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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
19 #include <linux/sched.h>
20 #include <linux/crc32c.h>
21 #include <linux/pagemap.h>
22 #include "hash.h"
23 #include "ctree.h"
24 #include "disk-io.h"
25 #include "print-tree.h"
26 #include "transaction.h"
27 #include "volumes.h"
28
29 #define BLOCK_GROUP_DATA EXTENT_WRITEBACK
30 #define BLOCK_GROUP_METADATA EXTENT_UPTODATE
31 #define BLOCK_GROUP_SYSTEM EXTENT_NEW
32
33 #define BLOCK_GROUP_DIRTY EXTENT_DIRTY
34
35 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
36 btrfs_root *extent_root);
37 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
38 btrfs_root *extent_root);
39 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
40 struct btrfs_root *root, u64 bytes_used,
41 u64 type, u64 chunk_tree, u64 chunk_objectid,
42 u64 size);
43
44
45 static int cache_block_group(struct btrfs_root *root,
46 struct btrfs_block_group_cache *block_group)
47 {
48 struct btrfs_path *path;
49 int ret;
50 struct btrfs_key key;
51 struct extent_buffer *leaf;
52 struct extent_io_tree *free_space_cache;
53 int slot;
54 u64 last = 0;
55 u64 hole_size;
56 u64 first_free;
57 int found = 0;
58
59 if (!block_group)
60 return 0;
61
62 root = root->fs_info->extent_root;
63 free_space_cache = &root->fs_info->free_space_cache;
64
65 if (block_group->cached)
66 return 0;
67
68 path = btrfs_alloc_path();
69 if (!path)
70 return -ENOMEM;
71
72 path->reada = 2;
73 first_free = block_group->key.objectid;
74 key.objectid = block_group->key.objectid;
75 key.offset = 0;
76 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
77 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
78 if (ret < 0)
79 return ret;
80 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
81 if (ret < 0)
82 return ret;
83 if (ret == 0) {
84 leaf = path->nodes[0];
85 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
86 if (key.objectid + key.offset > first_free)
87 first_free = key.objectid + key.offset;
88 }
89 while(1) {
90 leaf = path->nodes[0];
91 slot = path->slots[0];
92 if (slot >= btrfs_header_nritems(leaf)) {
93 ret = btrfs_next_leaf(root, path);
94 if (ret < 0)
95 goto err;
96 if (ret == 0) {
97 continue;
98 } else {
99 break;
100 }
101 }
102 btrfs_item_key_to_cpu(leaf, &key, slot);
103 if (key.objectid < block_group->key.objectid) {
104 goto next;
105 }
106 if (key.objectid >= block_group->key.objectid +
107 block_group->key.offset) {
108 break;
109 }
110
111 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
112 if (!found) {
113 last = first_free;
114 found = 1;
115 }
116 if (key.objectid > last) {
117 hole_size = key.objectid - last;
118 set_extent_dirty(free_space_cache, last,
119 last + hole_size - 1,
120 GFP_NOFS);
121 }
122 last = key.objectid + key.offset;
123 }
124 next:
125 path->slots[0]++;
126 }
127
128 if (!found)
129 last = first_free;
130 if (block_group->key.objectid +
131 block_group->key.offset > last) {
132 hole_size = block_group->key.objectid +
133 block_group->key.offset - last;
134 set_extent_dirty(free_space_cache, last,
135 last + hole_size - 1, GFP_NOFS);
136 }
137 block_group->cached = 1;
138 err:
139 btrfs_free_path(path);
140 return 0;
141 }
142
143 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
144 btrfs_fs_info *info,
145 u64 bytenr)
146 {
147 struct extent_io_tree *block_group_cache;
148 struct btrfs_block_group_cache *block_group = NULL;
149 u64 ptr;
150 u64 start;
151 u64 end;
152 int ret;
153
154 block_group_cache = &info->block_group_cache;
155 ret = find_first_extent_bit(block_group_cache,
156 bytenr, &start, &end,
157 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
158 BLOCK_GROUP_SYSTEM);
159 if (ret) {
160 return NULL;
161 }
162 ret = get_state_private(block_group_cache, start, &ptr);
163 if (ret)
164 return NULL;
165
166 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
167 if (block_group->key.objectid <= bytenr && bytenr <
168 block_group->key.objectid + block_group->key.offset)
169 return block_group;
170 return NULL;
171 }
172
173 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
174 {
175 return (cache->flags & bits) == bits;
176 }
177
178 static int noinline find_search_start(struct btrfs_root *root,
179 struct btrfs_block_group_cache **cache_ret,
180 u64 *start_ret, int num, int data)
181 {
182 int ret;
183 struct btrfs_block_group_cache *cache = *cache_ret;
184 struct extent_io_tree *free_space_cache;
185 struct extent_state *state;
186 u64 last;
187 u64 start = 0;
188 u64 cache_miss = 0;
189 u64 total_fs_bytes;
190 u64 search_start = *start_ret;
191 int wrapped = 0;
192
193 if (!cache)
194 goto out;
195 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
196 free_space_cache = &root->fs_info->free_space_cache;
197
198 again:
199 ret = cache_block_group(root, cache);
200 if (ret)
201 goto out;
202
203 last = max(search_start, cache->key.objectid);
204 if (!block_group_bits(cache, data)) {
205 goto new_group;
206 }
207
208 spin_lock_irq(&free_space_cache->lock);
209 state = find_first_extent_bit_state(free_space_cache, last, EXTENT_DIRTY);
210 while(1) {
211 if (!state) {
212 if (!cache_miss)
213 cache_miss = last;
214 spin_unlock_irq(&free_space_cache->lock);
215 goto new_group;
216 }
217
218 start = max(last, state->start);
219 last = state->end + 1;
220 if (last - start < num) {
221 if (last == cache->key.objectid + cache->key.offset)
222 cache_miss = start;
223 do {
224 state = extent_state_next(state);
225 } while(state && !(state->state & EXTENT_DIRTY));
226 continue;
227 }
228 spin_unlock_irq(&free_space_cache->lock);
229 if (start + num > cache->key.objectid + cache->key.offset)
230 goto new_group;
231 if (start + num > total_fs_bytes)
232 goto new_group;
233 if (!block_group_bits(cache, data)) {
234 printk("block group bits don't match %Lu %d\n", cache->flags, data);
235 }
236 *start_ret = start;
237 return 0;
238 }
239 out:
240 cache = btrfs_lookup_block_group(root->fs_info, search_start);
241 if (!cache) {
242 printk("Unable to find block group for %Lu\n", search_start);
243 WARN_ON(1);
244 }
245 return -ENOSPC;
246
247 new_group:
248 last = cache->key.objectid + cache->key.offset;
249 wrapped:
250 cache = btrfs_lookup_block_group(root->fs_info, last);
251 if (!cache || cache->key.objectid >= total_fs_bytes) {
252 no_cache:
253 if (!wrapped) {
254 wrapped = 1;
255 last = search_start;
256 goto wrapped;
257 }
258 goto out;
259 }
260 if (cache_miss && !cache->cached) {
261 cache_block_group(root, cache);
262 last = cache_miss;
263 cache = btrfs_lookup_block_group(root->fs_info, last);
264 }
265 cache = btrfs_find_block_group(root, cache, last, data, 0);
266 if (!cache)
267 goto no_cache;
268 *cache_ret = cache;
269 cache_miss = 0;
270 goto again;
271 }
272
273 static u64 div_factor(u64 num, int factor)
274 {
275 if (factor == 10)
276 return num;
277 num *= factor;
278 do_div(num, 10);
279 return num;
280 }
281
282 static int block_group_state_bits(u64 flags)
283 {
284 int bits = 0;
285 if (flags & BTRFS_BLOCK_GROUP_DATA)
286 bits |= BLOCK_GROUP_DATA;
287 if (flags & BTRFS_BLOCK_GROUP_METADATA)
288 bits |= BLOCK_GROUP_METADATA;
289 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
290 bits |= BLOCK_GROUP_SYSTEM;
291 return bits;
292 }
293
294 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
295 struct btrfs_block_group_cache
296 *hint, u64 search_start,
297 int data, int owner)
298 {
299 struct btrfs_block_group_cache *cache;
300 struct extent_io_tree *block_group_cache;
301 struct btrfs_block_group_cache *found_group = NULL;
302 struct btrfs_fs_info *info = root->fs_info;
303 u64 used;
304 u64 last = 0;
305 u64 hint_last;
306 u64 start;
307 u64 end;
308 u64 free_check;
309 u64 ptr;
310 u64 total_fs_bytes;
311 int bit;
312 int ret;
313 int full_search = 0;
314 int factor = 8;
315
316 block_group_cache = &info->block_group_cache;
317 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
318
319 if (!owner)
320 factor = 8;
321
322 bit = block_group_state_bits(data);
323
324 if (search_start && search_start < total_fs_bytes) {
325 struct btrfs_block_group_cache *shint;
326 shint = btrfs_lookup_block_group(info, search_start);
327 if (shint && block_group_bits(shint, data)) {
328 used = btrfs_block_group_used(&shint->item);
329 if (used + shint->pinned <
330 div_factor(shint->key.offset, factor)) {
331 return shint;
332 }
333 }
334 }
335 if (hint && block_group_bits(hint, data) &&
336 hint->key.objectid < total_fs_bytes) {
337 used = btrfs_block_group_used(&hint->item);
338 if (used + hint->pinned <
339 div_factor(hint->key.offset, factor)) {
340 return hint;
341 }
342 last = hint->key.objectid + hint->key.offset;
343 hint_last = last;
344 } else {
345 if (hint)
346 hint_last = max(hint->key.objectid, search_start);
347 else
348 hint_last = search_start;
349
350 if (hint_last >= total_fs_bytes)
351 hint_last = search_start;
352 last = hint_last;
353 }
354 again:
355 while(1) {
356 ret = find_first_extent_bit(block_group_cache, last,
357 &start, &end, bit);
358 if (ret)
359 break;
360
361 ret = get_state_private(block_group_cache, start, &ptr);
362 if (ret)
363 break;
364
365 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
366 last = cache->key.objectid + cache->key.offset;
367 used = btrfs_block_group_used(&cache->item);
368
369 if (cache->key.objectid > total_fs_bytes)
370 break;
371
372 if (block_group_bits(cache, data)) {
373 if (full_search)
374 free_check = cache->key.offset;
375 else
376 free_check = div_factor(cache->key.offset,
377 factor);
378
379 if (used + cache->pinned < free_check) {
380 found_group = cache;
381 goto found;
382 }
383 }
384 cond_resched();
385 }
386 if (!full_search) {
387 last = search_start;
388 full_search = 1;
389 goto again;
390 }
391 found:
392 return found_group;
393 }
394
395 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
396 u64 owner, u64 owner_offset)
397 {
398 u32 high_crc = ~(u32)0;
399 u32 low_crc = ~(u32)0;
400 __le64 lenum;
401
402 lenum = cpu_to_le64(root_objectid);
403 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
404 lenum = cpu_to_le64(ref_generation);
405 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
406 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
407 lenum = cpu_to_le64(owner);
408 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
409 lenum = cpu_to_le64(owner_offset);
410 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
411 }
412 return ((u64)high_crc << 32) | (u64)low_crc;
413 }
414
415 static int match_extent_ref(struct extent_buffer *leaf,
416 struct btrfs_extent_ref *disk_ref,
417 struct btrfs_extent_ref *cpu_ref)
418 {
419 int ret;
420 int len;
421
422 if (cpu_ref->objectid)
423 len = sizeof(*cpu_ref);
424 else
425 len = 2 * sizeof(u64);
426 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
427 len);
428 return ret == 0;
429 }
430
431 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
432 struct btrfs_root *root,
433 struct btrfs_path *path, u64 bytenr,
434 u64 root_objectid,
435 u64 ref_generation, u64 owner,
436 u64 owner_offset, int del)
437 {
438 u64 hash;
439 struct btrfs_key key;
440 struct btrfs_key found_key;
441 struct btrfs_extent_ref ref;
442 struct extent_buffer *leaf;
443 struct btrfs_extent_ref *disk_ref;
444 int ret;
445 int ret2;
446
447 btrfs_set_stack_ref_root(&ref, root_objectid);
448 btrfs_set_stack_ref_generation(&ref, ref_generation);
449 btrfs_set_stack_ref_objectid(&ref, owner);
450 btrfs_set_stack_ref_offset(&ref, owner_offset);
451
452 hash = hash_extent_ref(root_objectid, ref_generation, owner,
453 owner_offset);
454 key.offset = hash;
455 key.objectid = bytenr;
456 key.type = BTRFS_EXTENT_REF_KEY;
457
458 while (1) {
459 ret = btrfs_search_slot(trans, root, &key, path,
460 del ? -1 : 0, del);
461 if (ret < 0)
462 goto out;
463 leaf = path->nodes[0];
464 if (ret != 0) {
465 u32 nritems = btrfs_header_nritems(leaf);
466 if (path->slots[0] >= nritems) {
467 ret2 = btrfs_next_leaf(root, path);
468 if (ret2)
469 goto out;
470 leaf = path->nodes[0];
471 }
472 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
473 if (found_key.objectid != bytenr ||
474 found_key.type != BTRFS_EXTENT_REF_KEY)
475 goto out;
476 key.offset = found_key.offset;
477 if (del) {
478 btrfs_release_path(root, path);
479 continue;
480 }
481 }
482 disk_ref = btrfs_item_ptr(path->nodes[0],
483 path->slots[0],
484 struct btrfs_extent_ref);
485 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
486 ret = 0;
487 goto out;
488 }
489 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
490 key.offset = found_key.offset + 1;
491 btrfs_release_path(root, path);
492 }
493 out:
494 return ret;
495 }
496
497 /*
498 * Back reference rules. Back refs have three main goals:
499 *
500 * 1) differentiate between all holders of references to an extent so that
501 * when a reference is dropped we can make sure it was a valid reference
502 * before freeing the extent.
