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Btrfs: Avoid recursive chunk allocations
[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
39
40 static int cache_block_group(struct btrfs_root *root,
41 struct btrfs_block_group_cache *block_group)
42 {
43 struct btrfs_path *path;
44 int ret;
45 struct btrfs_key key;
46 struct extent_buffer *leaf;
47 struct extent_io_tree *free_space_cache;
48 int slot;
49 u64 last = 0;
50 u64 hole_size;
51 u64 first_free;
52 int found = 0;
53
54 if (!block_group)
55 return 0;
56
57 root = root->fs_info->extent_root;
58 free_space_cache = &root->fs_info->free_space_cache;
59
60 if (block_group->cached)
61 return 0;
62
63 path = btrfs_alloc_path();
64 if (!path)
65 return -ENOMEM;
66
67 path->reada = 2;
68 first_free = block_group->key.objectid;
69 key.objectid = block_group->key.objectid;
70 key.offset = 0;
71 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
72 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
73 if (ret < 0)
74 return ret;
75 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
76 if (ret < 0)
77 return ret;
78 if (ret == 0) {
79 leaf = path->nodes[0];
80 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
81 if (key.objectid + key.offset > first_free)
82 first_free = key.objectid + key.offset;
83 }
84 while(1) {
85 leaf = path->nodes[0];
86 slot = path->slots[0];
87 if (slot >= btrfs_header_nritems(leaf)) {
88 ret = btrfs_next_leaf(root, path);
89 if (ret < 0)
90 goto err;
91 if (ret == 0) {
92 continue;
93 } else {
94 break;
95 }
96 }
97 btrfs_item_key_to_cpu(leaf, &key, slot);
98 if (key.objectid < block_group->key.objectid) {
99 goto next;
100 }
101 if (key.objectid >= block_group->key.objectid +
102 block_group->key.offset) {
103 break;
104 }
105
106 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
107 if (!found) {
108 last = first_free;
109 found = 1;
110 }
111 if (key.objectid > last) {
112 hole_size = key.objectid - last;
113 set_extent_dirty(free_space_cache, last,
114 last + hole_size - 1,
115 GFP_NOFS);
116 }
117 last = key.objectid + key.offset;
118 }
119 next:
120 path->slots[0]++;
121 }
122
123 if (!found)
124 last = first_free;
125 if (block_group->key.objectid +
126 block_group->key.offset > last) {
127 hole_size = block_group->key.objectid +
128 block_group->key.offset - last;
129 set_extent_dirty(free_space_cache, last,
130 last + hole_size - 1, GFP_NOFS);
131 }
132 block_group->cached = 1;
133 err:
134 btrfs_free_path(path);
135 return 0;
136 }
137
138 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
139 btrfs_fs_info *info,
140 u64 bytenr)
141 {
142 struct extent_io_tree *block_group_cache;
143 struct btrfs_block_group_cache *block_group = NULL;
144 u64 ptr;
145 u64 start;
146 u64 end;
147 int ret;
148
149 block_group_cache = &info->block_group_cache;
150 ret = find_first_extent_bit(block_group_cache,
151 bytenr, &start, &end,
152 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
153 BLOCK_GROUP_SYSTEM);
154 if (ret) {
155 return NULL;
156 }
157 ret = get_state_private(block_group_cache, start, &ptr);
158 if (ret)
159 return NULL;
160
161 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
162 if (block_group->key.objectid <= bytenr && bytenr <
163 block_group->key.objectid + block_group->key.offset)
164 return block_group;
165 return NULL;
166 }
167
168 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
169 {
170 return (cache->flags & bits) == bits;
171 }
172
173 static int noinline find_search_start(struct btrfs_root *root,
174 struct btrfs_block_group_cache **cache_ret,
175 u64 *start_ret, int num, int data)
176 {
177 int ret;
178 struct btrfs_block_group_cache *cache = *cache_ret;
179 struct extent_io_tree *free_space_cache;
180 struct extent_state *state;
181 u64 last;
182 u64 start = 0;
183 u64 cache_miss = 0;
184 u64 total_fs_bytes;
185 u64 search_start = *start_ret;
186 int wrapped = 0;
187
188 if (!cache)
189 goto out;
190
191 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
192 free_space_cache = &root->fs_info->free_space_cache;
193
194 again:
195 ret = cache_block_group(root, cache);
196 if (ret)
197 goto out;
198
199 last = max(search_start, cache->key.objectid);
200 if (!block_group_bits(cache, data) || cache->ro) {
201 goto new_group;
202 }
203
204 spin_lock_irq(&free_space_cache->lock);
205 state = find_first_extent_bit_state(free_space_cache, last, EXTENT_DIRTY);
206 while(1) {
207 if (!state) {
208 if (!cache_miss)
209 cache_miss = last;
210 spin_unlock_irq(&free_space_cache->lock);
211 goto new_group;
212 }
213
214 start = max(last, state->start);
215 last = state->end + 1;
216 if (last - start < num) {
217 if (last == cache->key.objectid + cache->key.offset)
218 cache_miss = start;
219 do {
220 state = extent_state_next(state);
221 } while(state && !(state->state & EXTENT_DIRTY));
222 continue;
223 }
224 spin_unlock_irq(&free_space_cache->lock);
225 if (cache->ro)
226 goto new_group;
227 if (start + num > cache->key.objectid + cache->key.offset)
228 goto new_group;
229 if (start + num > total_fs_bytes)
230 goto new_group;
231 if (!block_group_bits(cache, data)) {
232 printk("block group bits don't match %Lu %d\n", cache->flags, data);
233 }
234 *start_ret = start;
235 return 0;
236 }
237 out:
238 cache = btrfs_lookup_block_group(root->fs_info, search_start);
239 if (!cache) {
240 printk("Unable to find block group for %Lu\n", search_start);
241 WARN_ON(1);
242 }
243 return -ENOSPC;
244
245 new_group:
246 last = cache->key.objectid + cache->key.offset;
247 wrapped:
248 cache = btrfs_lookup_block_group(root->fs_info, last);
249 if (!cache || cache->key.objectid >= total_fs_bytes) {
250 no_cache:
251 if (!wrapped) {
252 wrapped = 1;
253 last = search_start;
254 goto wrapped;
255 }
256 goto out;
257 }
258 if (cache_miss && !cache->cached) {
259 cache_block_group(root, cache);
260 last = cache_miss;
261 cache = btrfs_lookup_block_group(root->fs_info, last);
262 }
263 cache = btrfs_find_block_group(root, cache, last, data, 0);
264 if (!cache)
265 goto no_cache;
266 *cache_ret = cache;
267 cache_miss = 0;
268 goto again;
269 }
270
271 static u64 div_factor(u64 num, int factor)
272 {
273 if (factor == 10)
274 return num;
275 num *= factor;
276 do_div(num, 10);
277 return num;
278 }
279
280 static int block_group_state_bits(u64 flags)
281 {
282 int bits = 0;
283 if (flags & BTRFS_BLOCK_GROUP_DATA)
284 bits |= BLOCK_GROUP_DATA;
285 if (flags & BTRFS_BLOCK_GROUP_METADATA)
286 bits |= BLOCK_GROUP_METADATA;
287 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
288 bits |= BLOCK_GROUP_SYSTEM;
289 return bits;
290 }
291
292 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
293 struct btrfs_block_group_cache
294 *hint, u64 search_start,
295 int data, int owner)
296 {
297 struct btrfs_block_group_cache *cache;
298 struct extent_io_tree *block_group_cache;
299 struct btrfs_block_group_cache *found_group = NULL;
300 struct btrfs_fs_info *info = root->fs_info;
301 u64 used;
302 u64 last = 0;
303 u64 hint_last;
304 u64 start;
305 u64 end;
306 u64 free_check;
307 u64 ptr;
308 u64 total_fs_bytes;
309 int bit;
310 int ret;
311 int full_search = 0;
312 int factor = 10;
313
314 block_group_cache = &info->block_group_cache;
315 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
316
317 if (!owner)
318 factor = 10;
319
320 bit = block_group_state_bits(data);
321
322 if (search_start && search_start < total_fs_bytes) {
323 struct btrfs_block_group_cache *shint;
324 shint = btrfs_lookup_block_group(info, search_start);
325 if (shint && block_group_bits(shint, data) && !shint->ro) {
326 used = btrfs_block_group_used(&shint->item);
327 if (used + shint->pinned <
328 div_factor(shint->key.offset, factor)) {
329 return shint;
330 }
331 }
332 }
333 if (hint && !hint->ro && block_group_bits(hint, data) &&
334 hint->key.objectid < total_fs_bytes) {
335 used = btrfs_block_group_used(&hint->item);
336 if (used + hint->pinned <
337 div_factor(hint->key.offset, factor)) {
338 return hint;
339 }
340 last = hint->key.objectid + hint->key.offset;
341 hint_last = last;
342 } else {
343 if (hint)
344 hint_last = max(hint->key.objectid, search_start);
345 else
346 hint_last = search_start;
347
348 if (hint_last >= total_fs_bytes)
349 hint_last = search_start;
350 last = hint_last;
351 }
352 again:
353 while(1) {
354 ret = find_first_extent_bit(block_group_cache, last,
355 &start, &end, bit);
356 if (ret)
357 break;
358
359 ret = get_state_private(block_group_cache, start, &ptr);
360 if (ret)
361 break;
362
363 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
364 last = cache->key.objectid + cache->key.offset;
365 used = btrfs_block_group_used(&cache->item);
366
367 if (cache->key.objectid > total_fs_bytes)
368 break;
369
370 if (!cache->ro && block_group_bits(cache, data)) {
371 if (full_search)
372 free_check = cache->key.offset;
373 else
374 free_check = div_factor(cache->key.offset,
375 factor);
376
377 if (used + cache->pinned < free_check) {
378 found_group = cache;
379 goto found;
380 }
381 }
382 cond_resched();
383 }
384 if (!full_search) {
385 last = search_start;
386 full_search = 1;
387 goto again;
388 }
389 found:
390 return found_group;
391 }
392
393 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
394 u64 owner, u64 owner_offset)
395 {
396 u32 high_crc = ~(u32)0;
397 u32 low_crc = ~(u32)0;
398 __le64 lenum;
399 lenum = cpu_to_le64(root_objectid);
400 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
401 lenum = cpu_to_le64(ref_generation);
402 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
403 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
404 lenum = cpu_to_le64(owner);
405 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
406 lenum = cpu_to_le64(owner_offset);
407 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
408 }
409 return ((u64)high_crc << 32) | (u64)low_crc;
410 }
411
412 static int match_extent_ref(struct extent_buffer *leaf,
413 struct btrfs_extent_ref *disk_ref,
414 struct btrfs_extent_ref *cpu_ref)
415 {
416 int ret;
417 int len;
418
419 if (cpu_ref->objectid)
420 len = sizeof(*cpu_ref);
421 else
422 len = 2 * sizeof(u64);
423 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
424 len);
425 return ret == 0;
426 }
427
428 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
429 struct btrfs_root *root,
430 struct btrfs_path *path, u64 bytenr,
431 u64 root_objectid,
432 u64 ref_generation, u64 owner,
433 u64 owner_offset, int del)
434 {
435 u64 hash;
436 struct btrfs_key key;
437 struct btrfs_key found_key;
438 struct btrfs_extent_ref ref;
439 struct extent_buffer *leaf;
440 struct btrfs_extent_ref *disk_ref;
441 int ret;
442 int ret2;
443
444 btrfs_set_stack_ref_root(&ref, root_objectid);
445 btrfs_set_stack_ref_generation(&ref, ref_generation);
446 btrfs_set_stack_ref_objectid(&ref, owner);
447 btrfs_set_stack_ref_offset(&ref, owner_offset);
448
449 hash = hash_extent_ref(root_objectid, ref_generation, owner,
450 owner_offset);
451 key.offset = hash;
452 key.objectid = bytenr;
453 key.type = BTRFS_EXTENT_REF_KEY;
454
455 while (1) {
456 ret = btrfs_search_slot(trans, root, &key, path,
457 del ? -1 : 0, del);
458 if (ret < 0)
459 goto out;
460 leaf = path->nodes[0];
461 if (ret != 0) {
462 u32 nritems = btrfs_header_nritems(leaf);
463 if (path->slots[0] >= nritems) {
464 ret2 = btrfs_next_leaf(root, path);
465 if (ret2)
466 goto out;
467 leaf = path->nodes[0];
468 }
469 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
470 if (found_key.objectid != bytenr ||
471 found_key.type != BTRFS_EXTENT_REF_KEY)
472 goto out;
473 key.offset = found_key.offset;
474 if (del) {
475 btrfs_release_path(root, path);
476 continue;
477 }
478 }
479 disk_ref = btrfs_item_ptr(path->nodes[0],
480 path->slots[0],
481 struct btrfs_extent_ref);
482 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
483 ret = 0;
484 goto out;
485 }
486 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
487 key.offset = found_key.offset + 1;
488 btrfs_release_path(root, path);
489 }
490 out:
491 return ret;
492 }
493
494 /*
495 * Back reference rules. Back refs have three main goals:
496 *
497 * 1) differentiate between all holders of references to an extent so that
498 * when a reference is dropped we can make sure it was a valid reference
499 * before freeing the extent.
