?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
btrfs-progs: fsck: understand the -s option
[btrfs-progs-unstable/devel.git] / extent-tree.c
blob20cdffa8b1b6294bbaad5effadac1f779bf185db
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 <stdio.h>
20 #include <stdlib.h>
21 #include "kerncompat.h"
22 #include "radix-tree.h"
23 #include "ctree.h"
24 #include "disk-io.h"
25 #include "print-tree.h"
26 #include "transaction.h"
27 #include "crc32c.h"
28 #include "volumes.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 #define PENDING_EXTENT_INSERT 0
37 #define PENDING_EXTENT_DELETE 1
38 #define PENDING_BACKREF_UPDATE 2
39
40 struct pending_extent_op {
41 int type;
42 u64 bytenr;
43 u64 num_bytes;
44 u64 flags;
45 struct btrfs_disk_key key;
46 int level;
47 };
48
49 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
50 struct btrfs_root *root,
51 u64 root_objectid, u64 generation,
52 u64 flags, struct btrfs_disk_key *key,
53 int level, struct btrfs_key *ins);
54 static int __free_extent(struct btrfs_trans_handle *trans,
55 struct btrfs_root *root,
56 u64 bytenr, u64 num_bytes, u64 parent,
57 u64 root_objectid, u64 owner_objectid,
58 u64 owner_offset, int refs_to_drop);
59 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
60 btrfs_root *extent_root);
61 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
62 btrfs_root *extent_root);
63
64 static int remove_sb_from_cache(struct btrfs_root *root,
65 struct btrfs_block_group_cache *cache)
66 {
67 u64 bytenr;
68 u64 *logical;
69 int stripe_len;
70 int i, nr, ret;
71 struct extent_io_tree *free_space_cache;
72
73 free_space_cache = &root->fs_info->free_space_cache;
74 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
75 bytenr = btrfs_sb_offset(i);
76 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
77 cache->key.objectid, bytenr, 0,
78 &logical, &nr, &stripe_len);
79 BUG_ON(ret);
80 while (nr--) {
81 clear_extent_dirty(free_space_cache, logical[nr],
82 logical[nr] + stripe_len - 1, GFP_NOFS);
83 }
84 kfree(logical);
85 }
86 return 0;
87 }
88
89 static int cache_block_group(struct btrfs_root *root,
90 struct btrfs_block_group_cache *block_group)
91 {
92 struct btrfs_path *path;
93 int ret;
94 struct btrfs_key key;
95 struct extent_buffer *leaf;
96 struct extent_io_tree *free_space_cache;
97 int slot;
98 u64 last;
99 u64 hole_size;
100
101 if (!block_group)
102 return 0;
103
104 root = root->fs_info->extent_root;
105 free_space_cache = &root->fs_info->free_space_cache;
106
107 if (block_group->cached)
108 return 0;
109
110 path = btrfs_alloc_path();
111 if (!path)
112 return -ENOMEM;
113
114 path->reada = 2;
115 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
116 key.objectid = last;
117 key.offset = 0;
118 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
119 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
120 if (ret < 0)
121 goto err;
122
123 while(1) {
124 leaf = path->nodes[0];
125 slot = path->slots[0];
126 if (slot >= btrfs_header_nritems(leaf)) {
127 ret = btrfs_next_leaf(root, path);
128 if (ret < 0)
129 goto err;
130 if (ret == 0) {
131 continue;
132 } else {
133 break;
134 }
135 }
136 btrfs_item_key_to_cpu(leaf, &key, slot);
137 if (key.objectid < block_group->key.objectid) {
138 goto next;
139 }
140 if (key.objectid >= block_group->key.objectid +
141 block_group->key.offset) {
142 break;
143 }
144
145 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
146 if (key.objectid > last) {
147 hole_size = key.objectid - last;
148 set_extent_dirty(free_space_cache, last,
149 last + hole_size - 1,
150 GFP_NOFS);
151 }
152 last = key.objectid + key.offset;
153 }
154 next:
155 path->slots[0]++;
156 }
157
158 if (block_group->key.objectid +
159 block_group->key.offset > last) {
160 hole_size = block_group->key.objectid +
161 block_group->key.offset - last;
162 set_extent_dirty(free_space_cache, last,
163 last + hole_size - 1, GFP_NOFS);
164 }
165 remove_sb_from_cache(root, block_group);
166 block_group->cached = 1;
167 err:
168 btrfs_free_path(path);
169 return 0;
170 }
171
172 struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
173 btrfs_fs_info *info,
174 u64 bytenr)
175 {
176 struct extent_io_tree *block_group_cache;
177 struct btrfs_block_group_cache *block_group = NULL;
178 u64 ptr;
179 u64 start;
180 u64 end;
181 int ret;
182
183 bytenr = max_t(u64, bytenr,
184 BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
185 block_group_cache = &info->block_group_cache;
186 ret = find_first_extent_bit(block_group_cache,
187 bytenr, &start, &end,
188 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
189 BLOCK_GROUP_SYSTEM);
190 if (ret) {
191 return NULL;
192 }
193 ret = get_state_private(block_group_cache, start, &ptr);
194 if (ret)
195 return NULL;
196
197 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
198 return block_group;
199 }
200
201 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
202 btrfs_fs_info *info,
203 u64 bytenr)
204 {
205 struct extent_io_tree *block_group_cache;
206 struct btrfs_block_group_cache *block_group = NULL;
207 u64 ptr;
208 u64 start;
209 u64 end;
210 int ret;
211
212 block_group_cache = &info->block_group_cache;
213 ret = find_first_extent_bit(block_group_cache,
214 bytenr, &start, &end,
215 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
216 BLOCK_GROUP_SYSTEM);
217 if (ret) {
218 return NULL;
219 }
220 ret = get_state_private(block_group_cache, start, &ptr);
221 if (ret)
222 return NULL;
223
224 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
225 if (block_group->key.objectid <= bytenr && bytenr <
226 block_group->key.objectid + block_group->key.offset)
227 return block_group;
228 return NULL;
229 }
230
231 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
232 {
233 return (cache->flags & bits) == bits;
234 }
235
236 static int noinline find_search_start(struct btrfs_root *root,
237 struct btrfs_block_group_cache **cache_ret,
238 u64 *start_ret, int num, int data)
239 {
240 int ret;
241 struct btrfs_block_group_cache *cache = *cache_ret;
242 u64 last;
243 u64 start = 0;
244 u64 end = 0;
245 u64 search_start = *start_ret;
246 int wrapped = 0;
247
248 if (!cache) {
249 goto out;
250 }
251 again:
252 ret = cache_block_group(root, cache);
253 if (ret)
254 goto out;
255
256 last = max(search_start, cache->key.objectid);
257 if (cache->ro || !block_group_bits(cache, data)) {
258 goto new_group;
259 }
260
261 while(1) {
262 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
263 last, &start, &end, EXTENT_DIRTY);
264 if (ret) {
265 goto new_group;
266 }
267
268 start = max(last, start);
269 last = end + 1;
270 if (last - start < num) {
271 continue;
272 }
273 if (start + num > cache->key.objectid + cache->key.offset) {
274 goto new_group;
275 }
276 *start_ret = start;
277 return 0;
278 }
279 out:
280 cache = btrfs_lookup_block_group(root->fs_info, search_start);
281 if (!cache) {
282 printk("Unable to find block group for %llu\n",
283 (unsigned long long)search_start);
284 WARN_ON(1);
285 }
286 return -ENOSPC;
287
288 new_group:
289 last = cache->key.objectid + cache->key.offset;
290 wrapped:
291 cache = btrfs_lookup_first_block_group(root->fs_info, last);
292 if (!cache) {
293 no_cache:
294 if (!wrapped) {
295 wrapped = 1;
296 last = search_start;
297 goto wrapped;
298 }
299 goto out;
300 }
301 cache = btrfs_find_block_group(root, cache, last, data, 0);
302 cache = btrfs_find_block_group(root, cache, last, data, 0);
303 if (!cache)
304 goto no_cache;
305
306 *cache_ret = cache;
307 goto again;
308 }
309
310 static u64 div_factor(u64 num, int factor)
311 {
312 if (factor == 10)
313 return num;
314 num *= factor;
315 num /= 10;
316 return num;
317 }
318
319 static int block_group_state_bits(u64 flags)
320 {
321 int bits = 0;
322 if (flags & BTRFS_BLOCK_GROUP_DATA)
323 bits |= BLOCK_GROUP_DATA;
324 if (flags & BTRFS_BLOCK_GROUP_METADATA)
325 bits |= BLOCK_GROUP_METADATA;
326 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
327 bits |= BLOCK_GROUP_SYSTEM;
328 return bits;
329 }
330
331 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
332 struct btrfs_block_group_cache
333 *hint, u64 search_start,
334 int data, int owner)
335 {
336 struct btrfs_block_group_cache *cache;
337 struct extent_io_tree *block_group_cache;
338 struct btrfs_block_group_cache *found_group = NULL;
339 struct btrfs_fs_info *info = root->fs_info;
340 u64 used;
341 u64 last = 0;
342 u64 hint_last;
343 u64 start;
344 u64 end;
345 u64 free_check;
346 u64 ptr;
347 int bit;
348 int ret;
349 int full_search = 0;
350 int factor = 10;
351
352 block_group_cache = &info->block_group_cache;
353
354 if (!owner)
355 factor = 10;
356
357 bit = block_group_state_bits(data);
358
359 if (search_start) {
360 struct btrfs_block_group_cache *shint;
361 shint = btrfs_lookup_block_group(info, search_start);
362 if (shint && !shint->ro && block_group_bits(shint, data)) {
363 used = btrfs_block_group_used(&shint->item);
364 if (used + shint->pinned <
365 div_factor(shint->key.offset, factor)) {
366 return shint;
367 }
368 }
369 }
370 if (hint && !hint->ro && block_group_bits(hint, data)) {
371 used = btrfs_block_group_used(&hint->item);
372 if (used + hint->pinned <
373 div_factor(hint->key.offset, factor)) {
374 return hint;
375 }
376 last = hint->key.objectid + hint->key.offset;
377 hint_last = last;
378 } else {
379 if (hint)
380 hint_last = max(hint->key.objectid, search_start);
381 else
382 hint_last = search_start;
383
384 last = hint_last;
385 }
386 again:
387 while(1) {
388 ret = find_first_extent_bit(block_group_cache, last,
389 &start, &end, bit);
390 if (ret)
391 break;
392
393 ret = get_state_private(block_group_cache, start, &ptr);
394 if (ret)
395 break;
396
397 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
398 last = cache->key.objectid + cache->key.offset;
399 used = btrfs_block_group_used(&cache->item);
400
401 if (!cache->ro && block_group_bits(cache, data)) {
402 if (full_search)
403 free_check = cache->key.offset;
404 else
405 free_check = div_factor(cache->key.offset,
406 factor);
407
408 if (used + cache->pinned < free_check) {
409 found_group = cache;
410 goto found;
411 }
412 }
413 cond_resched();
414 }
415 if (!full_search) {
416 last = search_start;
417 full_search = 1;
418 goto again;
419 }
420 found:
421 return found_group;
422 }
423
424 /*
425 * Back reference rules. Back refs have three main goals:
426 *
427 * 1) differentiate between all holders of references to an extent so that
428 * when a reference is dropped we can make sure it was a valid reference
429 * before freeing the extent.
430 *
431 * 2) Provide enough information to quickly find the holders of an extent
432 * if we notice a given block is corrupted or bad.
433 *
434 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
435 * maintenance. This is actually the same as #2, but with a slightly
436 * different use case.
437 *
438 * There are two kinds of back refs. The implicit back refs is optimized
439 * for pointers in non-shared tree blocks. For a given pointer in a block,
440 * back refs of this kind provide information about the block's owner tree
441 * and the pointer's key. These information allow us to find the block by
442 * b-tree searching. The full back refs is for pointers in tree blocks not
443 * referenced by their owner trees. The location of tree block is recorded
444 * in the back refs. Actually the full back refs is generic, and can be
445 * used in all cases the implicit back refs is used. The major shortcoming
446 * of the full back refs is its overhead. Every time a tree block gets
447 * COWed, we have to update back refs entry for all pointers in it.
448 *
449 * For a newly allocated tree block, we use implicit back refs for
450 * pointers in it. This means most tree related operations only involve
451 * implicit back refs. For a tree block created in old transaction, the
452 * only way to drop a reference to it is COW it. So we can detect the
453 * event that tree block loses its owner tree's reference and do the
454 * back refs conversion.
455 *
456 * When a tree block is COW'd through a tree, there are four cases:
457 *
458 * The reference count of the block is one and the tree is the block's
459 * owner tree. Nothing to do in this case.
460 *
461 * The reference count of the block is one and the tree is not the
462 * block's owner tree. In this case, full back refs is used for pointers
463 * in the block. Remove these full back refs, add implicit back refs for
464 * every pointers in the new block.
465 *
466 * The reference count of the block is greater than one and the tree is
467 * the block's owner tree. In this case, implicit back refs is used for
468 * pointers in the block. Add full back refs for every pointers in the
469 * block, increase lower level extents' reference counts. The original
470 * implicit back refs are entailed to the new block.
471 *
472 * The reference count of the block is greater than one and the tree is
473 * not the block's owner tree. Add implicit back refs for every pointer in
474 * the new block, increase lower level extents' reference count.
475 *
476 * Back Reference Key composing:
477 *
478 * The key objectid corresponds to the first byte in the extent,
479 * The key type is used to differentiate between types of back refs.
