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ioctls to scan for btrfs filesystems
[btrfs-progs-unstable/devel.git] / extent-tree.c
blobec1a37ad3f8f793cf2d029e30fb5ca5cb7a00066
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 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
41 struct btrfs_root *root, u64 bytes_used,
42 u64 type, u64 chunk_tree, u64 chunk_objectid,
43 u64 size);
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);
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 u64 last;
185 u64 start = 0;
186 u64 end = 0;
187 u64 cache_miss = 0;
188 u64 search_start = *start_ret;
189 int wrapped = 0;
190
191 if (!cache) {
192 goto out;
193 }
194 again:
195 ret = cache_block_group(root, cache);
196 if (ret)
197 goto out;
198
199 last = max(search_start, cache->key.objectid);
200 if (!block_group_bits(cache, data)) {
201 goto new_group;
202 }
203
204 while(1) {
205 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
206 last, &start, &end, EXTENT_DIRTY);
207 if (ret) {
208 if (!cache_miss)
209 cache_miss = last;
210 goto new_group;
211 }
212
213 start = max(last, start);
214 last = end + 1;
215 if (last - start < num) {
216 if (last == cache->key.objectid + cache->key.offset)
217 cache_miss = start;
218 continue;
219 }
220 if (start + num > cache->key.objectid + cache->key.offset)
221 goto new_group;
222 *start_ret = start;
223 return 0;
224 }
225 out:
226 cache = btrfs_lookup_block_group(root->fs_info, search_start);
227 if (!cache) {
228 printk("Unable to find block group for %Lu\n", search_start);
229 WARN_ON(1);
230 }
231 return -ENOSPC;
232
233 new_group:
234 last = cache->key.objectid + cache->key.offset;
235 wrapped:
236 cache = btrfs_lookup_block_group(root->fs_info, last);
237 if (!cache) {
238 no_cache:
239 if (!wrapped) {
240 wrapped = 1;
241 last = search_start;
242 goto wrapped;
243 }
244 goto out;
245 }
246 if (cache_miss && !cache->cached) {
247 cache_block_group(root, cache);
248 last = cache_miss;
249 cache = btrfs_lookup_block_group(root->fs_info, last);
250 }
251 cache = btrfs_find_block_group(root, cache, last, data, 0);
252 if (!cache)
253 goto no_cache;
254 *cache_ret = cache;
255 cache_miss = 0;
256 goto again;
257 }
258
259 static u64 div_factor(u64 num, int factor)
260 {
261 if (factor == 10)
262 return num;
263 num *= factor;
264 num /= 10;
265 return num;
266 }
267
268 static int block_group_state_bits(u64 flags)
269 {
270 int bits = 0;
271 if (flags & BTRFS_BLOCK_GROUP_DATA)
272 bits |= BLOCK_GROUP_DATA;
273 if (flags & BTRFS_BLOCK_GROUP_METADATA)
274 bits |= BLOCK_GROUP_METADATA;
275 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
276 bits |= BLOCK_GROUP_SYSTEM;
277 return bits;
278 }
279
280 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
281 struct btrfs_block_group_cache
282 *hint, u64 search_start,
283 int data, int owner)
284 {
285 struct btrfs_block_group_cache *cache;
286 struct extent_io_tree *block_group_cache;
287 struct btrfs_block_group_cache *found_group = NULL;
288 struct btrfs_fs_info *info = root->fs_info;
289 u64 used;
290 u64 last = 0;
291 u64 hint_last;
292 u64 start;
293 u64 end;
294 u64 free_check;
295 u64 ptr;
296 int bit;
297 int ret;
298 int full_search = 0;
299 int factor = 8;
300
301 block_group_cache = &info->block_group_cache;
302
303 if (!owner)
304 factor = 8;
305
306 bit = block_group_state_bits(data);
307
308 if (search_start) {
309 struct btrfs_block_group_cache *shint;
310 shint = btrfs_lookup_block_group(info, search_start);
311 if (shint && block_group_bits(shint, data)) {
312 used = btrfs_block_group_used(&shint->item);
313 if (used + shint->pinned <
314 div_factor(shint->key.offset, factor)) {
315 return shint;
316 }
317 }
318 }
319 if (hint && block_group_bits(hint, data)) {
320 used = btrfs_block_group_used(&hint->item);
321 if (used + hint->pinned <
322 div_factor(hint->key.offset, factor)) {
323 return hint;
324 }
325 last = hint->key.objectid + hint->key.offset;
326 hint_last = last;
327 } else {
328 if (hint)
329 hint_last = max(hint->key.objectid, search_start);
330 else
331 hint_last = search_start;
332
333 last = hint_last;
334 }
335 again:
336 while(1) {
337 ret = find_first_extent_bit(block_group_cache, last,
338 &start, &end, bit);
339 if (ret)
340 break;
341
342 ret = get_state_private(block_group_cache, start, &ptr);
343 if (ret)
344 break;
345
346 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
347 last = cache->key.objectid + cache->key.offset;
348 used = btrfs_block_group_used(&cache->item);
349
350 if (full_search)
351 free_check = cache->key.offset;
352 else
353 free_check = div_factor(cache->key.offset, factor);
354
355 if (used + cache->pinned < free_check) {
356 found_group = cache;
357 goto found;
358 }
359 if (full_search) {
360 printk("failed on cache %Lu used %Lu total %Lu\n",
361 cache->key.objectid, used, cache->key.offset);
362 }
363 cond_resched();
364 }
365 if (!full_search) {
366 last = search_start;
367 full_search = 1;
368 goto again;
369 }
370 found:
371 return found_group;
372 }
373
374 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
375 u64 owner, u64 owner_offset)
376 {
377 u32 high_crc = ~(u32)0;
378 u32 low_crc = ~(u32)0;
379 __le64 lenum;
380
381 lenum = cpu_to_le64(root_objectid);
382 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
383 lenum = cpu_to_le64(ref_generation);
384 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
385 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
386 lenum = cpu_to_le64(owner);
387 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
388 lenum = cpu_to_le64(owner_offset);
389 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
390 }
391 return ((u64)high_crc << 32) | (u64)low_crc;
392 }
393
394 static int match_extent_ref(struct extent_buffer *leaf,
395 struct btrfs_extent_ref *disk_ref,
396 struct btrfs_extent_ref *cpu_ref)
397 {
398 int ret;
399 int len;
400
401 if (cpu_ref->objectid)
402 len = sizeof(*cpu_ref);
403 else
404 len = 2 * sizeof(u64);
405 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
406 len);
407 return ret == 0;
408 }
409
410 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
411 struct btrfs_root *root,
412 struct btrfs_path *path, u64 bytenr,
413 u64 root_objectid,
414 u64 ref_generation, u64 owner,
415 u64 owner_offset, int del)
416 {
417 u64 hash;
418 struct btrfs_key key;
419 struct btrfs_key found_key;
420 struct btrfs_extent_ref ref;
421 struct extent_buffer *leaf;
422 struct btrfs_extent_ref *disk_ref;
423 int ret;
424 int ret2;
425
426 btrfs_set_stack_ref_root(&ref, root_objectid);
427 btrfs_set_stack_ref_generation(&ref, ref_generation);
428 btrfs_set_stack_ref_objectid(&ref, owner);
429 btrfs_set_stack_ref_offset(&ref, owner_offset);
430
431 hash = hash_extent_ref(root_objectid, ref_generation, owner,
432 owner_offset);
433 key.offset = hash;
434 key.objectid = bytenr;
435 key.type = BTRFS_EXTENT_REF_KEY;
436
437 while (1) {
438 ret = btrfs_search_slot(trans, root, &key, path,
439 del ? -1 : 0, del);
440 if (ret < 0)
441 goto out;
442 leaf = path->nodes[0];
443 if (ret != 0) {
444 u32 nritems = btrfs_header_nritems(leaf);
445 if (path->slots[0] >= nritems) {
446 ret2 = btrfs_next_leaf(root, path);
447 if (ret2)
448 goto out;
449 leaf = path->nodes[0];
450 }
451 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
452 if (found_key.objectid != bytenr ||
453 found_key.type != BTRFS_EXTENT_REF_KEY)
454 goto out;
455 key.offset = found_key.offset;
456 if (del) {
457 btrfs_release_path(root, path);
458 continue;
459 }
460 }
461 disk_ref = btrfs_item_ptr(path->nodes[0],
462 path->slots[0],
463 struct btrfs_extent_ref);
464 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
465 ret = 0;
466 goto out;
467 }
468 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
469 key.offset = found_key.offset + 1;
470 btrfs_release_path(root, path);
471 }
472 out:
473 return ret;
474 }
475
476 /*
477 * Back reference rules. Back refs have three main goals:
478 *
479 * 1) differentiate between all holders of references to an extent so that
480 * when a reference is dropped we can make sure it was a valid reference
481 * before freeing the extent.
