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Btrfs: More throttle tuning
[linux-2.6/mini2440.git] / fs / btrfs / extent-tree.c
blob1aeb695078b90406b1ef215b55317a2967ba2e82
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/pagemap.h>
20 #include <linux/writeback.h>
21 #include "hash.h"
22 #include "crc32c.h"
23 #include "ctree.h"
24 #include "disk-io.h"
25 #include "print-tree.h"
26 #include "transaction.h"
27 #include "volumes.h"
28 #include "locking.h"
29 #include "ref-cache.h"
30
31 #define BLOCK_GROUP_DATA EXTENT_WRITEBACK
32 #define BLOCK_GROUP_METADATA EXTENT_UPTODATE
33 #define BLOCK_GROUP_SYSTEM EXTENT_NEW
34
35 #define BLOCK_GROUP_DIRTY EXTENT_DIRTY
36
37 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
38 btrfs_root *extent_root);
39 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
40 btrfs_root *extent_root);
41 static struct btrfs_block_group_cache *
42 __btrfs_find_block_group(struct btrfs_root *root,
43 struct btrfs_block_group_cache *hint,
44 u64 search_start, int data, int owner);
45
46 void maybe_lock_mutex(struct btrfs_root *root)
47 {
48 if (root != root->fs_info->extent_root &&
49 root != root->fs_info->chunk_root &&
50 root != root->fs_info->dev_root) {
51 mutex_lock(&root->fs_info->alloc_mutex);
52 }
53 }
54
55 void maybe_unlock_mutex(struct btrfs_root *root)
56 {
57 if (root != root->fs_info->extent_root &&
58 root != root->fs_info->chunk_root &&
59 root != root->fs_info->dev_root) {
60 mutex_unlock(&root->fs_info->alloc_mutex);
61 }
62 }
63
64 static int cache_block_group(struct btrfs_root *root,
65 struct btrfs_block_group_cache *block_group)
66 {
67 struct btrfs_path *path;
68 int ret;
69 struct btrfs_key key;
70 struct extent_buffer *leaf;
71 struct extent_io_tree *free_space_cache;
72 int slot;
73 u64 last = 0;
74 u64 hole_size;
75 u64 first_free;
76 int found = 0;
77
78 if (!block_group)
79 return 0;
80
81 root = root->fs_info->extent_root;
82 free_space_cache = &root->fs_info->free_space_cache;
83
84 if (block_group->cached)
85 return 0;
86
87 path = btrfs_alloc_path();
88 if (!path)
89 return -ENOMEM;
90
91 path->reada = 2;
92 /*
93 * we get into deadlocks with paths held by callers of this function.
94 * since the alloc_mutex is protecting things right now, just
95 * skip the locking here
96 */
97 path->skip_locking = 1;
98 first_free = block_group->key.objectid;
99 key.objectid = block_group->key.objectid;
100 key.offset = 0;
101 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
102 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
103 if (ret < 0)
104 return ret;
105 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
106 if (ret < 0)
107 return ret;
108 if (ret == 0) {
109 leaf = path->nodes[0];
110 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
111 if (key.objectid + key.offset > first_free)
112 first_free = key.objectid + key.offset;
113 }
114 while(1) {
115 leaf = path->nodes[0];
116 slot = path->slots[0];
117 if (slot >= btrfs_header_nritems(leaf)) {
118 ret = btrfs_next_leaf(root, path);
119 if (ret < 0)
120 goto err;
121 if (ret == 0) {
122 continue;
123 } else {
124 break;
125 }
126 }
127 btrfs_item_key_to_cpu(leaf, &key, slot);
128 if (key.objectid < block_group->key.objectid) {
129 goto next;
130 }
131 if (key.objectid >= block_group->key.objectid +
132 block_group->key.offset) {
133 break;
134 }
135
136 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
137 if (!found) {
138 last = first_free;
139 found = 1;
140 }
141 if (key.objectid > last) {
142 hole_size = key.objectid - last;
143 set_extent_dirty(free_space_cache, last,
144 last + hole_size - 1,
145 GFP_NOFS);
146 }
147 last = key.objectid + key.offset;
148 }
149 next:
150 path->slots[0]++;
151 }
152
153 if (!found)
154 last = first_free;
155 if (block_group->key.objectid +
156 block_group->key.offset > last) {
157 hole_size = block_group->key.objectid +
158 block_group->key.offset - last;
159 set_extent_dirty(free_space_cache, last,
160 last + hole_size - 1, GFP_NOFS);
161 }
162 block_group->cached = 1;
163 err:
164 btrfs_free_path(path);
165 return 0;
166 }
167
168 struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
169 btrfs_fs_info *info,
170 u64 bytenr)
171 {
172 struct extent_io_tree *block_group_cache;
173 struct btrfs_block_group_cache *block_group = NULL;
174 u64 ptr;
175 u64 start;
176 u64 end;
177 int ret;
178
179 bytenr = max_t(u64, bytenr,
180 BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
181 block_group_cache = &info->block_group_cache;
182 ret = find_first_extent_bit(block_group_cache,
183 bytenr, &start, &end,
184 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
185 BLOCK_GROUP_SYSTEM);
186 if (ret) {
187 return NULL;
188 }
189 ret = get_state_private(block_group_cache, start, &ptr);
190 if (ret)
191 return NULL;
192
193 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
194 return block_group;
195 }
196
197 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
198 btrfs_fs_info *info,
199 u64 bytenr)
200 {
201 struct extent_io_tree *block_group_cache;
202 struct btrfs_block_group_cache *block_group = NULL;
203 u64 ptr;
204 u64 start;
205 u64 end;
206 int ret;
207
208 bytenr = max_t(u64, bytenr,
209 BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
210 block_group_cache = &info->block_group_cache;
211 ret = find_first_extent_bit(block_group_cache,
212 bytenr, &start, &end,
213 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
214 BLOCK_GROUP_SYSTEM);
215 if (ret) {
216 return NULL;
217 }
218 ret = get_state_private(block_group_cache, start, &ptr);
219 if (ret)
220 return NULL;
221
222 block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr;
223 if (block_group->key.objectid <= bytenr && bytenr <
224 block_group->key.objectid + block_group->key.offset)
225 return block_group;
226 return NULL;
227 }
228
229 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
230 {
231 return (cache->flags & bits) == bits;
232 }
233
234 static int noinline find_search_start(struct btrfs_root *root,
235 struct btrfs_block_group_cache **cache_ret,
236 u64 *start_ret, u64 num, int data)
237 {
238 int ret;
239 struct btrfs_block_group_cache *cache = *cache_ret;
240 struct extent_io_tree *free_space_cache;
241 struct extent_state *state;
242 u64 last;
243 u64 start = 0;
244 u64 cache_miss = 0;
245 u64 total_fs_bytes;
246 u64 search_start = *start_ret;
247 int wrapped = 0;
248
249 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
250 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
251 free_space_cache = &root->fs_info->free_space_cache;
252
253 if (!cache)
254 goto out;
255
256 again:
257 ret = cache_block_group(root, cache);
258 if (ret) {
259 goto out;
260 }
261
262 last = max(search_start, cache->key.objectid);
263 if (!block_group_bits(cache, data) || cache->ro)
264 goto new_group;
265
266 spin_lock_irq(&free_space_cache->lock);
267 state = find_first_extent_bit_state(free_space_cache, last, EXTENT_DIRTY);
268 while(1) {
269 if (!state) {
270 if (!cache_miss)
271 cache_miss = last;
272 spin_unlock_irq(&free_space_cache->lock);
273 goto new_group;
274 }
275
276 start = max(last, state->start);
277 last = state->end + 1;
278 if (last - start < num) {
279 do {
280 state = extent_state_next(state);
281 } while(state && !(state->state & EXTENT_DIRTY));
282 continue;
283 }
284 spin_unlock_irq(&free_space_cache->lock);
285 if (cache->ro) {
286 goto new_group;
287 }
288 if (start + num > cache->key.objectid + cache->key.offset)
289 goto new_group;
290 if (!block_group_bits(cache, data)) {
291 printk("block group bits don't match %Lu %d\n", cache->flags, data);
292 }
293 *start_ret = start;
294 return 0;
295 }
296 out:
297 cache = btrfs_lookup_block_group(root->fs_info, search_start);
298 if (!cache) {
299 printk("Unable to find block group for %Lu\n", search_start);
300 WARN_ON(1);
301 }
302 return -ENOSPC;
303
304 new_group:
305 last = cache->key.objectid + cache->key.offset;
306 wrapped:
307 cache = btrfs_lookup_first_block_group(root->fs_info, last);
308 if (!cache || cache->key.objectid >= total_fs_bytes) {
309 no_cache:
310 if (!wrapped) {
311 wrapped = 1;
312 last = search_start;
313 goto wrapped;
314 }
315 goto out;
316 }
317 if (cache_miss && !cache->cached) {
318 cache_block_group(root, cache);
319 last = cache_miss;
320 cache = btrfs_lookup_first_block_group(root->fs_info, last);
321 }
322 cache_miss = 0;
323 cache = btrfs_find_block_group(root, cache, last, data, 0);
324 if (!cache)
325 goto no_cache;
326 *cache_ret = cache;
327 goto again;
328 }
329
330 static u64 div_factor(u64 num, int factor)
331 {
332 if (factor == 10)
333 return num;
334 num *= factor;
335 do_div(num, 10);
336 return num;
337 }
338
339 static int block_group_state_bits(u64 flags)
340 {
341 int bits = 0;
342 if (flags & BTRFS_BLOCK_GROUP_DATA)
343 bits |= BLOCK_GROUP_DATA;
344 if (flags & BTRFS_BLOCK_GROUP_METADATA)
345 bits |= BLOCK_GROUP_METADATA;
346 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
347 bits |= BLOCK_GROUP_SYSTEM;
348 return bits;
349 }
350
351 static struct btrfs_block_group_cache *
352 __btrfs_find_block_group(struct btrfs_root *root,
353 struct btrfs_block_group_cache *hint,
354 u64 search_start, int data, int owner)
355 {
356 struct btrfs_block_group_cache *cache;
357 struct extent_io_tree *block_group_cache;
358 struct btrfs_block_group_cache *found_group = NULL;
359 struct btrfs_fs_info *info = root->fs_info;
360 u64 used;
361 u64 last = 0;
362 u64 start;
363 u64 end;
364 u64 free_check;
365 u64 ptr;
366 int bit;
367 int ret;
368 int full_search = 0;
369 int factor = 10;
370 int wrapped = 0;
371
372 block_group_cache = &info->block_group_cache;
373
374 if (data & BTRFS_BLOCK_GROUP_METADATA)
375 factor = 9;
376
377 bit = block_group_state_bits(data);
378
379 if (search_start) {
380 struct btrfs_block_group_cache *shint;
381 shint = btrfs_lookup_first_block_group(info, search_start);
382 if (shint && block_group_bits(shint, data) && !shint->ro) {
383 spin_lock(&shint->lock);
384 used = btrfs_block_group_used(&shint->item);
385 if (used + shint->pinned <
386 div_factor(shint->key.offset, factor)) {
387 spin_unlock(&shint->lock);
388 return shint;
389 }
390 spin_unlock(&shint->lock);
391 }
392 }
393 if (hint && !hint->ro && block_group_bits(hint, data)) {
394 spin_lock(&hint->lock);
395 used = btrfs_block_group_used(&hint->item);
396 if (used + hint->pinned <
397 div_factor(hint->key.offset, factor)) {
398 spin_unlock(&hint->lock);
399 return hint;
400 }
401 spin_unlock(&hint->lock);
402 last = hint->key.objectid + hint->key.offset;
403 } else {
404 if (hint)
405 last = max(hint->key.objectid, search_start);
406 else
407 last = search_start;
408 }
409 again:
410 while(1) {
411 ret = find_first_extent_bit(block_group_cache, last,
412 &start, &end, bit);
413 if (ret)
414 break;
415
416 ret = get_state_private(block_group_cache, start, &ptr);
417 if (ret) {
418 last = end + 1;
419 continue;
420 }
421
422 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
423 spin_lock(&cache->lock);
424 last = cache->key.objectid + cache->key.offset;
425 used = btrfs_block_group_used(&cache->item);
426
427 if (!cache->ro && block_group_bits(cache, data)) {
428 free_check = div_factor(cache->key.offset, factor);
429 if (used + cache->pinned < free_check) {
430 found_group = cache;
431 spin_unlock(&cache->lock);
432 goto found;
433 }
434 }
435 spin_unlock(&cache->lock);
436 cond_resched();
437 }
438 if (!wrapped) {
439 last = search_start;
440 wrapped = 1;
441 goto again;
442 }
443 if (!full_search && factor < 10) {
444 last = search_start;
445 full_search = 1;
446 factor = 10;
447 goto again;
448 }
449 found:
450 return found_group;
451 }
452
453 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
454 struct btrfs_block_group_cache
455 *hint, u64 search_start,
456 int data, int owner)
457 {
458
459 struct btrfs_block_group_cache *ret;
460 ret = __btrfs_find_block_group(root, hint, search_start, data, owner);
461 return ret;
462 }
463 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
464 u64 owner, u64 owner_offset)
465 {
466 u32 high_crc = ~(u32)0;
467 u32 low_crc = ~(u32)0;
468 __le64 lenum;
469 lenum = cpu_to_le64(root_objectid);
470 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
471 lenum = cpu_to_le64(ref_generation);
472 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
473 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
474 lenum = cpu_to_le64(owner);
475 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
476 lenum = cpu_to_le64(owner_offset);
477 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
478 }
479 return ((u64)high_crc << 32) | (u64)low_crc;
480 }
481
482 static int match_extent_ref(struct extent_buffer *leaf,
483 struct btrfs_extent_ref *disk_ref,
484 struct btrfs_extent_ref *cpu_ref)
485 {
486 int ret;
487 int len;
488
489 if (cpu_ref->objectid)
490 len = sizeof(*cpu_ref);
491 else
492 len = 2 * sizeof(u64);
493 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
494 len);
495 return ret == 0;
496 }
497
498 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
499 struct btrfs_root *root,
500 struct btrfs_path *path, u64 bytenr,
501 u64 root_objectid,
502 u64 ref_generation, u64 owner,
503 u64 owner_offset, int del)
504 {
505 u64 hash;
506 struct btrfs_key key;
507 struct btrfs_key found_key;
508 struct btrfs_extent_ref ref;
509 struct extent_buffer *leaf;
510 struct btrfs_extent_ref *disk_ref;
511 int ret;
512 int ret2;
513
514 btrfs_set_stack_ref_root(&ref, root_objectid);
515 btrfs_set_stack_ref_generation(&ref, ref_generation);
516 btrfs_set_stack_ref_objectid(&ref, owner);
517 btrfs_set_stack_ref_offset(&ref, owner_offset);
518
519 hash = hash_extent_ref(root_objectid, ref_generation, owner,
520 owner_offset);
521 key.offset = hash;
522 key.objectid = bytenr;
523 key.type = BTRFS_EXTENT_REF_KEY;
524
525 while (1) {
526 ret = btrfs_search_slot(trans, root, &key, path,
527 del ? -1 : 0, del);
528 if (ret < 0)
529 goto out;
530 leaf = path->nodes[0];
531 if (ret != 0) {
532 u32 nritems = btrfs_header_nritems(leaf);
533 if (path->slots[0] >= nritems) {
534 ret2 = btrfs_next_leaf(root, path);
535 if (ret2)
536 goto out;
537 leaf = path->nodes[0];
538 }
539 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
540 if (found_key.objectid != bytenr ||
541 found_key.type != BTRFS_EXTENT_REF_KEY)
542 goto out;
543 key.offset = found_key.offset;
544 if (del) {
545 btrfs_release_path(root, path);
546 continue;
547 }
548 }
549 disk_ref = btrfs_item_ptr(path->nodes[0],
550 path->slots[0],
551 struct btrfs_extent_ref);
552 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
553 ret = 0;
554 goto out;
555 }
556 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
557 key.offset = found_key.offset + 1;
558 btrfs_release_path(root, path);
559 }
560 out:
561 return ret;
562 }
563
564 /*
565 * Back reference rules. Back refs have three main goals:
566 *
567 * 1) differentiate between all holders of references to an extent so that
568 * when a reference is dropped we can make sure it was a valid reference
569 * before freeing the extent.
