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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 "hash.h"
22 #include "crc32c.h"
23 #include "ctree.h"
24 #include "disk-io.h"
25 #include "print-tree.h"
26 #include "transaction.h"
27 #include "volumes.h"
28 #include "locking.h"
29
30 #define BLOCK_GROUP_DATA EXTENT_WRITEBACK
31 #define BLOCK_GROUP_METADATA EXTENT_UPTODATE
32 #define BLOCK_GROUP_SYSTEM EXTENT_NEW
33
34 #define BLOCK_GROUP_DIRTY EXTENT_DIRTY
35
36 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
37 btrfs_root *extent_root);
38 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
39 btrfs_root *extent_root);
40 static struct btrfs_block_group_cache *
41 __btrfs_find_block_group(struct btrfs_root *root,
42 struct btrfs_block_group_cache *hint,
43 u64 search_start, int data, int owner);
44
45 void maybe_lock_mutex(struct btrfs_root *root)
46 {
47 if (root != root->fs_info->extent_root &&
48 root != root->fs_info->chunk_root &&
49 root != root->fs_info->dev_root) {
50 mutex_lock(&root->fs_info->alloc_mutex);
51 }
52 }
53
54 void maybe_unlock_mutex(struct btrfs_root *root)
55 {
56 if (root != root->fs_info->extent_root &&
57 root != root->fs_info->chunk_root &&
58 root != root->fs_info->dev_root) {
59 mutex_unlock(&root->fs_info->alloc_mutex);
60 }
61 }
62
63 static int cache_block_group(struct btrfs_root *root,
64 struct btrfs_block_group_cache *block_group)
65 {
66 struct btrfs_path *path;
67 int ret;
68 struct btrfs_key key;
69 struct extent_buffer *leaf;
70 struct extent_io_tree *free_space_cache;
71 int slot;
72 u64 last = 0;
73 u64 hole_size;
74 u64 first_free;
75 int found = 0;
76
77 if (!block_group)
78 return 0;
79
80 root = root->fs_info->extent_root;
81 free_space_cache = &root->fs_info->free_space_cache;
82
83 if (block_group->cached)
84 return 0;
85
86 path = btrfs_alloc_path();
87 if (!path)
88 return -ENOMEM;
89
90 path->reada = 2;
91 /*
92 * we get into deadlocks with paths held by callers of this function.
93 * since the alloc_mutex is protecting things right now, just
94 * skip the locking here
95 */
96 path->skip_locking = 1;
97 first_free = block_group->key.objectid;
98 key.objectid = block_group->key.objectid;
99 key.offset = 0;
100 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
101 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
102 if (ret < 0)
103 return ret;
104 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
105 if (ret < 0)
106 return ret;
107 if (ret == 0) {
108 leaf = path->nodes[0];
109 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
110 if (key.objectid + key.offset > first_free)
111 first_free = key.objectid + key.offset;
112 }
113 while(1) {
114 leaf = path->nodes[0];
115 slot = path->slots[0];
116 if (slot >= btrfs_header_nritems(leaf)) {
117 ret = btrfs_next_leaf(root, path);
118 if (ret < 0)
119 goto err;
120 if (ret == 0) {
121 continue;
122 } else {
123 break;
124 }
125 }
126 btrfs_item_key_to_cpu(leaf, &key, slot);
127 if (key.objectid < block_group->key.objectid) {
128 goto next;
129 }
130 if (key.objectid >= block_group->key.objectid +
131 block_group->key.offset) {
132 break;
133 }
134
135 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
136 if (!found) {
137 last = first_free;
138 found = 1;
139 }
140 if (key.objectid > last) {
141 hole_size = key.objectid - last;
142 set_extent_dirty(free_space_cache, last,
143 last + hole_size - 1,
144 GFP_NOFS);
145 }
146 last = key.objectid + key.offset;
147 }
148 next:
149 path->slots[0]++;
150 }
151
152 if (!found)
153 last = first_free;
154 if (block_group->key.objectid +
155 block_group->key.offset > last) {
156 hole_size = block_group->key.objectid +
157 block_group->key.offset - last;
158 set_extent_dirty(free_space_cache, last,
159 last + hole_size - 1, GFP_NOFS);
160 }
161 block_group->cached = 1;
162 err:
163 btrfs_free_path(path);
164 return 0;
165 }
166
167 struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
168 btrfs_fs_info *info,
169 u64 bytenr)
170 {
171 struct extent_io_tree *block_group_cache;
172 struct btrfs_block_group_cache *block_group = NULL;
173 u64 ptr;
174 u64 start;
175 u64 end;
176 int ret;
177
178 bytenr = max_t(u64, bytenr,
179 BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
180 block_group_cache = &info->block_group_cache;
181 ret = find_first_extent_bit(block_group_cache,
182 bytenr, &start, &end,
183 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
184 BLOCK_GROUP_SYSTEM);
185 if (ret) {
186 return NULL;
187 }
188 ret = get_state_private(block_group_cache, start, &ptr);
189 if (ret)
190 return NULL;
191
192 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
193 return block_group;
194 }
195
196 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
197 btrfs_fs_info *info,
198 u64 bytenr)
199 {
200 struct extent_io_tree *block_group_cache;
201 struct btrfs_block_group_cache *block_group = NULL;
202 u64 ptr;
203 u64 start;
204 u64 end;
205 int ret;
206
207 bytenr = max_t(u64, bytenr,
208 BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
209 block_group_cache = &info->block_group_cache;
210 ret = find_first_extent_bit(block_group_cache,
211 bytenr, &start, &end,
212 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
213 BLOCK_GROUP_SYSTEM);
214 if (ret) {
215 return NULL;
216 }
217 ret = get_state_private(block_group_cache, start, &ptr);
218 if (ret)
219 return NULL;
220
221 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
222 if (block_group->key.objectid <= bytenr && bytenr <
223 block_group->key.objectid + block_group->key.offset)
224 return block_group;
225 return NULL;
226 }
227
228 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
229 {
230 return (cache->flags & bits) == bits;
231 }
232
233 static int noinline find_search_start(struct btrfs_root *root,
234 struct btrfs_block_group_cache **cache_ret,
235 u64 *start_ret, u64 num, int data)
236 {
237 int ret;
238 struct btrfs_block_group_cache *cache = *cache_ret;
239 struct extent_io_tree *free_space_cache;
240 struct extent_state *state;
241 u64 last;
242 u64 start = 0;
243 u64 cache_miss = 0;
244 u64 total_fs_bytes;
245 u64 search_start = *start_ret;
246 int wrapped = 0;
247
248 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
249 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
250 free_space_cache = &root->fs_info->free_space_cache;
251
252 if (!cache)
253 goto out;
254
255 again:
256 ret = cache_block_group(root, cache);
257 if (ret) {
258 goto out;
259 }
260
261 last = max(search_start, cache->key.objectid);
262 if (!block_group_bits(cache, data) || cache->ro)
263 goto new_group;
264
265 spin_lock_irq(&free_space_cache->lock);
266 state = find_first_extent_bit_state(free_space_cache, last, EXTENT_DIRTY);
267 while(1) {
268 if (!state) {
269 if (!cache_miss)
270 cache_miss = last;
271 spin_unlock_irq(&free_space_cache->lock);
272 goto new_group;
273 }
274
275 start = max(last, state->start);
276 last = state->end + 1;
277 if (last - start < num) {
278 do {
279 state = extent_state_next(state);
280 } while(state && !(state->state & EXTENT_DIRTY));
281 continue;
282 }
283 spin_unlock_irq(&free_space_cache->lock);
284 if (cache->ro) {
285 goto new_group;
286 }
287 if (start + num > cache->key.objectid + cache->key.offset)
288 goto new_group;
289 if (!block_group_bits(cache, data)) {
290 printk("block group bits don't match %Lu %d\n", cache->flags, data);
291 }
292 *start_ret = start;
293 return 0;
294 }
295 out:
296 cache = btrfs_lookup_block_group(root->fs_info, search_start);
297 if (!cache) {
298 printk("Unable to find block group for %Lu\n", search_start);
299 WARN_ON(1);
300 }
301 return -ENOSPC;
302
303 new_group:
304 last = cache->key.objectid + cache->key.offset;
305 wrapped:
306 cache = btrfs_lookup_first_block_group(root->fs_info, last);
307 if (!cache || cache->key.objectid >= total_fs_bytes) {
308 no_cache:
309 if (!wrapped) {
310 wrapped = 1;
311 last = search_start;
312 goto wrapped;
313 }
314 goto out;
315 }
316 if (cache_miss && !cache->cached) {
317 cache_block_group(root, cache);
318 last = cache_miss;
319 cache = btrfs_lookup_first_block_group(root->fs_info, last);
320 }
321 cache_miss = 0;
322 cache = __btrfs_find_block_group(root, cache, last, data, 0);
323 if (!cache)
324 goto no_cache;
325 *cache_ret = cache;
326 goto again;
327 }
328
329 static u64 div_factor(u64 num, int factor)
330 {
331 if (factor == 10)
332 return num;
333 num *= factor;
334 do_div(num, 10);
335 return num;
336 }
337
338 static int block_group_state_bits(u64 flags)
339 {
340 int bits = 0;
341 if (flags & BTRFS_BLOCK_GROUP_DATA)
342 bits |= BLOCK_GROUP_DATA;
343 if (flags & BTRFS_BLOCK_GROUP_METADATA)
344 bits |= BLOCK_GROUP_METADATA;
345 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
346 bits |= BLOCK_GROUP_SYSTEM;
347 return bits;
348 }
349
350 static struct btrfs_block_group_cache *
351 __btrfs_find_block_group(struct btrfs_root *root,
352 struct btrfs_block_group_cache *hint,
353 u64 search_start, int data, int owner)
354 {
355 struct btrfs_block_group_cache *cache;
356 struct extent_io_tree *block_group_cache;
357 struct btrfs_block_group_cache *found_group = NULL;
358 struct btrfs_fs_info *info = root->fs_info;
359 u64 used;
360 u64 last = 0;
361 u64 start;
362 u64 end;
363 u64 free_check;
364 u64 ptr;
365 int bit;
366 int ret;
367 int full_search = 0;
368 int factor = 10;
369 int wrapped = 0;
370
371 block_group_cache = &info->block_group_cache;
372
373 if (data & BTRFS_BLOCK_GROUP_METADATA)
374 factor = 9;
375
376 bit = block_group_state_bits(data);
377
378 if (search_start) {
379 struct btrfs_block_group_cache *shint;
380 shint = btrfs_lookup_first_block_group(info, search_start);
381 if (shint && block_group_bits(shint, data) && !shint->ro) {
382 used = btrfs_block_group_used(&shint->item);
383 if (used + shint->pinned <
384 div_factor(shint->key.offset, factor)) {
385 return shint;
386 }
387 }
388 }
389 if (hint && !hint->ro && block_group_bits(hint, data)) {
390 used = btrfs_block_group_used(&hint->item);
391 if (used + hint->pinned <
392 div_factor(hint->key.offset, factor)) {
393 return hint;
394 }
395 last = hint->key.objectid + hint->key.offset;
396 } else {
397 if (hint)
398 last = max(hint->key.objectid, search_start);
399 else
400 last = search_start;
401 }
402 again:
403 while(1) {
404 ret = find_first_extent_bit(block_group_cache, last,
405 &start, &end, bit);
406 if (ret)
407 break;
408
409 ret = get_state_private(block_group_cache, start, &ptr);
410 if (ret) {
411 last = end + 1;
412 continue;
413 }
414
415 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
416 last = cache->key.objectid + cache->key.offset;
417 used = btrfs_block_group_used(&cache->item);
418
419 if (!cache->ro && block_group_bits(cache, data)) {
420 free_check = div_factor(cache->key.offset, factor);
421 if (used + cache->pinned < free_check) {
422 found_group = cache;
423 goto found;
424 }
425 }
426 cond_resched();
427 }
428 if (!wrapped) {
429 last = search_start;
430 wrapped = 1;
431 goto again;
432 }
433 if (!full_search && factor < 10) {
434 last = search_start;
435 full_search = 1;
436 factor = 10;
437 goto again;
438 }
439 found:
440 return found_group;
441 }
442
443 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
444 struct btrfs_block_group_cache
445 *hint, u64 search_start,
446 int data, int owner)
447 {
448
449 struct btrfs_block_group_cache *ret;
450 mutex_lock(&root->fs_info->alloc_mutex);
451 ret = __btrfs_find_block_group(root, hint, search_start, data, owner);
452 mutex_unlock(&root->fs_info->alloc_mutex);
453 return ret;
454 }
455 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
456 u64 owner, u64 owner_offset)
457 {
458 u32 high_crc = ~(u32)0;
459 u32 low_crc = ~(u32)0;
460 __le64 lenum;
461 lenum = cpu_to_le64(root_objectid);
462 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
463 lenum = cpu_to_le64(ref_generation);
464 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
465 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
466 lenum = cpu_to_le64(owner);
467 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
468 lenum = cpu_to_le64(owner_offset);
469 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
470 }
471 return ((u64)high_crc << 32) | (u64)low_crc;
472 }
473
474 static int match_extent_ref(struct extent_buffer *leaf,
475 struct btrfs_extent_ref *disk_ref,
476 struct btrfs_extent_ref *cpu_ref)
477 {
478 int ret;
479 int len;
480
481 if (cpu_ref->objectid)
482 len = sizeof(*cpu_ref);
483 else
484 len = 2 * sizeof(u64);
485 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
486 len);
487 return ret == 0;
488 }
489
490 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
491 struct btrfs_root *root,
492 struct btrfs_path *path, u64 bytenr,
493 u64 root_objectid,
494 u64 ref_generation, u64 owner,
495 u64 owner_offset, int del)
496 {
497 u64 hash;
498 struct btrfs_key key;
499 struct btrfs_key found_key;
500 struct btrfs_extent_ref ref;
501 struct extent_buffer *leaf;
502 struct btrfs_extent_ref *disk_ref;
503 int ret;
504 int ret2;
505
506 btrfs_set_stack_ref_root(&ref, root_objectid);
507 btrfs_set_stack_ref_generation(&ref, ref_generation);
508 btrfs_set_stack_ref_objectid(&ref, owner);
509 btrfs_set_stack_ref_offset(&ref, owner_offset);
510
511 hash = hash_extent_ref(root_objectid, ref_generation, owner,
512 owner_offset);
513 key.offset = hash;
514 key.objectid = bytenr;
515 key.type = BTRFS_EXTENT_REF_KEY;
516
517 while (1) {
518 ret = btrfs_search_slot(trans, root, &key, path,
519 del ? -1 : 0, del);
520 if (ret < 0)
521 goto out;
522 leaf = path->nodes[0];
523 if (ret != 0) {
524 u32 nritems = btrfs_header_nritems(leaf);
525 if (path->slots[0] >= nritems) {
526 ret2 = btrfs_next_leaf(root, path);
527 if (ret2)
528 goto out;
529 leaf = path->nodes[0];
530 }
531 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
532 if (found_key.objectid != bytenr ||
533 found_key.type != BTRFS_EXTENT_REF_KEY)
534 goto out;
535 key.offset = found_key.offset;
536 if (del) {
537 btrfs_release_path(root, path);
538 continue;
539 }
540 }
541 disk_ref = btrfs_item_ptr(path->nodes[0],
542 path->slots[0],
543 struct btrfs_extent_ref);
544 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
545 ret = 0;
546 goto out;
547 }
548 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
549 key.offset = found_key.offset + 1;
550 btrfs_release_path(root, path);
551 }
552 out:
553 return ret;
554 }
555
556 /*
557 * Back reference rules. Back refs have three main goals:
558 *
559 * 1) differentiate between all holders of references to an extent so that
560 * when a reference is dropped we can make sure it was a valid reference
561 * before freeing the extent.
