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Btrfs: use hybrid extents+bitmap rb tree for free space
[linux-2.6/libata-dev.git] / fs / btrfs / extent-tree.c
blob98697be6bddedfa32469b3b0271a0f643cd8749c
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 <linux/blkdev.h>
22 #include <linux/sort.h>
23 #include <linux/rcupdate.h>
24 #include "compat.h"
25 #include "hash.h"
26 #include "ctree.h"
27 #include "disk-io.h"
28 #include "print-tree.h"
29 #include "transaction.h"
30 #include "volumes.h"
31 #include "locking.h"
32 #include "free-space-cache.h"
33
34 static int update_reserved_extents(struct btrfs_root *root,
35 u64 bytenr, u64 num, int reserve);
36 static int update_block_group(struct btrfs_trans_handle *trans,
37 struct btrfs_root *root,
38 u64 bytenr, u64 num_bytes, int alloc,
39 int mark_free);
40 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
41 struct btrfs_root *root,
42 u64 bytenr, u64 num_bytes, u64 parent,
43 u64 root_objectid, u64 owner_objectid,
44 u64 owner_offset, int refs_to_drop,
45 struct btrfs_delayed_extent_op *extra_op);
46 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
47 struct extent_buffer *leaf,
48 struct btrfs_extent_item *ei);
49 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
50 struct btrfs_root *root,
51 u64 parent, u64 root_objectid,
52 u64 flags, u64 owner, u64 offset,
53 struct btrfs_key *ins, int ref_mod);
54 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
55 struct btrfs_root *root,
56 u64 parent, u64 root_objectid,
57 u64 flags, struct btrfs_disk_key *key,
58 int level, struct btrfs_key *ins);
59
60 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
61 struct btrfs_root *extent_root, u64 alloc_bytes,
62 u64 flags, int force);
63
64 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
65 {
66 return (cache->flags & bits) == bits;
67 }
68
69 /*
70 * this adds the block group to the fs_info rb tree for the block group
71 * cache
72 */
73 static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
74 struct btrfs_block_group_cache *block_group)
75 {
76 struct rb_node **p;
77 struct rb_node *parent = NULL;
78 struct btrfs_block_group_cache *cache;
79
80 spin_lock(&info->block_group_cache_lock);
81 p = &info->block_group_cache_tree.rb_node;
82
83 while (*p) {
84 parent = *p;
85 cache = rb_entry(parent, struct btrfs_block_group_cache,
86 cache_node);
87 if (block_group->key.objectid < cache->key.objectid) {
88 p = &(*p)->rb_left;
89 } else if (block_group->key.objectid > cache->key.objectid) {
90 p = &(*p)->rb_right;
91 } else {
92 spin_unlock(&info->block_group_cache_lock);
93 return -EEXIST;
94 }
95 }
96
97 rb_link_node(&block_group->cache_node, parent, p);
98 rb_insert_color(&block_group->cache_node,
99 &info->block_group_cache_tree);
100 spin_unlock(&info->block_group_cache_lock);
101
102 return 0;
103 }
104
105 /*
106 * This will return the block group at or after bytenr if contains is 0, else
107 * it will return the block group that contains the bytenr
108 */
109 static struct btrfs_block_group_cache *
110 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
111 int contains)
112 {
113 struct btrfs_block_group_cache *cache, *ret = NULL;
114 struct rb_node *n;
115 u64 end, start;
116
117 spin_lock(&info->block_group_cache_lock);
118 n = info->block_group_cache_tree.rb_node;
119
120 while (n) {
121 cache = rb_entry(n, struct btrfs_block_group_cache,
122 cache_node);
123 end = cache->key.objectid + cache->key.offset - 1;
124 start = cache->key.objectid;
125
126 if (bytenr < start) {
127 if (!contains && (!ret || start < ret->key.objectid))
128 ret = cache;
129 n = n->rb_left;
130 } else if (bytenr > start) {
131 if (contains && bytenr <= end) {
132 ret = cache;
133 break;
134 }
135 n = n->rb_right;
136 } else {
137 ret = cache;
138 break;
139 }
140 }
141 if (ret)
142 atomic_inc(&ret->count);
143 spin_unlock(&info->block_group_cache_lock);
144
145 return ret;
146 }
147
148 /*
149 * this is only called by cache_block_group, since we could have freed extents
150 * we need to check the pinned_extents for any extents that can't be used yet
151 * since their free space will be released as soon as the transaction commits.
152 */
153 static int add_new_free_space(struct btrfs_block_group_cache *block_group,
154 struct btrfs_fs_info *info, u64 start, u64 end)
155 {
156 u64 extent_start, extent_end, size;
157 int ret;
158
159 while (start < end) {
160 ret = find_first_extent_bit(&info->pinned_extents, start,
161 &extent_start, &extent_end,
162 EXTENT_DIRTY);
163 if (ret)
164 break;
165
166 if (extent_start == start) {
167 start = extent_end + 1;
168 } else if (extent_start > start && extent_start < end) {
169 size = extent_start - start;
170 ret = btrfs_add_free_space(block_group, start,
171 size);
172 BUG_ON(ret);
173 start = extent_end + 1;
174 } else {
175 break;
176 }
177 }
178
179 if (start < end) {
180 size = end - start;
181 ret = btrfs_add_free_space(block_group, start, size);
182 BUG_ON(ret);
183 }
184
185 return 0;
186 }
187
188 static int remove_sb_from_cache(struct btrfs_root *root,
189 struct btrfs_block_group_cache *cache)
190 {
191 u64 bytenr;
192 u64 *logical;
193 int stripe_len;
194 int i, nr, ret;
195
196 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
197 bytenr = btrfs_sb_offset(i);
198 ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
199 cache->key.objectid, bytenr, 0,
200 &logical, &nr, &stripe_len);
201 BUG_ON(ret);
202 while (nr--) {
203 btrfs_remove_free_space(cache, logical[nr],
204 stripe_len);
205 }
206 kfree(logical);
207 }
208 return 0;
209 }
210
211 static int cache_block_group(struct btrfs_root *root,
212 struct btrfs_block_group_cache *block_group)
213 {
214 struct btrfs_path *path;
215 int ret = 0;
216 struct btrfs_key key;
217 struct extent_buffer *leaf;
218 int slot;
219 u64 last;
220
221 if (!block_group)
222 return 0;
223
224 root = root->fs_info->extent_root;
225
226 if (block_group->cached)
227 return 0;
228
229 path = btrfs_alloc_path();
230 if (!path)
231 return -ENOMEM;
232
233 path->reada = 2;
234 /*
235 * we get into deadlocks with paths held by callers of this function.
236 * since the alloc_mutex is protecting things right now, just
237 * skip the locking here
238 */
239 path->skip_locking = 1;
240 last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
241 key.objectid = last;
242 key.offset = 0;
243 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
244 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
245 if (ret < 0)
246 goto err;
247
248 while (1) {
249 leaf = path->nodes[0];
250 slot = path->slots[0];
251 if (slot >= btrfs_header_nritems(leaf)) {
252 ret = btrfs_next_leaf(root, path);
253 if (ret < 0)
254 goto err;
255 if (ret == 0)
256 continue;
257 else
258 break;
259 }
260 btrfs_item_key_to_cpu(leaf, &key, slot);
261 if (key.objectid < block_group->key.objectid)
262 goto next;
263
264 if (key.objectid >= block_group->key.objectid +
265 block_group->key.offset)
266 break;
267
268 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
269 add_new_free_space(block_group, root->fs_info, last,
270 key.objectid);
271
272 last = key.objectid + key.offset;
273 }
274 next:
275 path->slots[0]++;
276 }
277
278 add_new_free_space(block_group, root->fs_info, last,
279 block_group->key.objectid +
280 block_group->key.offset);
281
282 block_group->cached = 1;
283 remove_sb_from_cache(root, block_group);
284 ret = 0;
285 err:
286 btrfs_free_path(path);
287 return ret;
288 }
289
290 /*
291 * return the block group that starts at or after bytenr
292 */
293 static struct btrfs_block_group_cache *
294 btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
295 {
296 struct btrfs_block_group_cache *cache;
297
298 cache = block_group_cache_tree_search(info, bytenr, 0);
299
300 return cache;
301 }
302
303 /*
304 * return the block group that contains the given bytenr
305 */
306 struct btrfs_block_group_cache *btrfs_lookup_block_group(
307 struct btrfs_fs_info *info,
308 u64 bytenr)
309 {
310 struct btrfs_block_group_cache *cache;
311
312 cache = block_group_cache_tree_search(info, bytenr, 1);
313
314 return cache;
315 }
316
317 void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
318 {
319 if (atomic_dec_and_test(&cache->count))
320 kfree(cache);
321 }
322
323 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
324 u64 flags)
325 {
326 struct list_head *head = &info->space_info;
327 struct btrfs_space_info *found;
328
329 rcu_read_lock();
330 list_for_each_entry_rcu(found, head, list) {
331 if (found->flags == flags) {
332 rcu_read_unlock();
333 return found;
334 }
335 }
336 rcu_read_unlock();
337 return NULL;
338 }
339
340 /*
341 * after adding space to the filesystem, we need to clear the full flags
342 * on all the space infos.
343 */
344 void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
345 {
346 struct list_head *head = &info->space_info;
347 struct btrfs_space_info *found;
348
349 rcu_read_lock();
350 list_for_each_entry_rcu(found, head, list)
351 found->full = 0;
352 rcu_read_unlock();
353 }
354
355 static u64 div_factor(u64 num, int factor)
356 {
357 if (factor == 10)
358 return num;
359 num *= factor;
360 do_div(num, 10);
361 return num;
362 }
363
364 u64 btrfs_find_block_group(struct btrfs_root *root,
365 u64 search_start, u64 search_hint, int owner)
366 {
367 struct btrfs_block_group_cache *cache;
368 u64 used;
369 u64 last = max(search_hint, search_start);
370 u64 group_start = 0;
371 int full_search = 0;
372 int factor = 9;
373 int wrapped = 0;
374 again:
375 while (1) {
376 cache = btrfs_lookup_first_block_group(root->fs_info, last);
377 if (!cache)
378 break;
379
380 spin_lock(&cache->lock);
381 last = cache->key.objectid + cache->key.offset;
382 used = btrfs_block_group_used(&cache->item);
383
384 if ((full_search || !cache->ro) &&
385 block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
386 if (used + cache->pinned + cache->reserved <
387 div_factor(cache->key.offset, factor)) {
388 group_start = cache->key.objectid;
389 spin_unlock(&cache->lock);
390 btrfs_put_block_group(cache);
391 goto found;
392 }
393 }
394 spin_unlock(&cache->lock);
395 btrfs_put_block_group(cache);
396 cond_resched();
397 }
398 if (!wrapped) {
399 last = search_start;
400 wrapped = 1;
401 goto again;
402 }
403 if (!full_search && factor < 10) {
404 last = search_start;
405 full_search = 1;
406 factor = 10;
407 goto again;
408 }
409 found:
410 return group_start;
411 }
412
413 /* simple helper to search for an existing extent at a given offset */
414 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
415 {
416 int ret;
417 struct btrfs_key key;
418 struct btrfs_path *path;
419
420 path = btrfs_alloc_path();
421 BUG_ON(!path);
422 key.objectid = start;
423 key.offset = len;
424 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
425 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
426 0, 0);
427 btrfs_free_path(path);
428 return ret;
429 }
430
431 /*
432 * Back reference rules. Back refs have three main goals:
433 *
434 * 1) differentiate between all holders of references to an extent so that
435 * when a reference is dropped we can make sure it was a valid reference
436 * before freeing the extent.
437 *
438 * 2) Provide enough information to quickly find the holders of an extent
439 * if we notice a given block is corrupted or bad.
440 *
441 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
442 * maintenance. This is actually the same as #2, but with a slightly
443 * different use case.
444 *
445 * There are two kinds of back refs. The implicit back refs is optimized
446 * for pointers in non-shared tree blocks. For a given pointer in a block,
447 * back refs of this kind provide information about the block's owner tree
448 * and the pointer's key. These information allow us to find the block by
449 * b-tree searching. The full back refs is for pointers in tree blocks not
450 * referenced by their owner trees. The location of tree block is recorded
451 * in the back refs. Actually the full back refs is generic, and can be
452 * used in all cases the implicit back refs is used. The major shortcoming
453 * of the full back refs is its overhead. Every time a tree block gets
454 * COWed, we have to update back refs entry for all pointers in it.
455 *
456 * For a newly allocated tree block, we use implicit back refs for
457 * pointers in it. This means most tree related operations only involve
458 * implicit back refs. For a tree block created in old transaction, the
459 * only way to drop a reference to it is COW it. So we can detect the
460 * event that tree block loses its owner tree's reference and do the
461 * back refs conversion.
462 *
463 * When a tree block is COW'd through a tree, there are four cases:
464 *
465 * The reference count of the block is one and the tree is the block's
466 * owner tree. Nothing to do in this case.
467 *
468 * The reference count of the block is one and the tree is not the
469 * block's owner tree. In this case, full back refs is used for pointers
470 * in the block. Remove these full back refs, add implicit back refs for
471 * every pointers in the new block.
472 *
473 * The reference count of the block is greater than one and the tree is
474 * the block's owner tree. In this case, implicit back refs is used for
475 * pointers in the block. Add full back refs for every pointers in the
476 * block, increase lower level extents' reference counts. The original
477 * implicit back refs are entailed to the new block.
478 *
479 * The reference count of the block is greater than one and the tree is
480 * not the block's owner tree. Add implicit back refs for every pointer in
481 * the new block, increase lower level extents' reference count.
482 *
483 * Back Reference Key composing:
484 *
485 * The key objectid corresponds to the first byte in the extent,
486 * The key type is used to differentiate between types of back refs.
487 * There are different meanings of the key offset for different types
488 * of back refs.
489 *
490 * File extents can be referenced by:
491 *
492 * - multiple snapshots, subvolumes, or different generations in one subvol
493 * - different files inside a single subvolume
494 * - different offsets inside a file (bookend extents in file.c)
495 *
496 * The extent ref structure for the implicit back refs has fields for:
497 *
498 * - Objectid of the subvolume root
499 * - objectid of the file holding the reference
500 * - original offset in the file
501 * - how many bookend extents
502 *
503 * The key offset for the implicit back refs is hash of the first
504 * three fields.
505 *
506 * The extent ref structure for the full back refs has field for:
507 *
508 * - number of pointers in the tree leaf
509 *
510 * The key offset for the implicit back refs is the first byte of
511 * the tree leaf
512 *
513 * When a file extent is allocated, The implicit back refs is used.
514 * the fields are filled in:
515 *
516 * (root_key.objectid, inode objectid, offset in file, 1)
517 *
518 * When a file extent is removed file truncation, we find the
519 * corresponding implicit back refs and check the following fields:
520 *
521 * (btrfs_header_owner(leaf), inode objectid, offset in file)
522 *
523 * Btree extents can be referenced by:
524 *
525 * - Different subvolumes
526 *
527 * Both the implicit back refs and the full back refs for tree blocks
528 * only consist of key. The key offset for the implicit back refs is
529 * objectid of block's owner tree. The key offset for the full back refs
530 * is the first byte of parent block.
531 *
532 * When implicit back refs is used, information about the lowest key and
533 * level of the tree block are required. These information are stored in
534 * tree block info structure.