500 *
501 * 2) Provide enough information to quickly find the holders of an extent
502 * if we notice a given block is corrupted or bad.
503 *
504 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
505 * maintenance. This is actually the same as #2, but with a slightly
506 * different use case.
507 *
508 * File extents can be referenced by:
509 *
510 * - multiple snapshots, subvolumes, or different generations in one subvol
511 * - different files inside a single subvolume (in theory, not implemented yet)
512 * - different offsets inside a file (bookend extents in file.c)
513 *
514 * The extent ref structure has fields for:
515 *
516 * - Objectid of the subvolume root
517 * - Generation number of the tree holding the reference
518 * - objectid of the file holding the reference
519 * - offset in the file corresponding to the key holding the reference
520 *
521 * When a file extent is allocated the fields are filled in:
522 * (root_key.objectid, trans->transid, inode objectid, offset in file)
523 *
524 * When a leaf is cow'd new references are added for every file extent found
525 * in the leaf. It looks the same as the create case, but trans->transid
526 * will be different when the block is cow'd.
527 *
528 * (root_key.objectid, trans->transid, inode objectid, offset in file)
529 *
530 * When a file extent is removed either during snapshot deletion or file
531 * truncation, the corresponding back reference is found
532 * by searching for:
533 *
534 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
535 * inode objectid, offset in file)
536 *
537 * Btree extents can be referenced by:
538 *
539 * - Different subvolumes
540 * - Different generations of the same subvolume
541 *
542 * Storing sufficient information for a full reverse mapping of a btree
543 * block would require storing the lowest key of the block in the backref,
544 * and it would require updating that lowest key either before write out or
545 * every time it changed. Instead, the objectid of the lowest key is stored
546 * along with the level of the tree block. This provides a hint
547 * about where in the btree the block can be found. Searches through the
548 * btree only need to look for a pointer to that block, so they stop one
549 * level higher than the level recorded in the backref.
550 *
551 * Some btrees do not do reference counting on their extents. These
552 * include the extent tree and the tree of tree roots. Backrefs for these
553 * trees always have a generation of zero.
554 *
555 * When a tree block is created, back references are inserted:
556 *
557 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
558 *
559 * When a tree block is cow'd in a reference counted root,
560 * new back references are added for all the blocks it points to.
561 * These are of the form (trans->transid will have increased since creation):
562 *
563 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
564 *
565 * Because the lowest_key_objectid and the level are just hints
566 * they are not used when backrefs are deleted. When a backref is deleted:
567 *
568 * if backref was for a tree root:
569 * root_objectid = root->root_key.objectid
570 * else
571 * root_objectid = btrfs_header_owner(parent)
572 *
573 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
574 *
575 * Back Reference Key hashing:
576 *
577 * Back references have four fields, each 64 bits long. Unfortunately,
578 * This is hashed into a single 64 bit number and placed into the key offset.
579 * The key objectid corresponds to the first byte in the extent, and the
580 * key type is set to BTRFS_EXTENT_REF_KEY
581 */
582 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
583 struct btrfs_root *root,
584 struct btrfs_path *path, u64 bytenr,
585 u64 root_objectid, u64 ref_generation,
586 u64 owner, u64 owner_offset)
587 {
588 u64 hash;
589 struct btrfs_key key;
590 struct btrfs_extent_ref ref;
591 struct btrfs_extent_ref *disk_ref;
592 int ret;
593
594 btrfs_set_stack_ref_root(&ref, root_objectid);
595 btrfs_set_stack_ref_generation(&ref, ref_generation);
596 btrfs_set_stack_ref_objectid(&ref, owner);
597 btrfs_set_stack_ref_offset(&ref, owner_offset);
598
599 hash = hash_extent_ref(root_objectid, ref_generation, owner,
600 owner_offset);
601 key.offset = hash;
602 key.objectid = bytenr;
603 key.type = BTRFS_EXTENT_REF_KEY;
604
605 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
606 while (ret == -EEXIST) {
607 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
608 struct btrfs_extent_ref);
609 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
610 goto out;
611 key.offset++;
612 btrfs_release_path(root, path);
613 ret = btrfs_insert_empty_item(trans, root, path, &key,
614 sizeof(ref));
615 }
616 if (ret)
617 goto out;
618 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
619 struct btrfs_extent_ref);
620 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
621 sizeof(ref));
622 btrfs_mark_buffer_dirty(path->nodes[0]);
623 out:
624 btrfs_release_path(root, path);
625 return ret;
626 }
627
628 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
629 struct btrfs_root *root,
630 u64 bytenr, u64 num_bytes,
631 u64 root_objectid, u64 ref_generation,
632 u64 owner, u64 owner_offset)
633 {
634 struct btrfs_path *path;
635 int ret;
636 struct btrfs_key key;
637 struct extent_buffer *l;
638 struct btrfs_extent_item *item;
639 u32 refs;
640
641 WARN_ON(num_bytes < root->sectorsize);
642 path = btrfs_alloc_path();
643 if (!path)
644 return -ENOMEM;
645
646 path->reada = 1;
647 key.objectid = bytenr;
648 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
649 key.offset = num_bytes;
650 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
651 0, 1);
652 if (ret < 0)
653 return ret;
654 if (ret != 0) {
655 BUG();
656 }
657 BUG_ON(ret != 0);
658 l = path->nodes[0];
659 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
660 refs = btrfs_extent_refs(l, item);
661 btrfs_set_extent_refs(l, item, refs + 1);
662 btrfs_mark_buffer_dirty(path->nodes[0]);
663
664 btrfs_release_path(root->fs_info->extent_root, path);
665
666 path->reada = 1;
667 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
668 path, bytenr, root_objectid,
669 ref_generation, owner, owner_offset);
670 BUG_ON(ret);
671 finish_current_insert(trans, root->fs_info->extent_root);
672 del_pending_extents(trans, root->fs_info->extent_root);
673
674 btrfs_free_path(path);
675 return 0;
676 }
677
678 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
679 struct btrfs_root *root)
680 {
681 finish_current_insert(trans, root->fs_info->extent_root);
682 del_pending_extents(trans, root->fs_info->extent_root);
683 return 0;
684 }
685
686 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
687 struct btrfs_root *root, u64 bytenr,
688 u64 num_bytes, u32 *refs)
689 {
690 struct btrfs_path *path;
691 int ret;
692 struct btrfs_key key;
693 struct extent_buffer *l;
694 struct btrfs_extent_item *item;
695
696 WARN_ON(num_bytes < root->sectorsize);
697 path = btrfs_alloc_path();
698 path->reada = 1;
699 key.objectid = bytenr;
700 key.offset = num_bytes;
701 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
702 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
703 0, 0);
704 if (ret < 0)
705 goto out;
706 if (ret != 0) {
707 btrfs_print_leaf(root, path->nodes[0]);
708 printk("failed to find block number %Lu\n", bytenr);
709 BUG();
710 }
711 l = path->nodes[0];
712 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
713 *refs = btrfs_extent_refs(l, item);
714 out:
715 btrfs_free_path(path);
716 return 0;
717 }
718
719 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
720 struct btrfs_path *count_path,
721 u64 first_extent)
722 {
723 struct btrfs_root *extent_root = root->fs_info->extent_root;
724 struct btrfs_path *path;
725 u64 bytenr;
726 u64 found_objectid;
727 u64 root_objectid = root->root_key.objectid;
728 u32 total_count = 0;
729 u32 cur_count;
730 u32 nritems;
731 int ret;
732 struct btrfs_key key;
733 struct btrfs_key found_key;
734 struct extent_buffer *l;
735 struct btrfs_extent_item *item;
736 struct btrfs_extent_ref *ref_item;
737 int level = -1;
738
739 path = btrfs_alloc_path();
740 again:
741 if (level == -1)
742 bytenr = first_extent;
743 else
744 bytenr = count_path->nodes[level]->start;
745
746 cur_count = 0;
747 key.objectid = bytenr;
748 key.offset = 0;
749
750 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
751 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
752 if (ret < 0)
753 goto out;
754 BUG_ON(ret == 0);
755
756 l = path->nodes[0];
757 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
758
759 if (found_key.objectid != bytenr ||
760 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
761 goto out;
762 }
763
764 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
765 while (1) {
766 l = path->nodes[0];
767 nritems = btrfs_header_nritems(l);
768 if (path->slots[0] >= nritems) {
769 ret = btrfs_next_leaf(extent_root, path);
770 if (ret == 0)
771 continue;
772 break;
773 }
774 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
775 if (found_key.objectid != bytenr)
776 break;
777
778 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
779 path->slots[0]++;
780 continue;
781 }
782
783 cur_count++;
784 ref_item = btrfs_item_ptr(l, path->slots[0],
