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Fix compiler warning in volumes.c
[btrfs-progs-unstable/devel.git] / extent-tree.c
blob1d1dbc8b6f2e04c488c4d5d6895229ab434409a2
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include "kerncompat.h"
22 #include "radix-tree.h"
23 #include "ctree.h"
24 #include "disk-io.h"
25 #include "print-tree.h"
26 #include "transaction.h"
27 #include "crc32c.h"
28 #include "volumes.h"
29
30 #define BLOCK_GROUP_DATA EXTENT_WRITEBACK
31 #define BLOCK_GROUP_METADATA EXTENT_UPTODATE
32 #define BLOCK_GROUP_SYSTEM EXTENT_NEW
33
34 #define BLOCK_GROUP_DIRTY EXTENT_DIRTY
35
36 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
37 btrfs_root *extent_root);
38 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
39 btrfs_root *extent_root);
40
41 static int cache_block_group(struct btrfs_root *root,
42 struct btrfs_block_group_cache *block_group)
43 {
44 struct btrfs_path *path;
45 int ret;
46 struct btrfs_key key;
47 struct extent_buffer *leaf;
48 struct extent_io_tree *free_space_cache;
49 int slot;
50 u64 last = 0;
51 u64 hole_size;
52 u64 first_free;
53 int found = 0;
54
55 if (!block_group)
56 return 0;
57
58 root = root->fs_info->extent_root;
59 free_space_cache = &root->fs_info->free_space_cache;
60
61 if (block_group->cached)
62 return 0;
63
64 path = btrfs_alloc_path();
65 if (!path)
66 return -ENOMEM;
67
68 path->reada = 2;
69 first_free = block_group->key.objectid;
70 key.objectid = block_group->key.objectid;
71 key.offset = 0;
72 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
73 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
74 if (ret < 0)
75 return ret;
76 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
77 if (ret < 0)
78 return ret;
79 if (ret == 0) {
80 leaf = path->nodes[0];
81 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
82 if (key.objectid + key.offset > first_free)
83 first_free = key.objectid + key.offset;
84 }
85 while(1) {
86 leaf = path->nodes[0];
87 slot = path->slots[0];
88 if (slot >= btrfs_header_nritems(leaf)) {
89 ret = btrfs_next_leaf(root, path);
90 if (ret < 0)
91 goto err;
92 if (ret == 0) {
93 continue;
94 } else {
95 break;
96 }
97 }
98 btrfs_item_key_to_cpu(leaf, &key, slot);
99 if (key.objectid < block_group->key.objectid) {
100 goto next;
101 }
102 if (key.objectid >= block_group->key.objectid +
103 block_group->key.offset) {
104 break;
105 }
106
107 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
108 if (!found) {
109 last = first_free;
110 found = 1;
111 }
112 if (key.objectid > last) {
113 hole_size = key.objectid - last;
114 set_extent_dirty(free_space_cache, last,
115 last + hole_size - 1,
116 GFP_NOFS);
117 }
118 last = key.objectid + key.offset;
119 }
120 next:
121 path->slots[0]++;
122 }
123
124 if (!found)
125 last = first_free;
126 if (block_group->key.objectid +
127 block_group->key.offset > last) {
128 hole_size = block_group->key.objectid +
129 block_group->key.offset - last;
130 set_extent_dirty(free_space_cache, last,
131 last + hole_size - 1, GFP_NOFS);
132 }
133 block_group->cached = 1;
134 err:
135 btrfs_free_path(path);
136 return 0;
137 }
138
139 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
140 btrfs_fs_info *info,
141 u64 bytenr)
142 {
143 struct extent_io_tree *block_group_cache;
144 struct btrfs_block_group_cache *block_group = NULL;
145 u64 ptr;
146 u64 start;
147 u64 end;
148 int ret;
149
150 block_group_cache = &info->block_group_cache;
151 ret = find_first_extent_bit(block_group_cache,
152 bytenr, &start, &end,
153 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
154 BLOCK_GROUP_SYSTEM);
155 if (ret) {
156 return NULL;
157 }
158 ret = get_state_private(block_group_cache, start, &ptr);
159 if (ret)
160 return NULL;
161
162 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
163 if (block_group->key.objectid <= bytenr && bytenr <
164 block_group->key.objectid + block_group->key.offset)
165 return block_group;
166 return NULL;
167 }
168
169 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
170 {
171 return (cache->flags & bits) == bits;
172 }
173
174 static int noinline find_search_start(struct btrfs_root *root,
175 struct btrfs_block_group_cache **cache_ret,
176 u64 *start_ret, int num, int data)
177 {
178 int ret;
179 struct btrfs_block_group_cache *cache = *cache_ret;
180 u64 last;
181 u64 start = 0;
182 u64 end = 0;
183 u64 cache_miss = 0;
184 u64 search_start = *start_ret;
185 int wrapped = 0;
186
187 if (!cache) {
188 goto out;
189 }
190 again:
191 ret = cache_block_group(root, cache);
192 if (ret)
193 goto out;
194
195 last = max(search_start, cache->key.objectid);
196 if (!block_group_bits(cache, data)) {
197 goto new_group;
198 }
199
200 while(1) {
201 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
202 last, &start, &end, EXTENT_DIRTY);
203 if (ret) {
204 if (!cache_miss)
205 cache_miss = last;
206 goto new_group;
207 }
208
209 start = max(last, start);
210 last = end + 1;
211 if (last - start < num) {
212 if (last == cache->key.objectid + cache->key.offset)
213 cache_miss = start;
214 continue;
215 }
216 if (start + num > cache->key.objectid + cache->key.offset)
217 goto new_group;
218 *start_ret = start;
219 return 0;
220 }
221 out:
222 cache = btrfs_lookup_block_group(root->fs_info, search_start);
223 if (!cache) {
224 printk("Unable to find block group for %llu\n",
225 (unsigned long long)search_start);
226 WARN_ON(1);
227 }
228 return -ENOSPC;
229
230 new_group:
231 last = cache->key.objectid + cache->key.offset;
232 wrapped:
233 cache = btrfs_lookup_block_group(root->fs_info, last);
234 if (!cache) {
235 no_cache:
236 if (!wrapped) {
237 wrapped = 1;
238 last = search_start;
239 goto wrapped;
240 }
241 goto out;
242 }
243 if (cache_miss && !cache->cached) {
244 cache_block_group(root, cache);
245 last = cache_miss;
246 cache = btrfs_lookup_block_group(root->fs_info, last);
247 }
248 cache = btrfs_find_block_group(root, cache, last, data, 0);
249 if (!cache)
250 goto no_cache;
251 *cache_ret = cache;
252 cache_miss = 0;
253 goto again;
254 }
255
256 static u64 div_factor(u64 num, int factor)
257 {
258 if (factor == 10)
259 return num;
260 num *= factor;
261 num /= 10;
262 return num;
263 }
264
265 static int block_group_state_bits(u64 flags)
266 {
267 int bits = 0;
268 if (flags & BTRFS_BLOCK_GROUP_DATA)
269 bits |= BLOCK_GROUP_DATA;
270 if (flags & BTRFS_BLOCK_GROUP_METADATA)
271 bits |= BLOCK_GROUP_METADATA;
272 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
273 bits |= BLOCK_GROUP_SYSTEM;
274 return bits;
275 }
276
277 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
278 struct btrfs_block_group_cache
279 *hint, u64 search_start,
280 int data, int owner)
281 {
282 struct btrfs_block_group_cache *cache;
283 struct extent_io_tree *block_group_cache;
284 struct btrfs_block_group_cache *found_group = NULL;
285 struct btrfs_fs_info *info = root->fs_info;
286 u64 used;
287 u64 last = 0;
288 u64 hint_last;
289 u64 start;
290 u64 end;
291 u64 free_check;
292 u64 ptr;
293 int bit;
294 int ret;
295 int full_search = 0;
296 int factor = 10;
297
298 block_group_cache = &info->block_group_cache;
299
300 if (!owner)
301 factor = 10;
302
303 bit = block_group_state_bits(data);
304
305 if (search_start) {
306 struct btrfs_block_group_cache *shint;
307 shint = btrfs_lookup_block_group(info, search_start);
308 if (shint && block_group_bits(shint, data)) {
309 used = btrfs_block_group_used(&shint->item);
310 if (used + shint->pinned <
311 div_factor(shint->key.offset, factor)) {
312 return shint;
313 }
314 }
315 }
316 if (hint && block_group_bits(hint, data)) {
317 used = btrfs_block_group_used(&hint->item);
318 if (used + hint->pinned <
319 div_factor(hint->key.offset, factor)) {
320 return hint;
321 }
322 last = hint->key.objectid + hint->key.offset;
323 hint_last = last;
324 } else {
325 if (hint)
326 hint_last = max(hint->key.objectid, search_start);
327 else
328 hint_last = search_start;
329
330 last = hint_last;
331 }
332 again:
333 while(1) {
334 ret = find_first_extent_bit(block_group_cache, last,
335 &start, &end, bit);
336 if (ret)
337 break;
338
339 ret = get_state_private(block_group_cache, start, &ptr);
340 if (ret)
341 break;
342
343 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
344 last = cache->key.objectid + cache->key.offset;
345 used = btrfs_block_group_used(&cache->item);
346
347 if (block_group_bits(cache, data)) {
348 if (full_search)
349 free_check = cache->key.offset;
350 else
351 free_check = div_factor(cache->key.offset,
352 factor);
353
354 if (used + cache->pinned < free_check) {
355 found_group = cache;
356 goto found;
357 }
358 }
359 cond_resched();
360 }
361 if (!full_search) {
362 last = search_start;
363 full_search = 1;
364 goto again;
365 }
366 found:
367 return found_group;
368 }
369
370 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
371 u64 owner, u64 owner_offset)
372 {
373 u32 high_crc = ~(u32)0;
374 u32 low_crc = ~(u32)0;
375 __le64 lenum;
376