535 */
536
537 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
538 static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
539 struct btrfs_root *root,
540 struct btrfs_path *path,
541 u64 owner, u32 extra_size)
542 {
543 struct btrfs_extent_item *item;
544 struct btrfs_extent_item_v0 *ei0;
545 struct btrfs_extent_ref_v0 *ref0;
546 struct btrfs_tree_block_info *bi;
547 struct extent_buffer *leaf;
548 struct btrfs_key key;
549 struct btrfs_key found_key;
550 u32 new_size = sizeof(*item);
551 u64 refs;
552 int ret;
553
554 leaf = path->nodes[0];
555 BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
556
557 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
558 ei0 = btrfs_item_ptr(leaf, path->slots[0],
559 struct btrfs_extent_item_v0);
560 refs = btrfs_extent_refs_v0(leaf, ei0);
561
562 if (owner == (u64)-1) {
563 while (1) {
564 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
565 ret = btrfs_next_leaf(root, path);
566 if (ret < 0)
567 return ret;
568 BUG_ON(ret > 0);
569 leaf = path->nodes[0];
570 }
571 btrfs_item_key_to_cpu(leaf, &found_key,
572 path->slots[0]);
573 BUG_ON(key.objectid != found_key.objectid);
574 if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
575 path->slots[0]++;
576 continue;
577 }
578 ref0 = btrfs_item_ptr(leaf, path->slots[0],
579 struct btrfs_extent_ref_v0);
580 owner = btrfs_ref_objectid_v0(leaf, ref0);
581 break;
582 }
583 }
584 btrfs_release_path(root, path);
585
586 if (owner < BTRFS_FIRST_FREE_OBJECTID)
587 new_size += sizeof(*bi);
588
589 new_size -= sizeof(*ei0);
590 ret = btrfs_search_slot(trans, root, &key, path,
591 new_size + extra_size, 1);
592 if (ret < 0)
593 return ret;
594 BUG_ON(ret);
595
596 ret = btrfs_extend_item(trans, root, path, new_size);
597 BUG_ON(ret);
598
599 leaf = path->nodes[0];
600 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
601 btrfs_set_extent_refs(leaf, item, refs);
602 /* FIXME: get real generation */
603 btrfs_set_extent_generation(leaf, item, 0);
604 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
605 btrfs_set_extent_flags(leaf, item,
606 BTRFS_EXTENT_FLAG_TREE_BLOCK |
607 BTRFS_BLOCK_FLAG_FULL_BACKREF);
608 bi = (struct btrfs_tree_block_info *)(item + 1);
609 /* FIXME: get first key of the block */
610 memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
611 btrfs_set_tree_block_level(leaf, bi, (int)owner);
612 } else {
613 btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
614 }
615 btrfs_mark_buffer_dirty(leaf);
616 return 0;
617 }
618 #endif
619
620 static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
621 {
622 u32 high_crc = ~(u32)0;
623 u32 low_crc = ~(u32)0;
624 __le64 lenum;
625
626 lenum = cpu_to_le64(root_objectid);
627 high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
628 lenum = cpu_to_le64(owner);
629 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
630 lenum = cpu_to_le64(offset);
631 low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
632
633 return ((u64)high_crc << 31) ^ (u64)low_crc;
634 }
635
636 static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
637 struct btrfs_extent_data_ref *ref)
638 {
639 return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
640 btrfs_extent_data_ref_objectid(leaf, ref),
641 btrfs_extent_data_ref_offset(leaf, ref));
642 }
643
644 static int match_extent_data_ref(struct extent_buffer *leaf,
645 struct btrfs_extent_data_ref *ref,
646 u64 root_objectid, u64 owner, u64 offset)
647 {
648 if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
649 btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
650 btrfs_extent_data_ref_offset(leaf, ref) != offset)
651 return 0;
652 return 1;
653 }
654
655 static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
656 struct btrfs_root *root,
657 struct btrfs_path *path,
658 u64 bytenr, u64 parent,
659 u64 root_objectid,
660 u64 owner, u64 offset)
661 {
662 struct btrfs_key key;
663 struct btrfs_extent_data_ref *ref;
664 struct extent_buffer *leaf;
665 u32 nritems;
666 int ret;
667 int recow;
668 int err = -ENOENT;
669
670 key.objectid = bytenr;
671 if (parent) {
672 key.type = BTRFS_SHARED_DATA_REF_KEY;
673 key.offset = parent;
674 } else {
675 key.type = BTRFS_EXTENT_DATA_REF_KEY;
676 key.offset = hash_extent_data_ref(root_objectid,
677 owner, offset);
678 }
679 again:
680 recow = 0;
681 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
682 if (ret < 0) {
683 err = ret;
684 goto fail;
685 }
686
687 if (parent) {
688 if (!ret)
689 return 0;
690 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
691 key.type = BTRFS_EXTENT_REF_V0_KEY;
692 btrfs_release_path(root, path);
693 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
694 if (ret < 0) {
695 err = ret;
696 goto fail;
697 }
698 if (!ret)
699 return 0;
700 #endif
701 goto fail;
702 }
703
704 leaf = path->nodes[0];
705 nritems = btrfs_header_nritems(leaf);
706 while (1) {
707 if (path->slots[0] >= nritems) {
708 ret = btrfs_next_leaf(root, path);
709 if (ret < 0)
710 err = ret;
711 if (ret)
712 goto fail;
713
714 leaf = path->nodes[0];
715 nritems = btrfs_header_nritems(leaf);
716 recow = 1;
717 }
718
719 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
720 if (key.objectid != bytenr ||
721 key.type != BTRFS_EXTENT_DATA_REF_KEY)
722 goto fail;
723
724 ref = btrfs_item_ptr(leaf, path->slots[0],
725 struct btrfs_extent_data_ref);
726
727 if (match_extent_data_ref(leaf, ref, root_objectid,
728 owner, offset)) {
729 if (recow) {
730 btrfs_release_path(root, path);
731 goto again;
732 }
733 err = 0;
734 break;
735 }
736 path->slots[0]++;
737 }
738 fail:
739 return err;
740 }
741
742 static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
743 struct btrfs_root *root,
744 struct btrfs_path *path,
745 u64 bytenr, u64 parent,
746 u64 root_objectid, u64 owner,
747 u64 offset, int refs_to_add)
748 {
749 struct btrfs_key key;
750 struct extent_buffer *leaf;
751 u32 size;
752 u32 num_refs;
753 int ret;
754
755 key.objectid = bytenr;
756 if (parent) {
757 key.type = BTRFS_SHARED_DATA_REF_KEY;
758 key.offset = parent;
759 size = sizeof(struct btrfs_shared_data_ref);
760 } else {
761 key.type = BTRFS_EXTENT_DATA_REF_KEY;
762 key.offset = hash_extent_data_ref(root_objectid,
763 owner, offset);
764 size = sizeof(struct btrfs_extent_data_ref);
765 }
766
767 ret = btrfs_insert_empty_item(trans, root, path, &key, size);
768 if (ret && ret != -EEXIST)
769 goto fail;
770
771 leaf = path->nodes[0];
772 if (parent) {
773 struct btrfs_shared_data_ref *ref;
774 ref = btrfs_item_ptr(leaf, path->slots[0],
775 struct btrfs_shared_data_ref);
776 if (ret == 0) {
777 btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
778 } else {
779 num_refs = btrfs_shared_data_ref_count(leaf, ref);
780 num_refs += refs_to_add;
781 btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
782 }
783 } else {
784 struct btrfs_extent_data_ref *ref;
785 while (ret == -EEXIST) {
786 ref = btrfs_item_ptr(leaf, path->slots[0],
787 struct btrfs_extent_data_ref);
788 if (match_extent_data_ref(leaf, ref, root_objectid,
789 owner, offset))
790 break;
791 btrfs_release_path(root, path);
792 key.offset++;
793 ret = btrfs_insert_empty_item(trans, root, path, &key,
794 size);
795 if (ret && ret != -EEXIST)
796 goto fail;
797
798 leaf = path->nodes[0];
799 }
800 ref = btrfs_item_ptr(leaf, path->slots[0],
801 struct btrfs_extent_data_ref);
802 if (ret == 0) {
803 btrfs_set_extent_data_ref_root(leaf, ref,
804 root_objectid);
805 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
806 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
807 btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
808 } else {
809 num_refs = btrfs_extent_data_ref_count(leaf, ref);
810 num_refs += refs_to_add;
811 btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
812 }
813 }
814 btrfs_mark_buffer_dirty(leaf);
815 ret = 0;
816 fail:
817 btrfs_release_path(root, path);
818 return ret;
819 }
820
821 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
822 struct btrfs_root *root,
823 struct btrfs_path *path,
824 int refs_to_drop)
825 {
826 struct btrfs_key key;
827 struct btrfs_extent_data_ref *ref1 = NULL;
828 struct btrfs_shared_data_ref *ref2 = NULL;
829 struct extent_buffer *leaf;
830 u32 num_refs = 0;
831 int ret = 0;
832
833 leaf = path->nodes[0];
834 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
835
836 if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
837 ref1 = btrfs_item_ptr(leaf, path->slots[0],
838 struct btrfs_extent_data_ref);
839 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
840 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
841 ref2 = btrfs_item_ptr(leaf, path->slots[0],
842 struct btrfs_shared_data_ref);
843 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
844 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
845 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
846 struct btrfs_extent_ref_v0 *ref0;
847 ref0 = btrfs_item_ptr(leaf, path->slots[0],
848 struct btrfs_extent_ref_v0);
849 num_refs = btrfs_ref_count_v0(leaf, ref0);
850 #endif
851 } else {
852 BUG();
853 }
854
855 BUG_ON(num_refs < refs_to_drop);
856 num_refs -= refs_to_drop;
857
858 if (num_refs == 0) {
859 ret = btrfs_del_item(trans, root, path);
860 } else {
861 if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
862 btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
863 else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
864 btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
865 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
866 else {
867 struct btrfs_extent_ref_v0 *ref0;
868 ref0 = btrfs_item_ptr(leaf, path->slots[0],
869 struct btrfs_extent_ref_v0);
870 btrfs_set_ref_count_v0(leaf, ref0, num_refs);
871 }
872 #endif
873 btrfs_mark_buffer_dirty(leaf);
874 }
875 return ret;
876 }
877
878 static noinline u32 extent_data_ref_count(struct btrfs_root *root,
879 struct btrfs_path *path,
880 struct btrfs_extent_inline_ref *iref)
881 {
882 struct btrfs_key key;
883 struct extent_buffer *leaf;
884 struct btrfs_extent_data_ref *ref1;
885 struct btrfs_shared_data_ref *ref2;
886 u32 num_refs = 0;
887
888 leaf = path->nodes[0];
889 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
890 if (iref) {
891 if (btrfs_extent_inline_ref_type(leaf, iref) ==
892 BTRFS_EXTENT_DATA_REF_KEY) {
893 ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
894 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
895 } else {
896 ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
897 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
898 }
899 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
900 ref1 = btrfs_item_ptr(leaf, path->slots[0],
901 struct btrfs_extent_data_ref);
902 num_refs = btrfs_extent_data_ref_count(leaf, ref1);
903 } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
904 ref2 = btrfs_item_ptr(leaf, path->slots[0],
905 struct btrfs_shared_data_ref);
906 num_refs = btrfs_shared_data_ref_count(leaf, ref2);
907 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
908 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
909 struct btrfs_extent_ref_v0 *ref0;
910 ref0 = btrfs_item_ptr(leaf, path->slots[0],
911 struct btrfs_extent_ref_v0);
912 num_refs = btrfs_ref_count_v0(leaf, ref0);
913 #endif
914 } else {
915 WARN_ON(1);
916 }
917 return num_refs;
918 }
919
920 static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
921 struct btrfs_root *root,
922 struct btrfs_path *path,
923 u64 bytenr, u64 parent,
924 u64 root_objectid)
925 {
926 struct btrfs_key key;
927 int ret;
928
929 key.objectid = bytenr;
930 if (parent) {
931 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
932 key.offset = parent;
933 } else {
934 key.type = BTRFS_TREE_BLOCK_REF_KEY;
935 key.offset = root_objectid;
936 }
937
938 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
939 if (ret > 0)
940 ret = -ENOENT;
941 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
942 if (ret == -ENOENT && parent) {
943 btrfs_release_path(root, path);
944 key.type = BTRFS_EXTENT_REF_V0_KEY;
945 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
946 if (ret > 0)
947 ret = -ENOENT;
948 }
949 #endif
950 return ret;
951 }
952
953 static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
954 struct btrfs_root *root,
955 struct btrfs_path *path,
956 u64 bytenr, u64 parent,
957 u64 root_objectid)
958 {
959 struct btrfs_key key;
960 int ret;
961
962 key.objectid = bytenr;
963 if (parent) {
964 key.type = BTRFS_SHARED_BLOCK_REF_KEY;
965 key.offset = parent;
966 } else {
967 key.type = BTRFS_TREE_BLOCK_REF_KEY;
968 key.offset = root_objectid;
969 }
970
971 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
972 btrfs_release_path(root, path);
973 return ret;
974 }
975
976 static inline int extent_ref_type(u64 parent, u64 owner)
977 {
978 int type;
979 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
980 if (parent > 0)
981 type = BTRFS_SHARED_BLOCK_REF_KEY;
982 else
983 type = BTRFS_TREE_BLOCK_REF_KEY;
984 } else {
985 if (parent > 0)
986 type = BTRFS_SHARED_DATA_REF_KEY;
987 else
988 type = BTRFS_EXTENT_DATA_REF_KEY;
989 }
990 return type;
991 }
992
993 static int find_next_key(struct btrfs_path *path, int level,
994 struct btrfs_key *key)
995
996 {
997 for (; level < BTRFS_MAX_LEVEL; level++) {
998 if (!path->nodes[level])
999 break;
1000 if (path->slots[level] + 1 >=
1001 btrfs_header_nritems(path->nodes[level]))
1002 continue;
1003 if (level == 0)
1004 btrfs_item_key_to_cpu(path->nodes[level], key,
1005 path->slots[level] + 1);
1006 else
1007 btrfs_node_key_to_cpu(path->nodes[level], key,
1008 path->slots[level] + 1);
1009 return 0;
1010 }
1011 return 1;
1012 }
1013
1014 /*
1015 * look for inline back ref. if back ref is found, *ref_ret is set
1016 * to the address of inline back ref, and 0 is returned.
1017 *
1018 * if back ref isn't found, *ref_ret is set to the address where it
1019 * should be inserted, and -ENOENT is returned.
1020 *
1021 * if insert is true and there are too many inline back refs, the path
1022 * points to the extent item, and -EAGAIN is returned.
1023 *
1024 * NOTE: inline back refs are ordered in the same way that back ref
1025 * items in the tree are ordered.
1026 */
1027 static noinline_for_stack
1028 int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
1029 struct btrfs_root *root,
1030 struct btrfs_path *path,
1031 struct btrfs_extent_inline_ref **ref_ret,
1032 u64 bytenr, u64 num_bytes,
1033 u64 parent, u64 root_objectid,
1034 u64 owner, u64 offset, int insert)
1035 {
1036 struct btrfs_key key;
1037 struct extent_buffer *leaf;
1038 struct btrfs_extent_item *ei;
1039 struct btrfs_extent_inline_ref *iref;
1040 u64 flags;
1041 u64 item_size;
1042 unsigned long ptr;
1043 unsigned long end;
1044 int extra_size;
1045 int type;
1046 int want;
1047 int ret;
1048 int err = 0;
1049
1050 key.objectid = bytenr;
1051 key.type = BTRFS_EXTENT_ITEM_KEY;
1052 key.offset = num_bytes;
1053
1054 want = extent_ref_type(parent, owner);
1055 if (insert) {
1056 extra_size = btrfs_extent_inline_ref_size(want);
1057 path->keep_locks = 1;
1058 } else
1059 extra_size = -1;
1060 ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
1061 if (ret < 0) {
1062 err = ret;
1063 goto out;
1064 }
1065 BUG_ON(ret);
1066
1067 leaf = path->nodes[0];
1068 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1069 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1070 if (item_size < sizeof(*ei)) {
1071 if (!insert) {
1072 err = -ENOENT;
1073 goto out;
1074 }
1075 ret = convert_extent_item_v0(trans, root, path, owner,
1076 extra_size);
1077 if (ret < 0) {
1078 err = ret;
1079 goto out;
1080 }
1081 leaf = path->nodes[0];
1082 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1083 }
1084 #endif
1085 BUG_ON(item_size < sizeof(*ei));
1086
1087 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1088 flags = btrfs_extent_flags(leaf, ei);
1089
1090 ptr = (unsigned long)(ei + 1);
1091 end = (unsigned long)ei + item_size;
1092
1093 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1094 ptr += sizeof(struct btrfs_tree_block_info);
1095 BUG_ON(ptr > end);
1096 } else {
1097 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
1098 }
1099
1100 err = -ENOENT;
1101 while (1) {
1102 if (ptr >= end) {
1103 WARN_ON(ptr > end);
1104 break;
1105 }
1106 iref = (struct btrfs_extent_inline_ref *)ptr;
1107 type = btrfs_extent_inline_ref_type(leaf, iref);
1108 if (want < type)
1109 break;
1110 if (want > type) {
1111 ptr += btrfs_extent_inline_ref_size(type);
1112 continue;
1113 }
1114
1115 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1116 struct btrfs_extent_data_ref *dref;
1117 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1118 if (match_extent_data_ref(leaf, dref, root_objectid,
1119 owner, offset)) {
1120 err = 0;
1121 break;
1122 }
1123 if (hash_extent_data_ref_item(leaf, dref) <
1124 hash_extent_data_ref(root_objectid, owner, offset))
1125 break;
1126 } else {
1127 u64 ref_offset;
1128 ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
1129 if (parent > 0) {
1130 if (parent == ref_offset) {
1131 err = 0;
1132 break;
1133 }
1134 if (ref_offset < parent)
1135 break;
1136 } else {
1137 if (root_objectid == ref_offset) {
1138 err = 0;
1139 break;
1140 }
1141 if (ref_offset < root_objectid)
1142 break;
1143 }
1144 }
1145 ptr += btrfs_extent_inline_ref_size(type);
1146 }
1147 if (err == -ENOENT && insert) {
1148 if (item_size + extra_size >=
1149 BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
1150 err = -EAGAIN;
1151 goto out;
1152 }
1153 /*
1154 * To add new inline back ref, we have to make sure
1155 * there is no corresponding back ref item.
1156 * For simplicity, we just do not add new inline back
1157 * ref if there is any kind of item for this block
1158 */
1159 if (find_next_key(path, 0, &key) == 0 &&
1160 key.objectid == bytenr &&
1161 key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
1162 err = -EAGAIN;
1163 goto out;
1164 }
1165 }
1166 *ref_ret = (struct btrfs_extent_inline_ref *)ptr;
1167 out:
1168 if (insert) {
1169 path->keep_locks = 0;
1170 btrfs_unlock_up_safe(path, 1);
1171 }
1172 return err;
1173 }
1174
1175 /*
1176 * helper to add new inline back ref
1177 */
1178 static noinline_for_stack
1179 int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
1180 struct btrfs_root *root,
1181 struct btrfs_path *path,
1182 struct btrfs_extent_inline_ref *iref,
1183 u64 parent, u64 root_objectid,
1184 u64 owner, u64 offset, int refs_to_add,
1185 struct btrfs_delayed_extent_op *extent_op)
1186 {
1187 struct extent_buffer *leaf;
1188 struct btrfs_extent_item *ei;
1189 unsigned long ptr;
1190 unsigned long end;
1191 unsigned long item_offset;
1192 u64 refs;
1193 int size;
1194 int type;
1195 int ret;
1196
1197 leaf = path->nodes[0];
1198 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1199 item_offset = (unsigned long)iref - (unsigned long)ei;
1200
1201 type = extent_ref_type(parent, owner);
1202 size = btrfs_extent_inline_ref_size(type);
1203
1204 ret = btrfs_extend_item(trans, root, path, size);
1205 BUG_ON(ret);
1206
1207 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1208 refs = btrfs_extent_refs(leaf, ei);
1209 refs += refs_to_add;
1210 btrfs_set_extent_refs(leaf, ei, refs);
1211 if (extent_op)
1212 __run_delayed_extent_op(extent_op, leaf, ei);
1213
1214 ptr = (unsigned long)ei + item_offset;
1215 end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
1216 if (ptr < end - size)
1217 memmove_extent_buffer(leaf, ptr + size, ptr,
1218 end - size - ptr);
1219
1220 iref = (struct btrfs_extent_inline_ref *)ptr;
1221 btrfs_set_extent_inline_ref_type(leaf, iref, type);
1222 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1223 struct btrfs_extent_data_ref *dref;
