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btrfs-progs: use calloc instead of malloc+memset for tree roots
[btrfs-progs-unstable/devel.git] / extent-tree.c
blob0c8152a336b171ab5981f79db6a5dc530fd04fa5
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 <stdint.h>
22 #include "kerncompat.h"
23 #include "radix-tree.h"
24 #include "ctree.h"
25 #include "disk-io.h"
26 #include "print-tree.h"
27 #include "transaction.h"
28 #include "crc32c.h"
29 #include "volumes.h"
30 #include "free-space-cache.h"
31 #include "math.h"
32 #include "utils.h"
33
34 #define PENDING_EXTENT_INSERT 0
35 #define PENDING_EXTENT_DELETE 1
36 #define PENDING_BACKREF_UPDATE 2
37
38 struct pending_extent_op {
39 int type;
40 u64 bytenr;
41 u64 num_bytes;
42 u64 flags;
43 struct btrfs_disk_key key;
44 int level;
45 };
46
47 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
48 struct btrfs_root *root,
49 u64 root_objectid, u64 generation,
50 u64 flags, struct btrfs_disk_key *key,
51 int level, struct btrfs_key *ins);
52 static int __free_extent(struct btrfs_trans_handle *trans,
53 struct btrfs_root *root,
54 u64 bytenr, u64 num_bytes, u64 parent,
55 u64 root_objectid, u64 owner_objectid,
56 u64 owner_offset, int refs_to_drop);
57 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
58 btrfs_root *extent_root);
59 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
60 btrfs_root *extent_root);
61 static struct btrfs_block_group_cache *
62 btrfs_find_block_group(struct btrfs_root *root, struct btrfs_block_group_cache
63 *hint, u64 search_start, int data, int owner);
64
65 static int remove_sb_from_cache(struct btrfs_root *root,
66 struct btrfs_block_group_cache *cache)
67 {
68 u64 bytenr;
69 u64 *logical;
70 int stripe_len;
71 int i, nr, ret;
72 struct extent_io_tree *free_space_cache;
73
74 free_space_cache = &root->fs_info->free_space_cache;
75 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
76 bytenr = btrfs_sb_offset(i);
77 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
78 cache->key.objectid, bytenr, 0,
79 &logical, &nr, &stripe_len);
80 BUG_ON(ret);
81 while (nr--) {
82 clear_extent_dirty(free_space_cache, logical[nr],
83 logical[nr] + stripe_len - 1, GFP_NOFS);
84 }
85 kfree(logical);
86 }
87 return 0;
88 }
89
90 static int cache_block_group(struct btrfs_root *root,
91 struct btrfs_block_group_cache *block_group)
92 {
93 struct btrfs_path *path;
94 int ret;
95 struct btrfs_key key;
96 struct extent_buffer *leaf;
97 struct extent_io_tree *free_space_cache;
98 int slot;
99 u64 last;
100 u64 hole_size;
101
102 if (!block_group)
103 return 0;
104
105 root = root->fs_info->extent_root;
106 free_space_cache = &root->fs_info->free_space_cache;
107
108 if (block_group->cached)
109 return 0;
110
111 path = btrfs_alloc_path();
112 if (!path)
113 return -ENOMEM;
114
115 path->reada = 2;
116 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
117 key.objectid = last;
118 key.offset = 0;
119 key.type = 0;
120
121 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
122 if (ret < 0)
123 goto err;
124
125 while(1) {
126 leaf = path->nodes[0];
127 slot = path->slots[0];
128 if (slot >= btrfs_header_nritems(leaf)) {
129 ret = btrfs_next_leaf(root, path);
130 if (ret < 0)
131 goto err;
132 if (ret == 0) {
133 continue;
134 } else {
135 break;
136 }
137 }
138 btrfs_item_key_to_cpu(leaf, &key, slot);
139 if (key.objectid < block_group->key.objectid) {
140 goto next;
141 }
142 if (key.objectid >= block_group->key.objectid +
143 block_group->key.offset) {
144 break;
145 }
146
147 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
148 key.type == BTRFS_METADATA_ITEM_KEY) {
149 if (key.objectid > last) {
150 hole_size = key.objectid - last;
151 set_extent_dirty(free_space_cache, last,
152 last + hole_size - 1,
153 GFP_NOFS);
154 }
155 if (key.type == BTRFS_METADATA_ITEM_KEY)
156 last = key.objectid + root->leafsize;
157 else
158 last = key.objectid + key.offset;
159 }
160 next:
161 path->slots[0]++;
162 }
163
164 if (block_group->key.objectid +
165 block_group->key.offset > last) {
166 hole_size = block_group->key.objectid +
167 block_group->key.offset - last;
168 set_extent_dirty(free_space_cache, last,
169 last + hole_size - 1, GFP_NOFS);
170 }
171 remove_sb_from_cache(root, block_group);
172 block_group->cached = 1;
173 err:
174 btrfs_free_path(path);
175 return 0;
176 }
177
178 struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
179 btrfs_fs_info *info,
180 u64 bytenr)
181 {
182 struct extent_io_tree *block_group_cache;
183 struct btrfs_block_group_cache *block_group = NULL;
184 u64 ptr;
185 u64 start;
186 u64 end;
187 int ret;
188
189 bytenr = max_t(u64, bytenr,
190 BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
191 block_group_cache = &info->block_group_cache;
192 ret = find_first_extent_bit(block_group_cache,
193 bytenr, &start, &end,
194 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
195 BLOCK_GROUP_SYSTEM);
196 if (ret) {
197 return NULL;
198 }
199 ret = get_state_private(block_group_cache, start, &ptr);
200 if (ret)
201 return NULL;
202
203 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
204 return block_group;
205 }
206
207 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
208 btrfs_fs_info *info,
209 u64 bytenr)
210 {
211 struct extent_io_tree *block_group_cache;
212 struct btrfs_block_group_cache *block_group = NULL;
213 u64 ptr;
214 u64 start;
215 u64 end;
216 int ret;
217
218 block_group_cache = &info->block_group_cache;
219 ret = find_first_extent_bit(block_group_cache,
220 bytenr, &start, &end,
221 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
222 BLOCK_GROUP_SYSTEM);
223 if (ret) {
224 return NULL;
225 }
226 ret = get_state_private(block_group_cache, start, &ptr);
227 if (ret)
228 return NULL;
229
230 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
231 if (block_group->key.objectid <= bytenr && bytenr <
232 block_group->key.objectid + block_group->key.offset)
233 return block_group;
234 return NULL;
235 }
236
237 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
238 {
239 return (cache->flags & bits) == bits;
240 }
241
242 static int noinline find_search_start(struct btrfs_root *root,
243 struct btrfs_block_group_cache **cache_ret,
244 u64 *start_ret, int num, int data)
245 {
246 int ret;
247 struct btrfs_block_group_cache *cache = *cache_ret;
248 u64 last = *start_ret;
249 u64 start = 0;
250 u64 end = 0;
251 u64 search_start = *start_ret;
252 int wrapped = 0;
253
254 if (!cache)
255 goto out;
256 again:
257 ret = cache_block_group(root, cache);
258 if (ret)
259 goto out;
260
261 last = max(search_start, cache->key.objectid);
262 if (cache->ro || !block_group_bits(cache, data))
263 goto new_group;
264
265 while(1) {
266 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
267 last, &start, &end, EXTENT_DIRTY);
268 if (ret) {
269 goto new_group;
270 }
271
272 start = max(last, start);
273 last = end + 1;
274 if (last - start < num) {
275 continue;
276 }
277 if (start + num > cache->key.objectid + cache->key.offset) {
278 goto new_group;
279 }
280 *start_ret = start;
281 return 0;
282 }
283 out:
284 *start_ret = last;
285 cache = btrfs_lookup_block_group(root->fs_info, search_start);
286 if (!cache) {
287 printk("Unable to find block group for %llu\n",
288 (unsigned long long)search_start);
289 WARN_ON(1);
290 }
291 return -ENOSPC;
292
293 new_group:
294 last = cache->key.objectid + cache->key.offset;
295 wrapped:
296 cache = btrfs_lookup_first_block_group(root->fs_info, last);
297 if (!cache) {
298 if (!wrapped) {
299 wrapped = 1;
300 last = search_start;
301 goto wrapped;
302 }
303 goto out;
304 }
305 *cache_ret = cache;
306 goto again;
307 }
308
309 static int block_group_state_bits(u64 flags)
310 {
311 int bits = 0;
312 if (flags & BTRFS_BLOCK_GROUP_DATA)
313 bits |= BLOCK_GROUP_DATA;
314 if (flags & BTRFS_BLOCK_GROUP_METADATA)
315 bits |= BLOCK_GROUP_METADATA;
316 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
317 bits |= BLOCK_GROUP_SYSTEM;
318 return bits;
319 }
320
321 static struct btrfs_block_group_cache *
322 btrfs_find_block_group(struct btrfs_root *root, struct btrfs_block_group_cache
323 *hint, u64 search_start, int data, int owner)
324 {
325 struct btrfs_block_group_cache *cache;
326 struct extent_io_tree *block_group_cache;
327 struct btrfs_block_group_cache *found_group = NULL;
328 struct btrfs_fs_info *info = root->fs_info;
329 u64 used;
330 u64 last = 0;
331 u64 hint_last;
332 u64 start;
333 u64 end;
334 u64 free_check;
335 u64 ptr;
336 int bit;
337 int ret;
338 int full_search = 0;
339 int factor = 10;
340
341 block_group_cache = &info->block_group_cache;
342
343 if (!owner)
344 factor = 10;
345
346 bit = block_group_state_bits(data);
347
348 if (search_start) {
349 struct btrfs_block_group_cache *shint;
350 shint = btrfs_lookup_block_group(info, search_start);
351 if (shint && !shint->ro && block_group_bits(shint, data)) {
352 used = btrfs_block_group_used(&shint->item);
353 if (used + shint->pinned <
354 div_factor(shint->key.offset, factor)) {
355 return shint;
356 }
357 }
358 }
359 if (hint && !hint->ro && block_group_bits(hint, data)) {
360 used = btrfs_block_group_used(&hint->item);
361 if (used + hint->pinned <
362 div_factor(hint->key.offset, factor)) {
363 return hint;
364 }
365 last = hint->key.objectid + hint->key.offset;
366 hint_last = last;
367 } else {
368 if (hint)
369 hint_last = max(hint->key.objectid, search_start);
370 else
371 hint_last = search_start;
372
373 last = hint_last;
374 }
375 again:
376 while(1) {
377 ret = find_first_extent_bit(block_group_cache, last,
378 &start, &end, bit);
379 if (ret)
380 break;
381
382 ret = get_state_private(block_group_cache, start, &ptr);
383 if (ret)
384 break;
385
386 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
387 last = cache->key.objectid + cache->key.offset;
388 used = btrfs_block_group_used(&cache->item);
389
390 if (!cache->ro && block_group_bits(cache, data)) {
391 if (full_search)
392 free_check = cache->key.offset;
393 else
394 free_check = div_factor(cache->key.offset,
395 factor);
396
397 if (used + cache->pinned < free_check) {
398 found_group = cache;
399 goto found;
400 }
401 }
402 cond_resched();
403 }
404 if (!full_search) {
405 last = search_start;
406 full_search = 1;
407 goto again;
408 }
409 found:
410 return found_group;
411 }
412
413 /*
414 * Back reference rules. Back refs have three main goals:
415 *
416 * 1) differentiate between all holders of references to an extent so that
417 * when a reference is dropped we can make sure it was a valid reference
418 * before freeing the extent.
419 *
420 * 2) Provide enough information to quickly find the holders of an extent
421 * if we notice a given block is corrupted or bad.
422 *
423 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
424 * maintenance. This is actually the same as #2, but with a slightly
425 * different use case.
426 *
427 * There are two kinds of back refs. The implicit back refs is optimized
428 * for pointers in non-shared tree blocks. For a given pointer in a block,
429 * back refs of this kind provide information about the block's owner tree
430 * and the pointer's key. These information allow us to find the block by
431 * b-tree searching. The full back refs is for pointers in tree blocks not
432 * referenced by their owner trees. The location of tree block is recorded
433 * in the back refs. Actually the full back refs is generic, and can be
434 * used in all cases the implicit back refs is used. The major shortcoming
435 * of the full back refs is its overhead. Every time a tree block gets
436 * COWed, we have to update back refs entry for all pointers in it.
437 *
438 * For a newly allocated tree block, we use implicit back refs for
439 * pointers in it. This means most tree related operations only involve
440 * implicit back refs. For a tree block created in old transaction, the
441 * only way to drop a reference to it is COW it. So we can detect the
442 * event that tree block loses its owner tree's reference and do the
443 * back refs conversion.
444 *
445 * When a tree block is COW'd through a tree, there are four cases:
446 *
447 * The reference count of the block is one and the tree is the block's
448 * owner tree. Nothing to do in this case.
449 *
450 * The reference count of the block is one and the tree is not the
451 * block's owner tree. In this case, full back refs is used for pointers
452 * in the block. Remove these full back refs, add implicit back refs for
453 * every pointers in the new block.
454 *
455 * The reference count of the block is greater than one and the tree is
456 * the block's owner tree. In this case, implicit back refs is used for
457 * pointers in the block. Add full back refs for every pointers in the
458 * block, increase lower level extents' reference counts. The original
459 * implicit back refs are entailed to the new block.
460 *
461 * The reference count of the block is greater than one and the tree is
462 * not the block's owner tree. Add implicit back refs for every pointer in
463 * the new block, increase lower level extents' reference count.
464 *
465 * Back Reference Key composing:
466 *
467 * The key objectid corresponds to the first byte in the extent,
468 * The key type is used to differentiate between types of back refs.
469 * There are different meanings of the key offset for different types
470 * of back refs.
471 *
472 * File extents can be referenced by:
473 *
474 * - multiple snapshots, subvolumes, or different generations in one subvol
475 * - different files inside a single subvolume
476 * - different offsets inside a file (bookend extents in file.c)
477 *
478 * The extent ref structure for the implicit back refs has fields for:
479 *
480 * - Objectid of the subvolume root
481 * - objectid of the file holding the reference
482 * - original offset in the file
483 * - how many bookend extents
484 *
485 * The key offset for the implicit back refs is hash of the first
486 * three fields.
487 *
488 * The extent ref structure for the full back refs has field for:
489 *
490 * - number of pointers in the tree leaf
491 *
492 * The key offset for the implicit back refs is the first byte of
493 * the tree leaf
494 *
495 * When a file extent is allocated, The implicit back refs is used.
496 * the fields are filled in:
497 *
498 * (root_key.objectid, inode objectid, offset in file, 1)
499 *
500 * When a file extent is removed file truncation, we find the
501 * corresponding implicit back refs and check the following fields:
502 *
503 * (btrfs_header_owner(leaf), inode objectid, offset in file)
504 *
505 * Btree extents can be referenced by:
506 *
507 * - Different subvolumes
508 *
509 * Both the implicit back refs and the full back refs for tree blocks
510 * only consist of key. The key offset for the implicit back refs is
511 * objectid of block's owner tree. The key offset for the full back refs
512 * is the first byte of parent block.
513 *
514 * When implicit back refs is used, information about the lowest key and
515 * level of the tree block are required. These information are stored in
516 * tree block info structure.
