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Btrfs: removed unused #include <version.h>'s
[linux-2.6/mini2440.git] / fs / btrfs / extent-tree.c
blobcdc961e7556adfe4e18b93dd1e44f338534a4f27
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 "compat.h"
23 #include "hash.h"
24 #include "crc32c.h"
25 #include "ctree.h"
26 #include "disk-io.h"
27 #include "print-tree.h"
28 #include "transaction.h"
29 #include "volumes.h"
30 #include "locking.h"
31 #include "ref-cache.h"
32 #include "compat.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 list_head *cur;
329 struct btrfs_space_info *found;
330 list_for_each(cur, head) {
331 found = list_entry(cur, struct btrfs_space_info, list);
332 if (found->flags == flags)
333 return found;
334 }
335 return NULL;
336 }
337
338 static u64 div_factor(u64 num, int factor)
339 {
340 if (factor == 10)
341 return num;
342 num *= factor;
343 do_div(num, 10);
344 return num;
345 }
346
347 u64 btrfs_find_block_group(struct btrfs_root *root,
348 u64 search_start, u64 search_hint, int owner)
349 {
350 struct btrfs_block_group_cache *cache;
351 u64 used;
352 u64 last = max(search_hint, search_start);
353 u64 group_start = 0;
354 int full_search = 0;
355 int factor = 9;
356 int wrapped = 0;
357 again:
358 while (1) {
359 cache = btrfs_lookup_first_block_group(root->fs_info, last);
360 if (!cache)
361 break;
362
363 spin_lock(&cache->lock);
364 last = cache->key.objectid + cache->key.offset;
365 used = btrfs_block_group_used(&cache->item);
366
367 if ((full_search || !cache->ro) &&
368 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
369 if (used + cache->pinned + cache->reserved <
370 div_factor(cache->key.offset, factor)) {
371 group_start = cache->key.objectid;
372 spin_unlock(&cache->lock);
373 put_block_group(cache);
374 goto found;
375 }
376 }
377 spin_unlock(&cache->lock);
378 put_block_group(cache);
379 cond_resched();
380 }
381 if (!wrapped) {
382 last = search_start;
383 wrapped = 1;
384 goto again;
385 }
386 if (!full_search && factor < 10) {
387 last = search_start;
388 full_search = 1;
389 factor = 10;
390 goto again;
391 }
392 found:
393 return group_start;
394 }
395
396 /* simple helper to search for an existing extent at a given offset */
397 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
398 {
399 int ret;
400 struct btrfs_key key;
401 struct btrfs_path *path;
402
403 path = btrfs_alloc_path();
404 BUG_ON(!path);
405 key.objectid = start;
406 key.offset = len;
407 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
408 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
409 0, 0);
410 btrfs_free_path(path);
411 return ret;
412 }
413
414 /*
415 * Back reference rules. Back refs have three main goals:
416 *
417 * 1) differentiate between all holders of references to an extent so that
418 * when a reference is dropped we can make sure it was a valid reference
419 * before freeing the extent.
420 *
421 * 2) Provide enough information to quickly find the holders of an extent
422 * if we notice a given block is corrupted or bad.
423 *
424 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
425 * maintenance. This is actually the same as #2, but with a slightly
426 * different use case.
427 *
428 * File extents can be referenced by:
429 *
430 * - multiple snapshots, subvolumes, or different generations in one subvol
431 * - different files inside a single subvolume
432 * - different offsets inside a file (bookend extents in file.c)
433 *
434 * The extent ref structure has fields for:
435 *
436 * - Objectid of the subvolume root
437 * - Generation number of the tree holding the reference
438 * - objectid of the file holding the reference
439 * - number of references holding by parent node (alway 1 for tree blocks)
440 *
441 * Btree leaf may hold multiple references to a file extent. In most cases,
442 * these references are from same file and the corresponding offsets inside
443 * the file are close together.
444 *
445 * When a file extent is allocated the fields are filled in:
446 * (root_key.objectid, trans->transid, inode objectid, 1)
447 *
448 * When a leaf is cow'd new references are added for every file extent found
449 * in the leaf. It looks similar to the create case, but trans->transid will
450 * be different when the block is cow'd.
451 *
452 * (root_key.objectid, trans->transid, inode objectid,
453 * number of references in the leaf)
454 *
455 * When a file extent is removed either during snapshot deletion or
456 * file truncation, we find the corresponding back reference and check
457 * the following fields:
458 *
459 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
460 * inode objectid)
461 *
462 * Btree extents can be referenced by:
463 *
464 * - Different subvolumes
465 * - Different generations of the same subvolume
466 *
467 * When a tree block is created, back references are inserted:
468 *
469 * (root->root_key.objectid, trans->transid, level, 1)
470 *
471 * When a tree block is cow'd, new back references are added for all the
472 * blocks it points to. If the tree block isn't in reference counted root,
473 * the old back references are removed. These new back references are of
474 * the form (trans->transid will have increased since creation):
475 *
476 * (root->root_key.objectid, trans->transid, level, 1)
477 *
478 * When a backref is in deleting, the following fields are checked:
479 *
480 * if backref was for a tree root:
481 * (btrfs_header_owner(itself), btrfs_header_generation(itself), level)
482 * else
483 * (btrfs_header_owner(parent), btrfs_header_generation(parent), level)
484 *
485 * Back Reference Key composing:
486 *
487 * The key objectid corresponds to the first byte in the extent, the key
488 * type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first
489 * byte of parent extent. If a extent is tree root, the key offset is set
490 * to the key objectid.
491 */
492
493 static noinline int lookup_extent_backref(struct btrfs_trans_handle *trans,
494 struct btrfs_root *root,
495 struct btrfs_path *path,
496 u64 bytenr, u64 parent,
497 u64 ref_root, u64 ref_generation,
498 u64 owner_objectid, int del)
499 {
500 struct btrfs_key key;
501 struct btrfs_extent_ref *ref;
502 struct extent_buffer *leaf;
503 u64 ref_objectid;
504 int ret;
505
506 key.objectid = bytenr;
507 key.type = BTRFS_EXTENT_REF_KEY;
508 key.offset = parent;
509
510 ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1);
511 if (ret < 0)
512 goto out;
513 if (ret > 0) {
514 ret = -ENOENT;
515 goto out;
516 }
517
518 leaf = path->nodes[0];
519 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
520 ref_objectid = btrfs_ref_objectid(leaf, ref);
521 if (btrfs_ref_root(leaf, ref) != ref_root ||
522 btrfs_ref_generation(leaf, ref) != ref_generation ||
523 (ref_objectid != owner_objectid &&
524 ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
525 ret = -EIO;
526 WARN_ON(1);
527 goto out;
528 }
529 ret = 0;
530 out:
531 return ret;
532 }
533
534 /*
535 * updates all the backrefs that are pending on update_list for the
536 * extent_root
537 */
538 static noinline int update_backrefs(struct btrfs_trans_handle *trans,
539 struct btrfs_root *extent_root,
540 struct btrfs_path *path,
541 struct list_head *update_list)
542 {
543 struct btrfs_key key;
544 struct btrfs_extent_ref *ref;
545 struct btrfs_fs_info *info = extent_root->fs_info;
546 struct pending_extent_op *op;
547 struct extent_buffer *leaf;
548 int ret = 0;
549 struct list_head *cur = update_list->next;
550 u64 ref_objectid;
551 u64 ref_root = extent_root->root_key.objectid;
552
553 op = list_entry(cur, struct pending_extent_op, list);
554
555 search:
556 key.objectid = op->bytenr;
557 key.type = BTRFS_EXTENT_REF_KEY;
558 key.offset = op->orig_parent;
559
560 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 1);
561 BUG_ON(ret);
562
563 leaf = path->nodes[0];
564
565 loop:
566 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
567
568 ref_objectid = btrfs_ref_objectid(leaf, ref);
569
570 if (btrfs_ref_root(leaf, ref) != ref_root ||
571 btrfs_ref_generation(leaf, ref) != op->orig_generation ||
572 (ref_objectid != op->level &&
573 ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
574 printk(KERN_ERR "btrfs couldn't find %llu, parent %llu, "
575 "root %llu, owner %u\n",
576 (unsigned long long)op->bytenr,
577 (unsigned long long)op->orig_parent,
578 (unsigned long long)ref_root, op->level);
579 btrfs_print_leaf(extent_root, leaf);
580 BUG();
581 }
582
583 key.objectid = op->bytenr;
584 key.offset = op->parent;
585 key.type = BTRFS_EXTENT_REF_KEY;
586 ret = btrfs_set_item_key_safe(trans, extent_root, path, &key);
587 BUG_ON(ret);
588 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
589 btrfs_set_ref_generation(leaf, ref, op->generation);
590
591 cur = cur->next;
592
593 list_del_init(&op->list);
594 unlock_extent(&info->extent_ins, op->bytenr,
595 op->bytenr + op->num_bytes - 1, GFP_NOFS);
596 kfree(op);
597
598 if (cur == update_list) {
599 btrfs_mark_buffer_dirty(path->nodes[0]);
600 btrfs_release_path(extent_root, path);
601 goto out;
602 }
603
604 op = list_entry(cur, struct pending_extent_op, list);
605
606 path->slots[0]++;
607 while (path->slots[0] < btrfs_header_nritems(leaf)) {
608 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
609 if (key.objectid == op->bytenr &&
610 key.type == BTRFS_EXTENT_REF_KEY)
611 goto loop;
612 path->slots[0]++;
613 }
614
615 btrfs_mark_buffer_dirty(path->nodes[0]);
616 btrfs_release_path(extent_root, path);
617 goto search;
618
619 out:
620 return 0;
621 }
622
623 static noinline int insert_extents(struct btrfs_trans_handle *trans,
624 struct btrfs_root *extent_root,
625 struct btrfs_path *path,
626 struct list_head *insert_list, int nr)
627 {
628 struct btrfs_key *keys;
629 u32 *data_size;
630 struct pending_extent_op *op;
631 struct extent_buffer *leaf;
632 struct list_head *cur = insert_list->next;
633 struct btrfs_fs_info *info = extent_root->fs_info;
634 u64 ref_root = extent_root->root_key.objectid;
635 int i = 0, last = 0, ret;
636 int total = nr * 2;
637
638 if (!nr)
639 return 0;
640
641 keys = kzalloc(total * sizeof(struct btrfs_key), GFP_NOFS);
642 if (!keys)
643 return -ENOMEM;
644
645 data_size = kzalloc(total * sizeof(u32), GFP_NOFS);
646 if (!data_size) {
647 kfree(keys);
648 return -ENOMEM;
649 }
650
651 list_for_each_entry(op, insert_list, list) {
652 keys[i].objectid = op->bytenr;
653 keys[i].offset = op->num_bytes;
654 keys[i].type = BTRFS_EXTENT_ITEM_KEY;
655 data_size[i] = sizeof(struct btrfs_extent_item);
656 i++;
657
658 keys[i].objectid = op->bytenr;
659 keys[i].offset = op->parent;
660 keys[i].type = BTRFS_EXTENT_REF_KEY;
661 data_size[i] = sizeof(struct btrfs_extent_ref);
662 i++;
663 }
664
665 op = list_entry(cur, struct pending_extent_op, list);
666 i = 0;
667 while (i < total) {
668 int c;
669 ret = btrfs_insert_some_items(trans, extent_root, path,
670 keys+i, data_size+i, total-i);
671 BUG_ON(ret < 0);
672
673 if (last && ret > 1)
674 BUG();
675
676 leaf = path->nodes[0];
677 for (c = 0; c < ret; c++) {
678 int ref_first = keys[i].type == BTRFS_EXTENT_REF_KEY;
679
680 /*
681 * if the first item we inserted was a backref, then
682 * the EXTENT_ITEM will be the odd c's, else it will
683 * be the even c's
684 */
685 if ((ref_first && (c % 2)) ||
686 (!ref_first && !(c % 2))) {
687 struct btrfs_extent_item *itm;
688
689 itm = btrfs_item_ptr(leaf, path->slots[0] + c,
690 struct btrfs_extent_item);
691 btrfs_set_extent_refs(path->nodes[0], itm, 1);
692 op->del++;
693 } else {
694 struct btrfs_extent_ref *ref;
695
696 ref = btrfs_item_ptr(leaf, path->slots[0] + c,
697 struct btrfs_extent_ref);
698 btrfs_set_ref_root(leaf, ref, ref_root);
699 btrfs_set_ref_generation(leaf, ref,
700 op->generation);
701 btrfs_set_ref_objectid(leaf, ref, op->level);
702 btrfs_set_ref_num_refs(leaf, ref, 1);
703 op->del++;
704 }
705
706 /*
707 * using del to see when its ok to free up the
708 * pending_extent_op. In the case where we insert the
709 * last item on the list in order to help do batching
710 * we need to not free the extent op until we actually
711 * insert the extent_item
712 */
713 if (op->del == 2) {
714 unlock_extent(&info->extent_ins, op->bytenr,
715 op->bytenr + op->num_bytes - 1,
716 GFP_NOFS);
717 cur = cur->next;
718 list_del_init(&op->list);
719 kfree(op);
720 if (cur != insert_list)
721 op = list_entry(cur,
722 struct pending_extent_op,
723 list);
724 }
725 }
726 btrfs_mark_buffer_dirty(leaf);
727 btrfs_release_path(extent_root, path);
728
729 /*
730 * Ok backref's and items usually go right next to eachother,
731 * but if we could only insert 1 item that means that we
732 * inserted on the end of a leaf, and we have no idea what may
733 * be on the next leaf so we just play it safe. In order to
734 * try and help this case we insert the last thing on our
735 * insert list so hopefully it will end up being the last
736 * thing on the leaf and everything else will be before it,
737 * which will let us insert a whole bunch of items at the same
738 * time.
739 */
740 if (ret == 1 && !last && (i + ret < total)) {
741 /*
742 * last: where we will pick up the next time around
743 * i: our current key to insert, will be total - 1
744 * cur: the current op we are screwing with
745 * op: duh
746 */
747 last = i + ret;
748 i = total - 1;
749 cur = insert_list->prev;
750 op = list_entry(cur, struct pending_extent_op, list);
751 } else if (last) {
752 /*
753 * ok we successfully inserted the last item on the
754 * list, lets reset everything
755 *
756 * i: our current key to insert, so where we left off
757 * last time
758 * last: done with this
759 * cur: the op we are messing with
760 * op: duh
761 * total: since we inserted the last key, we need to
762 * decrement total so we dont overflow
763 */
764 i = last;
765 last = 0;
766 total--;
767 if (i < total) {
768 cur = insert_list->next;
769 op = list_entry(cur, struct pending_extent_op,
770 list);
771 }
772 } else {
773 i += ret;
774 }
775
776 cond_resched();
777 }
778 ret = 0;
779 kfree(keys);
780 kfree(data_size);
781 return ret;
782 }
783
784 static noinline int insert_extent_backref(struct btrfs_trans_handle *trans,
785 struct btrfs_root *root,
786 struct btrfs_path *path,
787 u64 bytenr, u64 parent,
788 u64 ref_root, u64 ref_generation,
789 u64 owner_objectid)
790 {
791 struct btrfs_key key;
792 struct extent_buffer *leaf;
793 struct btrfs_extent_ref *ref;
794 u32 num_refs;
795 int ret;
796
797 key.objectid = bytenr;
798 key.type = BTRFS_EXTENT_REF_KEY;
799 key.offset = parent;
800
801 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref));
802 if (ret == 0) {
803 leaf = path->nodes[0];
804 ref = btrfs_item_ptr(leaf, path->slots[0],
805 struct btrfs_extent_ref);
806 btrfs_set_ref_root(leaf, ref, ref_root);
807 btrfs_set_ref_generation(leaf, ref, ref_generation);
808 btrfs_set_ref_objectid(leaf, ref, owner_objectid);
809 btrfs_set_ref_num_refs(leaf, ref, 1);
810 } else if (ret == -EEXIST) {
811 u64 existing_owner;
812 BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID);
813 leaf = path->nodes[0];
814 ref = btrfs_item_ptr(leaf, path->slots[0],
815 struct btrfs_extent_ref);
816 if (btrfs_ref_root(leaf, ref) != ref_root ||
817 btrfs_ref_generation(leaf, ref) != ref_generation) {
818 ret = -EIO;
819 WARN_ON(1);
820 goto out;
821 }
822
823 num_refs = btrfs_ref_num_refs(leaf, ref);
824 BUG_ON(num_refs == 0);
825 btrfs_set_ref_num_refs(leaf, ref, num_refs + 1);
826
827 existing_owner = btrfs_ref_objectid(leaf, ref);
828 if (existing_owner != owner_objectid &&
829 existing_owner != BTRFS_MULTIPLE_OBJECTIDS) {
830 btrfs_set_ref_objectid(leaf, ref,
831 BTRFS_MULTIPLE_OBJECTIDS);
832 }
833 ret = 0;
834 } else {
835 goto out;
836 }
837 btrfs_mark_buffer_dirty(path->nodes[0]);
838 out:
839 btrfs_release_path(root, path);
840 return ret;
841 }
842
843 static noinline int remove_extent_backref(struct btrfs_trans_handle *trans,
844 struct btrfs_root *root,
845 struct btrfs_path *path)
846 {
847 struct extent_buffer *leaf;
848 struct btrfs_extent_ref *ref;
849 u32 num_refs;
850 int ret = 0;
851
852 leaf = path->nodes[0];
853 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
854 num_refs = btrfs_ref_num_refs(leaf, ref);
855 BUG_ON(num_refs == 0);
856 num_refs -= 1;
857 if (num_refs == 0) {
858 ret = btrfs_del_item(trans, root, path);
859 } else {
860 btrfs_set_ref_num_refs(leaf, ref, num_refs);
861 btrfs_mark_buffer_dirty(leaf);
862 }
863 btrfs_release_path(root, path);
864 return ret;
865 }
866
867 #ifdef BIO_RW_DISCARD
868 static void btrfs_issue_discard(struct block_device *bdev,
869 u64 start, u64 len)
870 {
871 blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL);
872 }
873 #endif
874
875 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
876 u64 num_bytes)
877 {
878 #ifdef BIO_RW_DISCARD
879 int ret;
880 u64 map_length = num_bytes;
881 struct btrfs_multi_bio *multi = NULL;
882
883 /* Tell the block device(s) that the sectors can be discarded */
884 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
885 bytenr, &map_length, &multi, 0);
886 if (!ret) {
887 struct btrfs_bio_stripe *stripe = multi->stripes;
888 int i;
889
890 if (map_length > num_bytes)
891 map_length = num_bytes;
892
893 for (i = 0; i < multi->num_stripes; i++, stripe++) {
894 btrfs_issue_discard(stripe->dev->bdev,
895 stripe->physical,
896 map_length);
897 }
898 kfree(multi);
899 }
900
901 return ret;
902 #else
903 return 0;
904 #endif
905 }
906
907 static noinline int free_extents(struct btrfs_trans_handle *trans,
908 struct btrfs_root *extent_root,
909 struct list_head *del_list)
910 {
911 struct btrfs_fs_info *info = extent_root->fs_info;
912 struct btrfs_path *path;
913 struct btrfs_key key, found_key;
914 struct extent_buffer *leaf;
915 struct list_head *cur;
916 struct pending_extent_op *op;
917 struct btrfs_extent_item *ei;
918 int ret, num_to_del, extent_slot = 0, found_extent = 0;
919 u32 refs;
920 u64 bytes_freed = 0;
921
922 path = btrfs_alloc_path();
923 if (!path)
924 return -ENOMEM;
925 path->reada = 1;
926
927 search:
928 /* search for the backref for the current ref we want to delete */
929 cur = del_list->next;
930 op = list_entry(cur, struct pending_extent_op, list);
931 ret = lookup_extent_backref(trans, extent_root, path, op->bytenr,
932 op->orig_parent,
933 extent_root->root_key.objectid,
934 op->orig_generation, op->level, 1);
935 if (ret) {
936 printk(KERN_ERR "btrfs unable to find backref byte nr %llu "
937 "root %llu gen %llu owner %u\n",
938 (unsigned long long)op->bytenr,
939 (unsigned long long)extent_root->root_key.objectid,
940 (unsigned long long)op->orig_generation, op->level);
941 btrfs_print_leaf(extent_root, path->nodes[0]);
942 WARN_ON(1);
943 goto out;
944 }
945
946 extent_slot = path->slots[0];
947 num_to_del = 1;
948 found_extent = 0;
949
950 /*
951 * if we aren't the first item on the leaf we can move back one and see
952 * if our ref is right next to our extent item
953 */
954 if (likely(extent_slot)) {
955 extent_slot--;
956 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
957 extent_slot);
958 if (found_key.objectid == op->bytenr &&
959 found_key.type == BTRFS_EXTENT_ITEM_KEY &&
960 found_key.offset == op->num_bytes) {
961 num_to_del++;
962 found_extent = 1;
963 }
964 }
965
966 /*
967 * if we didn't find the extent we need to delete the backref and then
968 * search for the extent item key so we can update its ref count
969 */
970 if (!found_extent) {
971 key.objectid = op->bytenr;
972 key.type = BTRFS_EXTENT_ITEM_KEY;
973 key.offset = op->num_bytes;
974
975 ret = remove_extent_backref(trans, extent_root, path);
976 BUG_ON(ret);
977 btrfs_release_path(extent_root, path);
978 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
979 BUG_ON(ret);
980 extent_slot = path->slots[0];
981 }
982
983 /* this is where we update the ref count for the extent */
984 leaf = path->nodes[0];
985 ei = btrfs_item_ptr(leaf, extent_slot, struct btrfs_extent_item);
986 refs = btrfs_extent_refs(leaf, ei);
987 BUG_ON(refs == 0);
988 refs--;
989 btrfs_set_extent_refs(leaf, ei, refs);
990
991 btrfs_mark_buffer_dirty(leaf);
992
993 /*
994 * This extent needs deleting. The reason cur_slot is extent_slot +
995 * num_to_del is because extent_slot points to the slot where the extent
996 * is, and if the backref was not right next to the extent we will be
997 * deleting at least 1 item, and will want to start searching at the
998 * slot directly next to extent_slot. However if we did find the
999 * backref next to the extent item them we will be deleting at least 2
1000 * items and will want to start searching directly after the ref slot
1001 */
1002 if (!refs) {
1003 struct list_head *pos, *n, *end;
1004 int cur_slot = extent_slot+num_to_del;
1005 u64 super_used;
1006 u64 root_used;
1007
1008 path->slots[0] = extent_slot;
1009 bytes_freed = op->num_bytes;
1010
1011 mutex_lock(&info->pinned_mutex);
1012 ret = pin_down_bytes(trans, extent_root, op->bytenr,
1013 op->num_bytes, op->level >=
1014 BTRFS_FIRST_FREE_OBJECTID);
1015 mutex_unlock(&info->pinned_mutex);
1016 BUG_ON(ret < 0);
1017 op->del = ret;
1018
1019 /*
1020 * we need to see if we can delete multiple things at once, so
1021 * start looping through the list of extents we are wanting to
1022 * delete and see if their extent/backref's are right next to
1023 * eachother and the extents only have 1 ref
1024 */
1025 for (pos = cur->next; pos != del_list; pos = pos->next) {
1026 struct pending_extent_op *tmp;
1027
1028 tmp = list_entry(pos, struct pending_extent_op, list);
1029
1030 /* we only want to delete extent+ref at this stage */
1031 if (cur_slot >= btrfs_header_nritems(leaf) - 1)
1032 break;
1033
1034 btrfs_item_key_to_cpu(leaf, &found_key, cur_slot);
1035 if (found_key.objectid != tmp->bytenr ||
1036 found_key.type != BTRFS_EXTENT_ITEM_KEY ||
1037 found_key.offset != tmp->num_bytes)
1038 break;
1039
1040 /* check to make sure this extent only has one ref */
1041 ei = btrfs_item_ptr(leaf, cur_slot,
1042 struct btrfs_extent_item);
1043 if (btrfs_extent_refs(leaf, ei) != 1)
1044 break;
1045
1046 btrfs_item_key_to_cpu(leaf, &found_key, cur_slot+1);
1047 if (found_key.objectid != tmp->bytenr ||
1048 found_key.type != BTRFS_EXTENT_REF_KEY ||
1049 found_key.offset != tmp->orig_parent)
1050 break;
1051
1052 /*
1053 * the ref is right next to the extent, we can set the
1054 * ref count to 0 since we will delete them both now
1055 */
1056 btrfs_set_extent_refs(leaf, ei, 0);
1057
1058 /* pin down the bytes for this extent */
1059 mutex_lock(&info->pinned_mutex);
1060 ret = pin_down_bytes(trans, extent_root, tmp->bytenr,
1061 tmp->num_bytes, tmp->level >=
1062 BTRFS_FIRST_FREE_OBJECTID);
1063 mutex_unlock(&info->pinned_mutex);
1064 BUG_ON(ret < 0);
1065
1066 /*
1067 * use the del field to tell if we need to go ahead and
1068 * free up the extent when we delete the item or not.