377 lenum = cpu_to_le64(root_objectid);
378 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
379 lenum = cpu_to_le64(ref_generation);
380 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
381 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
382 lenum = cpu_to_le64(owner);
383 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
384 lenum = cpu_to_le64(owner_offset);
385 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
386 }
387 return ((u64)high_crc << 32) | (u64)low_crc;
388 }
389
390 static int match_extent_ref(struct extent_buffer *leaf,
391 struct btrfs_extent_ref *disk_ref,
392 struct btrfs_extent_ref *cpu_ref)
393 {
394 int ret;
395 int len;
396
397 if (cpu_ref->objectid)
398 len = sizeof(*cpu_ref);
399 else
400 len = 2 * sizeof(u64);
401 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
402 len);
403 return ret == 0;
404 }
405
406 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
407 struct btrfs_root *root,
408 struct btrfs_path *path, u64 bytenr,
409 u64 root_objectid,
410 u64 ref_generation, u64 owner,
411 u64 owner_offset, int del)
412 {
413 u64 hash;
414 struct btrfs_key key;
415 struct btrfs_key found_key;
416 struct btrfs_extent_ref ref;
417 struct extent_buffer *leaf;
418 struct btrfs_extent_ref *disk_ref;
419 int ret;
420 int ret2;
421
422 btrfs_set_stack_ref_root(&ref, root_objectid);
423 btrfs_set_stack_ref_generation(&ref, ref_generation);
424 btrfs_set_stack_ref_objectid(&ref, owner);
425 btrfs_set_stack_ref_offset(&ref, owner_offset);
426
427 hash = hash_extent_ref(root_objectid, ref_generation, owner,
428 owner_offset);
429 key.offset = hash;
430 key.objectid = bytenr;
431 key.type = BTRFS_EXTENT_REF_KEY;
432
433 while (1) {
434 ret = btrfs_search_slot(trans, root, &key, path,
435 del ? -1 : 0, del);
436 if (ret < 0)
437 goto out;
438 leaf = path->nodes[0];
439 if (ret != 0) {
440 u32 nritems = btrfs_header_nritems(leaf);
441 if (path->slots[0] >= nritems) {
442 ret2 = btrfs_next_leaf(root, path);
443 if (ret2)
444 goto out;
445 leaf = path->nodes[0];
446 }
447 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
448 if (found_key.objectid != bytenr ||
449 found_key.type != BTRFS_EXTENT_REF_KEY)
450 goto out;
451 key.offset = found_key.offset;
452 if (del) {
453 btrfs_release_path(root, path);
454 continue;
455 }
456 }
457 disk_ref = btrfs_item_ptr(path->nodes[0],
458 path->slots[0],
459 struct btrfs_extent_ref);
460 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
461 ret = 0;
462 goto out;
463 }
464 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
465 key.offset = found_key.offset + 1;
466 btrfs_release_path(root, path);
467 }
468 out:
469 return ret;
470 }
471
472 /*
473 * Back reference rules. Back refs have three main goals:
474 *
475 * 1) differentiate between all holders of references to an extent so that
476 * when a reference is dropped we can make sure it was a valid reference
477 * before freeing the extent.
478 *
479 * 2) Provide enough information to quickly find the holders of an extent
480 * if we notice a given block is corrupted or bad.
481 *
482 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
483 * maintenance. This is actually the same as #2, but with a slightly
484 * different use case.
485 *
486 * File extents can be referenced by:
487 *
488 * - multiple snapshots, subvolumes, or different generations in one subvol
489 * - different files inside a single subvolume (in theory, not implemented yet)
490 * - different offsets inside a file (bookend extents in file.c)
491 *
492 * The extent ref structure has fields for:
493 *
494 * - Objectid of the subvolume root
495 * - Generation number of the tree holding the reference
496 * - objectid of the file holding the reference
497 * - offset in the file corresponding to the key holding the reference
498 *
499 * When a file extent is allocated the fields are filled in:
500 * (root_key.objectid, trans->transid, inode objectid, offset in file)
501 *
502 * When a leaf is cow'd new references are added for every file extent found
503 * in the leaf. It looks the same as the create case, but trans->transid
504 * will be different when the block is cow'd.
505 *
506 * (root_key.objectid, trans->transid, inode objectid, offset in file)
507 *
508 * When a file extent is removed either during snapshot deletion or file
509 * truncation, the corresponding back reference is found
510 * by searching for:
511 *
512 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
513 * inode objectid, offset in file)
514 *
515 * Btree extents can be referenced by:
516 *
517 * - Different subvolumes
518 * - Different generations of the same subvolume
519 *
520 * Storing sufficient information for a full reverse mapping of a btree
521 * block would require storing the lowest key of the block in the backref,
522 * and it would require updating that lowest key either before write out or
523 * every time it changed. Instead, the objectid of the lowest key is stored
524 * along with the level of the tree block. This provides a hint
525 * about where in the btree the block can be found. Searches through the
526 * btree only need to look for a pointer to that block, so they stop one
527 * level higher than the level recorded in the backref.
528 *
529 * Some btrees do not do reference counting on their extents. These
530 * include the extent tree and the tree of tree roots. Backrefs for these
531 * trees always have a generation of zero.
532 *
533 * When a tree block is created, back references are inserted:
534 *
535 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
536 *
537 * When a tree block is cow'd in a reference counted root,
538 * new back references are added for all the blocks it points to.
539 * These are of the form (trans->transid will have increased since creation):
540 *
541 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
542 *
543 * Because the lowest_key_objectid and the level are just hints
544 * they are not used when backrefs are deleted. When a backref is deleted:
545 *
546 * if backref was for a tree root:
547 * root_objectid = root->root_key.objectid
548 * else
549 * root_objectid = btrfs_header_owner(parent)
550 *
551 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
552 *
553 * Back Reference Key hashing:
554 *
555 * Back references have four fields, each 64 bits long. Unfortunately,
556 * This is hashed into a single 64 bit number and placed into the key offset.
557 * The key objectid corresponds to the first byte in the extent, and the
558 * key type is set to BTRFS_EXTENT_REF_KEY
559 */
560 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
561 struct btrfs_root *root,
562 struct btrfs_path *path, u64 bytenr,
563 u64 root_objectid, u64 ref_generation,
564 u64 owner, u64 owner_offset)
565 {
566 u64 hash;
567 struct btrfs_key key;
568 struct btrfs_extent_ref ref;
569 struct btrfs_extent_ref *disk_ref;
570 int ret;
571
572 btrfs_set_stack_ref_root(&ref, root_objectid);
573 btrfs_set_stack_ref_generation(&ref, ref_generation);
574 btrfs_set_stack_ref_objectid(&ref, owner);
575 btrfs_set_stack_ref_offset(&ref, owner_offset);
576
577 hash = hash_extent_ref(root_objectid, ref_generation, owner,
578 owner_offset);
579 key.offset = hash;
580 key.objectid = bytenr;
581 key.type = BTRFS_EXTENT_REF_KEY;
582
583 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
584 while (ret == -EEXIST) {
585 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
586 struct btrfs_extent_ref);
587 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
588 goto out;
589 key.offset++;
590 btrfs_release_path(root, path);
591 ret = btrfs_insert_empty_item(trans, root, path, &key,
592 sizeof(ref));
593 }
594 if (ret)
595 goto out;
596 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
597 struct btrfs_extent_ref);
598 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
599 sizeof(ref));
600 btrfs_mark_buffer_dirty(path->nodes[0]);
601 out:
602 btrfs_release_path(root, path);
603 return ret;
604 }
605
606 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
607 struct btrfs_root *root,
608 u64 bytenr, u64 num_bytes,
609 u64 root_objectid, u64 ref_generation,
610 u64 owner, u64 owner_offset)
611 {
612 struct btrfs_path *path;
613 int ret;
614 struct btrfs_key key;
615 struct extent_buffer *l;
616 struct btrfs_extent_item *item;
617 u32 refs;
618
619 WARN_ON(num_bytes < root->sectorsize);
620 path = btrfs_alloc_path();
621 if (!path)
622 return -ENOMEM;
623
624 key.objectid = bytenr;
625 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
626 key.offset = num_bytes;
627 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
628 0, 1);
629 if (ret < 0)
630 return ret;
631 if (ret != 0) {
632 BUG();
633 }
634 BUG_ON(ret != 0);
635 l = path->nodes[0];
636 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
637 refs = btrfs_extent_refs(l, item);
638 btrfs_set_extent_refs(l, item, refs + 1);
639 btrfs_mark_buffer_dirty(path->nodes[0]);
640
641 btrfs_release_path(root->fs_info->extent_root, path);