1224 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1225 btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
1226 btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
1227 btrfs_set_extent_data_ref_offset(leaf, dref, offset);
1228 btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
1229 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1230 struct btrfs_shared_data_ref *sref;
1231 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1232 btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
1233 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1234 } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
1235 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
1236 } else {
1237 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
1238 }
1239 btrfs_mark_buffer_dirty(leaf);
1240 return 0;
1241 }
1242
1243 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
1244 struct btrfs_root *root,
1245 struct btrfs_path *path,
1246 struct btrfs_extent_inline_ref **ref_ret,
1247 u64 bytenr, u64 num_bytes, u64 parent,
1248 u64 root_objectid, u64 owner, u64 offset)
1249 {
1250 int ret;
1251
1252 ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
1253 bytenr, num_bytes, parent,
1254 root_objectid, owner, offset, 0);
1255 if (ret != -ENOENT)
1256 return ret;
1257
1258 btrfs_release_path(root, path);
1259 *ref_ret = NULL;
1260
1261 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1262 ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
1263 root_objectid);
1264 } else {
1265 ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
1266 root_objectid, owner, offset);
1267 }
1268 return ret;
1269 }
1270
1271 /*
1272 * helper to update/remove inline back ref
1273 */
1274 static noinline_for_stack
1275 int update_inline_extent_backref(struct btrfs_trans_handle *trans,
1276 struct btrfs_root *root,
1277 struct btrfs_path *path,
1278 struct btrfs_extent_inline_ref *iref,
1279 int refs_to_mod,
1280 struct btrfs_delayed_extent_op *extent_op)
1281 {
1282 struct extent_buffer *leaf;
1283 struct btrfs_extent_item *ei;
1284 struct btrfs_extent_data_ref *dref = NULL;
1285 struct btrfs_shared_data_ref *sref = NULL;
1286 unsigned long ptr;
1287 unsigned long end;
1288 u32 item_size;
1289 int size;
1290 int type;
1291 int ret;
1292 u64 refs;
1293
1294 leaf = path->nodes[0];
1295 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1296 refs = btrfs_extent_refs(leaf, ei);
1297 WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
1298 refs += refs_to_mod;
1299 btrfs_set_extent_refs(leaf, ei, refs);
1300 if (extent_op)
1301 __run_delayed_extent_op(extent_op, leaf, ei);
1302
1303 type = btrfs_extent_inline_ref_type(leaf, iref);
1304
1305 if (type == BTRFS_EXTENT_DATA_REF_KEY) {
1306 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
1307 refs = btrfs_extent_data_ref_count(leaf, dref);
1308 } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
1309 sref = (struct btrfs_shared_data_ref *)(iref + 1);
1310 refs = btrfs_shared_data_ref_count(leaf, sref);
1311 } else {
1312 refs = 1;
1313 BUG_ON(refs_to_mod != -1);
1314 }
1315
1316 BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
1317 refs += refs_to_mod;
1318
1319 if (refs > 0) {
1320 if (type == BTRFS_EXTENT_DATA_REF_KEY)
1321 btrfs_set_extent_data_ref_count(leaf, dref, refs);
1322 else
1323 btrfs_set_shared_data_ref_count(leaf, sref, refs);
1324 } else {
1325 size = btrfs_extent_inline_ref_size(type);
1326 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1327 ptr = (unsigned long)iref;
1328 end = (unsigned long)ei + item_size;
1329 if (ptr + size < end)
1330 memmove_extent_buffer(leaf, ptr, ptr + size,
1331 end - ptr - size);
1332 item_size -= size;
1333 ret = btrfs_truncate_item(trans, root, path, item_size, 1);
1334 BUG_ON(ret);
1335 }
1336 btrfs_mark_buffer_dirty(leaf);
1337 return 0;
1338 }
1339
1340 static noinline_for_stack
1341 int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
1342 struct btrfs_root *root,
1343 struct btrfs_path *path,
1344 u64 bytenr, u64 num_bytes, u64 parent,
1345 u64 root_objectid, u64 owner,
1346 u64 offset, int refs_to_add,
1347 struct btrfs_delayed_extent_op *extent_op)
1348 {
1349 struct btrfs_extent_inline_ref *iref;
1350 int ret;
1351
1352 ret = lookup_inline_extent_backref(trans, root, path, &iref,
1353 bytenr, num_bytes, parent,
1354 root_objectid, owner, offset, 1);
1355 if (ret == 0) {
1356 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
1357 ret = update_inline_extent_backref(trans, root, path, iref,
1358 refs_to_add, extent_op);
1359 } else if (ret == -ENOENT) {
1360 ret = setup_inline_extent_backref(trans, root, path, iref,
1361 parent, root_objectid,
1362 owner, offset, refs_to_add,
1363 extent_op);
1364 }
1365 return ret;
1366 }
1367
1368 static int insert_extent_backref(struct btrfs_trans_handle *trans,
1369 struct btrfs_root *root,
1370 struct btrfs_path *path,
1371 u64 bytenr, u64 parent, u64 root_objectid,
1372 u64 owner, u64 offset, int refs_to_add)
1373 {
1374 int ret;
1375 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1376 BUG_ON(refs_to_add != 1);
1377 ret = insert_tree_block_ref(trans, root, path, bytenr,
1378 parent, root_objectid);
1379 } else {
1380 ret = insert_extent_data_ref(trans, root, path, bytenr,
1381 parent, root_objectid,
1382 owner, offset, refs_to_add);
1383 }
1384 return ret;
1385 }
1386
1387 static int remove_extent_backref(struct btrfs_trans_handle *trans,
1388 struct btrfs_root *root,
1389 struct btrfs_path *path,
1390 struct btrfs_extent_inline_ref *iref,
1391 int refs_to_drop, int is_data)
1392 {
1393 int ret;
1394
1395 BUG_ON(!is_data && refs_to_drop != 1);
1396 if (iref) {
1397 ret = update_inline_extent_backref(trans, root, path, iref,
1398 -refs_to_drop, NULL);
1399 } else if (is_data) {
1400 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
1401 } else {
1402 ret = btrfs_del_item(trans, root, path);
1403 }
1404 return ret;
1405 }
1406
1407 #ifdef BIO_RW_DISCARD
1408 static void btrfs_issue_discard(struct block_device *bdev,
1409 u64 start, u64 len)
1410 {
1411 blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL);
1412 }
1413 #endif
1414
1415 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
1416 u64 num_bytes)
1417 {
1418 #ifdef BIO_RW_DISCARD
1419 int ret;
1420 u64 map_length = num_bytes;
1421 struct btrfs_multi_bio *multi = NULL;
1422
1423 /* Tell the block device(s) that the sectors can be discarded */
1424 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
1425 bytenr, &map_length, &multi, 0);
1426 if (!ret) {
1427 struct btrfs_bio_stripe *stripe = multi->stripes;
1428 int i;
1429
1430 if (map_length > num_bytes)
1431 map_length = num_bytes;
1432
1433 for (i = 0; i < multi->num_stripes; i++, stripe++) {
1434 btrfs_issue_discard(stripe->dev->bdev,
1435 stripe->physical,
1436 map_length);
1437 }
1438 kfree(multi);
1439 }
1440
1441 return ret;
1442 #else
1443 return 0;
1444 #endif
1445 }
1446
1447 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1448 struct btrfs_root *root,
1449 u64 bytenr, u64 num_bytes, u64 parent,
1450 u64 root_objectid, u64 owner, u64 offset)
1451 {
1452 int ret;
1453 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
1454 root_objectid == BTRFS_TREE_LOG_OBJECTID);
1455
1456 if (owner < BTRFS_FIRST_FREE_OBJECTID) {
1457 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
1458 parent, root_objectid, (int)owner,
1459 BTRFS_ADD_DELAYED_REF, NULL);
1460 } else {
1461 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
1462 parent, root_objectid, owner, offset,
1463 BTRFS_ADD_DELAYED_REF, NULL);
1464 }
1465 return ret;
1466 }
1467
1468 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
1469 struct btrfs_root *root,
1470 u64 bytenr, u64 num_bytes,
1471 u64 parent, u64 root_objectid,
1472 u64 owner, u64 offset, int refs_to_add,
1473 struct btrfs_delayed_extent_op *extent_op)
1474 {
1475 struct btrfs_path *path;
1476 struct extent_buffer *leaf;
1477 struct btrfs_extent_item *item;
1478 u64 refs;
1479 int ret;
1480 int err = 0;
1481
1482 path = btrfs_alloc_path();
1483 if (!path)
1484 return -ENOMEM;
1485
1486 path->reada = 1;
1487 path->leave_spinning = 1;
1488 /* this will setup the path even if it fails to insert the back ref */
1489 ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
1490 path, bytenr, num_bytes, parent,
1491 root_objectid, owner, offset,
1492 refs_to_add, extent_op);
1493 if (ret == 0)
1494 goto out;
1495
1496 if (ret != -EAGAIN) {
1497 err = ret;
1498 goto out;
1499 }
1500
1501 leaf = path->nodes[0];
1502 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1503 refs = btrfs_extent_refs(leaf, item);
1504 btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
1505 if (extent_op)
1506 __run_delayed_extent_op(extent_op, leaf, item);
1507
1508 btrfs_mark_buffer_dirty(leaf);
1509 btrfs_release_path(root->fs_info->extent_root, path);
1510
1511 path->reada = 1;
1512 path->leave_spinning = 1;
1513
1514 /* now insert the actual backref */
1515 ret = insert_extent_backref(trans, root->fs_info->extent_root,
1516 path, bytenr, parent, root_objectid,
1517 owner, offset, refs_to_add);
1518 BUG_ON(ret);
1519 out:
1520 btrfs_free_path(path);
1521 return err;
1522 }
1523
1524 static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
1525 struct btrfs_root *root,
1526 struct btrfs_delayed_ref_node *node,
1527 struct btrfs_delayed_extent_op *extent_op,
1528 int insert_reserved)
1529 {
1530 int ret = 0;
1531 struct btrfs_delayed_data_ref *ref;
1532 struct btrfs_key ins;
1533 u64 parent = 0;
1534 u64 ref_root = 0;
1535 u64 flags = 0;
1536
1537 ins.objectid = node->bytenr;
1538 ins.offset = node->num_bytes;
1539 ins.type = BTRFS_EXTENT_ITEM_KEY;
1540
1541 ref = btrfs_delayed_node_to_data_ref(node);
1542 if (node->type == BTRFS_SHARED_DATA_REF_KEY)
1543 parent = ref->parent;
1544 else
1545 ref_root = ref->root;
1546
1547 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1548 if (extent_op) {
1549 BUG_ON(extent_op->update_key);
1550 flags |= extent_op->flags_to_set;
1551 }
1552 ret = alloc_reserved_file_extent(trans, root,
1553 parent, ref_root, flags,
1554 ref->objectid, ref->offset,
1555 &ins, node->ref_mod);
1556 update_reserved_extents(root, ins.objectid, ins.offset, 0);
1557 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1558 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1559 node->num_bytes, parent,
1560 ref_root, ref->objectid,
1561 ref->offset, node->ref_mod,
1562 extent_op);
1563 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1564 ret = __btrfs_free_extent(trans, root, node->bytenr,
1565 node->num_bytes, parent,
1566 ref_root, ref->objectid,
1567 ref->offset, node->ref_mod,
1568 extent_op);
1569 } else {
1570 BUG();
1571 }
1572 return ret;
1573 }
1574
1575 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
1576 struct extent_buffer *leaf,
1577 struct btrfs_extent_item *ei)
1578 {
1579 u64 flags = btrfs_extent_flags(leaf, ei);
1580 if (extent_op->update_flags) {
1581 flags |= extent_op->flags_to_set;
1582 btrfs_set_extent_flags(leaf, ei, flags);
1583 }
1584
1585 if (extent_op->update_key) {
1586 struct btrfs_tree_block_info *bi;
1587 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
1588 bi = (struct btrfs_tree_block_info *)(ei + 1);
1589 btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
1590 }
1591 }
1592
1593 static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
1594 struct btrfs_root *root,
1595 struct btrfs_delayed_ref_node *node,
1596 struct btrfs_delayed_extent_op *extent_op)
1597 {
1598 struct btrfs_key key;
1599 struct btrfs_path *path;
1600 struct btrfs_extent_item *ei;
1601 struct extent_buffer *leaf;
1602 u32 item_size;
1603 int ret;
1604 int err = 0;
1605
1606 path = btrfs_alloc_path();
1607 if (!path)
1608 return -ENOMEM;
1609
1610 key.objectid = node->bytenr;
1611 key.type = BTRFS_EXTENT_ITEM_KEY;
1612 key.offset = node->num_bytes;
1613
1614 path->reada = 1;
1615 path->leave_spinning = 1;
1616 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
1617 path, 0, 1);
1618 if (ret < 0) {
1619 err = ret;
1620 goto out;
1621 }
1622 if (ret > 0) {
1623 err = -EIO;
1624 goto out;
1625 }
1626
1627 leaf = path->nodes[0];
1628 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1629 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
1630 if (item_size < sizeof(*ei)) {
1631 ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
1632 path, (u64)-1, 0);
1633 if (ret < 0) {
1634 err = ret;
1635 goto out;
1636 }
1637 leaf = path->nodes[0];
1638 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1639 }
1640 #endif
1641 BUG_ON(item_size < sizeof(*ei));
1642 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
1643 __run_delayed_extent_op(extent_op, leaf, ei);
1644
1645 btrfs_mark_buffer_dirty(leaf);
1646 out:
1647 btrfs_free_path(path);
1648 return err;
1649 }
1650
1651 static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
1652 struct btrfs_root *root,
1653 struct btrfs_delayed_ref_node *node,
1654 struct btrfs_delayed_extent_op *extent_op,
1655 int insert_reserved)
1656 {
1657 int ret = 0;
1658 struct btrfs_delayed_tree_ref *ref;
1659 struct btrfs_key ins;
1660 u64 parent = 0;
1661 u64 ref_root = 0;
1662
1663 ins.objectid = node->bytenr;
1664 ins.offset = node->num_bytes;
1665 ins.type = BTRFS_EXTENT_ITEM_KEY;
1666
1667 ref = btrfs_delayed_node_to_tree_ref(node);
1668 if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1669 parent = ref->parent;
1670 else
1671 ref_root = ref->root;
1672
1673 BUG_ON(node->ref_mod != 1);
1674 if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
1675 BUG_ON(!extent_op || !extent_op->update_flags ||
1676 !extent_op->update_key);
1677 ret = alloc_reserved_tree_block(trans, root,
1678 parent, ref_root,
1679 extent_op->flags_to_set,
1680 &extent_op->key,
1681 ref->level, &ins);
1682 update_reserved_extents(root, ins.objectid, ins.offset, 0);
1683 } else if (node->action == BTRFS_ADD_DELAYED_REF) {
1684 ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
1685 node->num_bytes, parent, ref_root,
1686 ref->level, 0, 1, extent_op);
1687 } else if (node->action == BTRFS_DROP_DELAYED_REF) {
1688 ret = __btrfs_free_extent(trans, root, node->bytenr,
1689 node->num_bytes, parent, ref_root,
1690 ref->level, 0, 1, extent_op);
1691 } else {
1692 BUG();
1693 }
1694 return ret;
1695 }
1696
1697
1698 /* helper function to actually process a single delayed ref entry */
1699 static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
1700 struct btrfs_root *root,
1701 struct btrfs_delayed_ref_node *node,
1702 struct btrfs_delayed_extent_op *extent_op,
1703 int insert_reserved)
1704 {
1705 int ret;
1706 if (btrfs_delayed_ref_is_head(node)) {
1707 struct btrfs_delayed_ref_head *head;
1708 /*
1709 * we've hit the end of the chain and we were supposed
1710 * to insert this extent into the tree. But, it got
1711 * deleted before we ever needed to insert it, so all
1712 * we have to do is clean up the accounting
1713 */
1714 BUG_ON(extent_op);
1715 head = btrfs_delayed_node_to_head(node);
1716 if (insert_reserved) {
1717 if (head->is_data) {
1718 ret = btrfs_del_csums(trans, root,
1719 node->bytenr,
1720 node->num_bytes);
1721 BUG_ON(ret);
1722 }
1723 btrfs_update_pinned_extents(root, node->bytenr,
1724 node->num_bytes, 1);
1725 update_reserved_extents(root, node->bytenr,
1726 node->num_bytes, 0);
1727 }
1728 mutex_unlock(&head->mutex);
1729 return 0;
1730 }
1731
1732 if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1733 node->type == BTRFS_SHARED_BLOCK_REF_KEY)
1734 ret = run_delayed_tree_ref(trans, root, node, extent_op,
1735 insert_reserved);
1736 else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1737 node->type == BTRFS_SHARED_DATA_REF_KEY)
1738 ret = run_delayed_data_ref(trans, root, node, extent_op,
1739 insert_reserved);
1740 else
1741 BUG();
1742 return ret;
1743 }
1744
1745 static noinline struct btrfs_delayed_ref_node *
1746 select_delayed_ref(struct btrfs_delayed_ref_head *head)
1747 {
1748 struct rb_node *node;
1749 struct btrfs_delayed_ref_node *ref;
1750 int action = BTRFS_ADD_DELAYED_REF;
1751 again:
1752 /*
1753 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
1754 * this prevents ref count from going down to zero when
1755 * there still are pending delayed ref.
1756 */
1757 node = rb_prev(&head->node.rb_node);
1758 while (1) {
1759 if (!node)
1760 break;
1761 ref = rb_entry(node, struct btrfs_delayed_ref_node,
1762 rb_node);
1763 if (ref->bytenr != head->node.bytenr)
1764 break;
1765 if (ref->action == action)
1766 return ref;
1767 node = rb_prev(node);
1768 }
1769 if (action == BTRFS_ADD_DELAYED_REF) {
1770 action = BTRFS_DROP_DELAYED_REF;
1771 goto again;
1772 }
1773 return NULL;
1774 }
1775
1776 static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
1777 struct btrfs_root *root,
1778 struct list_head *cluster)
1779 {
1780 struct btrfs_delayed_ref_root *delayed_refs;
1781 struct btrfs_delayed_ref_node *ref;
1782 struct btrfs_delayed_ref_head *locked_ref = NULL;
1783 struct btrfs_delayed_extent_op *extent_op;
1784 int ret;
1785 int count = 0;
1786 int must_insert_reserved = 0;
1787
1788 delayed_refs = &trans->transaction->delayed_refs;
1789 while (1) {
1790 if (!locked_ref) {
1791 /* pick a new head ref from the cluster list */
1792 if (list_empty(cluster))
1793 break;
1794
1795 locked_ref = list_entry(cluster->next,
1796 struct btrfs_delayed_ref_head, cluster);
1797
1798 /* grab the lock that says we are going to process
1799 * all the refs for this head */
1800 ret = btrfs_delayed_ref_lock(trans, locked_ref);
1801
1802 /*
1803 * we may have dropped the spin lock to get the head
1804 * mutex lock, and that might have given someone else
1805 * time to free the head. If that's true, it has been
1806 * removed from our list and we can move on.
1807 */
1808 if (ret == -EAGAIN) {
1809 locked_ref = NULL;
1810 count++;
1811 continue;
1812 }
1813 }
1814
1815 /*
1816 * record the must insert reserved flag before we
1817 * drop the spin lock.
1818 */
1819 must_insert_reserved = locked_ref->must_insert_reserved;
1820 locked_ref->must_insert_reserved = 0;
1821
1822 extent_op = locked_ref->extent_op;
1823 locked_ref->extent_op = NULL;
1824
1825 /*
1826 * locked_ref is the head node, so we have to go one
1827 * node back for any delayed ref updates
1828 */
1829 ref = select_delayed_ref(locked_ref);
1830 if (!ref) {
1831 /* All delayed refs have been processed, Go ahead
1832 * and send the head node to run_one_delayed_ref,
1833 * so that any accounting fixes can happen
1834 */
1835 ref = &locked_ref->node;
1836
1837 if (extent_op && must_insert_reserved) {
1838 kfree(extent_op);
1839 extent_op = NULL;
1840 }
1841
1842 if (extent_op) {
1843 spin_unlock(&delayed_refs->lock);
1844
1845 ret = run_delayed_extent_op(trans, root,
1846 ref, extent_op);
1847 BUG_ON(ret);
1848 kfree(extent_op);
1849
1850 cond_resched();
1851 spin_lock(&delayed_refs->lock);
1852 continue;
1853 }
1854
1855 list_del_init(&locked_ref->cluster);
1856 locked_ref = NULL;
1857 }
1858
1859 ref->in_tree = 0;
1860 rb_erase(&ref->rb_node, &delayed_refs->root);
1861 delayed_refs->num_entries--;
1862
1863 spin_unlock(&delayed_refs->lock);
1864
1865 ret = run_one_delayed_ref(trans, root, ref, extent_op,
1866 must_insert_reserved);
1867 BUG_ON(ret);
1868
1869 btrfs_put_delayed_ref(ref);
1870 kfree(extent_op);
1871 count++;
1872
1873 cond_resched();
1874 spin_lock(&delayed_refs->lock);
1875 }
1876 return count;
1877 }
1878
1879 /*
1880 * this starts processing the delayed reference count updates and
1881 * extent insertions we have queued up so far. count can be
1882 * 0, which means to process everything in the tree at the start
1883 * of the run (but not newly added entries), or it can be some target
1884 * number you'd like to process.