1069 */
1070 tmp->del = ret;
1071 bytes_freed += tmp->num_bytes;
1072
1073 num_to_del += 2;
1074 cur_slot += 2;
1075 }
1076 end = pos;
1077
1078 /* update the free space counters */
1079 spin_lock(&info->delalloc_lock);
1080 super_used = btrfs_super_bytes_used(&info->super_copy);
1081 btrfs_set_super_bytes_used(&info->super_copy,
1082 super_used - bytes_freed);
1083
1084 root_used = btrfs_root_used(&extent_root->root_item);
1085 btrfs_set_root_used(&extent_root->root_item,
1086 root_used - bytes_freed);
1087 spin_unlock(&info->delalloc_lock);
1088
1089 /* delete the items */
1090 ret = btrfs_del_items(trans, extent_root, path,
1091 path->slots[0], num_to_del);
1092 BUG_ON(ret);
1093
1094 /*
1095 * loop through the extents we deleted and do the cleanup work
1096 * on them
1097 */
1098 for (pos = cur, n = pos->next; pos != end;
1099 pos = n, n = pos->next) {
1100 struct pending_extent_op *tmp;
1101 tmp = list_entry(pos, struct pending_extent_op, list);
1102
1103 /*
1104 * remember tmp->del tells us wether or not we pinned
1105 * down the extent
1106 */
1107 ret = update_block_group(trans, extent_root,
1108 tmp->bytenr, tmp->num_bytes, 0,
1109 tmp->del);
1110 BUG_ON(ret);
1111
1112 list_del_init(&tmp->list);
1113 unlock_extent(&info->extent_ins, tmp->bytenr,
1114 tmp->bytenr + tmp->num_bytes - 1,
1115 GFP_NOFS);
1116 kfree(tmp);
1117 }
1118 } else if (refs && found_extent) {
1119 /*
1120 * the ref and extent were right next to eachother, but the
1121 * extent still has a ref, so just free the backref and keep
1122 * going
1123 */
1124 ret = remove_extent_backref(trans, extent_root, path);
1125 BUG_ON(ret);
1126
1127 list_del_init(&op->list);
1128 unlock_extent(&info->extent_ins, op->bytenr,
1129 op->bytenr + op->num_bytes - 1, GFP_NOFS);
1130 kfree(op);
1131 } else {
1132 /*
1133 * the extent has multiple refs and the backref we were looking
1134 * for was not right next to it, so just unlock and go next,
1135 * we're good to go
1136 */
1137 list_del_init(&op->list);
1138 unlock_extent(&info->extent_ins, op->bytenr,
1139 op->bytenr + op->num_bytes - 1, GFP_NOFS);
1140 kfree(op);
1141 }
1142
1143 btrfs_release_path(extent_root, path);
1144 if (!list_empty(del_list))
1145 goto search;
1146
1147 out:
1148 btrfs_free_path(path);
1149 return ret;
1150 }
1151
1152 static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
1153 struct btrfs_root *root, u64 bytenr,
1154 u64 orig_parent, u64 parent,
1155 u64 orig_root, u64 ref_root,
1156 u64 orig_generation, u64 ref_generation,
1157 u64 owner_objectid)
1158 {
1159 int ret;
1160 struct btrfs_root *extent_root = root->fs_info->extent_root;
1161 struct btrfs_path *path;
1162
1163 if (root == root->fs_info->extent_root) {
1164 struct pending_extent_op *extent_op;
1165 u64 num_bytes;
1166
1167 BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL);
1168 num_bytes = btrfs_level_size(root, (int)owner_objectid);
1169 mutex_lock(&root->fs_info->extent_ins_mutex);
1170 if (test_range_bit(&root->fs_info->extent_ins, bytenr,
1171 bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
1172 u64 priv;
1173 ret = get_state_private(&root->fs_info->extent_ins,
1174 bytenr, &priv);
1175 BUG_ON(ret);
1176 extent_op = (struct pending_extent_op *)
1177 (unsigned long)priv;
1178 BUG_ON(extent_op->parent != orig_parent);
1179 BUG_ON(extent_op->generation != orig_generation);
1180
1181 extent_op->parent = parent;
1182 extent_op->generation = ref_generation;
1183 } else {
1184 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
1185 BUG_ON(!extent_op);
1186
1187 extent_op->type = PENDING_BACKREF_UPDATE;
1188 extent_op->bytenr = bytenr;
1189 extent_op->num_bytes = num_bytes;
1190 extent_op->parent = parent;
1191 extent_op->orig_parent = orig_parent;
1192 extent_op->generation = ref_generation;
1193 extent_op->orig_generation = orig_generation;
1194 extent_op->level = (int)owner_objectid;
1195 INIT_LIST_HEAD(&extent_op->list);
1196 extent_op->del = 0;
1197
1198 set_extent_bits(&root->fs_info->extent_ins,
1199 bytenr, bytenr + num_bytes - 1,
1200 EXTENT_WRITEBACK, GFP_NOFS);
1201 set_state_private(&root->fs_info->extent_ins,
1202 bytenr, (unsigned long)extent_op);
1203 }
1204 mutex_unlock(&root->fs_info->extent_ins_mutex);
1205 return 0;
1206 }
1207
1208 path = btrfs_alloc_path();
1209 if (!path)
1210 return -ENOMEM;
1211 ret = lookup_extent_backref(trans, extent_root, path,
1212 bytenr, orig_parent, orig_root,
1213 orig_generation, owner_objectid, 1);
1214 if (ret)
1215 goto out;
1216 ret = remove_extent_backref(trans, extent_root, path);
1217 if (ret)
1218 goto out;
1219 ret = insert_extent_backref(trans, extent_root, path, bytenr,
1220 parent, ref_root, ref_generation,
1221 owner_objectid);
1222 BUG_ON(ret);
1223 finish_current_insert(trans, extent_root, 0);
1224 del_pending_extents(trans, extent_root, 0);
1225 out:
1226 btrfs_free_path(path);
1227 return ret;
1228 }
1229
1230 int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
1231 struct btrfs_root *root, u64 bytenr,
1232 u64 orig_parent, u64 parent,
1233 u64 ref_root, u64 ref_generation,
1234 u64 owner_objectid)
1235 {
1236 int ret;
1237 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
1238 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
1239 return 0;
1240 ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent,
1241 parent, ref_root, ref_root,
1242 ref_generation, ref_generation,
1243 owner_objectid);
1244 return ret;
1245 }
1246
1247 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1248 struct btrfs_root *root, u64 bytenr,
1249 u64 orig_parent, u64 parent,
1250 u64 orig_root, u64 ref_root,
1251 u64 orig_generation, u64 ref_generation,
1252 u64 owner_objectid)
1253 {
1254 struct btrfs_path *path;
1255 int ret;
1256 struct btrfs_key key;
1257 struct extent_buffer *l;
1258 struct btrfs_extent_item *item;
1259 u32 refs;
1260
1261 path = btrfs_alloc_path();
1262 if (!path)
1263 return -ENOMEM;
1264
1265 path->reada = 1;
1266 key.objectid = bytenr;
1267 key.type = BTRFS_EXTENT_ITEM_KEY;
1268 key.offset = (u64)-1;
1269
1270 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1271 0, 1);
1272 if (ret < 0)
1273 return ret;
1274 BUG_ON(ret == 0 || path->slots[0] == 0);
1275
1276 path->slots[0]--;
1277 l = path->nodes[0];
1278
1279 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1280 if (key.objectid != bytenr) {
1281 btrfs_print_leaf(root->fs_info->extent_root, path->nodes[0]);
1282 printk(KERN_ERR "btrfs wanted %llu found %llu\n",
1283 (unsigned long long)bytenr,
1284 (unsigned long long)key.objectid);
1285 BUG();
1286 }
1287 BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY);
1288
1289 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1290 refs = btrfs_extent_refs(l, item);
1291 btrfs_set_extent_refs(l, item, refs + 1);
1292 btrfs_mark_buffer_dirty(path->nodes[0]);
1293
1294 btrfs_release_path(root->fs_info->extent_root, path);
1295
1296 path->reada = 1;
1297 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1298 path, bytenr, parent,
1299 ref_root, ref_generation,
1300 owner_objectid);
1301 BUG_ON(ret);
1302 finish_current_insert(trans, root->fs_info->extent_root, 0);
1303 del_pending_extents(trans, root->fs_info->extent_root, 0);
1304
1305 btrfs_free_path(path);
1306 return 0;
1307 }
1308
1309 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1310 struct btrfs_root *root,
1311 u64 bytenr, u64 num_bytes, u64 parent,
1312 u64 ref_root, u64 ref_generation,
1313 u64 owner_objectid)
1314 {
1315 int ret;
1316 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
1317 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
1318 return 0;
1319 ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent,
1320 0, ref_root, 0, ref_generation,
1321 owner_objectid);
1322 return ret;
1323 }
1324
1325 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
1326 struct btrfs_root *root)
1327 {
1328 finish_current_insert(trans, root->fs_info->extent_root, 1);
1329 del_pending_extents(trans, root->fs_info->extent_root, 1);
1330 return 0;
1331 }
1332
1333 int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
1334 struct btrfs_root *root, u64 bytenr,
1335 u64 num_bytes, u32 *refs)
1336 {
1337 struct btrfs_path *path;
1338 int ret;
1339 struct btrfs_key key;
1340 struct extent_buffer *l;
1341 struct btrfs_extent_item *item;
1342
1343 WARN_ON(num_bytes < root->sectorsize);
1344 path = btrfs_alloc_path();
1345 path->reada = 1;
1346 key.objectid = bytenr;
1347 key.offset = num_bytes;
1348 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1349 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1350 0, 0);
1351 if (ret < 0)
1352 goto out;
1353 if (ret != 0) {
1354 btrfs_print_leaf(root, path->nodes[0]);
1355 printk(KERN_INFO "btrfs failed to find block number %llu\n",
1356 (unsigned long long)bytenr);
1357 BUG();
1358 }
1359 l = path->nodes[0];
1360 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1361 *refs = btrfs_extent_refs(l, item);
1362 out:
1363 btrfs_free_path(path);
1364 return 0;
1365 }
1366
1367 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
1368 struct btrfs_root *root, u64 objectid, u64 bytenr)
1369 {
1370 struct btrfs_root *extent_root = root->fs_info->extent_root;
1371 struct btrfs_path *path;
1372 struct extent_buffer *leaf;
1373 struct btrfs_extent_ref *ref_item;
1374 struct btrfs_key key;
1375 struct btrfs_key found_key;
1376 u64 ref_root;
1377 u64 last_snapshot;
1378 u32 nritems;
1379 int ret;
1380
1381 key.objectid = bytenr;
1382 key.offset = (u64)-1;
1383 key.type = BTRFS_EXTENT_ITEM_KEY;
1384
1385 path = btrfs_alloc_path();
1386 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
1387 if (ret < 0)
1388 goto out;
1389 BUG_ON(ret == 0);
1390
1391 ret = -ENOENT;
1392 if (path->slots[0] == 0)
1393 goto out;
1394
1395 path->slots[0]--;
1396 leaf = path->nodes[0];
1397 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1398
1399 if (found_key.objectid != bytenr ||
1400 found_key.type != BTRFS_EXTENT_ITEM_KEY)
1401 goto out;
1402
1403 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1404 while (1) {
1405 leaf = path->nodes[0];
1406 nritems = btrfs_header_nritems(leaf);
1407 if (path->slots[0] >= nritems) {
1408 ret = btrfs_next_leaf(extent_root, path);
1409 if (ret < 0)
1410 goto out;
1411 if (ret == 0)
1412 continue;
1413 break;
1414 }
1415 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1416 if (found_key.objectid != bytenr)
1417 break;
1418
1419 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
1420 path->slots[0]++;
1421 continue;
1422 }
1423
1424 ref_item = btrfs_item_ptr(leaf, path->slots[0],
1425 struct btrfs_extent_ref);
1426 ref_root = btrfs_ref_root(leaf, ref_item);
1427 if ((ref_root != root->root_key.objectid &&
1428 ref_root != BTRFS_TREE_LOG_OBJECTID) ||
1429 objectid != btrfs_ref_objectid(leaf, ref_item)) {
1430 ret = 1;
1431 goto out;
1432 }
1433 if (btrfs_ref_generation(leaf, ref_item) <= last_snapshot) {
1434 ret = 1;
1435 goto out;
1436 }
1437
1438 path->slots[0]++;
1439 }
1440 ret = 0;
1441 out:
1442 btrfs_free_path(path);
1443 return ret;
1444 }
1445
1446 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1447 struct extent_buffer *buf, u32 nr_extents)
1448 {
1449 struct btrfs_key key;
1450 struct btrfs_file_extent_item *fi;
1451 u64 root_gen;
1452 u32 nritems;
1453 int i;
1454 int level;
1455 int ret = 0;
1456 int shared = 0;
1457
1458 if (!root->ref_cows)
1459 return 0;
1460
1461 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1462 shared = 0;
1463 root_gen = root->root_key.offset;
1464 } else {
1465 shared = 1;
1466 root_gen = trans->transid - 1;
1467 }
1468
1469 level = btrfs_header_level(buf);
1470 nritems = btrfs_header_nritems(buf);
1471
1472 if (level == 0) {
1473 struct btrfs_leaf_ref *ref;
1474 struct btrfs_extent_info *info;
1475
1476 ref = btrfs_alloc_leaf_ref(root, nr_extents);
1477 if (!ref) {
1478 ret = -ENOMEM;
1479 goto out;
1480 }
1481
1482 ref->root_gen = root_gen;
1483 ref->bytenr = buf->start;
1484 ref->owner = btrfs_header_owner(buf);
1485 ref->generation = btrfs_header_generation(buf);
1486 ref->nritems = nr_extents;
1487 info = ref->extents;
1488
1489 for (i = 0; nr_extents > 0 && i < nritems; i++) {
1490 u64 disk_bytenr;
1491 btrfs_item_key_to_cpu(buf, &key, i);
1492 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1493 continue;
1494 fi = btrfs_item_ptr(buf, i,
1495 struct btrfs_file_extent_item);
1496 if (btrfs_file_extent_type(buf, fi) ==
1497 BTRFS_FILE_EXTENT_INLINE)
1498 continue;
1499 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1500 if (disk_bytenr == 0)
1501 continue;
1502
1503 info->bytenr = disk_bytenr;
1504 info->num_bytes =
1505 btrfs_file_extent_disk_num_bytes(buf, fi);
1506 info->objectid = key.objectid;
1507 info->offset = key.offset;
1508 info++;
1509 }
1510
1511 ret = btrfs_add_leaf_ref(root, ref, shared);
1512 if (ret == -EEXIST && shared) {
1513 struct btrfs_leaf_ref *old;
1514 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
1515 BUG_ON(!old);
1516 btrfs_remove_leaf_ref(root, old);
1517 btrfs_free_leaf_ref(root, old);
1518 ret = btrfs_add_leaf_ref(root, ref, shared);
1519 }
1520 WARN_ON(ret);
1521 btrfs_free_leaf_ref(root, ref);
1522 }
1523 out:
1524 return ret;
1525 }
1526
1527 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1528 struct extent_buffer *orig_buf, struct extent_buffer *buf,
1529 u32 *nr_extents)
1530 {
1531 u64 bytenr;
1532 u64 ref_root;
1533 u64 orig_root;
1534 u64 ref_generation;
1535 u64 orig_generation;
1536 u32 nritems;
1537 u32 nr_file_extents = 0;
1538 struct btrfs_key key;
1539 struct btrfs_file_extent_item *fi;
1540 int i;
1541 int level;
1542 int ret = 0;
1543 int faili = 0;
1544 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
1545 u64, u64, u64, u64, u64, u64, u64, u64);
1546
1547 ref_root = btrfs_header_owner(buf);
1548 ref_generation = btrfs_header_generation(buf);
1549 orig_root = btrfs_header_owner(orig_buf);
1550 orig_generation = btrfs_header_generation(orig_buf);
1551
1552 nritems = btrfs_header_nritems(buf);
1553 level = btrfs_header_level(buf);
1554
1555 if (root->ref_cows) {
1556 process_func = __btrfs_inc_extent_ref;
1557 } else {
1558 if (level == 0 &&
1559 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1560 goto out;
1561 if (level != 0 &&
1562 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1563 goto out;
1564 process_func = __btrfs_update_extent_ref;
1565 }
1566
1567 for (i = 0; i < nritems; i++) {
1568 cond_resched();
1569 if (level == 0) {
1570 btrfs_item_key_to_cpu(buf, &key, i);
1571 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1572 continue;
1573 fi = btrfs_item_ptr(buf, i,
1574 struct btrfs_file_extent_item);
1575 if (btrfs_file_extent_type(buf, fi) ==
1576 BTRFS_FILE_EXTENT_INLINE)
1577 continue;
1578 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1579 if (bytenr == 0)
1580 continue;
1581
1582 nr_file_extents++;
1583
1584 ret = process_func(trans, root, bytenr,
1585 orig_buf->start, buf->start,
1586 orig_root, ref_root,
1587 orig_generation, ref_generation,
1588 key.objectid);
1589
1590 if (ret) {
1591 faili = i;
1592 WARN_ON(1);
1593 goto fail;
1594 }
1595 } else {
1596 bytenr = btrfs_node_blockptr(buf, i);
1597 ret = process_func(trans, root, bytenr,
1598 orig_buf->start, buf->start,
1599 orig_root, ref_root,
1600 orig_generation, ref_generation,
1601 level - 1);
1602 if (ret) {
1603 faili = i;
1604 WARN_ON(1);
1605 goto fail;
1606 }
1607 }
1608 }
1609 out:
1610 if (nr_extents) {
1611 if (level == 0)
1612 *nr_extents = nr_file_extents;
1613 else
1614 *nr_extents = nritems;
1615 }
1616 return 0;
1617 fail:
1618 WARN_ON(1);
1619 return ret;
1620 }
1621
1622 int btrfs_update_ref(struct btrfs_trans_handle *trans,
1623 struct btrfs_root *root, struct extent_buffer *orig_buf,
1624 struct extent_buffer *buf, int start_slot, int nr)
1625
1626 {
1627 u64 bytenr;
1628 u64 ref_root;
1629 u64 orig_root;
1630 u64 ref_generation;
1631 u64 orig_generation;
1632 struct btrfs_key key;
1633 struct btrfs_file_extent_item *fi;
1634 int i;
1635 int ret;
1636 int slot;
1637 int level;
1638
1639 BUG_ON(start_slot < 0);
1640 BUG_ON(start_slot + nr > btrfs_header_nritems(buf));
1641
1642 ref_root = btrfs_header_owner(buf);
1643 ref_generation = btrfs_header_generation(buf);
1644 orig_root = btrfs_header_owner(orig_buf);
1645 orig_generation = btrfs_header_generation(orig_buf);
1646 level = btrfs_header_level(buf);
1647
1648 if (!root->ref_cows) {
1649 if (level == 0 &&
1650 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1651 return 0;
1652 if (level != 0 &&
1653 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1654 return 0;
1655 }
1656
1657 for (i = 0, slot = start_slot; i < nr; i++, slot++) {
1658 cond_resched();
1659 if (level == 0) {
1660 btrfs_item_key_to_cpu(buf, &key, slot);
1661 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1662 continue;
1663 fi = btrfs_item_ptr(buf, slot,
1664 struct btrfs_file_extent_item);
1665 if (btrfs_file_extent_type(buf, fi) ==
1666 BTRFS_FILE_EXTENT_INLINE)
1667 continue;
1668 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1669 if (bytenr == 0)
1670 continue;
1671 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1672 orig_buf->start, buf->start,
1673 orig_root, ref_root,
1674 orig_generation, ref_generation,
1675 key.objectid);
1676 if (ret)
1677 goto fail;
1678 } else {
1679 bytenr = btrfs_node_blockptr(buf, slot);
1680 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1681 orig_buf->start, buf->start,
1682 orig_root, ref_root,
1683 orig_generation, ref_generation,
1684 level - 1);
1685 if (ret)
1686 goto fail;
1687 }
1688 }
1689 return 0;
1690 fail:
1691 WARN_ON(1);
1692 return -1;
1693 }
1694
1695 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1696 struct btrfs_root *root,
1697 struct btrfs_path *path,
1698 struct btrfs_block_group_cache *cache)
1699 {
1700 int ret;
1701 int pending_ret;
1702 struct btrfs_root *extent_root = root->fs_info->extent_root;
1703 unsigned long bi;
1704 struct extent_buffer *leaf;
1705
1706 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1707 if (ret < 0)
1708 goto fail;
1709 BUG_ON(ret);
1710
1711 leaf = path->nodes[0];
1712 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1713 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1714 btrfs_mark_buffer_dirty(leaf);
