 return ret;
2591 }
2592
2593 /*
2594 * find all the blocks marked as pending in the radix tree and remove
2595 * them from the extent map
2596 */
2597 static int del_pending_extents(struct btrfs_trans_handle *trans,
2598 struct btrfs_root *extent_root, int all)
2599 {
2600 int ret;
2601 int err = 0;
2602 u64 start;
2603 u64 end;
2604 u64 priv;
2605 u64 search = 0;
2606 int nr = 0, skipped = 0;
2607 struct extent_io_tree *pending_del;
2608 struct extent_io_tree *extent_ins;
2609 struct pending_extent_op *extent_op;
2610 struct btrfs_fs_info *info = extent_root->fs_info;
2611 struct list_head delete_list;
2612
2613 INIT_LIST_HEAD(&delete_list);
2614 extent_ins = &extent_root->fs_info->extent_ins;
2615 pending_del = &extent_root->fs_info->pending_del;
2616
2617 again:
2618 mutex_lock(&info->extent_ins_mutex);
2619 while (1) {
2620 ret = find_first_extent_bit(pending_del, search, &start, &end,
2621 EXTENT_WRITEBACK);
2622 if (ret) {
2623 if (all && skipped && !nr) {
2624 search = 0;
2625 skipped = 0;
2626 continue;
2627 }
2628 mutex_unlock(&info->extent_ins_mutex);
2629 break;
2630 }
2631
2632 ret = try_lock_extent(extent_ins, start, end, GFP_NOFS);
2633 if (!ret) {
2634 search = end+1;
2635 skipped = 1;
2636
2637 if (need_resched()) {
2638 mutex_unlock(&info->extent_ins_mutex);
2639 cond_resched();
2640 mutex_lock(&info->extent_ins_mutex);
2641 }
2642
2643 continue;
2644 }
2645 BUG_ON(ret < 0);
2646
2647 ret = get_state_private(pending_del, start, &priv);
2648 BUG_ON(ret);
2649 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2650
2651 clear_extent_bits(pending_del, start, end, EXTENT_WRITEBACK,
2652 GFP_NOFS);
2653 if (!test_range_bit(extent_ins, start, end,
2654 EXTENT_WRITEBACK, 0)) {
2655 list_add_tail(&extent_op->list, &delete_list);
2656 nr++;
2657 } else {
2658 kfree(extent_op);
2659
2660 ret = get_state_private(&info->extent_ins, start,
2661 &priv);
2662 BUG_ON(ret);
2663 extent_op = (struct pending_extent_op *)
2664 (unsigned long)priv;
2665
2666 clear_extent_bits(&info->extent_ins, start, end,
2667 EXTENT_WRITEBACK, GFP_NOFS);
2668
2669 if (extent_op->type == PENDING_BACKREF_UPDATE) {
2670 list_add_tail(&extent_op->list, &delete_list);
2671 search = end + 1;
2672 nr++;
2673 continue;
2674 }
2675
2676 mutex_lock(&extent_root->fs_info->pinned_mutex);
2677 ret = pin_down_bytes(trans, extent_root, start,
2678 end + 1 - start, 0);
2679 mutex_unlock(&extent_root->fs_info->pinned_mutex);
2680
2681 ret = update_block_group(trans, extent_root, start,
2682 end + 1 - start, 0, ret > 0);
2683
2684 unlock_extent(extent_ins, start, end, GFP_NOFS);
2685 BUG_ON(ret);
2686 kfree(extent_op);
2687 }
2688 if (ret)
2689 err = ret;
2690
2691 search = end + 1;
2692
2693 if (need_resched()) {
2694 mutex_unlock(&info->extent_ins_mutex);
2695 cond_resched();
2696 mutex_lock(&info->extent_ins_mutex);
2697 }
2698 }
2699
2700 if (nr) {
2701 ret = free_extents(trans, extent_root, &delete_list);
2702 BUG_ON(ret);
2703 }
2704
2705 if (all && skipped) {
2706 INIT_LIST_HEAD(&delete_list);
2707 search = 0;
2708 nr = 0;
2709 goto again;
2710 }
2711
2712 return err;
2713 }
2714
2715 /*
2716 * remove an extent from the root, returns 0 on success
2717 */
2718 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
2719 struct btrfs_root *root,
2720 u64 bytenr, u64 num_bytes, u64 parent,
2721 u64 root_objectid, u64 ref_generation,
2722 u64 owner_objectid, int pin)
2723 {
2724 struct btrfs_root *extent_root = root->fs_info->extent_root;
2725 int pending_ret;
2726 int ret;
2727
2728 WARN_ON(num_bytes < root->sectorsize);
2729 if (root == extent_root) {
2730 struct pending_extent_op *extent_op = NULL;
2731
2732 mutex_lock(&root->fs_info->extent_ins_mutex);
2733 if (test_range_bit(&root->fs_info->extent_ins, bytenr,
2734 bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
2735 u64 priv;
2736 ret = get_state_private(&root->fs_info->extent_ins,
2737 bytenr, &priv);
2738 BUG_ON(ret);
2739 extent_op = (struct pending_extent_op *)
2740 (unsigned long)priv;
2741
2742 extent_op->del = 1;
2743 if (extent_op->type == PENDING_EXTENT_INSERT) {
2744 mutex_unlock(&root->fs_info->extent_ins_mutex);
2745 return 0;
2746 }
2747 }
2748
2749 if (extent_op) {
2750 ref_generation = extent_op->orig_generation;
2751 parent = extent_op->orig_parent;
2752 }
2753
2754 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2755 BUG_ON(!extent_op);
2756
2757 extent_op->type = PENDING_EXTENT_DELETE;
2758 extent_op->bytenr = bytenr;
2759 extent_op->num_bytes = num_bytes;
2760 extent_op->parent = parent;
2761 extent_op->orig_parent = parent;
2762 extent_op->generation = ref_generation;
2763 extent_op->orig_generation = ref_generation;
2764 extent_op->level = (int)owner_objectid;
2765 INIT_LIST_HEAD(&extent_op->list);
2766 extent_op->del = 0;
2767
2768 set_extent_bits(&root->fs_info->pending_del,
2769 bytenr, bytenr + num_bytes - 1,
2770 EXTENT_WRITEBACK, GFP_NOFS);
2771 set_state_private(&root->fs_info->pending_del,
2772 bytenr, (unsigned long)extent_op);
2773 mutex_unlock(&root->fs_info->extent_ins_mutex);
2774 return 0;
2775 }
2776 /* if metadata always pin */
2777 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
2778 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2779 mutex_lock(&root->fs_info->pinned_mutex);
2780 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
2781 mutex_unlock(&root->fs_info->pinned_mutex);
2782 update_reserved_extents(root, bytenr, num_bytes, 0);
2783 return 0;
2784 }
2785 pin = 1;
2786 }
2787
2788 /* if data pin when any transaction has committed this */
2789 if (ref_generation != trans->transid)
2790 pin = 1;
2791
2792 ret = __free_extent(trans, root, bytenr, num_bytes, parent,
2793 root_objectid, ref_generation,
2794 owner_objectid, pin, pin == 0);
2795
2796 finish_current_insert(trans, root->fs_info->extent_root, 0);
2797 pending_ret = del_pending_extents(trans, root->fs_info->extent_root, 0);
2798 return ret ? ret : pending_ret;
2799 }
2800
2801 int btrfs_free_extent(struct btrfs_trans_handle *trans,
2802 struct btrfs_root *root,
2803 u64 bytenr, u64 num_bytes, u64 parent,
2804 u64 root_objectid, u64 ref_generation,
2805 u64 owner_objectid, int pin)
2806 {
2807 int ret;
2808
2809 ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent,
2810 root_objectid, ref_generation,
2811 owner_objectid, pin);
2812 return ret;
2813 }
2814
2815 static u64 stripe_align(struct btrfs_root *root, u64 val)
2816 {
2817 u64 mask = ((u64)root->stripesize - 1);
2818 u64 ret = (val + mask) & ~mask;
2819 return ret;
2820 }
2821
2822 /*
2823 * walks the btree of allocated extents and find a hole of a given size.
2824 * The key ins is changed to record the hole:
2825 * ins->objectid == block start
2826 * ins->flags = BTRFS_EXTENT_ITEM_KEY
2827 * ins->offset == number of blocks
2828 * Any available blocks before search_start are skipped.
2829 */
2830 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
2831 struct btrfs_root *orig_root,
2832 u64 num_bytes, u64 empty_size,
2833 u64 search_start, u64 search_end,
2834 u64 hint_byte, struct btrfs_key *ins,
2835 u64 exclude_start, u64 exclude_nr,
2836 int data)
2837 {
2838 int ret = 0;
2839 struct btrfs_root *root = orig_root->fs_info->extent_root;
2840 u64 total_needed = num_bytes;
2841 u64 *last_ptr = NULL;
2842 u64 last_wanted = 0;
2843 struct btrfs_block_group_cache *block_group = NULL;
2844 int chunk_alloc_done = 0;
2845 int empty_cluster = 2 * 1024 * 1024;
2846 int allowed_chunk_alloc = 0;
2847 struct list_head *head = NULL, *cur = NULL;
2848 int loop = 0;
2849 int extra_loop = 0;
2850 struct btrfs_space_info *space_info;
2851
2852 WARN_ON(num_bytes < root->sectorsize);
2853 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
2854 ins->objectid = 0;
2855 ins->offset = 0;
2856
2857 if (orig_root->ref_cows || empty_size)
2858 allowed_chunk_alloc = 1;
2859
2860 if (data & BTRFS_BLOCK_GROUP_METADATA) {
2861 last_ptr = &root->fs_info->last_alloc;
2862 empty_cluster = 64 * 1024;
2863 }
2864
2865 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
2866 last_ptr = &root->fs_info->last_data_alloc;
2867
2868 if (last_ptr) {
2869 if (*last_ptr) {
2870 hint_byte = *last_ptr;
2871 last_wanted = *last_ptr;
2872 } else
2873 empty_size += empty_cluster;
2874 } else {
2875 empty_cluster = 0;
2876 }
2877 search_start = max(search_start, first_logical_byte(root, 0));
2878 search_start = max(search_start, hint_byte);
2879
2880 if (last_wanted && search_start != last_wanted) {
2881 last_wanted = 0;
2882 empty_size += empty_cluster;
2883 }
2884
2885 total_needed += empty_size;
2886 block_group = btrfs_lookup_block_group(root->fs_info, search_start);
2887 if (!block_group)
2888 block_group = btrfs_lookup_first_block_group(root->fs_info,
2889 search_start);
2890 space_info = __find_space_info(root->fs_info, data);
2891
2892 down_read(&space_info->groups_sem);
2893 while (1) {
2894 struct btrfs_free_space *free_space;
2895 /*
2896 * the only way this happens if our hint points to a block
2897 * group thats not of the proper type, while looping this
2898 * should never happen
2899 */
2900 if (empty_size)
2901 extra_loop = 1;
2902
2903 if (!block_group)
2904 goto new_group_no_lock;
2905
2906 if (unlikely(!block_group->cached)) {
2907 mutex_lock(&block_group->cache_mutex);
2908 ret = cache_block_group(root, block_group);
2909 mutex_unlock(&block_group->cache_mutex);
2910 if (ret)
2911 break;
2912 }
2913
2914 mutex_lock(&block_group->alloc_mutex);
2915 if (unlikely(!block_group_bits(block_group, data)))
2916 goto new_group;
2917
2918 if (unlikely(block_group->ro))
2919 goto new_group;
2920
2921 free_space = btrfs_find_free_space(block_group, search_start,
2922 total_needed);
2923 if (free_space) {
2924 u64 start = block_group->key.objectid;
2925 u64 end = block_group->key.objectid +
2926 block_group->key.offset;
2927
2928 search_start = stripe_align(root, free_space->offset);
2929
2930 /* move on to the next group */
2931 if (search_start + num_bytes >= search_end)
2932 goto new_group;
2933
2934 /* move on to the next group */
2935 if (search_start + num_bytes > end)
2936 goto new_group;
2937
2938 if (last_wanted && search_start != last_wanted) {
2939 total_needed += empty_cluster;
2940 empty_size += empty_cluster;
2941 last_wanted = 0;
2942 /*
2943 * if search_start is still in this block group
2944 * then we just re-search this block group
2945 */
2946 if (search_start >= start &&
2947 search_start < end) {
2948 mutex_unlock(&block_group->alloc_mutex);
2949 continue;
2950 }
2951
2952 /* else we go to the next block group */
2953 goto new_group;
2954 }
2955
2956 if (exclude_nr > 0 &&
2957 (search_start + num_bytes > exclude_start &&
2958 search_start < exclude_start + exclude_nr)) {
2959 search_start = exclude_start + exclude_nr;
2960 /*
2961 * if search_start is still in this block group
2962 * then we just re-search this block group
2963 */
2964 if (search_start >= start &&
2965 search_start < end) {
2966 mutex_unlock(&block_group->alloc_mutex);
2967 last_wanted = 0;
2968 continue;
2969 }
2970
2971 /* else we go to the next block group */
2972 goto new_group;
2973 }
2974
2975 ins->objectid = search_start;
2976 ins->offset = num_bytes;
2977
2978 btrfs_remove_free_space_lock(block_group, search_start,
2979 num_bytes);
2980 /* we are all good, lets return */
2981 mutex_unlock(&block_group->alloc_mutex);
2982 break;
2983 }
2984 new_group:
2985 mutex_unlock(&block_group->alloc_mutex);
2986 put_block_group(block_group);
2987 block_group = NULL;
2988 new_group_no_lock:
2989 /* don't try to compare new allocations against the
2990 * last allocation any more
2991 */
2992 last_wanted = 0;
2993
2994 /*
2995 * Here's how this works.
2996 * loop == 0: we were searching a block group via a hint
2997 * and didn't find anything, so we start at
2998 * the head of the block groups and keep searching
2999 * loop == 1: we're searching through all of the block groups
3000 * if we hit the head again we have searched
3001 * all of the block groups for this space and we
3002 * need to try and allocate, if we cant error out.
3003 * loop == 2: we allocated more space and are looping through
3004 * all of the block groups again.
3005 */
3006 if (loop == 0) {
3007 head = &space_info->block_groups;
3008 cur = head->next;
3009 loop++;
3010 } else if (loop == 1 && cur == head) {
3011 int keep_going;
3012
3013 /* at this point we give up on the empty_size
3014 * allocations and just try to allocate the min
3015 * space.
3016 *
3017 * The extra_loop field was set if an empty_size
3018 * allocation was attempted above, and if this
3019 * is try we need to try the loop again without
3020 * the additional empty_size.
