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btrfs-progs: build with -D_FORTIFY_SOURCE=2
[btrfs-progs-unstable.git] / extent-tree.c
blob413c8161e4b570ee69e15e54f674d912dd046e0f
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include "kerncompat.h"
22 #include "radix-tree.h"
23 #include "ctree.h"
24 #include "disk-io.h"
25 #include "print-tree.h"
26 #include "transaction.h"
27 #include "crc32c.h"
28
29 #define BLOCK_GROUP_DATA EXTENT_WRITEBACK
30 #define BLOCK_GROUP_METADATA EXTENT_UPTODATE
31 #define BLOCK_GROUP_DIRTY EXTENT_DIRTY
32
33 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
34 btrfs_root *extent_root);
35 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
36 btrfs_root *extent_root);
37 static int find_previous_extent(struct btrfs_root *root,
38 struct btrfs_path *path)
39 {
40 struct btrfs_key found_key;
41 struct extent_buffer *leaf;
42 int ret;
43
44 while(1) {
45 if (path->slots[0] == 0) {
46 ret = btrfs_prev_leaf(root, path);
47 if (ret != 0)
48 return ret;
49 } else {
50 path->slots[0]--;
51 }
52 leaf = path->nodes[0];
53 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
54 if (found_key.type == BTRFS_EXTENT_ITEM_KEY)
55 return 0;
56 }
57 return 1;
58 }
59 static int cache_block_group(struct btrfs_root *root,
60 struct btrfs_block_group_cache *block_group)
61 {
62 struct btrfs_path *path;
63 int ret;
64 struct btrfs_key key;
65 struct extent_buffer *leaf;
66 struct extent_map_tree *free_space_cache;
67 int slot;
68 u64 last = 0;
69 u64 hole_size;
70 u64 first_free;
71 int found = 0;
72
73 if (!block_group)
74 return 0;
75
76 root = root->fs_info->extent_root;
77 free_space_cache = &root->fs_info->free_space_cache;
78
79 if (block_group->cached)
80 return 0;
81
82 path = btrfs_alloc_path();
83 if (!path)
84 return -ENOMEM;
85
86 path->reada = 2;
87 first_free = block_group->key.objectid;
88 key.objectid = block_group->key.objectid;
89 key.offset = 0;
90 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
91 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
92 if (ret < 0)
93 return ret;
94 ret = find_previous_extent(root, path);
95 if (ret < 0)
96 return ret;
97 if (ret == 0) {
98 leaf = path->nodes[0];
99 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
100 if (key.objectid + key.offset > first_free)
101 first_free = key.objectid + key.offset;
102 }
103 while(1) {
104 leaf = path->nodes[0];
105 slot = path->slots[0];
106 if (slot >= btrfs_header_nritems(leaf)) {
107 ret = btrfs_next_leaf(root, path);
108 if (ret < 0)
109 goto err;
110 if (ret == 0) {
111 continue;
112 } else {
113 break;
114 }
115 }
116 btrfs_item_key_to_cpu(leaf, &key, slot);
117 if (key.objectid < block_group->key.objectid) {
118 goto next;
119 }
120 if (key.objectid >= block_group->key.objectid +
121 block_group->key.offset) {
122 break;
123 }
124
125 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
126 if (!found) {
127 last = first_free;
128 found = 1;
129 }
130 if (key.objectid > last) {
131 hole_size = key.objectid - last;
132 set_extent_dirty(free_space_cache, last,
133 last + hole_size - 1,
134 GFP_NOFS);
135 }
136 last = key.objectid + key.offset;
137 }
138 next:
139 path->slots[0]++;
140 }
141
142 if (!found)
143 last = first_free;
144 if (block_group->key.objectid +
145 block_group->key.offset > last) {
146 hole_size = block_group->key.objectid +
147 block_group->key.offset - last;
148 set_extent_dirty(free_space_cache, last,
149 last + hole_size - 1, GFP_NOFS);
150 }
151 block_group->cached = 1;
152 err:
153 btrfs_free_path(path);
154 return 0;
155 }
156
157 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
158 btrfs_fs_info *info,
159 u64 bytenr)
160 {
161 struct extent_map_tree *block_group_cache;
162 struct btrfs_block_group_cache *block_group = NULL;
163 u64 ptr;
164 u64 start;
165 u64 end;
166 int ret;
167
168 block_group_cache = &info->block_group_cache;
169 ret = find_first_extent_bit(block_group_cache,
170 bytenr, &start, &end,
171 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA);
172 if (ret) {
173 return NULL;
174 }
175 ret = get_state_private(block_group_cache, start, &ptr);
176 if (ret)
177 return NULL;
178
179 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
180 if (block_group->key.objectid <= bytenr && bytenr <
181 block_group->key.objectid + block_group->key.offset)
182 return block_group;
183 return NULL;
184 }
185 static u64 noinline find_search_start(struct btrfs_root *root,
186 struct btrfs_block_group_cache **cache_ret,
187 u64 search_start, int num, int data)
188 {
189 int ret;
190 struct btrfs_block_group_cache *cache = *cache_ret;
191 u64 last;
192 u64 start = 0;
193 u64 end = 0;
194 u64 cache_miss = 0;
195 int wrapped = 0;
196
197 if (!cache) {
198 goto out;
199 }
200 again:
201 ret = cache_block_group(root, cache);
202 if (ret)
203 goto out;
204
205 last = max(search_start, cache->key.objectid);
206
207 while(1) {
208 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
209 last, &start, &end, EXTENT_DIRTY);
210 if (ret) {
211 if (!cache_miss)
212 cache_miss = last;
213 goto new_group;
214 }
215
216 start = max(last, start);
217 last = end + 1;
218 if (last - start < num) {
219 if (last == cache->key.objectid + cache->key.offset)
220 cache_miss = start;
221 continue;
222 }
223 if (data != BTRFS_BLOCK_GROUP_MIXED &&
224 start + num > cache->key.objectid + cache->key.offset)
225 goto new_group;
226 return start;
227 }
228 out:
229 cache = btrfs_lookup_block_group(root->fs_info, search_start);
230 if (!cache) {
231 printk("Unable to find block group for %Lu\n",
232 search_start);
233 WARN_ON(1);
234 return search_start;
235 }
236 return search_start;
237
238 new_group:
239 last = cache->key.objectid + cache->key.offset;
240 wrapped:
241 cache = btrfs_lookup_block_group(root->fs_info, last);
242 if (!cache) {
243 no_cache:
244 if (!wrapped) {
245 wrapped = 1;
246 last = search_start;
247 data = BTRFS_BLOCK_GROUP_MIXED;
248 goto wrapped;
249 }
250 goto out;
251 }
252 if (cache_miss && !cache->cached) {
253 cache_block_group(root, cache);
254 last = cache_miss;
255 cache = btrfs_lookup_block_group(root->fs_info, last);
256 }
257 cache = btrfs_find_block_group(root, cache, last, data, 0);
258 if (!cache)
259 goto no_cache;
260 *cache_ret = cache;
261 cache_miss = 0;
262 goto again;
263 }
264
265 static u64 div_factor(u64 num, int factor)
266 {
267 if (factor == 10)
268 return num;
269 num *= factor;
270 num /= 10;
271 return num;
272 }
273
274 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
275 struct btrfs_block_group_cache
276 *hint, u64 search_start,
277 int data, int owner)
278 {
279 struct btrfs_block_group_cache *cache;
280 struct extent_map_tree *block_group_cache;
281 struct btrfs_block_group_cache *found_group = NULL;
282 struct btrfs_fs_info *info = root->fs_info;
283 u64 used;
284 u64 last = 0;
285 u64 hint_last;
286 u64 start;
287 u64 end;
288 u64 free_check;
289 u64 ptr;
290 int bit;
291 int ret;
292 int full_search = 0;
293 int factor = 8;
294 int data_swap = 0;
295
296 block_group_cache = &info->block_group_cache;
297
298 if (!owner)
299 factor = 8;
300
301 if (data == BTRFS_BLOCK_GROUP_MIXED) {
302 bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
303 factor = 10;
304 } else if (data)
305 bit = BLOCK_GROUP_DATA;
306 else
307 bit = BLOCK_GROUP_METADATA;
308
309 if (search_start) {
310 struct btrfs_block_group_cache *shint;
311 shint = btrfs_lookup_block_group(info, search_start);
312 if (shint && (shint->data == data ||
313 shint->data == BTRFS_BLOCK_GROUP_MIXED)) {
314 used = btrfs_block_group_used(&shint->item);
315 if (used + shint->pinned <
316 div_factor(shint->key.offset, factor)) {
317 return shint;
318 }
319 }
320 }
321 if (hint && (hint->data == data ||
322 hint->data == BTRFS_BLOCK_GROUP_MIXED)) {
323 used = btrfs_block_group_used(&hint->item);