482 *
483 * 2) Provide enough information to quickly find the holders of an extent
484 * if we notice a given block is corrupted or bad.
485 *
486 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
487 * maintenance. This is actually the same as #2, but with a slightly
488 * different use case.
489 *
490 * File extents can be referenced by:
491 *
492 * - multiple snapshots, subvolumes, or different generations in one subvol
493 * - different files inside a single subvolume (in theory, not implemented yet)
494 * - different offsets inside a file (bookend extents in file.c)
495 *
496 * The extent ref structure has fields for:
497 *
498 * - Objectid of the subvolume root
499 * - Generation number of the tree holding the reference
500 * - objectid of the file holding the reference
501 * - offset in the file corresponding to the key holding the reference
502 *
503 * When a file extent is allocated the fields are filled in:
504 * (root_key.objectid, trans->transid, inode objectid, offset in file)
505 *
506 * When a leaf is cow'd new references are added for every file extent found
507 * in the leaf. It looks the same as the create case, but trans->transid
508 * will be different when the block is cow'd.
509 *
510 * (root_key.objectid, trans->transid, inode objectid, offset in file)
511 *
512 * When a file extent is removed either during snapshot deletion or file
513 * truncation, the corresponding back reference is found
514 * by searching for:
515 *
516 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
517 * inode objectid, offset in file)
518 *
519 * Btree extents can be referenced by:
520 *
521 * - Different subvolumes
522 * - Different generations of the same subvolume
523 *
524 * Storing sufficient information for a full reverse mapping of a btree
525 * block would require storing the lowest key of the block in the backref,
526 * and it would require updating that lowest key either before write out or
527 * every time it changed. Instead, the objectid of the lowest key is stored
528 * along with the level of the tree block. This provides a hint
529 * about where in the btree the block can be found. Searches through the
530 * btree only need to look for a pointer to that block, so they stop one
531 * level higher than the level recorded in the backref.
532 *
533 * Some btrees do not do reference counting on their extents. These
534 * include the extent tree and the tree of tree roots. Backrefs for these
535 * trees always have a generation of zero.
536 *
537 * When a tree block is created, back references are inserted:
538 *
539 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
540 *
541 * When a tree block is cow'd in a reference counted root,
542 * new back references are added for all the blocks it points to.
543 * These are of the form (trans->transid will have increased since creation):
544 *
545 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
546 *
547 * Because the lowest_key_objectid and the level are just hints
548 * they are not used when backrefs are deleted. When a backref is deleted:
549 *
550 * if backref was for a tree root:
551 * root_objectid = root->root_key.objectid
552 * else
553 * root_objectid = btrfs_header_owner(parent)
554 *
555 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
556 *
557 * Back Reference Key hashing:
558 *
559 * Back references have four fields, each 64 bits long. Unfortunately,
560 * This is hashed into a single 64 bit number and placed into the key offset.
561 * The key objectid corresponds to the first byte in the extent, and the
562 * key type is set to BTRFS_EXTENT_REF_KEY
563 */
564 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
565 struct btrfs_root *root,
566 struct btrfs_path *path, u64 bytenr,
567 u64 root_objectid, u64 ref_generation,
568 u64 owner, u64 owner_offset)
569 {
570 u64 hash;
571 struct btrfs_key key;
572 struct btrfs_extent_ref ref;
573 struct btrfs_extent_ref *disk_ref;
574 int ret;
575
576 btrfs_set_stack_ref_root(&ref, root_objectid);
577 btrfs_set_stack_ref_generation(&ref, ref_generation);
578 btrfs_set_stack_ref_objectid(&ref, owner);
579 btrfs_set_stack_ref_offset(&ref, owner_offset);
580
581 hash = hash_extent_ref(root_objectid, ref_generation, owner,
582 owner_offset);
583 key.offset = hash;
584 key.objectid = bytenr;
585 key.type = BTRFS_EXTENT_REF_KEY;
586
587 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
588 while (ret == -EEXIST) {
589 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
590 struct btrfs_extent_ref);
591 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
592 goto out;
593 key.offset++;
594 btrfs_release_path(root, path);
595 ret = btrfs_insert_empty_item(trans, root, path, &key,
596 sizeof(ref));
597 }
598 if (ret)
599 goto out;
600 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
601 struct btrfs_extent_ref);
602 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
603 sizeof(ref));
604 btrfs_mark_buffer_dirty(path->nodes[0]);
605 out:
606 btrfs_release_path(root, path);
607 return ret;
608 }
609
610 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
611 struct btrfs_root *root,
612 u64 bytenr, u64 num_bytes,
613 u64 root_objectid, u64 ref_generation,
614 u64 owner, u64 owner_offset)
615 {
616 struct btrfs_path *path;
617 int ret;
618 struct btrfs_key key;
619 struct extent_buffer *l;
620 struct btrfs_extent_item *item;
621 u32 refs;
622
623 WARN_ON(num_bytes < root->sectorsize);
624 path = btrfs_alloc_path();
625 if (!path)
626 return -ENOMEM;
627
628 key.objectid = bytenr;
629 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
630 key.offset = num_bytes;
631 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
632 0, 1);
633 if (ret < 0)
634 return ret;
635 if (ret != 0) {
636 BUG();
637 }
638 BUG_ON(ret != 0);
639 l = path->nodes[0];
640 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
641 refs = btrfs_extent_refs(l, item);
642 btrfs_set_extent_refs(l, item, refs + 1);
643 btrfs_mark_buffer_dirty(path->nodes[0]);
644
645 btrfs_release_path(root->fs_info->extent_root, path);
646
647 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
648 path, bytenr, root_objectid,
649 ref_generation, owner, owner_offset);
650 BUG_ON(ret);
651 finish_current_insert(trans, root->fs_info->extent_root);
652 del_pending_extents(trans, root->fs_info->extent_root);
653
654 btrfs_free_path(path);
655 return 0;
656 }
657
658 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
659 struct btrfs_root *root)
660 {
661 finish_current_insert(trans, root->fs_info->extent_root);
662 del_pending_extents(trans, root->fs_info->extent_root);
663 return 0;
664 }
665
666 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
667 struct btrfs_root *root, u64 bytenr,
668 u64 num_bytes, u32 *refs)
669 {
670 struct btrfs_path *path;
671 int ret;
672 struct btrfs_key key;
673 struct extent_buffer *l;
674 struct btrfs_extent_item *item;
675
676 WARN_ON(num_bytes < root->sectorsize);
677 path = btrfs_alloc_path();
678 key.objectid = bytenr;
679 key.offset = num_bytes;
680 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
681 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
682 0, 0);
683 if (ret < 0)
684 goto out;
685 if (ret != 0) {
686 btrfs_print_leaf(root, path->nodes[0]);
687 printk("failed to find block number %Lu\n", bytenr);
688 BUG();
689 }
690 l = path->nodes[0];
691 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
692 *refs = btrfs_extent_refs(l, item);
693 out:
694 btrfs_free_path(path);
695 return 0;
696 }
697
698 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
699 struct btrfs_path *count_path,
700 u64 first_extent)
701 {
702 struct btrfs_root *extent_root = root->fs_info->extent_root;
703 struct btrfs_path *path;
704 u64 bytenr;
705 u64 found_objectid;
706 u64 root_objectid = root->root_key.objectid;
707 u32 total_count = 0;