503 *
504 * 2) Provide enough information to quickly find the holders of an extent
505 * if we notice a given block is corrupted or bad.
506 *
507 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
508 * maintenance. This is actually the same as #2, but with a slightly
509 * different use case.
510 *
511 * File extents can be referenced by:
512 *
513 * - multiple snapshots, subvolumes, or different generations in one subvol
514 * - different files inside a single subvolume (in theory, not implemented yet)
515 * - different offsets inside a file (bookend extents in file.c)
516 *
517 * The extent ref structure has fields for:
518 *
519 * - Objectid of the subvolume root
520 * - Generation number of the tree holding the reference
521 * - objectid of the file holding the reference
522 * - offset in the file corresponding to the key holding the reference
523 *
524 * When a file extent is allocated the fields are filled in:
525 * (root_key.objectid, trans->transid, inode objectid, offset in file)
526 *
527 * When a leaf is cow'd new references are added for every file extent found
528 * in the leaf. It looks the same as the create case, but trans->transid
529 * will be different when the block is cow'd.
530 *
531 * (root_key.objectid, trans->transid, inode objectid, offset in file)
532 *
533 * When a file extent is removed either during snapshot deletion or file
534 * truncation, the corresponding back reference is found
535 * by searching for:
536 *
537 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
538 * inode objectid, offset in file)
539 *
540 * Btree extents can be referenced by:
541 *
542 * - Different subvolumes
543 * - Different generations of the same subvolume
544 *
545 * Storing sufficient information for a full reverse mapping of a btree
546 * block would require storing the lowest key of the block in the backref,
547 * and it would require updating that lowest key either before write out or
548 * every time it changed. Instead, the objectid of the lowest key is stored
549 * along with the level of the tree block. This provides a hint
550 * about where in the btree the block can be found. Searches through the
551 * btree only need to look for a pointer to that block, so they stop one
552 * level higher than the level recorded in the backref.
553 *
554 * Some btrees do not do reference counting on their extents. These
555 * include the extent tree and the tree of tree roots. Backrefs for these
556 * trees always have a generation of zero.
557 *
558 * When a tree block is created, back references are inserted:
559 *
560 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
561 *
562 * When a tree block is cow'd in a reference counted root,
563 * new back references are added for all the blocks it points to.
564 * These are of the form (trans->transid will have increased since creation):
565 *
566 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
567 *
568 * Because the lowest_key_objectid and the level are just hints
569 * they are not used when backrefs are deleted. When a backref is deleted:
570 *
571 * if backref was for a tree root:
572 * root_objectid = root->root_key.objectid
573 * else
574 * root_objectid = btrfs_header_owner(parent)
575 *
576 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
577 *
578 * Back Reference Key hashing:
579 *
580 * Back references have four fields, each 64 bits long. Unfortunately,
581 * This is hashed into a single 64 bit number and placed into the key offset.
582 * The key objectid corresponds to the first byte in the extent, and the
583 * key type is set to BTRFS_EXTENT_REF_KEY
584 */
585 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
586 struct btrfs_root *root,
587 struct btrfs_path *path, u64 bytenr,
588 u64 root_objectid, u64 ref_generation,
589 u64 owner, u64 owner_offset)
590 {
591 u64 hash;
592 struct btrfs_key key;
593 struct btrfs_extent_ref ref;
594 struct btrfs_extent_ref *disk_ref;
595 int ret;
596
597 btrfs_set_stack_ref_root(&ref, root_objectid);
598 btrfs_set_stack_ref_generation(&ref, ref_generation);
599 btrfs_set_stack_ref_objectid(&ref, owner);
600 btrfs_set_stack_ref_offset(&ref, owner_offset);
601
602 hash = hash_extent_ref(root_objectid, ref_generation, owner,
603 owner_offset);
604 key.offset = hash;
605 key.objectid = bytenr;
606 key.type = BTRFS_EXTENT_REF_KEY;
607
608 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
609 while (ret == -EEXIST) {
610 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
611 struct btrfs_extent_ref);
612 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
613 goto out;
614 key.offset++;
615 btrfs_release_path(root, path);
616 ret = btrfs_insert_empty_item(trans, root, path, &key,
617 sizeof(ref));
618 }
619 if (ret)
620 goto out;
621 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
622 struct btrfs_extent_ref);
623 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
624 sizeof(ref));
625 btrfs_mark_buffer_dirty(path->nodes[0]);
626 out:
627 btrfs_release_path(root, path);
628 return ret;
629 }
630
631 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
632 struct btrfs_root *root,
633 u64 bytenr, u64 num_bytes,
634 u64 root_objectid, u64 ref_generation,
635 u64 owner, u64 owner_offset)
636 {
637 struct btrfs_path *path;
638 int ret;
639 struct btrfs_key key;
640 struct extent_buffer *l;
641 struct btrfs_extent_item *item;
642 u32 refs;
643
644 WARN_ON(num_bytes < root->sectorsize);
645 path = btrfs_alloc_path();
646 if (!path)
647 return -ENOMEM;
648
649 path->reada = 0;
650 key.objectid = bytenr;
651 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
652 key.offset = num_bytes;
653 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
654 0, 1);
655 if (ret < 0)
656 return ret;
657 if (ret != 0) {
658 BUG();
659 }
660 BUG_ON(ret != 0);
661 l = path->nodes[0];
662 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
663 refs = btrfs_extent_refs(l, item);
664 btrfs_set_extent_refs(l, item, refs + 1);
665 btrfs_mark_buffer_dirty(path->nodes[0]);
666
667 btrfs_release_path(root->fs_info->extent_root, path);
668
669 path->reada = 0;
670 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
671 path, bytenr, root_objectid,
672 ref_generation, owner, owner_offset);
673 BUG_ON(ret);
674 finish_current_insert(trans, root->fs_info->extent_root);
675 del_pending_extents(trans, root->fs_info->extent_root);
676
677 btrfs_free_path(path);
678 return 0;
679 }
680
681 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
682 struct btrfs_root *root)
683 {
684 finish_current_insert(trans, root->fs_info->extent_root);
685 del_pending_extents(trans, root->fs_info->extent_root);
686 return 0;
687 }
688
689 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
690 struct btrfs_root *root, u64 bytenr,
691 u64 num_bytes, u32 *refs)
692 {
693 struct btrfs_path *path;
694 int ret;
695 struct btrfs_key key;
696 struct extent_buffer *l;
697 struct btrfs_extent_item *item;
698
699 WARN_ON(num_bytes < root->sectorsize);
700 path = btrfs_alloc_path();
701 path->reada = 0;
702 key.objectid = bytenr;
703 key.offset = num_bytes;
704 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
705 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
706 0, 0);
707 if (ret < 0)
708 goto out;
709 if (ret != 0) {
710 btrfs_print_leaf(root, path->nodes[0]);
711 printk("failed to find block number %Lu\n", bytenr);
712 BUG();
713 }
714 l = path->nodes[0];
715 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
716 *refs = btrfs_extent_refs(l, item);
717 out:
718 btrfs_free_path(path);
719 return 0;
720 }
721
722 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
723 struct btrfs_path *count_path,
724 u64 first_extent)
725 {
726 struct btrfs_root *extent_root = root->fs_info->extent_root;
727 struct btrfs_path *path;
728 u64 bytenr;
729 u64 found_objectid;
730 u64 root_objectid = root->root_key.objectid;
731 u32 total_count = 0;
732 u32 cur_count;
733 u32 nritems;
734 int ret;
735 struct btrfs_key key;
736 struct btrfs_key found_key;
737 struct extent_buffer *l;
738 struct btrfs_extent_item *item;
739 struct btrfs_extent_ref *ref_item;
740 int level = -1;
741
742 path = btrfs_alloc_path();
743 again:
744 if (level == -1)
745 bytenr = first_extent;
746 else
747 bytenr = count_path->nodes[level]->start;
748
749 cur_count = 0;
750 key.objectid = bytenr;
751 key.offset = 0;
752
753 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
754 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
755 if (ret < 0)
756 goto out;
757 BUG_ON(ret == 0);
758
759 l = path->nodes[0];
760 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
761
762 if (found_key.objectid != bytenr ||
763 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
764 goto out;
765 }
766
767 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
768 while (1) {
769 l = path->nodes[0];
770 nritems = btrfs_header_nritems(l);
771 if (path->slots[0] >= nritems) {
772 ret = btrfs_next_leaf(extent_root, path);
773 if (ret == 0)
774 continue;
775 break;
776 }
777 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
778 if (found_key.objectid != bytenr)
779 break;
780
781 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
782 path->slots[0]++;
783 continue;
784 }
785
786 cur_count++;
787 ref_item = btrfs_item_ptr(l, path->slots[0],
788 struct btrfs_extent_ref);
789 found_objectid = btrfs_ref_root(l, ref_item);
790
791 if (found_objectid != root_objectid) {
792 total_count = 2;
793 goto out;
794 }
795 total_count = 1;
796 path->slots[0]++;
797 }
798 if (cur_count == 0) {
799 total_count = 0;
800 goto out;
801 }
802 if (level >= 0 && root->node == count_path->nodes[level])
803 goto out;
804 level++;
805 btrfs_release_path(root, path);