562 *
563 * 2) Provide enough information to quickly find the holders of an extent
564 * if we notice a given block is corrupted or bad.
565 *
566 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
567 * maintenance. This is actually the same as #2, but with a slightly
568 * different use case.
569 *
570 * File extents can be referenced by:
571 *
572 * - multiple snapshots, subvolumes, or different generations in one subvol
573 * - different files inside a single subvolume (in theory, not implemented yet)
574 * - different offsets inside a file (bookend extents in file.c)
575 *
576 * The extent ref structure has fields for:
577 *
578 * - Objectid of the subvolume root
579 * - Generation number of the tree holding the reference
580 * - objectid of the file holding the reference
581 * - offset in the file corresponding to the key holding the reference
582 *
583 * When a file extent is allocated the fields are filled in:
584 * (root_key.objectid, trans->transid, inode objectid, offset in file)
585 *
586 * When a leaf is cow'd new references are added for every file extent found
587 * in the leaf. It looks the same as the create case, but trans->transid
588 * will be different when the block is cow'd.
589 *
590 * (root_key.objectid, trans->transid, inode objectid, offset in file)
591 *
592 * When a file extent is removed either during snapshot deletion or file
593 * truncation, the corresponding back reference is found
594 * by searching for:
595 *
596 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
597 * inode objectid, offset in file)
598 *
599 * Btree extents can be referenced by:
600 *
601 * - Different subvolumes
602 * - Different generations of the same subvolume
603 *
604 * Storing sufficient information for a full reverse mapping of a btree
605 * block would require storing the lowest key of the block in the backref,
606 * and it would require updating that lowest key either before write out or
607 * every time it changed. Instead, the objectid of the lowest key is stored
608 * along with the level of the tree block. This provides a hint
609 * about where in the btree the block can be found. Searches through the
610 * btree only need to look for a pointer to that block, so they stop one
611 * level higher than the level recorded in the backref.
612 *
613 * Some btrees do not do reference counting on their extents. These
614 * include the extent tree and the tree of tree roots. Backrefs for these
615 * trees always have a generation of zero.
616 *
617 * When a tree block is created, back references are inserted:
618 *
619 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
620 *
621 * When a tree block is cow'd in a reference counted root,
622 * new back references are added for all the blocks it points to.
623 * These are of the form (trans->transid will have increased since creation):
624 *
625 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
626 *
627 * Because the lowest_key_objectid and the level are just hints
628 * they are not used when backrefs are deleted. When a backref is deleted:
629 *
630 * if backref was for a tree root:
631 * root_objectid = root->root_key.objectid
632 * else
633 * root_objectid = btrfs_header_owner(parent)
634 *
635 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
636 *
637 * Back Reference Key hashing:
638 *
639 * Back references have four fields, each 64 bits long. Unfortunately,
640 * This is hashed into a single 64 bit number and placed into the key offset.
641 * The key objectid corresponds to the first byte in the extent, and the
642 * key type is set to BTRFS_EXTENT_REF_KEY
643 */
644 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
645 struct btrfs_root *root,
646 struct btrfs_path *path, u64 bytenr,
647 u64 root_objectid, u64 ref_generation,
648 u64 owner, u64 owner_offset)
649 {
650 u64 hash;
651 struct btrfs_key key;
652 struct btrfs_extent_ref ref;
653 struct btrfs_extent_ref *disk_ref;
654 int ret;
655
656 btrfs_set_stack_ref_root(&ref, root_objectid);
657 btrfs_set_stack_ref_generation(&ref, ref_generation);
658 btrfs_set_stack_ref_objectid(&ref, owner);
659 btrfs_set_stack_ref_offset(&ref, owner_offset);
660
661 hash = hash_extent_ref(root_objectid, ref_generation, owner,
662 owner_offset);
663 key.offset = hash;
664 key.objectid = bytenr;
665 key.type = BTRFS_EXTENT_REF_KEY;
666
667 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
668 while (ret == -EEXIST) {
669 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
670 struct btrfs_extent_ref);
671 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
672 goto out;
673 key.offset++;
674 btrfs_release_path(root, path);
675 ret = btrfs_insert_empty_item(trans, root, path, &key,
676 sizeof(ref));
677 }
678 if (ret)
679 goto out;
680 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
681 struct btrfs_extent_ref);
682 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
683 sizeof(ref));
684 btrfs_mark_buffer_dirty(path->nodes[0]);
685 out:
686 btrfs_release_path(root, path);
687 return ret;
688 }
689
690 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
691 struct btrfs_root *root,
692 u64 bytenr, u64 num_bytes,
693 u64 root_objectid, u64 ref_generation,
694 u64 owner, u64 owner_offset)
695 {
696 struct btrfs_path *path;
697 int ret;
698 struct btrfs_key key;
699 struct extent_buffer *l;
700 struct btrfs_extent_item *item;
701 u32 refs;
702
703 WARN_ON(num_bytes < root->sectorsize);
704 path = btrfs_alloc_path();
705 if (!path)
706 return -ENOMEM;
707
708 path->reada = 1;
709 key.objectid = bytenr;
710 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
711 key.offset = num_bytes;
712 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
713 0, 1);
714 if (ret < 0)
715 return ret;
716 if (ret != 0) {
717 BUG();
718 }
719 BUG_ON(ret != 0);
720 l = path->nodes[0];
721 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
722 refs = btrfs_extent_refs(l, item);
723 btrfs_set_extent_refs(l, item, refs + 1);
724 btrfs_mark_buffer_dirty(path->nodes[0]);
725
726 btrfs_release_path(root->fs_info->extent_root, path);
727
728 path->reada = 1;
729 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
730 path, bytenr, root_objectid,
731 ref_generation, owner, owner_offset);
732 BUG_ON(ret);
733 finish_current_insert(trans, root->fs_info->extent_root);
734 del_pending_extents(trans, root->fs_info->extent_root);
735
736 btrfs_free_path(path);
737 return 0;
738 }
739
740 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
741 struct btrfs_root *root,
742 u64 bytenr, u64 num_bytes,
743 u64 root_objectid, u64 ref_generation,
744 u64 owner, u64 owner_offset)
745 {
746 int ret;
747
748 mutex_lock(&root->fs_info->alloc_mutex);
749 ret = __btrfs_inc_extent_ref(trans, root, bytenr, num_bytes,
750 root_objectid, ref_generation,
751 owner, owner_offset);
752 mutex_unlock(&root->fs_info->alloc_mutex);
753 return ret;
754 }
755
756 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
757 struct btrfs_root *root)
758 {
759 finish_current_insert(trans, root->fs_info->extent_root);
760 del_pending_extents(trans, root->fs_info->extent_root);
761 return 0;
762 }
763
764 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
765 struct btrfs_root *root, u64 bytenr,
766 u64 num_bytes, u32 *refs)
767 {
768 struct btrfs_path *path;
769 int ret;
770 struct btrfs_key key;
771 struct extent_buffer *l;
772 struct btrfs_extent_item *item;
773
774 WARN_ON(num_bytes < root->sectorsize);
775 path = btrfs_alloc_path();
776 path->reada = 1;
777 key.objectid = bytenr;
778 key.offset = num_bytes;
779 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
780 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
781 0, 0);
782 if (ret < 0)
783 goto out;
784 if (ret != 0) {
785 btrfs_print_leaf(root, path->nodes[0]);
786 printk("failed to find block number %Lu\n", bytenr);
787 BUG();
788 }
789 l = path->nodes[0];
790 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
791 *refs = btrfs_extent_refs(l, item);
792 out:
793 btrfs_free_path(path);
794 return 0;
795 }
796
797 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
798 struct btrfs_path *count_path,
799 u64 expected_owner,
800 u64 first_extent)
801 {
802 struct btrfs_root *extent_root = root->fs_info->extent_root;
803 struct btrfs_path *path;
804 u64 bytenr;
805 u64 found_objectid;
806 u64 found_owner;
807 u64 root_objectid = root->root_key.objectid;
808 u32 total_count = 0;
809 u32 extent_refs;
810 u32 cur_count;
811 u32 nritems;
812 int ret;
813 struct btrfs_key key;
814 struct btrfs_key found_key;
815 struct extent_buffer *l;
816 struct btrfs_extent_item *item;
817 struct btrfs_extent_ref *ref_item;
818 int level = -1;
819
820 /* FIXME, needs locking */
821 BUG();
822
823 mutex_lock(&root->fs_info->alloc_mutex);
824 path = btrfs_alloc_path();
825 again:
826 if (level == -1)
827 bytenr = first_extent;
828 else
829 bytenr = count_path->nodes[level]->start;
830
831 cur_count = 0;
832 key.objectid = bytenr;
833 key.offset = 0;
834
835 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
836 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
837 if (ret < 0)
838 goto out;
839 BUG_ON(ret == 0);
840
841 l = path->nodes[0];
842 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
843
844 if (found_key.objectid != bytenr ||
845 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
846 goto out;
847 }
848
849 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
850 extent_refs = btrfs_extent_refs(l, item);
851 while (1) {
852 l = path->nodes[0];
853 nritems = btrfs_header_nritems(l);
854 if (path->slots[0] >= nritems) {
855 ret = btrfs_next_leaf(extent_root, path);
856 if (ret == 0)
857 continue;
858 break;
859 }
860 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
861 if (found_key.objectid != bytenr)
862 break;
863
864 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
865 path->slots[0]++;
866 continue;
867 }
868
869 cur_count++;
870 ref_item = btrfs_item_ptr(l, path->slots[0],
871 struct btrfs_extent_ref);
872 found_objectid = btrfs_ref_root(l, ref_item);
873
874 if (found_objectid != root_objectid) {
875 total_count = 2;
876 goto out;
877 }
878 if (level == -1) {
879 found_owner = btrfs_ref_objectid(l, ref_item);
880 if (found_owner != expected_owner) {
881 total_count = 2;
882 goto out;
883 }
884 /*
885 * nasty. we don't count a reference held by
886 * the running transaction. This allows nodatacow
887 * to avoid cow most of the time
888 */
889 if (found_owner >= BTRFS_FIRST_FREE_OBJECTID &&
890 btrfs_ref_generation(l, ref_item) ==
891 root->fs_info->generation) {
892 extent_refs--;
893 }
894 }
895 total_count = 1;
896 path->slots[0]++;
897 }
898 /*
899 * if there is more than one reference against a data extent,
900 * we have to assume the other ref is another snapshot
901 */
902 if (level == -1 && extent_refs > 1) {
903 total_count = 2;
904 goto out;
905 }
906 if (cur_count == 0) {
907 total_count = 0;
908 goto out;
909 }
910 if (level >= 0 && root->node == count_path->nodes[level])
911 goto out;
912 level++;
913 btrfs_release_path(root, path);
914 goto again;
915
916 out:
917 btrfs_free_path(path);
918 mutex_unlock(&root->fs_info->alloc_mutex);
919 return total_count;
920 }
921
922 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