708 u32 cur_count;
709 u32 refs;
710 u32 nritems;
711 int ret;
712 struct btrfs_key key;
713 struct btrfs_key found_key;
714 struct extent_buffer *l;
715 struct btrfs_extent_item *item;
716 struct btrfs_extent_ref *ref_item;
717 int level = -1;
718
719 path = btrfs_alloc_path();
720 again:
721 if (level == -1)
722 bytenr = first_extent;
723 else
724 bytenr = count_path->nodes[level]->start;
725
726 cur_count = 0;
727 key.objectid = bytenr;
728 key.offset = 0;
729
730 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
731 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
732 if (ret < 0)
733 goto out;
734 BUG_ON(ret == 0);
735
736 l = path->nodes[0];
737 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
738
739 if (found_key.objectid != bytenr ||
740 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
741 goto out;
742 }
743
744 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
745 refs = btrfs_extent_refs(l, item);
746 while (1) {
747 nritems = btrfs_header_nritems(l);
748 if (path->slots[0] >= nritems) {
749 ret = btrfs_next_leaf(extent_root, path);
750 if (ret == 0)
751 continue;
752 break;
753 }
754 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
755 if (found_key.objectid != bytenr)
756 break;
757 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
758 path->slots[0]++;
759 continue;
760 }
761
762 cur_count++;
763 ref_item = btrfs_item_ptr(l, path->slots[0],
764 struct btrfs_extent_ref);
765 found_objectid = btrfs_ref_root(l, ref_item);
766
767 if (found_objectid != root_objectid) {
768 total_count = 2;
769 goto out;
770 }
771 total_count = 1;
772 path->slots[0]++;
773 }
774 if (cur_count == 0) {
775 total_count = 0;
776 goto out;
777 }
778 if (level >= 0 && root->node == count_path->nodes[level])
779 goto out;
780 level++;
781 btrfs_release_path(root, path);
782 goto again;
783
784 out:
785 btrfs_free_path(path);
786 return total_count;
787 }
788 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
789 struct btrfs_root *root, u64 owner_objectid)
790 {
791 u64 generation;
792 u64 key_objectid;
793 u64 level;
794 u32 nritems;
795 struct btrfs_disk_key disk_key;
796
797 level = btrfs_header_level(root->node);
798 generation = trans->transid;
799 nritems = btrfs_header_nritems(root->node);
800 if (nritems > 0) {
801 if (level == 0)
802 btrfs_item_key(root->node, &disk_key, 0);
803 else
804 btrfs_node_key(root->node, &disk_key, 0);
805 key_objectid = btrfs_disk_key_objectid(&disk_key);
806 } else {
807 key_objectid = 0;
808 }
809 return btrfs_inc_extent_ref(trans, root, root->node->start,
810 root->node->len, owner_objectid,
811 generation, level, key_objectid);
812 }
813
814 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
815 struct extent_buffer *buf)
816 {
817 u64 bytenr;
818 u32 nritems;
819 struct btrfs_key key;
820 struct btrfs_file_extent_item *fi;
821 int i;
822 int level;
823 int ret;
824 int faili;
825
826 if (!root->ref_cows)
827 return 0;
828
829 level = btrfs_header_level(buf);
830 nritems = btrfs_header_nritems(buf);
831 for (i = 0; i < nritems; i++) {
832 if (level == 0) {
833 u64 disk_bytenr;
834 btrfs_item_key_to_cpu(buf, &key, i);
835 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
836 continue;
837 fi = btrfs_item_ptr(buf, i,
838 struct btrfs_file_extent_item);
839 if (btrfs_file_extent_type(buf, fi) ==
840 BTRFS_FILE_EXTENT_INLINE)
841 continue;
842 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
843 if (disk_bytenr == 0)
844 continue;
845 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
846 btrfs_file_extent_disk_num_bytes(buf, fi),
847 root->root_key.objectid, trans->transid,
848 key.objectid, key.offset);
849 if (ret) {
850 faili = i;
851 goto fail;
852 }
853 } else {
854 bytenr = btrfs_node_blockptr(buf, i);
855 btrfs_node_key_to_cpu(buf, &key, i);
856 ret = btrfs_inc_extent_ref(trans, root, bytenr,
857 btrfs_level_size(root, level - 1),
858 root->root_key.objectid,
859 trans->transid,
860 level - 1, key.objectid);
861 if (ret) {
862 faili = i;
863 goto fail;
864 }
865 }
866 }
867 return 0;
868 fail:
869 WARN_ON(1);
870 #if 0
871 for (i =0; i < faili; i++) {
872 if (level == 0) {
873 u64 disk_bytenr;
874 btrfs_item_key_to_cpu(buf, &key, i);
875 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
876 continue;
877 fi = btrfs_item_ptr(buf, i,
878 struct btrfs_file_extent_item);
879 if (btrfs_file_extent_type(buf, fi) ==
880 BTRFS_FILE_EXTENT_INLINE)
881 continue;
882 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
883 if (disk_bytenr == 0)
884 continue;
885 err = btrfs_free_extent(trans, root, disk_bytenr,
886 btrfs_file_extent_disk_num_bytes(buf,
887 fi), 0);
888 BUG_ON(err);
889 } else {
890 bytenr = btrfs_node_blockptr(buf, i);
891 err = btrfs_free_extent(trans, root, bytenr,
892 btrfs_level_size(root, level - 1), 0);
893 BUG_ON(err);
894 }
895 }
896 #endif
897 return ret;
898 }
899
900 static int write_one_cache_group(struct btrfs_trans_handle *trans,
901 struct btrfs_root *root,
902 struct btrfs_path *path,
903 struct btrfs_block_group_cache *cache)
904 {
905 int ret;
906 int pending_ret;
907 struct btrfs_root *extent_root = root->fs_info->extent_root;
908 unsigned long bi;
909 struct extent_buffer *leaf;
910
911 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
912 if (ret < 0)
913 goto fail;
914 BUG_ON(ret);
915
916 leaf = path->nodes[0];
917 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
918 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
919 btrfs_mark_buffer_dirty(leaf);
920 btrfs_release_path(extent_root, path);
921 fail:
922 finish_current_insert(trans, extent_root);
923 pending_ret = del_pending_extents(trans, extent_root);
924 if (ret)
925 return ret;
926 if (pending_ret)
927 return pending_ret;
928 return 0;
929
930 }
931
932 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
933 struct btrfs_root *root)
934 {
935 struct extent_io_tree *block_group_cache;
936 struct btrfs_block_group_cache *cache;
937 int ret;
938 int err = 0;
939 int werr = 0;
940 struct btrfs_path *path;
941 u64 last = 0;
942 u64 start;
943 u64 end;
944 u64 ptr;
945
946 block_group_cache = &root->fs_info->block_group_cache;
947 path = btrfs_alloc_path();
948 if (!path)
949 return -ENOMEM;
950
951 while(1) {
952 ret = find_first_extent_bit(block_group_cache, last,
953 &start, &end, BLOCK_GROUP_DIRTY);
954 if (ret)
955 break;
956
957 last = end + 1;
958 ret = get_state_private(block_group_cache, start, &ptr);
959 if (ret)
960 break;
961
962 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
963 err = write_one_cache_group(trans, root,
964 path, cache);
965 /*
966 * if we fail to write the cache group, we want
967 * to keep it marked dirty in hopes that a later
968 * write will work
969 */
970 if (err) {
971 werr = err;
972 continue;
973 }
974 clear_extent_bits(block_group_cache, start, end,
975 BLOCK_GROUP_DIRTY, GFP_NOFS);
976 }
977 btrfs_free_path(path);
978 return werr;
979 }
980
981 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
982 u64 flags)
983 {
984 struct list_head *head = &info->space_info;
985 struct list_head *cur;
986 struct btrfs_space_info *found;
987 list_for_each(cur, head) {
988 found = list_entry(cur, struct btrfs_space_info, list);
989 if (found->flags == flags)
990 return found;
991 }
992 return NULL;
993
994 }
995
996 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
997 struct btrfs_root *extent_root, u64 alloc_bytes,
998 u64 flags)
999 {
1000 struct btrfs_space_info *space_info;
1001 u64 thresh;
1002 u64 start;
1003 u64 num_bytes;
1004 int ret;
1005
1006 space_info = __find_space_info(extent_root->fs_info, flags);
1007 BUG_ON(!space_info);
1008
1009 if (space_info->full)
1010 return 0;
1011
1012 thresh = div_factor(space_info->total_bytes, 7);
1013 if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1014 thresh)
1015 return 0;
1016
