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Walk all block devices looking for btrfs
[btrfs-progs-unstable/devel.git] / extent-tree.c
blob3b5d2b6ed3f72be660f023b44940ac3e1c53cfc6
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 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 %Lu\n", bytenr);
684 BUG();
685 }
686 l = path->nodes[0];
687 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
688 *refs = btrfs_extent_refs(l, item);
689 out:
690 btrfs_free_path(path);
691 return 0;
692 }
693
694 u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
695 struct btrfs_path *count_path,
696 u64 first_extent)
697 {
698 struct btrfs_root *extent_root = root->fs_info->extent_root;
699 struct btrfs_path *path;
700 u64 bytenr;
701 u64 found_objectid;
702 u64 root_objectid = root->root_key.objectid;
703 u32 total_count = 0;
704 u32 cur_count;
705 u32 refs;
706 u32 nritems;
707 int ret;
708 struct btrfs_key key;
709 struct btrfs_key found_key;
710 struct extent_buffer *l;
711 struct btrfs_extent_item *item;
712 struct btrfs_extent_ref *ref_item;
713 int level = -1;
714
715 path = btrfs_alloc_path();
716 again:
717 if (level == -1)
718 bytenr = first_extent;
719 else
720 bytenr = count_path->nodes[level]->start;
721
722 cur_count = 0;
723 key.objectid = bytenr;
724 key.offset = 0;
725
726 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
727 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
728 if (ret < 0)
729 goto out;
730 BUG_ON(ret == 0);
731
732 l = path->nodes[0];
733 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
734
735 if (found_key.objectid != bytenr ||
736 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
737 goto out;
738 }
739
740 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
741 refs = btrfs_extent_refs(l, item);
742 while (1) {
743 nritems = btrfs_header_nritems(l);
744 if (path->slots[0] >= nritems) {
745 ret = btrfs_next_leaf(extent_root, path);
746 if (ret == 0)
747 continue;
748 break;
749 }
750 btrfs_item_key_to_cpu(l, &found_key, path->slots[0]);
751 if (found_key.objectid != bytenr)
752 break;
753 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
754 path->slots[0]++;
755 continue;
756 }
757
758 cur_count++;
759 ref_item = btrfs_item_ptr(l, path->slots[0],
760 struct btrfs_extent_ref);
761 found_objectid = btrfs_ref_root(l, ref_item);
762
763 if (found_objectid != root_objectid) {
764 total_count = 2;
765 goto out;
766 }
767 total_count = 1;
768 path->slots[0]++;
769 }
770 if (cur_count == 0) {
771 total_count = 0;
772 goto out;
773 }
774 if (level >= 0 && root->node == count_path->nodes[level])
775 goto out;
776 level++;
777 btrfs_release_path(root, path);
778 goto again;
779
780 out:
781 btrfs_free_path(path);
782 return total_count;
783 }
784 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
785 struct btrfs_root *root, u64 owner_objectid)
786 {
787 u64 generation;
788 u64 key_objectid;
789 u64 level;
790 u32 nritems;
791 struct btrfs_disk_key disk_key;
792
793 level = btrfs_header_level(root->node);
794 generation = trans->transid;
795 nritems = btrfs_header_nritems(root->node);
796 if (nritems > 0) {
797 if (level == 0)
798 btrfs_item_key(root->node, &disk_key, 0);
799 else
800 btrfs_node_key(root->node, &disk_key, 0);
801 key_objectid = btrfs_disk_key_objectid(&disk_key);
802 } else {
803 key_objectid = 0;
804 }
805 return btrfs_inc_extent_ref(trans, root, root->node->start,
806 root->node->len, owner_objectid,
807 generation, level, key_objectid);
808 }
809
810 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
811 struct extent_buffer *buf)
812 {
813 u64 bytenr;
814 u32 nritems;
815 struct btrfs_key key;
816 struct btrfs_file_extent_item *fi;
817 int i;
818 int level;
819 int ret;
820 int faili;
821
822 if (!root->ref_cows)
823 return 0;
824
825 level = btrfs_header_level(buf);
826 nritems = btrfs_header_nritems(buf);
827 for (i = 0; i < nritems; i++) {
828 if (level == 0) {
829 u64 disk_bytenr;
830 btrfs_item_key_to_cpu(buf, &key, i);
831 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
832 continue;
833 fi = btrfs_item_ptr(buf, i,
834 struct btrfs_file_extent_item);
835 if (btrfs_file_extent_type(buf, fi) ==
836 BTRFS_FILE_EXTENT_INLINE)
837 continue;
838 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
839 if (disk_bytenr == 0)
840 continue;
841 ret = btrfs_inc_extent_ref(trans, root, disk_bytenr,
842 btrfs_file_extent_disk_num_bytes(buf, fi),
843 root->root_key.objectid, trans->transid,
844 key.objectid, key.offset);
845 if (ret) {
846 faili = i;
847 goto fail;
848 }
849 } else {
850 bytenr = btrfs_node_blockptr(buf, i);
851 btrfs_node_key_to_cpu(buf, &key, i);
852 ret = btrfs_inc_extent_ref(trans, root, bytenr,
853 btrfs_level_size(root, level - 1),
854 root->root_key.objectid,
855 trans->transid,
856 level - 1, key.objectid);
857 if (ret) {
858 faili = i;
859 goto fail;
860 }
861 }
862 }
863 return 0;
864 fail:
865 WARN_ON(1);
866 #if 0
867 for (i =0; i < faili; i++) {
868 if (level == 0) {
869 u64 disk_bytenr;
870 btrfs_item_key_to_cpu(buf, &key, i);
871 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
872 continue;
873 fi = btrfs_item_ptr(buf, i,
874 struct btrfs_file_extent_item);
875 if (btrfs_file_extent_type(buf, fi) ==
876 BTRFS_FILE_EXTENT_INLINE)
877 continue;
878 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
879 if (disk_bytenr == 0)
880 continue;
881 err = btrfs_free_extent(trans, root, disk_bytenr,
882 btrfs_file_extent_disk_num_bytes(buf,
883 fi), 0);
884 BUG_ON(err);
885 } else {
886 bytenr = btrfs_node_blockptr(buf, i);
887 err = btrfs_free_extent(trans, root, bytenr,
888 btrfs_level_size(root, level - 1), 0);
889 BUG_ON(err);
890 }
891 }
892 #endif
893 return ret;
894 }
895
896 static int write_one_cache_group(struct btrfs_trans_handle *trans,
897 struct btrfs_root *root,
898 struct btrfs_path *path,
899 struct btrfs_block_group_cache *cache)
900 {
