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cpumask: remove cpumask_t assignment from vector_allocation_domain()
[linux-2.6/mini2440.git] / fs / btrfs / extent-tree.c
blob9abf81f71c46582db63b89c26d4e952651e3a1ee
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 do_chunk_alloc(struct btrfs_trans_handle *trans,
64 struct btrfs_root *extent_root, u64 alloc_bytes,
65 u64 flags, int force);
66
67 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
68 {
69 return (cache->flags & bits) == bits;
70 }
71
72 /*
73 * this adds the block group to the fs_info rb tree for the block group
74 * cache
75 */
76 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
77 struct btrfs_block_group_cache *block_group)
78 {
79 struct rb_node **p;
80 struct rb_node *parent = NULL;
81 struct btrfs_block_group_cache *cache;
82
83 spin_lock(&info->block_group_cache_lock);
84 p = &info->block_group_cache_tree.rb_node;
85
86 while (*p) {
87 parent = *p;
88 cache = rb_entry(parent, struct btrfs_block_group_cache,
89 cache_node);
90 if (block_group->key.objectid < cache->key.objectid) {
91 p = &(*p)->rb_left;
92 } else if (block_group->key.objectid > cache->key.objectid) {
93 p = &(*p)->rb_right;
94 } else {
95 spin_unlock(&info->block_group_cache_lock);
96 return -EEXIST;
97 }
98 }
99
100 rb_link_node(&block_group->cache_node, parent, p);
101 rb_insert_color(&block_group->cache_node,
102 &info->block_group_cache_tree);
103 spin_unlock(&info->block_group_cache_lock);
104
105 return 0;
106 }
107
108 /*
109 * This will return the block group at or after bytenr if contains is 0, else
110 * it will return the block group that contains the bytenr
111 */
112 static struct btrfs_block_group_cache *
113 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
114 int contains)
115 {
116 struct btrfs_block_group_cache *cache, *ret = NULL;
117 struct rb_node *n;
118 u64 end, start;
119
120 spin_lock(&info->block_group_cache_lock);
121 n = info->block_group_cache_tree.rb_node;
122
123 while (n) {
124 cache = rb_entry(n, struct btrfs_block_group_cache,
125 cache_node);
126 end = cache->key.objectid + cache->key.offset - 1;
127 start = cache->key.objectid;
128
129 if (bytenr < start) {
130 if (!contains && (!ret || start < ret->key.objectid))
131 ret = cache;
132 n = n->rb_left;
133 } else if (bytenr > start) {
134 if (contains && bytenr <= end) {
135 ret = cache;
136 break;
137 }
138 n = n->rb_right;
139 } else {
140 ret = cache;
141 break;
142 }
143 }
144 if (ret)
145 atomic_inc(&ret->count);
146 spin_unlock(&info->block_group_cache_lock);
147
148 return ret;
149 }
150
151 /*
152 * this is only called by cache_block_group, since we could have freed extents
153 * we need to check the pinned_extents for any extents that can't be used yet
154 * since their free space will be released as soon as the transaction commits.
155 */
156 static int add_new_free_space(struct btrfs_block_group_cache *block_group,
157 struct btrfs_fs_info *info, u64 start, u64 end)
158 {
159 u64 extent_start, extent_end, size;
160 int ret;
161
162 mutex_lock(&info->pinned_mutex);
163 while (start < end) {
164 ret = find_first_extent_bit(&info->pinned_extents, start,
165 &extent_start, &extent_end,
166 EXTENT_DIRTY);
167 if (ret)
168 break;
169
170 if (extent_start == start) {
171 start = extent_end + 1;
172 } else if (extent_start > start && extent_start < end) {
173 size = extent_start - start;
174 ret = btrfs_add_free_space(block_group, start,
175 size);
176 BUG_ON(ret);
177 start = extent_end + 1;
178 } else {
179 break;
180 }
181 }
182
183 if (start < end) {
184 size = end - start;
185 ret = btrfs_add_free_space(block_group, start, size);
186 BUG_ON(ret);
187 }
188 mutex_unlock(&info->pinned_mutex);
189
190 return 0;
191 }
192
193 static int remove_sb_from_cache(struct btrfs_root *root,
194 struct btrfs_block_group_cache *cache)
195 {
196 u64 bytenr;
197 u64 *logical;
198 int stripe_len;
199 int i, nr, ret;
200
201 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
202 bytenr = btrfs_sb_offset(i);
203 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
204 cache->key.objectid, bytenr, 0,
205 &logical, &nr, &stripe_len);
206 BUG_ON(ret);
207 while (nr--) {
208 btrfs_remove_free_space(cache, logical[nr],
209 stripe_len);
210 }
211 kfree(logical);
212 }
213 return 0;
214 }
215
216 static int cache_block_group(struct btrfs_root *root,
217 struct btrfs_block_group_cache *block_group)
218 {
219 struct btrfs_path *path;
220 int ret = 0;
221 struct btrfs_key key;
222 struct extent_buffer *leaf;
223 int slot;
224 u64 last;
225
226 if (!block_group)
227 return 0;
228
229 root = root->fs_info->extent_root;
230
231 if (block_group->cached)
232 return 0;
233
234 path = btrfs_alloc_path();
235 if (!path)
236 return -ENOMEM;
237
238 path->reada = 2;
239 /*
240 * we get into deadlocks with paths held by callers of this function.
241 * since the alloc_mutex is protecting things right now, just
242 * skip the locking here
243 */
244 path->skip_locking = 1;
245 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
246 key.objectid = last;
247 key.offset = 0;
248 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
249 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
250 if (ret < 0)
251 goto err;
252
253 while (1) {
254 leaf = path->nodes[0];
255 slot = path->slots[0];
256 if (slot >= btrfs_header_nritems(leaf)) {
257 ret = btrfs_next_leaf(root, path);
258 if (ret < 0)
259 goto err;
260 if (ret == 0)
261 continue;
262 else
263 break;
264 }
265 btrfs_item_key_to_cpu(leaf, &key, slot);
266 if (key.objectid < block_group->key.objectid)
267 goto next;
268
269 if (key.objectid >= block_group->key.objectid +
270 block_group->key.offset)
271 break;
272
273 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
274 add_new_free_space(block_group, root->fs_info, last,
275 key.objectid);
276
277 last = key.objectid + key.offset;
278 }
279 next:
280 path->slots[0]++;
281 }
282
283 add_new_free_space(block_group, root->fs_info, last,
284 block_group->key.objectid +
285 block_group->key.offset);
286
287 remove_sb_from_cache(root, block_group);
288 block_group->cached = 1;
289 ret = 0;
290 err:
291 btrfs_free_path(path);
292 return ret;
293 }
294
295 /*
296 * return the block group that starts at or after bytenr
297 */
298 static struct btrfs_block_group_cache *
299 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
300 {
301 struct btrfs_block_group_cache *cache;
302
303 cache = block_group_cache_tree_search(info, bytenr, 0);
304
305 return cache;
306 }
307
308 /*
309 * return the block group that contains teh given bytenr
310 */
311 struct btrfs_block_group_cache *btrfs_lookup_block_group(
312 struct btrfs_fs_info *info,
313 u64 bytenr)
314 {
315 struct btrfs_block_group_cache *cache;
316
317 cache = block_group_cache_tree_search(info, bytenr, 1);
318
319 return cache;
320 }
321
322 static inline void put_block_group(struct btrfs_block_group_cache *cache)
323 {
324 if (atomic_dec_and_test(&cache->count))
325 kfree(cache);
326 }
327
328 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
329 u64 flags)
330 {
331 struct list_head *head = &info->space_info;
332 struct btrfs_space_info *found;
333 list_for_each_entry(found, head, list) {
334 if (found->flags == flags)
335 return found;
336 }
337 return NULL;
338 }
339
340 static u64 div_factor(u64 num, int factor)
341 {
342 if (factor == 10)
343 return num;
344 num *= factor;
345 do_div(num, 10);
346 return num;
347 }
348
349 u64 btrfs_find_block_group(struct btrfs_root *root,
350 u64 search_start, u64 search_hint, int owner)
351 {
352 struct btrfs_block_group_cache *cache;
353 u64 used;
354 u64 last = max(search_hint, search_start);
355 u64 group_start = 0;
356 int full_search = 0;
357 int factor = 9;
358 int wrapped = 0;
359 again:
360 while (1) {
361 cache = btrfs_lookup_first_block_group(root->fs_info, last);
362 if (!cache)
363 break;
364
365 spin_lock(&cache->lock);
366 last = cache->key.objectid + cache->key.offset;
367 used = btrfs_block_group_used(&cache->item);
368
369 if ((full_search || !cache->ro) &&
370 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
371 if (used + cache->pinned + cache->reserved <
372 div_factor(cache->key.offset, factor)) {
373 group_start = cache->key.objectid;
374 spin_unlock(&cache->lock);
375 put_block_group(cache);
376 goto found;
377 }
378 }
379 spin_unlock(&cache->lock);
380 put_block_group(cache);
381 cond_resched();
382 }
383 if (!wrapped) {
384 last = search_start;
385 wrapped = 1;
386 goto again;
387 }
388 if (!full_search && factor < 10) {
389 last = search_start;
390 full_search = 1;
391 factor = 10;
392 goto again;
393 }
394 found:
395 return group_start;
396 }
397
398 /* simple helper to search for an existing extent at a given offset */
399 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
400 {
401 int ret;
402 struct btrfs_key key;
403 struct btrfs_path *path;
404
405 path = btrfs_alloc_path();
406 BUG_ON(!path);
407 key.objectid = start;
408 key.offset = len;
409 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
410 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
411 0, 0);
412 btrfs_free_path(path);
413 return ret;
414 }
415
416 /*
417 * Back reference rules. Back refs have three main goals:
418 *
419 * 1) differentiate between all holders of references to an extent so that
420 * when a reference is dropped we can make sure it was a valid reference
421 * before freeing the extent.
422 *
423 * 2) Provide enough information to quickly find the holders of an extent
424 * if we notice a given block is corrupted or bad.
425 *
426 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
427 * maintenance. This is actually the same as #2, but with a slightly
428 * different use case.
429 *
430 * File extents can be referenced by:
431 *
432 * - multiple snapshots, subvolumes, or different generations in one subvol
433 * - different files inside a single subvolume
434 * - different offsets inside a file (bookend extents in file.c)
435 *
436 * The extent ref structure has fields for:
437 *
438 * - Objectid of the subvolume root
439 * - Generation number of the tree holding the reference
440 * - objectid of the file holding the reference
441 * - number of references holding by parent node (alway 1 for tree blocks)
442 *
443 * Btree leaf may hold multiple references to a file extent. In most cases,
444 * these references are from same file and the corresponding offsets inside
445 * the file are close together.
446 *
447 * When a file extent is allocated the fields are filled in:
448 * (root_key.objectid, trans->transid, inode objectid, 1)
449 *
450 * When a leaf is cow'd new references are added for every file extent found
451 * in the leaf. It looks similar to the create case, but trans->transid will
452 * be different when the block is cow'd.
453 *
454 * (root_key.objectid, trans->transid, inode objectid,
455 * number of references in the leaf)
456 *
457 * When a file extent is removed either during snapshot deletion or
458 * file truncation, we find the corresponding back reference and check
459 * the following fields:
460 *
461 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
462 * inode objectid)
463 *
464 * Btree extents can be referenced by:
465 *
466 * - Different subvolumes
467 * - Different generations of the same subvolume
468 *
469 * When a tree block is created, back references are inserted:
470 *
471 * (root->root_key.objectid, trans->transid, level, 1)
472 *
473 * When a tree block is cow'd, new back references are added for all the
474 * blocks it points to. If the tree block isn't in reference counted root,
475 * the old back references are removed. These new back references are of
476 * the form (trans->transid will have increased since creation):
477 *
478 * (root->root_key.objectid, trans->transid, level, 1)
479 *
480 * When a backref is in deleting, the following fields are checked:
481 *
482 * if backref was for a tree root:
483 * (btrfs_header_owner(itself), btrfs_header_generation(itself), level)
484 * else
485 * (btrfs_header_owner(parent), btrfs_header_generation(parent), level)
486 *
487 * Back Reference Key composing:
488 *
489 * The key objectid corresponds to the first byte in the extent, the key
490 * type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first
491 * byte of parent extent. If a extent is tree root, the key offset is set
492 * to the key objectid.
493 */
494
495 static noinline int lookup_extent_backref(struct btrfs_trans_handle *trans,
496 struct btrfs_root *root,
497 struct btrfs_path *path,
498 u64 bytenr, u64 parent,
499 u64 ref_root, u64 ref_generation,
500 u64 owner_objectid, int del)
501 {
502 struct btrfs_key key;
503 struct btrfs_extent_ref *ref;
504 struct extent_buffer *leaf;
505 u64 ref_objectid;
506 int ret;
507
508 key.objectid = bytenr;
509 key.type = BTRFS_EXTENT_REF_KEY;
510 key.offset = parent;
511
512 ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1);
513 if (ret < 0)
514 goto out;
515 if (ret > 0) {
516 ret = -ENOENT;
517 goto out;
518 }
519
520 leaf = path->nodes[0];
521 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
522 ref_objectid = btrfs_ref_objectid(leaf, ref);
523 if (btrfs_ref_root(leaf, ref) != ref_root ||
524 btrfs_ref_generation(leaf, ref) != ref_generation ||
525 (ref_objectid != owner_objectid &&
526 ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
527 ret = -EIO;
528 WARN_ON(1);
529 goto out;
530 }
531 ret = 0;
532 out:
533 return ret;
534 }
535
536 /*
537 * updates all the backrefs that are pending on update_list for the
538 * extent_root
539 */
540 static noinline int update_backrefs(struct btrfs_trans_handle *trans,
541 struct btrfs_root *extent_root,
542 struct btrfs_path *path,
543 struct list_head *update_list)
544 {
545 struct btrfs_key key;
546 struct btrfs_extent_ref *ref;
547 struct btrfs_fs_info *info = extent_root->fs_info;
548 struct pending_extent_op *op;
549 struct extent_buffer *leaf;
550 int ret = 0;
551 struct list_head *cur = update_list->next;
552 u64 ref_objectid;
553 u64 ref_root = extent_root->root_key.objectid;
554
555 op = list_entry(cur, struct pending_extent_op, list);
556
557 search:
558 key.objectid = op->bytenr;
559 key.type = BTRFS_EXTENT_REF_KEY;
560 key.offset = op->orig_parent;
561
562 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 1);
563 BUG_ON(ret);
564
565 leaf = path->nodes[0];
566
567 loop:
568 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
569
570 ref_objectid = btrfs_ref_objectid(leaf, ref);
571
572 if (btrfs_ref_root(leaf, ref) != ref_root ||
573 btrfs_ref_generation(leaf, ref) != op->orig_generation ||
574 (ref_objectid != op->level &&
575 ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
576 printk(KERN_ERR "btrfs couldn't find %llu, parent %llu, "
577 "root %llu, owner %u\n",
578 (unsigned long long)op->bytenr,
579 (unsigned long long)op->orig_parent,
580 (unsigned long long)ref_root, op->level);
581 btrfs_print_leaf(extent_root, leaf);
582 BUG();
583 }
584
585 key.objectid = op->bytenr;
586 key.offset = op->parent;
587 key.type = BTRFS_EXTENT_REF_KEY;
588 ret = btrfs_set_item_key_safe(trans, extent_root, path, &key);
589 BUG_ON(ret);
590 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
591 btrfs_set_ref_generation(leaf, ref, op->generation);
592
593 cur = cur->next;
594
595 list_del_init(&op->list);
596 unlock_extent(&info->extent_ins, op->bytenr,
597 op->bytenr + op->num_bytes - 1, GFP_NOFS);
598 kfree(op);
599
600 if (cur == update_list) {
601 btrfs_mark_buffer_dirty(path->nodes[0]);
602 btrfs_release_path(extent_root, path);
603 goto out;
604 }
605
606 op = list_entry(cur, struct pending_extent_op, list);
607
608 path->slots[0]++;
609 while (path->slots[0] < btrfs_header_nritems(leaf)) {
610 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
611 if (key.objectid == op->bytenr &&
612 key.type == BTRFS_EXTENT_REF_KEY)
613 goto loop;
614 path->slots[0]++;
615 }
616
617 btrfs_mark_buffer_dirty(path->nodes[0]);
618 btrfs_release_path(extent_root, path);
619 goto search;
620
621 out:
622 return 0;
623 }
624
625 static noinline int insert_extents(struct btrfs_trans_handle *trans,
626 struct btrfs_root *extent_root,
627 struct btrfs_path *path,
628 struct list_head *insert_list, int nr)
629 {
630 struct btrfs_key *keys;
631 u32 *data_size;
632 struct pending_extent_op *op;
633 struct extent_buffer *leaf;
634 struct list_head *cur = insert_list->next;
635 struct btrfs_fs_info *info = extent_root->fs_info;
636 u64 ref_root = extent_root->root_key.objectid;
637 int i = 0, last = 0, ret;
638 int total = nr * 2;
639
640 if (!nr)
641 return 0;
642
643 keys = kzalloc(total * sizeof(struct btrfs_key), GFP_NOFS);
644 if (!keys)
645 return -ENOMEM;
646
647 data_size = kzalloc(total * sizeof(u32), GFP_NOFS);
648 if (!data_size) {
649 kfree(keys);
650 return -ENOMEM;
651 }
652
653 list_for_each_entry(op, insert_list, list) {
654 keys[i].objectid = op->bytenr;
655 keys[i].offset = op->num_bytes;
656 keys[i].type = BTRFS_EXTENT_ITEM_KEY;
657 data_size[i] = sizeof(struct btrfs_extent_item);
658 i++;
659
660 keys[i].objectid = op->bytenr;
661 keys[i].offset = op->parent;
662 keys[i].type = BTRFS_EXTENT_REF_KEY;
663 data_size[i] = sizeof(struct btrfs_extent_ref);
664 i++;
665 }
666
667 op = list_entry(cur, struct pending_extent_op, list);
668 i = 0;
669 while (i < total) {
670 int c;
671 ret = btrfs_insert_some_items(trans, extent_root, path,
672 keys+i, data_size+i, total-i);
673 BUG_ON(ret < 0);
674
675 if (last && ret > 1)
676 BUG();
677
678 leaf = path->nodes[0];
679 for (c = 0; c < ret; c++) {
680 int ref_first = keys[i].type == BTRFS_EXTENT_REF_KEY;
681
682 /*
683 * if the first item we inserted was a backref, then
684 * the EXTENT_ITEM will be the odd c's, else it will
685 * be the even c's
686 */
687 if ((ref_first && (c % 2)) ||
688 (!ref_first && !(c % 2))) {
689 struct btrfs_extent_item *itm;
690
691 itm = btrfs_item_ptr(leaf, path->slots[0] + c,
692 struct btrfs_extent_item);
693 btrfs_set_extent_refs(path->nodes[0], itm, 1);
694 op->del++;
695 } else {
696 struct btrfs_extent_ref *ref;
697
698 ref = btrfs_item_ptr(leaf, path->slots[0] + c,
699 struct btrfs_extent_ref);
700 btrfs_set_ref_root(leaf, ref, ref_root);
701 btrfs_set_ref_generation(leaf, ref,
702 op->generation);
703 btrfs_set_ref_objectid(leaf, ref, op->level);
704 btrfs_set_ref_num_refs(leaf, ref, 1);
705 op->del++;
706 }
707
708 /*
709 * using del to see when its ok to free up the
710 * pending_extent_op. In the case where we insert the
711 * last item on the list in order to help do batching
712 * we need to not free the extent op until we actually
713 * insert the extent_item
714 */
715 if (op->del == 2) {
716 unlock_extent(&info->extent_ins, op->bytenr,
717 op->bytenr + op->num_bytes - 1,
718 GFP_NOFS);
719 cur = cur->next;
720 list_del_init(&op->list);
721 kfree(op);
722 if (cur != insert_list)
723 op = list_entry(cur,
724 struct pending_extent_op,
725 list);
726 }
727 }
728 btrfs_mark_buffer_dirty(leaf);
729 btrfs_release_path(extent_root, path);
730
731 /*
732 * Ok backref's and items usually go right next to eachother,
733 * but if we could only insert 1 item that means that we
734 * inserted on the end of a leaf, and we have no idea what may
735 * be on the next leaf so we just play it safe. In order to
736 * try and help this case we insert the last thing on our
737 * insert list so hopefully it will end up being the last
738 * thing on the leaf and everything else will be before it,
739 * which will let us insert a whole bunch of items at the same
740 * time.