785 struct btrfs_extent_ref);
786 found_objectid = btrfs_ref_root(l, ref_item);
787
788 if (found_objectid != root_objectid) {
789 total_count = 2;
790 goto out;
791 }
792 total_count = 1;
793 path->slots[0]++;
794 }
795 if (cur_count == 0) {
796 total_count = 0;
797 goto out;
798 }
799 if (level >= 0 && root->node == count_path->nodes[level])
800 goto out;
801 level++;
802 btrfs_release_path(root, path);
803 goto again;
804
805 out:
806 btrfs_free_path(path);
807 return total_count;
808 }
809 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
810 struct btrfs_root *root, u64 owner_objectid)
811 {
812 u64 generation;
813 u64 key_objectid;
814 u64 level;
815 u32 nritems;
816 struct btrfs_disk_key disk_key;
817
818 level = btrfs_header_level(root->node);
819 generation = trans->transid;
820 nritems = btrfs_header_nritems(root->node);
821 if (nritems > 0) {
822 if (level == 0)
823 btrfs_item_key(root->node, &disk_key, 0);
824 else
825 btrfs_node_key(root->node, &disk_key, 0);
826 key_objectid = btrfs_disk_key_objectid(&disk_key);
827 } else {
828 key_objectid = 0;
829 }
830 return btrfs_inc_extent_ref(trans, root, root->node->start,
831 root->node->len, owner_objectid,
832 generation, level, key_objectid);
833 }
834
835 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
836 struct extent_buffer *buf)
837 {
838 u64 bytenr;
839 u32 nritems;
840 struct btrfs_key key;
841 struct btrfs_file_extent_item *fi;
842 int i;
843 int level;
844 int ret;
845 int faili;
846
847 if (!root->ref_cows)
848 return 0;
849
850 level = btrfs_header_level(buf);
851 nritems = btrfs_header_nritems(buf);
852 for (i = 0; i < nritems; i++) {
853 if (level == 0) {
854 u64 disk_bytenr;
855 btrfs_item_key_to_cpu(buf, &key, i);
856 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
857 continue;
858 fi = btrfs_item_ptr(buf, i,
859 struct btrfs_file_extent_item);
860 if (btrfs_file_extent_type(buf, fi) ==
861 BTRFS_FILE_EXTENT_INLINE)
862 continue;
863 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
864 if (disk_bytenr == 0)
865 continue;
866 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
867 btrfs_file_extent_disk_num_bytes(buf, fi),
868 root->root_key.objectid, trans->transid,
869 key.objectid, key.offset);
870 if (ret) {
871 faili = i;
872 goto fail;
873 }
874 } else {
875 bytenr = btrfs_node_blockptr(buf, i);
876 btrfs_node_key_to_cpu(buf, &key, i);
877 ret = btrfs_inc_extent_ref(trans, root, bytenr,
878 btrfs_level_size(root, level - 1),
879 root->root_key.objectid,
880 trans->transid,
881 level - 1, key.objectid);
882 if (ret) {
883 faili = i;
884 goto fail;
885 }
886 }
887 }
888 return 0;
889 fail:
890 WARN_ON(1);
891 #if 0
892 for (i =0; i < faili; i++) {
893 if (level == 0) {
894 u64 disk_bytenr;
895 btrfs_item_key_to_cpu(buf, &key, i);
896 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
897 continue;
898 fi = btrfs_item_ptr(buf, i,
899 struct btrfs_file_extent_item);
900 if (btrfs_file_extent_type(buf, fi) ==
901 BTRFS_FILE_EXTENT_INLINE)
902 continue;
903 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
904 if (disk_bytenr == 0)
905 continue;
906 err = btrfs_free_extent(trans, root, disk_bytenr,
907 btrfs_file_extent_disk_num_bytes(buf,
908 fi), 0);
909 BUG_ON(err);
910 } else {
911 bytenr = btrfs_node_blockptr(buf, i);
912 err = btrfs_free_extent(trans, root, bytenr,
913 btrfs_level_size(root, level - 1), 0);
914 BUG_ON(err);
915 }
916 }
917 #endif
918 return ret;
919 }
920
921 static int write_one_cache_group(struct btrfs_trans_handle *trans,
922 struct btrfs_root *root,
923 struct btrfs_path *path,
924 struct btrfs_block_group_cache *cache)
925 {
926 int ret;
927 int pending_ret;
928 struct btrfs_root *extent_root = root->fs_info->extent_root;
929 unsigned long bi;
930 struct extent_buffer *leaf;
931
932 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
933 if (ret < 0)
934 goto fail;
935 BUG_ON(ret);
936
937 leaf = path->nodes[0];
938 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
939 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
940 btrfs_mark_buffer_dirty(leaf);
941 btrfs_release_path(extent_root, path);
942 fail:
943 finish_current_insert(trans, extent_root);
944 pending_ret = del_pending_extents(trans, extent_root);
945 if (ret)
946 return ret;
947 if (pending_ret)
948 return pending_ret;
949 return 0;
950
951 }
952
953 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
954 struct btrfs_root *root)
955 {
956 struct extent_io_tree *block_group_cache;
957 struct btrfs_block_group_cache *cache;
958 int ret;
959 int err = 0;
960 int werr = 0;
961 struct btrfs_path *path;
962 u64 last = 0;
963 u64 start;
964 u64 end;
965 u64 ptr;
966
967 block_group_cache = &root->fs_info->block_group_cache;
968 path = btrfs_alloc_path();
969 if (!path)
970 return -ENOMEM;
971
972 while(1) {
973 ret = find_first_extent_bit(block_group_cache, last,
974 &start, &end, BLOCK_GROUP_DIRTY);
975 if (ret)
976 break;
977
978 last = end + 1;
979 ret = get_state_private(block_group_cache, start, &ptr);
980 if (ret)
981 break;
982 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
983 err = write_one_cache_group(trans, root,
984 path, cache);
985 /*
986 * if we fail to write the cache group, we want
987 * to keep it marked dirty in hopes that a later
988 * write will work
989 */
990 if (err) {
991 werr = err;
992 continue;
993 }
994 clear_extent_bits(block_group_cache, start, end,
995 BLOCK_GROUP_DIRTY, GFP_NOFS);
996 }
997 btrfs_free_path(path);
998 return werr;
999 }
1000
1001 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
1002 u64 flags)
1003 {
1004 struct list_head *head = &info->space_info;
1005 struct list_head *cur;
1006 struct btrfs_space_info *found;
1007 list_for_each(cur, head) {
1008 found = list_entry(cur, struct btrfs_space_info, list);
1009 if (found->flags == flags)
1010 return found;
1011 }
1012 return NULL;
1013
1014 }
1015
1016 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1017 u64 total_bytes, u64 bytes_used,
1018 struct btrfs_space_info **space_info)
1019 {
1020 struct btrfs_space_info *found;
1021
1022 found = __find_space_info(info, flags);
1023 if (found) {
1024 found->total_bytes += total_bytes;
1025 found->bytes_used += bytes_used;
1026 found->full = 0;
1027 WARN_ON(found->total_bytes < found->bytes_used);
1028 *space_info = found;
1029 return 0;
1030 }
1031 found = kmalloc(sizeof(*found), GFP_NOFS);
1032 if (!found)
1033 return -ENOMEM;
1034
1035 list_add(&found->list, &info->space_info);
1036 found->flags = flags;
1037 found->total_bytes = total_bytes;
1038 found->bytes_used = bytes_used;
1039 found->bytes_pinned = 0;
1040 found->full = 0;
1041 *space_info = found;
1042 return 0;
1043 }
1044
1045 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1046 {
1047 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1048 BTRFS_BLOCK_GROUP_RAID1 |
1049 BTRFS_BLOCK_GROUP_RAID10 |
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 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1098 BUG_ON(ret);
1099
1100 return 0;
1101 }
1102
1103 static int update_block_group(struct btrfs_trans_handle *trans,
1104 struct btrfs_root *root,
1105 u64 bytenr, u64 num_bytes, int alloc,
1106 int mark_free)
1107 {
1108 struct btrfs_block_group_cache *cache;
1109 struct btrfs_fs_info *info = root->fs_info;
1110 u64 total = num_bytes;
1111 u64 old_val;
1112 u64 byte_in_group;
1113 u64 start;
1114 u64 end;
1115
1116 while(total) {
1117 cache = btrfs_lookup_block_group(info, bytenr);
1118 if (!cache) {
1119 return -1;
1120 }
1121 byte_in_group = bytenr - cache->key.objectid;
1122 WARN_ON(byte_in_group > cache->key.offset);
1123 start = cache->key.objectid;
1124 end = start + cache->key.offset - 1;
1125 set_extent_bits(&info->block_group_cache, start, end,
1126 BLOCK_GROUP_DIRTY, GFP_NOFS);
1127
1128 old_val = btrfs_block_group_used(&cache->item);
1129 num_bytes = min(total, cache->key.offset - byte_in_group);
1130 if (alloc) {
1131 old_val += num_bytes;
1132 cache->space_info->bytes_used += num_bytes;
1133 } else {
1134 old_val -= num_bytes;
1135 cache->space_info->bytes_used -= num_bytes;
1136 if (mark_free) {
1137 set_extent_dirty(&info->free_space_cache,
1138 bytenr, bytenr + num_bytes - 1,
1139 GFP_NOFS);
1140 }
1141 }
1142 btrfs_set_block_group_used(&cache->item, old_val);
1143 total -= num_bytes;
1144 bytenr += num_bytes;
1145 }
1146 return 0;
1147 }
1148
1149 static int update_pinned_extents(struct btrfs_root *root,
1150 u64 bytenr, u64 num, int pin)
1151 {
1152 u64 len;
1153 struct btrfs_block_group_cache *cache;
1154 struct btrfs_fs_info *fs_info = root->fs_info;
1155
1156 if (pin) {
1157 set_extent_dirty(&fs_info->pinned_extents,
1158 bytenr, bytenr + num - 1, GFP_NOFS);
1159 } else {
1160 clear_extent_dirty(&fs_info->pinned_extents,
1161 bytenr, bytenr + num - 1, GFP_NOFS);
1162 }
1163 while (num > 0) {
1164 cache = btrfs_lookup_block_group(fs_info, bytenr);
1165 WARN_ON(!cache);
1166 len = min(num, cache->key.offset -
1167 (bytenr - cache->key.objectid));
1168 if (pin) {
1169 cache->pinned += len;
1170 cache->space_info->bytes_pinned += len;
1171 fs_info->total_pinned += len;
1172 } else {
1173 cache->pinned -= len;
1174 cache->space_info->bytes_pinned -= len;
1175 fs_info->total_pinned -= len;
1176 }
1177 bytenr += len;
1178 num -= len;
1179 }