517 */
518
519 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
520 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
521 struct btrfs_root *root,
522 struct btrfs_path *path,
523 u64 owner, u32 extra_size)
524 {
525 struct btrfs_extent_item *item;
526 struct btrfs_extent_item_v0 *ei0;
527 struct btrfs_extent_ref_v0 *ref0;
528 struct btrfs_tree_block_info *bi;
529 struct extent_buffer *leaf;
530 struct btrfs_key key;
531 struct btrfs_key found_key;
532 u32 new_size = sizeof(*item);
533 u64 refs;
534 int ret;
535
536 leaf = path->nodes[0];
537 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
538
539 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
540 ei0 = btrfs_item_ptr(leaf, path->slots[0],
541 struct btrfs_extent_item_v0);
542 refs = btrfs_extent_refs_v0(leaf, ei0);
543
544 if (owner == (u64)-1) {
545 while (1) {
546 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
547 ret = btrfs_next_leaf(root, path);
548 if (ret < 0)
549 return ret;
550 BUG_ON(ret > 0);
551 leaf = path->nodes[0];
552 }
553 btrfs_item_key_to_cpu(leaf, &found_key,
554 path->slots[0]);
555 BUG_ON(key.objectid != found_key.objectid);
556 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
557 path->slots[0]++;
558 continue;
559 }
560 ref0 = btrfs_item_ptr(leaf, path->slots[0],
561 struct btrfs_extent_ref_v0);
562 owner = btrfs_ref_objectid_v0(leaf, ref0);
563 break;
564 }
565 }
566 btrfs_release_path(path);
567
568 if (owner < BTRFS_FIRST_FREE_OBJECTID)
569 new_size += sizeof(*bi);
570
571 new_size -= sizeof(*ei0);
572 ret = btrfs_search_slot(trans, root, &key, path, new_size, 1);
573 if (ret < 0)
574 return ret;
575 BUG_ON(ret);
576
577 ret = btrfs_extend_item(trans, root, path, new_size);
578 BUG_ON(ret);
579
580 leaf = path->nodes[0];
581 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
582 btrfs_set_extent_refs(leaf, item, refs);
583 /* FIXME: get real generation */
584 btrfs_set_extent_generation(leaf, item, 0);
585 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
586 btrfs_set_extent_flags(leaf, item,
587 BTRFS_EXTENT_FLAG_TREE_BLOCK |
588 BTRFS_BLOCK_FLAG_FULL_BACKREF);
589 bi = (struct btrfs_tree_block_info *)(item + 1);
590 /* FIXME: get first key of the block */
591 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
592 btrfs_set_tree_block_level(leaf, bi, (int)owner);
593 } else {
594 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
595 }
596 btrfs_mark_buffer_dirty(leaf);
597 return 0;
598 }
599 #endif
600
601 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
602 {
603 u32 high_crc = ~(u32)0;
604 u32 low_crc = ~(u32)0;
605 __le64 lenum;
606
607 lenum = cpu_to_le64(root_objectid);
608 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
609 lenum = cpu_to_le64(owner);
610 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
611 lenum = cpu_to_le64(offset);
612 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
613
614 return ((u64)high_crc << 31) ^ (u64)low_crc;
615 }
616
617 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
618 struct btrfs_extent_data_ref *ref)
619 {
620 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
621 btrfs_extent_data_ref_objectid(leaf, ref),
622 btrfs_extent_data_ref_offset(leaf, ref));
623 }
624
625 static int match_extent_data_ref(struct extent_buffer *leaf,
626 struct btrfs_extent_data_ref *ref,
627 u64 root_objectid, u64 owner, u64 offset)
628 {
629 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
630 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
631 btrfs_extent_data_ref_offset(leaf, ref) != offset)
632 return 0;
633 return 1;
634 }
635
636 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
637 struct btrfs_root *root,
638 struct btrfs_path *path,
639 u64 bytenr, u64 parent,
640 u64 root_objectid,
641 u64 owner, u64 offset)
642 {
643 struct btrfs_key key;
644 struct btrfs_extent_data_ref *ref;
645 struct extent_buffer *leaf;
646 u32 nritems;
647 int ret;
648 int recow;
649 int err = -ENOENT;
650
651 key.objectid = bytenr;
652 if (parent) {
653 key.type = BTRFS_SHARED_DATA_REF_KEY;
654 key.offset = parent;
655 } else {
656 key.type = BTRFS_EXTENT_DATA_REF_KEY;
657 key.offset = hash_extent_data_ref(root_objectid,
658 owner, offset);
659 }
660 again:
661 recow = 0;
662 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
663 if (ret < 0) {
664 err = ret;
665 goto fail;
666 }
667
668 if (parent) {
669 if (!ret)
670 return 0;
671 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
672 key.type = BTRFS_EXTENT_REF_V0_KEY;
673 btrfs_release_path(path);
674 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
675 if (ret < 0) {
676 err = ret;
677 goto fail;
678 }
679 if (!ret)
680 return 0;
681 #endif
682 goto fail;
683 }
684
685 leaf = path->nodes[0];
686 nritems = btrfs_header_nritems(leaf);
687 while (1) {
688 if (path->slots[0] >= nritems) {
689 ret = btrfs_next_leaf(root, path);
690 if (ret < 0)
691 err = ret;
692 if (ret)
693 goto fail;
694
695 leaf = path->nodes[0];
696 nritems = btrfs_header_nritems(leaf);
697 recow = 1;
698 }
699
700 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
701 if (key.objectid != bytenr ||
702 key.type != BTRFS_EXTENT_DATA_REF_KEY)
703 goto fail;
704
705 ref = btrfs_item_ptr(leaf, path->slots[0],
706 struct btrfs_extent_data_ref);
707
708 if (match_extent_data_ref(leaf, ref, root_objectid,
709 owner, offset)) {
710 if (recow) {
711 btrfs_release_path(path);
712 goto again;
713 }
714 err = 0;
715 break;
716 }
717 path->slots[0]++;
718 }
719 fail:
720 return err;
721 }
722
723 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
724 struct btrfs_root *root,
725 struct btrfs_path *path,
726 u64 bytenr, u64 parent,
727 u64 root_objectid, u64 owner,
728 u64 offset, int refs_to_add)
729 {
730 struct btrfs_key key;
731 struct extent_buffer *leaf;
732 u32 size;
733 u32 num_refs;
734 int ret;
735
736 key.objectid = bytenr;
737 if (parent) {
738 key.type = BTRFS_SHARED_DATA_REF_KEY;
739 key.offset = parent;
740 size = sizeof(struct btrfs_shared_data_ref);
741 } else {
742 key.type = BTRFS_EXTENT_DATA_REF_KEY;
743 key.offset = hash_extent_data_ref(root_objectid,
744 owner, offset);
745 size = sizeof(struct btrfs_extent_data_ref);
746 }
747
748 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
749 if (ret && ret != -EEXIST)
750 goto fail;
751
752 leaf = path->nodes[0];
753 if (parent) {
754 struct btrfs_shared_data_ref *ref;
755 ref = btrfs_item_ptr(leaf, path->slots[0],
756 struct btrfs_shared_data_ref);
757 if (ret == 0) {
758 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
759 } else {
760 num_refs = btrfs_shared_data_ref_count(leaf, ref);
761 num_refs += refs_to_add;
762 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
763 }
764 } else {
765 struct btrfs_extent_data_ref *ref;
766 while (ret == -EEXIST) {
767 ref = btrfs_item_ptr(leaf, path->slots[0],
768 struct btrfs_extent_data_ref);
769 if (match_extent_data_ref(leaf, ref, root_objectid,
770 owner, offset))
771 break;
772 btrfs_release_path(path);
773
774 key.offset++;
775 ret = btrfs_insert_empty_item(trans, root, path, &key,
776 size);
777 if (ret && ret != -EEXIST)
778 goto fail;
779
780 leaf = path->nodes[0];
781 }
782 ref = btrfs_item_ptr(leaf, path->slots[0],
783 struct btrfs_extent_data_ref);
784 if (ret == 0) {
785 btrfs_set_extent_data_ref_root(leaf, ref,
786 root_objectid);
787 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
788 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
789 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
790 } else {
791 num_refs = btrfs_extent_data_ref_count(leaf, ref);
792 num_refs += refs_to_add;
793 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
794 }
795 }
796 btrfs_mark_buffer_dirty(leaf);
797 ret = 0;
798 fail:
799 btrfs_release_path(path);
800 return ret;
801 }
802
803 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
804 struct btrfs_root *root,
805 struct btrfs_path *path,
806 int refs_to_drop)
807 {
808 struct btrfs_key key;
809 struct btrfs_extent_data_ref *ref1 = NULL;
810 struct btrfs_shared_data_ref *ref2 = NULL;
811 struct extent_buffer *leaf;
812 u32 num_refs = 0;
813 int ret = 0;
814
815 leaf = path->nodes[0];
816 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
817
818 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
819 ref1 = btrfs_item_ptr(leaf, path->slots[0],
820 struct btrfs_extent_data_ref);
821 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
822 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
823 ref2 = btrfs_item_ptr(leaf, path->slots[0],
824 struct btrfs_shared_data_ref);
825 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
826 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
827 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
828 struct btrfs_extent_ref_v0 *ref0;
829 ref0 = btrfs_item_ptr(leaf, path->slots[0],
830 struct btrfs_extent_ref_v0);
831 num_refs = btrfs_ref_count_v0(leaf, ref0);
832 #endif
833 } else {
834 BUG();
835 }
836
837 BUG_ON(num_refs < refs_to_drop);
838 num_refs -= refs_to_drop;
839
840 if (num_refs == 0) {
841 ret = btrfs_del_item(trans, root, path);
842 } else {
843 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
844 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
845 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
846 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
847 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
848 else {
849 struct btrfs_extent_ref_v0 *ref0;
850 ref0 = btrfs_item_ptr(leaf, path->slots[0],
851 struct btrfs_extent_ref_v0);
852 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
853 }
854 #endif
855 btrfs_mark_buffer_dirty(leaf);
856 }
857 return ret;
858 }
859
860 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
861 struct btrfs_path *path,
862 struct btrfs_extent_inline_ref *iref)
863 {
864 struct btrfs_key key;
865 struct extent_buffer *leaf;
866 struct btrfs_extent_data_ref *ref1;
867 struct btrfs_shared_data_ref *ref2;
868 u32 num_refs = 0;
869
870 leaf = path->nodes[0];
871 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
872 if (iref) {
873 if (btrfs_extent_inline_ref_type(leaf, iref) ==
874 BTRFS_EXTENT_DATA_REF_KEY) {
875 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
876 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
877 } else {
878 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
879 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
880 }
881 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
882 ref1 = btrfs_item_ptr(leaf, path->slots[0],
883 struct btrfs_extent_data_ref);
884 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
885 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
886 ref2 = btrfs_item_ptr(leaf, path->slots[0],
887 struct btrfs_shared_data_ref);
888 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
889 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
890 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
891 struct btrfs_extent_ref_v0 *ref0;
892 ref0 = btrfs_item_ptr(leaf, path->slots[0],
893 struct btrfs_extent_ref_v0);
894 num_refs = btrfs_ref_count_v0(leaf, ref0);
895 #endif
896 } else {
897 BUG();
898 }
899 return num_refs;
900 }
901
902 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
903 struct btrfs_root *root,
904 struct btrfs_path *path,
905 u64 bytenr, u64 parent,
906 u64 root_objectid)
907 {
908 struct btrfs_key key;
909 int ret;
910
911 key.objectid = bytenr;
912 if (parent) {
913 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
914 key.offset = parent;
915 } else {
916 key.type = BTRFS_TREE_BLOCK_REF_KEY;
917 key.offset = root_objectid;
918 }
919
920 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
921 if (ret > 0)
922 ret = -ENOENT;
923 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
924 if (ret == -ENOENT && parent) {
925 btrfs_release_path(path);
926 key.type = BTRFS_EXTENT_REF_V0_KEY;
927 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
928 if (ret > 0)
929 ret = -ENOENT;
930 }
931 #endif
932 return ret;
933 }
934
935 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
936 struct btrfs_root *root,
937 struct btrfs_path *path,
938 u64 bytenr, u64 parent,
939 u64 root_objectid)
940 {
941 struct btrfs_key key;
942 int ret;
943
944 key.objectid = bytenr;
945 if (parent) {
946 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
947 key.offset = parent;
948 } else {
949 key.type = BTRFS_TREE_BLOCK_REF_KEY;
950 key.offset = root_objectid;
951 }
952
953 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
954
955 btrfs_release_path(path);
956 return ret;
957 }
958
959 static inline int extent_ref_type(u64 parent, u64 owner)
960 {
961 int type;
962 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
963 if (parent > 0)
964 type = BTRFS_SHARED_BLOCK_REF_KEY;
965 else
966 type = BTRFS_TREE_BLOCK_REF_KEY;
967 } else {
968 if (parent > 0)
969 type = BTRFS_SHARED_DATA_REF_KEY;
970 else
971 type = BTRFS_EXTENT_DATA_REF_KEY;
972 }
973 return type;
974 }
975
976 static int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
977 struct btrfs_root *root,
978 struct btrfs_path *path,
979 struct btrfs_extent_inline_ref **ref_ret,
980 u64 bytenr, u64 num_bytes,
981 u64 parent, u64 root_objectid,
982 u64 owner, u64 offset, int insert)
983 {
984 struct btrfs_key key;
985 struct extent_buffer *leaf;
986 struct btrfs_extent_item *ei;
987 struct btrfs_extent_inline_ref *iref;
988 u64 flags;
989 u32 item_size;
990 unsigned long ptr;
991 unsigned long end;
992 int extra_size;
993 int type;
994 int want;
995 int ret;
996 int err = 0;
997 int skinny_metadata =
998 btrfs_fs_incompat(root->fs_info,
999 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
1000
1001 key.objectid = bytenr;
1002 key.type = BTRFS_EXTENT_ITEM_KEY;
1003 key.offset = num_bytes;
1004
1005 want = extent_ref_type(parent, owner);
1006 if (insert)
1007 extra_size = btrfs_extent_inline_ref_size(want);
1008 else
1009 extra_size = -1;
1010
1011 if (owner < BTRFS_FIRST_FREE_OBJECTID && skinny_metadata) {
1012 skinny_metadata = 1;
1013 key.type = BTRFS_METADATA_ITEM_KEY;
1014 key.offset = owner;
1015 } else if (skinny_metadata) {
1016 skinny_metadata = 0;
1017 }
1018
1019 again:
1020 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1021 if (ret < 0) {
1022 err = ret;
1023 goto out;
1024 }
1025
1026 /*
1027 * We may be a newly converted file system which still has the old fat
1028 * extent entries for metadata, so try and see if we have one of those.
1029 */
1030 if (ret > 0 && skinny_metadata) {
1031 skinny_metadata = 0;
1032 if (path->slots[0]) {
1033 path->slots[0]--;
1034 btrfs_item_key_to_cpu(path->nodes[0], &key,
1035 path->slots[0]);
1036 if (key.objectid == bytenr &&
1037 key.type == BTRFS_EXTENT_ITEM_KEY &&
1038 key.offset == num_bytes)
1039 ret = 0;
1040 }
1041 if (ret) {
1042 key.type = BTRFS_EXTENT_ITEM_KEY;
1043 key.offset = num_bytes;
1044 btrfs_release_path(path);
1045 goto again;
1046 }
1047 }
1048
1049 if (ret) {
1050 printf("Failed to find [%llu, %u, %llu]\n", key.objectid, key.type, key.offset);
1051 return -ENOENT;
1052 }
1053
1054 BUG_ON(ret);
1055
1056 leaf = path->nodes[0];
1057 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1058 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1059 if (item_size < sizeof(*ei)) {
1060 if (!insert) {
1061 err = -ENOENT;
1062 goto out;
1063 }
1064 ret = convert_extent_item_v0(trans, root, path, owner,
1065 extra_size);
1066 if (ret < 0) {
1067 err = ret;
1068 goto out;
1069 }
1070 leaf = path->nodes[0];
1071 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1072 }
1073 #endif
1074 if (item_size < sizeof(*ei)) {
1075 printf("Size is %u, needs to be %u, slot %d\n",
1076 (unsigned)item_size,
1077 (unsigned)sizeof(*ei), path->slots[0]);
1078 btrfs_print_leaf(root, leaf);
1079 return -EINVAL;
1080 }
1081 BUG_ON(item_size < sizeof(*ei));
1082
1083 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1084 flags = btrfs_extent_flags(leaf, ei);
1085
1086 ptr = (unsigned long)(ei + 1);
1087 end = (unsigned long)ei + item_size;
1088
1089 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
1090 ptr += sizeof(struct btrfs_tree_block_info);
1091 BUG_ON(ptr > end);
1092 } else if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
1093 if (!(flags & BTRFS_EXTENT_FLAG_DATA)) {
1094 return -EIO;
1095 }
1096 }
1097
1098 err = -ENOENT;
1099 while (1) {
1100 if (ptr >= end) {
1101 WARN_ON(ptr > end);
1102 break;
1103 }
1104 iref = (struct btrfs_extent_inline_ref *)ptr;
1105 type = btrfs_extent_inline_ref_type(leaf, iref);
1106 if (want < type)
1107 break;
1108 if (want > type) {
1109 ptr += btrfs_extent_inline_ref_size(type);
1110 continue;
1111 }
1112
1113 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1114 struct btrfs_extent_data_ref *dref;
1115 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1116 if (match_extent_data_ref(leaf, dref, root_objectid,
1117 owner, offset)) {
1118 err = 0;
1119 break;
1120 }
1121 if (hash_extent_data_ref_item(leaf, dref) <
1122 hash_extent_data_ref(root_objectid, owner, offset))
1123 break;
1124 } else {
1125 u64 ref_offset;
1126 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1127 if (parent > 0) {
1128 if (parent == ref_offset) {
1129 err = 0;
1130 break;
1131 }
1132 if (ref_offset < parent)
1133 break;
1134 } else {
1135 if (root_objectid == ref_offset) {
1136 err = 0;
1137 break;
1138 }
1139 if (ref_offset < root_objectid)
1140 break;
1141 }
1142 }
1143 ptr += btrfs_extent_inline_ref_size(type);
1144 }
1145 if (err == -ENOENT && insert) {
1146 if (item_size + extra_size >=
1147 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1148 err = -EAGAIN;
1149 goto out;
1150 }
1151 /*
1152 * To add new inline back ref, we have to make sure
1153 * there is no corresponding back ref item.