741 */
742 if (ret == 1 && !last && (i + ret < total)) {
743 /*
744 * last: where we will pick up the next time around
745 * i: our current key to insert, will be total - 1
746 * cur: the current op we are screwing with
747 * op: duh
748 */
749 last = i + ret;
750 i = total - 1;
751 cur = insert_list->prev;
752 op = list_entry(cur, struct pending_extent_op, list);
753 } else if (last) {
754 /*
755 * ok we successfully inserted the last item on the
756 * list, lets reset everything
757 *
758 * i: our current key to insert, so where we left off
759 * last time
760 * last: done with this
761 * cur: the op we are messing with
762 * op: duh
763 * total: since we inserted the last key, we need to
764 * decrement total so we dont overflow
765 */
766 i = last;
767 last = 0;
768 total--;
769 if (i < total) {
770 cur = insert_list->next;
771 op = list_entry(cur, struct pending_extent_op,
772 list);
773 }
774 } else {
775 i += ret;
776 }
777
778 cond_resched();
779 }
780 ret = 0;
781 kfree(keys);
782 kfree(data_size);
783 return ret;
784 }
785
786 static noinline int insert_extent_backref(struct btrfs_trans_handle *trans,
787 struct btrfs_root *root,
788 struct btrfs_path *path,
789 u64 bytenr, u64 parent,
790 u64 ref_root, u64 ref_generation,
791 u64 owner_objectid)
792 {
793 struct btrfs_key key;
794 struct extent_buffer *leaf;
795 struct btrfs_extent_ref *ref;
796 u32 num_refs;
797 int ret;
798
799 key.objectid = bytenr;
800 key.type = BTRFS_EXTENT_REF_KEY;
801 key.offset = parent;
802
803 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref));
804 if (ret == 0) {
805 leaf = path->nodes[0];
806 ref = btrfs_item_ptr(leaf, path->slots[0],
807 struct btrfs_extent_ref);
808 btrfs_set_ref_root(leaf, ref, ref_root);
809 btrfs_set_ref_generation(leaf, ref, ref_generation);
810 btrfs_set_ref_objectid(leaf, ref, owner_objectid);
811 btrfs_set_ref_num_refs(leaf, ref, 1);
812 } else if (ret == -EEXIST) {
813 u64 existing_owner;
814 BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID);
815 leaf = path->nodes[0];
816 ref = btrfs_item_ptr(leaf, path->slots[0],
817 struct btrfs_extent_ref);
818 if (btrfs_ref_root(leaf, ref) != ref_root ||
819 btrfs_ref_generation(leaf, ref) != ref_generation) {
820 ret = -EIO;
821 WARN_ON(1);
822 goto out;
823 }
824
825 num_refs = btrfs_ref_num_refs(leaf, ref);
826 BUG_ON(num_refs == 0);
827 btrfs_set_ref_num_refs(leaf, ref, num_refs + 1);
828
829 existing_owner = btrfs_ref_objectid(leaf, ref);
830 if (existing_owner != owner_objectid &&
831 existing_owner != BTRFS_MULTIPLE_OBJECTIDS) {
832 btrfs_set_ref_objectid(leaf, ref,
833 BTRFS_MULTIPLE_OBJECTIDS);
834 }
835 ret = 0;
836 } else {
837 goto out;
838 }
839 btrfs_mark_buffer_dirty(path->nodes[0]);
840 out:
841 btrfs_release_path(root, path);
842 return ret;
843 }
844
845 static noinline int remove_extent_backref(struct btrfs_trans_handle *trans,
846 struct btrfs_root *root,
847 struct btrfs_path *path)
848 {
849 struct extent_buffer *leaf;
850 struct btrfs_extent_ref *ref;
851 u32 num_refs;
852 int ret = 0;
853
854 leaf = path->nodes[0];
855 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
856 num_refs = btrfs_ref_num_refs(leaf, ref);
857 BUG_ON(num_refs == 0);
858 num_refs -= 1;
859 if (num_refs == 0) {
860 ret = btrfs_del_item(trans, root, path);
861 } else {
862 btrfs_set_ref_num_refs(leaf, ref, num_refs);
863 btrfs_mark_buffer_dirty(leaf);
864 }
865 btrfs_release_path(root, path);
866 return ret;
867 }
868
869 #ifdef BIO_RW_DISCARD
870 static void btrfs_issue_discard(struct block_device *bdev,
871 u64 start, u64 len)
872 {
873 blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL);
874 }
875 #endif
876
877 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
878 u64 num_bytes)
879 {
880 #ifdef BIO_RW_DISCARD
881 int ret;
882 u64 map_length = num_bytes;
883 struct btrfs_multi_bio *multi = NULL;
884
885 /* Tell the block device(s) that the sectors can be discarded */
886 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
887 bytenr, &map_length, &multi, 0);
888 if (!ret) {
889 struct btrfs_bio_stripe *stripe = multi->stripes;
890 int i;
891
892 if (map_length > num_bytes)
893 map_length = num_bytes;
894
895 for (i = 0; i < multi->num_stripes; i++, stripe++) {
896 btrfs_issue_discard(stripe->dev->bdev,
897 stripe->physical,
898 map_length);
899 }
900 kfree(multi);
901 }
902
903 return ret;
904 #else
905 return 0;
906 #endif
907 }
908
909 static noinline int free_extents(struct btrfs_trans_handle *trans,
910 struct btrfs_root *extent_root,
911 struct list_head *del_list)
912 {
913 struct btrfs_fs_info *info = extent_root->fs_info;
914 struct btrfs_path *path;
915 struct btrfs_key key, found_key;
916 struct extent_buffer *leaf;
917 struct list_head *cur;
918 struct pending_extent_op *op;
919 struct btrfs_extent_item *ei;
920 int ret, num_to_del, extent_slot = 0, found_extent = 0;
921 u32 refs;
922 u64 bytes_freed = 0;
923
924 path = btrfs_alloc_path();
925 if (!path)
926 return -ENOMEM;
927 path->reada = 1;
928
929 search:
930 /* search for the backref for the current ref we want to delete */
931 cur = del_list->next;
932 op = list_entry(cur, struct pending_extent_op, list);
933 ret = lookup_extent_backref(trans, extent_root, path, op->bytenr,
934 op->orig_parent,
935 extent_root->root_key.objectid,
936 op->orig_generation, op->level, 1);
937 if (ret) {
938 printk(KERN_ERR "btrfs unable to find backref byte nr %llu "
939 "root %llu gen %llu owner %u\n",
940 (unsigned long long)op->bytenr,
941 (unsigned long long)extent_root->root_key.objectid,
942 (unsigned long long)op->orig_generation, op->level);
943 btrfs_print_leaf(extent_root, path->nodes[0]);
944 WARN_ON(1);
945 goto out;
946 }
947
948 extent_slot = path->slots[0];
949 num_to_del = 1;
950 found_extent = 0;
951
952 /*
953 * if we aren't the first item on the leaf we can move back one and see
954 * if our ref is right next to our extent item
955 */
956 if (likely(extent_slot)) {
957 extent_slot--;
958 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
959 extent_slot);
960 if (found_key.objectid == op->bytenr &&
961 found_key.type == BTRFS_EXTENT_ITEM_KEY &&
962 found_key.offset == op->num_bytes) {
963 num_to_del++;
964 found_extent = 1;
965 }
966 }
967
968 /*
969 * if we didn't find the extent we need to delete the backref and then
970 * search for the extent item key so we can update its ref count
971 */
972 if (!found_extent) {
973 key.objectid = op->bytenr;
974 key.type = BTRFS_EXTENT_ITEM_KEY;
975 key.offset = op->num_bytes;
976
977 ret = remove_extent_backref(trans, extent_root, path);
978 BUG_ON(ret);
979 btrfs_release_path(extent_root, path);
980 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
981 BUG_ON(ret);
982 extent_slot = path->slots[0];
983 }
984
985 /* this is where we update the ref count for the extent */
986 leaf = path->nodes[0];
987 ei = btrfs_item_ptr(leaf, extent_slot, struct btrfs_extent_item);
988 refs = btrfs_extent_refs(leaf, ei);
989 BUG_ON(refs == 0);
990 refs--;
991 btrfs_set_extent_refs(leaf, ei, refs);
992
993 btrfs_mark_buffer_dirty(leaf);
994
995 /*
996 * This extent needs deleting. The reason cur_slot is extent_slot +
997 * num_to_del is because extent_slot points to the slot where the extent
998 * is, and if the backref was not right next to the extent we will be
999 * deleting at least 1 item, and will want to start searching at the
1000 * slot directly next to extent_slot. However if we did find the
1001 * backref next to the extent item them we will be deleting at least 2
1002 * items and will want to start searching directly after the ref slot
1003 */
1004 if (!refs) {
1005 struct list_head *pos, *n, *end;
1006 int cur_slot = extent_slot+num_to_del;
1007 u64 super_used;
1008 u64 root_used;
1009
1010 path->slots[0] = extent_slot;
1011 bytes_freed = op->num_bytes;
1012
1013 mutex_lock(&info->pinned_mutex);
1014 ret = pin_down_bytes(trans, extent_root, op->bytenr,
1015 op->num_bytes, op->level >=
1016 BTRFS_FIRST_FREE_OBJECTID);
1017 mutex_unlock(&info->pinned_mutex);
1018 BUG_ON(ret < 0);
1019 op->del = ret;
1020
1021 /*
1022 * we need to see if we can delete multiple things at once, so
1023 * start looping through the list of extents we are wanting to
1024 * delete and see if their extent/backref's are right next to
1025 * eachother and the extents only have 1 ref
1026 */
1027 for (pos = cur->next; pos != del_list; pos = pos->next) {
1028 struct pending_extent_op *tmp;
1029
1030 tmp = list_entry(pos, struct pending_extent_op, list);
1031
1032 /* we only want to delete extent+ref at this stage */
1033 if (cur_slot >= btrfs_header_nritems(leaf) - 1)
1034 break;
1035
1036 btrfs_item_key_to_cpu(leaf, &found_key, cur_slot);
1037 if (found_key.objectid != tmp->bytenr ||
1038 found_key.type != BTRFS_EXTENT_ITEM_KEY ||
1039 found_key.offset != tmp->num_bytes)
1040 break;
1041
1042 /* check to make sure this extent only has one ref */
1043 ei = btrfs_item_ptr(leaf, cur_slot,
1044 struct btrfs_extent_item);
1045 if (btrfs_extent_refs(leaf, ei) != 1)
1046 break;
1047
1048 btrfs_item_key_to_cpu(leaf, &found_key, cur_slot+1);
1049 if (found_key.objectid != tmp->bytenr ||
1050 found_key.type != BTRFS_EXTENT_REF_KEY ||
1051 found_key.offset != tmp->orig_parent)
1052 break;
1053
1054 /*
1055 * the ref is right next to the extent, we can set the
1056 * ref count to 0 since we will delete them both now
1057 */
1058 btrfs_set_extent_refs(leaf, ei, 0);
1059
1060 /* pin down the bytes for this extent */
1061 mutex_lock(&info->pinned_mutex);
1062 ret = pin_down_bytes(trans, extent_root, tmp->bytenr,
1063 tmp->num_bytes, tmp->level >=
1064 BTRFS_FIRST_FREE_OBJECTID);
1065 mutex_unlock(&info->pinned_mutex);
1066 BUG_ON(ret < 0);
1067
1068 /*
1069 * use the del field to tell if we need to go ahead and
1070 * free up the extent when we delete the item or not.
1071 */
1072 tmp->del = ret;
1073 bytes_freed += tmp->num_bytes;
1074
1075 num_to_del += 2;
1076 cur_slot += 2;
1077 }
1078 end = pos;
1079
1080 /* update the free space counters */
1081 spin_lock(&info->delalloc_lock);
1082 super_used = btrfs_super_bytes_used(&info->super_copy);
1083 btrfs_set_super_bytes_used(&info->super_copy,
1084 super_used - bytes_freed);
1085
1086 root_used = btrfs_root_used(&extent_root->root_item);
1087 btrfs_set_root_used(&extent_root->root_item,
1088 root_used - bytes_freed);
1089 spin_unlock(&info->delalloc_lock);
1090
1091 /* delete the items */
1092 ret = btrfs_del_items(trans, extent_root, path,
1093 path->slots[0], num_to_del);
1094 BUG_ON(ret);
1095
1096 /*
1097 * loop through the extents we deleted and do the cleanup work
1098 * on them
1099 */
1100 for (pos = cur, n = pos->next; pos != end;
1101 pos = n, n = pos->next) {
1102 struct pending_extent_op *tmp;
1103 tmp = list_entry(pos, struct pending_extent_op, list);
1104
1105 /*
1106 * remember tmp->del tells us wether or not we pinned
1107 * down the extent
1108 */
1109 ret = update_block_group(trans, extent_root,
1110 tmp->bytenr, tmp->num_bytes, 0,
1111 tmp->del);
1112 BUG_ON(ret);
1113
1114 list_del_init(&tmp->list);
1115 unlock_extent(&info->extent_ins, tmp->bytenr,
1116 tmp->bytenr + tmp->num_bytes - 1,
1117 GFP_NOFS);
1118 kfree(tmp);
1119 }
1120 } else if (refs && found_extent) {
1121 /*
1122 * the ref and extent were right next to eachother, but the
1123 * extent still has a ref, so just free the backref and keep
1124 * going
1125 */
1126 ret = remove_extent_backref(trans, extent_root, path);
1127 BUG_ON(ret);
1128
1129 list_del_init(&op->list);
1130 unlock_extent(&info->extent_ins, op->bytenr,
1131 op->bytenr + op->num_bytes - 1, GFP_NOFS);
1132 kfree(op);
1133 } else {
1134 /*
1135 * the extent has multiple refs and the backref we were looking
1136 * for was not right next to it, so just unlock and go next,
1137 * we're good to go
1138 */
1139 list_del_init(&op->list);
1140 unlock_extent(&info->extent_ins, op->bytenr,
1141 op->bytenr + op->num_bytes - 1, GFP_NOFS);
1142 kfree(op);
1143 }
1144
1145 btrfs_release_path(extent_root, path);
1146 if (!list_empty(del_list))
1147 goto search;
1148
1149 out:
1150 btrfs_free_path(path);
1151 return ret;
1152 }
1153
1154 static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
1155 struct btrfs_root *root, u64 bytenr,
1156 u64 orig_parent, u64 parent,
1157 u64 orig_root, u64 ref_root,
1158 u64 orig_generation, u64 ref_generation,
1159 u64 owner_objectid)
1160 {
1161 int ret;
1162 struct btrfs_root *extent_root = root->fs_info->extent_root;
1163 struct btrfs_path *path;
1164
1165 if (root == root->fs_info->extent_root) {
1166 struct pending_extent_op *extent_op;
1167 u64 num_bytes;
1168
1169 BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL);
1170 num_bytes = btrfs_level_size(root, (int)owner_objectid);
1171 mutex_lock(&root->fs_info->extent_ins_mutex);
1172 if (test_range_bit(&root->fs_info->extent_ins, bytenr,
1173 bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
1174 u64 priv;
1175 ret = get_state_private(&root->fs_info->extent_ins,
1176 bytenr, &priv);
1177 BUG_ON(ret);
1178 extent_op = (struct pending_extent_op *)
1179 (unsigned long)priv;
1180 BUG_ON(extent_op->parent != orig_parent);
1181 BUG_ON(extent_op->generation != orig_generation);
1182
1183 extent_op->parent = parent;
1184 extent_op->generation = ref_generation;
1185 } else {
1186 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
1187 BUG_ON(!extent_op);
1188
1189 extent_op->type = PENDING_BACKREF_UPDATE;
1190 extent_op->bytenr = bytenr;
1191 extent_op->num_bytes = num_bytes;
1192 extent_op->parent = parent;
1193 extent_op->orig_parent = orig_parent;
1194 extent_op->generation = ref_generation;
1195 extent_op->orig_generation = orig_generation;
1196 extent_op->level = (int)owner_objectid;
1197 INIT_LIST_HEAD(&extent_op->list);
1198 extent_op->del = 0;
1199
1200 set_extent_bits(&root->fs_info->extent_ins,
1201 bytenr, bytenr + num_bytes - 1,
1202 EXTENT_WRITEBACK, GFP_NOFS);
1203 set_state_private(&root->fs_info->extent_ins,
1204 bytenr, (unsigned long)extent_op);
1205 }
1206 mutex_unlock(&root->fs_info->extent_ins_mutex);
1207 return 0;
1208 }
1209
1210 path = btrfs_alloc_path();
1211 if (!path)
1212 return -ENOMEM;
1213 ret = lookup_extent_backref(trans, extent_root, path,
1214 bytenr, orig_parent, orig_root,
1215 orig_generation, owner_objectid, 1);
1216 if (ret)
1217 goto out;
1218 ret = remove_extent_backref(trans, extent_root, path);
1219 if (ret)
1220 goto out;
1221 ret = insert_extent_backref(trans, extent_root, path, bytenr,
1222 parent, ref_root, ref_generation,
1223 owner_objectid);
1224 BUG_ON(ret);
1225 finish_current_insert(trans, extent_root, 0);
1226 del_pending_extents(trans, extent_root, 0);
1227 out:
1228 btrfs_free_path(path);
1229 return ret;
1230 }
1231
1232 int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
1233 struct btrfs_root *root, u64 bytenr,
1234 u64 orig_parent, u64 parent,
1235 u64 ref_root, u64 ref_generation,
1236 u64 owner_objectid)
1237 {
1238 int ret;
1239 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
1240 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
1241 return 0;
1242 ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent,
1243 parent, ref_root, ref_root,
1244 ref_generation, ref_generation,
1245 owner_objectid);
1246 return ret;
1247 }
1248
1249 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1250 struct btrfs_root *root, u64 bytenr,
1251 u64 orig_parent, u64 parent,
1252 u64 orig_root, u64 ref_root,
1253 u64 orig_generation, u64 ref_generation,
1254 u64 owner_objectid)
1255 {
1256 struct btrfs_path *path;
1257 int ret;
1258 struct btrfs_key key;
1259 struct extent_buffer *l;
1260 struct btrfs_extent_item *item;
1261 u32 refs;
1262
1263 path = btrfs_alloc_path();
1264 if (!path)
1265 return -ENOMEM;
1266
1267 path->reada = 1;
1268 key.objectid = bytenr;
1269 key.type = BTRFS_EXTENT_ITEM_KEY;
1270 key.offset = (u64)-1;
1271
1272 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1273 0, 1);
1274 if (ret < 0)
1275 return ret;
1276 BUG_ON(ret == 0 || path->slots[0] == 0);
1277
1278 path->slots[0]--;
1279 l = path->nodes[0];
1280
1281 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1282 if (key.objectid != bytenr) {
1283 btrfs_print_leaf(root->fs_info->extent_root, path->nodes[0]);
1284 printk(KERN_ERR "btrfs wanted %llu found %llu\n",
1285 (unsigned long long)bytenr,
1286 (unsigned long long)key.objectid);
1287 BUG();
1288 }
1289 BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY);
1290
1291 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1292 refs = btrfs_extent_refs(l, item);
1293 btrfs_set_extent_refs(l, item, refs + 1);
1294 btrfs_mark_buffer_dirty(path->nodes[0]);
1295
1296 btrfs_release_path(root->fs_info->extent_root, path);
1297
1298 path->reada = 1;
1299 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1300 path, bytenr, parent,
1301 ref_root, ref_generation,
1302 owner_objectid);
1303 BUG_ON(ret);
1304 finish_current_insert(trans, root->fs_info->extent_root, 0);
1305 del_pending_extents(trans, root->fs_info->extent_root, 0);
1306
1307 btrfs_free_path(path);
1308 return 0;
1309 }
1310
1311 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1312 struct btrfs_root *root,
1313 u64 bytenr, u64 num_bytes, u64 parent,
1314 u64 ref_root, u64 ref_generation,
1315 u64 owner_objectid)
1316 {
1317 int ret;
1318 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
1319 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
1320 return 0;
1321 ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent,
1322 0, ref_root, 0, ref_generation,
1323 owner_objectid);
1324 return ret;
1325 }
1326
1327 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
1328 struct btrfs_root *root)
1329 {
1330 u64 start;
1331 u64 end;
1332 int ret;
1333
1334 while(1) {
1335 finish_current_insert(trans, root->fs_info->extent_root, 1);
1336 del_pending_extents(trans, root->fs_info->extent_root, 1);
1337
1338 /* is there more work to do? */
1339 ret = find_first_extent_bit(&root->fs_info->pending_del,
1340 0, &start, &end, EXTENT_WRITEBACK);
1341 if (!ret)
1342 continue;
1343 ret = find_first_extent_bit(&root->fs_info->extent_ins,
1344 0, &start, &end, EXTENT_WRITEBACK);
1345 if (!ret)
1346 continue;
1347 break;
1348 }
1349 return 0;
1350 }
1351
1352 int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
1353 struct btrfs_root *root, u64 bytenr,
1354 u64 num_bytes, u32 *refs)
1355 {
1356 struct btrfs_path *path;
1357 int ret;
1358 struct btrfs_key key;
1359 struct extent_buffer *l;
1360 struct btrfs_extent_item *item;
1361
1362 WARN_ON(num_bytes < root->sectorsize);
1363 path = btrfs_alloc_path();
1364 path->reada = 1;
1365 key.objectid = bytenr;
1366 key.offset = num_bytes;
1367 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1368 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1369 0, 0);
1370 if (ret < 0)
1371 goto out;
1372 if (ret != 0) {
1373 btrfs_print_leaf(root, path->nodes[0]);
1374 printk(KERN_INFO "btrfs failed to find block number %llu\n",
1375 (unsigned long long)bytenr);
1376 BUG();
1377 }
1378 l = path->nodes[0];
1379 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1380 *refs = btrfs_extent_refs(l, item);
1381 out:
1382 btrfs_free_path(path);
1383 return 0;
1384 }
1385
1386 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
1387 struct btrfs_root *root, u64 objectid, u64 bytenr)
1388 {
1389 struct btrfs_root *extent_root = root->fs_info->extent_root;
1390 struct btrfs_path *path;
1391 struct extent_buffer *leaf;
1392 struct btrfs_extent_ref *ref_item;
1393 struct btrfs_key key;
1394 struct btrfs_key found_key;
1395 u64 ref_root;
1396 u64 last_snapshot;
1397 u32 nritems;
1398 int ret;
1399
1400 key.objectid = bytenr;
1401 key.offset = (u64)-1;
1402 key.type = BTRFS_EXTENT_ITEM_KEY;
1403
1404 path = btrfs_alloc_path();
1405 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
1406 if (ret < 0)
1407 goto out;
1408 BUG_ON(ret == 0);
1409
1410 ret = -ENOENT;
1411 if (path->slots[0] == 0)
1412 goto out;
1413
1414 path->slots[0]--;
1415 leaf = path->nodes[0];
1416 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1417
1418 if (found_key.objectid != bytenr ||
1419 found_key.type != BTRFS_EXTENT_ITEM_KEY)
1420 goto out;
1421
1422 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1423 while (1) {
1424 leaf = path->nodes[0];
1425 nritems = btrfs_header_nritems(leaf);
1426 if (path->slots[0] >= nritems) {
1427 ret = btrfs_next_leaf(extent_root, path);
1428 if (ret < 0)
1429 goto out;
1430 if (ret == 0)
1431 continue;
1432 break;
1433 }
1434 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1435 if (found_key.objectid != bytenr)
1436 break;
1437
1438 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
1439 path->slots[0]++;
1440 continue;
1441 }
1442
1443 ref_item = btrfs_item_ptr(leaf, path->slots[0],
1444 struct btrfs_extent_ref);
1445 ref_root = btrfs_ref_root(leaf, ref_item);
1446 if ((ref_root != root->root_key.objectid &&
1447 ref_root != BTRFS_TREE_LOG_OBJECTID) ||
1448 objectid != btrfs_ref_objectid(leaf, ref_item)) {
1449 ret = 1;
1450 goto out;
1451 }
1452 if (btrfs_ref_generation(leaf, ref_item) <= last_snapshot) {
1453 ret = 1;
1454 goto out;
1455 }
1456
1457 path->slots[0]++;
1458 }
1459 ret = 0;
1460 out:
1461 btrfs_free_path(path);
1462 return ret;
1463 }
1464
1465 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1466 struct extent_buffer *buf, u32 nr_extents)
1467 {
1468 struct btrfs_key key;
1469 struct btrfs_file_extent_item *fi;
1470 u64 root_gen;
1471 u32 nritems;
1472 int i;
1473 int level;
1474 int ret = 0;
1475 int shared = 0;
1476
1477 if (!root->ref_cows)
1478 return 0;
1479
1480 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1481 shared = 0;
1482 root_gen = root->root_key.offset;
1483 } else {
1484 shared = 1;
1485 root_gen = trans->transid - 1;
1486 }
1487
1488 level = btrfs_header_level(buf);
1489 nritems = btrfs_header_nritems(buf);
1490
1491 if (level == 0) {
1492 struct btrfs_leaf_ref *ref;
1493 struct btrfs_extent_info *info;
1494
1495 ref = btrfs_alloc_leaf_ref(root, nr_extents);
1496 if (!ref) {
1497 ret = -ENOMEM;
1498 goto out;
1499 }
1500
1501 ref->root_gen = root_gen;
1502 ref->bytenr = buf->start;
1503 ref->owner = btrfs_header_owner(buf);
1504 ref->generation = btrfs_header_generation(buf);
1505 ref->nritems = nr_extents;
1506 info = ref->extents;
1507
1508 for (i = 0; nr_extents > 0 && i < nritems; i++) {
1509 u64 disk_bytenr;
1510 btrfs_item_key_to_cpu(buf, &key, i);
1511 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1512 continue;
1513 fi = btrfs_item_ptr(buf, i,
1514 struct btrfs_file_extent_item);
1515 if (btrfs_file_extent_type(buf, fi) ==
1516 BTRFS_FILE_EXTENT_INLINE)
1517 continue;
1518 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1519 if (disk_bytenr == 0)
1520 continue;
1521
1522 info->bytenr = disk_bytenr;
1523 info->num_bytes =
1524 btrfs_file_extent_disk_num_bytes(buf, fi);
1525 info->objectid = key.objectid;
1526 info->offset = key.offset;
1527 info++;
1528 }
1529
1530 ret = btrfs_add_leaf_ref(root, ref, shared);
1531 if (ret == -EEXIST && shared) {
1532 struct btrfs_leaf_ref *old;
1533 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
1534 BUG_ON(!old);
1535 btrfs_remove_leaf_ref(root, old);
1536 btrfs_free_leaf_ref(root, old);
1537 ret = btrfs_add_leaf_ref(root, ref, shared);
1538 }
1539 WARN_ON(ret);
1540 btrfs_free_leaf_ref(root, ref);
1541 }
1542 out:
1543 return ret;
1544 }
1545
1546 /* when a block goes through cow, we update the reference counts of
1547 * everything that block points to. The internal pointers of the block
1548 * can be in just about any order, and it is likely to have clusters of
1549 * things that are close together and clusters of things that are not.
1550 *
1551 * To help reduce the seeks that come with updating all of these reference
1552 * counts, sort them by byte number before actual updates are done.
1553 *
1554 * struct refsort is used to match byte number to slot in the btree block.
1555 * we sort based on the byte number and then use the slot to actually
1556 * find the item.
1557 *
1558 * struct refsort is smaller than strcut btrfs_item and smaller than
1559 * struct btrfs_key_ptr. Since we're currently limited to the page size
1560 * for a btree block, there's no way for a kmalloc of refsorts for a
1561 * single node to be bigger than a page.
