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