1885 */
1886 int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
1887 struct btrfs_root *root, unsigned long count)
1888 {
1889 struct rb_node *node;
1890 struct btrfs_delayed_ref_root *delayed_refs;
1891 struct btrfs_delayed_ref_node *ref;
1892 struct list_head cluster;
1893 int ret;
1894 int run_all = count == (unsigned long)-1;
1895 int run_most = 0;
1896
1897 if (root == root->fs_info->extent_root)
1898 root = root->fs_info->tree_root;
1899
1900 delayed_refs = &trans->transaction->delayed_refs;
1901 INIT_LIST_HEAD(&cluster);
1902 again:
1903 spin_lock(&delayed_refs->lock);
1904 if (count == 0) {
1905 count = delayed_refs->num_entries * 2;
1906 run_most = 1;
1907 }
1908 while (1) {
1909 if (!(run_all || run_most) &&
1910 delayed_refs->num_heads_ready < 64)
1911 break;
1912
1913 /*
1914 * go find something we can process in the rbtree. We start at
1915 * the beginning of the tree, and then build a cluster
1916 * of refs to process starting at the first one we are able to
1917 * lock
1918 */
1919 ret = btrfs_find_ref_cluster(trans, &cluster,
1920 delayed_refs->run_delayed_start);
1921 if (ret)
1922 break;
1923
1924 ret = run_clustered_refs(trans, root, &cluster);
1925 BUG_ON(ret < 0);
1926
1927 count -= min_t(unsigned long, ret, count);
1928
1929 if (count == 0)
1930 break;
1931 }
1932
1933 if (run_all) {
1934 node = rb_first(&delayed_refs->root);
1935 if (!node)
1936 goto out;
1937 count = (unsigned long)-1;
1938
1939 while (node) {
1940 ref = rb_entry(node, struct btrfs_delayed_ref_node,
1941 rb_node);
1942 if (btrfs_delayed_ref_is_head(ref)) {
1943 struct btrfs_delayed_ref_head *head;
1944
1945 head = btrfs_delayed_node_to_head(ref);
1946 atomic_inc(&ref->refs);
1947
1948 spin_unlock(&delayed_refs->lock);
1949 mutex_lock(&head->mutex);
1950 mutex_unlock(&head->mutex);
1951
1952 btrfs_put_delayed_ref(ref);
1953 cond_resched();
1954 goto again;
1955 }
1956 node = rb_next(node);
1957 }
1958 spin_unlock(&delayed_refs->lock);
1959 schedule_timeout(1);
1960 goto again;
1961 }
1962 out:
1963 spin_unlock(&delayed_refs->lock);
1964 return 0;
1965 }
1966
1967 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
1968 struct btrfs_root *root,
1969 u64 bytenr, u64 num_bytes, u64 flags,
1970 int is_data)
1971 {
1972 struct btrfs_delayed_extent_op *extent_op;
1973 int ret;
1974
1975 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
1976 if (!extent_op)
1977 return -ENOMEM;
1978
1979 extent_op->flags_to_set = flags;
1980 extent_op->update_flags = 1;
1981 extent_op->update_key = 0;
1982 extent_op->is_data = is_data ? 1 : 0;
1983
1984 ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
1985 if (ret)
1986 kfree(extent_op);
1987 return ret;
1988 }
1989
1990 static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
1991 struct btrfs_root *root,
1992 struct btrfs_path *path,
1993 u64 objectid, u64 offset, u64 bytenr)
1994 {
1995 struct btrfs_delayed_ref_head *head;
1996 struct btrfs_delayed_ref_node *ref;
1997 struct btrfs_delayed_data_ref *data_ref;
1998 struct btrfs_delayed_ref_root *delayed_refs;
1999 struct rb_node *node;
2000 int ret = 0;
2001
2002 ret = -ENOENT;
2003 delayed_refs = &trans->transaction->delayed_refs;
2004 spin_lock(&delayed_refs->lock);
2005 head = btrfs_find_delayed_ref_head(trans, bytenr);
2006 if (!head)
2007 goto out;
2008
2009 if (!mutex_trylock(&head->mutex)) {
2010 atomic_inc(&head->node.refs);
2011 spin_unlock(&delayed_refs->lock);
2012
2013 btrfs_release_path(root->fs_info->extent_root, path);
2014
2015 mutex_lock(&head->mutex);
2016 mutex_unlock(&head->mutex);
2017 btrfs_put_delayed_ref(&head->node);
2018 return -EAGAIN;
2019 }
2020
2021 node = rb_prev(&head->node.rb_node);
2022 if (!node)
2023 goto out_unlock;
2024
2025 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2026
2027 if (ref->bytenr != bytenr)
2028 goto out_unlock;
2029
2030 ret = 1;
2031 if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
2032 goto out_unlock;
2033
2034 data_ref = btrfs_delayed_node_to_data_ref(ref);
2035
2036 node = rb_prev(node);
2037 if (node) {
2038 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
2039 if (ref->bytenr == bytenr)
2040 goto out_unlock;
2041 }
2042
2043 if (data_ref->root != root->root_key.objectid ||
2044 data_ref->objectid != objectid || data_ref->offset != offset)
2045 goto out_unlock;
2046
2047 ret = 0;
2048 out_unlock:
2049 mutex_unlock(&head->mutex);
2050 out:
2051 spin_unlock(&delayed_refs->lock);
2052 return ret;
2053 }
2054
2055 static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
2056 struct btrfs_root *root,
2057 struct btrfs_path *path,
2058 u64 objectid, u64 offset, u64 bytenr)
2059 {
2060 struct btrfs_root *extent_root = root->fs_info->extent_root;
2061 struct extent_buffer *leaf;
2062 struct btrfs_extent_data_ref *ref;
2063 struct btrfs_extent_inline_ref *iref;
2064 struct btrfs_extent_item *ei;
2065 struct btrfs_key key;
2066 u32 item_size;
2067 int ret;
2068
2069 key.objectid = bytenr;
2070 key.offset = (u64)-1;
2071 key.type = BTRFS_EXTENT_ITEM_KEY;
2072
2073 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
2074 if (ret < 0)
2075 goto out;
2076 BUG_ON(ret == 0);
2077
2078 ret = -ENOENT;
2079 if (path->slots[0] == 0)
2080 goto out;
2081
2082 path->slots[0]--;
2083 leaf = path->nodes[0];
2084 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2085
2086 if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
2087 goto out;
2088
2089 ret = 1;
2090 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2091 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
2092 if (item_size < sizeof(*ei)) {
2093 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
2094 goto out;
2095 }
2096 #endif
2097 ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
2098
2099 if (item_size != sizeof(*ei) +
2100 btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
2101 goto out;
2102
2103 if (btrfs_extent_generation(leaf, ei) <=
2104 btrfs_root_last_snapshot(&root->root_item))
2105 goto out;
2106
2107 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
2108 if (btrfs_extent_inline_ref_type(leaf, iref) !=
2109 BTRFS_EXTENT_DATA_REF_KEY)
2110 goto out;
2111
2112 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
2113 if (btrfs_extent_refs(leaf, ei) !=
2114 btrfs_extent_data_ref_count(leaf, ref) ||
2115 btrfs_extent_data_ref_root(leaf, ref) !=
2116 root->root_key.objectid ||
2117 btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
2118 btrfs_extent_data_ref_offset(leaf, ref) != offset)
2119 goto out;
2120
2121 ret = 0;
2122 out:
2123 return ret;
2124 }
2125
2126 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
2127 struct btrfs_root *root,
2128 u64 objectid, u64 offset, u64 bytenr)
2129 {
2130 struct btrfs_path *path;
2131 int ret;
2132 int ret2;
2133
2134 path = btrfs_alloc_path();
2135 if (!path)
2136 return -ENOENT;
2137
2138 do {
2139 ret = check_committed_ref(trans, root, path, objectid,
2140 offset, bytenr);
2141 if (ret && ret != -ENOENT)
2142 goto out;
2143
2144 ret2 = check_delayed_ref(trans, root, path, objectid,
2145 offset, bytenr);
2146 } while (ret2 == -EAGAIN);
2147
2148 if (ret2 && ret2 != -ENOENT) {
2149 ret = ret2;
2150 goto out;
2151 }
2152
2153 if (ret != -ENOENT || ret2 != -ENOENT)
2154 ret = 0;
2155 out:
2156 btrfs_free_path(path);
2157 return ret;
2158 }
2159
2160 #if 0
2161 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2162 struct extent_buffer *buf, u32 nr_extents)
2163 {
2164 struct btrfs_key key;
2165 struct btrfs_file_extent_item *fi;
2166 u64 root_gen;
2167 u32 nritems;
2168 int i;
2169 int level;
2170 int ret = 0;
2171 int shared = 0;
2172
2173 if (!root->ref_cows)
2174 return 0;
2175
2176 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
2177 shared = 0;
2178 root_gen = root->root_key.offset;
2179 } else {
2180 shared = 1;
2181 root_gen = trans->transid - 1;
2182 }
2183
2184 level = btrfs_header_level(buf);
2185 nritems = btrfs_header_nritems(buf);
2186
2187 if (level == 0) {
2188 struct btrfs_leaf_ref *ref;
2189 struct btrfs_extent_info *info;
2190
2191 ref = btrfs_alloc_leaf_ref(root, nr_extents);
2192 if (!ref) {
2193 ret = -ENOMEM;
2194 goto out;
2195 }
2196
2197 ref->root_gen = root_gen;
2198 ref->bytenr = buf->start;
2199 ref->owner = btrfs_header_owner(buf);
2200 ref->generation = btrfs_header_generation(buf);
2201 ref->nritems = nr_extents;
2202 info = ref->extents;
2203
2204 for (i = 0; nr_extents > 0 && i < nritems; i++) {
2205 u64 disk_bytenr;
2206 btrfs_item_key_to_cpu(buf, &key, i);
2207 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2208 continue;
2209 fi = btrfs_item_ptr(buf, i,
2210 struct btrfs_file_extent_item);
2211 if (btrfs_file_extent_type(buf, fi) ==
2212 BTRFS_FILE_EXTENT_INLINE)
2213 continue;
2214 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2215 if (disk_bytenr == 0)
2216 continue;
2217
2218 info->bytenr = disk_bytenr;
2219 info->num_bytes =
2220 btrfs_file_extent_disk_num_bytes(buf, fi);
2221 info->objectid = key.objectid;
2222 info->offset = key.offset;
2223 info++;
2224 }
2225
2226 ret = btrfs_add_leaf_ref(root, ref, shared);
2227 if (ret == -EEXIST && shared) {
2228 struct btrfs_leaf_ref *old;
2229 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
2230 BUG_ON(!old);
2231 btrfs_remove_leaf_ref(root, old);
2232 btrfs_free_leaf_ref(root, old);
2233 ret = btrfs_add_leaf_ref(root, ref, shared);
2234 }
2235 WARN_ON(ret);
2236 btrfs_free_leaf_ref(root, ref);
2237 }
2238 out:
2239 return ret;
2240 }
2241
2242 /* when a block goes through cow, we update the reference counts of
2243 * everything that block points to. The internal pointers of the block
2244 * can be in just about any order, and it is likely to have clusters of
2245 * things that are close together and clusters of things that are not.
2246 *
2247 * To help reduce the seeks that come with updating all of these reference
2248 * counts, sort them by byte number before actual updates are done.
2249 *
2250 * struct refsort is used to match byte number to slot in the btree block.
2251 * we sort based on the byte number and then use the slot to actually
2252 * find the item.
2253 *
2254 * struct refsort is smaller than strcut btrfs_item and smaller than
2255 * struct btrfs_key_ptr. Since we're currently limited to the page size
2256 * for a btree block, there's no way for a kmalloc of refsorts for a
2257 * single node to be bigger than a page.
2258 */
2259 struct refsort {
2260 u64 bytenr;
2261 u32 slot;
2262 };
2263
2264 /*
2265 * for passing into sort()
2266 */
2267 static int refsort_cmp(const void *a_void, const void *b_void)
2268 {
2269 const struct refsort *a = a_void;
2270 const struct refsort *b = b_void;
2271
2272 if (a->bytenr < b->bytenr)
2273 return -1;
2274 if (a->bytenr > b->bytenr)
2275 return 1;
2276 return 0;
2277 }
2278 #endif
2279
2280 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
2281 struct btrfs_root *root,
2282 struct extent_buffer *buf,
2283 int full_backref, int inc)
2284 {
2285 u64 bytenr;
2286 u64 num_bytes;
2287 u64 parent;
2288 u64 ref_root;
2289 u32 nritems;
2290 struct btrfs_key key;
2291 struct btrfs_file_extent_item *fi;
2292 int i;
2293 int level;
2294 int ret = 0;
2295 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
2296 u64, u64, u64, u64, u64, u64);
2297
2298 ref_root = btrfs_header_owner(buf);
2299 nritems = btrfs_header_nritems(buf);
2300 level = btrfs_header_level(buf);
2301
2302 if (!root->ref_cows && level == 0)
2303 return 0;
2304
2305 if (inc)
2306 process_func = btrfs_inc_extent_ref;
2307 else
2308 process_func = btrfs_free_extent;
2309
2310 if (full_backref)
2311 parent = buf->start;
2312 else
2313 parent = 0;
2314
2315 for (i = 0; i < nritems; i++) {
2316 if (level == 0) {
2317 btrfs_item_key_to_cpu(buf, &key, i);
2318 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2319 continue;
2320 fi = btrfs_item_ptr(buf, i,
2321 struct btrfs_file_extent_item);
2322 if (btrfs_file_extent_type(buf, fi) ==
2323 BTRFS_FILE_EXTENT_INLINE)
2324 continue;
2325 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
2326 if (bytenr == 0)
2327 continue;
2328
2329 num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
2330 key.offset -= btrfs_file_extent_offset(buf, fi);
2331 ret = process_func(trans, root, bytenr, num_bytes,
2332 parent, ref_root, key.objectid,
2333 key.offset);
2334 if (ret)
2335 goto fail;
2336 } else {
2337 bytenr = btrfs_node_blockptr(buf, i);
2338 num_bytes = btrfs_level_size(root, level - 1);
2339 ret = process_func(trans, root, bytenr, num_bytes,
2340 parent, ref_root, level - 1, 0);
2341 if (ret)
2342 goto fail;
2343 }
2344 }
2345 return 0;
2346 fail:
2347 BUG();
2348 return ret;
2349 }
2350
2351 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2352 struct extent_buffer *buf, int full_backref)
2353 {
2354 return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
2355 }
2356
2357 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2358 struct extent_buffer *buf, int full_backref)
2359 {
2360 return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
2361 }
2362
2363 static int write_one_cache_group(struct btrfs_trans_handle *trans,
2364 struct btrfs_root *root,
2365 struct btrfs_path *path,
2366 struct btrfs_block_group_cache *cache)
2367 {
2368 int ret;
2369 struct btrfs_root *extent_root = root->fs_info->extent_root;
2370 unsigned long bi;
2371 struct extent_buffer *leaf;
2372
2373 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
2374 if (ret < 0)
2375 goto fail;
2376 BUG_ON(ret);
2377
2378 leaf = path->nodes[0];
2379 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
2380 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
2381 btrfs_mark_buffer_dirty(leaf);
2382 btrfs_release_path(extent_root, path);
2383 fail:
2384 if (ret)
2385 return ret;
2386 return 0;
2387
2388 }
2389
2390 static struct btrfs_block_group_cache *
2391 next_block_group(struct btrfs_root *root,
2392 struct btrfs_block_group_cache *cache)
2393 {
2394 struct rb_node *node;
2395 spin_lock(&root->fs_info->block_group_cache_lock);
2396 node = rb_next(&cache->cache_node);
2397 btrfs_put_block_group(cache);
2398 if (node) {
2399 cache = rb_entry(node, struct btrfs_block_group_cache,
2400 cache_node);
2401 atomic_inc(&cache->count);
2402 } else
2403 cache = NULL;
2404 spin_unlock(&root->fs_info->block_group_cache_lock);
2405 return cache;
2406 }
2407
2408 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
2409 struct btrfs_root *root)
2410 {
2411 struct btrfs_block_group_cache *cache;
2412 int err = 0;
2413 struct btrfs_path *path;
2414 u64 last = 0;
2415
2416 path = btrfs_alloc_path();
2417 if (!path)
2418 return -ENOMEM;
2419
2420 while (1) {
2421 if (last == 0) {
2422 err = btrfs_run_delayed_refs(trans, root,
2423 (unsigned long)-1);
2424 BUG_ON(err);
2425 }
2426
2427 cache = btrfs_lookup_first_block_group(root->fs_info, last);
2428 while (cache) {
2429 if (cache->dirty)
2430 break;
2431 cache = next_block_group(root, cache);
2432 }
2433 if (!cache) {
2434 if (last == 0)
2435 break;
2436 last = 0;
2437 continue;
2438 }
2439
2440 cache->dirty = 0;
2441 last = cache->key.objectid + cache->key.offset;
2442
2443 err = write_one_cache_group(trans, root, path, cache);
2444 BUG_ON(err);
2445 btrfs_put_block_group(cache);
2446 }
2447
2448 btrfs_free_path(path);
2449 return 0;
2450 }
2451
2452 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
2453 {
2454 struct btrfs_block_group_cache *block_group;
2455 int readonly = 0;
2456
2457 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
2458 if (!block_group || block_group->ro)
2459 readonly = 1;
2460 if (block_group)
2461 btrfs_put_block_group(block_group);
2462 return readonly;
2463 }
2464
2465 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
2466 u64 total_bytes, u64 bytes_used,
2467 struct btrfs_space_info **space_info)
2468 {
2469 struct btrfs_space_info *found;
2470
2471 found = __find_space_info(info, flags);
2472 if (found) {
2473 spin_lock(&found->lock);
2474 found->total_bytes += total_bytes;
2475 found->bytes_used += bytes_used;
2476 found->full = 0;
2477 spin_unlock(&found->lock);
2478 *space_info = found;
2479 return 0;
2480 }
2481 found = kzalloc(sizeof(*found), GFP_NOFS);
2482 if (!found)
2483 return -ENOMEM;
2484
2485 INIT_LIST_HEAD(&found->block_groups);
2486 init_rwsem(&found->groups_sem);
2487 spin_lock_init(&found->lock);
2488 found->flags = flags;
2489 found->total_bytes = total_bytes;
2490 found->bytes_used = bytes_used;
2491 found->bytes_pinned = 0;
2492 found->bytes_reserved = 0;
2493 found->bytes_readonly = 0;
2494 found->bytes_delalloc = 0;
2495 found->full = 0;
2496 found->force_alloc = 0;
2497 *space_info = found;
2498 list_add_rcu(&found->list, &info->space_info);
2499 return 0;
2500 }
2501
2502 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
2503 {
2504 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
2505 BTRFS_BLOCK_GROUP_RAID1 |
2506 BTRFS_BLOCK_GROUP_RAID10 |
2507 BTRFS_BLOCK_GROUP_DUP);
2508 if (extra_flags) {
2509 if (flags & BTRFS_BLOCK_GROUP_DATA)
2510 fs_info->avail_data_alloc_bits |= extra_flags;
2511 if (flags & BTRFS_BLOCK_GROUP_METADATA)
2512 fs_info->avail_metadata_alloc_bits |= extra_flags;
2513 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
2514 fs_info->avail_system_alloc_bits |= extra_flags;
2515 }
2516 }
2517
2518 static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
2519 {
2520 spin_lock(&cache->space_info->lock);
2521 spin_lock(&cache->lock);
2522 if (!cache->ro) {
2523 cache->space_info->bytes_readonly += cache->key.offset -
2524 btrfs_block_group_used(&cache->item);
2525 cache->ro = 1;
2526 }
2527 spin_unlock(&cache->lock);
2528 spin_unlock(&cache->space_info->lock);
2529 }
2530
2531 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
2532 {
2533 u64 num_devices = root->fs_info->fs_devices->rw_devices;
2534
2535 if (num_devices == 1)
2536 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
2537 if (num_devices < 4)
2538 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
2539
2540 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
2541 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
2542 BTRFS_BLOCK_GROUP_RAID10))) {
2543 flags &= ~BTRFS_BLOCK_GROUP_DUP;
2544 }
2545
2546 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
2547 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
2548 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
2549 }
2550
2551 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
2552 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
2553 (flags & BTRFS_BLOCK_GROUP_RAID10) |
2554 (flags & BTRFS_BLOCK_GROUP_DUP)))
2555 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
2556 return flags;
2557 }
2558
2559 static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data)
2560 {
2561 struct btrfs_fs_info *info = root->fs_info;
2562 u64 alloc_profile;
2563
2564 if (data) {
2565 alloc_profile = info->avail_data_alloc_bits &
2566 info->data_alloc_profile;
2567 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2568 } else if (root == root->fs_info->chunk_root) {
2569 alloc_profile = info->avail_system_alloc_bits &
2570 info->system_alloc_profile;
2571 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2572 } else {
2573 alloc_profile = info->avail_metadata_alloc_bits &
2574 info->metadata_alloc_profile;
2575 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2576 }
2577
2578 return btrfs_reduce_alloc_profile(root, data);
2579 }
2580
2581 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
2582 {
2583 u64 alloc_target;
2584
2585 alloc_target = btrfs_get_alloc_profile(root, 1);
2586 BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
2587 alloc_target);
2588 }
2589
2590 /*
2591 * for now this just makes sure we have at least 5% of our metadata space free
2592 * for use.
2593 */
2594 int btrfs_check_metadata_free_space(struct btrfs_root *root)
2595 {
2596 struct btrfs_fs_info *info = root->fs_info;
2597 struct btrfs_space_info *meta_sinfo;
2598 u64 alloc_target, thresh;
2599 int committed = 0, ret;
2600
2601 /* get the space info for where the metadata will live */
2602 alloc_target = btrfs_get_alloc_profile(root, 0);
2603 meta_sinfo = __find_space_info(info, alloc_target);
2604
2605 again:
2606 spin_lock(&meta_sinfo->lock);
2607 if (!meta_sinfo->full)
2608 thresh = meta_sinfo->total_bytes * 80;
2609 else
2610 thresh = meta_sinfo->total_bytes * 95;
2611
2612 do_div(thresh, 100);
2613
2614 if (meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
2615 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly > thresh) {
2616 struct btrfs_trans_handle *trans;
2617 if (!meta_sinfo->full) {
2618 meta_sinfo->force_alloc = 1;
2619 spin_unlock(&meta_sinfo->lock);
2620
2621 trans = btrfs_start_transaction(root, 1);
2622 if (!trans)
2623 return -ENOMEM;
2624
2625 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2626 2 * 1024 * 1024, alloc_target, 0);
2627 btrfs_end_transaction(trans, root);
2628 goto again;
2629 }
2630 spin_unlock(&meta_sinfo->lock);
2631
2632 if (!committed) {
2633 committed = 1;
2634 trans = btrfs_join_transaction(root, 1);
2635 if (!trans)
2636 return -ENOMEM;
2637 ret = btrfs_commit_transaction(trans, root);
2638 if (ret)
2639 return ret;
2640 goto again;
2641 }
2642 return -ENOSPC;
2643 }
2644 spin_unlock(&meta_sinfo->lock);
2645
2646 return 0;
2647 }
2648
2649 /*
2650 * This will check the space that the inode allocates from to make sure we have
2651 * enough space for bytes.
2652 */
2653 int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
2654 u64 bytes)
2655 {
2656 struct btrfs_space_info *data_sinfo;
2657 int ret = 0, committed = 0;
2658
2659 /* make sure bytes are sectorsize aligned */
2660 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
2661
2662 data_sinfo = BTRFS_I(inode)->space_info;
2663 again:
2664 /* make sure we have enough space to handle the data first */
2665 spin_lock(&data_sinfo->lock);
2666 if (data_sinfo->total_bytes - data_sinfo->bytes_used -
2667 data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved -
2668 data_sinfo->bytes_pinned - data_sinfo->bytes_readonly -
2669 data_sinfo->bytes_may_use < bytes) {
2670 struct btrfs_trans_handle *trans;
2671
2672 /*
2673 * if we don't have enough free bytes in this space then we need
2674 * to alloc a new chunk.