1562 */
1563 struct refsort {
1564 u64 bytenr;
1565 u32 slot;
1566 };
1567
1568 /*
1569 * for passing into sort()
1570 */
1571 static int refsort_cmp(const void *a_void, const void *b_void)
1572 {
1573 const struct refsort *a = a_void;
1574 const struct refsort *b = b_void;
1575
1576 if (a->bytenr < b->bytenr)
1577 return -1;
1578 if (a->bytenr > b->bytenr)
1579 return 1;
1580 return 0;
1581 }
1582
1583
1584 noinline int btrfs_inc_ref(struct btrfs_trans_handle *trans,
1585 struct btrfs_root *root,
1586 struct extent_buffer *orig_buf,
1587 struct extent_buffer *buf, u32 *nr_extents)
1588 {
1589 u64 bytenr;
1590 u64 ref_root;
1591 u64 orig_root;
1592 u64 ref_generation;
1593 u64 orig_generation;
1594 struct refsort *sorted;
1595 u32 nritems;
1596 u32 nr_file_extents = 0;
1597 struct btrfs_key key;
1598 struct btrfs_file_extent_item *fi;
1599 int i;
1600 int level;
1601 int ret = 0;
1602 int faili = 0;
1603 int refi = 0;
1604 int slot;
1605 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
1606 u64, u64, u64, u64, u64, u64, u64, u64);
1607
1608 ref_root = btrfs_header_owner(buf);
1609 ref_generation = btrfs_header_generation(buf);
1610 orig_root = btrfs_header_owner(orig_buf);
1611 orig_generation = btrfs_header_generation(orig_buf);
1612
1613 nritems = btrfs_header_nritems(buf);
1614 level = btrfs_header_level(buf);
1615
1616 sorted = kmalloc(sizeof(struct refsort) * nritems, GFP_NOFS);
1617 BUG_ON(!sorted);
1618
1619 if (root->ref_cows) {
1620 process_func = __btrfs_inc_extent_ref;
1621 } else {
1622 if (level == 0 &&
1623 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1624 goto out;
1625 if (level != 0 &&
1626 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1627 goto out;
1628 process_func = __btrfs_update_extent_ref;
1629 }
1630
1631 /*
1632 * we make two passes through the items. In the first pass we
1633 * only record the byte number and slot. Then we sort based on
1634 * byte number and do the actual work based on the sorted results
1635 */
1636 for (i = 0; i < nritems; i++) {
1637 cond_resched();
1638 if (level == 0) {
1639 btrfs_item_key_to_cpu(buf, &key, i);
1640 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1641 continue;
1642 fi = btrfs_item_ptr(buf, i,
1643 struct btrfs_file_extent_item);
1644 if (btrfs_file_extent_type(buf, fi) ==
1645 BTRFS_FILE_EXTENT_INLINE)
1646 continue;
1647 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1648 if (bytenr == 0)
1649 continue;
1650
1651 nr_file_extents++;
1652 sorted[refi].bytenr = bytenr;
1653 sorted[refi].slot = i;
1654 refi++;
1655 } else {
1656 bytenr = btrfs_node_blockptr(buf, i);
1657 sorted[refi].bytenr = bytenr;
1658 sorted[refi].slot = i;
1659 refi++;
1660 }
1661 }
1662 /*
1663 * if refi == 0, we didn't actually put anything into the sorted
1664 * array and we're done
1665 */
1666 if (refi == 0)
1667 goto out;
1668
1669 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
1670
1671 for (i = 0; i < refi; i++) {
1672 cond_resched();
1673 slot = sorted[i].slot;
1674 bytenr = sorted[i].bytenr;
1675
1676 if (level == 0) {
1677 btrfs_item_key_to_cpu(buf, &key, slot);
1678
1679 ret = process_func(trans, root, bytenr,
1680 orig_buf->start, buf->start,
1681 orig_root, ref_root,
1682 orig_generation, ref_generation,
1683 key.objectid);
1684
1685 if (ret) {
1686 faili = slot;
1687 WARN_ON(1);
1688 goto fail;
1689 }
1690 } else {
1691 ret = process_func(trans, root, bytenr,
1692 orig_buf->start, buf->start,
1693 orig_root, ref_root,
1694 orig_generation, ref_generation,
1695 level - 1);
1696 if (ret) {
1697 faili = slot;
1698 WARN_ON(1);
1699 goto fail;
1700 }
1701 }
1702 }
1703 out:
1704 kfree(sorted);
1705 if (nr_extents) {
1706 if (level == 0)
1707 *nr_extents = nr_file_extents;
1708 else
1709 *nr_extents = nritems;
1710 }
1711 return 0;
1712 fail:
1713 kfree(sorted);
1714 WARN_ON(1);
1715 return ret;
1716 }
1717
1718 int btrfs_update_ref(struct btrfs_trans_handle *trans,
1719 struct btrfs_root *root, struct extent_buffer *orig_buf,
1720 struct extent_buffer *buf, int start_slot, int nr)
1721
1722 {
1723 u64 bytenr;
1724 u64 ref_root;
1725 u64 orig_root;
1726 u64 ref_generation;
1727 u64 orig_generation;
1728 struct btrfs_key key;
1729 struct btrfs_file_extent_item *fi;
1730 int i;
1731 int ret;
1732 int slot;
1733 int level;
1734
1735 BUG_ON(start_slot < 0);
1736 BUG_ON(start_slot + nr > btrfs_header_nritems(buf));
1737
1738 ref_root = btrfs_header_owner(buf);
1739 ref_generation = btrfs_header_generation(buf);
1740 orig_root = btrfs_header_owner(orig_buf);
1741 orig_generation = btrfs_header_generation(orig_buf);
1742 level = btrfs_header_level(buf);
1743
1744 if (!root->ref_cows) {
1745 if (level == 0 &&
1746 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1747 return 0;
1748 if (level != 0 &&
1749 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1750 return 0;
1751 }
1752
1753 for (i = 0, slot = start_slot; i < nr; i++, slot++) {
1754 cond_resched();
1755 if (level == 0) {
1756 btrfs_item_key_to_cpu(buf, &key, slot);
1757 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1758 continue;
1759 fi = btrfs_item_ptr(buf, slot,
1760 struct btrfs_file_extent_item);
1761 if (btrfs_file_extent_type(buf, fi) ==
1762 BTRFS_FILE_EXTENT_INLINE)
1763 continue;
1764 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1765 if (bytenr == 0)
1766 continue;
1767 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1768 orig_buf->start, buf->start,
1769 orig_root, ref_root,
1770 orig_generation, ref_generation,
1771 key.objectid);
1772 if (ret)
1773 goto fail;
1774 } else {
1775 bytenr = btrfs_node_blockptr(buf, slot);
1776 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1777 orig_buf->start, buf->start,
1778 orig_root, ref_root,
1779 orig_generation, ref_generation,
1780 level - 1);
1781 if (ret)
1782 goto fail;
1783 }
1784 }
1785 return 0;
1786 fail:
1787 WARN_ON(1);
1788 return -1;
1789 }
1790
1791 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1792 struct btrfs_root *root,
1793 struct btrfs_path *path,
1794 struct btrfs_block_group_cache *cache)
1795 {
1796 int ret;
1797 int pending_ret;
1798 struct btrfs_root *extent_root = root->fs_info->extent_root;
1799 unsigned long bi;
1800 struct extent_buffer *leaf;
1801
1802 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1803 if (ret < 0)
1804 goto fail;
1805 BUG_ON(ret);
1806
1807 leaf = path->nodes[0];
1808 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1809 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1810 btrfs_mark_buffer_dirty(leaf);
1811 btrfs_release_path(extent_root, path);
1812 fail:
1813 finish_current_insert(trans, extent_root, 0);
1814 pending_ret = del_pending_extents(trans, extent_root, 0);
1815 if (ret)
1816 return ret;
1817 if (pending_ret)
1818 return pending_ret;
1819 return 0;
1820
1821 }
1822
1823 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1824 struct btrfs_root *root)
1825 {
1826 struct btrfs_block_group_cache *cache, *entry;
1827 struct rb_node *n;
1828 int err = 0;
1829 int werr = 0;
1830 struct btrfs_path *path;
1831 u64 last = 0;
1832
1833 path = btrfs_alloc_path();
1834 if (!path)
1835 return -ENOMEM;
1836
1837 while (1) {
1838 cache = NULL;
1839 spin_lock(&root->fs_info->block_group_cache_lock);
1840 for (n = rb_first(&root->fs_info->block_group_cache_tree);
1841 n; n = rb_next(n)) {
1842 entry = rb_entry(n, struct btrfs_block_group_cache,
1843 cache_node);
1844 if (entry->dirty) {
1845 cache = entry;
1846 break;
1847 }
1848 }
1849 spin_unlock(&root->fs_info->block_group_cache_lock);
1850
1851 if (!cache)
1852 break;
1853
1854 cache->dirty = 0;
1855 last += cache->key.offset;
1856
1857 err = write_one_cache_group(trans, root,
1858 path, cache);
1859 /*
1860 * if we fail to write the cache group, we want
1861 * to keep it marked dirty in hopes that a later
1862 * write will work
1863 */
1864 if (err) {
1865 werr = err;
1866 continue;
1867 }
1868 }
1869 btrfs_free_path(path);
1870 return werr;
1871 }
1872
1873 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
1874 {
1875 struct btrfs_block_group_cache *block_group;
1876 int readonly = 0;
1877
1878 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
1879 if (!block_group || block_group->ro)
1880 readonly = 1;
1881 if (block_group)
1882 put_block_group(block_group);
1883 return readonly;
1884 }
1885
1886 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1887 u64 total_bytes, u64 bytes_used,
1888 struct btrfs_space_info **space_info)
1889 {
1890 struct btrfs_space_info *found;
1891
1892 found = __find_space_info(info, flags);
1893 if (found) {
1894 spin_lock(&found->lock);
1895 found->total_bytes += total_bytes;
1896 found->bytes_used += bytes_used;
1897 found->full = 0;
1898 spin_unlock(&found->lock);
1899 *space_info = found;
1900 return 0;
1901 }
1902 found = kzalloc(sizeof(*found), GFP_NOFS);
1903 if (!found)
1904 return -ENOMEM;
1905
1906 list_add(&found->list, &info->space_info);
1907 INIT_LIST_HEAD(&found->block_groups);
1908 init_rwsem(&found->groups_sem);
1909 spin_lock_init(&found->lock);
1910 found->flags = flags;
1911 found->total_bytes = total_bytes;
1912 found->bytes_used = bytes_used;
1913 found->bytes_pinned = 0;
1914 found->bytes_reserved = 0;
1915 found->bytes_readonly = 0;
1916 found->bytes_delalloc = 0;
1917 found->full = 0;
1918 found->force_alloc = 0;
1919 *space_info = found;
1920 return 0;
1921 }
1922
1923 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1924 {
1925 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1926 BTRFS_BLOCK_GROUP_RAID1 |
1927 BTRFS_BLOCK_GROUP_RAID10 |
1928 BTRFS_BLOCK_GROUP_DUP);
1929 if (extra_flags) {
1930 if (flags & BTRFS_BLOCK_GROUP_DATA)
1931 fs_info->avail_data_alloc_bits |= extra_flags;
1932 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1933 fs_info->avail_metadata_alloc_bits |= extra_flags;
1934 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1935 fs_info->avail_system_alloc_bits |= extra_flags;
1936 }
1937 }
1938
1939 static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
1940 {
1941 spin_lock(&cache->space_info->lock);
1942 spin_lock(&cache->lock);
1943 if (!cache->ro) {
1944 cache->space_info->bytes_readonly += cache->key.offset -
1945 btrfs_block_group_used(&cache->item);
1946 cache->ro = 1;
1947 }
1948 spin_unlock(&cache->lock);
1949 spin_unlock(&cache->space_info->lock);
1950 }
1951
1952 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
1953 {
1954 u64 num_devices = root->fs_info->fs_devices->rw_devices;
1955
1956 if (num_devices == 1)
1957 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
1958 if (num_devices < 4)
1959 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
1960
1961 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
1962 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
1963 BTRFS_BLOCK_GROUP_RAID10))) {
1964 flags &= ~BTRFS_BLOCK_GROUP_DUP;
1965 }
1966
1967 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
1968 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
1969 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
1970 }
1971
1972 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
1973 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
1974 (flags & BTRFS_BLOCK_GROUP_RAID10) |
1975 (flags & BTRFS_BLOCK_GROUP_DUP)))
1976 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
1977 return flags;
1978 }
1979
1980 static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data)
1981 {
1982 struct btrfs_fs_info *info = root->fs_info;
1983 u64 alloc_profile;
1984
1985 if (data) {
1986 alloc_profile = info->avail_data_alloc_bits &
1987 info->data_alloc_profile;
1988 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
1989 } else if (root == root->fs_info->chunk_root) {
1990 alloc_profile = info->avail_system_alloc_bits &
1991 info->system_alloc_profile;
1992 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
1993 } else {
1994 alloc_profile = info->avail_metadata_alloc_bits &
1995 info->metadata_alloc_profile;
1996 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
1997 }
1998
1999 return btrfs_reduce_alloc_profile(root, data);
2000 }
2001
2002 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
2003 {
2004 u64 alloc_target;
2005
2006 alloc_target = btrfs_get_alloc_profile(root, 1);
2007 BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
2008 alloc_target);
2009 }
2010
2011 /*
2012 * for now this just makes sure we have at least 5% of our metadata space free
2013 * for use.
2014 */
2015 int btrfs_check_metadata_free_space(struct btrfs_root *root)
2016 {
2017 struct btrfs_fs_info *info = root->fs_info;
2018 struct btrfs_space_info *meta_sinfo;
2019 u64 alloc_target, thresh;
2020 int committed = 0, ret;
2021
2022 /* get the space info for where the metadata will live */
2023 alloc_target = btrfs_get_alloc_profile(root, 0);
2024 meta_sinfo = __find_space_info(info, alloc_target);
2025
2026 again:
2027 spin_lock(&meta_sinfo->lock);
2028 if (!meta_sinfo->full)
2029 thresh = meta_sinfo->total_bytes * 80;
2030 else
2031 thresh = meta_sinfo->total_bytes * 95;
2032
2033 do_div(thresh, 100);
2034
2035 if (meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
2036 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly > thresh) {
2037 struct btrfs_trans_handle *trans;
2038 if (!meta_sinfo->full) {
2039 meta_sinfo->force_alloc = 1;
2040 spin_unlock(&meta_sinfo->lock);
2041
2042 trans = btrfs_start_transaction(root, 1);
2043 if (!trans)
2044 return -ENOMEM;
2045
2046 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2047 2 * 1024 * 1024, alloc_target, 0);
2048 btrfs_end_transaction(trans, root);
2049 goto again;
2050 }
2051 spin_unlock(&meta_sinfo->lock);
2052
2053 if (!committed) {
2054 committed = 1;
2055 trans = btrfs_join_transaction(root, 1);
2056 if (!trans)
2057 return -ENOMEM;
2058 ret = btrfs_commit_transaction(trans, root);
2059 if (ret)
2060 return ret;
2061 goto again;
2062 }
2063 return -ENOSPC;
2064 }
2065 spin_unlock(&meta_sinfo->lock);
2066
2067 return 0;
2068 }
2069
2070 /*
2071 * This will check the space that the inode allocates from to make sure we have
2072 * enough space for bytes.
2073 */
2074 int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
2075 u64 bytes)
2076 {
2077 struct btrfs_space_info *data_sinfo;
2078 int ret = 0, committed = 0;
2079
2080 /* make sure bytes are sectorsize aligned */
2081 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
2082
2083 data_sinfo = BTRFS_I(inode)->space_info;
2084 again:
2085 /* make sure we have enough space to handle the data first */
2086 spin_lock(&data_sinfo->lock);
2087 if (data_sinfo->total_bytes - data_sinfo->bytes_used -
2088 data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved -
2089 data_sinfo->bytes_pinned - data_sinfo->bytes_readonly -
2090 data_sinfo->bytes_may_use < bytes) {
2091 struct btrfs_trans_handle *trans;
2092
2093 /*
2094 * if we don't have enough free bytes in this space then we need
2095 * to alloc a new chunk.
2096 */
2097 if (!data_sinfo->full) {
2098 u64 alloc_target;
2099
2100 data_sinfo->force_alloc = 1;
2101 spin_unlock(&data_sinfo->lock);
2102
2103 alloc_target = btrfs_get_alloc_profile(root, 1);
2104 trans = btrfs_start_transaction(root, 1);
2105 if (!trans)
2106 return -ENOMEM;
2107
2108 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2109 bytes + 2 * 1024 * 1024,
2110 alloc_target, 0);
2111 btrfs_end_transaction(trans, root);
2112 if (ret)
2113 return ret;
2114 goto again;
2115 }
2116 spin_unlock(&data_sinfo->lock);
2117
2118 /* commit the current transaction and try again */
2119 if (!committed) {
2120 committed = 1;
2121 trans = btrfs_join_transaction(root, 1);
2122 if (!trans)
2123 return -ENOMEM;
2124 ret = btrfs_commit_transaction(trans, root);
2125 if (ret)
2126 return ret;
2127 goto again;
2128 }
2129
2130 printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes"
2131 ", %llu bytes_used, %llu bytes_reserved, "
2132 "%llu bytes_pinned, %llu bytes_readonly, %llu may use"
2133 "%llu total\n", bytes, data_sinfo->bytes_delalloc,
2134 data_sinfo->bytes_used, data_sinfo->bytes_reserved,
2135 data_sinfo->bytes_pinned, data_sinfo->bytes_readonly,
2136 data_sinfo->bytes_may_use, data_sinfo->total_bytes);
2137 return -ENOSPC;
2138 }
2139 data_sinfo->bytes_may_use += bytes;
2140 BTRFS_I(inode)->reserved_bytes += bytes;
2141 spin_unlock(&data_sinfo->lock);
2142
2143 return btrfs_check_metadata_free_space(root);
2144 }
2145
2146 /*
2147 * if there was an error for whatever reason after calling
2148 * btrfs_check_data_free_space, call this so we can cleanup the counters.
2149 */
2150 void btrfs_free_reserved_data_space(struct btrfs_root *root,
2151 struct inode *inode, u64 bytes)
2152 {
2153 struct btrfs_space_info *data_sinfo;
2154
2155 /* make sure bytes are sectorsize aligned */
2156 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
2157
2158 data_sinfo = BTRFS_I(inode)->space_info;
2159 spin_lock(&data_sinfo->lock);
2160 data_sinfo->bytes_may_use -= bytes;
2161 BTRFS_I(inode)->reserved_bytes -= bytes;
2162 spin_unlock(&data_sinfo->lock);
2163 }
2164
2165 /* called when we are adding a delalloc extent to the inode's io_tree */
2166 void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
2167 u64 bytes)
2168 {
2169 struct btrfs_space_info *data_sinfo;
2170
2171 /* get the space info for where this inode will be storing its data */
2172 data_sinfo = BTRFS_I(inode)->space_info;
2173
2174 /* make sure we have enough space to handle the data first */
2175 spin_lock(&data_sinfo->lock);
2176 data_sinfo->bytes_delalloc += bytes;
2177
2178 /*
2179 * we are adding a delalloc extent without calling
2180 * btrfs_check_data_free_space first. This happens on a weird
2181 * writepage condition, but shouldn't hurt our accounting
2182 */
2183 if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {
2184 data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;
2185 BTRFS_I(inode)->reserved_bytes = 0;
2186 } else {
2187 data_sinfo->bytes_may_use -= bytes;
2188 BTRFS_I(inode)->reserved_bytes -= bytes;
2189 }
2190
2191 spin_unlock(&data_sinfo->lock);
2192 }
2193
2194 /* called when we are clearing an delalloc extent from the inode's io_tree */
2195 void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
2196 u64 bytes)
2197 {
2198 struct btrfs_space_info *info;
2199
2200 info = BTRFS_I(inode)->space_info;
2201
2202 spin_lock(&info->lock);
2203 info->bytes_delalloc -= bytes;
2204 spin_unlock(&info->lock);
2205 }
2206
2207 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
2208 struct btrfs_root *extent_root, u64 alloc_bytes,
2209 u64 flags, int force)
2210 {
2211 struct btrfs_space_info *space_info;
2212 u64 thresh;
2213 int ret = 0;
2214
2215 mutex_lock(&extent_root->fs_info->chunk_mutex);
2216
2217 flags = btrfs_reduce_alloc_profile(extent_root, flags);
2218
2219 space_info = __find_space_info(extent_root->fs_info, flags);
2220 if (!space_info) {
2221 ret = update_space_info(extent_root->fs_info, flags,
2222 0, 0, &space_info);
2223 BUG_ON(ret);
2224 }
2225 BUG_ON(!space_info);
2226
2227 spin_lock(&space_info->lock);
2228 if (space_info->force_alloc) {
2229 force = 1;
2230 space_info->force_alloc = 0;
2231 }
2232 if (space_info->full) {
2233 spin_unlock(&space_info->lock);
2234 goto out;
2235 }
2236
2237 thresh = space_info->total_bytes - space_info->bytes_readonly;
2238 thresh = div_factor(thresh, 6);
2239 if (!force &&
2240 (space_info->bytes_used + space_info->bytes_pinned +
2241 space_info->bytes_reserved + alloc_bytes) < thresh) {
2242 spin_unlock(&space_info->lock);
2243 goto out;
2244 }
2245 spin_unlock(&space_info->lock);
2246
2247 ret = btrfs_alloc_chunk(trans, extent_root, flags);
2248 if (ret)
2249 space_info->full = 1;
2250 out:
2251 mutex_unlock(&extent_root->fs_info->chunk_mutex);
2252 return ret;
2253 }
2254
2255 static int update_block_group(struct btrfs_trans_handle *trans,
2256 struct btrfs_root *root,
2257 u64 bytenr, u64 num_bytes, int alloc,
2258 int mark_free)
2259 {
2260 struct btrfs_block_group_cache *cache;
2261 struct btrfs_fs_info *info = root->fs_info;
2262 u64 total = num_bytes;
2263 u64 old_val;
2264 u64 byte_in_group;
2265
2266 while (total) {
2267 cache = btrfs_lookup_block_group(info, bytenr);
2268 if (!cache)
2269 return -1;
2270 byte_in_group = bytenr - cache->key.objectid;
2271 WARN_ON(byte_in_group > cache->key.offset);
2272
2273 spin_lock(&cache->space_info->lock);
2274 spin_lock(&cache->lock);
2275 cache->dirty = 1;
2276 old_val = btrfs_block_group_used(&cache->item);
2277 num_bytes = min(total, cache->key.offset - byte_in_group);
2278 if (alloc) {
2279 old_val += num_bytes;
2280 cache->space_info->bytes_used += num_bytes;
2281 if (cache->ro)
2282 cache->space_info->bytes_readonly -= num_bytes;
2283 btrfs_set_block_group_used(&cache->item, old_val);
2284 spin_unlock(&cache->lock);
2285 spin_unlock(&cache->space_info->lock);
2286 } else {
2287 old_val -= num_bytes;
2288 cache->space_info->bytes_used -= num_bytes;
2289 if (cache->ro)
2290 cache->space_info->bytes_readonly += num_bytes;
2291 btrfs_set_block_group_used(&cache->item, old_val);
2292 spin_unlock(&cache->lock);
2293 spin_unlock(&cache->space_info->lock);
2294 if (mark_free) {
2295 int ret;
2296
2297 ret = btrfs_discard_extent(root, bytenr,
2298 num_bytes);
2299 WARN_ON(ret);
2300
2301 ret = btrfs_add_free_space(cache, bytenr,
2302 num_bytes);
2303 WARN_ON(ret);
2304 }
2305 }
2306 put_block_group(cache);
2307 total -= num_bytes;
2308 bytenr += num_bytes;
2309 }
2310 return 0;
2311 }
2312
2313 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
2314 {
2315 struct btrfs_block_group_cache *cache;
2316 u64 bytenr;
2317
2318 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
2319 if (!cache)
2320 return 0;
2321
2322 bytenr = cache->key.objectid;
2323 put_block_group(cache);
2324
2325 return bytenr;
2326 }
2327
2328 int btrfs_update_pinned_extents(struct btrfs_root *root,
2329 u64 bytenr, u64 num, int pin)
2330 {
2331 u64 len;
2332 struct btrfs_block_group_cache *cache;
2333 struct btrfs_fs_info *fs_info = root->fs_info;
2334
2335 WARN_ON(!mutex_is_locked(&root->fs_info->pinned_mutex));
2336 if (pin) {
2337 set_extent_dirty(&fs_info->pinned_extents,
2338 bytenr, bytenr + num - 1, GFP_NOFS);
2339 } else {
2340 clear_extent_dirty(&fs_info->pinned_extents,
2341 bytenr, bytenr + num - 1, GFP_NOFS);
2342 }
2343 while (num > 0) {
2344 cache = btrfs_lookup_block_group(fs_info, bytenr);
2345 BUG_ON(!cache);
2346 len = min(num, cache->key.offset -
2347 (bytenr - cache->key.objectid));
2348 if (pin) {
2349 spin_lock(&cache->space_info->lock);
2350 spin_lock(&cache->lock);
2351 cache->pinned += len;
2352 cache->space_info->bytes_pinned += len;
2353 spin_unlock(&cache->lock);
2354 spin_unlock(&cache->space_info->lock);
2355 fs_info->total_pinned += len;
2356 } else {
2357 spin_lock(&cache->space_info->lock);
2358 spin_lock(&cache->lock);
2359 cache->pinned -= len;
2360 cache->space_info->bytes_pinned -= len;
2361 spin_unlock(&cache->lock);
2362 spin_unlock(&cache->space_info->lock);
2363 fs_info->total_pinned -= len;
2364 if (cache->cached)
2365 btrfs_add_free_space(cache, bytenr, len);
2366 }
2367 put_block_group(cache);
2368 bytenr += len;
2369 num -= len;
2370 }
2371 return 0;
2372 }
2373
2374 static int update_reserved_extents(struct btrfs_root *root,
2375 u64 bytenr, u64 num, int reserve)
2376 {
2377 u64 len;
2378 struct btrfs_block_group_cache *cache;
2379 struct btrfs_fs_info *fs_info = root->fs_info;
2380
2381 while (num > 0) {
2382 cache = btrfs_lookup_block_group(fs_info, bytenr);
2383 BUG_ON(!cache);
2384 len = min(num, cache->key.offset -
2385 (bytenr - cache->key.objectid));
2386
2387 spin_lock(&cache->space_info->lock);
2388 spin_lock(&cache->lock);
2389 if (reserve) {
2390 cache->reserved += len;
2391 cache->space_info->bytes_reserved += len;
2392 } else {
2393 cache->reserved -= len;
2394 cache->space_info->bytes_reserved -= len;
2395 }
2396 spin_unlock(&cache->lock);
2397 spin_unlock(&cache->space_info->lock);
2398 put_block_group(cache);
2399 bytenr += len;
2400 num -= len;
2401 }
2402 return 0;
2403 }
2404
2405 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
2406 {
2407 u64 last = 0;
2408 u64 start;
2409 u64 end;
2410 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
2411 int ret;
2412
2413 mutex_lock(&root->fs_info->pinned_mutex);
2414 while (1) {
2415 ret = find_first_extent_bit(pinned_extents, last,
2416 &start, &end, EXTENT_DIRTY);
2417 if (ret)
2418 break;
2419 set_extent_dirty(copy, start, end, GFP_NOFS);
2420 last = end + 1;
2421 }
2422 mutex_unlock(&root->fs_info->pinned_mutex);
2423 return 0;
2424 }
2425
2426 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
2427 struct btrfs_root *root,
2428 struct extent_io_tree *unpin)
2429 {
2430 u64 start;
2431 u64 end;
2432 int ret;
2433
2434 mutex_lock(&root->fs_info->pinned_mutex);
2435 while (1) {
2436 ret = find_first_extent_bit(unpin, 0, &start, &end,
2437 EXTENT_DIRTY);
2438 if (ret)
2439 break;
2440
2441 ret = btrfs_discard_extent(root, start, end + 1 - start);
2442
2443 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
2444 clear_extent_dirty(unpin, start, end, GFP_NOFS);
2445
2446 if (need_resched()) {
2447 mutex_unlock(&root->fs_info->pinned_mutex);
2448 cond_resched();
2449 mutex_lock(&root->fs_info->pinned_mutex);
2450 }
2451 }
2452 mutex_unlock(&root->fs_info->pinned_mutex);
2453 return ret;
2454 }
2455
2456 static int finish_current_insert(struct btrfs_trans_handle *trans,
2457 struct btrfs_root *extent_root, int all)
2458 {
2459 u64 start;
2460 u64 end;
2461 u64 priv;
2462 u64 search = 0;
2463 struct btrfs_fs_info *info = extent_root->fs_info;
2464 struct btrfs_path *path;
2465 struct pending_extent_op *extent_op, *tmp;
2466 struct list_head insert_list, update_list;
2467 int ret;
2468 int num_inserts = 0, max_inserts, restart = 0;
2469
2470 path = btrfs_alloc_path();
2471 INIT_LIST_HEAD(&insert_list);
2472 INIT_LIST_HEAD(&update_list);
2473
2474 max_inserts = extent_root->leafsize /
2475 (2 * sizeof(struct btrfs_key) + 2 * sizeof(struct btrfs_item) +
2476 sizeof(struct btrfs_extent_ref) +
2477 sizeof(struct btrfs_extent_item));
2478 again:
2479 mutex_lock(&info->extent_ins_mutex);
2480 while (1) {
2481 ret = find_first_extent_bit(&info->extent_ins, search, &start,
2482 &end, EXTENT_WRITEBACK);
2483 if (ret) {
2484 if (restart && !num_inserts &&
2485 list_empty(&update_list)) {
2486 restart = 0;
2487 search = 0;
2488 continue;
2489 }
2490 break;
2491 }
2492
2493 ret = try_lock_extent(&info->extent_ins, start, end, GFP_NOFS);
2494 if (!ret) {
2495 if (all)
2496 restart = 1;
2497 search = end + 1;
2498 if (need_resched()) {
2499 mutex_unlock(&info->extent_ins_mutex);
2500 cond_resched();
2501 mutex_lock(&info->extent_ins_mutex);
2502 }
2503 continue;
2504 }
2505
2506 ret = get_state_private(&info->extent_ins, start, &priv);
2507 BUG_ON(ret);
2508 extent_op = (struct pending_extent_op *)(unsigned long) priv;
2509
2510 if (extent_op->type == PENDING_EXTENT_INSERT) {
2511 num_inserts++;
2512 list_add_tail(&extent_op->list, &insert_list);
2513 search = end + 1;
2514 if (num_inserts == max_inserts) {
2515 restart = 1;
2516 break;
2517 }
2518 } else if (extent_op->type == PENDING_BACKREF_UPDATE) {
2519 list_add_tail(&extent_op->list, &update_list);
2520 search = end + 1;
2521 } else {
2522 BUG();
2523 }
2524 }
2525
2526 /*
2527 * process the update list, clear the writeback bit for it, and if
2528 * somebody marked this thing for deletion then just unlock it and be
2529 * done, the free_extents will handle it
2530 */
2531 list_for_each_entry_safe(extent_op, tmp, &update_list, list) {
2532 clear_extent_bits(&info->extent_ins, extent_op->bytenr,
2533 extent_op->bytenr + extent_op->num_bytes - 1,
2534 EXTENT_WRITEBACK, GFP_NOFS);
2535 if (extent_op->del) {
2536 list_del_init(&extent_op->list);
2537 unlock_extent(&info->extent_ins, extent_op->bytenr,
2538 extent_op->bytenr + extent_op->num_bytes
2539 - 1, GFP_NOFS);
2540 kfree(extent_op);
2541 }
2542 }
2543 mutex_unlock(&info->extent_ins_mutex);
2544
2545 /*
2546 * still have things left on the update list, go ahead an update
2547 * everything
2548 */
2549 if (!list_empty(&update_list)) {
2550 ret = update_backrefs(trans, extent_root, path, &update_list);
2551 BUG_ON(ret);
2552
2553 /* we may have COW'ed new blocks, so lets start over */
2554 if (all)
2555 restart = 1;
2556 }
2557
2558 /*
2559 * if no inserts need to be done, but we skipped some extents and we
2560 * need to make sure everything is cleaned then reset everything and
2561 * go back to the beginning
2562 */
2563 if (!num_inserts && restart) {
2564 search = 0;
2565 restart = 0;
2566 INIT_LIST_HEAD(&update_list);
2567 INIT_LIST_HEAD(&insert_list);
2568 goto again;
2569 } else if (!num_inserts) {
2570 goto out;
2571 }
2572
2573 /*
2574 * process the insert extents list. Again if we are deleting this
2575 * extent, then just unlock it, pin down the bytes if need be, and be
2576 * done with it. Saves us from having to actually insert the extent
2577 * into the tree and then subsequently come along and delete it
2578 */
2579 mutex_lock(&info->extent_ins_mutex);
2580 list_for_each_entry_safe(extent_op, tmp, &insert_list, list) {
2581 clear_extent_bits(&info->extent_ins, extent_op->bytenr,
2582 extent_op->bytenr + extent_op->num_bytes - 1,
2583 EXTENT_WRITEBACK, GFP_NOFS);
2584 if (extent_op->del) {
2585 u64 used;
2586 list_del_init(&extent_op->list);
2587 unlock_extent(&info->extent_ins, extent_op->bytenr,
2588 extent_op->bytenr + extent_op->num_bytes
2589 - 1, GFP_NOFS);
2590
2591 mutex_lock(&extent_root->fs_info->pinned_mutex);
2592 ret = pin_down_bytes(trans, extent_root,
2593 extent_op->bytenr,
2594 extent_op->num_bytes, 0);
2595 mutex_unlock(&extent_root->fs_info->pinned_mutex);
2596
2597 spin_lock(&info->delalloc_lock);
2598 used = btrfs_super_bytes_used(&info->super_copy);
2599 btrfs_set_super_bytes_used(&info->super_copy,
2600 used - extent_op->num_bytes);
2601 used = btrfs_root_used(&extent_root->root_item);
2602 btrfs_set_root_used(&extent_root->root_item,
2603 used - extent_op->num_bytes);
2604 spin_unlock(&info->delalloc_lock);
2605
2606 ret = update_block_group(trans, extent_root,
2607 extent_op->bytenr,
2608 extent_op->num_bytes,
2609 0, ret > 0);
2610 BUG_ON(ret);
2611 kfree(extent_op);
2612 num_inserts--;
2613 }
2614 }
2615 mutex_unlock(&info->extent_ins_mutex);
2616
2617 ret = insert_extents(trans, extent_root, path, &insert_list,
2618 num_inserts);
2619 BUG_ON(ret);
2620
2621 /*
2622 * if restart is set for whatever reason we need to go back and start
2623 * searching through the pending list again.