1154 * For simplicity, we just do not add new inline back
1155 * ref if there is any back ref item.
1156 */
1157 if (find_next_key(path, &key) == 0 && key.objectid == bytenr &&
1158 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1159 err = -EAGAIN;
1160 goto out;
1161 }
1162 }
1163 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1164 out:
1165 return err;
1166 }
1167
1168 static int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
1169 struct btrfs_root *root,
1170 struct btrfs_path *path,
1171 struct btrfs_extent_inline_ref *iref,
1172 u64 parent, u64 root_objectid,
1173 u64 owner, u64 offset, int refs_to_add)
1174 {
1175 struct extent_buffer *leaf;
1176 struct btrfs_extent_item *ei;
1177 unsigned long ptr;
1178 unsigned long end;
1179 unsigned long item_offset;
1180 u64 refs;
1181 int size;
1182 int type;
1183 int ret;
1184
1185 leaf = path->nodes[0];
1186 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1187 item_offset = (unsigned long)iref - (unsigned long)ei;
1188
1189 type = extent_ref_type(parent, owner);
1190 size = btrfs_extent_inline_ref_size(type);
1191
1192 ret = btrfs_extend_item(trans, root, path, size);
1193 BUG_ON(ret);
1194
1195 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1196 refs = btrfs_extent_refs(leaf, ei);
1197 refs += refs_to_add;
1198 btrfs_set_extent_refs(leaf, ei, refs);
1199
1200 ptr = (unsigned long)ei + item_offset;
1201 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1202 if (ptr < end - size)
1203 memmove_extent_buffer(leaf, ptr + size, ptr,
1204 end - size - ptr);
1205
1206 iref = (struct btrfs_extent_inline_ref *)ptr;
1207 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1208 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1209 struct btrfs_extent_data_ref *dref;
1210 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1211 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1212 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1213 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1214 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1215 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1216 struct btrfs_shared_data_ref *sref;
1217 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1218 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1219 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1220 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1221 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1222 } else {
1223 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1224 }
1225 btrfs_mark_buffer_dirty(leaf);
1226 return 0;
1227 }
1228
1229 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1230 struct btrfs_root *root,
1231 struct btrfs_path *path,
1232 struct btrfs_extent_inline_ref **ref_ret,
1233 u64 bytenr, u64 num_bytes, u64 parent,
1234 u64 root_objectid, u64 owner, u64 offset)
1235 {
1236 int ret;
1237
1238 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1239 bytenr, num_bytes, parent,
1240 root_objectid, owner, offset, 0);
1241 if (ret != -ENOENT)
1242 return ret;
1243
1244 btrfs_release_path(path);
1245 *ref_ret = NULL;
1246
1247 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1248 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1249 root_objectid);
1250 } else {
1251 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1252 root_objectid, owner, offset);
1253 }
1254 return ret;
1255 }
1256
1257 static int update_inline_extent_backref(struct btrfs_trans_handle *trans,
1258 struct btrfs_root *root,
1259 struct btrfs_path *path,
1260 struct btrfs_extent_inline_ref *iref,
1261 int refs_to_mod)
1262 {
1263 struct extent_buffer *leaf;
1264 struct btrfs_extent_item *ei;
1265 struct btrfs_extent_data_ref *dref = NULL;
1266 struct btrfs_shared_data_ref *sref = NULL;
1267 unsigned long ptr;
1268 unsigned long end;
1269 u32 item_size;
1270 int size;
1271 int type;
1272 int ret;
1273 u64 refs;
1274
1275 leaf = path->nodes[0];
1276 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1277 refs = btrfs_extent_refs(leaf, ei);
1278 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1279 refs += refs_to_mod;
1280 btrfs_set_extent_refs(leaf, ei, refs);
1281
1282 type = btrfs_extent_inline_ref_type(leaf, iref);
1283
1284 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1285 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1286 refs = btrfs_extent_data_ref_count(leaf, dref);
1287 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1288 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1289 refs = btrfs_shared_data_ref_count(leaf, sref);
1290 } else {
1291 refs = 1;
1292 BUG_ON(refs_to_mod != -1);
1293 }
1294
1295 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1296 refs += refs_to_mod;
1297
1298 if (refs > 0) {
1299 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1300 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1301 else
1302 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1303 } else {
1304 size = btrfs_extent_inline_ref_size(type);
1305 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1306 ptr = (unsigned long)iref;
1307 end = (unsigned long)ei + item_size;
1308 if (ptr + size < end)
1309 memmove_extent_buffer(leaf, ptr, ptr + size,
1310 end - ptr - size);
1311 item_size -= size;
1312 ret = btrfs_truncate_item(trans, root, path, item_size, 1);
1313 BUG_ON(ret);
1314 }
1315 btrfs_mark_buffer_dirty(leaf);
1316 return 0;
1317 }
1318
1319 static int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1320 struct btrfs_root *root,
1321 struct btrfs_path *path,
1322 u64 bytenr, u64 num_bytes, u64 parent,
1323 u64 root_objectid, u64 owner,
1324 u64 offset, int refs_to_add)
1325 {
1326 struct btrfs_extent_inline_ref *iref;
1327 int ret;
1328
1329 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1330 bytenr, num_bytes, parent,
1331 root_objectid, owner, offset, 1);
1332 if (ret == 0) {
1333 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1334 ret = update_inline_extent_backref(trans, root, path, iref,
1335 refs_to_add);
1336 } else if (ret == -ENOENT) {
1337 ret = setup_inline_extent_backref(trans, root, path, iref,
1338 parent, root_objectid,
1339 owner, offset, refs_to_add);
1340 }
1341 return ret;
1342 }
1343
1344 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1345 struct btrfs_root *root,
1346 struct btrfs_path *path,
1347 u64 bytenr, u64 parent, u64 root_objectid,
1348 u64 owner, u64 offset, int refs_to_add)
1349 {
1350 int ret;
1351
1352 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
1353 ret = insert_extent_data_ref(trans, root, path, bytenr,
1354 parent, root_objectid,
1355 owner, offset, refs_to_add);
1356 } else {
1357 BUG_ON(refs_to_add != 1);
1358 ret = insert_tree_block_ref(trans, root, path, bytenr,
1359 parent, root_objectid);
1360 }
1361 return ret;
1362 }
1363
1364 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1365 struct btrfs_root *root,
1366 struct btrfs_path *path,
1367 struct btrfs_extent_inline_ref *iref,
1368 int refs_to_drop, int is_data)
1369 {
1370 int ret;
1371
1372 BUG_ON(!is_data && refs_to_drop != 1);
1373 if (iref) {
1374 ret = update_inline_extent_backref(trans, root, path, iref,
1375 -refs_to_drop);
1376 } else if (is_data) {
1377 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1378 } else {
1379 ret = btrfs_del_item(trans, root, path);
1380 }
1381 return ret;
1382 }
1383
1384 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1385 struct btrfs_root *root,
1386 u64 bytenr, u64 num_bytes, u64 parent,
1387 u64 root_objectid, u64 owner, u64 offset)
1388 {
1389 struct btrfs_path *path;
1390 struct extent_buffer *leaf;
1391 struct btrfs_extent_item *item;
1392 u64 refs;
1393 int ret;
1394 int err = 0;
1395
1396 path = btrfs_alloc_path();
1397 if (!path)
1398 return -ENOMEM;
1399
1400 path->reada = 1;
1401
1402 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1403 path, bytenr, num_bytes, parent,
1404 root_objectid, owner, offset, 1);
1405 if (ret == 0)
1406 goto out;
1407
1408 if (ret != -EAGAIN) {
1409 err = ret;
1410 goto out;
1411 }
1412
1413 leaf = path->nodes[0];
1414 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1415 refs = btrfs_extent_refs(leaf, item);
1416 btrfs_set_extent_refs(leaf, item, refs + 1);
1417
1418 btrfs_mark_buffer_dirty(leaf);
1419 btrfs_release_path(path);
1420
1421 path->reada = 1;
1422
1423 /* now insert the actual backref */
1424 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1425 path, bytenr, parent, root_objectid,
1426 owner, offset, 1);
1427 if (ret)
1428 err = ret;
1429 out:
1430 btrfs_free_path(path);
1431 finish_current_insert(trans, root->fs_info->extent_root);
1432 del_pending_extents(trans, root->fs_info->extent_root);
1433 BUG_ON(err);
1434 return err;
1435 }
1436
1437 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
1438 struct btrfs_root *root)
1439 {
1440 finish_current_insert(trans, root->fs_info->extent_root);
1441 del_pending_extents(trans, root->fs_info->extent_root);
1442 return 0;
1443 }
1444
1445 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
1446 struct btrfs_root *root, u64 bytenr,
1447 u64 offset, int metadata, u64 *refs, u64 *flags)
1448 {
1449 struct btrfs_path *path;
1450 int ret;
1451 struct btrfs_key key;
1452 struct extent_buffer *l;
1453 struct btrfs_extent_item *item;
1454 u32 item_size;
1455 u64 num_refs;
1456 u64 extent_flags;
1457
1458 if (metadata &&
1459 !btrfs_fs_incompat(root->fs_info,
1460 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)) {
1461 offset = root->leafsize;
1462 metadata = 0;
1463 }
1464
1465 path = btrfs_alloc_path();
1466 if (!path)
1467 return -ENOMEM;
1468 path->reada = 1;
1469
1470 key.objectid = bytenr;
1471 key.offset = offset;
1472 if (metadata)
1473 key.type = BTRFS_METADATA_ITEM_KEY;
1474 else
1475 key.type = BTRFS_EXTENT_ITEM_KEY;
1476
1477 again:
1478 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1479 0, 0);
1480 if (ret < 0)
1481 goto out;
1482
1483 /*
1484 * Deal with the fact that we may have mixed SKINNY and normal refs. If
1485 * we didn't find what we wanted check and see if we have a normal ref
1486 * right next to us, or re-search if we are on the edge of the leaf just
1487 * to make sure.