923 struct extent_buffer *buf)
924 {
925 u64 bytenr;
926 u32 nritems;
927 struct btrfs_key key;
928 struct btrfs_file_extent_item *fi;
929 int i;
930 int level;
931 int ret;
932 int faili;
933
934 if (!root->ref_cows)
935 return 0;
936
937 level = btrfs_header_level(buf);
938 nritems = btrfs_header_nritems(buf);
939 for (i = 0; i < nritems; i++) {
940 if (level == 0) {
941 u64 disk_bytenr;
942 btrfs_item_key_to_cpu(buf, &key, i);
943 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
944 continue;
945 fi = btrfs_item_ptr(buf, i,
946 struct btrfs_file_extent_item);
947 if (btrfs_file_extent_type(buf, fi) ==
948 BTRFS_FILE_EXTENT_INLINE)
949 continue;
950 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
951 if (disk_bytenr == 0)
952 continue;
953
954 mutex_lock(&root->fs_info->alloc_mutex);
955 ret = __btrfs_inc_extent_ref(trans, root, disk_bytenr,
956 btrfs_file_extent_disk_num_bytes(buf, fi),
957 root->root_key.objectid, trans->transid,
958 key.objectid, key.offset);
959 mutex_unlock(&root->fs_info->alloc_mutex);
960 if (ret) {
961 faili = i;
962 WARN_ON(1);
963 goto fail;
964 }
965 } else {
966 bytenr = btrfs_node_blockptr(buf, i);
967 btrfs_node_key_to_cpu(buf, &key, i);
968
969 mutex_lock(&root->fs_info->alloc_mutex);
970 ret = __btrfs_inc_extent_ref(trans, root, bytenr,
971 btrfs_level_size(root, level - 1),
972 root->root_key.objectid,
973 trans->transid,
974 level - 1, key.objectid);
975 mutex_unlock(&root->fs_info->alloc_mutex);
976 if (ret) {
977 faili = i;
978 WARN_ON(1);
979 goto fail;
980 }
981 }
982 }
983 return 0;
984 fail:
985 WARN_ON(1);
986 #if 0
987 for (i =0; i < faili; i++) {
988 if (level == 0) {
989 u64 disk_bytenr;
990 btrfs_item_key_to_cpu(buf, &key, i);
991 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
992 continue;
993 fi = btrfs_item_ptr(buf, i,
994 struct btrfs_file_extent_item);
995 if (btrfs_file_extent_type(buf, fi) ==
996 BTRFS_FILE_EXTENT_INLINE)
997 continue;
998 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
999 if (disk_bytenr == 0)
1000 continue;
1001 err = btrfs_free_extent(trans, root, disk_bytenr,
1002 btrfs_file_extent_disk_num_bytes(buf,
1003 fi), 0);
1004 BUG_ON(err);
1005 } else {
1006 bytenr = btrfs_node_blockptr(buf, i);
1007 err = btrfs_free_extent(trans, root, bytenr,
1008 btrfs_level_size(root, level - 1), 0);
1009 BUG_ON(err);
1010 }
1011 }
1012 #endif
1013 return ret;
1014 }
1015
1016 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1017 struct btrfs_root *root,
1018 struct btrfs_path *path,
1019 struct btrfs_block_group_cache *cache)
1020 {
1021 int ret;
1022 int pending_ret;
1023 struct btrfs_root *extent_root = root->fs_info->extent_root;
1024 unsigned long bi;
1025 struct extent_buffer *leaf;
1026
1027 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1028 if (ret < 0)
1029 goto fail;
1030 BUG_ON(ret);
1031
1032 leaf = path->nodes[0];
1033 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1034 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1035 btrfs_mark_buffer_dirty(leaf);
1036 btrfs_release_path(extent_root, path);
1037 fail:
1038 finish_current_insert(trans, extent_root);
1039 pending_ret = del_pending_extents(trans, extent_root);
1040 if (ret)
1041 return ret;
1042 if (pending_ret)
1043 return pending_ret;
1044 return 0;
1045
1046 }
1047
1048 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1049 struct btrfs_root *root)
1050 {
1051 struct extent_io_tree *block_group_cache;
1052 struct btrfs_block_group_cache *cache;
1053 int ret;
1054 int err = 0;
1055 int werr = 0;
1056 struct btrfs_path *path;
1057 u64 last = 0;
1058 u64 start;
1059 u64 end;
1060 u64 ptr;
1061
1062 block_group_cache = &root->fs_info->block_group_cache;
1063 path = btrfs_alloc_path();
1064 if (!path)
1065 return -ENOMEM;
1066
1067 mutex_lock(&root->fs_info->alloc_mutex);
1068 while(1) {
1069 ret = find_first_extent_bit(block_group_cache, last,
1070 &start, &end, BLOCK_GROUP_DIRTY);
1071 if (ret)
1072 break;
1073
1074 last = end + 1;
1075 ret = get_state_private(block_group_cache, start, &ptr);
1076 if (ret)
1077 break;
1078 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
1079 err = write_one_cache_group(trans, root,
1080 path, cache);
1081 /*
1082 * if we fail to write the cache group, we want
1083 * to keep it marked dirty in hopes that a later
1084 * write will work
1085 */
1086 if (err) {
1087 werr = err;
1088 continue;
1089 }
1090 clear_extent_bits(block_group_cache, start, end,
1091 BLOCK_GROUP_DIRTY, GFP_NOFS);
1092 }
1093 btrfs_free_path(path);
1094 mutex_unlock(&root->fs_info->alloc_mutex);
1095 return werr;
1096 }
1097
1098 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
1099 u64 flags)
1100 {
1101 struct list_head *head = &info->space_info;
1102 struct list_head *cur;
1103 struct btrfs_space_info *found;
1104 list_for_each(cur, head) {
1105 found = list_entry(cur, struct btrfs_space_info, list);
1106 if (found->flags == flags)
1107 return found;
1108 }
1109 return NULL;
1110
1111 }
1112
1113 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1114 u64 total_bytes, u64 bytes_used,
1115 struct btrfs_space_info **space_info)
1116 {
1117 struct btrfs_space_info *found;
1118
1119 found = __find_space_info(info, flags);
1120 if (found) {
1121 found->total_bytes += total_bytes;
1122 found->bytes_used += bytes_used;
1123 found->full = 0;
1124 WARN_ON(found->total_bytes < found->bytes_used);
1125 *space_info = found;
1126 return 0;
1127 }
1128 found = kmalloc(sizeof(*found), GFP_NOFS);
1129 if (!found)
1130 return -ENOMEM;
1131
1132 list_add(&found->list, &info->space_info);
1133 found->flags = flags;
1134 found->total_bytes = total_bytes;
1135 found->bytes_used = bytes_used;
1136 found->bytes_pinned = 0;
1137 found->full = 0;
1138 found->force_alloc = 0;
1139 *space_info = found;
1140 return 0;
1141 }
1142
1143 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1144 {
1145 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1146 BTRFS_BLOCK_GROUP_RAID1 |
1147 BTRFS_BLOCK_GROUP_RAID10 |
1148 BTRFS_BLOCK_GROUP_DUP);
1149 if (extra_flags) {
1150 if (flags & BTRFS_BLOCK_GROUP_DATA)
1151 fs_info->avail_data_alloc_bits |= extra_flags;
1152 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1153 fs_info->avail_metadata_alloc_bits |= extra_flags;
1154 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1155 fs_info->avail_system_alloc_bits |= extra_flags;
1156 }
1157 }
1158
1159 static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags)
1160 {
1161 u64 num_devices = root->fs_info->fs_devices->num_devices;
1162
1163 if (num_devices == 1)
1164 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
1165 if (num_devices < 4)
1166 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
1167
1168 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
1169 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
1170 BTRFS_BLOCK_GROUP_RAID10))) {
1171 flags &= ~BTRFS_BLOCK_GROUP_DUP;
1172 }
1173
1174 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
1175 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
1176 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
1177 }
1178
1179 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
1180 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
1181 (flags & BTRFS_BLOCK_GROUP_RAID10) |
1182 (flags & BTRFS_BLOCK_GROUP_DUP)))
1183 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
1184 return flags;
1185 }
1186
1187 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1188 struct btrfs_root *extent_root, u64 alloc_bytes,
1189 u64 flags, int force)
1190 {
1191 struct btrfs_space_info *space_info;
1192 u64 thresh;
1193 u64 start;
1194 u64 num_bytes;
1195 int ret;
1196
1197 flags = reduce_alloc_profile(extent_root, flags);
1198
1199 space_info = __find_space_info(extent_root->fs_info, flags);
1200 if (!space_info) {
1201 ret = update_space_info(extent_root->fs_info, flags,
1202 0, 0, &space_info);
1203 BUG_ON(ret);
1204 }
1205 BUG_ON(!space_info);
1206
1207 if (space_info->force_alloc) {
1208 force = 1;
1209 space_info->force_alloc = 0;
1210 }
1211 if (space_info->full)
1212 goto out;
1213
1214 thresh = div_factor(space_info->total_bytes, 6);
1215 if (!force &&
1216 (space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1217 thresh)
1218 goto out;
1219
1220 mutex_lock(&extent_root->fs_info->chunk_mutex);
1221 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1222 if (ret == -ENOSPC) {
1223 printk("space info full %Lu\n", flags);
1224 space_info->full = 1;
1225 goto out_unlock;
1226 }
1227 BUG_ON(ret);
1228
1229 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1230 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1231 BUG_ON(ret);
1232 out_unlock:
1233 mutex_unlock(&extent_root->fs_info->chunk_mutex);
1234 out:
1235 return 0;
1236 }
1237
1238 static int update_block_group(struct btrfs_trans_handle *trans,
1239 struct btrfs_root *root,
1240 u64 bytenr, u64 num_bytes, int alloc,
1241 int mark_free)
1242 {
1243 struct btrfs_block_group_cache *cache;
1244 struct btrfs_fs_info *info = root->fs_info;
1245 u64 total = num_bytes;
1246 u64 old_val;
1247 u64 byte_in_group;
1248 u64 start;
1249 u64 end;
1250
1251 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1252 while(total) {
1253 cache = btrfs_lookup_block_group(info, bytenr);
1254 if (!cache) {
1255 return -1;
1256 }
1257 byte_in_group = bytenr - cache->key.objectid;
1258 WARN_ON(byte_in_group > cache->key.offset);
1259 start = cache->key.objectid;
1260 end = start + cache->key.offset - 1;
1261 set_extent_bits(&info->block_group_cache, start, end,
1262 BLOCK_GROUP_DIRTY, GFP_NOFS);
1263
1264 old_val = btrfs_block_group_used(&cache->item);
1265 num_bytes = min(total, cache->key.offset - byte_in_group);
1266 if (alloc) {
1267 old_val += num_bytes;
1268 cache->space_info->bytes_used += num_bytes;
1269 } else {
1270 old_val -= num_bytes;
1271 cache->space_info->bytes_used -= num_bytes;
1272 if (mark_free) {
1273 set_extent_dirty(&info->free_space_cache,
1274 bytenr, bytenr + num_bytes - 1,
1275 GFP_NOFS);
1276 }
1277 }
1278 btrfs_set_block_group_used(&cache->item, old_val);
1279 total -= num_bytes;
1280 bytenr += num_bytes;
1281 }
1282 return 0;
1283 }
1284
1285 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
1286 {
1287 u64 start;
1288 u64 end;
1289 int ret;
1290 ret = find_first_extent_bit(&root->fs_info->block_group_cache,
1291 search_start, &start, &end,
1292 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
1293 BLOCK_GROUP_SYSTEM);
1294 if (ret)
1295 return 0;
1296 return start;
1297 }
1298
1299
1300 static int update_pinned_extents(struct btrfs_root *root,
1301 u64 bytenr, u64 num, int pin)
1302 {
1303 u64 len;
1304 struct btrfs_block_group_cache *cache;
1305 struct btrfs_fs_info *fs_info = root->fs_info;
1306
1307 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1308 if (pin) {
1309 set_extent_dirty(&fs_info->pinned_extents,
1310 bytenr, bytenr + num - 1, GFP_NOFS);
1311 } else {
1312 clear_extent_dirty(&fs_info->pinned_extents,
1313 bytenr, bytenr + num - 1, GFP_NOFS);
1314 }
1315 while (num > 0) {
1316 cache = btrfs_lookup_block_group(fs_info, bytenr);
1317 if (!cache) {
1318 u64 first = first_logical_byte(root, bytenr);
1319 WARN_ON(first < bytenr);
1320 len = min(first - bytenr, num);