2624 *
2625 * We just inserted some extents, which could have resulted in new
2626 * blocks being allocated, which would result in new blocks needing
2627 * updates, so if all is set we _must_ restart to get the updated
2628 * blocks.
2629 */
2630 if (restart || all) {
2631 INIT_LIST_HEAD(&insert_list);
2632 INIT_LIST_HEAD(&update_list);
2633 search = 0;
2634 restart = 0;
2635 num_inserts = 0;
2636 goto again;
2637 }
2638 out:
2639 btrfs_free_path(path);
2640 return 0;
2641 }
2642
2643 static int pin_down_bytes(struct btrfs_trans_handle *trans,
2644 struct btrfs_root *root,
2645 u64 bytenr, u64 num_bytes, int is_data)
2646 {
2647 int err = 0;
2648 struct extent_buffer *buf;
2649
2650 if (is_data)
2651 goto pinit;
2652
2653 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
2654 if (!buf)
2655 goto pinit;
2656
2657 /* we can reuse a block if it hasn't been written
2658 * and it is from this transaction. We can't
2659 * reuse anything from the tree log root because
2660 * it has tiny sub-transactions.
2661 */
2662 if (btrfs_buffer_uptodate(buf, 0) &&
2663 btrfs_try_tree_lock(buf)) {
2664 u64 header_owner = btrfs_header_owner(buf);
2665 u64 header_transid = btrfs_header_generation(buf);
2666 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
2667 header_owner != BTRFS_TREE_RELOC_OBJECTID &&
2668 header_transid == trans->transid &&
2669 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
2670 clean_tree_block(NULL, root, buf);
2671 btrfs_tree_unlock(buf);
2672 free_extent_buffer(buf);
2673 return 1;
2674 }
2675 btrfs_tree_unlock(buf);
2676 }
2677 free_extent_buffer(buf);
2678 pinit:
2679 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
2680
2681 BUG_ON(err < 0);
2682 return 0;
2683 }
2684
2685 /*
2686 * remove an extent from the root, returns 0 on success
2687 */
2688 static int __free_extent(struct btrfs_trans_handle *trans,
2689 struct btrfs_root *root,
2690 u64 bytenr, u64 num_bytes, u64 parent,
2691 u64 root_objectid, u64 ref_generation,
2692 u64 owner_objectid, int pin, int mark_free)
2693 {
2694 struct btrfs_path *path;
2695 struct btrfs_key key;
2696 struct btrfs_fs_info *info = root->fs_info;
2697 struct btrfs_root *extent_root = info->extent_root;
2698 struct extent_buffer *leaf;
2699 int ret;
2700 int extent_slot = 0;
2701 int found_extent = 0;
2702 int num_to_del = 1;
2703 struct btrfs_extent_item *ei;
2704 u32 refs;
2705
2706 key.objectid = bytenr;
2707 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
2708 key.offset = num_bytes;
2709 path = btrfs_alloc_path();
2710 if (!path)
2711 return -ENOMEM;
2712
2713 path->reada = 1;
2714 ret = lookup_extent_backref(trans, extent_root, path,
2715 bytenr, parent, root_objectid,
2716 ref_generation, owner_objectid, 1);
2717 if (ret == 0) {
2718 struct btrfs_key found_key;
2719 extent_slot = path->slots[0];
2720 while (extent_slot > 0) {
2721 extent_slot--;
2722 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2723 extent_slot);
2724 if (found_key.objectid != bytenr)
2725 break;
2726 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
2727 found_key.offset == num_bytes) {
2728 found_extent = 1;
2729 break;
2730 }
2731 if (path->slots[0] - extent_slot > 5)
2732 break;
2733 }
2734 if (!found_extent) {
2735 ret = remove_extent_backref(trans, extent_root, path);
2736 BUG_ON(ret);
2737 btrfs_release_path(extent_root, path);
2738 ret = btrfs_search_slot(trans, extent_root,
2739 &key, path, -1, 1);
2740 if (ret) {
2741 printk(KERN_ERR "umm, got %d back from search"
2742 ", was looking for %llu\n", ret,
2743 (unsigned long long)bytenr);
2744 btrfs_print_leaf(extent_root, path->nodes[0]);
2745 }
2746 BUG_ON(ret);
2747 extent_slot = path->slots[0];
2748 }
2749 } else {
2750 btrfs_print_leaf(extent_root, path->nodes[0]);
2751 WARN_ON(1);
2752 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
2753 "root %llu gen %llu owner %llu\n",
2754 (unsigned long long)bytenr,
2755 (unsigned long long)root_objectid,
2756 (unsigned long long)ref_generation,
2757 (unsigned long long)owner_objectid);
2758 }
2759
2760 leaf = path->nodes[0];
2761 ei = btrfs_item_ptr(leaf, extent_slot,
2762 struct btrfs_extent_item);
2763 refs = btrfs_extent_refs(leaf, ei);
2764 BUG_ON(refs == 0);
2765 refs -= 1;
2766 btrfs_set_extent_refs(leaf, ei, refs);
2767
2768 btrfs_mark_buffer_dirty(leaf);
2769
2770 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
2771 struct btrfs_extent_ref *ref;
2772 ref = btrfs_item_ptr(leaf, path->slots[0],
2773 struct btrfs_extent_ref);
2774 BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1);
2775 /* if the back ref and the extent are next to each other
2776 * they get deleted below in one shot
2777 */
2778 path->slots[0] = extent_slot;
2779 num_to_del = 2;
2780 } else if (found_extent) {
2781 /* otherwise delete the extent back ref */
2782 ret = remove_extent_backref(trans, extent_root, path);
2783 BUG_ON(ret);
2784 /* if refs are 0, we need to setup the path for deletion */
2785 if (refs == 0) {
2786 btrfs_release_path(extent_root, path);
2787 ret = btrfs_search_slot(trans, extent_root, &key, path,
2788 -1, 1);
2789 BUG_ON(ret);
2790 }
2791 }
2792
2793 if (refs == 0) {
2794 u64 super_used;
2795 u64 root_used;
2796
2797 if (pin) {
2798 mutex_lock(&root->fs_info->pinned_mutex);
2799 ret = pin_down_bytes(trans, root, bytenr, num_bytes,
2800 owner_objectid >= BTRFS_FIRST_FREE_OBJECTID);
2801 mutex_unlock(&root->fs_info->pinned_mutex);
2802 if (ret > 0)
2803 mark_free = 1;
2804 BUG_ON(ret < 0);
2805 }
2806 /* block accounting for super block */
2807 spin_lock(&info->delalloc_lock);
2808 super_used = btrfs_super_bytes_used(&info->super_copy);
2809 btrfs_set_super_bytes_used(&info->super_copy,
2810 super_used - num_bytes);
2811
2812 /* block accounting for root item */
2813 root_used = btrfs_root_used(&root->root_item);
2814 btrfs_set_root_used(&root->root_item,
2815 root_used - num_bytes);
2816 spin_unlock(&info->delalloc_lock);
2817 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
2818 num_to_del);
2819 BUG_ON(ret);
2820 btrfs_release_path(extent_root, path);
2821
2822 if (owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
2823 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
2824 BUG_ON(ret);
2825 }
2826
2827 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
2828 mark_free);
2829 BUG_ON(ret);
2830 }
2831 btrfs_free_path(path);
2832 finish_current_insert(trans, extent_root, 0);
2833 return ret;
2834 }
2835
2836 /*
2837 * find all the blocks marked as pending in the radix tree and remove
2838 * them from the extent map
2839 */
2840 static int del_pending_extents(struct btrfs_trans_handle *trans,
2841 struct btrfs_root *extent_root, int all)
2842 {
2843 int ret;
2844 int err = 0;
2845 u64 start;
2846 u64 end;
2847 u64 priv;
2848 u64 search = 0;
2849 int nr = 0, skipped = 0;
2850 struct extent_io_tree *pending_del;
2851 struct extent_io_tree *extent_ins;
2852 struct pending_extent_op *extent_op;
2853 struct btrfs_fs_info *info = extent_root->fs_info;
2854 struct list_head delete_list;
2855
2856 INIT_LIST_HEAD(&delete_list);
2857 extent_ins = &extent_root->fs_info->extent_ins;
2858 pending_del = &extent_root->fs_info->pending_del;
2859
2860 again:
2861 mutex_lock(&info->extent_ins_mutex);
2862 while (1) {
2863 ret = find_first_extent_bit(pending_del, search, &start, &end,
2864 EXTENT_WRITEBACK);
2865 if (ret) {
2866 if (all && skipped && !nr) {
2867 search = 0;
2868 skipped = 0;
2869 continue;
2870 }
2871 mutex_unlock(&info->extent_ins_mutex);
2872 break;
2873 }
2874
2875 ret = try_lock_extent(extent_ins, start, end, GFP_NOFS);
2876 if (!ret) {
2877 search = end+1;
2878 skipped = 1;
2879
2880 if (need_resched()) {
2881 mutex_unlock(&info->extent_ins_mutex);
2882 cond_resched();
2883 mutex_lock(&info->extent_ins_mutex);
2884 }
2885
2886 continue;
2887 }
2888 BUG_ON(ret < 0);
2889
2890 ret = get_state_private(pending_del, start, &priv);
2891 BUG_ON(ret);
2892 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2893
2894 clear_extent_bits(pending_del, start, end, EXTENT_WRITEBACK,
2895 GFP_NOFS);
2896 if (!test_range_bit(extent_ins, start, end,
2897 EXTENT_WRITEBACK, 0)) {
2898 list_add_tail(&extent_op->list, &delete_list);
2899 nr++;
2900 } else {
2901 kfree(extent_op);
2902
2903 ret = get_state_private(&info->extent_ins, start,
2904 &priv);
2905 BUG_ON(ret);
2906 extent_op = (struct pending_extent_op *)
2907 (unsigned long)priv;
2908
2909 clear_extent_bits(&info->extent_ins, start, end,
2910 EXTENT_WRITEBACK, GFP_NOFS);
2911
2912 if (extent_op->type == PENDING_BACKREF_UPDATE) {
2913 list_add_tail(&extent_op->list, &delete_list);
2914 search = end + 1;
2915 nr++;
2916 continue;
2917 }
2918
2919 mutex_lock(&extent_root->fs_info->pinned_mutex);
2920 ret = pin_down_bytes(trans, extent_root, start,
2921 end + 1 - start, 0);
2922 mutex_unlock(&extent_root->fs_info->pinned_mutex);
2923
2924 ret = update_block_group(trans, extent_root, start,
2925 end + 1 - start, 0, ret > 0);
2926
2927 unlock_extent(extent_ins, start, end, GFP_NOFS);
2928 BUG_ON(ret);
2929 kfree(extent_op);
2930 }
2931 if (ret)
2932 err = ret;
2933
2934 search = end + 1;
2935
2936 if (need_resched()) {
2937 mutex_unlock(&info->extent_ins_mutex);
2938 cond_resched();
2939 mutex_lock(&info->extent_ins_mutex);
2940 }
2941 }
2942
2943 if (nr) {
2944 ret = free_extents(trans, extent_root, &delete_list);
2945 BUG_ON(ret);
2946 }
2947
2948 if (all && skipped) {
2949 INIT_LIST_HEAD(&delete_list);
2950 search = 0;
2951 nr = 0;
2952 goto again;
2953 }
2954
2955 if (!err)
2956 finish_current_insert(trans, extent_root, 0);
2957 return err;
2958 }
2959
2960 /*
2961 * remove an extent from the root, returns 0 on success
2962 */
2963 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
2964 struct btrfs_root *root,
2965 u64 bytenr, u64 num_bytes, u64 parent,
2966 u64 root_objectid, u64 ref_generation,
2967 u64 owner_objectid, int pin)
2968 {
2969 struct btrfs_root *extent_root = root->fs_info->extent_root;
2970 int pending_ret;
2971 int ret;
2972
2973 WARN_ON(num_bytes < root->sectorsize);
2974 if (root == extent_root) {
2975 struct pending_extent_op *extent_op = NULL;
2976
2977 mutex_lock(&root->fs_info->extent_ins_mutex);
2978 if (test_range_bit(&root->fs_info->extent_ins, bytenr,
2979 bytenr + num_bytes - 1, EXTENT_WRITEBACK, 0)) {
2980 u64 priv;
2981 ret = get_state_private(&root->fs_info->extent_ins,
2982 bytenr, &priv);
2983 BUG_ON(ret);
2984 extent_op = (struct pending_extent_op *)
2985 (unsigned long)priv;
2986
2987 extent_op->del = 1;
2988 if (extent_op->type == PENDING_EXTENT_INSERT) {
2989 mutex_unlock(&root->fs_info->extent_ins_mutex);
2990 return 0;
2991 }
2992 }
2993
2994 if (extent_op) {
2995 ref_generation = extent_op->orig_generation;
2996 parent = extent_op->orig_parent;
2997 }
2998
2999 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
3000 BUG_ON(!extent_op);
3001
3002 extent_op->type = PENDING_EXTENT_DELETE;
3003 extent_op->bytenr = bytenr;
3004 extent_op->num_bytes = num_bytes;
3005 extent_op->parent = parent;
3006 extent_op->orig_parent = parent;
3007 extent_op->generation = ref_generation;
3008 extent_op->orig_generation = ref_generation;
3009 extent_op->level = (int)owner_objectid;
3010 INIT_LIST_HEAD(&extent_op->list);
3011 extent_op->del = 0;
3012
3013 set_extent_bits(&root->fs_info->pending_del,
3014 bytenr, bytenr + num_bytes - 1,
3015 EXTENT_WRITEBACK, GFP_NOFS);
3016 set_state_private(&root->fs_info->pending_del,
3017 bytenr, (unsigned long)extent_op);
3018 mutex_unlock(&root->fs_info->extent_ins_mutex);
3019 return 0;
3020 }
3021 /* if metadata always pin */
3022 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3023 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
3024 mutex_lock(&root->fs_info->pinned_mutex);
3025 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
3026 mutex_unlock(&root->fs_info->pinned_mutex);
3027 update_reserved_extents(root, bytenr, num_bytes, 0);
3028 return 0;
3029 }
3030 pin = 1;
3031 }
3032
3033 /* if data pin when any transaction has committed this */
3034 if (ref_generation != trans->transid)
3035 pin = 1;
3036
3037 ret = __free_extent(trans, root, bytenr, num_bytes, parent,
3038 root_objectid, ref_generation,
3039 owner_objectid, pin, pin == 0);
3040
3041 finish_current_insert(trans, root->fs_info->extent_root, 0);
3042 pending_ret = del_pending_extents(trans, root->fs_info->extent_root, 0);
3043 return ret ? ret : pending_ret;
3044 }
3045
3046 int btrfs_free_extent(struct btrfs_trans_handle *trans,
3047 struct btrfs_root *root,
3048 u64 bytenr, u64 num_bytes, u64 parent,
3049 u64 root_objectid, u64 ref_generation,
3050 u64 owner_objectid, int pin)
3051 {
3052 int ret;
3053
3054 ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent,
3055 root_objectid, ref_generation,
3056 owner_objectid, pin);
3057 return ret;
3058 }
3059
3060 static u64 stripe_align(struct btrfs_root *root, u64 val)
3061 {
3062 u64 mask = ((u64)root->stripesize - 1);
3063 u64 ret = (val + mask) & ~mask;
3064 return ret;
3065 }
3066
3067 /*
3068 * walks the btree of allocated extents and find a hole of a given size.
3069 * The key ins is changed to record the hole:
3070 * ins->objectid == block start
3071 * ins->flags = BTRFS_EXTENT_ITEM_KEY
3072 * ins->offset == number of blocks
3073 * Any available blocks before search_start are skipped.
3074 */
3075 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
3076 struct btrfs_root *orig_root,
3077 u64 num_bytes, u64 empty_size,
3078 u64 search_start, u64 search_end,
3079 u64 hint_byte, struct btrfs_key *ins,
3080 u64 exclude_start, u64 exclude_nr,
3081 int data)
3082 {
3083 int ret = 0;
3084 struct btrfs_root *root = orig_root->fs_info->extent_root;
3085 u64 total_needed = num_bytes;
3086 u64 *last_ptr = NULL;
3087 u64 last_wanted = 0;
3088 struct btrfs_block_group_cache *block_group = NULL;
3089 int chunk_alloc_done = 0;
3090 int empty_cluster = 2 * 1024 * 1024;
3091 int allowed_chunk_alloc = 0;
3092 struct list_head *head = NULL, *cur = NULL;
3093 int loop = 0;
3094 int extra_loop = 0;
3095 struct btrfs_space_info *space_info;
3096
3097 WARN_ON(num_bytes < root->sectorsize);
3098 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
3099 ins->objectid = 0;
3100 ins->offset = 0;
3101
3102 if (orig_root->ref_cows || empty_size)
3103 allowed_chunk_alloc = 1;
3104
3105 if (data & BTRFS_BLOCK_GROUP_METADATA) {
3106 last_ptr = &root->fs_info->last_alloc;
3107 if (!btrfs_test_opt(root, SSD))
3108 empty_cluster = 64 * 1024;
3109 }
3110
3111 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
3112 last_ptr = &root->fs_info->last_data_alloc;
3113
3114 if (last_ptr) {
3115 if (*last_ptr) {
3116 hint_byte = *last_ptr;
3117 last_wanted = *last_ptr;
3118 } else
3119 empty_size += empty_cluster;
3120 } else {
3121 empty_cluster = 0;
3122 }
3123 search_start = max(search_start, first_logical_byte(root, 0));
3124 search_start = max(search_start, hint_byte);
3125
3126 if (last_wanted && search_start != last_wanted) {
3127 last_wanted = 0;
3128 empty_size += empty_cluster;
3129 }
3130
3131 total_needed += empty_size;
3132 block_group = btrfs_lookup_block_group(root->fs_info, search_start);
3133 if (!block_group)
3134 block_group = btrfs_lookup_first_block_group(root->fs_info,
3135 search_start);
3136 space_info = __find_space_info(root->fs_info, data);
3137
3138 down_read(&space_info->groups_sem);
3139 while (1) {
3140 struct btrfs_free_space *free_space;
3141 /*
3142 * the only way this happens if our hint points to a block
3143 * group thats not of the proper type, while looping this
3144 * should never happen
3145 */
3146 if (empty_size)
3147 extra_loop = 1;
3148
3149 if (!block_group)
3150 goto new_group_no_lock;
3151
3152 if (unlikely(!block_group->cached)) {
3153 mutex_lock(&block_group->cache_mutex);
3154 ret = cache_block_group(root, block_group);
3155 mutex_unlock(&block_group->cache_mutex);
3156 if (ret)
3157 break;
3158 }
3159
3160 mutex_lock(&block_group->alloc_mutex);
3161 if (unlikely(!block_group_bits(block_group, data)))
3162 goto new_group;
3163
3164 if (unlikely(block_group->ro))
3165 goto new_group;
3166
3167 free_space = btrfs_find_free_space(block_group, search_start,
3168 total_needed);
3169 if (free_space) {
3170 u64 start = block_group->key.objectid;
3171 u64 end = block_group->key.objectid +
3172 block_group->key.offset;
3173
3174 search_start = stripe_align(root, free_space->offset);
3175
3176 /* move on to the next group */
3177 if (search_start + num_bytes >= search_end)
3178 goto new_group;
3179
3180 /* move on to the next group */
3181 if (search_start + num_bytes > end)
3182 goto new_group;
3183
3184 if (last_wanted && search_start != last_wanted) {
3185 total_needed += empty_cluster;
3186 empty_size += empty_cluster;
3187 last_wanted = 0;
3188 /*
3189 * if search_start is still in this block group
3190 * then we just re-search this block group
3191 */
3192 if (search_start >= start &&
3193 search_start < end) {
3194 mutex_unlock(&block_group->alloc_mutex);
3195 continue;
3196 }
3197
3198 /* else we go to the next block group */
3199 goto new_group;
3200 }
3201
3202 if (exclude_nr > 0 &&
3203 (search_start + num_bytes > exclude_start &&
3204 search_start < exclude_start + exclude_nr)) {
3205 search_start = exclude_start + exclude_nr;
3206 /*
3207 * if search_start is still in this block group
3208 * then we just re-search this block group
3209 */
3210 if (search_start >= start &&
3211 search_start < end) {
3212 mutex_unlock(&block_group->alloc_mutex);
3213 last_wanted = 0;
3214 continue;
3215 }
3216
3217 /* else we go to the next block group */
3218 goto new_group;
3219 }
3220
3221 ins->objectid = search_start;
3222 ins->offset = num_bytes;
3223
3224 btrfs_remove_free_space_lock(block_group, search_start,
3225 num_bytes);
3226 /* we are all good, lets return */
3227 mutex_unlock(&block_group->alloc_mutex);
3228 break;
3229 }
3230 new_group:
3231 mutex_unlock(&block_group->alloc_mutex);
3232 put_block_group(block_group);
3233 block_group = NULL;
3234 new_group_no_lock:
3235 /* don't try to compare new allocations against the
3236 * last allocation any more
3237 */
3238 last_wanted = 0;
3239
3240 /*
3241 * Here's how this works.