570 *
571 * 2) Provide enough information to quickly find the holders of an extent
572 * if we notice a given block is corrupted or bad.
573 *
574 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
575 * maintenance. This is actually the same as #2, but with a slightly
576 * different use case.
577 *
578 * File extents can be referenced by:
579 *
580 * - multiple snapshots, subvolumes, or different generations in one subvol
581 * - different files inside a single subvolume (in theory, not implemented yet)
582 * - different offsets inside a file (bookend extents in file.c)
583 *
584 * The extent ref structure has fields for:
585 *
586 * - Objectid of the subvolume root
587 * - Generation number of the tree holding the reference
588 * - objectid of the file holding the reference
589 * - offset in the file corresponding to the key holding the reference
590 *
591 * When a file extent is allocated the fields are filled in:
592 * (root_key.objectid, trans->transid, inode objectid, offset in file)
593 *
594 * When a leaf is cow'd new references are added for every file extent found
595 * in the leaf. It looks the same as the create case, but trans->transid
596 * will be different when the block is cow'd.
597 *
598 * (root_key.objectid, trans->transid, inode objectid, offset in file)
599 *
600 * When a file extent is removed either during snapshot deletion or file
601 * truncation, the corresponding back reference is found
602 * by searching for:
603 *
604 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
605 * inode objectid, offset in file)
606 *
607 * Btree extents can be referenced by:
608 *
609 * - Different subvolumes
610 * - Different generations of the same subvolume
611 *
612 * Storing sufficient information for a full reverse mapping of a btree
613 * block would require storing the lowest key of the block in the backref,
614 * and it would require updating that lowest key either before write out or
615 * every time it changed. Instead, the objectid of the lowest key is stored
616 * along with the level of the tree block. This provides a hint
617 * about where in the btree the block can be found. Searches through the
618 * btree only need to look for a pointer to that block, so they stop one
619 * level higher than the level recorded in the backref.
620 *
621 * Some btrees do not do reference counting on their extents. These
622 * include the extent tree and the tree of tree roots. Backrefs for these
623 * trees always have a generation of zero.
624 *
625 * When a tree block is created, back references are inserted:
626 *
627 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
628 *
629 * When a tree block is cow'd in a reference counted root,
630 * new back references are added for all the blocks it points to.
631 * These are of the form (trans->transid will have increased since creation):
632 *
633 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
634 *
635 * Because the lowest_key_objectid and the level are just hints
636 * they are not used when backrefs are deleted. When a backref is deleted:
637 *
638 * if backref was for a tree root:
639 * root_objectid = root->root_key.objectid
640 * else
641 * root_objectid = btrfs_header_owner(parent)
642 *
643 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
644 *
645 * Back Reference Key hashing:
646 *
647 * Back references have four fields, each 64 bits long. Unfortunately,
648 * This is hashed into a single 64 bit number and placed into the key offset.
649 * The key objectid corresponds to the first byte in the extent, and the
650 * key type is set to BTRFS_EXTENT_REF_KEY
651 */
652 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
653 struct btrfs_root *root,
654 struct btrfs_path *path, u64 bytenr,
655 u64 root_objectid, u64 ref_generation,
656 u64 owner, u64 owner_offset)
657 {
658 u64 hash;
659 struct btrfs_key key;
660 struct btrfs_extent_ref ref;
661 struct btrfs_extent_ref *disk_ref;
662 int ret;
663
664 btrfs_set_stack_ref_root(&ref, root_objectid);
665 btrfs_set_stack_ref_generation(&ref, ref_generation);
666 btrfs_set_stack_ref_objectid(&ref, owner);
667 btrfs_set_stack_ref_offset(&ref, owner_offset);
668
669 hash = hash_extent_ref(root_objectid, ref_generation, owner,
670 owner_offset);
671 key.offset = hash;
672 key.objectid = bytenr;
673 key.type = BTRFS_EXTENT_REF_KEY;
674
675 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
676 while (ret == -EEXIST) {
677 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
678 struct btrfs_extent_ref);
679 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
680 goto out;
681 key.offset++;
682 btrfs_release_path(root, path);
683 ret = btrfs_insert_empty_item(trans, root, path, &key,
684 sizeof(ref));
685 }
686 if (ret)
687 goto out;
688 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
689 struct btrfs_extent_ref);
690 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
691 sizeof(ref));
692 btrfs_mark_buffer_dirty(path->nodes[0]);
693 out:
694 btrfs_release_path(root, path);
695 return ret;
696 }
697
698 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
699 struct btrfs_root *root,
700 u64 bytenr, u64 num_bytes,
701 u64 root_objectid, u64 ref_generation,
702 u64 owner, u64 owner_offset)
703 {
704 struct btrfs_path *path;
705 int ret;
706 struct btrfs_key key;
707 struct extent_buffer *l;
708 struct btrfs_extent_item *item;
709 u32 refs;
710
711 WARN_ON(num_bytes < root->sectorsize);
712 path = btrfs_alloc_path();
713 if (!path)
714 return -ENOMEM;
715
716 path->reada = 1;
717 key.objectid = bytenr;
718 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
719 key.offset = num_bytes;
720 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
721 0, 1);
722 if (ret < 0)
723 return ret;
724 if (ret != 0) {
725 BUG();
726 }
727 BUG_ON(ret != 0);
728 l = path->nodes[0];
729 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
730 refs = btrfs_extent_refs(l, item);
731 btrfs_set_extent_refs(l, item, refs + 1);
732 btrfs_mark_buffer_dirty(path->nodes[0]);
733
734 btrfs_release_path(root->fs_info->extent_root, path);
735
736 path->reada = 1;
737 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
738 path, bytenr, root_objectid,
739 ref_generation, owner, owner_offset);
740 BUG_ON(ret);
741 finish_current_insert(trans, root->fs_info->extent_root);
742 del_pending_extents(trans, root->fs_info->extent_root);
743
744 btrfs_free_path(path);
745 return 0;
746 }
747
748 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
749 struct btrfs_root *root,
750 u64 bytenr, u64 num_bytes,
751 u64 root_objectid, u64 ref_generation,
752 u64 owner, u64 owner_offset)
753 {
754 int ret;
755
756 mutex_lock(&root->fs_info->alloc_mutex);
757 ret = __btrfs_inc_extent_ref(trans, root, bytenr, num_bytes,
758 root_objectid, ref_generation,
759 owner, owner_offset);
760 mutex_unlock(&root->fs_info->alloc_mutex);
761 return ret;
762 }
763
764 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
765 struct btrfs_root *root)
766 {
767 finish_current_insert(trans, root->fs_info->extent_root);
768 del_pending_extents(trans, root->fs_info->extent_root);
769 return 0;
770 }
771
772 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
773 struct btrfs_root *root, u64 bytenr,
774 u64 num_bytes, u32 *refs)
775 {
776 struct btrfs_path *path;
777 int ret;
778 struct btrfs_key key;
779 struct extent_buffer *l;
780 struct btrfs_extent_item *item;
781
782 WARN_ON(num_bytes < root->sectorsize);
783 path = btrfs_alloc_path();
784 path->reada = 1;
785 key.objectid = bytenr;
786 key.offset = num_bytes;
787 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
788 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
789 0, 0);
790 if (ret < 0)
791 goto out;
792 if (ret != 0) {
793 btrfs_print_leaf(root, path->nodes[0]);
794 printk("failed to find block number %Lu\n", bytenr);
795 BUG();
796 }
797 l = path->nodes[0];
798 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
799 *refs = btrfs_extent_refs(l, item);
800 out:
801 btrfs_free_path(path);
802 return 0;
803 }
804
805
806 static int get_reference_status(struct btrfs_root *root, u64 bytenr,
807 u64 parent_gen, u64 ref_objectid,
808 u64 *min_generation, u32 *ref_count)
809 {
810 struct btrfs_root *extent_root = root->fs_info->extent_root;
811 struct btrfs_path *path;
812 struct extent_buffer *leaf;
813 struct btrfs_extent_ref *ref_item;
814 struct btrfs_key key;
815 struct btrfs_key found_key;
816 u64 root_objectid = root->root_key.objectid;
817 u64 ref_generation;
818 u32 nritems;
819 int ret;
820
821 key.objectid = bytenr;
822 key.offset = 0;
823 key.type = BTRFS_EXTENT_ITEM_KEY;
824
825 path = btrfs_alloc_path();
826 mutex_lock(&root->fs_info->alloc_mutex);
827 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
828 if (ret < 0)
829 goto out;
830 BUG_ON(ret == 0);
831
832 leaf = path->nodes[0];
833 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
834
835 if (found_key.objectid != bytenr ||
836 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
837 ret = 1;
838 goto out;
839 }
840
841 *ref_count = 0;
842 *min_generation = (u64)-1;
843
844 while (1) {
845 leaf = path->nodes[0];
846 nritems = btrfs_header_nritems(leaf);
847 if (path->slots[0] >= nritems) {
848 ret = btrfs_next_leaf(extent_root, path);
849 if (ret < 0)
850 goto out;
851 if (ret == 0)
852 continue;
853 break;
854 }
855 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
856 if (found_key.objectid != bytenr)
857 break;
858
859 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
860 path->slots[0]++;
861 continue;
862 }
863
864 ref_item = btrfs_item_ptr(leaf, path->slots[0],
865 struct btrfs_extent_ref);
866 ref_generation = btrfs_ref_generation(leaf, ref_item);
867 /*
868 * For (parent_gen > 0 && parent_gen > ref_gen):
869 *
870 * we reach here through the oldest root, therefore
871 * all other reference from same snapshot should have
872 * a larger generation.