901 int ret;
902 int pending_ret;
903 struct btrfs_root *extent_root = root->fs_info->extent_root;
904 unsigned long bi;
905 struct extent_buffer *leaf;
906
907 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
908 if (ret < 0)
909 goto fail;
910 BUG_ON(ret);
911
912 leaf = path->nodes[0];
913 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
914 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
915 btrfs_mark_buffer_dirty(leaf);
916 btrfs_release_path(extent_root, path);
917 fail:
918 finish_current_insert(trans, extent_root);
919 pending_ret = del_pending_extents(trans, extent_root);
920 if (ret)
921 return ret;
922 if (pending_ret)
923 return pending_ret;
924 return 0;
925
926 }
927
928 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
929 struct btrfs_root *root)
930 {
931 struct extent_io_tree *block_group_cache;
932 struct btrfs_block_group_cache *cache;
933 int ret;
934 int err = 0;
935 int werr = 0;
936 struct btrfs_path *path;
937 u64 last = 0;
938 u64 start;
939 u64 end;
940 u64 ptr;
941
942 block_group_cache = &root->fs_info->block_group_cache;
943 path = btrfs_alloc_path();
944 if (!path)
945 return -ENOMEM;
946
947 while(1) {
948 ret = find_first_extent_bit(block_group_cache, last,
949 &start, &end, BLOCK_GROUP_DIRTY);
950 if (ret)
951 break;
952
953 last = end + 1;
954 ret = get_state_private(block_group_cache, start, &ptr);
955 if (ret)
956 break;
957
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 do_chunk_alloc(struct btrfs_trans_handle *trans,
993 struct btrfs_root *extent_root, u64 alloc_bytes,
994 u64 flags)
995 {
996 struct btrfs_space_info *space_info;
997 u64 thresh;
998 u64 start;
999 u64 num_bytes;
1000 int ret;
1001
1002 space_info = __find_space_info(extent_root->fs_info, flags);
1003 BUG_ON(!space_info);
1004
1005 if (space_info->full)
1006 return 0;
1007
1008 thresh = div_factor(space_info->total_bytes, 7);
1009 if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1010 thresh)
1011 return 0;
1012
1013 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1014 if (ret == -ENOSPC) {
1015 printk("space info full %Lu\n", flags);
1016 space_info->full = 1;
1017 return 0;
1018 }
1019
1020 BUG_ON(ret);
1021
1022 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1023 extent_root->fs_info->chunk_root->root_key.objectid,
1024 start, num_bytes);
1025 BUG_ON(ret);
1026 return 0;
1027 }
1028
1029 static int update_block_group(struct btrfs_trans_handle *trans,
1030 struct btrfs_root *root,
1031 u64 bytenr, u64 num_bytes, int alloc,
1032 int mark_free)
1033 {
1034 struct btrfs_block_group_cache *cache;
1035 struct btrfs_fs_info *info = root->fs_info;
1036 u64 total = num_bytes;
1037 u64 old_val;
1038 u64 byte_in_group;
1039 u64 start;
1040 u64 end;
1041
1042 while(total) {
1043 cache = btrfs_lookup_block_group(info, bytenr);
1044 if (!cache) {
1045 return -1;
1046 }
1047 byte_in_group = bytenr - cache->key.objectid;
1048 WARN_ON(byte_in_group > cache->key.offset);
1049 start = cache->key.objectid;
1050 end = start + cache->key.offset - 1;
1051 set_extent_bits(&info->block_group_cache, start, end,
1052 BLOCK_GROUP_DIRTY, GFP_NOFS);
1053
1054 old_val = btrfs_block_group_used(&cache->item);
1055 num_bytes = min(total, cache->key.offset - byte_in_group);
1056 if (alloc) {
1057 old_val += num_bytes;
1058 cache->space_info->bytes_used += num_bytes;
1059 } else {
1060 old_val -= num_bytes;
1061 cache->space_info->bytes_used -= num_bytes;
1062 if (mark_free) {
1063 set_extent_dirty(&info->free_space_cache,
1064 bytenr, bytenr + num_bytes - 1,
1065 GFP_NOFS);
1066 }
1067 }
1068 btrfs_set_block_group_used(&cache->item, old_val);
1069 total -= num_bytes;
1070 bytenr += num_bytes;
1071 }
1072 return 0;
1073 }
1074
1075 static int update_pinned_extents(struct btrfs_root *root,
1076 u64 bytenr, u64 num, int pin)
1077 {
1078 u64 len;
1079 struct btrfs_block_group_cache *cache;
1080 struct btrfs_fs_info *fs_info = root->fs_info;
1081
1082 if (pin) {
1083 set_extent_dirty(&fs_info->pinned_extents,
1084 bytenr, bytenr + num - 1, GFP_NOFS);
1085 } else {
1086 clear_extent_dirty(&fs_info->pinned_extents,
1087 bytenr, bytenr + num - 1, GFP_NOFS);
1088 }
1089 while (num > 0) {
1090 cache = btrfs_lookup_block_group(fs_info, bytenr);
1091 WARN_ON(!cache);
1092 len = min(num, cache->key.offset -
1093 (bytenr - cache->key.objectid));
1094 if (pin) {
1095 cache->pinned += len;
1096 cache->space_info->bytes_pinned += len;
1097 fs_info->total_pinned += len;
1098 } else {
1099 cache->pinned -= len;
1100 cache->space_info->bytes_pinned -= len;
1101 fs_info->total_pinned -= len;
1102 }
1103 bytenr += len;
1104 num -= len;
1105 }
1106 return 0;
1107 }
1108
1109 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1110 {
1111 u64 last = 0;
1112 u64 start;
1113 u64 end;
1114 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1115 int ret;
1116
1117 while(1) {
1118 ret = find_first_extent_bit(pinned_extents, last,
1119 &start, &end, EXTENT_DIRTY);
1120 if (ret)
1121 break;
1122 set_extent_dirty(copy, start, end, GFP_NOFS);
1123 last = end + 1;
1124 }
1125 return 0;
1126 }
1127
1128 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1129 struct btrfs_root *root,
1130 struct extent_io_tree *unpin)
1131 {
1132 u64 start;
1133 u64 end;
1134 int ret;
1135 struct extent_io_tree *free_space_cache;
1136 free_space_cache = &root->fs_info->free_space_cache;
1137
1138 while(1) {
1139 ret = find_first_extent_bit(unpin, 0, &start, &end,
1140 EXTENT_DIRTY);
1141 if (ret)
1142 break;
1143 update_pinned_extents(root, start, end + 1 - start, 0);
1144 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1145 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1146 }
1147 return 0;
1148 }
1149
1150 static int finish_current_insert(struct btrfs_trans_handle *trans,
1151 struct btrfs_root *extent_root)
1152 {
1153 u64 start;
1154 u64 end;
1155 struct btrfs_fs_info *info = extent_root->fs_info;