1017 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1018 if (ret == -ENOSPC) {
1019 printk("space info full %Lu\n", flags);
1020 space_info->full = 1;
1021 return 0;
1022 }
1023
1024 BUG_ON(ret);
1025
1026 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1027 extent_root->fs_info->chunk_root->root_key.objectid,
1028 start, num_bytes);
1029 BUG_ON(ret);
1030 return 0;
1031 }
1032
1033 static int update_block_group(struct btrfs_trans_handle *trans,
1034 struct btrfs_root *root,
1035 u64 bytenr, u64 num_bytes, int alloc,
1036 int mark_free)
1037 {
1038 struct btrfs_block_group_cache *cache;
1039 struct btrfs_fs_info *info = root->fs_info;
1040 u64 total = num_bytes;
1041 u64 old_val;
1042 u64 byte_in_group;
1043 u64 start;
1044 u64 end;
1045
1046 while(total) {
1047 cache = btrfs_lookup_block_group(info, bytenr);
1048 if (!cache) {
1049 return -1;
1050 }
1051 byte_in_group = bytenr - cache->key.objectid;
1052 WARN_ON(byte_in_group > cache->key.offset);
1053 start = cache->key.objectid;
1054 end = start + cache->key.offset - 1;
1055 set_extent_bits(&info->block_group_cache, start, end,
1056 BLOCK_GROUP_DIRTY, GFP_NOFS);
1057
1058 old_val = btrfs_block_group_used(&cache->item);
1059 num_bytes = min(total, cache->key.offset - byte_in_group);
1060 if (alloc) {
1061 old_val += num_bytes;
1062 cache->space_info->bytes_used += num_bytes;
1063 } else {
1064 old_val -= num_bytes;
1065 cache->space_info->bytes_used -= num_bytes;
1066 if (mark_free) {
1067 set_extent_dirty(&info->free_space_cache,
1068 bytenr, bytenr + num_bytes - 1,
1069 GFP_NOFS);
1070 }
1071 }
1072 btrfs_set_block_group_used(&cache->item, old_val);
1073 total -= num_bytes;
1074 bytenr += num_bytes;
1075 }
1076 return 0;
1077 }
1078
1079 static int update_pinned_extents(struct btrfs_root *root,
1080 u64 bytenr, u64 num, int pin)
1081 {
1082 u64 len;
1083 struct btrfs_block_group_cache *cache;
1084 struct btrfs_fs_info *fs_info = root->fs_info;
1085
1086 if (pin) {
1087 set_extent_dirty(&fs_info->pinned_extents,
1088 bytenr, bytenr + num - 1, GFP_NOFS);
1089 } else {
1090 clear_extent_dirty(&fs_info->pinned_extents,
1091 bytenr, bytenr + num - 1, GFP_NOFS);
1092 }
1093 while (num > 0) {
1094 cache = btrfs_lookup_block_group(fs_info, bytenr);
1095 WARN_ON(!cache);
1096 len = min(num, cache->key.offset -
1097 (bytenr - cache->key.objectid));
1098 if (pin) {
1099 cache->pinned += len;
1100 cache->space_info->bytes_pinned += len;
1101 fs_info->total_pinned += len;
1102 } else {
1103 cache->pinned -= len;
1104 cache->space_info->bytes_pinned -= len;
1105 fs_info->total_pinned -= len;
1106 }
1107 bytenr += len;
1108 num -= len;
1109 }
1110 return 0;
1111 }
1112
1113 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1114 {
1115 u64 last = 0;
1116 u64 start;
1117 u64 end;
1118 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1119 int ret;
1120
1121 while(1) {
1122 ret = find_first_extent_bit(pinned_extents, last,
1123 &start, &end, EXTENT_DIRTY);
1124 if (ret)
1125 break;
1126 set_extent_dirty(copy, start, end, GFP_NOFS);
1127 last = end + 1;
1128 }
1129 return 0;
1130 }
1131
1132 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1133 struct btrfs_root *root,
1134 struct extent_io_tree *unpin)
1135 {
1136 u64 start;
1137 u64 end;
1138 int ret;
1139 struct extent_io_tree *free_space_cache;
1140 free_space_cache = &root->fs_info->free_space_cache;
1141
1142 while(1) {
1143 ret = find_first_extent_bit(unpin, 0, &start, &end,
1144 EXTENT_DIRTY);
1145 if (ret)
1146 break;
1147 update_pinned_extents(root, start, end + 1 - start, 0);
1148 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1149 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1150 }
1151 return 0;
1152 }
1153
1154 static int finish_current_insert(struct btrfs_trans_handle *trans,
1155 struct btrfs_root *extent_root)
1156 {
1157 u64 start;
1158 u64 end;
1159 struct btrfs_fs_info *info = extent_root->fs_info;
1160 struct extent_buffer *eb;
1161 struct btrfs_path *path;
1162 struct btrfs_key ins;
1163 struct btrfs_disk_key first;
1164 struct btrfs_extent_item extent_item;
1165 int ret;
1166 int level;
1167 int err = 0;
1168
1169 btrfs_set_stack_extent_refs(&extent_item, 1);
1170 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1171 path = btrfs_alloc_path();
1172
1173 while(1) {
1174 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1175 &end, EXTENT_LOCKED);
1176 if (ret)
1177 break;
1178
1179 ins.objectid = start;
1180 ins.offset = end + 1 - start;
1181 err = btrfs_insert_item(trans, extent_root, &ins,
1182 &extent_item, sizeof(extent_item));
1183 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1184 GFP_NOFS);
1185 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1186 level = btrfs_header_level(eb);
1187 if (level == 0) {
1188 btrfs_item_key(eb, &first, 0);
1189 } else {
1190 btrfs_node_key(eb, &first, 0);
1191 }
1192 err = btrfs_insert_extent_backref(trans, extent_root, path,
1193 start, extent_root->root_key.objectid,
1194 0, level,
1195 btrfs_disk_key_objectid(&first));
1196 BUG_ON(err);
1197 free_extent_buffer(eb);
1198 }
1199 btrfs_free_path(path);
1200 return 0;
1201 }
1202
1203 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1204 int pending)
1205 {
1206 int err = 0;
1207 struct extent_buffer *buf;
1208
1209 if (!pending) {
1210 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1211 if (buf) {
1212 if (btrfs_buffer_uptodate(buf)) {
1213 u64 transid =
1214 root->fs_info->running_transaction->transid;
1215 if (btrfs_header_generation(buf) == transid) {
1216 free_extent_buffer(buf);
1217 return 1;
1218 }
1219 }
1220 free_extent_buffer(buf);
1221 }
1222 update_pinned_extents(root, bytenr, num_bytes, 1);
1223 } else {
1224 set_extent_bits(&root->fs_info->pending_del,
1225 bytenr, bytenr + num_bytes - 1,
1226 EXTENT_LOCKED, GFP_NOFS);
1227 }
1228 BUG_ON(err < 0);
1229 return 0;
1230 }
1231
1232 /*
1233 * remove an extent from the root, returns 0 on success
1234 */
1235 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1236 *root, u64 bytenr, u64 num_bytes,
1237 u64 root_objectid, u64 ref_generation,
1238 u64 owner_objectid, u64 owner_offset, int pin,
1239 int mark_free)
1240 {
1241 struct btrfs_path *path;
1242 struct btrfs_key key;
1243 struct btrfs_fs_info *info = root->fs_info;
1244 struct btrfs_extent_ops *ops = info->extent_ops;
1245 struct btrfs_root *extent_root = info->extent_root;
1246 struct extent_buffer *leaf;
1247 int ret;
1248 int extent_slot = 0;
1249 int found_extent = 0;
1250 int num_to_del = 1;
1251 struct btrfs_extent_item *ei;
1252 u32 refs;
1253
1254 key.objectid = bytenr;
1255 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1256 key.offset = num_bytes;
1257
1258 path = btrfs_alloc_path();
1259 if (!path)
1260 return -ENOMEM;
1261
1262 ret = lookup_extent_backref(trans, extent_root, path,
1263 bytenr, root_objectid,
1264 ref_generation,
1265 owner_objectid, owner_offset, 1);
1266 if (ret == 0) {
1267 struct btrfs_key found_key;
1268 extent_slot = path->slots[0];
1269 while(extent_slot > 0) {
1270 extent_slot--;
1271 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1272 extent_slot);
1273 if (found_key.objectid != bytenr)
1274 break;
1275 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1276 found_key.offset == num_bytes) {
1277 found_extent = 1;
1278 break;
1279 }
1280 if (path->slots[0] - extent_slot > 5)
1281 break;
1282 }
1283 if (!found_extent)
1284 ret = btrfs_del_item(trans, extent_root, path);
1285 } else {
1286 btrfs_print_leaf(extent_root, path->nodes[0]);
1287 WARN_ON(1);
1288 printk("Unable to find ref byte nr %Lu root %Lu "
1289 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1290 root_objectid, ref_generation, owner_objectid,
1291 owner_offset);
1292 }
1293 if (!found_extent) {
1294 btrfs_release_path(extent_root, path);
1295 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1296 if (ret < 0)
