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Add a min size parameter to btrfs_alloc_extent
[deliverable/linux.git] / fs / btrfs / extent-tree.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/pagemap.h>
20 #include "hash.h"
21 #include "crc32c.h"
22 #include "ctree.h"
23 #include "disk-io.h"
24 #include "print-tree.h"
25 #include "transaction.h"
26 #include "volumes.h"
27
28 #define BLOCK_GROUP_DATA EXTENT_WRITEBACK
29 #define BLOCK_GROUP_METADATA EXTENT_UPTODATE
30 #define BLOCK_GROUP_SYSTEM EXTENT_NEW
31
32 #define BLOCK_GROUP_DIRTY EXTENT_DIRTY
33
34 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
35 btrfs_root *extent_root);
36 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
37 btrfs_root *extent_root);
38 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
39 struct btrfs_root *root, u64 bytes_used,
40 u64 type, u64 chunk_tree, u64 chunk_objectid,
41 u64 size);
42
43
44 static int cache_block_group(struct btrfs_root *root,
45 struct btrfs_block_group_cache *block_group)
46 {
47 struct btrfs_path *path;
48 int ret;
49 struct btrfs_key key;
50 struct extent_buffer *leaf;
51 struct extent_io_tree *free_space_cache;
52 int slot;
53 u64 last = 0;
54 u64 hole_size;
55 u64 first_free;
56 int found = 0;
57
58 if (!block_group)
59 return 0;
60
61 root = root->fs_info->extent_root;
62 free_space_cache = &root->fs_info->free_space_cache;
63
64 if (block_group->cached)
65 return 0;
66
67 path = btrfs_alloc_path();
68 if (!path)
69 return -ENOMEM;
70
71 path->reada = 2;
72 first_free = block_group->key.objectid;
73 key.objectid = block_group->key.objectid;
74 key.offset = 0;
75 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
76 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
77 if (ret < 0)
78 return ret;
79 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
80 if (ret < 0)
81 return ret;
82 if (ret == 0) {
83 leaf = path->nodes[0];
84 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
85 if (key.objectid + key.offset > first_free)
86 first_free = key.objectid + key.offset;
87 }
88 while(1) {
89 leaf = path->nodes[0];
90 slot = path->slots[0];
91 if (slot >= btrfs_header_nritems(leaf)) {
92 ret = btrfs_next_leaf(root, path);
93 if (ret < 0)
94 goto err;
95 if (ret == 0) {
96 continue;
97 } else {
98 break;
99 }
100 }
101 btrfs_item_key_to_cpu(leaf, &key, slot);
102 if (key.objectid < block_group->key.objectid) {
103 goto next;
104 }
105 if (key.objectid >= block_group->key.objectid +
106 block_group->key.offset) {
107 break;
108 }
109
110 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
111 if (!found) {
112 last = first_free;
113 found = 1;
114 }
115 if (key.objectid > last) {
116 hole_size = key.objectid - last;
117 set_extent_dirty(free_space_cache, last,
118 last + hole_size - 1,
119 GFP_NOFS);
120 }
121 last = key.objectid + key.offset;
122 }
123 next:
124 path->slots[0]++;
125 }
126
127 if (!found)
128 last = first_free;
129 if (block_group->key.objectid +
130 block_group->key.offset > last) {
131 hole_size = block_group->key.objectid +
132 block_group->key.offset - last;
133 set_extent_dirty(free_space_cache, last,
134 last + hole_size - 1, GFP_NOFS);
135 }
136 block_group->cached = 1;
137 err:
138 btrfs_free_path(path);
139 return 0;
140 }
141
142 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
143 btrfs_fs_info *info,
144 u64 bytenr)
145 {
146 struct extent_io_tree *block_group_cache;
147 struct btrfs_block_group_cache *block_group = NULL;
148 u64 ptr;
149 u64 start;
150 u64 end;
151 int ret;
152
153 block_group_cache = &info->block_group_cache;
154 ret = find_first_extent_bit(block_group_cache,
155 bytenr, &start, &end,
156 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
157 BLOCK_GROUP_SYSTEM);
158 if (ret) {
159 return NULL;
160 }
161 ret = get_state_private(block_group_cache, start, &ptr);
162 if (ret)
163 return NULL;
164
165 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
166 if (block_group->key.objectid <= bytenr && bytenr <
167 block_group->key.objectid + block_group->key.offset)
168 return block_group;
169 return NULL;
170 }
171
172 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
173 {
174 return (cache->flags & bits) == bits;
175 }
176
177 static int noinline find_search_start(struct btrfs_root *root,
178 struct btrfs_block_group_cache **cache_ret,
179 u64 *start_ret, int num, int data)
180 {
181 int ret;
182 struct btrfs_block_group_cache *cache = *cache_ret;
183 struct extent_io_tree *free_space_cache;
184 struct extent_state *state;
185 u64 last;
186 u64 start = 0;
187 u64 cache_miss = 0;
188 u64 total_fs_bytes;
189 u64 search_start = *start_ret;
190 int wrapped = 0;
191
192 if (!cache)
193 goto out;
194 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
195 free_space_cache = &root->fs_info->free_space_cache;
196
197 again:
198 ret = cache_block_group(root, cache);
199 if (ret)
200 goto out;
201
202 last = max(search_start, cache->key.objectid);
203 if (!block_group_bits(cache, data)) {
204 goto new_group;
205 }
206
207 spin_lock_irq(&free_space_cache->lock);
208 state = find_first_extent_bit_state(free_space_cache, last, EXTENT_DIRTY);
209 while(1) {
210 if (!state) {
211 if (!cache_miss)
212 cache_miss = last;
213 spin_unlock_irq(&free_space_cache->lock);
214 goto new_group;
215 }
216
217 start = max(last, state->start);
218 last = state->end + 1;
219 if (last - start < num) {
220 if (last == cache->key.objectid + cache->key.offset)
221 cache_miss = start;
222 do {
223 state = extent_state_next(state);
224 } while(state && !(state->state & EXTENT_DIRTY));
225 continue;
226 }
227 spin_unlock_irq(&free_space_cache->lock);
228 if (start + num > cache->key.objectid + cache->key.offset)
229 goto new_group;
230 if (start + num > total_fs_bytes)
231 goto new_group;
232 if (!block_group_bits(cache, data)) {
233 printk("block group bits don't match %Lu %d\n", cache->flags, data);
234 }
235 *start_ret = start;
236 return 0;
237 }
238 out:
239 cache = btrfs_lookup_block_group(root->fs_info, search_start);
240 if (!cache) {
241 printk("Unable to find block group for %Lu\n", search_start);
242 WARN_ON(1);
243 }
244 return -ENOSPC;
245
246 new_group:
247 last = cache->key.objectid + cache->key.offset;
248 wrapped:
249 cache = btrfs_lookup_block_group(root->fs_info, last);
250 if (!cache || cache->key.objectid >= total_fs_bytes) {
251 no_cache:
252 if (!wrapped) {
253 wrapped = 1;
254 last = search_start;
255 goto wrapped;
256 }
257 goto out;
258 }
259 if (cache_miss && !cache->cached) {
260 cache_block_group(root, cache);
261 last = cache_miss;
262 cache = btrfs_lookup_block_group(root->fs_info, last);
263 }
264 cache = btrfs_find_block_group(root, cache, last, data, 0);
265 if (!cache)
266 goto no_cache;
267 *cache_ret = cache;
268 cache_miss = 0;
269 goto again;
270 }
271
272 static u64 div_factor(u64 num, int factor)
273 {
274 if (factor == 10)
275 return num;
276 num *= factor;
277 do_div(num, 10);
278 return num;
279 }
280
281 static int block_group_state_bits(u64 flags)
282 {
283 int bits = 0;
284 if (flags & BTRFS_BLOCK_GROUP_DATA)
285 bits |= BLOCK_GROUP_DATA;
286 if (flags & BTRFS_BLOCK_GROUP_METADATA)
287 bits |= BLOCK_GROUP_METADATA;
288 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
289 bits |= BLOCK_GROUP_SYSTEM;
290 return bits;
291 }
292
293 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
294 struct btrfs_block_group_cache
295 *hint, u64 search_start,
296 int data, int owner)
297 {
298 struct btrfs_block_group_cache *cache;
299 struct extent_io_tree *block_group_cache;
300 struct btrfs_block_group_cache *found_group = NULL;
301 struct btrfs_fs_info *info = root->fs_info;
302 u64 used;
303 u64 last = 0;
304 u64 hint_last;
305 u64 start;
306 u64 end;
307 u64 free_check;
308 u64 ptr;
309 u64 total_fs_bytes;
310 int bit;
311 int ret;
312 int full_search = 0;
313 int factor = 8;
314
315 block_group_cache = &info->block_group_cache;
316 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
317
318 if (!owner)
319 factor = 8;
320
321 bit = block_group_state_bits(data);
322
323 if (search_start && search_start < total_fs_bytes) {
324 struct btrfs_block_group_cache *shint;
325 shint = btrfs_lookup_block_group(info, search_start);
326 if (shint && block_group_bits(shint, data)) {
327 used = btrfs_block_group_used(&shint->item);
328 if (used + shint->pinned <
329 div_factor(shint->key.offset, factor)) {
330 return shint;
331 }
332 }
333 }
334 if (hint && block_group_bits(hint, data) &&
335 hint->key.objectid < total_fs_bytes) {
336 used = btrfs_block_group_used(&hint->item);
337 if (used + hint->pinned <
338 div_factor(hint->key.offset, factor)) {
339 return hint;
340 }
341 last = hint->key.objectid + hint->key.offset;
342 hint_last = last;
343 } else {
344 if (hint)
345 hint_last = max(hint->key.objectid, search_start);
346 else
347 hint_last = search_start;
348
349 if (hint_last >= total_fs_bytes)
350 hint_last = search_start;
351 last = hint_last;
352 }
353 again:
354 while(1) {
355 ret = find_first_extent_bit(block_group_cache, last,
356 &start, &end, bit);
357 if (ret)
358 break;
359
360 ret = get_state_private(block_group_cache, start, &ptr);
361 if (ret)
362 break;
363
364 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
365 last = cache->key.objectid + cache->key.offset;
366 used = btrfs_block_group_used(&cache->item);
367
368 if (cache->key.objectid > total_fs_bytes)
369 break;
370
371 if (block_group_bits(cache, data)) {
372 if (full_search)
373 free_check = cache->key.offset;
374 else
375 free_check = div_factor(cache->key.offset,
376 factor);
377
378 if (used + cache->pinned < free_check) {
379 found_group = cache;
380 goto found;
381 }
382 }
383 cond_resched();
384 }
385 if (!full_search) {
386 last = search_start;
387 full_search = 1;
388 goto again;
389 }
390 found:
391 return found_group;
392 }
393
394 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
395 u64 owner, u64 owner_offset)
396 {
397 u32 high_crc = ~(u32)0;
398 u32 low_crc = ~(u32)0;
399 __le64 lenum;
400 lenum = cpu_to_le64(root_objectid);
401 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
402 lenum = cpu_to_le64(ref_generation);
403 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
404 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
405 lenum = cpu_to_le64(owner);
406 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
407 lenum = cpu_to_le64(owner_offset);
408 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
409 }
410 return ((u64)high_crc << 32) | (u64)low_crc;
411 }
412
413 static int match_extent_ref(struct extent_buffer *leaf,
414 struct btrfs_extent_ref *disk_ref,
415 struct btrfs_extent_ref *cpu_ref)
416 {
417 int ret;
418 int len;
419
420 if (cpu_ref->objectid)
421 len = sizeof(*cpu_ref);
422 else
423 len = 2 * sizeof(u64);
424 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
425 len);
426 return ret == 0;
427 }
428
429 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
430 struct btrfs_root *root,
431 struct btrfs_path *path, u64 bytenr,
432 u64 root_objectid,
433 u64 ref_generation, u64 owner,
434 u64 owner_offset, int del)
435 {
436 u64 hash;
437 struct btrfs_key key;
438 struct btrfs_key found_key;
439 struct btrfs_extent_ref ref;
440 struct extent_buffer *leaf;
441 struct btrfs_extent_ref *disk_ref;
442 int ret;
443 int ret2;
444
445 btrfs_set_stack_ref_root(&ref, root_objectid);
446 btrfs_set_stack_ref_generation(&ref, ref_generation);
447 btrfs_set_stack_ref_objectid(&ref, owner);
448 btrfs_set_stack_ref_offset(&ref, owner_offset);
449
450 hash = hash_extent_ref(root_objectid, ref_generation, owner,
451 owner_offset);
452 key.offset = hash;
453 key.objectid = bytenr;
454 key.type = BTRFS_EXTENT_REF_KEY;
455
456 while (1) {
457 ret = btrfs_search_slot(trans, root, &key, path,
458 del ? -1 : 0, del);
459 if (ret < 0)
460 goto out;
461 leaf = path->nodes[0];
462 if (ret != 0) {
463 u32 nritems = btrfs_header_nritems(leaf);
464 if (path->slots[0] >= nritems) {
465 ret2 = btrfs_next_leaf(root, path);
466 if (ret2)
467 goto out;
468 leaf = path->nodes[0];
469 }
470 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
471 if (found_key.objectid != bytenr ||
472 found_key.type != BTRFS_EXTENT_REF_KEY)
473 goto out;
474 key.offset = found_key.offset;
475 if (del) {
476 btrfs_release_path(root, path);
477 continue;
478 }
479 }
480 disk_ref = btrfs_item_ptr(path->nodes[0],
481 path->slots[0],
482 struct btrfs_extent_ref);
483 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
484 ret = 0;
485 goto out;
486 }
487 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
488 key.offset = found_key.offset + 1;
489 btrfs_release_path(root, path);
490 }
491 out:
492 return ret;
493 }
494
495 /*
496 * Back reference rules. Back refs have three main goals:
497 *
498 * 1) differentiate between all holders of references to an extent so that
499 * when a reference is dropped we can make sure it was a valid reference
500 * before freeing the extent.