324 if (used + hint->pinned <
325 div_factor(hint->key.offset, factor)) {
326 return hint;
327 }
328 last = hint->key.objectid + hint->key.offset;
329 hint_last = last;
330 } else {
331 if (hint)
332 hint_last = max(hint->key.objectid, search_start);
333 else
334 hint_last = search_start;
335
336 last = hint_last;
337 }
338 again:
339 while(1) {
340 ret = find_first_extent_bit(block_group_cache, last,
341 &start, &end, bit);
342 if (ret)
343 break;
344
345 ret = get_state_private(block_group_cache, start, &ptr);
346 if (ret)
347 break;
348
349 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
350 last = cache->key.objectid + cache->key.offset;
351 used = btrfs_block_group_used(&cache->item);
352
353 if (full_search)
354 free_check = cache->key.offset;
355 else
356 free_check = div_factor(cache->key.offset, factor);
357 if (used + cache->pinned < free_check) {
358 found_group = cache;
359 goto found;
360 }
361 cond_resched();
362 }
363 if (!full_search) {
364 last = search_start;
365 full_search = 1;
366 goto again;
367 }
368 if (!data_swap) {
369 data_swap = 1;
370 bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
371 last = search_start;
372 goto again;
373 }
374 found:
375 return found_group;
376 }
377
378 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
379 u64 owner, u64 owner_offset)
380 {
381 u32 high_crc = ~(u32)0;
382 u32 low_crc = ~(u32)0;
383 __le64 lenum;
384
385 lenum = cpu_to_le64(root_objectid);
386 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
387 lenum = cpu_to_le64(ref_generation);
388 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
389
390 #if 0
391 lenum = cpu_to_le64(owner);
392 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
393 lenum = cpu_to_le64(owner_offset);
394 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
395 #endif
396 return ((u64)high_crc << 32) | (u64)low_crc;
397 }
398
399 static int match_extent_ref(struct extent_buffer *leaf,
400 struct btrfs_extent_ref *disk_ref,
401 struct btrfs_extent_ref *cpu_ref)
402 {
403 int ret;
404 int len;
405
406 if (cpu_ref->objectid)
407 len = sizeof(*cpu_ref);
408 else
409 len = 2 * sizeof(u64);
410 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
411 len);
412 return ret == 0;
413 }
414
415 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
416 struct btrfs_root *root,
417 struct btrfs_path *path, u64 bytenr,
418 u64 root_objectid,
419 u64 ref_generation, u64 owner,
420 u64 owner_offset, int del)
421 {
422 u64 hash;
423 struct btrfs_key key;
424 struct btrfs_key found_key;
425 struct btrfs_extent_ref ref;
426 struct extent_buffer *leaf;
427 struct btrfs_extent_ref *disk_ref;
428 int ret;
429 int ret2;
430
431 btrfs_set_stack_ref_root(&ref, root_objectid);
432 btrfs_set_stack_ref_generation(&ref, ref_generation);
433 btrfs_set_stack_ref_objectid(&ref, owner);
434 btrfs_set_stack_ref_offset(&ref, owner_offset);
435
436 hash = hash_extent_ref(root_objectid, ref_generation, owner,
437 owner_offset);
438 key.offset = hash;
439 key.objectid = bytenr;
440 key.type = BTRFS_EXTENT_REF_KEY;
441
442 while (1) {
443 ret = btrfs_search_slot(trans, root, &key, path,
444 del ? -1 : 0, del);
445 if (ret < 0)
446 goto out;
447 leaf = path->nodes[0];
448 if (ret != 0) {
449 u32 nritems = btrfs_header_nritems(leaf);
450 if (path->slots[0] >= nritems) {
451 ret2 = btrfs_next_leaf(root, path);
452 if (ret2)
453 goto out;
454 leaf = path->nodes[0];
455 }
456 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
457 if (found_key.objectid != bytenr ||
458 found_key.type != BTRFS_EXTENT_REF_KEY)
459 goto out;
460 key.offset = found_key.offset;
461 if (del) {
462 btrfs_release_path(root, path);
463 continue;
464 }
465 }
466 disk_ref = btrfs_item_ptr(path->nodes[0],
467 path->slots[0],
468 struct btrfs_extent_ref);
469 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
470 ret = 0;
471 goto out;
472 }
473 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
474 key.offset = found_key.offset + 1;
475 btrfs_release_path(root, path);
476 }
477 out:
478 return ret;
479 }
480
481 /*
482 * Back reference rules. Back refs have three main goals:
483 *
484 * 1) differentiate between all holders of references to an extent so that
485 * when a reference is dropped we can make sure it was a valid reference
486 * before freeing the extent.
487 *
488 * 2) Provide enough information to quickly find the holders of an extent
489 * if we notice a given block is corrupted or bad.
490 *
491 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
492 * maintenance. This is actually the same as #2, but with a slightly
493 * different use case.
494 *
495 * File extents can be referenced by:
496 *
497 * - multiple snapshots, subvolumes, or different generations in one subvol
498 * - different files inside a single subvolume (in theory, not implemented yet)
499 * - different offsets inside a file (bookend extents in file.c)
500 *
501 * The extent ref structure has fields for:
502 *
503 * - Objectid of the subvolume root
504 * - Generation number of the tree holding the reference
505 * - objectid of the file holding the reference
506 * - offset in the file corresponding to the key holding the reference
507 *
508 * When a file extent is allocated the fields are filled in:
509 * (root_key.objectid, trans->transid, inode objectid, offset in file)
510 *
511 * When a leaf is cow'd new references are added for every file extent found
512 * in the leaf. It looks the same as the create case, but trans->transid
513 * will be different when the block is cow'd.
514 *
515 * (root_key.objectid, trans->transid, inode objectid, offset in file)
516 *
517 * When a file extent is removed either during snapshot deletion or file
518 * truncation, the corresponding back reference is found
519 * by searching for:
520 *
521 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
522 * inode objectid, offset in file)
523 *
524 * Btree extents can be referenced by:
525 *
526 * - Different subvolumes
527 * - Different generations of the same subvolume
528 *
529 * Storing sufficient information for a full reverse mapping of a btree
530 * block would require storing the lowest key of the block in the backref,
531 * and it would require updating that lowest key either before write out or
532 * every time it changed. Instead, the objectid of the lowest key is stored
533 * along with the level of the tree block. This provides a hint
534 * about where in the btree the block can be found. Searches through the
535 * btree only need to look for a pointer to that block, so they stop one
536 * level higher than the level recorded in the backref.
537 *
538 * Some btrees do not do reference counting on their extents. These
539 * include the extent tree and the tree of tree roots. Backrefs for these
540 * trees always have a generation of zero.
541 *
542 * When a tree block is created, back references are inserted:
543 *
544 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
545 *
546 * When a tree block is cow'd in a reference counted root,
547 * new back references are added for all the blocks it points to.
548 * These are of the form (trans->transid will have increased since creation):
549 *
550 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
551 *
552 * Because the lowest_key_objectid and the level are just hints
553 * they are not used when backrefs are deleted. When a backref is deleted:
554 *
555 * if backref was for a tree root:
556 * root_objectid = root->root_key.objectid
557 * else
558 * root_objectid = btrfs_header_owner(parent)
559 *
560 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
561 *
562 * Back Reference Key hashing:
563 *
564 * Back references have four fields, each 64 bits long. Unfortunately,
565 * This is hashed into a single 64 bit number and placed into the key offset.