3021 */
3022 total_needed -= empty_size;
3023 empty_size = 0;
3024 keep_going = extra_loop;
3025 loop++;
3026
3027 if (allowed_chunk_alloc && !chunk_alloc_done) {
3028 up_read(&space_info->groups_sem);
3029 ret = do_chunk_alloc(trans, root, num_bytes +
3030 2 * 1024 * 1024, data, 1);
3031 down_read(&space_info->groups_sem);
3032 if (ret < 0)
3033 goto loop_check;
3034 head = &space_info->block_groups;
3035 /*
3036 * we've allocated a new chunk, keep
3037 * trying
3038 */
3039 keep_going = 1;
3040 chunk_alloc_done = 1;
3041 } else if (!allowed_chunk_alloc) {
3042 space_info->force_alloc = 1;
3043 }
3044 loop_check:
3045 if (keep_going) {
3046 cur = head->next;
3047 extra_loop = 0;
3048 } else {
3049 break;
3050 }
3051 } else if (cur == head) {
3052 break;
3053 }
3054
3055 block_group = list_entry(cur, struct btrfs_block_group_cache,
3056 list);
3057 atomic_inc(&block_group->count);
3058
3059 search_start = block_group->key.objectid;
3060 cur = cur->next;
3061 }
3062
3063 /* we found what we needed */
3064 if (ins->objectid) {
3065 if (!(data & BTRFS_BLOCK_GROUP_DATA))
3066 trans->block_group = block_group->key.objectid;
3067
3068 if (last_ptr)
3069 *last_ptr = ins->objectid + ins->offset;
3070 ret = 0;
3071 } else if (!ret) {
3072 printk(KERN_ERR "btrfs searching for %llu bytes, "
3073 "num_bytes %llu, loop %d, allowed_alloc %d\n",
3074 (unsigned long long)total_needed,
3075 (unsigned long long)num_bytes,
3076 loop, allowed_chunk_alloc);
3077 ret = -ENOSPC;
3078 }
3079 if (block_group)
3080 put_block_group(block_group);
3081
3082 up_read(&space_info->groups_sem);
3083 return ret;
3084 }
3085
3086 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
3087 {
3088 struct btrfs_block_group_cache *cache;
3089
3090 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
3091 (unsigned long long)(info->total_bytes - info->bytes_used -
3092 info->bytes_pinned - info->bytes_reserved),
3093 (info->full) ? "" : "not ");
3094
3095 down_read(&info->groups_sem);
3096 list_for_each_entry(cache, &info->block_groups, list) {
3097 spin_lock(&cache->lock);
3098 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
3099 "%llu pinned %llu reserved\n",
3100 (unsigned long long)cache->key.objectid,
3101 (unsigned long long)cache->key.offset,
3102 (unsigned long long)btrfs_block_group_used(&cache->item),
3103 (unsigned long long)cache->pinned,
3104 (unsigned long long)cache->reserved);
3105 btrfs_dump_free_space(cache, bytes);
3106 spin_unlock(&cache->lock);
3107 }
3108 up_read(&info->groups_sem);
3109 }
3110
3111 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
3112 struct btrfs_root *root,
3113 u64 num_bytes, u64 min_alloc_size,
3114 u64 empty_size, u64 hint_byte,
3115 u64 search_end, struct btrfs_key *ins,
3116 u64 data)
3117 {
3118 int ret;
3119 u64 search_start = 0;
3120 u64 alloc_profile;
3121 struct btrfs_fs_info *info = root->fs_info;
3122
3123 if (data) {
3124 alloc_profile = info->avail_data_alloc_bits &
3125 info->data_alloc_profile;
3126 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
3127 } else if (root == root->fs_info->chunk_root) {
3128 alloc_profile = info->avail_system_alloc_bits &
3129 info->system_alloc_profile;
3130 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
3131 } else {
3132 alloc_profile = info->avail_metadata_alloc_bits &
3133 info->metadata_alloc_profile;
3134 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
3135 }
3136 again:
3137 data = btrfs_reduce_alloc_profile(root, data);
3138 /*
3139 * the only place that sets empty_size is btrfs_realloc_node, which
3140 * is not called recursively on allocations
3141 */
3142 if (empty_size || root->ref_cows) {
3143 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
3144 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3145 2 * 1024 * 1024,
3146 BTRFS_BLOCK_GROUP_METADATA |
3147 (info->metadata_alloc_profile &
3148 info->avail_metadata_alloc_bits), 0);
3149 }
3150 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3151 num_bytes + 2 * 1024 * 1024, data, 0);
3152 }
3153
3154 WARN_ON(num_bytes < root->sectorsize);
3155 ret = find_free_extent(trans, root, num_bytes, empty_size,
3156 search_start, search_end, hint_byte, ins,
3157 trans->alloc_exclude_start,
3158 trans->alloc_exclude_nr, data);
3159
3160 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
3161 num_bytes = num_bytes >> 1;
3162 num_bytes = num_bytes & ~(root->sectorsize - 1);
3163 num_bytes = max(num_bytes, min_alloc_size);
3164 do_chunk_alloc(trans, root->fs_info->extent_root,
3165 num_bytes, data, 1);
3166 goto again;
3167 }
3168 if (ret) {
3169 struct btrfs_space_info *sinfo;
3170
3171 sinfo = __find_space_info(root->fs_info, data);
3172 printk(KERN_ERR "btrfs allocation failed flags %llu, "
3173 "wanted %llu\n", (unsigned long long)data,
3174 (unsigned long long)num_bytes);
3175 dump_space_info(sinfo, num_bytes);
3176 BUG();
3177 }
3178
3179 return ret;
3180 }
3181
3182 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
3183 {
3184 struct btrfs_block_group_cache *cache;
3185 int ret = 0;
3186
3187 cache = btrfs_lookup_block_group(root->fs_info, start);
3188 if (!cache) {
3189 printk(KERN_ERR "Unable to find block group for %llu\n",
3190 (unsigned long long)start);
3191 return -ENOSPC;
3192 }
3193
3194 ret = btrfs_discard_extent(root, start, len);
3195
3196 btrfs_add_free_space(cache, start, len);
3197 put_block_group(cache);
3198 update_reserved_extents(root, start, len, 0);
3199
3200 return ret;
3201 }
3202
3203 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
3204 struct btrfs_root *root,
3205 u64 num_bytes, u64 min_alloc_size,
3206 u64 empty_size, u64 hint_byte,
3207 u64 search_end, struct btrfs_key *ins,
3208 u64 data)
3209 {
3210 int ret;
3211 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
3212 empty_size, hint_byte, search_end, ins,
3213 data);
3214 update_reserved_extents(root, ins->objectid, ins->offset, 1);
3215 return ret;
3216 }
3217
3218 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
3219 struct btrfs_root *root, u64 parent,
3220 u64 root_objectid, u64 ref_generation,
3221 u64 owner, struct btrfs_key *ins)
3222 {
3223 int ret;
3224 int pending_ret;
3225 u64 super_used;
3226 u64 root_used;
3227 u64 num_bytes = ins->offset;
3228 u32 sizes[2];
3229 struct btrfs_fs_info *info = root->fs_info;
3230 struct btrfs_root *extent_root = info->extent_root;
3231 struct btrfs_extent_item *extent_item;
3232 struct btrfs_extent_ref *ref;
3233 struct btrfs_path *path;
3234 struct btrfs_key keys[2];
3235
3236 if (parent == 0)
3237 parent = ins->objectid;
3238
3239 /* block accounting for super block */
3240 spin_lock(&info->delalloc_lock);
3241 super_used = btrfs_super_bytes_used(&info->super_copy);
3242 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
3243
3244 /* block accounting for root item */
3245 root_used = btrfs_root_used(&root->root_item);
3246 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
3247 spin_unlock(&info->delalloc_lock);
3248
3249 if (root == extent_root) {
3250 struct pending_extent_op *extent_op;
3251
3252 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
3253 BUG_ON(!extent_op);
3254
3255 extent_op->type = PENDING_EXTENT_INSERT;
3256 extent_op->bytenr = ins->objectid;
3257 extent_op->num_bytes = ins->offset;
3258 extent_op->parent = parent;
3259 extent_op->orig_parent = 0;
3260 extent_op->generation = ref_generation;
3261 extent_op->orig_generation = 0;
3262 extent_op->level = (int)owner;
3263 INIT_LIST_HEAD(&extent_op->list);
3264 extent_op->del = 0;
3265
3266 mutex_lock(&root->fs_info->extent_ins_mutex);
3267 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
3268 ins->objectid + ins->offset - 1,
3269 EXTENT_WRITEBACK, GFP_NOFS);
3270 set_state_private(&root->fs_info->extent_ins,
3271 ins->objectid, (unsigned long)extent_op);
3272 mutex_unlock(&root->fs_info->extent_ins_mutex);
3273 goto update_block;
3274 }
3275
3276 memcpy(&keys[0], ins, sizeof(*ins));
3277 keys[1].objectid = ins->objectid;
3278 keys[1].type = BTRFS_EXTENT_REF_KEY;
3279 keys[1].offset = parent;
3280 sizes[0] = sizeof(*extent_item);
3281 sizes[1] = sizeof(*ref);
3282
3283 path = btrfs_alloc_path();
3284 BUG_ON(!path);
3285
3286 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
3287 sizes, 2);
3288 BUG_ON(ret);
3289
3290 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3291 struct btrfs_extent_item);
3292 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
3293 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
3294 struct btrfs_extent_ref);
3295
3296 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
3297 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
3298 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
3299 btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
3300
3301 btrfs_mark_buffer_dirty(path->nodes[0]);
3302
3303 trans->alloc_exclude_start = 0;
3304 trans->alloc_exclude_nr = 0;
3305 btrfs_free_path(path);
3306 finish_current_insert(trans, extent_root, 0);
3307 pending_ret = del_pending_extents(trans, extent_root, 0);
3308
3309 if (ret)
3310 goto out;
3311 if (pending_ret) {
3312 ret = pending_ret;
3313 goto out;
3314 }
3315
3316 update_block:
3317 ret = update_block_group(trans, root, ins->objectid,
3318 ins->offset, 1, 0);
3319 if (ret) {
3320 printk(KERN_ERR "btrfs update block group failed for %llu "
3321 "%llu\n", (unsigned long long)ins->objectid,
3322 (unsigned long long)ins->offset);
3323 BUG();
3324 }
3325 out:
3326 return ret;
3327 }
3328
3329 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
3330 struct btrfs_root *root, u64 parent,
3331 u64 root_objectid, u64 ref_generation,
3332 u64 owner, struct btrfs_key *ins)
3333 {
3334 int ret;
3335
3336 if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
3337 return 0;
3338 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
3339 ref_generation, owner, ins);
3340 update_reserved_extents(root, ins->objectid, ins->offset, 0);
3341 return ret;
3342 }
3343
3344 /*
3345 * this is used by the tree logging recovery code. It records that
3346 * an extent has been allocated and makes sure to clear the free
3347 * space cache bits as well
3348 */
3349 int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
3350 struct btrfs_root *root, u64 parent,
3351 u64 root_objectid, u64 ref_generation,
3352 u64 owner, struct btrfs_key *ins)
3353 {
3354 int ret;
3355 struct btrfs_block_group_cache *block_group;
3356
3357 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
3358 mutex_lock(&block_group->cache_mutex);
3359 cache_block_group(root, block_group);
3360 mutex_unlock(&block_group->cache_mutex);
3361
3362 ret = btrfs_remove_free_space(block_group, ins->objectid,
3363 ins->offset);
3364 BUG_ON(ret);
3365 put_block_group(block_group);
3366 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
3367 ref_generation, owner, ins);
3368 return ret;
3369 }
3370
3371 /*
3372 * finds a free extent and does all the dirty work required for allocation
3373 * returns the key for the extent through ins, and a tree buffer for
3374 * the first block of the extent through buf.
3375 *
3376 * returns 0 if everything worked, non-zero otherwise.
3377 */
3378 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
3379 struct btrfs_root *root,
3380 u64 num_bytes, u64 parent, u64 min_alloc_size,
3381 u64 root_objectid, u64 ref_generation,
3382 u64 owner_objectid, u64 empty_size, u64 hint_byte,
3383 u64 search_end, struct btrfs_key *ins, u64 data)
3384 {
3385 int ret;
3386
3387 ret = __btrfs_reserve_extent(trans, root, num_bytes,
3388 min_alloc_size, empty_size, hint_byte,
3389 search_end, ins, data);
3390 BUG_ON(ret);
3391 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
3392 ret = __btrfs_alloc_reserved_extent(trans, root, parent,
3393 root_objectid, ref_generation,
3394 owner_objectid, ins);
3395 BUG_ON(ret);
3396
3397 } else {
3398 update_reserved_extents(root, ins->objectid, ins->offset, 1);
3399 }
3400 return ret;
3401 }
3402
3403 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
3404 struct btrfs_root *root,
3405 u64 bytenr, u32 blocksize)
3406 {
3407 struct extent_buffer *buf;
3408
3409 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
3410 if (!buf)
3411 return ERR_PTR(-ENOMEM);
3412 btrfs_set_header_generation(buf, trans->transid);
3413 btrfs_tree_lock(buf);
3414 clean_tree_block(trans, root, buf);
3415
3416 btrfs_set_lock_blocking(buf);
3417 btrfs_set_buffer_uptodate(buf);
3418
3419 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
3420 set_extent_dirty(&root->dirty_log_pages, buf->start,
3421 buf->start + buf->len - 1, GFP_NOFS);
3422 } else {
3423 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
3424 buf->start + buf->len - 1, GFP_NOFS);
3425 }
3426 trans->blocks_used++;
3427 /* this returns a buffer locked for blocking */
3428 return buf;
3429 }
3430
3431 /*
3432 * helper function to allocate a block for a given tree
3433 * returns the tree buffer or NULL.
3434 */
3435 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
3436 struct btrfs_root *root,
3437 u32 blocksize, u64 parent,
3438 u64 root_objectid,
3439 u64 ref_generation,
3440 int level,
3441 u64 hint,
3442 u64 empty_size)
3443 {
3444 struct btrfs_key ins;
3445 int ret;
3446 struct extent_buffer *buf;
3447
3448 ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
3449 root_objectid, ref_generation, level,
3450 empty_size, hint, (u64)-1, &ins, 0);
3451 if (ret) {
3452 BUG_ON(ret > 0);
3453 return ERR_PTR(ret);
3454 }
3455
3456 buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
3457 return buf;
3458 }
3459
3460 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
3461 struct btrfs_root *root, struct extent_buffer *leaf)
3462 {
3463 u64 leaf_owner;
3464 u64 leaf_generation;
3465 struct refsort *sorted;
3466 struct btrfs_key key;
3467 struct btrfs_file_extent_item *fi;
3468 int i;
3469 int nritems;
3470 int ret;
3471 int refi = 0;
3472 int slot;
3473
3474 BUG_ON(!btrfs_is_leaf(leaf));
3475 nritems = btrfs_header_nritems(leaf);
3476 leaf_owner = btrfs_header_owner(leaf);
3477 leaf_generation = btrfs_header_generation(leaf);
3478
3479 sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
3480 /* we do this loop twice. The first time we build a list
3481 * of the extents we have a reference on, then we sort the list
3482 * by bytenr. The second time around we actually do the
3483 * extent freeing.