806 goto again;
807
808 out:
809 btrfs_free_path(path);
810 return total_count;
811 }
812 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
813 struct btrfs_root *root, u64 owner_objectid)
814 {
815 u64 generation;
816 u64 key_objectid;
817 u64 level;
818 u32 nritems;
819 struct btrfs_disk_key disk_key;
820
821 level = btrfs_header_level(root->node);
822 generation = trans->transid;
823 nritems = btrfs_header_nritems(root->node);
824 if (nritems > 0) {
825 if (level == 0)
826 btrfs_item_key(root->node, &disk_key, 0);
827 else
828 btrfs_node_key(root->node, &disk_key, 0);
829 key_objectid = btrfs_disk_key_objectid(&disk_key);
830 } else {
831 key_objectid = 0;
832 }
833 return btrfs_inc_extent_ref(trans, root, root->node->start,
834 root->node->len, owner_objectid,
835 generation, level, key_objectid);
836 }
837
838 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
839 struct extent_buffer *buf)
840 {
841 u64 bytenr;
842 u32 nritems;
843 struct btrfs_key key;
844 struct btrfs_file_extent_item *fi;
845 int i;
846 int level;
847 int ret;
848 int faili;
849
850 if (!root->ref_cows)
851 return 0;
852
853 level = btrfs_header_level(buf);
854 nritems = btrfs_header_nritems(buf);
855 for (i = 0; i < nritems; i++) {
856 if (level == 0) {
857 u64 disk_bytenr;
858 btrfs_item_key_to_cpu(buf, &key, i);
859 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
860 continue;
861 fi = btrfs_item_ptr(buf, i,
862 struct btrfs_file_extent_item);
863 if (btrfs_file_extent_type(buf, fi) ==
864 BTRFS_FILE_EXTENT_INLINE)
865 continue;
866 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
867 if (disk_bytenr == 0)
868 continue;
869 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
870 btrfs_file_extent_disk_num_bytes(buf, fi),
871 root->root_key.objectid, trans->transid,
872 key.objectid, key.offset);
873 if (ret) {
874 faili = i;
875 goto fail;
876 }
877 } else {
878 bytenr = btrfs_node_blockptr(buf, i);
879 btrfs_node_key_to_cpu(buf, &key, i);
880 ret = btrfs_inc_extent_ref(trans, root, bytenr,
881 btrfs_level_size(root, level - 1),
882 root->root_key.objectid,
883 trans->transid,
884 level - 1, key.objectid);
885 if (ret) {
886 faili = i;
887 goto fail;
888 }
889 }
890 }
891 return 0;
892 fail:
893 WARN_ON(1);
894 #if 0
895 for (i =0; i < faili; i++) {
896 if (level == 0) {
897 u64 disk_bytenr;
898 btrfs_item_key_to_cpu(buf, &key, i);
899 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
900 continue;
901 fi = btrfs_item_ptr(buf, i,
902 struct btrfs_file_extent_item);
903 if (btrfs_file_extent_type(buf, fi) ==
904 BTRFS_FILE_EXTENT_INLINE)
905 continue;
906 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
907 if (disk_bytenr == 0)
908 continue;
909 err = btrfs_free_extent(trans, root, disk_bytenr,
910 btrfs_file_extent_disk_num_bytes(buf,
911 fi), 0);
912 BUG_ON(err);
913 } else {
914 bytenr = btrfs_node_blockptr(buf, i);
915 err = btrfs_free_extent(trans, root, bytenr,
916 btrfs_level_size(root, level - 1), 0);
917 BUG_ON(err);
918 }
919 }
920 #endif
921 return ret;
922 }
923
924 static int write_one_cache_group(struct btrfs_trans_handle *trans,
925 struct btrfs_root *root,
926 struct btrfs_path *path,
927 struct btrfs_block_group_cache *cache)
928 {
929 int ret;
930 int pending_ret;
931 struct btrfs_root *extent_root = root->fs_info->extent_root;
932 unsigned long bi;
933 struct extent_buffer *leaf;
934
935 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
936 if (ret < 0)
937 goto fail;
938 BUG_ON(ret);
939
940 leaf = path->nodes[0];
941 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
942 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
943 btrfs_mark_buffer_dirty(leaf);
944 btrfs_release_path(extent_root, path);
945 fail:
946 finish_current_insert(trans, extent_root);
947 pending_ret = del_pending_extents(trans, extent_root);
948 if (ret)
949 return ret;
950 if (pending_ret)
951 return pending_ret;
952 return 0;
953
954 }
955
956 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
957 struct btrfs_root *root)
958 {
959 struct extent_io_tree *block_group_cache;
960 struct btrfs_block_group_cache *cache;
961 int ret;
962 int err = 0;
963 int werr = 0;
964 struct btrfs_path *path;
965 u64 last = 0;
966 u64 start;
967 u64 end;
968 u64 ptr;
969
970 block_group_cache = &root->fs_info->block_group_cache;
971 path = btrfs_alloc_path();
972 if (!path)
973 return -ENOMEM;
974
975 while(1) {
976 ret = find_first_extent_bit(block_group_cache, last,
977 &start, &end, BLOCK_GROUP_DIRTY);
978 if (ret)
979 break;
980
981 last = end + 1;
982 ret = get_state_private(block_group_cache, start, &ptr);
983 if (ret)
984 break;
985
986 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
987 err = write_one_cache_group(trans, root,
988 path, cache);
989 /*
990 * if we fail to write the cache group, we want
991 * to keep it marked dirty in hopes that a later
992 * write will work
993 */
994 if (err) {
995 werr = err;
996 continue;
997 }
998 clear_extent_bits(block_group_cache, start, end,
999 BLOCK_GROUP_DIRTY, GFP_NOFS);
1000 }
1001 btrfs_free_path(path);
1002 return werr;
1003 }
1004
1005 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
1006 u64 flags)
1007 {
1008 struct list_head *head = &info->space_info;
1009 struct list_head *cur;
1010 struct btrfs_space_info *found;
1011 list_for_each(cur, head) {
1012 found = list_entry(cur, struct btrfs_space_info, list);
1013 if (found->flags == flags)
1014 return found;
1015 }
1016 return NULL;
1017
1018 }
1019
1020 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1021 u64 total_bytes, u64 bytes_used,
1022 struct btrfs_space_info **space_info)
1023 {
1024 struct btrfs_space_info *found;
1025
1026 found = __find_space_info(info, flags);
1027 if (found) {
1028 found->total_bytes += total_bytes;
1029 found->bytes_used += bytes_used;
1030 WARN_ON(found->total_bytes < found->bytes_used);
1031 *space_info = found;
1032 return 0;
1033 }
1034 found = kmalloc(sizeof(*found), GFP_NOFS);
1035 if (!found)
1036 return -ENOMEM;
1037
1038 list_add(&found->list, &info->space_info);
1039 found->flags = flags;
1040 found->total_bytes = total_bytes;
1041 found->bytes_used = bytes_used;
1042 found->bytes_pinned = 0;
1043 found->full = 0;
1044 *space_info = found;
1045 return 0;
1046 }
1047
1048 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1049 {
1050 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1051 BTRFS_BLOCK_GROUP_RAID1 |
1052 BTRFS_BLOCK_GROUP_DUP);
1053 if (extra_flags) {
1054 if (flags & BTRFS_BLOCK_GROUP_DATA)
1055 fs_info->avail_data_alloc_bits |= extra_flags;
1056 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1057 fs_info->avail_metadata_alloc_bits |= extra_flags;
1058 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1059 fs_info->avail_system_alloc_bits |= extra_flags;
1060 }
1061 }
1062
1063 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1064 struct btrfs_root *extent_root, u64 alloc_bytes,
1065 u64 flags)
1066 {
1067 struct btrfs_space_info *space_info;
1068 u64 thresh;
1069 u64 start;
1070 u64 num_bytes;
1071 int ret;
1072
1073 space_info = __find_space_info(extent_root->fs_info, flags);
1074 if (!space_info) {
1075 ret = update_space_info(extent_root->fs_info, flags,
1076 0, 0, &space_info);
1077 BUG_ON(ret);
1078 }
1079 BUG_ON(!space_info);
1080
1081 if (space_info->full)
1082 return 0;
1083
1084 thresh = div_factor(space_info->total_bytes, 6);
1085 if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1086 thresh)
1087 return 0;
1088
1089 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1090 if (ret == -ENOSPC) {
1091 printk("space info full %Lu\n", flags);
1092 space_info->full = 1;
1093 return 0;
1094 }
1095
1096 BUG_ON(ret);
1097
1098 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1099 extent_root->fs_info->chunk_root->root_key.objectid,
1100 start, num_bytes);
1101 BUG_ON(ret);
1102
1103 return 0;
1104 }
1105
1106 static int update_block_group(struct btrfs_trans_handle *trans,
1107 struct btrfs_root *root,
1108 u64 bytenr, u64 num_bytes, int alloc,
1109 int mark_free)
1110 {
1111 struct btrfs_block_group_cache *cache;
1112 struct btrfs_fs_info *info = root->fs_info;
1113 u64 total = num_bytes;
1114 u64 old_val;
1115 u64 byte_in_group;
1116 u64 start;
1117 u64 end;
1118
1119 while(total) {
1120 cache = btrfs_lookup_block_group(info, bytenr);
1121 if (!cache) {
1122 return -1;
1123 }
1124 byte_in_group = bytenr - cache->key.objectid;
1125 WARN_ON(byte_in_group > cache->key.offset);
1126 start = cache->key.objectid;
1127 end = start + cache->key.offset - 1;
1128 set_extent_bits(&info->block_group_cache, start, end,
1129 BLOCK_GROUP_DIRTY, GFP_NOFS);
1130
1131 old_val = btrfs_block_group_used(&cache->item);
1132 num_bytes = min(total, cache->key.offset - byte_in_group);
1133 if (alloc) {
1134 old_val += num_bytes;
1135 cache->space_info->bytes_used += num_bytes;
1136 } else {
1137 old_val -= num_bytes;
1138 cache->space_info->bytes_used -= num_bytes;
1139 if (mark_free) {
1140 set_extent_dirty(&info->free_space_cache,
1141 bytenr, bytenr + num_bytes - 1,
1142 GFP_NOFS);
1143 }
1144 }
1145 btrfs_set_block_group_used(&cache->item, old_val);
1146 total -= num_bytes;
1147 bytenr += num_bytes;
1148 }
1149 return 0;
1150 }
1151
1152 static int update_pinned_extents(struct btrfs_root *root,
1153 u64 bytenr, u64 num, int pin)
1154 {
1155 u64 len;
1156 struct btrfs_block_group_cache *cache;
1157 struct btrfs_fs_info *fs_info = root->fs_info;
1158
1159 if (pin) {
1160 set_extent_dirty(&fs_info->pinned_extents,
1161 bytenr, bytenr + num - 1, GFP_NOFS);
1162 } else {
1163 clear_extent_dirty(&fs_info->pinned_extents,
1164 bytenr, bytenr + num - 1, GFP_NOFS);
1165 }
1166 while (num > 0) {
1167 cache = btrfs_lookup_block_group(fs_info, bytenr);