3242 * loop == 0: we were searching a block group via a hint
3243 * and didn't find anything, so we start at
3244 * the head of the block groups and keep searching
3245 * loop == 1: we're searching through all of the block groups
3246 * if we hit the head again we have searched
3247 * all of the block groups for this space and we
3248 * need to try and allocate, if we cant error out.
3249 * loop == 2: we allocated more space and are looping through
3250 * all of the block groups again.
3251 */
3252 if (loop == 0) {
3253 head = &space_info->block_groups;
3254 cur = head->next;
3255 loop++;
3256 } else if (loop == 1 && cur == head) {
3257 int keep_going;
3258
3259 /* at this point we give up on the empty_size
3260 * allocations and just try to allocate the min
3261 * space.
3262 *
3263 * The extra_loop field was set if an empty_size
3264 * allocation was attempted above, and if this
3265 * is try we need to try the loop again without
3266 * the additional empty_size.
3267 */
3268 total_needed -= empty_size;
3269 empty_size = 0;
3270 keep_going = extra_loop;
3271 loop++;
3272
3273 if (allowed_chunk_alloc && !chunk_alloc_done) {
3274 up_read(&space_info->groups_sem);
3275 ret = do_chunk_alloc(trans, root, num_bytes +
3276 2 * 1024 * 1024, data, 1);
3277 down_read(&space_info->groups_sem);
3278 if (ret < 0)
3279 goto loop_check;
3280 head = &space_info->block_groups;
3281 /*
3282 * we've allocated a new chunk, keep
3283 * trying
3284 */
3285 keep_going = 1;
3286 chunk_alloc_done = 1;
3287 } else if (!allowed_chunk_alloc) {
3288 space_info->force_alloc = 1;
3289 }
3290 loop_check:
3291 if (keep_going) {
3292 cur = head->next;
3293 extra_loop = 0;
3294 } else {
3295 break;
3296 }
3297 } else if (cur == head) {
3298 break;
3299 }
3300
3301 block_group = list_entry(cur, struct btrfs_block_group_cache,
3302 list);
3303 atomic_inc(&block_group->count);
3304
3305 search_start = block_group->key.objectid;
3306 cur = cur->next;
3307 }
3308
3309 /* we found what we needed */
3310 if (ins->objectid) {
3311 if (!(data & BTRFS_BLOCK_GROUP_DATA))
3312 trans->block_group = block_group->key.objectid;
3313
3314 if (last_ptr)
3315 *last_ptr = ins->objectid + ins->offset;
3316 ret = 0;
3317 } else if (!ret) {
3318 printk(KERN_ERR "btrfs searching for %llu bytes, "
3319 "num_bytes %llu, loop %d, allowed_alloc %d\n",
3320 (unsigned long long)total_needed,
3321 (unsigned long long)num_bytes,
3322 loop, allowed_chunk_alloc);
3323 ret = -ENOSPC;
3324 }
3325 if (block_group)
3326 put_block_group(block_group);
3327
3328 up_read(&space_info->groups_sem);
3329 return ret;
3330 }
3331
3332 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
3333 {
3334 struct btrfs_block_group_cache *cache;
3335
3336 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
3337 (unsigned long long)(info->total_bytes - info->bytes_used -
3338 info->bytes_pinned - info->bytes_reserved),
3339 (info->full) ? "" : "not ");
3340 printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu,"
3341 " may_use=%llu, used=%llu\n", info->total_bytes,
3342 info->bytes_pinned, info->bytes_delalloc, info->bytes_may_use,
3343 info->bytes_used);
3344
3345 down_read(&info->groups_sem);
3346 list_for_each_entry(cache, &info->block_groups, list) {
3347 spin_lock(&cache->lock);
3348 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
3349 "%llu pinned %llu reserved\n",
3350 (unsigned long long)cache->key.objectid,
3351 (unsigned long long)cache->key.offset,
3352 (unsigned long long)btrfs_block_group_used(&cache->item),
3353 (unsigned long long)cache->pinned,
3354 (unsigned long long)cache->reserved);
3355 btrfs_dump_free_space(cache, bytes);
3356 spin_unlock(&cache->lock);
3357 }
3358 up_read(&info->groups_sem);
3359 }
3360
3361 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
3362 struct btrfs_root *root,
3363 u64 num_bytes, u64 min_alloc_size,
3364 u64 empty_size, u64 hint_byte,
3365 u64 search_end, struct btrfs_key *ins,
3366 u64 data)
3367 {
3368 int ret;
3369 u64 search_start = 0;
3370 struct btrfs_fs_info *info = root->fs_info;
3371
3372 data = btrfs_get_alloc_profile(root, data);
3373 again:
3374 /*
3375 * the only place that sets empty_size is btrfs_realloc_node, which
3376 * is not called recursively on allocations
3377 */
3378 if (empty_size || root->ref_cows) {
3379 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
3380 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3381 2 * 1024 * 1024,
3382 BTRFS_BLOCK_GROUP_METADATA |
3383 (info->metadata_alloc_profile &
3384 info->avail_metadata_alloc_bits), 0);
3385 }
3386 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3387 num_bytes + 2 * 1024 * 1024, data, 0);
3388 }
3389
3390 WARN_ON(num_bytes < root->sectorsize);
3391 ret = find_free_extent(trans, root, num_bytes, empty_size,
3392 search_start, search_end, hint_byte, ins,
3393 trans->alloc_exclude_start,
3394 trans->alloc_exclude_nr, data);
3395
3396 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
3397 num_bytes = num_bytes >> 1;
3398 num_bytes = num_bytes & ~(root->sectorsize - 1);
3399 num_bytes = max(num_bytes, min_alloc_size);
3400 do_chunk_alloc(trans, root->fs_info->extent_root,
3401 num_bytes, data, 1);
3402 goto again;
3403 }
3404 if (ret) {
3405 struct btrfs_space_info *sinfo;
3406
3407 sinfo = __find_space_info(root->fs_info, data);
3408 printk(KERN_ERR "btrfs allocation failed flags %llu, "
3409 "wanted %llu\n", (unsigned long long)data,
3410 (unsigned long long)num_bytes);
3411 dump_space_info(sinfo, num_bytes);
3412 BUG();
3413 }
3414
3415 return ret;
3416 }
3417
3418 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
3419 {
3420 struct btrfs_block_group_cache *cache;
3421 int ret = 0;
3422
3423 cache = btrfs_lookup_block_group(root->fs_info, start);
3424 if (!cache) {
3425 printk(KERN_ERR "Unable to find block group for %llu\n",
3426 (unsigned long long)start);
3427 return -ENOSPC;
3428 }
3429
3430 ret = btrfs_discard_extent(root, start, len);
3431
3432 btrfs_add_free_space(cache, start, len);
3433 put_block_group(cache);
3434 update_reserved_extents(root, start, len, 0);
3435
3436 return ret;
3437 }
3438
3439 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
3440 struct btrfs_root *root,
3441 u64 num_bytes, u64 min_alloc_size,
3442 u64 empty_size, u64 hint_byte,
3443 u64 search_end, struct btrfs_key *ins,
3444 u64 data)
3445 {
3446 int ret;
3447 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
3448 empty_size, hint_byte, search_end, ins,
3449 data);
3450 update_reserved_extents(root, ins->objectid, ins->offset, 1);
3451 return ret;
3452 }
3453
3454 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
3455 struct btrfs_root *root, u64 parent,
3456 u64 root_objectid, u64 ref_generation,
3457 u64 owner, struct btrfs_key *ins)
3458 {
3459 int ret;
3460 int pending_ret;
3461 u64 super_used;
3462 u64 root_used;
3463 u64 num_bytes = ins->offset;
3464 u32 sizes[2];
3465 struct btrfs_fs_info *info = root->fs_info;
3466 struct btrfs_root *extent_root = info->extent_root;
3467 struct btrfs_extent_item *extent_item;
3468 struct btrfs_extent_ref *ref;
3469 struct btrfs_path *path;
3470 struct btrfs_key keys[2];
3471
3472 if (parent == 0)
3473 parent = ins->objectid;
3474
3475 /* block accounting for super block */
3476 spin_lock(&info->delalloc_lock);
3477 super_used = btrfs_super_bytes_used(&info->super_copy);
3478 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
3479
3480 /* block accounting for root item */
3481 root_used = btrfs_root_used(&root->root_item);
3482 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
3483 spin_unlock(&info->delalloc_lock);
3484
3485 if (root == extent_root) {
3486 struct pending_extent_op *extent_op;
3487
3488 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
3489 BUG_ON(!extent_op);
3490
3491 extent_op->type = PENDING_EXTENT_INSERT;
3492 extent_op->bytenr = ins->objectid;
3493 extent_op->num_bytes = ins->offset;
3494 extent_op->parent = parent;
3495 extent_op->orig_parent = 0;
3496 extent_op->generation = ref_generation;
3497 extent_op->orig_generation = 0;
3498 extent_op->level = (int)owner;
3499 INIT_LIST_HEAD(&extent_op->list);
3500 extent_op->del = 0;
3501
3502 mutex_lock(&root->fs_info->extent_ins_mutex);
3503 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
3504 ins->objectid + ins->offset - 1,
3505 EXTENT_WRITEBACK, GFP_NOFS);
3506 set_state_private(&root->fs_info->extent_ins,
3507 ins->objectid, (unsigned long)extent_op);
3508 mutex_unlock(&root->fs_info->extent_ins_mutex);
3509 goto update_block;
3510 }
3511
3512 memcpy(&keys[0], ins, sizeof(*ins));
3513 keys[1].objectid = ins->objectid;
3514 keys[1].type = BTRFS_EXTENT_REF_KEY;
3515 keys[1].offset = parent;
3516 sizes[0] = sizeof(*extent_item);
3517 sizes[1] = sizeof(*ref);
3518
3519 path = btrfs_alloc_path();
3520 BUG_ON(!path);
3521
3522 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
3523 sizes, 2);
3524 BUG_ON(ret);
3525
3526 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3527 struct btrfs_extent_item);
3528 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
3529 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
3530 struct btrfs_extent_ref);
3531
3532 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
3533 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
3534 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
3535 btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
3536
3537 btrfs_mark_buffer_dirty(path->nodes[0]);
3538
3539 trans->alloc_exclude_start = 0;
3540 trans->alloc_exclude_nr = 0;
3541 btrfs_free_path(path);
3542 finish_current_insert(trans, extent_root, 0);
3543 pending_ret = del_pending_extents(trans, extent_root, 0);
3544
3545 if (ret)
3546 goto out;
3547 if (pending_ret) {
3548 ret = pending_ret;
3549 goto out;
3550 }
3551
3552 update_block:
3553 ret = update_block_group(trans, root, ins->objectid,
3554 ins->offset, 1, 0);
3555 if (ret) {
3556 printk(KERN_ERR "btrfs update block group failed for %llu "
3557 "%llu\n", (unsigned long long)ins->objectid,
3558 (unsigned long long)ins->offset);
3559 BUG();
3560 }
3561 out:
3562 return ret;
3563 }
3564
3565 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
3566 struct btrfs_root *root, u64 parent,
3567 u64 root_objectid, u64 ref_generation,
3568 u64 owner, struct btrfs_key *ins)
3569 {
3570 int ret;
3571
3572 if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
3573 return 0;
3574 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
3575 ref_generation, owner, ins);
3576 update_reserved_extents(root, ins->objectid, ins->offset, 0);
3577 return ret;
3578 }
3579
3580 /*
3581 * this is used by the tree logging recovery code. It records that
3582 * an extent has been allocated and makes sure to clear the free
3583 * space cache bits as well
3584 */
3585 int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
3586 struct btrfs_root *root, u64 parent,
3587 u64 root_objectid, u64 ref_generation,
3588 u64 owner, struct btrfs_key *ins)
3589 {
3590 int ret;
3591 struct btrfs_block_group_cache *block_group;
3592
3593 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
3594 mutex_lock(&block_group->cache_mutex);
3595 cache_block_group(root, block_group);
3596 mutex_unlock(&block_group->cache_mutex);
3597
3598 ret = btrfs_remove_free_space(block_group, ins->objectid,
3599 ins->offset);
3600 BUG_ON(ret);
3601 put_block_group(block_group);
3602 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
3603 ref_generation, owner, ins);
3604 return ret;
3605 }
3606
3607 /*
3608 * finds a free extent and does all the dirty work required for allocation
3609 * returns the key for the extent through ins, and a tree buffer for
3610 * the first block of the extent through buf.
3611 *
3612 * returns 0 if everything worked, non-zero otherwise.
3613 */
3614 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
3615 struct btrfs_root *root,
3616 u64 num_bytes, u64 parent, u64 min_alloc_size,
3617 u64 root_objectid, u64 ref_generation,
3618 u64 owner_objectid, u64 empty_size, u64 hint_byte,
3619 u64 search_end, struct btrfs_key *ins, u64 data)
3620 {
3621 int ret;
3622
3623 ret = __btrfs_reserve_extent(trans, root, num_bytes,
3624 min_alloc_size, empty_size, hint_byte,
3625 search_end, ins, data);
3626 BUG_ON(ret);
3627 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
3628 ret = __btrfs_alloc_reserved_extent(trans, root, parent,
3629 root_objectid, ref_generation,
3630 owner_objectid, ins);
3631 BUG_ON(ret);
3632
3633 } else {
3634 update_reserved_extents(root, ins->objectid, ins->offset, 1);
3635 }
3636 return ret;
3637 }
3638
3639 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
3640 struct btrfs_root *root,
3641 u64 bytenr, u32 blocksize,
3642 int level)
3643 {
3644 struct extent_buffer *buf;
3645
3646 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
3647 if (!buf)
3648 return ERR_PTR(-ENOMEM);
3649 btrfs_set_header_generation(buf, trans->transid);
3650 btrfs_set_buffer_lockdep_class(buf, level);
3651 btrfs_tree_lock(buf);
3652 clean_tree_block(trans, root, buf);
3653
3654 btrfs_set_lock_blocking(buf);
3655 btrfs_set_buffer_uptodate(buf);
3656
3657 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
3658 set_extent_dirty(&root->dirty_log_pages, buf->start,
3659 buf->start + buf->len - 1, GFP_NOFS);
3660 } else {
3661 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
3662 buf->start + buf->len - 1, GFP_NOFS);
3663 }
3664 trans->blocks_used++;
3665 /* this returns a buffer locked for blocking */
3666 return buf;
3667 }
3668
3669 /*
3670 * helper function to allocate a block for a given tree
3671 * returns the tree buffer or NULL.
3672 */
3673 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
3674 struct btrfs_root *root,
3675 u32 blocksize, u64 parent,
3676 u64 root_objectid,
3677 u64 ref_generation,
3678 int level,
3679 u64 hint,
3680 u64 empty_size)
3681 {
3682 struct btrfs_key ins;
3683 int ret;
3684 struct extent_buffer *buf;
3685
3686 ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
3687 root_objectid, ref_generation, level,
3688 empty_size, hint, (u64)-1, &ins, 0);
3689 if (ret) {
3690 BUG_ON(ret > 0);
3691 return ERR_PTR(ret);
3692 }
3693
3694 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
3695 blocksize, level);
3696 return buf;
3697 }
3698
3699 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
3700 struct btrfs_root *root, struct extent_buffer *leaf)
3701 {
3702 u64 leaf_owner;
3703 u64 leaf_generation;
3704 struct refsort *sorted;
3705 struct btrfs_key key;
3706 struct btrfs_file_extent_item *fi;
3707 int i;
3708 int nritems;
3709 int ret;
3710 int refi = 0;
3711 int slot;
3712
3713 BUG_ON(!btrfs_is_leaf(leaf));
3714 nritems = btrfs_header_nritems(leaf);
3715 leaf_owner = btrfs_header_owner(leaf);
3716 leaf_generation = btrfs_header_generation(leaf);
3717
3718 sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
3719 /* we do this loop twice. The first time we build a list
3720 * of the extents we have a reference on, then we sort the list
3721 * by bytenr. The second time around we actually do the
3722 * extent freeing.
3723 */
3724 for (i = 0; i < nritems; i++) {
3725 u64 disk_bytenr;
3726 cond_resched();
3727
3728 btrfs_item_key_to_cpu(leaf, &key, i);
3729
3730 /* only extents have references, skip everything else */
3731 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
3732 continue;
3733
3734 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
3735
3736 /* inline extents live in the btree, they don't have refs */
3737 if (btrfs_file_extent_type(leaf, fi) ==
3738 BTRFS_FILE_EXTENT_INLINE)
3739 continue;
3740
3741 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
3742
3743 /* holes don't have refs */
3744 if (disk_bytenr == 0)
3745 continue;
3746
3747 sorted[refi].bytenr = disk_bytenr;
3748 sorted[refi].slot = i;
3749 refi++;
3750 }
3751
3752 if (refi == 0)
3753 goto out;
3754
3755 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
3756
3757 for (i = 0; i < refi; i++) {
3758 u64 disk_bytenr;
3759
3760 disk_bytenr = sorted[i].bytenr;
3761 slot = sorted[i].slot;
3762
3763 cond_resched();
3764
3765 btrfs_item_key_to_cpu(leaf, &key, slot);
3766 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
3767 continue;
3768
3769 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
3770
3771 ret = __btrfs_free_extent(trans, root, disk_bytenr,
3772 btrfs_file_extent_disk_num_bytes(leaf, fi),
3773 leaf->start, leaf_owner, leaf_generation,
3774 key.objectid, 0);
3775 BUG_ON(ret);
3776
3777 atomic_inc(&root->fs_info->throttle_gen);
3778 wake_up(&root->fs_info->transaction_throttle);
3779 cond_resched();
3780 }
3781 out:
3782 kfree(sorted);
3783 return 0;
3784 }
3785
3786 static noinline int cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
3787 struct btrfs_root *root,
3788 struct btrfs_leaf_ref *ref)
3789 {
3790 int i;
3791 int ret;
3792 struct btrfs_extent_info *info;
3793 struct refsort *sorted;
3794
3795 if (ref->nritems == 0)
3796 return 0;
3797
3798 sorted = kmalloc(sizeof(*sorted) * ref->nritems, GFP_NOFS);
3799 for (i = 0; i < ref->nritems; i++) {
3800 sorted[i].bytenr = ref->extents[i].bytenr;
3801 sorted[i].slot = i;
3802 }
3803 sort(sorted, ref->nritems, sizeof(struct refsort), refsort_cmp, NULL);
3804
3805 /*
3806 * the items in the ref were sorted when the ref was inserted
3807 * into the ref cache, so this is already in order
3808 */
3809 for (i = 0; i < ref->nritems; i++) {
3810 info = ref->extents + sorted[i].slot;
3811 ret = __btrfs_free_extent(trans, root, info->bytenr,
3812 info->num_bytes, ref->bytenr,
3813 ref->owner, ref->generation,
3814 info->objectid, 0);
3815
3816 atomic_inc(&root->fs_info->throttle_gen);
3817 wake_up(&root->fs_info->transaction_throttle);
3818 cond_resched();
3819
3820 BUG_ON(ret);
3821 info++;
3822 }
3823
3824 kfree(sorted);
3825 return 0;
3826 }
3827
3828 static int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start,
3829 u64 len, u32 *refs)
3830 {
3831 int ret;
3832
3833 ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
3834 BUG_ON(ret);
3835
3836 #if 0 /* some debugging code in case we see problems here */
3837 /* if the refs count is one, it won't get increased again. But
3838 * if the ref count is > 1, someone may be decreasing it at
3839 * the same time we are.
3840 */
3841 if (*refs != 1) {
3842 struct extent_buffer *eb = NULL;
3843 eb = btrfs_find_create_tree_block(root, start, len);
3844 if (eb)
3845 btrfs_tree_lock(eb);
3846
3847 mutex_lock(&root->fs_info->alloc_mutex);
3848 ret = lookup_extent_ref(NULL, root, start, len, refs);
3849 BUG_ON(ret);
3850 mutex_unlock(&root->fs_info->alloc_mutex);
3851
3852 if (eb) {
3853 btrfs_tree_unlock(eb);
3854 free_extent_buffer(eb);
3855 }
3856 if (*refs == 1) {
3857 printk(KERN_ERR "btrfs block %llu went down to one "
3858 "during drop_snap\n", (unsigned long long)start);
3859 }
3860
3861 }
3862 #endif
3863
3864 cond_resched();
3865 return ret;
3866 }
3867
3868 /*
3869 * this is used while deleting old snapshots, and it drops the refs
3870 * on a whole subtree starting from a level 1 node.
3871 *
3872 * The idea is to sort all the leaf pointers, and then drop the
3873 * ref on all the leaves in order. Most of the time the leaves
3874 * will have ref cache entries, so no leaf IOs will be required to
3875 * find the extents they have references on.
3876 *
3877 * For each leaf, any references it has are also dropped in order
3878 *
3879 * This ends up dropping the references in something close to optimal
3880 * order for reading and modifying the extent allocation tree.
3881 */
3882 static noinline int drop_level_one_refs(struct btrfs_trans_handle *trans,
3883 struct btrfs_root *root,
3884 struct btrfs_path *path)
3885 {
3886 u64 bytenr;
3887 u64 root_owner;
3888 u64 root_gen;
3889 struct extent_buffer *eb = path->nodes[1];
3890 struct extent_buffer *leaf;
3891 struct btrfs_leaf_ref *ref;
3892 struct refsort *sorted = NULL;
3893 int nritems = btrfs_header_nritems(eb);
3894 int ret;
3895 int i;
3896 int refi = 0;
3897 int slot = path->slots[1];
3898 u32 blocksize = btrfs_level_size(root, 0);
3899 u32 refs;
3900
3901 if (nritems == 0)
3902 goto out;
3903
3904 root_owner = btrfs_header_owner(eb);
3905 root_gen = btrfs_header_generation(eb);
3906 sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
3907
3908 /*
3909 * step one, sort all the leaf pointers so we don't scribble
3910 * randomly into the extent allocation tree
3911 */
3912 for (i = slot; i < nritems; i++) {
3913 sorted[refi].bytenr = btrfs_node_blockptr(eb, i);
3914 sorted[refi].slot = i;
3915 refi++;
3916 }
3917
3918 /*
3919 * nritems won't be zero, but if we're picking up drop_snapshot
3920 * after a crash, slot might be > 0, so double check things
3921 * just in case.
3922 */
3923 if (refi == 0)
3924 goto out;
3925
3926 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
3927
3928 /*
3929 * the first loop frees everything the leaves point to
3930 */
3931 for (i = 0; i < refi; i++) {
3932 u64 ptr_gen;
3933
3934 bytenr = sorted[i].bytenr;
3935
3936 /*
3937 * check the reference count on this leaf. If it is > 1
3938 * we just decrement it below and don't update any
3939 * of the refs the leaf points to.
3940 */
3941 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
3942 BUG_ON(ret);
3943 if (refs != 1)
3944 continue;
3945
3946 ptr_gen = btrfs_node_ptr_generation(eb, sorted[i].slot);
3947
3948 /*
3949 * the leaf only had one reference, which means the
3950 * only thing pointing to this leaf is the snapshot
3951 * we're deleting. It isn't possible for the reference
3952 * count to increase again later
3953 *
3954 * The reference cache is checked for the leaf,
3955 * and if found we'll be able to drop any refs held by
3956 * the leaf without needing to read it in.
3957 */
3958 ref = btrfs_lookup_leaf_ref(root, bytenr);
3959 if (ref && ref->generation != ptr_gen) {
3960 btrfs_free_leaf_ref(root, ref);
3961 ref = NULL;
3962 }
3963 if (ref) {
3964 ret = cache_drop_leaf_ref(trans, root, ref);
3965 BUG_ON(ret);
3966 btrfs_remove_leaf_ref(root, ref);
3967 btrfs_free_leaf_ref(root, ref);
3968 } else {
3969 /*
3970 * the leaf wasn't in the reference cache, so
3971 * we have to read it.
3972 */
3973 leaf = read_tree_block(root, bytenr, blocksize,
3974 ptr_gen);
3975 ret = btrfs_drop_leaf_ref(trans, root, leaf);
3976 BUG_ON(ret);
3977 free_extent_buffer(leaf);
3978 }
3979 atomic_inc(&root->fs_info->throttle_gen);
3980 wake_up(&root->fs_info->transaction_throttle);
3981 cond_resched();
3982 }
3983
3984 /*
3985 * run through the loop again to free the refs on the leaves.
3986 * This is faster than doing it in the loop above because
3987 * the leaves are likely to be clustered together. We end up
3988 * working in nice chunks on the extent allocation tree.
3989 */
3990 for (i = 0; i < refi; i++) {
3991 bytenr = sorted[i].bytenr;
3992 ret = __btrfs_free_extent(trans, root, bytenr,
3993 blocksize, eb->start,
3994 root_owner, root_gen, 0, 1);
3995 BUG_ON(ret);
3996
3997 atomic_inc(&root->fs_info->throttle_gen);
3998 wake_up(&root->fs_info->transaction_throttle);
3999 cond_resched();
4000 }
4001 out:
4002 kfree(sorted);
4003
4004 /*
4005 * update the path to show we've processed the entire level 1
4006 * node. This will get saved into the root's drop_snapshot_progress
4007 * field so these drops are not repeated again if this transaction
4008 * commits.
4009 */
4010 path->slots[1] = nritems;
4011 return 0;
4012 }
4013
4014 /*
4015 * helper function for drop_snapshot, this walks down the tree dropping ref
4016 * counts as it goes.