480 * There are different meanings of the key offset for different types
481 * of back refs.
482 *
483 * File extents can be referenced by:
484 *
485 * - multiple snapshots, subvolumes, or different generations in one subvol
486 * - different files inside a single subvolume
487 * - different offsets inside a file (bookend extents in file.c)
488 *
489 * The extent ref structure for the implicit back refs has fields for:
490 *
491 * - Objectid of the subvolume root
492 * - objectid of the file holding the reference
493 * - original offset in the file
494 * - how many bookend extents
495 *
496 * The key offset for the implicit back refs is hash of the first
497 * three fields.
498 *
499 * The extent ref structure for the full back refs has field for:
500 *
501 * - number of pointers in the tree leaf
502 *
503 * The key offset for the implicit back refs is the first byte of
504 * the tree leaf
505 *
506 * When a file extent is allocated, The implicit back refs is used.
507 * the fields are filled in:
508 *
509 * (root_key.objectid, inode objectid, offset in file, 1)
510 *
511 * When a file extent is removed file truncation, we find the
512 * corresponding implicit back refs and check the following fields:
513 *
514 * (btrfs_header_owner(leaf), inode objectid, offset in file)
515 *
516 * Btree extents can be referenced by:
517 *
518 * - Different subvolumes
519 *
520 * Both the implicit back refs and the full back refs for tree blocks
521 * only consist of key. The key offset for the implicit back refs is
522 * objectid of block's owner tree. The key offset for the full back refs
523 * is the first byte of parent block.
524 *
525 * When implicit back refs is used, information about the lowest key and
526 * level of the tree block are required. These information are stored in
527 * tree block info structure.
528 */
529
530 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
531 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
532 struct btrfs_root *root,
533 struct btrfs_path *path,
534 u64 owner, u32 extra_size)
535 {
536 struct btrfs_extent_item *item;
537 struct btrfs_extent_item_v0 *ei0;
538 struct btrfs_extent_ref_v0 *ref0;
539 struct btrfs_tree_block_info *bi;
540 struct extent_buffer *leaf;
541 struct btrfs_key key;
542 struct btrfs_key found_key;
543 u32 new_size = sizeof(*item);
544 u64 refs;
545 int ret;
546
547 leaf = path->nodes[0];
548 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
549
550 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
551 ei0 = btrfs_item_ptr(leaf, path->slots[0],
552 struct btrfs_extent_item_v0);
553 refs = btrfs_extent_refs_v0(leaf, ei0);
554
555 if (owner == (u64)-1) {
556 while (1) {
557 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
558 ret = btrfs_next_leaf(root, path);
559 if (ret < 0)
560 return ret;
561 BUG_ON(ret > 0);
562 leaf = path->nodes[0];
563 }
564 btrfs_item_key_to_cpu(leaf, &found_key,
565 path->slots[0]);
566 BUG_ON(key.objectid != found_key.objectid);
567 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
568 path->slots[0]++;
569 continue;
570 }
571 ref0 = btrfs_item_ptr(leaf, path->slots[0],
572 struct btrfs_extent_ref_v0);
573 owner = btrfs_ref_objectid_v0(leaf, ref0);
574 break;
575 }
576 }
577 btrfs_release_path(root, path);
578
579 if (owner < BTRFS_FIRST_FREE_OBJECTID)
580 new_size += sizeof(*bi);
581
582 new_size -= sizeof(*ei0);
583 ret = btrfs_search_slot(trans, root, &key, path, new_size, 1);
584 if (ret < 0)
585 return ret;
586 BUG_ON(ret);
587
588 ret = btrfs_extend_item(trans, root, path, new_size);
589 BUG_ON(ret);
590
591 leaf = path->nodes[0];
592 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
593 btrfs_set_extent_refs(leaf, item, refs);
594 /* FIXME: get real generation */
595 btrfs_set_extent_generation(leaf, item, 0);
596 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
597 btrfs_set_extent_flags(leaf, item,
598 BTRFS_EXTENT_FLAG_TREE_BLOCK |
599 BTRFS_BLOCK_FLAG_FULL_BACKREF);
600 bi = (struct btrfs_tree_block_info *)(item + 1);
601 /* FIXME: get first key of the block */
602 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
603 btrfs_set_tree_block_level(leaf, bi, (int)owner);
604 } else {
605 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
606 }
607 btrfs_mark_buffer_dirty(leaf);
608 return 0;
609 }
610 #endif
611
612 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
613 {
614 u32 high_crc = ~(u32)0;
615 u32 low_crc = ~(u32)0;
616 __le64 lenum;
617
618 lenum = cpu_to_le64(root_objectid);
619 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
620 lenum = cpu_to_le64(owner);
621 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
622 lenum = cpu_to_le64(offset);
623 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
624
625 return ((u64)high_crc << 31) ^ (u64)low_crc;
626 }
627
628 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
629 struct btrfs_extent_data_ref *ref)
630 {
631 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
632 btrfs_extent_data_ref_objectid(leaf, ref),
633 btrfs_extent_data_ref_offset(leaf, ref));
634 }
635
636 static int match_extent_data_ref(struct extent_buffer *leaf,
637 struct btrfs_extent_data_ref *ref,
638 u64 root_objectid, u64 owner, u64 offset)
639 {
640 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
641 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
642 btrfs_extent_data_ref_offset(leaf, ref) != offset)
643 return 0;
644 return 1;
645 }
646
647 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
648 struct btrfs_root *root,
649 struct btrfs_path *path,
650 u64 bytenr, u64 parent,
651 u64 root_objectid,
652 u64 owner, u64 offset)
653 {
654 struct btrfs_key key;
655 struct btrfs_extent_data_ref *ref;
656 struct extent_buffer *leaf;
657 u32 nritems;
658 int ret;
659 int recow;
660 int err = -ENOENT;
661
662 key.objectid = bytenr;
663 if (parent) {
664 key.type = BTRFS_SHARED_DATA_REF_KEY;
665 key.offset = parent;
666 } else {
667 key.type = BTRFS_EXTENT_DATA_REF_KEY;
668 key.offset = hash_extent_data_ref(root_objectid,
669 owner, offset);
670 }
671 again:
672 recow = 0;
673 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
674 if (ret < 0) {
675 err = ret;
676 goto fail;
677 }
678
679 if (parent) {
680 if (!ret)
681 return 0;
682 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
683 key.type = BTRFS_EXTENT_REF_V0_KEY;
684 btrfs_release_path(root, path);
685 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
686 if (ret < 0) {
687 err = ret;
688 goto fail;
689 }
690 if (!ret)
691 return 0;
692 #endif
693 goto fail;
694 }
695
696 leaf = path->nodes[0];
697 nritems = btrfs_header_nritems(leaf);
698 while (1) {
699 if (path->slots[0] >= nritems) {
700 ret = btrfs_next_leaf(root, path);
701 if (ret < 0)
702 err = ret;
703 if (ret)
704 goto fail;
705
706 leaf = path->nodes[0];
707 nritems = btrfs_header_nritems(leaf);
708 recow = 1;
709 }
710
711 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
712 if (key.objectid != bytenr ||
713 key.type != BTRFS_EXTENT_DATA_REF_KEY)
714 goto fail;
715
716 ref = btrfs_item_ptr(leaf, path->slots[0],
717 struct btrfs_extent_data_ref);
718
719 if (match_extent_data_ref(leaf, ref, root_objectid,
720 owner, offset)) {
721 if (recow) {
722 btrfs_release_path(root, path);
723 goto again;
724 }
725 err = 0;
726 break;
727 }
728 path->slots[0]++;
729 }
730 fail:
731 return err;
732 }
733
734 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
735 struct btrfs_root *root,
736 struct btrfs_path *path,
737 u64 bytenr, u64 parent,
738 u64 root_objectid, u64 owner,
739 u64 offset, int refs_to_add)
740 {
741 struct btrfs_key key;
742 struct extent_buffer *leaf;
743 u32 size;
744 u32 num_refs;
745 int ret;
746
747 key.objectid = bytenr;
748 if (parent) {
749 key.type = BTRFS_SHARED_DATA_REF_KEY;
750 key.offset = parent;
751 size = sizeof(struct btrfs_shared_data_ref);
752 } else {
753 key.type = BTRFS_EXTENT_DATA_REF_KEY;
754 key.offset = hash_extent_data_ref(root_objectid,
755 owner, offset);
756 size = sizeof(struct btrfs_extent_data_ref);
757 }
758
759 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
760 if (ret && ret != -EEXIST)
761 goto fail;
762
763 leaf = path->nodes[0];
764 if (parent) {
765 struct btrfs_shared_data_ref *ref;
766 ref = btrfs_item_ptr(leaf, path->slots[0],
767 struct btrfs_shared_data_ref);
768 if (ret == 0) {
769 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
770 } else {
771 num_refs = btrfs_shared_data_ref_count(leaf, ref);
772 num_refs += refs_to_add;
773 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
774 }
775 } else {
776 struct btrfs_extent_data_ref *ref;
777 while (ret == -EEXIST) {
778 ref = btrfs_item_ptr(leaf, path->slots[0],
779 struct btrfs_extent_data_ref);
780 if (match_extent_data_ref(leaf, ref, root_objectid,
781 owner, offset))
782 break;
783 btrfs_release_path(root, path);
784
785 key.offset++;
786 ret = btrfs_insert_empty_item(trans, root, path, &key,
787 size);
788 if (ret && ret != -EEXIST)
789 goto fail;
790
791 leaf = path->nodes[0];
792 }
793 ref = btrfs_item_ptr(leaf, path->slots[0],
794 struct btrfs_extent_data_ref);
795 if (ret == 0) {
796 btrfs_set_extent_data_ref_root(leaf, ref,
797 root_objectid);
798 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
799 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
800 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
801 } else {
802 num_refs = btrfs_extent_data_ref_count(leaf, ref);
803 num_refs += refs_to_add;
804 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
805 }
806 }
807 btrfs_mark_buffer_dirty(leaf);
808 ret = 0;
809 fail:
810 btrfs_release_path(root, path);
811 return ret;
812 }
813
814 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
815 struct btrfs_root *root,
816 struct btrfs_path *path,
817 int refs_to_drop)
818 {
819 struct btrfs_key key;
820 struct btrfs_extent_data_ref *ref1 = NULL;
821 struct btrfs_shared_data_ref *ref2 = NULL;
822 struct extent_buffer *leaf;
823 u32 num_refs = 0;
824 int ret = 0;
825
826 leaf = path->nodes[0];
827 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
828
829 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
830 ref1 = btrfs_item_ptr(leaf, path->slots[0],
831 struct btrfs_extent_data_ref);
832 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
833 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
834 ref2 = btrfs_item_ptr(leaf, path->slots[0],
835 struct btrfs_shared_data_ref);
836 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
837 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
838 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
839 struct btrfs_extent_ref_v0 *ref0;
840 ref0 = btrfs_item_ptr(leaf, path->slots[0],
841 struct btrfs_extent_ref_v0);
842 num_refs = btrfs_ref_count_v0(leaf, ref0);
843 #endif
844 } else {
845 BUG();
846 }
847
848 BUG_ON(num_refs < refs_to_drop);
849 num_refs -= refs_to_drop;
850
851 if (num_refs == 0) {
852 ret = btrfs_del_item(trans, root, path);
853 } else {
854 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
855 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
856 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
857 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
858 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
859 else {
860 struct btrfs_extent_ref_v0 *ref0;
861 ref0 = btrfs_item_ptr(leaf, path->slots[0],
862 struct btrfs_extent_ref_v0);
863 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
864 }
865 #endif
866 btrfs_mark_buffer_dirty(leaf);
867 }
868 return ret;
869 }
870
871 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
872 struct btrfs_path *path,
873 struct btrfs_extent_inline_ref *iref)
874 {
875 struct btrfs_key key;
876 struct extent_buffer *leaf;
877 struct btrfs_extent_data_ref *ref1;
878 struct btrfs_shared_data_ref *ref2;
879 u32 num_refs = 0;
880
881 leaf = path->nodes[0];
882 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
883 if (iref) {
884 if (btrfs_extent_inline_ref_type(leaf, iref) ==
885 BTRFS_EXTENT_DATA_REF_KEY) {
886 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
887 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
888 } else {
889 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
890 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
891 }
892 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
893 ref1 = btrfs_item_ptr(leaf, path->slots[0],
894 struct btrfs_extent_data_ref);
895 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
896 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
897 ref2 = btrfs_item_ptr(leaf, path->slots[0],