1488 */
1489 if (ret > 0 && metadata) {
1490 if (path->slots[0]) {
1491 path->slots[0]--;
1492 btrfs_item_key_to_cpu(path->nodes[0], &key,
1493 path->slots[0]);
1494 if (key.objectid == bytenr &&
1495 key.type == BTRFS_EXTENT_ITEM_KEY &&
1496 key.offset == root->leafsize)
1497 ret = 0;
1498 }
1499
1500 if (ret) {
1501 btrfs_release_path(path);
1502 key.type = BTRFS_EXTENT_ITEM_KEY;
1503 key.offset = root->leafsize;
1504 metadata = 0;
1505 goto again;
1506 }
1507 }
1508
1509 if (ret != 0) {
1510 ret = -EIO;
1511 goto out;
1512 }
1513
1514 l = path->nodes[0];
1515 item_size = btrfs_item_size_nr(l, path->slots[0]);
1516 if (item_size >= sizeof(*item)) {
1517 item = btrfs_item_ptr(l, path->slots[0],
1518 struct btrfs_extent_item);
1519 num_refs = btrfs_extent_refs(l, item);
1520 extent_flags = btrfs_extent_flags(l, item);
1521 } else {
1522 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1523 struct btrfs_extent_item_v0 *ei0;
1524 BUG_ON(item_size != sizeof(*ei0));
1525 ei0 = btrfs_item_ptr(l, path->slots[0],
1526 struct btrfs_extent_item_v0);
1527 num_refs = btrfs_extent_refs_v0(l, ei0);
1528 /* FIXME: this isn't correct for data */
1529 extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
1530 #else
1531 BUG();
1532 #endif
1533 }
1534 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1535 if (refs)
1536 *refs = num_refs;
1537 if (flags)
1538 *flags = extent_flags;
1539 out:
1540 btrfs_free_path(path);
1541 return ret;
1542 }
1543
1544 int btrfs_set_block_flags(struct btrfs_trans_handle *trans,
1545 struct btrfs_root *root,
1546 u64 bytenr, int level, u64 flags)
1547 {
1548 struct btrfs_path *path;
1549 int ret;
1550 struct btrfs_key key;
1551 struct extent_buffer *l;
1552 struct btrfs_extent_item *item;
1553 u32 item_size;
1554 int skinny_metadata =
1555 btrfs_fs_incompat(root->fs_info,
1556 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
1557
1558 path = btrfs_alloc_path();
1559 if (!path)
1560 return -ENOMEM;
1561 path->reada = 1;
1562
1563 key.objectid = bytenr;
1564 if (skinny_metadata) {
1565 key.offset = level;
1566 key.type = BTRFS_METADATA_ITEM_KEY;
1567 } else {
1568 key.offset = root->leafsize;
1569 key.type = BTRFS_EXTENT_ITEM_KEY;
1570 }
1571
1572 again:
1573 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
1574 0, 0);
1575 if (ret < 0)
1576 goto out;
1577
1578 if (ret > 0 && skinny_metadata) {
1579 skinny_metadata = 0;
1580 if (path->slots[0]) {
1581 path->slots[0]--;
1582 btrfs_item_key_to_cpu(path->nodes[0], &key,
1583 path->slots[0]);
1584 if (key.objectid == bytenr &&
1585 key.offset == root->leafsize &&
1586 key.type == BTRFS_EXTENT_ITEM_KEY)
1587 ret = 0;
1588 }
1589 if (ret) {
1590 btrfs_release_path(path);
1591 key.offset = root->leafsize;
1592 key.type = BTRFS_EXTENT_ITEM_KEY;
1593 goto again;
1594 }
1595 }
1596
1597 if (ret != 0) {
1598 btrfs_print_leaf(root, path->nodes[0]);
1599 printk("failed to find block number %Lu\n",
1600 (unsigned long long)bytenr);
1601 BUG();
1602 }
1603 l = path->nodes[0];
1604 item_size = btrfs_item_size_nr(l, path->slots[0]);
1605 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1606 if (item_size < sizeof(*item)) {
1607 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1608 path, (u64)-1, 0);
1609 if (ret < 0)
1610 goto out;
1611
1612 l = path->nodes[0];
1613 item_size = btrfs_item_size_nr(l, path->slots[0]);
1614 }
1615 #endif
1616 BUG_ON(item_size < sizeof(*item));
1617 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
1618 flags |= btrfs_extent_flags(l, item);
1619 btrfs_set_extent_flags(l, item, flags);
1620 out:
1621 btrfs_free_path(path);
1622 finish_current_insert(trans, root->fs_info->extent_root);
1623 del_pending_extents(trans, root->fs_info->extent_root);
1624 return ret;
1625 }
1626
1627 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
1628 struct btrfs_root *root,
1629 struct extent_buffer *buf,
1630 int record_parent, int inc)
1631 {
1632 u64 bytenr;
1633 u64 num_bytes;
1634 u64 parent;
1635 u64 ref_root;
1636 u32 nritems;
1637 struct btrfs_key key;
1638 struct btrfs_file_extent_item *fi;
1639 int i;
1640 int level;
1641 int ret = 0;
1642 int (*process_func)(struct btrfs_trans_handle *trans,
1643 struct btrfs_root *root,
1644 u64, u64, u64, u64, u64, u64);
1645
1646 ref_root = btrfs_header_owner(buf);
1647 nritems = btrfs_header_nritems(buf);
1648 level = btrfs_header_level(buf);
1649
1650 if (!root->ref_cows && level == 0)
1651 return 0;
1652
1653 if (inc)
1654 process_func = btrfs_inc_extent_ref;
1655 else
1656 process_func = btrfs_free_extent;
1657
1658 if (record_parent)
1659 parent = buf->start;
1660 else
1661 parent = 0;
1662
1663 for (i = 0; i < nritems; i++) {
1664 cond_resched();
1665 if (level == 0) {
1666 btrfs_item_key_to_cpu(buf, &key, i);
1667 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1668 continue;
1669 fi = btrfs_item_ptr(buf, i,
1670 struct btrfs_file_extent_item);
1671 if (btrfs_file_extent_type(buf, fi) ==
1672 BTRFS_FILE_EXTENT_INLINE)
1673 continue;
1674 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1675 if (bytenr == 0)
1676 continue;
1677
1678 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
1679 key.offset -= btrfs_file_extent_offset(buf, fi);
1680 ret = process_func(trans, root, bytenr, num_bytes,
1681 parent, ref_root, key.objectid,
1682 key.offset);
1683 if (ret) {
1684 WARN_ON(1);
1685 goto fail;
1686 }
1687 } else {
1688 bytenr = btrfs_node_blockptr(buf, i);
1689 num_bytes = btrfs_level_size(root, level - 1);
1690 ret = process_func(trans, root, bytenr, num_bytes,
1691 parent, ref_root, level - 1, 0);
1692 if (ret) {
1693 WARN_ON(1);
1694 goto fail;
1695 }
1696 }
1697 }
1698 return 0;
1699 fail:
1700 WARN_ON(1);
1701 return ret;
1702 }
1703
1704 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1705 struct extent_buffer *buf, int record_parent)
1706 {
1707 return __btrfs_mod_ref(trans, root, buf, record_parent, 1);
1708 }
1709
1710 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1711 struct extent_buffer *buf, int record_parent)
1712 {
1713 return __btrfs_mod_ref(trans, root, buf, record_parent, 0);
1714 }
1715
1716 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1717 struct btrfs_root *root,
1718 struct btrfs_path *path,
1719 struct btrfs_block_group_cache *cache)
1720 {
1721 int ret;
1722 int pending_ret;
1723 struct btrfs_root *extent_root = root->fs_info->extent_root;
1724 unsigned long bi;
1725 struct extent_buffer *leaf;
1726
1727 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1728 if (ret < 0)
1729 goto fail;
1730 BUG_ON(ret);
1731
1732 leaf = path->nodes[0];
1733 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1734 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1735 btrfs_mark_buffer_dirty(leaf);
1736 btrfs_release_path(path);
1737 fail:
1738 finish_current_insert(trans, extent_root);
1739 pending_ret = del_pending_extents(trans, extent_root);
1740 if (ret)
1741 return ret;
1742 if (pending_ret)
1743 return pending_ret;
1744 return 0;
1745
1746 }
1747
1748 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1749 struct btrfs_root *root)
1750 {
1751 struct extent_io_tree *block_group_cache;
1752 struct btrfs_block_group_cache *cache;
1753 int ret;
1754 struct btrfs_path *path;
1755 u64 last = 0;
1756 u64 start;
1757 u64 end;
1758 u64 ptr;
1759
1760 block_group_cache = &root->fs_info->block_group_cache;
1761 path = btrfs_alloc_path();
1762 if (!path)
1763 return -ENOMEM;
1764
1765 while(1) {
1766 ret = find_first_extent_bit(block_group_cache, last,
1767 &start, &end, BLOCK_GROUP_DIRTY);
1768 if (ret) {
1769 if (last == 0)
1770 break;
1771 last = 0;
1772 continue;
1773 }
1774
1775 last = end + 1;
1776 ret = get_state_private(block_group_cache, start, &ptr);
1777 BUG_ON(ret);
1778
1779 clear_extent_bits(block_group_cache, start, end,
1780 BLOCK_GROUP_DIRTY, GFP_NOFS);
1781
1782 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
1783 ret = write_one_cache_group(trans, root, path, cache);
1784 }
1785 btrfs_free_path(path);
1786 return 0;
1787 }
1788
1789 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
1790 u64 flags)
1791 {
1792 struct btrfs_space_info *found;
1793
1794 flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
1795
1796 list_for_each_entry(found, &info->space_info, list) {
1797 if (found->flags & flags)
1798 return found;
1799 }
1800 return NULL;
1801
1802 }
1803
1804 static int free_space_info(struct btrfs_fs_info *fs_info, u64 flags,
1805 u64 total_bytes, u64 bytes_used,
1806 struct btrfs_space_info **space_info)
1807 {
1808 struct btrfs_space_info *found;
1809
1810 /* only support free block group which is empty */
1811 if (bytes_used)
1812 return -ENOTEMPTY;
1813
1814 found = __find_space_info(fs_info, flags);
1815 if (!found)
1816 return -ENOENT;
1817 if (found->total_bytes < total_bytes) {
1818 fprintf(stderr,
1819 "WARNING: bad space info to free %llu only have %llu\n",
1820 total_bytes, found->total_bytes);
1821 return -EINVAL;
1822 }
1823 found->total_bytes -= total_bytes;
1824 if (space_info)
1825 *space_info = found;
1826 return 0;
1827 }
1828
1829 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1830 u64 total_bytes, u64 bytes_used,
1831 struct btrfs_space_info **space_info)
1832 {
1833 struct btrfs_space_info *found;
1834
1835 found = __find_space_info(info, flags);
1836 if (found) {
1837 found->total_bytes += total_bytes;
1838 found->bytes_used += bytes_used;
1839 if (found->total_bytes < found->bytes_used) {
1840 fprintf(stderr, "warning, bad space info total_bytes "
1841 "%llu used %llu\n",
1842 (unsigned long long)found->total_bytes,
1843 (unsigned long long)found->bytes_used);
1844 }
1845 *space_info = found;
1846 return 0;
1847 }
1848 found = kmalloc(sizeof(*found), GFP_NOFS);
1849 if (!found)
1850 return -ENOMEM;
1851
1852 list_add(&found->list, &info->space_info);
1853 found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
1854 found->total_bytes = total_bytes;
1855 found->bytes_used = bytes_used;
1856 found->bytes_pinned = 0;
1857 found->full = 0;
1858 *space_info = found;
1859 return 0;
1860 }
1861
1862
1863 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1864 {
1865 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1866 BTRFS_BLOCK_GROUP_RAID1 |
1867 BTRFS_BLOCK_GROUP_RAID10 |
1868 BTRFS_BLOCK_GROUP_RAID5 |
1869 BTRFS_BLOCK_GROUP_RAID6 |
1870 BTRFS_BLOCK_GROUP_DUP);
1871 if (extra_flags) {
1872 if (flags & BTRFS_BLOCK_GROUP_DATA)
1873 fs_info->avail_data_alloc_bits |= extra_flags;
1874 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1875 fs_info->avail_metadata_alloc_bits |= extra_flags;
1876 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1877 fs_info->avail_system_alloc_bits |= extra_flags;
1878 }
1879 }
1880
1881 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1882 struct btrfs_root *extent_root, u64 alloc_bytes,
1883 u64 flags)
1884 {
1885 struct btrfs_space_info *space_info;
1886 u64 thresh;
1887 u64 start;
1888 u64 num_bytes;
1889 int ret;
1890
1891 space_info = __find_space_info(extent_root->fs_info, flags);
1892 if (!space_info) {
1893 ret = update_space_info(extent_root->fs_info, flags,
1894 0, 0, &space_info);
1895 BUG_ON(ret);
1896 }
1897 BUG_ON(!space_info);
1898
1899 if (space_info->full)
1900 return 0;
1901
1902 thresh = div_factor(space_info->total_bytes, 7);
1903 if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1904 thresh)
1905 return 0;
1906
1907 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes,
1908 space_info->flags);
1909 if (ret == -ENOSPC) {
1910 space_info->full = 1;
1911 return 0;
1912 }
1913
1914 BUG_ON(ret);
1915
1916 ret = btrfs_make_block_group(trans, extent_root, 0, space_info->flags,
1917 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1918 BUG_ON(ret);
1919 return 0;
1920 }
1921
1922 static int update_block_group(struct btrfs_trans_handle *trans,
1923 struct btrfs_root *root,
1924 u64 bytenr, u64 num_bytes, int alloc,
1925 int mark_free)
1926 {
1927 struct btrfs_block_group_cache *cache;
1928 struct btrfs_fs_info *info = root->fs_info;
1929 u64 total = num_bytes;
1930 u64 old_val;
1931 u64 byte_in_group;
1932 u64 start;
1933 u64 end;
1934
1935 /* block accounting for super block */
1936 old_val = btrfs_super_bytes_used(info->super_copy);
1937 if (alloc)
1938 old_val += num_bytes;
1939 else
1940 old_val -= num_bytes;
1941 btrfs_set_super_bytes_used(info->super_copy, old_val);
1942
1943 /* block accounting for root item */
1944 old_val = btrfs_root_used(&root->root_item);
1945 if (alloc)
1946 old_val += num_bytes;
1947 else
1948 old_val -= num_bytes;
1949 btrfs_set_root_used(&root->root_item, old_val);
1950
1951 while(total) {
1952 cache = btrfs_lookup_block_group(info, bytenr);
1953 if (!cache) {
1954 return -1;
1955 }
1956 byte_in_group = bytenr - cache->key.objectid;
1957 WARN_ON(byte_in_group > cache->key.offset);
1958 start = cache->key.objectid;
1959 end = start + cache->key.offset - 1;
1960 set_extent_bits(&info->block_group_cache, start, end,
1961 BLOCK_GROUP_DIRTY, GFP_NOFS);
1962
1963 old_val = btrfs_block_group_used(&cache->item);
1964 num_bytes = min(total, cache->key.offset - byte_in_group);
1965
1966 if (alloc) {
1967 old_val += num_bytes;
1968 cache->space_info->bytes_used += num_bytes;
1969 } else {
1970 old_val -= num_bytes;
1971 cache->space_info->bytes_used -= num_bytes;
1972 if (mark_free) {
1973 set_extent_dirty(&info->free_space_cache,
1974 bytenr, bytenr + num_bytes - 1,
1975 GFP_NOFS);
1976 }
1977 }
1978 btrfs_set_block_group_used(&cache->item, old_val);
1979 total -= num_bytes;
1980 bytenr += num_bytes;
1981 }
1982 return 0;
1983 }
1984
1985 static int update_pinned_extents(struct btrfs_root *root,
1986 u64 bytenr, u64 num, int pin)
1987 {
1988 u64 len;
1989 struct btrfs_block_group_cache *cache;
1990 struct btrfs_fs_info *fs_info = root->fs_info;
1991
1992 if (pin) {
1993 set_extent_dirty(&fs_info->pinned_extents,
1994 bytenr, bytenr + num - 1, GFP_NOFS);
1995 } else {
1996 clear_extent_dirty(&fs_info->pinned_extents,
1997 bytenr, bytenr + num - 1, GFP_NOFS);
1998 }
1999 while (num > 0) {
2000 cache = btrfs_lookup_block_group(fs_info, bytenr);
2001 if (!cache) {
2002 len = min((u64)root->sectorsize, num);
2003 goto next;
2004 }
2005 WARN_ON(!cache);
2006 len = min(num, cache->key.offset -
2007 (bytenr - cache->key.objectid));
2008 if (pin) {
2009 cache->pinned += len;
2010 cache->space_info->bytes_pinned += len;
2011 fs_info->total_pinned += len;
2012 } else {
2013 cache->pinned -= len;
2014 cache->space_info->bytes_pinned -= len;
2015 fs_info->total_pinned -= len;
2016 }
2017 next:
2018 bytenr += len;
2019 num -= len;
2020 }
2021 return 0;
2022 }
2023
2024 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
2025 struct btrfs_root *root,
2026 struct extent_io_tree *unpin)
2027 {
2028 u64 start;
2029 u64 end;
2030 int ret;
2031 struct extent_io_tree *free_space_cache;
2032 free_space_cache = &root->fs_info->free_space_cache;
2033
2034 while(1) {
2035 ret = find_first_extent_bit(unpin, 0, &start, &end,
2036 EXTENT_DIRTY);
2037 if (ret)
2038 break;
2039 update_pinned_extents(root, start, end + 1 - start, 0);
2040 clear_extent_dirty(unpin, start, end, GFP_NOFS);
2041 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
2042 }
2043 return 0;
2044 }
2045
2046 static int extent_root_pending_ops(struct btrfs_fs_info *info)
2047 {
2048 u64 start;
2049 u64 end;
2050 int ret;
2051
2052 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
2053 &end, EXTENT_LOCKED);
2054 if (!ret) {
2055 ret = find_first_extent_bit(&info->pending_del, 0, &start, &end,
2056 EXTENT_LOCKED);
2057 }
2058 return ret == 0;
2059
2060 }
2061 static int finish_current_insert(struct btrfs_trans_handle *trans,
2062 struct btrfs_root *extent_root)
2063 {
2064 u64 start;
2065 u64 end;
2066 u64 priv;
2067 struct btrfs_fs_info *info = extent_root->fs_info;
2068 struct pending_extent_op *extent_op;
2069 struct btrfs_key key;
2070 int ret;
2071 int skinny_metadata =
2072 btrfs_fs_incompat(extent_root->fs_info,
2073 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
2074
2075 while(1) {
2076 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
2077 &end, EXTENT_LOCKED);
2078 if (ret)
2079 break;
2080
2081 ret = get_state_private(&info->extent_ins, start, &priv);
2082 BUG_ON(ret);
2083 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2084
2085 if (extent_op->type == PENDING_EXTENT_INSERT) {
2086 key.objectid = start;
2087 if (skinny_metadata) {
2088 key.offset = extent_op->level;
2089 key.type = BTRFS_METADATA_ITEM_KEY;
2090 } else {
2091 key.offset = extent_op->num_bytes;
2092 key.type = BTRFS_EXTENT_ITEM_KEY;
2093 }
2094 ret = alloc_reserved_tree_block(trans, extent_root,
2095 extent_root->root_key.objectid,
2096 trans->transid,
2097 extent_op->flags,
2098 &extent_op->key,
2099 extent_op->level, &key);
2100 BUG_ON(ret);
2101 } else {
2102 BUG_ON(1);
2103 }
2104
2105 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
2106 GFP_NOFS);
2107 kfree(extent_op);
2108 }
2109 return 0;
2110 }
2111
2112 static int pin_down_bytes(struct btrfs_trans_handle *trans,
2113 struct btrfs_root *root,
2114 u64 bytenr, u64 num_bytes, int is_data)
2115 {
2116 int err = 0;
2117 struct extent_buffer *buf;
2118
2119 if (is_data)
2120 goto pinit;
2121
2122 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
2123 if (!buf)
2124 goto pinit;
2125
2126 /* we can reuse a block if it hasn't been written
2127 * and it is from this transaction. We can't
2128 * reuse anything from the tree log root because
2129 * it has tiny sub-transactions.