1180 return 0;
1181 }
1182
1183 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1184 {
1185 u64 last = 0;
1186 u64 start;
1187 u64 end;
1188 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1189 int ret;
1190
1191 while(1) {
1192 ret = find_first_extent_bit(pinned_extents, last,
1193 &start, &end, EXTENT_DIRTY);
1194 if (ret)
1195 break;
1196 set_extent_dirty(copy, start, end, GFP_NOFS);
1197 last = end + 1;
1198 }
1199 return 0;
1200 }
1201
1202 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1203 struct btrfs_root *root,
1204 struct extent_io_tree *unpin)
1205 {
1206 u64 start;
1207 u64 end;
1208 int ret;
1209 struct extent_io_tree *free_space_cache;
1210 free_space_cache = &root->fs_info->free_space_cache;
1211
1212 while(1) {
1213 ret = find_first_extent_bit(unpin, 0, &start, &end,
1214 EXTENT_DIRTY);
1215 if (ret)
1216 break;
1217 update_pinned_extents(root, start, end + 1 - start, 0);
1218 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1219 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1220 }
1221 return 0;
1222 }
1223
1224 static int finish_current_insert(struct btrfs_trans_handle *trans,
1225 struct btrfs_root *extent_root)
1226 {
1227 u64 start;
1228 u64 end;
1229 struct btrfs_fs_info *info = extent_root->fs_info;
1230 struct extent_buffer *eb;
1231 struct btrfs_path *path;
1232 struct btrfs_key ins;
1233 struct btrfs_disk_key first;
1234 struct btrfs_extent_item extent_item;
1235 int ret;
1236 int level;
1237 int err = 0;
1238
1239 btrfs_set_stack_extent_refs(&extent_item, 1);
1240 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1241 path = btrfs_alloc_path();
1242
1243 while(1) {
1244 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1245 &end, EXTENT_LOCKED);
1246 if (ret)
1247 break;
1248
1249 ins.objectid = start;
1250 ins.offset = end + 1 - start;
1251 err = btrfs_insert_item(trans, extent_root, &ins,
1252 &extent_item, sizeof(extent_item));
1253 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1254 GFP_NOFS);
1255 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1256 level = btrfs_header_level(eb);
1257 if (level == 0) {
1258 btrfs_item_key(eb, &first, 0);
1259 } else {
1260 btrfs_node_key(eb, &first, 0);
1261 }
1262 err = btrfs_insert_extent_backref(trans, extent_root, path,
1263 start, extent_root->root_key.objectid,
1264 0, level,
1265 btrfs_disk_key_objectid(&first));
1266 BUG_ON(err);
1267 free_extent_buffer(eb);
1268 }
1269 btrfs_free_path(path);
1270 return 0;
1271 }
1272
1273 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1274 int pending)
1275 {
1276 int err = 0;
1277 struct extent_buffer *buf;
1278
1279 if (!pending) {
1280 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1281 if (buf) {
1282 if (btrfs_buffer_uptodate(buf)) {
1283 u64 transid =
1284 root->fs_info->running_transaction->transid;
1285 u64 header_transid =
1286 btrfs_header_generation(buf);
1287 if (header_transid == transid &&
1288 !btrfs_header_flag(buf,
1289 BTRFS_HEADER_FLAG_WRITTEN)) {
1290 clean_tree_block(NULL, root, buf);
1291 free_extent_buffer(buf);
1292 return 1;
1293 }
1294 }
1295 free_extent_buffer(buf);
1296 }
1297 update_pinned_extents(root, bytenr, num_bytes, 1);
1298 } else {
1299 set_extent_bits(&root->fs_info->pending_del,
1300 bytenr, bytenr + num_bytes - 1,
1301 EXTENT_LOCKED, GFP_NOFS);
1302 }
1303 BUG_ON(err < 0);
1304 return 0;
1305 }
1306
1307 /*
1308 * remove an extent from the root, returns 0 on success
1309 */
1310 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1311 *root, u64 bytenr, u64 num_bytes,
1312 u64 root_objectid, u64 ref_generation,
1313 u64 owner_objectid, u64 owner_offset, int pin,
1314 int mark_free)
1315 {
1316 struct btrfs_path *path;
1317 struct btrfs_key key;
1318 struct btrfs_fs_info *info = root->fs_info;
1319 struct btrfs_root *extent_root = info->extent_root;
1320 struct extent_buffer *leaf;
1321 int ret;
1322 int extent_slot = 0;
1323 int found_extent = 0;
1324 int num_to_del = 1;
1325 struct btrfs_extent_item *ei;
1326 u32 refs;
1327
1328 key.objectid = bytenr;
1329 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1330 key.offset = num_bytes;
1331 path = btrfs_alloc_path();
1332 if (!path)
1333 return -ENOMEM;
1334
1335 path->reada = 1;
1336 ret = lookup_extent_backref(trans, extent_root, path,
1337 bytenr, root_objectid,
1338 ref_generation,
1339 owner_objectid, owner_offset, 1);
1340 if (ret == 0) {
1341 struct btrfs_key found_key;
1342 extent_slot = path->slots[0];
1343 while(extent_slot > 0) {
1344 extent_slot--;
1345 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1346 extent_slot);
1347 if (found_key.objectid != bytenr)
1348 break;
1349 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1350 found_key.offset == num_bytes) {
1351 found_extent = 1;
1352 break;
1353 }
1354 if (path->slots[0] - extent_slot > 5)
1355 break;
1356 }
1357 if (!found_extent)
1358 ret = btrfs_del_item(trans, extent_root, path);
1359 } else {
1360 btrfs_print_leaf(extent_root, path->nodes[0]);
1361 WARN_ON(1);
1362 printk("Unable to find ref byte nr %Lu root %Lu "
1363 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1364 root_objectid, ref_generation, owner_objectid,
1365 owner_offset);
1366 }
1367 if (!found_extent) {
1368 btrfs_release_path(extent_root, path);
1369 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1370 if (ret < 0)
1371 return ret;
1372 BUG_ON(ret);
1373 extent_slot = path->slots[0];
1374 }
1375
1376 leaf = path->nodes[0];
1377 ei = btrfs_item_ptr(leaf, extent_slot,
1378 struct btrfs_extent_item);
1379 refs = btrfs_extent_refs(leaf, ei);
1380 BUG_ON(refs == 0);
1381 refs -= 1;
1382 btrfs_set_extent_refs(leaf, ei, refs);
1383
1384 btrfs_mark_buffer_dirty(leaf);
1385
1386 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1387 /* if the back ref and the extent are next to each other
1388 * they get deleted below in one shot
1389 */
1390 path->slots[0] = extent_slot;
1391 num_to_del = 2;
1392 } else if (found_extent) {
1393 /* otherwise delete the extent back ref */
1394 ret = btrfs_del_item(trans, extent_root, path);
1395 BUG_ON(ret);
1396 /* if refs are 0, we need to setup the path for deletion */
1397 if (refs == 0) {
1398 btrfs_release_path(extent_root, path);
1399 ret = btrfs_search_slot(trans, extent_root, &key, path,
1400 -1, 1);
1401 if (ret < 0)
1402 return ret;
1403 BUG_ON(ret);
1404 }
1405 }
1406
1407 if (refs == 0) {
1408 u64 super_used;
1409 u64 root_used;
1410
1411 if (pin) {
1412 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1413 if (ret > 0)
1414 mark_free = 1;
1415 BUG_ON(ret < 0);
1416 }
1417
1418 /* block accounting for super block */
1419 super_used = btrfs_super_bytes_used(&info->super_copy);
1420 btrfs_set_super_bytes_used(&info->super_copy,
1421 super_used - num_bytes);
1422
1423 /* block accounting for root item */
1424 root_used = btrfs_root_used(&root->root_item);
1425 btrfs_set_root_used(&root->root_item,
1426 root_used - num_bytes);
1427 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1428 num_to_del);
1429 if (ret) {
1430 return ret;
1431 }
1432 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1433 mark_free);
1434 BUG_ON(ret);
1435 }
1436 btrfs_free_path(path);
1437 finish_current_insert(trans, extent_root);
1438 return ret;
1439 }
1440
1441 /*
1442 * find all the blocks marked as pending in the radix tree and remove
1443 * them from the extent map
1444 */
1445 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1446 btrfs_root *extent_root)
1447 {
1448 int ret;
1449 int err = 0;
1450 u64 start;
1451 u64 end;
1452 struct extent_io_tree *pending_del;
1453 struct extent_io_tree *pinned_extents;
1454
1455 pending_del = &extent_root->fs_info->pending_del;
1456 pinned_extents = &extent_root->fs_info->pinned_extents;
1457
1458 while(1) {
1459 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1460 EXTENT_LOCKED);
1461 if (ret)
1462 break;
1463 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1464 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1465 GFP_NOFS);
1466 ret = __free_extent(trans, extent_root,
1467 start, end + 1 - start,
1468 extent_root->root_key.objectid,
1469 0, 0, 0, 0, 0);
1470 if (ret)
1471 err = ret;
1472 }
1473 return err;
1474 }
1475
1476 /*
1477 * remove an extent from the root, returns 0 on success
1478 */
1479 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1480 *root, u64 bytenr, u64 num_bytes,
1481 u64 root_objectid, u64 ref_generation,
1482 u64 owner_objectid, u64 owner_offset, int pin)
1483 {
1484 struct btrfs_root *extent_root = root->fs_info->extent_root;
1485 int pending_ret;
1486 int ret;
1487
1488 WARN_ON(num_bytes < root->sectorsize);
1489 if (!root->ref_cows)
1490 ref_generation = 0;
1491
1492 if (root == extent_root) {
1493 pin_down_bytes(root, bytenr, num_bytes, 1);
1494 return 0;
1495 }
1496 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1497 ref_generation, owner_objectid, owner_offset,
1498 pin, pin == 0);
1499 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1500 return ret ? ret : pending_ret;
1501 }
1502
1503 static u64 stripe_align(struct btrfs_root *root, u64 val)
1504 {
1505 u64 mask = ((u64)root->stripesize - 1);
1506 u64 ret = (val + mask) & ~mask;
1507 return ret;
1508 }
1509
1510 /*
1511 * walks the btree of allocated extents and find a hole of a given size.