1297 return ret;
1298 BUG_ON(ret);
1299 extent_slot = path->slots[0];
1300 }
1301
1302 leaf = path->nodes[0];
1303 ei = btrfs_item_ptr(leaf, extent_slot,
1304 struct btrfs_extent_item);
1305 refs = btrfs_extent_refs(leaf, ei);
1306 BUG_ON(refs == 0);
1307 refs -= 1;
1308 btrfs_set_extent_refs(leaf, ei, refs);
1309
1310 btrfs_mark_buffer_dirty(leaf);
1311
1312 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1313 /* if the back ref and the extent are next to each other
1314 * they get deleted below in one shot
1315 */
1316 path->slots[0] = extent_slot;
1317 num_to_del = 2;
1318 } else if (found_extent) {
1319 /* otherwise delete the extent back ref */
1320 ret = btrfs_del_item(trans, extent_root, path);
1321 BUG_ON(ret);
1322 /* if refs are 0, we need to setup the path for deletion */
1323 if (refs == 0) {
1324 btrfs_release_path(extent_root, path);
1325 ret = btrfs_search_slot(trans, extent_root, &key, path,
1326 -1, 1);
1327 if (ret < 0)
1328 return ret;
1329 BUG_ON(ret);
1330 }
1331 }
1332
1333 if (refs == 0) {
1334 u64 super_used;
1335 u64 root_used;
1336
1337 if (pin) {
1338 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1339 if (ret > 0)
1340 mark_free = 1;
1341 BUG_ON(ret < 0);
1342 }
1343
1344 /* block accounting for super block */
1345 super_used = btrfs_super_bytes_used(&info->super_copy);
1346 btrfs_set_super_bytes_used(&info->super_copy,
1347 super_used - num_bytes);
1348
1349 /* block accounting for root item */
1350 root_used = btrfs_root_used(&root->root_item);
1351 btrfs_set_root_used(&root->root_item,
1352 root_used - num_bytes);
1353 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1354 num_to_del);
1355 if (ret)
1356 return ret;
1357
1358 if (ops && ops->free_extent)
1359 ops->free_extent(root, bytenr, num_bytes);
1360
1361 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1362 mark_free);
1363 BUG_ON(ret);
1364 }
1365 btrfs_free_path(path);
1366 finish_current_insert(trans, extent_root);
1367 return ret;
1368 }
1369
1370 /*
1371 * find all the blocks marked as pending in the radix tree and remove
1372 * them from the extent map
1373 */
1374 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1375 btrfs_root *extent_root)
1376 {
1377 int ret;
1378 int err = 0;
1379 u64 start;
1380 u64 end;
1381 struct extent_io_tree *pending_del;
1382 struct extent_io_tree *pinned_extents;
1383
1384 pending_del = &extent_root->fs_info->pending_del;
1385 pinned_extents = &extent_root->fs_info->pinned_extents;
1386
1387 while(1) {
1388 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1389 EXTENT_LOCKED);
1390 if (ret)
1391 break;
1392 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1393 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1394 GFP_NOFS);
1395 ret = __free_extent(trans, extent_root,
1396 start, end + 1 - start,
1397 extent_root->root_key.objectid,
1398 0, 0, 0, 0, 0);
1399 if (ret)
1400 err = ret;
1401 }
1402 return err;
1403 }
1404
1405 /*
1406 * remove an extent from the root, returns 0 on success
1407 */
1408 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1409 *root, u64 bytenr, u64 num_bytes,
1410 u64 root_objectid, u64 ref_generation,
1411 u64 owner_objectid, u64 owner_offset, int pin)
1412 {
1413 struct btrfs_root *extent_root = root->fs_info->extent_root;
1414 int pending_ret;
1415 int ret;
1416
1417 WARN_ON(num_bytes < root->sectorsize);
1418 if (!root->ref_cows)
1419 ref_generation = 0;
1420
1421 if (root == extent_root) {
1422 pin_down_bytes(root, bytenr, num_bytes, 1);
1423 return 0;
1424 }
1425 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1426 ref_generation, owner_objectid, owner_offset,
1427 pin, pin == 0);
1428 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1429 return ret ? ret : pending_ret;
1430 }
1431
1432 static u64 stripe_align(struct btrfs_root *root, u64 val)
1433 {
1434 u64 mask = ((u64)root->stripesize - 1);
1435 u64 ret = (val + mask) & ~mask;
1436 return ret;
1437 }
1438
1439 /*
1440 * walks the btree of allocated extents and find a hole of a given size.
1441 * The key ins is changed to record the hole:
1442 * ins->objectid == block start
1443 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1444 * ins->offset == number of blocks
1445 * Any available blocks before search_start are skipped.
1446 */
1447 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1448 struct btrfs_root *orig_root,
1449 u64 num_bytes, u64 empty_size,
1450 u64 search_start, u64 search_end,
1451 u64 hint_byte, struct btrfs_key *ins,
1452 u64 exclude_start, u64 exclude_nr,
1453 int data)
1454 {
1455 int ret;
1456 u64 orig_search_start = search_start;
1457 struct btrfs_root * root = orig_root->fs_info->extent_root;
1458 struct btrfs_fs_info *info = root->fs_info;
1459 u64 total_needed = num_bytes;
1460 struct btrfs_block_group_cache *block_group;
1461 int full_scan = 0;
1462 int wrapped = 0;
1463
1464 WARN_ON(num_bytes < root->sectorsize);
1465 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1466
1467 if (search_end == (u64)-1)
1468 search_end = btrfs_super_total_bytes(&info->super_copy);
1469
1470 if (hint_byte) {
1471 block_group = btrfs_lookup_block_group(info, hint_byte);
1472 if (!block_group)
1473 hint_byte = search_start;
1474 block_group = btrfs_find_block_group(root, block_group,
1475 hint_byte, data, 1);
1476 } else {
1477 block_group = btrfs_find_block_group(root,
1478 trans->block_group,
1479 search_start, data, 1);
1480 }
1481
1482 total_needed += empty_size;
1483
1484 check_failed:
1485 if (!block_group) {
1486 block_group = btrfs_lookup_block_group(info, search_start);
1487 if (!block_group)
1488 block_group = btrfs_lookup_block_group(info,
1489 orig_search_start);
1490 }
1491 ret = find_search_start(root, &block_group, &search_start,
1492 total_needed, data);
1493 if (ret)
1494 goto error;
1495
1496 search_start = stripe_align(root, search_start);
1497 ins->objectid = search_start;
1498 ins->offset = num_bytes;
1499
1500 if (ins->objectid + num_bytes >= search_end)
1501 goto enospc;
1502
1503 if (ins->objectid + num_bytes >
1504 block_group->key.objectid + block_group->key.offset) {
1505 search_start = block_group->key.objectid +
1506 block_group->key.offset;
1507 goto new_group;
1508 }
1509
1510 if (test_range_bit(&info->extent_ins, ins->objectid,
1511 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1512 search_start = ins->objectid + num_bytes;
1513 goto new_group;
1514 }
1515
1516 if (test_range_bit(&info->pinned_extents, ins->objectid,
1517 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1518 search_start = ins->objectid + num_bytes;
1519 goto new_group;
1520 }
1521
1522 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1523 ins->objectid < exclude_start + exclude_nr)) {
1524 search_start = exclude_start + exclude_nr;
1525 goto new_group;
1526 }
1527
1528 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
1529 block_group = btrfs_lookup_block_group(info, ins->objectid);
1530 if (block_group)
1531 trans->block_group = block_group;
1532 }
1533 ins->offset = num_bytes;
1534 return 0;
1535
1536 new_group:
1537 if (search_start + num_bytes >= search_end) {
1538 enospc:
1539 search_start = orig_search_start;
1540 if (full_scan) {
1541 ret = -ENOSPC;
1542 goto error;
1543 }
1544 if (wrapped) {
1545 if (!full_scan)
1546 total_needed -= empty_size;
1547 full_scan = 1;
1548 } else
1549 wrapped = 1;
1550 }
1551 block_group = btrfs_lookup_block_group(info, search_start);
1552 cond_resched();
1553 block_group = btrfs_find_block_group(root, block_group,
1554 search_start, data, 0);
1555 goto check_failed;
1556
1557 error:
1558 return ret;
1559 }
1560 /*
1561 * finds a free extent and does all the dirty work required for allocation
1562 * returns the key for the extent through ins, and a tree buffer for
1563 * the first block of the extent through buf.