2130 */
2131 if (btrfs_buffer_uptodate(buf, 0)) {
2132 u64 header_owner = btrfs_header_owner(buf);
2133 u64 header_transid = btrfs_header_generation(buf);
2134 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
2135 header_transid == trans->transid &&
2136 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
2137 clean_tree_block(NULL, root, buf);
2138 free_extent_buffer(buf);
2139 return 1;
2140 }
2141 }
2142 free_extent_buffer(buf);
2143 pinit:
2144 update_pinned_extents(root, bytenr, num_bytes, 1);
2145
2146 BUG_ON(err < 0);
2147 return 0;
2148 }
2149
2150 void btrfs_pin_extent(struct btrfs_fs_info *fs_info,
2151 u64 bytenr, u64 num_bytes)
2152 {
2153 update_pinned_extents(fs_info->extent_root, bytenr, num_bytes, 1);
2154 }
2155
2156 void btrfs_unpin_extent(struct btrfs_fs_info *fs_info,
2157 u64 bytenr, u64 num_bytes)
2158 {
2159 update_pinned_extents(fs_info->extent_root, bytenr, num_bytes, 0);
2160 }
2161
2162 /*
2163 * remove an extent from the root, returns 0 on success
2164 */
2165 static int __free_extent(struct btrfs_trans_handle *trans,
2166 struct btrfs_root *root,
2167 u64 bytenr, u64 num_bytes, u64 parent,
2168 u64 root_objectid, u64 owner_objectid,
2169 u64 owner_offset, int refs_to_drop)
2170 {
2171
2172 struct btrfs_key key;
2173 struct btrfs_path *path;
2174 struct btrfs_extent_ops *ops = root->fs_info->extent_ops;
2175 struct btrfs_root *extent_root = root->fs_info->extent_root;
2176 struct extent_buffer *leaf;
2177 struct btrfs_extent_item *ei;
2178 struct btrfs_extent_inline_ref *iref;
2179 int ret;
2180 int is_data;
2181 int extent_slot = 0;
2182 int found_extent = 0;
2183 int num_to_del = 1;
2184 u32 item_size;
2185 u64 refs;
2186 int skinny_metadata =
2187 btrfs_fs_incompat(extent_root->fs_info,
2188 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
2189
2190 if (root->fs_info->free_extent_hook) {
2191 root->fs_info->free_extent_hook(trans, root, bytenr, num_bytes,
2192 parent, root_objectid, owner_objectid,
2193 owner_offset, refs_to_drop);
2194
2195 }
2196 path = btrfs_alloc_path();
2197 if (!path)
2198 return -ENOMEM;
2199
2200 path->reada = 1;
2201
2202 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
2203 if (is_data)
2204 skinny_metadata = 0;
2205 BUG_ON(!is_data && refs_to_drop != 1);
2206
2207 ret = lookup_extent_backref(trans, extent_root, path, &iref,
2208 bytenr, num_bytes, parent,
2209 root_objectid, owner_objectid,
2210 owner_offset);
2211 if (ret == 0) {
2212 extent_slot = path->slots[0];
2213 while (extent_slot >= 0) {
2214 btrfs_item_key_to_cpu(path->nodes[0], &key,
2215 extent_slot);
2216 if (key.objectid != bytenr)
2217 break;
2218 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
2219 key.offset == num_bytes) {
2220 found_extent = 1;
2221 break;
2222 }
2223 if (key.type == BTRFS_METADATA_ITEM_KEY &&
2224 key.offset == owner_objectid) {
2225 found_extent = 1;
2226 break;
2227 }
2228 if (path->slots[0] - extent_slot > 5)
2229 break;
2230 extent_slot--;
2231 }
2232 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2233 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
2234 if (found_extent && item_size < sizeof(*ei))
2235 found_extent = 0;
2236 #endif
2237 if (!found_extent) {
2238 BUG_ON(iref);
2239 ret = remove_extent_backref(trans, extent_root, path,
2240 NULL, refs_to_drop,
2241 is_data);
2242 BUG_ON(ret);
2243 btrfs_release_path(path);
2244
2245 key.objectid = bytenr;
2246
2247 if (skinny_metadata) {
2248 key.type = BTRFS_METADATA_ITEM_KEY;
2249 key.offset = owner_objectid;
2250 } else {
2251 key.type = BTRFS_EXTENT_ITEM_KEY;
2252 key.offset = num_bytes;
2253 }
2254
2255 ret = btrfs_search_slot(trans, extent_root,
2256 &key, path, -1, 1);
2257 if (ret > 0 && skinny_metadata && path->slots[0]) {
2258 path->slots[0]--;
2259 btrfs_item_key_to_cpu(path->nodes[0],
2260 &key,
2261 path->slots[0]);
2262 if (key.objectid == bytenr &&
2263 key.type == BTRFS_EXTENT_ITEM_KEY &&
2264 key.offset == num_bytes)
2265 ret = 0;
2266 }
2267
2268 if (ret > 0 && skinny_metadata) {
2269 skinny_metadata = 0;
2270 btrfs_release_path(path);
2271 key.type = BTRFS_EXTENT_ITEM_KEY;
2272 key.offset = num_bytes;
2273 ret = btrfs_search_slot(trans, extent_root,
2274 &key, path, -1, 1);
2275 }
2276
2277 if (ret) {
2278 printk(KERN_ERR "umm, got %d back from search"
2279 ", was looking for %llu\n", ret,
2280 (unsigned long long)bytenr);
2281 btrfs_print_leaf(extent_root, path->nodes[0]);
2282 }
2283 BUG_ON(ret);
2284 extent_slot = path->slots[0];
2285 }
2286 } else {
2287 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
2288 "parent %llu root %llu owner %llu offset %llu\n",
2289 (unsigned long long)bytenr,
2290 (unsigned long long)parent,
2291 (unsigned long long)root_objectid,
2292 (unsigned long long)owner_objectid,
2293 (unsigned long long)owner_offset);
2294 ret = -EIO;
2295 goto fail;
2296 }
2297
2298 leaf = path->nodes[0];
2299 item_size = btrfs_item_size_nr(leaf, extent_slot);
2300 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2301 if (item_size < sizeof(*ei)) {
2302 BUG_ON(found_extent || extent_slot != path->slots[0]);
2303 ret = convert_extent_item_v0(trans, extent_root, path,
2304 owner_objectid, 0);
2305 BUG_ON(ret < 0);
2306
2307 btrfs_release_path(path);
2308
2309 key.objectid = bytenr;
2310 key.type = BTRFS_EXTENT_ITEM_KEY;
2311 key.offset = num_bytes;
2312
2313 ret = btrfs_search_slot(trans, extent_root, &key, path,
2314 -1, 1);
2315 if (ret) {
2316 printk(KERN_ERR "umm, got %d back from search"
2317 ", was looking for %llu\n", ret,
2318 (unsigned long long)bytenr);
2319 btrfs_print_leaf(extent_root, path->nodes[0]);
2320 }
2321 BUG_ON(ret);
2322 extent_slot = path->slots[0];
2323 leaf = path->nodes[0];
2324 item_size = btrfs_item_size_nr(leaf, extent_slot);
2325 }
2326 #endif
2327 BUG_ON(item_size < sizeof(*ei));
2328 ei = btrfs_item_ptr(leaf, extent_slot,
2329 struct btrfs_extent_item);
2330 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
2331 key.type == BTRFS_EXTENT_ITEM_KEY) {
2332 struct btrfs_tree_block_info *bi;
2333 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
2334 bi = (struct btrfs_tree_block_info *)(ei + 1);
2335 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
2336 }
2337
2338 refs = btrfs_extent_refs(leaf, ei);
2339 BUG_ON(refs < refs_to_drop);
2340 refs -= refs_to_drop;
2341
2342 if (refs > 0) {
2343 /*
2344 * In the case of inline back ref, reference count will
2345 * be updated by remove_extent_backref
2346 */
2347 if (iref) {
2348 BUG_ON(!found_extent);
2349 } else {
2350 btrfs_set_extent_refs(leaf, ei, refs);
2351 btrfs_mark_buffer_dirty(leaf);
2352 }
2353 if (found_extent) {
2354 ret = remove_extent_backref(trans, extent_root, path,
2355 iref, refs_to_drop,
2356 is_data);
2357 BUG_ON(ret);
2358 }
2359 } else {
2360 int mark_free = 0;
2361 int pin = 1;
2362
2363 if (found_extent) {
2364 BUG_ON(is_data && refs_to_drop !=
2365 extent_data_ref_count(root, path, iref));
2366 if (iref) {
2367 BUG_ON(path->slots[0] != extent_slot);
2368 } else {
2369 BUG_ON(path->slots[0] != extent_slot + 1);
2370 path->slots[0] = extent_slot;
2371 num_to_del = 2;
2372 }
2373 }
2374
2375 if (ops && ops->free_extent) {
2376 ret = ops->free_extent(root, bytenr, num_bytes);
2377 if (ret > 0) {
2378 pin = 0;
2379 mark_free = 0;
2380 }
2381 }
2382
2383 if (pin) {
2384 ret = pin_down_bytes(trans, root, bytenr, num_bytes,
2385 is_data);
2386 if (ret > 0)
2387 mark_free = 1;
2388 BUG_ON(ret < 0);
2389 }
2390
2391 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
2392 num_to_del);
2393 BUG_ON(ret);
2394 btrfs_release_path(path);
2395
2396 if (is_data) {
2397 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
2398 BUG_ON(ret);
2399 }
2400
2401 update_block_group(trans, root, bytenr, num_bytes, 0, mark_free);
2402 }
2403 fail:
2404 btrfs_free_path(path);
2405 finish_current_insert(trans, extent_root);
2406 return ret;
2407 }
2408
2409 /*
2410 * find all the blocks marked as pending in the radix tree and remove
2411 * them from the extent map
2412 */
2413 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
2414 btrfs_root *extent_root)
2415 {
2416 int ret;
2417 int err = 0;
2418 u64 start;
2419 u64 end;
2420 u64 priv;
2421 struct extent_io_tree *pending_del;
2422 struct extent_io_tree *extent_ins;
2423 struct pending_extent_op *extent_op;
2424
2425 extent_ins = &extent_root->fs_info->extent_ins;
2426 pending_del = &extent_root->fs_info->pending_del;
2427
2428 while(1) {
2429 ret = find_first_extent_bit(pending_del, 0, &start, &end,
2430 EXTENT_LOCKED);
2431 if (ret)
2432 break;
2433
2434 ret = get_state_private(pending_del, start, &priv);
2435 BUG_ON(ret);
2436 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2437
2438 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
2439 GFP_NOFS);
2440
2441 if (!test_range_bit(extent_ins, start, end,
2442 EXTENT_LOCKED, 0)) {
2443 ret = __free_extent(trans, extent_root,
2444 start, end + 1 - start, 0,
2445 extent_root->root_key.objectid,
2446 extent_op->level, 0, 1);
2447 kfree(extent_op);
2448 } else {
2449 kfree(extent_op);
2450 ret = get_state_private(extent_ins, start, &priv);
2451 BUG_ON(ret);
2452 extent_op = (struct pending_extent_op *)
2453 (unsigned long)priv;
2454
2455 clear_extent_bits(extent_ins, start, end,
2456 EXTENT_LOCKED, GFP_NOFS);
2457
2458 if (extent_op->type == PENDING_BACKREF_UPDATE)
2459 BUG_ON(1);
2460
2461 kfree(extent_op);
2462 }
2463 if (ret)
2464 err = ret;
2465 }
2466 return err;
2467 }
2468
2469 /*
2470 * remove an extent from the root, returns 0 on success
2471 */
2472
2473 int btrfs_free_extent(struct btrfs_trans_handle *trans,
2474 struct btrfs_root *root,
2475 u64 bytenr, u64 num_bytes, u64 parent,
2476 u64 root_objectid, u64 owner, u64 offset)
2477 {
2478 struct btrfs_root *extent_root = root->fs_info->extent_root;
2479 int pending_ret;
2480 int ret;
2481
2482 WARN_ON(num_bytes < root->sectorsize);
2483 if (root == extent_root) {
2484 struct pending_extent_op *extent_op;
2485
2486 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2487 BUG_ON(!extent_op);
2488
2489 extent_op->type = PENDING_EXTENT_DELETE;
2490 extent_op->bytenr = bytenr;
2491 extent_op->num_bytes = num_bytes;
2492 extent_op->level = (int)owner;
2493
2494 set_extent_bits(&root->fs_info->pending_del,
2495 bytenr, bytenr + num_bytes - 1,
2496 EXTENT_LOCKED, GFP_NOFS);
2497 set_state_private(&root->fs_info->pending_del,
2498 bytenr, (unsigned long)extent_op);
2499 return 0;
2500 }
2501 ret = __free_extent(trans, root, bytenr, num_bytes, parent,
2502 root_objectid, owner, offset, 1);
2503 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
2504 return ret ? ret : pending_ret;
2505 }
2506
2507 static u64 stripe_align(struct btrfs_root *root, u64 val)
2508 {
2509 u64 mask = ((u64)root->stripesize - 1);
2510 u64 ret = (val + mask) & ~mask;
2511 return ret;
2512 }
2513
2514 /*
2515 * walks the btree of allocated extents and find a hole of a given size.
2516 * The key ins is changed to record the hole:
2517 * ins->objectid == block start
2518 * ins->flags = BTRFS_EXTENT_ITEM_KEY
2519 * ins->offset == number of blocks
2520 * Any available blocks before search_start are skipped.