1512 * The key ins is changed to record the hole:
1513 * ins->objectid == block start
1514 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1515 * ins->offset == number of blocks
1516 * Any available blocks before search_start are skipped.
1517 */
1518 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1519 struct btrfs_root *orig_root,
1520 u64 num_bytes, u64 empty_size,
1521 u64 search_start, u64 search_end,
1522 u64 hint_byte, struct btrfs_key *ins,
1523 u64 exclude_start, u64 exclude_nr,
1524 int data)
1525 {
1526 int ret;
1527 u64 orig_search_start = search_start;
1528 struct btrfs_root * root = orig_root->fs_info->extent_root;
1529 struct btrfs_fs_info *info = root->fs_info;
1530 u64 total_needed = num_bytes;
1531 u64 *last_ptr = NULL;
1532 struct btrfs_block_group_cache *block_group;
1533 int full_scan = 0;
1534 int wrapped = 0;
1535 int empty_cluster = 2 * 1024 * 1024;
1536
1537 WARN_ON(num_bytes < root->sectorsize);
1538 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1539
1540 if (data & BTRFS_BLOCK_GROUP_METADATA) {
1541 last_ptr = &root->fs_info->last_alloc;
1542 empty_cluster = 256 * 1024;
1543 }
1544
1545 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
1546 last_ptr = &root->fs_info->last_data_alloc;
1547 }
1548
1549 if (last_ptr) {
1550 if (*last_ptr)
1551 hint_byte = *last_ptr;
1552 else {
1553 empty_size += empty_cluster;
1554 }
1555 }
1556
1557 if (search_end == (u64)-1)
1558 search_end = btrfs_super_total_bytes(&info->super_copy);
1559
1560 if (hint_byte) {
1561 block_group = btrfs_lookup_block_group(info, hint_byte);
1562 if (!block_group)
1563 hint_byte = search_start;
1564 block_group = btrfs_find_block_group(root, block_group,
1565 hint_byte, data, 1);
1566 if (last_ptr && *last_ptr == 0 && block_group)
1567 hint_byte = block_group->key.objectid;
1568 } else {
1569 block_group = btrfs_find_block_group(root,
1570 trans->block_group,
1571 search_start, data, 1);
1572 }
1573 search_start = max(search_start, hint_byte);
1574
1575 total_needed += empty_size;
1576
1577 check_failed:
1578 if (!block_group) {
1579 block_group = btrfs_lookup_block_group(info, search_start);
1580 if (!block_group)
1581 block_group = btrfs_lookup_block_group(info,
1582 orig_search_start);
1583 }
1584 ret = find_search_start(root, &block_group, &search_start,
1585 total_needed, data);
1586 if (ret == -ENOSPC && last_ptr && *last_ptr) {
1587 *last_ptr = 0;
1588 block_group = btrfs_lookup_block_group(info,
1589 orig_search_start);
1590 search_start = orig_search_start;
1591 ret = find_search_start(root, &block_group, &search_start,
1592 total_needed, data);
1593 }
1594 if (ret == -ENOSPC)
1595 goto enospc;
1596 if (ret)
1597 goto error;
1598
1599 if (last_ptr && *last_ptr && search_start != *last_ptr) {
1600 *last_ptr = 0;
1601 if (!empty_size) {
1602 empty_size += empty_cluster;
1603 total_needed += empty_size;
1604 }
1605 block_group = btrfs_lookup_block_group(info,
1606 orig_search_start);
1607 search_start = orig_search_start;
1608 ret = find_search_start(root, &block_group,
1609 &search_start, total_needed, data);
1610 if (ret == -ENOSPC)
1611 goto enospc;
1612 if (ret)
1613 goto error;
1614 }
1615
1616 search_start = stripe_align(root, search_start);
1617 ins->objectid = search_start;
1618 ins->offset = num_bytes;
1619
1620 if (ins->objectid + num_bytes >= search_end)
1621 goto enospc;
1622
1623 if (ins->objectid + num_bytes >
1624 block_group->key.objectid + block_group->key.offset) {
1625 search_start = block_group->key.objectid +
1626 block_group->key.offset;
1627 goto new_group;
1628 }
1629
1630 if (test_range_bit(&info->extent_ins, ins->objectid,
1631 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1632 search_start = ins->objectid + num_bytes;
1633 goto new_group;
1634 }
1635
1636 if (test_range_bit(&info->pinned_extents, ins->objectid,
1637 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1638 search_start = ins->objectid + num_bytes;
1639 goto new_group;
1640 }
1641
1642 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1643 ins->objectid < exclude_start + exclude_nr)) {
1644 search_start = exclude_start + exclude_nr;
1645 goto new_group;
1646 }
1647
1648 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
1649 block_group = btrfs_lookup_block_group(info, ins->objectid);
1650 if (block_group)
1651 trans->block_group = block_group;
1652 }
1653 ins->offset = num_bytes;
1654 if (last_ptr) {
1655 *last_ptr = ins->objectid + ins->offset;
1656 if (*last_ptr ==
1657 btrfs_super_total_bytes(&root->fs_info->super_copy)) {
1658 *last_ptr = 0;
1659 }
1660 }
1661 return 0;
1662
1663 new_group:
1664 if (search_start + num_bytes >= search_end) {
1665 enospc:
1666 search_start = orig_search_start;
1667 if (full_scan) {
1668 ret = -ENOSPC;
1669 goto error;
1670 }
1671 if (wrapped) {
1672 if (!full_scan)
1673 total_needed -= empty_size;
1674 full_scan = 1;
1675 } else
1676 wrapped = 1;
1677 }
1678 block_group = btrfs_lookup_block_group(info, search_start);
1679 cond_resched();
1680 block_group = btrfs_find_block_group(root, block_group,
1681 search_start, data, 0);
1682 goto check_failed;
1683
1684 error:
1685 return ret;
1686 }
1687 /*
1688 * finds a free extent and does all the dirty work required for allocation
1689 * returns the key for the extent through ins, and a tree buffer for
1690 * the first block of the extent through buf.
1691 *
1692 * returns 0 if everything worked, non-zero otherwise.
1693 */
1694 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1695 struct btrfs_root *root,
1696 u64 num_bytes, u64 min_alloc_size,
1697 u64 root_objectid, u64 ref_generation,
1698 u64 owner, u64 owner_offset,
1699 u64 empty_size, u64 hint_byte,
1700 u64 search_end, struct btrfs_key *ins, int data)
1701 {
1702 int ret;
1703 int pending_ret;
1704 u64 super_used;
1705 u64 root_used;
1706 u64 search_start = 0;
1707 u64 alloc_profile;
1708 u32 sizes[2];
1709 struct btrfs_fs_info *info = root->fs_info;
1710 struct btrfs_root *extent_root = info->extent_root;
1711 struct btrfs_extent_item *extent_item;
1712 struct btrfs_extent_ref *ref;
1713 struct btrfs_path *path;
1714 struct btrfs_key keys[2];
1715
1716 if (data) {
1717 alloc_profile = info->avail_data_alloc_bits &
1718 info->data_alloc_profile;
1719 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
1720 } else if (root == root->fs_info->chunk_root) {
1721 alloc_profile = info->avail_system_alloc_bits &
1722 info->system_alloc_profile;
1723 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
1724 } else {
1725 alloc_profile = info->avail_metadata_alloc_bits &
1726 info->metadata_alloc_profile;
1727 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
1728 }
1729 again:
1730 if (root->ref_cows) {
1731 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
1732 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1733 2 * 1024 * 1024,
1734 BTRFS_BLOCK_GROUP_METADATA |
1735 (info->metadata_alloc_profile &
1736 info->avail_metadata_alloc_bits));
1737 BUG_ON(ret);
1738 }
1739 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1740 num_bytes + 2 * 1024 * 1024, data);
1741 BUG_ON(ret);
1742 }
1743
1744 WARN_ON(num_bytes < root->sectorsize);
1745 ret = find_free_extent(trans, root, num_bytes, empty_size,
1746 search_start, search_end, hint_byte, ins,
1747 trans->alloc_exclude_start,
1748 trans->alloc_exclude_nr, data);
1749
1750 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
1751 num_bytes = num_bytes >> 1;
1752 num_bytes = max(num_bytes, min_alloc_size);
1753 goto again;
1754 }
1755 BUG_ON(ret);
1756 if (ret)
1757 return ret;
1758
1759 /* block accounting for super block */
1760 super_used = btrfs_super_bytes_used(&info->super_copy);
1761 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1762
1763 /* block accounting for root item */
1764 root_used = btrfs_root_used(&root->root_item);
1765 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1766
1767 clear_extent_dirty(&root->fs_info->free_space_cache,
1768 ins->objectid, ins->objectid + ins->offset - 1,
1769 GFP_NOFS);
1770
1771 if (root == extent_root) {
1772 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1773 ins->objectid + ins->offset - 1,
1774 EXTENT_LOCKED, GFP_NOFS);
1775 goto update_block;
1776 }
1777
1778 WARN_ON(trans->alloc_exclude_nr);
1779 trans->alloc_exclude_start = ins->objectid;
1780 trans->alloc_exclude_nr = ins->offset;
1781
1782 memcpy(&keys[0], ins, sizeof(*ins));
1783 keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
1784 owner, owner_offset);
1785 keys[1].objectid = ins->objectid;
1786 keys[1].type = BTRFS_EXTENT_REF_KEY;
1787 sizes[0] = sizeof(*extent_item);
1788 sizes[1] = sizeof(*ref);
1789
1790 path = btrfs_alloc_path();
1791 BUG_ON(!path);
1792
1793 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
1794 sizes, 2);
1795
1796 BUG_ON(ret);
1797 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1798 struct btrfs_extent_item);
1799 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
1800 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1801 struct btrfs_extent_ref);
1802
1803 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
1804 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
1805 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
1806 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
1807
1808 btrfs_mark_buffer_dirty(path->nodes[0]);
1809
1810 trans->alloc_exclude_start = 0;
1811 trans->alloc_exclude_nr = 0;
1812 btrfs_free_path(path);
1813 finish_current_insert(trans, extent_root);
1814 pending_ret = del_pending_extents(trans, extent_root);
1815
1816 if (ret) {
1817 return ret;
1818 }
1819 if (pending_ret) {
1820 return pending_ret;
1821 }
1822
1823 update_block:
1824 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
1825 if (ret) {
1826 printk("update block group failed for %Lu %Lu\n",
1827 ins->objectid, ins->offset);
1828 BUG();
1829 }
1830 return 0;
1831 }
1832
1833 /*
1834 * helper function to allocate a block for a given tree
1835 * returns the tree buffer or NULL.