898 struct btrfs_shared_data_ref);
899 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
900 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
901 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
902 struct btrfs_extent_ref_v0 *ref0;
903 ref0 = btrfs_item_ptr(leaf, path->slots[0],
904 struct btrfs_extent_ref_v0);
905 num_refs = btrfs_ref_count_v0(leaf, ref0);
906 #endif
907 } else {
908 BUG();
909 }
910 return num_refs;
911 }
912
913 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
914 struct btrfs_root *root,
915 struct btrfs_path *path,
916 u64 bytenr, u64 parent,
917 u64 root_objectid)
918 {
919 struct btrfs_key key;
920 int ret;
921
922 key.objectid = bytenr;
923 if (parent) {
924 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
925 key.offset = parent;
926 } else {
927 key.type = BTRFS_TREE_BLOCK_REF_KEY;
928 key.offset = root_objectid;
929 }
930
931 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
932 if (ret > 0)
933 ret = -ENOENT;
934 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
935 if (ret == -ENOENT && parent) {
936 btrfs_release_path(root, path);
937 key.type = BTRFS_EXTENT_REF_V0_KEY;
938 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
939 if (ret > 0)
940 ret = -ENOENT;
941 }
942 #endif
943 return ret;
944 }
945
946 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
947 struct btrfs_root *root,
948 struct btrfs_path *path,
949 u64 bytenr, u64 parent,
950 u64 root_objectid)
951 {
952 struct btrfs_key key;
953 int ret;
954
955 key.objectid = bytenr;
956 if (parent) {
957 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
958 key.offset = parent;
959 } else {
960 key.type = BTRFS_TREE_BLOCK_REF_KEY;
961 key.offset = root_objectid;
962 }
963
964 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
965
966 btrfs_release_path(root, path);
967 return ret;
968 }
969
970 static inline int extent_ref_type(u64 parent, u64 owner)
971 {
972 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
973 if (parent > 0)
974 return BTRFS_SHARED_BLOCK_REF_KEY;
975 else
976 return BTRFS_TREE_BLOCK_REF_KEY;
977 } else {
978 if (parent > 0)
979 return BTRFS_SHARED_DATA_REF_KEY;
980 else
981 return BTRFS_EXTENT_DATA_REF_KEY;
982 }
983 }
984
985 static int find_next_key(struct btrfs_path *path, struct btrfs_key *key)
986
987 {
988 int level;
989 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
990 if (!path->nodes[level])
991 break;
992 if (path->slots[level] + 1 >=
993 btrfs_header_nritems(path->nodes[level]))
994 continue;
995 if (level == 0)
996 btrfs_item_key_to_cpu(path->nodes[level], key,
997 path->slots[level] + 1);
998 else
999 btrfs_node_key_to_cpu(path->nodes[level], key,
1000 path->slots[level] + 1);
1001 return 0;
1002 }
1003 return 1;
1004 }
1005
1006 static int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1007 struct btrfs_root *root,
1008 struct btrfs_path *path,
1009 struct btrfs_extent_inline_ref **ref_ret,
1010 u64 bytenr, u64 num_bytes,
1011 u64 parent, u64 root_objectid,
1012 u64 owner, u64 offset, int insert)
1013 {
1014 struct btrfs_key key;
1015 struct extent_buffer *leaf;
1016 struct btrfs_extent_item *ei;
1017 struct btrfs_extent_inline_ref *iref;
1018 u64 flags;
1019 u32 item_size;
1020 unsigned long ptr;
1021 unsigned long end;
1022 int extra_size;
1023 int type;
1024 int want;
1025 int ret;
1026 int err = 0;
1027
1028 key.objectid = bytenr;
1029 key.type = BTRFS_EXTENT_ITEM_KEY;
1030 key.offset = num_bytes;
1031
1032 want = extent_ref_type(parent, owner);
1033 if (insert)
1034 extra_size = btrfs_extent_inline_ref_size(want);
1035 else
1036 extra_size = -1;
1037 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1038 if (ret < 0) {
1039 err = ret;
1040 goto out;
1041 }
1042 if (ret) {
1043 printf("Failed to find [%llu, %u, %llu]\n", key.objectid, key.type, key.offset);
1044 return -ENOENT;
1045 }
1046
1047 BUG_ON(ret);
1048
1049 leaf = path->nodes[0];
1050 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1051 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1052 if (item_size < sizeof(*ei)) {
1053 if (!insert) {
1054 err = -ENOENT;
1055 goto out;
1056 }
1057 ret = convert_extent_item_v0(trans, root, path, owner,
1058 extra_size);
1059 if (ret < 0) {
1060 err = ret;
1061 goto out;
1062 }
1063 leaf = path->nodes[0];
1064 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1065 }
1066 #endif
1067 if (item_size < sizeof(*ei)) {
1068 printf("Size is %u, needs to be %u, slot %d\n",
1069 (unsigned)item_size,
1070 (unsigned)sizeof(*ei), path->slots[0]);
1071 btrfs_print_leaf(root, leaf);
1072 return -EINVAL;
1073 }
1074 BUG_ON(item_size < sizeof(*ei));
1075
1076 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1077 flags = btrfs_extent_flags(leaf, ei);
1078
1079 ptr = (unsigned long)(ei + 1);
1080 end = (unsigned long)ei + item_size;
1081
1082 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1083 ptr += sizeof(struct btrfs_tree_block_info);
1084 BUG_ON(ptr > end);
1085 } else {
1086 if (!(flags & BTRFS_EXTENT_FLAG_DATA)) {
1087 return -EIO;
1088 }
1089 }
1090
1091 err = -ENOENT;
1092 while (1) {
1093 if (ptr >= end) {
1094 WARN_ON(ptr > end);
1095 break;
1096 }
1097 iref = (struct btrfs_extent_inline_ref *)ptr;
1098 type = btrfs_extent_inline_ref_type(leaf, iref);
1099 if (want < type)
1100 break;
1101 if (want > type) {
1102 ptr += btrfs_extent_inline_ref_size(type);
1103 continue;
1104 }
1105
1106 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1107 struct btrfs_extent_data_ref *dref;
1108 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1109 if (match_extent_data_ref(leaf, dref, root_objectid,
1110 owner, offset)) {
1111 err = 0;
1112 break;
1113 }
1114 if (hash_extent_data_ref_item(leaf, dref) <
1115 hash_extent_data_ref(root_objectid, owner, offset))
1116 break;
1117 } else {
1118 u64 ref_offset;
1119 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1120 if (parent > 0) {
1121 if (parent == ref_offset) {
1122 err = 0;
1123 break;
1124 }
1125 if (ref_offset < parent)
1126 break;
1127 } else {
1128 if (root_objectid == ref_offset) {
1129 err = 0;
1130 break;
1131 }
1132 if (ref_offset < root_objectid)
1133 break;
1134 }
1135 }
1136 ptr += btrfs_extent_inline_ref_size(type);
1137 }
1138 if (err == -ENOENT && insert) {
1139 if (item_size + extra_size >=
1140 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1141 err = -EAGAIN;
1142 goto out;
1143 }
1144 /*
1145 * To add new inline back ref, we have to make sure
1146 * there is no corresponding back ref item.
1147 * For simplicity, we just do not add new inline back
1148 * ref if there is any back ref item.
1149 */
1150 if (find_next_key(path, &key) == 0 && key.objectid == bytenr &&
1151 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1152 err = -EAGAIN;
1153 goto out;
1154 }
1155 }
1156 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1157 out:
1158 return err;
1159 }
1160
1161 static int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
1162 struct btrfs_root *root,
1163 struct btrfs_path *path,
1164 struct btrfs_extent_inline_ref *iref,
1165 u64 parent, u64 root_objectid,
1166 u64 owner, u64 offset, int refs_to_add)
1167 {
1168 struct extent_buffer *leaf;
1169 struct btrfs_extent_item *ei;
1170 unsigned long ptr;
1171 unsigned long end;
1172 unsigned long item_offset;
1173 u64 refs;
1174 int size;
1175 int type;
1176 int ret;
1177
1178 leaf = path->nodes[0];
1179 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1180 item_offset = (unsigned long)iref - (unsigned long)ei;
1181
1182 type = extent_ref_type(parent, owner);
1183 size = btrfs_extent_inline_ref_size(type);
1184
1185 ret = btrfs_extend_item(trans, root, path, size);
1186 BUG_ON(ret);
1187
1188 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1189 refs = btrfs_extent_refs(leaf, ei);
1190 refs += refs_to_add;
1191 btrfs_set_extent_refs(leaf, ei, refs);
1192
1193 ptr = (unsigned long)ei + item_offset;
1194 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1195 if (ptr < end - size)
1196 memmove_extent_buffer(leaf, ptr + size, ptr,
1197 end - size - ptr);
1198
1199 iref = (struct btrfs_extent_inline_ref *)ptr;
1200 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1201 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1202 struct btrfs_extent_data_ref *dref;
1203 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1204 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1205 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1206 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1207 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1208 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1209 struct btrfs_shared_data_ref *sref;
1210 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1211 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1212 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1213 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1214 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1215 } else {
1216 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1217 }
1218 btrfs_mark_buffer_dirty(leaf);
1219 return 0;
1220 }
1221
1222 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1223 struct btrfs_root *root,
1224 struct btrfs_path *path,
1225 struct btrfs_extent_inline_ref **ref_ret,
1226 u64 bytenr, u64 num_bytes, u64 parent,
1227 u64 root_objectid, u64 owner, u64 offset)
1228 {
1229 int ret;
1230
1231 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1232 bytenr, num_bytes, parent,
1233 root_objectid, owner, offset, 0);
1234 if (ret != -ENOENT)
1235 return ret;
1236
1237 btrfs_release_path(root, path);
1238 *ref_ret = NULL;
1239
1240 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1241 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1242 root_objectid);
1243 } else {
1244 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1245 root_objectid, owner, offset);
1246 }
1247 return ret;
1248 }
1249
1250 static int update_inline_extent_backref(struct btrfs_trans_handle *trans,
1251 struct btrfs_root *root,
1252 struct btrfs_path *path,
1253 struct btrfs_extent_inline_ref *iref,
1254 int refs_to_mod)
1255 {
1256 struct extent_buffer *leaf;
1257 struct btrfs_extent_item *ei;
1258 struct btrfs_extent_data_ref *dref = NULL;
1259 struct btrfs_shared_data_ref *sref = NULL;
1260 unsigned long ptr;
1261 unsigned long end;
1262 u32 item_size;
1263 int size;
1264 int type;
1265 int ret;
1266 u64 refs;
1267
1268 leaf = path->nodes[0];
1269 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1270 refs = btrfs_extent_refs(leaf, ei);
1271 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1272 refs += refs_to_mod;
1273 btrfs_set_extent_refs(leaf, ei, refs);
1274
1275 type = btrfs_extent_inline_ref_type(leaf, iref);
1276
1277 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1278 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1279 refs = btrfs_extent_data_ref_count(leaf, dref);
1280 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1281 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1282 refs = btrfs_shared_data_ref_count(leaf, sref);
1283 } else {
1284 refs = 1;
1285 BUG_ON(refs_to_mod != -1);
1286 }
1287
1288 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1289 refs += refs_to_mod;
1290
1291 if (refs > 0) {
1292 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1293 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1294 else
1295 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1296 } else {
1297 size = btrfs_extent_inline_ref_size(type);
1298 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1299 ptr = (unsigned long)iref;
1300 end = (unsigned long)ei + item_size;
1301 if (ptr + size < end)
1302 memmove_extent_buffer(leaf, ptr, ptr + size,
1303 end - ptr - size);
1304 item_size -= size;
1305 ret = btrfs_truncate_item(trans, root, path, item_size, 1);
1306 BUG_ON(ret);
1307 }
1308 btrfs_mark_buffer_dirty(leaf);
1309 return 0;
1310 }
1311
1312 static int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1313 struct btrfs_root *root,
1314 struct btrfs_path *path,
1315 u64 bytenr, u64 num_bytes, u64 parent,
1316 u64 root_objectid, u64 owner,
1317 u64 offset, int refs_to_add)
1318 {
1319 struct btrfs_extent_inline_ref *iref;
1320 int ret;
1321
1322 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1323 bytenr, num_bytes, parent,
1324 root_objectid, owner, offset, 1);
1325 if (ret == 0) {
1326 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1327 ret = update_inline_extent_backref(trans, root, path, iref,
1328 refs_to_add);
1329 } else if (ret == -ENOENT) {