1321 } else {
1322 len = min(num, cache->key.offset -
1323 (bytenr - cache->key.objectid));
1324 }
1325 if (pin) {
1326 if (cache) {
1327 cache->pinned += len;
1328 cache->space_info->bytes_pinned += len;
1329 }
1330 fs_info->total_pinned += len;
1331 } else {
1332 if (cache) {
1333 cache->pinned -= len;
1334 cache->space_info->bytes_pinned -= len;
1335 }
1336 fs_info->total_pinned -= len;
1337 }
1338 bytenr += len;
1339 num -= len;
1340 }
1341 return 0;
1342 }
1343
1344 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1345 {
1346 u64 last = 0;
1347 u64 start;
1348 u64 end;
1349 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1350 int ret;
1351
1352 while(1) {
1353 ret = find_first_extent_bit(pinned_extents, last,
1354 &start, &end, EXTENT_DIRTY);
1355 if (ret)
1356 break;
1357 set_extent_dirty(copy, start, end, GFP_NOFS);
1358 last = end + 1;
1359 }
1360 return 0;
1361 }
1362
1363 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1364 struct btrfs_root *root,
1365 struct extent_io_tree *unpin)
1366 {
1367 u64 start;
1368 u64 end;
1369 int ret;
1370 struct extent_io_tree *free_space_cache;
1371 free_space_cache = &root->fs_info->free_space_cache;
1372
1373 mutex_lock(&root->fs_info->alloc_mutex);
1374 while(1) {
1375 ret = find_first_extent_bit(unpin, 0, &start, &end,
1376 EXTENT_DIRTY);
1377 if (ret)
1378 break;
1379 update_pinned_extents(root, start, end + 1 - start, 0);
1380 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1381 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1382 }
1383 mutex_unlock(&root->fs_info->alloc_mutex);
1384 return 0;
1385 }
1386
1387 static int finish_current_insert(struct btrfs_trans_handle *trans,
1388 struct btrfs_root *extent_root)
1389 {
1390 u64 start;
1391 u64 end;
1392 struct btrfs_fs_info *info = extent_root->fs_info;
1393 struct extent_buffer *eb;
1394 struct btrfs_path *path;
1395 struct btrfs_key ins;
1396 struct btrfs_disk_key first;
1397 struct btrfs_extent_item extent_item;
1398 int ret;
1399 int level;
1400 int err = 0;
1401
1402 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
1403 btrfs_set_stack_extent_refs(&extent_item, 1);
1404 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1405 path = btrfs_alloc_path();
1406
1407 while(1) {
1408 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1409 &end, EXTENT_LOCKED);
1410 if (ret)
1411 break;
1412
1413 ins.objectid = start;
1414 ins.offset = end + 1 - start;
1415 err = btrfs_insert_item(trans, extent_root, &ins,
1416 &extent_item, sizeof(extent_item));
1417 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1418 GFP_NOFS);
1419 eb = read_tree_block(extent_root, ins.objectid, ins.offset,
1420 trans->transid);
1421 btrfs_tree_lock(eb);
1422 level = btrfs_header_level(eb);
1423 if (level == 0) {
1424 btrfs_item_key(eb, &first, 0);
1425 } else {
1426 btrfs_node_key(eb, &first, 0);
1427 }
1428 btrfs_tree_unlock(eb);
1429 free_extent_buffer(eb);
1430 /*
1431 * the first key is just a hint, so the race we've created
1432 * against reading it is fine
1433 */
1434 err = btrfs_insert_extent_backref(trans, extent_root, path,
1435 start, extent_root->root_key.objectid,
1436 0, level,
1437 btrfs_disk_key_objectid(&first));
1438 BUG_ON(err);
1439 }
1440 btrfs_free_path(path);
1441 return 0;
1442 }
1443
1444 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1445 int pending)
1446 {
1447 int err = 0;
1448
1449 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1450 if (!pending) {
1451 struct extent_buffer *buf;
1452 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1453 if (buf) {
1454 if (!btrfs_try_tree_lock(buf) &&
1455 btrfs_buffer_uptodate(buf, 0)) {
1456 u64 transid =
1457 root->fs_info->running_transaction->transid;
1458 u64 header_transid =
1459 btrfs_header_generation(buf);
1460 if (header_transid == transid &&
1461 !btrfs_header_flag(buf,
1462 BTRFS_HEADER_FLAG_WRITTEN)) {
1463 clean_tree_block(NULL, root, buf);
1464 btrfs_tree_unlock(buf);
1465 free_extent_buffer(buf);
1466 return 1;
1467 }
1468 btrfs_tree_unlock(buf);
1469 }
1470 free_extent_buffer(buf);
1471 }
1472 update_pinned_extents(root, bytenr, num_bytes, 1);
1473 } else {
1474 set_extent_bits(&root->fs_info->pending_del,
1475 bytenr, bytenr + num_bytes - 1,
1476 EXTENT_LOCKED, GFP_NOFS);
1477 }
1478 BUG_ON(err < 0);
1479 return 0;
1480 }
1481
1482 /*
1483 * remove an extent from the root, returns 0 on success
1484 */
1485 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1486 *root, u64 bytenr, u64 num_bytes,
1487 u64 root_objectid, u64 ref_generation,
1488 u64 owner_objectid, u64 owner_offset, int pin,
1489 int mark_free)
1490 {
1491 struct btrfs_path *path;
1492 struct btrfs_key key;
1493 struct btrfs_fs_info *info = root->fs_info;
1494 struct btrfs_root *extent_root = info->extent_root;
1495 struct extent_buffer *leaf;
1496 int ret;
1497 int extent_slot = 0;
1498 int found_extent = 0;
1499 int num_to_del = 1;
1500 struct btrfs_extent_item *ei;
1501 u32 refs;
1502
1503 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1504 key.objectid = bytenr;
1505 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1506 key.offset = num_bytes;
1507 path = btrfs_alloc_path();
1508 if (!path)
1509 return -ENOMEM;
1510
1511 path->reada = 1;
1512 ret = lookup_extent_backref(trans, extent_root, path,
1513 bytenr, root_objectid,
1514 ref_generation,
1515 owner_objectid, owner_offset, 1);
1516 if (ret == 0) {
1517 struct btrfs_key found_key;
1518 extent_slot = path->slots[0];
1519 while(extent_slot > 0) {
1520 extent_slot--;
1521 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1522 extent_slot);
1523 if (found_key.objectid != bytenr)
1524 break;
1525 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1526 found_key.offset == num_bytes) {
1527 found_extent = 1;
1528 break;
1529 }
1530 if (path->slots[0] - extent_slot > 5)
1531 break;
1532 }
1533 if (!found_extent)
1534 ret = btrfs_del_item(trans, extent_root, path);
1535 } else {
1536 btrfs_print_leaf(extent_root, path->nodes[0]);
1537 WARN_ON(1);
1538 printk("Unable to find ref byte nr %Lu root %Lu "
1539 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1540 root_objectid, ref_generation, owner_objectid,
1541 owner_offset);
1542 }
1543 if (!found_extent) {
1544 btrfs_release_path(extent_root, path);
1545 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1546 if (ret < 0)
1547 return ret;
1548 BUG_ON(ret);
1549 extent_slot = path->slots[0];
1550 }
1551
1552 leaf = path->nodes[0];
1553 ei = btrfs_item_ptr(leaf, extent_slot,
1554 struct btrfs_extent_item);
1555 refs = btrfs_extent_refs(leaf, ei);
1556 BUG_ON(refs == 0);
1557 refs -= 1;
1558 btrfs_set_extent_refs(leaf, ei, refs);
1559
1560 btrfs_mark_buffer_dirty(leaf);
1561
1562 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1563 /* if the back ref and the extent are next to each other
1564 * they get deleted below in one shot
1565 */
1566 path->slots[0] = extent_slot;
1567 num_to_del = 2;
1568 } else if (found_extent) {
1569 /* otherwise delete the extent back ref */
1570 ret = btrfs_del_item(trans, extent_root, path);
1571 BUG_ON(ret);
1572 /* if refs are 0, we need to setup the path for deletion */
1573 if (refs == 0) {
1574 btrfs_release_path(extent_root, path);
1575 ret = btrfs_search_slot(trans, extent_root, &key, path,
1576 -1, 1);
1577 if (ret < 0)
1578 return ret;
1579 BUG_ON(ret);
1580 }
1581 }
1582
1583 if (refs == 0) {
1584 u64 super_used;
1585 u64 root_used;
1586
1587 if (pin) {
1588 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1589 if (ret > 0)
1590 mark_free = 1;
1591 BUG_ON(ret < 0);
1592 }
1593
1594 /* block accounting for super block */
1595 spin_lock_irq(&info->delalloc_lock);
1596 super_used = btrfs_super_bytes_used(&info->super_copy);
1597 btrfs_set_super_bytes_used(&info->super_copy,
1598 super_used - num_bytes);
1599 spin_unlock_irq(&info->delalloc_lock);
1600
1601 /* block accounting for root item */
1602 root_used = btrfs_root_used(&root->root_item);
1603 btrfs_set_root_used(&root->root_item,
1604 root_used - num_bytes);
1605 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1606 num_to_del);
1607 if (ret) {
1608 return ret;
1609 }
1610 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1611 mark_free);
1612 BUG_ON(ret);
1613 }
1614 btrfs_free_path(path);
1615 finish_current_insert(trans, extent_root);
1616 return ret;
1617 }
1618
1619 /*
1620 * find all the blocks marked as pending in the radix tree and remove
1621 * them from the extent map
1622 */
1623 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1624 btrfs_root *extent_root)
1625 {
1626 int ret;
1627 int err = 0;
1628 u64 start;
1629 u64 end;
1630 struct extent_io_tree *pending_del;
1631 struct extent_io_tree *pinned_extents;
1632
1633 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
1634 pending_del = &extent_root->fs_info->pending_del;
1635 pinned_extents = &extent_root->fs_info->pinned_extents;
1636
1637 while(1) {
1638 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1639 EXTENT_LOCKED);
1640 if (ret)
1641 break;
1642 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1643 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1644 GFP_NOFS);
1645 ret = __free_extent(trans, extent_root,
1646 start, end + 1 - start,
1647 extent_root->root_key.objectid,
1648 0, 0, 0, 0, 0);
1649 if (ret)
1650 err = ret;
1651 }
1652 return err;
1653 }
1654
1655 /*
1656 * remove an extent from the root, returns 0 on success
1657 */
1658 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
1659 struct btrfs_root *root, u64 bytenr,
1660 u64 num_bytes, u64 root_objectid,
1661 u64 ref_generation, u64 owner_objectid,
1662 u64 owner_offset, int pin)
1663 {
1664 struct btrfs_root *extent_root = root->fs_info->extent_root;
1665 int pending_ret;
1666 int ret;
1667
1668 WARN_ON(num_bytes < root->sectorsize);
1669 if (!root->ref_cows)
1670 ref_generation = 0;
1671
1672 if (root == extent_root) {
1673 pin_down_bytes(root, bytenr, num_bytes, 1);
1674 return 0;
1675 }
1676 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1677 ref_generation, owner_objectid, owner_offset,
1678 pin, pin == 0);
1679
1680 finish_current_insert(trans, root->fs_info->extent_root);
1681 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1682 return ret ? ret : pending_ret;
1683 }
1684
1685 int btrfs_free_extent(struct btrfs_trans_handle *trans,
1686 struct btrfs_root *root, u64 bytenr,
1687 u64 num_bytes, u64 root_objectid,
1688 u64 ref_generation, u64 owner_objectid,
1689 u64 owner_offset, int pin)
1690 {
1691 int ret;
1692
1693 maybe_lock_mutex(root);
1694 ret = __btrfs_free_extent(trans, root, bytenr, num_bytes,
1695 root_objectid, ref_generation,
1696 owner_objectid, owner_offset, pin);
1697 maybe_unlock_mutex(root);
1698 return ret;
1699 }
1700
1701 static u64 stripe_align(struct btrfs_root *root, u64 val)
1702 {
1703 u64 mask = ((u64)root->stripesize - 1);
1704 u64 ret = (val + mask) & ~mask;
1705 return ret;
1706 }
1707
1708 /*
1709 * walks the btree of allocated extents and find a hole of a given size.
1710 * The key ins is changed to record the hole:
1711 * ins->objectid == block start
1712 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1713 * ins->offset == number of blocks
1714 * Any available blocks before search_start are skipped.