1168 WARN_ON(!cache);
1169 len = min(num, cache->key.offset -
1170 (bytenr - cache->key.objectid));
1171 if (pin) {
1172 cache->pinned += len;
1173 cache->space_info->bytes_pinned += len;
1174 fs_info->total_pinned += len;
1175 } else {
1176 cache->pinned -= len;
1177 cache->space_info->bytes_pinned -= len;
1178 fs_info->total_pinned -= len;
1179 }
1180 bytenr += len;
1181 num -= len;
1182 }
1183 return 0;
1184 }
1185
1186 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1187 {
1188 u64 last = 0;
1189 u64 start;
1190 u64 end;
1191 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1192 int ret;
1193
1194 while(1) {
1195 ret = find_first_extent_bit(pinned_extents, last,
1196 &start, &end, EXTENT_DIRTY);
1197 if (ret)
1198 break;
1199 set_extent_dirty(copy, start, end, GFP_NOFS);
1200 last = end + 1;
1201 }
1202 return 0;
1203 }
1204
1205 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1206 struct btrfs_root *root,
1207 struct extent_io_tree *unpin)
1208 {
1209 u64 start;
1210 u64 end;
1211 int ret;
1212 struct extent_io_tree *free_space_cache;
1213 free_space_cache = &root->fs_info->free_space_cache;
1214
1215 while(1) {
1216 ret = find_first_extent_bit(unpin, 0, &start, &end,
1217 EXTENT_DIRTY);
1218 if (ret)
1219 break;
1220 update_pinned_extents(root, start, end + 1 - start, 0);
1221 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1222 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1223 }
1224 return 0;
1225 }
1226
1227 static int finish_current_insert(struct btrfs_trans_handle *trans,
1228 struct btrfs_root *extent_root)
1229 {
1230 u64 start;
1231 u64 end;
1232 struct btrfs_fs_info *info = extent_root->fs_info;
1233 struct extent_buffer *eb;
1234 struct btrfs_path *path;
1235 struct btrfs_key ins;
1236 struct btrfs_disk_key first;
1237 struct btrfs_extent_item extent_item;
1238 int ret;
1239 int level;
1240 int err = 0;
1241
1242 btrfs_set_stack_extent_refs(&extent_item, 1);
1243 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1244 path = btrfs_alloc_path();
1245
1246 while(1) {
1247 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1248 &end, EXTENT_LOCKED);
1249 if (ret)
1250 break;
1251
1252 ins.objectid = start;
1253 ins.offset = end + 1 - start;
1254 err = btrfs_insert_item(trans, extent_root, &ins,
1255 &extent_item, sizeof(extent_item));
1256 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1257 GFP_NOFS);
1258 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1259 level = btrfs_header_level(eb);
1260 if (level == 0) {
1261 btrfs_item_key(eb, &first, 0);
1262 } else {
1263 btrfs_node_key(eb, &first, 0);
1264 }
1265 err = btrfs_insert_extent_backref(trans, extent_root, path,
1266 start, extent_root->root_key.objectid,
1267 0, level,
1268 btrfs_disk_key_objectid(&first));
1269 BUG_ON(err);
1270 free_extent_buffer(eb);
1271 }
1272 btrfs_free_path(path);
1273 return 0;
1274 }
1275
1276 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1277 int pending)
1278 {
1279 int err = 0;
1280 struct extent_buffer *buf;
1281
1282 if (!pending) {
1283 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1284 if (buf) {
1285 if (btrfs_buffer_uptodate(buf)) {
1286 u64 transid =
1287 root->fs_info->running_transaction->transid;
1288 u64 header_transid =
1289 btrfs_header_generation(buf);
1290 if (header_transid == transid &&
1291 !btrfs_header_flag(buf,
1292 BTRFS_HEADER_FLAG_WRITTEN)) {
1293 clean_tree_block(NULL, root, buf);
1294 free_extent_buffer(buf);
1295 return 1;
1296 }
1297 }
1298 free_extent_buffer(buf);
1299 }
1300 update_pinned_extents(root, bytenr, num_bytes, 1);
1301 } else {
1302 set_extent_bits(&root->fs_info->pending_del,
1303 bytenr, bytenr + num_bytes - 1,
1304 EXTENT_LOCKED, GFP_NOFS);
1305 }
1306 BUG_ON(err < 0);
1307 return 0;
1308 }
1309
1310 /*
1311 * remove an extent from the root, returns 0 on success
1312 */
1313 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1314 *root, u64 bytenr, u64 num_bytes,
1315 u64 root_objectid, u64 ref_generation,
1316 u64 owner_objectid, u64 owner_offset, int pin,
1317 int mark_free)
1318 {
1319 struct btrfs_path *path;
1320 struct btrfs_key key;
1321 struct btrfs_fs_info *info = root->fs_info;
1322 struct btrfs_root *extent_root = info->extent_root;
1323 struct extent_buffer *leaf;
1324 int ret;
1325 int extent_slot = 0;
1326 int found_extent = 0;
1327 int num_to_del = 1;
1328 struct btrfs_extent_item *ei;
1329 u32 refs;
1330
1331 key.objectid = bytenr;
1332 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1333 key.offset = num_bytes;
1334 path = btrfs_alloc_path();
1335 if (!path)
1336 return -ENOMEM;
1337
1338 path->reada = 0;
1339 ret = lookup_extent_backref(trans, extent_root, path,
1340 bytenr, root_objectid,
1341 ref_generation,
1342 owner_objectid, owner_offset, 1);
1343 if (ret == 0) {
1344 struct btrfs_key found_key;
1345 extent_slot = path->slots[0];
1346 while(extent_slot > 0) {
1347 extent_slot--;
1348 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1349 extent_slot);
1350 if (found_key.objectid != bytenr)
1351 break;
1352 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1353 found_key.offset == num_bytes) {
1354 found_extent = 1;
1355 break;
1356 }
1357 if (path->slots[0] - extent_slot > 5)
1358 break;
1359 }
1360 if (!found_extent)
1361 ret = btrfs_del_item(trans, extent_root, path);
1362 } else {
1363 btrfs_print_leaf(extent_root, path->nodes[0]);
1364 WARN_ON(1);
1365 printk("Unable to find ref byte nr %Lu root %Lu "
1366 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1367 root_objectid, ref_generation, owner_objectid,
1368 owner_offset);
1369 }
1370 if (!found_extent) {
1371 btrfs_release_path(extent_root, path);
1372 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1373 if (ret < 0)
1374 return ret;
1375 BUG_ON(ret);
1376 extent_slot = path->slots[0];
1377 }
1378
1379 leaf = path->nodes[0];
1380 ei = btrfs_item_ptr(leaf, extent_slot,
1381 struct btrfs_extent_item);
1382 refs = btrfs_extent_refs(leaf, ei);
1383 BUG_ON(refs == 0);
1384 refs -= 1;
1385 btrfs_set_extent_refs(leaf, ei, refs);
1386
1387 btrfs_mark_buffer_dirty(leaf);
1388
1389 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1390 /* if the back ref and the extent are next to each other
1391 * they get deleted below in one shot
1392 */
1393 path->slots[0] = extent_slot;
1394 num_to_del = 2;
1395 } else if (found_extent) {
1396 /* otherwise delete the extent back ref */
1397 ret = btrfs_del_item(trans, extent_root, path);
1398 BUG_ON(ret);
1399 /* if refs are 0, we need to setup the path for deletion */
1400 if (refs == 0) {
1401 btrfs_release_path(extent_root, path);
1402 ret = btrfs_search_slot(trans, extent_root, &key, path,
1403 -1, 1);
1404 if (ret < 0)
1405 return ret;
1406 BUG_ON(ret);
1407 }
1408 }
1409
1410 if (refs == 0) {
1411 u64 super_used;
1412 u64 root_used;
1413
1414 if (pin) {
1415 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1416 if (ret > 0)
1417 mark_free = 1;
1418 BUG_ON(ret < 0);
1419 }
1420
1421 /* block accounting for super block */
1422 super_used = btrfs_super_bytes_used(&info->super_copy);
1423 btrfs_set_super_bytes_used(&info->super_copy,
1424 super_used - num_bytes);
1425
1426 /* block accounting for root item */
1427 root_used = btrfs_root_used(&root->root_item);
1428 btrfs_set_root_used(&root->root_item,
1429 root_used - num_bytes);
1430 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1431 num_to_del);
1432 if (ret) {
1433 return ret;
1434 }
1435 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1436 mark_free);
1437 BUG_ON(ret);
1438 }
1439 btrfs_free_path(path);
1440 finish_current_insert(trans, extent_root);
1441 return ret;
1442 }
1443
1444 /*
1445 * find all the blocks marked as pending in the radix tree and remove
1446 * them from the extent map
1447 */
1448 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1449 btrfs_root *extent_root)
1450 {
1451 int ret;
1452 int err = 0;
1453 u64 start;
1454 u64 end;
1455 struct extent_io_tree *pending_del;
1456 struct extent_io_tree *pinned_extents;
1457
1458 pending_del = &extent_root->fs_info->pending_del;
1459 pinned_extents = &extent_root->fs_info->pinned_extents;
1460
1461 while(1) {
1462 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1463 EXTENT_LOCKED);
1464 if (ret)
1465 break;
1466 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1467 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1468 GFP_NOFS);
1469 ret = __free_extent(trans, extent_root,
1470 start, end + 1 - start,
1471 extent_root->root_key.objectid,
1472 0, 0, 0, 0, 0);
1473 if (ret)
1474 err = ret;
1475 }
1476 return err;
1477 }
1478
1479 /*
1480 * remove an extent from the root, returns 0 on success
1481 */
1482 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1483 *root, u64 bytenr, u64 num_bytes,
1484 u64 root_objectid, u64 ref_generation,
1485 u64 owner_objectid, u64 owner_offset, int pin)
1486 {
1487 struct btrfs_root *extent_root = root->fs_info->extent_root;
1488 int pending_ret;
1489 int ret;
1490
1491 WARN_ON(num_bytes < root->sectorsize);
1492 if (!root->ref_cows)
1493 ref_generation = 0;
1494
1495 if (root == extent_root) {
1496 pin_down_bytes(root, bytenr, num_bytes, 1);
1497 return 0;
1498 }
1499 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1500 ref_generation, owner_objectid, owner_offset,
1501 pin, pin == 0);
1502 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1503 return ret ? ret : pending_ret;
1504 }
1505
1506 static u64 stripe_align(struct btrfs_root *root, u64 val)
1507 {
1508 u64 mask = ((u64)root->stripesize - 1);
1509 u64 ret = (val + mask) & ~mask;
1510 return ret;
1511 }
1512
1513 /*
1514 * walks the btree of allocated extents and find a hole of a given size.