2521 */
2522 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
2523 struct btrfs_root *orig_root,
2524 u64 num_bytes, u64 empty_size,
2525 u64 search_start, u64 search_end,
2526 u64 hint_byte, struct btrfs_key *ins,
2527 u64 exclude_start, u64 exclude_nr,
2528 int data)
2529 {
2530 int ret;
2531 u64 orig_search_start = search_start;
2532 struct btrfs_root * root = orig_root->fs_info->extent_root;
2533 struct btrfs_fs_info *info = root->fs_info;
2534 u64 total_needed = num_bytes;
2535 struct btrfs_block_group_cache *block_group;
2536 int full_scan = 0;
2537 int wrapped = 0;
2538
2539 WARN_ON(num_bytes < root->sectorsize);
2540 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
2541
2542 search_start = stripe_align(root, search_start);
2543
2544 if (hint_byte) {
2545 block_group = btrfs_lookup_first_block_group(info, hint_byte);
2546 if (!block_group)
2547 hint_byte = search_start;
2548 block_group = btrfs_find_block_group(root, block_group,
2549 hint_byte, data, 1);
2550 } else {
2551 block_group = btrfs_find_block_group(root,
2552 trans->block_group,
2553 search_start, data, 1);
2554 }
2555
2556 total_needed += empty_size;
2557
2558 check_failed:
2559 search_start = stripe_align(root, search_start);
2560 if (!block_group) {
2561 block_group = btrfs_lookup_first_block_group(info,
2562 search_start);
2563 if (!block_group)
2564 block_group = btrfs_lookup_first_block_group(info,
2565 orig_search_start);
2566 }
2567 ret = find_search_start(root, &block_group, &search_start,
2568 total_needed, data);
2569 if (ret)
2570 goto new_group;
2571
2572 ins->objectid = search_start;
2573 ins->offset = num_bytes;
2574
2575 if (ins->objectid + num_bytes >
2576 block_group->key.objectid + block_group->key.offset) {
2577 search_start = block_group->key.objectid +
2578 block_group->key.offset;
2579 goto new_group;
2580 }
2581
2582 if (test_range_bit(&info->extent_ins, ins->objectid,
2583 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
2584 search_start = ins->objectid + num_bytes;
2585 goto new_group;
2586 }
2587
2588 if (test_range_bit(&info->pinned_extents, ins->objectid,
2589 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
2590 search_start = ins->objectid + num_bytes;
2591 goto new_group;
2592 }
2593
2594 if (info->excluded_extents &&
2595 test_range_bit(info->excluded_extents, ins->objectid,
2596 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
2597 search_start = ins->objectid + num_bytes;
2598 goto new_group;
2599 }
2600
2601 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
2602 ins->objectid < exclude_start + exclude_nr)) {
2603 search_start = exclude_start + exclude_nr;
2604 goto new_group;
2605 }
2606
2607 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
2608 if (check_crossing_stripes(ins->objectid, num_bytes)) {
2609 search_start = round_down(ins->objectid + num_bytes,
2610 BTRFS_STRIPE_LEN);
2611 goto new_group;
2612 }
2613 block_group = btrfs_lookup_block_group(info, ins->objectid);
2614 if (block_group)
2615 trans->block_group = block_group;
2616 }
2617 ins->offset = num_bytes;
2618 return 0;
2619
2620 new_group:
2621 block_group = btrfs_lookup_first_block_group(info, search_start);
2622 if (!block_group) {
2623 search_start = orig_search_start;
2624 if (full_scan) {
2625 ret = -ENOSPC;
2626 goto error;
2627 }
2628 if (wrapped) {
2629 if (!full_scan)
2630 total_needed -= empty_size;
2631 full_scan = 1;
2632 } else
2633 wrapped = 1;
2634 }
2635 cond_resched();
2636 block_group = btrfs_find_block_group(root, block_group,
2637 search_start, data, 0);
2638 goto check_failed;
2639
2640 error:
2641 return ret;
2642 }
2643
2644 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2645 struct btrfs_root *root,
2646 u64 num_bytes, u64 empty_size,
2647 u64 hint_byte, u64 search_end,
2648 struct btrfs_key *ins, int data)
2649 {
2650 int ret;
2651 u64 search_start = 0;
2652 u64 alloc_profile;
2653 struct btrfs_fs_info *info = root->fs_info;
2654
2655 if (info->extent_ops) {
2656 struct btrfs_extent_ops *ops = info->extent_ops;
2657 ret = ops->alloc_extent(root, num_bytes, hint_byte, ins, !data);
2658 BUG_ON(ret);
2659 goto found;
2660 }
2661
2662 if (data) {
2663 alloc_profile = info->avail_data_alloc_bits &
2664 info->data_alloc_profile;
2665 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2666 } else if ((info->system_allocs > 0 || root == info->chunk_root) &&
2667 info->system_allocs >= 0) {
2668 alloc_profile = info->avail_system_alloc_bits &
2669 info->system_alloc_profile;
2670 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2671 } else {
2672 alloc_profile = info->avail_metadata_alloc_bits &
2673 info->metadata_alloc_profile;
2674 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2675 }
2676
2677 if (root->ref_cows) {
2678 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
2679 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2680 num_bytes,
2681 BTRFS_BLOCK_GROUP_METADATA);
2682 BUG_ON(ret);
2683 }
2684 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2685 num_bytes + 2 * 1024 * 1024, data);
2686 BUG_ON(ret);
2687 }
2688
2689 WARN_ON(num_bytes < root->sectorsize);
2690 ret = find_free_extent(trans, root, num_bytes, empty_size,
2691 search_start, search_end, hint_byte, ins,
2692 trans->alloc_exclude_start,
2693 trans->alloc_exclude_nr, data);
2694 BUG_ON(ret);
2695 found:
2696 clear_extent_dirty(&root->fs_info->free_space_cache,
2697 ins->objectid, ins->objectid + ins->offset - 1,
2698 GFP_NOFS);
2699 return ret;
2700 }
2701
2702 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
2703 struct btrfs_root *root,
2704 u64 root_objectid, u64 generation,
2705 u64 flags, struct btrfs_disk_key *key,
2706 int level, struct btrfs_key *ins)
2707 {
2708 int ret;
2709 struct btrfs_fs_info *fs_info = root->fs_info;
2710 struct btrfs_extent_item *extent_item;
2711 struct btrfs_tree_block_info *block_info;
2712 struct btrfs_extent_inline_ref *iref;
2713 struct btrfs_path *path;
2714 struct extent_buffer *leaf;
2715 u32 size = sizeof(*extent_item) + sizeof(*iref);
2716 int skinny_metadata =
2717 btrfs_fs_incompat(fs_info,
2718 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);
2719
2720 if (!skinny_metadata)
2721 size += sizeof(*block_info);
2722
2723 path = btrfs_alloc_path();
2724 BUG_ON(!path);
2725
2726 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
2727 ins, size);
2728 BUG_ON(ret);
2729
2730 leaf = path->nodes[0];
2731 extent_item = btrfs_item_ptr(leaf, path->slots[0],
2732 struct btrfs_extent_item);
2733 btrfs_set_extent_refs(leaf, extent_item, 1);
2734 btrfs_set_extent_generation(leaf, extent_item, generation);
2735 btrfs_set_extent_flags(leaf, extent_item,
2736 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
2737
2738 if (skinny_metadata) {
2739 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
2740 } else {
2741 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
2742 btrfs_set_tree_block_key(leaf, block_info, key);
2743 btrfs_set_tree_block_level(leaf, block_info, level);
2744 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
2745 }
2746
2747 btrfs_set_extent_inline_ref_type(leaf, iref, BTRFS_TREE_BLOCK_REF_KEY);
2748 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
2749
2750 btrfs_mark_buffer_dirty(leaf);
2751 btrfs_free_path(path);
2752
2753 ret = update_block_group(trans, root, ins->objectid, root->leafsize,
2754 1, 0);
2755 return ret;
2756 }
2757
2758 static int alloc_tree_block(struct btrfs_trans_handle *trans,
2759 struct btrfs_root *root, u64 num_bytes,
2760 u64 root_objectid, u64 generation,
2761 u64 flags, struct btrfs_disk_key *key,
2762 int level, u64 empty_size, u64 hint_byte,
2763 u64 search_end, struct btrfs_key *ins)
2764 {
2765 int ret;
2766 ret = btrfs_reserve_extent(trans, root, num_bytes, empty_size,
2767 hint_byte, search_end, ins, 0);
2768 BUG_ON(ret);
2769
2770 if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID) {
2771 struct pending_extent_op *extent_op;
2772
2773 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2774 BUG_ON(!extent_op);
2775
2776 extent_op->type = PENDING_EXTENT_INSERT;
2777 extent_op->bytenr = ins->objectid;
2778 extent_op->num_bytes = ins->offset;
2779 extent_op->level = level;
2780 extent_op->flags = flags;
2781 memcpy(&extent_op->key, key, sizeof(*key));
2782
2783 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2784 ins->objectid + ins->offset - 1,
2785 EXTENT_LOCKED, GFP_NOFS);
2786 set_state_private(&root->fs_info->extent_ins,
2787 ins->objectid, (unsigned long)extent_op);
2788 } else {
2789 if (btrfs_fs_incompat(root->fs_info,
2790 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)) {
2791 ins->offset = level;
2792 ins->type = BTRFS_METADATA_ITEM_KEY;
2793 }
2794 ret = alloc_reserved_tree_block(trans, root, root_objectid,
2795 generation, flags,
2796 key, level, ins);
2797 finish_current_insert(trans, root->fs_info->extent_root);
2798 del_pending_extents(trans, root->fs_info->extent_root);
2799 }
2800 return ret;
2801 }
2802
2803 /*
2804 * helper function to allocate a block for a given tree
2805 * returns the tree buffer or NULL.
2806 */
2807 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2808 struct btrfs_root *root,
2809 u32 blocksize, u64 root_objectid,
2810 struct btrfs_disk_key *key, int level,
2811 u64 hint, u64 empty_size)
2812 {
2813 struct btrfs_key ins;
2814 int ret;
2815 struct extent_buffer *buf;
2816
2817 ret = alloc_tree_block(trans, root, blocksize, root_objectid,
2818 trans->transid, 0, key, level,
2819 empty_size, hint, (u64)-1, &ins);
2820 if (ret) {
2821 BUG_ON(ret > 0);
2822 return ERR_PTR(ret);
2823 }
2824
2825 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
2826 if (!buf) {
2827 btrfs_free_extent(trans, root, ins.objectid, ins.offset,
2828 0, root->root_key.objectid, level, 0);
2829 BUG_ON(1);
2830 return ERR_PTR(-ENOMEM);
2831 }
2832 btrfs_set_buffer_uptodate(buf);
2833 trans->blocks_used++;
2834
2835 return buf;
2836 }
2837
2838 #if 0
2839
2840 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
2841 struct btrfs_root *root,
2842 struct extent_buffer *leaf)
2843 {
2844 u64 leaf_owner;
2845 u64 leaf_generation;
2846 struct btrfs_key key;
2847 struct btrfs_file_extent_item *fi;
2848 int i;
2849 int nritems;
2850 int ret;
2851
2852 BUG_ON(!btrfs_is_leaf(leaf));
2853 nritems = btrfs_header_nritems(leaf);
2854 leaf_owner = btrfs_header_owner(leaf);
2855 leaf_generation = btrfs_header_generation(leaf);
2856
2857 for (i = 0; i < nritems; i++) {
2858 u64 disk_bytenr;
2859
2860 btrfs_item_key_to_cpu(leaf, &key, i);
2861 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2862 continue;
2863 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2864 if (btrfs_file_extent_type(leaf, fi) ==
2865 BTRFS_FILE_EXTENT_INLINE)
2866 continue;
2867 /*
2868 * FIXME make sure to insert a trans record that
2869 * repeats the snapshot del on crash
2870 */
2871 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2872 if (disk_bytenr == 0)
2873 continue;
2874 ret = btrfs_free_extent(trans, root, disk_bytenr,
2875 btrfs_file_extent_disk_num_bytes(leaf, fi),
2876 leaf->start, leaf_owner, leaf_generation,
2877 key.objectid, 0);
2878 BUG_ON(ret);
2879 }
2880 return 0;
2881 }
2882
2883 static void noinline reada_walk_down(struct btrfs_root *root,
2884 struct extent_buffer *node,
2885 int slot)
2886 {
2887 u64 bytenr;
2888 u64 last = 0;
2889 u32 nritems;
2890 u32 refs;
2891 u32 blocksize;
2892 int ret;
2893 int i;
2894 int level;
2895 int skipped = 0;
2896
2897 nritems = btrfs_header_nritems(node);
2898 level = btrfs_header_level(node);
2899 if (level)
2900 return;
2901
2902 for (i = slot; i < nritems && skipped < 32; i++) {
2903 bytenr = btrfs_node_blockptr(node, i);
2904 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
2905 (last > bytenr && last - bytenr > 32 * 1024))) {
2906 skipped++;
2907 continue;
2908 }
2909 blocksize = btrfs_level_size(root, level - 1);
2910 if (i != slot) {
2911 ret = btrfs_lookup_extent_ref(NULL, root, bytenr,
2912 blocksize, &refs);
2913 BUG_ON(ret);
2914 if (refs != 1) {
2915 skipped++;
2916 continue;
2917 }
2918 }
2919 mutex_unlock(&root->fs_info->fs_mutex);
2920 ret = readahead_tree_block(root, bytenr, blocksize,
2921 btrfs_node_ptr_generation(node, i));
2922 last = bytenr + blocksize;
2923 cond_resched();
2924 mutex_lock(&root->fs_info->fs_mutex);
2925 if (ret)
2926 break;
2927 }
2928 }
2929
2930 /*
2931 * helper function for drop_snapshot, this walks down the tree dropping ref
2932 * counts as it goes.
