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Btrfs: Don't wait on tree block writeback before freeing them anymore
[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 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
191 free_space_cache = &root->fs_info->free_space_cache;
192
193 again:
194 ret = cache_block_group(root, cache);
195 if (ret)
196 goto out;
197
198 last = max(search_start, cache->key.objectid);
199 if (!block_group_bits(cache, data)) {
200 goto new_group;
201 }
202
203 spin_lock_irq(&free_space_cache->lock);
204 state = find_first_extent_bit_state(free_space_cache, last, EXTENT_DIRTY);
205 while(1) {
206 if (!state) {
207 if (!cache_miss)
208 cache_miss = last;
209 spin_unlock_irq(&free_space_cache->lock);
210 goto new_group;
211 }
212
213 start = max(last, state->start);
214 last = state->end + 1;
215 if (last - start < num) {
216 if (last == cache->key.objectid + cache->key.offset)
217 cache_miss = start;
218 do {
219 state = extent_state_next(state);
220 } while(state && !(state->state & EXTENT_DIRTY));
221 continue;
222 }
223 spin_unlock_irq(&free_space_cache->lock);
224 if (start + num > cache->key.objectid + cache->key.offset)
225 goto new_group;
226 if (start + num > total_fs_bytes)
227 goto new_group;
228 if (!block_group_bits(cache, data)) {
229 printk("block group bits don't match %Lu %d\n", cache->flags, data);
230 }
231 *start_ret = start;
232 return 0;
233 }
234 out:
235 cache = btrfs_lookup_block_group(root->fs_info, search_start);
236 if (!cache) {
237 printk("Unable to find block group for %Lu\n", search_start);
238 WARN_ON(1);
239 }
240 return -ENOSPC;
241
242 new_group:
243 last = cache->key.objectid + cache->key.offset;
244 wrapped:
245 cache = btrfs_lookup_block_group(root->fs_info, last);
246 if (!cache || cache->key.objectid >= total_fs_bytes) {
247 no_cache:
248 if (!wrapped) {
249 wrapped = 1;
250 last = search_start;
251 goto wrapped;
252 }
253 goto out;
254 }
255 if (cache_miss && !cache->cached) {
256 cache_block_group(root, cache);
257 last = cache_miss;
258 cache = btrfs_lookup_block_group(root->fs_info, last);
259 }
260 cache = btrfs_find_block_group(root, cache, last, data, 0);
261 if (!cache)
262 goto no_cache;
263 *cache_ret = cache;
264 cache_miss = 0;
265 goto again;
266 }
267
268 static u64 div_factor(u64 num, int factor)
269 {
270 if (factor == 10)
271 return num;
272 num *= factor;
273 do_div(num, 10);
274 return num;
275 }
276
277 static int block_group_state_bits(u64 flags)
278 {
279 int bits = 0;
280 if (flags & BTRFS_BLOCK_GROUP_DATA)
281 bits |= BLOCK_GROUP_DATA;
282 if (flags & BTRFS_BLOCK_GROUP_METADATA)
283 bits |= BLOCK_GROUP_METADATA;
284 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
285 bits |= BLOCK_GROUP_SYSTEM;
286 return bits;
287 }
288
289 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
290 struct btrfs_block_group_cache
291 *hint, u64 search_start,
292 int data, int owner)
293 {
294 struct btrfs_block_group_cache *cache;
295 struct extent_io_tree *block_group_cache;
296 struct btrfs_block_group_cache *found_group = NULL;
297 struct btrfs_fs_info *info = root->fs_info;
298 u64 used;
299 u64 last = 0;
300 u64 hint_last;
301 u64 start;
302 u64 end;
303 u64 free_check;
304 u64 ptr;
305 u64 total_fs_bytes;
306 int bit;
307 int ret;
308 int full_search = 0;
309 int factor = 8;
310
311 block_group_cache = &info->block_group_cache;
312 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
313
314 if (!owner)
315 factor = 8;
316
317 bit = block_group_state_bits(data);
318
319 if (search_start && search_start < total_fs_bytes) {
320 struct btrfs_block_group_cache *shint;
321 shint = btrfs_lookup_block_group(info, search_start);
322 if (shint && block_group_bits(shint, data)) {
323 used = btrfs_block_group_used(&shint->item);
324 if (used + shint->pinned <
325 div_factor(shint->key.offset, factor)) {
326 return shint;
327 }
328 }
329 }
330 if (hint && block_group_bits(hint, data) &&
331 hint->key.objectid < total_fs_bytes) {
332 used = btrfs_block_group_used(&hint->item);
333 if (used + hint->pinned <
334 div_factor(hint->key.offset, factor)) {
335 return hint;
336 }
337 last = hint->key.objectid + hint->key.offset;
338 hint_last = last;
339 } else {
340 if (hint)
341 hint_last = max(hint->key.objectid, search_start);
342 else
343 hint_last = search_start;
344
345 if (hint_last >= total_fs_bytes)
346 hint_last = search_start;
347 last = hint_last;
348 }
349 again:
350 while(1) {
351 ret = find_first_extent_bit(block_group_cache, last,
352 &start, &end, bit);
353 if (ret)
354 break;
355
356 ret = get_state_private(block_group_cache, start, &ptr);
357 if (ret)
358 break;
359
360 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
361 last = cache->key.objectid + cache->key.offset;
362 used = btrfs_block_group_used(&cache->item);
363
364 if (cache->key.objectid > total_fs_bytes)
365 break;
366
367 if (block_group_bits(cache, data)) {
368 if (full_search)
369 free_check = cache->key.offset;
370 else
371 free_check = div_factor(cache->key.offset,
372 factor);
373
374 if (used + cache->pinned < free_check) {
375 found_group = cache;
376 goto found;
377 }
378 }
379 cond_resched();
380 }
381 if (!full_search) {
382 last = search_start;
383 full_search = 1;
384 goto again;
385 }
386 found:
387 return found_group;
388 }
389
390 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
391 u64 owner, u64 owner_offset)
392 {
393 u32 high_crc = ~(u32)0;
394 u32 low_crc = ~(u32)0;
395 __le64 lenum;
396 lenum = cpu_to_le64(root_objectid);
397 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
398 lenum = cpu_to_le64(ref_generation);
399 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
400 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
401 lenum = cpu_to_le64(owner);
402 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
403 lenum = cpu_to_le64(owner_offset);
404 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
405 }
406 return ((u64)high_crc << 32) | (u64)low_crc;
407 }
408
409 static int match_extent_ref(struct extent_buffer *leaf,
410 struct btrfs_extent_ref *disk_ref,
411 struct btrfs_extent_ref *cpu_ref)
412 {
413 int ret;
414 int len;
415
416 if (cpu_ref->objectid)
417 len = sizeof(*cpu_ref);
418 else
419 len = 2 * sizeof(u64);
420 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
421 len);
422 return ret == 0;
423 }
424
425 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
426 struct btrfs_root *root,
427 struct btrfs_path *path, u64 bytenr,
428 u64 root_objectid,
429 u64 ref_generation, u64 owner,
430 u64 owner_offset, int del)
431 {
432 u64 hash;
433 struct btrfs_key key;
434 struct btrfs_key found_key;
435 struct btrfs_extent_ref ref;
436 struct extent_buffer *leaf;
437 struct btrfs_extent_ref *disk_ref;
438 int ret;
439 int ret2;
440
441 btrfs_set_stack_ref_root(&ref, root_objectid);
442 btrfs_set_stack_ref_generation(&ref, ref_generation);
443 btrfs_set_stack_ref_objectid(&ref, owner);
444 btrfs_set_stack_ref_offset(&ref, owner_offset);
445
446 hash = hash_extent_ref(root_objectid, ref_generation, owner,
447 owner_offset);
448 key.offset = hash;
449 key.objectid = bytenr;
450 key.type = BTRFS_EXTENT_REF_KEY;
451
452 while (1) {
453 ret = btrfs_search_slot(trans, root, &key, path,
454 del ? -1 : 0, del);
455 if (ret < 0)
456 goto out;
457 leaf = path->nodes[0];
458 if (ret != 0) {
459 u32 nritems = btrfs_header_nritems(leaf);
460 if (path->slots[0] >= nritems) {
461 ret2 = btrfs_next_leaf(root, path);
462 if (ret2)
463 goto out;
464 leaf = path->nodes[0];
465 }
466 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
467 if (found_key.objectid != bytenr ||
468 found_key.type != BTRFS_EXTENT_REF_KEY)
469 goto out;
470 key.offset = found_key.offset;
471 if (del) {
472 btrfs_release_path(root, path);
473 continue;
474 }
475 }
476 disk_ref = btrfs_item_ptr(path->nodes[0],
477 path->slots[0],
478 struct btrfs_extent_ref);
479 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
480 ret = 0;
481 goto out;
482 }
483 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
484 key.offset = found_key.offset + 1;
485 btrfs_release_path(root, path);
486 }
487 out:
488 return ret;
489 }
490
491 /*
492 * Back reference rules. Back refs have three main goals:
493 *
494 * 1) differentiate between all holders of references to an extent so that
495 * when a reference is dropped we can make sure it was a valid reference
496 * before freeing the extent.