1836 */
1837 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1838 struct btrfs_root *root,
1839 u32 blocksize,
1840 u64 root_objectid, u64 hint,
1841 u64 empty_size)
1842 {
1843 u64 ref_generation;
1844
1845 if (root->ref_cows)
1846 ref_generation = trans->transid;
1847 else
1848 ref_generation = 0;
1849
1850
1851 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1852 ref_generation, 0, 0, hint, empty_size);
1853 }
1854
1855 /*
1856 * helper function to allocate a block for a given tree
1857 * returns the tree buffer or NULL.
1858 */
1859 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1860 struct btrfs_root *root,
1861 u32 blocksize,
1862 u64 root_objectid,
1863 u64 ref_generation,
1864 u64 first_objectid,
1865 int level,
1866 u64 hint,
1867 u64 empty_size)
1868 {
1869 struct btrfs_key ins;
1870 int ret;
1871 struct extent_buffer *buf;
1872
1873 ret = btrfs_alloc_extent(trans, root, blocksize, blocksize,
1874 root_objectid, ref_generation,
1875 level, first_objectid, empty_size, hint,
1876 (u64)-1, &ins, 0);
1877 if (ret) {
1878 BUG_ON(ret > 0);
1879 return ERR_PTR(ret);
1880 }
1881 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1882 if (!buf) {
1883 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1884 root->root_key.objectid, ref_generation,
1885 0, 0, 0);
1886 return ERR_PTR(-ENOMEM);
1887 }
1888 btrfs_set_header_generation(buf, trans->transid);
1889 clean_tree_block(trans, root, buf);
1890 btrfs_set_buffer_uptodate(buf);
1891
1892 if (PageDirty(buf->first_page)) {
1893 printk("page %lu dirty\n", buf->first_page->index);
1894 WARN_ON(1);
1895 }
1896
1897 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
1898 buf->start + buf->len - 1, GFP_NOFS);
1899 if (!btrfs_test_opt(root, SSD))
1900 btrfs_set_buffer_defrag(buf);
1901 trans->blocks_used++;
1902 return buf;
1903 }
1904
1905 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
1906 struct btrfs_root *root,
1907 struct extent_buffer *leaf)
1908 {
1909 u64 leaf_owner;
1910 u64 leaf_generation;
1911 struct btrfs_key key;
1912 struct btrfs_file_extent_item *fi;
1913 int i;
1914 int nritems;
1915 int ret;
1916
1917 BUG_ON(!btrfs_is_leaf(leaf));
1918 nritems = btrfs_header_nritems(leaf);
1919 leaf_owner = btrfs_header_owner(leaf);
1920 leaf_generation = btrfs_header_generation(leaf);
1921
1922 for (i = 0; i < nritems; i++) {
1923 u64 disk_bytenr;
1924
1925 btrfs_item_key_to_cpu(leaf, &key, i);
1926 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1927 continue;
1928 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1929 if (btrfs_file_extent_type(leaf, fi) ==
1930 BTRFS_FILE_EXTENT_INLINE)
1931 continue;
1932 /*
1933 * FIXME make sure to insert a trans record that
1934 * repeats the snapshot del on crash
1935 */
1936 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1937 if (disk_bytenr == 0)
1938 continue;
1939 ret = btrfs_free_extent(trans, root, disk_bytenr,
1940 btrfs_file_extent_disk_num_bytes(leaf, fi),
1941 leaf_owner, leaf_generation,
1942 key.objectid, key.offset, 0);
1943 BUG_ON(ret);
1944 }
1945 return 0;
1946 }
1947
1948 static void noinline reada_walk_down(struct btrfs_root *root,
1949 struct extent_buffer *node,
1950 int slot)
1951 {
1952 u64 bytenr;
1953 u64 last = 0;
1954 u32 nritems;
1955 u32 refs;
1956 u32 blocksize;
1957 int ret;
1958 int i;
1959 int level;
1960 int skipped = 0;
1961
1962 nritems = btrfs_header_nritems(node);
1963 level = btrfs_header_level(node);
1964 if (level)
1965 return;
1966
1967 for (i = slot; i < nritems && skipped < 32; i++) {
1968 bytenr = btrfs_node_blockptr(node, i);
1969 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
1970 (last > bytenr && last - bytenr > 32 * 1024))) {
1971 skipped++;
1972 continue;
1973 }
1974 blocksize = btrfs_level_size(root, level - 1);
1975 if (i != slot) {
1976 ret = lookup_extent_ref(NULL, root, bytenr,
1977 blocksize, &refs);
1978 BUG_ON(ret);
1979 if (refs != 1) {
1980 skipped++;
1981 continue;
1982 }
1983 }
1984 mutex_unlock(&root->fs_info->fs_mutex);
1985 ret = readahead_tree_block(root, bytenr, blocksize);
1986 last = bytenr + blocksize;
1987 cond_resched();
1988 mutex_lock(&root->fs_info->fs_mutex);
1989 if (ret)
1990 break;
1991 }
1992 }
1993
1994 /*
1995 * helper function for drop_snapshot, this walks down the tree dropping ref
1996 * counts as it goes.
1997 */
1998 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
1999 struct btrfs_root *root,
2000 struct btrfs_path *path, int *level)
2001 {
2002 u64 root_owner;
2003 u64 root_gen;
2004 u64 bytenr;
2005 struct extent_buffer *next;
2006 struct extent_buffer *cur;
2007 struct extent_buffer *parent;
2008 u32 blocksize;
2009 int ret;
2010 u32 refs;
2011
2012 WARN_ON(*level < 0);
2013 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2014 ret = lookup_extent_ref(trans, root,
2015 path->nodes[*level]->start,
2016 path->nodes[*level]->len, &refs);
2017 BUG_ON(ret);
2018 if (refs > 1)
2019 goto out;
2020
2021 /*
2022 * walk down to the last node level and free all the leaves
2023 */
2024 while(*level >= 0) {
2025 WARN_ON(*level < 0);
2026 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2027 cur = path->nodes[*level];
2028
2029 if (btrfs_header_level(cur) != *level)
2030 WARN_ON(1);
2031
2032 if (path->slots[*level] >=
2033 btrfs_header_nritems(cur))
2034 break;
2035 if (*level == 0) {
2036 ret = drop_leaf_ref(trans, root, cur);
2037 BUG_ON(ret);
2038 break;
2039 }
2040 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2041 blocksize = btrfs_level_size(root, *level - 1);
2042 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
2043 BUG_ON(ret);
2044 if (refs != 1) {
2045 parent = path->nodes[*level];
2046 root_owner = btrfs_header_owner(parent);
2047 root_gen = btrfs_header_generation(parent);
2048 path->slots[*level]++;
2049 ret = btrfs_free_extent(trans, root, bytenr,
2050 blocksize, root_owner,
2051 root_gen, 0, 0, 1);
2052 BUG_ON(ret);
2053 continue;
2054 }
2055 next = btrfs_find_tree_block(root, bytenr, blocksize);
2056 if (!next || !btrfs_buffer_uptodate(next)) {
2057 free_extent_buffer(next);
2058 reada_walk_down(root, cur, path->slots[*level]);
2059
2060 mutex_unlock(&root->fs_info->fs_mutex);
2061 next = read_tree_block(root, bytenr, blocksize);
2062 mutex_lock(&root->fs_info->fs_mutex);
2063
2064 /* we've dropped the lock, double check */
2065 ret = lookup_extent_ref(trans, root, bytenr,
2066 blocksize, &refs);
2067 BUG_ON(ret);
2068 if (refs != 1) {
2069 parent = path->nodes[*level];
2070 root_owner = btrfs_header_owner(parent);
2071 root_gen = btrfs_header_generation(parent);
2072
2073 path->slots[*level]++;
2074 free_extent_buffer(next);
2075 ret = btrfs_free_extent(trans, root, bytenr,
2076 blocksize,
2077 root_owner,
2078 root_gen, 0, 0, 1);
2079 BUG_ON(ret);
2080 continue;
2081 }
2082 } else if (next) {
2083 btrfs_verify_block_csum(root, next);
2084 }
2085 WARN_ON(*level <= 0);
2086 if (path->nodes[*level-1])
2087 free_extent_buffer(path->nodes[*level-1]);
2088 path->nodes[*level-1] = next;
2089 *level = btrfs_header_level(next);
2090 path->slots[*level] = 0;
2091 }
2092 out:
2093 WARN_ON(*level < 0);
2094 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2095
2096 if (path->nodes[*level] == root->node) {
2097 root_owner = root->root_key.objectid;
2098 parent = path->nodes[*level];
2099 } else {
2100 parent = path->nodes[*level + 1];
2101 root_owner = btrfs_header_owner(parent);
2102 }
2103
2104 root_gen = btrfs_header_generation(parent);
2105 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
2106 path->nodes[*level]->len,
2107 root_owner, root_gen, 0, 0, 1);
2108 free_extent_buffer(path->nodes[*level]);
2109 path->nodes[*level] = NULL;
2110 *level += 1;
2111 BUG_ON(ret);
2112 return 0;
2113 }
2114
2115 /*
2116 * helper for dropping snapshots. This walks back up the tree in the path
2117 * to find the first node higher up where we haven't yet gone through
2118 * all the slots
2119 */
2120 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
2121 struct btrfs_root *root,
2122 struct btrfs_path *path, int *level)
2123 {
2124 u64 root_owner;
2125 u64 root_gen;
2126 struct btrfs_root_item *root_item = &root->root_item;
2127 int i;
2128 int slot;
2129 int ret;
2130
2131 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2132 slot = path->slots[i];
2133 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
2134 struct extent_buffer *node;
2135 struct btrfs_disk_key disk_key;
2136 node = path->nodes[i];
2137 path->slots[i]++;
2138 *level = i;
2139 WARN_ON(*level == 0);
2140 btrfs_node_key(node, &disk_key, path->slots[i]);
2141 memcpy(&root_item->drop_progress,
2142 &disk_key, sizeof(disk_key));
2143 root_item->drop_level = i;
2144 return 0;
2145 } else {
2146 if (path->nodes[*level] == root->node) {
2147 root_owner = root->root_key.objectid;
2148 root_gen =
2149 btrfs_header_generation(path->nodes[*level]);
2150 } else {
2151 struct extent_buffer *node;
2152 node = path->nodes[*level + 1];
2153 root_owner = btrfs_header_owner(node);
2154 root_gen = btrfs_header_generation(node);
2155 }
2156 ret = btrfs_free_extent(trans, root,
2157 path->nodes[*level]->start,
2158 path->nodes[*level]->len,
2159 root_owner, root_gen, 0, 0, 1);
2160 BUG_ON(ret);
2161 free_extent_buffer(path->nodes[*level]);
2162 path->nodes[*level] = NULL;
2163 *level = i + 1;
2164 }
2165 }
2166 return 1;
2167 }
2168
2169 /*
2170 * drop the reference count on the tree rooted at 'snap'. This traverses
2171 * the tree freeing any blocks that have a ref count of zero after being
2172 * decremented.