1715 btrfs_release_path(extent_root, path);
1716 fail:
1717 finish_current_insert(trans, extent_root, 0);
1718 pending_ret = del_pending_extents(trans, extent_root, 0);
1719 if (ret)
1720 return ret;
1721 if (pending_ret)
1722 return pending_ret;
1723 return 0;
1724
1725 }
1726
1727 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1728 struct btrfs_root *root)
1729 {
1730 struct btrfs_block_group_cache *cache, *entry;
1731 struct rb_node *n;
1732 int err = 0;
1733 int werr = 0;
1734 struct btrfs_path *path;
1735 u64 last = 0;
1736
1737 path = btrfs_alloc_path();
1738 if (!path)
1739 return -ENOMEM;
1740
1741 while (1) {
1742 cache = NULL;
1743 spin_lock(&root->fs_info->block_group_cache_lock);
1744 for (n = rb_first(&root->fs_info->block_group_cache_tree);
1745 n; n = rb_next(n)) {
1746 entry = rb_entry(n, struct btrfs_block_group_cache,
1747 cache_node);
1748 if (entry->dirty) {
1749 cache = entry;
1750 break;
1751 }
1752 }
1753 spin_unlock(&root->fs_info->block_group_cache_lock);
1754
1755 if (!cache)
1756 break;
1757
1758 cache->dirty = 0;
1759 last += cache->key.offset;
1760
1761 err = write_one_cache_group(trans, root,
1762 path, cache);
1763 /*
1764 * if we fail to write the cache group, we want
1765 * to keep it marked dirty in hopes that a later
1766 * write will work
1767 */
1768 if (err) {
1769 werr = err;
1770 continue;
1771 }
1772 }
1773 btrfs_free_path(path);
1774 return werr;
1775 }
1776
1777 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
1778 {
1779 struct btrfs_block_group_cache *block_group;
1780 int readonly = 0;
1781
1782 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
1783 if (!block_group || block_group->ro)
1784 readonly = 1;
1785 if (block_group)
1786 put_block_group(block_group);
1787 return readonly;
1788 }
1789
1790 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1791 u64 total_bytes, u64 bytes_used,
1792 struct btrfs_space_info **space_info)
1793 {
1794 struct btrfs_space_info *found;
1795
1796 found = __find_space_info(info, flags);
1797 if (found) {
1798 spin_lock(&found->lock);
1799 found->total_bytes += total_bytes;
1800 found->bytes_used += bytes_used;
1801 found->full = 0;
1802 spin_unlock(&found->lock);
1803 *space_info = found;
1804 return 0;
1805 }
1806 found = kzalloc(sizeof(*found), GFP_NOFS);
1807 if (!found)
1808 return -ENOMEM;
1809
1810 list_add(&found->list, &info->space_info);
1811 INIT_LIST_HEAD(&found->block_groups);
1812 init_rwsem(&found->groups_sem);
1813 spin_lock_init(&found->lock);
1814 found->flags = flags;
1815 found->total_bytes = total_bytes;
1816 found->bytes_used = bytes_used;
1817 found->bytes_pinned = 0;
1818 found->bytes_reserved = 0;
1819 found->bytes_readonly = 0;
1820 found->full = 0;
1821 found->force_alloc = 0;
1822 *space_info = found;
1823 return 0;
1824 }
1825
1826 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1827 {
1828 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1829 BTRFS_BLOCK_GROUP_RAID1 |
1830 BTRFS_BLOCK_GROUP_RAID10 |
1831 BTRFS_BLOCK_GROUP_DUP);
1832 if (extra_flags) {
1833 if (flags & BTRFS_BLOCK_GROUP_DATA)
1834 fs_info->avail_data_alloc_bits |= extra_flags;
1835 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1836 fs_info->avail_metadata_alloc_bits |= extra_flags;
1837 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1838 fs_info->avail_system_alloc_bits |= extra_flags;
1839 }
1840 }
1841
1842 static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
1843 {
1844 spin_lock(&cache->space_info->lock);
1845 spin_lock(&cache->lock);
1846 if (!cache->ro) {
1847 cache->space_info->bytes_readonly += cache->key.offset -
1848 btrfs_block_group_used(&cache->item);
1849 cache->ro = 1;
1850 }
1851 spin_unlock(&cache->lock);
1852 spin_unlock(&cache->space_info->lock);
1853 }
1854
1855 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
1856 {
1857 u64 num_devices = root->fs_info->fs_devices->rw_devices;
1858
1859 if (num_devices == 1)
1860 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
1861 if (num_devices < 4)
1862 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
1863
1864 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
1865 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
1866 BTRFS_BLOCK_GROUP_RAID10))) {
1867 flags &= ~BTRFS_BLOCK_GROUP_DUP;
1868 }
1869
1870 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
1871 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
1872 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
1873 }
1874
1875 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
1876 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
1877 (flags & BTRFS_BLOCK_GROUP_RAID10) |
1878 (flags & BTRFS_BLOCK_GROUP_DUP)))
1879 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
1880 return flags;
1881 }
1882
1883 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1884 struct btrfs_root *extent_root, u64 alloc_bytes,
1885 u64 flags, int force)
1886 {
1887 struct btrfs_space_info *space_info;
1888 u64 thresh;
1889 int ret = 0;
1890
1891 mutex_lock(&extent_root->fs_info->chunk_mutex);
1892
1893 flags = btrfs_reduce_alloc_profile(extent_root, flags);
1894
1895 space_info = __find_space_info(extent_root->fs_info, flags);
1896 if (!space_info) {
1897 ret = update_space_info(extent_root->fs_info, flags,
1898 0, 0, &space_info);
1899 BUG_ON(ret);
1900 }
1901 BUG_ON(!space_info);
1902
1903 spin_lock(&space_info->lock);
1904 if (space_info->force_alloc) {
1905 force = 1;
1906 space_info->force_alloc = 0;
1907 }
1908 if (space_info->full) {
1909 spin_unlock(&space_info->lock);
1910 goto out;
1911 }
1912
1913 thresh = space_info->total_bytes - space_info->bytes_readonly;
1914 thresh = div_factor(thresh, 6);
1915 if (!force &&
1916 (space_info->bytes_used + space_info->bytes_pinned +
1917 space_info->bytes_reserved + alloc_bytes) < thresh) {
1918 spin_unlock(&space_info->lock);
1919 goto out;
1920 }
1921 spin_unlock(&space_info->lock);
1922
1923 ret = btrfs_alloc_chunk(trans, extent_root, flags);
1924 if (ret)
1925 space_info->full = 1;
1926 out:
1927 mutex_unlock(&extent_root->fs_info->chunk_mutex);
1928 return ret;
1929 }
1930
1931 static int update_block_group(struct btrfs_trans_handle *trans,
1932 struct btrfs_root *root,
1933 u64 bytenr, u64 num_bytes, int alloc,
1934 int mark_free)
1935 {
1936 struct btrfs_block_group_cache *cache;
1937 struct btrfs_fs_info *info = root->fs_info;
1938 u64 total = num_bytes;
1939 u64 old_val;
1940 u64 byte_in_group;
1941
1942 while (total) {
1943 cache = btrfs_lookup_block_group(info, bytenr);
1944 if (!cache)
1945 return -1;
1946 byte_in_group = bytenr - cache->key.objectid;
1947 WARN_ON(byte_in_group > cache->key.offset);
1948
1949 spin_lock(&cache->space_info->lock);
1950 spin_lock(&cache->lock);
1951 cache->dirty = 1;
1952 old_val = btrfs_block_group_used(&cache->item);
1953 num_bytes = min(total, cache->key.offset - byte_in_group);
1954 if (alloc) {
1955 old_val += num_bytes;
1956 cache->space_info->bytes_used += num_bytes;
1957 if (cache->ro)
1958 cache->space_info->bytes_readonly -= num_bytes;
1959 btrfs_set_block_group_used(&cache->item, old_val);
1960 spin_unlock(&cache->lock);
1961 spin_unlock(&cache->space_info->lock);
1962 } else {
1963 old_val -= num_bytes;
1964 cache->space_info->bytes_used -= num_bytes;
1965 if (cache->ro)
1966 cache->space_info->bytes_readonly += num_bytes;
1967 btrfs_set_block_group_used(&cache->item, old_val);
1968 spin_unlock(&cache->lock);
1969 spin_unlock(&cache->space_info->lock);
1970 if (mark_free) {
1971 int ret;
1972
1973 ret = btrfs_discard_extent(root, bytenr,
1974 num_bytes);
1975 WARN_ON(ret);
1976
1977 ret = btrfs_add_free_space(cache, bytenr,
1978 num_bytes);
1979 WARN_ON(ret);
1980 }
1981 }
1982 put_block_group(cache);
1983 total -= num_bytes;
1984 bytenr += num_bytes;
1985 }
1986 return 0;
1987 }
1988
1989 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
1990 {
1991 struct btrfs_block_group_cache *cache;
1992 u64 bytenr;
1993
1994 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
1995 if (!cache)
1996 return 0;
1997
1998 bytenr = cache->key.objectid;
1999 put_block_group(cache);
2000
2001 return bytenr;
2002 }
2003
2004 int btrfs_update_pinned_extents(struct btrfs_root *root,
2005 u64 bytenr, u64 num, int pin)
2006 {
2007 u64 len;
2008 struct btrfs_block_group_cache *cache;
2009 struct btrfs_fs_info *fs_info = root->fs_info;
2010
2011 WARN_ON(!mutex_is_locked(&root->fs_info->pinned_mutex));
2012 if (pin) {
2013 set_extent_dirty(&fs_info->pinned_extents,
2014 bytenr, bytenr + num - 1, GFP_NOFS);
2015 } else {
2016 clear_extent_dirty(&fs_info->pinned_extents,
2017 bytenr, bytenr + num - 1, GFP_NOFS);
2018 }
2019 while (num > 0) {
2020 cache = btrfs_lookup_block_group(fs_info, bytenr);
2021 BUG_ON(!cache);
2022 len = min(num, cache->key.offset -
2023 (bytenr - cache->key.objectid));
2024 if (pin) {
2025 spin_lock(&cache->space_info->lock);
2026 spin_lock(&cache->lock);
2027 cache->pinned += len;
2028 cache->space_info->bytes_pinned += len;
2029 spin_unlock(&cache->lock);
2030 spin_unlock(&cache->space_info->lock);
2031 fs_info->total_pinned += len;
2032 } else {
2033 spin_lock(&cache->space_info->lock);
2034 spin_lock(&cache->lock);
2035 cache->pinned -= len;
2036 cache->space_info->bytes_pinned -= len;
2037 spin_unlock(&cache->lock);
2038 spin_unlock(&cache->space_info->lock);
2039 fs_info->total_pinned -= len;
2040 if (cache->cached)
2041 btrfs_add_free_space(cache, bytenr, len);
2042 }
2043 put_block_group(cache);
2044 bytenr += len;
2045 num -= len;
2046 }
2047 return 0;
2048 }
2049
2050 static int update_reserved_extents(struct btrfs_root *root,
2051 u64 bytenr, u64 num, int reserve)
2052 {
2053 u64 len;
2054 struct btrfs_block_group_cache *cache;
2055 struct btrfs_fs_info *fs_info = root->fs_info;
2056
2057 while (num > 0) {
2058 cache = btrfs_lookup_block_group(fs_info, bytenr);
2059 BUG_ON(!cache);
2060 len = min(num, cache->key.offset -
2061 (bytenr - cache->key.objectid));
2062
2063 spin_lock(&cache->space_info->lock);
2064 spin_lock(&cache->lock);
2065 if (reserve) {
2066 cache->reserved += len;
2067 cache->space_info->bytes_reserved += len;
2068 } else {
2069 cache->reserved -= len;
2070 cache->space_info->bytes_reserved -= len;
2071 }
2072 spin_unlock(&cache->lock);
2073 spin_unlock(&cache->space_info->lock);
2074 put_block_group(cache);
2075 bytenr += len;
2076 num -= len;
2077 }
2078 return 0;
2079 }
2080
2081 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
2082 {
2083 u64 last = 0;
2084 u64 start;
2085 u64 end;
2086 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
2087 int ret;
2088
2089 mutex_lock(&root->fs_info->pinned_mutex);
2090 while (1) {
2091 ret = find_first_extent_bit(pinned_extents, last,
2092 &start, &end, EXTENT_DIRTY);
2093 if (ret)
2094 break;
2095 set_extent_dirty(copy, start, end, GFP_NOFS);
2096 last = end + 1;
2097 }
2098 mutex_unlock(&root->fs_info->pinned_mutex);
2099 return 0;
2100 }
2101
2102 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
2103 struct btrfs_root *root,
2104 struct extent_io_tree *unpin)
2105 {
2106 u64 start;
2107 u64 end;
2108 int ret;
2109
2110 mutex_lock(&root->fs_info->pinned_mutex);
2111 while (1) {
2112 ret = find_first_extent_bit(unpin, 0, &start, &end,
2113 EXTENT_DIRTY);
2114 if (ret)
2115 break;
2116
2117 ret = btrfs_discard_extent(root, start, end + 1 - start);
2118
2119 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
2120 clear_extent_dirty(unpin, start, end, GFP_NOFS);
2121
2122 if (need_resched()) {
2123 mutex_unlock(&root->fs_info->pinned_mutex);
2124 cond_resched();
2125 mutex_lock(&root->fs_info->pinned_mutex);
2126 }
2127 }
2128 mutex_unlock(&root->fs_info->pinned_mutex);
2129 return ret;
2130 }
2131
2132 static int finish_current_insert(struct btrfs_trans_handle *trans,
2133 struct btrfs_root *extent_root, int all)
2134 {
2135 u64 start;
2136 u64 end;
2137 u64 priv;
2138 u64 search = 0;
2139 u64 skipped = 0;
2140 struct btrfs_fs_info *info = extent_root->fs_info;
2141 struct btrfs_path *path;
2142 struct pending_extent_op *extent_op, *tmp;
2143 struct list_head insert_list, update_list;
2144 int ret;
2145 int num_inserts = 0, max_inserts;
2146
2147 path = btrfs_alloc_path();
2148 INIT_LIST_HEAD(&insert_list);
2149 INIT_LIST_HEAD(&update_list);
2150
2151 max_inserts = extent_root->leafsize /
2152 (2 * sizeof(struct btrfs_key) + 2 * sizeof(struct btrfs_item) +
2153 sizeof(struct btrfs_extent_ref) +
2154 sizeof(struct btrfs_extent_item));
2155 again:
2156 mutex_lock(&info->extent_ins_mutex);
2157 while (1) {
2158 ret = find_first_extent_bit(&info->extent_ins, search, &start,
2159 &end, EXTENT_WRITEBACK);
2160 if (ret) {
2161 if (skipped && all && !num_inserts) {
2162 skipped = 0;
2163 search = 0;
2164 continue;
2165 }
2166 mutex_unlock(&info->extent_ins_mutex);
2167 break;
2168 }
2169
2170 ret = try_lock_extent(&info->extent_ins, start, end, GFP_NOFS);
2171 if (!ret) {
2172 skipped = 1;
2173 search = end + 1;
2174 if (need_resched()) {
2175 mutex_unlock(&info->extent_ins_mutex);
2176 cond_resched();
2177 mutex_lock(&info->extent_ins_mutex);
2178 }
2179 continue;
2180 }
2181
2182 ret = get_state_private(&info->extent_ins, start, &priv);
2183 BUG_ON(ret);
2184 extent_op = (struct pending_extent_op *)(unsigned long) priv;
2185
2186 if (extent_op->type == PENDING_EXTENT_INSERT) {
2187 num_inserts++;
2188 list_add_tail(&extent_op->list, &insert_list);
2189 search = end + 1;
2190 if (num_inserts == max_inserts) {
2191 mutex_unlock(&info->extent_ins_mutex);
2192 break;
2193 }
2194 } else if (extent_op->type == PENDING_BACKREF_UPDATE) {
2195 list_add_tail(&extent_op->list, &update_list);
2196 search = end + 1;
2197 } else {
2198 BUG();
2199 }
2200 }
2201
2202 /*
2203 * process the update list, clear the writeback bit for it, and if
2204 * somebody marked this thing for deletion then just unlock it and be
2205 * done, the free_extents will handle it
2206 */
2207 mutex_lock(&info->extent_ins_mutex);
2208 list_for_each_entry_safe(extent_op, tmp, &update_list, list) {
2209 clear_extent_bits(&info->extent_ins, extent_op->bytenr,
2210 extent_op->bytenr + extent_op->num_bytes - 1,
2211 EXTENT_WRITEBACK, GFP_NOFS);
2212 if (extent_op->del) {
2213 list_del_init(&extent_op->list);
2214 unlock_extent(&info->extent_ins, extent_op->bytenr,
2215 extent_op->bytenr + extent_op->num_bytes
2216 - 1, GFP_NOFS);
2217 kfree(extent_op);
2218 }
2219 }
2220 mutex_unlock(&info->extent_ins_mutex);
2221
2222 /*
2223 * still have things left on the update list, go ahead an update
2224 * everything
2225 */
2226 if (!list_empty(&update_list)) {
2227 ret = update_backrefs(trans, extent_root, path, &update_list);
2228 BUG_ON(ret);
2229 }
2230
2231 /*
2232 * if no inserts need to be done, but we skipped some extents and we
2233 * need to make sure everything is cleaned then reset everything and
2234 * go back to the beginning
2235 */
2236 if (!num_inserts && all && skipped) {
2237 search = 0;
2238 skipped = 0;
2239 INIT_LIST_HEAD(&update_list);
2240 INIT_LIST_HEAD(&insert_list);
2241 goto again;
2242 } else if (!num_inserts) {
2243 goto out;
2244 }
2245
2246 /*
2247 * process the insert extents list. Again if we are deleting this
2248 * extent, then just unlock it, pin down the bytes if need be, and be
2249 * done with it. Saves us from having to actually insert the extent
2250 * into the tree and then subsequently come along and delete it
2251 */
2252 mutex_lock(&info->extent_ins_mutex);
2253 list_for_each_entry_safe(extent_op, tmp, &insert_list, list) {
2254 clear_extent_bits(&info->extent_ins, extent_op->bytenr,
2255 extent_op->bytenr + extent_op->num_bytes - 1,
2256 EXTENT_WRITEBACK, GFP_NOFS);
2257 if (extent_op->del) {
2258 u64 used;
2259 list_del_init(&extent_op->list);
2260 unlock_extent(&info->extent_ins, extent_op->bytenr,
2261 extent_op->bytenr + extent_op->num_bytes
2262 - 1, GFP_NOFS);
2263
2264 mutex_lock(&extent_root->fs_info->pinned_mutex);
2265 ret = pin_down_bytes(trans, extent_root,
2266 extent_op->bytenr,
2267 extent_op->num_bytes, 0);
2268 mutex_unlock(&extent_root->fs_info->pinned_mutex);
2269
2270 spin_lock(&info->delalloc_lock);
2271 used = btrfs_super_bytes_used(&info->super_copy);
2272 btrfs_set_super_bytes_used(&info->super_copy,
2273 used - extent_op->num_bytes);
2274 used = btrfs_root_used(&extent_root->root_item);
2275 btrfs_set_root_used(&extent_root->root_item,
2276 used - extent_op->num_bytes);
2277 spin_unlock(&info->delalloc_lock);
2278
2279 ret = update_block_group(trans, extent_root,
2280 extent_op->bytenr,
2281 extent_op->num_bytes,
2282 0, ret > 0);
2283 BUG_ON(ret);
2284 kfree(extent_op);
2285 num_inserts--;
2286 }
2287 }
2288 mutex_unlock(&info->extent_ins_mutex);
2289
2290 ret = insert_extents(trans, extent_root, path, &insert_list,
2291 num_inserts);
2292 BUG_ON(ret);
2293
2294 /*
2295 * if we broke out of the loop in order to insert stuff because we hit
2296 * the maximum number of inserts at a time we can handle, then loop
2297 * back and pick up where we left off
2298 */
2299 if (num_inserts == max_inserts) {
2300 INIT_LIST_HEAD(&insert_list);
2301 INIT_LIST_HEAD(&update_list);
2302 num_inserts = 0;
2303 goto again;
2304 }
2305
2306 /*
2307 * again, if we need to make absolutely sure there are no more pending
2308 * extent operations left and we know that we skipped some, go back to
2309 * the beginning and do it all again
2310 */
2311 if (all && skipped) {
2312 INIT_LIST_HEAD(&insert_list);
2313 INIT_LIST_HEAD(&update_list);
2314 search = 0;
2315 skipped = 0;
2316 num_inserts = 0;
2317 goto again;
2318 }
2319 out:
2320 btrfs_free_path(path);
2321 return 0;
2322 }
2323
2324 static int pin_down_bytes(struct btrfs_trans_handle *trans,
2325 struct btrfs_root *root,
2326 u64 bytenr, u64 num_bytes, int is_data)
2327 {
2328 int err = 0;
2329 struct extent_buffer *buf;
2330
2331 if (is_data)
2332 goto pinit;
2333
2334 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
2335 if (!buf)
2336 goto pinit;
2337
2338 /* we can reuse a block if it hasn't been written
2339 * and it is from this transaction. We can't
2340 * reuse anything from the tree log root because
2341 * it has tiny sub-transactions.