1156 struct extent_buffer *eb;
1157 struct btrfs_path *path;
1158 struct btrfs_key ins;
1159 struct btrfs_disk_key first;
1160 struct btrfs_extent_item extent_item;
1161 int ret;
1162 int level;
1163 int err = 0;
1164
1165 btrfs_set_stack_extent_refs(&extent_item, 1);
1166 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1167 path = btrfs_alloc_path();
1168
1169 while(1) {
1170 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1171 &end, EXTENT_LOCKED);
1172 if (ret)
1173 break;
1174
1175 ins.objectid = start;
1176 ins.offset = end + 1 - start;
1177 err = btrfs_insert_item(trans, extent_root, &ins,
1178 &extent_item, sizeof(extent_item));
1179 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1180 GFP_NOFS);
1181 eb = read_tree_block(extent_root, ins.objectid, ins.offset);
1182 level = btrfs_header_level(eb);
1183 if (level == 0) {
1184 btrfs_item_key(eb, &first, 0);
1185 } else {
1186 btrfs_node_key(eb, &first, 0);
1187 }
1188 err = btrfs_insert_extent_backref(trans, extent_root, path,
1189 start, extent_root->root_key.objectid,
1190 0, level,
1191 btrfs_disk_key_objectid(&first));
1192 BUG_ON(err);
1193 free_extent_buffer(eb);
1194 }
1195 btrfs_free_path(path);
1196 return 0;
1197 }
1198
1199 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1200 int pending)
1201 {
1202 int err = 0;
1203 struct extent_buffer *buf;
1204
1205 if (!pending) {
1206 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1207 if (buf) {
1208 if (btrfs_buffer_uptodate(buf)) {
1209 u64 transid =
1210 root->fs_info->running_transaction->transid;
1211 if (btrfs_header_generation(buf) == transid) {
1212 free_extent_buffer(buf);
1213 return 1;
1214 }
1215 }
1216 free_extent_buffer(buf);
1217 }
1218 update_pinned_extents(root, bytenr, num_bytes, 1);
1219 } else {
1220 set_extent_bits(&root->fs_info->pending_del,
1221 bytenr, bytenr + num_bytes - 1,
1222 EXTENT_LOCKED, GFP_NOFS);
1223 }
1224 BUG_ON(err < 0);
1225 return 0;
1226 }
1227
1228 /*
1229 * remove an extent from the root, returns 0 on success
1230 */
1231 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1232 *root, u64 bytenr, u64 num_bytes,
1233 u64 root_objectid, u64 ref_generation,
1234 u64 owner_objectid, u64 owner_offset, int pin,
1235 int mark_free)
1236 {
1237 struct btrfs_path *path;
1238 struct btrfs_key key;
1239 struct btrfs_fs_info *info = root->fs_info;
1240 struct btrfs_extent_ops *ops = info->extent_ops;
1241 struct btrfs_root *extent_root = info->extent_root;
1242 struct extent_buffer *leaf;
1243 int ret;
1244 int extent_slot = 0;
1245 int found_extent = 0;
1246 int num_to_del = 1;
1247 struct btrfs_extent_item *ei;
1248 u32 refs;
1249
1250 key.objectid = bytenr;
1251 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1252 key.offset = num_bytes;
1253
1254 path = btrfs_alloc_path();
1255 if (!path)
1256 return -ENOMEM;
1257
1258 ret = lookup_extent_backref(trans, extent_root, path,
1259 bytenr, root_objectid,
1260 ref_generation,
1261 owner_objectid, owner_offset, 1);
1262 if (ret == 0) {
1263 struct btrfs_key found_key;
1264 extent_slot = path->slots[0];
1265 while(extent_slot > 0) {
1266 extent_slot--;
1267 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1268 extent_slot);
1269 if (found_key.objectid != bytenr)
1270 break;
1271 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1272 found_key.offset == num_bytes) {
1273 found_extent = 1;
1274 break;
1275 }
1276 if (path->slots[0] - extent_slot > 5)
1277 break;
1278 }
1279 if (!found_extent)
1280 ret = btrfs_del_item(trans, extent_root, path);
1281 } else {
1282 btrfs_print_leaf(extent_root, path->nodes[0]);
1283 WARN_ON(1);
1284 printk("Unable to find ref byte nr %Lu root %Lu "
1285 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1286 root_objectid, ref_generation, owner_objectid,
1287 owner_offset);
1288 }
1289 if (!found_extent) {
1290 btrfs_release_path(extent_root, path);
1291 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1292 if (ret < 0)
1293 return ret;
1294 BUG_ON(ret);
1295 extent_slot = path->slots[0];
1296 }
1297
1298 leaf = path->nodes[0];
1299 ei = btrfs_item_ptr(leaf, extent_slot,
1300 struct btrfs_extent_item);
1301 refs = btrfs_extent_refs(leaf, ei);
1302 BUG_ON(refs == 0);
1303 refs -= 1;
1304 btrfs_set_extent_refs(leaf, ei, refs);
1305
1306 btrfs_mark_buffer_dirty(leaf);
1307
1308 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1309 /* if the back ref and the extent are next to each other
1310 * they get deleted below in one shot
1311 */
1312 path->slots[0] = extent_slot;
1313 num_to_del = 2;
1314 } else if (found_extent) {
1315 /* otherwise delete the extent back ref */
1316 ret = btrfs_del_item(trans, extent_root, path);
1317 BUG_ON(ret);
1318 /* if refs are 0, we need to setup the path for deletion */
1319 if (refs == 0) {
1320 btrfs_release_path(extent_root, path);
1321 ret = btrfs_search_slot(trans, extent_root, &key, path,
1322 -1, 1);
1323 if (ret < 0)
1324 return ret;
1325 BUG_ON(ret);
1326 }
1327 }
1328
1329 if (refs == 0) {
1330 u64 super_used;
1331 u64 root_used;
1332
1333 if (pin) {
1334 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1335 if (ret > 0)
1336 mark_free = 1;
1337 BUG_ON(ret < 0);
1338 }
1339
1340 /* block accounting for super block */
1341 super_used = btrfs_super_bytes_used(&info->super_copy);
1342 btrfs_set_super_bytes_used(&info->super_copy,
1343 super_used - num_bytes);
1344
1345 /* block accounting for root item */
1346 root_used = btrfs_root_used(&root->root_item);
1347 btrfs_set_root_used(&root->root_item,
1348 root_used - num_bytes);
1349 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1350 num_to_del);
1351 if (ret)
1352 return ret;
1353
1354 if (ops && ops->free_extent)
1355 ops->free_extent(root, bytenr, num_bytes);
1356
1357 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1358 mark_free);
1359 BUG_ON(ret);
1360 }
1361 btrfs_free_path(path);