873 */
874 if ((root_objectid != btrfs_ref_root(leaf, ref_item)) ||
875 (parent_gen > 0 && parent_gen > ref_generation) ||
876 (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
877 ref_objectid != btrfs_ref_objectid(leaf, ref_item))) {
878 if (ref_count)
879 *ref_count = 2;
880 break;
881 }
882
883 *ref_count = 1;
884 if (*min_generation > ref_generation)
885 *min_generation = ref_generation;
886
887 path->slots[0]++;
888 }
889 ret = 0;
890 out:
891 mutex_unlock(&root->fs_info->alloc_mutex);
892 btrfs_free_path(path);
893 return ret;
894 }
895
896 int btrfs_cross_ref_exists(struct btrfs_root *root,
897 struct btrfs_key *key, u64 bytenr)
898 {
899 struct btrfs_trans_handle *trans;
900 struct btrfs_root *old_root;
901 struct btrfs_path *path = NULL;
902 struct extent_buffer *eb;
903 struct btrfs_file_extent_item *item;
904 u64 ref_generation;
905 u64 min_generation;
906 u64 extent_start;
907 u32 ref_count;
908 int level;
909 int ret;
910
911 BUG_ON(key->type != BTRFS_EXTENT_DATA_KEY);
912 ret = get_reference_status(root, bytenr, 0, key->objectid,
913 &min_generation, &ref_count);
914 if (ret)
915 return ret;
916
917 if (ref_count != 1)
918 return 1;
919
920 trans = btrfs_start_transaction(root, 0);
921 old_root = root->dirty_root->root;
922 ref_generation = old_root->root_key.offset;
923
924 /* all references are created in running transaction */
925 if (min_generation > ref_generation) {
926 ret = 0;
927 goto out;
928 }
929
930 path = btrfs_alloc_path();
931 if (!path) {
932 ret = -ENOMEM;
933 goto out;
934 }
935
936 path->skip_locking = 1;
937 /* if no item found, the extent is referenced by other snapshot */
938 ret = btrfs_search_slot(NULL, old_root, key, path, 0, 0);
939 if (ret)
940 goto out;
941
942 eb = path->nodes[0];
943 item = btrfs_item_ptr(eb, path->slots[0],
944 struct btrfs_file_extent_item);
945 if (btrfs_file_extent_type(eb, item) != BTRFS_FILE_EXTENT_REG ||
946 btrfs_file_extent_disk_bytenr(eb, item) != bytenr) {
947 ret = 1;
948 goto out;
949 }
950
951 for (level = BTRFS_MAX_LEVEL - 1; level >= -1; level--) {
952 if (level >= 0) {
953 eb = path->nodes[level];
954 if (!eb)
955 continue;
956 extent_start = eb->start;
957 } else
958 extent_start = bytenr;
959
960 ret = get_reference_status(root, extent_start, ref_generation,
961 0, &min_generation, &ref_count);
962 if (ret)
963 goto out;
964
965 if (ref_count != 1) {
966 ret = 1;
967 goto out;
968 }
969 if (level >= 0)
970 ref_generation = btrfs_header_generation(eb);
971 }
972 ret = 0;
973 out:
974 if (path)
975 btrfs_free_path(path);
976 btrfs_end_transaction(trans, root);
977 return ret;
978 }
979
980 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
981 struct extent_buffer *buf, int cache_ref)
982 {
983 u64 bytenr;
984 u32 nritems;
985 struct btrfs_key key;
986 struct btrfs_file_extent_item *fi;
987 int i;
988 int level;
989 int ret;
990 int faili;
991 int nr_file_extents = 0;
992
993 if (!root->ref_cows)
994 return 0;
995
996 level = btrfs_header_level(buf);
997 nritems = btrfs_header_nritems(buf);
998 for (i = 0; i < nritems; i++) {
999 cond_resched();
1000 if (level == 0) {
1001 u64 disk_bytenr;
1002 btrfs_item_key_to_cpu(buf, &key, i);
1003 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1004 continue;
1005 fi = btrfs_item_ptr(buf, i,
1006 struct btrfs_file_extent_item);
1007 if (btrfs_file_extent_type(buf, fi) ==
1008 BTRFS_FILE_EXTENT_INLINE)
1009 continue;
1010 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1011 if (disk_bytenr == 0)
1012 continue;
1013
1014 if (buf != root->commit_root)
1015 nr_file_extents++;
1016
1017 mutex_lock(&root->fs_info->alloc_mutex);
1018 ret = __btrfs_inc_extent_ref(trans, root, disk_bytenr,
1019 btrfs_file_extent_disk_num_bytes(buf, fi),
1020 root->root_key.objectid, trans->transid,
1021 key.objectid, key.offset);
1022 mutex_unlock(&root->fs_info->alloc_mutex);
1023 if (ret) {
1024 faili = i;
1025 WARN_ON(1);
1026 goto fail;
1027 }
1028 } else {
1029 bytenr = btrfs_node_blockptr(buf, i);
1030 btrfs_node_key_to_cpu(buf, &key, i);
1031
1032 mutex_lock(&root->fs_info->alloc_mutex);
1033 ret = __btrfs_inc_extent_ref(trans, root, bytenr,
1034 btrfs_level_size(root, level - 1),
1035 root->root_key.objectid,
1036 trans->transid,
1037 level - 1, key.objectid);
1038 mutex_unlock(&root->fs_info->alloc_mutex);
1039 if (ret) {
1040 faili = i;
1041 WARN_ON(1);
1042 goto fail;
1043 }
1044 }
1045 }
1046 /* cache orignal leaf block's references */
1047 if (level == 0 && cache_ref && buf != root->commit_root) {
1048 struct btrfs_leaf_ref *ref;
1049 struct btrfs_extent_info *info;
1050
1051 ref = btrfs_alloc_leaf_ref(root, nr_file_extents);
1052 if (!ref) {
1053 WARN_ON(1);
1054 goto out;
1055 }
1056
1057 ref->root_gen = root->root_key.offset;
1058 ref->bytenr = buf->start;
1059 ref->owner = btrfs_header_owner(buf);
1060 ref->generation = btrfs_header_generation(buf);
1061 ref->nritems = nr_file_extents;
1062 info = ref->extents;
1063
1064 for (i = 0; nr_file_extents > 0 && i < nritems; i++) {
1065 u64 disk_bytenr;
1066 btrfs_item_key_to_cpu(buf, &key, i);
1067 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1068 continue;
1069 fi = btrfs_item_ptr(buf, i,
1070 struct btrfs_file_extent_item);
1071 if (btrfs_file_extent_type(buf, fi) ==
1072 BTRFS_FILE_EXTENT_INLINE)
1073 continue;
1074 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1075 if (disk_bytenr == 0)
1076 continue;
1077
1078 info->bytenr = disk_bytenr;
1079 info->num_bytes =
1080 btrfs_file_extent_disk_num_bytes(buf, fi);
1081 info->objectid = key.objectid;
1082 info->offset = key.offset;
1083 info++;
1084 }
1085
1086 BUG_ON(!root->ref_tree);
1087 ret = btrfs_add_leaf_ref(root, ref);
1088 WARN_ON(ret);
1089 btrfs_free_leaf_ref(root, ref);
1090 }
1091 out:
1092 return 0;
1093 fail:
1094 WARN_ON(1);
1095 #if 0
1096 for (i =0; i < faili; i++) {
1097 if (level == 0) {
1098 u64 disk_bytenr;
1099 btrfs_item_key_to_cpu(buf, &key, i);
1100 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1101 continue;
1102 fi = btrfs_item_ptr(buf, i,
1103 struct btrfs_file_extent_item);
1104 if (btrfs_file_extent_type(buf, fi) ==
1105 BTRFS_FILE_EXTENT_INLINE)
1106 continue;
1107 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1108 if (disk_bytenr == 0)
1109 continue;
1110 err = btrfs_free_extent(trans, root, disk_bytenr,
1111 btrfs_file_extent_disk_num_bytes(buf,
1112 fi), 0);
1113 BUG_ON(err);
1114 } else {
1115 bytenr = btrfs_node_blockptr(buf, i);
1116 err = btrfs_free_extent(trans, root, bytenr,
1117 btrfs_level_size(root, level - 1), 0);
1118 BUG_ON(err);
1119 }
1120 }
1121 #endif
1122 return ret;
1123 }
1124
1125 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1126 struct btrfs_root *root,
1127 struct btrfs_path *path,
1128 struct btrfs_block_group_cache *cache)
1129 {
1130 int ret;
1131 int pending_ret;
1132 struct btrfs_root *extent_root = root->fs_info->extent_root;
1133 unsigned long bi;
1134 struct extent_buffer *leaf;
1135
1136 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1137 if (ret < 0)
1138 goto fail;
1139 BUG_ON(ret);
1140
1141 leaf = path->nodes[0];
1142 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1143 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1144 btrfs_mark_buffer_dirty(leaf);
1145 btrfs_release_path(extent_root, path);
1146 fail:
1147 finish_current_insert(trans, extent_root);
1148 pending_ret = del_pending_extents(trans, extent_root);
1149 if (ret)
1150 return ret;
1151 if (pending_ret)
1152 return pending_ret;
1153 return 0;
1154
1155 }
1156
1157 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1158 struct btrfs_root *root)
1159 {
1160 struct extent_io_tree *block_group_cache;
1161 struct btrfs_block_group_cache *cache;
1162 int ret;
1163 int err = 0;
1164 int werr = 0;
1165 struct btrfs_path *path;
1166 u64 last = 0;
1167 u64 start;
1168 u64 end;
1169 u64 ptr;
1170
1171 block_group_cache = &root->fs_info->block_group_cache;
1172 path = btrfs_alloc_path();
1173 if (!path)
1174 return -ENOMEM;
1175
1176 mutex_lock(&root->fs_info->alloc_mutex);
1177 while(1) {
1178 ret = find_first_extent_bit(block_group_cache, last,
1179 &start, &end, BLOCK_GROUP_DIRTY);
1180 if (ret)
1181 break;
1182
1183 last = end + 1;
1184 ret = get_state_private(block_group_cache, start, &ptr);
1185 if (ret)
1186 break;
1187 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
1188 err = write_one_cache_group(trans, root,
1189 path, cache);
1190 /*
1191 * if we fail to write the cache group, we want
1192 * to keep it marked dirty in hopes that a later
1193 * write will work
1194 */
1195 if (err) {
1196 werr = err;
1197 continue;
1198 }
1199 clear_extent_bits(block_group_cache, start, end,
1200 BLOCK_GROUP_DIRTY, GFP_NOFS);
1201 }
1202 btrfs_free_path(path);
1203 mutex_unlock(&root->fs_info->alloc_mutex);
1204 return werr;
1205 }
1206
1207 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
1208 u64 flags)
1209 {
1210 struct list_head *head = &info->space_info;
1211 struct list_head *cur;
1212 struct btrfs_space_info *found;
1213 list_for_each(cur, head) {
1214 found = list_entry(cur, struct btrfs_space_info, list);
1215 if (found->flags == flags)
1216 return found;
1217 }
1218 return NULL;
1219
1220 }
1221
1222 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1223 u64 total_bytes, u64 bytes_used,
1224 struct btrfs_space_info **space_info)
1225 {
1226 struct btrfs_space_info *found;
1227
1228 found = __find_space_info(info, flags);
1229 if (found) {
1230 found->total_bytes += total_bytes;
1231 found->bytes_used += bytes_used;
1232 found->full = 0;
1233 WARN_ON(found->total_bytes < found->bytes_used);
1234 *space_info = found;
1235 return 0;
1236 }
1237 found = kmalloc(sizeof(*found), GFP_NOFS);
1238 if (!found)
1239 return -ENOMEM;
1240
1241 list_add(&found->list, &info->space_info);
1242 found->flags = flags;
1243 found->total_bytes = total_bytes;
1244 found->bytes_used = bytes_used;
1245 found->bytes_pinned = 0;
1246 found->full = 0;
1247 found->force_alloc = 0;
1248 *space_info = found;
1249 return 0;
1250 }
1251
1252 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1253 {
1254 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1255 BTRFS_BLOCK_GROUP_RAID1 |
1256 BTRFS_BLOCK_GROUP_RAID10 |
1257 BTRFS_BLOCK_GROUP_DUP);
1258 if (extra_flags) {
1259 if (flags & BTRFS_BLOCK_GROUP_DATA)
1260 fs_info->avail_data_alloc_bits |= extra_flags;
1261 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1262 fs_info->avail_metadata_alloc_bits |= extra_flags;
1263 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1264 fs_info->avail_system_alloc_bits |= extra_flags;
1265 }
1266 }
1267
1268 static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags)
1269 {
1270 u64 num_devices = root->fs_info->fs_devices->num_devices;
1271
1272 if (num_devices == 1)
1273 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
1274 if (num_devices < 4)
1275 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
1276
1277 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
1278 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
1279 BTRFS_BLOCK_GROUP_RAID10))) {
1280 flags &= ~BTRFS_BLOCK_GROUP_DUP;
1281 }
1282
1283 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
1284 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
1285 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
1286 }
1287
1288 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
1289 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
1290 (flags & BTRFS_BLOCK_GROUP_RAID10) |
1291 (flags & BTRFS_BLOCK_GROUP_DUP)))
1292 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
1293 return flags;
1294 }
1295
1296 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1297 struct btrfs_root *extent_root, u64 alloc_bytes,
1298 u64 flags, int force)
1299 {
1300 struct btrfs_space_info *space_info;
1301 u64 thresh;
1302 u64 start;
1303 u64 num_bytes;
1304 int ret;
1305
1306 flags = reduce_alloc_profile(extent_root, flags);
1307
1308 space_info = __find_space_info(extent_root->fs_info, flags);
1309 if (!space_info) {
1310 ret = update_space_info(extent_root->fs_info, flags,
1311 0, 0, &space_info);
1312 BUG_ON(ret);
1313 }
1314 BUG_ON(!space_info);
1315
1316 if (space_info->force_alloc) {
1317 force = 1;
1318 space_info->force_alloc = 0;
1319 }
1320 if (space_info->full)
1321 goto out;
1322
1323 thresh = div_factor(space_info->total_bytes, 6);
1324 if (!force &&
1325 (space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1326 thresh)
1327 goto out;
1328
1329 mutex_lock(&extent_root->fs_info->chunk_mutex);
1330 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1331 if (ret == -ENOSPC) {
1332 printk("space info full %Lu\n", flags);
1333 space_info->full = 1;
1334 goto out_unlock;
1335 }
1336 BUG_ON(ret);
1337
1338 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1339 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1340 BUG_ON(ret);
1341 out_unlock:
1342 mutex_unlock(&extent_root->fs_info->chunk_mutex);
1343 out:
1344 return 0;
1345 }
1346
1347 static int update_block_group(struct btrfs_trans_handle *trans,
1348 struct btrfs_root *root,
1349 u64 bytenr, u64 num_bytes, int alloc,
1350 int mark_free)
1351 {
1352 struct btrfs_block_group_cache *cache;
1353 struct btrfs_fs_info *info = root->fs_info;
1354 u64 total = num_bytes;
1355 u64 old_val;
1356 u64 byte_in_group;
1357 u64 start;
1358 u64 end;
1359
1360 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1361 while(total) {
1362 cache = btrfs_lookup_block_group(info, bytenr);
1363 if (!cache) {
1364 return -1;
1365 }
1366 byte_in_group = bytenr - cache->key.objectid;
1367 WARN_ON(byte_in_group > cache->key.offset);
1368 start = cache->key.objectid;
1369 end = start + cache->key.offset - 1;
1370 set_extent_bits(&info->block_group_cache, start, end,
1371 BLOCK_GROUP_DIRTY, GFP_NOFS);
1372
1373 spin_lock(&cache->lock);
1374 old_val = btrfs_block_group_used(&cache->item);
1375 num_bytes = min(total, cache->key.offset - byte_in_group);
1376 if (alloc) {