2342 */
2343 if (btrfs_buffer_uptodate(buf, 0) &&
2344 btrfs_try_tree_lock(buf)) {
2345 u64 header_owner = btrfs_header_owner(buf);
2346 u64 header_transid = btrfs_header_generation(buf);
2347 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
2348 header_owner != BTRFS_TREE_RELOC_OBJECTID &&
2349 header_transid == trans->transid &&
2350 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
2351 clean_tree_block(NULL, root, buf);
2352 btrfs_tree_unlock(buf);
2353 free_extent_buffer(buf);
2354 return 1;
2355 }
2356 btrfs_tree_unlock(buf);
2357 }
2358 free_extent_buffer(buf);
2359 pinit:
2360 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
2361
2362 BUG_ON(err < 0);
2363 return 0;
2364 }
2365
2366 /*
2367 * remove an extent from the root, returns 0 on success
2368 */
2369 static int __free_extent(struct btrfs_trans_handle *trans,
2370 struct btrfs_root *root,
2371 u64 bytenr, u64 num_bytes, u64 parent,
2372 u64 root_objectid, u64 ref_generation,
2373 u64 owner_objectid, int pin, int mark_free)
2374 {
2375 struct btrfs_path *path;
2376 struct btrfs_key key;
2377 struct btrfs_fs_info *info = root->fs_info;
2378 struct btrfs_root *extent_root = info->extent_root;
2379 struct extent_buffer *leaf;
2380 int ret;
2381 int extent_slot = 0;
2382 int found_extent = 0;
2383 int num_to_del = 1;
2384 struct btrfs_extent_item *ei;
2385 u32 refs;
2386
2387 key.objectid = bytenr;
2388 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
2389 key.offset = num_bytes;
2390 path = btrfs_alloc_path();
2391 if (!path)
2392 return -ENOMEM;
2393
2394 path->reada = 1;
2395 ret = lookup_extent_backref(trans, extent_root, path,
2396 bytenr, parent, root_objectid,
2397 ref_generation, owner_objectid, 1);
2398 if (ret == 0) {
2399 struct btrfs_key found_key;
2400 extent_slot = path->slots[0];
2401 while (extent_slot > 0) {
2402 extent_slot--;
2403 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2404 extent_slot);
2405 if (found_key.objectid != bytenr)
2406 break;
2407 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
2408 found_key.offset == num_bytes) {
2409 found_extent = 1;
2410 break;
2411 }
2412 if (path->slots[0] - extent_slot > 5)
2413 break;
2414 }
2415 if (!found_extent) {
2416 ret = remove_extent_backref(trans, extent_root, path);
2417 BUG_ON(ret);
2418 btrfs_release_path(extent_root, path);
2419 ret = btrfs_search_slot(trans, extent_root,
2420 &key, path, -1, 1);
2421 if (ret) {
2422 printk(KERN_ERR "umm, got %d back from search"
2423 ", was looking for %llu\n", ret,
2424 (unsigned long long)bytenr);
2425 btrfs_print_leaf(extent_root, path->nodes[0]);
2426 }
2427 BUG_ON(ret);
2428 extent_slot = path->slots[0];
2429 }
2430 } else {
2431 btrfs_print_leaf(extent_root, path->nodes[0]);
2432 WARN_ON(1);
2433 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
2434 "root %llu gen %llu owner %llu\n",
2435 (unsigned long long)bytenr,
2436 (unsigned long long)root_objectid,
2437 (unsigned long long)ref_generation,
2438 (unsigned long long)owner_objectid);
2439 }
2440
2441 leaf = path->nodes[0];
2442 ei = btrfs_item_ptr(leaf, extent_slot,
2443 struct btrfs_extent_item);
2444 refs = btrfs_extent_refs(leaf, ei);
2445 BUG_ON(refs == 0);
2446 refs -= 1;
2447 btrfs_set_extent_refs(leaf, ei, refs);
2448
2449 btrfs_mark_buffer_dirty(leaf);
2450
2451 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
2452 struct btrfs_extent_ref *ref;
2453 ref = btrfs_item_ptr(leaf, path->slots[0],
2454 struct btrfs_extent_ref);
2455 BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1);
2456 /* if the back ref and the extent are next to each other
2457 * they get deleted below in one shot
2458 */
2459 path->slots[0] = extent_slot;
2460 num_to_del = 2;
2461 } else if (found_extent) {
2462 /* otherwise delete the extent back ref */
2463 ret = remove_extent_backref(trans, extent_root, path);
2464 BUG_ON(ret);
2465 /* if refs are 0, we need to setup the path for deletion */
2466 if (refs == 0) {
2467 btrfs_release_path(extent_root, path);
2468 ret = btrfs_search_slot(trans, extent_root, &key, path,
2469 -1, 1);
2470 BUG_ON(ret);
2471 }
2472 }
2473
2474 if (refs == 0) {
2475 u64 super_used;
2476 u64 root_used;
2477
2478 if (pin) {
2479 mutex_lock(&root->fs_info->pinned_mutex);
2480 ret = pin_down_bytes(trans, root, bytenr, num_bytes,
2481 owner_objectid >= BTRFS_FIRST_FREE_OBJECTID);
2482 mutex_unlock(&root->fs_info->pinned_mutex);
2483 if (ret > 0)
2484 mark_free = 1;
2485 BUG_ON(ret < 0);
2486 }
2487 /* block accounting for super block */
2488 spin_lock(&info->delalloc_lock);
2489 super_used = btrfs_super_bytes_used(&info->super_copy);
2490 btrfs_set_super_bytes_used(&info->super_copy,
2491 super_used - num_bytes);
2492
2493 /* block accounting for root item */
2494 root_used = btrfs_root_used(&root->root_item);
2495 btrfs_set_root_used(&root->root_item,
2496 root_used - num_bytes);
2497 spin_unlock(&info->delalloc_lock);
2498 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
2499 num_to_del);
2500 BUG_ON(ret);
2501 btrfs_release_path(extent_root, path);
2502
2503 if (owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
2504 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
2505 BUG_ON(ret);
2506 }
2507
2508 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
2509 mark_free);
2510 BUG_ON(ret);
2511 }
2512 btrfs_free_path(path);
2513 finish_current_insert(trans, extent_root, 0);
2514 return ret;
2515 }
2516
2517 /*
2518 * find all the blocks marked as pending in the radix tree and remove
2519 * them from the extent map
2520 */
2521 static int del_pending_extents(struct btrfs_trans_handle *trans,
2522 struct btrfs_root *extent_root, int all)
2523 {
2524 int ret;
2525 int err = 0;
2526 u64 start;
2527 u64 end;
2528 u64 priv;
2529 u64 search = 0;
2530 int nr = 0, skipped = 0;
2531 struct extent_io_tree *pending_del;
2532 struct extent_io_tree *extent_ins;
2533 struct pending_extent_op *extent_op;
2534 struct btrfs_fs_info *info = extent_root->fs_info;
2535 struct list_head delete_list;
2536
2537 INIT_LIST_HEAD(&delete_list);
2538 extent_ins = &extent_root->fs_info->extent_ins;
2539 pending_del = &extent_root->fs_info->pending_del;
2540
2541 again:
2542 mutex_lock(&info->extent_ins_mutex);
2543 while (1) {
2544 ret = find_first_extent_bit(pending_del, search, &start, &end,
2545 EXTENT_WRITEBACK);
2546 if (ret) {
2547 if (all && skipped && !nr) {
2548 search = 0;
2549 continue;
2550 }
2551 mutex_unlock(&info->extent_ins_mutex);
2552 break;
2553 }
2554
2555 ret = try_lock_extent(extent_ins, start, end, GFP_NOFS);
2556 if (!ret) {
2557 search = end+1;
2558 skipped = 1;
2559
2560 if (need_resched()) {
2561 mutex_unlock(&info->extent_ins_mutex);
2562 cond_resched();
2563 mutex_lock(&info->extent_ins_mutex);
2564 }
2565
2566 continue;
2567 }
2568 BUG_ON(ret < 0);
2569
2570 ret = get_state_private(pending_del, start, &priv);
2571 BUG_ON(ret);
2572 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2573
2574 clear_extent_bits(pending_del, start, end, EXTENT_WRITEBACK,
2575 GFP_NOFS);
2576 if (!test_range_bit(extent_ins, start, end,
2577 EXTENT_WRITEBACK, 0)) {
2578 list_add_tail(&extent_op->list, &delete_list);
2579 nr++;
2580 } else {
2581 kfree(extent_op);
2582
2583 ret = get_state_private(&info->extent_ins, start,
2584 &priv);
2585 BUG_ON(ret);
2586 extent_op = (struct pending_extent_op *)
2587 (unsigned long)priv;
2588
2589 clear_extent_bits(&info->extent_ins, start, end,
2590 EXTENT_WRITEBACK, GFP_NOFS);
2591
2592 if (extent_op->type == PENDING_BACKREF_UPDATE) {
2593 list_add_tail(&extent_op->list, &delete_list);
2594 search = end + 1;
2595 nr++;
2596 continue;
2597 }
2598
2599 mutex_lock(&extent_root->fs_info->pinned_mutex);
2600 ret = pin_down_bytes(trans, extent_root, start,
2601 end + 1 - start, 0);
2602 mutex_unlock(&extent_root->fs_info->pinned_mutex);
2603
2604 ret = update_block_group(trans, extent_root, start,
2605 end + 1 - start, 0, ret > 0);
2606
2607 unlock_extent(extent_ins, start, end, GFP_NOFS);
2608 BUG_ON(ret);
2609 kfree(extent_op);
2610 }
2611 if (ret)
2612 err = ret;
2613
2614 search = end + 1;
2615
2616 if (need_resched()) {
2617 mutex_unlock(&info->extent_ins_mutex);
2618 cond_resched();
2619 mutex_lock(&info->extent_ins_mutex);
2620 }
2621 }
2622
2623 if (nr) {
2624 ret = free_extents(trans, extent_root, &delete_list);
2625 BUG_ON(ret);
2626 }
2627
2628 if (all && skipped) {
2629 INIT_LIST_HEAD(&delete_list);
2630 search = 0;
2631 nr = 0;
2632 goto again;
2633 }
2634
2635 return err;
2636 }
2637
2638 /*
2639 * remove an extent from the root, returns 0 on success
2640 */
2641 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
2642 struct btrfs_root *root,
2643 u64 bytenr, u64 num_bytes, u64 parent,
2644 u64 root_objectid, u64 ref_generation,
2645 u64 owner_objectid, int pin)
2646 {
2647 struct btrfs_root *extent_root = root->fs_info->extent_root;
2648 int pending_ret;
2649 int ret;
2650
2651 WARN_ON(num_bytes < root->sectorsize);
2652 if (root == extent_root) {
2653 struct pending_extent_op *extent_op = NULL;
2654
2655 mutex_lock(&root->fs_info->extent_ins_mutex);
2656 if (test_range_bit(&root->fs_info->extent_ins, bytenr,
2657 bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
2658 u64 priv;
2659 ret = get_state_private(&root->fs_info->extent_ins,
2660 bytenr, &priv);
2661 BUG_ON(ret);
2662 extent_op = (struct pending_extent_op *)
2663 (unsigned long)priv;
2664
2665 extent_op->del = 1;
2666 if (extent_op->type == PENDING_EXTENT_INSERT) {
2667 mutex_unlock(&root->fs_info->extent_ins_mutex);
2668 return 0;
2669 }
2670 }
2671
2672 if (extent_op) {
2673 ref_generation = extent_op->orig_generation;
2674 parent = extent_op->orig_parent;
2675 }
2676
2677 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2678 BUG_ON(!extent_op);
2679
2680 extent_op->type = PENDING_EXTENT_DELETE;
2681 extent_op->bytenr = bytenr;
2682 extent_op->num_bytes = num_bytes;
2683 extent_op->parent = parent;
2684 extent_op->orig_parent = parent;
2685 extent_op->generation = ref_generation;
2686 extent_op->orig_generation = ref_generation;
2687 extent_op->level = (int)owner_objectid;
2688 INIT_LIST_HEAD(&extent_op->list);
2689 extent_op->del = 0;
2690
2691 set_extent_bits(&root->fs_info->pending_del,
2692 bytenr, bytenr + num_bytes - 1,
2693 EXTENT_WRITEBACK, GFP_NOFS);
2694 set_state_private(&root->fs_info->pending_del,
2695 bytenr, (unsigned long)extent_op);
2696 mutex_unlock(&root->fs_info->extent_ins_mutex);
2697 return 0;
2698 }
2699 /* if metadata always pin */
2700 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
2701 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2702 struct btrfs_block_group_cache *cache;
2703
2704 /* btrfs_free_reserved_extent */
2705 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
2706 BUG_ON(!cache);
2707 btrfs_add_free_space(cache, bytenr, num_bytes);
2708 put_block_group(cache);
2709 update_reserved_extents(root, bytenr, num_bytes, 0);
2710 return 0;
2711 }
2712 pin = 1;
2713 }
2714
2715 /* if data pin when any transaction has committed this */
2716 if (ref_generation != trans->transid)
2717 pin = 1;
2718
2719 ret = __free_extent(trans, root, bytenr, num_bytes, parent,
2720 root_objectid, ref_generation,
2721 owner_objectid, pin, pin == 0);
2722
2723 finish_current_insert(trans, root->fs_info->extent_root, 0);
2724 pending_ret = del_pending_extents(trans, root->fs_info->extent_root, 0);
2725 return ret ? ret : pending_ret;
2726 }
2727
2728 int btrfs_free_extent(struct btrfs_trans_handle *trans,
2729 struct btrfs_root *root,
2730 u64 bytenr, u64 num_bytes, u64 parent,
2731 u64 root_objectid, u64 ref_generation,
2732 u64 owner_objectid, int pin)
2733 {
2734 int ret;
2735
2736 ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent,
2737 root_objectid, ref_generation,
2738 owner_objectid, pin);
2739 return ret;
2740 }
2741
2742 static u64 stripe_align(struct btrfs_root *root, u64 val)
2743 {
2744 u64 mask = ((u64)root->stripesize - 1);
2745 u64 ret = (val + mask) & ~mask;
2746 return ret;
2747 }
2748
2749 /*
2750 * walks the btree of allocated extents and find a hole of a given size.
2751 * The key ins is changed to record the hole:
2752 * ins->objectid == block start
2753 * ins->flags = BTRFS_EXTENT_ITEM_KEY
2754 * ins->offset == number of blocks
2755 * Any available blocks before search_start are skipped.
2756 */
2757 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
2758 struct btrfs_root *orig_root,
2759 u64 num_bytes, u64 empty_size,
2760 u64 search_start, u64 search_end,
2761 u64 hint_byte, struct btrfs_key *ins,
2762 u64 exclude_start, u64 exclude_nr,
2763 int data)
2764 {
2765 int ret = 0;
2766 struct btrfs_root *root = orig_root->fs_info->extent_root;
2767 u64 total_needed = num_bytes;
2768 u64 *last_ptr = NULL;
2769 u64 last_wanted = 0;
2770 struct btrfs_block_group_cache *block_group = NULL;
2771 int chunk_alloc_done = 0;
2772 int empty_cluster = 2 * 1024 * 1024;
2773 int allowed_chunk_alloc = 0;
2774 struct list_head *head = NULL, *cur = NULL;
2775 int loop = 0;
2776 int extra_loop = 0;
2777 struct btrfs_space_info *space_info;
2778
2779 WARN_ON(num_bytes < root->sectorsize);
2780 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
2781 ins->objectid = 0;
2782 ins->offset = 0;
2783
2784 if (orig_root->ref_cows || empty_size)
2785 allowed_chunk_alloc = 1;
2786
2787 if (data & BTRFS_BLOCK_GROUP_METADATA) {
2788 last_ptr = &root->fs_info->last_alloc;
2789 empty_cluster = 64 * 1024;
2790 }
2791
2792 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
2793 last_ptr = &root->fs_info->last_data_alloc;
2794
2795 if (last_ptr) {
2796 if (*last_ptr) {
2797 hint_byte = *last_ptr;
2798 last_wanted = *last_ptr;
2799 } else
2800 empty_size += empty_cluster;
2801 } else {
2802 empty_cluster = 0;
2803 }
2804 search_start = max(search_start, first_logical_byte(root, 0));
2805 search_start = max(search_start, hint_byte);
2806
2807 if (last_wanted && search_start != last_wanted) {
2808 last_wanted = 0;
2809 empty_size += empty_cluster;
2810 }
2811
2812 total_needed += empty_size;
2813 block_group = btrfs_lookup_block_group(root->fs_info, search_start);
2814 if (!block_group)
2815 block_group = btrfs_lookup_first_block_group(root->fs_info,
2816 search_start);
2817 space_info = __find_space_info(root->fs_info, data);
2818
2819 down_read(&space_info->groups_sem);
2820 while (1) {
2821 struct btrfs_free_space *free_space;
2822 /*
2823 * the only way this happens if our hint points to a block
2824 * group thats not of the proper type, while looping this
2825 * should never happen
2826 */
2827 if (empty_size)
2828 extra_loop = 1;
2829
2830 if (!block_group)
2831 goto new_group_no_lock;
2832
2833 if (unlikely(!block_group->cached)) {
2834 mutex_lock(&block_group->cache_mutex);
2835 ret = cache_block_group(root, block_group);
2836 mutex_unlock(&block_group->cache_mutex);
2837 if (ret)
2838 break;
2839 }
2840
2841 mutex_lock(&block_group->alloc_mutex);
2842 if (unlikely(!block_group_bits(block_group, data)))
2843 goto new_group;
2844
2845 if (unlikely(block_group->ro))
2846 goto new_group;
2847
2848 free_space = btrfs_find_free_space(block_group, search_start,
2849 total_needed);
2850 if (free_space) {
2851 u64 start = block_group->key.objectid;
2852 u64 end = block_group->key.objectid +
2853 block_group->key.offset;
2854
2855 search_start = stripe_align(root, free_space->offset);
2856
2857 /* move on to the next group */
2858 if (search_start + num_bytes >= search_end)
2859 goto new_group;
2860
2861 /* move on to the next group */
2862 if (search_start + num_bytes > end)
2863 goto new_group;
2864
2865 if (last_wanted && search_start != last_wanted) {
2866 total_needed += empty_cluster;
2867 empty_size += empty_cluster;
2868 last_wanted = 0;
2869 /*
2870 * if search_start is still in this block group
2871 * then we just re-search this block group
2872 */
2873 if (search_start >= start &&
2874 search_start < end) {
2875 mutex_unlock(&block_group->alloc_mutex);
2876 continue;
2877 }
2878
2879 /* else we go to the next block group */
2880 goto new_group;
2881 }
2882
2883 if (exclude_nr > 0 &&
2884 (search_start + num_bytes > exclude_start &&
2885 search_start < exclude_start + exclude_nr)) {
2886 search_start = exclude_start + exclude_nr;
2887 /*
2888 * if search_start is still in this block group
2889 * then we just re-search this block group
2890 */
2891 if (search_start >= start &&
2892 search_start < end) {
2893 mutex_unlock(&block_group->alloc_mutex);
2894 last_wanted = 0;
2895 continue;
2896 }
2897
2898 /* else we go to the next block group */
2899 goto new_group;
2900 }
2901
2902 ins->objectid = search_start;
2903 ins->offset = num_bytes;
2904
2905 btrfs_remove_free_space_lock(block_group, search_start,
2906 num_bytes);
2907 /* we are all good, lets return */
2908 mutex_unlock(&block_group->alloc_mutex);
2909 break;
2910 }
2911 new_group:
2912 mutex_unlock(&block_group->alloc_mutex);
2913 put_block_group(block_group);
2914 block_group = NULL;
2915 new_group_no_lock:
2916 /* don't try to compare new allocations against the
2917 * last allocation any more
2918 */
2919 last_wanted = 0;
2920
2921 /*
2922 * Here's how this works.
2923 * loop == 0: we were searching a block group via a hint
2924 * and didn't find anything, so we start at
2925 * the head of the block groups and keep searching
2926 * loop == 1: we're searching through all of the block groups
2927 * if we hit the head again we have searched
2928 * all of the block groups for this space and we
2929 * need to try and allocate, if we cant error out.
2930 * loop == 2: we allocated more space and are looping through
2931 * all of the block groups again.
2932 */
2933 if (loop == 0) {
2934 head = &space_info->block_groups;
2935 cur = head->next;
2936 loop++;
2937 } else if (loop == 1 && cur == head) {
2938 int keep_going;
2939
2940 /* at this point we give up on the empty_size
2941 * allocations and just try to allocate the min
2942 * space.
2943 *
2944 * The extra_loop field was set if an empty_size
2945 * allocation was attempted above, and if this
2946 * is try we need to try the loop again without
2947 * the additional empty_size.