501 *
502 * 2) Provide enough information to quickly find the holders of an extent
503 * if we notice a given block is corrupted or bad.
504 *
505 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
506 * maintenance. This is actually the same as #2, but with a slightly
507 * different use case.
508 *
509 * File extents can be referenced by:
510 *
511 * - multiple snapshots, subvolumes, or different generations in one subvol
512 * - different files inside a single subvolume (in theory, not implemented yet)
513 * - different offsets inside a file (bookend extents in file.c)
514 *
515 * The extent ref structure has fields for:
516 *
517 * - Objectid of the subvolume root
518 * - Generation number of the tree holding the reference
519 * - objectid of the file holding the reference
520 * - offset in the file corresponding to the key holding the reference
521 *
522 * When a file extent is allocated the fields are filled in:
523 * (root_key.objectid, trans->transid, inode objectid, offset in file)
524 *
525 * When a leaf is cow'd new references are added for every file extent found
526 * in the leaf. It looks the same as the create case, but trans->transid
527 * will be different when the block is cow'd.
528 *
529 * (root_key.objectid, trans->transid, inode objectid, offset in file)
530 *
531 * When a file extent is removed either during snapshot deletion or file
532 * truncation, the corresponding back reference is found
533 * by searching for:
534 *
535 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
536 * inode objectid, offset in file)
537 *
538 * Btree extents can be referenced by:
539 *
540 * - Different subvolumes
541 * - Different generations of the same subvolume
542 *
543 * Storing sufficient information for a full reverse mapping of a btree
544 * block would require storing the lowest key of the block in the backref,
545 * and it would require updating that lowest key either before write out or
546 * every time it changed. Instead, the objectid of the lowest key is stored
547 * along with the level of the tree block. This provides a hint
548 * about where in the btree the block can be found. Searches through the
549 * btree only need to look for a pointer to that block, so they stop one
550 * level higher than the level recorded in the backref.
551 *
552 * Some btrees do not do reference counting on their extents. These
553 * include the extent tree and the tree of tree roots. Backrefs for these
554 * trees always have a generation of zero.
555 *
556 * When a tree block is created, back references are inserted:
557 *
558 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
559 *
560 * When a tree block is cow'd in a reference counted root,
561 * new back references are added for all the blocks it points to.
562 * These are of the form (trans->transid will have increased since creation):
563 *
564 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
565 *
566 * Because the lowest_key_objectid and the level are just hints
567 * they are not used when backrefs are deleted. When a backref is deleted:
568 *
569 * if backref was for a tree root:
570 * root_objectid = root->root_key.objectid
571 * else
572 * root_objectid = btrfs_header_owner(parent)
573 *
574 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
575 *
576 * Back Reference Key hashing:
577 *
578 * Back references have four fields, each 64 bits long. Unfortunately,
579 * This is hashed into a single 64 bit number and placed into the key offset.
580 * The key objectid corresponds to the first byte in the extent, and the
581 * key type is set to BTRFS_EXTENT_REF_KEY
582 */
583 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
584 struct btrfs_root *root,
585 struct btrfs_path *path, u64 bytenr,
586 u64 root_objectid, u64 ref_generation,
587 u64 owner, u64 owner_offset)
588 {
589 u64 hash;
590 struct btrfs_key key;
591 struct btrfs_extent_ref ref;
592 struct btrfs_extent_ref *disk_ref;
593 int ret;
594
595 btrfs_set_stack_ref_root(&ref, root_objectid);
596 btrfs_set_stack_ref_generation(&ref, ref_generation);
597 btrfs_set_stack_ref_objectid(&ref, owner);
598 btrfs_set_stack_ref_offset(&ref, owner_offset);
599
600 hash = hash_extent_ref(root_objectid, ref_generation, owner,
601 owner_offset);
602 key.offset = hash;
603 key.objectid = bytenr;
604 key.type = BTRFS_EXTENT_REF_KEY;
605
606 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
607 while (ret == -EEXIST) {
608 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
609 struct btrfs_extent_ref);
610 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
611 goto out;
612 key.offset++;
613 btrfs_release_path(root, path);
614 ret = btrfs_insert_empty_item(trans, root, path, &key,
615 sizeof(ref));
616 }
617 if (ret)
618 goto out;
619 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
620 struct btrfs_extent_ref);
621 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
622 sizeof(ref));
623 btrfs_mark_buffer_dirty(path->nodes[0]);
624 out:
625 btrfs_release_path(root, path);
626 return ret;
627 }
628
629 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
630 struct btrfs_root *root,
631 u64 bytenr, u64 num_bytes,
632 u64 root_objectid, u64 ref_generation,
633 u64 owner, u64 owner_offset)
634 {
635 struct btrfs_path *path;
636 int ret;
637 struct btrfs_key key;
638 struct extent_buffer *l;
639 struct btrfs_extent_item *item;
640 u32 refs;
641
642 WARN_ON(num_bytes < root->sectorsize);
643 path = btrfs_alloc_path();
644 if (!path)
645 return -ENOMEM;
646
647 path->reada = 0;
648 key.objectid = bytenr;
649 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
650 key.offset = num_bytes;
651 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
652 0, 1);
653 if (ret < 0)
654 return ret;
655 if (ret != 0) {
656 BUG();
657 }
658 BUG_ON(ret != 0);
659 l = path->nodes[0];
660 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
661 refs = btrfs_extent_refs(l, item);
662 btrfs_set_extent_refs(l, item, refs + 1);
663 btrfs_mark_buffer_dirty(path->nodes[0]);
664
665 btrfs_release_path(root->fs_info->extent_root, path);
666
667 path->reada = 0;
668 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
669 path, bytenr, root_objectid,
670 ref_generation, owner, owner_offset);
671 BUG_ON(ret);
672 finish_current_insert(trans, root->fs_info->extent_root);
673 del_pending_extents(trans, root->fs_info->extent_root);
674
675 btrfs_free_path(path);
676 return 0;
677 }
678
679 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
680 struct btrfs_root *root)
681 {
682 finish_current_insert(trans, root->fs_info->extent_root);
683 del_pending_extents(trans, root->fs_info->extent_root);
684 return 0;
685 }
686
687 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
688 struct btrfs_root *root, u64 bytenr,
689 u64 num_bytes, u32 *refs)
690 {
691 struct btrfs_path *path;
692 int ret;
693 struct btrfs_key key;
694 struct extent_buffer *l;
695 struct btrfs_extent_item *item;
696
697 WARN_ON(num_bytes < root->sectorsize);
698 path = btrfs_alloc_path();
699 path->reada = 0;
700 key.objectid = bytenr;
701 key.offset = num_bytes;
702 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
703 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
704 0, 0);
705 if (ret < 0)
706 goto out;
707 if (ret != 0) {
708 btrfs_print_leaf(root, path->nodes[0]);
709 printk("failed to find block number %Lu\n", bytenr);
710 BUG();
711 }
712 l = path->nodes[0];
713 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
714 *refs = btrfs_extent_refs(l, item);
715 out:
716 btrfs_free_path(path);
717 return 0;
718 }
719
720 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
721 struct btrfs_path *count_path,
722 u64 first_extent)
723 {
724 struct btrfs_root *extent_root = root->fs_info->extent_root;
725 struct btrfs_path *path;
726 u64 bytenr;
727 u64 found_objectid;
728 u64 root_objectid = root->root_key.objectid;
729 u32 total_count = 0;
730 u32 cur_count;
731 u32 nritems;
732 int ret;
733 struct btrfs_key key;
734 struct btrfs_key found_key;
735 struct extent_buffer *l;
736 struct btrfs_extent_item *item;
737 struct btrfs_extent_ref *ref_item;
738 int level = -1;
739
740 path = btrfs_alloc_path();
741 again:
742 if (level == -1)
743 bytenr = first_extent;
744 else
745 bytenr = count_path->nodes[level]->start;
746
747 cur_count = 0;
748 key.objectid = bytenr;
749 key.offset = 0;
750
751 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
752 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
753 if (ret < 0)
754 goto out;
755 BUG_ON(ret == 0);
756
757 l = path->nodes[0];
758 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
759
760 if (found_key.objectid != bytenr ||
761 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
762 goto out;
763 }
764
765 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
766 while (1) {
767 l = path->nodes[0];
768 nritems = btrfs_header_nritems(l);
769 if (path->slots[0] >= nritems) {
770 ret = btrfs_next_leaf(extent_root, path);
771 if (ret == 0)
772 continue;
773 break;
774 }
775 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
776 if (found_key.objectid != bytenr)
777 break;
778
779 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
780 path->slots[0]++;
781 continue;
782 }
783
784 cur_count++;
785 ref_item = btrfs_item_ptr(l, path->slots[0],
786 struct btrfs_extent_ref);
787 found_objectid = btrfs_ref_root(l, ref_item);
788
789 if (found_objectid != root_objectid) {
790 total_count = 2;
791 goto out;
792 }
793 total_count = 1;
794 path->slots[0]++;
795 }
796 if (cur_count == 0) {
797 total_count = 0;
798 goto out;
799 }
800 if (level >= 0 && root->node == count_path->nodes[level])
801 goto out;
802 level++;
803 btrfs_release_path(root, path);