497 *
498 * 2) Provide enough information to quickly find the holders of an extent
499 * if we notice a given block is corrupted or bad.
500 *
501 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
502 * maintenance. This is actually the same as #2, but with a slightly
503 * different use case.
504 *
505 * File extents can be referenced by:
506 *
507 * - multiple snapshots, subvolumes, or different generations in one subvol
508 * - different files inside a single subvolume (in theory, not implemented yet)
509 * - different offsets inside a file (bookend extents in file.c)
510 *
511 * The extent ref structure has fields for:
512 *
513 * - Objectid of the subvolume root
514 * - Generation number of the tree holding the reference
515 * - objectid of the file holding the reference
516 * - offset in the file corresponding to the key holding the reference
517 *
518 * When a file extent is allocated the fields are filled in:
519 * (root_key.objectid, trans->transid, inode objectid, offset in file)
520 *
521 * When a leaf is cow'd new references are added for every file extent found
522 * in the leaf. It looks the same as the create case, but trans->transid
523 * will be different when the block is cow'd.
524 *
525 * (root_key.objectid, trans->transid, inode objectid, offset in file)
526 *
527 * When a file extent is removed either during snapshot deletion or file
528 * truncation, the corresponding back reference is found
529 * by searching for:
530 *
531 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
532 * inode objectid, offset in file)
533 *
534 * Btree extents can be referenced by:
535 *
536 * - Different subvolumes
537 * - Different generations of the same subvolume
538 *
539 * Storing sufficient information for a full reverse mapping of a btree
540 * block would require storing the lowest key of the block in the backref,
541 * and it would require updating that lowest key either before write out or
542 * every time it changed. Instead, the objectid of the lowest key is stored
543 * along with the level of the tree block. This provides a hint
544 * about where in the btree the block can be found. Searches through the
545 * btree only need to look for a pointer to that block, so they stop one
546 * level higher than the level recorded in the backref.
547 *
548 * Some btrees do not do reference counting on their extents. These
549 * include the extent tree and the tree of tree roots. Backrefs for these
550 * trees always have a generation of zero.
551 *
552 * When a tree block is created, back references are inserted:
553 *
554 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
555 *
556 * When a tree block is cow'd in a reference counted root,
557 * new back references are added for all the blocks it points to.
558 * These are of the form (trans->transid will have increased since creation):
559 *
560 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
561 *
562 * Because the lowest_key_objectid and the level are just hints
563 * they are not used when backrefs are deleted. When a backref is deleted:
564 *
565 * if backref was for a tree root:
566 * root_objectid = root->root_key.objectid
567 * else
568 * root_objectid = btrfs_header_owner(parent)
569 *
570 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
571 *
572 * Back Reference Key hashing:
573 *
574 * Back references have four fields, each 64 bits long. Unfortunately,
575 * This is hashed into a single 64 bit number and placed into the key offset.
576 * The key objectid corresponds to the first byte in the extent, and the
577 * key type is set to BTRFS_EXTENT_REF_KEY
578 */
579 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
580 struct btrfs_root *root,
581 struct btrfs_path *path, u64 bytenr,
582 u64 root_objectid, u64 ref_generation,
583 u64 owner, u64 owner_offset)
584 {
585 u64 hash;
586 struct btrfs_key key;
587 struct btrfs_extent_ref ref;
588 struct btrfs_extent_ref *disk_ref;
589 int ret;
590
591 btrfs_set_stack_ref_root(&ref, root_objectid);
592 btrfs_set_stack_ref_generation(&ref, ref_generation);
593 btrfs_set_stack_ref_objectid(&ref, owner);
594 btrfs_set_stack_ref_offset(&ref, owner_offset);
595
596 hash = hash_extent_ref(root_objectid, ref_generation, owner,
597 owner_offset);
598 key.offset = hash;
599 key.objectid = bytenr;
600 key.type = BTRFS_EXTENT_REF_KEY;
601
602 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
603 while (ret == -EEXIST) {
604 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
605 struct btrfs_extent_ref);
606 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
607 goto out;
608 key.offset++;
609 btrfs_release_path(root, path);
610 ret = btrfs_insert_empty_item(trans, root, path, &key,
611 sizeof(ref));
612 }
613 if (ret)
614 goto out;
615 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
616 struct btrfs_extent_ref);
617 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
618 sizeof(ref));
619 btrfs_mark_buffer_dirty(path->nodes[0]);
620 out:
621 btrfs_release_path(root, path);
622 return ret;
623 }
624
625 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
626 struct btrfs_root *root,
627 u64 bytenr, u64 num_bytes,
628 u64 root_objectid, u64 ref_generation,
629 u64 owner, u64 owner_offset)
630 {
631 struct btrfs_path *path;
632 int ret;
633 struct btrfs_key key;
634 struct extent_buffer *l;
635 struct btrfs_extent_item *item;
636 u32 refs;
637
638 WARN_ON(num_bytes < root->sectorsize);
639 path = btrfs_alloc_path();
640 if (!path)
641 return -ENOMEM;
642
643 path->reada = 0;
644 key.objectid = bytenr;
645 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
646 key.offset = num_bytes;
647 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
648 0, 1);
649 if (ret < 0)
650 return ret;
651 if (ret != 0) {
652 BUG();
653 }
654 BUG_ON(ret != 0);
655 l = path->nodes[0];
656 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
657 refs = btrfs_extent_refs(l, item);
658 btrfs_set_extent_refs(l, item, refs + 1);
659 btrfs_mark_buffer_dirty(path->nodes[0]);
660
661 btrfs_release_path(root->fs_info->extent_root, path);
662
663 path->reada = 0;
664 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
665 path, bytenr, root_objectid,
666 ref_generation, owner, owner_offset);
667 BUG_ON(ret);
668 finish_current_insert(trans, root->fs_info->extent_root);
669 del_pending_extents(trans, root->fs_info->extent_root);
670
671 btrfs_free_path(path);
672 return 0;
673 }
674
675 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
676 struct btrfs_root *root)
677 {
678 finish_current_insert(trans, root->fs_info->extent_root);
679 del_pending_extents(trans, root->fs_info->extent_root);
680 return 0;
681 }
682
683 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
684 struct btrfs_root *root, u64 bytenr,
685 u64 num_bytes, u32 *refs)
686 {
687 struct btrfs_path *path;
688 int ret;
689 struct btrfs_key key;
690 struct extent_buffer *l;