3484 */
3485 for (i = 0; i < nritems; i++) {
3486 u64 disk_bytenr;
3487 cond_resched();
3488
3489 btrfs_item_key_to_cpu(leaf, &key, i);
3490
3491 /* only extents have references, skip everything else */
3492 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
3493 continue;
3494
3495 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
3496
3497 /* inline extents live in the btree, they don't have refs */
3498 if (btrfs_file_extent_type(leaf, fi) ==
3499 BTRFS_FILE_EXTENT_INLINE)
3500 continue;
3501
3502 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
3503
3504 /* holes don't have refs */
3505 if (disk_bytenr == 0)
3506 continue;
3507
3508 sorted[refi].bytenr = disk_bytenr;
3509 sorted[refi].slot = i;
3510 refi++;
3511 }
3512
3513 if (refi == 0)
3514 goto out;
3515
3516 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
3517
3518 for (i = 0; i < refi; i++) {
3519 u64 disk_bytenr;
3520
3521 disk_bytenr = sorted[i].bytenr;
3522 slot = sorted[i].slot;
3523
3524 cond_resched();
3525
3526 btrfs_item_key_to_cpu(leaf, &key, slot);
3527 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
3528 continue;
3529
3530 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
3531
3532 ret = __btrfs_free_extent(trans, root, disk_bytenr,
3533 btrfs_file_extent_disk_num_bytes(leaf, fi),
3534 leaf->start, leaf_owner, leaf_generation,
3535 key.objectid, 0);
3536 BUG_ON(ret);
3537
3538 atomic_inc(&root->fs_info->throttle_gen);
3539 wake_up(&root->fs_info->transaction_throttle);
3540 cond_resched();
3541 }
3542 out:
3543 kfree(sorted);
3544 return 0;
3545 }
3546
3547 static noinline int cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
3548 struct btrfs_root *root,
3549 struct btrfs_leaf_ref *ref)
3550 {
3551 int i;
3552 int ret;
3553 struct btrfs_extent_info *info;
3554 struct refsort *sorted;
3555
3556 if (ref->nritems == 0)
3557 return 0;
3558
3559 sorted = kmalloc(sizeof(*sorted) * ref->nritems, GFP_NOFS);
3560 for (i = 0; i < ref->nritems; i++) {
3561 sorted[i].bytenr = ref->extents[i].bytenr;
3562 sorted[i].slot = i;
3563 }
3564 sort(sorted, ref->nritems, sizeof(struct refsort), refsort_cmp, NULL);
3565
3566 /*
3567 * the items in the ref were sorted when the ref was inserted
3568 * into the ref cache, so this is already in order
3569 */
3570 for (i = 0; i < ref->nritems; i++) {
3571 info = ref->extents + sorted[i].slot;
3572 ret = __btrfs_free_extent(trans, root, info->bytenr,
3573 info->num_bytes, ref->bytenr,
3574 ref->owner, ref->generation,
3575 info->objectid, 0);
3576
3577 atomic_inc(&root->fs_info->throttle_gen);
3578 wake_up(&root->fs_info->transaction_throttle);
3579 cond_resched();
3580
3581 BUG_ON(ret);
3582 info++;
3583 }
3584
3585 kfree(sorted);
3586 return 0;
3587 }
3588
3589 static int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start,
3590 u64 len, u32 *refs)
3591 {
3592 int ret;
3593
3594 ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
3595 BUG_ON(ret);
3596
3597 #if 0 /* some debugging code in case we see problems here */
3598 /* if the refs count is one, it won't get increased again. But
3599 * if the ref count is > 1, someone may be decreasing it at
3600 * the same time we are.
3601 */
3602 if (*refs != 1) {
3603 struct extent_buffer *eb = NULL;
3604 eb = btrfs_find_create_tree_block(root, start, len);
3605 if (eb)
3606 btrfs_tree_lock(eb);
3607
3608 mutex_lock(&root->fs_info->alloc_mutex);
3609 ret = lookup_extent_ref(NULL, root, start, len, refs);
3610 BUG_ON(ret);
3611 mutex_unlock(&root->fs_info->alloc_mutex);
3612
3613 if (eb) {
3614 btrfs_tree_unlock(eb);
3615 free_extent_buffer(eb);
3616 }
3617 if (*refs == 1) {
3618 printk(KERN_ERR "btrfs block %llu went down to one "
3619 "during drop_snap\n", (unsigned long long)start);
3620 }
3621
3622 }
3623 #endif
3624
3625 cond_resched();
3626 return ret;
3627 }
3628
3629 /*
3630 * this is used while deleting old snapshots, and it drops the refs
3631 * on a whole subtree starting from a level 1 node.
3632 *
3633 * The idea is to sort all the leaf pointers, and then drop the
3634 * ref on all the leaves in order. Most of the time the leaves
3635 * will have ref cache entries, so no leaf IOs will be required to
3636 * find the extents they have references on.
3637 *
3638 * For each leaf, any references it has are also dropped in order
3639 *
3640 * This ends up dropping the references in something close to optimal
3641 * order for reading and modifying the extent allocation tree.
3642 */
3643 static noinline int drop_level_one_refs(struct btrfs_trans_handle *trans,
3644 struct btrfs_root *root,
3645 struct btrfs_path *path)
3646 {
3647 u64 bytenr;
3648 u64 root_owner;
3649 u64 root_gen;
3650 struct extent_buffer *eb = path->nodes[1];
3651 struct extent_buffer *leaf;
3652 struct btrfs_leaf_ref *ref;
3653 struct refsort *sorted = NULL;
3654 int nritems = btrfs_header_nritems(eb);
3655 int ret;
3656 int i;
3657 int refi = 0;
3658 int slot = path->slots[1];
3659 u32 blocksize = btrfs_level_size(root, 0);
3660 u32 refs;
3661
3662 if (nritems == 0)
3663 goto out;
3664
3665 root_owner = btrfs_header_owner(eb);
3666 root_gen = btrfs_header_generation(eb);
3667 sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
3668
3669 /*
3670 * step one, sort all the leaf pointers so we don't scribble
3671 * randomly into the extent allocation tree
3672 */
3673 for (i = slot; i < nritems; i++) {
3674 sorted[refi].bytenr = btrfs_node_blockptr(eb, i);
3675 sorted[refi].slot = i;
3676 refi++;
3677 }
3678
3679 /*
3680 * nritems won't be zero, but if we're picking up drop_snapshot
3681 * after a crash, slot might be > 0, so double check things
3682 * just in case.
3683 */
3684 if (refi == 0)
3685 goto out;
3686
3687 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
3688
3689 /*
3690 * the first loop frees everything the leaves point to
3691 */
3692 for (i = 0; i < refi; i++) {
3693 u64 ptr_gen;
3694
3695 bytenr = sorted[i].bytenr;
3696
3697 /*
3698 * check the reference count on this leaf. If it is > 1
3699 * we just decrement it below and don't update any
3700 * of the refs the leaf points to.
3701 */
3702 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
3703 BUG_ON(ret);
3704 if (refs != 1)
3705 continue;
3706
3707 ptr_gen = btrfs_node_ptr_generation(eb, sorted[i].slot);
3708
3709 /*
3710 * the leaf only had one reference, which means the
3711 * only thing pointing to this leaf is the snapshot
3712 * we're deleting. It isn't possible for the reference
3713 * count to increase again later
3714 *
3715 * The reference cache is checked for the leaf,
3716 * and if found we'll be able to drop any refs held by
3717 * the leaf without needing to read it in.
3718 */
3719 ref = btrfs_lookup_leaf_ref(root, bytenr);
3720 if (ref && ref->generation != ptr_gen) {
3721 btrfs_free_leaf_ref(root, ref);
3722 ref = NULL;
3723 }
3724 if (ref) {
3725 ret = cache_drop_leaf_ref(trans, root, ref);
3726 BUG_ON(ret);
3727 btrfs_remove_leaf_ref(root, ref);
3728 btrfs_free_leaf_ref(root, ref);
3729 } else {
3730 /*
3731 * the leaf wasn't in the reference cache, so
3732 * we have to read it.
3733 */
3734 leaf = read_tree_block(root, bytenr, blocksize,
3735 ptr_gen);
3736 ret = btrfs_drop_leaf_ref(trans, root, leaf);
3737 BUG_ON(ret);
3738 free_extent_buffer(leaf);
3739 }
3740 atomic_inc(&root->fs_info->throttle_gen);
3741 wake_up(&root->fs_info->transaction_throttle);
3742 cond_resched();
3743 }
3744
3745 /*
3746 * run through the loop again to free the refs on the leaves.
3747 * This is faster than doing it in the loop above because
3748 * the leaves are likely to be clustered together. We end up
3749 * working in nice chunks on the extent allocation tree.
3750 */
3751 for (i = 0; i < refi; i++) {
3752 bytenr = sorted[i].bytenr;
3753 ret = __btrfs_free_extent(trans, root, bytenr,
3754 blocksize, eb->start,
3755 root_owner, root_gen, 0, 1);
3756 BUG_ON(ret);
3757
3758 atomic_inc(&root->fs_info->throttle_gen);
3759 wake_up(&root->fs_info->transaction_throttle);
3760 cond_resched();
3761 }
3762 out:
3763 kfree(sorted);
3764
3765 /*
3766 * update the path to show we've processed the entire level 1
3767 * node. This will get saved into the root's drop_snapshot_progress
3768 * field so these drops are not repeated again if this transaction
3769 * commits.
3770 */
3771 path->slots[1] = nritems;
3772 return 0;
3773 }
3774
3775 /*
3776 * helper function for drop_snapshot, this walks down the tree dropping ref
3777 * counts as it goes.
3778 */
3779 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
3780 struct btrfs_root *root,
3781 struct btrfs_path *path, int *level)
3782 {
3783 u64 root_owner;
3784 u64 root_gen;
3785 u64 bytenr;
3786 u64 ptr_gen;
3787 struct extent_buffer *next;
3788 struct extent_buffer *cur;
3789 struct extent_buffer *parent;
3790 u32 blocksize;
3791 int ret;
3792 u32 refs;
3793
3794 WARN_ON(*level < 0);
3795 WARN_ON(*level >= BTRFS_MAX_LEVEL);
3796 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
3797 path->nodes[*level]->len, &refs);
3798 BUG_ON(ret);
3799 if (refs > 1)
3800 goto out;
3801
3802 /*
3803 * walk down to the last node level and free all the leaves
3804 */
3805 while (*level >= 0) {
3806 WARN_ON(*level < 0);
3807 WARN_ON(*level >= BTRFS_MAX_LEVEL);
3808 cur = path->nodes[*level];
3809
3810 if (btrfs_header_level(cur) != *level)
3811 WARN_ON(1);
3812
3813 if (path->slots[*level] >=
3814 btrfs_header_nritems(cur))
3815 break;
3816
3817 /* the new code goes down to level 1 and does all the
3818 * leaves pointed to that node in bulk. So, this check
3819 * for level 0 will always be false.
3820 *
3821 * But, the disk format allows the drop_snapshot_progress
3822 * field in the root to leave things in a state where
3823 * a leaf will need cleaning up here. If someone crashes
3824 * with the old code and then boots with the new code,
3825 * we might find a leaf here.
3826 */
3827 if (*level == 0) {
3828 ret = btrfs_drop_leaf_ref(trans, root, cur);
3829 BUG_ON(ret);
3830 break;
3831 }
3832
3833 /*
3834 * once we get to level one, process the whole node
3835 * at once, including everything below it.
3836 */
3837 if (*level == 1) {
3838 ret = drop_level_one_refs(trans, root, path);
3839 BUG_ON(ret);
3840 break;
3841 }
3842
3843 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
3844 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
3845 blocksize = btrfs_level_size(root, *level - 1);
3846
3847 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
3848 BUG_ON(ret);
3849
3850 /*
3851 * if there is more than one reference, we don't need
3852 * to read that node to drop any references it has. We
3853 * just drop the ref we hold on that node and move on to the
3854 * next slot in this level.
3855 */
3856 if (refs != 1) {
3857 parent = path->nodes[*level];
3858 root_owner = btrfs_header_owner(parent);
3859 root_gen = btrfs_header_generation(parent);
3860 path->slots[*level]++;
3861
3862 ret = __btrfs_free_extent(trans, root, bytenr,
3863 blocksize, parent->start,
3864 root_owner, root_gen,
3865 *level - 1, 1);
3866 BUG_ON(ret);
3867
3868 atomic_inc(&root->fs_info->throttle_gen);
3869 wake_up(&root->fs_info->transaction_throttle);
3870 cond_resched();
3871
3872 continue;
3873 }
3874
3875 /*
3876 * we need to keep freeing things in the next level down.
3877 * read the block and loop around to process it
3878 */
3879 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
3880 WARN_ON(*level <= 0);
3881 if (path->nodes[*level-1])
3882 free_extent_buffer(path->nodes[*level-1]);
3883 path->nodes[*level-1] = next;
3884 *level = btrfs_header_level(next);
3885 path->slots[*level] = 0;
3886 cond_resched();
3887 }
3888 out:
3889 WARN_ON(*level < 0);
3890 WARN_ON(*level >= BTRFS_MAX_LEVEL);
3891
3892 if (path->nodes[*level] == root->node) {
3893 parent = path->nodes[*level];
3894 bytenr = path->nodes[*level]->start;
3895 } else {
3896 parent = path->nodes[*level + 1];
3897 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
3898 }
3899
3900 blocksize = btrfs_level_size(root, *level);
3901 root_owner = btrfs_header_owner(parent);
3902 root_gen = btrfs_header_generation(parent);
3903
3904 /*
3905 * cleanup and free the reference on the last node
3906 * we processed
3907 */
3908 ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
3909 parent->start, root_owner, root_gen,
3910 *level, 1);
3911 free_extent_buffer(path->nodes[*level]);
3912 path->nodes[*level] = NULL;
3913
3914 *level += 1;
3915 BUG_ON(ret);
3916
3917 cond_resched();
3918 return 0;
3919 }
3920
3921 /*
3922 * helper function for drop_subtree, this function is similar to
3923 * walk_down_tree. The main difference is that it checks reference
3924 * counts while tree blocks are locked.