4017 */
4018 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
4019 struct btrfs_root *root,
4020 struct btrfs_path *path, int *level)
4021 {
4022 u64 root_owner;
4023 u64 root_gen;
4024 u64 bytenr;
4025 u64 ptr_gen;
4026 struct extent_buffer *next;
4027 struct extent_buffer *cur;
4028 struct extent_buffer *parent;
4029 u32 blocksize;
4030 int ret;
4031 u32 refs;
4032
4033 WARN_ON(*level < 0);
4034 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4035 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
4036 path->nodes[*level]->len, &refs);
4037 BUG_ON(ret);
4038 if (refs > 1)
4039 goto out;
4040
4041 /*
4042 * walk down to the last node level and free all the leaves
4043 */
4044 while (*level >= 0) {
4045 WARN_ON(*level < 0);
4046 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4047 cur = path->nodes[*level];
4048
4049 if (btrfs_header_level(cur) != *level)
4050 WARN_ON(1);
4051
4052 if (path->slots[*level] >=
4053 btrfs_header_nritems(cur))
4054 break;
4055
4056 /* the new code goes down to level 1 and does all the
4057 * leaves pointed to that node in bulk. So, this check
4058 * for level 0 will always be false.
4059 *
4060 * But, the disk format allows the drop_snapshot_progress
4061 * field in the root to leave things in a state where
4062 * a leaf will need cleaning up here. If someone crashes
4063 * with the old code and then boots with the new code,
4064 * we might find a leaf here.
4065 */
4066 if (*level == 0) {
4067 ret = btrfs_drop_leaf_ref(trans, root, cur);
4068 BUG_ON(ret);
4069 break;
4070 }
4071
4072 /*
4073 * once we get to level one, process the whole node
4074 * at once, including everything below it.
4075 */
4076 if (*level == 1) {
4077 ret = drop_level_one_refs(trans, root, path);
4078 BUG_ON(ret);
4079 break;
4080 }
4081
4082 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
4083 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
4084 blocksize = btrfs_level_size(root, *level - 1);
4085
4086 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
4087 BUG_ON(ret);
4088
4089 /*
4090 * if there is more than one reference, we don't need
4091 * to read that node to drop any references it has. We
4092 * just drop the ref we hold on that node and move on to the
4093 * next slot in this level.
4094 */
4095 if (refs != 1) {
4096 parent = path->nodes[*level];
4097 root_owner = btrfs_header_owner(parent);
4098 root_gen = btrfs_header_generation(parent);
4099 path->slots[*level]++;
4100
4101 ret = __btrfs_free_extent(trans, root, bytenr,
4102 blocksize, parent->start,
4103 root_owner, root_gen,
4104 *level - 1, 1);
4105 BUG_ON(ret);
4106
4107 atomic_inc(&root->fs_info->throttle_gen);
4108 wake_up(&root->fs_info->transaction_throttle);
4109 cond_resched();
4110
4111 continue;
4112 }
4113
4114 /*
4115 * we need to keep freeing things in the next level down.
4116 * read the block and loop around to process it
4117 */
4118 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
4119 WARN_ON(*level <= 0);
4120 if (path->nodes[*level-1])
4121 free_extent_buffer(path->nodes[*level-1]);
4122 path->nodes[*level-1] = next;
4123 *level = btrfs_header_level(next);
4124 path->slots[*level] = 0;
4125 cond_resched();
4126 }
4127 out:
4128 WARN_ON(*level < 0);
4129 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4130
4131 if (path->nodes[*level] == root->node) {
4132 parent = path->nodes[*level];
4133 bytenr = path->nodes[*level]->start;
4134 } else {
4135 parent = path->nodes[*level + 1];
4136 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
4137 }
4138
4139 blocksize = btrfs_level_size(root, *level);
4140 root_owner = btrfs_header_owner(parent);
4141 root_gen = btrfs_header_generation(parent);
4142
4143 /*
4144 * cleanup and free the reference on the last node
4145 * we processed
4146 */
4147 ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
4148 parent->start, root_owner, root_gen,
4149 *level, 1);
4150 free_extent_buffer(path->nodes[*level]);
4151 path->nodes[*level] = NULL;
4152
4153 *level += 1;
4154 BUG_ON(ret);
4155
4156 cond_resched();
4157 return 0;
4158 }
4159
4160 /*
4161 * helper function for drop_subtree, this function is similar to
4162 * walk_down_tree. The main difference is that it checks reference
4163 * counts while tree blocks are locked.
4164 */
4165 static noinline int walk_down_subtree(struct btrfs_trans_handle *trans,
4166 struct btrfs_root *root,
4167 struct btrfs_path *path, int *level)
4168 {
4169 struct extent_buffer *next;
4170 struct extent_buffer *cur;
4171 struct extent_buffer *parent;
4172 u64 bytenr;
4173 u64 ptr_gen;
4174 u32 blocksize;
4175 u32 refs;
4176 int ret;
4177
4178 cur = path->nodes[*level];
4179 ret = btrfs_lookup_extent_ref(trans, root, cur->start, cur->len,
4180 &refs);
4181 BUG_ON(ret);
4182 if (refs > 1)
4183 goto out;
4184
4185 while (*level >= 0) {
4186 cur = path->nodes[*level];
4187 if (*level == 0) {
4188 ret = btrfs_drop_leaf_ref(trans, root, cur);
4189 BUG_ON(ret);
4190 clean_tree_block(trans, root, cur);
4191 break;
4192 }
4193 if (path->slots[*level] >= btrfs_header_nritems(cur)) {
4194 clean_tree_block(trans, root, cur);
4195 break;
4196 }
4197
4198 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
4199 blocksize = btrfs_level_size(root, *level - 1);
4200 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
4201
4202 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
4203 btrfs_tree_lock(next);
4204 btrfs_set_lock_blocking(next);
4205
4206 ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize,
4207 &refs);
4208 BUG_ON(ret);
4209 if (refs > 1) {
4210 parent = path->nodes[*level];
4211 ret = btrfs_free_extent(trans, root, bytenr,
4212 blocksize, parent->start,
4213 btrfs_header_owner(parent),
4214 btrfs_header_generation(parent),
4215 *level - 1, 1);
4216 BUG_ON(ret);
4217 path->slots[*level]++;
4218 btrfs_tree_unlock(next);
4219 free_extent_buffer(next);
4220 continue;
4221 }
4222
4223 *level = btrfs_header_level(next);
4224 path->nodes[*level] = next;
4225 path->slots[*level] = 0;
4226 path->locks[*level] = 1;
4227 cond_resched();
4228 }
4229 out:
4230 parent = path->nodes[*level + 1];
4231 bytenr = path->nodes[*level]->start;
4232 blocksize = path->nodes[*level]->len;
4233
4234 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
4235 parent->start, btrfs_header_owner(parent),
4236 btrfs_header_generation(parent), *level, 1);
4237 BUG_ON(ret);
4238
4239 if (path->locks[*level]) {
4240 btrfs_tree_unlock(path->nodes[*level]);
4241 path->locks[*level] = 0;
4242 }
4243 free_extent_buffer(path->nodes[*level]);
4244 path->nodes[*level] = NULL;
4245 *level += 1;
4246 cond_resched();
4247 return 0;
4248 }
4249
4250 /*
4251 * helper for dropping snapshots. This walks back up the tree in the path
4252 * to find the first node higher up where we haven't yet gone through
4253 * all the slots
4254 */
4255 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
4256 struct btrfs_root *root,
4257 struct btrfs_path *path,
4258 int *level, int max_level)
4259 {
4260 u64 root_owner;
4261 u64 root_gen;
4262 struct btrfs_root_item *root_item = &root->root_item;
4263 int i;
4264 int slot;
4265 int ret;
4266
4267 for (i = *level; i < max_level && path->nodes[i]; i++) {
4268 slot = path->slots[i];
4269 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
4270 struct extent_buffer *node;
4271 struct btrfs_disk_key disk_key;
4272
4273 /*
4274 * there is more work to do in this level.
4275 * Update the drop_progress marker to reflect
4276 * the work we've done so far, and then bump
4277 * the slot number
4278 */
4279 node = path->nodes[i];
4280 path->slots[i]++;
4281 *level = i;
4282 WARN_ON(*level == 0);
4283 btrfs_node_key(node, &disk_key, path->slots[i]);
4284 memcpy(&root_item->drop_progress,
4285 &disk_key, sizeof(disk_key));
4286 root_item->drop_level = i;
4287 return 0;
4288 } else {
4289 struct extent_buffer *parent;
4290
4291 /*
4292 * this whole node is done, free our reference
4293 * on it and go up one level
4294 */
4295 if (path->nodes[*level] == root->node)
4296 parent = path->nodes[*level];
4297 else
4298 parent = path->nodes[*level + 1];
4299
4300 root_owner = btrfs_header_owner(parent);
4301 root_gen = btrfs_header_generation(parent);
4302
4303 clean_tree_block(trans, root, path->nodes[*level]);
4304 ret = btrfs_free_extent(trans, root,
4305 path->nodes[*level]->start,
4306 path->nodes[*level]->len,
4307 parent->start, root_owner,
4308 root_gen, *level, 1);
4309 BUG_ON(ret);
4310 if (path->locks[*level]) {
4311 btrfs_tree_unlock(path->nodes[*level]);
4312 path->locks[*level] = 0;
4313 }
4314 free_extent_buffer(path->nodes[*level]);
4315 path->nodes[*level] = NULL;
4316 *level = i + 1;
4317 }
4318 }
4319 return 1;
4320 }
4321
4322 /*
4323 * drop the reference count on the tree rooted at 'snap'. This traverses
4324 * the tree freeing any blocks that have a ref count of zero after being
4325 * decremented.
4326 */
4327 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
4328 *root)
4329 {
4330 int ret = 0;
4331 int wret;
4332 int level;
4333 struct btrfs_path *path;
4334 int i;
4335 int orig_level;
4336 struct btrfs_root_item *root_item = &root->root_item;
4337
4338 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
4339 path = btrfs_alloc_path();
4340 BUG_ON(!path);
4341
4342 level = btrfs_header_level(root->node);
4343 orig_level = level;
4344 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
4345 path->nodes[level] = root->node;
4346 extent_buffer_get(root->node);
4347 path->slots[level] = 0;
4348 } else {
4349 struct btrfs_key key;
4350 struct btrfs_disk_key found_key;
4351 struct extent_buffer *node;
4352
4353 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
4354 level = root_item->drop_level;
4355 path->lowest_level = level;
4356 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4357 if (wret < 0) {
4358 ret = wret;
4359 goto out;
4360 }
4361 node = path->nodes[level];
4362 btrfs_node_key(node, &found_key, path->slots[level]);
4363 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
4364 sizeof(found_key)));
4365 /*
4366 * unlock our path, this is safe because only this
4367 * function is allowed to delete this snapshot
4368 */
4369 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4370 if (path->nodes[i] && path->locks[i]) {
4371 path->locks[i] = 0;
4372 btrfs_tree_unlock(path->nodes[i]);
4373 }
4374 }
4375 }
4376 while (1) {
4377 wret = walk_down_tree(trans, root, path, &level);
4378 if (wret > 0)
4379 break;
4380 if (wret < 0)
4381 ret = wret;
4382
4383 wret = walk_up_tree(trans, root, path, &level,
4384 BTRFS_MAX_LEVEL);
4385 if (wret > 0)
4386 break;
4387 if (wret < 0)
4388 ret = wret;
4389 if (trans->transaction->in_commit) {
4390 ret = -EAGAIN;
4391 break;
4392 }
4393 atomic_inc(&root->fs_info->throttle_gen);
4394 wake_up(&root->fs_info->transaction_throttle);
4395 }
4396 for (i = 0; i <= orig_level; i++) {
4397 if (path->nodes[i]) {
4398 free_extent_buffer(path->nodes[i]);
4399 path->nodes[i] = NULL;
4400 }
4401 }
4402 out:
4403 btrfs_free_path(path);
4404 return ret;
4405 }
4406
4407 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
4408 struct btrfs_root *root,
4409 struct extent_buffer *node,
4410 struct extent_buffer *parent)
4411 {
4412 struct btrfs_path *path;
4413 int level;
4414 int parent_level;
4415 int ret = 0;
4416 int wret;
4417
4418 path = btrfs_alloc_path();
4419 BUG_ON(!path);
4420
4421 btrfs_assert_tree_locked(parent);
4422 parent_level = btrfs_header_level(parent);
4423 extent_buffer_get(parent);
4424 path->nodes[parent_level] = parent;
4425 path->slots[parent_level] = btrfs_header_nritems(parent);
4426
4427 btrfs_assert_tree_locked(node);
4428 level = btrfs_header_level(node);
4429 extent_buffer_get(node);
4430 path->nodes[level] = node;
4431 path->slots[level] = 0;
4432
4433 while (1) {
4434 wret = walk_down_subtree(trans, root, path, &level);
4435 if (wret < 0)
4436 ret = wret;
4437 if (wret != 0)
4438 break;
4439
4440 wret = walk_up_tree(trans, root, path, &level, parent_level);
4441 if (wret < 0)
4442 ret = wret;
4443 if (wret != 0)
4444 break;
4445 }
4446
4447 btrfs_free_path(path);
4448 return ret;
4449 }
4450
4451 static unsigned long calc_ra(unsigned long start, unsigned long last,
4452 unsigned long nr)
4453 {
4454 return min(last, start + nr - 1);
4455 }
4456
4457 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
4458 u64 len)
4459 {
4460 u64 page_start;
4461 u64 page_end;
4462 unsigned long first_index;
4463 unsigned long last_index;
4464 unsigned long i;
4465 struct page *page;
4466 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4467 struct file_ra_state *ra;
4468 struct btrfs_ordered_extent *ordered;
4469 unsigned int total_read = 0;
4470 unsigned int total_dirty = 0;
4471 int ret = 0;
4472
4473 ra = kzalloc(sizeof(*ra), GFP_NOFS);
4474
4475 mutex_lock(&inode->i_mutex);
4476 first_index = start >> PAGE_CACHE_SHIFT;
4477 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
4478
4479 /* make sure the dirty trick played by the caller work */
4480 ret = invalidate_inode_pages2_range(inode->i_mapping,
4481 first_index, last_index);
4482 if (ret)
4483 goto out_unlock;
4484
4485 file_ra_state_init(ra, inode->i_mapping);
4486
4487 for (i = first_index ; i <= last_index; i++) {
4488 if (total_read % ra->ra_pages == 0) {
4489 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
4490 calc_ra(i, last_index, ra->ra_pages));
4491 }
4492 total_read++;
4493 again:
4494 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
4495 BUG_ON(1);
4496 page = grab_cache_page(inode->i_mapping, i);
4497 if (!page) {
4498 ret = -ENOMEM;
4499 goto out_unlock;
4500 }
4501 if (!PageUptodate(page)) {
4502 btrfs_readpage(NULL, page);
4503 lock_page(page);
4504 if (!PageUptodate(page)) {
4505 unlock_page(page);
4506 page_cache_release(page);
4507 ret = -EIO;
4508 goto out_unlock;
4509 }
4510 }
4511 wait_on_page_writeback(page);
4512
4513 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
4514 page_end = page_start + PAGE_CACHE_SIZE - 1;
4515 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
4516
4517 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4518 if (ordered) {
4519 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
4520 unlock_page(page);
4521 page_cache_release(page);
4522 btrfs_start_ordered_extent(inode, ordered, 1);
4523 btrfs_put_ordered_extent(ordered);
4524 goto again;
4525 }
4526 set_page_extent_mapped(page);
4527
4528 if (i == first_index)
4529 set_extent_bits(io_tree, page_start, page_end,
4530 EXTENT_BOUNDARY, GFP_NOFS);
4531 btrfs_set_extent_delalloc(inode, page_start, page_end);
4532
4533 set_page_dirty(page);
4534 total_dirty++;
4535
4536 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
4537 unlock_page(page);
4538 page_cache_release(page);
4539 }
4540
4541 out_unlock:
4542 kfree(ra);
4543 mutex_unlock(&inode->i_mutex);
4544 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
4545 return ret;
4546 }
4547
4548 static noinline int relocate_data_extent(struct inode *reloc_inode,
4549 struct btrfs_key *extent_key,
4550 u64 offset)
4551 {
4552 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
4553 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
4554 struct extent_map *em;
4555 u64 start = extent_key->objectid - offset;
4556 u64 end = start + extent_key->offset - 1;
4557
4558 em = alloc_extent_map(GFP_NOFS);
4559 BUG_ON(!em || IS_ERR(em));
4560
4561 em->start = start;
4562 em->len = extent_key->offset;
4563 em->block_len = extent_key->offset;
4564 em->block_start = extent_key->objectid;
4565 em->bdev = root->fs_info->fs_devices->latest_bdev;
4566 set_bit(EXTENT_FLAG_PINNED, &em->flags);
4567
4568 /* setup extent map to cheat btrfs_readpage */
4569 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
4570 while (1) {
4571 int ret;
4572 spin_lock(&em_tree->lock);
4573 ret = add_extent_mapping(em_tree, em);
4574 spin_unlock(&em_tree->lock);
4575 if (ret != -EEXIST) {
4576 free_extent_map(em);
4577 break;
4578 }
4579 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
4580 }
4581 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
4582
4583 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
4584 }
4585
4586 struct btrfs_ref_path {
4587 u64 extent_start;
4588 u64 nodes[BTRFS_MAX_LEVEL];
4589 u64 root_objectid;
4590 u64 root_generation;
4591 u64 owner_objectid;
4592 u32 num_refs;
4593 int lowest_level;
4594 int current_level;
4595 int shared_level;
4596
4597 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
4598 u64 new_nodes[BTRFS_MAX_LEVEL];
4599 };
4600
4601 struct disk_extent {
4602 u64 ram_bytes;
4603 u64 disk_bytenr;
4604 u64 disk_num_bytes;
4605 u64 offset;
4606 u64 num_bytes;
4607 u8 compression;
4608 u8 encryption;
4609 u16 other_encoding;
4610 };
4611
4612 static int is_cowonly_root(u64 root_objectid)
4613 {
4614 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
4615 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
4616 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
4617 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
4618 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
4619 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
4620 return 1;
4621 return 0;
4622 }
4623
4624 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
4625 struct btrfs_root *extent_root,
4626 struct btrfs_ref_path *ref_path,
4627 int first_time)
4628 {
4629 struct extent_buffer *leaf;
4630 struct btrfs_path *path;
4631 struct btrfs_extent_ref *ref;
4632 struct btrfs_key key;
4633 struct btrfs_key found_key;
4634 u64 bytenr;
4635 u32 nritems;
4636 int level;
4637 int ret = 1;
4638
4639 path = btrfs_alloc_path();
4640 if (!path)
4641 return -ENOMEM;
4642
4643 if (first_time) {
4644 ref_path->lowest_level = -1;
4645 ref_path->current_level = -1;
4646 ref_path->shared_level = -1;
4647 goto walk_up;
4648 }
4649 walk_down:
4650 level = ref_path->current_level - 1;
4651 while (level >= -1) {
4652 u64 parent;
4653 if (level < ref_path->lowest_level)
4654 break;
4655
4656 if (level >= 0)
4657 bytenr = ref_path->nodes[level];
4658 else
4659 bytenr = ref_path->extent_start;
4660 BUG_ON(bytenr == 0);
4661
4662 parent = ref_path->nodes[level + 1];
4663 ref_path->nodes[level + 1] = 0;
4664 ref_path->current_level = level;
4665 BUG_ON(parent == 0);
4666
4667 key.objectid = bytenr;
4668 key.offset = parent + 1;
4669 key.type = BTRFS_EXTENT_REF_KEY;
4670
4671 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
4672 if (ret < 0)
4673 goto out;
4674 BUG_ON(ret == 0);
4675
4676 leaf = path->nodes[0];
4677 nritems = btrfs_header_nritems(leaf);
4678 if (path->slots[0] >= nritems) {
4679 ret = btrfs_next_leaf(extent_root, path);
4680 if (ret < 0)
4681 goto out;
4682 if (ret > 0)
4683 goto next;
4684 leaf = path->nodes[0];
4685 }
4686
4687 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4688 if (found_key.objectid == bytenr &&
4689 found_key.type == BTRFS_EXTENT_REF_KEY) {
4690 if (level < ref_path->shared_level)
4691 ref_path->shared_level = level;
4692 goto found;
4693 }
4694 next:
4695 level--;
4696 btrfs_release_path(extent_root, path);
4697 cond_resched();
4698 }
4699 /* reached lowest level */
4700 ret = 1;
4701 goto out;
4702 walk_up:
4703 level = ref_path->current_level;
4704 while (level < BTRFS_MAX_LEVEL - 1) {
4705 u64 ref_objectid;
4706
4707 if (level >= 0)
4708 bytenr = ref_path->nodes[level];
4709 else
4710 bytenr = ref_path->extent_start;
4711
4712 BUG_ON(bytenr == 0);
4713
4714 key.objectid = bytenr;
4715 key.offset = 0;
4716 key.type = BTRFS_EXTENT_REF_KEY;
4717
4718 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
4719 if (ret < 0)
4720 goto out;
4721
4722 leaf = path->nodes[0];
4723 nritems = btrfs_header_nritems(leaf);
4724 if (path->slots[0] >= nritems) {
4725 ret = btrfs_next_leaf(extent_root, path);
4726 if (ret < 0)
4727 goto out;
4728 if (ret > 0) {
4729 /* the extent was freed by someone */
4730 if (ref_path->lowest_level == level)
4731 goto out;
4732 btrfs_release_path(extent_root, path);
4733 goto walk_down;
4734 }
4735 leaf = path->nodes[0];
4736 }
4737
4738 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4739 if (found_key.objectid != bytenr ||
4740 found_key.type != BTRFS_EXTENT_REF_KEY) {
4741 /* the extent was freed by someone */
4742 if (ref_path->lowest_level == level) {
4743 ret = 1;
4744 goto out;
4745 }
4746 btrfs_release_path(extent_root, path);
4747 goto walk_down;
4748 }
4749 found:
4750 ref = btrfs_item_ptr(leaf, path->slots[0],
4751 struct btrfs_extent_ref);
4752 ref_objectid = btrfs_ref_objectid(leaf, ref);
4753 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
4754 if (first_time) {
4755 level = (int)ref_objectid;
4756 BUG_ON(level >= BTRFS_MAX_LEVEL);
4757 ref_path->lowest_level = level;
4758 ref_path->current_level = level;
4759 ref_path->nodes[level] = bytenr;
4760 } else {
4761 WARN_ON(ref_objectid != level);
4762 }
4763 } else {
4764 WARN_ON(level != -1);
4765 }
4766 first_time = 0;
4767
4768 if (ref_path->lowest_level == level) {
4769 ref_path->owner_objectid = ref_objectid;
4770 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
4771 }
4772
4773 /*
4774 * the block is tree root or the block isn't in reference
4775 * counted tree.
4776 */
4777 if (found_key.objectid == found_key.offset ||
4778 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
4779 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
4780 ref_path->root_generation =
4781 btrfs_ref_generation(leaf, ref);
4782 if (level < 0) {
4783 /* special reference from the tree log */
4784 ref_path->nodes[0] = found_key.offset;
4785 ref_path->current_level = 0;
4786 }
4787 ret = 0;
4788 goto out;
4789 }
4790
4791 level++;
4792 BUG_ON(ref_path->nodes[level] != 0);
4793 ref_path->nodes[level] = found_key.offset;
4794 ref_path->current_level = level;
4795
4796 /*
4797 * the reference was created in the running transaction,
4798 * no need to continue walking up.
