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