2173 */
2174 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2175 *root)
2176 {
2177 int ret = 0;
2178 int wret;
2179 int level;
2180 struct btrfs_path *path;
2181 int i;
2182 int orig_level;
2183 struct btrfs_root_item *root_item = &root->root_item;
2184
2185 path = btrfs_alloc_path();
2186 BUG_ON(!path);
2187
2188 level = btrfs_header_level(root->node);
2189 orig_level = level;
2190 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2191 path->nodes[level] = root->node;
2192 extent_buffer_get(root->node);
2193 path->slots[level] = 0;
2194 } else {
2195 struct btrfs_key key;
2196 struct btrfs_disk_key found_key;
2197 struct extent_buffer *node;
2198
2199 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2200 level = root_item->drop_level;
2201 path->lowest_level = level;
2202 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2203 if (wret < 0) {
2204 ret = wret;
2205 goto out;
2206 }
2207 node = path->nodes[level];
2208 btrfs_node_key(node, &found_key, path->slots[level]);
2209 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2210 sizeof(found_key)));
2211 }
2212 while(1) {
2213 wret = walk_down_tree(trans, root, path, &level);
2214 if (wret > 0)
2215 break;
2216 if (wret < 0)
2217 ret = wret;
2218
2219 wret = walk_up_tree(trans, root, path, &level);
2220 if (wret > 0)
2221 break;
2222 if (wret < 0)
2223 ret = wret;
2224 ret = -EAGAIN;
2225 break;
2226 }
2227 for (i = 0; i <= orig_level; i++) {
2228 if (path->nodes[i]) {
2229 free_extent_buffer(path->nodes[i]);
2230 path->nodes[i] = NULL;
2231 }
2232 }
2233 out:
2234 btrfs_free_path(path);
2235 return ret;
2236 }
2237
2238 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2239 {
2240 u64 start;
2241 u64 end;
2242 u64 ptr;
2243 int ret;
2244 while(1) {
2245 ret = find_first_extent_bit(&info->block_group_cache, 0,
2246 &start, &end, (unsigned int)-1);
2247 if (ret)
2248 break;
2249 ret = get_state_private(&info->block_group_cache, start, &ptr);
2250 if (!ret)
2251 kfree((void *)(unsigned long)ptr);
2252 clear_extent_bits(&info->block_group_cache, start,
2253 end, (unsigned int)-1, GFP_NOFS);
2254 }
2255 while(1) {
2256 ret = find_first_extent_bit(&info->free_space_cache, 0,
2257 &start, &end, EXTENT_DIRTY);
2258 if (ret)
2259 break;
2260 clear_extent_dirty(&info->free_space_cache, start,
2261 end, GFP_NOFS);
2262 }
2263 return 0;
2264 }
2265
2266 static int noinline relocate_inode_pages(struct inode *inode, u64 start,
2267 u64 len)
2268 {
2269 u64 page_start;
2270 u64 page_end;
2271 u64 delalloc_start;
2272 u64 existing_delalloc;
2273 unsigned long last_index;
2274 unsigned long i;
2275 struct page *page;
2276 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2277 struct file_ra_state *ra;
2278
2279 ra = kzalloc(sizeof(*ra), GFP_NOFS);
2280
2281 mutex_lock(&inode->i_mutex);
2282 i = start >> PAGE_CACHE_SHIFT;
2283 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
2284
2285 file_ra_state_init(ra, inode->i_mapping);
2286 btrfs_force_ra(inode->i_mapping, ra, NULL, i, last_index);
2287 kfree(ra);
2288
2289 for (; i <= last_index; i++) {
2290 page = grab_cache_page(inode->i_mapping, i);
2291 if (!page)
2292 goto out_unlock;
2293 if (!PageUptodate(page)) {
2294 btrfs_readpage(NULL, page);
2295 lock_page(page);
2296 if (!PageUptodate(page)) {
2297 unlock_page(page);
2298 page_cache_release(page);
2299 goto out_unlock;
2300 }
2301 }
2302 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2303 page_end = page_start + PAGE_CACHE_SIZE - 1;
2304
2305 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2306
2307 delalloc_start = page_start;
2308 existing_delalloc = count_range_bits(io_tree,
2309 &delalloc_start, page_end,
2310 PAGE_CACHE_SIZE, EXTENT_DELALLOC);
2311
2312 set_extent_delalloc(io_tree, page_start,
2313 page_end, GFP_NOFS);
2314
2315 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2316 set_page_dirty(page);
2317 unlock_page(page);
2318 page_cache_release(page);
2319 }
2320
2321 out_unlock:
2322 mutex_unlock(&inode->i_mutex);
2323 return 0;
2324 }
2325
2326 /*
2327 * note, this releases the path
2328 */
2329 static int noinline relocate_one_reference(struct btrfs_root *extent_root,
2330 struct btrfs_path *path,
2331 struct btrfs_key *extent_key)
2332 {
2333 struct inode *inode;
2334 struct btrfs_root *found_root;
2335 struct btrfs_key *root_location;
2336 struct btrfs_extent_ref *ref;
2337 u64 ref_root;
2338 u64 ref_gen;
2339 u64 ref_objectid;
2340 u64 ref_offset;
2341 int ret;
2342
2343 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
2344 struct btrfs_extent_ref);
2345 ref_root = btrfs_ref_root(path->nodes[0], ref);
2346 ref_gen = btrfs_ref_generation(path->nodes[0], ref);
2347 ref_objectid = btrfs_ref_objectid(path->nodes[0], ref);
2348 ref_offset = btrfs_ref_offset(path->nodes[0], ref);
2349 btrfs_release_path(extent_root, path);
2350
2351 root_location = kmalloc(sizeof(*root_location), GFP_NOFS);
2352 root_location->objectid = ref_root;
2353 if (ref_gen == 0)
2354 root_location->offset = 0;
2355 else
2356 root_location->offset = (u64)-1;
2357 root_location->type = BTRFS_ROOT_ITEM_KEY;
2358
2359 found_root = btrfs_read_fs_root_no_name(extent_root->fs_info,
2360 root_location);
2361 BUG_ON(!found_root);
2362 kfree(root_location);
2363
2364 if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
2365 mutex_unlock(&extent_root->fs_info->fs_mutex);
2366 inode = btrfs_iget_locked(extent_root->fs_info->sb,
2367 ref_objectid, found_root);
2368 if (inode->i_state & I_NEW) {
2369 /* the inode and parent dir are two different roots */
2370 BTRFS_I(inode)->root = found_root;
2371 BTRFS_I(inode)->location.objectid = ref_objectid;
2372 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
2373 BTRFS_I(inode)->location.offset = 0;
2374 btrfs_read_locked_inode(inode);
2375 unlock_new_inode(inode);
2376
2377 }
2378 /* this can happen if the reference is not against
2379 * the latest version of the tree root
2380 */
2381 if (is_bad_inode(inode)) {
2382 mutex_lock(&extent_root->fs_info->fs_mutex);
2383 goto out;
2384 }
2385 relocate_inode_pages(inode, ref_offset, extent_key->offset);
2386 /* FIXME, data=ordered will help get rid of this */
2387 filemap_fdatawrite(inode->i_mapping);
2388 iput(inode);
2389 mutex_lock(&extent_root->fs_info->fs_mutex);
2390 } else {
2391 struct btrfs_trans_handle *trans;
2392 struct btrfs_key found_key;
2393 struct extent_buffer *eb;
2394 int level;
2395 int i;
2396
2397 trans = btrfs_start_transaction(found_root, 1);
2398 eb = read_tree_block(found_root, extent_key->objectid,
2399 extent_key->offset);
2400 level = btrfs_header_level(eb);
2401
2402 if (level == 0)
2403 btrfs_item_key_to_cpu(eb, &found_key, 0);
2404 else
2405 btrfs_node_key_to_cpu(eb, &found_key, 0);
2406
2407 free_extent_buffer(eb);
2408
2409 path->lowest_level = level;
2410 path->reada = 2;
2411 ret = btrfs_search_slot(trans, found_root, &found_key, path,
2412 0, 1);
2413 path->lowest_level = 0;
2414 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
2415 if (!path->nodes[i])
2416 break;
2417 free_extent_buffer(path->nodes[i]);
2418 path->nodes[i] = NULL;
2419 }
2420 btrfs_release_path(found_root, path);
2421 btrfs_end_transaction(trans, found_root);
2422 }
2423
2424 out:
2425 return 0;
2426 }
2427
2428 static int noinline relocate_one_extent(struct btrfs_root *extent_root,
2429 struct btrfs_path *path,
2430 struct btrfs_key *extent_key)
2431 {
2432 struct btrfs_key key;
2433 struct btrfs_key found_key;
2434 struct extent_buffer *leaf;
2435 u32 nritems;
2436 u32 item_size;
2437 int ret = 0;
2438
2439 key.objectid = extent_key->objectid;
2440 key.type = BTRFS_EXTENT_REF_KEY;
2441 key.offset = 0;
2442
2443 while(1) {
2444 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2445
2446 if (ret < 0)
2447 goto out;
2448
2449 ret = 0;
2450 leaf = path->nodes[0];
2451 nritems = btrfs_header_nritems(leaf);
2452 if (path->slots[0] == nritems)
2453 goto out;
2454
2455 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2456 if (found_key.objectid != extent_key->objectid)
2457 break;
2458
2459 if (found_key.type != BTRFS_EXTENT_REF_KEY)
2460 break;
2461
2462 key.offset = found_key.offset + 1;
2463 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2464
2465 ret = relocate_one_reference(extent_root, path, extent_key);
2466 if (ret)
2467 goto out;
2468 }
2469 ret = 0;
2470 out:
2471 btrfs_release_path(extent_root, path);
2472 return ret;
2473 }
2474
2475 int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start)
2476 {
2477 struct btrfs_trans_handle *trans;
2478 struct btrfs_root *tree_root = root->fs_info->tree_root;
2479 struct btrfs_path *path;
2480 u64 cur_byte;
2481 u64 total_found;
2482 u64 shrink_last_byte;
2483 struct btrfs_block_group_cache *shrink_block_group;
2484 struct btrfs_fs_info *info = root->fs_info;
2485 struct btrfs_key key;
2486 struct btrfs_key found_key;
2487 struct extent_buffer *leaf;
2488 u32 nritems;
2489 int ret;
2490 int progress = 0;
2491