1515 * The key ins is changed to record the hole:
1516 * ins->objectid == block start
1517 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1518 * ins->offset == number of blocks
1519 * Any available blocks before search_start are skipped.
1520 */
1521 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1522 struct btrfs_root *orig_root,
1523 u64 num_bytes, u64 empty_size,
1524 u64 search_start, u64 search_end,
1525 u64 hint_byte, struct btrfs_key *ins,
1526 u64 exclude_start, u64 exclude_nr,
1527 int data)
1528 {
1529 int ret;
1530 u64 orig_search_start = search_start;
1531 struct btrfs_root * root = orig_root->fs_info->extent_root;
1532 struct btrfs_fs_info *info = root->fs_info;
1533 u64 total_needed = num_bytes;
1534 u64 *last_ptr = NULL;
1535 struct btrfs_block_group_cache *block_group;
1536 int full_scan = 0;
1537 int wrapped = 0;
1538 int empty_cluster = 2 * 1024 * 1024;
1539
1540 WARN_ON(num_bytes < root->sectorsize);
1541 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1542
1543 if (data & BTRFS_BLOCK_GROUP_METADATA) {
1544 last_ptr = &root->fs_info->last_alloc;
1545 empty_cluster = 256 * 1024;
1546 }
1547
1548 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
1549 last_ptr = &root->fs_info->last_data_alloc;
1550 }
1551
1552 if (last_ptr) {
1553 if (*last_ptr)
1554 hint_byte = *last_ptr;
1555 else {
1556 empty_size += empty_cluster;
1557 }
1558 }
1559
1560 if (search_end == (u64)-1)
1561 search_end = btrfs_super_total_bytes(&info->super_copy);
1562
1563 if (hint_byte) {
1564 block_group = btrfs_lookup_block_group(info, hint_byte);
1565 if (!block_group)
1566 hint_byte = search_start;
1567 block_group = btrfs_find_block_group(root, block_group,
1568 hint_byte, data, 1);
1569 if (last_ptr && *last_ptr == 0 && block_group)
1570 hint_byte = block_group->key.objectid;
1571 } else {
1572 block_group = btrfs_find_block_group(root,
1573 trans->block_group,
1574 search_start, data, 1);
1575 }
1576 search_start = max(search_start, hint_byte);
1577
1578 total_needed += empty_size;
1579
1580 check_failed:
1581 if (!block_group) {
1582 block_group = btrfs_lookup_block_group(info, search_start);
1583 if (!block_group)
1584 block_group = btrfs_lookup_block_group(info,
1585 orig_search_start);
1586 }
1587 ret = find_search_start(root, &block_group, &search_start,
1588 total_needed, data);
1589 if (ret == -ENOSPC && last_ptr && *last_ptr) {
1590 *last_ptr = 0;
1591 block_group = btrfs_lookup_block_group(info,
1592 orig_search_start);
1593 search_start = orig_search_start;
1594 ret = find_search_start(root, &block_group, &search_start,
1595 total_needed, data);
1596 }
1597 if (ret == -ENOSPC)
1598 goto enospc;
1599 if (ret)
1600 goto error;
1601
1602 if (last_ptr && *last_ptr && search_start != *last_ptr) {
1603 *last_ptr = 0;
1604 if (!empty_size) {
1605 empty_size += empty_cluster;
1606 total_needed += empty_size;
1607 }
1608 block_group = btrfs_lookup_block_group(info,
1609 orig_search_start);
1610 search_start = orig_search_start;
1611 ret = find_search_start(root, &block_group,
1612 &search_start, total_needed, data);
1613 if (ret == -ENOSPC)
1614 goto enospc;
1615 if (ret)
1616 goto error;
1617 }
1618
1619 search_start = stripe_align(root, search_start);
1620 ins->objectid = search_start;
1621 ins->offset = num_bytes;
1622
1623 if (ins->objectid + num_bytes >= search_end)
1624 goto enospc;
1625
1626 if (ins->objectid + num_bytes >
1627 block_group->key.objectid + block_group->key.offset) {
1628 search_start = block_group->key.objectid +
1629 block_group->key.offset;
1630 goto new_group;
1631 }
1632
1633 if (test_range_bit(&info->extent_ins, ins->objectid,
1634 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1635 search_start = ins->objectid + num_bytes;
1636 goto new_group;
1637 }
1638
1639 if (test_range_bit(&info->pinned_extents, ins->objectid,
1640 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1641 search_start = ins->objectid + num_bytes;
1642 goto new_group;
1643 }
1644
1645 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1646 ins->objectid < exclude_start + exclude_nr)) {
1647 search_start = exclude_start + exclude_nr;
1648 goto new_group;
1649 }
1650
1651 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
1652 block_group = btrfs_lookup_block_group(info, ins->objectid);
1653 if (block_group)
1654 trans->block_group = block_group;
1655 }
1656 ins->offset = num_bytes;
1657 if (last_ptr) {
1658 *last_ptr = ins->objectid + ins->offset;
1659 if (*last_ptr ==
1660 btrfs_super_total_bytes(&root->fs_info->super_copy)) {
1661 *last_ptr = 0;
1662 }
1663 }
1664 return 0;
1665
1666 new_group:
1667 if (search_start + num_bytes >= search_end) {
1668 enospc:
1669 search_start = orig_search_start;
1670 if (full_scan) {
1671 ret = -ENOSPC;
1672 goto error;
1673 }
1674 if (wrapped) {
1675 if (!full_scan)
1676 total_needed -= empty_size;
1677 full_scan = 1;
1678 } else
1679 wrapped = 1;
1680 }
1681 block_group = btrfs_lookup_block_group(info, search_start);
1682 cond_resched();
1683 block_group = btrfs_find_block_group(root, block_group,
1684 search_start, data, 0);
1685 goto check_failed;
1686
1687 error:
1688 return ret;
1689 }
1690 /*
1691 * finds a free extent and does all the dirty work required for allocation
1692 * returns the key for the extent through ins, and a tree buffer for
1693 * the first block of the extent through buf.
1694 *
1695 * returns 0 if everything worked, non-zero otherwise.
1696 */
1697 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1698 struct btrfs_root *root,
1699 u64 num_bytes, u64 root_objectid, u64 ref_generation,
1700 u64 owner, u64 owner_offset,
1701 u64 empty_size, u64 hint_byte,
1702 u64 search_end, struct btrfs_key *ins, int data)
1703 {
1704 int ret;
1705 int pending_ret;
1706 u64 super_used;
1707 u64 root_used;
1708 u64 search_start = 0;
1709 u64 new_hint;
1710 u64 alloc_profile;
1711 u32 sizes[2];
1712 struct btrfs_fs_info *info = root->fs_info;
1713 struct btrfs_root *extent_root = info->extent_root;
1714 struct btrfs_extent_item *extent_item;
1715 struct btrfs_extent_ref *ref;
1716 struct btrfs_path *path;
1717 struct btrfs_key keys[2];
1718
1719 if (data) {
1720 alloc_profile = info->avail_data_alloc_bits &
1721 info->data_alloc_profile;
1722 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
1723 } else if (root == root->fs_info->chunk_root) {
1724 alloc_profile = info->avail_system_alloc_bits &
1725 info->system_alloc_profile;
1726 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
1727 } else {
1728 alloc_profile = info->avail_metadata_alloc_bits &
1729 info->metadata_alloc_profile;
1730 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
1731 }
1732
1733 if (root->ref_cows) {
1734 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
1735 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1736 2 * 1024 * 1024,
1737 BTRFS_BLOCK_GROUP_METADATA |
1738 (info->metadata_alloc_profile &
1739 info->avail_metadata_alloc_bits));
1740 BUG_ON(ret);
1741 }
1742 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1743 num_bytes + 2 * 1024 * 1024, data);
1744 BUG_ON(ret);
1745 }
1746
1747 new_hint = max(hint_byte, root->fs_info->alloc_start);
1748 if (new_hint < btrfs_super_total_bytes(&info->super_copy))
1749 hint_byte = new_hint;
1750
1751 WARN_ON(num_bytes < root->sectorsize);
1752 ret = find_free_extent(trans, root, num_bytes, empty_size,
1753 search_start, search_end, hint_byte, ins,
1754 trans->alloc_exclude_start,
1755 trans->alloc_exclude_nr, data);
1756 BUG_ON(ret);
1757 if (ret)
1758 return ret;
1759
1760 /* block accounting for super block */
1761 super_used = btrfs_super_bytes_used(&info->super_copy);
1762 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1763
1764 /* block accounting for root item */
1765 root_used = btrfs_root_used(&root->root_item);
1766 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1767
1768 clear_extent_dirty(&root->fs_info->free_space_cache,
1769 ins->objectid, ins->objectid + ins->offset - 1,
1770 GFP_NOFS);
1771
1772 if (root == extent_root) {
1773 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1774 ins->objectid + ins->offset - 1,
1775 EXTENT_LOCKED, GFP_NOFS);
1776 goto update_block;
1777 }
1778
1779 WARN_ON(trans->alloc_exclude_nr);
1780 trans->alloc_exclude_start = ins->objectid;
1781 trans->alloc_exclude_nr = ins->offset;
1782
1783 memcpy(&keys[0], ins, sizeof(*ins));
1784 keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
1785 owner, owner_offset);
1786 keys[1].objectid = ins->objectid;
1787 keys[1].type = BTRFS_EXTENT_REF_KEY;
1788 sizes[0] = sizeof(*extent_item);
1789 sizes[1] = sizeof(*ref);
1790
1791 path = btrfs_alloc_path();
1792 BUG_ON(!path);
1793
1794 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
1795 sizes, 2);
1796
1797 BUG_ON(ret);
1798 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1799 struct btrfs_extent_item);
1800 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
1801 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1802 struct btrfs_extent_ref);
1803
1804 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
1805 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
1806 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
1807 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
1808
1809 btrfs_mark_buffer_dirty(path->nodes[0]);
1810
1811 trans->alloc_exclude_start = 0;
1812 trans->alloc_exclude_nr = 0;
1813 btrfs_free_path(path);
1814 finish_current_insert(trans, extent_root);
1815 pending_ret = del_pending_extents(trans, extent_root);
1816
1817 if (ret) {
1818 return ret;
1819 }
1820 if (pending_ret) {
1821 return pending_ret;
1822 }
1823
1824 update_block:
1825 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
1826 if (ret) {
1827 printk("update block group failed for %Lu %Lu\n",
1828 ins->objectid, ins->offset);
1829 BUG();
1830 }
1831 return 0;
1832 }
1833
1834 /*
1835 * helper function to allocate a block for a given tree
1836 * returns the tree buffer or NULL.