4799 */
4800 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
4801 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
4802 ref_path->root_generation =
4803 btrfs_ref_generation(leaf, ref);
4804 ret = 0;
4805 goto out;
4806 }
4807
4808 btrfs_release_path(extent_root, path);
4809 cond_resched();
4810 }
4811 /* reached max tree level, but no tree root found. */
4812 BUG();
4813 out:
4814 btrfs_free_path(path);
4815 return ret;
4816 }
4817
4818 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
4819 struct btrfs_root *extent_root,
4820 struct btrfs_ref_path *ref_path,
4821 u64 extent_start)
4822 {
4823 memset(ref_path, 0, sizeof(*ref_path));
4824 ref_path->extent_start = extent_start;
4825
4826 return __next_ref_path(trans, extent_root, ref_path, 1);
4827 }
4828
4829 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
4830 struct btrfs_root *extent_root,
4831 struct btrfs_ref_path *ref_path)
4832 {
4833 return __next_ref_path(trans, extent_root, ref_path, 0);
4834 }
4835
4836 static noinline int get_new_locations(struct inode *reloc_inode,
4837 struct btrfs_key *extent_key,
4838 u64 offset, int no_fragment,
4839 struct disk_extent **extents,
4840 int *nr_extents)
4841 {
4842 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
4843 struct btrfs_path *path;
4844 struct btrfs_file_extent_item *fi;
4845 struct extent_buffer *leaf;
4846 struct disk_extent *exts = *extents;
4847 struct btrfs_key found_key;
4848 u64 cur_pos;
4849 u64 last_byte;
4850 u32 nritems;
4851 int nr = 0;
4852 int max = *nr_extents;
4853 int ret;
4854
4855 WARN_ON(!no_fragment && *extents);
4856 if (!exts) {
4857 max = 1;
4858 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
4859 if (!exts)
4860 return -ENOMEM;
4861 }
4862
4863 path = btrfs_alloc_path();
4864 BUG_ON(!path);
4865
4866 cur_pos = extent_key->objectid - offset;
4867 last_byte = extent_key->objectid + extent_key->offset;
4868 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
4869 cur_pos, 0);
4870 if (ret < 0)
4871 goto out;
4872 if (ret > 0) {
4873 ret = -ENOENT;
4874 goto out;
4875 }
4876
4877 while (1) {
4878 leaf = path->nodes[0];
4879 nritems = btrfs_header_nritems(leaf);
4880 if (path->slots[0] >= nritems) {
4881 ret = btrfs_next_leaf(root, path);
4882 if (ret < 0)
4883 goto out;
4884 if (ret > 0)
4885 break;
4886 leaf = path->nodes[0];
4887 }
4888
4889 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4890 if (found_key.offset != cur_pos ||
4891 found_key.type != BTRFS_EXTENT_DATA_KEY ||
4892 found_key.objectid != reloc_inode->i_ino)
4893 break;
4894
4895 fi = btrfs_item_ptr(leaf, path->slots[0],
4896 struct btrfs_file_extent_item);
4897 if (btrfs_file_extent_type(leaf, fi) !=
4898 BTRFS_FILE_EXTENT_REG ||
4899 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
4900 break;
4901
4902 if (nr == max) {
4903 struct disk_extent *old = exts;
4904 max *= 2;
4905 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
4906 memcpy(exts, old, sizeof(*exts) * nr);
4907 if (old != *extents)
4908 kfree(old);
4909 }
4910
4911 exts[nr].disk_bytenr =
4912 btrfs_file_extent_disk_bytenr(leaf, fi);
4913 exts[nr].disk_num_bytes =
4914 btrfs_file_extent_disk_num_bytes(leaf, fi);
4915 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
4916 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4917 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
4918 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
4919 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
4920 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
4921 fi);
4922 BUG_ON(exts[nr].offset > 0);
4923 BUG_ON(exts[nr].compression || exts[nr].encryption);
4924 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
4925
4926 cur_pos += exts[nr].num_bytes;
4927 nr++;
4928
4929 if (cur_pos + offset >= last_byte)
4930 break;
4931
4932 if (no_fragment) {
4933 ret = 1;
4934 goto out;
4935 }
4936 path->slots[0]++;
4937 }
4938
4939 BUG_ON(cur_pos + offset > last_byte);
4940 if (cur_pos + offset < last_byte) {
4941 ret = -ENOENT;
4942 goto out;
4943 }
4944 ret = 0;
4945 out:
4946 btrfs_free_path(path);
4947 if (ret) {
4948 if (exts != *extents)
4949 kfree(exts);
4950 } else {
4951 *extents = exts;
4952 *nr_extents = nr;
4953 }
4954 return ret;
4955 }
4956
4957 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
4958 struct btrfs_root *root,
4959 struct btrfs_path *path,
4960 struct btrfs_key *extent_key,
4961 struct btrfs_key *leaf_key,
4962 struct btrfs_ref_path *ref_path,
4963 struct disk_extent *new_extents,
4964 int nr_extents)
4965 {
4966 struct extent_buffer *leaf;
4967 struct btrfs_file_extent_item *fi;
4968 struct inode *inode = NULL;
4969 struct btrfs_key key;
4970 u64 lock_start = 0;
4971 u64 lock_end = 0;
4972 u64 num_bytes;
4973 u64 ext_offset;
4974 u64 search_end = (u64)-1;
4975 u32 nritems;
4976 int nr_scaned = 0;
4977 int extent_locked = 0;
4978 int extent_type;
4979 int ret;
4980
4981 memcpy(&key, leaf_key, sizeof(key));
4982 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
4983 if (key.objectid < ref_path->owner_objectid ||
4984 (key.objectid == ref_path->owner_objectid &&
4985 key.type < BTRFS_EXTENT_DATA_KEY)) {
4986 key.objectid = ref_path->owner_objectid;
4987 key.type = BTRFS_EXTENT_DATA_KEY;
4988 key.offset = 0;
4989 }
4990 }
4991
4992 while (1) {
4993 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
4994 if (ret < 0)
4995 goto out;
4996
4997 leaf = path->nodes[0];
4998 nritems = btrfs_header_nritems(leaf);
4999 next:
5000 if (extent_locked && ret > 0) {
5001 /*
5002 * the file extent item was modified by someone
5003 * before the extent got locked.
5004 */
5005 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5006 lock_end, GFP_NOFS);
5007 extent_locked = 0;
5008 }
5009
5010 if (path->slots[0] >= nritems) {
5011 if (++nr_scaned > 2)
5012 break;
5013
5014 BUG_ON(extent_locked);
5015 ret = btrfs_next_leaf(root, path);
5016 if (ret < 0)
5017 goto out;
5018 if (ret > 0)
5019 break;
5020 leaf = path->nodes[0];
5021 nritems = btrfs_header_nritems(leaf);
5022 }
5023
5024 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
5025
5026 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
5027 if ((key.objectid > ref_path->owner_objectid) ||
5028 (key.objectid == ref_path->owner_objectid &&
5029 key.type > BTRFS_EXTENT_DATA_KEY) ||
5030 key.offset >= search_end)
5031 break;
5032 }
5033
5034 if (inode && key.objectid != inode->i_ino) {
5035 BUG_ON(extent_locked);
5036 btrfs_release_path(root, path);
5037 mutex_unlock(&inode->i_mutex);
5038 iput(inode);
5039 inode = NULL;
5040 continue;
5041 }
5042
5043 if (key.type != BTRFS_EXTENT_DATA_KEY) {
5044 path->slots[0]++;
5045 ret = 1;
5046 goto next;
5047 }
5048 fi = btrfs_item_ptr(leaf, path->slots[0],
5049 struct btrfs_file_extent_item);
5050 extent_type = btrfs_file_extent_type(leaf, fi);
5051 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
5052 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
5053 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
5054 extent_key->objectid)) {
5055 path->slots[0]++;
5056 ret = 1;
5057 goto next;
5058 }
5059
5060 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5061 ext_offset = btrfs_file_extent_offset(leaf, fi);
5062
5063 if (search_end == (u64)-1) {
5064 search_end = key.offset - ext_offset +
5065 btrfs_file_extent_ram_bytes(leaf, fi);
5066 }
5067
5068 if (!extent_locked) {
5069 lock_start = key.offset;
5070 lock_end = lock_start + num_bytes - 1;
5071 } else {
5072 if (lock_start > key.offset ||
5073 lock_end + 1 < key.offset + num_bytes) {
5074 unlock_extent(&BTRFS_I(inode)->io_tree,
5075 lock_start, lock_end, GFP_NOFS);
5076 extent_locked = 0;
5077 }
5078 }
5079
5080 if (!inode) {
5081 btrfs_release_path(root, path);
5082
5083 inode = btrfs_iget_locked(root->fs_info->sb,
5084 key.objectid, root);
5085 if (inode->i_state & I_NEW) {
5086 BTRFS_I(inode)->root = root;
5087 BTRFS_I(inode)->location.objectid =
5088 key.objectid;
5089 BTRFS_I(inode)->location.type =
5090 BTRFS_INODE_ITEM_KEY;
5091 BTRFS_I(inode)->location.offset = 0;
5092 btrfs_read_locked_inode(inode);
5093 unlock_new_inode(inode);
5094 }
5095 /*
5096 * some code call btrfs_commit_transaction while
5097 * holding the i_mutex, so we can't use mutex_lock
5098 * here.
5099 */
5100 if (is_bad_inode(inode) ||
5101 !mutex_trylock(&inode->i_mutex)) {
5102 iput(inode);
5103 inode = NULL;
5104 key.offset = (u64)-1;
5105 goto skip;
5106 }
5107 }
5108
5109 if (!extent_locked) {
5110 struct btrfs_ordered_extent *ordered;
5111
5112 btrfs_release_path(root, path);
5113
5114 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5115 lock_end, GFP_NOFS);
5116 ordered = btrfs_lookup_first_ordered_extent(inode,
5117 lock_end);
5118 if (ordered &&
5119 ordered->file_offset <= lock_end &&
5120 ordered->file_offset + ordered->len > lock_start) {
5121 unlock_extent(&BTRFS_I(inode)->io_tree,
5122 lock_start, lock_end, GFP_NOFS);
5123 btrfs_start_ordered_extent(inode, ordered, 1);
5124 btrfs_put_ordered_extent(ordered);
5125 key.offset += num_bytes;
5126 goto skip;
5127 }
5128 if (ordered)
5129 btrfs_put_ordered_extent(ordered);
5130
5131 extent_locked = 1;
5132 continue;
5133 }
5134
5135 if (nr_extents == 1) {
5136 /* update extent pointer in place */
5137 btrfs_set_file_extent_disk_bytenr(leaf, fi,
5138 new_extents[0].disk_bytenr);
5139 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
5140 new_extents[0].disk_num_bytes);
5141 btrfs_mark_buffer_dirty(leaf);
5142
5143 btrfs_drop_extent_cache(inode, key.offset,
5144 key.offset + num_bytes - 1, 0);
5145
5146 ret = btrfs_inc_extent_ref(trans, root,
5147 new_extents[0].disk_bytenr,
5148 new_extents[0].disk_num_bytes,
5149 leaf->start,
5150 root->root_key.objectid,
5151 trans->transid,
5152 key.objectid);
5153 BUG_ON(ret);
5154
5155 ret = btrfs_free_extent(trans, root,
5156 extent_key->objectid,
5157 extent_key->offset,
5158 leaf->start,
5159 btrfs_header_owner(leaf),
5160 btrfs_header_generation(leaf),
5161 key.objectid, 0);
5162 BUG_ON(ret);
5163
5164 btrfs_release_path(root, path);
5165 key.offset += num_bytes;
5166 } else {
5167 BUG_ON(1);
5168 #if 0
5169 u64 alloc_hint;
5170 u64 extent_len;
5171 int i;
5172 /*
5173 * drop old extent pointer at first, then insert the
5174 * new pointers one bye one
5175 */
5176 btrfs_release_path(root, path);
5177 ret = btrfs_drop_extents(trans, root, inode, key.offset,
5178 key.offset + num_bytes,
5179 key.offset, &alloc_hint);
5180 BUG_ON(ret);
5181
5182 for (i = 0; i < nr_extents; i++) {
5183 if (ext_offset >= new_extents[i].num_bytes) {
5184 ext_offset -= new_extents[i].num_bytes;
5185 continue;
5186 }
5187 extent_len = min(new_extents[i].num_bytes -
5188 ext_offset, num_bytes);
5189
5190 ret = btrfs_insert_empty_item(trans, root,
5191 path, &key,
5192 sizeof(*fi));
5193 BUG_ON(ret);
5194
5195 leaf = path->nodes[0];
5196 fi = btrfs_item_ptr(leaf, path->slots[0],
5197 struct btrfs_file_extent_item);
5198 btrfs_set_file_extent_generation(leaf, fi,
5199 trans->transid);
5200 btrfs_set_file_extent_type(leaf, fi,
5201 BTRFS_FILE_EXTENT_REG);
5202 btrfs_set_file_extent_disk_bytenr(leaf, fi,
5203 new_extents[i].disk_bytenr);
5204 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
5205 new_extents[i].disk_num_bytes);
5206 btrfs_set_file_extent_ram_bytes(leaf, fi,
5207 new_extents[i].ram_bytes);
5208
5209 btrfs_set_file_extent_compression(leaf, fi,
5210 new_extents[i].compression);
5211 btrfs_set_file_extent_encryption(leaf, fi,
5212 new_extents[i].encryption);
5213 btrfs_set_file_extent_other_encoding(leaf, fi,
5214 new_extents[i].other_encoding);
5215
5216 btrfs_set_file_extent_num_bytes(leaf, fi,
5217 extent_len);
5218 ext_offset += new_extents[i].offset;
5219 btrfs_set_file_extent_offset(leaf, fi,
5220 ext_offset);
5221 btrfs_mark_buffer_dirty(leaf);
5222
5223 btrfs_drop_extent_cache(inode, key.offset,
5224 key.offset + extent_len - 1, 0);
5225
5226 ret = btrfs_inc_extent_ref(trans, root,
5227 new_extents[i].disk_bytenr,
5228 new_extents[i].disk_num_bytes,
5229 leaf->start,
5230 root->root_key.objectid,
5231 trans->transid, key.objectid);
5232 BUG_ON(ret);
5233 btrfs_release_path(root, path);
5234
5235 inode_add_bytes(inode, extent_len);
5236
5237 ext_offset = 0;
5238 num_bytes -= extent_len;
5239 key.offset += extent_len;
5240
5241 if (num_bytes == 0)
5242 break;
5243 }
5244 BUG_ON(i >= nr_extents);
5245 #endif
5246 }
5247
5248 if (extent_locked) {
5249 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5250 lock_end, GFP_NOFS);
5251 extent_locked = 0;
5252 }
5253 skip:
5254 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
5255 key.offset >= search_end)
5256 break;
5257
5258 cond_resched();
5259 }
5260 ret = 0;
5261 out:
5262 btrfs_release_path(root, path);
5263 if (inode) {
5264 mutex_unlock(&inode->i_mutex);
5265 if (extent_locked) {
5266 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5267 lock_end, GFP_NOFS);
5268 }
5269 iput(inode);
5270 }
5271 return ret;
5272 }
5273
5274 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
5275 struct btrfs_root *root,
5276 struct extent_buffer *buf, u64 orig_start)
5277 {
5278 int level;
5279 int ret;
5280
5281 BUG_ON(btrfs_header_generation(buf) != trans->transid);
5282 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5283
5284 level = btrfs_header_level(buf);
5285 if (level == 0) {
5286 struct btrfs_leaf_ref *ref;
5287 struct btrfs_leaf_ref *orig_ref;
5288
5289 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
5290 if (!orig_ref)
5291 return -ENOENT;
5292
5293 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
5294 if (!ref) {
5295 btrfs_free_leaf_ref(root, orig_ref);
5296 return -ENOMEM;
5297 }
5298
5299 ref->nritems = orig_ref->nritems;
5300 memcpy(ref->extents, orig_ref->extents,
5301 sizeof(ref->extents[0]) * ref->nritems);
5302
5303 btrfs_free_leaf_ref(root, orig_ref);
5304
5305 ref->root_gen = trans->transid;
5306 ref->bytenr = buf->start;
5307 ref->owner = btrfs_header_owner(buf);
5308 ref->generation = btrfs_header_generation(buf);
5309
5310 ret = btrfs_add_leaf_ref(root, ref, 0);
5311 WARN_ON(ret);
5312 btrfs_free_leaf_ref(root, ref);
5313 }
5314 return 0;
5315 }
5316
5317 static noinline int invalidate_extent_cache(struct btrfs_root *root,
5318 struct extent_buffer *leaf,
5319 struct btrfs_block_group_cache *group,
5320 struct btrfs_root *target_root)
5321 {
5322 struct btrfs_key key;
5323 struct inode *inode = NULL;
5324 struct btrfs_file_extent_item *fi;
5325 u64 num_bytes;
5326 u64 skip_objectid = 0;
5327 u32 nritems;
5328 u32 i;
5329
5330 nritems = btrfs_header_nritems(leaf);
5331 for (i = 0; i < nritems; i++) {
5332 btrfs_item_key_to_cpu(leaf, &key, i);
5333 if (key.objectid == skip_objectid ||
5334 key.type != BTRFS_EXTENT_DATA_KEY)
5335 continue;
5336 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
5337 if (btrfs_file_extent_type(leaf, fi) ==
5338 BTRFS_FILE_EXTENT_INLINE)
5339 continue;
5340 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
5341 continue;
5342 if (!inode || inode->i_ino != key.objectid) {
5343 iput(inode);
5344 inode = btrfs_ilookup(target_root->fs_info->sb,
5345 key.objectid, target_root, 1);
5346 }
5347 if (!inode) {
5348 skip_objectid = key.objectid;
5349 continue;
5350 }
5351 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5352
5353 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
5354 key.offset + num_bytes - 1, GFP_NOFS);
5355 btrfs_drop_extent_cache(inode, key.offset,
5356 key.offset + num_bytes - 1, 1);
5357 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
5358 key.offset + num_bytes - 1, GFP_NOFS);
5359 cond_resched();
5360 }
5361 iput(inode);
5362 return 0;
5363 }
5364
5365 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
5366 struct btrfs_root *root,
5367 struct extent_buffer *leaf,
5368 struct btrfs_block_group_cache *group,
5369 struct inode *reloc_inode)
5370 {
5371 struct btrfs_key key;
5372 struct btrfs_key extent_key;
5373 struct btrfs_file_extent_item *fi;
5374 struct btrfs_leaf_ref *ref;
5375 struct disk_extent *new_extent;
5376 u64 bytenr;
5377 u64 num_bytes;
5378 u32 nritems;
5379 u32 i;
5380 int ext_index;
5381 int nr_extent;
5382 int ret;
5383
5384 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
5385 BUG_ON(!new_extent);
5386
5387 ref = btrfs_lookup_leaf_ref(root, leaf->start);
5388 BUG_ON(!ref);
5389
5390 ext_index = -1;
5391 nritems = btrfs_header_nritems(leaf);
5392 for (i = 0; i < nritems; i++) {
5393 btrfs_item_key_to_cpu(leaf, &key, i);
5394 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
5395 continue;
5396 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
5397 if (btrfs_file_extent_type(leaf, fi) ==
5398 BTRFS_FILE_EXTENT_INLINE)
5399 continue;
5400 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
5401 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
5402 if (bytenr == 0)
5403 continue;
5404
5405 ext_index++;
5406 if (bytenr >= group->key.objectid + group->key.offset ||
5407 bytenr + num_bytes <= group->key.objectid)
5408 continue;
5409
5410 extent_key.objectid = bytenr;
5411 extent_key.offset = num_bytes;
5412 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
5413 nr_extent = 1;
5414 ret = get_new_locations(reloc_inode, &extent_key,
5415 group->key.objectid, 1,
5416 &new_extent, &nr_extent);
5417 if (ret > 0)
5418 continue;
5419 BUG_ON(ret < 0);
5420
5421 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
5422 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
5423 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
5424 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
5425
5426 btrfs_set_file_extent_disk_bytenr(leaf, fi,
5427 new_extent->disk_bytenr);
5428 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
5429 new_extent->disk_num_bytes);
5430 btrfs_mark_buffer_dirty(leaf);
5431
5432 ret = btrfs_inc_extent_ref(trans, root,
5433 new_extent->disk_bytenr,
5434 new_extent->disk_num_bytes,
5435 leaf->start,
5436 root->root_key.objectid,
5437 trans->transid, key.objectid);
5438 BUG_ON(ret);
5439 ret = btrfs_free_extent(trans, root,
5440 bytenr, num_bytes, leaf->start,
5441 btrfs_header_owner(leaf),
5442 btrfs_header_generation(leaf),
5443 key.objectid, 0);
5444 BUG_ON(ret);
5445 cond_resched();
5446 }
5447 kfree(new_extent);
5448 BUG_ON(ext_index + 1 != ref->nritems);
5449 btrfs_free_leaf_ref(root, ref);
5450 return 0;
5451 }
5452
5453 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
5454 struct btrfs_root *root)
5455 {
5456 struct btrfs_root *reloc_root;
5457 int ret;
5458
5459 if (root->reloc_root) {
5460 reloc_root = root->reloc_root;
5461 root->reloc_root = NULL;
5462 list_add(&reloc_root->dead_list,
5463 &root->fs_info->dead_reloc_roots);
5464
5465 btrfs_set_root_bytenr(&reloc_root->root_item,
5466 reloc_root->node->start);
5467 btrfs_set_root_level(&root->root_item,
5468 btrfs_header_level(reloc_root->node));
5469 memset(&reloc_root->root_item.drop_progress, 0,
5470 sizeof(struct btrfs_disk_key));
5471 reloc_root->root_item.drop_level = 0;
5472
5473 ret = btrfs_update_root(trans, root->fs_info->tree_root,
5474 &reloc_root->root_key,
5475 &reloc_root->root_item);
5476 BUG_ON(ret);
5477 }
5478 return 0;
5479 }
5480
5481 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
5482 {
5483 struct btrfs_trans_handle *trans;
5484 struct btrfs_root *reloc_root;
5485 struct btrfs_root *prev_root = NULL;
5486 struct list_head dead_roots;
5487 int ret;
5488 unsigned long nr;
5489
5490 INIT_LIST_HEAD(&dead_roots);
5491 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
5492
5493 while (!list_empty(&dead_roots)) {
5494 reloc_root = list_entry(dead_roots.prev,
5495 struct btrfs_root, dead_list);
5496 list_del_init(&reloc_root->dead_list);
5497
5498 BUG_ON(reloc_root->commit_root != NULL);
5499 while (1) {
5500 trans = btrfs_join_transaction(root, 1);
5501 BUG_ON(!trans);
5502
5503 mutex_lock(&root->fs_info->drop_mutex);
5504 ret = btrfs_drop_snapshot(trans, reloc_root);
5505 if (ret != -EAGAIN)
5506 break;
5507 mutex_unlock(&root->fs_info->drop_mutex);
5508
5509 nr = trans->blocks_used;
5510 ret = btrfs_end_transaction(trans, root);
5511 BUG_ON(ret);
5512 btrfs_btree_balance_dirty(root, nr);
5513 }
5514
5515 free_extent_buffer(reloc_root->node);
5516
5517 ret = btrfs_del_root(trans, root->fs_info->tree_root,
5518 &reloc_root->root_key);
5519 BUG_ON(ret);
5520 mutex_unlock(&root->fs_info->drop_mutex);
5521
5522 nr = trans->blocks_used;
5523 ret = btrfs_end_transaction(trans, root);
5524 BUG_ON(ret);
5525 btrfs_btree_balance_dirty(root, nr);
5526
5527 kfree(prev_root);
5528 prev_root = reloc_root;
5529 }
5530 if (prev_root) {
5531 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
5532 kfree(prev_root);
5533 }
5534 return 0;
5535 }
5536
5537 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
5538 {
5539 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
5540 return 0;
5541 }
5542
5543 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
5544 {
5545 struct btrfs_root *reloc_root;
5546 struct btrfs_trans_handle *trans;
5547 struct btrfs_key location;
5548 int found;
5549 int ret;
5550
5551 mutex_lock(&root->fs_info->tree_reloc_mutex);
5552 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
5553 BUG_ON(ret);
5554 found = !list_empty(&root->fs_info->dead_reloc_roots);
5555 mutex_unlock(&root->fs_info->tree_reloc_mutex);
5556
5557 if (found) {
5558 trans = btrfs_start_transaction(root, 1);
5559 BUG_ON(!trans);
5560 ret = btrfs_commit_transaction(trans, root);
5561 BUG_ON(ret);
5562 }
5563
5564 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
5565 location.offset = (u64)-1;
5566 location.type = BTRFS_ROOT_ITEM_KEY;
5567
5568 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
5569 BUG_ON(!reloc_root);
5570 btrfs_orphan_cleanup(reloc_root);
5571 return 0;
5572 }
5573
5574 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
5575 struct btrfs_root *root)
5576 {
5577 struct btrfs_root *reloc_root;
5578 struct extent_buffer *eb;
5579 struct btrfs_root_item *root_item;
5580 struct btrfs_key root_key;
5581 int ret;
5582
5583 BUG_ON(!root->ref_cows);
5584 if (root->reloc_root)
5585 return 0;
5586
5587 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
5588 BUG_ON(!root_item);
5589
5590 ret = btrfs_copy_root(trans, root, root->commit_root,
5591 &eb, BTRFS_TREE_RELOC_OBJECTID);
5592 BUG_ON(ret);
5593
5594 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
5595 root_key.offset = root->root_key.objectid;
5596 root_key.type = BTRFS_ROOT_ITEM_KEY;
5597
5598 memcpy(root_item, &root->root_item, sizeof(root_item));
5599 btrfs_set_root_refs(root_item, 0);
5600 btrfs_set_root_bytenr(root_item, eb->start);
5601 btrfs_set_root_level(root_item, btrfs_header_level(eb));
5602 btrfs_set_root_generation(root_item, trans->transid);
5603
5604 btrfs_tree_unlock(eb);
5605 free_extent_buffer(eb);
5606
5607 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
5608 &root_key, root_item);
5609 BUG_ON(ret);
5610 kfree(root_item);
5611
5612 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
5613 &root_key);
5614 BUG_ON(!reloc_root);
5615 reloc_root->last_trans = trans->transid;
5616 reloc_root->commit_root = NULL;
5617 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
5618
5619 root->reloc_root = reloc_root;
5620 return 0;
5621 }
5622
5623 /*
5624 * Core function of space balance.
5625 *
5626 * The idea is using reloc trees to relocate tree blocks in reference
5627 * counted roots. There is one reloc tree for each subvol, and all
5628 * reloc trees share same root key objectid. Reloc trees are snapshots
5629 * of the latest committed roots of subvols (root->commit_root).
5630 *
5631 * To relocate a tree block referenced by a subvol, there are two steps.
5632 * COW the block through subvol's reloc tree, then update block pointer
5633 * in the subvol to point to the new block. Since all reloc trees share
5634 * same root key objectid, doing special handing for tree blocks owned
5635 * by them is easy. Once a tree block has been COWed in one reloc tree,
5636 * we can use the resulting new block directly when the same block is
5637 * required to COW again through other reloc trees. By this way, relocated
5638 * tree blocks are shared between reloc trees, so they are also shared
5639 * between subvols.
5640 */
5641 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
5642 struct btrfs_root *root,
5643 struct btrfs_path *path,
5644 struct btrfs_key *first_key,
5645 struct btrfs_ref_path *ref_path,
5646 struct btrfs_block_group_cache *group,
5647 struct inode *reloc_inode)
5648 {
5649 struct btrfs_root *reloc_root;
5650 struct extent_buffer *eb = NULL;
5651 struct btrfs_key *keys;
5652 u64 *nodes;
5653 int level;
5654 int shared_level;
5655 int lowest_level = 0;
5656 int ret;
5657
5658 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
5659 lowest_level = ref_path->owner_objectid;
5660
5661 if (!root->ref_cows) {
5662 path->lowest_level = lowest_level;
5663 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
5664 BUG_ON(ret < 0);
5665 path->lowest_level = 0;
5666 btrfs_release_path(root, path);
5667 return 0;
5668 }
5669
5670 mutex_lock(&root->fs_info->tree_reloc_mutex);
5671 ret = init_reloc_tree(trans, root);
5672 BUG_ON(ret);
5673 reloc_root = root->reloc_root;
5674
5675 shared_level = ref_path->shared_level;
5676 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
5677
5678 keys = ref_path->node_keys;
5679 nodes = ref_path->new_nodes;
5680 memset(&keys[shared_level + 1], 0,
5681 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
5682 memset(&nodes[shared_level + 1], 0,
5683 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
5684
5685 if (nodes[lowest_level] == 0) {
5686 path->lowest_level = lowest_level;
5687 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
5688 0, 1);
5689 BUG_ON(ret);
5690 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
5691 eb = path->nodes[level];
5692 if (!eb || eb == reloc_root->node)
5693 break;
5694 nodes[level] = eb->start;
5695 if (level == 0)
5696 btrfs_item_key_to_cpu(eb, &keys[level], 0);
5697 else
5698 btrfs_node_key_to_cpu(eb, &keys[level], 0);
5699 }
5700 if (nodes[0] &&
5701 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5702 eb = path->nodes[0];
5703 ret = replace_extents_in_leaf(trans, reloc_root, eb,
5704 group, reloc_inode);
5705 BUG_ON(ret);
5706 }
5707 btrfs_release_path(reloc_root, path);
5708 } else {
5709 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
5710 lowest_level);
5711 BUG_ON(ret);
5712 }
5713
5714 /*
5715 * replace tree blocks in the fs tree with tree blocks in
5716 * the reloc tree.