804 goto again;
805
806 out:
807 btrfs_free_path(path);
808 return total_count;
809 }
810 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
811 struct btrfs_root *root, u64 owner_objectid)
812 {
813 u64 generation;
814 u64 key_objectid;
815 u64 level;
816 u32 nritems;
817 struct btrfs_disk_key disk_key;
818
819 level = btrfs_header_level(root->node);
820 generation = trans->transid;
821 nritems = btrfs_header_nritems(root->node);
822 if (nritems > 0) {
823 if (level == 0)
824 btrfs_item_key(root->node, &disk_key, 0);
825 else
826 btrfs_node_key(root->node, &disk_key, 0);
827 key_objectid = btrfs_disk_key_objectid(&disk_key);
828 } else {
829 key_objectid = 0;
830 }
831 return btrfs_inc_extent_ref(trans, root, root->node->start,
832 root->node->len, owner_objectid,
833 generation, level, key_objectid);
834 }
835
836 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
837 struct extent_buffer *buf)
838 {
839 u64 bytenr;
840 u32 nritems;
841 struct btrfs_key key;
842 struct btrfs_file_extent_item *fi;
843 int i;
844 int level;
845 int ret;
846 int faili;
847
848 if (!root->ref_cows)
849 return 0;
850
851 level = btrfs_header_level(buf);
852 nritems = btrfs_header_nritems(buf);
853 for (i = 0; i < nritems; i++) {
854 if (level == 0) {
855 u64 disk_bytenr;
856 btrfs_item_key_to_cpu(buf, &key, i);
857 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
858 continue;
859 fi = btrfs_item_ptr(buf, i,
860 struct btrfs_file_extent_item);
861 if (btrfs_file_extent_type(buf, fi) ==
862 BTRFS_FILE_EXTENT_INLINE)
863 continue;
864 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
865 if (disk_bytenr == 0)
866 continue;
867 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
868 btrfs_file_extent_disk_num_bytes(buf, fi),
869 root->root_key.objectid, trans->transid,
870 key.objectid, key.offset);
871 if (ret) {
872 faili = i;
873 goto fail;
874 }
875 } else {
876 bytenr = btrfs_node_blockptr(buf, i);
877 btrfs_node_key_to_cpu(buf, &key, i);
878 ret = btrfs_inc_extent_ref(trans, root, bytenr,
879 btrfs_level_size(root, level - 1),
880 root->root_key.objectid,
881 trans->transid,
882 level - 1, key.objectid);
883 if (ret) {
884 faili = i;
885 goto fail;
886 }
887 }
888 }
889 return 0;
890 fail:
891 WARN_ON(1);
892 #if 0
893 for (i =0; i < faili; i++) {
894 if (level == 0) {
895 u64 disk_bytenr;
896 btrfs_item_key_to_cpu(buf, &key, i);
897 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
898 continue;
899 fi = btrfs_item_ptr(buf, i,
900 struct btrfs_file_extent_item);
901 if (btrfs_file_extent_type(buf, fi) ==
902 BTRFS_FILE_EXTENT_INLINE)
903 continue;
904 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
905 if (disk_bytenr == 0)
906 continue;
907 err = btrfs_free_extent(trans, root, disk_bytenr,
908 btrfs_file_extent_disk_num_bytes(buf,
909 fi), 0);
910 BUG_ON(err);
911 } else {
912 bytenr = btrfs_node_blockptr(buf, i);
913 err = btrfs_free_extent(trans, root, bytenr,
914 btrfs_level_size(root, level - 1), 0);
915 BUG_ON(err);
916 }
917 }
918 #endif
919 return ret;
920 }
921
922 static int write_one_cache_group(struct btrfs_trans_handle *trans,
923 struct btrfs_root *root,
924 struct btrfs_path *path,
925 struct btrfs_block_group_cache *cache)
926 {
927 int ret;
928 int pending_ret;
929 struct btrfs_root *extent_root = root->fs_info->extent_root;
930 unsigned long bi;
931 struct extent_buffer *leaf;
932
933 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
934 if (ret < 0)
935 goto fail;
936 BUG_ON(ret);
937
938 leaf = path->nodes[0];
939 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
940 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
941 btrfs_mark_buffer_dirty(leaf);
942 btrfs_release_path(extent_root, path);
943 fail:
944 finish_current_insert(trans, extent_root);
945 pending_ret = del_pending_extents(trans, extent_root);
946 if (ret)
947 return ret;
948 if (pending_ret)
949 return pending_ret;
950 return 0;
951
952 }
953
954 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
955 struct btrfs_root *root)
956 {
957 struct extent_io_tree *block_group_cache;
958 struct btrfs_block_group_cache *cache;
959 int ret;
960 int err = 0;
961 int werr = 0;
962 struct btrfs_path *path;
963 u64 last = 0;
964 u64 start;
965 u64 end;
966 u64 ptr;
967
968 block_group_cache = &root->fs_info->block_group_cache;
969 path = btrfs_alloc_path();
970 if (!path)
971 return -ENOMEM;
972
973 while(1) {
974 ret = find_first_extent_bit(block_group_cache, last,
975 &start, &end, BLOCK_GROUP_DIRTY);
976 if (ret)
977 break;
978
979 last = end + 1;
980 ret = get_state_private(block_group_cache, start, &ptr);
981 if (ret)
982 break;
983
984 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
985 err = write_one_cache_group(trans, root,
986 path, cache);
987 /*
988 * if we fail to write the cache group, we want
989 * to keep it marked dirty in hopes that a later
990 * write will work
991 */
992 if (err) {
993 werr = err;
994 continue;
995 }
996 clear_extent_bits(block_group_cache, start, end,
997 BLOCK_GROUP_DIRTY, GFP_NOFS);
998 }
999 btrfs_free_path(path);
1000 return werr;
1001 }
1002
1003 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
1004 u64 flags)
1005 {
1006 struct list_head *head = &info->space_info;
1007 struct list_head *cur;
1008 struct btrfs_space_info *found;
1009 list_for_each(cur, head) {
1010 found = list_entry(cur, struct btrfs_space_info, list);
1011 if (found->flags == flags)
1012 return found;
1013 }
1014 return NULL;
1015
1016 }
1017
1018 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1019 u64 total_bytes, u64 bytes_used,
1020 struct btrfs_space_info **space_info)
1021 {
1022 struct btrfs_space_info *found;
1023
1024 found = __find_space_info(info, flags);
1025 if (found) {
1026 found->total_bytes += total_bytes;
1027 found->bytes_used += bytes_used;
1028 WARN_ON(found->total_bytes < found->bytes_used);
1029 *space_info = found;
1030 return 0;
1031 }
1032 found = kmalloc(sizeof(*found), GFP_NOFS);
1033 if (!found)
1034 return -ENOMEM;
1035
1036 list_add(&found->list, &info->space_info);
1037 found->flags = flags;
1038 found->total_bytes = total_bytes;
1039 found->bytes_used = bytes_used;
1040 found->bytes_pinned = 0;
1041 found->full = 0;
1042 *space_info = found;
1043 return 0;
1044 }
1045
1046 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1047 {
1048 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1049 BTRFS_BLOCK_GROUP_RAID1 |
1050 BTRFS_BLOCK_GROUP_DUP);
1051 if (extra_flags) {
1052 if (flags & BTRFS_BLOCK_GROUP_DATA)
1053 fs_info->avail_data_alloc_bits |= extra_flags;
1054 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1055 fs_info->avail_metadata_alloc_bits |= extra_flags;
1056 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1057 fs_info->avail_system_alloc_bits |= extra_flags;
1058 }
1059 }
1060
1061 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1062 struct btrfs_root *extent_root, u64 alloc_bytes,
1063 u64 flags)
1064 {
1065 struct btrfs_space_info *space_info;
1066 u64 thresh;
1067 u64 start;
1068 u64 num_bytes;
1069 int ret;
1070
1071 space_info = __find_space_info(extent_root->fs_info, flags);
1072 if (!space_info) {
1073 ret = update_space_info(extent_root->fs_info, flags,
1074 0, 0, &space_info);
1075 BUG_ON(ret);
1076 }
1077 BUG_ON(!space_info);
1078
1079 if (space_info->full)
1080 return 0;
1081
1082 thresh = div_factor(space_info->total_bytes, 6);
1083 if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1084 thresh)
1085 return 0;
1086
1087 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1088 if (ret == -ENOSPC) {
1089 printk("space info full %Lu\n", flags);
1090 space_info->full = 1;
1091 return 0;
1092 }
1093
1094 BUG_ON(ret);
1095
1096 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1097 extent_root->fs_info->chunk_root->root_key.objectid,
1098 start, num_bytes);
1099 BUG_ON(ret);
1100
1101 return 0;
1102 }
1103
1104 static int update_block_group(struct btrfs_trans_handle *trans,
1105 struct btrfs_root *root,
1106 u64 bytenr, u64 num_bytes, int alloc,
1107 int mark_free)
1108 {
1109 struct btrfs_block_group_cache *cache;
1110 struct btrfs_fs_info *info = root->fs_info;
1111 u64 total = num_bytes;
1112 u64 old_val;
1113 u64 byte_in_group;
1114 u64 start;
1115 u64 end;
1116
1117 while(total) {
1118 cache = btrfs_lookup_block_group(info, bytenr);
1119 if (!cache) {
1120 return -1;
1121 }
1122 byte_in_group = bytenr - cache->key.objectid;
1123 WARN_ON(byte_in_group > cache->key.offset);
1124 start = cache->key.objectid;
1125 end = start + cache->key.offset - 1;
1126 set_extent_bits(&info->block_group_cache, start, end,
1127 BLOCK_GROUP_DIRTY, GFP_NOFS);
1128
1129 old_val = btrfs_block_group_used(&cache->item);
1130 num_bytes = min(total, cache->key.offset - byte_in_group);
1131 if (alloc) {
1132 old_val += num_bytes;
1133 cache->space_info->bytes_used += num_bytes;
1134 } else {
1135 old_val -= num_bytes;
1136 cache->space_info->bytes_used -= num_bytes;
1137 if (mark_free) {
1138 set_extent_dirty(&info->free_space_cache,
1139 bytenr, bytenr + num_bytes - 1,
1140 GFP_NOFS);
1141 }
1142 }
1143 btrfs_set_block_group_used(&cache->item, old_val);
1144 total -= num_bytes;
1145 bytenr += num_bytes;
1146 }
1147 return 0;
1148 }
1149
1150 static int update_pinned_extents(struct btrfs_root *root,
1151 u64 bytenr, u64 num, int pin)
1152 {
1153 u64 len;
1154 struct btrfs_block_group_cache *cache;
1155 struct btrfs_fs_info *fs_info = root->fs_info;
1156
1157 if (pin) {
1158 set_extent_dirty(&fs_info->pinned_extents,
1159 bytenr, bytenr + num - 1, GFP_NOFS);
1160 } else {
1161 clear_extent_dirty(&fs_info->pinned_extents,
1162 bytenr, bytenr + num - 1, GFP_NOFS);
1163 }
1164 while (num > 0) {
1165 cache = btrfs_lookup_block_group(fs_info, bytenr);