3925 */
3926 static noinline int walk_down_subtree(struct btrfs_trans_handle *trans,
3927 struct btrfs_root *root,
3928 struct btrfs_path *path, int *level)
3929 {
3930 struct extent_buffer *next;
3931 struct extent_buffer *cur;
3932 struct extent_buffer *parent;
3933 u64 bytenr;
3934 u64 ptr_gen;
3935 u32 blocksize;
3936 u32 refs;
3937 int ret;
3938
3939 cur = path->nodes[*level];
3940 ret = btrfs_lookup_extent_ref(trans, root, cur->start, cur->len,
3941 &refs);
3942 BUG_ON(ret);
3943 if (refs > 1)
3944 goto out;
3945
3946 while (*level >= 0) {
3947 cur = path->nodes[*level];
3948 if (*level == 0) {
3949 ret = btrfs_drop_leaf_ref(trans, root, cur);
3950 BUG_ON(ret);
3951 clean_tree_block(trans, root, cur);
3952 break;
3953 }
3954 if (path->slots[*level] >= btrfs_header_nritems(cur)) {
3955 clean_tree_block(trans, root, cur);
3956 break;
3957 }
3958
3959 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
3960 blocksize = btrfs_level_size(root, *level - 1);
3961 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
3962
3963 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
3964 btrfs_tree_lock(next);
3965 btrfs_set_lock_blocking(next);
3966
3967 ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize,
3968 &refs);
3969 BUG_ON(ret);
3970 if (refs > 1) {
3971 parent = path->nodes[*level];
3972 ret = btrfs_free_extent(trans, root, bytenr,
3973 blocksize, parent->start,
3974 btrfs_header_owner(parent),
3975 btrfs_header_generation(parent),
3976 *level - 1, 1);
3977 BUG_ON(ret);
3978 path->slots[*level]++;
3979 btrfs_tree_unlock(next);
3980 free_extent_buffer(next);
3981 continue;
3982 }
3983
3984 *level = btrfs_header_level(next);
3985 path->nodes[*level] = next;
3986 path->slots[*level] = 0;
3987 path->locks[*level] = 1;
3988 cond_resched();
3989 }
3990 out:
3991 parent = path->nodes[*level + 1];
3992 bytenr = path->nodes[*level]->start;
3993 blocksize = path->nodes[*level]->len;
3994
3995 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
3996 parent->start, btrfs_header_owner(parent),
3997 btrfs_header_generation(parent), *level, 1);
3998 BUG_ON(ret);
3999
4000 if (path->locks[*level]) {
4001 btrfs_tree_unlock(path->nodes[*level]);
4002 path->locks[*level] = 0;
4003 }
4004 free_extent_buffer(path->nodes[*level]);
4005 path->nodes[*level] = NULL;
4006 *level += 1;
4007 cond_resched();
4008 return 0;
4009 }
4010
4011 /*
4012 * helper for dropping snapshots. This walks back up the tree in the path
4013 * to find the first node higher up where we haven't yet gone through
4014 * all the slots
4015 */
4016 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
4017 struct btrfs_root *root,
4018 struct btrfs_path *path,
4019 int *level, int max_level)
4020 {
4021 u64 root_owner;
4022 u64 root_gen;
4023 struct btrfs_root_item *root_item = &root->root_item;
4024 int i;
4025 int slot;
4026 int ret;
4027
4028 for (i = *level; i < max_level && path->nodes[i]; i++) {
4029 slot = path->slots[i];
4030 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
4031 struct extent_buffer *node;
4032 struct btrfs_disk_key disk_key;
4033
4034 /*
4035 * there is more work to do in this level.
4036 * Update the drop_progress marker to reflect
4037 * the work we've done so far, and then bump
4038 * the slot number
4039 */
4040 node = path->nodes[i];
4041 path->slots[i]++;
4042 *level = i;
4043 WARN_ON(*level == 0);
4044 btrfs_node_key(node, &disk_key, path->slots[i]);
4045 memcpy(&root_item->drop_progress,
4046 &disk_key, sizeof(disk_key));
4047 root_item->drop_level = i;
4048 return 0;
4049 } else {
4050 struct extent_buffer *parent;
4051
4052 /*
4053 * this whole node is done, free our reference
4054 * on it and go up one level
4055 */
4056 if (path->nodes[*level] == root->node)
4057 parent = path->nodes[*level];
4058 else
4059 parent = path->nodes[*level + 1];
4060
4061 root_owner = btrfs_header_owner(parent);
4062 root_gen = btrfs_header_generation(parent);
4063
4064 clean_tree_block(trans, root, path->nodes[*level]);
4065 ret = btrfs_free_extent(trans, root,
4066 path->nodes[*level]->start,
4067 path->nodes[*level]->len,
4068 parent->start, root_owner,
4069 root_gen, *level, 1);
4070 BUG_ON(ret);
4071 if (path->locks[*level]) {
4072 btrfs_tree_unlock(path->nodes[*level]);
4073 path->locks[*level] = 0;
4074 }
4075 free_extent_buffer(path->nodes[*level]);
4076 path->nodes[*level] = NULL;
4077 *level = i + 1;
4078 }
4079 }
4080 return 1;
4081 }
4082
4083 /*
4084 * drop the reference count on the tree rooted at 'snap'. This traverses
4085 * the tree freeing any blocks that have a ref count of zero after being
4086 * decremented.
4087 */
4088 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
4089 *root)
4090 {
4091 int ret = 0;
4092 int wret;
4093 int level;
4094 struct btrfs_path *path;
4095 int i;
4096 int orig_level;
4097 struct btrfs_root_item *root_item = &root->root_item;
4098
4099 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
4100 path = btrfs_alloc_path();
4101 BUG_ON(!path);
4102
4103 level = btrfs_header_level(root->node);
4104 orig_level = level;
4105 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
4106 path->nodes[level] = root->node;
4107 extent_buffer_get(root->node);
4108 path->slots[level] = 0;
4109 } else {
4110 struct btrfs_key key;
4111 struct btrfs_disk_key found_key;
4112 struct extent_buffer *node;
4113
4114 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
4115 level = root_item->drop_level;
4116 path->lowest_level = level;
4117 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4118 if (wret < 0) {
4119 ret = wret;
4120 goto out;
4121 }
4122 node = path->nodes[level];
4123 btrfs_node_key(node, &found_key, path->slots[level]);
4124 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
4125 sizeof(found_key)));
4126 /*
4127 * unlock our path, this is safe because only this
4128 * function is allowed to delete this snapshot
4129 */
4130 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4131 if (path->nodes[i] && path->locks[i]) {
4132 path->locks[i] = 0;
4133 btrfs_tree_unlock(path->nodes[i]);
4134 }
4135 }
4136 }
4137 while (1) {
4138 wret = walk_down_tree(trans, root, path, &level);
4139 if (wret > 0)
4140 break;
4141 if (wret < 0)
4142 ret = wret;
4143
4144 wret = walk_up_tree(trans, root, path, &level,
4145 BTRFS_MAX_LEVEL);
4146 if (wret > 0)
4147 break;
4148 if (wret < 0)
4149 ret = wret;
4150 if (trans->transaction->in_commit) {
4151 ret = -EAGAIN;
4152 break;
4153 }
4154 atomic_inc(&root->fs_info->throttle_gen);
4155 wake_up(&root->fs_info->transaction_throttle);
4156 }
4157 for (i = 0; i <= orig_level; i++) {
4158 if (path->nodes[i]) {
4159 free_extent_buffer(path->nodes[i]);
4160 path->nodes[i] = NULL;
4161 }
4162 }
4163 out:
4164 btrfs_free_path(path);
4165 return ret;
4166 }
4167
4168 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
4169 struct btrfs_root *root,
4170 struct extent_buffer *node,
4171 struct extent_buffer *parent)
4172 {
4173 struct btrfs_path *path;
4174 int level;
4175 int parent_level;
4176 int ret = 0;
4177 int wret;
4178
4179 path = btrfs_alloc_path();
4180 BUG_ON(!path);
4181
4182 BUG_ON(!btrfs_tree_locked(parent));
4183 parent_level = btrfs_header_level(parent);
4184 extent_buffer_get(parent);
4185 path->nodes[parent_level] = parent;
4186 path->slots[parent_level] = btrfs_header_nritems(parent);
4187
4188 BUG_ON(!btrfs_tree_locked(node));
4189 level = btrfs_header_level(node);
4190 extent_buffer_get(node);
4191 path->nodes[level] = node;
4192 path->slots[level] = 0;
4193
4194 while (1) {
4195 wret = walk_down_subtree(trans, root, path, &level);
4196 if (wret < 0)
4197 ret = wret;
4198 if (wret != 0)
4199 break;
4200
4201 wret = walk_up_tree(trans, root, path, &level, parent_level);
4202 if (wret < 0)
4203 ret = wret;
4204 if (wret != 0)
4205 break;
4206 }
4207
4208 btrfs_free_path(path);
4209 return ret;
4210 }
4211
4212 static unsigned long calc_ra(unsigned long start, unsigned long last,
4213 unsigned long nr)
4214 {
4215 return min(last, start + nr - 1);
4216 }
4217
4218 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
4219 u64 len)
4220 {
4221 u64 page_start;
4222 u64 page_end;
4223 unsigned long first_index;
4224 unsigned long last_index;
4225 unsigned long i;
4226 struct page *page;
4227 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4228 struct file_ra_state *ra;
4229 struct btrfs_ordered_extent *ordered;
4230 unsigned int total_read = 0;
4231 unsigned int total_dirty = 0;
4232 int ret = 0;
4233
4234 ra = kzalloc(sizeof(*ra), GFP_NOFS);
4235
4236 mutex_lock(&inode->i_mutex);
4237 first_index = start >> PAGE_CACHE_SHIFT;
4238 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
4239
4240 /* make sure the dirty trick played by the caller work */
4241 ret = invalidate_inode_pages2_range(inode->i_mapping,
4242 first_index, last_index);
4243 if (ret)
4244 goto out_unlock;
4245
4246 file_ra_state_init(ra, inode->i_mapping);
4247
4248 for (i = first_index ; i <= last_index; i++) {
4249 if (total_read % ra->ra_pages == 0) {
4250 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
4251 calc_ra(i, last_index, ra->ra_pages));
4252 }
4253 total_read++;
4254 again:
4255 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
4256 BUG_ON(1);
4257 page = grab_cache_page(inode->i_mapping, i);
4258 if (!page) {
4259 ret = -ENOMEM;
4260 goto out_unlock;
4261 }
4262 if (!PageUptodate(page)) {
4263 btrfs_readpage(NULL, page);
4264 lock_page(page);
4265 if (!PageUptodate(page)) {
4266 unlock_page(page);
4267 page_cache_release(page);
4268 ret = -EIO;
4269 goto out_unlock;
4270 }
4271 }
4272 wait_on_page_writeback(page);
4273
4274 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
4275 page_end = page_start + PAGE_CACHE_SIZE - 1;
4276 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
4277
4278 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4279 if (ordered) {
4280 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
4281 unlock_page(page);
4282 page_cache_release(page);
4283 btrfs_start_ordered_extent(inode, ordered, 1);
4284 btrfs_put_ordered_extent(ordered);
4285 goto again;
4286 }
4287 set_page_extent_mapped(page);
4288
4289 if (i == first_index)
4290 set_extent_bits(io_tree, page_start, page_end,
4291 EXTENT_BOUNDARY, GFP_NOFS);
4292 btrfs_set_extent_delalloc(inode, page_start, page_end);
4293
4294 set_page_dirty(page);
4295 total_dirty++;
4296
4297 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
4298 unlock_page(page);
4299 page_cache_release(page);
4300 }
4301
4302 out_unlock:
4303 kfree(ra);
4304 mutex_unlock(&inode->i_mutex);
4305 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
4306 return ret;
4307 }
4308
4309 static noinline int relocate_data_extent(struct inode *reloc_inode,
4310 struct btrfs_key *extent_key,
4311 u64 offset)
4312 {
4313 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
4314 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
4315 struct extent_map *em;
4316 u64 start = extent_key->objectid - offset;
4317 u64 end = start + extent_key->offset - 1;
4318
4319 em = alloc_extent_map(GFP_NOFS);
4320 BUG_ON(!em || IS_ERR(em));
4321
4322 em->start = start;
4323 em->len = extent_key->offset;
4324 em->block_len = extent_key->offset;
4325 em->block_start = extent_key->objectid;
4326 em->bdev = root->fs_info->fs_devices->latest_bdev;
4327 set_bit(EXTENT_FLAG_PINNED, &em->flags);
4328
4329 /* setup extent map to cheat btrfs_readpage */
4330 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
4331 while (1) {
4332 int ret;
4333 spin_lock(&em_tree->lock);
4334 ret = add_extent_mapping(em_tree, em);
4335 spin_unlock(&em_tree->lock);
4336 if (ret != -EEXIST) {
4337 free_extent_map(em);
4338 break;
4339 }
4340 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
4341 }
4342 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
4343
4344 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
4345 }
4346
4347 struct btrfs_ref_path {
4348 u64 extent_start;
4349 u64 nodes[BTRFS_MAX_LEVEL];
4350 u64 root_objectid;
4351 u64 root_generation;
4352 u64 owner_objectid;
4353 u32 num_refs;
4354 int lowest_level;
4355 int current_level;
4356 int shared_level;
4357
4358 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
4359 u64 new_nodes[BTRFS_MAX_LEVEL];
4360 };
4361
4362 struct disk_extent {
4363 u64 ram_bytes;
4364 u64 disk_bytenr;
4365 u64 disk_num_bytes;
4366 u64 offset;
4367 u64 num_bytes;
4368 u8 compression;
4369 u8 encryption;
4370 u16 other_encoding;
4371 };
4372
4373 static int is_cowonly_root(u64 root_objectid)
4374 {
4375 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
4376 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
4377 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
4378 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
4379 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
4380 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
4381 return 1;
4382 return 0;
4383 }
4384
4385 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
4386 struct btrfs_root *extent_root,
4387 struct btrfs_ref_path *ref_path,
4388 int first_time)
4389 {
4390 struct extent_buffer *leaf;
4391 struct btrfs_path *path;
4392 struct btrfs_extent_ref *ref;
4393 struct btrfs_key key;
4394 struct btrfs_key found_key;
4395 u64 bytenr;
4396 u32 nritems;
4397 int level;
4398 int ret = 1;
4399
4400 path = btrfs_alloc_path();
4401 if (!path)
4402 return -ENOMEM;
4403
4404 if (first_time) {
4405 ref_path->lowest_level = -1;
4406 ref_path->current_level = -1;
4407 ref_path->shared_level = -1;
4408 goto walk_up;
4409 }
4410 walk_down:
4411 level = ref_path->current_level - 1;
4412 while (level >= -1) {
4413 u64 parent;
4414 if (level < ref_path->lowest_level)
4415 break;
4416
4417 if (level >= 0)
4418 bytenr = ref_path->nodes[level];
4419 else
4420 bytenr = ref_path->extent_start;
4421 BUG_ON(bytenr == 0);
4422
4423 parent = ref_path->nodes[level + 1];
4424 ref_path->nodes[level + 1] = 0;
4425 ref_path->current_level = level;
4426 BUG_ON(parent == 0);
4427
4428 key.objectid = bytenr;
4429 key.offset = parent + 1;
4430 key.type = BTRFS_EXTENT_REF_KEY;
4431
4432 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
4433 if (ret < 0)
4434 goto out;
4435 BUG_ON(ret == 0);
4436
4437 leaf = path->nodes[0];
4438 nritems = btrfs_header_nritems(leaf);
4439 if (path->slots[0] >= nritems) {
4440 ret = btrfs_next_leaf(extent_root, path);
4441 if (ret < 0)
4442 goto out;
4443 if (ret > 0)
4444 goto next;
4445 leaf = path->nodes[0];
4446 }
4447
4448 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4449 if (found_key.objectid == bytenr &&
4450 found_key.type == BTRFS_EXTENT_REF_KEY) {
4451 if (level < ref_path->shared_level)
4452 ref_path->shared_level = level;
4453 goto found;
4454 }
4455 next:
4456 level--;
4457 btrfs_release_path(extent_root, path);
4458 cond_resched();
4459 }
4460 /* reached lowest level */
4461 ret = 1;
4462 goto out;
4463 walk_up:
4464 level = ref_path->current_level;
4465 while (level < BTRFS_MAX_LEVEL - 1) {
4466 u64 ref_objectid;
4467
4468 if (level >= 0)
4469 bytenr = ref_path->nodes[level];
4470 else
4471 bytenr = ref_path->extent_start;
4472
4473 BUG_ON(bytenr == 0);
4474
4475 key.objectid = bytenr;
4476 key.offset = 0;
4477 key.type = BTRFS_EXTENT_REF_KEY;
4478
4479 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
4480 if (ret < 0)
4481 goto out;
4482
4483 leaf = path->nodes[0];
4484 nritems = btrfs_header_nritems(leaf);
4485 if (path->slots[0] >= nritems) {
4486 ret = btrfs_next_leaf(extent_root, path);
4487 if (ret < 0)
4488 goto out;
4489 if (ret > 0) {
4490 /* the extent was freed by someone */
4491 if (ref_path->lowest_level == level)
4492 goto out;
4493 btrfs_release_path(extent_root, path);
4494 goto walk_down;
4495 }
4496 leaf = path->nodes[0];
4497 }
4498
4499 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4500 if (found_key.objectid != bytenr ||
4501 found_key.type != BTRFS_EXTENT_REF_KEY) {
4502 /* the extent was freed by someone */
4503 if (ref_path->lowest_level == level) {
4504 ret = 1;
4505 goto out;
4506 }
4507 btrfs_release_path(extent_root, path);
4508 goto walk_down;
4509 }
4510 found:
4511 ref = btrfs_item_ptr(leaf, path->slots[0],
4512 struct btrfs_extent_ref);
4513 ref_objectid = btrfs_ref_objectid(leaf, ref);
4514 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
4515 if (first_time) {
4516 level = (int)ref_objectid;
4517 BUG_ON(level >= BTRFS_MAX_LEVEL);
4518 ref_path->lowest_level = level;
4519 ref_path->current_level = level;
4520 ref_path->nodes[level] = bytenr;
4521 } else {
4522 WARN_ON(ref_objectid != level);
4523 }
4524 } else {
4525 WARN_ON(level != -1);
4526 }
4527 first_time = 0;
4528
4529 if (ref_path->lowest_level == level) {
4530 ref_path->owner_objectid = ref_objectid;
4531 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
4532 }
4533
4534 /*
4535 * the block is tree root or the block isn't in reference
4536 * counted tree.