1837 */
1838 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1839 struct btrfs_root *root,
1840 u32 blocksize,
1841 u64 root_objectid, u64 hint,
1842 u64 empty_size)
1843 {
1844 u64 ref_generation;
1845
1846 if (root->ref_cows)
1847 ref_generation = trans->transid;
1848 else
1849 ref_generation = 0;
1850
1851
1852 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1853 ref_generation, 0, 0, hint, empty_size);
1854 }
1855
1856 /*
1857 * helper function to allocate a block for a given tree
1858 * returns the tree buffer or NULL.
1859 */
1860 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1861 struct btrfs_root *root,
1862 u32 blocksize,
1863 u64 root_objectid,
1864 u64 ref_generation,
1865 u64 first_objectid,
1866 int level,
1867 u64 hint,
1868 u64 empty_size)
1869 {
1870 struct btrfs_key ins;
1871 int ret;
1872 struct extent_buffer *buf;
1873
1874 ret = btrfs_alloc_extent(trans, root, blocksize,
1875 root_objectid, ref_generation,
1876 level, first_objectid, empty_size, hint,
1877 (u64)-1, &ins, 0);
1878 if (ret) {
1879 BUG_ON(ret > 0);
1880 return ERR_PTR(ret);
1881 }
1882 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1883 if (!buf) {
1884 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1885 root->root_key.objectid, ref_generation,
1886 0, 0, 0);
1887 return ERR_PTR(-ENOMEM);
1888 }
1889 btrfs_set_header_generation(buf, trans->transid);
1890 clean_tree_block(trans, root, buf);
1891 wait_on_tree_block_writeback(root, buf);
1892 btrfs_set_buffer_uptodate(buf);
1893
1894 if (PageDirty(buf->first_page)) {
1895 printk("page %lu dirty\n", buf->first_page->index);
1896 WARN_ON(1);
1897 }
1898
1899 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
1900 buf->start + buf->len - 1, GFP_NOFS);
1901 if (!btrfs_test_opt(root, SSD))
1902 btrfs_set_buffer_defrag(buf);
1903 trans->blocks_used++;
1904 return buf;
1905 }
1906
1907 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
1908 struct btrfs_root *root,
1909 struct extent_buffer *leaf)
1910 {
1911 u64 leaf_owner;
1912 u64 leaf_generation;
1913 struct btrfs_key key;
1914 struct btrfs_file_extent_item *fi;
1915 int i;
1916 int nritems;
1917 int ret;
1918
1919 BUG_ON(!btrfs_is_leaf(leaf));
1920 nritems = btrfs_header_nritems(leaf);
1921 leaf_owner = btrfs_header_owner(leaf);
1922 leaf_generation = btrfs_header_generation(leaf);
1923
1924 for (i = 0; i < nritems; i++) {
1925 u64 disk_bytenr;
1926
1927 btrfs_item_key_to_cpu(leaf, &key, i);
1928 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1929 continue;
1930 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1931 if (btrfs_file_extent_type(leaf, fi) ==
1932 BTRFS_FILE_EXTENT_INLINE)
1933 continue;
1934 /*
1935 * FIXME make sure to insert a trans record that
1936 * repeats the snapshot del on crash
1937 */
1938 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1939 if (disk_bytenr == 0)
1940 continue;
1941 ret = btrfs_free_extent(trans, root, disk_bytenr,
1942 btrfs_file_extent_disk_num_bytes(leaf, fi),
1943 leaf_owner, leaf_generation,
1944 key.objectid, key.offset, 0);
1945 BUG_ON(ret);
1946 }
1947 return 0;
1948 }
1949
1950 static void noinline reada_walk_down(struct btrfs_root *root,
1951 struct extent_buffer *node,
1952 int slot)
1953 {
1954 u64 bytenr;
1955 u64 last = 0;
1956 u32 nritems;
1957 u32 refs;
1958 u32 blocksize;
1959 int ret;
1960 int i;
1961 int level;
1962 int skipped = 0;
1963
1964 nritems = btrfs_header_nritems(node);
1965 level = btrfs_header_level(node);
1966 if (level)
1967 return;
1968
1969 for (i = slot; i < nritems && skipped < 32; i++) {
1970 bytenr = btrfs_node_blockptr(node, i);
1971 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
1972 (last > bytenr && last - bytenr > 32 * 1024))) {
1973 skipped++;
1974 continue;
1975 }
1976 blocksize = btrfs_level_size(root, level - 1);
1977 if (i != slot) {
1978 ret = lookup_extent_ref(NULL, root, bytenr,
1979 blocksize, &refs);
1980 BUG_ON(ret);
1981 if (refs != 1) {
1982 skipped++;
1983 continue;
1984 }
1985 }
1986 mutex_unlock(&root->fs_info->fs_mutex);
1987 ret = readahead_tree_block(root, bytenr, blocksize);
1988 last = bytenr + blocksize;
1989 cond_resched();
1990 mutex_lock(&root->fs_info->fs_mutex);
1991 if (ret)
1992 break;
1993 }
1994 }
1995
1996 /*
1997 * helper function for drop_snapshot, this walks down the tree dropping ref
1998 * counts as it goes.
1999 */
2000 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2001 struct btrfs_root *root,
2002 struct btrfs_path *path, int *level)
2003 {
2004 u64 root_owner;
2005 u64 root_gen;
2006 u64 bytenr;
2007 struct extent_buffer *next;
2008 struct extent_buffer *cur;
2009 struct extent_buffer *parent;
2010 u32 blocksize;
2011 int ret;
2012 u32 refs;
2013
2014 WARN_ON(*level < 0);
2015 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2016 ret = lookup_extent_ref(trans, root,
2017 path->nodes[*level]->start,
2018 path->nodes[*level]->len, &refs);
2019 BUG_ON(ret);
2020 if (refs > 1)
2021 goto out;
2022
2023 /*
2024 * walk down to the last node level and free all the leaves
2025 */
2026 while(*level >= 0) {
2027 WARN_ON(*level < 0);
2028 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2029 cur = path->nodes[*level];
2030
2031 if (btrfs_header_level(cur) != *level)
2032 WARN_ON(1);
2033
2034 if (path->slots[*level] >=
2035 btrfs_header_nritems(cur))
2036 break;
2037 if (*level == 0) {
2038 ret = drop_leaf_ref(trans, root, cur);
2039 BUG_ON(ret);
2040 break;
2041 }
2042 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2043 blocksize = btrfs_level_size(root, *level - 1);
2044 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
2045 BUG_ON(ret);
2046 if (refs != 1) {
2047 parent = path->nodes[*level];
2048 root_owner = btrfs_header_owner(parent);
2049 root_gen = btrfs_header_generation(parent);
2050 path->slots[*level]++;
2051 ret = btrfs_free_extent(trans, root, bytenr,
2052 blocksize, root_owner,
2053 root_gen, 0, 0, 1);
2054 BUG_ON(ret);
2055 continue;
2056 }
2057 next = btrfs_find_tree_block(root, bytenr, blocksize);
2058 if (!next || !btrfs_buffer_uptodate(next)) {
2059 free_extent_buffer(next);
2060 reada_walk_down(root, cur, path->slots[*level]);
2061
2062 mutex_unlock(&root->fs_info->fs_mutex);
2063 next = read_tree_block(root, bytenr, blocksize);
2064 mutex_lock(&root->fs_info->fs_mutex);
2065
2066 /* we've dropped the lock, double check */
2067 ret = lookup_extent_ref(trans, root, bytenr,
2068 blocksize, &refs);
2069 BUG_ON(ret);
2070 if (refs != 1) {
2071 parent = path->nodes[*level];
2072 root_owner = btrfs_header_owner(parent);
2073 root_gen = btrfs_header_generation(parent);
2074
2075 path->slots[*level]++;
2076 free_extent_buffer(next);
2077 ret = btrfs_free_extent(trans, root, bytenr,
2078 blocksize,
2079 root_owner,
2080 root_gen, 0, 0, 1);
2081 BUG_ON(ret);
2082 continue;
2083 }
2084 } else if (next) {
2085 btrfs_verify_block_csum(root, next);
2086 }
2087 WARN_ON(*level <= 0);
2088 if (path->nodes[*level-1])
2089 free_extent_buffer(path->nodes[*level-1]);
2090 path->nodes[*level-1] = next;
2091 *level = btrfs_header_level(next);
2092 path->slots[*level] = 0;
2093 }
2094 out:
2095 WARN_ON(*level < 0);
2096 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2097
2098 if (path->nodes[*level] == root->node) {
2099 root_owner = root->root_key.objectid;
2100 parent = path->nodes[*level];
2101 } else {
2102 parent = path->nodes[*level + 1];
2103 root_owner = btrfs_header_owner(parent);
2104 }
2105
2106 root_gen = btrfs_header_generation(parent);
2107 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
2108 path->nodes[*level]->len,
2109 root_owner, root_gen, 0, 0, 1);
2110 free_extent_buffer(path->nodes[*level]);
2111 path->nodes[*level] = NULL;
2112 *level += 1;
2113 BUG_ON(ret);
2114 return 0;
2115 }
2116
2117 /*
2118 * helper for dropping snapshots. This walks back up the tree in the path
2119 * to find the first node higher up where we haven't yet gone through
2120 * all the slots
2121 */
2122 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
2123 struct btrfs_root *root,
2124 struct btrfs_path *path, int *level)
2125 {
2126 u64 root_owner;
2127 u64 root_gen;
2128 struct btrfs_root_item *root_item = &root->root_item;
2129 int i;
2130 int slot;
2131 int ret;
2132
2133 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2134 slot = path->slots[i];
2135 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
2136 struct extent_buffer *node;
2137 struct btrfs_disk_key disk_key;
2138 node = path->nodes[i];
2139 path->slots[i]++;
2140 *level = i;
2141 WARN_ON(*level == 0);
2142 btrfs_node_key(node, &disk_key, path->slots[i]);
2143 memcpy(&root_item->drop_progress,
2144 &disk_key, sizeof(disk_key));
2145 root_item->drop_level = i;
2146 return 0;
2147 } else {
2148 if (path->nodes[*level] == root->node) {
2149 root_owner = root->root_key.objectid;
2150 root_gen =
2151 btrfs_header_generation(path->nodes[*level]);
2152 } else {
2153 struct extent_buffer *node;
2154 node = path->nodes[*level + 1];
2155 root_owner = btrfs_header_owner(node);
2156 root_gen = btrfs_header_generation(node);
2157 }
2158 ret = btrfs_free_extent(trans, root,
2159 path->nodes[*level]->start,
2160 path->nodes[*level]->len,
2161 root_owner, root_gen, 0, 0, 1);
2162 BUG_ON(ret);
2163 free_extent_buffer(path->nodes[*level]);
2164 path->nodes[*level] = NULL;
2165 *level = i + 1;
2166 }
2167 }
2168 return 1;
2169 }
2170
2171 /*
2172 * drop the reference count on the tree rooted at 'snap'. This traverses
2173 * the tree freeing any blocks that have a ref count of zero after being
2174 * decremented.