1166 WARN_ON(!cache);
1167 len = min(num, cache->key.offset -
1168 (bytenr - cache->key.objectid));
1169 if (pin) {
1170 cache->pinned += len;
1171 cache->space_info->bytes_pinned += len;
1172 fs_info->total_pinned += len;
1173 } else {
1174 cache->pinned -= len;
1175 cache->space_info->bytes_pinned -= len;
1176 fs_info->total_pinned -= len;
1177 }
1178 bytenr += len;
1179 num -= len;
1180 }
1181 return 0;
1182 }
1183
1184 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1185 {
1186 u64 last = 0;
1187 u64 start;
1188 u64 end;
1189 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1190 int ret;
1191
1192 while(1) {
1193 ret = find_first_extent_bit(pinned_extents, last,
1194 &start, &end, EXTENT_DIRTY);
1195 if (ret)
1196 break;
1197 set_extent_dirty(copy, start, end, GFP_NOFS);
1198 last = end + 1;
1199 }
1200 return 0;
1201 }
1202
1203 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1204 struct btrfs_root *root,
1205 struct extent_io_tree *unpin)
1206 {
1207 u64 start;
1208 u64 end;
1209 int ret;
1210 struct extent_io_tree *free_space_cache;
1211 free_space_cache = &root->fs_info->free_space_cache;
1212
1213 while(1) {
1214 ret = find_first_extent_bit(unpin, 0, &start, &end,
1215 EXTENT_DIRTY);
1216 if (ret)
1217 break;
1218 update_pinned_extents(root, start, end + 1 - start, 0);
1219 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1220 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1221 }
1222 return 0;
1223 }
1224
1225 static int finish_current_insert(struct btrfs_trans_handle *trans,
1226 struct btrfs_root *extent_root)
1227 {
1228 u64 start;
1229 u64 end;
1230 struct btrfs_fs_info *info = extent_root->fs_info;
1231 struct extent_buffer *eb;
1232 struct btrfs_path *path;
1233 struct btrfs_key ins;
1234 struct btrfs_disk_key first;
1235 struct btrfs_extent_item extent_item;
1236 int ret;
1237 int level;
1238 int err = 0;
1239
1240 btrfs_set_stack_extent_refs(&extent_item, 1);
1241 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1242 path = btrfs_alloc_path();
1243
1244 while(1) {
1245 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1246 &end, EXTENT_LOCKED);
1247 if (ret)
1248 break;
1249
1250 ins.objectid = start;
1251 ins.offset = end + 1 - start;
1252 err = btrfs_insert_item(trans, extent_root, &ins,
1253 &extent_item, sizeof(extent_item));
1254 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1255 GFP_NOFS);
1256 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1257 level = btrfs_header_level(eb);
1258 if (level == 0) {
1259 btrfs_item_key(eb, &first, 0);
1260 } else {
1261 btrfs_node_key(eb, &first, 0);
1262 }
1263 err = btrfs_insert_extent_backref(trans, extent_root, path,
1264 start, extent_root->root_key.objectid,
1265 0, level,
1266 btrfs_disk_key_objectid(&first));
1267 BUG_ON(err);
1268 free_extent_buffer(eb);
1269 }
1270 btrfs_free_path(path);
1271 return 0;
1272 }
1273
1274 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1275 int pending)
1276 {
1277 int err = 0;
1278 struct extent_buffer *buf;
1279
1280 if (!pending) {
1281 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1282 if (buf) {
1283 if (btrfs_buffer_uptodate(buf)) {
1284 u64 transid =
1285 root->fs_info->running_transaction->transid;
1286 u64 header_transid =
1287 btrfs_header_generation(buf);
1288 if (header_transid == transid &&
1289 !btrfs_header_flag(buf,
1290 BTRFS_HEADER_FLAG_WRITTEN)) {
1291 clean_tree_block(NULL, root, buf);
1292 free_extent_buffer(buf);
1293 return 1;
1294 }
1295 }
1296 free_extent_buffer(buf);
1297 }
1298 update_pinned_extents(root, bytenr, num_bytes, 1);
1299 } else {
1300 set_extent_bits(&root->fs_info->pending_del,
1301 bytenr, bytenr + num_bytes - 1,
1302 EXTENT_LOCKED, GFP_NOFS);
1303 }
1304 BUG_ON(err < 0);
1305 return 0;
1306 }
1307
1308 /*
1309 * remove an extent from the root, returns 0 on success
1310 */
1311 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1312 *root, u64 bytenr, u64 num_bytes,
1313 u64 root_objectid, u64 ref_generation,
1314 u64 owner_objectid, u64 owner_offset, int pin,
1315 int mark_free)
1316 {
1317 struct btrfs_path *path;
1318 struct btrfs_key key;
1319 struct btrfs_fs_info *info = root->fs_info;
1320 struct btrfs_root *extent_root = info->extent_root;
1321 struct extent_buffer *leaf;
1322 int ret;
1323 int extent_slot = 0;
1324 int found_extent = 0;
1325 int num_to_del = 1;
1326 struct btrfs_extent_item *ei;
1327 u32 refs;
1328
1329 key.objectid = bytenr;
1330 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1331 key.offset = num_bytes;
1332 path = btrfs_alloc_path();
1333 if (!path)
1334 return -ENOMEM;
1335
1336 path->reada = 0;
1337 ret = lookup_extent_backref(trans, extent_root, path,
1338 bytenr, root_objectid,
1339 ref_generation,
1340 owner_objectid, owner_offset, 1);
1341 if (ret == 0) {
1342 struct btrfs_key found_key;
1343 extent_slot = path->slots[0];
1344 while(extent_slot > 0) {
1345 extent_slot--;
1346 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1347 extent_slot);
1348 if (found_key.objectid != bytenr)
1349 break;
1350 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1351 found_key.offset == num_bytes) {
1352 found_extent = 1;
1353 break;
1354 }
1355 if (path->slots[0] - extent_slot > 5)
1356 break;
1357 }
1358 if (!found_extent)
1359 ret = btrfs_del_item(trans, extent_root, path);
1360 } else {
1361 btrfs_print_leaf(extent_root, path->nodes[0]);
1362 WARN_ON(1);
1363 printk("Unable to find ref byte nr %Lu root %Lu "
1364 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1365 root_objectid, ref_generation, owner_objectid,
1366 owner_offset);
1367 }
1368 if (!found_extent) {
1369 btrfs_release_path(extent_root, path);
1370 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1371 if (ret < 0)
1372 return ret;
1373 BUG_ON(ret);
1374 extent_slot = path->slots[0];
1375 }
1376
1377 leaf = path->nodes[0];
1378 ei = btrfs_item_ptr(leaf, extent_slot,
1379 struct btrfs_extent_item);
1380 refs = btrfs_extent_refs(leaf, ei);
1381 BUG_ON(refs == 0);
1382 refs -= 1;
1383 btrfs_set_extent_refs(leaf, ei, refs);
1384
1385 btrfs_mark_buffer_dirty(leaf);
1386
1387 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1388 /* if the back ref and the extent are next to each other
1389 * they get deleted below in one shot
1390 */
1391 path->slots[0] = extent_slot;
1392 num_to_del = 2;
1393 } else if (found_extent) {
1394 /* otherwise delete the extent back ref */
1395 ret = btrfs_del_item(trans, extent_root, path);
1396 BUG_ON(ret);
1397 /* if refs are 0, we need to setup the path for deletion */
1398 if (refs == 0) {
1399 btrfs_release_path(extent_root, path);
1400 ret = btrfs_search_slot(trans, extent_root, &key, path,
1401 -1, 1);
1402 if (ret < 0)
1403 return ret;
1404 BUG_ON(ret);
1405 }
1406 }
1407
1408 if (refs == 0) {
1409 u64 super_used;
1410 u64 root_used;
1411
1412 if (pin) {
1413 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1414 if (ret > 0)
1415 mark_free = 1;
1416 BUG_ON(ret < 0);
1417 }
1418
1419 /* block accounting for super block */
1420 super_used = btrfs_super_bytes_used(&info->super_copy);
1421 btrfs_set_super_bytes_used(&info->super_copy,
1422 super_used - num_bytes);
1423
1424 /* block accounting for root item */
1425 root_used = btrfs_root_used(&root->root_item);
1426 btrfs_set_root_used(&root->root_item,
1427 root_used - num_bytes);
1428 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1429 num_to_del);
1430 if (ret) {
1431 return ret;
1432 }
1433 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1434 mark_free);
1435 BUG_ON(ret);
1436 }
1437 btrfs_free_path(path);
1438 finish_current_insert(trans, extent_root);
1439 return ret;
1440 }
1441
1442 /*
1443 * find all the blocks marked as pending in the radix tree and remove
1444 * them from the extent map
1445 */
1446 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1447 btrfs_root *extent_root)
1448 {
1449 int ret;
1450 int err = 0;
1451 u64 start;
1452 u64 end;
1453 struct extent_io_tree *pending_del;
1454 struct extent_io_tree *pinned_extents;
1455
1456 pending_del = &extent_root->fs_info->pending_del;
1457 pinned_extents = &extent_root->fs_info->pinned_extents;
1458
1459 while(1) {
1460 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1461 EXTENT_LOCKED);
1462 if (ret)
1463 break;
1464 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1465 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1466 GFP_NOFS);
1467 ret = __free_extent(trans, extent_root,
1468 start, end + 1 - start,
1469 extent_root->root_key.objectid,
1470 0, 0, 0, 0, 0);
1471 if (ret)
1472 err = ret;
1473 }
1474 return err;
1475 }
1476
1477 /*
1478 * remove an extent from the root, returns 0 on success
1479 */
1480 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1481 *root, u64 bytenr, u64 num_bytes,
1482 u64 root_objectid, u64 ref_generation,
1483 u64 owner_objectid, u64 owner_offset, int pin)
1484 {
1485 struct btrfs_root *extent_root = root->fs_info->extent_root;
1486 int pending_ret;
1487 int ret;
1488
1489 WARN_ON(num_bytes < root->sectorsize);
1490 if (!root->ref_cows)
1491 ref_generation = 0;
1492
1493 if (root == extent_root) {
1494 pin_down_bytes(root, bytenr, num_bytes, 1);
1495 return 0;
1496 }
1497 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1498 ref_generation, owner_objectid, owner_offset,
1499 pin, pin == 0);
1500 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1501 return ret ? ret : pending_ret;
1502 }
1503
1504 static u64 stripe_align(struct btrfs_root *root, u64 val)
1505 {
1506 u64 mask = ((u64)root->stripesize - 1);
1507 u64 ret = (val + mask) & ~mask;
1508 return ret;
1509 }
1510
1511 /*
1512 * walks the btree of allocated extents and find a hole of a given size.