1362 finish_current_insert(trans, extent_root);
1363 return ret;
1364 }
1365
1366 /*
1367 * find all the blocks marked as pending in the radix tree and remove
1368 * them from the extent map
1369 */
1370 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1371 btrfs_root *extent_root)
1372 {
1373 int ret;
1374 int err = 0;
1375 u64 start;
1376 u64 end;
1377 struct extent_io_tree *pending_del;
1378 struct extent_io_tree *pinned_extents;
1379
1380 pending_del = &extent_root->fs_info->pending_del;
1381 pinned_extents = &extent_root->fs_info->pinned_extents;
1382
1383 while(1) {
1384 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1385 EXTENT_LOCKED);
1386 if (ret)
1387 break;
1388 update_pinned_extents(extent_root, start, end + 1 - start, 1);
1389 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1390 GFP_NOFS);
1391 ret = __free_extent(trans, extent_root,
1392 start, end + 1 - start,
1393 extent_root->root_key.objectid,
1394 0, 0, 0, 0, 0);
1395 if (ret)
1396 err = ret;
1397 }
1398 return err;
1399 }
1400
1401 /*
1402 * remove an extent from the root, returns 0 on success
1403 */
1404 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1405 *root, u64 bytenr, u64 num_bytes,
1406 u64 root_objectid, u64 ref_generation,
1407 u64 owner_objectid, u64 owner_offset, int pin)
1408 {
1409 struct btrfs_root *extent_root = root->fs_info->extent_root;
1410 int pending_ret;
1411 int ret;
1412
1413 WARN_ON(num_bytes < root->sectorsize);
1414 if (!root->ref_cows)
1415 ref_generation = 0;
1416
1417 if (root == extent_root) {
1418 pin_down_bytes(root, bytenr, num_bytes, 1);
1419 return 0;
1420 }
1421 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1422 ref_generation, owner_objectid, owner_offset,
1423 pin, pin == 0);
1424 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1425 return ret ? ret : pending_ret;
1426 }
1427
1428 static u64 stripe_align(struct btrfs_root *root, u64 val)
1429 {
1430 u64 mask = ((u64)root->stripesize - 1);
1431 u64 ret = (val + mask) & ~mask;
1432 return ret;
1433 }
1434
1435 /*
1436 * walks the btree of allocated extents and find a hole of a given size.
1437 * The key ins is changed to record the hole:
1438 * ins->objectid == block start
1439 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1440 * ins->offset == number of blocks
1441 * Any available blocks before search_start are skipped.
1442 */
1443 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1444 struct btrfs_root *orig_root,
1445 u64 num_bytes, u64 empty_size,
1446 u64 search_start, u64 search_end,
1447 u64 hint_byte, struct btrfs_key *ins,
1448 u64 exclude_start, u64 exclude_nr,
1449 int data)
1450 {
1451 int ret;
1452 u64 orig_search_start = search_start;
1453 struct btrfs_root * root = orig_root->fs_info->extent_root;
1454 struct btrfs_fs_info *info = root->fs_info;
1455 u64 total_needed = num_bytes;
1456 struct btrfs_block_group_cache *block_group;
1457 int full_scan = 0;
1458 int wrapped = 0;
1459
1460 WARN_ON(num_bytes < root->sectorsize);
1461 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1462
1463 if (search_end == (u64)-1)
1464 search_end = btrfs_super_total_bytes(&info->super_copy);
1465
1466 if (hint_byte) {
1467 block_group = btrfs_lookup_block_group(info, hint_byte);
1468 if (!block_group)
1469 hint_byte = search_start;
1470 block_group = btrfs_find_block_group(root, block_group,
1471 hint_byte, data, 1);
1472 } else {
1473 block_group = btrfs_find_block_group(root,
1474 trans->block_group,
1475 search_start, data, 1);
1476 }
1477
1478 total_needed += empty_size;
1479
1480 check_failed:
1481 if (!block_group) {
1482 block_group = btrfs_lookup_block_group(info, search_start);
1483 if (!block_group)
1484 block_group = btrfs_lookup_block_group(info,
1485 orig_search_start);
1486 }
1487 ret = find_search_start(root, &block_group, &search_start,
1488 total_needed, data);
1489 if (ret)
1490 goto error;
1491
1492 search_start = stripe_align(root, search_start);
1493 ins->objectid = search_start;
1494 ins->offset = num_bytes;
1495
1496 if (ins->objectid + num_bytes >= search_end)
1497 goto enospc;
1498
1499 if (ins->objectid + num_bytes >
1500 block_group->key.objectid + block_group->key.offset) {
1501 search_start = block_group->key.objectid +
1502 block_group->key.offset;
1503 goto new_group;
1504 }
1505
1506 if (test_range_bit(&info->extent_ins, ins->objectid,
1507 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1508 search_start = ins->objectid + num_bytes;
1509 goto new_group;
1510 }
1511
1512 if (test_range_bit(&info->pinned_extents, ins->objectid,
1513 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
1514 search_start = ins->objectid + num_bytes;
1515 goto new_group;
1516 }
1517
1518 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
1519 ins->objectid < exclude_start + exclude_nr)) {
1520 search_start = exclude_start + exclude_nr;
1521 goto new_group;
1522 }
1523
1524 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
1525 block_group = btrfs_lookup_block_group(info, ins->objectid);
1526 if (block_group)
1527 trans->block_group = block_group;
1528 }
1529 ins->offset = num_bytes;
1530 return 0;
1531
1532 new_group:
1533 if (search_start + num_bytes >= search_end) {
1534 enospc:
1535 search_start = orig_search_start;
1536 if (full_scan) {
1537 ret = -ENOSPC;
1538 goto error;
1539 }
1540 if (wrapped) {
1541 if (!full_scan)
1542 total_needed -= empty_size;
1543 full_scan = 1;
1544 } else
1545 wrapped = 1;
1546 }
1547 block_group = btrfs_lookup_block_group(info, search_start);
1548 cond_resched();
1549 block_group = btrfs_find_block_group(root, block_group,
1550 search_start, data, 0);
1551 goto check_failed;
1552
1553 error:
1554 return ret;
1555 }
1556 /*
1557 * finds a free extent and does all the dirty work required for allocation
1558 * returns the key for the extent through ins, and a tree buffer for
1559 * the first block of the extent through buf.