1715 */
1716 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1717 struct btrfs_root *orig_root,
1718 u64 num_bytes, u64 empty_size,
1719 u64 search_start, u64 search_end,
1720 u64 hint_byte, struct btrfs_key *ins,
1721 u64 exclude_start, u64 exclude_nr,
1722 int data)
1723 {
1724 int ret;
1725 u64 orig_search_start;
1726 struct btrfs_root * root = orig_root->fs_info->extent_root;
1727 struct btrfs_fs_info *info = root->fs_info;
1728 u64 total_needed = num_bytes;
1729 u64 *last_ptr = NULL;
1730 struct btrfs_block_group_cache *block_group;
1731 int full_scan = 0;
1732 int wrapped = 0;
1733 int chunk_alloc_done = 0;
1734 int empty_cluster = 2 * 1024 * 1024;
1735 int allowed_chunk_alloc = 0;
1736
1737 WARN_ON(num_bytes < root->sectorsize);
1738 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1739
1740 if (orig_root->ref_cows || empty_size)
1741 allowed_chunk_alloc = 1;
1742
1743 if (data & BTRFS_BLOCK_GROUP_METADATA) {
1744 last_ptr = &root->fs_info->last_alloc;
1745 empty_cluster = 256 * 1024;
1746 }
1747
1748 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
1749 last_ptr = &root->fs_info->last_data_alloc;
1750 }
1751
1752 if (last_ptr) {
1753 if (*last_ptr)
1754 hint_byte = *last_ptr;
1755 else {
1756 empty_size += empty_cluster;
1757 }
1758 }
1759
1760 search_start = max(search_start, first_logical_byte(root, 0));
1761 orig_search_start = search_start;
1762
1763 if (search_end == (u64)-1)
1764 search_end = btrfs_super_total_bytes(&info->super_copy);
1765
1766 if (hint_byte) {
1767 block_group = btrfs_lookup_first_block_group(info, hint_byte);
1768 if (!block_group)
1769 hint_byte = search_start;
1770 block_group = __btrfs_find_block_group(root, block_group,
1771 hint_byte, data, 1);
1772 if (last_ptr && *last_ptr == 0 && block_group)
1773 hint_byte = block_group->key.objectid;
1774 } else {
1775 block_group = __btrfs_find_block_group(root,
1776 trans->block_group,
1777 search_start, data, 1);
1778 }
1779 search_start = max(search_start, hint_byte);
1780
1781 total_needed += empty_size;
1782
1783 check_failed:
1784 if (!block_group) {
1785 block_group = btrfs_lookup_first_block_group(info,
1786 search_start);
1787 if (!block_group)
1788 block_group = btrfs_lookup_first_block_group(info,
1789 orig_search_start);
1790 }
1791 if (full_scan && !chunk_alloc_done) {
1792 if (allowed_chunk_alloc) {
1793 do_chunk_alloc(trans, root,
1794 num_bytes + 2 * 1024 * 1024, data, 1);
1795 allowed_chunk_alloc = 0;
1796 } else if (block_group && block_group_bits(block_group, data)) {
1797 block_group->space_info->force_alloc = 1;
1798 }
1799 chunk_alloc_done = 1;
1800 }
1801 ret = find_search_start(root, &block_group, &search_start,
1802 total_needed, data);
1803 if (ret == -ENOSPC && last_ptr && *last_ptr) {
1804 *last_ptr = 0;
1805 block_group = btrfs_lookup_first_block_group(info,
1806 orig_search_start);
1807 search_start = orig_search_start;
1808 ret = find_search_start(root, &block_group, &search_start,
1809 total_needed, data);
1810 }
1811 if (ret == -ENOSPC)
1812 goto enospc;
1813 if (ret)
1814 goto error;
1815
1816 if (last_ptr && *last_ptr && search_start != *last_ptr) {
1817 *last_ptr = 0;
1818 if (!empty_size) {
1819 empty_size += empty_cluster;
1820 total_needed += empty_size;
1821 }
1822 block_group = btrfs_lookup_first_block_group(info,
1823 orig_search_start);
1824 search_start = orig_search_start;
1825 ret = find_search_start(root, &block_group,
1826 &search_start, total_needed, data);
1827 if (ret == -ENOSPC)
1828 goto enospc;
1829 if (ret)
1830 goto error;
1831 }
1832
1833 search_start = stripe_align(root, search_start);
1834 ins->objectid = search_start;
1835 ins->offset = num_bytes;
1836
1837 if (ins->objectid + num_bytes >= search_end)
1838 goto enospc;
1839
1840 if (ins->objectid + num_bytes >
1841 block_group->key.objectid + block_group->key.offset) {
1842 search_start = block_group->key.objectid +
1843 block_group->key.offset;
1844 goto new_group;
1845 }
1846
1847 if (test_range_bit(&info->extent_ins, ins->objectid,
1848 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1849 search_start = ins->objectid + num_bytes;
1850 goto new_group;
1851 }
1852
1853 if (test_range_bit(&info->pinned_extents, ins->objectid,
1854 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1855 search_start = ins->objectid + num_bytes;
1856 goto new_group;
1857 }
1858
1859 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1860 ins->objectid < exclude_start + exclude_nr)) {
1861 search_start = exclude_start + exclude_nr;
1862 goto new_group;
1863 }
1864
1865 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
1866 block_group = btrfs_lookup_block_group(info, ins->objectid);
1867 if (block_group)
1868 trans->block_group = block_group;
1869 }
1870 ins->offset = num_bytes;
1871 if (last_ptr) {
1872 *last_ptr = ins->objectid + ins->offset;
1873 if (*last_ptr ==
1874 btrfs_super_total_bytes(&root->fs_info->super_copy)) {
1875 *last_ptr = 0;
1876 }
1877 }
1878 return 0;
1879
1880 new_group:
1881 if (search_start + num_bytes >= search_end) {
1882 enospc:
1883 search_start = orig_search_start;
1884 if (full_scan) {
1885 ret = -ENOSPC;
1886 goto error;
1887 }
1888 if (wrapped) {
1889 if (!full_scan)
1890 total_needed -= empty_size;
1891 full_scan = 1;
1892 } else
1893 wrapped = 1;
1894 }
1895 block_group = btrfs_lookup_first_block_group(info, search_start);
1896 cond_resched();
1897 block_group = __btrfs_find_block_group(root, block_group,
1898 search_start, data, 0);
1899 goto check_failed;
1900
1901 error:
1902 return ret;
1903 }
1904
1905 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
1906 struct btrfs_root *root,
1907 u64 num_bytes, u64 min_alloc_size,
1908 u64 empty_size, u64 hint_byte,
1909 u64 search_end, struct btrfs_key *ins,
1910 u64 data)
1911 {
1912 int ret;
1913 u64 search_start = 0;
1914 u64 alloc_profile;
1915 struct btrfs_fs_info *info = root->fs_info;
1916
1917 if (data) {
1918 alloc_profile = info->avail_data_alloc_bits &
1919 info->data_alloc_profile;
1920 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
1921 } else if (root == root->fs_info->chunk_root) {
1922 alloc_profile = info->avail_system_alloc_bits &
1923 info->system_alloc_profile;
1924 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
1925 } else {
1926 alloc_profile = info->avail_metadata_alloc_bits &
1927 info->metadata_alloc_profile;
1928 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
1929 }
1930 again:
1931 data = reduce_alloc_profile(root, data);
1932 /*
1933 * the only place that sets empty_size is btrfs_realloc_node, which
1934 * is not called recursively on allocations
1935 */
1936 if (empty_size || root->ref_cows) {
1937 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
1938 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1939 2 * 1024 * 1024,
1940 BTRFS_BLOCK_GROUP_METADATA |
1941 (info->metadata_alloc_profile &
1942 info->avail_metadata_alloc_bits), 0);
1943 BUG_ON(ret);
1944 }
1945 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1946 num_bytes + 2 * 1024 * 1024, data, 0);
1947 BUG_ON(ret);
1948 }
1949
1950 WARN_ON(num_bytes < root->sectorsize);
1951 ret = find_free_extent(trans, root, num_bytes, empty_size,
1952 search_start, search_end, hint_byte, ins,
1953 trans->alloc_exclude_start,
1954 trans->alloc_exclude_nr, data);
1955
1956 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
1957 num_bytes = num_bytes >> 1;
1958 num_bytes = max(num_bytes, min_alloc_size);
1959 do_chunk_alloc(trans, root->fs_info->extent_root,
1960 num_bytes, data, 1);
1961 goto again;
1962 }
1963 if (ret) {
1964 printk("allocation failed flags %Lu\n", data);
1965 BUG();
1966 }
1967 clear_extent_dirty(&root->fs_info->free_space_cache,
1968 ins->objectid, ins->objectid + ins->offset - 1,
1969 GFP_NOFS);
1970 return 0;
1971 }
1972
1973 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
1974 struct btrfs_root *root,
1975 u64 num_bytes, u64 min_alloc_size,
1976 u64 empty_size, u64 hint_byte,
1977 u64 search_end, struct btrfs_key *ins,
1978 u64 data)
1979 {
1980 int ret;
1981 maybe_lock_mutex(root);
1982 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
1983 empty_size, hint_byte, search_end, ins,
1984 data);
1985 maybe_unlock_mutex(root);
1986 return ret;
1987 }
1988
1989 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
1990 struct btrfs_root *root,
1991 u64 root_objectid, u64 ref_generation,
1992 u64 owner, u64 owner_offset,
1993 struct btrfs_key *ins)
1994 {
1995 int ret;
1996 int pending_ret;
1997 u64 super_used;
1998 u64 root_used;
1999 u64 num_bytes = ins->offset;
2000 u32 sizes[2];
2001 struct btrfs_fs_info *info = root->fs_info;
2002 struct btrfs_root *extent_root = info->extent_root;
2003 struct btrfs_extent_item *extent_item;
2004 struct btrfs_extent_ref *ref;
2005 struct btrfs_path *path;
2006 struct btrfs_key keys[2];
2007
2008 /* block accounting for super block */
2009 spin_lock_irq(&info->delalloc_lock);
2010 super_used = btrfs_super_bytes_used(&info->super_copy);
2011 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
2012 spin_unlock_irq(&info->delalloc_lock);
2013
2014 /* block accounting for root item */
2015 root_used = btrfs_root_used(&root->root_item);
2016 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
2017
2018 if (root == extent_root) {
2019 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2020 ins->objectid + ins->offset - 1,
2021 EXTENT_LOCKED, GFP_NOFS);
2022 goto update_block;
2023 }
2024
2025 memcpy(&keys[0], ins, sizeof(*ins));
2026 keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
2027 owner, owner_offset);
2028 keys[1].objectid = ins->objectid;
2029 keys[1].type = BTRFS_EXTENT_REF_KEY;
2030 sizes[0] = sizeof(*extent_item);
2031 sizes[1] = sizeof(*ref);
2032
2033 path = btrfs_alloc_path();
2034 BUG_ON(!path);
2035
2036 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
2037 sizes, 2);
2038
2039 BUG_ON(ret);
2040 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2041 struct btrfs_extent_item);
2042 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
2043 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
2044 struct btrfs_extent_ref);
2045
2046 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
2047 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
2048 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
2049 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
2050
2051 btrfs_mark_buffer_dirty(path->nodes[0]);
2052
2053 trans->alloc_exclude_start = 0;
2054 trans->alloc_exclude_nr = 0;
2055 btrfs_free_path(path);
2056 finish_current_insert(trans, extent_root);
2057 pending_ret = del_pending_extents(trans, extent_root);
2058
2059 if (ret)
2060 goto out;
2061 if (pending_ret) {
2062 ret = pending_ret;
2063 goto out;
2064 }
2065
2066 update_block:
2067 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
2068 if (ret) {
2069 printk("update block group failed for %Lu %Lu\n",
2070 ins->objectid, ins->offset);
2071 BUG();
2072 }
2073 out:
2074 return ret;
2075 }
2076
2077 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2078 struct btrfs_root *root,
2079 u64 root_objectid, u64 ref_generation,
2080 u64 owner, u64 owner_offset,
2081 struct btrfs_key *ins)
2082 {
2083 int ret;
2084 maybe_lock_mutex(root);
2085 ret = __btrfs_alloc_reserved_extent(trans, root, root_objectid,
2086 ref_generation, owner,
2087 owner_offset, ins);
2088 maybe_unlock_mutex(root);
2089 return ret;
2090 }
2091 /*
2092 * finds a free extent and does all the dirty work required for allocation
2093 * returns the key for the extent through ins, and a tree buffer for
2094 * the first block of the extent through buf.
2095 *
2096 * returns 0 if everything worked, non-zero otherwise.
2097 */
2098 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
2099 struct btrfs_root *root,
2100 u64 num_bytes, u64 min_alloc_size,
2101 u64 root_objectid, u64 ref_generation,
2102 u64 owner, u64 owner_offset,
2103 u64 empty_size, u64 hint_byte,
2104 u64 search_end, struct btrfs_key *ins, u64 data)
2105 {
2106 int ret;
2107
2108 maybe_lock_mutex(root);
2109
2110 ret = __btrfs_reserve_extent(trans, root, num_bytes,
2111 min_alloc_size, empty_size, hint_byte,
2112 search_end, ins, data);
2113 BUG_ON(ret);
2114 ret = __btrfs_alloc_reserved_extent(trans, root, root_objectid,
2115 ref_generation, owner,
2116 owner_offset, ins);
2117 BUG_ON(ret);
2118
2119 maybe_unlock_mutex(root);
2120 return ret;
2121 }
2122 /*
2123 * helper function to allocate a block for a given tree
2124 * returns the tree buffer or NULL.