4537 */
4538 if (found_key.objectid == found_key.offset ||
4539 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
4540 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
4541 ref_path->root_generation =
4542 btrfs_ref_generation(leaf, ref);
4543 if (level < 0) {
4544 /* special reference from the tree log */
4545 ref_path->nodes[0] = found_key.offset;
4546 ref_path->current_level = 0;
4547 }
4548 ret = 0;
4549 goto out;
4550 }
4551
4552 level++;
4553 BUG_ON(ref_path->nodes[level] != 0);
4554 ref_path->nodes[level] = found_key.offset;
4555 ref_path->current_level = level;
4556
4557 /*
4558 * the reference was created in the running transaction,
4559 * no need to continue walking up.
4560 */
4561 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
4562 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
4563 ref_path->root_generation =
4564 btrfs_ref_generation(leaf, ref);
4565 ret = 0;
4566 goto out;
4567 }
4568
4569 btrfs_release_path(extent_root, path);
4570 cond_resched();
4571 }
4572 /* reached max tree level, but no tree root found. */
4573 BUG();
4574 out:
4575 btrfs_free_path(path);
4576 return ret;
4577 }
4578
4579 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
4580 struct btrfs_root *extent_root,
4581 struct btrfs_ref_path *ref_path,
4582 u64 extent_start)
4583 {
4584 memset(ref_path, 0, sizeof(*ref_path));
4585 ref_path->extent_start = extent_start;
4586
4587 return __next_ref_path(trans, extent_root, ref_path, 1);
4588 }
4589
4590 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
4591 struct btrfs_root *extent_root,
4592 struct btrfs_ref_path *ref_path)
4593 {
4594 return __next_ref_path(trans, extent_root, ref_path, 0);
4595 }
4596
4597 static noinline int get_new_locations(struct inode *reloc_inode,
4598 struct btrfs_key *extent_key,
4599 u64 offset, int no_fragment,
4600 struct disk_extent **extents,
4601 int *nr_extents)
4602 {
4603 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
4604 struct btrfs_path *path;
4605 struct btrfs_file_extent_item *fi;
4606 struct extent_buffer *leaf;
4607 struct disk_extent *exts = *extents;
4608 struct btrfs_key found_key;
4609 u64 cur_pos;
4610 u64 last_byte;
4611 u32 nritems;
4612 int nr = 0;
4613 int max = *nr_extents;
4614 int ret;
4615
4616 WARN_ON(!no_fragment && *extents);
4617 if (!exts) {
4618 max = 1;
4619 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
4620 if (!exts)
4621 return -ENOMEM;
4622 }
4623
4624 path = btrfs_alloc_path();
4625 BUG_ON(!path);
4626
4627 cur_pos = extent_key->objectid - offset;
4628 last_byte = extent_key->objectid + extent_key->offset;
4629 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
4630 cur_pos, 0);
4631 if (ret < 0)
4632 goto out;
4633 if (ret > 0) {
4634 ret = -ENOENT;
4635 goto out;
4636 }
4637
4638 while (1) {
4639 leaf = path->nodes[0];
4640 nritems = btrfs_header_nritems(leaf);
4641 if (path->slots[0] >= nritems) {
4642 ret = btrfs_next_leaf(root, path);
4643 if (ret < 0)
4644 goto out;
4645 if (ret > 0)
4646 break;
4647 leaf = path->nodes[0];
4648 }
4649
4650 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4651 if (found_key.offset != cur_pos ||
4652 found_key.type != BTRFS_EXTENT_DATA_KEY ||
4653 found_key.objectid != reloc_inode->i_ino)
4654 break;
4655
4656 fi = btrfs_item_ptr(leaf, path->slots[0],
4657 struct btrfs_file_extent_item);
4658 if (btrfs_file_extent_type(leaf, fi) !=
4659 BTRFS_FILE_EXTENT_REG ||
4660 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
4661 break;
4662
4663 if (nr == max) {
4664 struct disk_extent *old = exts;
4665 max *= 2;
4666 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
4667 memcpy(exts, old, sizeof(*exts) * nr);
4668 if (old != *extents)
4669 kfree(old);
4670 }
4671
4672 exts[nr].disk_bytenr =
4673 btrfs_file_extent_disk_bytenr(leaf, fi);
4674 exts[nr].disk_num_bytes =
4675 btrfs_file_extent_disk_num_bytes(leaf, fi);
4676 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
4677 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4678 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
4679 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
4680 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
4681 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
4682 fi);
4683 BUG_ON(exts[nr].offset > 0);
4684 BUG_ON(exts[nr].compression || exts[nr].encryption);
4685 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
4686
4687 cur_pos += exts[nr].num_bytes;
4688 nr++;
4689
4690 if (cur_pos + offset >= last_byte)
4691 break;
4692
4693 if (no_fragment) {
4694 ret = 1;
4695 goto out;
4696 }
4697 path->slots[0]++;
4698 }
4699
4700 BUG_ON(cur_pos + offset > last_byte);
4701 if (cur_pos + offset < last_byte) {
4702 ret = -ENOENT;
4703 goto out;
4704 }
4705 ret = 0;
4706 out:
4707 btrfs_free_path(path);
4708 if (ret) {
4709 if (exts != *extents)
4710 kfree(exts);
4711 } else {
4712 *extents = exts;
4713 *nr_extents = nr;
4714 }
4715 return ret;
4716 }
4717
4718 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
4719 struct btrfs_root *root,
4720 struct btrfs_path *path,
4721 struct btrfs_key *extent_key,
4722 struct btrfs_key *leaf_key,
4723 struct btrfs_ref_path *ref_path,
4724 struct disk_extent *new_extents,
4725 int nr_extents)
4726 {
4727 struct extent_buffer *leaf;
4728 struct btrfs_file_extent_item *fi;
4729 struct inode *inode = NULL;
4730 struct btrfs_key key;
4731 u64 lock_start = 0;
4732 u64 lock_end = 0;
4733 u64 num_bytes;
4734 u64 ext_offset;
4735 u64 search_end = (u64)-1;
4736 u32 nritems;
4737 int nr_scaned = 0;
4738 int extent_locked = 0;
4739 int extent_type;
4740 int ret;
4741
4742 memcpy(&key, leaf_key, sizeof(key));
4743 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
4744 if (key.objectid < ref_path->owner_objectid ||
4745 (key.objectid == ref_path->owner_objectid &&
4746 key.type < BTRFS_EXTENT_DATA_KEY)) {
4747 key.objectid = ref_path->owner_objectid;
4748 key.type = BTRFS_EXTENT_DATA_KEY;
4749 key.offset = 0;
4750 }
4751 }
4752
4753 while (1) {
4754 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
4755 if (ret < 0)
4756 goto out;
4757
4758 leaf = path->nodes[0];
4759 nritems = btrfs_header_nritems(leaf);
4760 next:
4761 if (extent_locked && ret > 0) {
4762 /*
4763 * the file extent item was modified by someone
4764 * before the extent got locked.
4765 */
4766 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
4767 lock_end, GFP_NOFS);
4768 extent_locked = 0;
4769 }
4770
4771 if (path->slots[0] >= nritems) {
4772 if (++nr_scaned > 2)
4773 break;
4774
4775 BUG_ON(extent_locked);
4776 ret = btrfs_next_leaf(root, path);
4777 if (ret < 0)
4778 goto out;
4779 if (ret > 0)
4780 break;
4781 leaf = path->nodes[0];
4782 nritems = btrfs_header_nritems(leaf);
4783 }
4784
4785 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4786
4787 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
4788 if ((key.objectid > ref_path->owner_objectid) ||
4789 (key.objectid == ref_path->owner_objectid &&
4790 key.type > BTRFS_EXTENT_DATA_KEY) ||
4791 key.offset >= search_end)
4792 break;
4793 }
4794
4795 if (inode && key.objectid != inode->i_ino) {
4796 BUG_ON(extent_locked);
4797 btrfs_release_path(root, path);
4798 mutex_unlock(&inode->i_mutex);
4799 iput(inode);
4800 inode = NULL;
4801 continue;
4802 }
4803
4804 if (key.type != BTRFS_EXTENT_DATA_KEY) {
4805 path->slots[0]++;
4806 ret = 1;
4807 goto next;
4808 }
4809 fi = btrfs_item_ptr(leaf, path->slots[0],
4810 struct btrfs_file_extent_item);
4811 extent_type = btrfs_file_extent_type(leaf, fi);
4812 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
4813 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
4814 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
4815 extent_key->objectid)) {
4816 path->slots[0]++;
4817 ret = 1;
4818 goto next;
4819 }
4820
4821 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4822 ext_offset = btrfs_file_extent_offset(leaf, fi);
4823
4824 if (search_end == (u64)-1) {
4825 search_end = key.offset - ext_offset +
4826 btrfs_file_extent_ram_bytes(leaf, fi);
4827 }
4828
4829 if (!extent_locked) {
4830 lock_start = key.offset;
4831 lock_end = lock_start + num_bytes - 1;
4832 } else {
4833 if (lock_start > key.offset ||
4834 lock_end + 1 < key.offset + num_bytes) {
4835 unlock_extent(&BTRFS_I(inode)->io_tree,
4836 lock_start, lock_end, GFP_NOFS);
4837 extent_locked = 0;
4838 }
4839 }
4840
4841 if (!inode) {
4842 btrfs_release_path(root, path);
4843
4844 inode = btrfs_iget_locked(root->fs_info->sb,
4845 key.objectid, root);
4846 if (inode->i_state & I_NEW) {
4847 BTRFS_I(inode)->root = root;
4848 BTRFS_I(inode)->location.objectid =
4849 key.objectid;
4850 BTRFS_I(inode)->location.type =
4851 BTRFS_INODE_ITEM_KEY;
4852 BTRFS_I(inode)->location.offset = 0;
4853 btrfs_read_locked_inode(inode);
4854 unlock_new_inode(inode);
4855 }
4856 /*
4857 * some code call btrfs_commit_transaction while
4858 * holding the i_mutex, so we can't use mutex_lock
4859 * here.