1560 *
1561 * returns 0 if everything worked, non-zero otherwise.
1562 */
1563 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
1564 struct btrfs_root *root,
1565 u64 num_bytes, u64 root_objectid, u64 ref_generation,
1566 u64 owner, u64 owner_offset,
1567 u64 empty_size, u64 hint_byte,
1568 u64 search_end, struct btrfs_key *ins, int data)
1569 {
1570 int ret;
1571 int pending_ret;
1572 u64 super_used, root_used;
1573 u64 search_start = 0;
1574 struct btrfs_fs_info *info = root->fs_info;
1575 struct btrfs_extent_ops *ops = info->extent_ops;
1576 u32 sizes[2];
1577 struct btrfs_root *extent_root = info->extent_root;
1578 struct btrfs_path *path;
1579 struct btrfs_extent_item *extent_item;
1580 struct btrfs_extent_ref *ref;
1581 struct btrfs_key keys[2];
1582
1583 if (data) {
1584 data = BTRFS_BLOCK_GROUP_DATA;
1585 } else if (root == root->fs_info->chunk_root ||
1586 info->force_system_allocs) {
1587 data = BTRFS_BLOCK_GROUP_SYSTEM;
1588 } else {
1589 data = BTRFS_BLOCK_GROUP_METADATA;
1590 }
1591
1592 if (root->ref_cows) {
1593 if (data != BTRFS_BLOCK_GROUP_METADATA) {
1594 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1595 num_bytes,
1596 BTRFS_BLOCK_GROUP_METADATA);
1597 BUG_ON(ret);
1598 }
1599 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
1600 num_bytes, data);
1601 BUG_ON(ret);
1602 }
1603
1604 WARN_ON(num_bytes < root->sectorsize);
1605 if (ops && ops->alloc_extent) {
1606 ret = ops->alloc_extent(root, num_bytes, hint_byte, ins);
1607 } else {
1608 ret = find_free_extent(trans, root, num_bytes, empty_size,
1609 search_start, search_end, hint_byte,
1610 ins, trans->alloc_exclude_start,
1611 trans->alloc_exclude_nr, data);
1612 }
1613 BUG_ON(ret);
1614 if (ret)
1615 return ret;
1616
1617 /* block accounting for super block */
1618 super_used = btrfs_super_bytes_used(&info->super_copy);
1619 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
1620
1621 /* block accounting for root item */
1622 root_used = btrfs_root_used(&root->root_item);
1623 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
1624
1625 clear_extent_dirty(&root->fs_info->free_space_cache,
1626 ins->objectid, ins->objectid + ins->offset - 1,
1627 GFP_NOFS);
1628
1629 if (root == extent_root) {
1630 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
1631 ins->objectid + ins->offset - 1,
1632 EXTENT_LOCKED, GFP_NOFS);
1633 goto update_block;
1634 }
1635
1636 WARN_ON(trans->alloc_exclude_nr);
1637 trans->alloc_exclude_start = ins->objectid;
1638 trans->alloc_exclude_nr = ins->offset;
1639
1640 memcpy(&keys[0], ins, sizeof(*ins));
1641 keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
1642 owner, owner_offset);
1643 keys[1].objectid = ins->objectid;
1644 keys[1].type = BTRFS_EXTENT_REF_KEY;
1645 sizes[0] = sizeof(*extent_item);
1646 sizes[1] = sizeof(*ref);
1647
1648 path = btrfs_alloc_path();
1649 BUG_ON(!path);
1650
1651 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
1652 sizes, 2);
1653
1654 BUG_ON(ret);
1655 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1656 struct btrfs_extent_item);
1657 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
1658 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
1659 struct btrfs_extent_ref);
1660
1661 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
1662 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
1663 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
1664 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
1665
1666 btrfs_mark_buffer_dirty(path->nodes[0]);
1667
1668 trans->alloc_exclude_start = 0;
1669 trans->alloc_exclude_nr = 0;
1670 btrfs_free_path(path);
1671 finish_current_insert(trans, extent_root);
1672 pending_ret = del_pending_extents(trans, extent_root);
1673
1674 if (ret) {
1675 return ret;
1676 }
1677 if (pending_ret) {
1678 return pending_ret;
1679 }
1680
1681 update_block:
1682 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
1683 if (ret) {
1684 printk("update block group failed for %Lu %Lu\n",
1685 ins->objectid, ins->offset);
1686 BUG();
1687 }
1688 return 0;
1689 }
1690
1691 /*
1692 * helper function to allocate a block for a given tree
1693 * returns the tree buffer or NULL.
1694 */
1695 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1696 struct btrfs_root *root,
1697 u32 blocksize,
1698 u64 root_objectid, u64 hint,
1699 u64 empty_size)
1700 {
1701 u64 ref_generation;
1702
1703 if (root->ref_cows)
1704 ref_generation = trans->transid;
1705 else
1706 ref_generation = 0;
1707
1708
1709 return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid,
1710 ref_generation, 0, 0, hint, empty_size);
1711 }
1712
1713 /*
1714 * helper function to allocate a block for a given tree
1715 * returns the tree buffer or NULL.