2125 */
2126 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2127 struct btrfs_root *root,
2128 u32 blocksize,
2129 u64 root_objectid,
2130 u64 ref_generation,
2131 u64 first_objectid,
2132 int level,
2133 u64 hint,
2134 u64 empty_size)
2135 {
2136 struct btrfs_key ins;
2137 int ret;
2138 struct extent_buffer *buf;
2139
2140 ret = btrfs_alloc_extent(trans, root, blocksize, blocksize,
2141 root_objectid, ref_generation,
2142 level, first_objectid, empty_size, hint,
2143 (u64)-1, &ins, 0);
2144 if (ret) {
2145 BUG_ON(ret > 0);
2146 return ERR_PTR(ret);
2147 }
2148 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
2149 if (!buf) {
2150 btrfs_free_extent(trans, root, ins.objectid, blocksize,
2151 root->root_key.objectid, ref_generation,
2152 0, 0, 0);
2153 return ERR_PTR(-ENOMEM);
2154 }
2155 btrfs_set_header_generation(buf, trans->transid);
2156 btrfs_tree_lock(buf);
2157 clean_tree_block(trans, root, buf);
2158 btrfs_set_buffer_uptodate(buf);
2159
2160 if (PageDirty(buf->first_page)) {
2161 printk("page %lu dirty\n", buf->first_page->index);
2162 WARN_ON(1);
2163 }
2164
2165 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
2166 buf->start + buf->len - 1, GFP_NOFS);
2167 trans->blocks_used++;
2168 return buf;
2169 }
2170
2171 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
2172 struct btrfs_root *root,
2173 struct extent_buffer *leaf)
2174 {
2175 u64 leaf_owner;
2176 u64 leaf_generation;
2177 struct btrfs_key key;
2178 struct btrfs_file_extent_item *fi;
2179 int i;
2180 int nritems;
2181 int ret;
2182
2183 BUG_ON(!btrfs_is_leaf(leaf));
2184 nritems = btrfs_header_nritems(leaf);
2185 leaf_owner = btrfs_header_owner(leaf);
2186 leaf_generation = btrfs_header_generation(leaf);
2187
2188 mutex_unlock(&root->fs_info->alloc_mutex);
2189
2190 for (i = 0; i < nritems; i++) {
2191 u64 disk_bytenr;
2192
2193 btrfs_item_key_to_cpu(leaf, &key, i);
2194 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2195 continue;
2196 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2197 if (btrfs_file_extent_type(leaf, fi) ==
2198 BTRFS_FILE_EXTENT_INLINE)
2199 continue;
2200 /*
2201 * FIXME make sure to insert a trans record that
2202 * repeats the snapshot del on crash
2203 */
2204 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2205 if (disk_bytenr == 0)
2206 continue;
2207
2208 mutex_lock(&root->fs_info->alloc_mutex);
2209 ret = __btrfs_free_extent(trans, root, disk_bytenr,
2210 btrfs_file_extent_disk_num_bytes(leaf, fi),
2211 leaf_owner, leaf_generation,
2212 key.objectid, key.offset, 0);
2213 mutex_unlock(&root->fs_info->alloc_mutex);
2214 BUG_ON(ret);
2215 }
2216
2217 mutex_lock(&root->fs_info->alloc_mutex);
2218 return 0;
2219 }
2220
2221 static void noinline reada_walk_down(struct btrfs_root *root,
2222 struct extent_buffer *node,
2223 int slot)
2224 {
2225 u64 bytenr;
2226 u64 last = 0;
2227 u32 nritems;
2228 u32 refs;
2229 u32 blocksize;
2230 int ret;
2231 int i;
2232 int level;
2233 int skipped = 0;
2234
2235 nritems = btrfs_header_nritems(node);
2236 level = btrfs_header_level(node);
2237 if (level)
2238 return;
2239
2240 for (i = slot; i < nritems && skipped < 32; i++) {
2241 bytenr = btrfs_node_blockptr(node, i);
2242 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
2243 (last > bytenr && last - bytenr > 32 * 1024))) {
2244 skipped++;
2245 continue;
2246 }
2247 blocksize = btrfs_level_size(root, level - 1);
2248 if (i != slot) {
2249 ret = lookup_extent_ref(NULL, root, bytenr,
2250 blocksize, &refs);
2251 BUG_ON(ret);
2252 if (refs != 1) {
2253 skipped++;
2254 continue;
2255 }
2256 }
2257 ret = readahead_tree_block(root, bytenr, blocksize,
2258 btrfs_node_ptr_generation(node, i));
2259 last = bytenr + blocksize;
2260 cond_resched();
2261 if (ret)
2262 break;
2263 }
2264 }
2265
2266 /*
2267 * we want to avoid as much random IO as we can with the alloc mutex
2268 * held, so drop the lock and do the lookup, then do it again with the
2269 * lock held.
2270 */
2271 int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len,
2272 u32 *refs)
2273 {
2274 mutex_unlock(&root->fs_info->alloc_mutex);
2275 lookup_extent_ref(NULL, root, start, len, refs);
2276 cond_resched();
2277 mutex_lock(&root->fs_info->alloc_mutex);
2278 return lookup_extent_ref(NULL, root, start, len, refs);
2279 }
2280
2281 /*
2282 * helper function for drop_snapshot, this walks down the tree dropping ref
2283 * counts as it goes.
2284 */
2285 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2286 struct btrfs_root *root,
2287 struct btrfs_path *path, int *level)
2288 {
2289 u64 root_owner;
2290 u64 root_gen;
2291 u64 bytenr;
2292 u64 ptr_gen;
2293 struct extent_buffer *next;
2294 struct extent_buffer *cur;
2295 struct extent_buffer *parent;
2296 u32 blocksize;
2297 int ret;
2298 u32 refs;
2299
2300 mutex_lock(&root->fs_info->alloc_mutex);
2301
2302 WARN_ON(*level < 0);
2303 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2304 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
2305 path->nodes[*level]->len, &refs);
2306 BUG_ON(ret);
2307 if (refs > 1)
2308 goto out;
2309
2310 /*
2311 * walk down to the last node level and free all the leaves
2312 */
2313 while(*level >= 0) {
2314 WARN_ON(*level < 0);
2315 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2316 cur = path->nodes[*level];
2317
2318 if (btrfs_header_level(cur) != *level)
2319 WARN_ON(1);
2320
2321 if (path->slots[*level] >=
2322 btrfs_header_nritems(cur))
2323 break;
2324 if (*level == 0) {
2325 ret = drop_leaf_ref(trans, root, cur);
2326 BUG_ON(ret);
2327 break;
2328 }
2329 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2330 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2331 blocksize = btrfs_level_size(root, *level - 1);
2332
2333 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
2334 BUG_ON(ret);
2335 if (refs != 1) {
2336 parent = path->nodes[*level];
2337 root_owner = btrfs_header_owner(parent);
2338 root_gen = btrfs_header_generation(parent);
2339 path->slots[*level]++;
2340 ret = __btrfs_free_extent(trans, root, bytenr,
2341 blocksize, root_owner,
2342 root_gen, 0, 0, 1);
2343 BUG_ON(ret);
2344 continue;
2345 }
2346 next = btrfs_find_tree_block(root, bytenr, blocksize);
2347 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2348 free_extent_buffer(next);
2349 mutex_unlock(&root->fs_info->alloc_mutex);
2350
2351 if (path->slots[*level] == 0)
2352 reada_walk_down(root, cur, path->slots[*level]);
2353
2354 next = read_tree_block(root, bytenr, blocksize,
2355 ptr_gen);
2356 cond_resched();
2357 mutex_lock(&root->fs_info->alloc_mutex);
2358
2359 /* we've dropped the lock, double check */
2360 ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
2361 &refs);
2362 BUG_ON(ret);
2363 if (refs != 1) {
2364 parent = path->nodes[*level];
2365 root_owner = btrfs_header_owner(parent);
2366 root_gen = btrfs_header_generation(parent);
2367
2368 path->slots[*level]++;
2369 free_extent_buffer(next);
2370 ret = __btrfs_free_extent(trans, root, bytenr,
2371 blocksize,
2372 root_owner,
2373 root_gen, 0, 0, 1);
2374 BUG_ON(ret);
2375 continue;
2376 }
2377 }
2378 WARN_ON(*level <= 0);
2379 if (path->nodes[*level-1])
2380 free_extent_buffer(path->nodes[*level-1]);
2381 path->nodes[*level-1] = next;
2382 *level = btrfs_header_level(next);
2383 path->slots[*level] = 0;
2384 }
2385 out:
2386 WARN_ON(*level < 0);
2387 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2388
2389 if (path->nodes[*level] == root->node) {
2390 root_owner = root->root_key.objectid;
2391 parent = path->nodes[*level];
2392 } else {
2393 parent = path->nodes[*level + 1];
2394 root_owner = btrfs_header_owner(parent);
2395 }
2396
2397 root_gen = btrfs_header_generation(parent);
2398 ret = __btrfs_free_extent(trans, root, path->nodes[*level]->start,
2399 path->nodes[*level]->len,
2400 root_owner, root_gen, 0, 0, 1);
2401 free_extent_buffer(path->nodes[*level]);
2402 path->nodes[*level] = NULL;
2403 *level += 1;
2404 BUG_ON(ret);
2405 mutex_unlock(&root->fs_info->alloc_mutex);
2406 cond_resched();
2407 return 0;
2408 }
2409
2410 /*
2411 * helper for dropping snapshots. This walks back up the tree in the path
2412 * to find the first node higher up where we haven't yet gone through
2413 * all the slots
2414 */
2415 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
2416 struct btrfs_root *root,
2417 struct btrfs_path *path, int *level)
2418 {
2419 u64 root_owner;
2420 u64 root_gen;
2421 struct btrfs_root_item *root_item = &root->root_item;
2422 int i;
2423 int slot;
2424 int ret;
2425
2426 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2427 slot = path->slots[i];
2428 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
2429 struct extent_buffer *node;
2430 struct btrfs_disk_key disk_key;
2431 node = path->nodes[i];
2432 path->slots[i]++;
2433 *level = i;
2434 WARN_ON(*level == 0);
2435 btrfs_node_key(node, &disk_key, path->slots[i]);
2436 memcpy(&root_item->drop_progress,
2437 &disk_key, sizeof(disk_key));
2438 root_item->drop_level = i;
2439 return 0;
2440 } else {
2441 if (path->nodes[*level] == root->node) {
2442 root_owner = root->root_key.objectid;
2443 root_gen =
2444 btrfs_header_generation(path->nodes[*level]);
2445 } else {
2446 struct extent_buffer *node;
2447 node = path->nodes[*level + 1];
2448 root_owner = btrfs_header_owner(node);
2449 root_gen = btrfs_header_generation(node);
2450 }
2451 ret = btrfs_free_extent(trans, root,
2452 path->nodes[*level]->start,
2453 path->nodes[*level]->len,
2454 root_owner, root_gen, 0, 0, 1);
2455 BUG_ON(ret);
2456 free_extent_buffer(path->nodes[*level]);
2457 path->nodes[*level] = NULL;
2458 *level = i + 1;
2459 }
2460 }
2461 return 1;
2462 }
2463
2464 /*
2465 * drop the reference count on the tree rooted at 'snap'. This traverses
2466 * the tree freeing any blocks that have a ref count of zero after being
2467 * decremented.
2468 */
2469 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2470 *root)
2471 {
2472 int ret = 0;
2473 int wret;
2474 int level;
2475 struct btrfs_path *path;
2476 int i;
2477 int orig_level;
2478 struct btrfs_root_item *root_item = &root->root_item;
2479
2480 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
2481 path = btrfs_alloc_path();
2482 BUG_ON(!path);
2483
2484 level = btrfs_header_level(root->node);
2485 orig_level = level;
2486 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2487 path->nodes[level] = root->node;
2488 extent_buffer_get(root->node);
2489 path->slots[level] = 0;
2490 } else {
2491 struct btrfs_key key;
2492 struct btrfs_disk_key found_key;
2493 struct extent_buffer *node;
2494
2495 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2496 level = root_item->drop_level;
2497 path->lowest_level = level;
2498 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2499 if (wret < 0) {
2500 ret = wret;
2501 goto out;
2502 }
2503 node = path->nodes[level];
2504 btrfs_node_key(node, &found_key, path->slots[level]);
2505 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2506 sizeof(found_key)));
2507 /*
2508 * unlock our path, this is safe because only this
2509 * function is allowed to delete this snapshot
2510 */
2511 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
2512 if (path->nodes[i] && path->locks[i]) {
2513 path->locks[i] = 0;
2514 btrfs_tree_unlock(path->nodes[i]);
2515 }
2516 }
2517 }
2518 while(1) {
2519 wret = walk_down_tree(trans, root, path, &level);
2520 if (wret > 0)
2521 break;
2522 if (wret < 0)
2523 ret = wret;
2524
2525 wret = walk_up_tree(trans, root, path, &level);
2526 if (wret > 0)
2527 break;
2528 if (wret < 0)
2529 ret = wret;
2530 if (trans->transaction->in_commit) {
2531 ret = -EAGAIN;
2532 break;
2533 }
2534 }
2535 for (i = 0; i <= orig_level; i++) {
2536 if (path->nodes[i]) {
2537 free_extent_buffer(path->nodes[i]);
2538 path->nodes[i] = NULL;
2539 }
2540 }
2541 out:
2542 btrfs_free_path(path);
2543 return ret;
2544 }
2545
2546 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2547 {
2548 u64 start;
2549 u64 end;
2550 u64 ptr;
2551 int ret;
2552
2553 mutex_lock(&info->alloc_mutex);
2554 while(1) {
2555 ret = find_first_extent_bit(&info->block_group_cache, 0,
2556 &start, &end, (unsigned int)-1);
2557 if (ret)
2558 break;
2559 ret = get_state_private(&info->block_group_cache, start, &ptr);
2560 if (!ret)
2561 kfree((void *)(unsigned long)ptr);
2562 clear_extent_bits(&info->block_group_cache, start,
2563 end, (unsigned int)-1, GFP_NOFS);
2564 }
2565 while(1) {
2566 ret = find_first_extent_bit(&info->free_space_cache, 0,
2567 &start, &end, EXTENT_DIRTY);
2568 if (ret)
2569 break;
2570 clear_extent_dirty(&info->free_space_cache, start,
2571 end, GFP_NOFS);
2572 }
2573 mutex_unlock(&info->alloc_mutex);
2574 return 0;
2575 }
2576
2577 static unsigned long calc_ra(unsigned long start, unsigned long last,
2578 unsigned long nr)
2579 {
2580 return min(last, start + nr - 1);
2581 }
2582
2583 static int noinline relocate_inode_pages(struct inode *inode, u64 start,
2584 u64 len)
2585 {
2586 u64 page_start;
2587 u64 page_end;
2588 unsigned long last_index;
2589 unsigned long i;
2590 struct page *page;
2591 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2592 struct file_ra_state *ra;
2593 unsigned long total_read = 0;
2594 unsigned long ra_pages;
2595 struct btrfs_trans_handle *trans;
2596
2597 ra = kzalloc(sizeof(*ra), GFP_NOFS);
2598
2599 mutex_lock(&inode->i_mutex);
2600 i = start >> PAGE_CACHE_SHIFT;
2601 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
2602
2603 ra_pages = BTRFS_I(inode)->root->fs_info->bdi.ra_pages;
2604
2605 file_ra_state_init(ra, inode->i_mapping);
2606
2607 for (; i <= last_index; i++) {
2608 if (total_read % ra_pages == 0) {
2609 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
2610 calc_ra(i, last_index, ra_pages));
2611 }
2612 total_read++;
2613 if (((u64)i << PAGE_CACHE_SHIFT) > inode->i_size)
2614 goto truncate_racing;
2615
2616 page = grab_cache_page(inode->i_mapping, i);
2617 if (!page) {
2618 goto out_unlock;
2619 }
2620 if (!PageUptodate(page)) {
2621 btrfs_readpage(NULL, page);
2622 lock_page(page);
2623 if (!PageUptodate(page)) {
2624 unlock_page(page);
2625 page_cache_release(page);
2626 goto out_unlock;
2627 }
2628 }
2629 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
2630 ClearPageDirty(page);
2631 #else
2632 cancel_dirty_page(page, PAGE_CACHE_SIZE);
2633 #endif
2634 wait_on_page_writeback(page);
2635 set_page_extent_mapped(page);
2636 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2637 page_end = page_start + PAGE_CACHE_SIZE - 1;
2638
2639 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2640
2641 set_extent_delalloc(io_tree, page_start,
2642 page_end, GFP_NOFS);
2643 set_page_dirty(page);
2644
2645 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2646 unlock_page(page);
2647 page_cache_release(page);
2648 }
2649 balance_dirty_pages_ratelimited_nr(inode->i_mapping,
2650 total_read);
2651
2652 out_unlock:
2653 kfree(ra);
2654 trans = btrfs_start_transaction(BTRFS_I(inode)->root, 1);
2655 if (trans) {
2656 btrfs_end_transaction(trans, BTRFS_I(inode)->root);
2657 mark_inode_dirty(inode);
2658 }
2659 mutex_unlock(&inode->i_mutex);
2660 return 0;
2661
2662 truncate_racing:
2663 vmtruncate(inode, inode->i_size);
2664 balance_dirty_pages_ratelimited_nr(inode->i_mapping,
2665 total_read);
2666 goto out_unlock;
2667 }
2668
2669 /*
2670 * The back references tell us which tree holds a ref on a block,
2671 * but it is possible for the tree root field in the reference to
2672 * reflect the original root before a snapshot was made. In this
2673 * case we should search through all the children of a given root
2674 * to find potential holders of references on a block.