2675 */
2676 if (!data_sinfo->full) {
2677 u64 alloc_target;
2678
2679 data_sinfo->force_alloc = 1;
2680 spin_unlock(&data_sinfo->lock);
2681
2682 alloc_target = btrfs_get_alloc_profile(root, 1);
2683 trans = btrfs_start_transaction(root, 1);
2684 if (!trans)
2685 return -ENOMEM;
2686
2687 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2688 bytes + 2 * 1024 * 1024,
2689 alloc_target, 0);
2690 btrfs_end_transaction(trans, root);
2691 if (ret)
2692 return ret;
2693 goto again;
2694 }
2695 spin_unlock(&data_sinfo->lock);
2696
2697 /* commit the current transaction and try again */
2698 if (!committed) {
2699 committed = 1;
2700 trans = btrfs_join_transaction(root, 1);
2701 if (!trans)
2702 return -ENOMEM;
2703 ret = btrfs_commit_transaction(trans, root);
2704 if (ret)
2705 return ret;
2706 goto again;
2707 }
2708
2709 printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes"
2710 ", %llu bytes_used, %llu bytes_reserved, "
2711 "%llu bytes_pinned, %llu bytes_readonly, %llu may use "
2712 "%llu total\n", (unsigned long long)bytes,
2713 (unsigned long long)data_sinfo->bytes_delalloc,
2714 (unsigned long long)data_sinfo->bytes_used,
2715 (unsigned long long)data_sinfo->bytes_reserved,
2716 (unsigned long long)data_sinfo->bytes_pinned,
2717 (unsigned long long)data_sinfo->bytes_readonly,
2718 (unsigned long long)data_sinfo->bytes_may_use,
2719 (unsigned long long)data_sinfo->total_bytes);
2720 return -ENOSPC;
2721 }
2722 data_sinfo->bytes_may_use += bytes;
2723 BTRFS_I(inode)->reserved_bytes += bytes;
2724 spin_unlock(&data_sinfo->lock);
2725
2726 return btrfs_check_metadata_free_space(root);
2727 }
2728
2729 /*
2730 * if there was an error for whatever reason after calling
2731 * btrfs_check_data_free_space, call this so we can cleanup the counters.
2732 */
2733 void btrfs_free_reserved_data_space(struct btrfs_root *root,
2734 struct inode *inode, u64 bytes)
2735 {
2736 struct btrfs_space_info *data_sinfo;
2737
2738 /* make sure bytes are sectorsize aligned */
2739 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
2740
2741 data_sinfo = BTRFS_I(inode)->space_info;
2742 spin_lock(&data_sinfo->lock);
2743 data_sinfo->bytes_may_use -= bytes;
2744 BTRFS_I(inode)->reserved_bytes -= bytes;
2745 spin_unlock(&data_sinfo->lock);
2746 }
2747
2748 /* called when we are adding a delalloc extent to the inode's io_tree */
2749 void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
2750 u64 bytes)
2751 {
2752 struct btrfs_space_info *data_sinfo;
2753
2754 /* get the space info for where this inode will be storing its data */
2755 data_sinfo = BTRFS_I(inode)->space_info;
2756
2757 /* make sure we have enough space to handle the data first */
2758 spin_lock(&data_sinfo->lock);
2759 data_sinfo->bytes_delalloc += bytes;
2760
2761 /*
2762 * we are adding a delalloc extent without calling
2763 * btrfs_check_data_free_space first. This happens on a weird
2764 * writepage condition, but shouldn't hurt our accounting
2765 */
2766 if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {
2767 data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;
2768 BTRFS_I(inode)->reserved_bytes = 0;
2769 } else {
2770 data_sinfo->bytes_may_use -= bytes;
2771 BTRFS_I(inode)->reserved_bytes -= bytes;
2772 }
2773
2774 spin_unlock(&data_sinfo->lock);
2775 }
2776
2777 /* called when we are clearing an delalloc extent from the inode's io_tree */
2778 void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
2779 u64 bytes)
2780 {
2781 struct btrfs_space_info *info;
2782
2783 info = BTRFS_I(inode)->space_info;
2784
2785 spin_lock(&info->lock);
2786 info->bytes_delalloc -= bytes;
2787 spin_unlock(&info->lock);
2788 }
2789
2790 static void force_metadata_allocation(struct btrfs_fs_info *info)
2791 {
2792 struct list_head *head = &info->space_info;
2793 struct btrfs_space_info *found;
2794
2795 rcu_read_lock();
2796 list_for_each_entry_rcu(found, head, list) {
2797 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
2798 found->force_alloc = 1;
2799 }
2800 rcu_read_unlock();
2801 }
2802
2803 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
2804 struct btrfs_root *extent_root, u64 alloc_bytes,
2805 u64 flags, int force)
2806 {
2807 struct btrfs_space_info *space_info;
2808 struct btrfs_fs_info *fs_info = extent_root->fs_info;
2809 u64 thresh;
2810 int ret = 0;
2811
2812 mutex_lock(&fs_info->chunk_mutex);
2813
2814 flags = btrfs_reduce_alloc_profile(extent_root, flags);
2815
2816 space_info = __find_space_info(extent_root->fs_info, flags);
2817 if (!space_info) {
2818 ret = update_space_info(extent_root->fs_info, flags,
2819 0, 0, &space_info);
2820 BUG_ON(ret);
2821 }
2822 BUG_ON(!space_info);
2823
2824 spin_lock(&space_info->lock);
2825 if (space_info->force_alloc) {
2826 force = 1;
2827 space_info->force_alloc = 0;
2828 }
2829 if (space_info->full) {
2830 spin_unlock(&space_info->lock);
2831 goto out;
2832 }
2833
2834 thresh = space_info->total_bytes - space_info->bytes_readonly;
2835 thresh = div_factor(thresh, 6);
2836 if (!force &&
2837 (space_info->bytes_used + space_info->bytes_pinned +
2838 space_info->bytes_reserved + alloc_bytes) < thresh) {
2839 spin_unlock(&space_info->lock);
2840 goto out;
2841 }
2842 spin_unlock(&space_info->lock);
2843
2844 /*
2845 * if we're doing a data chunk, go ahead and make sure that
2846 * we keep a reasonable number of metadata chunks allocated in the
2847 * FS as well.
2848 */
2849 if (flags & BTRFS_BLOCK_GROUP_DATA) {
2850 fs_info->data_chunk_allocations++;
2851 if (!(fs_info->data_chunk_allocations %
2852 fs_info->metadata_ratio))
2853 force_metadata_allocation(fs_info);
2854 }
2855
2856 ret = btrfs_alloc_chunk(trans, extent_root, flags);
2857 if (ret)
2858 space_info->full = 1;
2859 out:
2860 mutex_unlock(&extent_root->fs_info->chunk_mutex);
2861 return ret;
2862 }
2863
2864 static int update_block_group(struct btrfs_trans_handle *trans,
2865 struct btrfs_root *root,
2866 u64 bytenr, u64 num_bytes, int alloc,
2867 int mark_free)
2868 {
2869 struct btrfs_block_group_cache *cache;
2870 struct btrfs_fs_info *info = root->fs_info;
2871 u64 total = num_bytes;
2872 u64 old_val;
2873 u64 byte_in_group;
2874
2875 /* block accounting for super block */
2876 spin_lock(&info->delalloc_lock);
2877 old_val = btrfs_super_bytes_used(&info->super_copy);
2878 if (alloc)
2879 old_val += num_bytes;
2880 else
2881 old_val -= num_bytes;
2882 btrfs_set_super_bytes_used(&info->super_copy, old_val);
2883
2884 /* block accounting for root item */
2885 old_val = btrfs_root_used(&root->root_item);
2886 if (alloc)
2887 old_val += num_bytes;
2888 else
2889 old_val -= num_bytes;
2890 btrfs_set_root_used(&root->root_item, old_val);
2891 spin_unlock(&info->delalloc_lock);
2892
2893 while (total) {
2894 cache = btrfs_lookup_block_group(info, bytenr);
2895 if (!cache)
2896 return -1;
2897 byte_in_group = bytenr - cache->key.objectid;
2898 WARN_ON(byte_in_group > cache->key.offset);
2899
2900 spin_lock(&cache->space_info->lock);
2901 spin_lock(&cache->lock);
2902 cache->dirty = 1;
2903 old_val = btrfs_block_group_used(&cache->item);
2904 num_bytes = min(total, cache->key.offset - byte_in_group);
2905 if (alloc) {
2906 old_val += num_bytes;
2907 cache->space_info->bytes_used += num_bytes;
2908 if (cache->ro)
2909 cache->space_info->bytes_readonly -= num_bytes;
2910 btrfs_set_block_group_used(&cache->item, old_val);
2911 spin_unlock(&cache->lock);
2912 spin_unlock(&cache->space_info->lock);
2913 } else {
2914 old_val -= num_bytes;
2915 cache->space_info->bytes_used -= num_bytes;
2916 if (cache->ro)
2917 cache->space_info->bytes_readonly += num_bytes;
2918 btrfs_set_block_group_used(&cache->item, old_val);
2919 spin_unlock(&cache->lock);
2920 spin_unlock(&cache->space_info->lock);
2921 if (mark_free) {
2922 int ret;
2923
2924 ret = btrfs_discard_extent(root, bytenr,
2925 num_bytes);
2926 WARN_ON(ret);
2927
2928 ret = btrfs_add_free_space(cache, bytenr,
2929 num_bytes);
2930 WARN_ON(ret);
2931 }
2932 }
2933 btrfs_put_block_group(cache);
2934 total -= num_bytes;
2935 bytenr += num_bytes;
2936 }
2937 return 0;
2938 }
2939
2940 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
2941 {
2942 struct btrfs_block_group_cache *cache;
2943 u64 bytenr;
2944
2945 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
2946 if (!cache)
2947 return 0;
2948
2949 bytenr = cache->key.objectid;
2950 btrfs_put_block_group(cache);
2951
2952 return bytenr;
2953 }
2954
2955 int btrfs_update_pinned_extents(struct btrfs_root *root,
2956 u64 bytenr, u64 num, int pin)
2957 {
2958 u64 len;
2959 struct btrfs_block_group_cache *cache;
2960 struct btrfs_fs_info *fs_info = root->fs_info;
2961
2962 if (pin) {
2963 set_extent_dirty(&fs_info->pinned_extents,
2964 bytenr, bytenr + num - 1, GFP_NOFS);
2965 } else {
2966 clear_extent_dirty(&fs_info->pinned_extents,
2967 bytenr, bytenr + num - 1, GFP_NOFS);
2968 }
2969
2970 while (num > 0) {
2971 cache = btrfs_lookup_block_group(fs_info, bytenr);
2972 BUG_ON(!cache);
2973 len = min(num, cache->key.offset -
2974 (bytenr - cache->key.objectid));
2975 if (pin) {
2976 spin_lock(&cache->space_info->lock);
2977 spin_lock(&cache->lock);
2978 cache->pinned += len;
2979 cache->space_info->bytes_pinned += len;
2980 spin_unlock(&cache->lock);
2981 spin_unlock(&cache->space_info->lock);
2982 fs_info->total_pinned += len;
2983 } else {
2984 spin_lock(&cache->space_info->lock);
2985 spin_lock(&cache->lock);
2986 cache->pinned -= len;
2987 cache->space_info->bytes_pinned -= len;
2988 spin_unlock(&cache->lock);
2989 spin_unlock(&cache->space_info->lock);
2990 fs_info->total_pinned -= len;
2991 if (cache->cached)
2992 btrfs_add_free_space(cache, bytenr, len);
2993 }
2994 btrfs_put_block_group(cache);
2995 bytenr += len;
2996 num -= len;
2997 }
2998 return 0;
2999 }
3000
3001 static int update_reserved_extents(struct btrfs_root *root,
3002 u64 bytenr, u64 num, int reserve)
3003 {
3004 u64 len;
3005 struct btrfs_block_group_cache *cache;
3006 struct btrfs_fs_info *fs_info = root->fs_info;
3007
3008 while (num > 0) {
3009 cache = btrfs_lookup_block_group(fs_info, bytenr);
3010 BUG_ON(!cache);
3011 len = min(num, cache->key.offset -
3012 (bytenr - cache->key.objectid));
3013
3014 spin_lock(&cache->space_info->lock);
3015 spin_lock(&cache->lock);
3016 if (reserve) {
3017 cache->reserved += len;
3018 cache->space_info->bytes_reserved += len;
3019 } else {
3020 cache->reserved -= len;
3021 cache->space_info->bytes_reserved -= len;
3022 }
3023 spin_unlock(&cache->lock);
3024 spin_unlock(&cache->space_info->lock);
3025 btrfs_put_block_group(cache);
3026 bytenr += len;
3027 num -= len;
3028 }
3029 return 0;
3030 }
3031
3032 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
3033 {
3034 u64 last = 0;
3035 u64 start;
3036 u64 end;
3037 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
3038 int ret;
3039
3040 while (1) {
3041 ret = find_first_extent_bit(pinned_extents, last,
3042 &start, &end, EXTENT_DIRTY);
3043 if (ret)
3044 break;
3045 set_extent_dirty(copy, start, end, GFP_NOFS);
3046 last = end + 1;
3047 }
3048 return 0;
3049 }
3050
3051 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
3052 struct btrfs_root *root,
3053 struct extent_io_tree *unpin)
3054 {
3055 u64 start;
3056 u64 end;
3057 int ret;
3058
3059 while (1) {
3060 ret = find_first_extent_bit(unpin, 0, &start, &end,
3061 EXTENT_DIRTY);
3062 if (ret)
3063 break;
3064
3065 ret = btrfs_discard_extent(root, start, end + 1 - start);
3066
3067 /* unlocks the pinned mutex */
3068 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
3069 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3070
3071 cond_resched();
3072 }
3073 return ret;
3074 }
3075
3076 static int pin_down_bytes(struct btrfs_trans_handle *trans,
3077 struct btrfs_root *root,
3078 struct btrfs_path *path,
3079 u64 bytenr, u64 num_bytes, int is_data,
3080 struct extent_buffer **must_clean)
3081 {
3082 int err = 0;
3083 struct extent_buffer *buf;
3084
3085 if (is_data)
3086 goto pinit;
3087
3088 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
3089 if (!buf)
3090 goto pinit;
3091
3092 /* we can reuse a block if it hasn't been written
3093 * and it is from this transaction. We can't
3094 * reuse anything from the tree log root because
3095 * it has tiny sub-transactions.
3096 */
3097 if (btrfs_buffer_uptodate(buf, 0) &&
3098 btrfs_try_tree_lock(buf)) {
3099 u64 header_owner = btrfs_header_owner(buf);
3100 u64 header_transid = btrfs_header_generation(buf);
3101 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
3102 header_transid == trans->transid &&
3103 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
3104 *must_clean = buf;
3105 return 1;
3106 }
3107 btrfs_tree_unlock(buf);
3108 }
3109 free_extent_buffer(buf);
3110 pinit:
3111 btrfs_set_path_blocking(path);
3112 /* unlocks the pinned mutex */
3113 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
3114
3115 BUG_ON(err < 0);
3116 return 0;
3117 }
3118
3119
3120 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
3121 struct btrfs_root *root,
3122 u64 bytenr, u64 num_bytes, u64 parent,
3123 u64 root_objectid, u64 owner_objectid,
3124 u64 owner_offset, int refs_to_drop,
3125 struct btrfs_delayed_extent_op *extent_op)
3126 {
3127 struct btrfs_key key;
3128 struct btrfs_path *path;
3129 struct btrfs_fs_info *info = root->fs_info;
3130 struct btrfs_root *extent_root = info->extent_root;
3131 struct extent_buffer *leaf;
3132 struct btrfs_extent_item *ei;
3133 struct btrfs_extent_inline_ref *iref;
3134 int ret;
3135 int is_data;
3136 int extent_slot = 0;
3137 int found_extent = 0;
3138 int num_to_del = 1;
3139 u32 item_size;
3140 u64 refs;
3141
3142 path = btrfs_alloc_path();
3143 if (!path)
3144 return -ENOMEM;
3145
3146 path->reada = 1;
3147 path->leave_spinning = 1;
3148
3149 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
3150 BUG_ON(!is_data && refs_to_drop != 1);
3151
3152 ret = lookup_extent_backref(trans, extent_root, path, &iref,
3153 bytenr, num_bytes, parent,
3154 root_objectid, owner_objectid,
3155 owner_offset);
3156 if (ret == 0) {
3157 extent_slot = path->slots[0];
3158 while (extent_slot >= 0) {
3159 btrfs_item_key_to_cpu(path->nodes[0], &key,
3160 extent_slot);
3161 if (key.objectid != bytenr)
3162 break;
3163 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3164 key.offset == num_bytes) {
3165 found_extent = 1;
3166 break;
3167 }
3168 if (path->slots[0] - extent_slot > 5)
3169 break;
3170 extent_slot--;
3171 }
3172 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3173 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
3174 if (found_extent && item_size < sizeof(*ei))
3175 found_extent = 0;
3176 #endif
3177 if (!found_extent) {
3178 BUG_ON(iref);
3179 ret = remove_extent_backref(trans, extent_root, path,
3180 NULL, refs_to_drop,
3181 is_data);
3182 BUG_ON(ret);
3183 btrfs_release_path(extent_root, path);
3184 path->leave_spinning = 1;
3185
3186 key.objectid = bytenr;
3187 key.type = BTRFS_EXTENT_ITEM_KEY;
3188 key.offset = num_bytes;
3189
3190 ret = btrfs_search_slot(trans, extent_root,
3191 &key, path, -1, 1);
3192 if (ret) {
3193 printk(KERN_ERR "umm, got %d back from search"
3194 ", was looking for %llu\n", ret,
3195 (unsigned long long)bytenr);
3196 btrfs_print_leaf(extent_root, path->nodes[0]);
3197 }
3198 BUG_ON(ret);
3199 extent_slot = path->slots[0];
3200 }
3201 } else {
3202 btrfs_print_leaf(extent_root, path->nodes[0]);
3203 WARN_ON(1);
3204 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
3205 "parent %llu root %llu owner %llu offset %llu\n",
3206 (unsigned long long)bytenr,
3207 (unsigned long long)parent,
3208 (unsigned long long)root_objectid,
3209 (unsigned long long)owner_objectid,
3210 (unsigned long long)owner_offset);
3211 }
3212
3213 leaf = path->nodes[0];
3214 item_size = btrfs_item_size_nr(leaf, extent_slot);
3215 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3216 if (item_size < sizeof(*ei)) {
3217 BUG_ON(found_extent || extent_slot != path->slots[0]);
3218 ret = convert_extent_item_v0(trans, extent_root, path,
3219 owner_objectid, 0);
3220 BUG_ON(ret < 0);
3221
3222 btrfs_release_path(extent_root, path);
3223 path->leave_spinning = 1;
3224
3225 key.objectid = bytenr;
3226 key.type = BTRFS_EXTENT_ITEM_KEY;
3227 key.offset = num_bytes;
3228
3229 ret = btrfs_search_slot(trans, extent_root, &key, path,
3230 -1, 1);
3231 if (ret) {
3232 printk(KERN_ERR "umm, got %d back from search"
3233 ", was looking for %llu\n", ret,
3234 (unsigned long long)bytenr);
3235 btrfs_print_leaf(extent_root, path->nodes[0]);
3236 }
3237 BUG_ON(ret);
3238 extent_slot = path->slots[0];
3239 leaf = path->nodes[0];
3240 item_size = btrfs_item_size_nr(leaf, extent_slot);
3241 }
3242 #endif
3243 BUG_ON(item_size < sizeof(*ei));
3244 ei = btrfs_item_ptr(leaf, extent_slot,
3245 struct btrfs_extent_item);
3246 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3247 struct btrfs_tree_block_info *bi;
3248 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
3249 bi = (struct btrfs_tree_block_info *)(ei + 1);
3250 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
3251 }
3252
3253 refs = btrfs_extent_refs(leaf, ei);
3254 BUG_ON(refs < refs_to_drop);
3255 refs -= refs_to_drop;
3256
3257 if (refs > 0) {
3258 if (extent_op)
3259 __run_delayed_extent_op(extent_op, leaf, ei);
3260 /*
3261 * In the case of inline back ref, reference count will
3262 * be updated by remove_extent_backref
3263 */
3264 if (iref) {
3265 BUG_ON(!found_extent);
3266 } else {
3267 btrfs_set_extent_refs(leaf, ei, refs);
3268 btrfs_mark_buffer_dirty(leaf);
3269 }
3270 if (found_extent) {
3271 ret = remove_extent_backref(trans, extent_root, path,
3272 iref, refs_to_drop,
3273 is_data);
3274 BUG_ON(ret);
3275 }
3276 } else {
3277 int mark_free = 0;
3278 struct extent_buffer *must_clean = NULL;
3279
3280 if (found_extent) {
3281 BUG_ON(is_data && refs_to_drop !=
3282 extent_data_ref_count(root, path, iref));
3283 if (iref) {
3284 BUG_ON(path->slots[0] != extent_slot);
3285 } else {
3286 BUG_ON(path->slots[0] != extent_slot + 1);
3287 path->slots[0] = extent_slot;
3288 num_to_del = 2;
3289 }
3290 }
3291
3292 ret = pin_down_bytes(trans, root, path, bytenr,
3293 num_bytes, is_data, &must_clean);
3294 if (ret > 0)
3295 mark_free = 1;
3296 BUG_ON(ret < 0);
3297 /*
3298 * it is going to be very rare for someone to be waiting
3299 * on the block we're freeing. del_items might need to
3300 * schedule, so rather than get fancy, just force it
3301 * to blocking here
3302 */
3303 if (must_clean)
3304 btrfs_set_lock_blocking(must_clean);
3305
3306 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
3307 num_to_del);
3308 BUG_ON(ret);
3309 btrfs_release_path(extent_root, path);
3310
3311 if (must_clean) {
3312 clean_tree_block(NULL, root, must_clean);
3313 btrfs_tree_unlock(must_clean);
3314 free_extent_buffer(must_clean);
3315 }
3316
3317 if (is_data) {
3318 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
3319 BUG_ON(ret);
3320 } else {
3321 invalidate_mapping_pages(info->btree_inode->i_mapping,
3322 bytenr >> PAGE_CACHE_SHIFT,
3323 (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
3324 }
3325
3326 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
3327 mark_free);
3328 BUG_ON(ret);
3329 }
3330 btrfs_free_path(path);
3331 return ret;
3332 }
3333
3334 /*
3335 * when we free an extent, it is possible (and likely) that we free the last
3336 * delayed ref for that extent as well. This searches the delayed ref tree for
3337 * a given extent, and if there are no other delayed refs to be processed, it
3338 * removes it from the tree.