1513 * The key ins is changed to record the hole:
1514 * ins->objectid == block start
1515 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1516 * ins->offset == number of blocks
1517 * Any available blocks before search_start are skipped.
1518 */
1519 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1520 struct btrfs_root *orig_root,
1521 u64 num_bytes, u64 empty_size,
1522 u64 search_start, u64 search_end,
1523 u64 hint_byte, struct btrfs_key *ins,
1524 u64 exclude_start, u64 exclude_nr,
1525 int data)
1526 {
1527 int ret;
1528 u64 orig_search_start = search_start;
1529 struct btrfs_root * root = orig_root->fs_info->extent_root;
1530 struct btrfs_fs_info *info = root->fs_info;
1531 u64 total_needed = num_bytes;
1532 u64 *last_ptr = NULL;
1533 struct btrfs_block_group_cache *block_group;
1534 int full_scan = 0;
1535 int wrapped = 0;
1536 int empty_cluster = 2 * 1024 * 1024;
1537
1538 WARN_ON(num_bytes < root->sectorsize);
1539 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1540
1541 if (data & BTRFS_BLOCK_GROUP_METADATA) {
1542 last_ptr = &root->fs_info->last_alloc;
1543 empty_cluster = 256 * 1024;
1544 }
1545
1546 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
1547 last_ptr = &root->fs_info->last_data_alloc;
1548 }
1549
1550 if (last_ptr) {
1551 if (*last_ptr)
1552 hint_byte = *last_ptr;
1553 else {
1554 empty_size += empty_cluster;
1555 }
1556 }
1557
1558 if (search_end == (u64)-1)
1559 search_end = btrfs_super_total_bytes(&info->super_copy);
1560
1561 if (hint_byte) {
1562 block_group = btrfs_lookup_block_group(info, hint_byte);
1563 if (!block_group)
1564 hint_byte = search_start;
1565 block_group = btrfs_find_block_group(root, block_group,
1566 hint_byte, data, 1);
1567 if (last_ptr && *last_ptr == 0 && block_group)
1568 hint_byte = block_group->key.objectid;
1569 } else {
1570 block_group = btrfs_find_block_group(root,
1571 trans->block_group,
1572 search_start, data, 1);
1573 }
1574 search_start = max(search_start, hint_byte);
1575
1576 total_needed += empty_size;
1577
1578 check_failed:
1579 if (!block_group) {
1580 block_group = btrfs_lookup_block_group(info, search_start);
1581 if (!block_group)
1582 block_group = btrfs_lookup_block_group(info,
1583 orig_search_start);
1584 }
1585 ret = find_search_start(root, &block_group, &search_start,
1586 total_needed, data);
1587 if (ret == -ENOSPC && last_ptr && *last_ptr) {
1588 *last_ptr = 0;
1589 block_group = btrfs_lookup_block_group(info,
1590 orig_search_start);
1591 search_start = orig_search_start;
1592 ret = find_search_start(root, &block_group, &search_start,
1593 total_needed, data);
1594 }
1595 if (ret == -ENOSPC)
1596 goto enospc;
1597 if (ret)
1598 goto error;
1599
1600 if (last_ptr && *last_ptr && search_start != *last_ptr) {
1601 *last_ptr = 0;
1602 if (!empty_size) {
1603 empty_size += empty_cluster;
1604 total_needed += empty_size;
1605 }
1606 block_group = btrfs_lookup_block_group(info,
1607 orig_search_start);
1608 search_start = orig_search_start;
1609 ret = find_search_start(root, &block_group,
1610 &search_start, total_needed, data);
1611 if (ret == -ENOSPC)
1612 goto enospc;
1613 if (ret)
1614 goto error;
1615 }
1616
1617 search_start = stripe_align(root, search_start);
1618 ins->objectid = search_start;
1619 ins->offset = num_bytes;
1620
1621 if (ins->objectid + num_bytes >= search_end)
1622 goto enospc;
1623
1624 if (ins->objectid + num_bytes >
1625 block_group->key.objectid + block_group->key.offset) {
1626 search_start = block_group->key.objectid +
1627 block_group->key.offset;
1628 goto new_group;
1629 }
1630
1631 if (test_range_bit(&info->extent_ins, ins->objectid,
1632 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1633 search_start = ins->objectid + num_bytes;
1634 goto new_group;
1635 }
1636
1637 if (test_range_bit(&info->pinned_extents, ins->objectid,
1638 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1639 search_start = ins->objectid + num_bytes;
1640 goto new_group;
1641 }
1642
1643 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1644 ins->objectid < exclude_start + exclude_nr)) {
1645 search_start = exclude_start + exclude_nr;
1646 goto new_group;
1647 }
1648
1649 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
1650 block_group = btrfs_lookup_block_group(info, ins->objectid);
1651 if (block_group)
1652 trans->block_group = block_group;
1653 }
1654 ins->offset = num_bytes;
1655 if (last_ptr) {
1656 *last_ptr = ins->objectid + ins->offset;
1657 if (*last_ptr ==
1658 btrfs_super_total_bytes(&root->fs_info->super_copy)) {
1659 *last_ptr = 0;
1660 }
1661 }
1662 return 0;
1663
1664 new_group:
1665 if (search_start + num_bytes >= search_end) {
1666 enospc:
1667 search_start = orig_search_start;
1668 if (full_scan) {
1669 ret = -ENOSPC;
1670 goto error;
1671 }
1672 if (wrapped) {
1673 if (!full_scan)
1674 total_needed -= empty_size;
1675 full_scan = 1;
1676 } else
1677 wrapped = 1;
1678 }
1679 block_group = btrfs_lookup_block_group(info, search_start);
1680 cond_resched();
1681 block_group = btrfs_find_block_group(root, block_group,
1682 search_start, data, 0);
1683 goto check_failed;
1684
1685 error:
1686 return ret;
1687 }
1688 /*
1689 * finds a free extent and does all the dirty work required for allocation
1690 * returns the key for the extent through ins, and a tree buffer for
1691 * the first block of the extent through buf.
1692 *
1693 * returns 0 if everything worked, non-zero otherwise.
1694 */
1695 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1696 struct btrfs_root *root,
1697 u64 num_bytes, u64 min_alloc_size,
1698 u64 root_objectid, u64 ref_generation,
1699 u64 owner, u64 owner_offset,
1700 u64 empty_size, u64 hint_byte,
1701 u64 search_end, struct btrfs_key *ins, int data)
1702 {
1703 int ret;
1704 int pending_ret;
1705 u64 super_used;
1706 u64 root_used;
1707 u64 search_start = 0;
1708 u64 new_hint;
1709 u64 alloc_profile;
1710 u32 sizes[2];
1711 struct btrfs_fs_info *info = root->fs_info;
1712 struct btrfs_root *extent_root = info->extent_root;
1713 struct btrfs_extent_item *extent_item;
1714 struct btrfs_extent_ref *ref;
1715 struct btrfs_path *path;
1716 struct btrfs_key keys[2];
1717
1718 if (data) {
1719 alloc_profile = info->avail_data_alloc_bits &
1720 info->data_alloc_profile;
1721 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
1722 } else if (root == root->fs_info->chunk_root) {
1723 alloc_profile = info->avail_system_alloc_bits &
1724 info->system_alloc_profile;
1725 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
1726 } else {
1727 alloc_profile = info->avail_metadata_alloc_bits &
1728 info->metadata_alloc_profile;
1729 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
1730 }
1731 again:
1732 if (root->ref_cows) {
1733 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
1734 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1735 2 * 1024 * 1024,
1736 BTRFS_BLOCK_GROUP_METADATA |
1737 (info->metadata_alloc_profile &
1738 info->avail_metadata_alloc_bits));
1739 BUG_ON(ret);
1740 }
1741 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1742 num_bytes + 2 * 1024 * 1024, data);
1743 BUG_ON(ret);
1744 }
1745
1746 new_hint = max(hint_byte, root->fs_info->alloc_start);
1747 if (new_hint < btrfs_super_total_bytes(&info->super_copy))
1748 hint_byte = new_hint;
1749
1750 WARN_ON(num_bytes < root->sectorsize);
1751 ret = find_free_extent(trans, root, num_bytes, empty_size,
1752 search_start, search_end, hint_byte, ins,
1753 trans->alloc_exclude_start,
1754 trans->alloc_exclude_nr, data);
1755 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
1756 num_bytes = num_bytes >> 1;
1757 num_bytes = max(num_bytes, min_alloc_size);
1758 goto again;
1759 }
1760 BUG_ON(ret);
1761 if (ret)
1762 return ret;
1763
1764 /* block accounting for super block */
1765 super_used = btrfs_super_bytes_used(&info->super_copy);
1766 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1767
1768 /* block accounting for root item */
1769 root_used = btrfs_root_used(&root->root_item);
1770 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1771
1772 clear_extent_dirty(&root->fs_info->free_space_cache,
1773 ins->objectid, ins->objectid + ins->offset - 1,
1774 GFP_NOFS);
1775
1776 if (root == extent_root) {
1777 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1778 ins->objectid + ins->offset - 1,
1779 EXTENT_LOCKED, GFP_NOFS);
1780 goto update_block;
1781 }
1782
1783 WARN_ON(trans->alloc_exclude_nr);
1784 trans->alloc_exclude_start = ins->objectid;
1785 trans->alloc_exclude_nr = ins->offset;
1786
1787 memcpy(&keys[0], ins, sizeof(*ins));
1788 keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
1789 owner, owner_offset);
1790 keys[1].objectid = ins->objectid;
1791 keys[1].type = BTRFS_EXTENT_REF_KEY;
1792 sizes[0] = sizeof(*extent_item);
1793 sizes[1] = sizeof(*ref);
1794
1795 path = btrfs_alloc_path();
1796 BUG_ON(!path);
1797
1798 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
1799 sizes, 2);
1800
1801 BUG_ON(ret);
1802 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1803 struct btrfs_extent_item);
1804 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
1805 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1806 struct btrfs_extent_ref);
1807
1808 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
1809 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
1810 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
1811 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
1812
1813 btrfs_mark_buffer_dirty(path->nodes[0]);
1814
1815 trans->alloc_exclude_start = 0;
1816 trans->alloc_exclude_nr = 0;
1817 btrfs_free_path(path);
1818 finish_current_insert(trans, extent_root);
1819 pending_ret = del_pending_extents(trans, extent_root);
1820
1821 if (ret) {
1822 return ret;
1823 }
1824 if (pending_ret) {
1825 return pending_ret;
1826 }
1827
1828 update_block:
1829 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
1830 if (ret) {
1831 printk("update block group failed for %Lu %Lu\n",
1832 ins->objectid, ins->offset);
1833 BUG();
1834 }
1835 return 0;
1836 }
1837
1838 /*
1839 * helper function to allocate a block for a given tree
1840 * returns the tree buffer or NULL.