2675 *
2676 * Instead, we do something a little less fancy and just search
2677 * all the roots for a given key/block combination.
2678 */
2679 static int find_root_for_ref(struct btrfs_root *root,
2680 struct btrfs_path *path,
2681 struct btrfs_key *key0,
2682 int level,
2683 int file_key,
2684 struct btrfs_root **found_root,
2685 u64 bytenr)
2686 {
2687 struct btrfs_key root_location;
2688 struct btrfs_root *cur_root = *found_root;
2689 struct btrfs_file_extent_item *file_extent;
2690 u64 root_search_start = BTRFS_FS_TREE_OBJECTID;
2691 u64 found_bytenr;
2692 int ret;
2693
2694 root_location.offset = (u64)-1;
2695 root_location.type = BTRFS_ROOT_ITEM_KEY;
2696 path->lowest_level = level;
2697 path->reada = 0;
2698 while(1) {
2699 ret = btrfs_search_slot(NULL, cur_root, key0, path, 0, 0);
2700 found_bytenr = 0;
2701 if (ret == 0 && file_key) {
2702 struct extent_buffer *leaf = path->nodes[0];
2703 file_extent = btrfs_item_ptr(leaf, path->slots[0],
2704 struct btrfs_file_extent_item);
2705 if (btrfs_file_extent_type(leaf, file_extent) ==
2706 BTRFS_FILE_EXTENT_REG) {
2707 found_bytenr =
2708 btrfs_file_extent_disk_bytenr(leaf,
2709 file_extent);
2710 }
2711 } else if (!file_key) {
2712 if (path->nodes[level])
2713 found_bytenr = path->nodes[level]->start;
2714 }
2715
2716 btrfs_release_path(cur_root, path);
2717
2718 if (found_bytenr == bytenr) {
2719 *found_root = cur_root;
2720 ret = 0;
2721 goto out;
2722 }
2723 ret = btrfs_search_root(root->fs_info->tree_root,
2724 root_search_start, &root_search_start);
2725 if (ret)
2726 break;
2727
2728 root_location.objectid = root_search_start;
2729 cur_root = btrfs_read_fs_root_no_name(root->fs_info,
2730 &root_location);
2731 if (!cur_root) {
2732 ret = 1;
2733 break;
2734 }
2735 }
2736 out:
2737 path->lowest_level = 0;
2738 return ret;
2739 }
2740
2741 /*
2742 * note, this releases the path
2743 */
2744 static int noinline relocate_one_reference(struct btrfs_root *extent_root,
2745 struct btrfs_path *path,
2746 struct btrfs_key *extent_key,
2747 u64 *last_file_objectid,
2748 u64 *last_file_offset,
2749 u64 *last_file_root,
2750 u64 last_extent)
2751 {
2752 struct inode *inode;
2753 struct btrfs_root *found_root;
2754 struct btrfs_key root_location;
2755 struct btrfs_key found_key;
2756 struct btrfs_extent_ref *ref;
2757 u64 ref_root;
2758 u64 ref_gen;
2759 u64 ref_objectid;
2760 u64 ref_offset;
2761 int ret;
2762 int level;
2763
2764 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
2765
2766 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
2767 struct btrfs_extent_ref);
2768 ref_root = btrfs_ref_root(path->nodes[0], ref);
2769 ref_gen = btrfs_ref_generation(path->nodes[0], ref);
2770 ref_objectid = btrfs_ref_objectid(path->nodes[0], ref);
2771 ref_offset = btrfs_ref_offset(path->nodes[0], ref);
2772 btrfs_release_path(extent_root, path);
2773
2774 root_location.objectid = ref_root;
2775 if (ref_gen == 0)
2776 root_location.offset = 0;
2777 else
2778 root_location.offset = (u64)-1;
2779 root_location.type = BTRFS_ROOT_ITEM_KEY;
2780
2781 found_root = btrfs_read_fs_root_no_name(extent_root->fs_info,
2782 &root_location);
2783 BUG_ON(!found_root);
2784 mutex_unlock(&extent_root->fs_info->alloc_mutex);
2785
2786 if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
2787 found_key.objectid = ref_objectid;
2788 found_key.type = BTRFS_EXTENT_DATA_KEY;
2789 found_key.offset = ref_offset;
2790 level = 0;
2791
2792 if (last_extent == extent_key->objectid &&
2793 *last_file_objectid == ref_objectid &&
2794 *last_file_offset == ref_offset &&
2795 *last_file_root == ref_root)
2796 goto out;
2797
2798 ret = find_root_for_ref(extent_root, path, &found_key,
2799 level, 1, &found_root,
2800 extent_key->objectid);
2801
2802 if (ret)
2803 goto out;
2804
2805 if (last_extent == extent_key->objectid &&
2806 *last_file_objectid == ref_objectid &&
2807 *last_file_offset == ref_offset &&
2808 *last_file_root == ref_root)
2809 goto out;
2810
2811 inode = btrfs_iget_locked(extent_root->fs_info->sb,
2812 ref_objectid, found_root);
2813 if (inode->i_state & I_NEW) {
2814 /* the inode and parent dir are two different roots */
2815 BTRFS_I(inode)->root = found_root;
2816 BTRFS_I(inode)->location.objectid = ref_objectid;
2817 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
2818 BTRFS_I(inode)->location.offset = 0;
2819 btrfs_read_locked_inode(inode);
2820 unlock_new_inode(inode);
2821
2822 }
2823 /* this can happen if the reference is not against
2824 * the latest version of the tree root
2825 */
2826 if (is_bad_inode(inode))
2827 goto out;
2828
2829 *last_file_objectid = inode->i_ino;
2830 *last_file_root = found_root->root_key.objectid;
2831 *last_file_offset = ref_offset;
2832
2833 relocate_inode_pages(inode, ref_offset, extent_key->offset);
2834 iput(inode);
2835 } else {
2836 struct btrfs_trans_handle *trans;
2837 struct extent_buffer *eb;
2838 int needs_lock = 0;
2839
2840 eb = read_tree_block(found_root, extent_key->objectid,
2841 extent_key->offset, 0);
2842 btrfs_tree_lock(eb);
2843 level = btrfs_header_level(eb);
2844
2845 if (level == 0)
2846 btrfs_item_key_to_cpu(eb, &found_key, 0);
2847 else
2848 btrfs_node_key_to_cpu(eb, &found_key, 0);
2849
2850 btrfs_tree_unlock(eb);
2851 free_extent_buffer(eb);
2852
2853 ret = find_root_for_ref(extent_root, path, &found_key,
2854 level, 0, &found_root,
2855 extent_key->objectid);
2856
2857 if (ret)
2858 goto out;
2859
2860 /*
2861 * right here almost anything could happen to our key,
2862 * but that's ok. The cow below will either relocate it
2863 * or someone else will have relocated it. Either way,
2864 * it is in a different spot than it was before and
2865 * we're happy.
2866 */
2867
2868 trans = btrfs_start_transaction(found_root, 1);
2869
2870 if (found_root == extent_root->fs_info->extent_root ||
2871 found_root == extent_root->fs_info->chunk_root ||
2872 found_root == extent_root->fs_info->dev_root) {
2873 needs_lock = 1;
2874 mutex_lock(&extent_root->fs_info->alloc_mutex);
2875 }
2876
2877 path->lowest_level = level;
2878 path->reada = 2;
2879 ret = btrfs_search_slot(trans, found_root, &found_key, path,
2880 0, 1);
2881 path->lowest_level = 0;
2882 btrfs_release_path(found_root, path);
2883
2884 if (found_root == found_root->fs_info->extent_root)
2885 btrfs_extent_post_op(trans, found_root);
2886 if (needs_lock)
2887 mutex_unlock(&extent_root->fs_info->alloc_mutex);
2888
2889 btrfs_end_transaction(trans, found_root);
2890
2891 }
2892 out:
2893 mutex_lock(&extent_root->fs_info->alloc_mutex);
2894 return 0;
2895 }
2896
2897 static int noinline del_extent_zero(struct btrfs_root *extent_root,
2898 struct btrfs_path *path,
2899 struct btrfs_key *extent_key)
2900 {
2901 int ret;
2902 struct btrfs_trans_handle *trans;
2903
2904 trans = btrfs_start_transaction(extent_root, 1);
2905 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
2906 if (ret > 0) {
2907 ret = -EIO;
2908 goto out;
2909 }
2910 if (ret < 0)
2911 goto out;
2912 ret = btrfs_del_item(trans, extent_root, path);
2913 out:
2914 btrfs_end_transaction(trans, extent_root);
2915 return ret;
2916 }
2917
2918 static int noinline relocate_one_extent(struct btrfs_root *extent_root,
2919 struct btrfs_path *path,
2920 struct btrfs_key *extent_key)
2921 {
2922 struct btrfs_key key;
2923 struct btrfs_key found_key;
2924 struct extent_buffer *leaf;
2925 u64 last_file_objectid = 0;
2926 u64 last_file_root = 0;
2927 u64 last_file_offset = (u64)-1;
2928 u64 last_extent = 0;
2929 u32 nritems;
2930 u32 item_size;
2931 int ret = 0;
2932
2933 if (extent_key->objectid == 0) {
2934 ret = del_extent_zero(extent_root, path, extent_key);
2935 goto out;
2936 }
2937 key.objectid = extent_key->objectid;
2938 key.type = BTRFS_EXTENT_REF_KEY;
2939 key.offset = 0;
2940
2941 while(1) {
2942 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2943
2944 if (ret < 0)
2945 goto out;
2946
2947 ret = 0;
2948 leaf = path->nodes[0];
2949 nritems = btrfs_header_nritems(leaf);
2950 if (path->slots[0] == nritems) {
2951 ret = btrfs_next_leaf(extent_root, path);
2952 if (ret > 0) {
2953 ret = 0;
2954 goto out;
2955 }
2956 if (ret < 0)
2957 goto out;
2958 leaf = path->nodes[0];
2959 }
2960
2961 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2962 if (found_key.objectid != extent_key->objectid) {
2963 break;
2964 }
2965
2966 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
2967 break;
2968 }
2969
2970 key.offset = found_key.offset + 1;
2971 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2972
2973 ret = relocate_one_reference(extent_root, path, extent_key,
2974 &last_file_objectid,
2975 &last_file_offset,
2976 &last_file_root, last_extent);
2977 if (ret)
2978 goto out;
2979 last_extent = extent_key->objectid;
2980 }
2981 ret = 0;
2982 out:
2983 btrfs_release_path(extent_root, path);
2984 return ret;
2985 }
2986
2987 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
2988 {
2989 u64 num_devices;
2990 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
2991 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
2992
2993 num_devices = root->fs_info->fs_devices->num_devices;
2994 if (num_devices == 1) {
2995 stripped |= BTRFS_BLOCK_GROUP_DUP;
2996 stripped = flags & ~stripped;
2997
2998 /* turn raid0 into single device chunks */
2999 if (flags & BTRFS_BLOCK_GROUP_RAID0)
3000 return stripped;
3001
3002 /* turn mirroring into duplication */
3003 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
3004 BTRFS_BLOCK_GROUP_RAID10))
3005 return stripped | BTRFS_BLOCK_GROUP_DUP;
3006 return flags;
3007 } else {
3008 /* they already had raid on here, just return */
3009 if (flags & stripped)
3010 return flags;
3011
3012 stripped |= BTRFS_BLOCK_GROUP_DUP;
3013 stripped = flags & ~stripped;
3014
3015 /* switch duplicated blocks with raid1 */
3016 if (flags & BTRFS_BLOCK_GROUP_DUP)
3017 return stripped | BTRFS_BLOCK_GROUP_RAID1;
3018
3019 /* turn single device chunks into raid0 */
3020 return stripped | BTRFS_BLOCK_GROUP_RAID0;
3021 }
3022 return flags;
3023 }
3024
3025 int __alloc_chunk_for_shrink(struct btrfs_root *root,
3026 struct btrfs_block_group_cache *shrink_block_group,
3027 int force)
3028 {
3029 struct btrfs_trans_handle *trans;
3030 u64 new_alloc_flags;
3031 u64 calc;
3032
3033 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
3034
3035 mutex_unlock(&root->fs_info->alloc_mutex);
3036 trans = btrfs_start_transaction(root, 1);
3037 mutex_lock(&root->fs_info->alloc_mutex);
3038
3039 new_alloc_flags = update_block_group_flags(root,
3040 shrink_block_group->flags);
3041 if (new_alloc_flags != shrink_block_group->flags) {
3042 calc =
3043 btrfs_block_group_used(&shrink_block_group->item);
3044 } else {
3045 calc = shrink_block_group->key.offset;
3046 }