2948 */
2949 total_needed -= empty_size;
2950 empty_size = 0;
2951 keep_going = extra_loop;
2952 loop++;
2953
2954 if (allowed_chunk_alloc && !chunk_alloc_done) {
2955 up_read(&space_info->groups_sem);
2956 ret = do_chunk_alloc(trans, root, num_bytes +
2957 2 * 1024 * 1024, data, 1);
2958 down_read(&space_info->groups_sem);
2959 if (ret < 0)
2960 goto loop_check;
2961 head = &space_info->block_groups;
2962 /*
2963 * we've allocated a new chunk, keep
2964 * trying
2965 */
2966 keep_going = 1;
2967 chunk_alloc_done = 1;
2968 } else if (!allowed_chunk_alloc) {
2969 space_info->force_alloc = 1;
2970 }
2971 loop_check:
2972 if (keep_going) {
2973 cur = head->next;
2974 extra_loop = 0;
2975 } else {
2976 break;
2977 }
2978 } else if (cur == head) {
2979 break;
2980 }
2981
2982 block_group = list_entry(cur, struct btrfs_block_group_cache,
2983 list);
2984 atomic_inc(&block_group->count);
2985
2986 search_start = block_group->key.objectid;
2987 cur = cur->next;
2988 }
2989
2990 /* we found what we needed */
2991 if (ins->objectid) {
2992 if (!(data & BTRFS_BLOCK_GROUP_DATA))
2993 trans->block_group = block_group->key.objectid;
2994
2995 if (last_ptr)
2996 *last_ptr = ins->objectid + ins->offset;
2997 ret = 0;
2998 } else if (!ret) {
2999 printk(KERN_ERR "btrfs searching for %llu bytes, "
3000 "num_bytes %llu, loop %d, allowed_alloc %d\n",
3001 (unsigned long long)total_needed,
3002 (unsigned long long)num_bytes,
3003 loop, allowed_chunk_alloc);
3004 ret = -ENOSPC;
3005 }
3006 if (block_group)
3007 put_block_group(block_group);
3008
3009 up_read(&space_info->groups_sem);
3010 return ret;
3011 }
3012
3013 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
3014 {
3015 struct btrfs_block_group_cache *cache;
3016 struct list_head *l;
3017
3018 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
3019 (unsigned long long)(info->total_bytes - info->bytes_used -
3020 info->bytes_pinned - info->bytes_reserved),
3021 (info->full) ? "" : "not ");
3022
3023 down_read(&info->groups_sem);
3024 list_for_each(l, &info->block_groups) {
3025 cache = list_entry(l, struct btrfs_block_group_cache, list);
3026 spin_lock(&cache->lock);
3027 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
3028 "%llu pinned %llu reserved\n",
3029 (unsigned long long)cache->key.objectid,
3030 (unsigned long long)cache->key.offset,
3031 (unsigned long long)btrfs_block_group_used(&cache->item),
3032 (unsigned long long)cache->pinned,
3033 (unsigned long long)cache->reserved);
3034 btrfs_dump_free_space(cache, bytes);
3035 spin_unlock(&cache->lock);
3036 }
3037 up_read(&info->groups_sem);
3038 }
3039
3040 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
3041 struct btrfs_root *root,
3042 u64 num_bytes, u64 min_alloc_size,
3043 u64 empty_size, u64 hint_byte,
3044 u64 search_end, struct btrfs_key *ins,
3045 u64 data)
3046 {
3047 int ret;
3048 u64 search_start = 0;
3049 u64 alloc_profile;
3050 struct btrfs_fs_info *info = root->fs_info;
3051
3052 if (data) {
3053 alloc_profile = info->avail_data_alloc_bits &
3054 info->data_alloc_profile;
3055 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
3056 } else if (root == root->fs_info->chunk_root) {
3057 alloc_profile = info->avail_system_alloc_bits &
3058 info->system_alloc_profile;
3059 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
3060 } else {
3061 alloc_profile = info->avail_metadata_alloc_bits &
3062 info->metadata_alloc_profile;
3063 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
3064 }
3065 again:
3066 data = btrfs_reduce_alloc_profile(root, data);
3067 /*
3068 * the only place that sets empty_size is btrfs_realloc_node, which
3069 * is not called recursively on allocations
3070 */
3071 if (empty_size || root->ref_cows) {
3072 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
3073 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3074 2 * 1024 * 1024,
3075 BTRFS_BLOCK_GROUP_METADATA |
3076 (info->metadata_alloc_profile &
3077 info->avail_metadata_alloc_bits), 0);
3078 }
3079 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3080 num_bytes + 2 * 1024 * 1024, data, 0);
3081 }
3082
3083 WARN_ON(num_bytes < root->sectorsize);
3084 ret = find_free_extent(trans, root, num_bytes, empty_size,
3085 search_start, search_end, hint_byte, ins,
3086 trans->alloc_exclude_start,
3087 trans->alloc_exclude_nr, data);
3088
3089 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
3090 num_bytes = num_bytes >> 1;
3091 num_bytes = num_bytes & ~(root->sectorsize - 1);
3092 num_bytes = max(num_bytes, min_alloc_size);
3093 do_chunk_alloc(trans, root->fs_info->extent_root,
3094 num_bytes, data, 1);
3095 goto again;
3096 }
3097 if (ret) {
3098 struct btrfs_space_info *sinfo;
3099
3100 sinfo = __find_space_info(root->fs_info, data);
3101 printk(KERN_ERR "btrfs allocation failed flags %llu, "
3102 "wanted %llu\n", (unsigned long long)data,
3103 (unsigned long long)num_bytes);
3104 dump_space_info(sinfo, num_bytes);
3105 BUG();
3106 }
3107
3108 return ret;
3109 }
3110
3111 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
3112 {
3113 struct btrfs_block_group_cache *cache;
3114 int ret = 0;
3115
3116 cache = btrfs_lookup_block_group(root->fs_info, start);
3117 if (!cache) {
3118 printk(KERN_ERR "Unable to find block group for %llu\n",
3119 (unsigned long long)start);
3120 return -ENOSPC;
3121 }
3122
3123 ret = btrfs_discard_extent(root, start, len);
3124
3125 btrfs_add_free_space(cache, start, len);
3126 put_block_group(cache);
3127 update_reserved_extents(root, start, len, 0);
3128
3129 return ret;
3130 }
3131
3132 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
3133 struct btrfs_root *root,
3134 u64 num_bytes, u64 min_alloc_size,
3135 u64 empty_size, u64 hint_byte,
3136 u64 search_end, struct btrfs_key *ins,
3137 u64 data)
3138 {
3139 int ret;
3140 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
3141 empty_size, hint_byte, search_end, ins,
3142 data);
3143 update_reserved_extents(root, ins->objectid, ins->offset, 1);
3144 return ret;
3145 }
3146
3147 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
3148 struct btrfs_root *root, u64 parent,
3149 u64 root_objectid, u64 ref_generation,
3150 u64 owner, struct btrfs_key *ins)
3151 {
3152 int ret;
3153 int pending_ret;
3154 u64 super_used;
3155 u64 root_used;
3156 u64 num_bytes = ins->offset;
3157 u32 sizes[2];
3158 struct btrfs_fs_info *info = root->fs_info;
3159 struct btrfs_root *extent_root = info->extent_root;
3160 struct btrfs_extent_item *extent_item;
3161 struct btrfs_extent_ref *ref;
3162 struct btrfs_path *path;
3163 struct btrfs_key keys[2];
3164
3165 if (parent == 0)
3166 parent = ins->objectid;
3167
3168 /* block accounting for super block */
3169 spin_lock(&info->delalloc_lock);
3170 super_used = btrfs_super_bytes_used(&info->super_copy);
3171 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
3172
3173 /* block accounting for root item */
3174 root_used = btrfs_root_used(&root->root_item);
3175 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
3176 spin_unlock(&info->delalloc_lock);
3177
3178 if (root == extent_root) {
3179 struct pending_extent_op *extent_op;
3180
3181 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
3182 BUG_ON(!extent_op);
3183
3184 extent_op->type = PENDING_EXTENT_INSERT;
3185 extent_op->bytenr = ins->objectid;
3186 extent_op->num_bytes = ins->offset;
3187 extent_op->parent = parent;
3188 extent_op->orig_parent = 0;
3189 extent_op->generation = ref_generation;
3190 extent_op->orig_generation = 0;
3191 extent_op->level = (int)owner;
3192 INIT_LIST_HEAD(&extent_op->list);
3193 extent_op->del = 0;
3194
3195 mutex_lock(&root->fs_info->extent_ins_mutex);
3196 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
3197 ins->objectid + ins->offset - 1,
3198 EXTENT_WRITEBACK, GFP_NOFS);
3199 set_state_private(&root->fs_info->extent_ins,
3200 ins->objectid, (unsigned long)extent_op);
3201 mutex_unlock(&root->fs_info->extent_ins_mutex);
3202 goto update_block;
3203 }
3204
3205 memcpy(&keys[0], ins, sizeof(*ins));
3206 keys[1].objectid = ins->objectid;
3207 keys[1].type = BTRFS_EXTENT_REF_KEY;
3208 keys[1].offset = parent;
3209 sizes[0] = sizeof(*extent_item);
3210 sizes[1] = sizeof(*ref);
3211
3212 path = btrfs_alloc_path();
3213 BUG_ON(!path);
3214
3215 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
3216 sizes, 2);
3217 BUG_ON(ret);
3218
3219 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3220 struct btrfs_extent_item);
3221 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
3222 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
3223 struct btrfs_extent_ref);
3224
3225 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
3226 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
3227 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
3228 btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
3229
3230 btrfs_mark_buffer_dirty(path->nodes[0]);
3231
3232 trans->alloc_exclude_start = 0;
3233 trans->alloc_exclude_nr = 0;
3234 btrfs_free_path(path);
3235 finish_current_insert(trans, extent_root, 0);
3236 pending_ret = del_pending_extents(trans, extent_root, 0);
3237
3238 if (ret)
3239 goto out;
3240 if (pending_ret) {
3241 ret = pending_ret;
3242 goto out;
3243 }
3244
3245 update_block:
3246 ret = update_block_group(trans, root, ins->objectid,
3247 ins->offset, 1, 0);
3248 if (ret) {
3249 printk(KERN_ERR "btrfs update block group failed for %llu "
3250 "%llu\n", (unsigned long long)ins->objectid,
3251 (unsigned long long)ins->offset);
3252 BUG();
3253 }
3254 out:
3255 return ret;
3256 }
3257
3258 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
3259 struct btrfs_root *root, u64 parent,
3260 u64 root_objectid, u64 ref_generation,
3261 u64 owner, struct btrfs_key *ins)
3262 {
3263 int ret;
3264
3265 if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
3266 return 0;
3267 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
3268 ref_generation, owner, ins);
3269 update_reserved_extents(root, ins->objectid, ins->offset, 0);
3270 return ret;
3271 }
3272
3273 /*
3274 * this is used by the tree logging recovery code. It records that
3275 * an extent has been allocated and makes sure to clear the free
3276 * space cache bits as well
3277 */
3278 int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
3279 struct btrfs_root *root, u64 parent,
3280 u64 root_objectid, u64 ref_generation,
3281 u64 owner, struct btrfs_key *ins)
3282 {
3283 int ret;
3284 struct btrfs_block_group_cache *block_group;
3285
3286 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
3287 mutex_lock(&block_group->cache_mutex);
3288 cache_block_group(root, block_group);
3289 mutex_unlock(&block_group->cache_mutex);
3290
3291 ret = btrfs_remove_free_space(block_group, ins->objectid,
3292 ins->offset);
3293 BUG_ON(ret);
3294 put_block_group(block_group);
3295 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
3296 ref_generation, owner, ins);
3297 return ret;
3298 }
3299
3300 /*
3301 * finds a free extent and does all the dirty work required for allocation
3302 * returns the key for the extent through ins, and a tree buffer for
3303 * the first block of the extent through buf.
3304 *
3305 * returns 0 if everything worked, non-zero otherwise.
3306 */
3307 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
3308 struct btrfs_root *root,
3309 u64 num_bytes, u64 parent, u64 min_alloc_size,
3310 u64 root_objectid, u64 ref_generation,
3311 u64 owner_objectid, u64 empty_size, u64 hint_byte,
3312 u64 search_end, struct btrfs_key *ins, u64 data)
3313 {
3314 int ret;
3315
3316 ret = __btrfs_reserve_extent(trans, root, num_bytes,
3317 min_alloc_size, empty_size, hint_byte,
3318 search_end, ins, data);
3319 BUG_ON(ret);
3320 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
3321 ret = __btrfs_alloc_reserved_extent(trans, root, parent,
3322 root_objectid, ref_generation,
3323 owner_objectid, ins);
3324 BUG_ON(ret);
3325
3326 } else {
3327 update_reserved_extents(root, ins->objectid, ins->offset, 1);
3328 }
3329 return ret;
3330 }
3331
3332 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
3333 struct btrfs_root *root,
3334 u64 bytenr, u32 blocksize)
3335 {
3336 struct extent_buffer *buf;
3337
3338 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
3339 if (!buf)
3340 return ERR_PTR(-ENOMEM);
3341 btrfs_set_header_generation(buf, trans->transid);
3342 btrfs_tree_lock(buf);
3343 clean_tree_block(trans, root, buf);
3344 btrfs_set_buffer_uptodate(buf);
3345 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
3346 set_extent_dirty(&root->dirty_log_pages, buf->start,
3347 buf->start + buf->len - 1, GFP_NOFS);
3348 } else {
3349 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
3350 buf->start + buf->len - 1, GFP_NOFS);
3351 }
3352 trans->blocks_used++;
3353 return buf;
3354 }
3355
3356 /*
3357 * helper function to allocate a block for a given tree
3358 * returns the tree buffer or NULL.
3359 */
3360 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
3361 struct btrfs_root *root,
3362 u32 blocksize, u64 parent,
3363 u64 root_objectid,
3364 u64 ref_generation,
3365 int level,
3366 u64 hint,
3367 u64 empty_size)
3368 {
3369 struct btrfs_key ins;
3370 int ret;
3371 struct extent_buffer *buf;
3372
3373 ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
3374 root_objectid, ref_generation, level,
3375 empty_size, hint, (u64)-1, &ins, 0);
3376 if (ret) {
3377 BUG_ON(ret > 0);
3378 return ERR_PTR(ret);
3379 }
3380
3381 buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
3382 return buf;
3383 }
3384
3385 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
3386 struct btrfs_root *root, struct extent_buffer *leaf)
3387 {
3388 u64 leaf_owner;
3389 u64 leaf_generation;
3390 struct btrfs_key key;
3391 struct btrfs_file_extent_item *fi;
3392 int i;
3393 int nritems;
3394 int ret;
3395
3396 BUG_ON(!btrfs_is_leaf(leaf));
3397 nritems = btrfs_header_nritems(leaf);
3398 leaf_owner = btrfs_header_owner(leaf);
3399 leaf_generation = btrfs_header_generation(leaf);
3400
3401 for (i = 0; i < nritems; i++) {
3402 u64 disk_bytenr;
3403 cond_resched();
3404
3405 btrfs_item_key_to_cpu(leaf, &key, i);
3406 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
3407 continue;
3408 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
3409 if (btrfs_file_extent_type(leaf, fi) ==
3410 BTRFS_FILE_EXTENT_INLINE)
3411 continue;
3412 /*
3413 * FIXME make sure to insert a trans record that
3414 * repeats the snapshot del on crash
3415 */
3416 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
3417 if (disk_bytenr == 0)
3418 continue;
3419
3420 ret = __btrfs_free_extent(trans, root, disk_bytenr,
3421 btrfs_file_extent_disk_num_bytes(leaf, fi),
3422 leaf->start, leaf_owner, leaf_generation,
3423 key.objectid, 0);
3424 BUG_ON(ret);
3425
3426 atomic_inc(&root->fs_info->throttle_gen);
3427 wake_up(&root->fs_info->transaction_throttle);
3428 cond_resched();
3429 }
3430 return 0;
3431 }
3432
3433 static noinline int cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
3434 struct btrfs_root *root,
3435 struct btrfs_leaf_ref *ref)
3436 {
3437 int i;
3438 int ret;
3439 struct btrfs_extent_info *info = ref->extents;
3440
3441 for (i = 0; i < ref->nritems; i++) {
3442 ret = __btrfs_free_extent(trans, root, info->bytenr,
3443 info->num_bytes, ref->bytenr,
3444 ref->owner, ref->generation,
3445 info->objectid, 0);
3446
3447 atomic_inc(&root->fs_info->throttle_gen);
3448 wake_up(&root->fs_info->transaction_throttle);
3449 cond_resched();
3450
3451 BUG_ON(ret);
3452 info++;
3453 }
3454
3455 return 0;
3456 }
3457
3458 static int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start,
3459 u64 len, u32 *refs)
3460 {
3461 int ret;
3462
3463 ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
3464 BUG_ON(ret);
3465
3466 #if 0 /* some debugging code in case we see problems here */
3467 /* if the refs count is one, it won't get increased again. But
3468 * if the ref count is > 1, someone may be decreasing it at
3469 * the same time we are.
3470 */
3471 if (*refs != 1) {
3472 struct extent_buffer *eb = NULL;
3473 eb = btrfs_find_create_tree_block(root, start, len);
3474 if (eb)
3475 btrfs_tree_lock(eb);
3476
3477 mutex_lock(&root->fs_info->alloc_mutex);
3478 ret = lookup_extent_ref(NULL, root, start, len, refs);
3479 BUG_ON(ret);
3480 mutex_unlock(&root->fs_info->alloc_mutex);
3481
3482 if (eb) {
3483 btrfs_tree_unlock(eb);
3484 free_extent_buffer(eb);
3485 }
3486 if (*refs == 1) {
3487 printk(KERN_ERR "btrfs block %llu went down to one "
3488 "during drop_snap\n", (unsigned long long)start);
3489 }
3490
3491 }
3492 #endif
3493
3494 cond_resched();
3495 return ret;
3496 }
3497
3498 /*
3499 * helper function for drop_snapshot, this walks down the tree dropping ref
3500 * counts as it goes.
3501 */
3502 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
3503 struct btrfs_root *root,
3504 struct btrfs_path *path, int *level)
3505 {
3506 u64 root_owner;
3507 u64 root_gen;
3508 u64 bytenr;
3509 u64 ptr_gen;
3510 struct extent_buffer *next;
3511 struct extent_buffer *cur;
3512 struct extent_buffer *parent;
3513 struct btrfs_leaf_ref *ref;
3514 u32 blocksize;
3515 int ret;
3516 u32 refs;
3517
3518 WARN_ON(*level < 0);
3519 WARN_ON(*level >= BTRFS_MAX_LEVEL);
3520 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
3521 path->nodes[*level]->len, &refs);
3522 BUG_ON(ret);
3523 if (refs > 1)
3524 goto out;
3525
3526 /*
3527 * walk down to the last node level and free all the leaves
3528 */
3529 while (*level >= 0) {
3530 WARN_ON(*level < 0);
3531 WARN_ON(*level >= BTRFS_MAX_LEVEL);
3532 cur = path->nodes[*level];
3533
3534 if (btrfs_header_level(cur) != *level)
3535 WARN_ON(1);
3536
3537 if (path->slots[*level] >=
3538 btrfs_header_nritems(cur))
3539 break;
3540 if (*level == 0) {
3541 ret = btrfs_drop_leaf_ref(trans, root, cur);
3542 BUG_ON(ret);
3543 break;
3544 }
3545 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
3546 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
3547 blocksize = btrfs_level_size(root, *level - 1);
3548
3549 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
3550 BUG_ON(ret);
3551 if (refs != 1) {
3552 parent = path->nodes[*level];
3553 root_owner = btrfs_header_owner(parent);
3554 root_gen = btrfs_header_generation(parent);
3555 path->slots[*level]++;
3556
3557 ret = __btrfs_free_extent(trans, root, bytenr,
3558 blocksize, parent->start,
3559 root_owner, root_gen,
3560 *level - 1, 1);
3561 BUG_ON(ret);
3562
3563 atomic_inc(&root->fs_info->throttle_gen);
3564 wake_up(&root->fs_info->transaction_throttle);
3565 cond_resched();
3566
3567 continue;
3568 }
3569 /*
3570 * at this point, we have a single ref, and since the
3571 * only place referencing this extent is a dead root
3572 * the reference count should never go higher.
3573 * So, we don't need to check it again
3574 */
3575 if (*level == 1) {
3576 ref = btrfs_lookup_leaf_ref(root, bytenr);
3577 if (ref && ref->generation != ptr_gen) {
3578 btrfs_free_leaf_ref(root, ref);
3579 ref = NULL;
3580 }
3581 if (ref) {
3582 ret = cache_drop_leaf_ref(trans, root, ref);
3583 BUG_ON(ret);
3584 btrfs_remove_leaf_ref(root, ref);
3585 btrfs_free_leaf_ref(root, ref);
3586 *level = 0;
3587 break;
3588 }
3589 }
3590 next = btrfs_find_tree_block(root, bytenr, blocksize);
3591 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
3592 free_extent_buffer(next);
3593
3594 next = read_tree_block(root, bytenr, blocksize,
3595 ptr_gen);
3596 cond_resched();
3597 #if 0
3598 /*
3599 * this is a debugging check and can go away
3600 * the ref should never go all the way down to 1
3601 * at this point
3602 */
3603 ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
3604 &refs);
3605 BUG_ON(ret);
3606 WARN_ON(refs != 1);
3607 #endif
3608 }
3609 WARN_ON(*level <= 0);
3610 if (path->nodes[*level-1])
3611 free_extent_buffer(path->nodes[*level-1]);
3612 path->nodes[*level-1] = next;
3613 *level = btrfs_header_level(next);
3614 path->slots[*level] = 0;
3615 cond_resched();
3616 }
3617 out:
3618 WARN_ON(*level < 0);
3619 WARN_ON(*level >= BTRFS_MAX_LEVEL);
3620
3621 if (path->nodes[*level] == root->node) {
3622 parent = path->nodes[*level];
3623 bytenr = path->nodes[*level]->start;
3624 } else {
3625 parent = path->nodes[*level + 1];
3626 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
3627 }
3628
3629 blocksize = btrfs_level_size(root, *level);
3630 root_owner = btrfs_header_owner(parent);
3631 root_gen = btrfs_header_generation(parent);
3632
3633 ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
3634 parent->start, root_owner, root_gen,
3635 *level, 1);
3636 free_extent_buffer(path->nodes[*level]);
3637 path->nodes[*level] = NULL;
3638 *level += 1;
3639 BUG_ON(ret);
3640
3641 cond_resched();
3642 return 0;
3643 }
3644
3645 /*
3646 * helper function for drop_subtree, this function is similar to
3647 * walk_down_tree. The main difference is that it checks reference
3648 * counts while tree blocks are locked.
3649 */
3650 static noinline int walk_down_subtree(struct btrfs_trans_handle *trans,
3651 struct btrfs_root *root,
3652 struct btrfs_path *path, int *level)
3653 {
3654 struct extent_buffer *next;
3655 struct extent_buffer *cur;
3656 struct extent_buffer *parent;
3657 u64 bytenr;
3658 u64 ptr_gen;
3659 u32 blocksize;
3660 u32 refs;
3661 int ret;
3662
3663 cur = path->nodes[*level];
3664 ret = btrfs_lookup_extent_ref(trans, root, cur->start, cur->len,
3665 &refs);
3666 BUG_ON(ret);
3667 if (refs > 1)
3668 goto out;
3669
3670 while (*level >= 0) {
3671 cur = path->nodes[*level];
3672 if (*level == 0) {
3673 ret = btrfs_drop_leaf_ref(trans, root, cur);
3674 BUG_ON(ret);
3675 clean_tree_block(trans, root, cur);
3676 break;
3677 }
3678 if (path->slots[*level] >= btrfs_header_nritems(cur)) {
3679 clean_tree_block(trans, root, cur);
3680 break;
3681 }
3682
3683 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
3684 blocksize = btrfs_level_size(root, *level - 1);
3685 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
3686
3687 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
3688 btrfs_tree_lock(next);
3689
3690 ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize,
3691 &refs);
3692 BUG_ON(ret);
3693 if (refs > 1) {
3694 parent = path->nodes[*level];
3695 ret = btrfs_free_extent(trans, root, bytenr,
3696 blocksize, parent->start,
3697 btrfs_header_owner(parent),
3698 btrfs_header_generation(parent),
3699 *level - 1, 1);
3700 BUG_ON(ret);
3701 path->slots[*level]++;
3702 btrfs_tree_unlock(next);
3703 free_extent_buffer(next);
3704 continue;
3705 }
3706
3707 *level = btrfs_header_level(next);
3708 path->nodes[*level] = next;
3709 path->slots[*level] = 0;
3710 path->locks[*level] = 1;
3711 cond_resched();
3712 }
3713 out:
3714 parent = path->nodes[*level + 1];
3715 bytenr = path->nodes[*level]->start;
3716 blocksize = path->nodes[*level]->len;
3717
3718 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
3719 parent->start, btrfs_header_owner(parent),
3720 btrfs_header_generation(parent), *level, 1);
3721 BUG_ON(ret);
3722
3723 if (path->locks[*level]) {
3724 btrfs_tree_unlock(path->nodes[*level]);
3725 path->locks[*level] = 0;
3726 }
3727 free_extent_buffer(path->nodes[*level]);
3728 path->nodes[*level] = NULL;
3729 *level += 1;
3730 cond_resched();
3731 return 0;
3732 }
3733
3734 /*
3735 * helper for dropping snapshots. This walks back up the tree in the path
3736 * to find the first node higher up where we haven't yet gone through
3737 * all the slots
3738 */
3739 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
3740 struct btrfs_root *root,
3741 struct btrfs_path *path,
3742 int *level, int max_level)
3743 {
3744 u64 root_owner;
3745 u64 root_gen;
3746 struct btrfs_root_item *root_item = &root->root_item;
3747 int i;
3748 int slot;
3749 int ret;
3750
3751 for (i = *level; i < max_level && path->nodes[i]; i++) {
3752 slot = path->slots[i];
3753 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
3754 struct extent_buffer *node;
3755 struct btrfs_disk_key disk_key;
3756 node = path->nodes[i];
3757 path->slots[i]++;
3758 *level = i;
3759 WARN_ON(*level == 0);
3760 btrfs_node_key(node, &disk_key, path->slots[i]);
3761 memcpy(&root_item->drop_progress,
3762 &disk_key, sizeof(disk_key));
3763 root_item->drop_level = i;
3764 return 0;
3765 } else {
3766 struct extent_buffer *parent;
3767 if (path->nodes[*level] == root->node)
3768 parent = path->nodes[*level];
3769 else
3770 parent = path->nodes[*level + 1];
3771
3772 root_owner = btrfs_header_owner(parent);
3773 root_gen = btrfs_header_generation(parent);
3774
3775 clean_tree_block(trans, root, path->nodes[*level]);
3776 ret = btrfs_free_extent(trans, root,
3777 path->nodes[*level]->start,
3778 path->nodes[*level]->len,
3779 parent->start, root_owner,
3780 root_gen, *level, 1);
3781 BUG_ON(ret);
3782 if (path->locks[*level]) {
3783 btrfs_tree_unlock(path->nodes[*level]);
3784 path->locks[*level] = 0;
3785 }
3786 free_extent_buffer(path->nodes[*level]);
3787 path->nodes[*level] = NULL;
3788 *level = i + 1;
3789 }
3790 }
3791 return 1;
3792 }
3793
3794 /*
3795 * drop the reference count on the tree rooted at 'snap'. This traverses
3796 * the tree freeing any blocks that have a ref count of zero after being
3797 * decremented.