691 struct btrfs_extent_item *item;
692
693 WARN_ON(num_bytes < root->sectorsize);
694 path = btrfs_alloc_path();
695 path->reada = 0;
696 key.objectid = bytenr;
697 key.offset = num_bytes;
698 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
699 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
700 0, 0);
701 if (ret < 0)
702 goto out;
703 if (ret != 0) {
704 btrfs_print_leaf(root, path->nodes[0]);
705 printk("failed to find block number %Lu\n", bytenr);
706 BUG();
707 }
708 l = path->nodes[0];
709 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
710 *refs = btrfs_extent_refs(l, item);
711 out:
712 btrfs_free_path(path);
713 return 0;
714 }
715
716 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
717 struct btrfs_path *count_path,
718 u64 first_extent)
719 {
720 struct btrfs_root *extent_root = root->fs_info->extent_root;
721 struct btrfs_path *path;
722 u64 bytenr;
723 u64 found_objectid;
724 u64 root_objectid = root->root_key.objectid;
725 u32 total_count = 0;
726 u32 cur_count;
727 u32 nritems;
728 int ret;
729 struct btrfs_key key;
730 struct btrfs_key found_key;
731 struct extent_buffer *l;
732 struct btrfs_extent_item *item;
733 struct btrfs_extent_ref *ref_item;
734 int level = -1;
735
736 path = btrfs_alloc_path();
737 again:
738 if (level == -1)
739 bytenr = first_extent;
740 else
741 bytenr = count_path->nodes[level]->start;
742
743 cur_count = 0;
744 key.objectid = bytenr;
745 key.offset = 0;
746
747 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
748 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
749 if (ret < 0)
750 goto out;
751 BUG_ON(ret == 0);
752
753 l = path->nodes[0];
754 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
755
756 if (found_key.objectid != bytenr ||
757 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
758 goto out;
759 }
760
761 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
762 while (1) {
763 l = path->nodes[0];
764 nritems = btrfs_header_nritems(l);
765 if (path->slots[0] >= nritems) {
766 ret = btrfs_next_leaf(extent_root, path);
767 if (ret == 0)
768 continue;
769 break;
770 }
771 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
772 if (found_key.objectid != bytenr)
773 break;
774
775 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
776 path->slots[0]++;
777 continue;
778 }
779
780 cur_count++;
781 ref_item = btrfs_item_ptr(l, path->slots[0],
782 struct btrfs_extent_ref);
783 found_objectid = btrfs_ref_root(l, ref_item);
784
785 if (found_objectid != root_objectid) {
786 total_count = 2;
787 goto out;
788 }
789 total_count = 1;
790 path->slots[0]++;
791 }
792 if (cur_count == 0) {
793 total_count = 0;
794 goto out;
795 }
796 if (level >= 0 && root->node == count_path->nodes[level])
797 goto out;
798 level++;
799 btrfs_release_path(root, path);
800 goto again;
801
802 out:
803 btrfs_free_path(path);
804 return total_count;
805 }
806 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
807 struct btrfs_root *root, u64 owner_objectid)
808 {
809 u64 generation;
810 u64 key_objectid;
811 u64 level;
812 u32 nritems;
813 struct btrfs_disk_key disk_key;
814
815 level = btrfs_header_level(root->node);
816 generation = trans->transid;
817 nritems = btrfs_header_nritems(root->node);
818 if (nritems > 0) {
819 if (level == 0)
820 btrfs_item_key(root->node, &disk_key, 0);
821 else
822 btrfs_node_key(root->node, &disk_key, 0);
823 key_objectid = btrfs_disk_key_objectid(&disk_key);
824 } else {
825 key_objectid = 0;
826 }
827 return btrfs_inc_extent_ref(trans, root, root->node->start,
828 root->node->len, owner_objectid,
829 generation, level, key_objectid);
830 }
831
832 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
833 struct extent_buffer *buf)
834 {
835 u64 bytenr;
836 u32 nritems;
837 struct btrfs_key key;
838 struct btrfs_file_extent_item *fi;
839 int i;
840 int level;
841 int ret;
842 int faili;
843
844 if (!root->ref_cows)
845 return 0;
846
847 level = btrfs_header_level(buf);
848 nritems = btrfs_header_nritems(buf);
849 for (i = 0; i < nritems; i++) {
850 if (level == 0) {
851 u64 disk_bytenr;
852 btrfs_item_key_to_cpu(buf, &key, i);
853 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
854 continue;
855 fi = btrfs_item_ptr(buf, i,
856 struct btrfs_file_extent_item);
857 if (btrfs_file_extent_type(buf, fi) ==
858 BTRFS_FILE_EXTENT_INLINE)
859 continue;
860 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
861 if (disk_bytenr == 0)
862 continue;
863 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
864 btrfs_file_extent_disk_num_bytes(buf, fi),
865 root->root_key.objectid, trans->transid,
866 key.objectid, key.offset);
867 if (ret) {
868 faili = i;
869 goto fail;
870 }
871 } else {
872 bytenr = btrfs_node_blockptr(buf, i);
873 btrfs_node_key_to_cpu(buf, &key, i);
874 ret = btrfs_inc_extent_ref(trans, root, bytenr,
875 btrfs_level_size(root, level - 1),
876 root->root_key.objectid,
877 trans->transid,
878 level - 1, key.objectid);
879 if (ret) {
880 faili = i;
881 goto fail;
882 }
883 }
884 }
885 return 0;
886 fail:
887 WARN_ON(1);
888 #if 0
889 for (i =0; i < faili; i++) {
890 if (level == 0) {
891 u64 disk_bytenr;
892 btrfs_item_key_to_cpu(buf, &key, i);
893 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
894 continue;
895 fi = btrfs_item_ptr(buf, i,
896 struct btrfs_file_extent_item);
897 if (btrfs_file_extent_type(buf, fi) ==
898 BTRFS_FILE_EXTENT_INLINE)
899 continue;
900 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
901 if (disk_bytenr == 0)
902 continue;
903 err = btrfs_free_extent(trans, root, disk_bytenr,
904 btrfs_file_extent_disk_num_bytes(buf,
905 fi), 0);
906 BUG_ON(err);
907 } else {
908 bytenr = btrfs_node_blockptr(buf, i);
909 err = btrfs_free_extent(trans, root, bytenr,
910 btrfs_level_size(root, level - 1), 0);
911 BUG_ON(err);
912 }
913 }
914 #endif
915 return ret;
916 }
917
918 static int write_one_cache_group(struct btrfs_trans_handle *trans,
919 struct btrfs_root *root,
920 struct btrfs_path *path,
921 struct btrfs_block_group_cache *cache)
922 {
923 int ret;
924 int pending_ret;
925 struct btrfs_root *extent_root = root->fs_info->extent_root;
926 unsigned long bi;
927 struct extent_buffer *leaf;
928
929 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
930 if (ret < 0)
931 goto fail;
932 BUG_ON(ret);
933
934 leaf = path->nodes[0];
935 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
936 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
937 btrfs_mark_buffer_dirty(leaf);
938 btrfs_release_path(extent_root, path);
939 fail:
940 finish_current_insert(trans, extent_root);
941 pending_ret = del_pending_extents(trans, extent_root);
942 if (ret)
943 return ret;
944 if (pending_ret)
945 return pending_ret;
946 return 0;
947
948 }
949
950 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
951 struct btrfs_root *root)
952 {
953 struct extent_io_tree *block_group_cache;