4860 */
4861 if (is_bad_inode(inode) ||
4862 !mutex_trylock(&inode->i_mutex)) {
4863 iput(inode);
4864 inode = NULL;
4865 key.offset = (u64)-1;
4866 goto skip;
4867 }
4868 }
4869
4870 if (!extent_locked) {
4871 struct btrfs_ordered_extent *ordered;
4872
4873 btrfs_release_path(root, path);
4874
4875 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
4876 lock_end, GFP_NOFS);
4877 ordered = btrfs_lookup_first_ordered_extent(inode,
4878 lock_end);
4879 if (ordered &&
4880 ordered->file_offset <= lock_end &&
4881 ordered->file_offset + ordered->len > lock_start) {
4882 unlock_extent(&BTRFS_I(inode)->io_tree,
4883 lock_start, lock_end, GFP_NOFS);
4884 btrfs_start_ordered_extent(inode, ordered, 1);
4885 btrfs_put_ordered_extent(ordered);
4886 key.offset += num_bytes;
4887 goto skip;
4888 }
4889 if (ordered)
4890 btrfs_put_ordered_extent(ordered);
4891
4892 extent_locked = 1;
4893 continue;
4894 }
4895
4896 if (nr_extents == 1) {
4897 /* update extent pointer in place */
4898 btrfs_set_file_extent_disk_bytenr(leaf, fi,
4899 new_extents[0].disk_bytenr);
4900 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4901 new_extents[0].disk_num_bytes);
4902 btrfs_mark_buffer_dirty(leaf);
4903
4904 btrfs_drop_extent_cache(inode, key.offset,
4905 key.offset + num_bytes - 1, 0);
4906
4907 ret = btrfs_inc_extent_ref(trans, root,
4908 new_extents[0].disk_bytenr,
4909 new_extents[0].disk_num_bytes,
4910 leaf->start,
4911 root->root_key.objectid,
4912 trans->transid,
4913 key.objectid);
4914 BUG_ON(ret);
4915
4916 ret = btrfs_free_extent(trans, root,
4917 extent_key->objectid,
4918 extent_key->offset,
4919 leaf->start,
4920 btrfs_header_owner(leaf),
4921 btrfs_header_generation(leaf),
4922 key.objectid, 0);
4923 BUG_ON(ret);
4924
4925 btrfs_release_path(root, path);
4926 key.offset += num_bytes;
4927 } else {
4928 BUG_ON(1);
4929 #if 0
4930 u64 alloc_hint;
4931 u64 extent_len;
4932 int i;
4933 /*
4934 * drop old extent pointer at first, then insert the
4935 * new pointers one bye one
4936 */
4937 btrfs_release_path(root, path);
4938 ret = btrfs_drop_extents(trans, root, inode, key.offset,
4939 key.offset + num_bytes,
4940 key.offset, &alloc_hint);
4941 BUG_ON(ret);
4942
4943 for (i = 0; i < nr_extents; i++) {
4944 if (ext_offset >= new_extents[i].num_bytes) {
4945 ext_offset -= new_extents[i].num_bytes;
4946 continue;
4947 }
4948 extent_len = min(new_extents[i].num_bytes -
4949 ext_offset, num_bytes);
4950
4951 ret = btrfs_insert_empty_item(trans, root,
4952 path, &key,
4953 sizeof(*fi));
4954 BUG_ON(ret);
4955
4956 leaf = path->nodes[0];
4957 fi = btrfs_item_ptr(leaf, path->slots[0],
4958 struct btrfs_file_extent_item);
4959 btrfs_set_file_extent_generation(leaf, fi,
4960 trans->transid);
4961 btrfs_set_file_extent_type(leaf, fi,
4962 BTRFS_FILE_EXTENT_REG);
4963 btrfs_set_file_extent_disk_bytenr(leaf, fi,
4964 new_extents[i].disk_bytenr);
4965 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4966 new_extents[i].disk_num_bytes);
4967 btrfs_set_file_extent_ram_bytes(leaf, fi,
4968 new_extents[i].ram_bytes);
4969
4970 btrfs_set_file_extent_compression(leaf, fi,
4971 new_extents[i].compression);
4972 btrfs_set_file_extent_encryption(leaf, fi,
4973 new_extents[i].encryption);
4974 btrfs_set_file_extent_other_encoding(leaf, fi,
4975 new_extents[i].other_encoding);
4976
4977 btrfs_set_file_extent_num_bytes(leaf, fi,
4978 extent_len);
4979 ext_offset += new_extents[i].offset;
4980 btrfs_set_file_extent_offset(leaf, fi,
4981 ext_offset);
4982 btrfs_mark_buffer_dirty(leaf);
4983
4984 btrfs_drop_extent_cache(inode, key.offset,
4985 key.offset + extent_len - 1, 0);
4986
4987 ret = btrfs_inc_extent_ref(trans, root,
4988 new_extents[i].disk_bytenr,
4989 new_extents[i].disk_num_bytes,
4990 leaf->start,
4991 root->root_key.objectid,
4992 trans->transid, key.objectid);
4993 BUG_ON(ret);
4994 btrfs_release_path(root, path);
4995
4996 inode_add_bytes(inode, extent_len);
4997
4998 ext_offset = 0;
4999 num_bytes -= extent_len;
5000 key.offset += extent_len;
5001
5002 if (num_bytes == 0)
5003 break;
5004 }
5005 BUG_ON(i >= nr_extents);
5006 #endif
5007 }
5008
5009 if (extent_locked) {
5010 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5011 lock_end, GFP_NOFS);
5012 extent_locked = 0;
5013 }
5014 skip:
5015 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
5016 key.offset >= search_end)
5017 break;
5018
5019 cond_resched();
5020 }
5021 ret = 0;
5022 out:
5023 btrfs_release_path(root, path);
5024 if (inode) {
5025 mutex_unlock(&inode->i_mutex);
5026 if (extent_locked) {
5027 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5028 lock_end, GFP_NOFS);
5029 }
5030 iput(inode);
5031 }
5032 return ret;
5033 }
5034
5035 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
5036 struct btrfs_root *root,
5037 struct extent_buffer *buf, u64 orig_start)
5038 {
5039 int level;
5040 int ret;
5041
5042 BUG_ON(btrfs_header_generation(buf) != trans->transid);
5043 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5044
5045 level = btrfs_header_level(buf);
5046 if (level == 0) {
5047 struct btrfs_leaf_ref *ref;
5048 struct btrfs_leaf_ref *orig_ref;
5049
5050 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
5051 if (!orig_ref)
5052 return -ENOENT;
5053
5054 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
5055 if (!ref) {
5056 btrfs_free_leaf_ref(root, orig_ref);
5057 return -ENOMEM;
5058 }
5059
5060 ref->nritems = orig_ref->nritems;
5061 memcpy(ref->extents, orig_ref->extents,
5062 sizeof(ref->extents[0]) * ref->nritems);
5063
5064 btrfs_free_leaf_ref(root, orig_ref);
5065
5066 ref->root_gen = trans->transid;
5067 ref->bytenr = buf->start;
5068 ref->owner = btrfs_header_owner(buf);
5069 ref->generation = btrfs_header_generation(buf);
5070
5071 ret = btrfs_add_leaf_ref(root, ref, 0);
5072 WARN_ON(ret);
5073 btrfs_free_leaf_ref(root, ref);
5074 }
5075 return 0;
5076 }
5077
5078 static noinline int invalidate_extent_cache(struct btrfs_root *root,
5079 struct extent_buffer *leaf,
5080 struct btrfs_block_group_cache *group,
5081 struct btrfs_root *target_root)
5082 {
5083 struct btrfs_key key;
5084 struct inode *inode = NULL;
5085 struct btrfs_file_extent_item *fi;
5086 u64 num_bytes;
5087 u64 skip_objectid = 0;
5088 u32 nritems;
5089 u32 i;
5090
5091 nritems = btrfs_header_nritems(leaf);
5092 for (i = 0; i < nritems; i++) {
5093 btrfs_item_key_to_cpu(leaf, &key, i);
5094 if (key.objectid == skip_objectid ||
5095 key.type != BTRFS_EXTENT_DATA_KEY)
5096 continue;
5097 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
5098 if (btrfs_file_extent_type(leaf, fi) ==
5099 BTRFS_FILE_EXTENT_INLINE)
5100 continue;
5101 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
5102 continue;
5103 if (!inode || inode->i_ino != key.objectid) {
5104 iput(inode);
5105 inode = btrfs_ilookup(target_root->fs_info->sb,
5106 key.objectid, target_root, 1);
5107 }
5108 if (!inode) {
5109 skip_objectid = key.objectid;
5110 continue;
5111 }
5112 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5113
5114 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
5115 key.offset + num_bytes - 1, GFP_NOFS);
5116 btrfs_drop_extent_cache(inode, key.offset,
5117 key.offset + num_bytes - 1, 1);
5118 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
5119 key.offset + num_bytes - 1, GFP_NOFS);
5120 cond_resched();
5121 }
5122 iput(inode);
5123 return 0;
5124 }
5125
5126 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
5127 struct btrfs_root *root,
5128 struct extent_buffer *leaf,
5129 struct btrfs_block_group_cache *group,
5130 struct inode *reloc_inode)
5131 {
5132 struct btrfs_key key;
5133 struct btrfs_key extent_key;
5134 struct btrfs_file_extent_item *fi;
5135 struct btrfs_leaf_ref *ref;
5136 struct disk_extent *new_extent;
5137 u64 bytenr;
5138 u64 num_bytes;
5139 u32 nritems;
5140 u32 i;
5141 int ext_index;
5142 int nr_extent;
5143 int ret;
5144
5145 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
5146 BUG_ON(!new_extent);
5147
5148 ref = btrfs_lookup_leaf_ref(root, leaf->start);
5149 BUG_ON(!ref);
5150
5151 ext_index = -1;
5152 nritems = btrfs_header_nritems(leaf);
5153 for (i = 0; i < nritems; i++) {
5154 btrfs_item_key_to_cpu(leaf, &key, i);
5155 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
5156 continue;
5157 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
5158 if (btrfs_file_extent_type(leaf, fi) ==
5159 BTRFS_FILE_EXTENT_INLINE)
5160 continue;
5161 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
5162 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
5163 if (bytenr == 0)
5164 continue;
5165
5166 ext_index++;
5167 if (bytenr >= group->key.objectid + group->key.offset ||
5168 bytenr + num_bytes <= group->key.objectid)
5169 continue;
5170
5171 extent_key.objectid = bytenr;
5172 extent_key.offset = num_bytes;
5173 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
5174 nr_extent = 1;
5175 ret = get_new_locations(reloc_inode, &extent_key,
5176 group->key.objectid, 1,
5177 &new_extent, &nr_extent);
5178 if (ret > 0)
5179 continue;
5180 BUG_ON(ret < 0);
5181
5182 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
5183 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
5184 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
5185 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
5186
5187 btrfs_set_file_extent_disk_bytenr(leaf, fi,
5188 new_extent->disk_bytenr);
5189 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
5190 new_extent->disk_num_bytes);
5191 btrfs_mark_buffer_dirty(leaf);
5192
5193 ret = btrfs_inc_extent_ref(trans, root,
5194 new_extent->disk_bytenr,
5195 new_extent->disk_num_bytes,
5196 leaf->start,
5197 root->root_key.objectid,
5198 trans->transid, key.objectid);
5199 BUG_ON(ret);
5200 ret = btrfs_free_extent(trans, root,
5201 bytenr, num_bytes, leaf->start,
5202 btrfs_header_owner(leaf),
5203 btrfs_header_generation(leaf),
5204 key.objectid, 0);
5205 BUG_ON(ret);
5206 cond_resched();
5207 }
5208 kfree(new_extent);
5209 BUG_ON(ext_index + 1 != ref->nritems);
5210 btrfs_free_leaf_ref(root, ref);
5211 return 0;
5212 }
5213
5214 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
5215 struct btrfs_root *root)
5216 {
5217 struct btrfs_root *reloc_root;
5218 int ret;
5219
5220 if (root->reloc_root) {
5221 reloc_root = root->reloc_root;
5222 root->reloc_root = NULL;
5223 list_add(&reloc_root->dead_list,
5224 &root->fs_info->dead_reloc_roots);
5225
5226 btrfs_set_root_bytenr(&reloc_root->root_item,
5227 reloc_root->node->start);
5228 btrfs_set_root_level(&root->root_item,
5229 btrfs_header_level(reloc_root->node));
5230 memset(&reloc_root->root_item.drop_progress, 0,
5231 sizeof(struct btrfs_disk_key));
5232 reloc_root->root_item.drop_level = 0;
5233
5234 ret = btrfs_update_root(trans, root->fs_info->tree_root,
5235 &reloc_root->root_key,
5236 &reloc_root->root_item);
5237 BUG_ON(ret);
5238 }
5239 return 0;
5240 }
5241
5242 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
5243 {
5244 struct btrfs_trans_handle *trans;
5245 struct btrfs_root *reloc_root;
5246 struct btrfs_root *prev_root = NULL;
5247 struct list_head dead_roots;
5248 int ret;
5249 unsigned long nr;
5250
5251 INIT_LIST_HEAD(&dead_roots);
5252 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
5253
5254 while (!list_empty(&dead_roots)) {
5255 reloc_root = list_entry(dead_roots.prev,
5256 struct btrfs_root, dead_list);
5257 list_del_init(&reloc_root->dead_list);
5258
5259 BUG_ON(reloc_root->commit_root != NULL);
5260 while (1) {
5261 trans = btrfs_join_transaction(root, 1);
5262 BUG_ON(!trans);
5263
5264 mutex_lock(&root->fs_info->drop_mutex);
5265 ret = btrfs_drop_snapshot(trans, reloc_root);
5266 if (ret != -EAGAIN)
5267 break;
5268 mutex_unlock(&root->fs_info->drop_mutex);
5269
5270 nr = trans->blocks_used;
5271 ret = btrfs_end_transaction(trans, root);
5272 BUG_ON(ret);
5273 btrfs_btree_balance_dirty(root, nr);
5274 }
5275
5276 free_extent_buffer(reloc_root->node);
5277
5278 ret = btrfs_del_root(trans, root->fs_info->tree_root,
5279 &reloc_root->root_key);
5280 BUG_ON(ret);
5281 mutex_unlock(&root->fs_info->drop_mutex);
5282
5283 nr = trans->blocks_used;
5284 ret = btrfs_end_transaction(trans, root);
5285 BUG_ON(ret);
5286 btrfs_btree_balance_dirty(root, nr);
5287
5288 kfree(prev_root);
5289 prev_root = reloc_root;
5290 }
5291 if (prev_root) {
5292 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
5293 kfree(prev_root);
5294 }
5295 return 0;
5296 }
5297
5298 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
5299 {
5300 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
5301 return 0;
5302 }
5303
5304 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
5305 {
5306 struct btrfs_root *reloc_root;
5307 struct btrfs_trans_handle *trans;
5308 struct btrfs_key location;
5309 int found;
5310 int ret;
5311
5312 mutex_lock(&root->fs_info->tree_reloc_mutex);
5313 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
5314 BUG_ON(ret);
5315 found = !list_empty(&root->fs_info->dead_reloc_roots);
5316 mutex_unlock(&root->fs_info->tree_reloc_mutex);
5317
5318 if (found) {
5319 trans = btrfs_start_transaction(root, 1);
5320 BUG_ON(!trans);
5321 ret = btrfs_commit_transaction(trans, root);
5322 BUG_ON(ret);
5323 }
5324
5325 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
5326 location.offset = (u64)-1;
5327 location.type = BTRFS_ROOT_ITEM_KEY;
5328
5329 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
5330 BUG_ON(!reloc_root);
5331 btrfs_orphan_cleanup(reloc_root);
5332 return 0;
5333 }
5334
5335 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
5336 struct btrfs_root *root)
5337 {
5338 struct btrfs_root *reloc_root;
5339 struct extent_buffer *eb;
5340 struct btrfs_root_item *root_item;
5341 struct btrfs_key root_key;
5342 int ret;
5343
5344 BUG_ON(!root->ref_cows);
5345 if (root->reloc_root)
5346 return 0;
5347
5348 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
5349 BUG_ON(!root_item);
5350
5351 ret = btrfs_copy_root(trans, root, root->commit_root,
5352 &eb, BTRFS_TREE_RELOC_OBJECTID);
5353 BUG_ON(ret);
5354
5355 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
5356 root_key.offset = root->root_key.objectid;
5357 root_key.type = BTRFS_ROOT_ITEM_KEY;
5358
5359 memcpy(root_item, &root->root_item, sizeof(root_item));
5360 btrfs_set_root_refs(root_item, 0);
5361 btrfs_set_root_bytenr(root_item, eb->start);
5362 btrfs_set_root_level(root_item, btrfs_header_level(eb));
5363 btrfs_set_root_generation(root_item, trans->transid);
5364
5365 btrfs_tree_unlock(eb);
5366 free_extent_buffer(eb);
5367
5368 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
5369 &root_key, root_item);
5370 BUG_ON(ret);
5371 kfree(root_item);
5372
5373 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
5374 &root_key);
5375 BUG_ON(!reloc_root);
5376 reloc_root->last_trans = trans->transid;
5377 reloc_root->commit_root = NULL;
5378 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
5379
5380 root->reloc_root = reloc_root;
5381 return 0;
5382 }
5383
5384 /*
5385 * Core function of space balance.