642
643 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
644 path, bytenr, root_objectid,
645 ref_generation, owner, owner_offset);
646 BUG_ON(ret);
647 finish_current_insert(trans, root->fs_info->extent_root);
648 del_pending_extents(trans, root->fs_info->extent_root);
649
650 btrfs_free_path(path);
651 return 0;
652 }
653
654 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
655 struct btrfs_root *root)
656 {
657 finish_current_insert(trans, root->fs_info->extent_root);
658 del_pending_extents(trans, root->fs_info->extent_root);
659 return 0;
660 }
661
662 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
663 struct btrfs_root *root, u64 bytenr,
664 u64 num_bytes, u32 *refs)
665 {
666 struct btrfs_path *path;
667 int ret;
668 struct btrfs_key key;
669 struct extent_buffer *l;
670 struct btrfs_extent_item *item;
671
672 WARN_ON(num_bytes < root->sectorsize);
673 path = btrfs_alloc_path();
674 key.objectid = bytenr;
675 key.offset = num_bytes;
676 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
677 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
678 0, 0);
679 if (ret < 0)
680 goto out;
681 if (ret != 0) {
682 btrfs_print_leaf(root, path->nodes[0]);
683 printk("failed to find block number %llu\n",
684 (unsigned long long)bytenr);
685 BUG();
686 }
687 l = path->nodes[0];
688 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
689 *refs = btrfs_extent_refs(l, item);
690 out:
691 btrfs_free_path(path);
692 return 0;
693 }
694
695 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
696 struct btrfs_path *count_path,
697 u64 first_extent)
698 {
699 struct btrfs_root *extent_root = root->fs_info->extent_root;
700 struct btrfs_path *path;
701 u64 bytenr;
702 u64 found_objectid;
703 u64 root_objectid = root->root_key.objectid;
704 u32 total_count = 0;
705 u32 cur_count;
706 u32 refs;
707 u32 nritems;
708 int ret;
709 struct btrfs_key key;
710 struct btrfs_key found_key;
711 struct extent_buffer *l;
712 struct btrfs_extent_item *item;
713 struct btrfs_extent_ref *ref_item;
714 int level = -1;
715
716 path = btrfs_alloc_path();
717 again:
718 if (level == -1)
719 bytenr = first_extent;
720 else
721 bytenr = count_path->nodes[level]->start;
722
723 cur_count = 0;
724 key.objectid = bytenr;
725 key.offset = 0;
726
727 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
728 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
729 if (ret < 0)
730 goto out;
731 BUG_ON(ret == 0);
732
733 l = path->nodes[0];
734 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
735
736 if (found_key.objectid != bytenr ||
737 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
738 goto out;
739 }
740
741 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
742 refs = btrfs_extent_refs(l, item);
743 while (1) {
744 nritems = btrfs_header_nritems(l);
745 if (path->slots[0] >= nritems) {
746 ret = btrfs_next_leaf(extent_root, path);
747 if (ret == 0)
748 continue;
749 break;
750 }
751 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
752 if (found_key.objectid != bytenr)
753 break;
754 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
755 path->slots[0]++;
756 continue;
757 }
758
759 cur_count++;
760 ref_item = btrfs_item_ptr(l, path->slots[0],
761 struct btrfs_extent_ref);
762 found_objectid = btrfs_ref_root(l, ref_item);
763
764 if (found_objectid != root_objectid) {
765 total_count = 2;
766 goto out;
767 }
768 total_count = 1;
769 path->slots[0]++;
770 }
771 if (cur_count == 0) {
772 total_count = 0;
773 goto out;
774 }
775 if (level >= 0 && root->node == count_path->nodes[level])
776 goto out;
777 level++;
778 btrfs_release_path(root, path);
779 goto again;
780
781 out:
782 btrfs_free_path(path);
783 return total_count;
784 }
785 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
786 struct btrfs_root *root, u64 owner_objectid)
787 {
788 u64 generation;
789 u64 key_objectid;
790 u64 level;
791 u32 nritems;
792 struct btrfs_disk_key disk_key;
793
794 level = btrfs_header_level(root->node);
795 generation = trans->transid;
796 nritems = btrfs_header_nritems(root->node);
797 if (nritems > 0) {
798 if (level == 0)
799 btrfs_item_key(root->node, &disk_key, 0);
800 else
801 btrfs_node_key(root->node, &disk_key, 0);
802 key_objectid = btrfs_disk_key_objectid(&disk_key);
803 } else {
804 key_objectid = 0;
805 }
806 return btrfs_inc_extent_ref(trans, root, root->node->start,
807 root->node->len, owner_objectid,
808 generation, level, key_objectid);
809 }
810
811 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
812 struct extent_buffer *buf)
813 {
814 u64 bytenr;
815 u32 nritems;
816 struct btrfs_key key;
817 struct btrfs_file_extent_item *fi;
818 int i;
819 int level;
820 int ret;
821 int faili;
822
823 if (!root->ref_cows)
824 return 0;
825
826 level = btrfs_header_level(buf);
827 nritems = btrfs_header_nritems(buf);
828 for (i = 0; i < nritems; i++) {
829 if (level == 0) {
830 u64 disk_bytenr;
831 btrfs_item_key_to_cpu(buf, &key, i);
832 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
833 continue;
834 fi = btrfs_item_ptr(buf, i,
835 struct btrfs_file_extent_item);
836 if (btrfs_file_extent_type(buf, fi) ==
837 BTRFS_FILE_EXTENT_INLINE)
838 continue;
839 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
840 if (disk_bytenr == 0)
841 continue;
842 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
843 btrfs_file_extent_disk_num_bytes(buf, fi),
844 root->root_key.objectid, trans->transid,
845 key.objectid, key.offset);
846 if (ret) {
847 faili = i;
848 goto fail;
849 }
850 } else {
851 bytenr = btrfs_node_blockptr(buf, i);
852 btrfs_node_key_to_cpu(buf, &key, i);
853 ret = btrfs_inc_extent_ref(trans, root, bytenr,
854 btrfs_level_size(root, level - 1),
855 root->root_key.objectid,
856 trans->transid,
857 level - 1, key.objectid);
858 if (ret) {
859 faili = i;
860 goto fail;
861 }
862 }
863 }
864 return 0;
865 fail:
866 WARN_ON(1);
867 #if 0
868 for (i =0; i < faili; i++) {
869 if (level == 0) {
870 u64 disk_bytenr;
871 btrfs_item_key_to_cpu(buf, &key, i);
872 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
873 continue;
874 fi = btrfs_item_ptr(buf, i,
875 struct btrfs_file_extent_item);
876 if (btrfs_file_extent_type(buf, fi) ==
877 BTRFS_FILE_EXTENT_INLINE)
878 continue;
879 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
880 if (disk_bytenr == 0)
881 continue;
882 err = btrfs_free_extent(trans, root, disk_bytenr,
883 btrfs_file_extent_disk_num_bytes(buf,
884 fi), 0);
885 BUG_ON(err);
886 } else {
887 bytenr = btrfs_node_blockptr(buf, i);
888 err = btrfs_free_extent(trans, root, bytenr,
889 btrfs_level_size(root, level - 1), 0);
890 BUG_ON(err);
891 }
892 }
893 #endif
894 return ret;
895 }
896
897 static int write_one_cache_group(struct btrfs_trans_handle *trans,
898 struct btrfs_root *root,
899 struct btrfs_path *path,
900 struct btrfs_block_group_cache *cache)
901 {
902 int ret;
903 int pending_ret;
904 struct btrfs_root *extent_root = root->fs_info->extent_root;
905 unsigned long bi;
906 struct extent_buffer *leaf;
907
908 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
909 if (ret < 0)
910 goto fail;
911 BUG_ON(ret);
912
913 leaf = path->nodes[0];
914 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
915 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
916 btrfs_mark_buffer_dirty(leaf);
917 btrfs_release_path(extent_root, path);
918 fail:
919 finish_current_insert(trans, extent_root);
920 pending_ret = del_pending_extents(trans, extent_root);
921 if (ret)
922 return ret;
923 if (pending_ret)
924 return pending_ret;
925 return 0;
926
927 }
928
929 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
930 struct btrfs_root *root)
931 {
932 struct extent_io_tree *block_group_cache;
933 struct btrfs_block_group_cache *cache;
934 int ret;
935 int err = 0;
936 int werr = 0;
937 struct btrfs_path *path;
938 u64 last = 0;
939 u64 start;
940 u64 end;
941 u64 ptr;
942
943 block_group_cache = &root->fs_info->block_group_cache;
944 path = btrfs_alloc_path();
945 if (!path)
946 return -ENOMEM;
947
948 while(1) {
949 ret = find_first_extent_bit(block_group_cache, last,
950 &start, &end, BLOCK_GROUP_DIRTY);
951 if (ret)
952 break;
953
954 last = end + 1;
955 ret = get_state_private(block_group_cache, start, &ptr);
956 if (ret)
957 break;
958 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
959 err = write_one_cache_group(trans, root,
960 path, cache);
961 /*
962 * if we fail to write the cache group, we want
963 * to keep it marked dirty in hopes that a later
964 * write will work
965 */
966 if (err) {
967 werr = err;
968 continue;
969 }
970 clear_extent_bits(block_group_cache, start, end,
971 BLOCK_GROUP_DIRTY, GFP_NOFS);
972 }
973 btrfs_free_path(path);
974 return werr;
975 }
976
977 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
978 u64 flags)
979 {
980 struct list_head *head = &info->space_info;
981 struct list_head *cur;
982 struct btrfs_space_info *found;
983 list_for_each(cur, head) {