1564 *
1565 * returns 0 if everything worked, non-zero otherwise.
1566 */
1567 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1568 struct btrfs_root *root,
1569 u64 num_bytes, u64 root_objectid, u64 ref_generation,
1570 u64 owner, u64 owner_offset,
1571 u64 empty_size, u64 hint_byte,
1572 u64 search_end, struct btrfs_key *ins, int data)
1573 {
1574 int ret;
1575 int pending_ret;
1576 u64 super_used, root_used;
1577 u64 search_start = 0;
1578 struct btrfs_fs_info *info = root->fs_info;
1579 struct btrfs_extent_ops *ops = info->extent_ops;
1580 u32 sizes[2];
1581 struct btrfs_root *extent_root = info->extent_root;
1582 struct btrfs_path *path;
1583 struct btrfs_extent_item *extent_item;
1584 struct btrfs_extent_ref *ref;
1585 struct btrfs_key keys[2];
1586
1587 if (data) {
1588 data = BTRFS_BLOCK_GROUP_DATA;
1589 } else if (root == root->fs_info->chunk_root ||
1590 info->force_system_allocs) {
1591 data = BTRFS_BLOCK_GROUP_SYSTEM;
1592 } else {
1593 data = BTRFS_BLOCK_GROUP_METADATA;
1594 }
1595
1596 if (root->ref_cows) {
1597 if (data != BTRFS_BLOCK_GROUP_METADATA) {
1598 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1599 num_bytes,
1600 BTRFS_BLOCK_GROUP_METADATA);
1601 BUG_ON(ret);
1602 }
1603 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1604 num_bytes, data);
1605 BUG_ON(ret);
1606 }
1607
1608 WARN_ON(num_bytes < root->sectorsize);
1609 if (ops && ops->alloc_extent) {
1610 ret = ops->alloc_extent(root, num_bytes, hint_byte, ins);
1611 } else {
1612 ret = find_free_extent(trans, root, num_bytes, empty_size,
1613 search_start, search_end, hint_byte,
1614 ins, trans->alloc_exclude_start,
1615 trans->alloc_exclude_nr, data);
1616 }
1617 BUG_ON(ret);
1618 if (ret)
1619 return ret;
1620
1621 /* block accounting for super block */
1622 super_used = btrfs_super_bytes_used(&info->super_copy);
1623 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1624
1625 /* block accounting for root item */
1626 root_used = btrfs_root_used(&root->root_item);
1627 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1628
1629 clear_extent_dirty(&root->fs_info->free_space_cache,
1630 ins->objectid, ins->objectid + ins->offset - 1,
1631 GFP_NOFS);
1632
1633 if (root == extent_root) {
1634 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1635 ins->objectid + ins->offset - 1,
1636 EXTENT_LOCKED, GFP_NOFS);
1637 goto update_block;
1638 }
1639
1640 WARN_ON(trans->alloc_exclude_nr);
1641 trans->alloc_exclude_start = ins->objectid;
1642 trans->alloc_exclude_nr = ins->offset;
1643
1644 memcpy(&keys[0], ins, sizeof(*ins));
1645 keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
1646 owner, owner_offset);
1647 keys[1].objectid = ins->objectid;
1648 keys[1].type = BTRFS_EXTENT_REF_KEY;
1649 sizes[0] = sizeof(*extent_item);
1650 sizes[1] = sizeof(*ref);
1651
1652 path = btrfs_alloc_path();
1653 BUG_ON(!path);
1654
1655 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
1656 sizes, 2);
1657
1658 BUG_ON(ret);
1659 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1660 struct btrfs_extent_item);
1661 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
1662 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1663 struct btrfs_extent_ref);
1664
1665 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
1666 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
1667 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
1668 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
1669
1670 btrfs_mark_buffer_dirty(path->nodes[0]);
1671
1672 trans->alloc_exclude_start = 0;
1673 trans->alloc_exclude_nr = 0;
1674 btrfs_free_path(path);
1675 finish_current_insert(trans, extent_root);
1676 pending_ret = del_pending_extents(trans, extent_root);
1677
1678 if (ret) {
1679 return ret;
1680 }
1681 if (pending_ret) {
1682 return pending_ret;
1683 }
1684
1685 update_block:
1686 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
1687 if (ret) {
1688 printk("update block group failed for %Lu %Lu\n",
1689 ins->objectid, ins->offset);
1690 BUG();
1691 }
1692 return 0;
1693 }
1694
1695 /*
1696 * helper function to allocate a block for a given tree
1697 * returns the tree buffer or NULL.
1698 */
1699 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1700 struct btrfs_root *root,
1701 u32 blocksize,
1702 u64 root_objectid, u64 hint,
1703 u64 empty_size)
1704 {
1705 u64 ref_generation;
1706
1707 if (root->ref_cows)
1708 ref_generation = trans->transid;
1709 else
1710 ref_generation = 0;
1711
1712
1713 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1714 ref_generation, 0, 0, hint, empty_size);
1715 }
1716
1717 /*
1718 * helper function to allocate a block for a given tree
1719 * returns the tree buffer or NULL.
1720 */
1721 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1722 struct btrfs_root *root,
1723 u32 blocksize,
1724 u64 root_objectid,
1725 u64 ref_generation,
1726 u64 first_objectid,
1727 int level,
1728 u64 hint,
1729 u64 empty_size)
1730 {
1731 struct btrfs_key ins;
1732 int ret;
1733 struct extent_buffer *buf;
1734
1735 ret = btrfs_alloc_extent(trans, root, blocksize,
1736 root_objectid, ref_generation,
1737 level, first_objectid, empty_size, hint,
1738 (u64)-1, &ins, 0);
1739 if (ret) {
1740 BUG_ON(ret > 0);
1741 return ERR_PTR(ret);
1742 }
1743 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1744 if (!buf) {
1745 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1746 root->root_key.objectid, ref_generation,
1747 0, 0, 0);
1748 BUG_ON(1);
1749 return ERR_PTR(-ENOMEM);
1750 }
1751 btrfs_set_buffer_uptodate(buf);
1752 trans->blocks_used++;
1753 return buf;
1754 }
1755
1756 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
1757 struct btrfs_root *root,
1758 struct extent_buffer *leaf)
1759 {
1760 u64 leaf_owner;
1761 u64 leaf_generation;
1762 struct btrfs_key key;
1763 struct btrfs_file_extent_item *fi;
1764 int i;
1765 int nritems;
1766 int ret;
1767
1768 BUG_ON(!btrfs_is_leaf(leaf));
1769 nritems = btrfs_header_nritems(leaf);
1770 leaf_owner = btrfs_header_owner(leaf);
1771 leaf_generation = btrfs_header_generation(leaf);
1772
1773 for (i = 0; i < nritems; i++) {
1774 u64 disk_bytenr;
1775
1776 btrfs_item_key_to_cpu(leaf, &key, i);
1777 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1778 continue;
1779 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1780 if (btrfs_file_extent_type(leaf, fi) ==
1781 BTRFS_FILE_EXTENT_INLINE)
1782 continue;
1783 /*
1784 * FIXME make sure to insert a trans record that
1785 * repeats the snapshot del on crash
1786 */
1787 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1788 if (disk_bytenr == 0)
1789 continue;
1790 ret = btrfs_free_extent(trans, root, disk_bytenr,
1791 btrfs_file_extent_disk_num_bytes(leaf, fi),
1792 leaf_owner, leaf_generation,
1793 key.objectid, key.offset, 0);
1794 BUG_ON(ret);
1795 }
1796 return 0;
1797 }
1798
1799 static void noinline reada_walk_down(struct btrfs_root *root,
1800 struct extent_buffer *node,
1801 int slot)
1802 {
1803 u64 bytenr;
1804 u64 last = 0;
1805 u32 nritems;
1806 u32 refs;
1807 u32 blocksize;
1808 int ret;
1809 int i;
1810 int level;
1811 int skipped = 0;
1812
1813 nritems = btrfs_header_nritems(node);
1814 level = btrfs_header_level(node);
1815 if (level)
1816 return;
1817
1818 for (i = slot; i < nritems && skipped < 32; i++) {
1819 bytenr = btrfs_node_blockptr(node, i);
1820 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
1821 (last > bytenr && last - bytenr > 32 * 1024))) {
1822 skipped++;
1823 continue;
1824 }
1825 blocksize = btrfs_level_size(root, level - 1);
1826 if (i != slot) {
1827 ret = lookup_extent_ref(NULL, root, bytenr,
1828 blocksize, &refs);
1829 BUG_ON(ret);
1830 if (refs != 1) {
1831 skipped++;
1832 continue;
1833 }
1834 }
1835 mutex_unlock(&root->fs_info->fs_mutex);
1836 ret = readahead_tree_block(root, bytenr, blocksize);
1837 last = bytenr + blocksize;
1838 cond_resched();
1839 mutex_lock(&root->fs_info->fs_mutex);
1840 if (ret)
1841 break;
1842 }
1843 }
1844
1845 /*
1846 * helper function for drop_snapshot, this walks down the tree dropping ref
1847 * counts as it goes.