1716 */
1717 struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
1718 struct btrfs_root *root,
1719 u32 blocksize,
1720 u64 root_objectid,
1721 u64 ref_generation,
1722 u64 first_objectid,
1723 int level,
1724 u64 hint,
1725 u64 empty_size)
1726 {
1727 struct btrfs_key ins;
1728 int ret;
1729 struct extent_buffer *buf;
1730
1731 ret = btrfs_alloc_extent(trans, root, blocksize,
1732 root_objectid, ref_generation,
1733 level, first_objectid, empty_size, hint,
1734 (u64)-1, &ins, 0);
1735 if (ret) {
1736 BUG_ON(ret > 0);
1737 return ERR_PTR(ret);
1738 }
1739 buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize);
1740 if (!buf) {
1741 btrfs_free_extent(trans, root, ins.objectid, blocksize,
1742 root->root_key.objectid, ref_generation,
1743 0, 0, 0);
1744 BUG_ON(1);
1745 return ERR_PTR(-ENOMEM);
1746 }
1747 btrfs_set_buffer_uptodate(buf);
1748 trans->blocks_used++;
1749 return buf;
1750 }
1751
1752 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
1753 struct btrfs_root *root,
1754 struct extent_buffer *leaf)
1755 {
1756 u64 leaf_owner;
1757 u64 leaf_generation;
1758 struct btrfs_key key;
1759 struct btrfs_file_extent_item *fi;
1760 int i;
1761 int nritems;
1762 int ret;
1763
1764 BUG_ON(!btrfs_is_leaf(leaf));
1765 nritems = btrfs_header_nritems(leaf);
1766 leaf_owner = btrfs_header_owner(leaf);
1767 leaf_generation = btrfs_header_generation(leaf);
1768
1769 for (i = 0; i < nritems; i++) {
1770 u64 disk_bytenr;
1771
1772 btrfs_item_key_to_cpu(leaf, &key, i);
1773 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1774 continue;
1775 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1776 if (btrfs_file_extent_type(leaf, fi) ==
1777 BTRFS_FILE_EXTENT_INLINE)
1778 continue;
1779 /*
1780 * FIXME make sure to insert a trans record that
1781 * repeats the snapshot del on crash
1782 */
1783 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1784 if (disk_bytenr == 0)
1785 continue;
1786 ret = btrfs_free_extent(trans, root, disk_bytenr,
1787 btrfs_file_extent_disk_num_bytes(leaf, fi),
1788 leaf_owner, leaf_generation,
1789 key.objectid, key.offset, 0);
1790 BUG_ON(ret);
1791 }
1792 return 0;
1793 }
1794
1795 static void noinline reada_walk_down(struct btrfs_root *root,
1796 struct extent_buffer *node,
1797 int slot)
1798 {
1799 u64 bytenr;
1800 u64 last = 0;
1801 u32 nritems;
1802 u32 refs;
1803 u32 blocksize;
1804 int ret;
1805 int i;
1806 int level;
1807 int skipped = 0;
1808
1809 nritems = btrfs_header_nritems(node);
1810 level = btrfs_header_level(node);
1811 if (level)
1812 return;
1813
1814 for (i = slot; i < nritems && skipped < 32; i++) {
1815 bytenr = btrfs_node_blockptr(node, i);
1816 if (last && ((bytenr > last && bytenr - last > 32 * 1024) ||
1817 (last > bytenr && last - bytenr > 32 * 1024))) {
1818 skipped++;
1819 continue;
1820 }
1821 blocksize = btrfs_level_size(root, level - 1);
1822 if (i != slot) {
1823 ret = lookup_extent_ref(NULL, root, bytenr,
1824 blocksize, &refs);
1825 BUG_ON(ret);
1826 if (refs != 1) {
1827 skipped++;
1828 continue;
1829 }
1830 }
1831 mutex_unlock(&root->fs_info->fs_mutex);
1832 ret = readahead_tree_block(root, bytenr, blocksize);
1833 last = bytenr + blocksize;
1834 cond_resched();
1835 mutex_lock(&root->fs_info->fs_mutex);
1836 if (ret)
1837 break;
1838 }
1839 }
1840
1841 /*
1842 * helper function for drop_snapshot, this walks down the tree dropping ref
1843 * counts as it goes.
1844 */
1845 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
1846 struct btrfs_root *root,
1847 struct btrfs_path *path, int *level)
1848 {
1849 u64 root_owner;
1850 u64 root_gen;
1851 u64 bytenr;
1852 struct extent_buffer *next;
1853 struct extent_buffer *cur;
1854 struct extent_buffer *parent;
1855 u32 blocksize;
1856 int ret;
1857 u32 refs;
1858
1859 WARN_ON(*level < 0);
1860 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1861 ret = lookup_extent_ref(trans, root,
1862 path->nodes[*level]->start,
1863 path->nodes[*level]->len, &refs);
1864 BUG_ON(ret);
1865 if (refs > 1)
1866 goto out;
1867
1868 /*
1869 * walk down to the last node level and free all the leaves
1870 */
1871 while(*level >= 0) {
1872 WARN_ON(*level < 0);
1873 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1874 cur = path->nodes[*level];
1875
1876 if (btrfs_header_level(cur) != *level)
1877 WARN_ON(1);
1878
1879 if (path->slots[*level] >=
1880 btrfs_header_nritems(cur))
1881 break;
1882 if (*level == 0) {
1883 ret = drop_leaf_ref(trans, root, cur);
1884 BUG_ON(ret);
1885 break;
1886 }
1887 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1888 blocksize = btrfs_level_size(root, *level - 1);
1889 ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
1890 BUG_ON(ret);
1891 if (refs != 1) {
1892 parent = path->nodes[*level];
1893 root_owner = btrfs_header_owner(parent);
1894 root_gen = btrfs_header_generation(parent);
1895 path->slots[*level]++;
1896 ret = btrfs_free_extent(trans, root, bytenr,
1897 blocksize, root_owner,
1898 root_gen, 0, 0, 1);
1899 BUG_ON(ret);
1900 continue;
1901 }
1902 next = btrfs_find_tree_block(root, bytenr, blocksize);
1903 if (!next || !btrfs_buffer_uptodate(next)) {
1904 free_extent_buffer(next);
1905 reada_walk_down(root, cur, path->slots[*level]);
1906 mutex_unlock(&root->fs_info->fs_mutex);
1907 next = read_tree_block(root, bytenr, blocksize);
1908 mutex_lock(&root->fs_info->fs_mutex);
1909
1910 /* we dropped the lock, check one more time */
1911 ret = lookup_extent_ref(trans, root, bytenr,
1912 blocksize, &refs);
1913 BUG_ON(ret);
1914 if (refs != 1) {
1915 parent = path->nodes[*level];
1916 root_owner = btrfs_header_owner(parent);
1917 root_gen = btrfs_header_generation(parent);
1918
1919 path->slots[*level]++;
1920 free_extent_buffer(next);
1921 ret = btrfs_free_extent(trans, root, bytenr,