566 * The key objectid corresponds to the first byte in the extent, and the
567 * key type is set to BTRFS_EXTENT_REF_KEY
568 */
569 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
570 struct btrfs_root *root,
571 struct btrfs_path *path, u64 bytenr,
572 u64 root_objectid, u64 ref_generation,
573 u64 owner, u64 owner_offset)
574 {
575 u64 hash;
576 struct btrfs_key key;
577 struct btrfs_extent_ref ref;
578 struct btrfs_extent_ref *disk_ref;
579 int ret;
580
581 btrfs_set_stack_ref_root(&ref, root_objectid);
582 btrfs_set_stack_ref_generation(&ref, ref_generation);
583 btrfs_set_stack_ref_objectid(&ref, owner);
584 btrfs_set_stack_ref_offset(&ref, owner_offset);
585
586 hash = hash_extent_ref(root_objectid, ref_generation, owner,
587 owner_offset);
588 key.offset = hash;
589 key.objectid = bytenr;
590 key.type = BTRFS_EXTENT_REF_KEY;
591
592 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
593 while (ret == -EEXIST) {
594 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
595 struct btrfs_extent_ref);
596 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
597 goto out;
598 key.offset++;
599 btrfs_release_path(root, path);
600 ret = btrfs_insert_empty_item(trans, root, path, &key,
601 sizeof(ref));
602 }
603 if (ret)
604 goto out;
605 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
606 struct btrfs_extent_ref);
607 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
608 sizeof(ref));
609 btrfs_mark_buffer_dirty(path->nodes[0]);
610 out:
611 btrfs_release_path(root, path);
612 return ret;
613 }
614
615 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
616 struct btrfs_root *root,
617 u64 bytenr, u64 num_bytes,
618 u64 root_objectid, u64 ref_generation,
619 u64 owner, u64 owner_offset)
620 {
621 struct btrfs_path *path;
622 int ret;
623 struct btrfs_key key;
624 struct extent_buffer *l;
625 struct btrfs_extent_item *item;
626 u32 refs;
627
628 WARN_ON(num_bytes < root->sectorsize);
629 path = btrfs_alloc_path();
630 if (!path)
631 return -ENOMEM;
632
633 key.objectid = bytenr;
634 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
635 key.offset = num_bytes;
636 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
637 0, 1);
638 if (ret < 0)
639 return ret;
640 if (ret != 0) {
641 BUG();
642 }
643 BUG_ON(ret != 0);
644 l = path->nodes[0];
645 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
646 refs = btrfs_extent_refs(l, item);
647 btrfs_set_extent_refs(l, item, refs + 1);
648 btrfs_mark_buffer_dirty(path->nodes[0]);
649
650 btrfs_release_path(root->fs_info->extent_root, path);
651
652 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
653 path, bytenr, root_objectid,
654 ref_generation, owner, owner_offset);
655 BUG_ON(ret);
656 finish_current_insert(trans, root->fs_info->extent_root);
657 del_pending_extents(trans, root->fs_info->extent_root);
658
659 btrfs_free_path(path);
660 return 0;
661 }
662
663 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
664 struct btrfs_root *root)
665 {
666 finish_current_insert(trans, root->fs_info->extent_root);
667 del_pending_extents(trans, root->fs_info->extent_root);
668 return 0;
669 }
670
671 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
672 struct btrfs_root *root, u64 bytenr,
673 u64 num_bytes, u32 *refs)
674 {
675 struct btrfs_path *path;
676 int ret;
677 struct btrfs_key key;
678 struct extent_buffer *l;
679 struct btrfs_extent_item *item;
680
681 WARN_ON(num_bytes < root->sectorsize);
682 path = btrfs_alloc_path();
683 key.objectid = bytenr;
684 key.offset = num_bytes;
685 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
686 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
687 0, 0);
688 if (ret < 0)
689 goto out;
690 if (ret != 0) {
691 btrfs_print_leaf(root, path->nodes[0]);
692 printk("failed to find block number %Lu\n", bytenr);
693 BUG();
694 }
695 l = path->nodes[0];
696 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
697 *refs = btrfs_extent_refs(l, item);
698 out:
699 btrfs_free_path(path);
700 return 0;
701 }
702
703 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
704 struct btrfs_path *count_path,
705 u64 first_extent)
706 {
707 struct btrfs_root *extent_root = root->fs_info->extent_root;
708 struct btrfs_path *path;
709 u64 bytenr;
710 u64 found_objectid;
711 u64 root_objectid = root->root_key.objectid;
712 u32 total_count = 0;
713 u32 cur_count;
714 u32 refs;
715 u32 nritems;
716 int ret;
717 struct btrfs_key key;
718 struct btrfs_key found_key;
719 struct extent_buffer *l;
720 struct btrfs_extent_item *item;
721 struct btrfs_extent_ref *ref_item;
722 int level = -1;
723
724 path = btrfs_alloc_path();
725 again:
726 if (level == -1)
727 bytenr = first_extent;
728 else
729 bytenr = count_path->nodes[level]->start;
730
731 cur_count = 0;
732 key.objectid = bytenr;
733 key.offset = 0;
734
735 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
736 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
737 if (ret < 0)
738 goto out;
739 BUG_ON(ret == 0);
740
741 l = path->nodes[0];
742 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
743
744 if (found_key.objectid != bytenr ||
745 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
746 goto out;
747 }
748
749 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
750 refs = btrfs_extent_refs(l, item);
751 while (1) {
752 nritems = btrfs_header_nritems(l);
753 if (path->slots[0] >= nritems) {
754 ret = btrfs_next_leaf(extent_root, path);
755 if (ret == 0)
756 continue;
757 break;
758 }
759 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
760 if (found_key.objectid != bytenr)
761 break;
762 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
763 path->slots[0]++;
764 continue;
765 }
766
767 cur_count++;
768 ref_item = btrfs_item_ptr(l, path->slots[0],
769 struct btrfs_extent_ref);
770 found_objectid = btrfs_ref_root(l, ref_item);
771
772 if (found_objectid != root_objectid) {
773 total_count = 2;
774 goto out;
775 }
776 total_count = 1;
777 path->slots[0]++;
778 }
779 if (cur_count == 0) {
780 total_count = 0;
781 goto out;
782 }
783 if (level >= 0 && root->node == count_path->nodes[level])
784 goto out;
785 level++;
786 btrfs_release_path(root, path);
787 goto again;
788
789 out:
790 btrfs_free_path(path);
791 return total_count;
792 }
793 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
794 struct btrfs_root *root, u64 owner_objectid)
795 {
796 u64 generation;
797 u64 key_objectid;
798 u64 level;
799 u32 nritems;
800 struct btrfs_disk_key disk_key;
801
802 level = btrfs_header_level(root->node);
803 generation = trans->transid;
804 nritems = btrfs_header_nritems(root->node);
805 if (nritems > 0) {
806 if (level == 0)
807 btrfs_item_key(root->node, &disk_key, 0);
808 else
809 btrfs_node_key(root->node, &disk_key, 0);
810 key_objectid = btrfs_disk_key_objectid(&disk_key);
811 } else {
812 key_objectid = 0;
813 }
814 return btrfs_inc_extent_ref(trans, root, root->node->start,
815 root->node->len, owner_objectid,
816 generation, level, key_objectid);
817 }
818
819 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
820 struct extent_buffer *buf)
821 {
822 u64 bytenr;
823 u32 nritems;
824 struct btrfs_key key;
825 struct btrfs_file_extent_item *fi;
826 int i;
827 int level;
828 int ret;
829 int faili;
830
831 if (!root->ref_cows)
832 return 0;
833
834 level = btrfs_header_level(buf);
835 nritems = btrfs_header_nritems(buf);
836 for (i = 0; i < nritems; i++) {
837 if (level == 0) {
838 u64 disk_bytenr;
839 btrfs_item_key_to_cpu(buf, &key, i);
840 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
841 continue;
842 fi = btrfs_item_ptr(buf, i,
843 struct btrfs_file_extent_item);
844 if (btrfs_file_extent_type(buf, fi) ==
845 BTRFS_FILE_EXTENT_INLINE)
846 continue;
847 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
848 if (disk_bytenr == 0)
849 continue;
850 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
851 btrfs_file_extent_disk_num_bytes(buf, fi),
852 root->root_key.objectid, trans->transid,
853 key.objectid, key.offset);
854 if (ret) {
855 faili = i;
856 goto fail;
857 }
858 } else {
859 bytenr = btrfs_node_blockptr(buf, i);
860 btrfs_node_key_to_cpu(buf, &key, i);
861 ret = btrfs_inc_extent_ref(trans, root, bytenr,
862 btrfs_level_size(root, level - 1),
863 root->root_key.objectid,
864 trans->transid,
865 level - 1, key.objectid);
866 if (ret) {
867 faili = i;
868 goto fail;
869 }
870 }
871 }
872 return 0;
873 fail:
874 WARN_ON(1);
875 #if 0
876 for (i =0; i < faili; i++) {
877 if (level == 0) {
878 u64 disk_bytenr;
879 btrfs_item_key_to_cpu(buf, &key, i);