1377 old_val += num_bytes;
1378 cache->space_info->bytes_used += num_bytes;
1379 btrfs_set_block_group_used(&cache->item, old_val);
1380 spin_unlock(&cache->lock);
1381 } else {
1382 old_val -= num_bytes;
1383 cache->space_info->bytes_used -= num_bytes;
1384 btrfs_set_block_group_used(&cache->item, old_val);
1385 spin_unlock(&cache->lock);
1386 if (mark_free) {
1387 set_extent_dirty(&info->free_space_cache,
1388 bytenr, bytenr + num_bytes - 1,
1389 GFP_NOFS);
1390 }
1391 }
1392 total -= num_bytes;
1393 bytenr += num_bytes;
1394 }
1395 return 0;
1396 }
1397
1398 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
1399 {
1400 u64 start;
1401 u64 end;
1402 int ret;
1403 ret = find_first_extent_bit(&root->fs_info->block_group_cache,
1404 search_start, &start, &end,
1405 BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA |
1406 BLOCK_GROUP_SYSTEM);
1407 if (ret)
1408 return 0;
1409 return start;
1410 }
1411
1412
1413 static int update_pinned_extents(struct btrfs_root *root,
1414 u64 bytenr, u64 num, int pin)
1415 {
1416 u64 len;
1417 struct btrfs_block_group_cache *cache;
1418 struct btrfs_fs_info *fs_info = root->fs_info;
1419
1420 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1421 if (pin) {
1422 set_extent_dirty(&fs_info->pinned_extents,
1423 bytenr, bytenr + num - 1, GFP_NOFS);
1424 } else {
1425 clear_extent_dirty(&fs_info->pinned_extents,
1426 bytenr, bytenr + num - 1, GFP_NOFS);
1427 }
1428 while (num > 0) {
1429 cache = btrfs_lookup_block_group(fs_info, bytenr);
1430 if (!cache) {
1431 u64 first = first_logical_byte(root, bytenr);
1432 WARN_ON(first < bytenr);
1433 len = min(first - bytenr, num);
1434 } else {
1435 len = min(num, cache->key.offset -
1436 (bytenr - cache->key.objectid));
1437 }
1438 if (pin) {
1439 if (cache) {
1440 spin_lock(&cache->lock);
1441 cache->pinned += len;
1442 cache->space_info->bytes_pinned += len;
1443 spin_unlock(&cache->lock);
1444 }
1445 fs_info->total_pinned += len;
1446 } else {
1447 if (cache) {
1448 spin_lock(&cache->lock);
1449 cache->pinned -= len;
1450 cache->space_info->bytes_pinned -= len;
1451 spin_unlock(&cache->lock);
1452 }
1453 fs_info->total_pinned -= len;
1454 }
1455 bytenr += len;
1456 num -= len;
1457 }
1458 return 0;
1459 }
1460
1461 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1462 {
1463 u64 last = 0;
1464 u64 start;
1465 u64 end;
1466 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1467 int ret;
1468
1469 while(1) {
1470 ret = find_first_extent_bit(pinned_extents, last,
1471 &start, &end, EXTENT_DIRTY);
1472 if (ret)
1473 break;
1474 set_extent_dirty(copy, start, end, GFP_NOFS);
1475 last = end + 1;
1476 }
1477 return 0;
1478 }
1479
1480 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1481 struct btrfs_root *root,
1482 struct extent_io_tree *unpin)
1483 {
1484 u64 start;
1485 u64 end;
1486 int ret;
1487 struct extent_io_tree *free_space_cache;
1488 free_space_cache = &root->fs_info->free_space_cache;
1489
1490 mutex_lock(&root->fs_info->alloc_mutex);
1491 while(1) {
1492 ret = find_first_extent_bit(unpin, 0, &start, &end,
1493 EXTENT_DIRTY);
1494 if (ret)
1495 break;
1496 update_pinned_extents(root, start, end + 1 - start, 0);
1497 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1498 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
1499 if (need_resched()) {
1500 mutex_unlock(&root->fs_info->alloc_mutex);
1501 cond_resched();
1502 mutex_lock(&root->fs_info->alloc_mutex);
1503 }
1504 }
1505 mutex_unlock(&root->fs_info->alloc_mutex);
1506 return 0;
1507 }
1508
1509 static int finish_current_insert(struct btrfs_trans_handle *trans,
1510 struct btrfs_root *extent_root)
1511 {
1512 u64 start;
1513 u64 end;
1514 struct btrfs_fs_info *info = extent_root->fs_info;
1515 struct extent_buffer *eb;
1516 struct btrfs_path *path;
1517 struct btrfs_key ins;
1518 struct btrfs_disk_key first;
1519 struct btrfs_extent_item extent_item;
1520 int ret;
1521 int level;
1522 int err = 0;
1523
1524 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
1525 btrfs_set_stack_extent_refs(&extent_item, 1);
1526 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1527 path = btrfs_alloc_path();
1528
1529 while(1) {
1530 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1531 &end, EXTENT_LOCKED);
1532 if (ret)
1533 break;
1534
1535 ins.objectid = start;
1536 ins.offset = end + 1 - start;
1537 err = btrfs_insert_item(trans, extent_root, &ins,
1538 &extent_item, sizeof(extent_item));
1539 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1540 GFP_NOFS);
1541
1542 eb = btrfs_find_tree_block(extent_root, ins.objectid,
1543 ins.offset);
1544
1545 if (!btrfs_buffer_uptodate(eb, trans->transid)) {
1546 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1547 btrfs_read_buffer(eb, trans->transid);
1548 mutex_lock(&extent_root->fs_info->alloc_mutex);
1549 }
1550
1551 btrfs_tree_lock(eb);
1552 level = btrfs_header_level(eb);
1553 if (level == 0) {
1554 btrfs_item_key(eb, &first, 0);
1555 } else {
1556 btrfs_node_key(eb, &first, 0);
1557 }
1558 btrfs_tree_unlock(eb);
1559 free_extent_buffer(eb);
1560 /*
1561 * the first key is just a hint, so the race we've created
1562 * against reading it is fine
1563 */
1564 err = btrfs_insert_extent_backref(trans, extent_root, path,
1565 start, extent_root->root_key.objectid,
1566 0, level,
1567 btrfs_disk_key_objectid(&first));
1568 BUG_ON(err);
1569 if (need_resched()) {
1570 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1571 cond_resched();
1572 mutex_lock(&extent_root->fs_info->alloc_mutex);
1573 }
1574 }
1575 btrfs_free_path(path);
1576 return 0;
1577 }
1578
1579 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1580 int pending)
1581 {
1582 int err = 0;
1583
1584 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1585 if (!pending) {
1586 struct extent_buffer *buf;
1587 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1588 if (buf) {
1589 if (btrfs_buffer_uptodate(buf, 0) &&
1590 btrfs_try_tree_lock(buf)) {
1591 u64 transid =
1592 root->fs_info->running_transaction->transid;
1593 u64 header_transid =
1594 btrfs_header_generation(buf);
1595 if (header_transid == transid &&
1596 !btrfs_header_flag(buf,
1597 BTRFS_HEADER_FLAG_WRITTEN)) {
1598 clean_tree_block(NULL, root, buf);
1599 btrfs_tree_unlock(buf);
1600 free_extent_buffer(buf);
1601 return 1;
1602 }
1603 btrfs_tree_unlock(buf);
1604 }
1605 free_extent_buffer(buf);
1606 }
1607 update_pinned_extents(root, bytenr, num_bytes, 1);
1608 } else {
1609 set_extent_bits(&root->fs_info->pending_del,
1610 bytenr, bytenr + num_bytes - 1,
1611 EXTENT_LOCKED, GFP_NOFS);
1612 }
1613 BUG_ON(err < 0);
1614 return 0;
1615 }
1616
1617 /*
1618 * remove an extent from the root, returns 0 on success
1619 */
1620 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1621 *root, u64 bytenr, u64 num_bytes,
1622 u64 root_objectid, u64 ref_generation,
1623 u64 owner_objectid, u64 owner_offset, int pin,
1624 int mark_free)
1625 {
1626 struct btrfs_path *path;
1627 struct btrfs_key key;
1628 struct btrfs_fs_info *info = root->fs_info;
1629 struct btrfs_root *extent_root = info->extent_root;
1630 struct extent_buffer *leaf;
1631 int ret;
1632 int extent_slot = 0;
1633 int found_extent = 0;
1634 int num_to_del = 1;
1635 struct btrfs_extent_item *ei;
1636 u32 refs;
1637
1638 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1639 key.objectid = bytenr;
1640 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1641 key.offset = num_bytes;
1642 path = btrfs_alloc_path();
1643 if (!path)
1644 return -ENOMEM;
1645
1646 path->reada = 1;
1647 ret = lookup_extent_backref(trans, extent_root, path,
1648 bytenr, root_objectid,
1649 ref_generation,
1650 owner_objectid, owner_offset, 1);
1651 if (ret == 0) {
1652 struct btrfs_key found_key;
1653 extent_slot = path->slots[0];
1654 while(extent_slot > 0) {
1655 extent_slot--;
1656 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1657 extent_slot);
1658 if (found_key.objectid != bytenr)
1659 break;
1660 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1661 found_key.offset == num_bytes) {
1662 found_extent = 1;
1663 break;
1664 }
1665 if (path->slots[0] - extent_slot > 5)
1666 break;
1667 }
1668 if (!found_extent)
1669 ret = btrfs_del_item(trans, extent_root, path);
1670 } else {
1671 btrfs_print_leaf(extent_root, path->nodes[0]);
1672 WARN_ON(1);
1673 printk("Unable to find ref byte nr %Lu root %Lu "
1674 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1675 root_objectid, ref_generation, owner_objectid,
1676 owner_offset);
1677 }
1678 if (!found_extent) {
1679 btrfs_release_path(extent_root, path);
1680 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1681 if (ret < 0)
1682 return ret;
1683 BUG_ON(ret);
1684 extent_slot = path->slots[0];
1685 }
1686
1687 leaf = path->nodes[0];
1688 ei = btrfs_item_ptr(leaf, extent_slot,
1689 struct btrfs_extent_item);
1690 refs = btrfs_extent_refs(leaf, ei);
1691 BUG_ON(refs == 0);
1692 refs -= 1;
1693 btrfs_set_extent_refs(leaf, ei, refs);
1694
1695 btrfs_mark_buffer_dirty(leaf);
1696
1697 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1698 /* if the back ref and the extent are next to each other
1699 * they get deleted below in one shot
1700 */
1701 path->slots[0] = extent_slot;
1702 num_to_del = 2;
1703 } else if (found_extent) {
1704 /* otherwise delete the extent back ref */
1705 ret = btrfs_del_item(trans, extent_root, path);
1706 BUG_ON(ret);
1707 /* if refs are 0, we need to setup the path for deletion */
1708 if (refs == 0) {
1709 btrfs_release_path(extent_root, path);
1710 ret = btrfs_search_slot(trans, extent_root, &key, path,
1711 -1, 1);
1712 if (ret < 0)
1713 return ret;
1714 BUG_ON(ret);
1715 }
1716 }
1717
1718 if (refs == 0) {
1719 u64 super_used;
1720 u64 root_used;
1721
1722 if (pin) {
1723 ret = pin_down_bytes(root, bytenr, num_bytes, 0);
1724 if (ret > 0)
1725 mark_free = 1;
1726 BUG_ON(ret < 0);
1727 }
1728
1729 /* block accounting for super block */
1730 spin_lock_irq(&info->delalloc_lock);
1731 super_used = btrfs_super_bytes_used(&info->super_copy);
1732 btrfs_set_super_bytes_used(&info->super_copy,
1733 super_used - num_bytes);
1734 spin_unlock_irq(&info->delalloc_lock);
1735
1736 /* block accounting for root item */
1737 root_used = btrfs_root_used(&root->root_item);
1738 btrfs_set_root_used(&root->root_item,
1739 root_used - num_bytes);
1740 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1741 num_to_del);
1742 if (ret) {
1743 return ret;
1744 }
1745 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1746 mark_free);
1747 BUG_ON(ret);
1748 }
1749 btrfs_free_path(path);
1750 finish_current_insert(trans, extent_root);
1751 return ret;
1752 }
1753
1754 /*
1755 * find all the blocks marked as pending in the radix tree and remove
1756 * them from the extent map
1757 */
1758 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1759 btrfs_root *extent_root)
1760 {
1761 int ret;
1762 int err = 0;
1763 u64 start;
1764 u64 end;
1765 struct extent_io_tree *pending_del;
1766 struct extent_io_tree *pinned_extents;
1767
1768 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
1769 pending_del = &extent_root->fs_info->pending_del;
1770 pinned_extents = &extent_root->fs_info->pinned_extents;
1771
1772 while(1) {
1773 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1774 EXTENT_LOCKED);
1775 if (ret)
1776 break;
1777 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1778 GFP_NOFS);
1779 if (!test_range_bit(&extent_root->fs_info->extent_ins,
1780 start, end, EXTENT_LOCKED, 0)) {
1781 update_pinned_extents(extent_root, start,
1782 end + 1 - start, 1);
1783 ret = __free_extent(trans, extent_root,
1784 start, end + 1 - start,
1785 extent_root->root_key.objectid,
1786 0, 0, 0, 0, 0);
1787 } else {
1788 clear_extent_bits(&extent_root->fs_info->extent_ins,
1789 start, end, EXTENT_LOCKED, GFP_NOFS);
1790 }
1791 if (ret)
1792 err = ret;
1793
1794 if (need_resched()) {
1795 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1796 cond_resched();
1797 mutex_lock(&extent_root->fs_info->alloc_mutex);
1798 }
1799 }
1800 return err;
1801 }
1802
1803 /*
1804 * remove an extent from the root, returns 0 on success
1805 */
1806 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
1807 struct btrfs_root *root, u64 bytenr,
1808 u64 num_bytes, u64 root_objectid,
1809 u64 ref_generation, u64 owner_objectid,
1810 u64 owner_offset, int pin)
1811 {
1812 struct btrfs_root *extent_root = root->fs_info->extent_root;
1813 int pending_ret;
1814 int ret;
1815
1816 WARN_ON(num_bytes < root->sectorsize);
1817 if (!root->ref_cows)
1818 ref_generation = 0;
1819
1820 if (root == extent_root) {
1821 pin_down_bytes(root, bytenr, num_bytes, 1);
1822 return 0;
1823 }
1824 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1825 ref_generation, owner_objectid, owner_offset,
1826 pin, pin == 0);
1827
1828 finish_current_insert(trans, root->fs_info->extent_root);
1829 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1830 return ret ? ret : pending_ret;
1831 }
1832
1833 int btrfs_free_extent(struct btrfs_trans_handle *trans,
1834 struct btrfs_root *root, u64 bytenr,
1835 u64 num_bytes, u64 root_objectid,
1836 u64 ref_generation, u64 owner_objectid,
1837 u64 owner_offset, int pin)
1838 {
1839 int ret;
1840
1841 maybe_lock_mutex(root);
1842 ret = __btrfs_free_extent(trans, root, bytenr, num_bytes,
1843 root_objectid, ref_generation,
1844 owner_objectid, owner_offset, pin);
1845 maybe_unlock_mutex(root);
1846 return ret;
1847 }
1848
1849 static u64 stripe_align(struct btrfs_root *root, u64 val)
1850 {
1851 u64 mask = ((u64)root->stripesize - 1);
1852 u64 ret = (val + mask) & ~mask;
1853 return ret;
1854 }
1855
1856 /*
1857 * walks the btree of allocated extents and find a hole of a given size.
1858 * The key ins is changed to record the hole:
1859 * ins->objectid == block start
1860 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1861 * ins->offset == number of blocks
1862 * Any available blocks before search_start are skipped.