984 found = list_entry(cur, struct btrfs_space_info, list);
985 if (found->flags == flags)
986 return found;
987 }
988 return NULL;
989
990 }
991
992 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
993 u64 total_bytes, u64 bytes_used,
994 struct btrfs_space_info **space_info)
995 {
996 struct btrfs_space_info *found;
997
998 found = __find_space_info(info, flags);
999 if (found) {
1000 found->total_bytes += total_bytes;
1001 found->bytes_used += bytes_used;
1002 WARN_ON(found->total_bytes < found->bytes_used);
1003 *space_info = found;
1004 return 0;
1005 }
1006 found = kmalloc(sizeof(*found), GFP_NOFS);
1007 if (!found)
1008 return -ENOMEM;
1009
1010 list_add(&found->list, &info->space_info);
1011 found->flags = flags;
1012 found->total_bytes = total_bytes;
1013 found->bytes_used = bytes_used;
1014 found->bytes_pinned = 0;
1015 found->full = 0;
1016 *space_info = found;
1017 return 0;
1018 }
1019
1020
1021 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1022 {
1023 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1024 BTRFS_BLOCK_GROUP_RAID1 |
1025 BTRFS_BLOCK_GROUP_DUP);
1026 if (extra_flags) {
1027 if (flags & BTRFS_BLOCK_GROUP_DATA)
1028 fs_info->avail_data_alloc_bits |= extra_flags;
1029 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1030 fs_info->avail_metadata_alloc_bits |= extra_flags;
1031 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1032 fs_info->avail_system_alloc_bits |= extra_flags;
1033 }
1034 }
1035
1036 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1037 struct btrfs_root *extent_root, u64 alloc_bytes,
1038 u64 flags)
1039 {
1040 struct btrfs_space_info *space_info;
1041 u64 thresh;
1042 u64 start;
1043 u64 num_bytes;
1044 int ret;
1045
1046 space_info = __find_space_info(extent_root->fs_info, flags);
1047 if (!space_info) {
1048 ret = update_space_info(extent_root->fs_info, flags,
1049 0, 0, &space_info);
1050 BUG_ON(ret);
1051 }
1052 BUG_ON(!space_info);
1053
1054 if (space_info->full)
1055 return 0;
1056
1057 thresh = div_factor(space_info->total_bytes, 7);
1058 if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1059 thresh)
1060 return 0;
1061
1062 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1063 if (ret == -ENOSPC) {
1064 space_info->full = 1;
1065 return 0;
1066 }
1067
1068 BUG_ON(ret);
1069
1070 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1071 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1072 BUG_ON(ret);
1073 return 0;
1074 }
1075
1076 static int update_block_group(struct btrfs_trans_handle *trans,
1077 struct btrfs_root *root,
1078 u64 bytenr, u64 num_bytes, int alloc,
1079 int mark_free)
1080 {
1081 struct btrfs_block_group_cache *cache;
1082 struct btrfs_fs_info *info = root->fs_info;
1083 u64 total = num_bytes;
1084 u64 old_val;
1085 u64 byte_in_group;
1086 u64 start;
1087 u64 end;
1088
1089 while(total) {
1090 cache = btrfs_lookup_block_group(info, bytenr);
1091 if (!cache) {
1092 return -1;
1093 }
1094 byte_in_group = bytenr - cache->key.objectid;
1095 WARN_ON(byte_in_group > cache->key.offset);
1096 start = cache->key.objectid;
1097 end = start + cache->key.offset - 1;
1098 set_extent_bits(&info->block_group_cache, start, end,
1099 BLOCK_GROUP_DIRTY, GFP_NOFS);
1100
1101 old_val = btrfs_block_group_used(&cache->item);
1102 num_bytes = min(total, cache->key.offset - byte_in_group);
1103 if (alloc) {
1104 old_val += num_bytes;
1105 cache->space_info->bytes_used += num_bytes;
1106 } else {
1107 old_val -= num_bytes;
1108 cache->space_info->bytes_used -= num_bytes;
1109 if (mark_free) {
1110 set_extent_dirty(&info->free_space_cache,
1111 bytenr, bytenr + num_bytes - 1,
1112 GFP_NOFS);
1113 }
1114 }
1115 btrfs_set_block_group_used(&cache->item, old_val);
1116 total -= num_bytes;
1117 bytenr += num_bytes;
1118 }
1119 return 0;
1120 }
1121
1122 static int update_pinned_extents(struct btrfs_root *root,
1123 u64 bytenr, u64 num, int pin)
1124 {
1125 u64 len;
1126 struct btrfs_block_group_cache *cache;
1127 struct btrfs_fs_info *fs_info = root->fs_info;
1128
1129 if (pin) {
1130 set_extent_dirty(&fs_info->pinned_extents,
1131 bytenr, bytenr + num - 1, GFP_NOFS);
1132 } else {
1133 clear_extent_dirty(&fs_info->pinned_extents,
1134 bytenr, bytenr + num - 1, GFP_NOFS);
1135 }
1136 while (num > 0) {
1137 cache = btrfs_lookup_block_group(fs_info, bytenr);
1138 WARN_ON(!cache);
1139 len = min(num, cache->key.offset -
1140 (bytenr - cache->key.objectid));
1141 if (pin) {
1142 cache->pinned += len;
1143 cache->space_info->bytes_pinned += len;
1144 fs_info->total_pinned += len;
1145 } else {
1146 cache->pinned -= len;
1147 cache->space_info->bytes_pinned -= len;
1148 fs_info->total_pinned -= len;
1149 }
1150 bytenr += len;
1151 num -= len;
1152 }
1153 return 0;
1154 }
1155
1156 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1157 {
1158 u64 last = 0;
1159 u64 start;
1160 u64 end;
1161 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1162 int ret;
1163
1164 while(1) {
1165 ret = find_first_extent_bit(pinned_extents, last,
1166 &start, &end, EXTENT_DIRTY);
1167 if (ret)
1168 break;
1169 set_extent_dirty(copy, start, end, GFP_NOFS);
1170 last = end + 1;
1171 }
1172 return 0;
1173 }
1174
1175 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1176 struct btrfs_root *root,
1177 struct extent_io_tree *unpin)
1178 {
1179 u64 start;
1180 u64 end;
1181 int ret;
1182 struct extent_io_tree *free_space_cache;
1183 free_space_cache = &root->fs_info->free_space_cache;
1184
1185 while(1) {
1186 ret = find_first_extent_bit(unpin, 0, &start, &end,
1187 EXTENT_DIRTY);
1188 if (ret)
1189 break;
1190 update_pinned_extents(root, start, end + 1 - start, 0);
1191 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1192 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1193 }
1194 return 0;
1195 }
1196
1197 static int finish_current_insert(struct btrfs_trans_handle *trans,
1198 struct btrfs_root *extent_root)
1199 {
1200 u64 start;
1201 u64 end;
1202 struct btrfs_fs_info *info = extent_root->fs_info;
1203 struct extent_buffer *eb;
1204 struct btrfs_path *path;
1205 struct btrfs_key ins;
1206 struct btrfs_disk_key first;
1207 struct btrfs_extent_item extent_item;
1208 int ret;
1209 int level;
1210 int err = 0;
1211
1212 btrfs_set_stack_extent_refs(&extent_item, 1);
1213 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1214 path = btrfs_alloc_path();
1215
1216 while(1) {
1217 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1218 &end, EXTENT_LOCKED);
1219 if (ret)
1220 break;
1221
1222 ins.objectid = start;
1223 ins.offset = end + 1 - start;
1224 err = btrfs_insert_item(trans, extent_root, &ins,
1225 &extent_item, sizeof(extent_item));
1226 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1227 GFP_NOFS);
1228 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1229 level = btrfs_header_level(eb);
1230 if (level == 0) {
1231 btrfs_item_key(eb, &first, 0);
1232 } else {
1233 btrfs_node_key(eb, &first, 0);
1234 }
1235 err = btrfs_insert_extent_backref(trans, extent_root, path,
1236 start, extent_root->root_key.objectid,
1237 0, level,
1238 btrfs_disk_key_objectid(&first));
1239 BUG_ON(err);
1240 free_extent_buffer(eb);
1241 }
1242 btrfs_free_path(path);
1243 return 0;
1244 }
1245
1246 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1247 int pending)
1248 {
1249 int err = 0;
1250 struct extent_buffer *buf;
1251
1252 if (!pending) {
1253 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1254 if (buf) {
1255 if (btrfs_buffer_uptodate(buf)) {
1256 u64 transid =
1257 root->fs_info->running_transaction->transid;
1258 if (btrfs_header_generation(buf) ==
1259 transid && !btrfs_header_flag(buf,
1260 BTRFS_HEADER_FLAG_WRITTEN)) {
1261 free_extent_buffer(buf);
1262 return 1;
1263 }
1264 }
1265 free_extent_buffer(buf);
1266 }
1267 update_pinned_extents(root, bytenr, num_bytes, 1);
1268 } else {
1269 set_extent_bits(&root->fs_info->pending_del,
1270 bytenr, bytenr + num_bytes - 1,
1271 EXTENT_LOCKED, GFP_NOFS);
1272 }
1273 BUG_ON(err < 0);
1274 return 0;
1275 }
1276
1277 /*
1278 * remove an extent from the root, returns 0 on success
1279 */
1280 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1281 *root, u64 bytenr, u64 num_bytes,
1282 u64 root_objectid, u64 ref_generation,
1283 u64 owner_objectid, u64 owner_offset, int pin,
1284 int mark_free)
1285 {
1286 struct btrfs_path *path;
1287 struct btrfs_key key;
1288 struct btrfs_fs_info *info = root->fs_info;
1289 struct btrfs_extent_ops *ops = info->extent_ops;
1290 struct btrfs_root *extent_root = info->extent_root;
1291 struct extent_buffer *leaf;
1292 int ret;
1293 int extent_slot = 0;
1294 int found_extent = 0;
1295 int num_to_del = 1;
1296 struct btrfs_extent_item *ei;
1297 u32 refs;
1298
1299 key.objectid = bytenr;
1300 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1301 key.offset = num_bytes;
1302
1303 path = btrfs_alloc_path();
1304 if (!path)
1305 return -ENOMEM;
1306
1307 ret = lookup_extent_backref(trans, extent_root, path,