1330 ret = setup_inline_extent_backref(trans, root, path, iref,
1331 parent, root_objectid,
1332 owner, offset, refs_to_add);
1333 }
1334 return ret;
1335 }
1336
1337 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1338 struct btrfs_root *root,
1339 struct btrfs_path *path,
1340 u64 bytenr, u64 parent, u64 root_objectid,
1341 u64 owner, u64 offset, int refs_to_add)
1342 {
1343 int ret;
1344
1345 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
1346 ret = insert_extent_data_ref(trans, root, path, bytenr,
1347 parent, root_objectid,
1348 owner, offset, refs_to_add);
1349 } else {
1350 BUG_ON(refs_to_add != 1);
1351 ret = insert_tree_block_ref(trans, root, path, bytenr,
1352 parent, root_objectid);
1353 }
1354 return ret;
1355 }
1356
1357 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1358 struct btrfs_root *root,
1359 struct btrfs_path *path,
1360 struct btrfs_extent_inline_ref *iref,
1361 int refs_to_drop, int is_data)
1362 {
1363 int ret;
1364
1365 BUG_ON(!is_data && refs_to_drop != 1);
1366 if (iref) {
1367 ret = update_inline_extent_backref(trans, root, path, iref,
1368 -refs_to_drop);
1369 } else if (is_data) {
1370 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1371 } else {
1372 ret = btrfs_del_item(trans, root, path);
1373 }
1374 return ret;
1375 }
1376
1377 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1378 struct btrfs_root *root,
1379 u64 bytenr, u64 num_bytes, u64 parent,
1380 u64 root_objectid, u64 owner, u64 offset)
1381 {
1382 struct btrfs_path *path;
1383 struct extent_buffer *leaf;
1384 struct btrfs_extent_item *item;
1385 u64 refs;
1386 int ret;
1387 int err = 0;
1388
1389 path = btrfs_alloc_path();
1390 if (!path)
1391 return -ENOMEM;
1392
1393 path->reada = 1;
1394 path->leave_spinning = 1;
1395
1396 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1397 path, bytenr, num_bytes, parent,
1398 root_objectid, owner, offset, 1);
1399 if (ret == 0)
1400 goto out;
1401
1402 if (ret != -EAGAIN) {
1403 err = ret;
1404 goto out;
1405 }
1406
1407 leaf = path->nodes[0];
1408 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1409 refs = btrfs_extent_refs(leaf, item);
1410 btrfs_set_extent_refs(leaf, item, refs + 1);
1411
1412 btrfs_mark_buffer_dirty(leaf);
1413 btrfs_release_path(root->fs_info->extent_root, path);
1414
1415 path->reada = 1;
1416 path->leave_spinning = 1;
1417
1418 /* now insert the actual backref */
1419 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1420 path, bytenr, parent, root_objectid,
1421 owner, offset, 1);
1422 if (ret)
1423 err = ret;
1424 out:
1425 btrfs_free_path(path);
1426 finish_current_insert(trans, root->fs_info->extent_root);
1427 del_pending_extents(trans, root->fs_info->extent_root);
1428 BUG_ON(err);
1429 return err;
1430 }
1431
1432 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
1433 struct btrfs_root *root)
1434 {
1435 finish_current_insert(trans, root->fs_info->extent_root);
1436 del_pending_extents(trans, root->fs_info->extent_root);
1437 return 0;
1438 }
1439
1440 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
1441 struct btrfs_root *root, u64 bytenr,
1442 u64 num_bytes, u64 *refs, u64 *flags)
1443 {
1444 struct btrfs_path *path;
1445 int ret;
1446 struct btrfs_key key;
1447 struct extent_buffer *l;
1448 struct btrfs_extent_item *item;
1449 u32 item_size;
1450 u64 num_refs;
1451 u64 extent_flags;
1452
1453 WARN_ON(num_bytes < root->sectorsize);
1454 path = btrfs_alloc_path();
1455 path->reada = 1;
1456 key.objectid = bytenr;
1457 key.offset = num_bytes;
1458 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1459 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1460 0, 0);
1461 if (ret < 0)
1462 goto out;
1463 if (ret != 0) {
1464 ret = -EIO;
1465 goto out;
1466 }
1467
1468 l = path->nodes[0];
1469 item_size = btrfs_item_size_nr(l, path->slots[0]);
1470 if (item_size >= sizeof(*item)) {
1471 item = btrfs_item_ptr(l, path->slots[0],
1472 struct btrfs_extent_item);
1473 num_refs = btrfs_extent_refs(l, item);
1474 extent_flags = btrfs_extent_flags(l, item);
1475 } else {
1476 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1477 struct btrfs_extent_item_v0 *ei0;
1478 BUG_ON(item_size != sizeof(*ei0));
1479 ei0 = btrfs_item_ptr(l, path->slots[0],
1480 struct btrfs_extent_item_v0);
1481 num_refs = btrfs_extent_refs_v0(l, ei0);
1482 /* FIXME: this isn't correct for data */
1483 extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
1484 #else
1485 BUG();
1486 #endif
1487 }
1488 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1489 if (refs)
1490 *refs = num_refs;
1491 if (flags)
1492 *flags = extent_flags;
1493 out:
1494 btrfs_free_path(path);
1495 return 0;
1496 }
1497
1498 int btrfs_set_block_flags(struct btrfs_trans_handle *trans,
1499 struct btrfs_root *root,
1500 u64 bytenr, u64 num_bytes, u64 flags)
1501 {
1502 struct btrfs_path *path;
1503 int ret;
1504 struct btrfs_key key;
1505 struct extent_buffer *l;
1506 struct btrfs_extent_item *item;
1507 u32 item_size;
1508
1509 WARN_ON(num_bytes < root->sectorsize);
1510 path = btrfs_alloc_path();
1511 path->reada = 1;
1512 key.objectid = bytenr;
1513 key.offset = num_bytes;
1514 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1515 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1516 0, 0);
1517 if (ret < 0)
1518 goto out;
1519 if (ret != 0) {
1520 btrfs_print_leaf(root, path->nodes[0]);
1521 printk("failed to find block number %Lu\n",
1522 (unsigned long long)bytenr);
1523 BUG();
1524 }
1525 l = path->nodes[0];
1526 item_size = btrfs_item_size_nr(l, path->slots[0]);
1527 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1528 if (item_size < sizeof(*item)) {
1529 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1530 path, (u64)-1, 0);
1531 if (ret < 0)
1532 goto out;
1533
1534 l = path->nodes[0];
1535 item_size = btrfs_item_size_nr(l, path->slots[0]);
1536 }
1537 #endif
1538 BUG_ON(item_size < sizeof(*item));
1539 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1540 flags |= btrfs_extent_flags(l, item);
1541 btrfs_set_extent_flags(l, item, flags);
1542 out:
1543 btrfs_free_path(path);
1544 finish_current_insert(trans, root->fs_info->extent_root);
1545 del_pending_extents(trans, root->fs_info->extent_root);
1546 return ret;
1547 }
1548
1549 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
1550 struct btrfs_root *root,
1551 struct extent_buffer *buf,
1552 int record_parent, int inc)
1553 {
1554 u64 bytenr;
1555 u64 num_bytes;
1556 u64 parent;
1557 u64 ref_root;
1558 u32 nritems;
1559 struct btrfs_key key;
1560 struct btrfs_file_extent_item *fi;
1561 int i;
1562 int level;
1563 int ret = 0;
1564 int (*process_func)(struct btrfs_trans_handle *trans,
1565 struct btrfs_root *root,
1566 u64, u64, u64, u64, u64, u64);
1567
1568 ref_root = btrfs_header_owner(buf);
1569 nritems = btrfs_header_nritems(buf);
1570 level = btrfs_header_level(buf);
1571
1572 if (!root->ref_cows && level == 0)
1573 return 0;
1574
1575 if (inc)
1576 process_func = btrfs_inc_extent_ref;
1577 else
1578 process_func = btrfs_free_extent;
1579
1580 if (record_parent)
1581 parent = buf->start;
1582 else
1583 parent = 0;
1584
1585 for (i = 0; i < nritems; i++) {
1586 cond_resched();
1587 if (level == 0) {
1588 btrfs_item_key_to_cpu(buf, &key, i);
1589 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1590 continue;
1591 fi = btrfs_item_ptr(buf, i,
1592 struct btrfs_file_extent_item);
1593 if (btrfs_file_extent_type(buf, fi) ==
1594 BTRFS_FILE_EXTENT_INLINE)
1595 continue;
1596 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1597 if (bytenr == 0)
1598 continue;
1599
1600 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
1601 key.offset -= btrfs_file_extent_offset(buf, fi);
1602 ret = process_func(trans, root, bytenr, num_bytes,
1603 parent, ref_root, key.objectid,
1604 key.offset);
1605 if (ret) {
1606 WARN_ON(1);
1607 goto fail;
1608 }
1609 } else {
1610 bytenr = btrfs_node_blockptr(buf, i);
1611 num_bytes = btrfs_level_size(root, level - 1);
1612 ret = process_func(trans, root, bytenr, num_bytes,
1613 parent, ref_root, level - 1, 0);
1614 if (ret) {
1615 WARN_ON(1);
1616 goto fail;
1617 }
1618 }
1619 }
1620 return 0;
1621 fail:
1622 WARN_ON(1);
1623 return ret;
1624 }
1625
1626 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1627 struct extent_buffer *buf, int record_parent)
1628 {
1629 return __btrfs_mod_ref(trans, root, buf, record_parent, 1);
1630 }
1631
1632 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1633 struct extent_buffer *buf, int record_parent)
1634 {
1635 return __btrfs_mod_ref(trans, root, buf, record_parent, 0);
1636 }
1637
1638 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1639 struct btrfs_root *root,
1640 struct btrfs_path *path,
1641 struct btrfs_block_group_cache *cache)
1642 {
1643 int ret;
1644 int pending_ret;
1645 struct btrfs_root *extent_root = root->fs_info->extent_root;
1646 unsigned long bi;
1647 struct extent_buffer *leaf;
1648
1649 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1650 if (ret < 0)
1651 goto fail;
1652 BUG_ON(ret);
1653
1654 leaf = path->nodes[0];
1655 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1656 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1657 btrfs_mark_buffer_dirty(leaf);
1658 btrfs_release_path(extent_root, path);
1659 fail:
1660 finish_current_insert(trans, extent_root);
1661 pending_ret = del_pending_extents(trans, extent_root);
1662 if (ret)
1663 return ret;
1664 if (pending_ret)
1665 return pending_ret;
1666 return 0;
1667
1668 }
1669
1670 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1671 struct btrfs_root *root)
1672 {
1673 struct extent_io_tree *block_group_cache;
1674 struct btrfs_block_group_cache *cache;
1675 int ret;
1676 struct btrfs_path *path;
1677 u64 last = 0;
1678 u64 start;
1679 u64 end;
1680 u64 ptr;
1681
1682 block_group_cache = &root->fs_info->block_group_cache;
1683 path = btrfs_alloc_path();
1684 if (!path)
1685 return -ENOMEM;
1686
1687 while(1) {
1688 ret = find_first_extent_bit(block_group_cache, last,
1689 &start, &end, BLOCK_GROUP_DIRTY);
1690 if (ret) {
1691 if (last == 0)
1692 break;
1693 last = 0;
1694 continue;
1695 }
1696
1697 last = end + 1;
1698 ret = get_state_private(block_group_cache, start, &ptr);
1699 BUG_ON(ret);
1700
1701 clear_extent_bits(block_group_cache, start, end,
1702 BLOCK_GROUP_DIRTY, GFP_NOFS);
1703
1704 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
1705 ret = write_one_cache_group(trans, root, path, cache);
1706 }
1707 btrfs_free_path(path);
1708 return 0;
1709 }
1710
1711 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
1712 u64 flags)
1713 {
1714 struct list_head *head = &info->space_info;
1715 struct list_head *cur;
1716 struct btrfs_space_info *found;
1717 list_for_each(cur, head) {
1718 found = list_entry(cur, struct btrfs_space_info, list);
1719 if (found->flags & flags)
1720 return found;
1721 }
1722 return NULL;
1723
1724 }
1725
1726 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1727 u64 total_bytes, u64 bytes_used,
1728 struct btrfs_space_info **space_info)
1729 {
1730 struct btrfs_space_info *found;
1731
1732 found = __find_space_info(info, flags);
1733 if (found) {
1734 found->total_bytes += total_bytes;
1735 found->bytes_used += bytes_used;
1736 if (found->total_bytes < found->bytes_used) {
1737 fprintf(stderr, "warning, bad space info total_bytes "
1738 "%llu used %llu\n",
1739 (unsigned long long)found->total_bytes,
1740 (unsigned long long)found->bytes_used);
1741 }
1742 *space_info = found;
1743 return 0;
1744 }
1745 found = kmalloc(sizeof(*found), GFP_NOFS);
1746 if (!found)
1747 return -ENOMEM;
1748
1749 list_add(&found->list, &info->space_info);
1750 found->flags = flags;
1751 found->total_bytes = total_bytes;
1752 found->bytes_used = bytes_used;
1753 found->bytes_pinned = 0;
1754 found->full = 0;
1755 *space_info = found;
1756 return 0;
1757 }
1758
1759
1760 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1761 {
1762 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1763 BTRFS_BLOCK_GROUP_RAID1 |
1764 BTRFS_BLOCK_GROUP_RAID10 |
1765 BTRFS_BLOCK_GROUP_DUP);
1766 if (extra_flags) {
1767 if (flags & BTRFS_BLOCK_GROUP_DATA)
1768 fs_info->avail_data_alloc_bits |= extra_flags;
1769 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1770 fs_info->avail_metadata_alloc_bits |= extra_flags;
1771 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1772 fs_info->avail_system_alloc_bits |= extra_flags;
1773 }
1774 }
1775
1776 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1777 struct btrfs_root *extent_root, u64 alloc_bytes,
1778 u64 flags)
1779 {