5717 */
5718 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
5719 BUG_ON(ret < 0);
5720
5721 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5722 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
5723 0, 0);
5724 BUG_ON(ret);
5725 extent_buffer_get(path->nodes[0]);
5726 eb = path->nodes[0];
5727 btrfs_release_path(reloc_root, path);
5728 ret = invalidate_extent_cache(reloc_root, eb, group, root);
5729 BUG_ON(ret);
5730 free_extent_buffer(eb);
5731 }
5732
5733 mutex_unlock(&root->fs_info->tree_reloc_mutex);
5734 path->lowest_level = 0;
5735 return 0;
5736 }
5737
5738 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
5739 struct btrfs_root *root,
5740 struct btrfs_path *path,
5741 struct btrfs_key *first_key,
5742 struct btrfs_ref_path *ref_path)
5743 {
5744 int ret;
5745
5746 ret = relocate_one_path(trans, root, path, first_key,
5747 ref_path, NULL, NULL);
5748 BUG_ON(ret);
5749
5750 if (root == root->fs_info->extent_root)
5751 btrfs_extent_post_op(trans, root);
5752
5753 return 0;
5754 }
5755
5756 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
5757 struct btrfs_root *extent_root,
5758 struct btrfs_path *path,
5759 struct btrfs_key *extent_key)
5760 {
5761 int ret;
5762
5763 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
5764 if (ret)
5765 goto out;
5766 ret = btrfs_del_item(trans, extent_root, path);
5767 out:
5768 btrfs_release_path(extent_root, path);
5769 return ret;
5770 }
5771
5772 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
5773 struct btrfs_ref_path *ref_path)
5774 {
5775 struct btrfs_key root_key;
5776
5777 root_key.objectid = ref_path->root_objectid;
5778 root_key.type = BTRFS_ROOT_ITEM_KEY;
5779 if (is_cowonly_root(ref_path->root_objectid))
5780 root_key.offset = 0;
5781 else
5782 root_key.offset = (u64)-1;
5783
5784 return btrfs_read_fs_root_no_name(fs_info, &root_key);
5785 }
5786
5787 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
5788 struct btrfs_path *path,
5789 struct btrfs_key *extent_key,
5790 struct btrfs_block_group_cache *group,
5791 struct inode *reloc_inode, int pass)
5792 {
5793 struct btrfs_trans_handle *trans;
5794 struct btrfs_root *found_root;
5795 struct btrfs_ref_path *ref_path = NULL;
5796 struct disk_extent *new_extents = NULL;
5797 int nr_extents = 0;
5798 int loops;
5799 int ret;
5800 int level;
5801 struct btrfs_key first_key;
5802 u64 prev_block = 0;
5803
5804
5805 trans = btrfs_start_transaction(extent_root, 1);
5806 BUG_ON(!trans);
5807
5808 if (extent_key->objectid == 0) {
5809 ret = del_extent_zero(trans, extent_root, path, extent_key);
5810 goto out;
5811 }
5812
5813 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
5814 if (!ref_path) {
5815 ret = -ENOMEM;
5816 goto out;
5817 }
5818
5819 for (loops = 0; ; loops++) {
5820 if (loops == 0) {
5821 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
5822 extent_key->objectid);
5823 } else {
5824 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
5825 }
5826 if (ret < 0)
5827 goto out;
5828 if (ret > 0)
5829 break;
5830
5831 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
5832 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
5833 continue;
5834
5835 found_root = read_ref_root(extent_root->fs_info, ref_path);
5836 BUG_ON(!found_root);
5837 /*
5838 * for reference counted tree, only process reference paths
5839 * rooted at the latest committed root.
5840 */
5841 if (found_root->ref_cows &&
5842 ref_path->root_generation != found_root->root_key.offset)
5843 continue;
5844
5845 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5846 if (pass == 0) {
5847 /*
5848 * copy data extents to new locations
5849 */
5850 u64 group_start = group->key.objectid;
5851 ret = relocate_data_extent(reloc_inode,
5852 extent_key,
5853 group_start);
5854 if (ret < 0)
5855 goto out;
5856 break;
5857 }
5858 level = 0;
5859 } else {
5860 level = ref_path->owner_objectid;
5861 }
5862
5863 if (prev_block != ref_path->nodes[level]) {
5864 struct extent_buffer *eb;
5865 u64 block_start = ref_path->nodes[level];
5866 u64 block_size = btrfs_level_size(found_root, level);
5867
5868 eb = read_tree_block(found_root, block_start,
5869 block_size, 0);
5870 btrfs_tree_lock(eb);
5871 BUG_ON(level != btrfs_header_level(eb));
5872
5873 if (level == 0)
5874 btrfs_item_key_to_cpu(eb, &first_key, 0);
5875 else
5876 btrfs_node_key_to_cpu(eb, &first_key, 0);
5877
5878 btrfs_tree_unlock(eb);
5879 free_extent_buffer(eb);
5880 prev_block = block_start;
5881 }
5882
5883 mutex_lock(&extent_root->fs_info->trans_mutex);
5884 btrfs_record_root_in_trans(found_root);
5885 mutex_unlock(&extent_root->fs_info->trans_mutex);
5886 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
5887 /*
5888 * try to update data extent references while
5889 * keeping metadata shared between snapshots.
5890 */
5891 if (pass == 1) {
5892 ret = relocate_one_path(trans, found_root,
5893 path, &first_key, ref_path,
5894 group, reloc_inode);
5895 if (ret < 0)
5896 goto out;
5897 continue;
5898 }
5899 /*
5900 * use fallback method to process the remaining
5901 * references.
5902 */
5903 if (!new_extents) {
5904 u64 group_start = group->key.objectid;
5905 new_extents = kmalloc(sizeof(*new_extents),
5906 GFP_NOFS);
5907 nr_extents = 1;
5908 ret = get_new_locations(reloc_inode,
5909 extent_key,
5910 group_start, 1,
5911 &new_extents,
5912 &nr_extents);
5913 if (ret)
5914 goto out;
5915 }
5916 ret = replace_one_extent(trans, found_root,
5917 path, extent_key,
5918 &first_key, ref_path,
5919 new_extents, nr_extents);
5920 } else {
5921 ret = relocate_tree_block(trans, found_root, path,
5922 &first_key, ref_path);
5923 }
5924 if (ret < 0)
5925 goto out;
5926 }
5927 ret = 0;
5928 out:
5929 btrfs_end_transaction(trans, extent_root);
5930 kfree(new_extents);
5931 kfree(ref_path);
5932 return ret;
5933 }
5934
5935 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
5936 {
5937 u64 num_devices;
5938 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
5939 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
5940
5941 num_devices = root->fs_info->fs_devices->rw_devices;
5942 if (num_devices == 1) {
5943 stripped |= BTRFS_BLOCK_GROUP_DUP;
5944 stripped = flags & ~stripped;
5945
5946 /* turn raid0 into single device chunks */
5947 if (flags & BTRFS_BLOCK_GROUP_RAID0)
5948 return stripped;
5949
5950 /* turn mirroring into duplication */
5951 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
5952 BTRFS_BLOCK_GROUP_RAID10))
5953 return stripped | BTRFS_BLOCK_GROUP_DUP;
5954 return flags;
5955 } else {
5956 /* they already had raid on here, just return */
5957 if (flags & stripped)
5958 return flags;
5959
5960 stripped |= BTRFS_BLOCK_GROUP_DUP;
5961 stripped = flags & ~stripped;
5962
5963 /* switch duplicated blocks with raid1 */
5964 if (flags & BTRFS_BLOCK_GROUP_DUP)
5965 return stripped | BTRFS_BLOCK_GROUP_RAID1;
5966
5967 /* turn single device chunks into raid0 */
5968 return stripped | BTRFS_BLOCK_GROUP_RAID0;
5969 }
5970 return flags;
5971 }
5972
5973 static int __alloc_chunk_for_shrink(struct btrfs_root *root,
5974 struct btrfs_block_group_cache *shrink_block_group,
5975 int force)
5976 {
5977 struct btrfs_trans_handle *trans;
5978 u64 new_alloc_flags;
5979 u64 calc;
5980
5981 spin_lock(&shrink_block_group->lock);
5982 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
5983 spin_unlock(&shrink_block_group->lock);
5984
5985 trans = btrfs_start_transaction(root, 1);
5986 spin_lock(&shrink_block_group->lock);
5987
5988 new_alloc_flags = update_block_group_flags(root,
5989 shrink_block_group->flags);
5990 if (new_alloc_flags != shrink_block_group->flags) {
5991 calc =
5992 btrfs_block_group_used(&shrink_block_group->item);
5993 } else {
5994 calc = shrink_block_group->key.offset;
5995 }
5996 spin_unlock(&shrink_block_group->lock);
5997
5998 do_chunk_alloc(trans, root->fs_info->extent_root,
5999 calc + 2 * 1024 * 1024, new_alloc_flags, force);
6000
6001 btrfs_end_transaction(trans, root);
6002 } else
6003 spin_unlock(&shrink_block_group->lock);
6004 return 0;
6005 }
6006
6007 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
6008 struct btrfs_root *root,
6009 u64 objectid, u64 size)
6010 {
6011 struct btrfs_path *path;
6012 struct btrfs_inode_item *item;
6013 struct extent_buffer *leaf;
6014 int ret;
6015
6016 path = btrfs_alloc_path();
6017 if (!path)
6018 return -ENOMEM;
6019
6020 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
6021 if (ret)
6022 goto out;
6023
6024 leaf = path->nodes[0];
6025 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
6026 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
6027 btrfs_set_inode_generation(leaf, item, 1);
6028 btrfs_set_inode_size(leaf, item, size);
6029 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
6030 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS);
6031 btrfs_mark_buffer_dirty(leaf);
6032 btrfs_release_path(root, path);
6033 out:
6034 btrfs_free_path(path);
6035 return ret;
6036 }
6037
6038 static noinline struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
6039 struct btrfs_block_group_cache *group)
6040 {
6041 struct inode *inode = NULL;
6042 struct btrfs_trans_handle *trans;
6043 struct btrfs_root *root;
6044 struct btrfs_key root_key;
6045 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
6046 int err = 0;
6047
6048 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
6049 root_key.type = BTRFS_ROOT_ITEM_KEY;
6050 root_key.offset = (u64)-1;
6051 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
6052 if (IS_ERR(root))
6053 return ERR_CAST(root);
6054
6055 trans = btrfs_start_transaction(root, 1);
6056 BUG_ON(!trans);
6057
6058 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
6059 if (err)
6060 goto out;
6061
6062 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
6063 BUG_ON(err);
6064
6065 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
6066 group->key.offset, 0, group->key.offset,
6067 0, 0, 0);
6068 BUG_ON(err);
6069
6070 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
6071 if (inode->i_state & I_NEW) {
6072 BTRFS_I(inode)->root = root;
6073 BTRFS_I(inode)->location.objectid = objectid;
6074 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
6075 BTRFS_I(inode)->location.offset = 0;
6076 btrfs_read_locked_inode(inode);
6077 unlock_new_inode(inode);
6078 BUG_ON(is_bad_inode(inode));
6079 } else {
6080 BUG_ON(1);
6081 }
6082 BTRFS_I(inode)->index_cnt = group->key.objectid;
6083
6084 err = btrfs_orphan_add(trans, inode);
6085 out:
6086 btrfs_end_transaction(trans, root);
6087 if (err) {
6088 if (inode)
6089 iput(inode);
6090 inode = ERR_PTR(err);
6091 }
6092 return inode;
6093 }
6094
6095 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
6096 {
6097
6098 struct btrfs_ordered_sum *sums;
6099 struct btrfs_sector_sum *sector_sum;
6100 struct btrfs_ordered_extent *ordered;
6101 struct btrfs_root *root = BTRFS_I(inode)->root;
6102 struct list_head list;
6103 size_t offset;
6104 int ret;
6105 u64 disk_bytenr;
6106
6107 INIT_LIST_HEAD(&list);
6108
6109 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
6110 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
6111
6112 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
6113 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
6114 disk_bytenr + len - 1, &list);
6115
6116 while (!list_empty(&list)) {
6117 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
6118 list_del_init(&sums->list);
6119
6120 sector_sum = sums->sums;
6121 sums->bytenr = ordered->start;
6122
6123 offset = 0;
6124 while (offset < sums->len) {
6125 sector_sum->bytenr += ordered->start - disk_bytenr;
6126 sector_sum++;
6127 offset += root->sectorsize;
6128 }
6129
6130 btrfs_add_ordered_sum(inode, ordered, sums);
6131 }
6132 btrfs_put_ordered_extent(ordered);
6133 return 0;
6134 }
6135
6136 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
6137 {
6138 struct btrfs_trans_handle *trans;
6139 struct btrfs_path *path;
6140 struct btrfs_fs_info *info = root->fs_info;
6141 struct extent_buffer *leaf;
6142 struct inode *reloc_inode;
6143 struct btrfs_block_group_cache *block_group;
6144 struct btrfs_key key;
6145 u64 skipped;
6146 u64 cur_byte;
6147 u64 total_found;
6148 u32 nritems;
6149 int ret;
6150 int progress;
6151 int pass = 0;
6152
6153 root = root->fs_info->extent_root;
6154
6155 block_group = btrfs_lookup_block_group(info, group_start);
6156 BUG_ON(!block_group);
6157
6158 printk(KERN_INFO "btrfs relocating block group %llu flags %llu\n",
6159 (unsigned long long)block_group->key.objectid,
6160 (unsigned long long)block_group->flags);
6161
6162 path = btrfs_alloc_path();
6163 BUG_ON(!path);
6164
6165 reloc_inode = create_reloc_inode(info, block_group);
6166 BUG_ON(IS_ERR(reloc_inode));
6167
6168 __alloc_chunk_for_shrink(root, block_group, 1);
6169 set_block_group_readonly(block_group);
6170
6171 btrfs_start_delalloc_inodes(info->tree_root);
6172 btrfs_wait_ordered_extents(info->tree_root, 0);
6173 again:
6174 skipped = 0;
6175 total_found = 0;
6176 progress = 0;
6177 key.objectid = block_group->key.objectid;
6178 key.offset = 0;
6179 key.type = 0;
6180 cur_byte = key.objectid;
6181
6182 trans = btrfs_start_transaction(info->tree_root, 1);
6183 btrfs_commit_transaction(trans, info->tree_root);
6184
6185 mutex_lock(&root->fs_info->cleaner_mutex);
6186 btrfs_clean_old_snapshots(info->tree_root);
6187 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
6188 mutex_unlock(&root->fs_info->cleaner_mutex);
6189
6190 while (1) {
6191 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6192 if (ret < 0)
6193 goto out;
6194 next:
6195 leaf = path->nodes[0];
6196 nritems = btrfs_header_nritems(leaf);
6197 if (path->slots[0] >= nritems) {
6198 ret = btrfs_next_leaf(root, path);
6199 if (ret < 0)
6200 goto out;
6201 if (ret == 1) {
6202 ret = 0;
6203 break;
6204 }
6205 leaf = path->nodes[0];
6206 nritems = btrfs_header_nritems(leaf);
6207 }
6208
6209 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
6210
6211 if (key.objectid >= block_group->key.objectid +
6212 block_group->key.offset)
6213 break;
6214
6215 if (progress && need_resched()) {
6216 btrfs_release_path(root, path);
6217 cond_resched();
6218 progress = 0;
6219 continue;
6220 }
6221 progress = 1;
6222
6223 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
6224 key.objectid + key.offset <= cur_byte) {
6225 path->slots[0]++;
6226 goto next;
6227 }
6228
6229 total_found++;
6230 cur_byte = key.objectid + key.offset;
6231 btrfs_release_path(root, path);
6232
6233 __alloc_chunk_for_shrink(root, block_group, 0);
6234 ret = relocate_one_extent(root, path, &key, block_group,
6235 reloc_inode, pass);
6236 BUG_ON(ret < 0);
6237 if (ret > 0)
6238 skipped++;
6239
6240 key.objectid = cur_byte;
6241 key.type = 0;
6242 key.offset = 0;
6243 }
6244
6245 btrfs_release_path(root, path);
6246
6247 if (pass == 0) {
6248 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
6249 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
6250 }
6251
6252 if (total_found > 0) {
6253 printk(KERN_INFO "btrfs found %llu extents in pass %d\n",
6254 (unsigned long long)total_found, pass);
6255 pass++;
6256 if (total_found == skipped && pass > 2) {
6257 iput(reloc_inode);
6258 reloc_inode = create_reloc_inode(info, block_group);
6259 pass = 0;
6260 }
6261 goto again;
6262 }
6263
6264 /* delete reloc_inode */
6265 iput(reloc_inode);
6266
6267 /* unpin extents in this range */
6268 trans = btrfs_start_transaction(info->tree_root, 1);
6269 btrfs_commit_transaction(trans, info->tree_root);
6270
6271 spin_lock(&block_group->lock);
6272 WARN_ON(block_group->pinned > 0);
6273 WARN_ON(block_group->reserved > 0);
6274 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
6275 spin_unlock(&block_group->lock);
6276 put_block_group(block_group);
6277 ret = 0;
6278 out:
6279 btrfs_free_path(path);
6280 return ret;
6281 }
6282
6283 static int find_first_block_group(struct btrfs_root *root,
6284 struct btrfs_path *path, struct btrfs_key *key)
6285 {
6286 int ret = 0;
6287 struct btrfs_key found_key;
6288 struct extent_buffer *leaf;
6289 int slot;
6290
6291 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
6292 if (ret < 0)
6293 goto out;
6294
6295 while (1) {
6296 slot = path->slots[0];
6297 leaf = path->nodes[0];
6298 if (slot >= btrfs_header_nritems(leaf)) {
6299 ret = btrfs_next_leaf(root, path);
6300 if (ret == 0)
6301 continue;
6302 if (ret < 0)
6303 goto out;
6304 break;
6305 }
6306 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6307
6308 if (found_key.objectid >= key->objectid &&
6309 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
6310 ret = 0;
6311 goto out;
6312 }
6313 path->slots[0]++;
6314 }
6315 ret = -ENOENT;
6316 out:
6317 return ret;
6318 }
6319
6320 int btrfs_free_block_groups(struct btrfs_fs_info *info)
6321 {
6322 struct btrfs_block_group_cache *block_group;
6323 struct rb_node *n;
6324
6325 spin_lock(&info->block_group_cache_lock);
6326 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
6327 block_group = rb_entry(n, struct btrfs_block_group_cache,
6328 cache_node);
6329 rb_erase(&block_group->cache_node,
6330 &info->block_group_cache_tree);
6331 spin_unlock(&info->block_group_cache_lock);
6332
6333 btrfs_remove_free_space_cache(block_group);
6334 down_write(&block_group->space_info->groups_sem);
6335 list_del(&block_group->list);
6336 up_write(&block_group->space_info->groups_sem);
6337
6338 WARN_ON(atomic_read(&block_group->count) != 1);
6339 kfree(block_group);
6340
6341 spin_lock(&info->block_group_cache_lock);
6342 }
6343 spin_unlock(&info->block_group_cache_lock);
6344 return 0;
6345 }
6346
6347 int btrfs_read_block_groups(struct btrfs_root *root)
6348 {
6349 struct btrfs_path *path;
6350 int ret;
6351 struct btrfs_block_group_cache *cache;
6352 struct btrfs_fs_info *info = root->fs_info;
6353 struct btrfs_space_info *space_info;
6354 struct btrfs_key key;
6355 struct btrfs_key found_key;
6356 struct extent_buffer *leaf;
6357
6358 root = info->extent_root;
6359 key.objectid = 0;
6360 key.offset = 0;
6361 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
6362 path = btrfs_alloc_path();
6363 if (!path)
6364 return -ENOMEM;
6365
6366 while (1) {
6367 ret = find_first_block_group(root, path, &key);
6368 if (ret > 0) {
6369 ret = 0;
6370 goto error;
6371 }
6372 if (ret != 0)
6373 goto error;
6374
6375 leaf = path->nodes[0];
6376 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6377 cache = kzalloc(sizeof(*cache), GFP_NOFS);
6378 if (!cache) {
6379 ret = -ENOMEM;
6380 break;
6381 }
6382
6383 atomic_set(&cache->count, 1);
6384 spin_lock_init(&cache->lock);
6385 mutex_init(&cache->alloc_mutex);
6386 mutex_init(&cache->cache_mutex);
6387 INIT_LIST_HEAD(&cache->list);
6388 read_extent_buffer(leaf, &cache->item,
6389 btrfs_item_ptr_offset(leaf, path->slots[0]),
6390 sizeof(cache->item));
6391 memcpy(&cache->key, &found_key, sizeof(found_key));
6392
6393 key.objectid = found_key.objectid + found_key.offset;
6394 btrfs_release_path(root, path);
6395 cache->flags = btrfs_block_group_flags(&cache->item);
6396
6397 ret = update_space_info(info, cache->flags, found_key.offset,
6398 btrfs_block_group_used(&cache->item),
6399 &space_info);
6400 BUG_ON(ret);
6401 cache->space_info = space_info;
6402 down_write(&space_info->groups_sem);
6403 list_add_tail(&cache->list, &space_info->block_groups);
6404 up_write(&space_info->groups_sem);
6405
6406 ret = btrfs_add_block_group_cache(root->fs_info, cache);
6407 BUG_ON(ret);
6408
6409 set_avail_alloc_bits(root->fs_info, cache->flags);
6410 if (btrfs_chunk_readonly(root, cache->key.objectid))
6411 set_block_group_readonly(cache);
6412 }
6413 ret = 0;
6414 error:
6415 btrfs_free_path(path);
6416 return ret;
6417 }
6418
6419 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
6420 struct btrfs_root *root, u64 bytes_used,
6421 u64 type, u64 chunk_objectid, u64 chunk_offset,
6422 u64 size)
6423 {
6424 int ret;
6425 struct btrfs_root *extent_root;
6426 struct btrfs_block_group_cache *cache;
6427
6428 extent_root = root->fs_info->extent_root;
6429
6430 root->fs_info->last_trans_new_blockgroup = trans->transid;
6431
6432 cache = kzalloc(sizeof(*cache), GFP_NOFS);
6433 if (!cache)
6434 return -ENOMEM;
6435
6436 cache->key.objectid = chunk_offset;
6437 cache->key.offset = size;
6438 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
6439 atomic_set(&cache->count, 1);
6440 spin_lock_init(&cache->lock);
6441 mutex_init(&cache->alloc_mutex);
6442 mutex_init(&cache->cache_mutex);
6443 INIT_LIST_HEAD(&cache->list);
6444
6445 btrfs_set_block_group_used(&cache->item, bytes_used);
6446 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
6447 cache->flags = type;
6448 btrfs_set_block_group_flags(&cache->item, type);
6449
6450 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
6451 &cache->space_info);
6452 BUG_ON(ret);
6453 down_write(&cache->space_info->groups_sem);
6454 list_add_tail(&cache->list, &cache->space_info->block_groups);
6455 up_write(&cache->space_info->groups_sem);
6456
6457 ret = btrfs_add_block_group_cache(root->fs_info, cache);
6458 BUG_ON(ret);
6459
6460 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
6461 sizeof(cache->item));
6462 BUG_ON(ret);
6463
6464 finish_current_insert(trans, extent_root, 0);
6465 ret = del_pending_extents(trans, extent_root, 0);
6466 BUG_ON(ret);
6467 set_avail_alloc_bits(extent_root->fs_info, type);
6468
6469 return 0;
6470 }
6471
6472 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
6473 struct btrfs_root *root, u64 group_start)
6474 {
6475 struct btrfs_path *path;
6476 struct btrfs_block_group_cache *block_group;
6477 struct btrfs_key key;
6478 int ret;
6479
6480 root = root->fs_info->extent_root;
6481
6482 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
6483 BUG_ON(!block_group);
6484 BUG_ON(!block_group->ro);
6485
6486 memcpy(&key, &block_group->key, sizeof(key));
6487
6488 path = btrfs_alloc_path();
6489 BUG_ON(!path);
6490
6491 spin_lock(&root->fs_info->block_group_cache_lock);
6492 rb_erase(&block_group->cache_node,
6493 &root->fs_info->block_group_cache_tree);
6494 spin_unlock(&root->fs_info->block_group_cache_lock);
6495 btrfs_remove_free_space_cache(block_group);
6496 down_write(&block_group->space_info->groups_sem);
6497 list_del(&block_group->list);
6498 up_write(&block_group->space_info->groups_sem);
6499
6500 spin_lock(&block_group->space_info->lock);
6501 block_group->space_info->total_bytes -= block_group->key.offset;
6502 block_group->space_info->bytes_readonly -= block_group->key.offset;
6503 spin_unlock(&block_group->space_info->lock);
6504 block_group->space_info->full = 0;
6505
6506 put_block_group(block_group);
6507 put_block_group(block_group);
6508
6509 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
6510 if (ret > 0)
6511 ret = -EIO;
6512 if (ret < 0)
6513 goto out;
6514
6515 ret = btrfs_del_item(trans, root, path);
6516 out:
6517 btrfs_free_path(path);
6518 return ret;
6519 }
Support for the Chinese Samsung S3C2440 based development boards