2933 */
2934 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2935 struct btrfs_root *root,
2936 struct btrfs_path *path, int *level)
2937 {
2938 u64 root_owner;
2939 u64 root_gen;
2940 u64 bytenr;
2941 u64 ptr_gen;
2942 struct extent_buffer *next;
2943 struct extent_buffer *cur;
2944 struct extent_buffer *parent;
2945 u32 blocksize;
2946 int ret;
2947 u32 refs;
2948
2949 WARN_ON(*level < 0);
2950 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2951 ret = btrfs_lookup_extent_ref(trans, root,
2952 path->nodes[*level]->start,
2953 path->nodes[*level]->len, &refs);
2954 BUG_ON(ret);
2955 if (refs > 1)
2956 goto out;
2957
2958 /*
2959 * walk down to the last node level and free all the leaves
2960 */
2961 while(*level >= 0) {
2962 WARN_ON(*level < 0);
2963 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2964 cur = path->nodes[*level];
2965
2966 if (btrfs_header_level(cur) != *level)
2967 WARN_ON(1);
2968
2969 if (path->slots[*level] >=
2970 btrfs_header_nritems(cur))
2971 break;
2972 if (*level == 0) {
2973 ret = drop_leaf_ref(trans, root, cur);
2974 BUG_ON(ret);
2975 break;
2976 }
2977 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2978 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2979 blocksize = btrfs_level_size(root, *level - 1);
2980 ret = btrfs_lookup_extent_ref(trans, root, bytenr, blocksize,
2981 &refs);
2982 BUG_ON(ret);
2983 if (refs != 1) {
2984 parent = path->nodes[*level];
2985 root_owner = btrfs_header_owner(parent);
2986 root_gen = btrfs_header_generation(parent);
2987 path->slots[*level]++;
2988 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
2989 parent->start, root_owner,
2990 root_gen, *level - 1, 1);
2991 BUG_ON(ret);
2992 continue;
2993 }
2994 next = btrfs_find_tree_block(root, bytenr, blocksize);
2995 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2996 free_extent_buffer(next);
2997 reada_walk_down(root, cur, path->slots[*level]);
2998 mutex_unlock(&root->fs_info->fs_mutex);
2999 next = read_tree_block(root, bytenr, blocksize,
3000 ptr_gen);
3001 mutex_lock(&root->fs_info->fs_mutex);
3002 if (!extent_buffer_uptodate(next)) {
3003 if (IS_ERR(next))
3004 ret = PTR_ERR(next);
3005 else
3006 ret = -EIO;
3007 break;
3008 }
3009 }
3010 WARN_ON(*level <= 0);
3011 if (path->nodes[*level-1])
3012 free_extent_buffer(path->nodes[*level-1]);
3013 path->nodes[*level-1] = next;
3014 *level = btrfs_header_level(next);
3015 path->slots[*level] = 0;
3016 }
3017 out:
3018 WARN_ON(*level < 0);
3019 WARN_ON(*level >= BTRFS_MAX_LEVEL);
3020
3021 if (path->nodes[*level] == root->node) {
3022 root_owner = root->root_key.objectid;
3023 parent = path->nodes[*level];
3024 } else {
3025 parent = path->nodes[*level + 1];
3026 root_owner = btrfs_header_owner(parent);
3027 }
3028
3029 root_gen = btrfs_header_generation(parent);
3030 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
3031 path->nodes[*level]->len, parent->start,
3032 root_owner, root_gen, *level, 1);
3033 free_extent_buffer(path->nodes[*level]);
3034 path->nodes[*level] = NULL;
3035 *level += 1;
3036 BUG_ON(ret);
3037 return 0;
3038 }
3039
3040 /*
3041 * helper for dropping snapshots. This walks back up the tree in the path
3042 * to find the first node higher up where we haven't yet gone through
3043 * all the slots
3044 */
3045 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
3046 struct btrfs_root *root,
3047 struct btrfs_path *path, int *level)
3048 {
3049 u64 root_owner;
3050 u64 root_gen;
3051 struct btrfs_root_item *root_item = &root->root_item;
3052 int i;
3053 int slot;
3054 int ret;
3055
3056 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
3057 slot = path->slots[i];
3058 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
3059 struct extent_buffer *node;
3060 struct btrfs_disk_key disk_key;
3061 node = path->nodes[i];
3062 path->slots[i]++;
3063 *level = i;
3064 WARN_ON(*level == 0);
3065 btrfs_node_key(node, &disk_key, path->slots[i]);
3066 memcpy(&root_item->drop_progress,
3067 &disk_key, sizeof(disk_key));
3068 root_item->drop_level = i;
3069 return 0;
3070 } else {
3071 struct extent_buffer *parent;
3072 if (path->nodes[*level] == root->node)
3073 parent = path->nodes[*level];
3074 else
3075 parent = path->nodes[*level + 1];
3076
3077 root_owner = btrfs_header_owner(parent);
3078 root_gen = btrfs_header_generation(parent);
3079 ret = btrfs_free_extent(trans, root,
3080 path->nodes[*level]->start,
3081 path->nodes[*level]->len,
3082 parent->start, root_owner,
3083 root_gen, *level, 1);
3084 BUG_ON(ret);
3085 free_extent_buffer(path->nodes[*level]);
3086 path->nodes[*level] = NULL;
3087 *level = i + 1;
3088 }
3089 }
3090 return 1;
3091 }
3092
3093 #endif
3094
3095 int btrfs_free_block_groups(struct btrfs_fs_info *info)
3096 {
3097 struct btrfs_space_info *sinfo;
3098 struct btrfs_block_group_cache *cache;
3099 u64 start;
3100 u64 end;
3101 u64 ptr;
3102 int ret;
3103
3104 while(1) {
3105 ret = find_first_extent_bit(&info->block_group_cache, 0,
3106 &start, &end, (unsigned int)-1);
3107 if (ret)
3108 break;
3109 ret = get_state_private(&info->block_group_cache, start, &ptr);
3110 if (!ret) {
3111 cache = u64_to_ptr(ptr);
3112 if (cache->free_space_ctl) {
3113 btrfs_remove_free_space_cache(cache);
3114 kfree(cache->free_space_ctl);
3115 }
3116 kfree(cache);
3117 }
3118 clear_extent_bits(&info->block_group_cache, start,
3119 end, (unsigned int)-1, GFP_NOFS);
3120 }
3121 while(1) {
3122 ret = find_first_extent_bit(&info->free_space_cache, 0,
3123 &start, &end, EXTENT_DIRTY);
3124 if (ret)
3125 break;
3126 clear_extent_dirty(&info->free_space_cache, start,
3127 end, GFP_NOFS);
3128 }
3129
3130 while (!list_empty(&info->space_info)) {
3131 sinfo = list_entry(info->space_info.next,
3132 struct btrfs_space_info, list);
3133 list_del_init(&sinfo->list);
3134 kfree(sinfo);
3135 }
3136 return 0;
3137 }
3138
3139 static int find_first_block_group(struct btrfs_root *root,
3140 struct btrfs_path *path, struct btrfs_key *key)
3141 {
3142 int ret;
3143 struct btrfs_key found_key;
3144 struct extent_buffer *leaf;
3145 int slot;
3146
3147 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
3148 if (ret < 0)
3149 return ret;
3150 while(1) {
3151 slot = path->slots[0];
3152 leaf = path->nodes[0];
3153 if (slot >= btrfs_header_nritems(leaf)) {
3154 ret = btrfs_next_leaf(root, path);
3155 if (ret == 0)
3156 continue;
3157 if (ret < 0)
3158 goto error;
3159 break;
3160 }
3161 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3162
3163 if (found_key.objectid >= key->objectid &&
3164 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
3165 return 0;
3166 path->slots[0]++;
3167 }
3168 ret = -ENOENT;
3169 error:
3170 return ret;
3171 }
3172
3173 static void account_super_bytes(struct btrfs_fs_info *fs_info,
3174 struct btrfs_block_group_cache *cache)
3175 {
3176 u64 bytenr;
3177 u64 *logical;
3178 int stripe_len;
3179 int i, nr, ret;
3180
3181 if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
3182 stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
3183 cache->bytes_super += stripe_len;
3184 }
3185
3186 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
3187 bytenr = btrfs_sb_offset(i);
3188 ret = btrfs_rmap_block(&fs_info->mapping_tree,
3189 cache->key.objectid, bytenr,
3190 0, &logical, &nr, &stripe_len);
3191 if (ret)
3192 return;
3193
3194 while (nr--) {
3195 u64 start, len;
3196
3197 if (logical[nr] > cache->key.objectid +
3198 cache->key.offset)
3199 continue;
3200
3201 if (logical[nr] + stripe_len <= cache->key.objectid)
3202 continue;
3203
3204 start = logical[nr];
3205 if (start < cache->key.objectid) {
3206 start = cache->key.objectid;
3207 len = (logical[nr] + stripe_len) - start;
3208 } else {
3209 len = min_t(u64, stripe_len,
3210 cache->key.objectid +
3211 cache->key.offset - start);
3212 }
3213
3214 cache->bytes_super += len;
3215 }
3216
3217 kfree(logical);
3218 }
3219 }
3220
3221 int btrfs_read_block_groups(struct btrfs_root *root)
3222 {
3223 struct btrfs_path *path;
3224 int ret;
3225 int bit;
3226 struct btrfs_block_group_cache *cache;
3227 struct btrfs_fs_info *info = root->fs_info;
3228 struct btrfs_space_info *space_info;
3229 struct extent_io_tree *block_group_cache;
3230 struct btrfs_key key;
3231 struct btrfs_key found_key;
3232 struct extent_buffer *leaf;
3233
3234 block_group_cache = &info->block_group_cache;
3235
3236 root = info->extent_root;
3237 key.objectid = 0;
3238 key.offset = 0;
3239 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3240 path = btrfs_alloc_path();
3241 if (!path)
3242 return -ENOMEM;
3243
3244 while(1) {
3245 ret = find_first_block_group(root, path, &key);
3246 if (ret > 0) {
3247 ret = 0;
3248 goto error;
3249 }
3250 if (ret != 0) {
3251 goto error;
3252 }
3253 leaf = path->nodes[0];
3254 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3255 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3256 if (!cache) {
3257 ret = -ENOMEM;
3258 break;
3259 }
3260
3261 read_extent_buffer(leaf, &cache->item,
3262 btrfs_item_ptr_offset(leaf, path->slots[0]),
3263 sizeof(cache->item));
3264 memcpy(&cache->key, &found_key, sizeof(found_key));
3265 cache->cached = 0;
3266 cache->pinned = 0;
3267 key.objectid = found_key.objectid + found_key.offset;
3268 btrfs_release_path(path);
3269 cache->flags = btrfs_block_group_flags(&cache->item);
3270 bit = 0;
3271 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
3272 bit = BLOCK_GROUP_DATA;
3273 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
3274 bit = BLOCK_GROUP_SYSTEM;
3275 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
3276 bit = BLOCK_GROUP_METADATA;
3277 }
3278 set_avail_alloc_bits(info, cache->flags);
3279 if (btrfs_chunk_readonly(root, cache->key.objectid))
3280 cache->ro = 1;
3281
3282 account_super_bytes(info, cache);
3283
3284 ret = update_space_info(info, cache->flags, found_key.offset,
3285 btrfs_block_group_used(&cache->item),
3286 &space_info);
3287 BUG_ON(ret);
3288 cache->space_info = space_info;
3289
3290 /* use EXTENT_LOCKED to prevent merging */
3291 set_extent_bits(block_group_cache, found_key.objectid,
3292 found_key.objectid + found_key.offset - 1,
3293 bit | EXTENT_LOCKED, GFP_NOFS);
3294 set_state_private(block_group_cache, found_key.objectid,
3295 (unsigned long)cache);
3296 }
3297 ret = 0;
3298 error:
3299 btrfs_free_path(path);
3300 return ret;
3301 }
3302
3303 struct btrfs_block_group_cache *
3304 btrfs_add_block_group(struct btrfs_fs_info *fs_info, u64 bytes_used, u64 type,
3305 u64 chunk_objectid, u64 chunk_offset, u64 size)
3306 {
3307 int ret;
3308 int bit = 0;
3309 struct btrfs_block_group_cache *cache;
3310 struct extent_io_tree *block_group_cache;
3311
3312 block_group_cache = &fs_info->block_group_cache;
3313
3314 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3315 BUG_ON(!cache);
3316 cache->key.objectid = chunk_offset;
3317 cache->key.offset = size;
3318
3319 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3320 btrfs_set_block_group_used(&cache->item, bytes_used);
3321 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
3322 cache->flags = type;
3323 btrfs_set_block_group_flags(&cache->item, type);
3324
3325 account_super_bytes(fs_info, cache);
3326 ret = update_space_info(fs_info, cache->flags, size, bytes_used,
3327 &cache->space_info);
3328 BUG_ON(ret);
3329
3330 bit = block_group_state_bits(type);
3331 ret = set_extent_bits(block_group_cache, chunk_offset,
3332 chunk_offset + size - 1,
3333 bit | EXTENT_LOCKED, GFP_NOFS);
3334 BUG_ON(ret);
3335
3336 ret = set_state_private(block_group_cache, chunk_offset,
3337 (unsigned long)cache);
3338 BUG_ON(ret);
3339 set_avail_alloc_bits(fs_info, type);
3340
3341 return cache;
3342 }
3343
3344 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
3345 struct btrfs_root *root, u64 bytes_used,
3346 u64 type, u64 chunk_objectid, u64 chunk_offset,
3347 u64 size)
3348 {
3349 int ret;
3350 struct btrfs_root *extent_root;
3351 struct btrfs_block_group_cache *cache;
3352
3353 cache = btrfs_add_block_group(root->fs_info, bytes_used, type,
3354 chunk_objectid, chunk_offset, size);
3355 extent_root = root->fs_info->extent_root;
3356 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
3357 sizeof(cache->item));
3358 BUG_ON(ret);
3359
3360 ret = finish_current_insert(trans, extent_root);
3361 BUG_ON(ret);
3362 ret = del_pending_extents(trans, extent_root);
3363 BUG_ON(ret);
3364
3365 return 0;
3366 }
3367
3368 /*
3369 * This is for converter use only.
3370 *
3371 * In that case, we don't know where are free blocks located.
3372 * Therefore all block group cache entries must be setup properly
3373 * before doing any block allocation.
3374 */
3375 int btrfs_make_block_groups(struct btrfs_trans_handle *trans,
3376 struct btrfs_root *root)
3377 {
3378 u64 total_bytes;
3379 u64 cur_start;
3380 u64 group_type;
3381 u64 group_size;
3382 u64 group_align;
3383 u64 total_data = 0;
3384 u64 total_metadata = 0;
3385 u64 chunk_objectid;
3386 int ret;
3387 int bit;
3388 struct btrfs_root *extent_root;
3389 struct btrfs_block_group_cache *cache;
3390 struct extent_io_tree *block_group_cache;
3391
3392 extent_root = root->fs_info->extent_root;
3393 block_group_cache = &root->fs_info->block_group_cache;
3394 chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3395 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
3396 group_align = 64 * root->sectorsize;
3397
3398 cur_start = 0;
3399 while (cur_start < total_bytes) {
3400 group_size = total_bytes / 12;
3401 group_size = min_t(u64, group_size, total_bytes - cur_start);
3402 if (cur_start == 0) {
3403 bit = BLOCK_GROUP_SYSTEM;
3404 group_type = BTRFS_BLOCK_GROUP_SYSTEM;
3405 group_size /= 4;
3406 group_size &= ~(group_align - 1);
3407 group_size = max_t(u64, group_size, 8 * 1024 * 1024);
3408 group_size = min_t(u64, group_size, 32 * 1024 * 1024);
3409 } else {
3410 group_size &= ~(group_align - 1);
3411 if (total_data >= total_metadata * 2) {
3412 group_type = BTRFS_BLOCK_GROUP_METADATA;
3413 group_size = min_t(u64, group_size,
3414 1ULL * 1024 * 1024 * 1024);
3415 total_metadata += group_size;
3416 } else {
3417 group_type = BTRFS_BLOCK_GROUP_DATA;
3418 group_size = min_t(u64, group_size,
3419 5ULL * 1024 * 1024 * 1024);
3420 total_data += group_size;
3421 }
3422 if ((total_bytes - cur_start) * 4 < group_size * 5)
3423 group_size = total_bytes - cur_start;
3424 }
3425
3426 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3427 BUG_ON(!cache);
3428
3429 cache->key.objectid = cur_start;
3430 cache->key.offset = group_size;
3431 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3432
3433 btrfs_set_block_group_used(&cache->item, 0);
3434 btrfs_set_block_group_chunk_objectid(&cache->item,
3435 chunk_objectid);
3436 btrfs_set_block_group_flags(&cache->item, group_type);
3437
3438 cache->flags = group_type;
3439
3440 ret = update_space_info(root->fs_info, group_type, group_size,
3441 0, &cache->space_info);
3442 BUG_ON(ret);
3443 set_avail_alloc_bits(extent_root->fs_info, group_type);
3444
3445 set_extent_bits(block_group_cache, cur_start,
3446 cur_start + group_size - 1,
3447 bit | EXTENT_LOCKED, GFP_NOFS);
3448 set_state_private(block_group_cache, cur_start,
3449 (unsigned long)cache);
3450 cur_start += group_size;
3451 }
3452 /* then insert all the items */
3453 cur_start = 0;
3454 while(cur_start < total_bytes) {
3455 cache = btrfs_lookup_block_group(root->fs_info, cur_start);
3456 BUG_ON(!cache);
3457
3458 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
3459 sizeof(cache->item));
3460 BUG_ON(ret);
3461
3462 finish_current_insert(trans, extent_root);
3463 ret = del_pending_extents(trans, extent_root);
3464 BUG_ON(ret);
3465
3466 cur_start = cache->key.objectid + cache->key.offset;
3467 }
3468 return 0;
3469 }
3470
3471 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
3472 struct btrfs_root *root,
3473 u64 bytenr, u64 num_bytes, int alloc,
3474 int mark_free)
3475 {
3476 return update_block_group(trans, root, bytenr, num_bytes,
3477 alloc, mark_free);
3478 }
3479
3480 /*
3481 * Just remove a block group item in extent tree
3482 * Caller should ensure the block group is empty and all space is pinned.
3483 * Or new tree block/data may be allocated into it.