1308 bytenr, root_objectid,
1309 ref_generation,
1310 owner_objectid, owner_offset, 1);
1311 if (ret == 0) {
1312 struct btrfs_key found_key;
1313 extent_slot = path->slots[0];
1314 while(extent_slot > 0) {
1315 extent_slot--;
1316 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1317 extent_slot);
1318 if (found_key.objectid != bytenr)
1319 break;
1320 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1321 found_key.offset == num_bytes) {
1322 found_extent = 1;
1323 break;
1324 }
1325 if (path->slots[0] - extent_slot > 5)
1326 break;
1327 }
1328 if (!found_extent)
1329 ret = btrfs_del_item(trans, extent_root, path);
1330 } else {
1331 btrfs_print_leaf(extent_root, path->nodes[0]);
1332 WARN_ON(1);
1333 printk("Unable to find ref byte nr %llu root %llu "
1334 " gen %llu owner %llu offset %llu\n",
1335 (unsigned long long)bytenr,
1336 (unsigned long long)root_objectid,
1337 (unsigned long long)ref_generation,
1338 (unsigned long long)owner_objectid,
1339 (unsigned long long)owner_offset);
1340 }
1341 if (!found_extent) {
1342 btrfs_release_path(extent_root, path);
1343 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1344 if (ret < 0)
1345 return ret;
1346 BUG_ON(ret);
1347 extent_slot = path->slots[0];
1348 }
1349
1350 leaf = path->nodes[0];
1351 ei = btrfs_item_ptr(leaf, extent_slot,
1352 struct btrfs_extent_item);
1353 refs = btrfs_extent_refs(leaf, ei);
1354 BUG_ON(refs == 0);
1355 refs -= 1;
1356 btrfs_set_extent_refs(leaf, ei, refs);
1357
1358 btrfs_mark_buffer_dirty(leaf);
1359
1360 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1361 /* if the back ref and the extent are next to each other
1362 * they get deleted below in one shot
1363 */
1364 path->slots[0] = extent_slot;
1365 num_to_del = 2;
1366 } else if (found_extent) {
1367 /* otherwise delete the extent back ref */
1368 ret = btrfs_del_item(trans, extent_root, path);
1369 BUG_ON(ret);
1370 /* if refs are 0, we need to setup the path for deletion */
1371 if (refs == 0) {
1372 btrfs_release_path(extent_root, path);
1373 ret = btrfs_search_slot(trans, extent_root, &key, path,
1374 -1, 1);
1375 if (ret < 0)
1376 return ret;
1377 BUG_ON(ret);
1378 }
1379 }
1380
1381 if (refs == 0) {
1382 u64 super_used;
1383 u64 root_used;
1384
1385 if (pin) {
1386 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1387 if (ret > 0)
1388 mark_free = 1;
1389 BUG_ON(ret < 0);
1390 }
1391
1392 /* block accounting for super block */
1393 super_used = btrfs_super_bytes_used(&info->super_copy);
1394 btrfs_set_super_bytes_used(&info->super_copy,
1395 super_used - num_bytes);
1396
1397 /* block accounting for root item */
1398 root_used = btrfs_root_used(&root->root_item);
1399 btrfs_set_root_used(&root->root_item,
1400 root_used - num_bytes);
1401 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1402 num_to_del);
1403 if (ret)
1404 return ret;
1405
1406 if (ops && ops->free_extent)
1407 ops->free_extent(root, bytenr, num_bytes);
1408
1409 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1410 mark_free);
1411 BUG_ON(ret);
1412 }
1413 btrfs_free_path(path);
1414 finish_current_insert(trans, extent_root);
1415 return ret;
1416 }
1417
1418 /*
1419 * find all the blocks marked as pending in the radix tree and remove
1420 * them from the extent map
1421 */
1422 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1423 btrfs_root *extent_root)
1424 {
1425 int ret;
1426 int err = 0;
1427 u64 start;
1428 u64 end;
1429 struct extent_io_tree *pending_del;
1430 struct extent_io_tree *pinned_extents;
1431
1432 pending_del = &extent_root->fs_info->pending_del;
1433 pinned_extents = &extent_root->fs_info->pinned_extents;
1434
1435 while(1) {
1436 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1437 EXTENT_LOCKED);
1438 if (ret)
1439 break;
1440 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1441 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1442 GFP_NOFS);
1443 ret = __free_extent(trans, extent_root,
1444 start, end + 1 - start,
1445 extent_root->root_key.objectid,
1446 0, 0, 0, 0, 0);
1447 if (ret)
1448 err = ret;
1449 }
1450 return err;
1451 }
1452
1453 /*
1454 * remove an extent from the root, returns 0 on success
1455 */
1456 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1457 *root, u64 bytenr, u64 num_bytes,
1458 u64 root_objectid, u64 ref_generation,
1459 u64 owner_objectid, u64 owner_offset, int pin)
1460 {
1461 struct btrfs_root *extent_root = root->fs_info->extent_root;
1462 int pending_ret;
1463 int ret;
1464
1465 WARN_ON(num_bytes < root->sectorsize);
1466 if (!root->ref_cows)
1467 ref_generation = 0;
1468
1469 if (root == extent_root) {
1470 pin_down_bytes(root, bytenr, num_bytes, 1);
1471 return 0;
1472 }
1473 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1474 ref_generation, owner_objectid, owner_offset,
1475 pin, pin == 0);
1476 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1477 return ret ? ret : pending_ret;
1478 }
1479
1480 static u64 stripe_align(struct btrfs_root *root, u64 val)
1481 {
1482 u64 mask = ((u64)root->stripesize - 1);
1483 u64 ret = (val + mask) & ~mask;
1484 return ret;
1485 }
1486
1487 /*
1488 * walks the btree of allocated extents and find a hole of a given size.
1489 * The key ins is changed to record the hole:
1490 * ins->objectid == block start
1491 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1492 * ins->offset == number of blocks
1493 * Any available blocks before search_start are skipped.
1494 */
1495 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1496 struct btrfs_root *orig_root,
1497 u64 num_bytes, u64 empty_size,
1498 u64 search_start, u64 search_end,
1499 u64 hint_byte, struct btrfs_key *ins,
1500 u64 exclude_start, u64 exclude_nr,
1501 int data)
1502 {
1503 int ret;
1504 u64 orig_search_start = search_start;
1505 struct btrfs_root * root = orig_root->fs_info->extent_root;
1506 struct btrfs_fs_info *info = root->fs_info;
1507 u64 total_needed = num_bytes;
1508 struct btrfs_block_group_cache *block_group;
1509 int full_scan = 0;
1510 int wrapped = 0;
1511
1512 WARN_ON(num_bytes < root->sectorsize);
1513 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1514
1515 if (search_end == (u64)-1)
1516 search_end = btrfs_super_total_bytes(&info->super_copy);
1517
1518 if (hint_byte) {
1519 block_group = btrfs_lookup_block_group(info, hint_byte);
1520 if (!block_group)
1521 hint_byte = search_start;
1522 block_group = btrfs_find_block_group(root, block_group,
1523 hint_byte, data, 1);
1524 } else {
1525 block_group = btrfs_find_block_group(root,
1526 trans->block_group,
1527 search_start, data, 1);
1528 }
1529
1530 total_needed += empty_size;
1531
1532 check_failed:
1533 if (!block_group) {
1534 block_group = btrfs_lookup_block_group(info, search_start);
1535 if (!block_group)
1536 block_group = btrfs_lookup_block_group(info,
1537 orig_search_start);
1538 }
1539 ret = find_search_start(root, &block_group, &search_start,
1540 total_needed, data);
1541 if (ret)
1542 goto error;
1543
1544 search_start = stripe_align(root, search_start);
1545 ins->objectid = search_start;
1546 ins->offset = num_bytes;
1547
1548 if (ins->objectid + num_bytes >= search_end)
1549 goto enospc;
1550
1551 if (ins->objectid + num_bytes >
1552 block_group->key.objectid + block_group->key.offset) {
1553 search_start = block_group->key.objectid +
1554 block_group->key.offset;
1555 goto new_group;
1556 }
1557
1558 if (test_range_bit(&info->extent_ins, ins->objectid,
1559 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1560 search_start = ins->objectid + num_bytes;
1561 goto new_group;
1562 }
1563
1564 if (test_range_bit(&info->pinned_extents, ins->objectid,
1565 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1566 search_start = ins->objectid + num_bytes;
1567 goto new_group;
1568 }
1569
1570 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1571 ins->objectid < exclude_start + exclude_nr)) {
1572 search_start = exclude_start + exclude_nr;
1573 goto new_group;
1574 }
1575
1576 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
1577 block_group = btrfs_lookup_block_group(info, ins->objectid);
1578 if (block_group)
1579 trans->block_group = block_group;
1580 }
1581 ins->offset = num_bytes;
1582 return 0;
1583
1584 new_group:
1585 if (search_start + num_bytes >= search_end) {
1586 enospc:
1587 search_start = orig_search_start;
1588 if (full_scan) {
1589 ret = -ENOSPC;
1590 goto error;
1591 }
1592 if (wrapped) {
1593 if (!full_scan)
1594 total_needed -= empty_size;
1595 full_scan = 1;
1596 } else
1597 wrapped = 1;
1598 }
1599 block_group = btrfs_lookup_block_group(info, search_start);
1600 cond_resched();
1601 block_group = btrfs_find_block_group(root, block_group,
1602 search_start, data, 0);
1603 goto check_failed;
1604
1605 error:
1606 return ret;
1607 }
1608 /*
1609 * finds a free extent and does all the dirty work required for allocation
1610 * returns the key for the extent through ins, and a tree buffer for
1611 * the first block of the extent through buf.