954 struct btrfs_block_group_cache *cache;
955 int ret;
956 int err = 0;
957 int werr = 0;
958 struct btrfs_path *path;
959 u64 last = 0;
960 u64 start;
961 u64 end;
962 u64 ptr;
963
964 block_group_cache = &root->fs_info->block_group_cache;
965 path = btrfs_alloc_path();
966 if (!path)
967 return -ENOMEM;
968
969 while(1) {
970 ret = find_first_extent_bit(block_group_cache, last,
971 &start, &end, BLOCK_GROUP_DIRTY);
972 if (ret)
973 break;
974
975 last = end + 1;
976 ret = get_state_private(block_group_cache, start, &ptr);
977 if (ret)
978 break;
979 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
980 err = write_one_cache_group(trans, root,
981 path, cache);
982 /*
983 * if we fail to write the cache group, we want
984 * to keep it marked dirty in hopes that a later
985 * write will work
986 */
987 if (err) {
988 werr = err;
989 continue;
990 }
991 clear_extent_bits(block_group_cache, start, end,
992 BLOCK_GROUP_DIRTY, GFP_NOFS);
993 }
994 btrfs_free_path(path);
995 return werr;
996 }
997
998 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
999 u64 flags)
1000 {
1001 struct list_head *head = &info->space_info;
1002 struct list_head *cur;
1003 struct btrfs_space_info *found;
1004 list_for_each(cur, head) {
1005 found = list_entry(cur, struct btrfs_space_info, list);
1006 if (found->flags == flags)
1007 return found;
1008 }
1009 return NULL;
1010
1011 }
1012
1013 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1014 u64 total_bytes, u64 bytes_used,
1015 struct btrfs_space_info **space_info)
1016 {
1017 struct btrfs_space_info *found;
1018
1019 found = __find_space_info(info, flags);
1020 if (found) {
1021 found->total_bytes += total_bytes;
1022 found->bytes_used += bytes_used;
1023 WARN_ON(found->total_bytes < found->bytes_used);
1024 *space_info = found;
1025 return 0;
1026 }
1027 found = kmalloc(sizeof(*found), GFP_NOFS);
1028 if (!found)
1029 return -ENOMEM;
1030
1031 list_add(&found->list, &info->space_info);
1032 found->flags = flags;
1033 found->total_bytes = total_bytes;
1034 found->bytes_used = bytes_used;
1035 found->bytes_pinned = 0;
1036 found->full = 0;
1037 *space_info = found;
1038 return 0;
1039 }
1040
1041 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1042 {
1043 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1044 BTRFS_BLOCK_GROUP_RAID1 |
1045 BTRFS_BLOCK_GROUP_RAID10 |
1046 BTRFS_BLOCK_GROUP_DUP);
1047 if (extra_flags) {
1048 if (flags & BTRFS_BLOCK_GROUP_DATA)
1049 fs_info->avail_data_alloc_bits |= extra_flags;
1050 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1051 fs_info->avail_metadata_alloc_bits |= extra_flags;
1052 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1053 fs_info->avail_system_alloc_bits |= extra_flags;
1054 }
1055 }
1056
1057 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1058 struct btrfs_root *extent_root, u64 alloc_bytes,
1059 u64 flags)
1060 {
1061 struct btrfs_space_info *space_info;
1062 u64 thresh;
1063 u64 start;
1064 u64 num_bytes;
1065 int ret;
1066
1067 space_info = __find_space_info(extent_root->fs_info, flags);
1068 if (!space_info) {
1069 ret = update_space_info(extent_root->fs_info, flags,
1070 0, 0, &space_info);
1071 BUG_ON(ret);
1072 }
1073 BUG_ON(!space_info);
1074
1075 if (space_info->full)
1076 return 0;
1077
1078 thresh = div_factor(space_info->total_bytes, 6);
1079 if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1080 thresh)
1081 return 0;
1082
1083 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1084 if (ret == -ENOSPC) {
1085 printk("space info full %Lu\n", flags);
1086 space_info->full = 1;
1087 return 0;
1088 }
1089
1090 BUG_ON(ret);
1091
1092 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1093 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1094 BUG_ON(ret);
1095
1096 return 0;
1097 }
1098
1099 static int update_block_group(struct btrfs_trans_handle *trans,
1100 struct btrfs_root *root,
1101 u64 bytenr, u64 num_bytes, int alloc,
1102 int mark_free)
1103 {
1104 struct btrfs_block_group_cache *cache;
1105 struct btrfs_fs_info *info = root->fs_info;
1106 u64 total = num_bytes;
1107 u64 old_val;
1108 u64 byte_in_group;
1109 u64 start;
1110 u64 end;
1111
1112 while(total) {
1113 cache = btrfs_lookup_block_group(info, bytenr);
1114 if (!cache) {
1115 return -1;
1116 }
1117 byte_in_group = bytenr - cache->key.objectid;
1118 WARN_ON(byte_in_group > cache->key.offset);
1119 start = cache->key.objectid;
1120 end = start + cache->key.offset - 1;
1121 set_extent_bits(&info->block_group_cache, start, end,
1122 BLOCK_GROUP_DIRTY, GFP_NOFS);
1123
1124 old_val = btrfs_block_group_used(&cache->item);
1125 num_bytes = min(total, cache->key.offset - byte_in_group);
1126 if (alloc) {
1127 old_val += num_bytes;
1128 cache->space_info->bytes_used += num_bytes;
1129 } else {
1130 old_val -= num_bytes;
1131 cache->space_info->bytes_used -= num_bytes;
1132 if (mark_free) {
1133 set_extent_dirty(&info->free_space_cache,
1134 bytenr, bytenr + num_bytes - 1,
1135 GFP_NOFS);
1136 }
1137 }
1138 btrfs_set_block_group_used(&cache->item, old_val);
1139 total -= num_bytes;
1140 bytenr += num_bytes;
1141 }
1142 return 0;
1143 }
1144
1145 static int update_pinned_extents(struct btrfs_root *root,
1146 u64 bytenr, u64 num, int pin)
1147 {
1148 u64 len;
1149 struct btrfs_block_group_cache *cache;
1150 struct btrfs_fs_info *fs_info = root->fs_info;
1151
1152 if (pin) {
1153 set_extent_dirty(&fs_info->pinned_extents,
1154 bytenr, bytenr + num - 1, GFP_NOFS);
1155 } else {
1156 clear_extent_dirty(&fs_info->pinned_extents,
1157 bytenr, bytenr + num - 1, GFP_NOFS);
1158 }
1159 while (num > 0) {
1160 cache = btrfs_lookup_block_group(fs_info, bytenr);
1161 WARN_ON(!cache);
1162 len = min(num, cache->key.offset -
1163 (bytenr - cache->key.objectid));
1164 if (pin) {
1165 cache->pinned += len;
1166 cache->space_info->bytes_pinned += len;
1167 fs_info->total_pinned += len;
1168 } else {
1169 cache->pinned -= len;
1170 cache->space_info->bytes_pinned -= len;
1171 fs_info->total_pinned -= len;
1172 }
1173 bytenr += len;
1174 num -= len;
1175 }
1176 return 0;
1177 }
1178
1179 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1180 {
1181 u64 last = 0;
1182 u64 start;
1183 u64 end;
1184 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1185 int ret;
1186
1187 while(1) {
1188 ret = find_first_extent_bit(pinned_extents, last,
1189 &start, &end, EXTENT_DIRTY);
1190 if (ret)
1191 break;
1192 set_extent_dirty(copy, start, end, GFP_NOFS);
1193 last = end + 1;
1194 }
1195 return 0;
1196 }
1197
1198 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1199 struct btrfs_root *root,
1200 struct extent_io_tree *unpin)
1201 {
1202 u64 start;
1203 u64 end;
1204 int ret;
1205 struct extent_io_tree *free_space_cache;
1206 free_space_cache = &root->fs_info->free_space_cache;
1207
1208 while(1) {
1209 ret = find_first_extent_bit(unpin, 0, &start, &end,
1210 EXTENT_DIRTY);
1211 if (ret)
1212 break;