880 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
881 continue;
882 fi = btrfs_item_ptr(buf, i,
883 struct btrfs_file_extent_item);
884 if (btrfs_file_extent_type(buf, fi) ==
885 BTRFS_FILE_EXTENT_INLINE)
886 continue;
887 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
888 if (disk_bytenr == 0)
889 continue;
890 err = btrfs_free_extent(trans, root, disk_bytenr,
891 btrfs_file_extent_disk_num_bytes(buf,
892 fi), 0);
893 BUG_ON(err);
894 } else {
895 bytenr = btrfs_node_blockptr(buf, i);
896 err = btrfs_free_extent(trans, root, bytenr,
897 btrfs_level_size(root, level - 1), 0);
898 BUG_ON(err);
899 }
900 }
901 #endif
902 return ret;
903 }
904
905 static int write_one_cache_group(struct btrfs_trans_handle *trans,
906 struct btrfs_root *root,
907 struct btrfs_path *path,
908 struct btrfs_block_group_cache *cache)
909 {
910 int ret;
911 int pending_ret;
912 struct btrfs_root *extent_root = root->fs_info->extent_root;
913 unsigned long bi;
914 struct extent_buffer *leaf;
915
916 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
917 if (ret < 0)
918 goto fail;
919 BUG_ON(ret);
920
921 leaf = path->nodes[0];
922 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
923 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
924 btrfs_mark_buffer_dirty(leaf);
925 btrfs_release_path(extent_root, path);
926 fail:
927 finish_current_insert(trans, extent_root);
928 pending_ret = del_pending_extents(trans, extent_root);
929 if (ret)
930 return ret;
931 if (pending_ret)
932 return pending_ret;
933 return 0;
934
935 }
936
937 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
938 struct btrfs_root *root)
939 {
940 struct extent_map_tree *block_group_cache;
941 struct btrfs_block_group_cache *cache;
942 int ret;
943 int err = 0;
944 int werr = 0;
945 struct btrfs_path *path;
946 u64 last = 0;
947 u64 start;
948 u64 end;
949 u64 ptr;
950
951 block_group_cache = &root->fs_info->block_group_cache;
952 path = btrfs_alloc_path();
953 if (!path)
954 return -ENOMEM;
955
956 while(1) {
957 ret = find_first_extent_bit(block_group_cache, last,
958 &start, &end, BLOCK_GROUP_DIRTY);
959 if (ret)
960 break;
961
962 last = end + 1;
963 ret = get_state_private(block_group_cache, start, &ptr);
964 if (ret)
965 break;
966
967 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
968 err = write_one_cache_group(trans, root,
969 path, cache);
970 /*
971 * if we fail to write the cache group, we want
972 * to keep it marked dirty in hopes that a later
973 * write will work
974 */
975 if (err) {
976 werr = err;
977 continue;
978 }
979 clear_extent_bits(block_group_cache, start, end,
980 BLOCK_GROUP_DIRTY, GFP_NOFS);
981 }
982 btrfs_free_path(path);
983 return werr;
984 }
985
986 static int update_block_group(struct btrfs_trans_handle *trans,
987 struct btrfs_root *root,
988 u64 bytenr, u64 num_bytes, int alloc,
989 int mark_free, int data)
990 {
991 struct btrfs_block_group_cache *cache;
992 struct btrfs_fs_info *info = root->fs_info;
993 u64 total = num_bytes;
994 u64 old_val;
995 u64 byte_in_group;
996 u64 start;
997 u64 end;
998
999 while(total) {
1000 cache = btrfs_lookup_block_group(info, bytenr);
1001 if (!cache) {
1002 return -1;
1003 }
1004 byte_in_group = bytenr - cache->key.objectid;
1005 WARN_ON(byte_in_group > cache->key.offset);
1006 start = cache->key.objectid;
1007 end = start + cache->key.offset - 1;
1008 set_extent_bits(&info->block_group_cache, start, end,
1009 BLOCK_GROUP_DIRTY, GFP_NOFS);
1010
1011 old_val = btrfs_block_group_used(&cache->item);
1012 num_bytes = min(total, cache->key.offset - byte_in_group);
1013 if (alloc) {
1014 if (cache->data != data &&
1015 old_val < (cache->key.offset >> 1)) {
1016 int bit_to_clear;
1017 int bit_to_set;
1018 cache->data = data;
1019 if (data) {
1020 bit_to_clear = BLOCK_GROUP_METADATA;
1021 bit_to_set = BLOCK_GROUP_DATA;
1022 cache->item.flags &=
1023 ~BTRFS_BLOCK_GROUP_MIXED;
1024 cache->item.flags |=
1025 BTRFS_BLOCK_GROUP_DATA;
1026 } else {
1027 bit_to_clear = BLOCK_GROUP_DATA;
1028 bit_to_set = BLOCK_GROUP_METADATA;
1029 cache->item.flags &=
1030 ~BTRFS_BLOCK_GROUP_MIXED;
1031 cache->item.flags &=
1032 ~BTRFS_BLOCK_GROUP_DATA;
1033 }
1034 clear_extent_bits(&info->block_group_cache,
1035 start, end, bit_to_clear,
1036 GFP_NOFS);
1037 set_extent_bits(&info->block_group_cache,
1038 start, end, bit_to_set,
1039 GFP_NOFS);
1040 } else if (cache->data != data &&
1041 cache->data != BTRFS_BLOCK_GROUP_MIXED) {
1042 cache->data = BTRFS_BLOCK_GROUP_MIXED;
1043 set_extent_bits(&info->block_group_cache,
1044 start, end,
1045 BLOCK_GROUP_DATA |
1046 BLOCK_GROUP_METADATA,
1047 GFP_NOFS);
1048 }
1049 old_val += num_bytes;
1050 } else {
1051 old_val -= num_bytes;
1052 if (mark_free) {
1053 set_extent_dirty(&info->free_space_cache,
1054 bytenr, bytenr + num_bytes - 1,
1055 GFP_NOFS);
1056 }
1057 }
1058 btrfs_set_block_group_used(&cache->item, old_val);
1059 total -= num_bytes;
1060 bytenr += num_bytes;
1061 }
1062 return 0;
1063 }
1064 static int update_pinned_extents(struct btrfs_root *root,
1065 u64 bytenr, u64 num, int pin)
1066 {
1067 u64 len;
1068 struct btrfs_block_group_cache *cache;
1069 struct btrfs_fs_info *fs_info = root->fs_info;
1070
1071 if (pin) {
1072 set_extent_dirty(&fs_info->pinned_extents,
1073 bytenr, bytenr + num - 1, GFP_NOFS);
1074 } else {
1075 clear_extent_dirty(&fs_info->pinned_extents,
1076 bytenr, bytenr + num - 1, GFP_NOFS);
1077 }
1078 while (num > 0) {
1079 cache = btrfs_lookup_block_group(fs_info, bytenr);
1080 WARN_ON(!cache);
1081 len = min(num, cache->key.offset -
1082 (bytenr - cache->key.objectid));
1083 if (pin) {
1084 cache->pinned += len;
1085 fs_info->total_pinned += len;
1086 } else {
1087 cache->pinned -= len;
1088 fs_info->total_pinned -= len;
1089 }
1090 bytenr += len;
1091 num -= len;
1092 }
1093 return 0;
1094 }
1095
1096 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_map_tree *copy)
1097 {
1098 u64 last = 0;
1099 u64 start;
1100 u64 end;
1101 struct extent_map_tree *pinned_extents = &root->fs_info->pinned_extents;
1102 int ret;
1103
1104 while(1) {
1105 ret = find_first_extent_bit(pinned_extents, last,
1106 &start, &end, EXTENT_DIRTY);
1107 if (ret)
1108 break;
1109 set_extent_dirty(copy, start, end, GFP_NOFS);
1110 last = end + 1;
1111 }
1112 return 0;
1113 }
1114
1115 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1116 struct btrfs_root *root,
1117 struct extent_map_tree *unpin)
1118 {
1119 u64 start;
1120 u64 end;
1121 int ret;
1122 struct extent_map_tree *free_space_cache;
1123 free_space_cache = &root->fs_info->free_space_cache;
1124
1125 while(1) {
1126 ret = find_first_extent_bit(unpin, 0, &start, &end,
1127 EXTENT_DIRTY);
1128 if (ret)
1129 break;
1130 update_pinned_extents(root, start, end + 1 - start, 0);
1131 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1132 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1133 }
1134 return 0;
1135 }
1136
1137 static int finish_current_insert(struct btrfs_trans_handle *trans,
1138 struct btrfs_root *extent_root)
1139 {
1140 u64 start;
1141 u64 end;
1142 struct btrfs_fs_info *info = extent_root->fs_info;
1143 struct extent_buffer *eb;
1144 struct btrfs_path *path;
1145 struct btrfs_key ins;
1146 struct btrfs_disk_key first;
1147 struct btrfs_extent_item extent_item;
1148 int ret;
1149 int level;
1150 int err = 0;
1151
1152 btrfs_set_stack_extent_refs(&extent_item, 1);
1153 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1154 path = btrfs_alloc_path();
1155
1156 while(1) {
1157 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1158 &end, EXTENT_LOCKED);
1159 if (ret)
1160 break;
1161
1162 ins.objectid = start;
1163 ins.offset = end + 1 - start;
1164 err = btrfs_insert_item(trans, extent_root, &ins,
1165 &extent_item, sizeof(extent_item));
1166 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1167 GFP_NOFS);
1168 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1169 level = btrfs_header_level(eb);
1170 if (level == 0) {
1171 btrfs_item_key(eb, &first, 0);
1172 } else {
1173 btrfs_node_key(eb, &first, 0);
1174 }
1175 err = btrfs_insert_extent_backref(trans, extent_root, path,
1176 start, extent_root->root_key.objectid,
1177 0, level,
1178 btrfs_disk_key_objectid(&first));
1179 BUG_ON(err);
1180 free_extent_buffer(eb);
1181 }
1182 btrfs_free_path(path);
1183 return 0;
1184 }
1185
1186 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1187 int pending)
1188 {
1189 int err = 0;
1190 struct extent_buffer *buf;
1191
1192 if (!pending) {
1193 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1194 if (buf) {