1780 struct btrfs_space_info *space_info;
1781 u64 thresh;
1782 u64 start;
1783 u64 num_bytes;
1784 int ret;
1785
1786 space_info = __find_space_info(extent_root->fs_info, flags);
1787 if (!space_info) {
1788 ret = update_space_info(extent_root->fs_info, flags,
1789 0, 0, &space_info);
1790 BUG_ON(ret);
1791 }
1792 BUG_ON(!space_info);
1793
1794 if (space_info->full)
1795 return 0;
1796
1797 thresh = div_factor(space_info->total_bytes, 7);
1798 if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1799 thresh)
1800 return 0;
1801
1802 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes,
1803 space_info->flags);
1804 if (ret == -ENOSPC) {
1805 space_info->full = 1;
1806 return 0;
1807 }
1808
1809 BUG_ON(ret);
1810
1811 ret = btrfs_make_block_group(trans, extent_root, 0, space_info->flags,
1812 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1813 BUG_ON(ret);
1814 return 0;
1815 }
1816
1817 static int update_block_group(struct btrfs_trans_handle *trans,
1818 struct btrfs_root *root,
1819 u64 bytenr, u64 num_bytes, int alloc,
1820 int mark_free)
1821 {
1822 struct btrfs_block_group_cache *cache;
1823 struct btrfs_fs_info *info = root->fs_info;
1824 u64 total = num_bytes;
1825 u64 old_val;
1826 u64 byte_in_group;
1827 u64 start;
1828 u64 end;
1829
1830 /* block accounting for super block */
1831 old_val = btrfs_super_bytes_used(&info->super_copy);
1832 if (alloc)
1833 old_val += num_bytes;
1834 else
1835 old_val -= num_bytes;
1836 btrfs_set_super_bytes_used(&info->super_copy, old_val);
1837
1838 /* block accounting for root item */
1839 old_val = btrfs_root_used(&root->root_item);
1840 if (alloc)
1841 old_val += num_bytes;
1842 else
1843 old_val -= num_bytes;
1844 btrfs_set_root_used(&root->root_item, old_val);
1845
1846 while(total) {
1847 cache = btrfs_lookup_block_group(info, bytenr);
1848 if (!cache) {
1849 return -1;
1850 }
1851 byte_in_group = bytenr - cache->key.objectid;
1852 WARN_ON(byte_in_group > cache->key.offset);
1853 start = cache->key.objectid;
1854 end = start + cache->key.offset - 1;
1855 set_extent_bits(&info->block_group_cache, start, end,
1856 BLOCK_GROUP_DIRTY, GFP_NOFS);
1857
1858 old_val = btrfs_block_group_used(&cache->item);
1859 num_bytes = min(total, cache->key.offset - byte_in_group);
1860
1861 if (alloc) {
1862 old_val += num_bytes;
1863 cache->space_info->bytes_used += num_bytes;
1864 } else {
1865 old_val -= num_bytes;
1866 cache->space_info->bytes_used -= num_bytes;
1867 if (mark_free) {
1868 set_extent_dirty(&info->free_space_cache,
1869 bytenr, bytenr + num_bytes - 1,
1870 GFP_NOFS);
1871 }
1872 }
1873 btrfs_set_block_group_used(&cache->item, old_val);
1874 total -= num_bytes;
1875 bytenr += num_bytes;
1876 }
1877 return 0;
1878 }
1879
1880 static int update_pinned_extents(struct btrfs_root *root,
1881 u64 bytenr, u64 num, int pin)
1882 {
1883 u64 len;
1884 struct btrfs_block_group_cache *cache;
1885 struct btrfs_fs_info *fs_info = root->fs_info;
1886
1887 if (pin) {
1888 set_extent_dirty(&fs_info->pinned_extents,
1889 bytenr, bytenr + num - 1, GFP_NOFS);
1890 } else {
1891 clear_extent_dirty(&fs_info->pinned_extents,
1892 bytenr, bytenr + num - 1, GFP_NOFS);
1893 }
1894 while (num > 0) {
1895 cache = btrfs_lookup_block_group(fs_info, bytenr);
1896 if (!cache) {
1897 len = min((u64)root->sectorsize, num);
1898 goto next;
1899 }
1900 WARN_ON(!cache);
1901 len = min(num, cache->key.offset -
1902 (bytenr - cache->key.objectid));
1903 if (pin) {
1904 cache->pinned += len;
1905 cache->space_info->bytes_pinned += len;
1906 fs_info->total_pinned += len;
1907 } else {
1908 cache->pinned -= len;
1909 cache->space_info->bytes_pinned -= len;
1910 fs_info->total_pinned -= len;
1911 }
1912 next:
1913 bytenr += len;
1914 num -= len;
1915 }
1916 return 0;
1917 }
1918
1919 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1920 {
1921 u64 last = 0;
1922 u64 start;
1923 u64 end;
1924 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1925 int ret;
1926
1927 while(1) {
1928 ret = find_first_extent_bit(pinned_extents, last,
1929 &start, &end, EXTENT_DIRTY);
1930 if (ret)
1931 break;
1932 set_extent_dirty(copy, start, end, GFP_NOFS);
1933 last = end + 1;
1934 }
1935 return 0;
1936 }
1937
1938 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1939 struct btrfs_root *root,
1940 struct extent_io_tree *unpin)
1941 {
1942 u64 start;
1943 u64 end;
1944 int ret;
1945 struct extent_io_tree *free_space_cache;
1946 free_space_cache = &root->fs_info->free_space_cache;
1947
1948 while(1) {
1949 ret = find_first_extent_bit(unpin, 0, &start, &end,
1950 EXTENT_DIRTY);
1951 if (ret)
1952 break;
1953 update_pinned_extents(root, start, end + 1 - start, 0);
1954 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1955 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1956 }
1957 return 0;
1958 }
1959
1960 static int extent_root_pending_ops(struct btrfs_fs_info *info)
1961 {
1962 u64 start;
1963 u64 end;
1964 int ret;
1965
1966 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1967 &end, EXTENT_LOCKED);
1968 if (!ret) {
1969 ret = find_first_extent_bit(&info->pending_del, 0, &start, &end,
1970 EXTENT_LOCKED);
1971 }
1972 return ret == 0;
1973
1974 }
1975 static int finish_current_insert(struct btrfs_trans_handle *trans,
1976 struct btrfs_root *extent_root)
1977 {
1978 u64 start;
1979 u64 end;
1980 u64 priv;
1981 struct btrfs_fs_info *info = extent_root->fs_info;
1982 struct btrfs_path *path;
1983 struct pending_extent_op *extent_op;
1984 struct btrfs_key key;
1985 int ret;
1986
1987 path = btrfs_alloc_path();
1988
1989 while(1) {
1990 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1991 &end, EXTENT_LOCKED);
1992 if (ret)
1993 break;
1994
1995 ret = get_state_private(&info->extent_ins, start, &priv);
1996 BUG_ON(ret);
1997 extent_op = (struct pending_extent_op *)(unsigned long)priv;
1998
1999 if (extent_op->type == PENDING_EXTENT_INSERT) {
2000 key.objectid = start;
2001 key.offset = end + 1 - start;
2002 key.type = BTRFS_EXTENT_ITEM_KEY;
2003 ret = alloc_reserved_tree_block(trans, extent_root,
2004 extent_root->root_key.objectid,
2005 trans->transid,
2006 extent_op->flags,
2007 &extent_op->key,
2008 extent_op->level, &key);
2009 } else {
2010 BUG_ON(1);
2011 }
2012
2013 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
2014 GFP_NOFS);
2015 kfree(extent_op);
2016 }
2017 btrfs_free_path(path);
2018 return 0;
2019 }
2020
2021 static int pin_down_bytes(struct btrfs_trans_handle *trans,
2022 struct btrfs_root *root,
2023 u64 bytenr, u64 num_bytes, int is_data)
2024 {
2025 int err = 0;
2026 struct extent_buffer *buf;
2027
2028 if (is_data)
2029 goto pinit;
2030
2031 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
2032 if (!buf)
2033 goto pinit;
2034
2035 /* we can reuse a block if it hasn't been written
2036 * and it is from this transaction. We can't
2037 * reuse anything from the tree log root because
2038 * it has tiny sub-transactions.
2039 */
2040 if (btrfs_buffer_uptodate(buf, 0)) {
2041 u64 header_owner = btrfs_header_owner(buf);
2042 u64 header_transid = btrfs_header_generation(buf);
2043 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
2044 header_transid == trans->transid &&
2045 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
2046 clean_tree_block(NULL, root, buf);
2047 free_extent_buffer(buf);
2048 return 1;
2049 }
2050 }
2051 free_extent_buffer(buf);
2052 pinit:
2053 update_pinned_extents(root, bytenr, num_bytes, 1);
2054
2055 BUG_ON(err < 0);
2056 return 0;
2057 }
2058
2059 void btrfs_pin_extent(struct btrfs_fs_info *fs_info,
2060 u64 bytenr, u64 num_bytes)
2061 {
2062 update_pinned_extents(fs_info->extent_root, bytenr, num_bytes, 1);
2063 }
2064
2065 /*
2066 * remove an extent from the root, returns 0 on success
2067 */
2068 static int __free_extent(struct btrfs_trans_handle *trans,
2069 struct btrfs_root *root,
2070 u64 bytenr, u64 num_bytes, u64 parent,
2071 u64 root_objectid, u64 owner_objectid,
2072 u64 owner_offset, int refs_to_drop)
2073 {
2074
2075 struct btrfs_key key;
2076 struct btrfs_path *path;
2077 struct btrfs_extent_ops *ops = root->fs_info->extent_ops;
2078 struct btrfs_root *extent_root = root->fs_info->extent_root;
2079 struct extent_buffer *leaf;
2080 struct btrfs_extent_item *ei;
2081 struct btrfs_extent_inline_ref *iref;
2082 int ret;
2083 int is_data;
2084 int extent_slot = 0;
2085 int found_extent = 0;
2086 int num_to_del = 1;
2087 u32 item_size;
2088 u64 refs;
2089
2090 if (root->fs_info->free_extent_hook) {
2091 root->fs_info->free_extent_hook(trans, root, bytenr, num_bytes,
2092 parent, root_objectid, owner_objectid,
2093 owner_offset, refs_to_drop);
2094
2095 }
2096 path = btrfs_alloc_path();
2097 if (!path)
2098 return -ENOMEM;
2099
2100 path->reada = 1;
2101 path->leave_spinning = 1;
2102
2103 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
2104 BUG_ON(!is_data && refs_to_drop != 1);
2105
2106 ret = lookup_extent_backref(trans, extent_root, path, &iref,
2107 bytenr, num_bytes, parent,
2108 root_objectid, owner_objectid,
2109 owner_offset);
2110 if (ret == 0) {
2111 extent_slot = path->slots[0];
2112 while (extent_slot >= 0) {
2113 btrfs_item_key_to_cpu(path->nodes[0], &key,
2114 extent_slot);
2115 if (key.objectid != bytenr)
2116 break;
2117 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
2118 key.offset == num_bytes) {
2119 found_extent = 1;
2120 break;
2121 }
2122 if (path->slots[0] - extent_slot > 5)
2123 break;
2124 extent_slot--;
2125 }
2126 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2127 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
2128 if (found_extent && item_size < sizeof(*ei))
2129 found_extent = 0;
2130 #endif
2131 if (!found_extent) {
2132 BUG_ON(iref);
2133 ret = remove_extent_backref(trans, extent_root, path,
2134 NULL, refs_to_drop,
2135 is_data);
2136 BUG_ON(ret);
2137 btrfs_release_path(extent_root, path);
2138 path->leave_spinning = 1;
2139
2140 key.objectid = bytenr;
2141 key.type = BTRFS_EXTENT_ITEM_KEY;
2142 key.offset = num_bytes;
2143
2144 ret = btrfs_search_slot(trans, extent_root,
2145 &key, path, -1, 1);
2146 if (ret) {
2147 printk(KERN_ERR "umm, got %d back from search"
2148 ", was looking for %llu\n", ret,
2149 (unsigned long long)bytenr);
2150 btrfs_print_leaf(extent_root, path->nodes[0]);
2151 }
2152 BUG_ON(ret);
2153 extent_slot = path->slots[0];
2154 }
2155 } else {
2156 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
2157 "parent %llu root %llu owner %llu offset %llu\n",
2158 (unsigned long long)bytenr,
2159 (unsigned long long)parent,
2160 (unsigned long long)root_objectid,
2161 (unsigned long long)owner_objectid,
2162 (unsigned long long)owner_offset);
2163 ret = -EIO;
2164 goto fail;
2165 }
2166
2167 leaf = path->nodes[0];
2168 item_size = btrfs_item_size_nr(leaf, extent_slot);
2169 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2170 if (item_size < sizeof(*ei)) {
2171 BUG_ON(found_extent || extent_slot != path->slots[0]);
2172 ret = convert_extent_item_v0(trans, extent_root, path,
2173 owner_objectid, 0);
2174 BUG_ON(ret < 0);
2175
2176 btrfs_release_path(extent_root, path);
2177 path->leave_spinning = 1;
2178
2179 key.objectid = bytenr;
2180 key.type = BTRFS_EXTENT_ITEM_KEY;
2181 key.offset = num_bytes;
2182
2183 ret = btrfs_search_slot(trans, extent_root, &key, path,
2184 -1, 1);
2185 if (ret) {
2186 printk(KERN_ERR "umm, got %d back from search"
2187 ", was looking for %llu\n", ret,
2188 (unsigned long long)bytenr);
2189 btrfs_print_leaf(extent_root, path->nodes[0]);
2190 }
2191 BUG_ON(ret);
2192 extent_slot = path->slots[0];
2193 leaf = path->nodes[0];
2194 item_size = btrfs_item_size_nr(leaf, extent_slot);
2195 }
2196 #endif
2197 BUG_ON(item_size < sizeof(*ei));
2198 ei = btrfs_item_ptr(leaf, extent_slot,
2199 struct btrfs_extent_item);
2200 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
2201 struct btrfs_tree_block_info *bi;
2202 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
2203 bi = (struct btrfs_tree_block_info *)(ei + 1);
2204 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
2205 }
2206
2207 refs = btrfs_extent_refs(leaf, ei);
2208 BUG_ON(refs < refs_to_drop);
2209 refs -= refs_to_drop;
2210
2211 if (refs > 0) {
2212 /*
2213 * In the case of inline back ref, reference count will
2214 * be updated by remove_extent_backref
2215 */
2216 if (iref) {
2217 BUG_ON(!found_extent);
2218 } else {
2219 btrfs_set_extent_refs(leaf, ei, refs);
2220 btrfs_mark_buffer_dirty(leaf);
2221 }
2222 if (found_extent) {
2223 ret = remove_extent_backref(trans, extent_root, path,
2224 iref, refs_to_drop,
2225 is_data);
2226 BUG_ON(ret);
2227 }