1841 */
1842 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1843 struct btrfs_root *root,
1844 u32 blocksize,
1845 u64 root_objectid, u64 hint,
1846 u64 empty_size)
1847 {
1848 u64 ref_generation;
1849
1850 if (root->ref_cows)
1851 ref_generation = trans->transid;
1852 else
1853 ref_generation = 0;
1854
1855
1856 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1857 ref_generation, 0, 0, hint, empty_size);
1858 }
1859
1860 /*
1861 * helper function to allocate a block for a given tree
1862 * returns the tree buffer or NULL.
1863 */
1864 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1865 struct btrfs_root *root,
1866 u32 blocksize,
1867 u64 root_objectid,
1868 u64 ref_generation,
1869 u64 first_objectid,
1870 int level,
1871 u64 hint,
1872 u64 empty_size)
1873 {
1874 struct btrfs_key ins;
1875 int ret;
1876 struct extent_buffer *buf;
1877
1878 ret = btrfs_alloc_extent(trans, root, blocksize, blocksize,
1879 root_objectid, ref_generation,
1880 level, first_objectid, empty_size, hint,
1881 (u64)-1, &ins, 0);
1882 if (ret) {
1883 BUG_ON(ret > 0);
1884 return ERR_PTR(ret);
1885 }
1886 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1887 if (!buf) {
1888 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1889 root->root_key.objectid, ref_generation,
1890 0, 0, 0);
1891 return ERR_PTR(-ENOMEM);
1892 }
1893 btrfs_set_header_generation(buf, trans->transid);
1894 clean_tree_block(trans, root, buf);
1895 wait_on_tree_block_writeback(root, buf);
1896 btrfs_set_buffer_uptodate(buf);
1897
1898 if (PageDirty(buf->first_page)) {
1899 printk("page %lu dirty\n", buf->first_page->index);
1900 WARN_ON(1);
1901 }
1902
1903 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
1904 buf->start + buf->len - 1, GFP_NOFS);
1905 if (!btrfs_test_opt(root, SSD))
1906 btrfs_set_buffer_defrag(buf);
1907 trans->blocks_used++;
1908 return buf;
1909 }
1910
1911 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
1912 struct btrfs_root *root,
1913 struct extent_buffer *leaf)
1914 {
1915 u64 leaf_owner;
1916 u64 leaf_generation;
1917 struct btrfs_key key;
1918 struct btrfs_file_extent_item *fi;
1919 int i;
1920 int nritems;
1921 int ret;
1922
1923 BUG_ON(!btrfs_is_leaf(leaf));
1924 nritems = btrfs_header_nritems(leaf);
1925 leaf_owner = btrfs_header_owner(leaf);
1926 leaf_generation = btrfs_header_generation(leaf);
1927
1928 for (i = 0; i < nritems; i++) {
1929 u64 disk_bytenr;
1930
1931 btrfs_item_key_to_cpu(leaf, &key, i);
1932 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1933 continue;
1934 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1935 if (btrfs_file_extent_type(leaf, fi) ==
1936 BTRFS_FILE_EXTENT_INLINE)
1937 continue;
1938 /*
1939 * FIXME make sure to insert a trans record that
1940 * repeats the snapshot del on crash
1941 */
1942 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1943 if (disk_bytenr == 0)
1944 continue;
1945 ret = btrfs_free_extent(trans, root, disk_bytenr,
1946 btrfs_file_extent_disk_num_bytes(leaf, fi),
1947 leaf_owner, leaf_generation,
1948 key.objectid, key.offset, 0);
1949 BUG_ON(ret);
1950 }
1951 return 0;
1952 }
1953
1954 static void noinline reada_walk_down(struct btrfs_root *root,
1955 struct extent_buffer *node,
1956 int slot)
1957 {
1958 u64 bytenr;
1959 u64 last = 0;
1960 u32 nritems;
1961 u32 refs;
1962 u32 blocksize;
1963 int ret;
1964 int i;
1965 int level;
1966 int skipped = 0;
1967
1968 nritems = btrfs_header_nritems(node);
1969 level = btrfs_header_level(node);
1970 if (level)
1971 return;
1972
1973 for (i = slot; i < nritems && skipped < 32; i++) {
1974 bytenr = btrfs_node_blockptr(node, i);
1975 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
1976 (last > bytenr && last - bytenr > 32 * 1024))) {
1977 skipped++;
1978 continue;
1979 }
1980 blocksize = btrfs_level_size(root, level - 1);
1981 if (i != slot) {
1982 ret = lookup_extent_ref(NULL, root, bytenr,
1983 blocksize, &refs);
1984 BUG_ON(ret);
1985 if (refs != 1) {
1986 skipped++;
1987 continue;
1988 }
1989 }
1990 mutex_unlock(&root->fs_info->fs_mutex);
1991 ret = readahead_tree_block(root, bytenr, blocksize);
1992 last = bytenr + blocksize;
1993 cond_resched();
1994 mutex_lock(&root->fs_info->fs_mutex);
1995 if (ret)
1996 break;
1997 }
1998 }
1999
2000 /*
2001 * helper function for drop_snapshot, this walks down the tree dropping ref
2002 * counts as it goes.
2003 */
2004 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2005 struct btrfs_root *root,
2006 struct btrfs_path *path, int *level)
2007 {
2008 u64 root_owner;
2009 u64 root_gen;
2010 u64 bytenr;
2011 struct extent_buffer *next;
2012 struct extent_buffer *cur;
2013 struct extent_buffer *parent;
2014 u32 blocksize;
2015 int ret;
2016 u32 refs;
2017
2018 WARN_ON(*level < 0);
2019 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2020 ret = lookup_extent_ref(trans, root,
2021 path->nodes[*level]->start,
2022 path->nodes[*level]->len, &refs);
2023 BUG_ON(ret);
2024 if (refs > 1)
2025 goto out;
2026
2027 /*
2028 * walk down to the last node level and free all the leaves
2029 */
2030 while(*level >= 0) {
2031 WARN_ON(*level < 0);
2032 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2033 cur = path->nodes[*level];
2034
2035 if (btrfs_header_level(cur) != *level)
2036 WARN_ON(1);
2037
2038 if (path->slots[*level] >=
2039 btrfs_header_nritems(cur))
2040 break;
2041 if (*level == 0) {
2042 ret = drop_leaf_ref(trans, root, cur);
2043 BUG_ON(ret);
2044 break;
2045 }
2046 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2047 blocksize = btrfs_level_size(root, *level - 1);
2048 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
2049 BUG_ON(ret);
2050 if (refs != 1) {
2051 parent = path->nodes[*level];
2052 root_owner = btrfs_header_owner(parent);
2053 root_gen = btrfs_header_generation(parent);
2054 path->slots[*level]++;
2055 ret = btrfs_free_extent(trans, root, bytenr,
2056 blocksize, root_owner,
2057 root_gen, 0, 0, 1);
2058 BUG_ON(ret);
2059 continue;
2060 }
2061 next = btrfs_find_tree_block(root, bytenr, blocksize);
2062 if (!next || !btrfs_buffer_uptodate(next)) {
2063 free_extent_buffer(next);
2064 reada_walk_down(root, cur, path->slots[*level]);
2065
2066 mutex_unlock(&root->fs_info->fs_mutex);
2067 next = read_tree_block(root, bytenr, blocksize);
2068 mutex_lock(&root->fs_info->fs_mutex);
2069
2070 /* we've dropped the lock, double check */
2071 ret = lookup_extent_ref(trans, root, bytenr,
2072 blocksize, &refs);
2073 BUG_ON(ret);
2074 if (refs != 1) {
2075 parent = path->nodes[*level];
2076 root_owner = btrfs_header_owner(parent);
2077 root_gen = btrfs_header_generation(parent);
2078
2079 path->slots[*level]++;
2080 free_extent_buffer(next);
2081 ret = btrfs_free_extent(trans, root, bytenr,
2082 blocksize,
2083 root_owner,
2084 root_gen, 0, 0, 1);
2085 BUG_ON(ret);
2086 continue;
2087 }
2088 } else if (next) {
2089 btrfs_verify_block_csum(root, next);
2090 }
2091 WARN_ON(*level <= 0);
2092 if (path->nodes[*level-1])
2093 free_extent_buffer(path->nodes[*level-1]);
2094 path->nodes[*level-1] = next;
2095 *level = btrfs_header_level(next);
2096 path->slots[*level] = 0;
2097 }
2098 out:
2099 WARN_ON(*level < 0);
2100 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2101
2102 if (path->nodes[*level] == root->node) {
2103 root_owner = root->root_key.objectid;
2104 parent = path->nodes[*level];
2105 } else {
2106 parent = path->nodes[*level + 1];
2107 root_owner = btrfs_header_owner(parent);
2108 }
2109
2110 root_gen = btrfs_header_generation(parent);
2111 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
2112 path->nodes[*level]->len,
2113 root_owner, root_gen, 0, 0, 1);
2114 free_extent_buffer(path->nodes[*level]);
2115 path->nodes[*level] = NULL;
2116 *level += 1;
2117 BUG_ON(ret);
2118 return 0;
2119 }
2120
2121 /*
2122 * helper for dropping snapshots. This walks back up the tree in the path
2123 * to find the first node higher up where we haven't yet gone through
2124 * all the slots
2125 */
2126 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
2127 struct btrfs_root *root,
2128 struct btrfs_path *path, int *level)
2129 {
2130 u64 root_owner;
2131 u64 root_gen;
2132 struct btrfs_root_item *root_item = &root->root_item;
2133 int i;
2134 int slot;
2135 int ret;
2136
2137 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2138 slot = path->slots[i];
2139 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
2140 struct extent_buffer *node;
2141 struct btrfs_disk_key disk_key;
2142 node = path->nodes[i];
2143 path->slots[i]++;
2144 *level = i;
2145 WARN_ON(*level == 0);
2146 btrfs_node_key(node, &disk_key, path->slots[i]);
2147 memcpy(&root_item->drop_progress,
2148 &disk_key, sizeof(disk_key));
2149 root_item->drop_level = i;
2150 return 0;
2151 } else {
2152 if (path->nodes[*level] == root->node) {
2153 root_owner = root->root_key.objectid;
2154 root_gen =
2155 btrfs_header_generation(path->nodes[*level]);
2156 } else {
2157 struct extent_buffer *node;
2158 node = path->nodes[*level + 1];
2159 root_owner = btrfs_header_owner(node);
2160 root_gen = btrfs_header_generation(node);
2161 }
2162 ret = btrfs_free_extent(trans, root,
2163 path->nodes[*level]->start,
2164 path->nodes[*level]->len,
2165 root_owner, root_gen, 0, 0, 1);
2166 BUG_ON(ret);
2167 free_extent_buffer(path->nodes[*level]);
2168 path->nodes[*level] = NULL;
2169 *level = i + 1;
2170 }
2171 }
2172 return 1;
2173 }
2174
2175 /*
2176 * drop the reference count on the tree rooted at 'snap'. This traverses
2177 * the tree freeing any blocks that have a ref count of zero after being
2178 * decremented.