3339 */
3340 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
3341 struct btrfs_root *root, u64 bytenr)
3342 {
3343 struct btrfs_delayed_ref_head *head;
3344 struct btrfs_delayed_ref_root *delayed_refs;
3345 struct btrfs_delayed_ref_node *ref;
3346 struct rb_node *node;
3347 int ret;
3348
3349 delayed_refs = &trans->transaction->delayed_refs;
3350 spin_lock(&delayed_refs->lock);
3351 head = btrfs_find_delayed_ref_head(trans, bytenr);
3352 if (!head)
3353 goto out;
3354
3355 node = rb_prev(&head->node.rb_node);
3356 if (!node)
3357 goto out;
3358
3359 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3360
3361 /* there are still entries for this ref, we can't drop it */
3362 if (ref->bytenr == bytenr)
3363 goto out;
3364
3365 if (head->extent_op) {
3366 if (!head->must_insert_reserved)
3367 goto out;
3368 kfree(head->extent_op);
3369 head->extent_op = NULL;
3370 }
3371
3372 /*
3373 * waiting for the lock here would deadlock. If someone else has it
3374 * locked they are already in the process of dropping it anyway
3375 */
3376 if (!mutex_trylock(&head->mutex))
3377 goto out;
3378
3379 /*
3380 * at this point we have a head with no other entries. Go
3381 * ahead and process it.
3382 */
3383 head->node.in_tree = 0;
3384 rb_erase(&head->node.rb_node, &delayed_refs->root);
3385
3386 delayed_refs->num_entries--;
3387
3388 /*
3389 * we don't take a ref on the node because we're removing it from the
3390 * tree, so we just steal the ref the tree was holding.
3391 */
3392 delayed_refs->num_heads--;
3393 if (list_empty(&head->cluster))
3394 delayed_refs->num_heads_ready--;
3395
3396 list_del_init(&head->cluster);
3397 spin_unlock(&delayed_refs->lock);
3398
3399 ret = run_one_delayed_ref(trans, root->fs_info->tree_root,
3400 &head->node, head->extent_op,
3401 head->must_insert_reserved);
3402 BUG_ON(ret);
3403 btrfs_put_delayed_ref(&head->node);
3404 return 0;
3405 out:
3406 spin_unlock(&delayed_refs->lock);
3407 return 0;
3408 }
3409
3410 int btrfs_free_extent(struct btrfs_trans_handle *trans,
3411 struct btrfs_root *root,
3412 u64 bytenr, u64 num_bytes, u64 parent,
3413 u64 root_objectid, u64 owner, u64 offset)
3414 {
3415 int ret;
3416
3417 /*
3418 * tree log blocks never actually go into the extent allocation
3419 * tree, just update pinning info and exit early.
3420 */
3421 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
3422 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
3423 /* unlocks the pinned mutex */
3424 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
3425 update_reserved_extents(root, bytenr, num_bytes, 0);
3426 ret = 0;
3427 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
3428 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
3429 parent, root_objectid, (int)owner,
3430 BTRFS_DROP_DELAYED_REF, NULL);
3431 BUG_ON(ret);
3432 ret = check_ref_cleanup(trans, root, bytenr);
3433 BUG_ON(ret);
3434 } else {
3435 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
3436 parent, root_objectid, owner,
3437 offset, BTRFS_DROP_DELAYED_REF, NULL);
3438 BUG_ON(ret);
3439 }
3440 return ret;
3441 }
3442
3443 static u64 stripe_align(struct btrfs_root *root, u64 val)
3444 {
3445 u64 mask = ((u64)root->stripesize - 1);
3446 u64 ret = (val + mask) & ~mask;
3447 return ret;
3448 }
3449
3450 /*
3451 * walks the btree of allocated extents and find a hole of a given size.
3452 * The key ins is changed to record the hole:
3453 * ins->objectid == block start
3454 * ins->flags = BTRFS_EXTENT_ITEM_KEY
3455 * ins->offset == number of blocks
3456 * Any available blocks before search_start are skipped.
3457 */
3458 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
3459 struct btrfs_root *orig_root,
3460 u64 num_bytes, u64 empty_size,
3461 u64 search_start, u64 search_end,
3462 u64 hint_byte, struct btrfs_key *ins,
3463 u64 exclude_start, u64 exclude_nr,
3464 int data)
3465 {
3466 int ret = 0;
3467 struct btrfs_root *root = orig_root->fs_info->extent_root;
3468 struct btrfs_free_cluster *last_ptr = NULL;
3469 struct btrfs_block_group_cache *block_group = NULL;
3470 int empty_cluster = 2 * 1024 * 1024;
3471 int allowed_chunk_alloc = 0;
3472 struct btrfs_space_info *space_info;
3473 int last_ptr_loop = 0;
3474 int loop = 0;
3475
3476 WARN_ON(num_bytes < root->sectorsize);
3477 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
3478 ins->objectid = 0;
3479 ins->offset = 0;
3480
3481 space_info = __find_space_info(root->fs_info, data);
3482
3483 if (orig_root->ref_cows || empty_size)
3484 allowed_chunk_alloc = 1;
3485
3486 if (data & BTRFS_BLOCK_GROUP_METADATA) {
3487 last_ptr = &root->fs_info->meta_alloc_cluster;
3488 if (!btrfs_test_opt(root, SSD))
3489 empty_cluster = 64 * 1024;
3490 }
3491
3492 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
3493 last_ptr = &root->fs_info->data_alloc_cluster;
3494 }
3495
3496 if (last_ptr) {
3497 spin_lock(&last_ptr->lock);
3498 if (last_ptr->block_group)
3499 hint_byte = last_ptr->window_start;
3500 spin_unlock(&last_ptr->lock);
3501 }
3502
3503 search_start = max(search_start, first_logical_byte(root, 0));
3504 search_start = max(search_start, hint_byte);
3505
3506 if (!last_ptr) {
3507 empty_cluster = 0;
3508 loop = 1;
3509 }
3510
3511 if (search_start == hint_byte) {
3512 block_group = btrfs_lookup_block_group(root->fs_info,
3513 search_start);
3514 if (block_group && block_group_bits(block_group, data)) {
3515 down_read(&space_info->groups_sem);
3516 if (list_empty(&block_group->list) ||
3517 block_group->ro) {
3518 /*
3519 * someone is removing this block group,
3520 * we can't jump into the have_block_group
3521 * target because our list pointers are not
3522 * valid
3523 */
3524 btrfs_put_block_group(block_group);
3525 up_read(&space_info->groups_sem);
3526 } else
3527 goto have_block_group;
3528 } else if (block_group) {
3529 btrfs_put_block_group(block_group);
3530 }
3531 }
3532
3533 search:
3534 down_read(&space_info->groups_sem);
3535 list_for_each_entry(block_group, &space_info->block_groups, list) {
3536 u64 offset;
3537
3538 atomic_inc(&block_group->count);
3539 search_start = block_group->key.objectid;
3540
3541 have_block_group:
3542 if (unlikely(!block_group->cached)) {
3543 mutex_lock(&block_group->cache_mutex);
3544 ret = cache_block_group(root, block_group);
3545 mutex_unlock(&block_group->cache_mutex);
3546 if (ret) {
3547 btrfs_put_block_group(block_group);
3548 break;
3549 }
3550 }
3551
3552 if (unlikely(block_group->ro))
3553 goto loop;
3554
3555 if (last_ptr) {
3556 /*
3557 * the refill lock keeps out other
3558 * people trying to start a new cluster
3559 */
3560 spin_lock(&last_ptr->refill_lock);
3561 if (last_ptr->block_group &&
3562 (last_ptr->block_group->ro ||
3563 !block_group_bits(last_ptr->block_group, data))) {
3564 offset = 0;
3565 goto refill_cluster;
3566 }
3567
3568 offset = btrfs_alloc_from_cluster(block_group, last_ptr,
3569 num_bytes, search_start);
3570 if (offset) {
3571 /* we have a block, we're done */
3572 spin_unlock(&last_ptr->refill_lock);
3573 goto checks;
3574 }
3575
3576 spin_lock(&last_ptr->lock);
3577 /*
3578 * whoops, this cluster doesn't actually point to
3579 * this block group. Get a ref on the block
3580 * group is does point to and try again
3581 */
3582 if (!last_ptr_loop && last_ptr->block_group &&
3583 last_ptr->block_group != block_group) {
3584
3585 btrfs_put_block_group(block_group);
3586 block_group = last_ptr->block_group;
3587 atomic_inc(&block_group->count);
3588 spin_unlock(&last_ptr->lock);
3589 spin_unlock(&last_ptr->refill_lock);
3590
3591 last_ptr_loop = 1;
3592 search_start = block_group->key.objectid;
3593 /*
3594 * we know this block group is properly
3595 * in the list because
3596 * btrfs_remove_block_group, drops the
3597 * cluster before it removes the block
3598 * group from the list
3599 */
3600 goto have_block_group;
3601 }
3602 spin_unlock(&last_ptr->lock);
3603 refill_cluster:
3604 /*
3605 * this cluster didn't work out, free it and
3606 * start over
3607 */
3608 btrfs_return_cluster_to_free_space(NULL, last_ptr);
3609
3610 last_ptr_loop = 0;
3611
3612 /* allocate a cluster in this block group */
3613 ret = btrfs_find_space_cluster(trans, root,
3614 block_group, last_ptr,
3615 offset, num_bytes,
3616 empty_cluster + empty_size);
3617 if (ret == 0) {
3618 /*
3619 * now pull our allocation out of this
3620 * cluster
3621 */
3622 offset = btrfs_alloc_from_cluster(block_group,
3623 last_ptr, num_bytes,
3624 search_start);
3625 if (offset) {
3626 /* we found one, proceed */
3627 spin_unlock(&last_ptr->refill_lock);
3628 goto checks;
3629 }
3630 }
3631 /*
3632 * at this point we either didn't find a cluster
3633 * or we weren't able to allocate a block from our
3634 * cluster. Free the cluster we've been trying
3635 * to use, and go to the next block group
3636 */
3637 if (loop < 2) {
3638 btrfs_return_cluster_to_free_space(NULL,
3639 last_ptr);
3640 spin_unlock(&last_ptr->refill_lock);
3641 goto loop;
3642 }
3643 spin_unlock(&last_ptr->refill_lock);
3644 }
3645
3646 offset = btrfs_find_space_for_alloc(block_group, search_start,
3647 num_bytes, empty_size);
3648 if (!offset)
3649 goto loop;
3650 checks:
3651 search_start = stripe_align(root, offset);
3652 /* move on to the next group */
3653 if (search_start + num_bytes >= search_end) {
3654 btrfs_add_free_space(block_group, offset, num_bytes);
3655 goto loop;
3656 }
3657
3658 /* move on to the next group */
3659 if (search_start + num_bytes >
3660 block_group->key.objectid + block_group->key.offset) {
3661 btrfs_add_free_space(block_group, offset, num_bytes);
3662 goto loop;
3663 }
3664
3665 if (exclude_nr > 0 &&
3666 (search_start + num_bytes > exclude_start &&
3667 search_start < exclude_start + exclude_nr)) {
3668 search_start = exclude_start + exclude_nr;
3669
3670 btrfs_add_free_space(block_group, offset, num_bytes);
3671 /*
3672 * if search_start is still in this block group
3673 * then we just re-search this block group
3674 */
3675 if (search_start >= block_group->key.objectid &&
3676 search_start < (block_group->key.objectid +
3677 block_group->key.offset))
3678 goto have_block_group;
3679 goto loop;
3680 }
3681
3682 ins->objectid = search_start;
3683 ins->offset = num_bytes;
3684
3685 if (offset < search_start)
3686 btrfs_add_free_space(block_group, offset,
3687 search_start - offset);
3688 BUG_ON(offset > search_start);
3689
3690 /* we are all good, lets return */
3691 break;
3692 loop:
3693 btrfs_put_block_group(block_group);
3694 }
3695 up_read(&space_info->groups_sem);
3696
3697 /* loop == 0, try to find a clustered alloc in every block group
3698 * loop == 1, try again after forcing a chunk allocation
3699 * loop == 2, set empty_size and empty_cluster to 0 and try again
3700 */
3701 if (!ins->objectid && loop < 3 &&
3702 (empty_size || empty_cluster || allowed_chunk_alloc)) {
3703 if (loop >= 2) {
3704 empty_size = 0;
3705 empty_cluster = 0;
3706 }
3707
3708 if (allowed_chunk_alloc) {
3709 ret = do_chunk_alloc(trans, root, num_bytes +
3710 2 * 1024 * 1024, data, 1);
3711 allowed_chunk_alloc = 0;
3712 } else {
3713 space_info->force_alloc = 1;
3714 }
3715
3716 if (loop < 3) {
3717 loop++;
3718 goto search;
3719 }
3720 ret = -ENOSPC;
3721 } else if (!ins->objectid) {
3722 ret = -ENOSPC;
3723 }
3724
3725 /* we found what we needed */
3726 if (ins->objectid) {
3727 if (!(data & BTRFS_BLOCK_GROUP_DATA))
3728 trans->block_group = block_group->key.objectid;
3729
3730 btrfs_put_block_group(block_group);
3731 ret = 0;
3732 }
3733
3734 return ret;
3735 }
3736
3737 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
3738 {
3739 struct btrfs_block_group_cache *cache;
3740
3741 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
3742 (unsigned long long)(info->total_bytes - info->bytes_used -
3743 info->bytes_pinned - info->bytes_reserved),
3744 (info->full) ? "" : "not ");
3745 printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu,"
3746 " may_use=%llu, used=%llu\n",
3747 (unsigned long long)info->total_bytes,
3748 (unsigned long long)info->bytes_pinned,
3749 (unsigned long long)info->bytes_delalloc,
3750 (unsigned long long)info->bytes_may_use,
3751 (unsigned long long)info->bytes_used);
3752
3753 down_read(&info->groups_sem);
3754 list_for_each_entry(cache, &info->block_groups, list) {
3755 spin_lock(&cache->lock);
3756 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
3757 "%llu pinned %llu reserved\n",
3758 (unsigned long long)cache->key.objectid,
3759 (unsigned long long)cache->key.offset,
3760 (unsigned long long)btrfs_block_group_used(&cache->item),
3761 (unsigned long long)cache->pinned,
3762 (unsigned long long)cache->reserved);
3763 btrfs_dump_free_space(cache, bytes);
3764 spin_unlock(&cache->lock);
3765 }
3766 up_read(&info->groups_sem);
3767 }
3768
3769 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
3770 struct btrfs_root *root,
3771 u64 num_bytes, u64 min_alloc_size,
3772 u64 empty_size, u64 hint_byte,
3773 u64 search_end, struct btrfs_key *ins,
3774 u64 data)
3775 {
3776 int ret;
3777 u64 search_start = 0;
3778 struct btrfs_fs_info *info = root->fs_info;
3779
3780 data = btrfs_get_alloc_profile(root, data);
3781 again:
3782 /*
3783 * the only place that sets empty_size is btrfs_realloc_node, which
3784 * is not called recursively on allocations
3785 */
3786 if (empty_size || root->ref_cows) {
3787 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
3788 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3789 2 * 1024 * 1024,
3790 BTRFS_BLOCK_GROUP_METADATA |
3791 (info->metadata_alloc_profile &
3792 info->avail_metadata_alloc_bits), 0);
3793 }
3794 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3795 num_bytes + 2 * 1024 * 1024, data, 0);
3796 }
3797
3798 WARN_ON(num_bytes < root->sectorsize);
3799 ret = find_free_extent(trans, root, num_bytes, empty_size,
3800 search_start, search_end, hint_byte, ins,
3801 trans->alloc_exclude_start,
3802 trans->alloc_exclude_nr, data);
3803
3804 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
3805 num_bytes = num_bytes >> 1;
3806 num_bytes = num_bytes & ~(root->sectorsize - 1);
3807 num_bytes = max(num_bytes, min_alloc_size);
3808 do_chunk_alloc(trans, root->fs_info->extent_root,
3809 num_bytes, data, 1);
3810 goto again;
3811 }
3812 if (ret) {
3813 struct btrfs_space_info *sinfo;
3814
3815 sinfo = __find_space_info(root->fs_info, data);
3816 printk(KERN_ERR "btrfs allocation failed flags %llu, "
3817 "wanted %llu\n", (unsigned long long)data,
3818 (unsigned long long)num_bytes);
3819 dump_space_info(sinfo, num_bytes);
3820 BUG();
3821 }
3822
3823 return ret;
3824 }
3825
3826 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
3827 {
3828 struct btrfs_block_group_cache *cache;
3829 int ret = 0;
3830
3831 cache = btrfs_lookup_block_group(root->fs_info, start);
3832 if (!cache) {
3833 printk(KERN_ERR "Unable to find block group for %llu\n",
3834 (unsigned long long)start);
3835 return -ENOSPC;
3836 }
3837
3838 ret = btrfs_discard_extent(root, start, len);
3839
3840 btrfs_add_free_space(cache, start, len);
3841 btrfs_put_block_group(cache);
3842 update_reserved_extents(root, start, len, 0);
3843
3844 return ret;
3845 }
3846
3847 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
3848 struct btrfs_root *root,
3849 u64 num_bytes, u64 min_alloc_size,
3850 u64 empty_size, u64 hint_byte,
3851 u64 search_end, struct btrfs_key *ins,
3852 u64 data)
3853 {
3854 int ret;
3855 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
3856 empty_size, hint_byte, search_end, ins,
3857 data);
3858 update_reserved_extents(root, ins->objectid, ins->offset, 1);
3859 return ret;
3860 }
3861
3862 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
3863 struct btrfs_root *root,
3864 u64 parent, u64 root_objectid,
3865 u64 flags, u64 owner, u64 offset,
3866 struct btrfs_key *ins, int ref_mod)
3867 {
3868 int ret;
3869 struct btrfs_fs_info *fs_info = root->fs_info;
3870 struct btrfs_extent_item *extent_item;
3871 struct btrfs_extent_inline_ref *iref;
3872 struct btrfs_path *path;
3873 struct extent_buffer *leaf;
3874 int type;
3875 u32 size;
3876
3877 if (parent > 0)
3878 type = BTRFS_SHARED_DATA_REF_KEY;
3879 else
3880 type = BTRFS_EXTENT_DATA_REF_KEY;
3881
3882 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
3883
3884 path = btrfs_alloc_path();
3885 BUG_ON(!path);
3886
3887 path->leave_spinning = 1;
3888 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
3889 ins, size);
3890 BUG_ON(ret);
3891
3892 leaf = path->nodes[0];
3893 extent_item = btrfs_item_ptr(leaf, path->slots[0],
3894 struct btrfs_extent_item);
3895 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
3896 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
3897 btrfs_set_extent_flags(leaf, extent_item,
3898 flags | BTRFS_EXTENT_FLAG_DATA);
3899
3900 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
3901 btrfs_set_extent_inline_ref_type(leaf, iref, type);
3902 if (parent > 0) {
3903 struct btrfs_shared_data_ref *ref;
3904 ref = (struct btrfs_shared_data_ref *)(iref + 1);
3905 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
3906 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
3907 } else {
3908 struct btrfs_extent_data_ref *ref;
3909 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
3910 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
3911 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
3912 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
3913 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
3914 }
3915
3916 btrfs_mark_buffer_dirty(path->nodes[0]);
3917 btrfs_free_path(path);
3918
3919 ret = update_block_group(trans, root, ins->objectid, ins->offset,
3920 1, 0);
3921 if (ret) {
3922 printk(KERN_ERR "btrfs update block group failed for %llu "
3923 "%llu\n", (unsigned long long)ins->objectid,
3924 (unsigned long long)ins->offset);
3925 BUG();
3926 }
3927 return ret;
3928 }
3929
3930 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
3931 struct btrfs_root *root,
3932 u64 parent, u64 root_objectid,
3933 u64 flags, struct btrfs_disk_key *key,
3934 int level, struct btrfs_key *ins)
3935 {
3936 int ret;
3937 struct btrfs_fs_info *fs_info = root->fs_info;
3938 struct btrfs_extent_item *extent_item;
3939 struct btrfs_tree_block_info *block_info;
3940 struct btrfs_extent_inline_ref *iref;
3941 struct btrfs_path *path;
3942 struct extent_buffer *leaf;
3943 u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
3944
3945 path = btrfs_alloc_path();
3946 BUG_ON(!path);
3947
3948 path->leave_spinning = 1;
3949 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
3950 ins, size);
3951 BUG_ON(ret);
3952
3953 leaf = path->nodes[0];
3954 extent_item = btrfs_item_ptr(leaf, path->slots[0],
3955 struct btrfs_extent_item);
3956 btrfs_set_extent_refs(leaf, extent_item, 1);
3957 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
3958 btrfs_set_extent_flags(leaf, extent_item,
3959 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
3960 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
3961
3962 btrfs_set_tree_block_key(leaf, block_info, key);
3963 btrfs_set_tree_block_level(leaf, block_info, level);
3964
3965 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
3966 if (parent > 0) {
3967 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
3968 btrfs_set_extent_inline_ref_type(leaf, iref,
3969 BTRFS_SHARED_BLOCK_REF_KEY);
3970 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
3971 } else {
3972 btrfs_set_extent_inline_ref_type(leaf, iref,
3973 BTRFS_TREE_BLOCK_REF_KEY);
3974 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
3975 }
3976
3977 btrfs_mark_buffer_dirty(leaf);
3978 btrfs_free_path(path);
3979
3980 ret = update_block_group(trans, root, ins->objectid, ins->offset,
3981 1, 0);
3982 if (ret) {
3983 printk(KERN_ERR "btrfs update block group failed for %llu "
3984 "%llu\n", (unsigned long long)ins->objectid,
3985 (unsigned long long)ins->offset);
3986 BUG();
3987 }
3988 return ret;
3989 }
3990
3991 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
3992 struct btrfs_root *root,
3993 u64 root_objectid, u64 owner,
3994 u64 offset, struct btrfs_key *ins)
3995 {
3996 int ret;
3997
3998 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
3999
4000 ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
4001 0, root_objectid, owner, offset,
4002 BTRFS_ADD_DELAYED_EXTENT, NULL);
4003 return ret;
4004 }
4005
4006 /*
4007 * this is used by the tree logging recovery code. It records that
4008 * an extent has been allocated and makes sure to clear the free
4009 * space cache bits as well
4010 */
4011 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
4012 struct btrfs_root *root,
4013 u64 root_objectid, u64 owner, u64 offset,
4014 struct btrfs_key *ins)
4015 {
4016 int ret;
4017 struct btrfs_block_group_cache *block_group;
4018
4019 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
4020 mutex_lock(&block_group->cache_mutex);
4021 cache_block_group(root, block_group);
4022 mutex_unlock(&block_group->cache_mutex);
4023
4024 ret = btrfs_remove_free_space(block_group, ins->objectid,
4025 ins->offset);
4026 BUG_ON(ret);
4027 btrfs_put_block_group(block_group);
4028 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
4029 0, owner, offset, ins, 1);
4030 return ret;
4031 }
4032
4033 /*
4034 * finds a free extent and does all the dirty work required for allocation
4035 * returns the key for the extent through ins, and a tree buffer for
4036 * the first block of the extent through buf.