2228 } else {
2229 int mark_free = 0;
2230 int pin = 1;
2231
2232 if (found_extent) {
2233 BUG_ON(is_data && refs_to_drop !=
2234 extent_data_ref_count(root, path, iref));
2235 if (iref) {
2236 BUG_ON(path->slots[0] != extent_slot);
2237 } else {
2238 BUG_ON(path->slots[0] != extent_slot + 1);
2239 path->slots[0] = extent_slot;
2240 num_to_del = 2;
2241 }
2242 }
2243
2244 if (ops && ops->free_extent) {
2245 ret = ops->free_extent(root, bytenr, num_bytes);
2246 if (ret > 0) {
2247 pin = 0;
2248 mark_free = 0;
2249 }
2250 }
2251
2252 if (pin) {
2253 ret = pin_down_bytes(trans, root, bytenr, num_bytes,
2254 is_data);
2255 if (ret > 0)
2256 mark_free = 1;
2257 BUG_ON(ret < 0);
2258 }
2259
2260 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
2261 num_to_del);
2262 BUG_ON(ret);
2263 btrfs_release_path(extent_root, path);
2264
2265 if (is_data) {
2266 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
2267 BUG_ON(ret);
2268 }
2269
2270 update_block_group(trans, root, bytenr, num_bytes, 0, mark_free);
2271 }
2272 fail:
2273 btrfs_free_path(path);
2274 finish_current_insert(trans, extent_root);
2275 return ret;
2276 }
2277
2278 /*
2279 * find all the blocks marked as pending in the radix tree and remove
2280 * them from the extent map
2281 */
2282 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
2283 btrfs_root *extent_root)
2284 {
2285 int ret;
2286 int err = 0;
2287 u64 start;
2288 u64 end;
2289 u64 priv;
2290 struct extent_io_tree *pending_del;
2291 struct extent_io_tree *extent_ins;
2292 struct pending_extent_op *extent_op;
2293
2294 extent_ins = &extent_root->fs_info->extent_ins;
2295 pending_del = &extent_root->fs_info->pending_del;
2296
2297 while(1) {
2298 ret = find_first_extent_bit(pending_del, 0, &start, &end,
2299 EXTENT_LOCKED);
2300 if (ret)
2301 break;
2302
2303 ret = get_state_private(pending_del, start, &priv);
2304 BUG_ON(ret);
2305 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2306
2307 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
2308 GFP_NOFS);
2309
2310 if (!test_range_bit(extent_ins, start, end,
2311 EXTENT_LOCKED, 0)) {
2312 ret = __free_extent(trans, extent_root,
2313 start, end + 1 - start, 0,
2314 extent_root->root_key.objectid,
2315 extent_op->level, 0, 1);
2316 kfree(extent_op);
2317 } else {
2318 kfree(extent_op);
2319 ret = get_state_private(extent_ins, start, &priv);
2320 BUG_ON(ret);
2321 extent_op = (struct pending_extent_op *)
2322 (unsigned long)priv;
2323
2324 clear_extent_bits(extent_ins, start, end,
2325 EXTENT_LOCKED, GFP_NOFS);
2326
2327 if (extent_op->type == PENDING_BACKREF_UPDATE)
2328 BUG_ON(1);
2329
2330 kfree(extent_op);
2331 }
2332 if (ret)
2333 err = ret;
2334 }
2335 return err;
2336 }
2337
2338 /*
2339 * remove an extent from the root, returns 0 on success
2340 */
2341
2342 int btrfs_free_extent(struct btrfs_trans_handle *trans,
2343 struct btrfs_root *root,
2344 u64 bytenr, u64 num_bytes, u64 parent,
2345 u64 root_objectid, u64 owner, u64 offset)
2346 {
2347 struct btrfs_root *extent_root = root->fs_info->extent_root;
2348 int pending_ret;
2349 int ret;
2350
2351 WARN_ON(num_bytes < root->sectorsize);
2352 if (root == extent_root) {
2353 struct pending_extent_op *extent_op;
2354
2355 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2356 BUG_ON(!extent_op);
2357
2358 extent_op->type = PENDING_EXTENT_DELETE;
2359 extent_op->bytenr = bytenr;
2360 extent_op->num_bytes = num_bytes;
2361 extent_op->level = (int)owner;
2362
2363 set_extent_bits(&root->fs_info->pending_del,
2364 bytenr, bytenr + num_bytes - 1,
2365 EXTENT_LOCKED, GFP_NOFS);
2366 set_state_private(&root->fs_info->pending_del,
2367 bytenr, (unsigned long)extent_op);
2368 return 0;
2369 }
2370 ret = __free_extent(trans, root, bytenr, num_bytes, parent,
2371 root_objectid, owner, offset, 1);
2372 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
2373 return ret ? ret : pending_ret;
2374 }
2375
2376 static u64 stripe_align(struct btrfs_root *root, u64 val)
2377 {
2378 u64 mask = ((u64)root->stripesize - 1);
2379 u64 ret = (val + mask) & ~mask;
2380 return ret;
2381 }
2382
2383 /*
2384 * walks the btree of allocated extents and find a hole of a given size.
2385 * The key ins is changed to record the hole:
2386 * ins->objectid == block start
2387 * ins->flags = BTRFS_EXTENT_ITEM_KEY
2388 * ins->offset == number of blocks
2389 * Any available blocks before search_start are skipped.
2390 */
2391 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
2392 struct btrfs_root *orig_root,
2393 u64 num_bytes, u64 empty_size,
2394 u64 search_start, u64 search_end,
2395 u64 hint_byte, struct btrfs_key *ins,
2396 u64 exclude_start, u64 exclude_nr,
2397 int data)
2398 {
2399 int ret;
2400 u64 orig_search_start = search_start;
2401 struct btrfs_root * root = orig_root->fs_info->extent_root;
2402 struct btrfs_fs_info *info = root->fs_info;
2403 u64 total_needed = num_bytes;
2404 struct btrfs_block_group_cache *block_group;
2405 int full_scan = 0;
2406 int wrapped = 0;
2407
2408 WARN_ON(num_bytes < root->sectorsize);
2409 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
2410
2411 if (hint_byte) {
2412 block_group = btrfs_lookup_first_block_group(info, hint_byte);
2413 if (!block_group)
2414 hint_byte = search_start;
2415 block_group = btrfs_find_block_group(root, block_group,
2416 hint_byte, data, 1);
2417 } else {
2418 block_group = btrfs_find_block_group(root,
2419 trans->block_group,
2420 search_start, data, 1);
2421 }
2422
2423 total_needed += empty_size;
2424
2425 check_failed:
2426 if (!block_group) {
2427 block_group = btrfs_lookup_first_block_group(info,
2428 search_start);
2429 if (!block_group)
2430 block_group = btrfs_lookup_first_block_group(info,
2431 orig_search_start);
2432 }
2433 ret = find_search_start(root, &block_group, &search_start,
2434 total_needed, data);
2435 if (ret)
2436 goto error;
2437
2438 search_start = stripe_align(root, search_start);
2439 ins->objectid = search_start;
2440 ins->offset = num_bytes;
2441
2442 if (ins->objectid + num_bytes >
2443 block_group->key.objectid + block_group->key.offset) {
2444 search_start = block_group->key.objectid +
2445 block_group->key.offset;
2446 goto new_group;
2447 }
2448
2449 if (test_range_bit(&info->extent_ins, ins->objectid,
2450 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
2451 search_start = ins->objectid + num_bytes;
2452 goto new_group;
2453 }
2454
2455 if (test_range_bit(&info->pinned_extents, ins->objectid,
2456 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
2457 search_start = ins->objectid + num_bytes;
2458 goto new_group;
2459 }
2460
2461 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
2462 ins->objectid < exclude_start + exclude_nr)) {
2463 search_start = exclude_start + exclude_nr;
2464 goto new_group;
2465 }
2466
2467 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
2468 block_group = btrfs_lookup_block_group(info, ins->objectid);
2469 if (block_group)
2470 trans->block_group = block_group;
2471 }
2472 ins->offset = num_bytes;
2473 return 0;
2474
2475 new_group:
2476 block_group = btrfs_lookup_first_block_group(info, search_start);
2477 if (!block_group) {
2478 search_start = orig_search_start;
2479 if (full_scan) {
2480 ret = -ENOSPC;
2481 goto error;
2482 }
2483 if (wrapped) {
2484 if (!full_scan)
2485 total_needed -= empty_size;
2486 full_scan = 1;
2487 } else
2488 wrapped = 1;
2489 }
2490 cond_resched();
2491 block_group = btrfs_find_block_group(root, block_group,
2492 search_start, data, 0);
2493 goto check_failed;
2494
2495 error:
2496 return ret;
2497 }
2498
2499 static int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2500 struct btrfs_root *root,
2501 u64 num_bytes, u64 empty_size,
2502 u64 hint_byte, u64 search_end,
2503 struct btrfs_key *ins, int data)
2504 {
2505 int ret;
2506 u64 search_start = 0;
2507 u64 alloc_profile;
2508 struct btrfs_fs_info *info = root->fs_info;
2509
2510 if (info->extent_ops) {
2511 struct btrfs_extent_ops *ops = info->extent_ops;
2512 ret = ops->alloc_extent(root, num_bytes, hint_byte, ins);
2513 BUG_ON(ret);
2514 goto found;
2515 }
2516
2517 if (data) {
2518 alloc_profile = info->avail_data_alloc_bits &
2519 info->data_alloc_profile;
2520 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2521 } else if ((info->system_allocs > 0 || root == info->chunk_root) &&
2522 info->system_allocs >= 0) {
2523 alloc_profile = info->avail_system_alloc_bits &
2524 info->system_alloc_profile;
2525 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2526 } else {
2527 alloc_profile = info->avail_metadata_alloc_bits &
2528 info->metadata_alloc_profile;
2529 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2530 }
2531
2532 if (root->ref_cows) {
2533 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
2534 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2535 num_bytes,
2536 BTRFS_BLOCK_GROUP_METADATA);
2537 BUG_ON(ret);
2538 }
2539 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2540 num_bytes + 2 * 1024 * 1024, data);
2541 BUG_ON(ret);
2542 }
2543
2544 WARN_ON(num_bytes < root->sectorsize);
2545 ret = find_free_extent(trans, root, num_bytes, empty_size,
2546 search_start, search_end, hint_byte, ins,
2547 trans->alloc_exclude_start,
2548 trans->alloc_exclude_nr, data);
2549 BUG_ON(ret);
2550 found:
2551 clear_extent_dirty(&root->fs_info->free_space_cache,
2552 ins->objectid, ins->objectid + ins->offset - 1,
2553 GFP_NOFS);
2554 return ret;
2555 }
2556
2557 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
2558 struct btrfs_root *root,
2559 u64 root_objectid, u64 generation,
2560 u64 flags, struct btrfs_disk_key *key,
2561 int level, struct btrfs_key *ins)
2562 {
2563 int ret;
2564 struct btrfs_fs_info *fs_info = root->fs_info;
2565 struct btrfs_extent_item *extent_item;
2566 struct btrfs_tree_block_info *block_info;
2567 struct btrfs_extent_inline_ref *iref;
2568 struct btrfs_path *path;
2569 struct extent_buffer *leaf;
2570 u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
2571
2572 path = btrfs_alloc_path();
2573 BUG_ON(!path);
2574
2575 path->leave_spinning = 1;
2576 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
2577 ins, size);
2578 BUG_ON(ret);
2579
2580 leaf = path->nodes[0];
2581 extent_item = btrfs_item_ptr(leaf, path->slots[0],
2582 struct btrfs_extent_item);
2583 btrfs_set_extent_refs(leaf, extent_item, 1);
2584 btrfs_set_extent_generation(leaf, extent_item, generation);
2585 btrfs_set_extent_flags(leaf, extent_item,
2586 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
2587 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
2588
2589 btrfs_set_tree_block_key(leaf, block_info, key);
2590 btrfs_set_tree_block_level(leaf, block_info, level);
2591
2592 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
2593 btrfs_set_extent_inline_ref_type(leaf, iref, BTRFS_TREE_BLOCK_REF_KEY);
2594 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
2595
2596 btrfs_mark_buffer_dirty(leaf);
2597 btrfs_free_path(path);
2598
2599 ret = update_block_group(trans, root, ins->objectid, ins->offset,
2600 1, 0);
2601 return 0;
2602 }
2603
2604 static int alloc_tree_block(struct btrfs_trans_handle *trans,
2605 struct btrfs_root *root, u64 num_bytes,
2606 u64 root_objectid, u64 generation,
2607 u64 flags, struct btrfs_disk_key *key,
2608 int level, u64 empty_size, u64 hint_byte,
2609 u64 search_end, struct btrfs_key *ins)
2610 {
2611 int ret;
2612 ret = btrfs_reserve_extent(trans, root, num_bytes, empty_size,
2613 hint_byte, search_end, ins, 0);
2614 BUG_ON(ret);
2615
2616 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID) {
2617 struct pending_extent_op *extent_op;
2618
2619 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2620 BUG_ON(!extent_op);
2621
2622 extent_op->type = PENDING_EXTENT_INSERT;
2623 extent_op->bytenr = ins->objectid;
2624 extent_op->num_bytes = ins->offset;
2625 extent_op->level = level;
2626 extent_op->flags = flags;
2627 memcpy(&extent_op->key, key, sizeof(*key));
2628
2629 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2630 ins->objectid + ins->offset - 1,
2631 EXTENT_LOCKED, GFP_NOFS);
2632 set_state_private(&root->fs_info->extent_ins,
2633 ins->objectid, (unsigned long)extent_op);
2634 } else {
2635 ret = alloc_reserved_tree_block(trans, root, root_objectid,
2636 generation, flags,
2637 key, level, ins);
2638 finish_current_insert(trans, root->fs_info->extent_root);
2639 del_pending_extents(trans, root->fs_info->extent_root);
2640 }
2641 return ret;
2642 }
2643
2644 /*
2645 * helper function to allocate a block for a given tree
2646 * returns the tree buffer or NULL.