1863 */
1864 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1865 struct btrfs_root *orig_root,
1866 u64 num_bytes, u64 empty_size,
1867 u64 search_start, u64 search_end,
1868 u64 hint_byte, struct btrfs_key *ins,
1869 u64 exclude_start, u64 exclude_nr,
1870 int data)
1871 {
1872 int ret;
1873 u64 orig_search_start;
1874 struct btrfs_root * root = orig_root->fs_info->extent_root;
1875 struct btrfs_fs_info *info = root->fs_info;
1876 u64 total_needed = num_bytes;
1877 u64 *last_ptr = NULL;
1878 struct btrfs_block_group_cache *block_group;
1879 int full_scan = 0;
1880 int wrapped = 0;
1881 int chunk_alloc_done = 0;
1882 int empty_cluster = 2 * 1024 * 1024;
1883 int allowed_chunk_alloc = 0;
1884
1885 WARN_ON(num_bytes < root->sectorsize);
1886 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1887
1888 if (orig_root->ref_cows || empty_size)
1889 allowed_chunk_alloc = 1;
1890
1891 if (data & BTRFS_BLOCK_GROUP_METADATA) {
1892 last_ptr = &root->fs_info->last_alloc;
1893 empty_cluster = 256 * 1024;
1894 }
1895
1896 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
1897 last_ptr = &root->fs_info->last_data_alloc;
1898 }
1899
1900 if (last_ptr) {
1901 if (*last_ptr)
1902 hint_byte = *last_ptr;
1903 else {
1904 empty_size += empty_cluster;
1905 }
1906 }
1907
1908 search_start = max(search_start, first_logical_byte(root, 0));
1909 orig_search_start = search_start;
1910
1911 if (search_end == (u64)-1)
1912 search_end = btrfs_super_total_bytes(&info->super_copy);
1913
1914 if (hint_byte) {
1915 block_group = btrfs_lookup_first_block_group(info, hint_byte);
1916 if (!block_group)
1917 hint_byte = search_start;
1918 block_group = btrfs_find_block_group(root, block_group,
1919 hint_byte, data, 1);
1920 if (last_ptr && *last_ptr == 0 && block_group)
1921 hint_byte = block_group->key.objectid;
1922 } else {
1923 block_group = btrfs_find_block_group(root,
1924 trans->block_group,
1925 search_start, data, 1);
1926 }
1927 search_start = max(search_start, hint_byte);
1928
1929 total_needed += empty_size;
1930
1931 check_failed:
1932 if (!block_group) {
1933 block_group = btrfs_lookup_first_block_group(info,
1934 search_start);
1935 if (!block_group)
1936 block_group = btrfs_lookup_first_block_group(info,
1937 orig_search_start);
1938 }
1939 if (full_scan && !chunk_alloc_done) {
1940 if (allowed_chunk_alloc) {
1941 do_chunk_alloc(trans, root,
1942 num_bytes + 2 * 1024 * 1024, data, 1);
1943 allowed_chunk_alloc = 0;
1944 } else if (block_group && block_group_bits(block_group, data)) {
1945 block_group->space_info->force_alloc = 1;
1946 }
1947 chunk_alloc_done = 1;
1948 }
1949 ret = find_search_start(root, &block_group, &search_start,
1950 total_needed, data);
1951 if (ret == -ENOSPC && last_ptr && *last_ptr) {
1952 *last_ptr = 0;
1953 block_group = btrfs_lookup_first_block_group(info,
1954 orig_search_start);
1955 search_start = orig_search_start;
1956 ret = find_search_start(root, &block_group, &search_start,
1957 total_needed, data);
1958 }
1959 if (ret == -ENOSPC)
1960 goto enospc;
1961 if (ret)
1962 goto error;
1963
1964 if (last_ptr && *last_ptr && search_start != *last_ptr) {
1965 *last_ptr = 0;
1966 if (!empty_size) {
1967 empty_size += empty_cluster;
1968 total_needed += empty_size;
1969 }
1970 block_group = btrfs_lookup_first_block_group(info,
1971 orig_search_start);
1972 search_start = orig_search_start;
1973 ret = find_search_start(root, &block_group,
1974 &search_start, total_needed, data);
1975 if (ret == -ENOSPC)
1976 goto enospc;
1977 if (ret)
1978 goto error;
1979 }
1980
1981 search_start = stripe_align(root, search_start);
1982 ins->objectid = search_start;
1983 ins->offset = num_bytes;
1984
1985 if (ins->objectid + num_bytes >= search_end)
1986 goto enospc;
1987
1988 if (ins->objectid + num_bytes >
1989 block_group->key.objectid + block_group->key.offset) {
1990 search_start = block_group->key.objectid +
1991 block_group->key.offset;
1992 goto new_group;
1993 }
1994
1995 if (test_range_bit(&info->extent_ins, ins->objectid,
1996 ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
1997 search_start = ins->objectid + num_bytes;
1998 goto new_group;
1999 }
2000
2001 if (test_range_bit(&info->pinned_extents, ins->objectid,
2002 ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) {
2003 search_start = ins->objectid + num_bytes;
2004 goto new_group;
2005 }
2006
2007 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
2008 ins->objectid < exclude_start + exclude_nr)) {
2009 search_start = exclude_start + exclude_nr;
2010 goto new_group;
2011 }
2012
2013 if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
2014 block_group = btrfs_lookup_block_group(info, ins->objectid);
2015 if (block_group)
2016 trans->block_group = block_group;
2017 }
2018 ins->offset = num_bytes;
2019 if (last_ptr) {
2020 *last_ptr = ins->objectid + ins->offset;
2021 if (*last_ptr ==
2022 btrfs_super_total_bytes(&root->fs_info->super_copy)) {
2023 *last_ptr = 0;
2024 }
2025 }
2026 return 0;
2027
2028 new_group:
2029 if (search_start + num_bytes >= search_end) {
2030 enospc:
2031 search_start = orig_search_start;
2032 if (full_scan) {
2033 ret = -ENOSPC;
2034 goto error;
2035 }
2036 if (wrapped) {
2037 if (!full_scan)
2038 total_needed -= empty_size;
2039 full_scan = 1;
2040 } else
2041 wrapped = 1;
2042 }
2043 block_group = btrfs_lookup_first_block_group(info, search_start);
2044 cond_resched();
2045 block_group = btrfs_find_block_group(root, block_group,
2046 search_start, data, 0);
2047 goto check_failed;
2048
2049 error:
2050 return ret;
2051 }
2052
2053 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2054 struct btrfs_root *root,
2055 u64 num_bytes, u64 min_alloc_size,
2056 u64 empty_size, u64 hint_byte,
2057 u64 search_end, struct btrfs_key *ins,
2058 u64 data)
2059 {
2060 int ret;
2061 u64 search_start = 0;
2062 u64 alloc_profile;
2063 struct btrfs_fs_info *info = root->fs_info;
2064
2065 if (data) {
2066 alloc_profile = info->avail_data_alloc_bits &
2067 info->data_alloc_profile;
2068 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2069 } else if (root == root->fs_info->chunk_root) {
2070 alloc_profile = info->avail_system_alloc_bits &
2071 info->system_alloc_profile;
2072 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2073 } else {
2074 alloc_profile = info->avail_metadata_alloc_bits &
2075 info->metadata_alloc_profile;
2076 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2077 }
2078 again:
2079 data = reduce_alloc_profile(root, data);
2080 /*
2081 * the only place that sets empty_size is btrfs_realloc_node, which
2082 * is not called recursively on allocations
2083 */
2084 if (empty_size || root->ref_cows) {
2085 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
2086 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2087 2 * 1024 * 1024,
2088 BTRFS_BLOCK_GROUP_METADATA |
2089 (info->metadata_alloc_profile &
2090 info->avail_metadata_alloc_bits), 0);
2091 BUG_ON(ret);
2092 }
2093 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2094 num_bytes + 2 * 1024 * 1024, data, 0);
2095 BUG_ON(ret);
2096 }
2097
2098 WARN_ON(num_bytes < root->sectorsize);
2099 ret = find_free_extent(trans, root, num_bytes, empty_size,
2100 search_start, search_end, hint_byte, ins,
2101 trans->alloc_exclude_start,
2102 trans->alloc_exclude_nr, data);
2103
2104 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
2105 num_bytes = num_bytes >> 1;
2106 num_bytes = max(num_bytes, min_alloc_size);
2107 do_chunk_alloc(trans, root->fs_info->extent_root,
2108 num_bytes, data, 1);
2109 goto again;
2110 }
2111 if (ret) {
2112 printk("allocation failed flags %Lu\n", data);
2113 BUG();
2114 }
2115 clear_extent_dirty(&root->fs_info->free_space_cache,
2116 ins->objectid, ins->objectid + ins->offset - 1,
2117 GFP_NOFS);
2118 return 0;
2119 }
2120
2121 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
2122 {
2123 maybe_lock_mutex(root);
2124 set_extent_dirty(&root->fs_info->free_space_cache,
2125 start, start + len - 1, GFP_NOFS);
2126 maybe_unlock_mutex(root);
2127 return 0;
2128 }
2129
2130 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2131 struct btrfs_root *root,
2132 u64 num_bytes, u64 min_alloc_size,
2133 u64 empty_size, u64 hint_byte,
2134 u64 search_end, struct btrfs_key *ins,
2135 u64 data)
2136 {
2137 int ret;
2138 maybe_lock_mutex(root);
2139 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
2140 empty_size, hint_byte, search_end, ins,
2141 data);
2142 maybe_unlock_mutex(root);
2143 return ret;
2144 }
2145
2146 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2147 struct btrfs_root *root,
2148 u64 root_objectid, u64 ref_generation,
2149 u64 owner, u64 owner_offset,
2150 struct btrfs_key *ins)
2151 {
2152 int ret;
2153 int pending_ret;
2154 u64 super_used;
2155 u64 root_used;
2156 u64 num_bytes = ins->offset;
2157 u32 sizes[2];
2158 struct btrfs_fs_info *info = root->fs_info;
2159 struct btrfs_root *extent_root = info->extent_root;
2160 struct btrfs_extent_item *extent_item;
2161 struct btrfs_extent_ref *ref;
2162 struct btrfs_path *path;
2163 struct btrfs_key keys[2];
2164
2165 /* block accounting for super block */
2166 spin_lock_irq(&info->delalloc_lock);
2167 super_used = btrfs_super_bytes_used(&info->super_copy);
2168 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
2169 spin_unlock_irq(&info->delalloc_lock);
2170
2171 /* block accounting for root item */
2172 root_used = btrfs_root_used(&root->root_item);
2173 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
2174
2175 if (root == extent_root) {
2176 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2177 ins->objectid + ins->offset - 1,
2178 EXTENT_LOCKED, GFP_NOFS);
2179 goto update_block;
2180 }
2181
2182 memcpy(&keys[0], ins, sizeof(*ins));
2183 keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
2184 owner, owner_offset);
2185 keys[1].objectid = ins->objectid;
2186 keys[1].type = BTRFS_EXTENT_REF_KEY;
2187 sizes[0] = sizeof(*extent_item);
2188 sizes[1] = sizeof(*ref);
2189
2190 path = btrfs_alloc_path();
2191 BUG_ON(!path);
2192
2193 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
2194 sizes, 2);
2195
2196 BUG_ON(ret);
2197 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2198 struct btrfs_extent_item);
2199 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
2200 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
2201 struct btrfs_extent_ref);
2202
2203 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
2204 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
2205 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
2206 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
2207
2208 btrfs_mark_buffer_dirty(path->nodes[0]);
2209
2210 trans->alloc_exclude_start = 0;
2211 trans->alloc_exclude_nr = 0;
2212 btrfs_free_path(path);
2213 finish_current_insert(trans, extent_root);
2214 pending_ret = del_pending_extents(trans, extent_root);
2215
2216 if (ret)
2217 goto out;
2218 if (pending_ret) {
2219 ret = pending_ret;
2220 goto out;
2221 }
2222
2223 update_block:
2224 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
2225 if (ret) {
2226 printk("update block group failed for %Lu %Lu\n",
2227 ins->objectid, ins->offset);
2228 BUG();
2229 }
2230 out:
2231 return ret;
2232 }
2233
2234 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2235 struct btrfs_root *root,
2236 u64 root_objectid, u64 ref_generation,
2237 u64 owner, u64 owner_offset,
2238 struct btrfs_key *ins)
2239 {
2240 int ret;
2241 maybe_lock_mutex(root);
2242 ret = __btrfs_alloc_reserved_extent(trans, root, root_objectid,
2243 ref_generation, owner,
2244 owner_offset, ins);
2245 maybe_unlock_mutex(root);
2246 return ret;
2247 }
2248 /*
2249 * finds a free extent and does all the dirty work required for allocation
2250 * returns the key for the extent through ins, and a tree buffer for
2251 * the first block of the extent through buf.
2252 *
2253 * returns 0 if everything worked, non-zero otherwise.
2254 */
2255 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
2256 struct btrfs_root *root,
2257 u64 num_bytes, u64 min_alloc_size,
2258 u64 root_objectid, u64 ref_generation,
2259 u64 owner, u64 owner_offset,
2260 u64 empty_size, u64 hint_byte,
2261 u64 search_end, struct btrfs_key *ins, u64 data)
2262 {
2263 int ret;
2264
2265 maybe_lock_mutex(root);
2266
2267 ret = __btrfs_reserve_extent(trans, root, num_bytes,
2268 min_alloc_size, empty_size, hint_byte,
2269 search_end, ins, data);
2270 BUG_ON(ret);
2271 ret = __btrfs_alloc_reserved_extent(trans, root, root_objectid,
2272 ref_generation, owner,
2273 owner_offset, ins);
2274 BUG_ON(ret);
2275
2276 maybe_unlock_mutex(root);
2277 return ret;
2278 }
2279
2280 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
2281 struct btrfs_root *root,
2282 u64 bytenr, u32 blocksize)
2283 {
2284 struct extent_buffer *buf;
2285
2286 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
2287 if (!buf)
2288 return ERR_PTR(-ENOMEM);
2289 btrfs_set_header_generation(buf, trans->transid);
2290 btrfs_tree_lock(buf);
2291 clean_tree_block(trans, root, buf);
2292 btrfs_set_buffer_uptodate(buf);
2293 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
2294 buf->start + buf->len - 1, GFP_NOFS);
2295 trans->blocks_used++;
2296 return buf;
2297 }
2298
2299 /*
2300 * helper function to allocate a block for a given tree
2301 * returns the tree buffer or NULL.