4037 *
4038 * returns 0 if everything worked, non-zero otherwise.
4039 */
4040 static int alloc_tree_block(struct btrfs_trans_handle *trans,
4041 struct btrfs_root *root,
4042 u64 num_bytes, u64 parent, u64 root_objectid,
4043 struct btrfs_disk_key *key, int level,
4044 u64 empty_size, u64 hint_byte, u64 search_end,
4045 struct btrfs_key *ins)
4046 {
4047 int ret;
4048 u64 flags = 0;
4049
4050 ret = __btrfs_reserve_extent(trans, root, num_bytes, num_bytes,
4051 empty_size, hint_byte, search_end,
4052 ins, 0);
4053 BUG_ON(ret);
4054
4055 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
4056 if (parent == 0)
4057 parent = ins->objectid;
4058 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
4059 } else
4060 BUG_ON(parent > 0);
4061
4062 update_reserved_extents(root, ins->objectid, ins->offset, 1);
4063 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
4064 struct btrfs_delayed_extent_op *extent_op;
4065 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
4066 BUG_ON(!extent_op);
4067 if (key)
4068 memcpy(&extent_op->key, key, sizeof(extent_op->key));
4069 else
4070 memset(&extent_op->key, 0, sizeof(extent_op->key));
4071 extent_op->flags_to_set = flags;
4072 extent_op->update_key = 1;
4073 extent_op->update_flags = 1;
4074 extent_op->is_data = 0;
4075
4076 ret = btrfs_add_delayed_tree_ref(trans, ins->objectid,
4077 ins->offset, parent, root_objectid,
4078 level, BTRFS_ADD_DELAYED_EXTENT,
4079 extent_op);
4080 BUG_ON(ret);
4081 }
4082 return ret;
4083 }
4084
4085 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
4086 struct btrfs_root *root,
4087 u64 bytenr, u32 blocksize,
4088 int level)
4089 {
4090 struct extent_buffer *buf;
4091
4092 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
4093 if (!buf)
4094 return ERR_PTR(-ENOMEM);
4095 btrfs_set_header_generation(buf, trans->transid);
4096 btrfs_set_buffer_lockdep_class(buf, level);
4097 btrfs_tree_lock(buf);
4098 clean_tree_block(trans, root, buf);
4099
4100 btrfs_set_lock_blocking(buf);
4101 btrfs_set_buffer_uptodate(buf);
4102
4103 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
4104 set_extent_dirty(&root->dirty_log_pages, buf->start,
4105 buf->start + buf->len - 1, GFP_NOFS);
4106 } else {
4107 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
4108 buf->start + buf->len - 1, GFP_NOFS);
4109 }
4110 trans->blocks_used++;
4111 /* this returns a buffer locked for blocking */
4112 return buf;
4113 }
4114
4115 /*
4116 * helper function to allocate a block for a given tree
4117 * returns the tree buffer or NULL.
4118 */
4119 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
4120 struct btrfs_root *root, u32 blocksize,
4121 u64 parent, u64 root_objectid,
4122 struct btrfs_disk_key *key, int level,
4123 u64 hint, u64 empty_size)
4124 {
4125 struct btrfs_key ins;
4126 int ret;
4127 struct extent_buffer *buf;
4128
4129 ret = alloc_tree_block(trans, root, blocksize, parent, root_objectid,
4130 key, level, empty_size, hint, (u64)-1, &ins);
4131 if (ret) {
4132 BUG_ON(ret > 0);
4133 return ERR_PTR(ret);
4134 }
4135
4136 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
4137 blocksize, level);
4138 return buf;
4139 }
4140
4141 #if 0
4142 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
4143 struct btrfs_root *root, struct extent_buffer *leaf)
4144 {
4145 u64 disk_bytenr;
4146 u64 num_bytes;
4147 struct btrfs_key key;
4148 struct btrfs_file_extent_item *fi;
4149 u32 nritems;
4150 int i;
4151 int ret;
4152
4153 BUG_ON(!btrfs_is_leaf(leaf));
4154 nritems = btrfs_header_nritems(leaf);
4155
4156 for (i = 0; i < nritems; i++) {
4157 cond_resched();
4158 btrfs_item_key_to_cpu(leaf, &key, i);
4159
4160 /* only extents have references, skip everything else */
4161 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
4162 continue;
4163
4164 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4165
4166 /* inline extents live in the btree, they don't have refs */
4167 if (btrfs_file_extent_type(leaf, fi) ==
4168 BTRFS_FILE_EXTENT_INLINE)
4169 continue;
4170
4171 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
4172
4173 /* holes don't have refs */
4174 if (disk_bytenr == 0)
4175 continue;
4176
4177 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
4178 ret = btrfs_free_extent(trans, root, disk_bytenr, num_bytes,
4179 leaf->start, 0, key.objectid, 0);
4180 BUG_ON(ret);
4181 }
4182 return 0;
4183 }
4184
4185 static noinline int cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
4186 struct btrfs_root *root,
4187 struct btrfs_leaf_ref *ref)
4188 {
4189 int i;
4190 int ret;
4191 struct btrfs_extent_info *info;
4192 struct refsort *sorted;
4193
4194 if (ref->nritems == 0)
4195 return 0;
4196
4197 sorted = kmalloc(sizeof(*sorted) * ref->nritems, GFP_NOFS);
4198 for (i = 0; i < ref->nritems; i++) {
4199 sorted[i].bytenr = ref->extents[i].bytenr;
4200 sorted[i].slot = i;
4201 }
4202 sort(sorted, ref->nritems, sizeof(struct refsort), refsort_cmp, NULL);
4203
4204 /*
4205 * the items in the ref were sorted when the ref was inserted
4206 * into the ref cache, so this is already in order
4207 */
4208 for (i = 0; i < ref->nritems; i++) {
4209 info = ref->extents + sorted[i].slot;
4210 ret = btrfs_free_extent(trans, root, info->bytenr,
4211 info->num_bytes, ref->bytenr,
4212 ref->owner, ref->generation,
4213 info->objectid, 0);
4214
4215 atomic_inc(&root->fs_info->throttle_gen);
4216 wake_up(&root->fs_info->transaction_throttle);
4217 cond_resched();
4218
4219 BUG_ON(ret);
4220 info++;
4221 }
4222
4223 kfree(sorted);
4224 return 0;
4225 }
4226
4227
4228 static int drop_snap_lookup_refcount(struct btrfs_trans_handle *trans,
4229 struct btrfs_root *root, u64 start,
4230 u64 len, u32 *refs)
4231 {
4232 int ret;
4233
4234 ret = btrfs_lookup_extent_refs(trans, root, start, len, refs);
4235 BUG_ON(ret);
4236
4237 #if 0 /* some debugging code in case we see problems here */
4238 /* if the refs count is one, it won't get increased again. But
4239 * if the ref count is > 1, someone may be decreasing it at
4240 * the same time we are.
4241 */
4242 if (*refs != 1) {
4243 struct extent_buffer *eb = NULL;
4244 eb = btrfs_find_create_tree_block(root, start, len);
4245 if (eb)
4246 btrfs_tree_lock(eb);
4247
4248 mutex_lock(&root->fs_info->alloc_mutex);
4249 ret = lookup_extent_ref(NULL, root, start, len, refs);
4250 BUG_ON(ret);
4251 mutex_unlock(&root->fs_info->alloc_mutex);
4252
4253 if (eb) {
4254 btrfs_tree_unlock(eb);
4255 free_extent_buffer(eb);
4256 }
4257 if (*refs == 1) {
4258 printk(KERN_ERR "btrfs block %llu went down to one "
4259 "during drop_snap\n", (unsigned long long)start);
4260 }
4261
4262 }
4263 #endif
4264
4265 cond_resched();
4266 return ret;
4267 }
4268
4269
4270 /*
4271 * this is used while deleting old snapshots, and it drops the refs
4272 * on a whole subtree starting from a level 1 node.
4273 *
4274 * The idea is to sort all the leaf pointers, and then drop the
4275 * ref on all the leaves in order. Most of the time the leaves
4276 * will have ref cache entries, so no leaf IOs will be required to
4277 * find the extents they have references on.
4278 *
4279 * For each leaf, any references it has are also dropped in order
4280 *
4281 * This ends up dropping the references in something close to optimal
4282 * order for reading and modifying the extent allocation tree.
4283 */
4284 static noinline int drop_level_one_refs(struct btrfs_trans_handle *trans,
4285 struct btrfs_root *root,
4286 struct btrfs_path *path)
4287 {
4288 u64 bytenr;
4289 u64 root_owner;
4290 u64 root_gen;
4291 struct extent_buffer *eb = path->nodes[1];
4292 struct extent_buffer *leaf;
4293 struct btrfs_leaf_ref *ref;
4294 struct refsort *sorted = NULL;
4295 int nritems = btrfs_header_nritems(eb);
4296 int ret;
4297 int i;
4298 int refi = 0;
4299 int slot = path->slots[1];
4300 u32 blocksize = btrfs_level_size(root, 0);
4301 u32 refs;
4302
4303 if (nritems == 0)
4304 goto out;
4305
4306 root_owner = btrfs_header_owner(eb);
4307 root_gen = btrfs_header_generation(eb);
4308 sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
4309
4310 /*
4311 * step one, sort all the leaf pointers so we don't scribble
4312 * randomly into the extent allocation tree
4313 */
4314 for (i = slot; i < nritems; i++) {
4315 sorted[refi].bytenr = btrfs_node_blockptr(eb, i);
4316 sorted[refi].slot = i;
4317 refi++;
4318 }
4319
4320 /*
4321 * nritems won't be zero, but if we're picking up drop_snapshot
4322 * after a crash, slot might be > 0, so double check things
4323 * just in case.
4324 */
4325 if (refi == 0)
4326 goto out;
4327
4328 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
4329
4330 /*
4331 * the first loop frees everything the leaves point to
4332 */
4333 for (i = 0; i < refi; i++) {
4334 u64 ptr_gen;
4335
4336 bytenr = sorted[i].bytenr;
4337
4338 /*
4339 * check the reference count on this leaf. If it is > 1
4340 * we just decrement it below and don't update any
4341 * of the refs the leaf points to.
4342 */
4343 ret = drop_snap_lookup_refcount(trans, root, bytenr,
4344 blocksize, &refs);
4345 BUG_ON(ret);
4346 if (refs != 1)
4347 continue;
4348
4349 ptr_gen = btrfs_node_ptr_generation(eb, sorted[i].slot);
4350
4351 /*
4352 * the leaf only had one reference, which means the
4353 * only thing pointing to this leaf is the snapshot
4354 * we're deleting. It isn't possible for the reference
4355 * count to increase again later
4356 *
4357 * The reference cache is checked for the leaf,
4358 * and if found we'll be able to drop any refs held by
4359 * the leaf without needing to read it in.
4360 */
4361 ref = btrfs_lookup_leaf_ref(root, bytenr);
4362 if (ref && ref->generation != ptr_gen) {
4363 btrfs_free_leaf_ref(root, ref);
4364 ref = NULL;
4365 }
4366 if (ref) {
4367 ret = cache_drop_leaf_ref(trans, root, ref);
4368 BUG_ON(ret);
4369 btrfs_remove_leaf_ref(root, ref);
4370 btrfs_free_leaf_ref(root, ref);
4371 } else {
4372 /*
4373 * the leaf wasn't in the reference cache, so
4374 * we have to read it.
4375 */
4376 leaf = read_tree_block(root, bytenr, blocksize,
4377 ptr_gen);
4378 ret = btrfs_drop_leaf_ref(trans, root, leaf);
4379 BUG_ON(ret);
4380 free_extent_buffer(leaf);
4381 }
4382 atomic_inc(&root->fs_info->throttle_gen);
4383 wake_up(&root->fs_info->transaction_throttle);
4384 cond_resched();
4385 }
4386
4387 /*
4388 * run through the loop again to free the refs on the leaves.
4389 * This is faster than doing it in the loop above because
4390 * the leaves are likely to be clustered together. We end up
4391 * working in nice chunks on the extent allocation tree.
4392 */
4393 for (i = 0; i < refi; i++) {
4394 bytenr = sorted[i].bytenr;
4395 ret = btrfs_free_extent(trans, root, bytenr,
4396 blocksize, eb->start,
4397 root_owner, root_gen, 0, 1);
4398 BUG_ON(ret);
4399
4400 atomic_inc(&root->fs_info->throttle_gen);
4401 wake_up(&root->fs_info->transaction_throttle);
4402 cond_resched();
4403 }
4404 out:
4405 kfree(sorted);
4406
4407 /*
4408 * update the path to show we've processed the entire level 1
4409 * node. This will get saved into the root's drop_snapshot_progress
4410 * field so these drops are not repeated again if this transaction
4411 * commits.
4412 */
4413 path->slots[1] = nritems;
4414 return 0;
4415 }
4416
4417 /*
4418 * helper function for drop_snapshot, this walks down the tree dropping ref
4419 * counts as it goes.
4420 */
4421 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
4422 struct btrfs_root *root,
4423 struct btrfs_path *path, int *level)
4424 {
4425 u64 root_owner;
4426 u64 root_gen;
4427 u64 bytenr;
4428 u64 ptr_gen;
4429 struct extent_buffer *next;
4430 struct extent_buffer *cur;
4431 struct extent_buffer *parent;
4432 u32 blocksize;
4433 int ret;
4434 u32 refs;
4435
4436 WARN_ON(*level < 0);
4437 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4438 ret = drop_snap_lookup_refcount(trans, root, path->nodes[*level]->start,
4439 path->nodes[*level]->len, &refs);
4440 BUG_ON(ret);
4441 if (refs > 1)
4442 goto out;
4443
4444 /*
4445 * walk down to the last node level and free all the leaves
4446 */
4447 while (*level >= 0) {
4448 WARN_ON(*level < 0);
4449 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4450 cur = path->nodes[*level];
4451
4452 if (btrfs_header_level(cur) != *level)
4453 WARN_ON(1);
4454
4455 if (path->slots[*level] >=
4456 btrfs_header_nritems(cur))
4457 break;
4458
4459 /* the new code goes down to level 1 and does all the
4460 * leaves pointed to that node in bulk. So, this check
4461 * for level 0 will always be false.
4462 *
4463 * But, the disk format allows the drop_snapshot_progress
4464 * field in the root to leave things in a state where
4465 * a leaf will need cleaning up here. If someone crashes
4466 * with the old code and then boots with the new code,
4467 * we might find a leaf here.
4468 */
4469 if (*level == 0) {
4470 ret = btrfs_drop_leaf_ref(trans, root, cur);
4471 BUG_ON(ret);
4472 break;
4473 }
4474
4475 /*
4476 * once we get to level one, process the whole node
4477 * at once, including everything below it.
4478 */
4479 if (*level == 1) {
4480 ret = drop_level_one_refs(trans, root, path);
4481 BUG_ON(ret);
4482 break;
4483 }
4484
4485 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
4486 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
4487 blocksize = btrfs_level_size(root, *level - 1);
4488
4489 ret = drop_snap_lookup_refcount(trans, root, bytenr,
4490 blocksize, &refs);
4491 BUG_ON(ret);
4492
4493 /*
4494 * if there is more than one reference, we don't need
4495 * to read that node to drop any references it has. We
4496 * just drop the ref we hold on that node and move on to the
4497 * next slot in this level.
4498 */
4499 if (refs != 1) {
4500 parent = path->nodes[*level];
4501 root_owner = btrfs_header_owner(parent);
4502 root_gen = btrfs_header_generation(parent);
4503 path->slots[*level]++;
4504
4505 ret = btrfs_free_extent(trans, root, bytenr,
4506 blocksize, parent->start,
4507 root_owner, root_gen,
4508 *level - 1, 1);
4509 BUG_ON(ret);
4510
4511 atomic_inc(&root->fs_info->throttle_gen);
4512 wake_up(&root->fs_info->transaction_throttle);
4513 cond_resched();
4514
4515 continue;
4516 }
4517
4518 /*
4519 * we need to keep freeing things in the next level down.