1195 if (btrfs_buffer_uptodate(buf)) {
1196 u64 transid =
1197 root->fs_info->running_transaction->transid;
1198 if (btrfs_header_generation(buf) == transid) {
1199 free_extent_buffer(buf);
1200 return 1;
1201 }
1202 }
1203 free_extent_buffer(buf);
1204 }
1205 update_pinned_extents(root, bytenr, num_bytes, 1);
1206 } else {
1207 set_extent_bits(&root->fs_info->pending_del,
1208 bytenr, bytenr + num_bytes - 1,
1209 EXTENT_LOCKED, GFP_NOFS);
1210 }
1211 BUG_ON(err < 0);
1212 return 0;
1213 }
1214
1215 /*
1216 * remove an extent from the root, returns 0 on success
1217 */
1218 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1219 *root, u64 bytenr, u64 num_bytes,
1220 u64 root_objectid, u64 ref_generation,
1221 u64 owner_objectid, u64 owner_offset, int pin,
1222 int mark_free)
1223 {
1224 struct btrfs_path *path;
1225 struct btrfs_key key;
1226 struct btrfs_fs_info *info = root->fs_info;
1227 struct btrfs_extent_ops *ops = info->extent_ops;
1228 struct btrfs_root *extent_root = info->extent_root;
1229 struct extent_buffer *leaf;
1230 int ret;
1231 struct btrfs_extent_item *ei;
1232 u32 refs;
1233
1234 key.objectid = bytenr;
1235 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1236 key.offset = num_bytes;
1237
1238 path = btrfs_alloc_path();
1239 if (!path)
1240 return -ENOMEM;
1241
1242 ret = lookup_extent_backref(trans, extent_root, path,
1243 bytenr, root_objectid,
1244 ref_generation,
1245 owner_objectid, owner_offset, 1);
1246 if (ret == 0) {
1247 ret = btrfs_del_item(trans, extent_root, path);
1248 } else {
1249 btrfs_print_leaf(extent_root, path->nodes[0]);
1250 WARN_ON(1);
1251 printk("Unable to find ref byte nr %Lu root %Lu "
1252 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1253 root_objectid, ref_generation, owner_objectid,
1254 owner_offset);
1255 }
1256 btrfs_release_path(extent_root, path);
1257 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1258 if (ret < 0)
1259 return ret;
1260 BUG_ON(ret);
1261
1262 leaf = path->nodes[0];
1263 ei = btrfs_item_ptr(leaf, path->slots[0],
1264 struct btrfs_extent_item);
1265 refs = btrfs_extent_refs(leaf, ei);
1266 BUG_ON(refs == 0);
1267 refs -= 1;
1268 btrfs_set_extent_refs(leaf, ei, refs);
1269 btrfs_mark_buffer_dirty(leaf);
1270
1271 if (refs == 0) {
1272 u64 super_used;
1273 u64 root_used;
1274
1275 if (pin) {
1276 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1277 if (ret > 0)
1278 mark_free = 1;
1279 BUG_ON(ret < 0);
1280 }
1281
1282 /* block accounting for super block */
1283 super_used = btrfs_super_bytes_used(&info->super_copy);
1284 btrfs_set_super_bytes_used(&info->super_copy,
1285 super_used - num_bytes);
1286
1287 /* block accounting for root item */
1288 root_used = btrfs_root_used(&root->root_item);
1289 btrfs_set_root_used(&root->root_item,
1290 root_used - num_bytes);
1291 ret = btrfs_del_item(trans, extent_root, path);
1292 if (ret)
1293 return ret;
1294
1295 if (ops && ops->free_extent)
1296 ops->free_extent(root, bytenr, num_bytes);
1297
1298 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1299 mark_free, 0);
1300 BUG_ON(ret);
1301 }
1302 btrfs_free_path(path);
1303 finish_current_insert(trans, extent_root);
1304 return ret;
1305 }
1306
1307 /*
1308 * find all the blocks marked as pending in the radix tree and remove
1309 * them from the extent map
1310 */
1311 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1312 btrfs_root *extent_root)
1313 {
1314 int ret;
1315 int err = 0;
1316 u64 start;
1317 u64 end;
1318 struct extent_map_tree *pending_del;
1319 struct extent_map_tree *pinned_extents;
1320
1321 pending_del = &extent_root->fs_info->pending_del;
1322 pinned_extents = &extent_root->fs_info->pinned_extents;
1323
1324 while(1) {
1325 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1326 EXTENT_LOCKED);
1327 if (ret)
1328 break;
1329 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1330 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1331 GFP_NOFS);
1332 ret = __free_extent(trans, extent_root,
1333 start, end + 1 - start,
1334 extent_root->root_key.objectid,
1335 0, 0, 0, 0, 0);
1336 if (ret)
1337 err = ret;
1338 }
1339 return err;
1340 }
1341
1342 /*
1343 * remove an extent from the root, returns 0 on success
1344 */
1345 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1346 *root, u64 bytenr, u64 num_bytes,
1347 u64 root_objectid, u64 ref_generation,
1348 u64 owner_objectid, u64 owner_offset, int pin)
1349 {
1350 struct btrfs_root *extent_root = root->fs_info->extent_root;
1351 int pending_ret;
1352 int ret;
1353
1354 WARN_ON(num_bytes < root->sectorsize);
1355 if (!root->ref_cows)
1356 ref_generation = 0;
1357
1358 if (root == extent_root) {
1359 pin_down_bytes(root, bytenr, num_bytes, 1);
1360 return 0;
1361 }
1362 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1363 ref_generation, owner_objectid, owner_offset,
1364 pin, pin == 0);
1365 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1366 return ret ? ret : pending_ret;
1367 }
1368
1369 static u64 stripe_align(struct btrfs_root *root, u64 val)
1370 {
1371 u64 mask = ((u64)root->stripesize - 1);
1372 u64 ret = (val + mask) & ~mask;
1373 return ret;
1374 }
1375
1376 /*
1377 * walks the btree of allocated extents and find a hole of a given size.
1378 * The key ins is changed to record the hole:
1379 * ins->objectid == block start
1380 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1381 * ins->offset == number of blocks
1382 * Any available blocks before search_start are skipped.
1383 */
1384 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1385 struct btrfs_root *orig_root,
1386 u64 num_bytes, u64 empty_size,
1387 u64 search_start, u64 search_end,
1388 u64 hint_byte, struct btrfs_key *ins,
1389 u64 exclude_start, u64 exclude_nr,
1390 int data)
1391 {
1392 struct btrfs_path *path;
1393 struct btrfs_key key;
1394 u64 hole_size = 0;
1395 u64 aligned;
1396 int ret;
1397 int slot = 0;
1398 u64 last_byte = 0;
1399 u64 orig_search_start = search_start;
1400 int start_found;
1401 struct extent_buffer *l;
1402 struct btrfs_root * root = orig_root->fs_info->extent_root;
1403 struct btrfs_fs_info *info = root->fs_info;
1404 u64 total_needed = num_bytes;
1405 int level;
1406 struct btrfs_block_group_cache *block_group;
1407 int full_scan = 0;
1408 int wrapped = 0;
1409 u64 cached_start;
1410
1411 WARN_ON(num_bytes < root->sectorsize);
1412 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1413
1414 level = btrfs_header_level(root->node);
1415
1416 if (num_bytes >= 32 * 1024 * 1024 && hint_byte) {
1417 data = BTRFS_BLOCK_GROUP_MIXED;
1418 }
1419
1420 if (search_end == (u64)-1)
1421 search_end = btrfs_super_total_bytes(&info->super_copy);
1422 if (hint_byte) {
1423 block_group = btrfs_lookup_block_group(info, hint_byte);
1424 if (!block_group)
1425 hint_byte = search_start;
1426 block_group = btrfs_find_block_group(root, block_group,
1427 hint_byte, data, 1);
1428 } else {
1429 block_group = btrfs_find_block_group(root,
1430 trans->block_group,
1431 search_start, data, 1);
1432 }
1433
1434 total_needed += empty_size;
1435 path = btrfs_alloc_path();
1436 check_failed:
1437 if (!block_group) {
1438 block_group = btrfs_lookup_block_group(info, search_start);
1439 if (!block_group)
1440 block_group = btrfs_lookup_block_group(info,
1441 orig_search_start);
1442 }
1443 search_start = find_search_start(root, &block_group, search_start,
1444 total_needed, data);
1445 search_start = stripe_align(root, search_start);
1446 cached_start = search_start;
1447 btrfs_init_path(path);
1448 ins->objectid = search_start;
1449 ins->offset = 0;
1450 start_found = 0;
1451 path->reada = 2;
1452
1453 ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
1454 if (ret < 0)
1455 goto error;
1456 ret = find_previous_extent(root, path);
1457 if (ret < 0)
1458 goto error;
1459 l = path->nodes[0];
1460 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1461 while (1) {
1462 l = path->nodes[0];
1463 slot = path->slots[0];
1464 if (slot >= btrfs_header_nritems(l)) {
1465 ret = btrfs_next_leaf(root, path);
1466 if (ret == 0)
1467 continue;
1468 if (ret < 0)
1469 goto error;
1470
1471 search_start = max(search_start,
1472 block_group->key.objectid);
1473 if (!start_found) {
1474 aligned = stripe_align(root, search_start);
1475 ins->objectid = aligned;
1476 if (aligned >= search_end) {
1477 ret = -ENOSPC;
1478 goto error;
1479 }
1480 ins->offset = search_end - aligned;
1481 start_found = 1;
1482 goto check_pending;
1483 }
1484 ins->objectid = stripe_align(root,
1485 last_byte > search_start ?