2302 */
2303 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2304 struct btrfs_root *root,
2305 u32 blocksize,
2306 u64 root_objectid,
2307 u64 ref_generation,
2308 u64 first_objectid,
2309 int level,
2310 u64 hint,
2311 u64 empty_size)
2312 {
2313 struct btrfs_key ins;
2314 int ret;
2315 struct extent_buffer *buf;
2316
2317 ret = btrfs_alloc_extent(trans, root, blocksize, blocksize,
2318 root_objectid, ref_generation,
2319 level, first_objectid, empty_size, hint,
2320 (u64)-1, &ins, 0);
2321 if (ret) {
2322 BUG_ON(ret > 0);
2323 return ERR_PTR(ret);
2324 }
2325
2326 buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
2327 return buf;
2328 }
2329
2330 static int noinline drop_leaf_ref_no_cache(struct btrfs_trans_handle *trans,
2331 struct btrfs_root *root,
2332 struct extent_buffer *leaf)
2333 {
2334 u64 leaf_owner;
2335 u64 leaf_generation;
2336 struct btrfs_key key;
2337 struct btrfs_file_extent_item *fi;
2338 int i;
2339 int nritems;
2340 int ret;
2341
2342 BUG_ON(!btrfs_is_leaf(leaf));
2343 nritems = btrfs_header_nritems(leaf);
2344 leaf_owner = btrfs_header_owner(leaf);
2345 leaf_generation = btrfs_header_generation(leaf);
2346
2347 for (i = 0; i < nritems; i++) {
2348 u64 disk_bytenr;
2349 cond_resched();
2350
2351 btrfs_item_key_to_cpu(leaf, &key, i);
2352 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2353 continue;
2354 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2355 if (btrfs_file_extent_type(leaf, fi) ==
2356 BTRFS_FILE_EXTENT_INLINE)
2357 continue;
2358 /*
2359 * FIXME make sure to insert a trans record that
2360 * repeats the snapshot del on crash
2361 */
2362 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2363 if (disk_bytenr == 0)
2364 continue;
2365
2366 mutex_lock(&root->fs_info->alloc_mutex);
2367 ret = __btrfs_free_extent(trans, root, disk_bytenr,
2368 btrfs_file_extent_disk_num_bytes(leaf, fi),
2369 leaf_owner, leaf_generation,
2370 key.objectid, key.offset, 0);
2371 mutex_unlock(&root->fs_info->alloc_mutex);
2372
2373 atomic_inc(&root->fs_info->throttle_gen);
2374 wake_up(&root->fs_info->transaction_throttle);
2375 cond_resched();
2376
2377 BUG_ON(ret);
2378 }
2379 return 0;
2380 }
2381
2382 static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans,
2383 struct btrfs_root *root,
2384 struct btrfs_leaf_ref *ref)
2385 {
2386 int i;
2387 int ret;
2388 struct btrfs_extent_info *info = ref->extents;
2389
2390 for (i = 0; i < ref->nritems; i++) {
2391 mutex_lock(&root->fs_info->alloc_mutex);
2392 ret = __btrfs_free_extent(trans, root,
2393 info->bytenr, info->num_bytes,
2394 ref->owner, ref->generation,
2395 info->objectid, info->offset, 0);
2396 mutex_unlock(&root->fs_info->alloc_mutex);
2397
2398 atomic_inc(&root->fs_info->throttle_gen);
2399 wake_up(&root->fs_info->transaction_throttle);
2400 cond_resched();
2401
2402 BUG_ON(ret);
2403 info++;
2404 }
2405
2406 return 0;
2407 }
2408
2409 int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len,
2410 u32 *refs)
2411 {
2412 int ret;
2413
2414 ret = lookup_extent_ref(NULL, root, start, len, refs);
2415 BUG_ON(ret);
2416
2417 #if 0 // some debugging code in case we see problems here
2418 /* if the refs count is one, it won't get increased again. But
2419 * if the ref count is > 1, someone may be decreasing it at
2420 * the same time we are.
2421 */
2422 if (*refs != 1) {
2423 struct extent_buffer *eb = NULL;
2424 eb = btrfs_find_create_tree_block(root, start, len);
2425 if (eb)
2426 btrfs_tree_lock(eb);
2427
2428 mutex_lock(&root->fs_info->alloc_mutex);
2429 ret = lookup_extent_ref(NULL, root, start, len, refs);
2430 BUG_ON(ret);
2431 mutex_unlock(&root->fs_info->alloc_mutex);
2432
2433 if (eb) {
2434 btrfs_tree_unlock(eb);
2435 free_extent_buffer(eb);
2436 }
2437 if (*refs == 1) {
2438 printk("block %llu went down to one during drop_snap\n",
2439 (unsigned long long)start);
2440 }
2441
2442 }
2443 #endif
2444
2445 cond_resched();
2446 return ret;
2447 }
2448
2449 /*
2450 * helper function for drop_snapshot, this walks down the tree dropping ref
2451 * counts as it goes.
2452 */
2453 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2454 struct btrfs_root *root,
2455 struct btrfs_path *path, int *level)
2456 {
2457 u64 root_owner;
2458 u64 root_gen;
2459 u64 bytenr;
2460 u64 ptr_gen;
2461 struct extent_buffer *next;
2462 struct extent_buffer *cur;
2463 struct extent_buffer *parent;
2464 struct btrfs_leaf_ref *ref;
2465 u32 blocksize;
2466 int ret;
2467 u32 refs;
2468
2469 WARN_ON(*level < 0);
2470 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2471 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
2472 path->nodes[*level]->len, &refs);
2473 BUG_ON(ret);
2474 if (refs > 1)
2475 goto out;
2476
2477 /*
2478 * walk down to the last node level and free all the leaves
2479 */
2480 while(*level >= 0) {
2481 WARN_ON(*level < 0);
2482 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2483 cur = path->nodes[*level];
2484
2485 if (btrfs_header_level(cur) != *level)
2486 WARN_ON(1);
2487
2488 if (path->slots[*level] >=
2489 btrfs_header_nritems(cur))
2490 break;
2491 if (*level == 0) {
2492 ret = drop_leaf_ref_no_cache(trans, root, cur);
2493 BUG_ON(ret);
2494 break;
2495 }
2496 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2497 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2498 blocksize = btrfs_level_size(root, *level - 1);
2499
2500 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
2501 BUG_ON(ret);
2502 if (refs != 1) {
2503 parent = path->nodes[*level];
2504 root_owner = btrfs_header_owner(parent);
2505 root_gen = btrfs_header_generation(parent);
2506 path->slots[*level]++;
2507
2508 mutex_lock(&root->fs_info->alloc_mutex);
2509 ret = __btrfs_free_extent(trans, root, bytenr,
2510 blocksize, root_owner,
2511 root_gen, 0, 0, 1);
2512 BUG_ON(ret);
2513 mutex_unlock(&root->fs_info->alloc_mutex);
2514
2515 atomic_inc(&root->fs_info->throttle_gen);
2516 wake_up(&root->fs_info->transaction_throttle);
2517 cond_resched();
2518
2519 continue;
2520 }
2521 /*
2522 * at this point, we have a single ref, and since the
2523 * only place referencing this extent is a dead root
2524 * the reference count should never go higher.
2525 * So, we don't need to check it again
2526 */
2527 if (*level == 1) {
2528 struct btrfs_key key;
2529 btrfs_node_key_to_cpu(cur, &key, path->slots[*level]);
2530 ref = btrfs_lookup_leaf_ref(root, bytenr);
2531 if (ref) {
2532 ret = drop_leaf_ref(trans, root, ref);
2533 BUG_ON(ret);
2534 btrfs_remove_leaf_ref(root, ref);
2535 btrfs_free_leaf_ref(root, ref);
2536 *level = 0;
2537 break;
2538 }
2539 if (printk_ratelimit())
2540 printk("leaf ref miss for bytenr %llu\n",
2541 (unsigned long long)bytenr);
2542 }
2543 next = btrfs_find_tree_block(root, bytenr, blocksize);
2544 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2545 free_extent_buffer(next);
2546
2547 next = read_tree_block(root, bytenr, blocksize,
2548 ptr_gen);
2549 cond_resched();
2550 #if 0
2551 /*
2552 * this is a debugging check and can go away
2553 * the ref should never go all the way down to 1
2554 * at this point
2555 */
2556 ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
2557 &refs);
2558 BUG_ON(ret);
2559 WARN_ON(refs != 1);
2560 #endif
2561 }
2562 WARN_ON(*level <= 0);
2563 if (path->nodes[*level-1])
2564 free_extent_buffer(path->nodes[*level-1]);
2565 path->nodes[*level-1] = next;
2566 *level = btrfs_header_level(next);
2567 path->slots[*level] = 0;
2568 cond_resched();
2569 }
2570 out:
2571 WARN_ON(*level < 0);
2572 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2573
2574 if (path->nodes[*level] == root->node) {
2575 parent = path->nodes[*level];
2576 bytenr = path->nodes[*level]->start;
2577 } else {
2578 parent = path->nodes[*level + 1];
2579 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
2580 }
2581
2582 blocksize = btrfs_level_size(root, *level);
2583 root_owner = btrfs_header_owner(parent);
2584 root_gen = btrfs_header_generation(parent);
2585
2586 mutex_lock(&root->fs_info->alloc_mutex);
2587 ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
2588 root_owner, root_gen, 0, 0, 1);
2589 free_extent_buffer(path->nodes[*level]);
2590 path->nodes[*level] = NULL;
2591 *level += 1;
2592 BUG_ON(ret);
2593 mutex_unlock(&root->fs_info->alloc_mutex);
2594
2595 cond_resched();
2596 return 0;
2597 }
2598
2599 /*
2600 * helper for dropping snapshots. This walks back up the tree in the path
2601 * to find the first node higher up where we haven't yet gone through
2602 * all the slots
2603 */
2604 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
2605 struct btrfs_root *root,
2606 struct btrfs_path *path, int *level)
2607 {
2608 u64 root_owner;
2609 u64 root_gen;
2610 struct btrfs_root_item *root_item = &root->root_item;
2611 int i;
2612 int slot;
2613 int ret;
2614
2615 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2616 slot = path->slots[i];
2617 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
2618 struct extent_buffer *node;
2619 struct btrfs_disk_key disk_key;
2620 node = path->nodes[i];
2621 path->slots[i]++;
2622 *level = i;
2623 WARN_ON(*level == 0);
2624 btrfs_node_key(node, &disk_key, path->slots[i]);
2625 memcpy(&root_item->drop_progress,
2626 &disk_key, sizeof(disk_key));
2627 root_item->drop_level = i;
2628 return 0;
2629 } else {
2630 if (path->nodes[*level] == root->node) {
2631 root_owner = root->root_key.objectid;
2632 root_gen =
2633 btrfs_header_generation(path->nodes[*level]);
2634 } else {
2635 struct extent_buffer *node;
2636 node = path->nodes[*level + 1];
2637 root_owner = btrfs_header_owner(node);
2638 root_gen = btrfs_header_generation(node);
2639 }
2640 ret = btrfs_free_extent(trans, root,
2641 path->nodes[*level]->start,
2642 path->nodes[*level]->len,
2643 root_owner, root_gen, 0, 0, 1);
2644 BUG_ON(ret);
2645 free_extent_buffer(path->nodes[*level]);
2646 path->nodes[*level] = NULL;
2647 *level = i + 1;
2648 }
2649 }
2650 return 1;
2651 }
2652
2653 /*
2654 * drop the reference count on the tree rooted at 'snap'. This traverses
2655 * the tree freeing any blocks that have a ref count of zero after being
2656 * decremented.
2657 */
2658 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2659 *root)
2660 {
2661 int ret = 0;
2662 int wret;
2663 int level;
2664 struct btrfs_path *path;
2665 int i;
2666 int orig_level;
2667 struct btrfs_root_item *root_item = &root->root_item;
2668
2669 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
2670 path = btrfs_alloc_path();
2671 BUG_ON(!path);
2672
2673 level = btrfs_header_level(root->node);
2674 orig_level = level;
2675 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2676 path->nodes[level] = root->node;
2677 extent_buffer_get(root->node);
2678 path->slots[level] = 0;
2679 } else {
2680 struct btrfs_key key;
2681 struct btrfs_disk_key found_key;
2682 struct extent_buffer *node;
2683
2684 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2685 level = root_item->drop_level;
2686 path->lowest_level = level;
2687 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2688 if (wret < 0) {
2689 ret = wret;
2690 goto out;
2691 }
2692 node = path->nodes[level];
2693 btrfs_node_key(node, &found_key, path->slots[level]);
2694 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2695 sizeof(found_key)));
2696 /*
2697 * unlock our path, this is safe because only this
2698 * function is allowed to delete this snapshot
2699 */
2700 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
2701 if (path->nodes[i] && path->locks[i]) {
2702 path->locks[i] = 0;
2703 btrfs_tree_unlock(path->nodes[i]);
2704 }
2705 }
2706 }
2707 while(1) {
2708 wret = walk_down_tree(trans, root, path, &level);
2709 if (wret > 0)
2710 break;
2711 if (wret < 0)
2712 ret = wret;
2713
2714 wret = walk_up_tree(trans, root, path, &level);
2715 if (wret > 0)
2716 break;
2717 if (wret < 0)
2718 ret = wret;
2719 if (trans->transaction->in_commit) {
2720 ret = -EAGAIN;
2721 break;
2722 }
2723 atomic_inc(&root->fs_info->throttle_gen);
2724 wake_up(&root->fs_info->transaction_throttle);
2725 }
2726 for (i = 0; i <= orig_level; i++) {
2727 if (path->nodes[i]) {
2728 free_extent_buffer(path->nodes[i]);
2729 path->nodes[i] = NULL;
2730 }
2731 }
2732 out:
2733 btrfs_free_path(path);
2734 return ret;
2735 }
2736
2737 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2738 {
2739 u64 start;
2740 u64 end;
2741 u64 ptr;
2742 int ret;
2743
2744 mutex_lock(&info->alloc_mutex);
2745 while(1) {
2746 ret = find_first_extent_bit(&info->block_group_cache, 0,
2747 &start, &end, (unsigned int)-1);
2748 if (ret)
2749 break;
2750 ret = get_state_private(&info->block_group_cache, start, &ptr);
2751 if (!ret)
2752 kfree((void *)(unsigned long)ptr);
2753 clear_extent_bits(&info->block_group_cache, start,
2754 end, (unsigned int)-1, GFP_NOFS);
2755 }
2756 while(1) {
2757 ret = find_first_extent_bit(&info->free_space_cache, 0,
2758 &start, &end, EXTENT_DIRTY);
2759 if (ret)
2760 break;
2761 clear_extent_dirty(&info->free_space_cache, start,
2762 end, GFP_NOFS);
2763 }
2764 mutex_unlock(&info->alloc_mutex);
2765 return 0;
2766 }
2767
2768 static unsigned long calc_ra(unsigned long start, unsigned long last,
2769 unsigned long nr)
2770 {
2771 return min(last, start + nr - 1);
2772 }
2773
2774 static int noinline relocate_inode_pages(struct inode *inode, u64 start,
2775 u64 len)
2776 {
2777 u64 page_start;
2778 u64 page_end;
2779 unsigned long last_index;
2780 unsigned long i;
2781 struct page *page;
2782 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2783 struct file_ra_state *ra;
2784 unsigned long total_read = 0;
2785 unsigned long ra_pages;
2786 struct btrfs_ordered_extent *ordered;
2787 struct btrfs_trans_handle *trans;
2788
2789 ra = kzalloc(sizeof(*ra), GFP_NOFS);
2790
2791 mutex_lock(&inode->i_mutex);
2792 i = start >> PAGE_CACHE_SHIFT;
2793 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
2794
2795 ra_pages = BTRFS_I(inode)->root->fs_info->bdi.ra_pages;
2796
2797 file_ra_state_init(ra, inode->i_mapping);
2798
2799 for (; i <= last_index; i++) {
2800 if (total_read % ra_pages == 0) {
2801 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
2802 calc_ra(i, last_index, ra_pages));
2803 }
2804 total_read++;
2805 again:
2806 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
2807 goto truncate_racing;
2808 page = grab_cache_page(inode->i_mapping, i);
2809 if (!page) {
2810 goto out_unlock;
2811 }
2812 if (!PageUptodate(page)) {
2813 btrfs_readpage(NULL, page);
2814 lock_page(page);
2815 if (!PageUptodate(page)) {
2816 unlock_page(page);
2817 page_cache_release(page);
2818 goto out_unlock;
2819 }
2820 }
2821 wait_on_page_writeback(page);
2822
2823 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2824 page_end = page_start + PAGE_CACHE_SIZE - 1;
2825 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2826
2827 ordered = btrfs_lookup_ordered_extent(inode, page_start);
2828 if (ordered) {
2829 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2830 unlock_page(page);
2831 page_cache_release(page);
2832 btrfs_start_ordered_extent(inode, ordered, 1);
2833 btrfs_put_ordered_extent(ordered);
2834 goto again;
2835 }
2836 set_page_extent_mapped(page);
2837
2838 /*
2839 * make sure page_mkwrite is called for this page if userland
2840 * wants to change it from mmap
2841 */
2842 clear_page_dirty_for_io(page);
2843
2844 set_extent_delalloc(io_tree, page_start,
2845 page_end, GFP_NOFS);
2846 set_page_dirty(page);
2847
2848 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2849 unlock_page(page);
2850 page_cache_release(page);
2851 }
2852
2853 out_unlock:
2854 /* we have to start the IO in order to get the ordered extents
2855 * instantiated. This allows the relocation to code to wait
2856 * for all the ordered extents to hit the disk.