2179 */
2180 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2181 *root)
2182 {
2183 int ret = 0;
2184 int wret;
2185 int level;
2186 struct btrfs_path *path;
2187 int i;
2188 int orig_level;
2189 struct btrfs_root_item *root_item = &root->root_item;
2190
2191 path = btrfs_alloc_path();
2192 BUG_ON(!path);
2193
2194 level = btrfs_header_level(root->node);
2195 orig_level = level;
2196 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2197 path->nodes[level] = root->node;
2198 extent_buffer_get(root->node);
2199 path->slots[level] = 0;
2200 } else {
2201 struct btrfs_key key;
2202 struct btrfs_disk_key found_key;
2203 struct extent_buffer *node;
2204
2205 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2206 level = root_item->drop_level;
2207 path->lowest_level = level;
2208 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2209 if (wret < 0) {
2210 ret = wret;
2211 goto out;
2212 }
2213 node = path->nodes[level];
2214 btrfs_node_key(node, &found_key, path->slots[level]);
2215 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2216 sizeof(found_key)));
2217 }
2218 while(1) {
2219 wret = walk_down_tree(trans, root, path, &level);
2220 if (wret > 0)
2221 break;
2222 if (wret < 0)
2223 ret = wret;
2224
2225 wret = walk_up_tree(trans, root, path, &level);
2226 if (wret > 0)
2227 break;
2228 if (wret < 0)
2229 ret = wret;
2230 ret = -EAGAIN;
2231 break;
2232 }
2233 for (i = 0; i <= orig_level; i++) {
2234 if (path->nodes[i]) {
2235 free_extent_buffer(path->nodes[i]);
2236 path->nodes[i] = NULL;
2237 }
2238 }
2239 out:
2240 btrfs_free_path(path);
2241 return ret;
2242 }
2243
2244 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2245 {
2246 u64 start;
2247 u64 end;
2248 u64 ptr;
2249 int ret;
2250 while(1) {
2251 ret = find_first_extent_bit(&info->block_group_cache, 0,
2252 &start, &end, (unsigned int)-1);
2253 if (ret)
2254 break;
2255 ret = get_state_private(&info->block_group_cache, start, &ptr);
2256 if (!ret)
2257 kfree((void *)(unsigned long)ptr);
2258 clear_extent_bits(&info->block_group_cache, start,
2259 end, (unsigned int)-1, GFP_NOFS);
2260 }
2261 while(1) {
2262 ret = find_first_extent_bit(&info->free_space_cache, 0,
2263 &start, &end, EXTENT_DIRTY);
2264 if (ret)
2265 break;
2266 clear_extent_dirty(&info->free_space_cache, start,
2267 end, GFP_NOFS);
2268 }
2269 return 0;
2270 }
2271
2272 static int noinline relocate_inode_pages(struct inode *inode, u64 start,
2273 u64 len)
2274 {
2275 u64 page_start;
2276 u64 page_end;
2277 u64 delalloc_start;
2278 u64 existing_delalloc;
2279 unsigned long last_index;
2280 unsigned long i;
2281 struct page *page;
2282 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2283 struct file_ra_state *ra;
2284
2285 ra = kzalloc(sizeof(*ra), GFP_NOFS);
2286
2287 mutex_lock(&inode->i_mutex);
2288 i = start >> PAGE_CACHE_SHIFT;
2289 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
2290
2291 file_ra_state_init(ra, inode->i_mapping);
2292 btrfs_force_ra(inode->i_mapping, ra, NULL, i, last_index);
2293 kfree(ra);
2294
2295 for (; i <= last_index; i++) {
2296 page = grab_cache_page(inode->i_mapping, i);
2297 if (!page)
2298 goto out_unlock;
2299 if (!PageUptodate(page)) {
2300 btrfs_readpage(NULL, page);
2301 lock_page(page);
2302 if (!PageUptodate(page)) {
2303 unlock_page(page);
2304 page_cache_release(page);
2305 goto out_unlock;
2306 }
2307 }
2308 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2309 page_end = page_start + PAGE_CACHE_SIZE - 1;
2310
2311 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2312
2313 delalloc_start = page_start;
2314 existing_delalloc = count_range_bits(io_tree,
2315 &delalloc_start, page_end,
2316 PAGE_CACHE_SIZE, EXTENT_DELALLOC);
2317
2318 set_extent_delalloc(io_tree, page_start,
2319 page_end, GFP_NOFS);
2320
2321 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2322 set_page_dirty(page);
2323 unlock_page(page);
2324 page_cache_release(page);
2325 }
2326
2327 out_unlock:
2328 mutex_unlock(&inode->i_mutex);
2329 return 0;
2330 }
2331
2332 /*
2333 * note, this releases the path
2334 */
2335 static int noinline relocate_one_reference(struct btrfs_root *extent_root,
2336 struct btrfs_path *path,
2337 struct btrfs_key *extent_key)
2338 {
2339 struct inode *inode;
2340 struct btrfs_root *found_root;
2341 struct btrfs_key *root_location;
2342 struct btrfs_extent_ref *ref;
2343 u64 ref_root;
2344 u64 ref_gen;
2345 u64 ref_objectid;
2346 u64 ref_offset;
2347 int ret;
2348
2349 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
2350 struct btrfs_extent_ref);
2351 ref_root = btrfs_ref_root(path->nodes[0], ref);
2352 ref_gen = btrfs_ref_generation(path->nodes[0], ref);
2353 ref_objectid = btrfs_ref_objectid(path->nodes[0], ref);
2354 ref_offset = btrfs_ref_offset(path->nodes[0], ref);
2355 btrfs_release_path(extent_root, path);
2356
2357 root_location = kmalloc(sizeof(*root_location), GFP_NOFS);
2358 root_location->objectid = ref_root;
2359 if (ref_gen == 0)
2360 root_location->offset = 0;
2361 else
2362 root_location->offset = (u64)-1;
2363 root_location->type = BTRFS_ROOT_ITEM_KEY;
2364
2365 found_root = btrfs_read_fs_root_no_name(extent_root->fs_info,
2366 root_location);
2367 BUG_ON(!found_root);
2368 kfree(root_location);
2369
2370 if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
2371 mutex_unlock(&extent_root->fs_info->fs_mutex);
2372 inode = btrfs_iget_locked(extent_root->fs_info->sb,
2373 ref_objectid, found_root);
2374 if (inode->i_state & I_NEW) {
2375 /* the inode and parent dir are two different roots */
2376 BTRFS_I(inode)->root = found_root;
2377 BTRFS_I(inode)->location.objectid = ref_objectid;
2378 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
2379 BTRFS_I(inode)->location.offset = 0;
2380 btrfs_read_locked_inode(inode);
2381 unlock_new_inode(inode);
2382
2383 }
2384 /* this can happen if the reference is not against
2385 * the latest version of the tree root
2386 */
2387 if (is_bad_inode(inode)) {
2388 mutex_lock(&extent_root->fs_info->fs_mutex);
2389 goto out;
2390 }
2391 relocate_inode_pages(inode, ref_offset, extent_key->offset);
2392 /* FIXME, data=ordered will help get rid of this */
2393 filemap_fdatawrite(inode->i_mapping);
2394 iput(inode);
2395 mutex_lock(&extent_root->fs_info->fs_mutex);
2396 } else {
2397 struct btrfs_trans_handle *trans;
2398 struct btrfs_key found_key;
2399 struct extent_buffer *eb;
2400 int level;
2401 int i;
2402
2403 trans = btrfs_start_transaction(found_root, 1);
2404 eb = read_tree_block(found_root, extent_key->objectid,
2405 extent_key->offset);
2406 level = btrfs_header_level(eb);
2407
2408 if (level == 0)
2409 btrfs_item_key_to_cpu(eb, &found_key, 0);
2410 else
2411 btrfs_node_key_to_cpu(eb, &found_key, 0);
2412
2413 free_extent_buffer(eb);
2414
2415 path->lowest_level = level;
2416 path->reada = 2;
2417 ret = btrfs_search_slot(trans, found_root, &found_key, path,
2418 0, 1);
2419 path->lowest_level = 0;
2420 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
2421 if (!path->nodes[i])
2422 break;
2423 free_extent_buffer(path->nodes[i]);
2424 path->nodes[i] = NULL;
2425 }
2426 btrfs_release_path(found_root, path);
2427 btrfs_end_transaction(trans, found_root);
2428 }
2429
2430 out:
2431 return 0;
2432 }
2433
2434 static int noinline relocate_one_extent(struct btrfs_root *extent_root,
2435 struct btrfs_path *path,
2436 struct btrfs_key *extent_key)
2437 {
2438 struct btrfs_key key;
2439 struct btrfs_key found_key;
2440 struct extent_buffer *leaf;
2441 u32 nritems;
2442 u32 item_size;
2443 int ret = 0;
2444
2445 key.objectid = extent_key->objectid;
2446 key.type = BTRFS_EXTENT_REF_KEY;
2447 key.offset = 0;
2448
2449 while(1) {
2450 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2451
2452 if (ret < 0)
2453 goto out;
2454
2455 ret = 0;
2456 leaf = path->nodes[0];
2457 nritems = btrfs_header_nritems(leaf);
2458 if (path->slots[0] == nritems)
2459 goto out;
2460
2461 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2462 if (found_key.objectid != extent_key->objectid)
2463 break;
2464
2465 if (found_key.type != BTRFS_EXTENT_REF_KEY)
2466 break;
2467
2468 key.offset = found_key.offset + 1;
2469 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2470
2471 ret = relocate_one_reference(extent_root, path, extent_key);
2472 if (ret)
2473 goto out;
2474 }
2475 ret = 0;
2476 out:
2477 btrfs_release_path(extent_root, path);
2478 return ret;
2479 }
2480
2481 int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 new_size)
2482 {
2483 struct btrfs_trans_handle *trans;
2484 struct btrfs_root *tree_root = root->fs_info->tree_root;
2485 struct btrfs_path *path;
2486 u64 cur_byte;
2487 u64 total_found;
2488 struct btrfs_fs_info *info = root->fs_info;
2489 struct extent_io_tree *block_group_cache;
2490 struct btrfs_key key;
2491 struct btrfs_key found_key;
2492 struct extent_buffer *leaf;
2493 u32 nritems;
2494 int ret;
2495 int progress = 0;
2496
2497 btrfs_set_super_total_bytes(&info->super_copy, new_size);
2498 clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1,
2499 GFP_NOFS);
2500 block_group_cache = &info->block_group_cache;
2501 path = btrfs_alloc_path();
2502 root = root->fs_info->extent_root;
2503 path->reada = 2;
2504
2505 again:
2506 total_found = 0;
2507 key.objectid = new_size;
2508 key.offset = 0;
2509 key.type = 0;