1486 last_byte : search_start);
1487 if (search_end <= ins->objectid) {
1488 ret = -ENOSPC;
1489 goto error;
1490 }
1491 ins->offset = search_end - ins->objectid;
1492 BUG_ON(ins->objectid >= search_end);
1493 goto check_pending;
1494 }
1495 btrfs_item_key_to_cpu(l, &key, slot);
1496
1497 if (key.objectid >= search_start && key.objectid > last_byte &&
1498 start_found) {
1499 if (last_byte < search_start)
1500 last_byte = search_start;
1501 aligned = stripe_align(root, last_byte);
1502 hole_size = key.objectid - aligned;
1503 if (key.objectid > aligned && hole_size >= num_bytes) {
1504 ins->objectid = aligned;
1505 ins->offset = hole_size;
1506 goto check_pending;
1507 }
1508 }
1509 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
1510 if (!start_found && btrfs_key_type(&key) ==
1511 BTRFS_BLOCK_GROUP_ITEM_KEY) {
1512 last_byte = key.objectid;
1513 start_found = 1;
1514 }
1515 goto next;
1516 }
1517
1518
1519 start_found = 1;
1520 last_byte = key.objectid + key.offset;
1521
1522 if (!full_scan && data != BTRFS_BLOCK_GROUP_MIXED &&
1523 last_byte >= block_group->key.objectid +
1524 block_group->key.offset) {
1525 btrfs_release_path(root, path);
1526 search_start = block_group->key.objectid +
1527 block_group->key.offset;
1528 goto new_group;
1529 }
1530 next:
1531 path->slots[0]++;
1532 cond_resched();
1533 }
1534 check_pending:
1535 /* we have to make sure we didn't find an extent that has already
1536 * been allocated by the map tree or the original allocation
1537 */
1538 btrfs_release_path(root, path);
1539 BUG_ON(ins->objectid < search_start);
1540
1541 if (ins->objectid + num_bytes >= search_end)
1542 goto enospc;
1543 if (!full_scan && data != BTRFS_BLOCK_GROUP_MIXED &&
1544 ins->objectid + num_bytes > block_group->
1545 key.objectid + block_group->key.offset) {
1546 search_start = block_group->key.objectid +
1547 block_group->key.offset;
1548 goto new_group;
1549 }
1550 if (test_range_bit(&info->extent_ins, ins->objectid,
1551 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1552 search_start = ins->objectid + num_bytes;
1553 goto new_group;
1554 }
1555 if (test_range_bit(&info->pinned_extents, ins->objectid,
1556 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1557 search_start = ins->objectid + num_bytes;
1558 goto new_group;
1559 }
1560 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1561 ins->objectid < exclude_start + exclude_nr)) {
1562 search_start = exclude_start + exclude_nr;
1563 goto new_group;
1564 }
1565 if (!data) {
1566 block_group = btrfs_lookup_block_group(info, ins->objectid);
1567 if (block_group)
1568 trans->block_group = block_group;
1569 }
1570 ins->offset = num_bytes;
1571 btrfs_free_path(path);
1572 return 0;
1573
1574 new_group:
1575 if (search_start + num_bytes >= search_end) {
1576 enospc:
1577 search_start = orig_search_start;
1578 if (full_scan) {
1579 ret = -ENOSPC;
1580 goto error;
1581 }
1582 if (wrapped) {
1583 if (!full_scan)
1584 total_needed -= empty_size;
1585 full_scan = 1;
1586 data = BTRFS_BLOCK_GROUP_MIXED;
1587 } else
1588 wrapped = 1;
1589 }
1590 block_group = btrfs_lookup_block_group(info, search_start);
1591 cond_resched();
1592 block_group = btrfs_find_block_group(root, block_group,
1593 search_start, data, 0);
1594 goto check_failed;
1595
1596 error:
1597 btrfs_release_path(root, path);
1598 btrfs_free_path(path);
1599 return ret;
1600 }
1601 /*
1602 * finds a free extent and does all the dirty work required for allocation
1603 * returns the key for the extent through ins, and a tree buffer for
1604 * the first block of the extent through buf.
1605 *
1606 * returns 0 if everything worked, non-zero otherwise.
1607 */
1608 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1609 struct btrfs_root *root,
1610 u64 num_bytes, u64 root_objectid, u64 ref_generation,
1611 u64 owner, u64 owner_offset,
1612 u64 empty_size, u64 hint_byte,
1613 u64 search_end, struct btrfs_key *ins, int data)
1614 {
1615 int ret;
1616 int pending_ret;
1617 u64 super_used, root_used;
1618 u64 search_start = 0;
1619 /*
1620 u64 new_hint;
1621 */
1622 struct btrfs_fs_info *info = root->fs_info;
1623 struct btrfs_extent_ops *ops = info->extent_ops;
1624 struct btrfs_root *extent_root = info->extent_root;
1625 struct btrfs_extent_item extent_item;
1626 struct btrfs_path *path;
1627
1628 btrfs_set_stack_extent_refs(&extent_item, 1);
1629
1630 /*
1631 new_hint = max(hint_byte, root->fs_info->alloc_start);
1632 if (new_hint < btrfs_super_total_bytes(&info->super_copy))
1633 hint_byte = new_hint;
1634 */
1635 WARN_ON(num_bytes < root->sectorsize);
1636 if (ops && ops->alloc_extent) {
1637 ret = ops->alloc_extent(root, num_bytes, hint_byte, ins);
1638 } else {
1639 ret = find_free_extent(trans, root, num_bytes, empty_size,
1640 search_start, search_end, hint_byte,
1641 ins, trans->alloc_exclude_start,
1642 trans->alloc_exclude_nr, data);
1643 }
1644 BUG_ON(ret);
1645 if (ret)
1646 return ret;
1647
1648 /* block accounting for super block */
1649 super_used = btrfs_super_bytes_used(&info->super_copy);
1650 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1651
1652 /* block accounting for root item */
1653 root_used = btrfs_root_used(&root->root_item);
1654 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1655
1656 clear_extent_dirty(&root->fs_info->free_space_cache,
1657 ins->objectid, ins->objectid + ins->offset - 1,
1658 GFP_NOFS);
1659
1660 if (root == extent_root) {
1661 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1662 ins->objectid + ins->offset - 1,
1663 EXTENT_LOCKED, GFP_NOFS);
1664 WARN_ON(data == 1);
1665 goto update_block;
1666 }
1667
1668 WARN_ON(trans->alloc_exclude_nr);
1669 trans->alloc_exclude_start = ins->objectid;
1670 trans->alloc_exclude_nr = ins->offset;
1671 ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
1672 sizeof(extent_item));
1673
1674 trans->alloc_exclude_start = 0;
1675 trans->alloc_exclude_nr = 0;
1676 BUG_ON(ret);
1677
1678 path = btrfs_alloc_path();
1679 BUG_ON(!path);
1680 ret = btrfs_insert_extent_backref(trans, extent_root, path,
1681 ins->objectid, root_objectid,
1682 ref_generation, owner, owner_offset);
1683
1684 BUG_ON(ret);
1685 btrfs_free_path(path);
1686 finish_current_insert(trans, extent_root);
1687 pending_ret = del_pending_extents(trans, extent_root);
1688
1689 if (ret) {
1690 return ret;
1691 }
1692 if (pending_ret) {
1693 return pending_ret;
1694 }
1695
1696 update_block:
1697 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0,
1698 data);
1699 BUG_ON(ret);
1700 return 0;
1701 }
1702
1703 /*
1704 * helper function to allocate a block for a given tree
1705 * returns the tree buffer or NULL.
1706 */
1707 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1708 struct btrfs_root *root,
1709 u32 blocksize,
1710 u64 root_objectid, u64 hint,
1711 u64 empty_size)
1712 {
1713 u64 ref_generation;
1714
1715 if (root->ref_cows)
1716 ref_generation = trans->transid;
1717 else
1718 ref_generation = 0;
1719
1720
1721 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1722 ref_generation, 0, 0, hint, empty_size);
1723 }
1724
1725 /*
1726 * helper function to allocate a block for a given tree
1727 * returns the tree buffer or NULL.