2857 *
2858 * Otherwise, it would constantly loop over the same extents
2859 * because the old ones don't get deleted until the IO is
2860 * started
2861 */
2862 btrfs_fdatawrite_range(inode->i_mapping, start, start + len - 1,
2863 WB_SYNC_NONE);
2864 kfree(ra);
2865 trans = btrfs_start_transaction(BTRFS_I(inode)->root, 1);
2866 if (trans) {
2867 btrfs_end_transaction(trans, BTRFS_I(inode)->root);
2868 mark_inode_dirty(inode);
2869 }
2870 mutex_unlock(&inode->i_mutex);
2871 return 0;
2872
2873 truncate_racing:
2874 vmtruncate(inode, inode->i_size);
2875 balance_dirty_pages_ratelimited_nr(inode->i_mapping,
2876 total_read);
2877 goto out_unlock;
2878 }
2879
2880 /*
2881 * The back references tell us which tree holds a ref on a block,
2882 * but it is possible for the tree root field in the reference to
2883 * reflect the original root before a snapshot was made. In this
2884 * case we should search through all the children of a given root
2885 * to find potential holders of references on a block.
2886 *
2887 * Instead, we do something a little less fancy and just search
2888 * all the roots for a given key/block combination.
2889 */
2890 static int find_root_for_ref(struct btrfs_root *root,
2891 struct btrfs_path *path,
2892 struct btrfs_key *key0,
2893 int level,
2894 int file_key,
2895 struct btrfs_root **found_root,
2896 u64 bytenr)
2897 {
2898 struct btrfs_key root_location;
2899 struct btrfs_root *cur_root = *found_root;
2900 struct btrfs_file_extent_item *file_extent;
2901 u64 root_search_start = BTRFS_FS_TREE_OBJECTID;
2902 u64 found_bytenr;
2903 int ret;
2904
2905 root_location.offset = (u64)-1;
2906 root_location.type = BTRFS_ROOT_ITEM_KEY;
2907 path->lowest_level = level;
2908 path->reada = 0;
2909 while(1) {
2910 ret = btrfs_search_slot(NULL, cur_root, key0, path, 0, 0);
2911 found_bytenr = 0;
2912 if (ret == 0 && file_key) {
2913 struct extent_buffer *leaf = path->nodes[0];
2914 file_extent = btrfs_item_ptr(leaf, path->slots[0],
2915 struct btrfs_file_extent_item);
2916 if (btrfs_file_extent_type(leaf, file_extent) ==
2917 BTRFS_FILE_EXTENT_REG) {
2918 found_bytenr =
2919 btrfs_file_extent_disk_bytenr(leaf,
2920 file_extent);
2921 }
2922 } else if (!file_key) {
2923 if (path->nodes[level])
2924 found_bytenr = path->nodes[level]->start;
2925 }
2926
2927 btrfs_release_path(cur_root, path);
2928
2929 if (found_bytenr == bytenr) {
2930 *found_root = cur_root;
2931 ret = 0;
2932 goto out;
2933 }
2934 ret = btrfs_search_root(root->fs_info->tree_root,
2935 root_search_start, &root_search_start);
2936 if (ret)
2937 break;
2938
2939 root_location.objectid = root_search_start;
2940 cur_root = btrfs_read_fs_root_no_name(root->fs_info,
2941 &root_location);
2942 if (!cur_root) {
2943 ret = 1;
2944 break;
2945 }
2946 }
2947 out:
2948 path->lowest_level = 0;
2949 return ret;
2950 }
2951
2952 /*
2953 * note, this releases the path
2954 */
2955 static int noinline relocate_one_reference(struct btrfs_root *extent_root,
2956 struct btrfs_path *path,
2957 struct btrfs_key *extent_key,
2958 u64 *last_file_objectid,
2959 u64 *last_file_offset,
2960 u64 *last_file_root,
2961 u64 last_extent)
2962 {
2963 struct inode *inode;
2964 struct btrfs_root *found_root;
2965 struct btrfs_key root_location;
2966 struct btrfs_key found_key;
2967 struct btrfs_extent_ref *ref;
2968 u64 ref_root;
2969 u64 ref_gen;
2970 u64 ref_objectid;
2971 u64 ref_offset;
2972 int ret;
2973 int level;
2974
2975 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
2976
2977 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
2978 struct btrfs_extent_ref);
2979 ref_root = btrfs_ref_root(path->nodes[0], ref);
2980 ref_gen = btrfs_ref_generation(path->nodes[0], ref);
2981 ref_objectid = btrfs_ref_objectid(path->nodes[0], ref);
2982 ref_offset = btrfs_ref_offset(path->nodes[0], ref);
2983 btrfs_release_path(extent_root, path);
2984
2985 root_location.objectid = ref_root;
2986 if (ref_gen == 0)
2987 root_location.offset = 0;
2988 else
2989 root_location.offset = (u64)-1;
2990 root_location.type = BTRFS_ROOT_ITEM_KEY;
2991
2992 found_root = btrfs_read_fs_root_no_name(extent_root->fs_info,
2993 &root_location);
2994 BUG_ON(!found_root);
2995 mutex_unlock(&extent_root->fs_info->alloc_mutex);
2996
2997 if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
2998 found_key.objectid = ref_objectid;
2999 found_key.type = BTRFS_EXTENT_DATA_KEY;
3000 found_key.offset = ref_offset;
3001 level = 0;
3002
3003 if (last_extent == extent_key->objectid &&
3004 *last_file_objectid == ref_objectid &&
3005 *last_file_offset == ref_offset &&
3006 *last_file_root == ref_root)
3007 goto out;
3008
3009 ret = find_root_for_ref(extent_root, path, &found_key,
3010 level, 1, &found_root,
3011 extent_key->objectid);
3012
3013 if (ret)
3014 goto out;
3015
3016 if (last_extent == extent_key->objectid &&
3017 *last_file_objectid == ref_objectid &&
3018 *last_file_offset == ref_offset &&
3019 *last_file_root == ref_root)
3020 goto out;
3021
3022 inode = btrfs_iget_locked(extent_root->fs_info->sb,
3023 ref_objectid, found_root);
3024 if (inode->i_state & I_NEW) {
3025 /* the inode and parent dir are two different roots */
3026 BTRFS_I(inode)->root = found_root;
3027 BTRFS_I(inode)->location.objectid = ref_objectid;
3028 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
3029 BTRFS_I(inode)->location.offset = 0;
3030 btrfs_read_locked_inode(inode);
3031 unlock_new_inode(inode);
3032
3033 }
3034 /* this can happen if the reference is not against
3035 * the latest version of the tree root
3036 */
3037 if (is_bad_inode(inode))
3038 goto out;
3039
3040 *last_file_objectid = inode->i_ino;
3041 *last_file_root = found_root->root_key.objectid;
3042 *last_file_offset = ref_offset;
3043
3044 relocate_inode_pages(inode, ref_offset, extent_key->offset);
3045 iput(inode);
3046 } else {
3047 struct btrfs_trans_handle *trans;
3048 struct extent_buffer *eb;
3049 int needs_lock = 0;
3050
3051 eb = read_tree_block(found_root, extent_key->objectid,
3052 extent_key->offset, 0);
3053 btrfs_tree_lock(eb);
3054 level = btrfs_header_level(eb);
3055
3056 if (level == 0)
3057 btrfs_item_key_to_cpu(eb, &found_key, 0);
3058 else
3059 btrfs_node_key_to_cpu(eb, &found_key, 0);
3060
3061 btrfs_tree_unlock(eb);
3062 free_extent_buffer(eb);
3063
3064 ret = find_root_for_ref(extent_root, path, &found_key,
3065 level, 0, &found_root,
3066 extent_key->objectid);
3067
3068 if (ret)
3069 goto out;
3070
3071 /*
3072 * right here almost anything could happen to our key,
3073 * but that's ok. The cow below will either relocate it
3074 * or someone else will have relocated it. Either way,
3075 * it is in a different spot than it was before and
3076 * we're happy.