3798 */
3799 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
3800 *root)
3801 {
3802 int ret = 0;
3803 int wret;
3804 int level;
3805 struct btrfs_path *path;
3806 int i;
3807 int orig_level;
3808 struct btrfs_root_item *root_item = &root->root_item;
3809
3810 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
3811 path = btrfs_alloc_path();
3812 BUG_ON(!path);
3813
3814 level = btrfs_header_level(root->node);
3815 orig_level = level;
3816 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
3817 path->nodes[level] = root->node;
3818 extent_buffer_get(root->node);
3819 path->slots[level] = 0;
3820 } else {
3821 struct btrfs_key key;
3822 struct btrfs_disk_key found_key;
3823 struct extent_buffer *node;
3824
3825 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
3826 level = root_item->drop_level;
3827 path->lowest_level = level;
3828 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3829 if (wret < 0) {
3830 ret = wret;
3831 goto out;
3832 }
3833 node = path->nodes[level];
3834 btrfs_node_key(node, &found_key, path->slots[level]);
3835 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
3836 sizeof(found_key)));
3837 /*
3838 * unlock our path, this is safe because only this
3839 * function is allowed to delete this snapshot
3840 */
3841 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
3842 if (path->nodes[i] && path->locks[i]) {
3843 path->locks[i] = 0;
3844 btrfs_tree_unlock(path->nodes[i]);
3845 }
3846 }
3847 }
3848 while (1) {
3849 wret = walk_down_tree(trans, root, path, &level);
3850 if (wret > 0)
3851 break;
3852 if (wret < 0)
3853 ret = wret;
3854
3855 wret = walk_up_tree(trans, root, path, &level,
3856 BTRFS_MAX_LEVEL);
3857 if (wret > 0)
3858 break;
3859 if (wret < 0)
3860 ret = wret;
3861 if (trans->transaction->in_commit) {
3862 ret = -EAGAIN;
3863 break;
3864 }
3865 atomic_inc(&root->fs_info->throttle_gen);
3866 wake_up(&root->fs_info->transaction_throttle);
3867 }
3868 for (i = 0; i <= orig_level; i++) {
3869 if (path->nodes[i]) {
3870 free_extent_buffer(path->nodes[i]);
3871 path->nodes[i] = NULL;
3872 }
3873 }
3874 out:
3875 btrfs_free_path(path);
3876 return ret;
3877 }
3878
3879 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
3880 struct btrfs_root *root,
3881 struct extent_buffer *node,
3882 struct extent_buffer *parent)
3883 {
3884 struct btrfs_path *path;
3885 int level;
3886 int parent_level;
3887 int ret = 0;
3888 int wret;
3889
3890 path = btrfs_alloc_path();
3891 BUG_ON(!path);
3892
3893 BUG_ON(!btrfs_tree_locked(parent));
3894 parent_level = btrfs_header_level(parent);
3895 extent_buffer_get(parent);
3896 path->nodes[parent_level] = parent;
3897 path->slots[parent_level] = btrfs_header_nritems(parent);
3898
3899 BUG_ON(!btrfs_tree_locked(node));
3900 level = btrfs_header_level(node);
3901 extent_buffer_get(node);
3902 path->nodes[level] = node;
3903 path->slots[level] = 0;
3904
3905 while (1) {
3906 wret = walk_down_subtree(trans, root, path, &level);
3907 if (wret < 0)
3908 ret = wret;
3909 if (wret != 0)
3910 break;
3911
3912 wret = walk_up_tree(trans, root, path, &level, parent_level);
3913 if (wret < 0)
3914 ret = wret;
3915 if (wret != 0)
3916 break;
3917 }
3918
3919 btrfs_free_path(path);
3920 return ret;
3921 }
3922
3923 static unsigned long calc_ra(unsigned long start, unsigned long last,
3924 unsigned long nr)
3925 {
3926 return min(last, start + nr - 1);
3927 }
3928
3929 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
3930 u64 len)
3931 {
3932 u64 page_start;
3933 u64 page_end;
3934 unsigned long first_index;
3935 unsigned long last_index;
3936 unsigned long i;
3937 struct page *page;
3938 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3939 struct file_ra_state *ra;
3940 struct btrfs_ordered_extent *ordered;
3941 unsigned int total_read = 0;
3942 unsigned int total_dirty = 0;
3943 int ret = 0;
3944
3945 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3946
3947 mutex_lock(&inode->i_mutex);
3948 first_index = start >> PAGE_CACHE_SHIFT;
3949 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
3950
3951 /* make sure the dirty trick played by the caller work */
3952 ret = invalidate_inode_pages2_range(inode->i_mapping,
3953 first_index, last_index);
3954 if (ret)
3955 goto out_unlock;
3956
3957 file_ra_state_init(ra, inode->i_mapping);
3958
3959 for (i = first_index ; i <= last_index; i++) {
3960 if (total_read % ra->ra_pages == 0) {
3961 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
3962 calc_ra(i, last_index, ra->ra_pages));
3963 }
3964 total_read++;
3965 again:
3966 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
3967 BUG_ON(1);
3968 page = grab_cache_page(inode->i_mapping, i);
3969 if (!page) {
3970 ret = -ENOMEM;
3971 goto out_unlock;
3972 }
3973 if (!PageUptodate(page)) {
3974 btrfs_readpage(NULL, page);
3975 lock_page(page);
3976 if (!PageUptodate(page)) {
3977 unlock_page(page);
3978 page_cache_release(page);
3979 ret = -EIO;
3980 goto out_unlock;
3981 }
3982 }
3983 wait_on_page_writeback(page);
3984
3985 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
3986 page_end = page_start + PAGE_CACHE_SIZE - 1;
3987 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
3988
3989 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3990 if (ordered) {
3991 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3992 unlock_page(page);
3993 page_cache_release(page);
3994 btrfs_start_ordered_extent(inode, ordered, 1);
3995 btrfs_put_ordered_extent(ordered);
3996 goto again;
3997 }
3998 set_page_extent_mapped(page);
3999
4000 if (i == first_index)
4001 set_extent_bits(io_tree, page_start, page_end,
4002 EXTENT_BOUNDARY, GFP_NOFS);
4003 btrfs_set_extent_delalloc(inode, page_start, page_end);
4004
4005 set_page_dirty(page);
4006 total_dirty++;
4007
4008 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
4009 unlock_page(page);
4010 page_cache_release(page);
4011 }
4012
4013 out_unlock:
4014 kfree(ra);
4015 mutex_unlock(&inode->i_mutex);
4016 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
4017 return ret;
4018 }
4019
4020 static noinline int relocate_data_extent(struct inode *reloc_inode,
4021 struct btrfs_key *extent_key,
4022 u64 offset)
4023 {
4024 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
4025 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
4026 struct extent_map *em;
4027 u64 start = extent_key->objectid - offset;
4028 u64 end = start + extent_key->offset - 1;
4029
4030 em = alloc_extent_map(GFP_NOFS);
4031 BUG_ON(!em || IS_ERR(em));
4032
4033 em->start = start;
4034 em->len = extent_key->offset;
4035 em->block_len = extent_key->offset;
4036 em->block_start = extent_key->objectid;
4037 em->bdev = root->fs_info->fs_devices->latest_bdev;
4038 set_bit(EXTENT_FLAG_PINNED, &em->flags);
4039
4040 /* setup extent map to cheat btrfs_readpage */
4041 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
4042 while (1) {
4043 int ret;
4044 spin_lock(&em_tree->lock);
4045 ret = add_extent_mapping(em_tree, em);
4046 spin_unlock(&em_tree->lock);
4047 if (ret != -EEXIST) {
4048 free_extent_map(em);
4049 break;
4050 }
4051 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
4052 }
4053 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
4054
4055 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
4056 }
4057
4058 struct btrfs_ref_path {
4059 u64 extent_start;
4060 u64 nodes[BTRFS_MAX_LEVEL];
4061 u64 root_objectid;
4062 u64 root_generation;
4063 u64 owner_objectid;
4064 u32 num_refs;
4065 int lowest_level;
4066 int current_level;
4067 int shared_level;
4068
4069 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
4070 u64 new_nodes[BTRFS_MAX_LEVEL];
4071 };
4072
4073 struct disk_extent {
4074 u64 ram_bytes;
4075 u64 disk_bytenr;
4076 u64 disk_num_bytes;
4077 u64 offset;
4078 u64 num_bytes;
4079 u8 compression;
4080 u8 encryption;
4081 u16 other_encoding;
4082 };
4083
4084 static int is_cowonly_root(u64 root_objectid)
4085 {
4086 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
4087 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
4088 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
4089 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
4090 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
4091 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
4092 return 1;
4093 return 0;
4094 }
4095
4096 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
4097 struct btrfs_root *extent_root,
4098 struct btrfs_ref_path *ref_path,
4099 int first_time)
4100 {
4101 struct extent_buffer *leaf;
4102 struct btrfs_path *path;
4103 struct btrfs_extent_ref *ref;
4104 struct btrfs_key key;
4105 struct btrfs_key found_key;
4106 u64 bytenr;
4107 u32 nritems;
4108 int level;
4109 int ret = 1;
4110
4111 path = btrfs_alloc_path();
4112 if (!path)
4113 return -ENOMEM;
4114
4115 if (first_time) {
4116 ref_path->lowest_level = -1;
4117 ref_path->current_level = -1;
4118 ref_path->shared_level = -1;
4119 goto walk_up;
4120 }
4121 walk_down:
4122 level = ref_path->current_level - 1;
4123 while (level >= -1) {
4124 u64 parent;
4125 if (level < ref_path->lowest_level)
4126 break;
4127
4128 if (level >= 0)
4129 bytenr = ref_path->nodes[level];
4130 else
4131 bytenr = ref_path->extent_start;
4132 BUG_ON(bytenr == 0);
4133
4134 parent = ref_path->nodes[level + 1];
4135 ref_path->nodes[level + 1] = 0;
4136 ref_path->current_level = level;
4137 BUG_ON(parent == 0);
4138
4139 key.objectid = bytenr;
4140 key.offset = parent + 1;
4141 key.type = BTRFS_EXTENT_REF_KEY;
4142
4143 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
4144 if (ret < 0)
4145 goto out;
4146 BUG_ON(ret == 0);
4147
4148 leaf = path->nodes[0];
4149 nritems = btrfs_header_nritems(leaf);
4150 if (path->slots[0] >= nritems) {
4151 ret = btrfs_next_leaf(extent_root, path);
4152 if (ret < 0)
4153 goto out;
4154 if (ret > 0)
4155 goto next;
4156 leaf = path->nodes[0];
4157 }
4158
4159 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4160 if (found_key.objectid == bytenr &&
4161 found_key.type == BTRFS_EXTENT_REF_KEY) {
4162 if (level < ref_path->shared_level)
4163 ref_path->shared_level = level;
4164 goto found;
4165 }
4166 next:
4167 level--;
4168 btrfs_release_path(extent_root, path);
4169 cond_resched();
4170 }
4171 /* reached lowest level */
4172 ret = 1;
4173 goto out;
4174 walk_up:
4175 level = ref_path->current_level;
4176 while (level < BTRFS_MAX_LEVEL - 1) {
4177 u64 ref_objectid;
4178
4179 if (level >= 0)
4180 bytenr = ref_path->nodes[level];
4181 else
4182 bytenr = ref_path->extent_start;
4183
4184 BUG_ON(bytenr == 0);
4185
4186 key.objectid = bytenr;
4187 key.offset = 0;
4188 key.type = BTRFS_EXTENT_REF_KEY;
4189
4190 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
4191 if (ret < 0)
4192 goto out;
4193
4194 leaf = path->nodes[0];
4195 nritems = btrfs_header_nritems(leaf);
4196 if (path->slots[0] >= nritems) {
4197 ret = btrfs_next_leaf(extent_root, path);
4198 if (ret < 0)
4199 goto out;
4200 if (ret > 0) {
4201 /* the extent was freed by someone */
4202 if (ref_path->lowest_level == level)
4203 goto out;
4204 btrfs_release_path(extent_root, path);
4205 goto walk_down;
4206 }
4207 leaf = path->nodes[0];
4208 }
4209
4210 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4211 if (found_key.objectid != bytenr ||
4212 found_key.type != BTRFS_EXTENT_REF_KEY) {
4213 /* the extent was freed by someone */
4214 if (ref_path->lowest_level == level) {
4215 ret = 1;
4216 goto out;
4217 }
4218 btrfs_release_path(extent_root, path);
4219 goto walk_down;
4220 }
4221 found:
4222 ref = btrfs_item_ptr(leaf, path->slots[0],
4223 struct btrfs_extent_ref);
4224 ref_objectid = btrfs_ref_objectid(leaf, ref);
4225 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
4226 if (first_time) {
4227 level = (int)ref_objectid;
4228 BUG_ON(level >= BTRFS_MAX_LEVEL);
4229 ref_path->lowest_level = level;
4230 ref_path->current_level = level;
4231 ref_path->nodes[level] = bytenr;
4232 } else {
4233 WARN_ON(ref_objectid != level);
4234 }
4235 } else {
4236 WARN_ON(level != -1);
4237 }
4238 first_time = 0;
4239
4240 if (ref_path->lowest_level == level) {
4241 ref_path->owner_objectid = ref_objectid;
4242 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
4243 }
4244
4245 /*
4246 * the block is tree root or the block isn't in reference
4247 * counted tree.
4248 */
4249 if (found_key.objectid == found_key.offset ||
4250 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
4251 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
4252 ref_path->root_generation =
4253 btrfs_ref_generation(leaf, ref);
4254 if (level < 0) {
4255 /* special reference from the tree log */
4256 ref_path->nodes[0] = found_key.offset;
4257 ref_path->current_level = 0;
4258 }
4259 ret = 0;
4260 goto out;
4261 }
4262
4263 level++;
4264 BUG_ON(ref_path->nodes[level] != 0);
4265 ref_path->nodes[level] = found_key.offset;
4266 ref_path->current_level = level;
4267
4268 /*
4269 * the reference was created in the running transaction,
4270 * no need to continue walking up.
4271 */
4272 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
4273 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
4274 ref_path->root_generation =
4275 btrfs_ref_generation(leaf, ref);
4276 ret = 0;
4277 goto out;
4278 }
4279
4280 btrfs_release_path(extent_root, path);
4281 cond_resched();
4282 }
4283 /* reached max tree level, but no tree root found. */
4284 BUG();
4285 out:
4286 btrfs_free_path(path);
4287 return ret;
4288 }
4289
4290 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
4291 struct btrfs_root *extent_root,
4292 struct btrfs_ref_path *ref_path,
4293 u64 extent_start)
4294 {
4295 memset(ref_path, 0, sizeof(*ref_path));
4296 ref_path->extent_start = extent_start;
4297
4298 return __next_ref_path(trans, extent_root, ref_path, 1);
4299 }
4300
4301 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
4302 struct btrfs_root *extent_root,
4303 struct btrfs_ref_path *ref_path)
4304 {
4305 return __next_ref_path(trans, extent_root, ref_path, 0);
4306 }
4307
4308 static noinline int get_new_locations(struct inode *reloc_inode,
4309 struct btrfs_key *extent_key,
4310 u64 offset, int no_fragment,
4311 struct disk_extent **extents,
4312 int *nr_extents)
4313 {
4314 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
4315 struct btrfs_path *path;
4316 struct btrfs_file_extent_item *fi;
4317 struct extent_buffer *leaf;
4318 struct disk_extent *exts = *extents;
4319 struct btrfs_key found_key;
4320 u64 cur_pos;
4321 u64 last_byte;
4322 u32 nritems;
4323 int nr = 0;
4324 int max = *nr_extents;
4325 int ret;
4326
4327 WARN_ON(!no_fragment && *extents);
4328 if (!exts) {
4329 max = 1;
4330 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
4331 if (!exts)
4332 return -ENOMEM;
4333 }
4334
4335 path = btrfs_alloc_path();
4336 BUG_ON(!path);
4337
4338 cur_pos = extent_key->objectid - offset;
4339 last_byte = extent_key->objectid + extent_key->offset;
4340 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
4341 cur_pos, 0);
4342 if (ret < 0)
4343 goto out;
4344 if (ret > 0) {
4345 ret = -ENOENT;
4346 goto out;
4347 }
4348
4349 while (1) {
4350 leaf = path->nodes[0];
4351 nritems = btrfs_header_nritems(leaf);
4352 if (path->slots[0] >= nritems) {
4353 ret = btrfs_next_leaf(root, path);
4354 if (ret < 0)
4355 goto out;
4356 if (ret > 0)
4357 break;
4358 leaf = path->nodes[0];
4359 }
4360
4361 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4362 if (found_key.offset != cur_pos ||
4363 found_key.type != BTRFS_EXTENT_DATA_KEY ||
4364 found_key.objectid != reloc_inode->i_ino)
4365 break;
4366
4367 fi = btrfs_item_ptr(leaf, path->slots[0],
4368 struct btrfs_file_extent_item);
4369 if (btrfs_file_extent_type(leaf, fi) !=
4370 BTRFS_FILE_EXTENT_REG ||
4371 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
4372 break;
4373
4374 if (nr == max) {
4375 struct disk_extent *old = exts;
4376 max *= 2;
4377 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
4378 memcpy(exts, old, sizeof(*exts) * nr);
4379 if (old != *extents)
4380 kfree(old);
4381 }
4382
4383 exts[nr].disk_bytenr =
4384 btrfs_file_extent_disk_bytenr(leaf, fi);
4385 exts[nr].disk_num_bytes =
4386 btrfs_file_extent_disk_num_bytes(leaf, fi);
4387 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
4388 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4389 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
4390 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
4391 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
4392 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
4393 fi);
4394 BUG_ON(exts[nr].offset > 0);
4395 BUG_ON(exts[nr].compression || exts[nr].encryption);
4396 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
4397
4398 cur_pos += exts[nr].num_bytes;
4399 nr++;
4400
4401 if (cur_pos + offset >= last_byte)
4402 break;
4403
4404 if (no_fragment) {
4405 ret = 1;
4406 goto out;
4407 }
4408 path->slots[0]++;
4409 }
4410
4411 BUG_ON(cur_pos + offset > last_byte);
4412 if (cur_pos + offset < last_byte) {
4413 ret = -ENOENT;
4414 goto out;
4415 }
4416 ret = 0;
4417 out:
4418 btrfs_free_path(path);
4419 if (ret) {
4420 if (exts != *extents)
4421 kfree(exts);
4422 } else {
4423 *extents = exts;
4424 *nr_extents = nr;
4425 }
4426 return ret;
4427 }
4428
4429 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
4430 struct btrfs_root *root,
4431 struct btrfs_path *path,
4432 struct btrfs_key *extent_key,
4433 struct btrfs_key *leaf_key,
4434 struct btrfs_ref_path *ref_path,
4435 struct disk_extent *new_extents,
4436 int nr_extents)
4437 {
4438 struct extent_buffer *leaf;
4439 struct btrfs_file_extent_item *fi;
4440 struct inode *inode = NULL;
4441 struct btrfs_key key;
4442 u64 lock_start = 0;
4443 u64 lock_end = 0;
4444 u64 num_bytes;
4445 u64 ext_offset;
4446 u64 first_pos;
4447 u32 nritems;
4448 int nr_scaned = 0;
4449 int extent_locked = 0;
4450 int extent_type;
4451 int ret;
4452
4453 memcpy(&key, leaf_key, sizeof(key));
4454 first_pos = INT_LIMIT(loff_t) - extent_key->offset;
4455 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
4456 if (key.objectid < ref_path->owner_objectid ||
4457 (key.objectid == ref_path->owner_objectid &&
4458 key.type < BTRFS_EXTENT_DATA_KEY)) {
4459 key.objectid = ref_path->owner_objectid;
4460 key.type = BTRFS_EXTENT_DATA_KEY;
4461 key.offset = 0;
4462 }
4463 }
4464
4465 while (1) {
4466 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
4467 if (ret < 0)
4468 goto out;
4469
4470 leaf = path->nodes[0];
4471 nritems = btrfs_header_nritems(leaf);
4472 next:
4473 if (extent_locked && ret > 0) {
4474 /*
4475 * the file extent item was modified by someone
4476 * before the extent got locked.
4477 */
4478 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
4479 lock_end, GFP_NOFS);
4480 extent_locked = 0;
4481 }
4482
4483 if (path->slots[0] >= nritems) {
4484 if (++nr_scaned > 2)
4485 break;
4486
4487 BUG_ON(extent_locked);
4488 ret = btrfs_next_leaf(root, path);
4489 if (ret < 0)
4490 goto out;
4491 if (ret > 0)
4492 break;
4493 leaf = path->nodes[0];
4494 nritems = btrfs_header_nritems(leaf);
4495 }
4496
4497 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4498
4499 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
4500 if ((key.objectid > ref_path->owner_objectid) ||
4501 (key.objectid == ref_path->owner_objectid &&
4502 key.type > BTRFS_EXTENT_DATA_KEY) ||
4503 (key.offset >= first_pos + extent_key->offset))
4504 break;
4505 }
4506
4507 if (inode && key.objectid != inode->i_ino) {
4508 BUG_ON(extent_locked);
4509 btrfs_release_path(root, path);
4510 mutex_unlock(&inode->i_mutex);
4511 iput(inode);
4512 inode = NULL;
4513 continue;
4514 }
4515
4516 if (key.type != BTRFS_EXTENT_DATA_KEY) {
4517 path->slots[0]++;
4518 ret = 1;
4519 goto next;
4520 }
4521 fi = btrfs_item_ptr(leaf, path->slots[0],
4522 struct btrfs_file_extent_item);
4523 extent_type = btrfs_file_extent_type(leaf, fi);
4524 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
4525 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
4526 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
4527 extent_key->objectid)) {
4528 path->slots[0]++;
4529 ret = 1;
4530 goto next;
4531 }
4532
4533 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4534 ext_offset = btrfs_file_extent_offset(leaf, fi);
4535
4536 if (first_pos > key.offset - ext_offset)
4537 first_pos = key.offset - ext_offset;
4538
4539 if (!extent_locked) {
4540 lock_start = key.offset;
4541 lock_end = lock_start + num_bytes - 1;
4542 } else {
4543 if (lock_start > key.offset ||
4544 lock_end + 1 < key.offset + num_bytes) {
4545 unlock_extent(&BTRFS_I(inode)->io_tree,
4546 lock_start, lock_end, GFP_NOFS);
4547 extent_locked = 0;
4548 }
4549 }
4550
4551 if (!inode) {
4552 btrfs_release_path(root, path);
4553
4554 inode = btrfs_iget_locked(root->fs_info->sb,
4555 key.objectid, root);
4556 if (inode->i_state & I_NEW) {
4557 BTRFS_I(inode)->root = root;
4558 BTRFS_I(inode)->location.objectid =
4559 key.objectid;
4560 BTRFS_I(inode)->location.type =
4561 BTRFS_INODE_ITEM_KEY;
4562 BTRFS_I(inode)->location.offset = 0;
4563 btrfs_read_locked_inode(inode);
4564 unlock_new_inode(inode);
4565 }
4566 /*
4567 * some code call btrfs_commit_transaction while
4568 * holding the i_mutex, so we can't use mutex_lock
4569 * here.