1213 update_pinned_extents(root, start, end + 1 - start, 0);
1214 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1215 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1216 }
1217 return 0;
1218 }
1219
1220 static int finish_current_insert(struct btrfs_trans_handle *trans,
1221 struct btrfs_root *extent_root)
1222 {
1223 u64 start;
1224 u64 end;
1225 struct btrfs_fs_info *info = extent_root->fs_info;
1226 struct extent_buffer *eb;
1227 struct btrfs_path *path;
1228 struct btrfs_key ins;
1229 struct btrfs_disk_key first;
1230 struct btrfs_extent_item extent_item;
1231 int ret;
1232 int level;
1233 int err = 0;
1234
1235 btrfs_set_stack_extent_refs(&extent_item, 1);
1236 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1237 path = btrfs_alloc_path();
1238
1239 while(1) {
1240 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1241 &end, EXTENT_LOCKED);
1242 if (ret)
1243 break;
1244
1245 ins.objectid = start;
1246 ins.offset = end + 1 - start;
1247 err = btrfs_insert_item(trans, extent_root, &ins,
1248 &extent_item, sizeof(extent_item));
1249 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1250 GFP_NOFS);
1251 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1252 level = btrfs_header_level(eb);
1253 if (level == 0) {
1254 btrfs_item_key(eb, &first, 0);
1255 } else {
1256 btrfs_node_key(eb, &first, 0);
1257 }
1258 err = btrfs_insert_extent_backref(trans, extent_root, path,
1259 start, extent_root->root_key.objectid,
1260 0, level,
1261 btrfs_disk_key_objectid(&first));
1262 BUG_ON(err);
1263 free_extent_buffer(eb);
1264 }
1265 btrfs_free_path(path);
1266 return 0;
1267 }
1268
1269 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1270 int pending)
1271 {
1272 int err = 0;
1273 struct extent_buffer *buf;
1274
1275 if (!pending) {
1276 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1277 if (buf) {
1278 if (btrfs_buffer_uptodate(buf)) {
1279 u64 transid =
1280 root->fs_info->running_transaction->transid;
1281 u64 header_transid =
1282 btrfs_header_generation(buf);
1283 if (header_transid == transid &&
1284 !btrfs_header_flag(buf,
1285 BTRFS_HEADER_FLAG_WRITTEN)) {
1286 clean_tree_block(NULL, root, buf);
1287 free_extent_buffer(buf);
1288 return 1;
1289 }
1290 }
1291 free_extent_buffer(buf);
1292 }
1293 update_pinned_extents(root, bytenr, num_bytes, 1);
1294 } else {
1295 set_extent_bits(&root->fs_info->pending_del,
1296 bytenr, bytenr + num_bytes - 1,
1297 EXTENT_LOCKED, GFP_NOFS);
1298 }
1299 BUG_ON(err < 0);
1300 return 0;
1301 }
1302
1303 /*
1304 * remove an extent from the root, returns 0 on success
1305 */
1306 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1307 *root, u64 bytenr, u64 num_bytes,
1308 u64 root_objectid, u64 ref_generation,
1309 u64 owner_objectid, u64 owner_offset, int pin,
1310 int mark_free)
1311 {
1312 struct btrfs_path *path;
1313 struct btrfs_key key;
1314 struct btrfs_fs_info *info = root->fs_info;
1315 struct btrfs_root *extent_root = info->extent_root;
1316 struct extent_buffer *leaf;
1317 int ret;
1318 int extent_slot = 0;
1319 int found_extent = 0;
1320 int num_to_del = 1;
1321 struct btrfs_extent_item *ei;
1322 u32 refs;
1323
1324 key.objectid = bytenr;
1325 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1326 key.offset = num_bytes;
1327 path = btrfs_alloc_path();
1328 if (!path)
1329 return -ENOMEM;
1330
1331 path->reada = 0;
1332 ret = lookup_extent_backref(trans, extent_root, path,
1333 bytenr, root_objectid,
1334 ref_generation,
1335 owner_objectid, owner_offset, 1);
1336 if (ret == 0) {
1337 struct btrfs_key found_key;
1338 extent_slot = path->slots[0];
1339 while(extent_slot > 0) {
1340 extent_slot--;
1341 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1342 extent_slot);
1343 if (found_key.objectid != bytenr)
1344 break;
1345 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1346 found_key.offset == num_bytes) {
1347 found_extent = 1;
1348 break;
1349 }
1350 if (path->slots[0] - extent_slot > 5)
1351 break;
1352 }
1353 if (!found_extent)
1354 ret = btrfs_del_item(trans, extent_root, path);
1355 } else {
1356 btrfs_print_leaf(extent_root, path->nodes[0]);
1357 WARN_ON(1);
1358 printk("Unable to find ref byte nr %Lu root %Lu "
1359 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1360 root_objectid, ref_generation, owner_objectid,
1361 owner_offset);
1362 }
1363 if (!found_extent) {
1364 btrfs_release_path(extent_root, path);
1365 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1366 if (ret < 0)
1367 return ret;
1368 BUG_ON(ret);
1369 extent_slot = path->slots[0];
1370 }
1371
1372 leaf = path->nodes[0];
1373 ei = btrfs_item_ptr(leaf, extent_slot,
1374 struct btrfs_extent_item);
1375 refs = btrfs_extent_refs(leaf, ei);
1376 BUG_ON(refs == 0);
1377 refs -= 1;
1378 btrfs_set_extent_refs(leaf, ei, refs);
1379
1380 btrfs_mark_buffer_dirty(leaf);
1381
1382 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1383 /* if the back ref and the extent are next to each other
1384 * they get deleted below in one shot
1385 */
1386 path->slots[0] = extent_slot;
1387 num_to_del = 2;
1388 } else if (found_extent) {
1389 /* otherwise delete the extent back ref */
1390 ret = btrfs_del_item(trans, extent_root, path);
1391 BUG_ON(ret);
1392 /* if refs are 0, we need to setup the path for deletion */
1393 if (refs == 0) {
1394 btrfs_release_path(extent_root, path);
1395 ret = btrfs_search_slot(trans, extent_root, &key, path,
1396 -1, 1);
1397 if (ret < 0)
1398 return ret;
1399 BUG_ON(ret);
1400 }
1401 }
1402
1403 if (refs == 0) {
1404 u64 super_used;
1405 u64 root_used;
1406
1407 if (pin) {
1408 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1409 if (ret > 0)
1410 mark_free = 1;
1411 BUG_ON(ret < 0);
1412 }
1413
1414 /* block accounting for super block */
1415 super_used = btrfs_super_bytes_used(&info->super_copy);
1416 btrfs_set_super_bytes_used(&info->super_copy,
1417 super_used - num_bytes);
1418
1419 /* block accounting for root item */
1420 root_used = btrfs_root_used(&root->root_item);
1421 btrfs_set_root_used(&root->root_item,
1422 root_used - num_bytes);
1423 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1424 num_to_del);
1425 if (ret) {
1426 return ret;
1427 }
1428 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1429 mark_free);
1430 BUG_ON(ret);
1431 }
1432 btrfs_free_path(path);
1433 finish_current_insert(trans, extent_root);
1434 return ret;
1435 }
1436
1437 /*
1438 * find all the blocks marked as pending in the radix tree and remove
1439 * them from the extent map
1440 */
1441 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1442 btrfs_root *extent_root)
1443 {
1444 int ret;
1445 int err = 0;
1446 u64 start;
1447 u64 end;
1448 struct extent_io_tree *pending_del;
1449 struct extent_io_tree *pinned_extents;
1450
1451 pending_del = &extent_root->fs_info->pending_del;
1452 pinned_extents = &extent_root->fs_info->pinned_extents;
1453
1454 while(1) {