1728 */
1729 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1730 struct btrfs_root *root,
1731 u32 blocksize,
1732 u64 root_objectid,
1733 u64 ref_generation,
1734 u64 first_objectid,
1735 int level,
1736 u64 hint,
1737 u64 empty_size)
1738 {
1739 struct btrfs_key ins;
1740 int ret;
1741 struct extent_buffer *buf;
1742
1743 ret = btrfs_alloc_extent(trans, root, blocksize,
1744 root_objectid, ref_generation,
1745 level, first_objectid, empty_size, hint,
1746 (u64)-1, &ins, 0);
1747 if (ret) {
1748 BUG_ON(ret > 0);
1749 return ERR_PTR(ret);
1750 }
1751 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1752 if (!buf) {
1753 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1754 root->root_key.objectid, ref_generation,
1755 0, 0, 0);
1756 return ERR_PTR(-ENOMEM);
1757 }
1758 btrfs_set_buffer_uptodate(buf);
1759 /*
1760 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
1761 buf->start + buf->len - 1, GFP_NOFS);
1762 set_extent_bits(&BTRFS_I(root->fs_info->btree_inode)->extent_tree,
1763 buf->start, buf->start + buf->len - 1,
1764 EXTENT_CSUM, GFP_NOFS);
1765 buf->flags |= EXTENT_CSUM;
1766 btrfs_set_buffer_defrag(buf);
1767 */
1768 trans->blocks_used++;
1769 return buf;
1770 }
1771
1772 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
1773 struct btrfs_root *root,
1774 struct extent_buffer *leaf)
1775 {
1776 u64 leaf_owner;
1777 u64 leaf_generation;
1778 struct btrfs_key key;
1779 struct btrfs_file_extent_item *fi;
1780 int i;
1781 int nritems;
1782 int ret;
1783
1784 BUG_ON(!btrfs_is_leaf(leaf));
1785 nritems = btrfs_header_nritems(leaf);
1786 leaf_owner = btrfs_header_owner(leaf);
1787 leaf_generation = btrfs_header_generation(leaf);
1788
1789 for (i = 0; i < nritems; i++) {
1790 u64 disk_bytenr;
1791
1792 btrfs_item_key_to_cpu(leaf, &key, i);
1793 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1794 continue;
1795 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1796 if (btrfs_file_extent_type(leaf, fi) ==
1797 BTRFS_FILE_EXTENT_INLINE)
1798 continue;
1799 /*
1800 * FIXME make sure to insert a trans record that
1801 * repeats the snapshot del on crash
1802 */
1803 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1804 if (disk_bytenr == 0)
1805 continue;
1806 ret = btrfs_free_extent(trans, root, disk_bytenr,
1807 btrfs_file_extent_disk_num_bytes(leaf, fi),
1808 leaf_owner, leaf_generation,
1809 key.objectid, key.offset, 0);
1810 BUG_ON(ret);
1811 }
1812 return 0;
1813 }
1814
1815 static void noinline reada_walk_down(struct btrfs_root *root,
1816 struct extent_buffer *node)
1817 {
1818 int i;
1819 u32 nritems;
1820 u64 bytenr;
1821 int ret;
1822 u32 refs;
1823 int level;
1824 u32 blocksize;
1825
1826 nritems = btrfs_header_nritems(node);
1827 level = btrfs_header_level(node);
1828 for (i = 0; i < nritems; i++) {
1829 bytenr = btrfs_node_blockptr(node, i);
1830 blocksize = btrfs_level_size(root, level - 1);
1831 ret = lookup_extent_ref(NULL, root, bytenr, blocksize, &refs);
1832 BUG_ON(ret);
1833 if (refs != 1)
1834 continue;
1835 mutex_unlock(&root->fs_info->fs_mutex);
1836 ret = readahead_tree_block(root, bytenr, blocksize);
1837 cond_resched();
1838 mutex_lock(&root->fs_info->fs_mutex);
1839 if (ret)
1840 break;
1841 }
1842 }
1843
1844 /*
1845 * helper function for drop_snapshot, this walks down the tree dropping ref
1846 * counts as it goes.
1847 */
1848 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
1849 struct btrfs_root *root,
1850 struct btrfs_path *path, int *level)
1851 {
1852 u64 root_owner;
1853 u64 root_gen;
1854 u64 bytenr;
1855 struct extent_buffer *next;
1856 struct extent_buffer *cur;
1857 struct extent_buffer *parent;
1858 u32 blocksize;
1859 int ret;
1860 u32 refs;
1861
1862 WARN_ON(*level < 0);
1863 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1864 ret = lookup_extent_ref(trans, root,
1865 path->nodes[*level]->start,
1866 path->nodes[*level]->len, &refs);
1867 BUG_ON(ret);
1868 if (refs > 1)
1869 goto out;
1870
1871 /*
1872 * walk down to the last node level and free all the leaves
1873 */
1874 while(*level >= 0) {
1875 WARN_ON(*level < 0);
1876 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1877 cur = path->nodes[*level];
1878
1879 if (*level > 0 && path->slots[*level] == 0)
1880 reada_walk_down(root, cur);
1881
1882 if (btrfs_header_level(cur) != *level)
1883 WARN_ON(1);
1884
1885 if (path->slots[*level] >=
1886 btrfs_header_nritems(cur))
1887 break;
1888 if (*level == 0) {
1889 ret = drop_leaf_ref(trans, root, cur);
1890 BUG_ON(ret);
1891 break;
1892 }
1893 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1894 blocksize = btrfs_level_size(root, *level - 1);
1895 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
1896 BUG_ON(ret);
1897 if (refs != 1) {
1898 parent = path->nodes[*level];
1899 root_owner = btrfs_header_owner(parent);
1900 root_gen = btrfs_header_generation(parent);
1901 path->slots[*level]++;
1902 ret = btrfs_free_extent(trans, root, bytenr,
1903 blocksize, root_owner,
1904 root_gen, 0, 0, 1);
1905 BUG_ON(ret);
1906 continue;
1907 }
1908 next = btrfs_find_tree_block(root, bytenr, blocksize);
1909 if (!next || !btrfs_buffer_uptodate(next)) {
1910 free_extent_buffer(next);
1911 mutex_unlock(&root->fs_info->fs_mutex);
1912 next = read_tree_block(root, bytenr, blocksize);
1913 mutex_lock(&root->fs_info->fs_mutex);
1914
1915 /* we dropped the lock, check one more time */
1916 ret = lookup_extent_ref(trans, root, bytenr,
1917 blocksize, &refs);
1918 BUG_ON(ret);
1919 if (refs != 1) {
1920 parent = path->nodes[*level];
1921 root_owner = btrfs_header_owner(parent);
1922 root_gen = btrfs_header_generation(parent);
1923
1924 path->slots[*level]++;
1925 free_extent_buffer(next);
1926 ret = btrfs_free_extent(trans, root, bytenr,
1927 blocksize,
1928 root_owner,
1929 root_gen, 0, 0, 1);
1930 BUG_ON(ret);
1931 continue;
1932 }
1933 }
1934 WARN_ON(*level <= 0);
1935 if (path->nodes[*level-1])
1936 free_extent_buffer(path->nodes[*level-1]);
1937 path->nodes[*level-1] = next;
1938 *level = btrfs_header_level(next);
1939 path->slots[*level] = 0;
1940 }
1941 out:
1942 WARN_ON(*level < 0);
1943 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1944
1945 if (path->nodes[*level] == root->node) {
1946 root_owner = root->root_key.objectid;
1947 parent = path->nodes[*level];
1948 } else {
1949 parent = path->nodes[*level + 1];
1950 root_owner = btrfs_header_owner(parent);
1951 }
1952
1953 root_gen = btrfs_header_generation(parent);
1954 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
1955 path->nodes[*level]->len,
1956 root_owner, root_gen, 0, 0, 1);
1957 free_extent_buffer(path->nodes[*level]);
1958 path->nodes[*level] = NULL;
1959 *level += 1;
1960 BUG_ON(ret);
1961 return 0;
1962 }
1963
1964 /*
1965 * helper for dropping snapshots. This walks back up the tree in the path
1966 * to find the first node higher up where we haven't yet gone through
1967 * all the slots
1968 */
1969 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
1970 struct btrfs_root *root,
1971 struct btrfs_path *path, int *level)
1972 {
1973 u64 root_owner;
1974 u64 root_gen;
1975 struct btrfs_root_item *root_item = &root->root_item;
1976 int i;
1977 int slot;
1978 int ret;
1979
1980 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1981 slot = path->slots[i];
1982 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
1983 struct extent_buffer *node;
1984 struct btrfs_disk_key disk_key;
1985 node = path->nodes[i];
1986 path->slots[i]++;
1987 *level = i;
1988 WARN_ON(*level == 0);
1989 btrfs_node_key(node, &disk_key, path->slots[i]);
1990 memcpy(&root_item->drop_progress,
1991 &disk_key, sizeof(disk_key));
1992 root_item->drop_level = i;
1993 return 0;
1994 } else {
1995 if (path->nodes[*level] == root->node) {
1996 root_owner = root->root_key.objectid;
1997 root_gen =
1998 btrfs_header_generation(path->nodes[*level]);
1999 } else {
2000 struct extent_buffer *node;
2001 node = path->nodes[*level + 1];
2002 root_owner = btrfs_header_owner(node);
2003 root_gen = btrfs_header_generation(node);
2004 }
2005 ret = btrfs_free_extent(trans, root,
2006 path->nodes[*level]->start,
2007 path->nodes[*level]->len,
2008 root_owner, root_gen, 0, 0, 1);
2009 BUG_ON(ret);
2010 free_extent_buffer(path->nodes[*level]);
2011 path->nodes[*level] = NULL;
2012 *level = i + 1;
2013 }
2014 }
2015 return 1;
2016 }
2017
2018 /*
2019 * drop the reference count on the tree rooted at 'snap'. This traverses
2020 * the tree freeing any blocks that have a ref count of zero after being
2021 * decremented.