2510 cur_byte = key.objectid;
2511
2512 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2513 if (ret < 0)
2514 goto out;
2515
2516 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
2517 if (ret < 0)
2518 goto out;
2519 if (ret == 0) {
2520 leaf = path->nodes[0];
2521 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2522 if (found_key.objectid + found_key.offset > new_size) {
2523 cur_byte = found_key.objectid;
2524 key.objectid = cur_byte;
2525 }
2526 }
2527 btrfs_release_path(root, path);
2528
2529 while(1) {
2530 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2531 if (ret < 0)
2532 goto out;
2533
2534 leaf = path->nodes[0];
2535 nritems = btrfs_header_nritems(leaf);
2536 next:
2537 if (path->slots[0] >= nritems) {
2538 ret = btrfs_next_leaf(root, path);
2539 if (ret < 0)
2540 goto out;
2541 if (ret == 1) {
2542 ret = 0;
2543 break;
2544 }
2545 leaf = path->nodes[0];
2546 nritems = btrfs_header_nritems(leaf);
2547 }
2548
2549 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2550
2551 if (progress && need_resched()) {
2552 memcpy(&key, &found_key, sizeof(key));
2553 mutex_unlock(&root->fs_info->fs_mutex);
2554 cond_resched();
2555 mutex_lock(&root->fs_info->fs_mutex);
2556 btrfs_release_path(root, path);
2557 btrfs_search_slot(NULL, root, &key, path, 0, 0);
2558 progress = 0;
2559 goto next;
2560 }
2561 progress = 1;
2562
2563 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY ||
2564 found_key.objectid + found_key.offset <= cur_byte) {
2565 path->slots[0]++;
2566 goto next;
2567 }
2568
2569 total_found++;
2570 cur_byte = found_key.objectid + found_key.offset;
2571 key.objectid = cur_byte;
2572 btrfs_release_path(root, path);
2573 ret = relocate_one_extent(root, path, &found_key);
2574 }
2575
2576 btrfs_release_path(root, path);
2577
2578 if (total_found > 0) {
2579 trans = btrfs_start_transaction(tree_root, 1);
2580 btrfs_commit_transaction(trans, tree_root);
2581
2582 mutex_unlock(&root->fs_info->fs_mutex);
2583 btrfs_clean_old_snapshots(tree_root);
2584 mutex_lock(&root->fs_info->fs_mutex);
2585
2586 trans = btrfs_start_transaction(tree_root, 1);
2587 btrfs_commit_transaction(trans, tree_root);
2588 goto again;
2589 }
2590
2591 trans = btrfs_start_transaction(root, 1);
2592 key.objectid = new_size;
2593 key.offset = 0;
2594 key.type = 0;
2595 while(1) {
2596 u64 ptr;
2597
2598 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2599 if (ret < 0)
2600 goto out;
2601
2602 leaf = path->nodes[0];
2603 nritems = btrfs_header_nritems(leaf);
2604 bg_next:
2605 if (path->slots[0] >= nritems) {
2606 ret = btrfs_next_leaf(root, path);
2607 if (ret < 0)
2608 break;
2609 if (ret == 1) {
2610 ret = 0;
2611 break;
2612 }
2613 leaf = path->nodes[0];
2614 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2615
2616 /*
2617 * btrfs_next_leaf doesn't cow buffers, we have to
2618 * do the search again
2619 */
2620 memcpy(&key, &found_key, sizeof(key));
2621 btrfs_release_path(root, path);
2622 goto resched_check;
2623 }
2624
2625 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2626 if (btrfs_key_type(&found_key) != BTRFS_BLOCK_GROUP_ITEM_KEY) {
2627 printk("shrinker found key %Lu %u %Lu\n",
2628 found_key.objectid, found_key.type,
2629 found_key.offset);
2630 path->slots[0]++;
2631 goto bg_next;
2632 }
2633 ret = get_state_private(&info->block_group_cache,
2634 found_key.objectid, &ptr);
2635 if (!ret)
2636 kfree((void *)(unsigned long)ptr);
2637
2638 clear_extent_bits(&info->block_group_cache, found_key.objectid,
2639 found_key.objectid + found_key.offset - 1,
2640 (unsigned int)-1, GFP_NOFS);
2641
2642 key.objectid = found_key.objectid + 1;
2643 btrfs_del_item(trans, root, path);
2644 btrfs_release_path(root, path);
2645 resched_check:
2646 if (need_resched()) {
2647 mutex_unlock(&root->fs_info->fs_mutex);
2648 cond_resched();
2649 mutex_lock(&root->fs_info->fs_mutex);
2650 }
2651 }
2652 clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1,
2653 GFP_NOFS);
2654 btrfs_commit_transaction(trans, root);
2655 out:
2656 btrfs_free_path(path);
2657 return ret;
2658 }
2659
2660 int btrfs_grow_extent_tree(struct btrfs_trans_handle *trans,
2661 struct btrfs_root *root, u64 new_size)
2662 {
2663 btrfs_set_super_total_bytes(&root->fs_info->super_copy, new_size);
2664 return 0;
2665 }
2666
2667 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
2668 struct btrfs_key *key)
2669 {
2670 int ret;
2671 struct btrfs_key found_key;
2672 struct extent_buffer *leaf;
2673 int slot;
2674
2675 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
2676 if (ret < 0)
2677 return ret;
2678 while(1) {
2679 slot = path->slots[0];
2680 leaf = path->nodes[0];
2681 if (slot >= btrfs_header_nritems(leaf)) {
2682 ret = btrfs_next_leaf(root, path);
2683 if (ret == 0)
2684 continue;
2685 if (ret < 0)
2686 goto error;
2687 break;
2688 }
2689 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2690
2691 if (found_key.objectid >= key->objectid &&
2692 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
2693 return 0;
2694 path->slots[0]++;
2695 }
2696 ret = -ENOENT;
2697 error:
2698 return ret;
2699 }
2700
2701 int btrfs_read_block_groups(struct btrfs_root *root)
2702 {
2703 struct btrfs_path *path;
2704 int ret;
2705 int bit;
2706 struct btrfs_block_group_cache *cache;
2707 struct btrfs_fs_info *info = root->fs_info;
2708 struct btrfs_space_info *space_info;
2709 struct extent_io_tree *block_group_cache;
2710 struct btrfs_key key;
2711 struct btrfs_key found_key;
2712 struct extent_buffer *leaf;
2713
2714 block_group_cache = &info->block_group_cache;
2715 root = info->extent_root;
2716 key.objectid = 0;
2717 key.offset = 0;
2718 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2719 path = btrfs_alloc_path();
2720 if (!path)
2721 return -ENOMEM;
2722
2723 while(1) {
2724 ret = find_first_block_group(root, path, &key);
2725 if (ret > 0) {
2726 ret = 0;
2727 goto error;
2728 }
2729 if (ret != 0)
2730 goto error;
2731
2732 leaf = path->nodes[0];
2733 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2734 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2735 if (!cache) {
2736 ret = -ENOMEM;
2737 break;
2738 }
2739
2740 read_extent_buffer(leaf, &cache->item,
2741 btrfs_item_ptr_offset(leaf, path->slots[0]),
2742 sizeof(cache->item));
2743 memcpy(&cache->key, &found_key, sizeof(found_key));
2744 cache->cached = 0;
2745 cache->pinned = 0;
2746
2747 key.objectid = found_key.objectid + found_key.offset;
2748 btrfs_release_path(root, path);
2749 cache->flags = btrfs_block_group_flags(&cache->item);
2750 bit = 0;
2751 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
2752 bit = BLOCK_GROUP_DATA;
2753 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
2754 bit = BLOCK_GROUP_SYSTEM;
2755 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
2756 bit = BLOCK_GROUP_METADATA;
2757 }
2758 set_avail_alloc_bits(info, cache->flags);
2759
2760 ret = update_space_info(info, cache->flags, found_key.offset,
2761 btrfs_block_group_used(&cache->item),
2762 &space_info);
2763 BUG_ON(ret);
2764 cache->space_info = space_info;
2765
2766 /* use EXTENT_LOCKED to prevent merging */
2767 set_extent_bits(block_group_cache, found_key.objectid,
2768 found_key.objectid + found_key.offset - 1,
2769 bit | EXTENT_LOCKED, GFP_NOFS);
2770 set_state_private(block_group_cache, found_key.objectid,
2771 (unsigned long)cache);
2772
2773 if (key.objectid >=
2774 btrfs_super_total_bytes(&info->super_copy))
2775 break;
2776 }
2777 ret = 0;
2778 error:
2779 btrfs_free_path(path);
2780 return ret;
2781 }
2782
2783 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
2784 struct btrfs_root *root, u64 bytes_used,
2785 u64 type, u64 chunk_tree, u64 chunk_objectid,
2786 u64 size)
2787 {
2788 int ret;
2789 int bit = 0;
2790 struct btrfs_root *extent_root;
2791 struct btrfs_block_group_cache *cache;
2792 struct extent_io_tree *block_group_cache;
2793
2794 extent_root = root->fs_info->extent_root;
2795 block_group_cache = &root->fs_info->block_group_cache;
2796
2797 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2798 BUG_ON(!cache);
2799 cache->key.objectid = chunk_objectid;
2800 cache->key.offset = size;
2801 cache->cached = 0;
2802 cache->pinned = 0;
2803 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2804 memset(&cache->item, 0, sizeof(cache->item));
2805 btrfs_set_block_group_used(&cache->item, bytes_used);
2806 btrfs_set_block_group_chunk_tree(&cache->item, chunk_tree);
2807 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
2808 cache->flags = type;
2809 btrfs_set_block_group_flags(&cache->item, type);
2810
2811 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
2812 &cache->space_info);
2813 BUG_ON(ret);
2814
2815 bit = block_group_state_bits(type);
2816 set_extent_bits(block_group_cache, chunk_objectid,
2817 chunk_objectid + size - 1,
2818 bit | EXTENT_LOCKED, GFP_NOFS);
2819 set_state_private(block_group_cache, chunk_objectid,
2820 (unsigned long)cache);
2821
2822 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
2823 sizeof(cache->item));
2824 BUG_ON(ret);
2825
2826 finish_current_insert(trans, extent_root);
2827 ret = del_pending_extents(trans, extent_root);
2828 BUG_ON(ret);
2829 set_avail_alloc_bits(extent_root->fs_info, type);
2830 return 0;
2831 }
Linux kernel - Deliverables
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