3484 */
3485 static int free_block_group_item(struct btrfs_trans_handle *trans,
3486 struct btrfs_fs_info *fs_info,
3487 u64 bytenr, u64 len)
3488 {
3489 struct btrfs_path *path;
3490 struct btrfs_key key;
3491 struct btrfs_root *root = fs_info->extent_root;
3492 int ret = 0;
3493
3494 key.objectid = bytenr;
3495 key.offset = len;
3496 key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
3497
3498 path = btrfs_alloc_path();
3499 if (!path)
3500 return -ENOMEM;
3501
3502 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3503 if (ret > 0) {
3504 ret = -ENOENT;
3505 goto out;
3506 }
3507 if (ret < 0)
3508 goto out;
3509
3510 ret = btrfs_del_item(trans, root, path);
3511 out:
3512 btrfs_free_path(path);
3513 return ret;
3514 }
3515
3516 static int free_dev_extent_item(struct btrfs_trans_handle *trans,
3517 struct btrfs_fs_info *fs_info,
3518 u64 devid, u64 dev_offset)
3519 {
3520 struct btrfs_root *root = fs_info->dev_root;
3521 struct btrfs_path *path;
3522 struct btrfs_key key;
3523 int ret;
3524
3525 path = btrfs_alloc_path();
3526 if (!path)
3527 return -ENOMEM;
3528
3529 key.objectid = devid;
3530 key.type = BTRFS_DEV_EXTENT_KEY;
3531 key.offset = dev_offset;
3532
3533 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3534 if (ret < 0)
3535 goto out;
3536 if (ret > 0) {
3537 ret = -ENOENT;
3538 goto out;
3539 }
3540
3541 ret = btrfs_del_item(trans, root, path);
3542 out:
3543 btrfs_free_path(path);
3544 return ret;
3545 }
3546
3547 static int free_chunk_dev_extent_items(struct btrfs_trans_handle *trans,
3548 struct btrfs_fs_info *fs_info,
3549 u64 chunk_offset)
3550 {
3551 struct btrfs_chunk *chunk = NULL;
3552 struct btrfs_root *root= fs_info->chunk_root;
3553 struct btrfs_path *path;
3554 struct btrfs_key key;
3555 u16 num_stripes;
3556 int i;
3557 int ret;
3558
3559 path = btrfs_alloc_path();
3560 if (!path)
3561 return -ENOMEM;
3562
3563 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3564 key.type = BTRFS_CHUNK_ITEM_KEY;
3565 key.offset = chunk_offset;
3566
3567 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
3568 if (ret < 0)
3569 goto out;
3570 if (ret > 0) {
3571 ret = -ENOENT;
3572 goto out;
3573 }
3574 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
3575 struct btrfs_chunk);
3576 num_stripes = btrfs_chunk_num_stripes(path->nodes[0], chunk);
3577 for (i = 0; i < num_stripes; i++) {
3578 ret = free_dev_extent_item(trans, fs_info,
3579 btrfs_stripe_devid_nr(path->nodes[0], chunk, i),
3580 btrfs_stripe_offset_nr(path->nodes[0], chunk, i));
3581 if (ret < 0)
3582 goto out;
3583 }
3584 out:
3585 btrfs_free_path(path);
3586 return ret;
3587 }
3588
3589 static int free_system_chunk_item(struct btrfs_super_block *super,
3590 struct btrfs_key *key)
3591 {
3592 struct btrfs_disk_key *disk_key;
3593 struct btrfs_key cpu_key;
3594 u32 array_size = btrfs_super_sys_array_size(super);
3595 char *ptr = (char *)super->sys_chunk_array;
3596 int cur = 0;
3597 int ret = -ENOENT;
3598
3599 while (cur < btrfs_super_sys_array_size(super)) {
3600 struct btrfs_chunk *chunk;
3601 u32 num_stripes;
3602 u32 chunk_len;
3603
3604 disk_key = (struct btrfs_disk_key *)(ptr + cur);
3605 btrfs_disk_key_to_cpu(&cpu_key, disk_key);
3606 if (cpu_key.type != BTRFS_CHUNK_ITEM_KEY) {
3607 /* just in case */
3608 ret = -EIO;
3609 goto out;
3610 }
3611
3612 chunk = (struct btrfs_chunk *)(ptr + cur + sizeof(*disk_key));
3613 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
3614 chunk_len = btrfs_chunk_item_size(num_stripes) +
3615 sizeof(*disk_key);
3616
3617 if (key->objectid == cpu_key.objectid &&
3618 key->offset == cpu_key.offset &&
3619 key->type == cpu_key.type) {
3620 memmove(ptr + cur, ptr + cur + chunk_len,
3621 array_size - cur - chunk_len);
3622 array_size -= chunk_len;
3623 btrfs_set_super_sys_array_size(super, array_size);
3624 ret = 0;
3625 goto out;
3626 }
3627
3628 cur += chunk_len;
3629 }
3630 out:
3631 return ret;
3632 }
3633
3634 static int free_chunk_item(struct btrfs_trans_handle *trans,
3635 struct btrfs_fs_info *fs_info,
3636 u64 bytenr, u64 len)
3637 {
3638 struct btrfs_path *path;
3639 struct btrfs_key key;
3640 struct btrfs_root *root = fs_info->chunk_root;
3641 struct btrfs_chunk *chunk;
3642 u64 chunk_type;
3643 int ret;
3644
3645 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3646 key.offset = bytenr;
3647 key.type = BTRFS_CHUNK_ITEM_KEY;
3648
3649 path = btrfs_alloc_path();
3650 if (!path)
3651 return -ENOMEM;
3652
3653 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3654 if (ret > 0) {
3655 ret = -ENOENT;
3656 goto out;
3657 }
3658 if (ret < 0)
3659 goto out;
3660 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
3661 struct btrfs_chunk);
3662 chunk_type = btrfs_chunk_type(path->nodes[0], chunk);
3663
3664 ret = btrfs_del_item(trans, root, path);
3665 if (ret < 0)
3666 goto out;
3667
3668 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
3669 ret = free_system_chunk_item(fs_info->super_copy, &key);
3670 out:
3671 btrfs_free_path(path);
3672 return ret;
3673 }
3674
3675 static u64 get_dev_extent_len(struct map_lookup *map)
3676 {
3677 int div;
3678
3679 switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
3680 case 0: /* Single */
3681 case BTRFS_BLOCK_GROUP_DUP:
3682 case BTRFS_BLOCK_GROUP_RAID1:
3683 div = 1;
3684 break;
3685 case BTRFS_BLOCK_GROUP_RAID5:
3686 div = (map->num_stripes - 1);
3687 break;
3688 case BTRFS_BLOCK_GROUP_RAID6:
3689 div = (map->num_stripes - 2);
3690 break;
3691 case BTRFS_BLOCK_GROUP_RAID10:
3692 div = (map->num_stripes / map->sub_stripes);
3693 break;
3694 default:
3695 /* normally, read chunk security hook should handled it */
3696 BUG_ON(1);
3697 }
3698 return map->ce.size / div;
3699 }
3700
3701 /* free block group/chunk related caches */
3702 static int free_block_group_cache(struct btrfs_trans_handle *trans,
3703 struct btrfs_fs_info *fs_info,
3704 u64 bytenr, u64 len)
3705 {
3706 struct btrfs_block_group_cache *cache;
3707 struct cache_extent *ce;
3708 struct map_lookup *map;
3709 int ret;
3710 int i;
3711 u64 flags;
3712
3713 /* Free block group cache first */
3714 cache = btrfs_lookup_block_group(fs_info, bytenr);
3715 if (!cache)
3716 return -ENOENT;
3717 flags = cache->flags;
3718 if (cache->free_space_ctl) {
3719 btrfs_remove_free_space_cache(cache);
3720 kfree(cache->free_space_ctl);
3721 }
3722 clear_extent_bits(&fs_info->block_group_cache, bytenr, bytenr + len,
3723 (unsigned int)-1, GFP_NOFS);
3724 ret = free_space_info(fs_info, flags, len, 0, NULL);
3725 if (ret < 0)
3726 goto out;
3727 kfree(cache);
3728
3729 /* Then free mapping info and dev usage info */
3730 ce = search_cache_extent(&fs_info->mapping_tree.cache_tree, bytenr);
3731 if (!ce || ce->start != bytenr) {
3732 ret = -ENOENT;
3733 goto out;
3734 }
3735 map = container_of(ce, struct map_lookup, ce);
3736 for (i = 0; i < map->num_stripes; i++) {
3737 struct btrfs_device *device;
3738
3739 device = map->stripes[i].dev;
3740 device->bytes_used -= get_dev_extent_len(map);
3741 ret = btrfs_update_device(trans, device);
3742 if (ret < 0)
3743 goto out;
3744 }
3745 remove_cache_extent(&fs_info->mapping_tree.cache_tree, ce);
3746 free(map);
3747 out:
3748 return ret;
3749 }
3750
3751 int btrfs_free_block_group(struct btrfs_trans_handle *trans,
3752 struct btrfs_fs_info *fs_info, u64 bytenr, u64 len)
3753 {
3754 struct btrfs_root *extent_root = fs_info->extent_root;
3755 struct btrfs_path *path;
3756 struct btrfs_block_group_item *bgi;
3757 struct btrfs_key key;
3758 int ret = 0;
3759
3760 path = btrfs_alloc_path();
3761 if (!path)
3762 return -ENOMEM;
3763
3764 key.objectid = bytenr;
3765 key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
3766 key.offset = len;
3767
3768 /* Double check the block group to ensure it's empty */
3769 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3770 if (ret > 0) {
3771 ret = -ENONET;
3772 goto out;
3773 }
3774 if (ret < 0)
3775 goto out;
3776
3777 bgi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3778 struct btrfs_block_group_item);
3779 if (btrfs_disk_block_group_used(path->nodes[0], bgi)) {
3780 fprintf(stderr,
3781 "WARNING: block group [%llu,%llu) is not empty\n",
3782 bytenr, bytenr + len);
3783 ret = -EINVAL;
3784 goto out;
3785 }
3786 btrfs_release_path(path);
3787
3788 /*
3789 * Now pin all space in the block group, to prevent further transaction
3790 * allocate space from it.
3791 * Every operation needs a transaction must be in the range.
3792 */
3793 btrfs_pin_extent(fs_info, bytenr, len);
3794
3795 /* delete block group item and chunk item */
3796 ret = free_block_group_item(trans, fs_info, bytenr, len);
3797 if (ret < 0) {
3798 fprintf(stderr,
3799 "failed to free block group item for [%llu,%llu)\n",
3800 bytenr, bytenr + len);
3801 btrfs_unpin_extent(fs_info, bytenr, len);
3802 goto out;
3803 }
3804
3805 ret = free_chunk_dev_extent_items(trans, fs_info, bytenr);
3806 if (ret < 0) {
3807 fprintf(stderr,
3808 "failed to dev extents belongs to [%llu,%llu)\n",
3809 bytenr, bytenr + len);
3810 btrfs_unpin_extent(fs_info, bytenr, len);
3811 goto out;
3812 }
3813 ret = free_chunk_item(trans, fs_info, bytenr, len);
3814 if (ret < 0) {
3815 fprintf(stderr,
3816 "failed to free chunk for [%llu,%llu)\n",
3817 bytenr, bytenr + len);
3818 btrfs_unpin_extent(fs_info, bytenr, len);
3819 goto out;
3820 }
3821
3822 /* Now release the block_group_cache */
3823 ret = free_block_group_cache(trans, fs_info, bytenr, len);
3824 btrfs_unpin_extent(fs_info, bytenr, len);
3825
3826 out:
3827 btrfs_free_path(path);
3828 return ret;
3829 }
3830
3831 /*
3832 * Fixup block accounting. The initial block accounting created by
3833 * make_block_groups isn't accuracy in this case.
3834 */
3835 int btrfs_fix_block_accounting(struct btrfs_trans_handle *trans,
3836 struct btrfs_root *root)
3837 {
3838 int ret;
3839 int slot;
3840 u64 start = 0;
3841 u64 bytes_used = 0;
3842 struct btrfs_path path;
3843 struct btrfs_key key;
3844 struct extent_buffer *leaf;
3845 struct btrfs_block_group_cache *cache;
3846 struct btrfs_fs_info *fs_info = root->fs_info;
3847
3848 root = root->fs_info->extent_root;
3849
3850 while(extent_root_pending_ops(fs_info)) {
3851 ret = finish_current_insert(trans, root);
3852 if (ret)
3853 return ret;
3854 ret = del_pending_extents(trans, root);
3855 if (ret)
3856 return ret;
3857 }
3858
3859 while(1) {
3860 cache = btrfs_lookup_first_block_group(fs_info, start);
3861 if (!cache)
3862 break;
3863 start = cache->key.objectid + cache->key.offset;
3864 btrfs_set_block_group_used(&cache->item, 0);
3865 cache->space_info->bytes_used = 0;
3866 set_extent_bits(&root->fs_info->block_group_cache,
3867 cache->key.objectid,
3868 cache->key.objectid + cache->key.offset -1,
3869 BLOCK_GROUP_DIRTY, GFP_NOFS);
3870 }
3871
3872 btrfs_init_path(&path);
3873 key.offset = 0;
3874 key.objectid = 0;
3875 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
3876 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
3877 &key, &path, 0, 0);
3878 if (ret < 0)
3879 return ret;
3880 while(1) {
3881 leaf = path.nodes[0];
3882 slot = path.slots[0];
3883 if (slot >= btrfs_header_nritems(leaf)) {
3884 ret = btrfs_next_leaf(root, &path);
3885 if (ret < 0)
3886 return ret;
3887 if (ret > 0)
3888 break;
3889 leaf = path.nodes[0];
3890 slot = path.slots[0];
3891 }
3892 btrfs_item_key_to_cpu(leaf, &key, slot);
3893 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
3894 bytes_used += key.offset;
3895 ret = btrfs_update_block_group(trans, root,
3896 key.objectid, key.offset, 1, 0);
3897 BUG_ON(ret);
3898 } else if (key.type == BTRFS_METADATA_ITEM_KEY) {
3899 bytes_used += root->leafsize;
3900 ret = btrfs_update_block_group(trans, root,
3901 key.objectid, root->leafsize, 1, 0);
3902 BUG_ON(ret);
3903 }
3904 path.slots[0]++;
3905 }
3906 btrfs_set_super_bytes_used(root->fs_info->super_copy, bytes_used);
3907 btrfs_release_path(&path);
3908 return 0;
3909 }
3910
3911 /*
3912 * Record a file extent. Do all the required works, such as inserting
3913 * file extent item, inserting extent item and backref item into extent
3914 * tree and updating block accounting.
3915 */
3916 int btrfs_record_file_extent(struct btrfs_trans_handle *trans,
3917 struct btrfs_root *root, u64 objectid,
3918 struct btrfs_inode_item *inode,
3919 u64 file_pos, u64 disk_bytenr,
3920 u64 num_bytes)
3921 {
3922 int ret;
3923 struct btrfs_fs_info *info = root->fs_info;
3924 struct btrfs_root *extent_root = info->extent_root;
3925 struct extent_buffer *leaf;
3926 struct btrfs_file_extent_item *fi;
3927 struct btrfs_key ins_key;
3928 struct btrfs_path path;
3929 struct btrfs_extent_item *ei;
3930 u64 nbytes;
3931
3932 if (disk_bytenr == 0) {
3933 ret = btrfs_insert_file_extent(trans, root, objectid,
3934 file_pos, disk_bytenr,
3935 num_bytes, num_bytes);
3936 return ret;
3937 }
3938
3939 btrfs_init_path(&path);
3940
3941 ins_key.objectid = objectid;
3942 ins_key.offset = file_pos;
3943 btrfs_set_key_type(&ins_key, BTRFS_EXTENT_DATA_KEY);
3944 ret = btrfs_insert_empty_item(trans, root, &path, &ins_key,
3945 sizeof(*fi));
3946 if (ret)
3947 goto fail;
3948 leaf = path.nodes[0];
3949 fi = btrfs_item_ptr(leaf, path.slots[0],
3950 struct btrfs_file_extent_item);
3951 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
3952 btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG);
3953 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
3954 btrfs_set_file_extent_disk_num_bytes(leaf, fi, num_bytes);
3955 btrfs_set_file_extent_offset(leaf, fi, 0);
3956 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
3957 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
3958 btrfs_set_file_extent_compression(leaf, fi, 0);
3959 btrfs_set_file_extent_encryption(leaf, fi, 0);
3960 btrfs_set_file_extent_other_encoding(leaf, fi, 0);
3961 btrfs_mark_buffer_dirty(leaf);
3962
3963 nbytes = btrfs_stack_inode_nbytes(inode) + num_bytes;
3964 btrfs_set_stack_inode_nbytes(inode, nbytes);
3965
3966 btrfs_release_path(&path);
3967
3968 ins_key.objectid = disk_bytenr;
3969 ins_key.offset = num_bytes;
3970 ins_key.type = BTRFS_EXTENT_ITEM_KEY;
3971
3972 ret = btrfs_insert_empty_item(trans, extent_root, &path,
3973 &ins_key, sizeof(*ei));
3974 if (ret == 0) {
3975 leaf = path.nodes[0];
3976 ei = btrfs_item_ptr(leaf, path.slots[0],
3977 struct btrfs_extent_item);
3978
3979 btrfs_set_extent_refs(leaf, ei, 0);
3980 btrfs_set_extent_generation(leaf, ei, 0);
3981 btrfs_set_extent_flags(leaf, ei, BTRFS_EXTENT_FLAG_DATA);
3982
3983 btrfs_mark_buffer_dirty(leaf);
3984
3985 ret = btrfs_update_block_group(trans, root, disk_bytenr,
3986 num_bytes, 1, 0);
3987 if (ret)
3988 goto fail;
3989 } else if (ret != -EEXIST) {
3990 goto fail;
3991 }
3992 btrfs_extent_post_op(trans, extent_root);
3993
3994 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr, num_bytes, 0,
3995 root->root_key.objectid,
3996 objectid, file_pos);
3997 if (ret)
3998 goto fail;
3999 ret = 0;
4000 fail:
4001 btrfs_release_path(&path);
4002 return ret;
4003 }
(deprecated) Btrfs progs developments and patch integration