2647 */
2648 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2649 struct btrfs_root *root,
2650 u32 blocksize, u64 root_objectid,
2651 struct btrfs_disk_key *key, int level,
2652 u64 hint, u64 empty_size)
2653 {
2654 struct btrfs_key ins;
2655 int ret;
2656 struct extent_buffer *buf;
2657
2658 ret = alloc_tree_block(trans, root, blocksize, root_objectid,
2659 trans->transid, 0, key, level,
2660 empty_size, hint, (u64)-1, &ins);
2661 if (ret) {
2662 BUG_ON(ret > 0);
2663 return ERR_PTR(ret);
2664 }
2665
2666 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
2667 if (!buf) {
2668 btrfs_free_extent(trans, root, ins.objectid, ins.offset,
2669 0, root->root_key.objectid, level, 0);
2670 BUG_ON(1);
2671 return ERR_PTR(-ENOMEM);
2672 }
2673 btrfs_set_buffer_uptodate(buf);
2674 trans->blocks_used++;
2675
2676 return buf;
2677 }
2678
2679 #if 0
2680
2681 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
2682 struct btrfs_root *root,
2683 struct extent_buffer *leaf)
2684 {
2685 u64 leaf_owner;
2686 u64 leaf_generation;
2687 struct btrfs_key key;
2688 struct btrfs_file_extent_item *fi;
2689 int i;
2690 int nritems;
2691 int ret;
2692
2693 BUG_ON(!btrfs_is_leaf(leaf));
2694 nritems = btrfs_header_nritems(leaf);
2695 leaf_owner = btrfs_header_owner(leaf);
2696 leaf_generation = btrfs_header_generation(leaf);
2697
2698 for (i = 0; i < nritems; i++) {
2699 u64 disk_bytenr;
2700
2701 btrfs_item_key_to_cpu(leaf, &key, i);
2702 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2703 continue;
2704 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2705 if (btrfs_file_extent_type(leaf, fi) ==
2706 BTRFS_FILE_EXTENT_INLINE)
2707 continue;
2708 /*
2709 * FIXME make sure to insert a trans record that
2710 * repeats the snapshot del on crash
2711 */
2712 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2713 if (disk_bytenr == 0)
2714 continue;
2715 ret = btrfs_free_extent(trans, root, disk_bytenr,
2716 btrfs_file_extent_disk_num_bytes(leaf, fi),
2717 leaf->start, leaf_owner, leaf_generation,
2718 key.objectid, 0);
2719 BUG_ON(ret);
2720 }
2721 return 0;
2722 }
2723
2724 static void noinline reada_walk_down(struct btrfs_root *root,
2725 struct extent_buffer *node,
2726 int slot)
2727 {
2728 u64 bytenr;
2729 u64 last = 0;
2730 u32 nritems;
2731 u32 refs;
2732 u32 blocksize;
2733 int ret;
2734 int i;
2735 int level;
2736 int skipped = 0;
2737
2738 nritems = btrfs_header_nritems(node);
2739 level = btrfs_header_level(node);
2740 if (level)
2741 return;
2742
2743 for (i = slot; i < nritems && skipped < 32; i++) {
2744 bytenr = btrfs_node_blockptr(node, i);
2745 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
2746 (last > bytenr && last - bytenr > 32 * 1024))) {
2747 skipped++;
2748 continue;
2749 }
2750 blocksize = btrfs_level_size(root, level - 1);
2751 if (i != slot) {
2752 ret = btrfs_lookup_extent_ref(NULL, root, bytenr,
2753 blocksize, &refs);
2754 BUG_ON(ret);
2755 if (refs != 1) {
2756 skipped++;
2757 continue;
2758 }
2759 }
2760 mutex_unlock(&root->fs_info->fs_mutex);
2761 ret = readahead_tree_block(root, bytenr, blocksize,
2762 btrfs_node_ptr_generation(node, i));
2763 last = bytenr + blocksize;
2764 cond_resched();
2765 mutex_lock(&root->fs_info->fs_mutex);
2766 if (ret)
2767 break;
2768 }
2769 }
2770
2771 /*
2772 * helper function for drop_snapshot, this walks down the tree dropping ref
2773 * counts as it goes.
2774 */
2775 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2776 struct btrfs_root *root,
2777 struct btrfs_path *path, int *level)
2778 {
2779 u64 root_owner;
2780 u64 root_gen;
2781 u64 bytenr;
2782 u64 ptr_gen;
2783 struct extent_buffer *next;
2784 struct extent_buffer *cur;
2785 struct extent_buffer *parent;
2786 u32 blocksize;
2787 int ret;
2788 u32 refs;
2789
2790 WARN_ON(*level < 0);
2791 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2792 ret = btrfs_lookup_extent_ref(trans, root,
2793 path->nodes[*level]->start,
2794 path->nodes[*level]->len, &refs);
2795 BUG_ON(ret);
2796 if (refs > 1)
2797 goto out;
2798
2799 /*
2800 * walk down to the last node level and free all the leaves
2801 */
2802 while(*level >= 0) {
2803 WARN_ON(*level < 0);
2804 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2805 cur = path->nodes[*level];
2806
2807 if (btrfs_header_level(cur) != *level)
2808 WARN_ON(1);
2809
2810 if (path->slots[*level] >=
2811 btrfs_header_nritems(cur))
2812 break;
2813 if (*level == 0) {
2814 ret = drop_leaf_ref(trans, root, cur);
2815 BUG_ON(ret);
2816 break;
2817 }
2818 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2819 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2820 blocksize = btrfs_level_size(root, *level - 1);
2821 ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize,
2822 &refs);
2823 BUG_ON(ret);
2824 if (refs != 1) {
2825 parent = path->nodes[*level];
2826 root_owner = btrfs_header_owner(parent);
2827 root_gen = btrfs_header_generation(parent);
2828 path->slots[*level]++;
2829 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
2830 parent->start, root_owner,
2831 root_gen, *level - 1, 1);
2832 BUG_ON(ret);
2833 continue;
2834 }
2835 next = btrfs_find_tree_block(root, bytenr, blocksize);
2836 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2837 free_extent_buffer(next);
2838 reada_walk_down(root, cur, path->slots[*level]);
2839 mutex_unlock(&root->fs_info->fs_mutex);
2840 next = read_tree_block(root, bytenr, blocksize,
2841 ptr_gen);
2842 mutex_lock(&root->fs_info->fs_mutex);
2843 }
2844 WARN_ON(*level <= 0);
2845 if (path->nodes[*level-1])
2846 free_extent_buffer(path->nodes[*level-1]);
2847 path->nodes[*level-1] = next;
2848 *level = btrfs_header_level(next);
2849 path->slots[*level] = 0;
2850 }
2851 out:
2852 WARN_ON(*level < 0);
2853 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2854
2855 if (path->nodes[*level] == root->node) {
2856 root_owner = root->root_key.objectid;
2857 parent = path->nodes[*level];
2858 } else {
2859 parent = path->nodes[*level + 1];
2860 root_owner = btrfs_header_owner(parent);
2861 }
2862
2863 root_gen = btrfs_header_generation(parent);
2864 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
2865 path->nodes[*level]->len, parent->start,
2866 root_owner, root_gen, *level, 1);
2867 free_extent_buffer(path->nodes[*level]);
2868 path->nodes[*level] = NULL;
2869 *level += 1;
2870 BUG_ON(ret);
2871 return 0;
2872 }
2873
2874 /*
2875 * helper for dropping snapshots. This walks back up the tree in the path
2876 * to find the first node higher up where we haven't yet gone through
2877 * all the slots
2878 */
2879 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
2880 struct btrfs_root *root,
2881 struct btrfs_path *path, int *level)
2882 {
2883 u64 root_owner;
2884 u64 root_gen;
2885 struct btrfs_root_item *root_item = &root->root_item;
2886 int i;
2887 int slot;
2888 int ret;
2889
2890 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2891 slot = path->slots[i];
2892 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
2893 struct extent_buffer *node;
2894 struct btrfs_disk_key disk_key;
2895 node = path->nodes[i];
2896 path->slots[i]++;
2897 *level = i;
2898 WARN_ON(*level == 0);
2899 btrfs_node_key(node, &disk_key, path->slots[i]);
2900 memcpy(&root_item->drop_progress,
2901 &disk_key, sizeof(disk_key));
2902 root_item->drop_level = i;
2903 return 0;
2904 } else {
2905 struct extent_buffer *parent;
2906 if (path->nodes[*level] == root->node)
2907 parent = path->nodes[*level];
2908 else
2909 parent = path->nodes[*level + 1];
2910
2911 root_owner = btrfs_header_owner(parent);
2912 root_gen = btrfs_header_generation(parent);
2913 ret = btrfs_free_extent(trans, root,
2914 path->nodes[*level]->start,
2915 path->nodes[*level]->len,
2916 parent->start, root_owner,
2917 root_gen, *level, 1);
2918 BUG_ON(ret);
2919 free_extent_buffer(path->nodes[*level]);
2920 path->nodes[*level] = NULL;
2921 *level = i + 1;
2922 }
2923 }
2924 return 1;
2925 }
2926
2927 /*
2928 * drop the reference count on the tree rooted at 'snap'. This traverses
2929 * the tree freeing any blocks that have a ref count of zero after being
2930 * decremented.