1922 blocksize,
1923 root_owner,
1924 root_gen, 0, 0, 1);
1925 BUG_ON(ret);
1926 continue;
1927 }
1928 }
1929 WARN_ON(*level <= 0);
1930 if (path->nodes[*level-1])
1931 free_extent_buffer(path->nodes[*level-1]);
1932 path->nodes[*level-1] = next;
1933 *level = btrfs_header_level(next);
1934 path->slots[*level] = 0;
1935 }
1936 out:
1937 WARN_ON(*level < 0);
1938 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1939
1940 if (path->nodes[*level] == root->node) {
1941 root_owner = root->root_key.objectid;
1942 parent = path->nodes[*level];
1943 } else {
1944 parent = path->nodes[*level + 1];
1945 root_owner = btrfs_header_owner(parent);
1946 }
1947
1948 root_gen = btrfs_header_generation(parent);
1949 ret = btrfs_free_extent(trans, root, path->nodes[*level]->start,
1950 path->nodes[*level]->len,
1951 root_owner, root_gen, 0, 0, 1);
1952 free_extent_buffer(path->nodes[*level]);
1953 path->nodes[*level] = NULL;
1954 *level += 1;
1955 BUG_ON(ret);
1956 return 0;
1957 }
1958
1959 /*
1960 * helper for dropping snapshots. This walks back up the tree in the path
1961 * to find the first node higher up where we haven't yet gone through
1962 * all the slots
1963 */
1964 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
1965 struct btrfs_root *root,
1966 struct btrfs_path *path, int *level)
1967 {
1968 u64 root_owner;
1969 u64 root_gen;
1970 struct btrfs_root_item *root_item = &root->root_item;
1971 int i;
1972 int slot;
1973 int ret;
1974
1975 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1976 slot = path->slots[i];
1977 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
1978 struct extent_buffer *node;
1979 struct btrfs_disk_key disk_key;
1980 node = path->nodes[i];
1981 path->slots[i]++;
1982 *level = i;
1983 WARN_ON(*level == 0);
1984 btrfs_node_key(node, &disk_key, path->slots[i]);
1985 memcpy(&root_item->drop_progress,
1986 &disk_key, sizeof(disk_key));
1987 root_item->drop_level = i;
1988 return 0;
1989 } else {
1990 if (path->nodes[*level] == root->node) {
1991 root_owner = root->root_key.objectid;
1992 root_gen =
1993 btrfs_header_generation(path->nodes[*level]);
1994 } else {
1995 struct extent_buffer *node;
1996 node = path->nodes[*level + 1];
1997 root_owner = btrfs_header_owner(node);
1998 root_gen = btrfs_header_generation(node);
1999 }
2000 ret = btrfs_free_extent(trans, root,
2001 path->nodes[*level]->start,
2002 path->nodes[*level]->len,
2003 root_owner, root_gen, 0, 0, 1);
2004 BUG_ON(ret);
2005 free_extent_buffer(path->nodes[*level]);
2006 path->nodes[*level] = NULL;
2007 *level = i + 1;
2008 }
2009 }
2010 return 1;
2011 }
2012
2013 /*
2014 * drop the reference count on the tree rooted at 'snap'. This traverses
2015 * the tree freeing any blocks that have a ref count of zero after being
2016 * decremented.
2017 */
2018 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2019 *root)
2020 {
2021 int ret = 0;
2022 int wret;
2023 int level;
2024 struct btrfs_path *path;
2025 int i;
2026 int orig_level;
2027 struct btrfs_root_item *root_item = &root->root_item;
2028
2029 path = btrfs_alloc_path();
2030 BUG_ON(!path);
2031
2032 level = btrfs_header_level(root->node);
2033 orig_level = level;
2034 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2035 path->nodes[level] = root->node;
2036 extent_buffer_get(root->node);
2037 path->slots[level] = 0;
2038 } else {
2039 struct btrfs_key key;
2040 struct btrfs_disk_key found_key;
2041 struct extent_buffer *node;
2042
2043 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2044 level = root_item->drop_level;
2045 path->lowest_level = level;
2046 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2047 if (wret < 0) {
2048 ret = wret;
2049 goto out;
2050 }
2051 node = path->nodes[level];
2052 btrfs_node_key(node, &found_key, path->slots[level]);
2053 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2054 sizeof(found_key)));
2055 }
2056 while(1) {
2057 wret = walk_down_tree(trans, root, path, &level);
2058 if (wret < 0)
2059 ret = wret;
2060 if (wret != 0)
2061 break;
2062
2063 wret = walk_up_tree(trans, root, path, &level);
2064 if (wret < 0)
2065 ret = wret;
2066 if (wret != 0)
2067 break;
2068 /*
2069 ret = -EAGAIN;
2070 break;
2071 */
2072 }
2073 for (i = 0; i <= orig_level; i++) {
2074 if (path->nodes[i]) {
2075 free_extent_buffer(path->nodes[i]);
2076 path->nodes[i] = NULL;
2077 }
2078 }
2079 out:
2080 btrfs_free_path(path);
2081 return ret;
2082 }
2083
2084 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2085 {
2086 u64 start;
2087 u64 end;
2088 u64 ptr;
2089 int ret;
2090 while(1) {
2091 ret = find_first_extent_bit(&info->block_group_cache, 0,
2092 &start, &end, (unsigned int)-1);
2093 if (ret)
2094 break;
2095 ret = get_state_private(&info->block_group_cache, start, &ptr);
2096 if (!ret)
2097 kfree((void *)(unsigned long)ptr);
2098 clear_extent_bits(&info->block_group_cache, start,
2099 end, (unsigned int)-1, GFP_NOFS);
2100 }
2101 while(1) {
2102 ret = find_first_extent_bit(&info->free_space_cache, 0,
2103 &start, &end, EXTENT_DIRTY);
2104 if (ret)
2105 break;
2106 clear_extent_dirty(&info->free_space_cache, start,
2107 end, GFP_NOFS);
2108 }
2109 return 0;
2110 }
2111
2112 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
2113 struct btrfs_key *key)
2114 {
2115 int ret;
2116 struct btrfs_key found_key;
2117 struct extent_buffer *leaf;
2118 int slot;
2119
2120 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
2121 if (ret < 0)
2122 return ret;
2123 while(1) {
2124 slot = path->slots[0];
2125 leaf = path->nodes[0];
2126 if (slot >= btrfs_header_nritems(leaf)) {
2127 ret = btrfs_next_leaf(root, path);
2128 if (ret == 0)
2129 continue;
2130 if (ret < 0)
2131 goto error;
2132 break;
2133 }
2134 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2135