3077 */
3078
3079 trans = btrfs_start_transaction(found_root, 1);
3080
3081 if (found_root == extent_root->fs_info->extent_root ||
3082 found_root == extent_root->fs_info->chunk_root ||
3083 found_root == extent_root->fs_info->dev_root) {
3084 needs_lock = 1;
3085 mutex_lock(&extent_root->fs_info->alloc_mutex);
3086 }
3087
3088 path->lowest_level = level;
3089 path->reada = 2;
3090 ret = btrfs_search_slot(trans, found_root, &found_key, path,
3091 0, 1);
3092 path->lowest_level = 0;
3093 btrfs_release_path(found_root, path);
3094
3095 if (found_root == found_root->fs_info->extent_root)
3096 btrfs_extent_post_op(trans, found_root);
3097 if (needs_lock)
3098 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3099
3100 btrfs_end_transaction(trans, found_root);
3101
3102 }
3103 out:
3104 mutex_lock(&extent_root->fs_info->alloc_mutex);
3105 return 0;
3106 }
3107
3108 static int noinline del_extent_zero(struct btrfs_root *extent_root,
3109 struct btrfs_path *path,
3110 struct btrfs_key *extent_key)
3111 {
3112 int ret;
3113 struct btrfs_trans_handle *trans;
3114
3115 trans = btrfs_start_transaction(extent_root, 1);
3116 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
3117 if (ret > 0) {
3118 ret = -EIO;
3119 goto out;
3120 }
3121 if (ret < 0)
3122 goto out;
3123 ret = btrfs_del_item(trans, extent_root, path);
3124 out:
3125 btrfs_end_transaction(trans, extent_root);
3126 return ret;
3127 }
3128
3129 static int noinline relocate_one_extent(struct btrfs_root *extent_root,
3130 struct btrfs_path *path,
3131 struct btrfs_key *extent_key)
3132 {
3133 struct btrfs_key key;
3134 struct btrfs_key found_key;
3135 struct extent_buffer *leaf;
3136 u64 last_file_objectid = 0;
3137 u64 last_file_root = 0;
3138 u64 last_file_offset = (u64)-1;
3139 u64 last_extent = 0;
3140 u32 nritems;
3141 u32 item_size;
3142 int ret = 0;
3143
3144 if (extent_key->objectid == 0) {
3145 ret = del_extent_zero(extent_root, path, extent_key);
3146 goto out;
3147 }
3148 key.objectid = extent_key->objectid;
3149 key.type = BTRFS_EXTENT_REF_KEY;
3150 key.offset = 0;
3151
3152 while(1) {
3153 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
3154
3155 if (ret < 0)
3156 goto out;
3157
3158 ret = 0;
3159 leaf = path->nodes[0];
3160 nritems = btrfs_header_nritems(leaf);
3161 if (path->slots[0] == nritems) {
3162 ret = btrfs_next_leaf(extent_root, path);
3163 if (ret > 0) {
3164 ret = 0;
3165 goto out;
3166 }
3167 if (ret < 0)
3168 goto out;
3169 leaf = path->nodes[0];
3170 }
3171
3172 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3173 if (found_key.objectid != extent_key->objectid) {
3174 break;
3175 }
3176
3177 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
3178 break;
3179 }
3180
3181 key.offset = found_key.offset + 1;
3182 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
3183
3184 ret = relocate_one_reference(extent_root, path, extent_key,
3185 &last_file_objectid,
3186 &last_file_offset,
3187 &last_file_root, last_extent);
3188 if (ret)
3189 goto out;
3190 last_extent = extent_key->objectid;
3191 }
3192 ret = 0;
3193 out:
3194 btrfs_release_path(extent_root, path);
3195 return ret;
3196 }
3197
3198 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
3199 {
3200 u64 num_devices;
3201 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
3202 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
3203
3204 num_devices = root->fs_info->fs_devices->num_devices;
3205 if (num_devices == 1) {
3206 stripped |= BTRFS_BLOCK_GROUP_DUP;
3207 stripped = flags & ~stripped;
3208
3209 /* turn raid0 into single device chunks */
3210 if (flags & BTRFS_BLOCK_GROUP_RAID0)
3211 return stripped;
3212
3213 /* turn mirroring into duplication */
3214 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
3215 BTRFS_BLOCK_GROUP_RAID10))
3216 return stripped | BTRFS_BLOCK_GROUP_DUP;
3217 return flags;
3218 } else {
3219 /* they already had raid on here, just return */
3220 if (flags & stripped)
3221 return flags;
3222
3223 stripped |= BTRFS_BLOCK_GROUP_DUP;
3224 stripped = flags & ~stripped;
3225
3226 /* switch duplicated blocks with raid1 */
3227 if (flags & BTRFS_BLOCK_GROUP_DUP)
3228 return stripped | BTRFS_BLOCK_GROUP_RAID1;
3229
3230 /* turn single device chunks into raid0 */
3231 return stripped | BTRFS_BLOCK_GROUP_RAID0;
3232 }
3233 return flags;
3234 }
3235
3236 int __alloc_chunk_for_shrink(struct btrfs_root *root,
3237 struct btrfs_block_group_cache *shrink_block_group,
3238 int force)
3239 {
3240 struct btrfs_trans_handle *trans;
3241 u64 new_alloc_flags;
3242 u64 calc;
3243
3244 spin_lock(&shrink_block_group->lock);
3245 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
3246 spin_unlock(&shrink_block_group->lock);
3247 mutex_unlock(&root->fs_info->alloc_mutex);
3248
3249 trans = btrfs_start_transaction(root, 1);
3250 mutex_lock(&root->fs_info->alloc_mutex);
3251 spin_lock(&shrink_block_group->lock);
3252
3253 new_alloc_flags = update_block_group_flags(root,
3254 shrink_block_group->flags);
3255 if (new_alloc_flags != shrink_block_group->flags) {
3256 calc =
3257 btrfs_block_group_used(&shrink_block_group->item);
3258 } else {
3259 calc = shrink_block_group->key.offset;
3260 }
3261 spin_unlock(&shrink_block_group->lock);
3262
3263 do_chunk_alloc(trans, root->fs_info->extent_root,
3264 calc + 2 * 1024 * 1024, new_alloc_flags, force);
3265
3266 mutex_unlock(&root->fs_info->alloc_mutex);
3267 btrfs_end_transaction(trans, root);
3268 mutex_lock(&root->fs_info->alloc_mutex);
3269 } else
3270 spin_unlock(&shrink_block_group->lock);
3271 return 0;
3272 }
3273
3274 int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start)
3275 {
3276 struct btrfs_trans_handle *trans;
3277 struct btrfs_root *tree_root = root->fs_info->tree_root;
3278 struct btrfs_path *path;
3279 u64 cur_byte;
3280 u64 total_found;
3281 u64 shrink_last_byte;
3282 struct btrfs_block_group_cache *shrink_block_group;
3283 struct btrfs_fs_info *info = root->fs_info;
3284 struct btrfs_key key;
3285 struct btrfs_key found_key;
3286 struct extent_buffer *leaf;
3287 u32 nritems;
3288 int ret;
3289 int progress;
3290
3291 mutex_lock(&root->fs_info->alloc_mutex);
3292 shrink_block_group = btrfs_lookup_block_group(root->fs_info,
3293 shrink_start);
3294 BUG_ON(!shrink_block_group);
3295
3296 shrink_last_byte = shrink_block_group->key.objectid +
3297 shrink_block_group->key.offset;
3298
3299 shrink_block_group->space_info->total_bytes -=
3300 shrink_block_group->key.offset;
3301 path = btrfs_alloc_path();
3302 root = root->fs_info->extent_root;
3303 path->reada = 2;
3304
3305 printk("btrfs relocating block group %llu flags %llu\n",
3306 (unsigned long long)shrink_start,
3307 (unsigned long long)shrink_block_group->flags);
3308
3309 __alloc_chunk_for_shrink(root, shrink_block_group, 1);
3310
3311 again:
3312
3313 shrink_block_group->ro = 1;
3314
3315 total_found = 0;
3316 progress = 0;
3317 key.objectid = shrink_start;
3318 key.offset = 0;
3319 key.type = 0;
3320 cur_byte = key.objectid;
3321
3322 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3323 if (ret < 0)
3324 goto out;
3325
3326 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
3327 if (ret < 0)
3328 goto out;
3329
3330 if (ret == 0) {
3331 leaf = path->nodes[0];
3332 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3333 if (found_key.objectid + found_key.offset > shrink_start &&
3334 found_key.objectid < shrink_last_byte) {
3335 cur_byte = found_key.objectid;
3336 key.objectid = cur_byte;
3337 }
3338 }
3339 btrfs_release_path(root, path);
3340
3341 while(1) {
3342 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3343 if (ret < 0)
3344 goto out;
3345
3346 next:
3347 leaf = path->nodes[0];
3348 nritems = btrfs_header_nritems(leaf);
3349 if (path->slots[0] >= nritems) {
3350 ret = btrfs_next_leaf(root, path);
3351 if (ret < 0)
3352 goto out;
3353 if (ret == 1) {
3354 ret = 0;
3355 break;
3356 }
3357 leaf = path->nodes[0];
3358 nritems = btrfs_header_nritems(leaf);
3359 }
3360
3361 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3362
3363 if (found_key.objectid >= shrink_last_byte)
3364 break;
3365
3366 if (progress && need_resched()) {
3367 memcpy(&key, &found_key, sizeof(key));
3368 cond_resched();
3369 btrfs_release_path(root, path);
3370 btrfs_search_slot(NULL, root, &key, path, 0, 0);
3371 progress = 0;
3372 goto next;
3373 }
3374 progress = 1;
3375
3376 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY ||
3377 found_key.objectid + found_key.offset <= cur_byte) {
3378 memcpy(&key, &found_key, sizeof(key));
3379 key.offset++;
3380 path->slots[0]++;
3381 goto next;
3382 }
3383
3384 total_found++;
3385 cur_byte = found_key.objectid + found_key.offset;
3386 key.objectid = cur_byte;
3387 btrfs_release_path(root, path);
3388 ret = relocate_one_extent(root, path, &found_key);
3389 __alloc_chunk_for_shrink(root, shrink_block_group, 0);
3390 }
3391
3392 btrfs_release_path(root, path);
3393
3394 if (total_found > 0) {
3395 printk("btrfs relocate found %llu last extent was %llu\n",
3396 (unsigned long long)total_found,
3397 (unsigned long long)found_key.objectid);
3398 mutex_unlock(&root->fs_info->alloc_mutex);
3399 trans = btrfs_start_transaction(tree_root, 1);
3400 btrfs_commit_transaction(trans, tree_root);
3401
3402 btrfs_clean_old_snapshots(tree_root);
3403
3404 btrfs_wait_ordered_extents(tree_root);
3405
3406 trans = btrfs_start_transaction(tree_root, 1);
3407 btrfs_commit_transaction(trans, tree_root);
3408 mutex_lock(&root->fs_info->alloc_mutex);
3409 goto again;
3410 }
3411
3412 /*
3413 * we've freed all the extents, now remove the block
3414 * group item from the tree
3415 */
3416 mutex_unlock(&root->fs_info->alloc_mutex);
3417
3418 trans = btrfs_start_transaction(root, 1);
3419
3420 mutex_lock(&root->fs_info->alloc_mutex);
3421 memcpy(&key, &shrink_block_group->key, sizeof(key));
3422
3423 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3424 if (ret > 0)
3425 ret = -EIO;
3426 if (ret < 0) {
3427 btrfs_end_transaction(trans, root);
3428 goto out;
3429 }
3430
3431 clear_extent_bits(&info->block_group_cache, key.objectid,
3432 key.objectid + key.offset - 1,
3433 (unsigned int)-1, GFP_NOFS);
3434
3435
3436 clear_extent_bits(&info->free_space_cache,
3437 key.objectid, key.objectid + key.offset - 1,
3438 (unsigned int)-1, GFP_NOFS);
3439
3440 memset(shrink_block_group, 0, sizeof(*shrink_block_group));
3441 kfree(shrink_block_group);
3442
3443 btrfs_del_item(trans, root, path);
3444 btrfs_release_path(root, path);
3445 mutex_unlock(&root->fs_info->alloc_mutex);
3446 btrfs_commit_transaction(trans, root);
3447
3448 mutex_lock(&root->fs_info->alloc_mutex);
3449
3450 /* the code to unpin extents might set a few bits in the free
3451 * space cache for this range again
3452 */
3453 clear_extent_bits(&info->free_space_cache,
3454 key.objectid, key.objectid + key.offset - 1,
3455 (unsigned int)-1, GFP_NOFS);
3456 out:
3457 btrfs_free_path(path);
3458 mutex_unlock(&root->fs_info->alloc_mutex);
3459 return ret;
3460 }
3461
3462 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
3463 struct btrfs_key *key)
3464 {
3465 int ret = 0;
3466 struct btrfs_key found_key;
3467 struct extent_buffer *leaf;
3468 int slot;
3469
3470 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
3471 if (ret < 0)
3472 goto out;
3473
3474 while(1) {
3475 slot = path->slots[0];
3476 leaf = path->nodes[0];
3477 if (slot >= btrfs_header_nritems(leaf)) {
3478 ret = btrfs_next_leaf(root, path);
3479 if (ret == 0)
3480 continue;
3481 if (ret < 0)
3482 goto out;
3483 break;
3484 }
3485 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3486
3487 if (found_key.objectid >= key->objectid &&
3488 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
3489 ret = 0;
3490 goto out;
3491 }
3492 path->slots[0]++;
3493 }
3494 ret = -ENOENT;
3495 out:
3496 return ret;
3497 }
3498
3499 int btrfs_read_block_groups(struct btrfs_root *root)
3500 {
3501 struct btrfs_path *path;
3502 int ret;
3503 int bit;
3504 struct btrfs_block_group_cache *cache;
3505 struct btrfs_fs_info *info = root->fs_info;
3506 struct btrfs_space_info *space_info;
3507 struct extent_io_tree *block_group_cache;
3508 struct btrfs_key key;
3509 struct btrfs_key found_key;
3510 struct extent_buffer *leaf;
3511
3512 block_group_cache = &info->block_group_cache;
3513 root = info->extent_root;
3514 key.objectid = 0;
3515 key.offset = 0;
3516 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3517 path = btrfs_alloc_path();
3518 if (!path)
3519 return -ENOMEM;
3520
3521 mutex_lock(&root->fs_info->alloc_mutex);
3522 while(1) {
3523 ret = find_first_block_group(root, path, &key);
3524 if (ret > 0) {
3525 ret = 0;
3526 goto error;
3527 }
3528 if (ret != 0)
3529 goto error;
3530
3531 leaf = path->nodes[0];
3532 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3533 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3534 if (!cache) {
3535 ret = -ENOMEM;
3536 break;
3537 }
3538
3539 spin_lock_init(&cache->lock);
3540 read_extent_buffer(leaf, &cache->item,
3541 btrfs_item_ptr_offset(leaf, path->slots[0]),
3542 sizeof(cache->item));
3543 memcpy(&cache->key, &found_key, sizeof(found_key));
3544
3545 key.objectid = found_key.objectid + found_key.offset;
3546 btrfs_release_path(root, path);
3547 cache->flags = btrfs_block_group_flags(&cache->item);
3548 bit = 0;
3549 if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
3550 bit = BLOCK_GROUP_DATA;
3551 } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
3552 bit = BLOCK_GROUP_SYSTEM;
3553 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
3554 bit = BLOCK_GROUP_METADATA;
3555 }
3556 set_avail_alloc_bits(info, cache->flags);
3557
3558 ret = update_space_info(info, cache->flags, found_key.offset,
3559 btrfs_block_group_used(&cache->item),
3560 &space_info);
3561 BUG_ON(ret);
3562 cache->space_info = space_info;
3563
3564 /* use EXTENT_LOCKED to prevent merging */
3565 set_extent_bits(block_group_cache, found_key.objectid,
3566 found_key.objectid + found_key.offset - 1,
3567 EXTENT_LOCKED, GFP_NOFS);
3568 set_state_private(block_group_cache, found_key.objectid,
3569 (unsigned long)cache);
3570 set_extent_bits(block_group_cache, found_key.objectid,
3571 found_key.objectid + found_key.offset - 1,
3572 bit | EXTENT_LOCKED, GFP_NOFS);
3573 if (key.objectid >=
3574 btrfs_super_total_bytes(&info->super_copy))
3575 break;
3576 }
3577 ret = 0;
3578 error:
3579 btrfs_free_path(path);
3580 mutex_unlock(&root->fs_info->alloc_mutex);
3581 return ret;
3582 }
3583
3584 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
3585 struct btrfs_root *root, u64 bytes_used,
3586 u64 type, u64 chunk_objectid, u64 chunk_offset,
3587 u64 size)
3588 {
3589 int ret;
3590 int bit = 0;
3591 struct btrfs_root *extent_root;
3592 struct btrfs_block_group_cache *cache;
3593 struct extent_io_tree *block_group_cache;
3594
3595 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
3596 extent_root = root->fs_info->extent_root;
3597 block_group_cache = &root->fs_info->block_group_cache;
3598
3599 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3600 BUG_ON(!cache);
3601 cache->key.objectid = chunk_offset;
3602 cache->key.offset = size;
3603 spin_lock_init(&cache->lock);
3604 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3605
3606 btrfs_set_block_group_used(&cache->item, bytes_used);
3607 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
3608 cache->flags = type;
3609 btrfs_set_block_group_flags(&cache->item, type);
3610
3611 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
3612 &cache->space_info);
3613 BUG_ON(ret);
3614
3615 bit = block_group_state_bits(type);
3616 set_extent_bits(block_group_cache, chunk_offset,
3617 chunk_offset + size - 1,
3618 EXTENT_LOCKED, GFP_NOFS);
3619 set_state_private(block_group_cache, chunk_offset,
3620 (unsigned long)cache);
3621 set_extent_bits(block_group_cache, chunk_offset,
3622 chunk_offset + size - 1,
3623 bit | EXTENT_LOCKED, GFP_NOFS);
3624
3625 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
3626 sizeof(cache->item));
3627 BUG_ON(ret);
3628
3629 finish_current_insert(trans, extent_root);
3630 ret = del_pending_extents(trans, extent_root);
3631 BUG_ON(ret);
3632 set_avail_alloc_bits(extent_root->fs_info, type);
3633
3634 return 0;
3635 }
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