2492 shrink_block_group = btrfs_lookup_block_group(root->fs_info,
2493 shrink_start);
2494 BUG_ON(!shrink_block_group);
2495
2496 shrink_last_byte = shrink_start + shrink_block_group->key.offset;
2497
2498 shrink_block_group->space_info->total_bytes -=
2499 shrink_block_group->key.offset;
2500 printk("shrink_extent_tree %Lu -> %Lu type %Lu\n", shrink_start, shrink_last_byte, shrink_block_group->flags);
2501 path = btrfs_alloc_path();
2502 root = root->fs_info->extent_root;
2503 path->reada = 2;
2504
2505 again:
2506 trans = btrfs_start_transaction(root, 1);
2507 do_chunk_alloc(trans, root->fs_info->extent_root,
2508 btrfs_block_group_used(&shrink_block_group->item) +
2509 2 * 1024 * 1024, shrink_block_group->flags);
2510 btrfs_end_transaction(trans, root);
2511 shrink_block_group->ro = 1;
2512
2513 total_found = 0;
2514 key.objectid = shrink_start;
2515 key.offset = 0;
2516 key.type = 0;
2517 cur_byte = key.objectid;
2518
2519 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2520 if (ret < 0)
2521 goto out;
2522
2523 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
2524 if (ret < 0)
2525 goto out;
2526
2527 if (ret == 0) {
2528 leaf = path->nodes[0];
2529 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2530 if (found_key.objectid + found_key.offset > shrink_start &&
2531 found_key.objectid < shrink_last_byte) {
2532 cur_byte = found_key.objectid;
2533 key.objectid = cur_byte;
2534 }
2535 }
2536 btrfs_release_path(root, path);
2537
2538 while(1) {
2539 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2540 if (ret < 0)
2541 goto out;
2542
2543 leaf = path->nodes[0];
2544 nritems = btrfs_header_nritems(leaf);
2545 next:
2546 if (path->slots[0] >= nritems) {
2547 ret = btrfs_next_leaf(root, path);
2548 if (ret < 0)
2549 goto out;
2550 if (ret == 1) {
2551 ret = 0;
2552 break;
2553 }
2554 leaf = path->nodes[0];
2555 nritems = btrfs_header_nritems(leaf);
2556 }
2557
2558 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2559
2560 if (found_key.objectid >= shrink_last_byte)
2561 break;
2562
2563 if (progress && need_resched()) {
2564 memcpy(&key, &found_key, sizeof(key));
2565 mutex_unlock(&root->fs_info->fs_mutex);
2566 cond_resched();
2567 mutex_lock(&root->fs_info->fs_mutex);
2568 btrfs_release_path(root, path);
2569 btrfs_search_slot(NULL, root, &key, path, 0, 0);
2570 progress = 0;
2571 goto next;
2572 }
2573 progress = 1;
2574
2575 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY ||
2576 found_key.objectid + found_key.offset <= cur_byte) {
2577 path->slots[0]++;
2578 goto next;
2579 }
2580
2581 total_found++;
2582 cur_byte = found_key.objectid + found_key.offset;
2583 key.objectid = cur_byte;
2584 btrfs_release_path(root, path);
2585 ret = relocate_one_extent(root, path, &found_key);
2586 }
2587
2588 btrfs_release_path(root, path);
2589
2590 if (total_found > 0) {
2591 trans = btrfs_start_transaction(tree_root, 1);
2592 btrfs_commit_transaction(trans, tree_root);
2593
2594 mutex_unlock(&root->fs_info->fs_mutex);
2595 btrfs_clean_old_snapshots(tree_root);
2596 mutex_lock(&root->fs_info->fs_mutex);
2597
2598 trans = btrfs_start_transaction(tree_root, 1);
2599 btrfs_commit_transaction(trans, tree_root);
2600 goto again;
2601 }
2602
2603 /*
2604 * we've freed all the extents, now remove the block
2605 * group item from the tree
2606 */
2607 trans = btrfs_start_transaction(root, 1);
2608 memcpy(&key, &shrink_block_group->key, sizeof(key));
2609
2610 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2611 if (ret > 0)
2612 ret = -EIO;
2613 if (ret < 0)
2614 goto out;
2615
2616 leaf = path->nodes[0];
2617 nritems = btrfs_header_nritems(leaf);
2618 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2619 kfree(shrink_block_group);
2620
2621 clear_extent_bits(&info->block_group_cache, found_key.objectid,
2622 found_key.objectid + found_key.offset - 1,
2623 (unsigned int)-1, GFP_NOFS);
2624
2625 btrfs_del_item(trans, root, path);
2626 clear_extent_dirty(&info->free_space_cache,
2627 shrink_start, shrink_last_byte - 1,
2628 GFP_NOFS);
2629 btrfs_commit_transaction(trans, root);
2630 out:
2631 btrfs_free_path(path);
2632 return ret;
2633 }
2634
2635 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
2636 struct btrfs_key *key)
2637 {
2638 int ret;
2639 struct btrfs_key found_key;
2640 struct extent_buffer *leaf;
2641 int slot;
2642
2643 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
2644 if (ret < 0)
2645 return ret;
2646 while(1) {
2647 slot = path->slots[0];
2648 leaf = path->nodes[0];
2649 if (slot >= btrfs_header_nritems(leaf)) {
2650 ret = btrfs_next_leaf(root, path);
2651 if (ret == 0)
2652 continue;
2653 if (ret < 0)
2654 goto error;
2655 break;
2656 }
2657 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2658
2659 if (found_key.objectid >= key->objectid &&
2660 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
2661 return 0;
2662 path->slots[0]++;
2663 }
2664 ret = -ENOENT;
2665 error:
2666 return ret;
2667 }
2668
2669 int btrfs_read_block_groups(struct btrfs_root *root)
2670 {
2671 struct btrfs_path *path;
2672 int ret;
2673 int bit;
2674 struct btrfs_block_group_cache *cache;
2675 struct btrfs_fs_info *info = root->fs_info;
2676 struct btrfs_space_info *space_info;
2677 struct extent_io_tree *block_group_cache;
2678 struct btrfs_key key;
2679 struct btrfs_key found_key;
2680 struct extent_buffer *leaf;
2681
2682 block_group_cache = &info->block_group_cache;
2683 root = info->extent_root;
2684 key.objectid = 0;
2685 key.offset = 0;
2686 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2687 path = btrfs_alloc_path();
2688 if (!path)
2689 return -ENOMEM;
2690
2691 while(1) {
2692 ret = find_first_block_group(root, path, &key);
2693 if (ret > 0) {
2694 ret = 0;
2695 goto error;
2696 }
2697 if (ret != 0)
2698 goto error;
2699
2700 leaf = path->nodes[0];
2701 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2702 cache = kzalloc(sizeof(*cache), GFP_NOFS);
2703 if (!cache) {
2704 ret = -ENOMEM;
2705 break;
2706 }
2707
2708 read_extent_buffer(leaf, &cache->item,
2709 btrfs_item_ptr_offset(leaf, path->slots[0]),
2710 sizeof(cache->item));
2711 memcpy(&cache->key, &found_key, sizeof(found_key));
2712
2713 key.objectid = found_key.objectid + found_key.offset;
2714 btrfs_release_path(root, path);
2715 cache->flags = btrfs_block_group_flags(&cache->item);
2716 bit = 0;
2717 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
2718 bit = BLOCK_GROUP_DATA;
2719 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
2720 bit = BLOCK_GROUP_SYSTEM;
2721 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
2722 bit = BLOCK_GROUP_METADATA;
2723 }
2724 set_avail_alloc_bits(info, cache->flags);
2725
2726 ret = update_space_info(info, cache->flags, found_key.offset,
2727 btrfs_block_group_used(&cache->item),
2728 &space_info);
2729 BUG_ON(ret);
2730 cache->space_info = space_info;
2731
2732 /* use EXTENT_LOCKED to prevent merging */
2733 set_extent_bits(block_group_cache, found_key.objectid,
2734 found_key.objectid + found_key.offset - 1,
2735 bit | EXTENT_LOCKED, GFP_NOFS);
2736 set_state_private(block_group_cache, found_key.objectid,
2737 (unsigned long)cache);
2738
2739 if (key.objectid >=
2740 btrfs_super_total_bytes(&info->super_copy))
2741 break;
2742 }
2743 ret = 0;
2744 error:
2745 btrfs_free_path(path);
2746 return ret;
2747 }
2748
2749 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
2750 struct btrfs_root *root, u64 bytes_used,
2751 u64 type, u64 chunk_objectid, u64 chunk_offset,
2752 u64 size)
2753 {
2754 int ret;
2755 int bit = 0;
2756 struct btrfs_root *extent_root;
2757 struct btrfs_block_group_cache *cache;
2758 struct extent_io_tree *block_group_cache;
2759
2760 extent_root = root->fs_info->extent_root;
2761 block_group_cache = &root->fs_info->block_group_cache;
2762
2763 cache = kzalloc(sizeof(*cache), GFP_NOFS);
2764 BUG_ON(!cache);
2765 cache->key.objectid = chunk_offset;
2766 cache->key.offset = size;
2767
2768 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2769 memset(&cache->item, 0, sizeof(cache->item));
2770 btrfs_set_block_group_used(&cache->item, bytes_used);
2771 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
2772 cache->flags = type;
2773 btrfs_set_block_group_flags(&cache->item, type);
2774
2775 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
2776 &cache->space_info);
2777 BUG_ON(ret);
2778
2779 bit = block_group_state_bits(type);
2780 set_extent_bits(block_group_cache, chunk_offset,
2781 chunk_offset + size - 1,
2782 bit | EXTENT_LOCKED, GFP_NOFS);
2783
2784 set_state_private(block_group_cache, chunk_offset,
2785 (unsigned long)cache);
2786 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
2787 sizeof(cache->item));
2788 BUG_ON(ret);
2789
2790 finish_current_insert(trans, extent_root);
2791 ret = del_pending_extents(trans, extent_root);
2792 BUG_ON(ret);
2793 set_avail_alloc_bits(extent_root->fs_info, type);
2794 return 0;
2795 }
Linux kernel - Deliverables
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