2136 if (found_key.objectid >= key->objectid &&
2137 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY)
2138 return 0;
2139 path->slots[0]++;
2140 }
2141 ret = -ENOENT;
2142 error:
2143 return ret;
2144 }
2145
2146 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
2147 u64 total_bytes, u64 bytes_used,
2148 struct btrfs_space_info **space_info)
2149 {
2150 struct btrfs_space_info *found;
2151
2152 found = __find_space_info(info, flags);
2153 if (found) {
2154 found->total_bytes += total_bytes;
2155 found->bytes_used += bytes_used;
2156 WARN_ON(found->total_bytes < found->bytes_used);
2157 *space_info = found;
2158 return 0;
2159 }
2160 found = kmalloc(sizeof(*found), GFP_NOFS);
2161 if (!found)
2162 return -ENOMEM;
2163
2164 list_add(&found->list, &info->space_info);
2165 found->flags = flags;
2166 found->total_bytes = total_bytes;
2167 found->bytes_used = bytes_used;
2168 found->bytes_pinned = 0;
2169 found->full = 0;
2170 *space_info = found;
2171 return 0;
2172 }
2173
2174 int btrfs_read_block_groups(struct btrfs_root *root)
2175 {
2176 struct btrfs_path *path;
2177 int ret;
2178 int bit;
2179 struct btrfs_block_group_cache *cache;
2180 struct btrfs_fs_info *info = root->fs_info;
2181 struct btrfs_space_info *space_info;
2182 struct extent_io_tree *block_group_cache;
2183 struct btrfs_key key;
2184 struct btrfs_key found_key;
2185 struct extent_buffer *leaf;
2186
2187 block_group_cache = &info->block_group_cache;
2188
2189 root = info->extent_root;
2190 key.objectid = 0;
2191 key.offset = 0;
2192 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2193 path = btrfs_alloc_path();
2194 if (!path)
2195 return -ENOMEM;
2196
2197 while(1) {
2198 ret = find_first_block_group(root, path, &key);
2199 if (ret > 0) {
2200 ret = 0;
2201 goto error;
2202 }
2203 if (ret != 0) {
2204 goto error;
2205 }
2206 leaf = path->nodes[0];
2207 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2208 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2209 if (!cache) {
2210 ret = -ENOMEM;
2211 break;
2212 }
2213
2214 read_extent_buffer(leaf, &cache->item,
2215 btrfs_item_ptr_offset(leaf, path->slots[0]),
2216 sizeof(cache->item));
2217 memcpy(&cache->key, &found_key, sizeof(found_key));
2218 cache->cached = 0;
2219 cache->pinned = 0;
2220 key.objectid = found_key.objectid + found_key.offset;
2221 btrfs_release_path(root, path);
2222 cache->flags = btrfs_block_group_flags(&cache->item);
2223 bit = 0;
2224 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
2225 bit = BLOCK_GROUP_DATA;
2226 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
2227 bit = BLOCK_GROUP_SYSTEM;
2228 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
2229 bit = BLOCK_GROUP_METADATA;
2230 }
2231
2232 ret = update_space_info(info, cache->flags, found_key.offset,
2233 btrfs_block_group_used(&cache->item),
2234 &space_info);
2235 BUG_ON(ret);
2236 cache->space_info = space_info;
2237
2238 /* use EXTENT_LOCKED to prevent merging */
2239 set_extent_bits(block_group_cache, found_key.objectid,
2240 found_key.objectid + found_key.offset - 1,
2241 bit | EXTENT_LOCKED, GFP_NOFS);
2242 set_state_private(block_group_cache, found_key.objectid,
2243 (unsigned long)cache);
2244
2245 if (key.objectid >=
2246 btrfs_super_total_bytes(&info->super_copy))
2247 break;
2248 }
2249 ret = 0;
2250 error:
2251 btrfs_free_path(path);
2252 return ret;
2253 }
2254
2255 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
2256 struct btrfs_root *root, u64 bytes_used,
2257 u64 type, u64 chunk_tree, u64 chunk_objectid,
2258 u64 size)
2259 {
2260 int ret;
2261 int bit = 0;
2262 struct btrfs_root *extent_root;
2263 struct btrfs_block_group_cache *cache;
2264 struct extent_io_tree *block_group_cache;
2265
2266 extent_root = root->fs_info->extent_root;
2267 block_group_cache = &root->fs_info->block_group_cache;
2268
2269 cache = kmalloc(sizeof(*cache), GFP_NOFS);
2270 BUG_ON(!cache);
2271 cache->key.objectid = chunk_objectid;
2272 cache->key.offset = size;
2273 cache->cached = 0;
2274 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
2275 memset(&cache->item, 0, sizeof(cache->item));
2276 btrfs_set_block_group_used(&cache->item, bytes_used);
2277 btrfs_set_block_group_chunk_tree(&cache->item, chunk_tree);
2278 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
2279 cache->flags = type;
2280 btrfs_set_block_group_flags(&cache->item, type);
2281
2282 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
2283 &cache->space_info);
2284 BUG_ON(ret);
2285
2286 if (type & BTRFS_BLOCK_GROUP_DATA) {
2287 bit = BLOCK_GROUP_DATA;
2288 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2289 bit = BLOCK_GROUP_SYSTEM;
2290 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2291 bit = BLOCK_GROUP_METADATA;
2292 }
2293 set_extent_bits(block_group_cache, chunk_objectid,
2294 chunk_objectid + size - 1,
2295 bit | EXTENT_LOCKED, GFP_NOFS);
2296 set_state_private(block_group_cache, chunk_objectid,
2297 (unsigned long)cache);
2298
2299 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
2300 sizeof(cache->item));
2301 BUG_ON(ret);
2302
2303 finish_current_insert(trans, extent_root);
2304 ret = del_pending_extents(trans, extent_root);
2305 BUG_ON(ret);
2306 return 0;
2307 }
2308
2309 u64 btrfs_hash_extent_ref(u64 root_objectid, u64 ref_generation,
2310 u64 owner, u64 owner_offset)
2311 {
2312 return hash_extent_ref(root_objectid, ref_generation,
2313 owner, owner_offset);
2314 }
2315
2316 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
2317 struct btrfs_root *root,
2318 u64 bytenr, u64 num_bytes, int alloc,
2319 int mark_free)
2320 {
2321 return update_block_group(trans, root, bytenr, num_bytes,
2322 alloc, mark_free);
2323 }
(deprecated) Btrfs progs developments and patch integration