1455 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1456 EXTENT_LOCKED);
1457 if (ret)
1458 break;
1459 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1460 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1461 GFP_NOFS);
1462 ret = __free_extent(trans, extent_root,
1463 start, end + 1 - start,
1464 extent_root->root_key.objectid,
1465 0, 0, 0, 0, 0);
1466 if (ret)
1467 err = ret;
1468 }
1469 return err;
1470 }
1471
1472 /*
1473 * remove an extent from the root, returns 0 on success
1474 */
1475 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1476 *root, u64 bytenr, u64 num_bytes,
1477 u64 root_objectid, u64 ref_generation,
1478 u64 owner_objectid, u64 owner_offset, int pin)
1479 {
1480 struct btrfs_root *extent_root = root->fs_info->extent_root;
1481 int pending_ret;
1482 int ret;
1483
1484 WARN_ON(num_bytes < root->sectorsize);
1485 if (!root->ref_cows)
1486 ref_generation = 0;
1487
1488 if (root == extent_root) {
1489 pin_down_bytes(root, bytenr, num_bytes, 1);
1490 return 0;
1491 }
1492 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1493 ref_generation, owner_objectid, owner_offset,
1494 pin, pin == 0);
1495 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1496 return ret ? ret : pending_ret;
1497 }
1498
1499 static u64 stripe_align(struct btrfs_root *root, u64 val)
1500 {
1501 u64 mask = ((u64)root->stripesize - 1);
1502 u64 ret = (val + mask) & ~mask;
1503 return ret;
1504 }
1505
1506 /*
1507 * walks the btree of allocated extents and find a hole of a given size.
1508 * The key ins is changed to record the hole:
1509 * ins->objectid == block start
1510 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1511 * ins->offset == number of blocks
1512 * Any available blocks before search_start are skipped.
1513 */
1514 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1515 struct btrfs_root *orig_root,
1516 u64 num_bytes, u64 empty_size,
1517 u64 search_start, u64 search_end,
1518 u64 hint_byte, struct btrfs_key *ins,
1519 u64 exclude_start, u64 exclude_nr,
1520 int data)
1521 {
1522 int ret;
1523 u64 orig_search_start = search_start;
1524 struct btrfs_root * root = orig_root->fs_info->extent_root;
1525 struct btrfs_fs_info *info = root->fs_info;
1526 u64 total_needed = num_bytes;
1527 u64 *last_ptr = NULL;
1528 struct btrfs_block_group_cache *block_group;
1529 int full_scan = 0;
1530 int wrapped = 0;
1531 int empty_cluster = 2 * 1024 * 1024;
1532
1533 WARN_ON(num_bytes < root->sectorsize);
1534 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1535
1536 if (data & BTRFS_BLOCK_GROUP_METADATA) {
1537 last_ptr = &root->fs_info->last_alloc;
1538 empty_cluster = 256 * 1024;
1539 }
1540
1541 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
1542 last_ptr = &root->fs_info->last_data_alloc;
1543 }
1544
1545 if (last_ptr) {
1546 if (*last_ptr)
1547 hint_byte = *last_ptr;
1548 else {
1549 empty_size += empty_cluster;
1550 }
1551 }
1552
1553 if (search_end == (u64)-1)
1554 search_end = btrfs_super_total_bytes(&info->super_copy);
1555
1556 if (hint_byte) {
1557 block_group = btrfs_lookup_block_group(info, hint_byte);
1558 if (!block_group)
1559 hint_byte = search_start;
1560 block_group = btrfs_find_block_group(root, block_group,
1561 hint_byte, data, 1);
1562 if (last_ptr && *last_ptr == 0 && block_group)
1563 hint_byte = block_group->key.objectid;
1564 } else {
1565 block_group = btrfs_find_block_group(root,
1566 trans->block_group,
1567 search_start, data, 1);
1568 }
1569 search_start = max(search_start, hint_byte);
1570
1571 total_needed += empty_size;
1572
1573 check_failed:
1574 if (!block_group) {
1575 block_group = btrfs_lookup_block_group(info, search_start);
1576 if (!block_group)
1577 block_group = btrfs_lookup_block_group(info,
1578 orig_search_start);
1579 }
1580 ret = find_search_start(root, &block_group, &search_start,
1581 total_needed, data);
1582 if (ret == -ENOSPC && last_ptr && *last_ptr) {
1583 *last_ptr = 0;
1584 block_group = btrfs_lookup_block_group(info,
1585 orig_search_start);
1586 search_start = orig_search_start;
1587 ret = find_search_start(root, &block_group, &search_start,
1588 total_needed, data);
1589 }
1590 if (ret == -ENOSPC)
1591 goto enospc;
1592 if (ret)
1593 goto error;
1594
1595 if (last_ptr && *last_ptr && search_start != *last_ptr) {
1596 *last_ptr = 0;
1597 if (!empty_size) {
1598 empty_size += empty_cluster;
1599 total_needed += empty_size;
1600 }
1601 block_group = btrfs_lookup_block_group(info,
1602 orig_search_start);
1603 search_start = orig_search_start;
1604 ret = find_search_start(root, &block_group,
1605 &search_start, total_needed, data);
1606 if (ret == -ENOSPC)
1607 goto enospc;
1608 if (ret)
1609 goto error;
1610 }
1611
1612 search_start = stripe_align(root, search_start);
1613 ins->objectid = search_start;
1614 ins->offset = num_bytes;
1615
1616 if (ins->objectid + num_bytes >= search_end)
1617 goto enospc;
1618
1619 if (ins->objectid + num_bytes >
1620 block_group->key.objectid + block_group->key.offset) {
1621 search_start = block_group->key.objectid +
1622 block_group->key.offset;
1623 goto new_group;
1624 }
1625
1626 if (test_range_bit(&info->extent_ins, ins->objectid,
1627 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1628 search_start = ins->objectid + num_bytes;
1629 goto new_group;
1630 }
1631
1632 if (test_range_bit(&info->pinned_extents, ins->objectid,
1633 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1634 search_start = ins->objectid + num_bytes;
1635 goto new_group;
1636 }
1637
1638 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1639 ins->objectid < exclude_start + exclude_nr)) {
1640 search_start = exclude_start + exclude_nr;
1641 goto new_group;
1642 }
1643
1644 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
1645 block_group = btrfs_lookup_block_group(info, ins->objectid);
1646 if (block_group)
1647 trans->block_group = block_group;
1648 }
1649 ins->offset = num_bytes;
1650 if (last_ptr) {
1651 *last_ptr = ins->objectid + ins->offset;
1652 if (*last_ptr ==
1653 btrfs_super_total_bytes(&root->fs_info->super_copy)) {
1654 *last_ptr = 0;
1655 }
1656 }
1657 return 0;
1658
1659 new_group:
1660 if (search_start + num_bytes >= search_end) {
1661 enospc:
1662 search_start = orig_search_start;
1663 if (full_scan) {
1664 ret = -ENOSPC;
1665 goto error;
1666 }
1667 if (wrapped) {
1668 if (!full_scan)
1669 total_needed -= empty_size;
1670 full_scan = 1;
1671 } else
1672 wrapped = 1;
1673 }
1674 block_group = btrfs_lookup_block_group(info, search_start);
1675 cond_resched();
1676 block_group = btrfs_find_block_group(root, block_group,
1677 search_start, data, 0);
1678 goto check_failed;
1679
1680 error:
1681 return ret;
1682 }
1683 /*
1684 * finds a free extent and does all the dirty work required for allocation
1685 * returns the key for the extent through ins, and a tree buffer for
1686 * the first block of the extent through buf.