4570 */
4571 if (is_bad_inode(inode) ||
4572 !mutex_trylock(&inode->i_mutex)) {
4573 iput(inode);
4574 inode = NULL;
4575 key.offset = (u64)-1;
4576 goto skip;
4577 }
4578 }
4579
4580 if (!extent_locked) {
4581 struct btrfs_ordered_extent *ordered;
4582
4583 btrfs_release_path(root, path);
4584
4585 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
4586 lock_end, GFP_NOFS);
4587 ordered = btrfs_lookup_first_ordered_extent(inode,
4588 lock_end);
4589 if (ordered &&
4590 ordered->file_offset <= lock_end &&
4591 ordered->file_offset + ordered->len > lock_start) {
4592 unlock_extent(&BTRFS_I(inode)->io_tree,
4593 lock_start, lock_end, GFP_NOFS);
4594 btrfs_start_ordered_extent(inode, ordered, 1);
4595 btrfs_put_ordered_extent(ordered);
4596 key.offset += num_bytes;
4597 goto skip;
4598 }
4599 if (ordered)
4600 btrfs_put_ordered_extent(ordered);
4601
4602 extent_locked = 1;
4603 continue;
4604 }
4605
4606 if (nr_extents == 1) {
4607 /* update extent pointer in place */
4608 btrfs_set_file_extent_disk_bytenr(leaf, fi,
4609 new_extents[0].disk_bytenr);
4610 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4611 new_extents[0].disk_num_bytes);
4612 btrfs_mark_buffer_dirty(leaf);
4613
4614 btrfs_drop_extent_cache(inode, key.offset,
4615 key.offset + num_bytes - 1, 0);
4616
4617 ret = btrfs_inc_extent_ref(trans, root,
4618 new_extents[0].disk_bytenr,
4619 new_extents[0].disk_num_bytes,
4620 leaf->start,
4621 root->root_key.objectid,
4622 trans->transid,
4623 key.objectid);
4624 BUG_ON(ret);
4625
4626 ret = btrfs_free_extent(trans, root,
4627 extent_key->objectid,
4628 extent_key->offset,
4629 leaf->start,
4630 btrfs_header_owner(leaf),
4631 btrfs_header_generation(leaf),
4632 key.objectid, 0);
4633 BUG_ON(ret);
4634
4635 btrfs_release_path(root, path);
4636 key.offset += num_bytes;
4637 } else {
4638 BUG_ON(1);
4639 #if 0
4640 u64 alloc_hint;
4641 u64 extent_len;
4642 int i;
4643 /*
4644 * drop old extent pointer at first, then insert the
4645 * new pointers one bye one
4646 */
4647 btrfs_release_path(root, path);
4648 ret = btrfs_drop_extents(trans, root, inode, key.offset,
4649 key.offset + num_bytes,
4650 key.offset, &alloc_hint);
4651 BUG_ON(ret);
4652
4653 for (i = 0; i < nr_extents; i++) {
4654 if (ext_offset >= new_extents[i].num_bytes) {
4655 ext_offset -= new_extents[i].num_bytes;
4656 continue;
4657 }
4658 extent_len = min(new_extents[i].num_bytes -
4659 ext_offset, num_bytes);
4660
4661 ret = btrfs_insert_empty_item(trans, root,
4662 path, &key,
4663 sizeof(*fi));
4664 BUG_ON(ret);
4665
4666 leaf = path->nodes[0];
4667 fi = btrfs_item_ptr(leaf, path->slots[0],
4668 struct btrfs_file_extent_item);
4669 btrfs_set_file_extent_generation(leaf, fi,
4670 trans->transid);
4671 btrfs_set_file_extent_type(leaf, fi,
4672 BTRFS_FILE_EXTENT_REG);
4673 btrfs_set_file_extent_disk_bytenr(leaf, fi,
4674 new_extents[i].disk_bytenr);
4675 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4676 new_extents[i].disk_num_bytes);
4677 btrfs_set_file_extent_ram_bytes(leaf, fi,
4678 new_extents[i].ram_bytes);
4679
4680 btrfs_set_file_extent_compression(leaf, fi,
4681 new_extents[i].compression);
4682 btrfs_set_file_extent_encryption(leaf, fi,
4683 new_extents[i].encryption);
4684 btrfs_set_file_extent_other_encoding(leaf, fi,
4685 new_extents[i].other_encoding);
4686
4687 btrfs_set_file_extent_num_bytes(leaf, fi,
4688 extent_len);
4689 ext_offset += new_extents[i].offset;
4690 btrfs_set_file_extent_offset(leaf, fi,
4691 ext_offset);
4692 btrfs_mark_buffer_dirty(leaf);
4693
4694 btrfs_drop_extent_cache(inode, key.offset,
4695 key.offset + extent_len - 1, 0);
4696
4697 ret = btrfs_inc_extent_ref(trans, root,
4698 new_extents[i].disk_bytenr,
4699 new_extents[i].disk_num_bytes,
4700 leaf->start,
4701 root->root_key.objectid,
4702 trans->transid, key.objectid);
4703 BUG_ON(ret);
4704 btrfs_release_path(root, path);
4705
4706 inode_add_bytes(inode, extent_len);
4707
4708 ext_offset = 0;
4709 num_bytes -= extent_len;
4710 key.offset += extent_len;
4711
4712 if (num_bytes == 0)
4713 break;
4714 }
4715 BUG_ON(i >= nr_extents);
4716 #endif
4717 }
4718
4719 if (extent_locked) {
4720 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
4721 lock_end, GFP_NOFS);
4722 extent_locked = 0;
4723 }
4724 skip:
4725 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
4726 key.offset >= first_pos + extent_key->offset)
4727 break;
4728
4729 cond_resched();
4730 }
4731 ret = 0;
4732 out:
4733 btrfs_release_path(root, path);
4734 if (inode) {
4735 mutex_unlock(&inode->i_mutex);
4736 if (extent_locked) {
4737 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
4738 lock_end, GFP_NOFS);
4739 }
4740 iput(inode);
4741 }
4742 return ret;
4743 }
4744
4745 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
4746 struct btrfs_root *root,
4747 struct extent_buffer *buf, u64 orig_start)
4748 {
4749 int level;
4750 int ret;
4751
4752 BUG_ON(btrfs_header_generation(buf) != trans->transid);
4753 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
4754
4755 level = btrfs_header_level(buf);
4756 if (level == 0) {
4757 struct btrfs_leaf_ref *ref;
4758 struct btrfs_leaf_ref *orig_ref;
4759
4760 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
4761 if (!orig_ref)
4762 return -ENOENT;
4763
4764 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
4765 if (!ref) {
4766 btrfs_free_leaf_ref(root, orig_ref);
4767 return -ENOMEM;
4768 }
4769
4770 ref->nritems = orig_ref->nritems;
4771 memcpy(ref->extents, orig_ref->extents,
4772 sizeof(ref->extents[0]) * ref->nritems);
4773
4774 btrfs_free_leaf_ref(root, orig_ref);
4775
4776 ref->root_gen = trans->transid;
4777 ref->bytenr = buf->start;
4778 ref->owner = btrfs_header_owner(buf);
4779 ref->generation = btrfs_header_generation(buf);
4780 ret = btrfs_add_leaf_ref(root, ref, 0);
4781 WARN_ON(ret);
4782 btrfs_free_leaf_ref(root, ref);
4783 }
4784 return 0;
4785 }
4786
4787 static noinline int invalidate_extent_cache(struct btrfs_root *root,
4788 struct extent_buffer *leaf,
4789 struct btrfs_block_group_cache *group,
4790 struct btrfs_root *target_root)
4791 {
4792 struct btrfs_key key;
4793 struct inode *inode = NULL;
4794 struct btrfs_file_extent_item *fi;
4795 u64 num_bytes;
4796 u64 skip_objectid = 0;
4797 u32 nritems;
4798 u32 i;
4799
4800 nritems = btrfs_header_nritems(leaf);
4801 for (i = 0; i < nritems; i++) {
4802 btrfs_item_key_to_cpu(leaf, &key, i);
4803 if (key.objectid == skip_objectid ||
4804 key.type != BTRFS_EXTENT_DATA_KEY)
4805 continue;
4806 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4807 if (btrfs_file_extent_type(leaf, fi) ==
4808 BTRFS_FILE_EXTENT_INLINE)
4809 continue;
4810 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
4811 continue;
4812 if (!inode || inode->i_ino != key.objectid) {
4813 iput(inode);
4814 inode = btrfs_ilookup(target_root->fs_info->sb,
4815 key.objectid, target_root, 1);
4816 }
4817 if (!inode) {
4818 skip_objectid = key.objectid;
4819 continue;
4820 }
4821 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4822
4823 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4824 key.offset + num_bytes - 1, GFP_NOFS);
4825 btrfs_drop_extent_cache(inode, key.offset,
4826 key.offset + num_bytes - 1, 1);
4827 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4828 key.offset + num_bytes - 1, GFP_NOFS);
4829 cond_resched();
4830 }
4831 iput(inode);
4832 return 0;
4833 }
4834
4835 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
4836 struct btrfs_root *root,
4837 struct extent_buffer *leaf,
4838 struct btrfs_block_group_cache *group,
4839 struct inode *reloc_inode)
4840 {
4841 struct btrfs_key key;
4842 struct btrfs_key extent_key;
4843 struct btrfs_file_extent_item *fi;
4844 struct btrfs_leaf_ref *ref;
4845 struct disk_extent *new_extent;
4846 u64 bytenr;
4847 u64 num_bytes;
4848 u32 nritems;
4849 u32 i;
4850 int ext_index;
4851 int nr_extent;
4852 int ret;
4853
4854 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
4855 BUG_ON(!new_extent);
4856
4857 ref = btrfs_lookup_leaf_ref(root, leaf->start);
4858 BUG_ON(!ref);
4859
4860 ext_index = -1;
4861 nritems = btrfs_header_nritems(leaf);
4862 for (i = 0; i < nritems; i++) {
4863 btrfs_item_key_to_cpu(leaf, &key, i);
4864 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
4865 continue;
4866 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4867 if (btrfs_file_extent_type(leaf, fi) ==
4868 BTRFS_FILE_EXTENT_INLINE)
4869 continue;
4870 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
4871 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
4872 if (bytenr == 0)
4873 continue;
4874
4875 ext_index++;
4876 if (bytenr >= group->key.objectid + group->key.offset ||
4877 bytenr + num_bytes <= group->key.objectid)
4878 continue;
4879
4880 extent_key.objectid = bytenr;
4881 extent_key.offset = num_bytes;
4882 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
4883 nr_extent = 1;
4884 ret = get_new_locations(reloc_inode, &extent_key,
4885 group->key.objectid, 1,
4886 &new_extent, &nr_extent);
4887 if (ret > 0)
4888 continue;
4889 BUG_ON(ret < 0);
4890
4891 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
4892 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
4893 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
4894 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
4895
4896 btrfs_set_file_extent_disk_bytenr(leaf, fi,
4897 new_extent->disk_bytenr);
4898 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4899 new_extent->disk_num_bytes);
4900 btrfs_mark_buffer_dirty(leaf);
4901
4902 ret = btrfs_inc_extent_ref(trans, root,
4903 new_extent->disk_bytenr,
4904 new_extent->disk_num_bytes,
4905 leaf->start,
4906 root->root_key.objectid,
4907 trans->transid, key.objectid);
4908 BUG_ON(ret);
4909 ret = btrfs_free_extent(trans, root,
4910 bytenr, num_bytes, leaf->start,
4911 btrfs_header_owner(leaf),
4912 btrfs_header_generation(leaf),
4913 key.objectid, 0);
4914 BUG_ON(ret);
4915 cond_resched();
4916 }
4917 kfree(new_extent);
4918 BUG_ON(ext_index + 1 != ref->nritems);
4919 btrfs_free_leaf_ref(root, ref);
4920 return 0;
4921 }
4922
4923 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
4924 struct btrfs_root *root)
4925 {
4926 struct btrfs_root *reloc_root;
4927 int ret;
4928
4929 if (root->reloc_root) {
4930 reloc_root = root->reloc_root;
4931 root->reloc_root = NULL;
4932 list_add(&reloc_root->dead_list,
4933 &root->fs_info->dead_reloc_roots);
4934
4935 btrfs_set_root_bytenr(&reloc_root->root_item,
4936 reloc_root->node->start);
4937 btrfs_set_root_level(&root->root_item,
4938 btrfs_header_level(reloc_root->node));
4939 memset(&reloc_root->root_item.drop_progress, 0,
4940 sizeof(struct btrfs_disk_key));
4941 reloc_root->root_item.drop_level = 0;
4942
4943 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4944 &reloc_root->root_key,
4945 &reloc_root->root_item);
4946 BUG_ON(ret);
4947 }
4948 return 0;
4949 }
4950
4951 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
4952 {
4953 struct btrfs_trans_handle *trans;
4954 struct btrfs_root *reloc_root;
4955 struct btrfs_root *prev_root = NULL;
4956 struct list_head dead_roots;
4957 int ret;
4958 unsigned long nr;
4959
4960 INIT_LIST_HEAD(&dead_roots);
4961 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
4962
4963 while (!list_empty(&dead_roots)) {
4964 reloc_root = list_entry(dead_roots.prev,
4965 struct btrfs_root, dead_list);
4966 list_del_init(&reloc_root->dead_list);
4967
4968 BUG_ON(reloc_root->commit_root != NULL);
4969 while (1) {
4970 trans = btrfs_join_transaction(root, 1);
4971 BUG_ON(!trans);
4972
4973 mutex_lock(&root->fs_info->drop_mutex);
4974 ret = btrfs_drop_snapshot(trans, reloc_root);
4975 if (ret != -EAGAIN)
4976 break;
4977 mutex_unlock(&root->fs_info->drop_mutex);
4978
4979 nr = trans->blocks_used;
4980 ret = btrfs_end_transaction(trans, root);
4981 BUG_ON(ret);
4982 btrfs_btree_balance_dirty(root, nr);
4983 }
4984
4985 free_extent_buffer(reloc_root->node);
4986
4987 ret = btrfs_del_root(trans, root->fs_info->tree_root,
4988 &reloc_root->root_key);
4989 BUG_ON(ret);
4990 mutex_unlock(&root->fs_info->drop_mutex);
4991
4992 nr = trans->blocks_used;
4993 ret = btrfs_end_transaction(trans, root);
4994 BUG_ON(ret);
4995 btrfs_btree_balance_dirty(root, nr);
4996
4997 kfree(prev_root);
4998 prev_root = reloc_root;
4999 }
5000 if (prev_root) {
5001 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
5002 kfree(prev_root);
5003 }
5004 return 0;
5005 }
5006
5007 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
5008 {
5009 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
5010 return 0;
5011 }
5012
5013 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
5014 {
5015 struct btrfs_root *reloc_root;
5016 struct btrfs_trans_handle *trans;
5017 struct btrfs_key location;
5018 int found;
5019 int ret;
5020
5021 mutex_lock(&root->fs_info->tree_reloc_mutex);
5022 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
5023 BUG_ON(ret);
5024 found = !list_empty(&root->fs_info->dead_reloc_roots);
5025 mutex_unlock(&root->fs_info->tree_reloc_mutex);
5026
5027 if (found) {
5028 trans = btrfs_start_transaction(root, 1);
5029 BUG_ON(!trans);
5030 ret = btrfs_commit_transaction(trans, root);
5031 BUG_ON(ret);
5032 }
5033
5034 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
5035 location.offset = (u64)-1;
5036 location.type = BTRFS_ROOT_ITEM_KEY;
5037
5038 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
5039 BUG_ON(!reloc_root);
5040 btrfs_orphan_cleanup(reloc_root);
5041 return 0;
5042 }
5043
5044 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
5045 struct btrfs_root *root)
5046 {
5047 struct btrfs_root *reloc_root;
5048 struct extent_buffer *eb;
5049 struct btrfs_root_item *root_item;
5050 struct btrfs_key root_key;
5051 int ret;
5052
5053 BUG_ON(!root->ref_cows);
5054 if (root->reloc_root)
5055 return 0;
5056
5057 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
5058 BUG_ON(!root_item);
5059
5060 ret = btrfs_copy_root(trans, root, root->commit_root,
5061 &eb, BTRFS_TREE_RELOC_OBJECTID);
5062 BUG_ON(ret);
5063
5064 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
5065 root_key.offset = root->root_key.objectid;
5066 root_key.type = BTRFS_ROOT_ITEM_KEY;
5067
5068 memcpy(root_item, &root->root_item, sizeof(root_item));
5069 btrfs_set_root_refs(root_item, 0);
5070 btrfs_set_root_bytenr(root_item, eb->start);
5071 btrfs_set_root_level(root_item, btrfs_header_level(eb));
5072 btrfs_set_root_generation(root_item, trans->transid);
5073
5074 btrfs_tree_unlock(eb);
5075 free_extent_buffer(eb);
5076
5077 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
5078 &root_key, root_item);
5079 BUG_ON(ret);
5080 kfree(root_item);
5081
5082 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
5083 &root_key);
5084 BUG_ON(!reloc_root);
5085 reloc_root->last_trans = trans->transid;
5086 reloc_root->commit_root = NULL;
5087 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
5088
5089 root->reloc_root = reloc_root;
5090 return 0;
5091 }
5092
5093 /*
5094 * Core function of space balance.
5095 *
5096 * The idea is using reloc trees to relocate tree blocks in reference
5097 * counted roots. There is one reloc tree for each subvol, and all
5098 * reloc trees share same root key objectid. Reloc trees are snapshots
5099 * of the latest committed roots of subvols (root->commit_root).
5100 *
5101 * To relocate a tree block referenced by a subvol, there are two steps.
5102 * COW the block through subvol's reloc tree, then update block pointer
5103 * in the subvol to point to the new block. Since all reloc trees share
5104 * same root key objectid, doing special handing for tree blocks owned
5105 * by them is easy. Once a tree block has been COWed in one reloc tree,
5106 * we can use the resulting new block directly when the same block is
5107 * required to COW again through other reloc trees. By this way, relocated
5108 * tree blocks are shared between reloc trees, so they are also shared
5109 * between subvols.
5110 */
5111 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
5112 struct btrfs_root *root,
5113 struct btrfs_path *path,
5114 struct btrfs_key *first_key,
5115 struct btrfs_ref_path *ref_path,
5116 struct btrfs_block_group_cache *group,
5117 struct inode *reloc_inode)
5118 {
5119 struct btrfs_root *reloc_root;
5120 struct extent_buffer *eb = NULL;
5121 struct btrfs_key *keys;
5122 u64 *nodes;
5123 int level;
5124 int shared_level;
5125 int lowest_level = 0;
5126 int ret;
5127
5128 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
5129 lowest_level = ref_path->owner_objectid;
5130
5131 if (!root->ref_cows) {
5132 path->lowest_level = lowest_level;
5133 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
5134 BUG_ON(ret < 0);
5135 path->lowest_level = 0;
5136 btrfs_release_path(root, path);
5137 return 0;
5138 }
5139
5140 mutex_lock(&root->fs_info->tree_reloc_mutex);
5141 ret = init_reloc_tree(trans, root);
5142 BUG_ON(ret);
5143 reloc_root = root->reloc_root;
5144
5145 shared_level = ref_path->shared_level;
5146 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
5147
5148 keys = ref_path->node_keys;
5149 nodes = ref_path->new_nodes;
5150 memset(&keys[shared_level + 1], 0,
5151 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
5152 memset(&nodes[shared_level + 1], 0,
5153 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
5154
5155 if (nodes[lowest_level] == 0) {
5156 path->lowest_level = lowest_level;
5157 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
5158 0, 1);
5159 BUG_ON(ret);
5160 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
5161 eb = path->nodes[level];
5162 if (!eb || eb == reloc_root->node)
5163 break;
5164 nodes[level] = eb->start;
5165 if (level == 0)
5166 btrfs_item_key_to_cpu(eb, &keys[level], 0);
5167 else
5168 btrfs_node_key_to_cpu(eb, &keys[level], 0);
5169 }
5170 if (nodes[0] &&
5171 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5172 eb = path->nodes[0];
5173 ret = replace_extents_in_leaf(trans, reloc_root, eb,
5174 group, reloc_inode);
5175 BUG_ON(ret);
5176 }
5177 btrfs_release_path(reloc_root, path);
5178 } else {
5179 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
5180 lowest_level);
5181 BUG_ON(ret);
5182 }
5183
5184 /*
5185 * replace tree blocks in the fs tree with tree blocks in
5186 * the reloc tree.