3047 do_chunk_alloc(trans, root->fs_info->extent_root,
3048 calc + 2 * 1024 * 1024, new_alloc_flags, force);
3049
3050 mutex_unlock(&root->fs_info->alloc_mutex);
3051 btrfs_end_transaction(trans, root);
3052 mutex_lock(&root->fs_info->alloc_mutex);
3053 }
3054 return 0;
3055 }
3056
3057 int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start)
3058 {
3059 struct btrfs_trans_handle *trans;
3060 struct btrfs_root *tree_root = root->fs_info->tree_root;
3061 struct btrfs_path *path;
3062 u64 cur_byte;
3063 u64 total_found;
3064 u64 shrink_last_byte;
3065 struct btrfs_block_group_cache *shrink_block_group;
3066 struct btrfs_fs_info *info = root->fs_info;
3067 struct btrfs_key key;
3068 struct btrfs_key found_key;
3069 struct extent_buffer *leaf;
3070 u32 nritems;
3071 int ret;
3072 int progress;
3073
3074 mutex_lock(&root->fs_info->alloc_mutex);
3075 shrink_block_group = btrfs_lookup_block_group(root->fs_info,
3076 shrink_start);
3077 BUG_ON(!shrink_block_group);
3078
3079 shrink_last_byte = shrink_block_group->key.objectid +
3080 shrink_block_group->key.offset;
3081
3082 shrink_block_group->space_info->total_bytes -=
3083 shrink_block_group->key.offset;
3084 path = btrfs_alloc_path();
3085 root = root->fs_info->extent_root;
3086 path->reada = 2;
3087
3088 printk("btrfs relocating block group %llu flags %llu\n",
3089 (unsigned long long)shrink_start,
3090 (unsigned long long)shrink_block_group->flags);
3091
3092 __alloc_chunk_for_shrink(root, shrink_block_group, 1);
3093
3094 again:
3095
3096 shrink_block_group->ro = 1;
3097
3098 total_found = 0;
3099 progress = 0;
3100 key.objectid = shrink_start;
3101 key.offset = 0;
3102 key.type = 0;
3103 cur_byte = key.objectid;
3104
3105 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3106 if (ret < 0)
3107 goto out;
3108
3109 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
3110 if (ret < 0)
3111 goto out;
3112
3113 if (ret == 0) {
3114 leaf = path->nodes[0];
3115 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3116 if (found_key.objectid + found_key.offset > shrink_start &&
3117 found_key.objectid < shrink_last_byte) {
3118 cur_byte = found_key.objectid;
3119 key.objectid = cur_byte;
3120 }
3121 }
3122 btrfs_release_path(root, path);
3123
3124 while(1) {
3125 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3126 if (ret < 0)
3127 goto out;
3128
3129 next:
3130 leaf = path->nodes[0];
3131 nritems = btrfs_header_nritems(leaf);
3132 if (path->slots[0] >= nritems) {
3133 ret = btrfs_next_leaf(root, path);
3134 if (ret < 0)
3135 goto out;
3136 if (ret == 1) {
3137 ret = 0;
3138 break;
3139 }
3140 leaf = path->nodes[0];
3141 nritems = btrfs_header_nritems(leaf);
3142 }
3143
3144 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3145
3146 if (found_key.objectid >= shrink_last_byte)
3147 break;
3148
3149 if (progress && need_resched()) {
3150 memcpy(&key, &found_key, sizeof(key));
3151 cond_resched();
3152 btrfs_release_path(root, path);
3153 btrfs_search_slot(NULL, root, &key, path, 0, 0);
3154 progress = 0;
3155 goto next;
3156 }
3157 progress = 1;
3158
3159 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY ||
3160 found_key.objectid + found_key.offset <= cur_byte) {
3161 memcpy(&key, &found_key, sizeof(key));
3162 key.offset++;
3163 path->slots[0]++;
3164 goto next;
3165 }
3166
3167 total_found++;
3168 cur_byte = found_key.objectid + found_key.offset;
3169 key.objectid = cur_byte;
3170 btrfs_release_path(root, path);
3171 ret = relocate_one_extent(root, path, &found_key);
3172 __alloc_chunk_for_shrink(root, shrink_block_group, 0);
3173 }
3174
3175 btrfs_release_path(root, path);
3176
3177 if (total_found > 0) {
3178 printk("btrfs relocate found %llu last extent was %llu\n",
3179 (unsigned long long)total_found,
3180 (unsigned long long)found_key.objectid);
3181 mutex_unlock(&root->fs_info->alloc_mutex);
3182 trans = btrfs_start_transaction(tree_root, 1);
3183 btrfs_commit_transaction(trans, tree_root);
3184
3185 btrfs_clean_old_snapshots(tree_root);
3186
3187 trans = btrfs_start_transaction(tree_root, 1);
3188 btrfs_commit_transaction(trans, tree_root);
3189 mutex_lock(&root->fs_info->alloc_mutex);
3190 goto again;
3191 }
3192
3193 /*
3194 * we've freed all the extents, now remove the block
3195 * group item from the tree
3196 */
3197 mutex_unlock(&root->fs_info->alloc_mutex);
3198
3199 trans = btrfs_start_transaction(root, 1);
3200 mutex_lock(&root->fs_info->alloc_mutex);
3201 memcpy(&key, &shrink_block_group->key, sizeof(key));
3202
3203 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3204 if (ret > 0)
3205 ret = -EIO;
3206 if (ret < 0)
3207 goto out;
3208
3209 clear_extent_bits(&info->block_group_cache, key.objectid,
3210 key.objectid + key.offset - 1,
3211 (unsigned int)-1, GFP_NOFS);
3212
3213
3214 clear_extent_bits(&info->free_space_cache,
3215 key.objectid, key.objectid + key.offset - 1,
3216 (unsigned int)-1, GFP_NOFS);
3217
3218 memset(shrink_block_group, 0, sizeof(*shrink_block_group));
3219 kfree(shrink_block_group);
3220
3221 btrfs_del_item(trans, root, path);
3222 btrfs_release_path(root, path);
3223 mutex_unlock(&root->fs_info->alloc_mutex);
3224 btrfs_commit_transaction(trans, root);
3225
3226 mutex_lock(&root->fs_info->alloc_mutex);
3227
3228 /* the code to unpin extents might set a few bits in the free
3229 * space cache for this range again
3230 */
3231 clear_extent_bits(&info->free_space_cache,
3232 key.objectid, key.objectid + key.offset - 1,
3233 (unsigned int)-1, GFP_NOFS);
3234 out:
3235 btrfs_free_path(path);
3236 mutex_unlock(&root->fs_info->alloc_mutex);
3237 return ret;
3238 }
3239
3240 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
3241 struct btrfs_key *key)
3242 {
3243 int ret = 0;
3244 struct btrfs_key found_key;
3245 struct extent_buffer *leaf;
3246 int slot;
3247
3248 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
3249 if (ret < 0)
3250 goto out;
3251
3252 while(1) {
3253 slot = path->slots[0];
3254 leaf = path->nodes[0];
3255 if (slot >= btrfs_header_nritems(leaf)) {
3256 ret = btrfs_next_leaf(root, path);
3257 if (ret == 0)
3258 continue;
3259 if (ret < 0)
3260 goto out;
3261 break;
3262 }
3263 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3264
3265 if (found_key.objectid >= key->objectid &&
3266 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
3267 ret = 0;
3268 goto out;
3269 }
3270 path->slots[0]++;
3271 }
3272 ret = -ENOENT;
3273 out:
3274 return ret;
3275 }
3276
3277 int btrfs_read_block_groups(struct btrfs_root *root)
3278 {
3279 struct btrfs_path *path;
3280 int ret;
3281 int bit;
3282 struct btrfs_block_group_cache *cache;
3283 struct btrfs_fs_info *info = root->fs_info;
3284 struct btrfs_space_info *space_info;
3285 struct extent_io_tree *block_group_cache;
3286 struct btrfs_key key;
3287 struct btrfs_key found_key;
3288 struct extent_buffer *leaf;
3289
3290 block_group_cache = &info->block_group_cache;
3291 root = info->extent_root;
3292 key.objectid = 0;
3293 key.offset = 0;
3294 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3295 path = btrfs_alloc_path();
3296 if (!path)
3297 return -ENOMEM;
3298
3299 mutex_lock(&root->fs_info->alloc_mutex);
3300 while(1) {
3301 ret = find_first_block_group(root, path, &key);
3302 if (ret > 0) {
3303 ret = 0;
3304 goto error;
3305 }
3306 if (ret != 0)
3307 goto error;
3308
3309 leaf = path->nodes[0];
3310 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3311 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3312 if (!cache) {
3313 ret = -ENOMEM;
3314 break;
3315 }
3316
3317 read_extent_buffer(leaf, &cache->item,
3318 btrfs_item_ptr_offset(leaf, path->slots[0]),
3319 sizeof(cache->item));
3320 memcpy(&cache->key, &found_key, sizeof(found_key));
3321
3322 key.objectid = found_key.objectid + found_key.offset;
3323 btrfs_release_path(root, path);
3324 cache->flags = btrfs_block_group_flags(&cache->item);
3325 bit = 0;
3326 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
3327 bit = BLOCK_GROUP_DATA;
3328 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
3329 bit = BLOCK_GROUP_SYSTEM;
3330 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
3331 bit = BLOCK_GROUP_METADATA;
3332 }
3333 set_avail_alloc_bits(info, cache->flags);
3334
3335 ret = update_space_info(info, cache->flags, found_key.offset,
3336 btrfs_block_group_used(&cache->item),
3337 &space_info);
3338 BUG_ON(ret);
3339 cache->space_info = space_info;
3340
3341 /* use EXTENT_LOCKED to prevent merging */
3342 set_extent_bits(block_group_cache, found_key.objectid,
3343 found_key.objectid + found_key.offset - 1,
3344 bit | EXTENT_LOCKED, GFP_NOFS);
3345 set_state_private(block_group_cache, found_key.objectid,
3346 (unsigned long)cache);
3347
3348 /* hack for now */
3349 if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
3350 cache_block_group(root->fs_info->extent_root,
3351 cache);
3352 }
3353 if (key.objectid >=
3354 btrfs_super_total_bytes(&info->super_copy))
3355 break;
3356 }
3357 ret = 0;
3358 error:
3359 btrfs_free_path(path);
3360 mutex_unlock(&root->fs_info->alloc_mutex);
3361 return ret;
3362 }
3363
3364 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
3365 struct btrfs_root *root, u64 bytes_used,
3366 u64 type, u64 chunk_objectid, u64 chunk_offset,
3367 u64 size)
3368 {
3369 int ret;
3370 int bit = 0;
3371 struct btrfs_root *extent_root;
3372 struct btrfs_block_group_cache *cache;
3373 struct extent_io_tree *block_group_cache;
3374
3375 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
3376 extent_root = root->fs_info->extent_root;
3377 block_group_cache = &root->fs_info->block_group_cache;
3378
3379 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3380 BUG_ON(!cache);
3381 cache->key.objectid = chunk_offset;
3382 cache->key.offset = size;
3383 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3384
3385 btrfs_set_block_group_used(&cache->item, bytes_used);
3386 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
3387 cache->flags = type;
3388 btrfs_set_block_group_flags(&cache->item, type);
3389
3390 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
3391 &cache->space_info);
3392 BUG_ON(ret);
3393
3394 bit = block_group_state_bits(type);
3395 set_extent_bits(block_group_cache, chunk_offset,
3396 chunk_offset + size - 1,
3397 bit | EXTENT_LOCKED, GFP_NOFS);
3398
3399 set_state_private(block_group_cache, chunk_offset,
3400 (unsigned long)cache);
3401 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
3402 sizeof(cache->item));
3403 BUG_ON(ret);
3404
3405 finish_current_insert(trans, extent_root);
3406 ret = del_pending_extents(trans, extent_root);
3407 BUG_ON(ret);
3408 set_avail_alloc_bits(extent_root->fs_info, type);
3409
3410 return 0;
3411 }
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