2022 */
2023 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2024 *root)
2025 {
2026 int ret = 0;
2027 int wret;
2028 int level;
2029 struct btrfs_path *path;
2030 int i;
2031 int orig_level;
2032 struct btrfs_root_item *root_item = &root->root_item;
2033
2034 path = btrfs_alloc_path();
2035 BUG_ON(!path);
2036
2037 level = btrfs_header_level(root->node);
2038 orig_level = level;
2039 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2040 path->nodes[level] = root->node;
2041 extent_buffer_get(root->node);
2042 path->slots[level] = 0;
2043 } else {
2044 struct btrfs_key key;
2045 struct btrfs_disk_key found_key;
2046 struct extent_buffer *node;
2047
2048 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2049 level = root_item->drop_level;
2050 path->lowest_level = level;
2051 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2052 if (wret < 0) {
2053 ret = wret;
2054 goto out;
2055 }
2056 node = path->nodes[level];
2057 btrfs_node_key(node, &found_key, path->slots[level]);
2058 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2059 sizeof(found_key)));
2060 }
2061 while(1) {
2062 wret = walk_down_tree(trans, root, path, &level);
2063 if (wret < 0)
2064 ret = wret;
2065 if (wret != 0)
2066 break;
2067
2068 wret = walk_up_tree(trans, root, path, &level);
2069 if (wret < 0)
2070 ret = wret;
2071 if (wret != 0)
2072 break;
2073 /*
2074 ret = -EAGAIN;
2075 break;
2076 */
2077 }
2078 for (i = 0; i <= orig_level; i++) {
2079 if (path->nodes[i]) {
2080 free_extent_buffer(path->nodes[i]);
2081 path->nodes[i] = NULL;
2082 }
2083 }
2084 out:
2085 btrfs_free_path(path);
2086 return ret;
2087 }
2088
2089 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2090 {
2091 u64 start;
2092 u64 end;
2093 u64 ptr;
2094 int ret;
2095 while(1) {
2096 ret = find_first_extent_bit(&info->block_group_cache, 0,
2097 &start, &end, (unsigned int)-1);
2098 if (ret)
2099 break;
2100 ret = get_state_private(&info->block_group_cache, start, &ptr);
2101 if (!ret)
2102 kfree((void *)(unsigned long)ptr);
2103 clear_extent_bits(&info->block_group_cache, start,
2104 end, (unsigned int)-1, GFP_NOFS);
2105 }
2106 while(1) {
2107 ret = find_first_extent_bit(&info->free_space_cache, 0,
2108 &start, &end, EXTENT_DIRTY);
2109 if (ret)
2110 break;
2111 clear_extent_dirty(&info->free_space_cache, start,
2112 end, GFP_NOFS);
2113 }
2114 return 0;
2115 }
2116
2117 int btrfs_read_block_groups(struct btrfs_root *root)
2118 {
2119 struct btrfs_path *path;
2120 int ret;
2121 int err = 0;
2122 int bit;
2123 struct btrfs_block_group_cache *cache;
2124 struct btrfs_fs_info *info = root->fs_info;
2125 struct extent_map_tree *block_group_cache;
2126 struct btrfs_key key;
2127 struct btrfs_key found_key;
2128 struct extent_buffer *leaf;
2129
2130 block_group_cache = &info->block_group_cache;
2131
2132 root = info->extent_root;
2133 key.objectid = 0;
2134 key.offset = BTRFS_BLOCK_GROUP_SIZE;
2135 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2136
2137 path = btrfs_alloc_path();
2138 if (!path)
2139 return -ENOMEM;
2140
2141 while(1) {
2142 ret = btrfs_search_slot(NULL, info->extent_root,
2143 &key, path, 0, 0);
2144 if (ret != 0) {
2145 err = ret;
2146 break;
2147 }
2148 leaf = path->nodes[0];
2149 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2150 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2151 if (!cache) {
2152 err = -1;
2153 break;
2154 }
2155
2156 read_extent_buffer(leaf, &cache->item,
2157 btrfs_item_ptr_offset(leaf, path->slots[0]),
2158 sizeof(cache->item));
2159 memcpy(&cache->key, &found_key, sizeof(found_key));
2160 cache->cached = 0;
2161 cache->pinned = 0;
2162 key.objectid = found_key.objectid + found_key.offset;
2163 btrfs_release_path(root, path);
2164
2165 if (cache->item.flags & BTRFS_BLOCK_GROUP_MIXED) {
2166 bit = BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA;
2167 cache->data = BTRFS_BLOCK_GROUP_MIXED;
2168 } else if (cache->item.flags & BTRFS_BLOCK_GROUP_DATA) {
2169 bit = BLOCK_GROUP_DATA;
2170 cache->data = BTRFS_BLOCK_GROUP_DATA;
2171 } else {
2172 bit = BLOCK_GROUP_METADATA;
2173 cache->data = 0;
2174 }
2175
2176 /* use EXTENT_LOCKED to prevent merging */
2177 set_extent_bits(block_group_cache, found_key.objectid,
2178 found_key.objectid + found_key.offset - 1,
2179 bit | EXTENT_LOCKED, GFP_NOFS);
2180 set_state_private(block_group_cache, found_key.objectid,
2181 (unsigned long)cache);
2182
2183 if (key.objectid >=
2184 btrfs_super_total_bytes(&info->super_copy))
2185 break;
2186 }
2187
2188 btrfs_free_path(path);
2189 return 0;
2190 }
2191
2192 static int btrfs_insert_block_group(struct btrfs_trans_handle *trans,
2193 struct btrfs_root *root,
2194 struct btrfs_key *key,
2195 struct btrfs_block_group_item *bi)
2196 {
2197 int ret;
2198 int pending_ret;
2199 struct btrfs_root *extent_root;
2200
2201 extent_root = root->fs_info->extent_root;
2202 ret = btrfs_insert_item(trans, extent_root, key, bi, sizeof(*bi));
2203 finish_current_insert(trans, extent_root);
2204 pending_ret = del_pending_extents(trans, extent_root);
2205 if (ret)
2206 return ret;
2207 if (pending_ret)
2208 return pending_ret;
2209 return 0;
2210 }
2211
2212 int btrfs_make_block_groups(struct btrfs_trans_handle *trans,
2213 struct btrfs_root *root)
2214 {
2215 u64 group_size;
2216 u64 bytes_used;
2217 u64 total_bytes;
2218 u64 cur_start;
2219 u64 nr = 0;
2220 int ret;
2221 int bit;
2222 struct btrfs_root *extent_root;
2223 struct btrfs_block_group_cache *cache;
2224 struct extent_map_tree *block_group_cache;
2225
2226 extent_root = root->fs_info->extent_root;
2227 block_group_cache = &root->fs_info->block_group_cache;
2228 group_size = BTRFS_BLOCK_GROUP_SIZE;
2229 bytes_used = btrfs_super_bytes_used(&root->fs_info->super_copy);
2230 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
2231
2232 cur_start = 0;
2233 while (cur_start < total_bytes) {
2234 cache = malloc(sizeof(*cache));
2235 BUG_ON(!cache);
2236 cache->key.objectid = cur_start;
2237 cache->key.offset = group_size;
2238 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2239 memset(&cache->item, 0, sizeof(cache->item));
2240 if (nr == 0)
2241 btrfs_set_block_group_used(&cache->item, bytes_used);
2242 if (nr++ % 3) {
2243 bit = BLOCK_GROUP_DATA;
2244 cache->data = 1;
2245 cache->item.flags |= BTRFS_BLOCK_GROUP_DATA;
2246 } else {
2247 bit = BLOCK_GROUP_METADATA;
2248 cache->data = 0;
2249 }
2250
2251 set_extent_bits(block_group_cache, cur_start,
2252 cur_start + group_size - 1,
2253 bit | EXTENT_LOCKED, GFP_NOFS);
2254 set_state_private(block_group_cache, cur_start,
2255 (unsigned long)cache);
2256 cur_start += group_size;
2257 }
2258 /* then insert all the items */
2259 cur_start = 0;
2260 while(cur_start < total_bytes) {
2261 cache = btrfs_lookup_block_group(root->fs_info, cur_start);
2262 BUG_ON(!cache);
2263 ret = btrfs_insert_block_group(trans, root, &cache->key,
2264 &cache->item);
2265 BUG_ON(ret);
2266 cur_start += group_size;
2267 }
2268 return 0;
2269 }
2270
2271 u64 btrfs_hash_extent_ref(u64 root_objectid, u64 ref_generation,
2272 u64 owner, u64 owner_offset)
2273 {
2274 return hash_extent_ref(root_objectid, ref_generation,
2275 owner, owner_offset);
2276 }
2277
2278 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
2279 struct btrfs_root *root,
2280 u64 bytenr, u64 num_bytes, int alloc,
2281 int mark_free, int data)
2282 {
2283 return update_block_group(trans, root, bytenr, num_bytes,
2284 alloc, mark_free, data);
2285 }
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