1612 *
1613 * returns 0 if everything worked, non-zero otherwise.
1614 */
1615 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1616 struct btrfs_root *root,
1617 u64 num_bytes, u64 root_objectid, u64 ref_generation,
1618 u64 owner, u64 owner_offset,
1619 u64 empty_size, u64 hint_byte,
1620 u64 search_end, struct btrfs_key *ins, int data)
1621 {
1622 int ret;
1623 int pending_ret;
1624 u64 super_used, root_used;
1625 u64 search_start = 0;
1626 u64 alloc_profile;
1627 u32 sizes[2];
1628 struct btrfs_fs_info *info = root->fs_info;
1629 struct btrfs_root *extent_root = info->extent_root;
1630 struct btrfs_path *path;
1631 struct btrfs_extent_item *extent_item;
1632 struct btrfs_extent_ref *ref;
1633 struct btrfs_key keys[2];
1634
1635 if (info->extent_ops) {
1636 struct btrfs_extent_ops *ops = info->extent_ops;
1637 ret = ops->alloc_extent(root, num_bytes, hint_byte, ins);
1638 BUG_ON(ret);
1639 goto found;
1640 }
1641
1642 if (data) {
1643 alloc_profile = info->avail_data_alloc_bits &
1644 info->data_alloc_profile;
1645 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
1646 } else if ((info->system_allocs > 0 || root == info->chunk_root) &&
1647 info->system_allocs >= 0) {
1648 alloc_profile = info->avail_system_alloc_bits &
1649 info->system_alloc_profile;
1650 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
1651 } else {
1652 alloc_profile = info->avail_metadata_alloc_bits &
1653 info->metadata_alloc_profile;
1654 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
1655 }
1656
1657 if (root->ref_cows) {
1658 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
1659 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1660 num_bytes,
1661 BTRFS_BLOCK_GROUP_METADATA);
1662 BUG_ON(ret);
1663 }
1664 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1665 num_bytes + 2 * 1024 * 1024, data);
1666 BUG_ON(ret);
1667 }
1668
1669 WARN_ON(num_bytes < root->sectorsize);
1670 ret = find_free_extent(trans, root, num_bytes, empty_size,
1671 search_start, search_end, hint_byte, ins,
1672 trans->alloc_exclude_start,
1673 trans->alloc_exclude_nr, data);
1674 BUG_ON(ret);
1675 found:
1676 if (ret)
1677 return ret;
1678
1679 /* block accounting for super block */
1680 super_used = btrfs_super_bytes_used(&info->super_copy);
1681 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1682
1683 /* block accounting for root item */
1684 root_used = btrfs_root_used(&root->root_item);
1685 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1686
1687 clear_extent_dirty(&root->fs_info->free_space_cache,
1688 ins->objectid, ins->objectid + ins->offset - 1,
1689 GFP_NOFS);
1690
1691 if (root == extent_root) {
1692 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1693 ins->objectid + ins->offset - 1,
1694 EXTENT_LOCKED, GFP_NOFS);
1695 goto update_block;
1696 }
1697
1698 WARN_ON(trans->alloc_exclude_nr);
1699 trans->alloc_exclude_start = ins->objectid;
1700 trans->alloc_exclude_nr = ins->offset;
1701
1702 memcpy(&keys[0], ins, sizeof(*ins));
1703 keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
1704 owner, owner_offset);
1705 keys[1].objectid = ins->objectid;
1706 keys[1].type = BTRFS_EXTENT_REF_KEY;
1707 sizes[0] = sizeof(*extent_item);
1708 sizes[1] = sizeof(*ref);
1709
1710 path = btrfs_alloc_path();
1711 BUG_ON(!path);
1712
1713 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
1714 sizes, 2);
1715
1716 BUG_ON(ret);
1717 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1718 struct btrfs_extent_item);
1719 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
1720 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1721 struct btrfs_extent_ref);
1722
1723 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
1724 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
1725 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
1726 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
1727
1728 btrfs_mark_buffer_dirty(path->nodes[0]);
1729
1730 trans->alloc_exclude_start = 0;
1731 trans->alloc_exclude_nr = 0;
1732 btrfs_free_path(path);
1733 finish_current_insert(trans, extent_root);
1734 pending_ret = del_pending_extents(trans, extent_root);
1735
1736 if (ret) {
1737 return ret;
1738 }
1739 if (pending_ret) {
1740 return pending_ret;
1741 }
1742
1743 update_block:
1744 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
1745 if (ret) {
1746 printk("update block group failed for %llu %llu\n",
1747 (unsigned long long)ins->objectid,
1748 (unsigned long long)ins->offset);
1749 BUG();
1750 }
1751 return 0;
1752 }
1753
1754 /*
1755 * helper function to allocate a block for a given tree
1756 * returns the tree buffer or NULL.
1757 */
1758 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1759 struct btrfs_root *root,
1760 u32 blocksize,
1761 u64 root_objectid, u64 hint,
1762 u64 empty_size)
1763 {
1764 u64 ref_generation;
1765
1766 if (root->ref_cows)
1767 ref_generation = trans->transid;
1768 else
1769 ref_generation = 0;
1770
1771
1772 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1773 ref_generation, 0, 0, hint, empty_size);
1774 }
1775
1776 /*
1777 * helper function to allocate a block for a given tree
1778 * returns the tree buffer or NULL.
1779 */
1780 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1781 struct btrfs_root *root,
1782 u32 blocksize,
1783 u64 root_objectid,
1784 u64 ref_generation,
1785 u64 first_objectid,
1786 int level,
1787 u64 hint,
1788 u64 empty_size)
1789 {
1790 struct btrfs_key ins;
1791 int ret;
1792 struct extent_buffer *buf;
1793
1794 ret = btrfs_alloc_extent(trans, root, blocksize,
1795 root_objectid, ref_generation,
1796 level, first_objectid, empty_size, hint,
1797 (u64)-1, &ins, 0);
1798 if (ret) {
1799 BUG_ON(ret > 0);
1800 return ERR_PTR(ret);
1801 }
1802 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1803 if (!buf) {
1804 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1805 root->root_key.objectid, ref_generation,
1806 0, 0, 0);
1807 BUG_ON(1);
1808 return ERR_PTR(-ENOMEM);
1809 }
1810 btrfs_set_buffer_uptodate(buf);
1811 trans->blocks_used++;
1812 return buf;
1813 }
1814
1815 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
1816 struct btrfs_root *root,
1817 struct extent_buffer *leaf)
1818 {
1819 u64 leaf_owner;
1820 u64 leaf_generation;
1821 struct btrfs_key key;
1822 struct btrfs_file_extent_item *fi;
1823 int i;
1824 int nritems;
1825 int ret;
1826
1827 BUG_ON(!btrfs_is_leaf(leaf));
1828 nritems = btrfs_header_nritems(leaf);
1829 leaf_owner = btrfs_header_owner(leaf);
1830 leaf_generation = btrfs_header_generation(leaf);
1831
1832 for (i = 0; i < nritems; i++) {
1833 u64 disk_bytenr;
1834
1835 btrfs_item_key_to_cpu(leaf, &key, i);
1836 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1837 continue;
1838 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1839 if (btrfs_file_extent_type(leaf, fi) ==
1840 BTRFS_FILE_EXTENT_INLINE)
1841 continue;
1842 /*
1843 * FIXME make sure to insert a trans record that
1844 * repeats the snapshot del on crash
1845 */
1846 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1847 if (disk_bytenr == 0)
1848 continue;
1849 ret = btrfs_free_extent(trans, root, disk_bytenr,
1850 btrfs_file_extent_disk_num_bytes(leaf, fi),
1851 leaf_owner, leaf_generation,
1852 key.objectid, key.offset, 0);
1853 BUG_ON(ret);
1854 }
1855 return 0;
1856 }
1857
1858 static void noinline reada_walk_down(struct btrfs_root *root,
1859 struct extent_buffer *node,
1860 int slot)
1861 {
1862 u64 bytenr;
1863 u64 last = 0;
1864 u32 nritems;
1865 u32 refs;
1866 u32 blocksize;
1867 int ret;
1868 int i;
1869 int level;
1870 int skipped = 0;
1871
1872 nritems = btrfs_header_nritems(node);
1873 level = btrfs_header_level(node);
1874 if (level)
1875 return;
1876
1877 for (i = slot; i < nritems && skipped < 32; i++) {
1878 bytenr = btrfs_node_blockptr(node, i);
1879 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
1880 (last > bytenr && last - bytenr > 32 * 1024))) {
1881 skipped++;
1882 continue;
1883 }
1884 blocksize = btrfs_level_size(root, level - 1);
1885 if (i != slot) {
1886 ret = lookup_extent_ref(NULL, root, bytenr,
1887 blocksize, &refs);
1888 BUG_ON(ret);
1889 if (refs != 1) {
1890 skipped++;
1891 continue;
1892 }
1893 }
1894 mutex_unlock(&root->fs_info->fs_mutex);
1895 ret = readahead_tree_block(root, bytenr, blocksize);
1896 last = bytenr + blocksize;
1897 cond_resched();
1898 mutex_lock(&root->fs_info->fs_mutex);
1899 if (ret)
1900 break;
1901 }
1902 }
1903
1904 /*
1905 * helper function for drop_snapshot, this walks down the tree dropping ref
1906 * counts as it goes.