1848 */
1849 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
1850 struct btrfs_root *root,
1851 struct btrfs_path *path, int *level)
1852 {
1853 u64 root_owner;
1854 u64 root_gen;
1855 u64 bytenr;
1856 struct extent_buffer *next;
1857 struct extent_buffer *cur;
1858 struct extent_buffer *parent;
1859 u32 blocksize;
1860 int ret;
1861 u32 refs;
1862
1863 WARN_ON(*level < 0);
1864 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1865 ret = lookup_extent_ref(trans, root,
1866 path->nodes[*level]->start,
1867 path->nodes[*level]->len, &refs);
1868 BUG_ON(ret);
1869 if (refs > 1)
1870 goto out;
1871
1872 /*
1873 * walk down to the last node level and free all the leaves
1874 */
1875 while(*level >= 0) {
1876 WARN_ON(*level < 0);
1877 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1878 cur = path->nodes[*level];
1879
1880 if (btrfs_header_level(cur) != *level)
1881 WARN_ON(1);
1882
1883 if (path->slots[*level] >=
1884 btrfs_header_nritems(cur))
1885 break;
1886 if (*level == 0) {
1887 ret = drop_leaf_ref(trans, root, cur);
1888 BUG_ON(ret);
1889 break;
1890 }
1891 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1892 blocksize = btrfs_level_size(root, *level - 1);
1893 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
1894 BUG_ON(ret);
1895 if (refs != 1) {
1896 parent = path->nodes[*level];
1897 root_owner = btrfs_header_owner(parent);
1898 root_gen = btrfs_header_generation(parent);
1899 path->slots[*level]++;
1900 ret = btrfs_free_extent(trans, root, bytenr,
1901 blocksize, root_owner,
1902 root_gen, 0, 0, 1);
1903 BUG_ON(ret);
1904 continue;
1905 }
1906 next = btrfs_find_tree_block(root, bytenr, blocksize);
1907 if (!next || !btrfs_buffer_uptodate(next)) {
1908 free_extent_buffer(next);
1909 reada_walk_down(root, cur, path->slots[*level]);
1910 mutex_unlock(&root->fs_info->fs_mutex);
1911 next = read_tree_block(root, bytenr, blocksize);
1912 mutex_lock(&root->fs_info->fs_mutex);
1913
1914 /* we dropped the lock, check one more time */
1915 ret = lookup_extent_ref(trans, root, bytenr,
1916 blocksize, &refs);
1917 BUG_ON(ret);
1918 if (refs != 1) {
1919 parent = path->nodes[*level];
1920 root_owner = btrfs_header_owner(parent);
1921 root_gen = btrfs_header_generation(parent);
1922
1923 path->slots[*level]++;
1924 free_extent_buffer(next);
1925 ret = btrfs_free_extent(trans, root, bytenr,
1926 blocksize,
1927 root_owner,
1928 root_gen, 0, 0, 1);
1929 BUG_ON(ret);
1930 continue;
1931 }
1932 }
1933 WARN_ON(*level <= 0);
1934 if (path->nodes[*level-1])
1935 free_extent_buffer(path->nodes[*level-1]);
1936 path->nodes[*level-1] = next;
1937 *level = btrfs_header_level(next);
1938 path->slots[*level] = 0;
1939 }
1940 out:
1941 WARN_ON(*level < 0);
1942 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1943
1944 if (path->nodes[*level] == root->node) {
1945 root_owner = root->root_key.objectid;
1946 parent = path->nodes[*level];
1947 } else {
1948 parent = path->nodes[*level + 1];
1949 root_owner = btrfs_header_owner(parent);
1950 }
1951
1952 root_gen = btrfs_header_generation(parent);
1953 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
1954 path->nodes[*level]->len,
1955 root_owner, root_gen, 0, 0, 1);
1956 free_extent_buffer(path->nodes[*level]);
1957 path->nodes[*level] = NULL;
1958 *level += 1;
1959 BUG_ON(ret);
1960 return 0;
1961 }
1962
1963 /*
1964 * helper for dropping snapshots. This walks back up the tree in the path
1965 * to find the first node higher up where we haven't yet gone through
1966 * all the slots
1967 */
1968 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
1969 struct btrfs_root *root,
1970 struct btrfs_path *path, int *level)
1971 {
1972 u64 root_owner;
1973 u64 root_gen;
1974 struct btrfs_root_item *root_item = &root->root_item;
1975 int i;
1976 int slot;
1977 int ret;
1978
1979 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1980 slot = path->slots[i];
1981 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
1982 struct extent_buffer *node;
1983 struct btrfs_disk_key disk_key;
1984 node = path->nodes[i];
1985 path->slots[i]++;
1986 *level = i;
1987 WARN_ON(*level == 0);
1988 btrfs_node_key(node, &disk_key, path->slots[i]);
1989 memcpy(&root_item->drop_progress,
1990 &disk_key, sizeof(disk_key));
1991 root_item->drop_level = i;
1992 return 0;
1993 } else {
1994 if (path->nodes[*level] == root->node) {
1995 root_owner = root->root_key.objectid;
1996 root_gen =
1997 btrfs_header_generation(path->nodes[*level]);
1998 } else {
1999 struct extent_buffer *node;
2000 node = path->nodes[*level + 1];
2001 root_owner = btrfs_header_owner(node);
2002 root_gen = btrfs_header_generation(node);
2003 }
2004 ret = btrfs_free_extent(trans, root,
2005 path->nodes[*level]->start,
2006 path->nodes[*level]->len,
2007 root_owner, root_gen, 0, 0, 1);
2008 BUG_ON(ret);
2009 free_extent_buffer(path->nodes[*level]);
2010 path->nodes[*level] = NULL;
2011 *level = i + 1;
2012 }
2013 }
2014 return 1;
2015 }
2016
2017 /*
2018 * drop the reference count on the tree rooted at 'snap'. This traverses
2019 * the tree freeing any blocks that have a ref count of zero after being
2020 * decremented.