2931 */
2932 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2933 *root)
2934 {
2935 int ret = 0;
2936 int wret;
2937 int level;
2938 struct btrfs_path *path;
2939 int i;
2940 int orig_level;
2941 struct btrfs_root_item *root_item = &root->root_item;
2942
2943 path = btrfs_alloc_path();
2944 BUG_ON(!path);
2945
2946 level = btrfs_header_level(root->node);
2947 orig_level = level;
2948 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2949 path->nodes[level] = root->node;
2950 extent_buffer_get(root->node);
2951 path->slots[level] = 0;
2952 } else {
2953 struct btrfs_key key;
2954 struct btrfs_disk_key found_key;
2955 struct extent_buffer *node;
2956
2957 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2958 level = root_item->drop_level;
2959 path->lowest_level = level;
2960 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2961 if (wret < 0) {
2962 ret = wret;
2963 goto out;
2964 }
2965 node = path->nodes[level];
2966 btrfs_node_key(node, &found_key, path->slots[level]);
2967 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2968 sizeof(found_key)));
2969 }
2970 while(1) {
2971 wret = walk_down_tree(trans, root, path, &level);
2972 if (wret < 0)
2973 ret = wret;
2974 if (wret != 0)
2975 break;
2976
2977 wret = walk_up_tree(trans, root, path, &level);
2978 if (wret < 0)
2979 ret = wret;
2980 if (wret != 0)
2981 break;
2982 /*
2983 ret = -EAGAIN;
2984 break;
2985 */
2986 }
2987 for (i = 0; i <= orig_level; i++) {
2988 if (path->nodes[i]) {
2989 free_extent_buffer(path->nodes[i]);
2990 path->nodes[i] = NULL;
2991 }
2992 }
2993 out:
2994 btrfs_free_path(path);
2995 return ret;
2996 }
2997
2998 #endif
2999
3000 int btrfs_free_block_groups(struct btrfs_fs_info *info)
3001 {
3002 u64 start;
3003 u64 end;
3004 u64 ptr;
3005 int ret;
3006 while(1) {
3007 ret = find_first_extent_bit(&info->block_group_cache, 0,
3008 &start, &end, (unsigned int)-1);
3009 if (ret)
3010 break;
3011 ret = get_state_private(&info->block_group_cache, start, &ptr);
3012 if (!ret)
3013 kfree((void *)(unsigned long)ptr);
3014 clear_extent_bits(&info->block_group_cache, start,
3015 end, (unsigned int)-1, GFP_NOFS);
3016 }
3017 while(1) {
3018 ret = find_first_extent_bit(&info->free_space_cache, 0,
3019 &start, &end, EXTENT_DIRTY);
3020 if (ret)
3021 break;
3022 clear_extent_dirty(&info->free_space_cache, start,
3023 end, GFP_NOFS);
3024 }
3025 return 0;
3026 }
3027
3028 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
3029 struct btrfs_key *key)
3030 {
3031 int ret;
3032 struct btrfs_key found_key;
3033 struct extent_buffer *leaf;
3034 int slot;
3035
3036 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
3037 if (ret < 0)
3038 return ret;
3039 while(1) {
3040 slot = path->slots[0];
3041 leaf = path->nodes[0];
3042 if (slot >= btrfs_header_nritems(leaf)) {
3043 ret = btrfs_next_leaf(root, path);
3044 if (ret == 0)
3045 continue;
3046 if (ret < 0)
3047 goto error;
3048 break;
3049 }
3050 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3051
3052 if (found_key.objectid >= key->objectid &&
3053 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
3054 return 0;
3055 path->slots[0]++;
3056 }
3057 ret = -ENOENT;
3058 error:
3059 return ret;
3060 }
3061
3062 int btrfs_read_block_groups(struct btrfs_root *root)
3063 {
3064 struct btrfs_path *path;
3065 int ret;
3066 int bit;
3067 struct btrfs_block_group_cache *cache;
3068 struct btrfs_fs_info *info = root->fs_info;
3069 struct btrfs_space_info *space_info;
3070 struct extent_io_tree *block_group_cache;
3071 struct btrfs_key key;
3072 struct btrfs_key found_key;
3073 struct extent_buffer *leaf;
3074
3075 block_group_cache = &info->block_group_cache;
3076
3077 root = info->extent_root;
3078 key.objectid = 0;
3079 key.offset = 0;
3080 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3081 path = btrfs_alloc_path();
3082 if (!path)
3083 return -ENOMEM;
3084
3085 while(1) {
3086 ret = find_first_block_group(root, path, &key);
3087 if (ret > 0) {
3088 ret = 0;
3089 goto error;
3090 }
3091 if (ret != 0) {
3092 goto error;
3093 }
3094 leaf = path->nodes[0];
3095 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3096 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3097 if (!cache) {
3098 ret = -ENOMEM;
3099 break;
3100 }
3101
3102 read_extent_buffer(leaf, &cache->item,
3103 btrfs_item_ptr_offset(leaf, path->slots[0]),
3104 sizeof(cache->item));
3105 memcpy(&cache->key, &found_key, sizeof(found_key));
3106 cache->cached = 0;
3107 cache->pinned = 0;
3108 key.objectid = found_key.objectid + found_key.offset;
3109 btrfs_release_path(root, path);
3110 cache->flags = btrfs_block_group_flags(&cache->item);
3111 bit = 0;
3112 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
3113 bit = BLOCK_GROUP_DATA;
3114 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
3115 bit = BLOCK_GROUP_SYSTEM;
3116 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
3117 bit = BLOCK_GROUP_METADATA;
3118 }
3119 set_avail_alloc_bits(info, cache->flags);
3120 if (btrfs_chunk_readonly(root, cache->key.objectid))
3121 cache->ro = 1;
3122
3123 ret = update_space_info(info, cache->flags, found_key.offset,
3124 btrfs_block_group_used(&cache->item),
3125 &space_info);
3126 BUG_ON(ret);
3127 cache->space_info = space_info;
3128
3129 /* use EXTENT_LOCKED to prevent merging */
3130 set_extent_bits(block_group_cache, found_key.objectid,
3131 found_key.objectid + found_key.offset - 1,
3132 bit | EXTENT_LOCKED, GFP_NOFS);
3133 set_state_private(block_group_cache, found_key.objectid,
3134 (unsigned long)cache);
3135 }
3136 ret = 0;
3137 error:
3138 btrfs_free_path(path);
3139 return ret;
3140 }
3141
3142 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
3143 struct btrfs_root *root, u64 bytes_used,
3144 u64 type, u64 chunk_objectid, u64 chunk_offset,
3145 u64 size)
3146 {
3147 int ret;
3148 int bit = 0;
3149 struct btrfs_root *extent_root;
3150 struct btrfs_block_group_cache *cache;
3151 struct extent_io_tree *block_group_cache;
3152
3153 extent_root = root->fs_info->extent_root;
3154 block_group_cache = &root->fs_info->block_group_cache;
3155
3156 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3157 BUG_ON(!cache);
3158 cache->key.objectid = chunk_offset;
3159 cache->key.offset = size;
3160
3161 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3162 btrfs_set_block_group_used(&cache->item, bytes_used);
3163 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
3164 cache->flags = type;
3165 btrfs_set_block_group_flags(&cache->item, type);
3166
3167 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
3168 &cache->space_info);
3169 BUG_ON(ret);
3170
3171 bit = block_group_state_bits(type);
3172 set_extent_bits(block_group_cache, chunk_offset,
3173 chunk_offset + size - 1,
3174 bit | EXTENT_LOCKED, GFP_NOFS);
3175
3176 set_state_private(block_group_cache, chunk_offset,
3177 (unsigned long)cache);
3178 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
3179 sizeof(cache->item));
3180 BUG_ON(ret);
3181
3182 finish_current_insert(trans, extent_root);
3183 ret = del_pending_extents(trans, extent_root);
3184 set_avail_alloc_bits(extent_root->fs_info, type);
3185 return 0;
3186 }
3187
3188 /*
3189 * This is for converter use only.
3190 *
3191 * In that case, we don't know where are free blocks located.
3192 * Therefore all block group cache entries must be setup properly
3193 * before doing any block allocation.
3194 */
3195 int btrfs_make_block_groups(struct btrfs_trans_handle *trans,
3196 struct btrfs_root *root)
3197 {
3198 u64 total_bytes;
3199 u64 cur_start;
3200 u64 group_type;
3201 u64 group_size;
3202 u64 group_align;
3203 u64 total_data = 0;
3204 u64 total_metadata = 0;
3205 u64 chunk_objectid;
3206 int ret;
3207 int bit;
3208 struct btrfs_root *extent_root;
3209 struct btrfs_block_group_cache *cache;
3210 struct extent_io_tree *block_group_cache;
3211
3212 extent_root = root->fs_info->extent_root;
3213 block_group_cache = &root->fs_info->block_group_cache;
3214 chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3215 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
3216 group_align = 64 * root->sectorsize;
3217
3218 cur_start = 0;
3219 while (cur_start < total_bytes) {
3220 group_size = total_bytes / 12;
3221 group_size = min_t(u64, group_size, total_bytes - cur_start);
3222 if (cur_start == 0) {
3223 bit = BLOCK_GROUP_SYSTEM;
3224 group_type = BTRFS_BLOCK_GROUP_SYSTEM;
3225 group_size /= 4;
3226 group_size &= ~(group_align - 1);
3227 group_size = max_t(u64, group_size, 8 * 1024 * 1024);
3228 group_size = min_t(u64, group_size, 32 * 1024 * 1024);
3229 } else {
3230 group_size &= ~(group_align - 1);
3231 if (total_data >= total_metadata * 2) {
3232 group_type = BTRFS_BLOCK_GROUP_METADATA;
3233 group_size = min_t(u64, group_size,
3234 1ULL * 1024 * 1024 * 1024);
3235 total_metadata += group_size;
3236 } else {
3237 group_type = BTRFS_BLOCK_GROUP_DATA;
3238 group_size = min_t(u64, group_size,
3239 5ULL * 1024 * 1024 * 1024);
3240 total_data += group_size;
3241 }
3242 if ((total_bytes - cur_start) * 4 < group_size * 5)
3243 group_size = total_bytes - cur_start;
3244 }
3245
3246 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3247 BUG_ON(!cache);
3248
3249 cache->key.objectid = cur_start;
3250 cache->key.offset = group_size;
3251 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3252
3253 btrfs_set_block_group_used(&cache->item, 0);
3254 btrfs_set_block_group_chunk_objectid(&cache->item,
3255 chunk_objectid);
3256 btrfs_set_block_group_flags(&cache->item, group_type);
3257
3258 cache->flags = group_type;
3259
3260 ret = update_space_info(root->fs_info, group_type, group_size,
3261 0, &cache->space_info);
3262 BUG_ON(ret);
3263 set_avail_alloc_bits(extent_root->fs_info, group_type);
3264
3265 set_extent_bits(block_group_cache, cur_start,
3266 cur_start + group_size - 1,
3267 bit | EXTENT_LOCKED, GFP_NOFS);
3268 set_state_private(block_group_cache, cur_start,
3269 (unsigned long)cache);
3270 cur_start += group_size;
3271 }
3272 /* then insert all the items */
3273 cur_start = 0;
3274 while(cur_start < total_bytes) {
3275 cache = btrfs_lookup_block_group(root->fs_info, cur_start);
3276 BUG_ON(!cache);
3277
3278 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
3279 sizeof(cache->item));
3280 BUG_ON(ret);
3281
3282 finish_current_insert(trans, extent_root);
3283 ret = del_pending_extents(trans, extent_root);
3284 BUG_ON(ret);
3285
3286 cur_start = cache->key.objectid + cache->key.offset;
3287 }
3288 return 0;
3289 }
3290
3291 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
3292 struct btrfs_root *root,
3293 u64 bytenr, u64 num_bytes, int alloc,
3294 int mark_free)
3295 {
3296 return update_block_group(trans, root, bytenr, num_bytes,
3297 alloc, mark_free);
3298 }
3299
3300 static int btrfs_count_extents_in_block_group(struct btrfs_root *root,
3301 struct btrfs_path *path, u64 start,
3302 u64 len,
3303 u64 *total)
3304 {
3305 struct btrfs_key key;
3306 struct extent_buffer *leaf;
3307 u64 bytes_used = 0;
3308 int ret;
3309 int slot;
3310
3311 key.offset = 0;
3312 key.objectid = start;
3313 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
3314 ret = btrfs_search_slot(NULL, root->fs_info->extent_root,
3315 &key, path, 0, 0);
3316 if (ret < 0)
3317 return ret;
3318 while(1) {
3319 leaf = path->nodes[0];
3320 slot = path->slots[0];
3321 if (slot >= btrfs_header_nritems(leaf)) {
3322 ret = btrfs_next_leaf(root, path);
3323 if (ret < 0)
3324 return ret;
3325 if (ret > 0)
3326 break;
3327 leaf = path->nodes[0];
3328 slot = path->slots[0];
3329 }
3330 btrfs_item_key_to_cpu(leaf, &key, slot);
3331 if (key.objectid > start + len)
3332 break;
3333 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3334 bytes_used += key.offset;
3335 path->slots[0]++;
3336 }
3337 *total = bytes_used;
3338 btrfs_release_path(root, path);
3339 return 0;
3340 }
3341
3342 int btrfs_check_block_accounting(struct btrfs_root *root)
3343 {
3344 int ret;
3345 u64 start = 0;
3346 u64 bytes_used = 0;
3347 struct btrfs_path path;
3348 struct btrfs_block_group_cache *cache;
3349 struct btrfs_fs_info *fs_info = root->fs_info;
3350
3351 btrfs_init_path(&path);
3352
3353 while(1) {
3354 cache = btrfs_lookup_block_group(fs_info, start);
3355 if (!cache)
3356 break;
3357
3358 ret = btrfs_count_extents_in_block_group(root, &path,
3359 cache->key.objectid,
3360 cache->key.offset,
3361 &bytes_used);
3362
3363 if (ret == 0) {
3364 u64 on_disk = btrfs_block_group_used(&cache->item);
3365 if (on_disk != bytes_used) {
3366 fprintf(stderr, "bad block group accounting found %llu "
3367 "expected %llu block group %llu\n",
3368 (unsigned long long)bytes_used,
3369 (unsigned long long)on_disk,
3370 (unsigned long long)cache->key.objectid);
3371 }
3372 }
3373 start = cache->key.objectid + cache->key.offset;
3374
3375 cache->space_info->bytes_used = 0;
3376 }
3377 return 0;
3378 }
3379
3380 /*
3381 * Fixup block accounting. The initial block accounting created by
3382 * make_block_groups isn't accuracy in this case.
3383 */
3384 int btrfs_fix_block_accounting(struct btrfs_trans_handle *trans,
3385 struct btrfs_root *root)
3386 {
3387 int ret;
3388 int slot;
3389 u64 start = 0;
3390 u64 bytes_used = 0;
3391 struct btrfs_path path;
3392 struct btrfs_key key;
3393 struct extent_buffer *leaf;
3394 struct btrfs_block_group_cache *cache;
3395 struct btrfs_fs_info *fs_info = root->fs_info;
3396
3397 root = root->fs_info->extent_root;
3398
3399 while(extent_root_pending_ops(fs_info)) {
3400 ret = finish_current_insert(trans, root);
3401 if (ret)
3402 return ret;
3403 ret = del_pending_extents(trans, root);
3404 if (ret)
3405 return ret;
3406 }
3407
3408 while(1) {
3409 cache = btrfs_lookup_block_group(fs_info, start);
3410 if (!cache)
3411 break;
3412 start = cache->key.objectid + cache->key.offset;
3413 btrfs_set_block_group_used(&cache->item, 0);
3414 cache->space_info->bytes_used = 0;
3415 set_extent_bits(&root->fs_info->block_group_cache,
3416 cache->key.objectid,
3417 cache->key.objectid + cache->key.offset -1,
3418 BLOCK_GROUP_DIRTY, GFP_NOFS);
3419 }
3420
3421 btrfs_init_path(&path);
3422 key.offset = 0;
3423 key.objectid = 0;
3424 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
3425 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
3426 &key, &path, 0, 0);
3427 if (ret < 0)
3428 return ret;
3429 while(1) {
3430 leaf = path.nodes[0];
3431 slot = path.slots[0];
3432 if (slot >= btrfs_header_nritems(leaf)) {
3433 ret = btrfs_next_leaf(root, &path);
3434 if (ret < 0)
3435 return ret;
3436 if (ret > 0)
3437 break;
3438 leaf = path.nodes[0];
3439 slot = path.slots[0];
3440 }
3441 btrfs_item_key_to_cpu(leaf, &key, slot);
3442 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
3443 bytes_used += key.offset;
3444 ret = btrfs_update_block_group(trans, root,
3445 key.objectid, key.offset, 1, 0);
3446 BUG_ON(ret);
3447 }
3448 path.slots[0]++;
3449 }
3450 btrfs_set_super_bytes_used(&root->fs_info->super_copy, bytes_used);
3451 btrfs_release_path(root, &path);
3452 return 0;
3453 }
(deprecated) Btrfs progs developments and patch integration