1907 */
1908 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
1909 struct btrfs_root *root,
1910 struct btrfs_path *path, int *level)
1911 {
1912 u64 root_owner;
1913 u64 root_gen;
1914 u64 bytenr;
1915 struct extent_buffer *next;
1916 struct extent_buffer *cur;
1917 struct extent_buffer *parent;
1918 u32 blocksize;
1919 int ret;
1920 u32 refs;
1921
1922 WARN_ON(*level < 0);
1923 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1924 ret = lookup_extent_ref(trans, root,
1925 path->nodes[*level]->start,
1926 path->nodes[*level]->len, &refs);
1927 BUG_ON(ret);
1928 if (refs > 1)
1929 goto out;
1930
1931 /*
1932 * walk down to the last node level and free all the leaves
1933 */
1934 while(*level >= 0) {
1935 WARN_ON(*level < 0);
1936 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1937 cur = path->nodes[*level];
1938
1939 if (btrfs_header_level(cur) != *level)
1940 WARN_ON(1);
1941
1942 if (path->slots[*level] >=
1943 btrfs_header_nritems(cur))
1944 break;
1945 if (*level == 0) {
1946 ret = drop_leaf_ref(trans, root, cur);
1947 BUG_ON(ret);
1948 break;
1949 }
1950 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1951 blocksize = btrfs_level_size(root, *level - 1);
1952 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
1953 BUG_ON(ret);
1954 if (refs != 1) {
1955 parent = path->nodes[*level];
1956 root_owner = btrfs_header_owner(parent);
1957 root_gen = btrfs_header_generation(parent);
1958 path->slots[*level]++;
1959 ret = btrfs_free_extent(trans, root, bytenr,
1960 blocksize, root_owner,
1961 root_gen, 0, 0, 1);
1962 BUG_ON(ret);
1963 continue;
1964 }
1965 next = btrfs_find_tree_block(root, bytenr, blocksize);
1966 if (!next || !btrfs_buffer_uptodate(next)) {
1967 free_extent_buffer(next);
1968 reada_walk_down(root, cur, path->slots[*level]);
1969 mutex_unlock(&root->fs_info->fs_mutex);
1970 next = read_tree_block(root, bytenr, blocksize);
1971 mutex_lock(&root->fs_info->fs_mutex);
1972
1973 /* we dropped the lock, check one more time */
1974 ret = lookup_extent_ref(trans, root, bytenr,
1975 blocksize, &refs);
1976 BUG_ON(ret);
1977 if (refs != 1) {
1978 parent = path->nodes[*level];
1979 root_owner = btrfs_header_owner(parent);
1980 root_gen = btrfs_header_generation(parent);
1981
1982 path->slots[*level]++;
1983 free_extent_buffer(next);
1984 ret = btrfs_free_extent(trans, root, bytenr,
1985 blocksize,
1986 root_owner,
1987 root_gen, 0, 0, 1);
1988 BUG_ON(ret);
1989 continue;
1990 }
1991 }
1992 WARN_ON(*level <= 0);
1993 if (path->nodes[*level-1])
1994 free_extent_buffer(path->nodes[*level-1]);
1995 path->nodes[*level-1] = next;
1996 *level = btrfs_header_level(next);
1997 path->slots[*level] = 0;
1998 }
1999 out:
2000 WARN_ON(*level < 0);
2001 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2002
2003 if (path->nodes[*level] == root->node) {
2004 root_owner = root->root_key.objectid;
2005 parent = path->nodes[*level];
2006 } else {
2007 parent = path->nodes[*level + 1];
2008 root_owner = btrfs_header_owner(parent);
2009 }
2010
2011 root_gen = btrfs_header_generation(parent);
2012 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
2013 path->nodes[*level]->len,
2014 root_owner, root_gen, 0, 0, 1);
2015 free_extent_buffer(path->nodes[*level]);
2016 path->nodes[*level] = NULL;
2017 *level += 1;
2018 BUG_ON(ret);
2019 return 0;
2020 }
2021
2022 /*
2023 * helper for dropping snapshots. This walks back up the tree in the path
2024 * to find the first node higher up where we haven't yet gone through
2025 * all the slots
2026 */
2027 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
2028 struct btrfs_root *root,
2029 struct btrfs_path *path, int *level)
2030 {
2031 u64 root_owner;
2032 u64 root_gen;
2033 struct btrfs_root_item *root_item = &root->root_item;
2034 int i;
2035 int slot;
2036 int ret;
2037
2038 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2039 slot = path->slots[i];
2040 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
2041 struct extent_buffer *node;
2042 struct btrfs_disk_key disk_key;
2043 node = path->nodes[i];
2044 path->slots[i]++;
2045 *level = i;
2046 WARN_ON(*level == 0);
2047 btrfs_node_key(node, &disk_key, path->slots[i]);
2048 memcpy(&root_item->drop_progress,
2049 &disk_key, sizeof(disk_key));
2050 root_item->drop_level = i;
2051 return 0;
2052 } else {
2053 if (path->nodes[*level] == root->node) {
2054 root_owner = root->root_key.objectid;
2055 root_gen =
2056 btrfs_header_generation(path->nodes[*level]);
2057 } else {
2058 struct extent_buffer *node;
2059 node = path->nodes[*level + 1];
2060 root_owner = btrfs_header_owner(node);
2061 root_gen = btrfs_header_generation(node);
2062 }
2063 ret = btrfs_free_extent(trans, root,
2064 path->nodes[*level]->start,
2065 path->nodes[*level]->len,
2066 root_owner, root_gen, 0, 0, 1);
2067 BUG_ON(ret);
2068 free_extent_buffer(path->nodes[*level]);
2069 path->nodes[*level] = NULL;
2070 *level = i + 1;
2071 }
2072 }
2073 return 1;
2074 }
2075
2076 /*
2077 * drop the reference count on the tree rooted at 'snap'. This traverses
2078 * the tree freeing any blocks that have a ref count of zero after being
2079 * decremented.
2080 */
2081 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2082 *root)
2083 {
2084 int ret = 0;
2085 int wret;
2086 int level;
2087 struct btrfs_path *path;
2088 int i;
2089 int orig_level;
2090 struct btrfs_root_item *root_item = &root->root_item;
2091
2092 path = btrfs_alloc_path();
2093 BUG_ON(!path);
2094
2095 level = btrfs_header_level(root->node);
2096 orig_level = level;
2097 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2098 path->nodes[level] = root->node;
2099 extent_buffer_get(root->node);
2100 path->slots[level] = 0;
2101 } else {
2102 struct btrfs_key key;
2103 struct btrfs_disk_key found_key;
2104 struct extent_buffer *node;
2105
2106 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2107 level = root_item->drop_level;
2108 path->lowest_level = level;
2109 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2110 if (wret < 0) {
2111 ret = wret;
2112 goto out;
2113 }
2114 node = path->nodes[level];
2115 btrfs_node_key(node, &found_key, path->slots[level]);
2116 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2117 sizeof(found_key)));
2118 }
2119 while(1) {
2120 wret = walk_down_tree(trans, root, path, &level);
2121 if (wret < 0)
2122 ret = wret;
2123 if (wret != 0)
2124 break;
2125
2126 wret = walk_up_tree(trans, root, path, &level);
2127 if (wret < 0)
2128 ret = wret;
2129 if (wret != 0)
2130 break;
2131 /*
2132 ret = -EAGAIN;
2133 break;
2134 */
2135 }
2136 for (i = 0; i <= orig_level; i++) {
2137 if (path->nodes[i]) {
2138 free_extent_buffer(path->nodes[i]);
2139 path->nodes[i] = NULL;
2140 }
2141 }
2142 out:
2143 btrfs_free_path(path);
2144 return ret;
2145 }
2146
2147 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2148 {
2149 u64 start;
2150 u64 end;
2151 u64 ptr;
2152 int ret;
2153 while(1) {
2154 ret = find_first_extent_bit(&info->block_group_cache, 0,
2155 &start, &end, (unsigned int)-1);
2156 if (ret)
2157 break;
2158 ret = get_state_private(&info->block_group_cache, start, &ptr);
2159 if (!ret)
2160 kfree((void *)(unsigned long)ptr);
2161 clear_extent_bits(&info->block_group_cache, start,
2162 end, (unsigned int)-1, GFP_NOFS);
2163 }
2164 while(1) {
2165 ret = find_first_extent_bit(&info->free_space_cache, 0,
2166 &start, &end, EXTENT_DIRTY);
2167 if (ret)
2168 break;
2169 clear_extent_dirty(&info->free_space_cache, start,
2170 end, GFP_NOFS);
2171 }
2172 return 0;
2173 }
2174
2175 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
2176 struct btrfs_key *key)
2177 {
2178 int ret;
2179 struct btrfs_key found_key;
2180 struct extent_buffer *leaf;
2181 int slot;
2182
2183 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
2184 if (ret < 0)
2185 return ret;
2186 while(1) {
2187 slot = path->slots[0];
2188 leaf = path->nodes[0];
2189 if (slot >= btrfs_header_nritems(leaf)) {
2190 ret = btrfs_next_leaf(root, path);
2191 if (ret == 0)
2192 continue;
2193 if (ret < 0)
2194 goto error;
2195 break;
2196 }