2021 */
2022 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2023 *root)
2024 {
2025 int ret = 0;
2026 int wret;
2027 int level;
2028 struct btrfs_path *path;
2029 int i;
2030 int orig_level;
2031 struct btrfs_root_item *root_item = &root->root_item;
2032
2033 path = btrfs_alloc_path();
2034 BUG_ON(!path);
2035
2036 level = btrfs_header_level(root->node);
2037 orig_level = level;
2038 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2039 path->nodes[level] = root->node;
2040 extent_buffer_get(root->node);
2041 path->slots[level] = 0;
2042 } else {
2043 struct btrfs_key key;
2044 struct btrfs_disk_key found_key;
2045 struct extent_buffer *node;
2046
2047 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2048 level = root_item->drop_level;
2049 path->lowest_level = level;
2050 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2051 if (wret < 0) {
2052 ret = wret;
2053 goto out;
2054 }
2055 node = path->nodes[level];
2056 btrfs_node_key(node, &found_key, path->slots[level]);
2057 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2058 sizeof(found_key)));
2059 }
2060 while(1) {
2061 wret = walk_down_tree(trans, root, path, &level);
2062 if (wret < 0)
2063 ret = wret;
2064 if (wret != 0)
2065 break;
2066
2067 wret = walk_up_tree(trans, root, path, &level);
2068 if (wret < 0)
2069 ret = wret;
2070 if (wret != 0)
2071 break;
2072 /*
2073 ret = -EAGAIN;
2074 break;
2075 */
2076 }
2077 for (i = 0; i <= orig_level; i++) {
2078 if (path->nodes[i]) {
2079 free_extent_buffer(path->nodes[i]);
2080 path->nodes[i] = NULL;
2081 }
2082 }
2083 out:
2084 btrfs_free_path(path);
2085 return ret;
2086 }
2087
2088 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2089 {
2090 u64 start;
2091 u64 end;
2092 u64 ptr;
2093 int ret;
2094 while(1) {
2095 ret = find_first_extent_bit(&info->block_group_cache, 0,
2096 &start, &end, (unsigned int)-1);
2097 if (ret)
2098 break;
2099 ret = get_state_private(&info->block_group_cache, start, &ptr);
2100 if (!ret)
2101 kfree((void *)(unsigned long)ptr);
2102 clear_extent_bits(&info->block_group_cache, start,
2103 end, (unsigned int)-1, GFP_NOFS);
2104 }
2105 while(1) {
2106 ret = find_first_extent_bit(&info->free_space_cache, 0,
2107 &start, &end, EXTENT_DIRTY);
2108 if (ret)
2109 break;
2110 clear_extent_dirty(&info->free_space_cache, start,
2111 end, GFP_NOFS);
2112 }
2113 return 0;
2114 }
2115
2116 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
2117 struct btrfs_key *key)
2118 {
2119 int ret;
2120 struct btrfs_key found_key;
2121 struct extent_buffer *leaf;
2122 int slot;
2123
2124 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
2125 if (ret < 0)
2126 return ret;
2127 while(1) {
2128 slot = path->slots[0];
2129 leaf = path->nodes[0];
2130 if (slot >= btrfs_header_nritems(leaf)) {
2131 ret = btrfs_next_leaf(root, path);
2132 if (ret == 0)
2133 continue;
2134 if (ret < 0)
2135 goto error;
2136 break;
2137 }
2138 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2139
2140 if (found_key.objectid >= key->objectid &&
2141 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
2142 return 0;
2143 path->slots[0]++;
2144 }
2145 ret = -ENOENT;
2146 error:
2147 return ret;
2148 }
2149
2150 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
2151 u64 total_bytes, u64 bytes_used,
2152 struct btrfs_space_info **space_info)
2153 {
2154 struct btrfs_space_info *found;
2155
2156 found = __find_space_info(info, flags);
2157 if (found) {
2158 found->total_bytes += total_bytes;
2159 found->bytes_used += bytes_used;
2160 WARN_ON(found->total_bytes < found->bytes_used);
2161 *space_info = found;
2162 return 0;
2163 }
2164 found = kmalloc(sizeof(*found), GFP_NOFS);
2165 if (!found)
2166 return -ENOMEM;
2167
2168 list_add(&found->list, &info->space_info);
2169 found->flags = flags;
2170 found->total_bytes = total_bytes;
2171 found->bytes_used = bytes_used;
2172 found->bytes_pinned = 0;
2173 found->full = 0;
2174 *space_info = found;
2175 return 0;
2176 }
2177
2178 int btrfs_read_block_groups(struct btrfs_root *root)
2179 {
2180 struct btrfs_path *path;
2181 int ret;
2182 int bit;
2183 struct btrfs_block_group_cache *cache;
2184 struct btrfs_fs_info *info = root->fs_info;
2185 struct btrfs_space_info *space_info;
2186 struct extent_io_tree *block_group_cache;
2187 struct btrfs_key key;
2188 struct btrfs_key found_key;
2189 struct extent_buffer *leaf;
2190
2191 block_group_cache = &info->block_group_cache;
2192
2193 root = info->extent_root;
2194 key.objectid = 0;
2195 key.offset = 0;
2196 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2197 path = btrfs_alloc_path();
2198 if (!path)
2199 return -ENOMEM;
2200
2201 while(1) {
2202 ret = find_first_block_group(root, path, &key);
2203 if (ret > 0) {
2204 ret = 0;
2205 goto error;
2206 }
2207 if (ret != 0) {
2208 goto error;
2209 }
2210 leaf = path->nodes[0];
2211 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2212 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2213 if (!cache) {
2214 ret = -ENOMEM;
2215 break;
2216 }
2217
2218 read_extent_buffer(leaf, &cache->item,
2219 btrfs_item_ptr_offset(leaf, path->slots[0]),
2220 sizeof(cache->item));
2221 memcpy(&cache->key, &found_key, sizeof(found_key));
2222 cache->cached = 0;
2223 cache->pinned = 0;
2224 key.objectid = found_key.objectid + found_key.offset;
2225 btrfs_release_path(root, path);
2226 cache->flags = btrfs_block_group_flags(&cache->item);
2227 bit = 0;
2228 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
2229 bit = BLOCK_GROUP_DATA;
2230 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
2231 bit = BLOCK_GROUP_SYSTEM;
2232 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
2233 bit = BLOCK_GROUP_METADATA;
2234 }
2235
2236 ret = update_space_info(info, cache->flags, found_key.offset,
2237 btrfs_block_group_used(&cache->item),
2238 &space_info);
2239 BUG_ON(ret);
2240 cache->space_info = space_info;
2241
2242 /* use EXTENT_LOCKED to prevent merging */
2243 set_extent_bits(block_group_cache, found_key.objectid,
2244 found_key.objectid + found_key.offset - 1,
2245 bit | EXTENT_LOCKED, GFP_NOFS);
2246 set_state_private(block_group_cache, found_key.objectid,
2247 (unsigned long)cache);
2248
2249 if (key.objectid >=
2250 btrfs_super_total_bytes(&info->super_copy))
2251 break;
2252 }
2253 ret = 0;
2254 error:
2255 btrfs_free_path(path);
2256 return ret;
2257 }
2258
2259 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
2260 struct btrfs_root *root, u64 bytes_used,
2261 u64 type, u64 chunk_tree, u64 chunk_objectid,
2262 u64 size)
2263 {
2264 int ret;
2265 int bit = 0;
2266 struct btrfs_root *extent_root;
2267 struct btrfs_block_group_cache *cache;
2268 struct extent_io_tree *block_group_cache;
2269
2270 extent_root = root->fs_info->extent_root;
2271 block_group_cache = &root->fs_info->block_group_cache;
2272
2273 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2274 BUG_ON(!cache);
2275 cache->key.objectid = chunk_objectid;
2276 cache->key.offset = size;
2277 cache->cached = 0;
2278 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2279 memset(&cache->item, 0, sizeof(cache->item));
2280 btrfs_set_block_group_used(&cache->item, bytes_used);
2281 btrfs_set_block_group_chunk_tree(&cache->item, chunk_tree);
2282 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
2283 cache->flags = type;
2284 btrfs_set_block_group_flags(&cache->item, type);
2285
2286 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
2287 &cache->space_info);
2288 BUG_ON(ret);
2289
2290 if (type & BTRFS_BLOCK_GROUP_DATA) {
2291 bit = BLOCK_GROUP_DATA;
2292 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2293 bit = BLOCK_GROUP_SYSTEM;
2294 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2295 bit = BLOCK_GROUP_METADATA;
2296 }
2297 set_extent_bits(block_group_cache, chunk_objectid,
2298 chunk_objectid + size - 1,
2299 bit | EXTENT_LOCKED, GFP_NOFS);
2300 set_state_private(block_group_cache, chunk_objectid,
2301 (unsigned long)cache);
2302
2303 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
2304 sizeof(cache->item));
2305 BUG_ON(ret);
2306
2307 finish_current_insert(trans, extent_root);
2308 ret = del_pending_extents(trans, extent_root);
2309 BUG_ON(ret);
2310 return 0;
2311 }
2312
2313 u64 btrfs_hash_extent_ref(u64 root_objectid, u64 ref_generation,
2314 u64 owner, u64 owner_offset)
2315 {
2316 return hash_extent_ref(root_objectid, ref_generation,
2317 owner, owner_offset);
2318 }
2319
2320 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
2321 struct btrfs_root *root,
2322 u64 bytenr, u64 num_bytes, int alloc,
2323 int mark_free)
2324 {
2325 return update_block_group(trans, root, bytenr, num_bytes,
2326 alloc, mark_free);
2327 }
(deprecated) Btrfs progs developments and patch integration