2175 */
2176 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2177 *root)
2178 {
2179 int ret = 0;
2180 int wret;
2181 int level;
2182 struct btrfs_path *path;
2183 int i;
2184 int orig_level;
2185 struct btrfs_root_item *root_item = &root->root_item;
2186
2187 path = btrfs_alloc_path();
2188 BUG_ON(!path);
2189
2190 level = btrfs_header_level(root->node);
2191 orig_level = level;
2192 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2193 path->nodes[level] = root->node;
2194 extent_buffer_get(root->node);
2195 path->slots[level] = 0;
2196 } else {
2197 struct btrfs_key key;
2198 struct btrfs_disk_key found_key;
2199 struct extent_buffer *node;
2200
2201 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2202 level = root_item->drop_level;
2203 path->lowest_level = level;
2204 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2205 if (wret < 0) {
2206 ret = wret;
2207 goto out;
2208 }
2209 node = path->nodes[level];
2210 btrfs_node_key(node, &found_key, path->slots[level]);
2211 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2212 sizeof(found_key)));
2213 }
2214 while(1) {
2215 wret = walk_down_tree(trans, root, path, &level);
2216 if (wret > 0)
2217 break;
2218 if (wret < 0)
2219 ret = wret;
2220
2221 wret = walk_up_tree(trans, root, path, &level);
2222 if (wret > 0)
2223 break;
2224 if (wret < 0)
2225 ret = wret;
2226 ret = -EAGAIN;
2227 break;
2228 }
2229 for (i = 0; i <= orig_level; i++) {
2230 if (path->nodes[i]) {
2231 free_extent_buffer(path->nodes[i]);
2232 path->nodes[i] = NULL;
2233 }
2234 }
2235 out:
2236 btrfs_free_path(path);
2237 return ret;
2238 }
2239
2240 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2241 {
2242 u64 start;
2243 u64 end;
2244 u64 ptr;
2245 int ret;
2246 while(1) {
2247 ret = find_first_extent_bit(&info->block_group_cache, 0,
2248 &start, &end, (unsigned int)-1);
2249 if (ret)
2250 break;
2251 ret = get_state_private(&info->block_group_cache, start, &ptr);
2252 if (!ret)
2253 kfree((void *)(unsigned long)ptr);
2254 clear_extent_bits(&info->block_group_cache, start,
2255 end, (unsigned int)-1, GFP_NOFS);
2256 }
2257 while(1) {
2258 ret = find_first_extent_bit(&info->free_space_cache, 0,
2259 &start, &end, EXTENT_DIRTY);
2260 if (ret)
2261 break;
2262 clear_extent_dirty(&info->free_space_cache, start,
2263 end, GFP_NOFS);
2264 }
2265 return 0;
2266 }
2267
2268 static int noinline relocate_inode_pages(struct inode *inode, u64 start,
2269 u64 len)
2270 {
2271 u64 page_start;
2272 u64 page_end;
2273 u64 delalloc_start;
2274 u64 existing_delalloc;
2275 unsigned long last_index;
2276 unsigned long i;
2277 struct page *page;
2278 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2279 struct file_ra_state *ra;
2280
2281 ra = kzalloc(sizeof(*ra), GFP_NOFS);
2282
2283 mutex_lock(&inode->i_mutex);
2284 i = start >> PAGE_CACHE_SHIFT;
2285 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
2286
2287 file_ra_state_init(ra, inode->i_mapping);
2288 btrfs_force_ra(inode->i_mapping, ra, NULL, i, last_index);
2289 kfree(ra);
2290
2291 for (; i <= last_index; i++) {
2292 page = grab_cache_page(inode->i_mapping, i);
2293 if (!page)
2294 goto out_unlock;
2295 if (!PageUptodate(page)) {
2296 btrfs_readpage(NULL, page);
2297 lock_page(page);
2298 if (!PageUptodate(page)) {
2299 unlock_page(page);
2300 page_cache_release(page);
2301 goto out_unlock;
2302 }
2303 }
2304 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2305 page_end = page_start + PAGE_CACHE_SIZE - 1;
2306
2307 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2308
2309 delalloc_start = page_start;
2310 existing_delalloc = count_range_bits(io_tree,
2311 &delalloc_start, page_end,
2312 PAGE_CACHE_SIZE, EXTENT_DELALLOC);
2313
2314 set_extent_delalloc(io_tree, page_start,
2315 page_end, GFP_NOFS);
2316
2317 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2318 set_page_dirty(page);
2319 unlock_page(page);
2320 page_cache_release(page);
2321 }
2322
2323 out_unlock:
2324 mutex_unlock(&inode->i_mutex);
2325 return 0;
2326 }
2327
2328 /*
2329 * note, this releases the path
2330 */
2331 static int noinline relocate_one_reference(struct btrfs_root *extent_root,
2332 struct btrfs_path *path,
2333 struct btrfs_key *extent_key)
2334 {
2335 struct inode *inode;
2336 struct btrfs_root *found_root;
2337 struct btrfs_key *root_location;
2338 struct btrfs_extent_ref *ref;
2339 u64 ref_root;
2340 u64 ref_gen;
2341 u64 ref_objectid;
2342 u64 ref_offset;
2343 int ret;
2344
2345 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
2346 struct btrfs_extent_ref);
2347 ref_root = btrfs_ref_root(path->nodes[0], ref);
2348 ref_gen = btrfs_ref_generation(path->nodes[0], ref);
2349 ref_objectid = btrfs_ref_objectid(path->nodes[0], ref);
2350 ref_offset = btrfs_ref_offset(path->nodes[0], ref);
2351 btrfs_release_path(extent_root, path);
2352
2353 root_location = kmalloc(sizeof(*root_location), GFP_NOFS);
2354 root_location->objectid = ref_root;
2355 if (ref_gen == 0)
2356 root_location->offset = 0;
2357 else
2358 root_location->offset = (u64)-1;
2359 root_location->type = BTRFS_ROOT_ITEM_KEY;
2360
2361 found_root = btrfs_read_fs_root_no_name(extent_root->fs_info,
2362 root_location);
2363 BUG_ON(!found_root);
2364 kfree(root_location);
2365
2366 if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
2367 mutex_unlock(&extent_root->fs_info->fs_mutex);
2368 inode = btrfs_iget_locked(extent_root->fs_info->sb,
2369 ref_objectid, found_root);
2370 if (inode->i_state & I_NEW) {
2371 /* the inode and parent dir are two different roots */
2372 BTRFS_I(inode)->root = found_root;
2373 BTRFS_I(inode)->location.objectid = ref_objectid;
2374 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
2375 BTRFS_I(inode)->location.offset = 0;
2376 btrfs_read_locked_inode(inode);
2377 unlock_new_inode(inode);
2378
2379 }
2380 /* this can happen if the reference is not against
2381 * the latest version of the tree root
2382 */
2383 if (is_bad_inode(inode)) {
2384 mutex_lock(&extent_root->fs_info->fs_mutex);
2385 goto out;
2386 }
2387 relocate_inode_pages(inode, ref_offset, extent_key->offset);
2388 /* FIXME, data=ordered will help get rid of this */
2389 filemap_fdatawrite(inode->i_mapping);
2390 iput(inode);
2391 mutex_lock(&extent_root->fs_info->fs_mutex);
2392 } else {
2393 struct btrfs_trans_handle *trans;
2394 struct btrfs_key found_key;
2395 struct extent_buffer *eb;
2396 int level;
2397 int i;
2398
2399 trans = btrfs_start_transaction(found_root, 1);
2400 eb = read_tree_block(found_root, extent_key->objectid,
2401 extent_key->offset);
2402 level = btrfs_header_level(eb);
2403
2404 if (level == 0)
2405 btrfs_item_key_to_cpu(eb, &found_key, 0);
2406 else
2407 btrfs_node_key_to_cpu(eb, &found_key, 0);
2408
2409 free_extent_buffer(eb);
2410
2411 path->lowest_level = level;
2412 path->reada = 2;
2413 ret = btrfs_search_slot(trans, found_root, &found_key, path,
2414 0, 1);
2415 path->lowest_level = 0;
2416 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
2417 if (!path->nodes[i])
2418 break;
2419 free_extent_buffer(path->nodes[i]);
2420 path->nodes[i] = NULL;
2421 }
2422 btrfs_release_path(found_root, path);
2423 btrfs_end_transaction(trans, found_root);
2424 }
2425
2426 out:
2427 return 0;
2428 }
2429
2430 static int noinline relocate_one_extent(struct btrfs_root *extent_root,
2431 struct btrfs_path *path,
2432 struct btrfs_key *extent_key)
2433 {
2434 struct btrfs_key key;
2435 struct btrfs_key found_key;
2436 struct extent_buffer *leaf;
2437 u32 nritems;
2438 u32 item_size;
2439 int ret = 0;
2440
2441 key.objectid = extent_key->objectid;
2442 key.type = BTRFS_EXTENT_REF_KEY;
2443 key.offset = 0;
2444
2445 while(1) {
2446 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2447
2448 if (ret < 0)
2449 goto out;
2450
2451 ret = 0;
2452 leaf = path->nodes[0];
2453 nritems = btrfs_header_nritems(leaf);
2454 if (path->slots[0] == nritems)
2455 goto out;
2456
2457 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2458 if (found_key.objectid != extent_key->objectid)
2459 break;
2460
2461 if (found_key.type != BTRFS_EXTENT_REF_KEY)
2462 break;
2463
2464 key.offset = found_key.offset + 1;
2465 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2466
2467 ret = relocate_one_reference(extent_root, path, extent_key);
2468 if (ret)
2469 goto out;
2470 }
2471 ret = 0;
2472 out:
2473 btrfs_release_path(extent_root, path);
2474 return ret;
2475 }
2476
2477 int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 new_size)
2478 {
2479 struct btrfs_trans_handle *trans;
2480 struct btrfs_root *tree_root = root->fs_info->tree_root;
2481 struct btrfs_path *path;
2482 u64 cur_byte;
2483 u64 total_found;
2484 struct btrfs_fs_info *info = root->fs_info;
2485 struct extent_io_tree *block_group_cache;
2486 struct btrfs_key key;
2487 struct btrfs_key found_key;
2488 struct extent_buffer *leaf;
2489 u32 nritems;
2490 int ret;
2491 int progress = 0;
2492
2493 btrfs_set_super_total_bytes(&info->super_copy, new_size);
2494 clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1,
2495 GFP_NOFS);
2496 block_group_cache = &info->block_group_cache;
2497 path = btrfs_alloc_path();
2498 root = root->fs_info->extent_root;
2499 path->reada = 2;
2500
2501 again:
2502 total_found = 0;
2503 key.objectid = new_size;
2504 key.offset = 0;
2505 key.type = 0;
