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