5386 *
5387 * The idea is using reloc trees to relocate tree blocks in reference
5388 * counted roots. There is one reloc tree for each subvol, and all
5389 * reloc trees share same root key objectid. Reloc trees are snapshots
5390 * of the latest committed roots of subvols (root->commit_root).
5391 *
5392 * To relocate a tree block referenced by a subvol, there are two steps.
5393 * COW the block through subvol's reloc tree, then update block pointer
5394 * in the subvol to point to the new block. Since all reloc trees share
5395 * same root key objectid, doing special handing for tree blocks owned
5396 * by them is easy. Once a tree block has been COWed in one reloc tree,
5397 * we can use the resulting new block directly when the same block is
5398 * required to COW again through other reloc trees. By this way, relocated
5399 * tree blocks are shared between reloc trees, so they are also shared
5400 * between subvols.
5401 */
5402 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
5403 struct btrfs_root *root,
5404 struct btrfs_path *path,
5405 struct btrfs_key *first_key,
5406 struct btrfs_ref_path *ref_path,
5407 struct btrfs_block_group_cache *group,
5408 struct inode *reloc_inode)
5409 {
5410 struct btrfs_root *reloc_root;
5411 struct extent_buffer *eb = NULL;
5412 struct btrfs_key *keys;
5413 u64 *nodes;
5414 int level;
5415 int shared_level;
5416 int lowest_level = 0;
5417 int ret;
5418
5419 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
5420 lowest_level = ref_path->owner_objectid;
5421
5422 if (!root->ref_cows) {
5423 path->lowest_level = lowest_level;
5424 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
5425 BUG_ON(ret < 0);
5426 path->lowest_level = 0;
5427 btrfs_release_path(root, path);
5428 return 0;
5429 }
5430
5431 mutex_lock(&root->fs_info->tree_reloc_mutex);
5432 ret = init_reloc_tree(trans, root);
5433 BUG_ON(ret);
5434 reloc_root = root->reloc_root;
5435
5436 shared_level = ref_path->shared_level;
5437 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
5438
5439 keys = ref_path->node_keys;
5440 nodes = ref_path->new_nodes;
5441 memset(&keys[shared_level + 1], 0,
5442 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
5443 memset(&nodes[shared_level + 1], 0,
5444 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
5445
5446 if (nodes[lowest_level] == 0) {
5447 path->lowest_level = lowest_level;
5448 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
5449 0, 1);
5450 BUG_ON(ret);
5451 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
5452 eb = path->nodes[level];
5453 if (!eb || eb == reloc_root->node)
5454 break;
5455 nodes[level] = eb->start;
5456 if (level == 0)
5457 btrfs_item_key_to_cpu(eb, &keys[level], 0);
5458 else
5459 btrfs_node_key_to_cpu(eb, &keys[level], 0);
5460 }
5461 if (nodes[0] &&
5462 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5463 eb = path->nodes[0];
5464 ret = replace_extents_in_leaf(trans, reloc_root, eb,
5465 group, reloc_inode);
5466 BUG_ON(ret);
5467 }
5468 btrfs_release_path(reloc_root, path);
5469 } else {
5470 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
5471 lowest_level);
5472 BUG_ON(ret);
5473 }
5474
5475 /*
5476 * replace tree blocks in the fs tree with tree blocks in
5477 * the reloc tree.
5478 */
5479 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
5480 BUG_ON(ret < 0);
5481
5482 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5483 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
5484 0, 0);
5485 BUG_ON(ret);
5486 extent_buffer_get(path->nodes[0]);
5487 eb = path->nodes[0];
5488 btrfs_release_path(reloc_root, path);
5489 ret = invalidate_extent_cache(reloc_root, eb, group, root);
5490 BUG_ON(ret);
5491 free_extent_buffer(eb);
5492 }
5493
5494 mutex_unlock(&root->fs_info->tree_reloc_mutex);
5495 path->lowest_level = 0;
5496 return 0;
5497 }
5498
5499 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
5500 struct btrfs_root *root,
5501 struct btrfs_path *path,
5502 struct btrfs_key *first_key,
5503 struct btrfs_ref_path *ref_path)
5504 {
5505 int ret;
5506
5507 ret = relocate_one_path(trans, root, path, first_key,
5508 ref_path, NULL, NULL);
5509 BUG_ON(ret);
5510
5511 if (root == root->fs_info->extent_root)
5512 btrfs_extent_post_op(trans, root);
5513
5514 return 0;
5515 }
5516
5517 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
5518 struct btrfs_root *extent_root,
5519 struct btrfs_path *path,
5520 struct btrfs_key *extent_key)
5521 {
5522 int ret;
5523
5524 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
5525 if (ret)
5526 goto out;
5527 ret = btrfs_del_item(trans, extent_root, path);
5528 out:
5529 btrfs_release_path(extent_root, path);
5530 return ret;
5531 }
5532
5533 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
5534 struct btrfs_ref_path *ref_path)
5535 {
5536 struct btrfs_key root_key;
5537
5538 root_key.objectid = ref_path->root_objectid;
5539 root_key.type = BTRFS_ROOT_ITEM_KEY;
5540 if (is_cowonly_root(ref_path->root_objectid))
5541 root_key.offset = 0;
5542 else
5543 root_key.offset = (u64)-1;
5544
5545 return btrfs_read_fs_root_no_name(fs_info, &root_key);
5546 }
5547
5548 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
5549 struct btrfs_path *path,
5550 struct btrfs_key *extent_key,
5551 struct btrfs_block_group_cache *group,
5552 struct inode *reloc_inode, int pass)
5553 {
5554 struct btrfs_trans_handle *trans;
5555 struct btrfs_root *found_root;
5556 struct btrfs_ref_path *ref_path = NULL;
5557 struct disk_extent *new_extents = NULL;
5558 int nr_extents = 0;
5559 int loops;
5560 int ret;
5561 int level;
5562 struct btrfs_key first_key;
5563 u64 prev_block = 0;
5564
5565
5566 trans = btrfs_start_transaction(extent_root, 1);
5567 BUG_ON(!trans);
5568
5569 if (extent_key->objectid == 0) {
5570 ret = del_extent_zero(trans, extent_root, path, extent_key);
5571 goto out;
5572 }
5573
5574 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
5575 if (!ref_path) {
5576 ret = -ENOMEM;
5577 goto out;
5578 }
5579
5580 for (loops = 0; ; loops++) {
5581 if (loops == 0) {
5582 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
5583 extent_key->objectid);
5584 } else {
5585 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
5586 }
5587 if (ret < 0)
5588 goto out;
5589 if (ret > 0)
5590 break;
5591
5592 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
5593 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
5594 continue;
5595
5596 found_root = read_ref_root(extent_root->fs_info, ref_path);
5597 BUG_ON(!found_root);
5598 /*
5599 * for reference counted tree, only process reference paths
5600 * rooted at the latest committed root.
5601 */
5602 if (found_root->ref_cows &&
5603 ref_path->root_generation != found_root->root_key.offset)
5604 continue;
5605
5606 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5607 if (pass == 0) {
5608 /*
5609 * copy data extents to new locations
5610 */
5611 u64 group_start = group->key.objectid;
5612 ret = relocate_data_extent(reloc_inode,
5613 extent_key,
5614 group_start);
5615 if (ret < 0)
5616 goto out;
5617 break;
5618 }
5619 level = 0;
5620 } else {
5621 level = ref_path->owner_objectid;
5622 }
5623
5624 if (prev_block != ref_path->nodes[level]) {
5625 struct extent_buffer *eb;
5626 u64 block_start = ref_path->nodes[level];
5627 u64 block_size = btrfs_level_size(found_root, level);
5628
5629 eb = read_tree_block(found_root, block_start,
5630 block_size, 0);
5631 btrfs_tree_lock(eb);
5632 BUG_ON(level != btrfs_header_level(eb));
5633
5634 if (level == 0)
5635 btrfs_item_key_to_cpu(eb, &first_key, 0);
5636 else
5637 btrfs_node_key_to_cpu(eb, &first_key, 0);
5638
5639 btrfs_tree_unlock(eb);
5640 free_extent_buffer(eb);
5641 prev_block = block_start;
5642 }
5643
5644 btrfs_record_root_in_trans(found_root);
5645 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5646 /*
5647 * try to update data extent references while
5648 * keeping metadata shared between snapshots.
5649 */
5650 if (pass == 1) {
5651 ret = relocate_one_path(trans, found_root,
5652 path, &first_key, ref_path,
5653 group, reloc_inode);
5654 if (ret < 0)
5655 goto out;
5656 continue;
5657 }
5658 /*
5659 * use fallback method to process the remaining
5660 * references.
5661 */
5662 if (!new_extents) {
5663 u64 group_start = group->key.objectid;
5664 new_extents = kmalloc(sizeof(*new_extents),
5665 GFP_NOFS);
5666 nr_extents = 1;
5667 ret = get_new_locations(reloc_inode,
5668 extent_key,
5669 group_start, 1,
5670 &new_extents,
5671 &nr_extents);
5672 if (ret)
5673 goto out;
5674 }
5675 ret = replace_one_extent(trans, found_root,
5676 path, extent_key,
5677 &first_key, ref_path,
5678 new_extents, nr_extents);
5679 } else {
5680 ret = relocate_tree_block(trans, found_root, path,
5681 &first_key, ref_path);
5682 }
5683 if (ret < 0)
5684 goto out;
5685 }
5686 ret = 0;
5687 out:
5688 btrfs_end_transaction(trans, extent_root);
5689 kfree(new_extents);
5690 kfree(ref_path);
5691 return ret;
5692 }
5693
5694 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
5695 {
5696 u64 num_devices;
5697 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
5698 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
5699
5700 num_devices = root->fs_info->fs_devices->rw_devices;
5701 if (num_devices == 1) {
5702 stripped |= BTRFS_BLOCK_GROUP_DUP;
5703 stripped = flags & ~stripped;
5704
5705 /* turn raid0 into single device chunks */
5706 if (flags & BTRFS_BLOCK_GROUP_RAID0)
5707 return stripped;
5708
5709 /* turn mirroring into duplication */
5710 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
5711 BTRFS_BLOCK_GROUP_RAID10))
5712 return stripped | BTRFS_BLOCK_GROUP_DUP;
5713 return flags;
5714 } else {
5715 /* they already had raid on here, just return */
5716 if (flags & stripped)
5717 return flags;
5718
5719 stripped |= BTRFS_BLOCK_GROUP_DUP;
5720 stripped = flags & ~stripped;
5721
5722 /* switch duplicated blocks with raid1 */
5723 if (flags & BTRFS_BLOCK_GROUP_DUP)
5724 return stripped | BTRFS_BLOCK_GROUP_RAID1;
5725
5726 /* turn single device chunks into raid0 */
5727 return stripped | BTRFS_BLOCK_GROUP_RAID0;
5728 }
5729 return flags;
5730 }
5731
5732 static int __alloc_chunk_for_shrink(struct btrfs_root *root,
5733 struct btrfs_block_group_cache *shrink_block_group,
5734 int force)
5735 {
5736 struct btrfs_trans_handle *trans;
5737 u64 new_alloc_flags;
5738 u64 calc;
5739
5740 spin_lock(&shrink_block_group->lock);
5741 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
5742 spin_unlock(&shrink_block_group->lock);
5743
5744 trans = btrfs_start_transaction(root, 1);
5745 spin_lock(&shrink_block_group->lock);
5746
5747 new_alloc_flags = update_block_group_flags(root,
5748 shrink_block_group->flags);
5749 if (new_alloc_flags != shrink_block_group->flags) {
5750 calc =
5751 btrfs_block_group_used(&shrink_block_group->item);
5752 } else {
5753 calc = shrink_block_group->key.offset;
5754 }
5755 spin_unlock(&shrink_block_group->lock);
5756
5757 do_chunk_alloc(trans, root->fs_info->extent_root,
5758 calc + 2 * 1024 * 1024, new_alloc_flags, force);
5759
5760 btrfs_end_transaction(trans, root);
5761 } else
5762 spin_unlock(&shrink_block_group->lock);
5763 return 0;
5764 }
5765
5766 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
5767 struct btrfs_root *root,
5768 u64 objectid, u64 size)
5769 {
5770 struct btrfs_path *path;
5771 struct btrfs_inode_item *item;
5772 struct extent_buffer *leaf;
5773 int ret;
5774
5775 path = btrfs_alloc_path();
5776 if (!path)
5777 return -ENOMEM;
5778
5779 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
5780 if (ret)
5781 goto out;
5782
5783 leaf = path->nodes[0];
5784 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
5785 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
5786 btrfs_set_inode_generation(leaf, item, 1);
5787 btrfs_set_inode_size(leaf, item, size);
5788 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
5789 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS);
5790 btrfs_mark_buffer_dirty(leaf);
5791 btrfs_release_path(root, path);
5792 out:
5793 btrfs_free_path(path);
5794 return ret;
5795 }
5796
5797 static noinline struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
5798 struct btrfs_block_group_cache *group)
5799 {
5800 struct inode *inode = NULL;
5801 struct btrfs_trans_handle *trans;
5802 struct btrfs_root *root;
5803 struct btrfs_key root_key;
5804 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
5805 int err = 0;
5806
5807 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
5808 root_key.type = BTRFS_ROOT_ITEM_KEY;
5809 root_key.offset = (u64)-1;
5810 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
5811 if (IS_ERR(root))
5812 return ERR_CAST(root);
5813
5814 trans = btrfs_start_transaction(root, 1);
5815 BUG_ON(!trans);
5816
5817 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
5818 if (err)
5819 goto out;
5820
5821 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
5822 BUG_ON(err);
5823
5824 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
5825 group->key.offset, 0, group->key.offset,