1687 *
1688 * returns 0 if everything worked, non-zero otherwise.
1689 */
1690 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1691 struct btrfs_root *root,
1692 u64 num_bytes, u64 min_alloc_size,
1693 u64 root_objectid, u64 ref_generation,
1694 u64 owner, u64 owner_offset,
1695 u64 empty_size, u64 hint_byte,
1696 u64 search_end, struct btrfs_key *ins, int data)
1697 {
1698 int ret;
1699 int pending_ret;
1700 u64 super_used;
1701 u64 root_used;
1702 u64 search_start = 0;
1703 u64 new_hint;
1704 u64 alloc_profile;
1705 u32 sizes[2];
1706 struct btrfs_fs_info *info = root->fs_info;
1707 struct btrfs_root *extent_root = info->extent_root;
1708 struct btrfs_extent_item *extent_item;
1709 struct btrfs_extent_ref *ref;
1710 struct btrfs_path *path;
1711 struct btrfs_key keys[2];
1712
1713 if (data) {
1714 alloc_profile = info->avail_data_alloc_bits &
1715 info->data_alloc_profile;
1716 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
1717 } else if (root == root->fs_info->chunk_root) {
1718 alloc_profile = info->avail_system_alloc_bits &
1719 info->system_alloc_profile;
1720 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
1721 } else {
1722 alloc_profile = info->avail_metadata_alloc_bits &
1723 info->metadata_alloc_profile;
1724 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
1725 }
1726 again:
1727 if (root->ref_cows) {
1728 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
1729 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1730 2 * 1024 * 1024,
1731 BTRFS_BLOCK_GROUP_METADATA |
1732 (info->metadata_alloc_profile &
1733 info->avail_metadata_alloc_bits));
1734 BUG_ON(ret);
1735 }
1736 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1737 num_bytes + 2 * 1024 * 1024, data);
1738 BUG_ON(ret);
1739 }
1740
1741 new_hint = max(hint_byte, root->fs_info->alloc_start);
1742 if (new_hint < btrfs_super_total_bytes(&info->super_copy))
1743 hint_byte = new_hint;
1744
1745 WARN_ON(num_bytes < root->sectorsize);
1746 ret = find_free_extent(trans, root, num_bytes, empty_size,
1747 search_start, search_end, hint_byte, ins,
1748 trans->alloc_exclude_start,
1749 trans->alloc_exclude_nr, data);
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 new_size)
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 struct btrfs_fs_info *info = root->fs_info;
2483 struct extent_io_tree *block_group_cache;
2484 struct btrfs_key key;
2485 struct btrfs_key found_key;
2486 struct extent_buffer *leaf;
2487 u32 nritems;
2488 int ret;
2489 int progress = 0;
2490
2491 btrfs_set_super_total_bytes(&info->super_copy, new_size);
2492 clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1,
2493 GFP_NOFS);
2494 block_group_cache = &info->block_group_cache;
2495 path = btrfs_alloc_path();
2496 root = root->fs_info->extent_root;
2497 path->reada = 2;
2498
2499 again:
2500 total_found = 0;
2501 key.objectid = new_size;
2502 key.offset = 0;
2503 key.type = 0;
2504 cur_byte = key.objectid;
2505
2506 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2507 if (ret < 0)
2508 goto out;
2509
2510 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
2511 if (ret < 0)
2512 goto out;
2513 if (ret == 0) {
2514 leaf = path->nodes[0];
2515 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2516 if (found_key.objectid + found_key.offset > new_size) {
2517 cur_byte = found_key.objectid;
2518 key.objectid = cur_byte;
2519 }
2520 }
2521 btrfs_release_path(root, path);
2522
2523 while(1) {
2524 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2525 if (ret < 0)
2526 goto out;
2527
2528 leaf = path->nodes[0];
2529 nritems = btrfs_header_nritems(leaf);
2530 next:
2531 if (path->slots[0] >= nritems) {
2532 ret = btrfs_next_leaf(root, path);
2533 if (ret < 0)
2534 goto out;
2535 if (ret == 1) {
2536 ret = 0;
2537 break;
2538 }
2539 leaf = path->nodes[0];
2540 nritems = btrfs_header_nritems(leaf);
2541 }
2542
2543 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2544
2545 if (progress && need_resched()) {
2546 memcpy(&key, &found_key, sizeof(key));
2547 mutex_unlock(&root->fs_info->fs_mutex);
2548 cond_resched();
2549 mutex_lock(&root->fs_info->fs_mutex);
2550 btrfs_release_path(root, path);
2551 btrfs_search_slot(NULL, root, &key, path, 0, 0);
2552 progress = 0;
2553 goto next;
2554 }
2555 progress = 1;
2556
2557 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY ||
2558 found_key.objectid + found_key.offset <= cur_byte) {
2559 path->slots[0]++;
2560 goto next;
2561 }
2562
2563 total_found++;
2564 cur_byte = found_key.objectid + found_key.offset;
2565 key.objectid = cur_byte;
2566 btrfs_release_path(root, path);
2567 ret = relocate_one_extent(root, path, &found_key);
2568 }
2569
2570 btrfs_release_path(root, path);
2571
2572 if (total_found > 0) {
2573 trans = btrfs_start_transaction(tree_root, 1);
2574 btrfs_commit_transaction(trans, tree_root);
2575
2576 mutex_unlock(&root->fs_info->fs_mutex);
2577 btrfs_clean_old_snapshots(tree_root);
2578 mutex_lock(&root->fs_info->fs_mutex);
2579
2580 trans = btrfs_start_transaction(tree_root, 1);
2581 btrfs_commit_transaction(trans, tree_root);
2582 goto again;
2583 }
2584
2585 trans = btrfs_start_transaction(root, 1);
2586 key.objectid = new_size;
2587 key.offset = 0;
2588 key.type = 0;
2589 while(1) {
2590 u64 ptr;
2591
2592 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2593 if (ret < 0)
2594 goto out;
2595
2596 leaf = path->nodes[0];
2597 nritems = btrfs_header_nritems(leaf);
2598 bg_next:
2599 if (path->slots[0] >= nritems) {
2600 ret = btrfs_next_leaf(root, path);
2601 if (ret < 0)
2602 break;
2603 if (ret == 1) {
2604 ret = 0;
2605 break;
2606 }
2607 leaf = path->nodes[0];
2608 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2609
2610 /*
2611 * btrfs_next_leaf doesn't cow buffers, we have to
2612 * do the search again
2613 */
2614 memcpy(&key, &found_key, sizeof(key));
2615 btrfs_release_path(root, path);
2616 goto resched_check;
2617 }
2618
2619 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2620 if (btrfs_key_type(&found_key) != BTRFS_BLOCK_GROUP_ITEM_KEY) {
2621 printk("shrinker found key %Lu %u %Lu\n",