5187 */
5188 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
5189 BUG_ON(ret < 0);
5190
5191 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5192 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
5193 0, 0);
5194 BUG_ON(ret);
5195 extent_buffer_get(path->nodes[0]);
5196 eb = path->nodes[0];
5197 btrfs_release_path(reloc_root, path);
5198 ret = invalidate_extent_cache(reloc_root, eb, group, root);
5199 BUG_ON(ret);
5200 free_extent_buffer(eb);
5201 }
5202
5203 mutex_unlock(&root->fs_info->tree_reloc_mutex);
5204 path->lowest_level = 0;
5205 return 0;
5206 }
5207
5208 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
5209 struct btrfs_root *root,
5210 struct btrfs_path *path,
5211 struct btrfs_key *first_key,
5212 struct btrfs_ref_path *ref_path)
5213 {
5214 int ret;
5215
5216 ret = relocate_one_path(trans, root, path, first_key,
5217 ref_path, NULL, NULL);
5218 BUG_ON(ret);
5219
5220 if (root == root->fs_info->extent_root)
5221 btrfs_extent_post_op(trans, root);
5222
5223 return 0;
5224 }
5225
5226 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
5227 struct btrfs_root *extent_root,
5228 struct btrfs_path *path,
5229 struct btrfs_key *extent_key)
5230 {
5231 int ret;
5232
5233 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
5234 if (ret)
5235 goto out;
5236 ret = btrfs_del_item(trans, extent_root, path);
5237 out:
5238 btrfs_release_path(extent_root, path);
5239 return ret;
5240 }
5241
5242 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
5243 struct btrfs_ref_path *ref_path)
5244 {
5245 struct btrfs_key root_key;
5246
5247 root_key.objectid = ref_path->root_objectid;
5248 root_key.type = BTRFS_ROOT_ITEM_KEY;
5249 if (is_cowonly_root(ref_path->root_objectid))
5250 root_key.offset = 0;
5251 else
5252 root_key.offset = (u64)-1;
5253
5254 return btrfs_read_fs_root_no_name(fs_info, &root_key);
5255 }
5256
5257 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
5258 struct btrfs_path *path,
5259 struct btrfs_key *extent_key,
5260 struct btrfs_block_group_cache *group,
5261 struct inode *reloc_inode, int pass)
5262 {
5263 struct btrfs_trans_handle *trans;
5264 struct btrfs_root *found_root;
5265 struct btrfs_ref_path *ref_path = NULL;
5266 struct disk_extent *new_extents = NULL;
5267 int nr_extents = 0;
5268 int loops;
5269 int ret;
5270 int level;
5271 struct btrfs_key first_key;
5272 u64 prev_block = 0;
5273
5274
5275 trans = btrfs_start_transaction(extent_root, 1);
5276 BUG_ON(!trans);
5277
5278 if (extent_key->objectid == 0) {
5279 ret = del_extent_zero(trans, extent_root, path, extent_key);
5280 goto out;
5281 }
5282
5283 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
5284 if (!ref_path) {
5285 ret = -ENOMEM;
5286 goto out;
5287 }
5288
5289 for (loops = 0; ; loops++) {
5290 if (loops == 0) {
5291 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
5292 extent_key->objectid);
5293 } else {
5294 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
5295 }
5296 if (ret < 0)
5297 goto out;
5298 if (ret > 0)
5299 break;
5300
5301 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
5302 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
5303 continue;
5304
5305 found_root = read_ref_root(extent_root->fs_info, ref_path);
5306 BUG_ON(!found_root);
5307 /*
5308 * for reference counted tree, only process reference paths
5309 * rooted at the latest committed root.
5310 */
5311 if (found_root->ref_cows &&
5312 ref_path->root_generation != found_root->root_key.offset)
5313 continue;
5314
5315 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5316 if (pass == 0) {
5317 /*
5318 * copy data extents to new locations
5319 */
5320 u64 group_start = group->key.objectid;
5321 ret = relocate_data_extent(reloc_inode,
5322 extent_key,
5323 group_start);
5324 if (ret < 0)
5325 goto out;
5326 break;
5327 }
5328 level = 0;
5329 } else {
5330 level = ref_path->owner_objectid;
5331 }
5332
5333 if (prev_block != ref_path->nodes[level]) {
5334 struct extent_buffer *eb;
5335 u64 block_start = ref_path->nodes[level];
5336 u64 block_size = btrfs_level_size(found_root, level);
5337
5338 eb = read_tree_block(found_root, block_start,
5339 block_size, 0);
5340 btrfs_tree_lock(eb);
5341 BUG_ON(level != btrfs_header_level(eb));
5342
5343 if (level == 0)
5344 btrfs_item_key_to_cpu(eb, &first_key, 0);
5345 else
5346 btrfs_node_key_to_cpu(eb, &first_key, 0);
5347
5348 btrfs_tree_unlock(eb);
5349 free_extent_buffer(eb);
5350 prev_block = block_start;
5351 }
5352
5353 btrfs_record_root_in_trans(found_root);
5354 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5355 /*
5356 * try to update data extent references while
5357 * keeping metadata shared between snapshots.
5358 */
5359 if (pass == 1) {
5360 ret = relocate_one_path(trans, found_root,
5361 path, &first_key, ref_path,
5362 group, reloc_inode);
5363 if (ret < 0)
5364 goto out;
5365 continue;
5366 }
5367 /*
5368 * use fallback method to process the remaining
5369 * references.
5370 */
5371 if (!new_extents) {
5372 u64 group_start = group->key.objectid;
5373 new_extents = kmalloc(sizeof(*new_extents),
5374 GFP_NOFS);
5375 nr_extents = 1;
5376 ret = get_new_locations(reloc_inode,
5377 extent_key,
5378 group_start, 1,
5379 &new_extents,
5380 &nr_extents);
5381 if (ret)
5382 goto out;
5383 }
5384 ret = replace_one_extent(trans, found_root,
5385 path, extent_key,
5386 &first_key, ref_path,
5387 new_extents, nr_extents);
5388 } else {
5389 ret = relocate_tree_block(trans, found_root, path,
5390 &first_key, ref_path);
5391 }
5392 if (ret < 0)
5393 goto out;
5394 }
5395 ret = 0;
5396 out:
5397 btrfs_end_transaction(trans, extent_root);
5398 kfree(new_extents);
5399 kfree(ref_path);
5400 return ret;
5401 }
5402
5403 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
5404 {
5405 u64 num_devices;
5406 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
5407 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
5408
5409 num_devices = root->fs_info->fs_devices->rw_devices;
5410 if (num_devices == 1) {
5411 stripped |= BTRFS_BLOCK_GROUP_DUP;
5412 stripped = flags & ~stripped;
5413
5414 /* turn raid0 into single device chunks */
5415 if (flags & BTRFS_BLOCK_GROUP_RAID0)
5416 return stripped;
5417
5418 /* turn mirroring into duplication */
5419 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
5420 BTRFS_BLOCK_GROUP_RAID10))
5421 return stripped | BTRFS_BLOCK_GROUP_DUP;
5422 return flags;
5423 } else {
5424 /* they already had raid on here, just return */
5425 if (flags & stripped)
5426 return flags;
5427
5428 stripped |= BTRFS_BLOCK_GROUP_DUP;
5429 stripped = flags & ~stripped;
5430
5431 /* switch duplicated blocks with raid1 */
5432 if (flags & BTRFS_BLOCK_GROUP_DUP)
5433 return stripped | BTRFS_BLOCK_GROUP_RAID1;
5434
5435 /* turn single device chunks into raid0 */
5436 return stripped | BTRFS_BLOCK_GROUP_RAID0;
5437 }
5438 return flags;
5439 }
5440
5441 static int __alloc_chunk_for_shrink(struct btrfs_root *root,
5442 struct btrfs_block_group_cache *shrink_block_group,
5443 int force)
5444 {
5445 struct btrfs_trans_handle *trans;
5446 u64 new_alloc_flags;
5447 u64 calc;
5448
5449 spin_lock(&shrink_block_group->lock);
5450 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
5451 spin_unlock(&shrink_block_group->lock);
5452
5453 trans = btrfs_start_transaction(root, 1);
5454 spin_lock(&shrink_block_group->lock);
5455
5456 new_alloc_flags = update_block_group_flags(root,
5457 shrink_block_group->flags);
5458 if (new_alloc_flags != shrink_block_group->flags) {
5459 calc =
5460 btrfs_block_group_used(&shrink_block_group->item);
5461 } else {
5462 calc = shrink_block_group->key.offset;
5463 }
5464 spin_unlock(&shrink_block_group->lock);
5465
5466 do_chunk_alloc(trans, root->fs_info->extent_root,
5467 calc + 2 * 1024 * 1024, new_alloc_flags, force);
5468
5469 btrfs_end_transaction(trans, root);
5470 } else
5471 spin_unlock(&shrink_block_group->lock);
5472 return 0;
5473 }
5474
5475 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
5476 struct btrfs_root *root,
5477 u64 objectid, u64 size)
5478 {
5479 struct btrfs_path *path;
5480 struct btrfs_inode_item *item;
5481 struct extent_buffer *leaf;
5482 int ret;
5483
5484 path = btrfs_alloc_path();
5485 if (!path)
5486 return -ENOMEM;
5487
5488 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
5489 if (ret)
5490 goto out;
5491
5492 leaf = path->nodes[0];
5493 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
5494 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
5495 btrfs_set_inode_generation(leaf, item, 1);
5496 btrfs_set_inode_size(leaf, item, size);
5497 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
5498 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS);
5499 btrfs_mark_buffer_dirty(leaf);
5500 btrfs_release_path(root, path);
5501 out:
5502 btrfs_free_path(path);
5503 return ret;
5504 }
5505
5506 static noinline struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
5507 struct btrfs_block_group_cache *group)
5508 {
5509 struct inode *inode = NULL;
5510 struct btrfs_trans_handle *trans;
5511 struct btrfs_root *root;
5512 struct btrfs_key root_key;
5513 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
5514 int err = 0;
5515
5516 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
5517 root_key.type = BTRFS_ROOT_ITEM_KEY;
5518 root_key.offset = (u64)-1;
5519 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
5520 if (IS_ERR(root))
5521 return ERR_CAST(root);
5522
5523 trans = btrfs_start_transaction(root, 1);
5524 BUG_ON(!trans);
5525
5526 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
5527 if (err)
5528 goto out;
5529
5530 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
5531 BUG_ON(err);
5532
5533 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
5534 group->key.offset, 0, group->key.offset,
5535 0, 0, 0);
5536 BUG_ON(err);
5537
5538 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
5539 if (inode->i_state & I_NEW) {
5540 BTRFS_I(inode)->root = root;
5541 BTRFS_I(inode)->location.objectid = objectid;
5542 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
5543 BTRFS_I(inode)->location.offset = 0;
5544 btrfs_read_locked_inode(inode);
5545 unlock_new_inode(inode);
5546 BUG_ON(is_bad_inode(inode));
5547 } else {
5548 BUG_ON(1);
5549 }
5550 BTRFS_I(inode)->index_cnt = group->key.objectid;
5551
5552 err = btrfs_orphan_add(trans, inode);
5553 out:
5554 btrfs_end_transaction(trans, root);
5555 if (err) {
5556 if (inode)
5557 iput(inode);
5558 inode = ERR_PTR(err);
5559 }
5560 return inode;
5561 }
5562
5563 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
5564 {
5565
5566 struct btrfs_ordered_sum *sums;
5567 struct btrfs_sector_sum *sector_sum;
5568 struct btrfs_ordered_extent *ordered;
5569 struct btrfs_root *root = BTRFS_I(inode)->root;
5570 struct list_head list;
5571 size_t offset;
5572 int ret;
5573 u64 disk_bytenr;
5574
5575 INIT_LIST_HEAD(&list);
5576
5577 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
5578 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
5579
5580 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
5581 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
5582 disk_bytenr + len - 1, &list);
5583
5584 while (!list_empty(&list)) {
5585 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
5586 list_del_init(&sums->list);
5587
5588 sector_sum = sums->sums;
5589 sums->bytenr = ordered->start;
5590
5591 offset = 0;
5592 while (offset < sums->len) {
5593 sector_sum->bytenr += ordered->start - disk_bytenr;
5594 sector_sum++;
5595 offset += root->sectorsize;
5596 }
5597
5598 btrfs_add_ordered_sum(inode, ordered, sums);
5599 }
5600 btrfs_put_ordered_extent(ordered);
5601 return 0;
5602 }
5603
5604 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
5605 {
5606 struct btrfs_trans_handle *trans;
5607 struct btrfs_path *path;
5608 struct btrfs_fs_info *info = root->fs_info;
5609 struct extent_buffer *leaf;
5610 struct inode *reloc_inode;
5611 struct btrfs_block_group_cache *block_group;
5612 struct btrfs_key key;
5613 u64 skipped;
5614 u64 cur_byte;
5615 u64 total_found;
5616 u32 nritems;
5617 int ret;
5618 int progress;
5619 int pass = 0;
5620
5621 root = root->fs_info->extent_root;
5622
5623 block_group = btrfs_lookup_block_group(info, group_start);
5624 BUG_ON(!block_group);
5625
5626 printk(KERN_INFO "btrfs relocating block group %llu flags %llu\n",
5627 (unsigned long long)block_group->key.objectid,
5628 (unsigned long long)block_group->flags);
5629
5630 path = btrfs_alloc_path();
5631 BUG_ON(!path);
5632
5633 reloc_inode = create_reloc_inode(info, block_group);
5634 BUG_ON(IS_ERR(reloc_inode));
5635
5636 __alloc_chunk_for_shrink(root, block_group, 1);
5637 set_block_group_readonly(block_group);
5638
5639 btrfs_start_delalloc_inodes(info->tree_root);
5640 btrfs_wait_ordered_extents(info->tree_root, 0);
5641 again:
5642 skipped = 0;
5643 total_found = 0;
5644 progress = 0;
5645 key.objectid = block_group->key.objectid;
5646 key.offset = 0;
5647 key.type = 0;
5648 cur_byte = key.objectid;
5649
5650 trans = btrfs_start_transaction(info->tree_root, 1);
5651 btrfs_commit_transaction(trans, info->tree_root);
5652
5653 mutex_lock(&root->fs_info->cleaner_mutex);
5654 btrfs_clean_old_snapshots(info->tree_root);
5655 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
5656 mutex_unlock(&root->fs_info->cleaner_mutex);
5657
5658 while (1) {
5659 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5660 if (ret < 0)
5661 goto out;
5662 next:
5663 leaf = path->nodes[0];
5664 nritems = btrfs_header_nritems(leaf);
5665 if (path->slots[0] >= nritems) {
5666 ret = btrfs_next_leaf(root, path);
5667 if (ret < 0)
5668 goto out;
5669 if (ret == 1) {
5670 ret = 0;
5671 break;
5672 }
5673 leaf = path->nodes[0];
5674 nritems = btrfs_header_nritems(leaf);
5675 }
5676
5677 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
5678
5679 if (key.objectid >= block_group->key.objectid +
5680 block_group->key.offset)
5681 break;
5682
5683 if (progress && need_resched()) {
5684 btrfs_release_path(root, path);
5685 cond_resched();
5686 progress = 0;
5687 continue;
5688 }
5689 progress = 1;
5690
5691 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
5692 key.objectid + key.offset <= cur_byte) {
5693 path->slots[0]++;
5694 goto next;
5695 }
5696
5697 total_found++;
5698 cur_byte = key.objectid + key.offset;
5699 btrfs_release_path(root, path);
5700
5701 __alloc_chunk_for_shrink(root, block_group, 0);
5702 ret = relocate_one_extent(root, path, &key, block_group,
5703 reloc_inode, pass);
5704 BUG_ON(ret < 0);
5705 if (ret > 0)
5706 skipped++;
5707
5708 key.objectid = cur_byte;
5709 key.type = 0;
5710 key.offset = 0;
5711 }
5712
5713 btrfs_release_path(root, path);
5714
5715 if (pass == 0) {
5716 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
5717 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
5718 }
5719
5720 if (total_found > 0) {
5721 printk(KERN_INFO "btrfs found %llu extents in pass %d\n",
5722 (unsigned long long)total_found, pass);
5723 pass++;
5724 if (total_found == skipped && pass > 2) {
5725 iput(reloc_inode);
5726 reloc_inode = create_reloc_inode(info, block_group);
5727 pass = 0;
5728 }
5729 goto again;
5730 }
5731
5732 /* delete reloc_inode */
5733 iput(reloc_inode);
5734
5735 /* unpin extents in this range */
5736 trans = btrfs_start_transaction(info->tree_root, 1);
5737 btrfs_commit_transaction(trans, info->tree_root);
5738
5739 spin_lock(&block_group->lock);
5740 WARN_ON(block_group->pinned > 0);
5741 WARN_ON(block_group->reserved > 0);
5742 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
5743 spin_unlock(&block_group->lock);
5744 put_block_group(block_group);
5745 ret = 0;
5746 out:
5747 btrfs_free_path(path);
5748 return ret;
5749 }
5750
5751 static int find_first_block_group(struct btrfs_root *root,
5752 struct btrfs_path *path, struct btrfs_key *key)
5753 {
5754 int ret = 0;
5755 struct btrfs_key found_key;
5756 struct extent_buffer *leaf;
5757 int slot;
5758
5759 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
5760 if (ret < 0)
5761 goto out;
5762
5763 while (1) {
5764 slot = path->slots[0];
5765 leaf = path->nodes[0];
5766 if (slot >= btrfs_header_nritems(leaf)) {
5767 ret = btrfs_next_leaf(root, path);
5768 if (ret == 0)
5769 continue;
5770 if (ret < 0)
5771 goto out;
5772 break;
5773 }
5774 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5775
5776 if (found_key.objectid >= key->objectid &&
5777 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
5778 ret = 0;
5779 goto out;
5780 }
5781 path->slots[0]++;
5782 }
5783 ret = -ENOENT;
5784 out:
5785 return ret;
5786 }
5787
5788 int btrfs_free_block_groups(struct btrfs_fs_info *info)
5789 {
5790 struct btrfs_block_group_cache *block_group;
5791 struct rb_node *n;
5792
5793 spin_lock(&info->block_group_cache_lock);
5794 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
5795 block_group = rb_entry(n, struct btrfs_block_group_cache,
5796 cache_node);
5797 rb_erase(&block_group->cache_node,
5798 &info->block_group_cache_tree);
5799 spin_unlock(&info->block_group_cache_lock);
5800
5801 btrfs_remove_free_space_cache(block_group);
5802 down_write(&block_group->space_info->groups_sem);
5803 list_del(&block_group->list);
5804 up_write(&block_group->space_info->groups_sem);
5805
5806 WARN_ON(atomic_read(&block_group->count) != 1);
5807 kfree(block_group);
5808
5809 spin_lock(&info->block_group_cache_lock);
5810 }
5811 spin_unlock(&info->block_group_cache_lock);
5812 return 0;
5813 }
5814
5815 int btrfs_read_block_groups(struct btrfs_root *root)
5816 {
5817 struct btrfs_path *path;
5818 int ret;
5819 struct btrfs_block_group_cache *cache;
5820 struct btrfs_fs_info *info = root->fs_info;
5821 struct btrfs_space_info *space_info;
5822 struct btrfs_key key;
5823 struct btrfs_key found_key;
5824 struct extent_buffer *leaf;
5825
5826 root = info->extent_root;
5827 key.objectid = 0;
5828 key.offset = 0;
5829 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5830 path = btrfs_alloc_path();
5831 if (!path)
5832 return -ENOMEM;
5833
5834 while (1) {
5835 ret = find_first_block_group(root, path, &key);
5836 if (ret > 0) {
5837 ret = 0;
5838 goto error;
5839 }
5840 if (ret != 0)
5841 goto error;
5842
5843 leaf = path->nodes[0];
5844 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5845 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5846 if (!cache) {
5847 ret = -ENOMEM;
5848 break;
5849 }
5850
5851 atomic_set(&cache->count, 1);
5852 spin_lock_init(&cache->lock);
5853 mutex_init(&cache->alloc_mutex);
5854 mutex_init(&cache->cache_mutex);
5855 INIT_LIST_HEAD(&cache->list);
5856 read_extent_buffer(leaf, &cache->item,
5857 btrfs_item_ptr_offset(leaf, path->slots[0]),
5858 sizeof(cache->item));
5859 memcpy(&cache->key, &found_key, sizeof(found_key));
5860
5861 key.objectid = found_key.objectid + found_key.offset;
5862 btrfs_release_path(root, path);
5863 cache->flags = btrfs_block_group_flags(&cache->item);
5864
5865 ret = update_space_info(info, cache->flags, found_key.offset,
5866 btrfs_block_group_used(&cache->item),
5867 &space_info);
5868 BUG_ON(ret);
5869 cache->space_info = space_info;
5870 down_write(&space_info->groups_sem);
5871 list_add_tail(&cache->list, &space_info->block_groups);
5872 up_write(&space_info->groups_sem);
5873
5874 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5875 BUG_ON(ret);
5876
5877 set_avail_alloc_bits(root->fs_info, cache->flags);
5878 if (btrfs_chunk_readonly(root, cache->key.objectid))
5879 set_block_group_readonly(cache);
5880 }
5881 ret = 0;
5882 error:
5883 btrfs_free_path(path);
5884 return ret;
5885 }
5886
5887 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
5888 struct btrfs_root *root, u64 bytes_used,
5889 u64 type, u64 chunk_objectid, u64 chunk_offset,
5890 u64 size)
5891 {
5892 int ret;
5893 struct btrfs_root *extent_root;
5894 struct btrfs_block_group_cache *cache;
5895
5896 extent_root = root->fs_info->extent_root;
5897
5898 root->fs_info->last_trans_new_blockgroup = trans->transid;
5899
5900 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5901 if (!cache)
5902 return -ENOMEM;
5903
5904 cache->key.objectid = chunk_offset;
5905 cache->key.offset = size;
5906 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
5907 atomic_set(&cache->count, 1);
5908 spin_lock_init(&cache->lock);
5909 mutex_init(&cache->alloc_mutex);
5910 mutex_init(&cache->cache_mutex);
5911 INIT_LIST_HEAD(&cache->list);
5912
5913 btrfs_set_block_group_used(&cache->item, bytes_used);
5914 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
5915 cache->flags = type;
5916 btrfs_set_block_group_flags(&cache->item, type);
5917
5918 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
5919 &cache->space_info);
5920 BUG_ON(ret);
5921 down_write(&cache->space_info->groups_sem);
5922 list_add_tail(&cache->list, &cache->space_info->block_groups);
5923 up_write(&cache->space_info->groups_sem);
5924
5925 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5926 BUG_ON(ret);
5927
5928 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
5929 sizeof(cache->item));
5930 BUG_ON(ret);
5931
5932 finish_current_insert(trans, extent_root, 0);
5933 ret = del_pending_extents(trans, extent_root, 0);
5934 BUG_ON(ret);
5935 set_avail_alloc_bits(extent_root->fs_info, type);
5936
5937 return 0;
5938 }
5939
5940 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
5941 struct btrfs_root *root, u64 group_start)
5942 {
5943 struct btrfs_path *path;
5944 struct btrfs_block_group_cache *block_group;
5945 struct btrfs_key key;
5946 int ret;
5947
5948 root = root->fs_info->extent_root;
5949
5950 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
5951 BUG_ON(!block_group);
5952 BUG_ON(!block_group->ro);
5953
5954 memcpy(&key, &block_group->key, sizeof(key));
5955
5956 path = btrfs_alloc_path();
5957 BUG_ON(!path);
5958
5959 btrfs_remove_free_space_cache(block_group);
5960 rb_erase(&block_group->cache_node,
5961 &root->fs_info->block_group_cache_tree);
5962 down_write(&block_group->space_info->groups_sem);
5963 list_del(&block_group->list);
5964 up_write(&block_group->space_info->groups_sem);
5965
5966 spin_lock(&block_group->space_info->lock);
5967 block_group->space_info->total_bytes -= block_group->key.offset;
5968 block_group->space_info->bytes_readonly -= block_group->key.offset;
5969 spin_unlock(&block_group->space_info->lock);
5970 block_group->space_info->full = 0;
5971
5972 put_block_group(block_group);
5973 put_block_group(block_group);
5974
5975 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
5976 if (ret > 0)
5977 ret = -EIO;
5978 if (ret < 0)
5979 goto out;
5980
5981 ret = btrfs_del_item(trans, root, path);
5982 out:
5983 btrfs_free_path(path);
5984 return ret;
5985 }
Support for the Chinese Samsung S3C2440 based development boards