2506 cur_byte = key.objectid;
2507
2508 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2509 if (ret < 0)
2510 goto out;
2511
2512 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
2513 if (ret < 0)
2514 goto out;
2515 if (ret == 0) {
2516 leaf = path->nodes[0];
2517 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2518 if (found_key.objectid + found_key.offset > new_size) {
2519 cur_byte = found_key.objectid;
2520 key.objectid = cur_byte;
2521 }
2522 }
2523 btrfs_release_path(root, path);
2524
2525 while(1) {
2526 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2527 if (ret < 0)
2528 goto out;
2529
2530 leaf = path->nodes[0];
2531 nritems = btrfs_header_nritems(leaf);
2532 next:
2533 if (path->slots[0] >= nritems) {
2534 ret = btrfs_next_leaf(root, path);
2535 if (ret < 0)
2536 goto out;
2537 if (ret == 1) {
2538 ret = 0;
2539 break;
2540 }
2541 leaf = path->nodes[0];
2542 nritems = btrfs_header_nritems(leaf);
2543 }
2544
2545 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2546
2547 if (progress && need_resched()) {
2548 memcpy(&key, &found_key, sizeof(key));
2549 mutex_unlock(&root->fs_info->fs_mutex);
2550 cond_resched();
2551 mutex_lock(&root->fs_info->fs_mutex);
2552 btrfs_release_path(root, path);
2553 btrfs_search_slot(NULL, root, &key, path, 0, 0);
2554 progress = 0;
2555 goto next;
2556 }
2557 progress = 1;
2558
2559 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY ||
2560 found_key.objectid + found_key.offset <= cur_byte) {
2561 path->slots[0]++;
2562 goto next;
2563 }
2564
2565 total_found++;
2566 cur_byte = found_key.objectid + found_key.offset;
2567 key.objectid = cur_byte;
2568 btrfs_release_path(root, path);
2569 ret = relocate_one_extent(root, path, &found_key);
2570 }
2571
2572 btrfs_release_path(root, path);
2573
2574 if (total_found > 0) {
2575 trans = btrfs_start_transaction(tree_root, 1);
2576 btrfs_commit_transaction(trans, tree_root);
2577
2578 mutex_unlock(&root->fs_info->fs_mutex);
2579 btrfs_clean_old_snapshots(tree_root);
2580 mutex_lock(&root->fs_info->fs_mutex);
2581
2582 trans = btrfs_start_transaction(tree_root, 1);
2583 btrfs_commit_transaction(trans, tree_root);
2584 goto again;
2585 }
2586
2587 trans = btrfs_start_transaction(root, 1);
2588 key.objectid = new_size;
2589 key.offset = 0;
2590 key.type = 0;
2591 while(1) {
2592 u64 ptr;
2593
2594 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2595 if (ret < 0)
2596 goto out;
2597
2598 leaf = path->nodes[0];
2599 nritems = btrfs_header_nritems(leaf);
2600 bg_next:
2601 if (path->slots[0] >= nritems) {
2602 ret = btrfs_next_leaf(root, path);
2603 if (ret < 0)
2604 break;
2605 if (ret == 1) {
2606 ret = 0;
2607 break;
2608 }
2609 leaf = path->nodes[0];
2610 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2611
2612 /*
2613 * btrfs_next_leaf doesn't cow buffers, we have to
2614 * do the search again
2615 */
2616 memcpy(&key, &found_key, sizeof(key));
2617 btrfs_release_path(root, path);
2618 goto resched_check;
2619 }
2620
2621 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2622 if (btrfs_key_type(&found_key) != BTRFS_BLOCK_GROUP_ITEM_KEY) {
2623 printk("shrinker found key %Lu %u %Lu\n",
2624 found_key.objectid, found_key.type,
2625 found_key.offset);
2626 path->slots[0]++;
2627 goto bg_next;
2628 }
2629 ret = get_state_private(&info->block_group_cache,
2630 found_key.objectid, &ptr);
2631 if (!ret)
2632 kfree((void *)(unsigned long)ptr);
2633
2634 clear_extent_bits(&info->block_group_cache, found_key.objectid,
2635 found_key.objectid + found_key.offset - 1,
2636 (unsigned int)-1, GFP_NOFS);
2637
2638 key.objectid = found_key.objectid + 1;
2639 btrfs_del_item(trans, root, path);
2640 btrfs_release_path(root, path);
2641 resched_check:
2642 if (need_resched()) {
2643 mutex_unlock(&root->fs_info->fs_mutex);
2644 cond_resched();
2645 mutex_lock(&root->fs_info->fs_mutex);
2646 }
2647 }
2648 clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1,
2649 GFP_NOFS);
2650 btrfs_commit_transaction(trans, root);
2651 out:
2652 btrfs_free_path(path);
2653 return ret;
2654 }
2655
2656 int btrfs_grow_extent_tree(struct btrfs_trans_handle *trans,
2657 struct btrfs_root *root, u64 new_size)
2658 {
2659 btrfs_set_super_total_bytes(&root->fs_info->super_copy, new_size);
2660 return 0;
2661 }
2662
2663 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
2664 struct btrfs_key *key)
2665 {
2666 int ret;
2667 struct btrfs_key found_key;
2668 struct extent_buffer *leaf;
2669 int slot;
2670
2671 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
2672 if (ret < 0)
2673 return ret;
2674 while(1) {
2675 slot = path->slots[0];
2676 leaf = path->nodes[0];
2677 if (slot >= btrfs_header_nritems(leaf)) {
2678 ret = btrfs_next_leaf(root, path);
2679 if (ret == 0)
2680 continue;
2681 if (ret < 0)
2682 goto error;
2683 break;
2684 }
2685 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2686
2687 if (found_key.objectid >= key->objectid &&
2688 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
2689 return 0;
2690 path->slots[0]++;
2691 }
2692 ret = -ENOENT;
2693 error:
2694 return ret;
2695 }
2696
2697 int btrfs_read_block_groups(struct btrfs_root *root)
2698 {
2699 struct btrfs_path *path;
2700 int ret;
2701 int bit;
2702 struct btrfs_block_group_cache *cache;
2703 struct btrfs_fs_info *info = root->fs_info;
2704 struct btrfs_space_info *space_info;
2705 struct extent_io_tree *block_group_cache;
2706 struct btrfs_key key;
2707 struct btrfs_key found_key;
2708 struct extent_buffer *leaf;
2709
2710 block_group_cache = &info->block_group_cache;
2711 root = info->extent_root;
2712 key.objectid = 0;
2713 key.offset = 0;
2714 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2715 path = btrfs_alloc_path();
2716 if (!path)
2717 return -ENOMEM;
2718
2719 while(1) {
2720 ret = find_first_block_group(root, path, &key);
2721 if (ret > 0) {
2722 ret = 0;
2723 goto error;
2724 }
2725 if (ret != 0)
2726 goto error;
2727
2728 leaf = path->nodes[0];
2729 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2730 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2731 if (!cache) {
2732 ret = -ENOMEM;
2733 break;
2734 }
2735
2736 read_extent_buffer(leaf, &cache->item,
2737 btrfs_item_ptr_offset(leaf, path->slots[0]),
2738 sizeof(cache->item));
2739 memcpy(&cache->key, &found_key, sizeof(found_key));
2740 cache->cached = 0;
2741 cache->pinned = 0;
2742
2743 key.objectid = found_key.objectid + found_key.offset;
2744 btrfs_release_path(root, path);
2745 cache->flags = btrfs_block_group_flags(&cache->item);
2746 bit = 0;
2747 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
2748 bit = BLOCK_GROUP_DATA;
2749 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
2750 bit = BLOCK_GROUP_SYSTEM;
2751 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
2752 bit = BLOCK_GROUP_METADATA;
2753 }
2754 set_avail_alloc_bits(info, cache->flags);
2755
2756 ret = update_space_info(info, cache->flags, found_key.offset,
2757 btrfs_block_group_used(&cache->item),
2758 &space_info);
2759 BUG_ON(ret);
2760 cache->space_info = space_info;
2761
2762 /* use EXTENT_LOCKED to prevent merging */
2763 set_extent_bits(block_group_cache, found_key.objectid,
2764 found_key.objectid + found_key.offset - 1,
2765 bit | EXTENT_LOCKED, GFP_NOFS);
2766 set_state_private(block_group_cache, found_key.objectid,
2767 (unsigned long)cache);
2768
2769 if (key.objectid >=
2770 btrfs_super_total_bytes(&info->super_copy))
2771 break;
2772 }
2773 ret = 0;
2774 error:
2775 btrfs_free_path(path);
2776 return ret;
2777 }
2778
2779 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
2780 struct btrfs_root *root, u64 bytes_used,
2781 u64 type, u64 chunk_tree, u64 chunk_objectid,
2782 u64 size)
2783 {
2784 int ret;
2785 int bit = 0;
2786 struct btrfs_root *extent_root;
2787 struct btrfs_block_group_cache *cache;
2788 struct extent_io_tree *block_group_cache;
2789
2790 extent_root = root->fs_info->extent_root;
2791 block_group_cache = &root->fs_info->block_group_cache;
2792
2793 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2794 BUG_ON(!cache);
2795 cache->key.objectid = chunk_objectid;
2796 cache->key.offset = size;
2797 cache->cached = 0;
2798 cache->pinned = 0;
2799 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2800 memset(&cache->item, 0, sizeof(cache->item));
2801 btrfs_set_block_group_used(&cache->item, bytes_used);
2802 btrfs_set_block_group_chunk_tree(&cache->item, chunk_tree);
2803 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
2804 cache->flags = type;
2805 btrfs_set_block_group_flags(&cache->item, type);
2806
2807 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
2808 &cache->space_info);
2809 BUG_ON(ret);
2810
2811 bit = block_group_state_bits(type);
2812 set_extent_bits(block_group_cache, chunk_objectid,
2813 chunk_objectid + size - 1,
2814 bit | EXTENT_LOCKED, GFP_NOFS);
2815 set_state_private(block_group_cache, chunk_objectid,
2816 (unsigned long)cache);
2817
2818 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
2819 sizeof(cache->item));
2820 BUG_ON(ret);
2821
2822 finish_current_insert(trans, extent_root);
2823 ret = del_pending_extents(trans, extent_root);
2824 BUG_ON(ret);
2825 set_avail_alloc_bits(extent_root->fs_info, type);
2826 return 0;
2827 }
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