2622 found_key.objectid, found_key.type,
2623 found_key.offset);
2624 path->slots[0]++;
2625 goto bg_next;
2626 }
2627 ret = get_state_private(&info->block_group_cache,
2628 found_key.objectid, &ptr);
2629 if (!ret)
2630 kfree((void *)(unsigned long)ptr);
2631
2632 clear_extent_bits(&info->block_group_cache, found_key.objectid,
2633 found_key.objectid + found_key.offset - 1,
2634 (unsigned int)-1, GFP_NOFS);
2635
2636 key.objectid = found_key.objectid + 1;
2637 btrfs_del_item(trans, root, path);
2638 btrfs_release_path(root, path);
2639 resched_check:
2640 if (need_resched()) {
2641 mutex_unlock(&root->fs_info->fs_mutex);
2642 cond_resched();
2643 mutex_lock(&root->fs_info->fs_mutex);
2644 }
2645 }
2646 clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1,
2647 GFP_NOFS);
2648 btrfs_commit_transaction(trans, root);
2649 out:
2650 btrfs_free_path(path);
2651 return ret;
2652 }
2653
2654 int btrfs_grow_extent_tree(struct btrfs_trans_handle *trans,
2655 struct btrfs_root *root, u64 new_size)
2656 {
2657 btrfs_set_super_total_bytes(&root->fs_info->super_copy, new_size);
2658 return 0;
2659 }
2660
2661 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
2662 struct btrfs_key *key)
2663 {
2664 int ret;
2665 struct btrfs_key found_key;
2666 struct extent_buffer *leaf;
2667 int slot;
2668
2669 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
2670 if (ret < 0)
2671 return ret;
2672 while(1) {
2673 slot = path->slots[0];
2674 leaf = path->nodes[0];
2675 if (slot >= btrfs_header_nritems(leaf)) {
2676 ret = btrfs_next_leaf(root, path);
2677 if (ret == 0)
2678 continue;
2679 if (ret < 0)
2680 goto error;
2681 break;
2682 }
2683 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2684
2685 if (found_key.objectid >= key->objectid &&
2686 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
2687 return 0;
2688 path->slots[0]++;
2689 }
2690 ret = -ENOENT;
2691 error:
2692 return ret;
2693 }
2694
2695 int btrfs_read_block_groups(struct btrfs_root *root)
2696 {
2697 struct btrfs_path *path;
2698 int ret;
2699 int bit;
2700 struct btrfs_block_group_cache *cache;
2701 struct btrfs_fs_info *info = root->fs_info;
2702 struct btrfs_space_info *space_info;
2703 struct extent_io_tree *block_group_cache;
2704 struct btrfs_key key;
2705 struct btrfs_key found_key;
2706 struct extent_buffer *leaf;
2707
2708 block_group_cache = &info->block_group_cache;
2709 root = info->extent_root;
2710 key.objectid = 0;
2711 key.offset = 0;
2712 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2713 path = btrfs_alloc_path();
2714 if (!path)
2715 return -ENOMEM;
2716
2717 while(1) {
2718 ret = find_first_block_group(root, path, &key);
2719 if (ret > 0) {
2720 ret = 0;
2721 goto error;
2722 }
2723 if (ret != 0)
2724 goto error;
2725
2726 leaf = path->nodes[0];
2727 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2728 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2729 if (!cache) {
2730 ret = -ENOMEM;
2731 break;
2732 }
2733
2734 read_extent_buffer(leaf, &cache->item,
2735 btrfs_item_ptr_offset(leaf, path->slots[0]),
2736 sizeof(cache->item));
2737 memcpy(&cache->key, &found_key, sizeof(found_key));
2738 cache->cached = 0;
2739 cache->pinned = 0;
2740
2741 key.objectid = found_key.objectid + found_key.offset;
2742 btrfs_release_path(root, path);
2743 cache->flags = btrfs_block_group_flags(&cache->item);
2744 bit = 0;
2745 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
2746 bit = BLOCK_GROUP_DATA;
2747 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
2748 bit = BLOCK_GROUP_SYSTEM;
2749 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
2750 bit = BLOCK_GROUP_METADATA;
2751 }
2752 set_avail_alloc_bits(info, cache->flags);
2753
2754 ret = update_space_info(info, cache->flags, found_key.offset,
2755 btrfs_block_group_used(&cache->item),
2756 &space_info);
2757 BUG_ON(ret);
2758 cache->space_info = space_info;
2759
2760 /* use EXTENT_LOCKED to prevent merging */
2761 set_extent_bits(block_group_cache, found_key.objectid,
2762 found_key.objectid + found_key.offset - 1,
2763 bit | EXTENT_LOCKED, GFP_NOFS);
2764 set_state_private(block_group_cache, found_key.objectid,
2765 (unsigned long)cache);
2766
2767 if (key.objectid >=
2768 btrfs_super_total_bytes(&info->super_copy))
2769 break;
2770 }
2771 ret = 0;
2772 error:
2773 btrfs_free_path(path);
2774 return ret;
2775 }
2776
2777 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
2778 struct btrfs_root *root, u64 bytes_used,
2779 u64 type, u64 chunk_objectid, u64 chunk_offset,
2780 u64 size)
2781 {
2782 int ret;
2783 int bit = 0;
2784 struct btrfs_root *extent_root;
2785 struct btrfs_block_group_cache *cache;
2786 struct extent_io_tree *block_group_cache;
2787
2788 extent_root = root->fs_info->extent_root;
2789 block_group_cache = &root->fs_info->block_group_cache;
2790
2791 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2792 BUG_ON(!cache);
2793 cache->key.objectid = chunk_offset;
2794 cache->key.offset = size;
2795 cache->cached = 0;
2796 cache->pinned = 0;
2797
2798 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2799 memset(&cache->item, 0, sizeof(cache->item));
2800 btrfs_set_block_group_used(&cache->item, bytes_used);
2801 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
2802 cache->flags = type;
2803 btrfs_set_block_group_flags(&cache->item, type);
2804
2805 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
2806 &cache->space_info);
2807 BUG_ON(ret);
2808
2809 bit = block_group_state_bits(type);
2810 set_extent_bits(block_group_cache, chunk_offset,
2811 chunk_offset + size - 1,
2812 bit | EXTENT_LOCKED, GFP_NOFS);
2813
2814 set_state_private(block_group_cache, chunk_offset,
2815 (unsigned long)cache);
2816 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
2817 sizeof(cache->item));
2818 BUG_ON(ret);
2819
2820 finish_current_insert(trans, extent_root);
2821 ret = del_pending_extents(trans, extent_root);
2822 BUG_ON(ret);
2823 set_avail_alloc_bits(extent_root->fs_info, type);
2824 return 0;
2825 }
Linux kernel - Deliverables
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