2197 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2198
2199 if (found_key.objectid >= key->objectid &&
2200 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
2201 return 0;
2202 path->slots[0]++;
2203 }
2204 ret = -ENOENT;
2205 error:
2206 return ret;
2207 }
2208
2209 int btrfs_read_block_groups(struct btrfs_root *root)
2210 {
2211 struct btrfs_path *path;
2212 int ret;
2213 int bit;
2214 struct btrfs_block_group_cache *cache;
2215 struct btrfs_fs_info *info = root->fs_info;
2216 struct btrfs_space_info *space_info;
2217 struct extent_io_tree *block_group_cache;
2218 struct btrfs_key key;
2219 struct btrfs_key found_key;
2220 struct extent_buffer *leaf;
2221
2222 block_group_cache = &info->block_group_cache;
2223
2224 root = info->extent_root;
2225 key.objectid = 0;
2226 key.offset = 0;
2227 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2228 path = btrfs_alloc_path();
2229 if (!path)
2230 return -ENOMEM;
2231
2232 while(1) {
2233 ret = find_first_block_group(root, path, &key);
2234 if (ret > 0) {
2235 ret = 0;
2236 goto error;
2237 }
2238 if (ret != 0) {
2239 goto error;
2240 }
2241 leaf = path->nodes[0];
2242 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2243 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2244 if (!cache) {
2245 ret = -ENOMEM;
2246 break;
2247 }
2248
2249 read_extent_buffer(leaf, &cache->item,
2250 btrfs_item_ptr_offset(leaf, path->slots[0]),
2251 sizeof(cache->item));
2252 memcpy(&cache->key, &found_key, sizeof(found_key));
2253 cache->cached = 0;
2254 cache->pinned = 0;
2255 key.objectid = found_key.objectid + found_key.offset;
2256 btrfs_release_path(root, path);
2257 cache->flags = btrfs_block_group_flags(&cache->item);
2258 bit = 0;
2259 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
2260 bit = BLOCK_GROUP_DATA;
2261 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
2262 bit = BLOCK_GROUP_SYSTEM;
2263 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
2264 bit = BLOCK_GROUP_METADATA;
2265 }
2266 set_avail_alloc_bits(info, cache->flags);
2267
2268 ret = update_space_info(info, cache->flags, found_key.offset,
2269 btrfs_block_group_used(&cache->item),
2270 &space_info);
2271 BUG_ON(ret);
2272 cache->space_info = space_info;
2273
2274 /* use EXTENT_LOCKED to prevent merging */
2275 set_extent_bits(block_group_cache, found_key.objectid,
2276 found_key.objectid + found_key.offset - 1,
2277 bit | EXTENT_LOCKED, GFP_NOFS);
2278 set_state_private(block_group_cache, found_key.objectid,
2279 (unsigned long)cache);
2280
2281 if (key.objectid >=
2282 btrfs_super_total_bytes(&info->super_copy))
2283 break;
2284 }
2285 ret = 0;
2286 error:
2287 btrfs_free_path(path);
2288 return ret;
2289 }
2290
2291 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
2292 struct btrfs_root *root, u64 bytes_used,
2293 u64 type, u64 chunk_objectid, u64 chunk_offset,
2294 u64 size)
2295 {
2296 int ret;
2297 int bit = 0;
2298 struct btrfs_root *extent_root;
2299 struct btrfs_block_group_cache *cache;
2300 struct extent_io_tree *block_group_cache;
2301
2302 extent_root = root->fs_info->extent_root;
2303 block_group_cache = &root->fs_info->block_group_cache;
2304
2305 cache = kzalloc(sizeof(*cache), GFP_NOFS);
2306 BUG_ON(!cache);
2307 cache->key.objectid = chunk_offset;
2308 cache->key.offset = size;
2309
2310 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2311 btrfs_set_block_group_used(&cache->item, bytes_used);
2312 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
2313 cache->flags = type;
2314 btrfs_set_block_group_flags(&cache->item, type);
2315
2316 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
2317 &cache->space_info);
2318 BUG_ON(ret);
2319
2320 bit = block_group_state_bits(type);
2321 set_extent_bits(block_group_cache, chunk_offset,
2322 chunk_offset + size - 1,
2323 bit | EXTENT_LOCKED, GFP_NOFS);
2324
2325 set_state_private(block_group_cache, chunk_offset,
2326 (unsigned long)cache);
2327 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
2328 sizeof(cache->item));
2329 BUG_ON(ret);
2330
2331 finish_current_insert(trans, extent_root);
2332 ret = del_pending_extents(trans, extent_root);
2333 BUG_ON(ret);
2334 set_avail_alloc_bits(extent_root->fs_info, type);
2335 return 0;
2336 }
2337
2338 /*
2339 * This is for converter use only.
2340 *
2341 * In that case, we don't know where are free blocks located.
2342 * Therefore all block group cache entries must be setup properly
2343 * before doing any block allocation.
2344 */
2345 int btrfs_make_block_groups(struct btrfs_trans_handle *trans,
2346 struct btrfs_root *root)
2347 {
2348 u64 total_bytes;
2349 u64 cur_start;
2350 u64 group_type;
2351 u64 group_size;
2352 u64 group_align;
2353 u64 total_data = 0;
2354 u64 total_metadata = 0;
2355 u64 chunk_objectid;
2356 int ret;
2357 int bit;
2358 struct btrfs_root *extent_root;
2359 struct btrfs_block_group_cache *cache;
2360 struct extent_io_tree *block_group_cache;
2361
2362 extent_root = root->fs_info->extent_root;
2363 block_group_cache = &root->fs_info->block_group_cache;
2364 chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2365 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
2366 group_align = 64 * root->sectorsize;
2367
2368 cur_start = 0;
2369 while (cur_start < total_bytes) {
2370 group_size = total_bytes / 12;
2371 group_size = min_t(u64, group_size, total_bytes - cur_start);
2372 if (cur_start == 0) {
2373 bit = BLOCK_GROUP_SYSTEM;
2374 group_type = BTRFS_BLOCK_GROUP_SYSTEM;
2375 group_size /= 4;
2376 group_size &= ~(group_align - 1);
2377 group_size = max_t(u64, group_size, 32 * 1024 * 1024);
2378 group_size = min_t(u64, group_size, 128 * 1024 * 1024);
2379 } else {
2380 group_size &= ~(group_align - 1);
2381 if (total_data >= total_metadata * 2) {
2382 group_type = BTRFS_BLOCK_GROUP_METADATA;
2383 group_size = min_t(u64, group_size,
2384 1ULL * 1024 * 1024 * 1024);
2385 total_metadata += group_size;
2386 } else {
2387 group_type = BTRFS_BLOCK_GROUP_DATA;
2388 group_size = min_t(u64, group_size,
2389 5ULL * 1024 * 1024 * 1024);
2390 total_data += group_size;
2391 }
2392 if ((total_bytes - cur_start) * 4 < group_size * 5)
2393 group_size = total_bytes - cur_start;
2394 }
2395
2396 cache = kzalloc(sizeof(*cache), GFP_NOFS);
2397 BUG_ON(!cache);
2398
2399 cache->key.objectid = cur_start;
2400 cache->key.offset = group_size;
2401 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2402
2403 btrfs_set_block_group_used(&cache->item, 0);
2404 btrfs_set_block_group_chunk_objectid(&cache->item,
2405 chunk_objectid);
2406 btrfs_set_block_group_flags(&cache->item, group_type);
2407
2408 cache->flags = group_type;
2409
2410 ret = update_space_info(root->fs_info, group_type, group_size,
2411 0, &cache->space_info);
2412 BUG_ON(ret);
2413 set_avail_alloc_bits(extent_root->fs_info, group_type);
2414
2415 set_extent_bits(block_group_cache, cur_start,
2416 cur_start + group_size - 1,
2417 bit | EXTENT_LOCKED, GFP_NOFS);
2418 set_state_private(block_group_cache, cur_start,
2419 (unsigned long)cache);
2420 cur_start += group_size;
2421 }
2422 /* then insert all the items */
2423 cur_start = 0;
2424 while(cur_start < total_bytes) {
2425 cache = btrfs_lookup_block_group(root->fs_info, cur_start);
2426 BUG_ON(!cache);
2427
2428 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
2429 sizeof(cache->item));
2430 BUG_ON(ret);
2431
2432 finish_current_insert(trans, extent_root);
2433 ret = del_pending_extents(trans, extent_root);
2434 BUG_ON(ret);
2435
2436 cur_start = cache->key.objectid + cache->key.offset;
2437 }
2438 return 0;
2439 }
2440
2441 u64 btrfs_hash_extent_ref(u64 root_objectid, u64 ref_generation,
2442 u64 owner, u64 owner_offset)
2443 {
2444 return hash_extent_ref(root_objectid, ref_generation,
2445 owner, owner_offset);
2446 }
2447
2448 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
2449 struct btrfs_root *root,
2450 u64 bytenr, u64 num_bytes, int alloc,
2451 int mark_free)
2452 {
2453 return update_block_group(trans, root, bytenr, num_bytes,
2454 alloc, mark_free);
2455 }
(deprecated) Btrfs progs developments and patch integration