5826 0, 0, 0);
5827 BUG_ON(err);
5828
5829 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
5830 if (inode->i_state & I_NEW) {
5831 BTRFS_I(inode)->root = root;
5832 BTRFS_I(inode)->location.objectid = objectid;
5833 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
5834 BTRFS_I(inode)->location.offset = 0;
5835 btrfs_read_locked_inode(inode);
5836 unlock_new_inode(inode);
5837 BUG_ON(is_bad_inode(inode));
5838 } else {
5839 BUG_ON(1);
5840 }
5841 BTRFS_I(inode)->index_cnt = group->key.objectid;
5842
5843 err = btrfs_orphan_add(trans, inode);
5844 out:
5845 btrfs_end_transaction(trans, root);
5846 if (err) {
5847 if (inode)
5848 iput(inode);
5849 inode = ERR_PTR(err);
5850 }
5851 return inode;
5852 }
5853
5854 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
5855 {
5856
5857 struct btrfs_ordered_sum *sums;
5858 struct btrfs_sector_sum *sector_sum;
5859 struct btrfs_ordered_extent *ordered;
5860 struct btrfs_root *root = BTRFS_I(inode)->root;
5861 struct list_head list;
5862 size_t offset;
5863 int ret;
5864 u64 disk_bytenr;
5865
5866 INIT_LIST_HEAD(&list);
5867
5868 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
5869 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
5870
5871 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
5872 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
5873 disk_bytenr + len - 1, &list);
5874
5875 while (!list_empty(&list)) {
5876 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
5877 list_del_init(&sums->list);
5878
5879 sector_sum = sums->sums;
5880 sums->bytenr = ordered->start;
5881
5882 offset = 0;
5883 while (offset < sums->len) {
5884 sector_sum->bytenr += ordered->start - disk_bytenr;
5885 sector_sum++;
5886 offset += root->sectorsize;
5887 }
5888
5889 btrfs_add_ordered_sum(inode, ordered, sums);
5890 }
5891 btrfs_put_ordered_extent(ordered);
5892 return 0;
5893 }
5894
5895 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
5896 {
5897 struct btrfs_trans_handle *trans;
5898 struct btrfs_path *path;
5899 struct btrfs_fs_info *info = root->fs_info;
5900 struct extent_buffer *leaf;
5901 struct inode *reloc_inode;
5902 struct btrfs_block_group_cache *block_group;
5903 struct btrfs_key key;
5904 u64 skipped;
5905 u64 cur_byte;
5906 u64 total_found;
5907 u32 nritems;
5908 int ret;
5909 int progress;
5910 int pass = 0;
5911
5912 root = root->fs_info->extent_root;
5913
5914 block_group = btrfs_lookup_block_group(info, group_start);
5915 BUG_ON(!block_group);
5916
5917 printk(KERN_INFO "btrfs relocating block group %llu flags %llu\n",
5918 (unsigned long long)block_group->key.objectid,
5919 (unsigned long long)block_group->flags);
5920
5921 path = btrfs_alloc_path();
5922 BUG_ON(!path);
5923
5924 reloc_inode = create_reloc_inode(info, block_group);
5925 BUG_ON(IS_ERR(reloc_inode));
5926
5927 __alloc_chunk_for_shrink(root, block_group, 1);
5928 set_block_group_readonly(block_group);
5929
5930 btrfs_start_delalloc_inodes(info->tree_root);
5931 btrfs_wait_ordered_extents(info->tree_root, 0);
5932 again:
5933 skipped = 0;
5934 total_found = 0;
5935 progress = 0;
5936 key.objectid = block_group->key.objectid;
5937 key.offset = 0;
5938 key.type = 0;
5939 cur_byte = key.objectid;
5940
5941 trans = btrfs_start_transaction(info->tree_root, 1);
5942 btrfs_commit_transaction(trans, info->tree_root);
5943
5944 mutex_lock(&root->fs_info->cleaner_mutex);
5945 btrfs_clean_old_snapshots(info->tree_root);
5946 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
5947 mutex_unlock(&root->fs_info->cleaner_mutex);
5948
5949 while (1) {
5950 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5951 if (ret < 0)
5952 goto out;
5953 next:
5954 leaf = path->nodes[0];
5955 nritems = btrfs_header_nritems(leaf);
5956 if (path->slots[0] >= nritems) {
5957 ret = btrfs_next_leaf(root, path);
5958 if (ret < 0)
5959 goto out;
5960 if (ret == 1) {
5961 ret = 0;
5962 break;
5963 }
5964 leaf = path->nodes[0];
5965 nritems = btrfs_header_nritems(leaf);
5966 }
5967
5968 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
5969
5970 if (key.objectid >= block_group->key.objectid +
5971 block_group->key.offset)
5972 break;
5973
5974 if (progress && need_resched()) {
5975 btrfs_release_path(root, path);
5976 cond_resched();
5977 progress = 0;
5978 continue;
5979 }
5980 progress = 1;
5981
5982 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
5983 key.objectid + key.offset <= cur_byte) {
5984 path->slots[0]++;
5985 goto next;
5986 }
5987
5988 total_found++;
5989 cur_byte = key.objectid + key.offset;
5990 btrfs_release_path(root, path);
5991
5992 __alloc_chunk_for_shrink(root, block_group, 0);
5993 ret = relocate_one_extent(root, path, &key, block_group,
5994 reloc_inode, pass);
5995 BUG_ON(ret < 0);
5996 if (ret > 0)
5997 skipped++;
5998
5999 key.objectid = cur_byte;
6000 key.type = 0;
6001 key.offset = 0;
6002 }
6003
6004 btrfs_release_path(root, path);
6005
6006 if (pass == 0) {
6007 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
6008 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
6009 }
6010
6011 if (total_found > 0) {
6012 printk(KERN_INFO "btrfs found %llu extents in pass %d\n",
6013 (unsigned long long)total_found, pass);
6014 pass++;
6015 if (total_found == skipped && pass > 2) {
6016 iput(reloc_inode);
6017 reloc_inode = create_reloc_inode(info, block_group);
6018 pass = 0;
6019 }
6020 goto again;
6021 }
6022
6023 /* delete reloc_inode */
6024 iput(reloc_inode);
6025
6026 /* unpin extents in this range */
6027 trans = btrfs_start_transaction(info->tree_root, 1);
6028 btrfs_commit_transaction(trans, info->tree_root);
6029
6030 spin_lock(&block_group->lock);
6031 WARN_ON(block_group->pinned > 0);
6032 WARN_ON(block_group->reserved > 0);
6033 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
6034 spin_unlock(&block_group->lock);
6035 put_block_group(block_group);
6036 ret = 0;
6037 out:
6038 btrfs_free_path(path);
6039 return ret;
6040 }
6041
6042 static int find_first_block_group(struct btrfs_root *root,
6043 struct btrfs_path *path, struct btrfs_key *key)
6044 {
6045 int ret = 0;
6046 struct btrfs_key found_key;
6047 struct extent_buffer *leaf;
6048 int slot;
6049
6050 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
6051 if (ret < 0)
6052 goto out;
6053
6054 while (1) {
6055 slot = path->slots[0];
6056 leaf = path->nodes[0];
6057 if (slot >= btrfs_header_nritems(leaf)) {
6058 ret = btrfs_next_leaf(root, path);
6059 if (ret == 0)
6060 continue;
6061 if (ret < 0)
6062 goto out;
6063 break;
6064 }
6065 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6066
6067 if (found_key.objectid >= key->objectid &&
6068 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
6069 ret = 0;
6070 goto out;
6071 }
6072 path->slots[0]++;
6073 }
6074 ret = -ENOENT;
6075 out:
6076 return ret;
6077 }
6078
6079 int btrfs_free_block_groups(struct btrfs_fs_info *info)
6080 {
6081 struct btrfs_block_group_cache *block_group;
6082 struct rb_node *n;
6083
6084 spin_lock(&info->block_group_cache_lock);
6085 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
6086 block_group = rb_entry(n, struct btrfs_block_group_cache,
6087 cache_node);
6088 rb_erase(&block_group->cache_node,
6089 &info->block_group_cache_tree);
6090 spin_unlock(&info->block_group_cache_lock);
6091
6092 btrfs_remove_free_space_cache(block_group);
6093 down_write(&block_group->space_info->groups_sem);
6094 list_del(&block_group->list);
6095 up_write(&block_group->space_info->groups_sem);
6096
6097 WARN_ON(atomic_read(&block_group->count) != 1);
6098 kfree(block_group);
6099
6100 spin_lock(&info->block_group_cache_lock);
6101 }
6102 spin_unlock(&info->block_group_cache_lock);
6103 return 0;
6104 }
6105
6106 int btrfs_read_block_groups(struct btrfs_root *root)
6107 {
6108 struct btrfs_path *path;
6109 int ret;
6110 struct btrfs_block_group_cache *cache;
6111 struct btrfs_fs_info *info = root->fs_info;
6112 struct btrfs_space_info *space_info;
6113 struct btrfs_key key;
6114 struct btrfs_key found_key;
6115 struct extent_buffer *leaf;
6116
6117 root = info->extent_root;
6118 key.objectid = 0;
6119 key.offset = 0;
6120 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
6121 path = btrfs_alloc_path();
6122 if (!path)
6123 return -ENOMEM;
6124
6125 while (1) {
6126 ret = find_first_block_group(root, path, &key);
6127 if (ret > 0) {
6128 ret = 0;
6129 goto error;
6130 }
6131 if (ret != 0)
6132 goto error;
6133
6134 leaf = path->nodes[0];
6135 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6136 cache = kzalloc(sizeof(*cache), GFP_NOFS);
6137 if (!cache) {
6138 ret = -ENOMEM;
6139 break;
6140 }
6141
6142 atomic_set(&cache->count, 1);
6143 spin_lock_init(&cache->lock);
6144 mutex_init(&cache->alloc_mutex);
6145 mutex_init(&cache->cache_mutex);
6146 INIT_LIST_HEAD(&cache->list);
6147 read_extent_buffer(leaf, &cache->item,
6148 btrfs_item_ptr_offset(leaf, path->slots[0]),
6149 sizeof(cache->item));
6150 memcpy(&cache->key, &found_key, sizeof(found_key));
6151
6152 key.objectid = found_key.objectid + found_key.offset;
6153 btrfs_release_path(root, path);
6154 cache->flags = btrfs_block_group_flags(&cache->item);
6155
6156 ret = update_space_info(info, cache->flags, found_key.offset,
6157 btrfs_block_group_used(&cache->item),
6158 &space_info);
6159 BUG_ON(ret);
6160 cache->space_info = space_info;
6161 down_write(&space_info->groups_sem);
6162 list_add_tail(&cache->list, &space_info->block_groups);
6163 up_write(&space_info->groups_sem);
6164
6165 ret = btrfs_add_block_group_cache(root->fs_info, cache);
6166 BUG_ON(ret);
6167
6168 set_avail_alloc_bits(root->fs_info, cache->flags);
6169 if (btrfs_chunk_readonly(root, cache->key.objectid))
6170 set_block_group_readonly(cache);
6171 }
6172 ret = 0;
6173 error:
6174 btrfs_free_path(path);
6175 return ret;
6176 }
6177
6178 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
6179 struct btrfs_root *root, u64 bytes_used,
6180 u64 type, u64 chunk_objectid, u64 chunk_offset,
6181 u64 size)
6182 {
6183 int ret;
6184 struct btrfs_root *extent_root;
6185 struct btrfs_block_group_cache *cache;
6186
6187 extent_root = root->fs_info->extent_root;
6188
6189 root->fs_info->last_trans_new_blockgroup = trans->transid;
6190
6191 cache = kzalloc(sizeof(*cache), GFP_NOFS);
6192 if (!cache)
6193 return -ENOMEM;
6194
6195 cache->key.objectid = chunk_offset;
6196 cache->key.offset = size;
6197 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
6198 atomic_set(&cache->count, 1);
6199 spin_lock_init(&cache->lock);
6200 mutex_init(&cache->alloc_mutex);
6201 mutex_init(&cache->cache_mutex);
6202 INIT_LIST_HEAD(&cache->list);
6203
6204 btrfs_set_block_group_used(&cache->item, bytes_used);
6205 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
6206 cache->flags = type;
6207 btrfs_set_block_group_flags(&cache->item, type);
6208
6209 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
6210 &cache->space_info);
6211 BUG_ON(ret);
6212 down_write(&cache->space_info->groups_sem);
6213 list_add_tail(&cache->list, &cache->space_info->block_groups);
6214 up_write(&cache->space_info->groups_sem);
6215
6216 ret = btrfs_add_block_group_cache(root->fs_info, cache);
6217 BUG_ON(ret);
6218
6219 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
6220 sizeof(cache->item));
6221 BUG_ON(ret);
6222
6223 finish_current_insert(trans, extent_root, 0);
6224 ret = del_pending_extents(trans, extent_root, 0);
6225 BUG_ON(ret);
6226 set_avail_alloc_bits(extent_root->fs_info, type);
6227
6228 return 0;
6229 }
6230
6231 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
6232 struct btrfs_root *root, u64 group_start)
6233 {
6234 struct btrfs_path *path;
6235 struct btrfs_block_group_cache *block_group;
6236 struct btrfs_key key;
6237 int ret;
6238
6239 root = root->fs_info->extent_root;
6240
6241 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
6242 BUG_ON(!block_group);
6243 BUG_ON(!block_group->ro);
6244
6245 memcpy(&key, &block_group->key, sizeof(key));
6246
6247 path = btrfs_alloc_path();
6248 BUG_ON(!path);
6249
6250 spin_lock(&root->fs_info->block_group_cache_lock);
6251 rb_erase(&block_group->cache_node,
6252 &root->fs_info->block_group_cache_tree);
6253 spin_unlock(&root->fs_info->block_group_cache_lock);
6254 btrfs_remove_free_space_cache(block_group);
6255 down_write(&block_group->space_info->groups_sem);
6256 list_del(&block_group->list);
6257 up_write(&block_group->space_info->groups_sem);
6258
6259 spin_lock(&block_group->space_info->lock);
6260 block_group->space_info->total_bytes -= block_group->key.offset;
6261 block_group->space_info->bytes_readonly -= block_group->key.offset;
6262 spin_unlock(&block_group->space_info->lock);
6263 block_group->space_info->full = 0;
6264
6265 put_block_group(block_group);
6266 put_block_group(block_group);
6267
6268 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
6269 if (ret > 0)
6270 ret = -EIO;
6271 if (ret < 0)
6272 goto out;
6273
6274 ret = btrfs_del_item(trans, root, path);
6275 out:
6276 btrfs_free_path(path);
6277 return ret;
6278 }
kernel-based virtual machine