4520 * read the block and loop around to process it
4521 */
4522 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
4523 WARN_ON(*level <= 0);
4524 if (path->nodes[*level-1])
4525 free_extent_buffer(path->nodes[*level-1]);
4526 path->nodes[*level-1] = next;
4527 *level = btrfs_header_level(next);
4528 path->slots[*level] = 0;
4529 cond_resched();
4530 }
4531 out:
4532 WARN_ON(*level < 0);
4533 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4534
4535 if (path->nodes[*level] == root->node) {
4536 parent = path->nodes[*level];
4537 bytenr = path->nodes[*level]->start;
4538 } else {
4539 parent = path->nodes[*level + 1];
4540 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
4541 }
4542
4543 blocksize = btrfs_level_size(root, *level);
4544 root_owner = btrfs_header_owner(parent);
4545 root_gen = btrfs_header_generation(parent);
4546
4547 /*
4548 * cleanup and free the reference on the last node
4549 * we processed
4550 */
4551 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
4552 parent->start, root_owner, root_gen,
4553 *level, 1);
4554 free_extent_buffer(path->nodes[*level]);
4555 path->nodes[*level] = NULL;
4556
4557 *level += 1;
4558 BUG_ON(ret);
4559
4560 cond_resched();
4561 return 0;
4562 }
4563 #endif
4564
4565 struct walk_control {
4566 u64 refs[BTRFS_MAX_LEVEL];
4567 u64 flags[BTRFS_MAX_LEVEL];
4568 struct btrfs_key update_progress;
4569 int stage;
4570 int level;
4571 int shared_level;
4572 int update_ref;
4573 int keep_locks;
4574 };
4575
4576 #define DROP_REFERENCE 1
4577 #define UPDATE_BACKREF 2
4578
4579 /*
4580 * hepler to process tree block while walking down the tree.
4581 *
4582 * when wc->stage == DROP_REFERENCE, this function checks
4583 * reference count of the block. if the block is shared and
4584 * we need update back refs for the subtree rooted at the
4585 * block, this function changes wc->stage to UPDATE_BACKREF
4586 *
4587 * when wc->stage == UPDATE_BACKREF, this function updates
4588 * back refs for pointers in the block.
4589 *
4590 * NOTE: return value 1 means we should stop walking down.
4591 */
4592 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
4593 struct btrfs_root *root,
4594 struct btrfs_path *path,
4595 struct walk_control *wc)
4596 {
4597 int level = wc->level;
4598 struct extent_buffer *eb = path->nodes[level];
4599 struct btrfs_key key;
4600 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
4601 int ret;
4602
4603 if (wc->stage == UPDATE_BACKREF &&
4604 btrfs_header_owner(eb) != root->root_key.objectid)
4605 return 1;
4606
4607 /*
4608 * when reference count of tree block is 1, it won't increase
4609 * again. once full backref flag is set, we never clear it.
4610 */
4611 if ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
4612 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag))) {
4613 BUG_ON(!path->locks[level]);
4614 ret = btrfs_lookup_extent_info(trans, root,
4615 eb->start, eb->len,
4616 &wc->refs[level],
4617 &wc->flags[level]);
4618 BUG_ON(ret);
4619 BUG_ON(wc->refs[level] == 0);
4620 }
4621
4622 if (wc->stage == DROP_REFERENCE &&
4623 wc->update_ref && wc->refs[level] > 1) {
4624 BUG_ON(eb == root->node);
4625 BUG_ON(path->slots[level] > 0);
4626 if (level == 0)
4627 btrfs_item_key_to_cpu(eb, &key, path->slots[level]);
4628 else
4629 btrfs_node_key_to_cpu(eb, &key, path->slots[level]);
4630 if (btrfs_header_owner(eb) == root->root_key.objectid &&
4631 btrfs_comp_cpu_keys(&key, &wc->update_progress) >= 0) {
4632 wc->stage = UPDATE_BACKREF;
4633 wc->shared_level = level;
4634 }
4635 }
4636
4637 if (wc->stage == DROP_REFERENCE) {
4638 if (wc->refs[level] > 1)
4639 return 1;
4640
4641 if (path->locks[level] && !wc->keep_locks) {
4642 btrfs_tree_unlock(eb);
4643 path->locks[level] = 0;
4644 }
4645 return 0;
4646 }
4647
4648 /* wc->stage == UPDATE_BACKREF */
4649 if (!(wc->flags[level] & flag)) {
4650 BUG_ON(!path->locks[level]);
4651 ret = btrfs_inc_ref(trans, root, eb, 1);
4652 BUG_ON(ret);
4653 ret = btrfs_dec_ref(trans, root, eb, 0);
4654 BUG_ON(ret);
4655 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
4656 eb->len, flag, 0);
4657 BUG_ON(ret);
4658 wc->flags[level] |= flag;
4659 }
4660
4661 /*
4662 * the block is shared by multiple trees, so it's not good to
4663 * keep the tree lock
4664 */
4665 if (path->locks[level] && level > 0) {
4666 btrfs_tree_unlock(eb);
4667 path->locks[level] = 0;
4668 }
4669 return 0;
4670 }
4671
4672 /*
4673 * hepler to process tree block while walking up the tree.
4674 *
4675 * when wc->stage == DROP_REFERENCE, this function drops
4676 * reference count on the block.
4677 *
4678 * when wc->stage == UPDATE_BACKREF, this function changes
4679 * wc->stage back to DROP_REFERENCE if we changed wc->stage
4680 * to UPDATE_BACKREF previously while processing the block.
4681 *
4682 * NOTE: return value 1 means we should stop walking up.
4683 */
4684 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
4685 struct btrfs_root *root,
4686 struct btrfs_path *path,
4687 struct walk_control *wc)
4688 {
4689 int ret = 0;
4690 int level = wc->level;
4691 struct extent_buffer *eb = path->nodes[level];
4692 u64 parent = 0;
4693
4694 if (wc->stage == UPDATE_BACKREF) {
4695 BUG_ON(wc->shared_level < level);
4696 if (level < wc->shared_level)
4697 goto out;
4698
4699 BUG_ON(wc->refs[level] <= 1);
4700 ret = find_next_key(path, level + 1, &wc->update_progress);
4701 if (ret > 0)
4702 wc->update_ref = 0;
4703
4704 wc->stage = DROP_REFERENCE;
4705 wc->shared_level = -1;
4706 path->slots[level] = 0;
4707
4708 /*
4709 * check reference count again if the block isn't locked.
4710 * we should start walking down the tree again if reference
4711 * count is one.
4712 */
4713 if (!path->locks[level]) {
4714 BUG_ON(level == 0);
4715 btrfs_tree_lock(eb);
4716 btrfs_set_lock_blocking(eb);
4717 path->locks[level] = 1;
4718
4719 ret = btrfs_lookup_extent_info(trans, root,
4720 eb->start, eb->len,
4721 &wc->refs[level],
4722 &wc->flags[level]);
4723 BUG_ON(ret);
4724 BUG_ON(wc->refs[level] == 0);
4725 if (wc->refs[level] == 1) {
4726 btrfs_tree_unlock(eb);
4727 path->locks[level] = 0;
4728 return 1;
4729 }
4730 } else {
4731 BUG_ON(level != 0);
4732 }
4733 }
4734
4735 /* wc->stage == DROP_REFERENCE */
4736 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
4737
4738 if (wc->refs[level] == 1) {
4739 if (level == 0) {
4740 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4741 ret = btrfs_dec_ref(trans, root, eb, 1);
4742 else
4743 ret = btrfs_dec_ref(trans, root, eb, 0);
4744 BUG_ON(ret);
4745 }
4746 /* make block locked assertion in clean_tree_block happy */
4747 if (!path->locks[level] &&
4748 btrfs_header_generation(eb) == trans->transid) {
4749 btrfs_tree_lock(eb);
4750 btrfs_set_lock_blocking(eb);
4751 path->locks[level] = 1;
4752 }
4753 clean_tree_block(trans, root, eb);
4754 }
4755
4756 if (eb == root->node) {
4757 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4758 parent = eb->start;
4759 else
4760 BUG_ON(root->root_key.objectid !=
4761 btrfs_header_owner(eb));
4762 } else {
4763 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4764 parent = path->nodes[level + 1]->start;
4765 else
4766 BUG_ON(root->root_key.objectid !=
4767 btrfs_header_owner(path->nodes[level + 1]));
4768 }
4769
4770 ret = btrfs_free_extent(trans, root, eb->start, eb->len, parent,
4771 root->root_key.objectid, level, 0);
4772 BUG_ON(ret);
4773 out:
4774 wc->refs[level] = 0;
4775 wc->flags[level] = 0;
4776 return ret;
4777 }
4778
4779 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
4780 struct btrfs_root *root,
4781 struct btrfs_path *path,
4782 struct walk_control *wc)
4783 {
4784 struct extent_buffer *next;
4785 struct extent_buffer *cur;
4786 u64 bytenr;
4787 u64 ptr_gen;
4788 u32 blocksize;
4789 int level = wc->level;
4790 int ret;
4791
4792 while (level >= 0) {
4793 cur = path->nodes[level];
4794 BUG_ON(path->slots[level] >= btrfs_header_nritems(cur));
4795
4796 ret = walk_down_proc(trans, root, path, wc);
4797 if (ret > 0)
4798 break;
4799
4800 if (level == 0)
4801 break;
4802
4803 bytenr = btrfs_node_blockptr(cur, path->slots[level]);
4804 blocksize = btrfs_level_size(root, level - 1);
4805 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[level]);
4806
4807 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
4808 btrfs_tree_lock(next);
4809 btrfs_set_lock_blocking(next);
4810
4811 level--;
4812 BUG_ON(level != btrfs_header_level(next));
4813 path->nodes[level] = next;
4814 path->slots[level] = 0;
4815 path->locks[level] = 1;
4816 wc->level = level;
4817 }
4818 return 0;
4819 }
4820
4821 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
4822 struct btrfs_root *root,
4823 struct btrfs_path *path,
4824 struct walk_control *wc, int max_level)
4825 {
4826 int level = wc->level;
4827 int ret;
4828
4829 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
4830 while (level < max_level && path->nodes[level]) {
4831 wc->level = level;
4832 if (path->slots[level] + 1 <
4833 btrfs_header_nritems(path->nodes[level])) {
4834 path->slots[level]++;
4835 return 0;
4836 } else {
4837 ret = walk_up_proc(trans, root, path, wc);
4838 if (ret > 0)
4839 return 0;
4840
4841 if (path->locks[level]) {
4842 btrfs_tree_unlock(path->nodes[level]);
4843 path->locks[level] = 0;
4844 }
4845 free_extent_buffer(path->nodes[level]);
4846 path->nodes[level] = NULL;
4847 level++;
4848 }
4849 }
4850 return 1;
4851 }
4852
4853 /*
4854 * drop a subvolume tree.
4855 *
4856 * this function traverses the tree freeing any blocks that only
4857 * referenced by the tree.
4858 *
4859 * when a shared tree block is found. this function decreases its
4860 * reference count by one. if update_ref is true, this function
4861 * also make sure backrefs for the shared block and all lower level
4862 * blocks are properly updated.
4863 */
4864 int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref)
4865 {
4866 struct btrfs_path *path;
4867 struct btrfs_trans_handle *trans;
4868 struct btrfs_root *tree_root = root->fs_info->tree_root;
4869 struct btrfs_root_item *root_item = &root->root_item;
4870 struct walk_control *wc;
4871 struct btrfs_key key;
4872 int err = 0;
4873 int ret;
4874 int level;
4875
4876 path = btrfs_alloc_path();
4877 BUG_ON(!path);
4878
4879 wc = kzalloc(sizeof(*wc), GFP_NOFS);
4880 BUG_ON(!wc);
4881
4882 trans = btrfs_start_transaction(tree_root, 1);
4883
4884 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
4885 level = btrfs_header_level(root->node);
4886 path->nodes[level] = btrfs_lock_root_node(root);
4887 btrfs_set_lock_blocking(path->nodes[level]);
4888 path->slots[level] = 0;
4889 path->locks[level] = 1;
4890 memset(&wc->update_progress, 0,
4891 sizeof(wc->update_progress));
4892 } else {
4893 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
4894 memcpy(&wc->update_progress, &key,
4895 sizeof(wc->update_progress));
4896
4897 level = root_item->drop_level;
4898 BUG_ON(level == 0);
4899 path->lowest_level = level;
4900 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4901 path->lowest_level = 0;
4902 if (ret < 0) {
4903 err = ret;
4904 goto out;
4905 }
4906 btrfs_node_key_to_cpu(path->nodes[level], &key,
4907 path->slots[level]);
4908 WARN_ON(memcmp(&key, &wc->update_progress, sizeof(key)));
4909
4910 /*
4911 * unlock our path, this is safe because only this
4912 * function is allowed to delete this snapshot
4913 */
4914 btrfs_unlock_up_safe(path, 0);
4915
4916 level = btrfs_header_level(root->node);
4917 while (1) {
4918 btrfs_tree_lock(path->nodes[level]);
4919 btrfs_set_lock_blocking(path->nodes[level]);
4920
4921 ret = btrfs_lookup_extent_info(trans, root,
4922 path->nodes[level]->start,
4923 path->nodes[level]->len,
4924 &wc->refs[level],
4925 &wc->flags[level]);
4926 BUG_ON(ret);
4927 BUG_ON(wc->refs[level] == 0);
4928
4929 if (level == root_item->drop_level)
4930 break;
4931
4932 btrfs_tree_unlock(path->nodes[level]);
4933 WARN_ON(wc->refs[level] != 1);
4934 level--;
4935 }
4936 }
4937
4938 wc->level = level;
4939 wc->shared_level = -1;
4940 wc->stage = DROP_REFERENCE;
4941 wc->update_ref = update_ref;
4942 wc->keep_locks = 0;
4943
4944 while (1) {
4945 ret = walk_down_tree(trans, root, path, wc);
4946 if (ret < 0) {
4947 err = ret;
4948 break;
4949 }
4950
4951 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
4952 if (ret < 0) {
4953 err = ret;
4954 break;
4955 }
4956
4957 if (ret > 0) {
4958 BUG_ON(wc->stage != DROP_REFERENCE);
4959 break;
4960 }
4961
4962 if (wc->stage == DROP_REFERENCE) {
4963 level = wc->level;
4964 btrfs_node_key(path->nodes[level],
4965 &root_item->drop_progress,
4966 path->slots[level]);
4967 root_item->drop_level = level;
4968 }
4969
4970 BUG_ON(wc->level == 0);
4971 if (trans->transaction->in_commit ||
4972 trans->transaction->delayed_refs.flushing) {
4973 ret = btrfs_update_root(trans, tree_root,
4974 &root->root_key,
4975 root_item);
4976 BUG_ON(ret);
4977
4978 btrfs_end_transaction(trans, tree_root);
4979 trans = btrfs_start_transaction(tree_root, 1);
4980 } else {
4981 unsigned long update;
4982 update = trans->delayed_ref_updates;
4983 trans->delayed_ref_updates = 0;
4984 if (update)
4985 btrfs_run_delayed_refs(trans, tree_root,
4986 update);
4987 }
4988 }
4989 btrfs_release_path(root, path);
4990 BUG_ON(err);
4991
4992 ret = btrfs_del_root(trans, tree_root, &root->root_key);
4993 BUG_ON(ret);
4994
4995 free_extent_buffer(root->node);
4996 free_extent_buffer(root->commit_root);
4997 kfree(root);
4998 out:
4999 btrfs_end_transaction(trans, tree_root);
5000 kfree(wc);
5001 btrfs_free_path(path);
5002 return err;
5003 }
5004
5005 /*
5006 * drop subtree rooted at tree block 'node'.
5007 *
5008 * NOTE: this function will unlock and release tree block 'node'
5009 */
5010 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
5011 struct btrfs_root *root,
5012 struct extent_buffer *node,
5013 struct extent_buffer *parent)
5014 {
5015 struct btrfs_path *path;
5016 struct walk_control *wc;
5017 int level;
5018 int parent_level;
5019 int ret = 0;
5020 int wret;
5021
5022 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5023
5024 path = btrfs_alloc_path();
5025 BUG_ON(!path);
5026
5027 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5028 BUG_ON(!wc);
5029
5030 btrfs_assert_tree_locked(parent);
5031 parent_level = btrfs_header_level(parent);
5032 extent_buffer_get(parent);
5033 path->nodes[parent_level] = parent;
5034 path->slots[parent_level] = btrfs_header_nritems(parent);
5035
5036 btrfs_assert_tree_locked(node);
5037 level = btrfs_header_level(node);
5038 path->nodes[level] = node;
5039 path->slots[level] = 0;
5040 path->locks[level] = 1;
5041
5042 wc->refs[parent_level] = 1;
5043 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5044 wc->level = level;
5045 wc->shared_level = -1;
5046 wc->stage = DROP_REFERENCE;
5047 wc->update_ref = 0;
5048 wc->keep_locks = 1;
5049
5050 while (1) {
5051 wret = walk_down_tree(trans, root, path, wc);
5052 if (wret < 0) {
5053 ret = wret;
5054 break;
5055 }
5056
5057 wret = walk_up_tree(trans, root, path, wc, parent_level);
5058 if (wret < 0)
5059 ret = wret;
5060 if (wret != 0)
5061 break;
5062 }
5063
5064 kfree(wc);
5065 btrfs_free_path(path);
5066 return ret;
5067 }
5068
5069 #if 0
5070 static unsigned long calc_ra(unsigned long start, unsigned long last,
5071 unsigned long nr)
5072 {
5073 return min(last, start + nr - 1);
5074 }
5075
5076 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
5077 u64 len)
5078 {
5079 u64 page_start;
5080 u64 page_end;
5081 unsigned long first_index;
5082 unsigned long last_index;
5083 unsigned long i;
5084 struct page *page;
5085 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5086 struct file_ra_state *ra;
5087 struct btrfs_ordered_extent *ordered;
5088 unsigned int total_read = 0;
5089 unsigned int total_dirty = 0;
5090 int ret = 0;
5091
5092 ra = kzalloc(sizeof(*ra), GFP_NOFS);
5093
5094 mutex_lock(&inode->i_mutex);
5095 first_index = start >> PAGE_CACHE_SHIFT;
5096 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
5097
5098 /* make sure the dirty trick played by the caller work */
5099 ret = invalidate_inode_pages2_range(inode->i_mapping,
5100 first_index, last_index);
5101 if (ret)
5102 goto out_unlock;
5103
5104 file_ra_state_init(ra, inode->i_mapping);
5105
5106 for (i = first_index ; i <= last_index; i++) {
5107 if (total_read % ra->ra_pages == 0) {
5108 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
5109 calc_ra(i, last_index, ra->ra_pages));
5110 }
5111 total_read++;
5112 again:
5113 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
5114 BUG_ON(1);
5115 page = grab_cache_page(inode->i_mapping, i);
5116 if (!page) {
5117 ret = -ENOMEM;
5118 goto out_unlock;
5119 }
5120 if (!PageUptodate(page)) {
5121 btrfs_readpage(NULL, page);
5122 lock_page(page);
5123 if (!PageUptodate(page)) {
5124 unlock_page(page);
5125 page_cache_release(page);
5126 ret = -EIO;
5127 goto out_unlock;
5128 }
5129 }
5130 wait_on_page_writeback(page);
5131
5132 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
5133 page_end = page_start + PAGE_CACHE_SIZE - 1;
5134 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
5135
5136 ordered = btrfs_lookup_ordered_extent(inode, page_start);
5137 if (ordered) {
5138 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5139 unlock_page(page);
5140 page_cache_release(page);
5141 btrfs_start_ordered_extent(inode, ordered, 1);
5142 btrfs_put_ordered_extent(ordered);
5143 goto again;
5144 }
5145 set_page_extent_mapped(page);
5146
5147 if (i == first_index)
5148 set_extent_bits(io_tree, page_start, page_end,
5149 EXTENT_BOUNDARY, GFP_NOFS);
5150 btrfs_set_extent_delalloc(inode, page_start, page_end);
5151
5152 set_page_dirty(page);
5153 total_dirty++;
5154
5155 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5156 unlock_page(page);
5157 page_cache_release(page);
5158 }
5159
5160 out_unlock:
5161 kfree(ra);
5162 mutex_unlock(&inode->i_mutex);
5163 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
5164 return ret;
5165 }
5166
5167 static noinline int relocate_data_extent(struct inode *reloc_inode,
5168 struct btrfs_key *extent_key,
5169 u64 offset)
5170 {
5171 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5172 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
5173 struct extent_map *em;
5174 u64 start = extent_key->objectid - offset;
5175 u64 end = start + extent_key->offset - 1;
5176
5177 em = alloc_extent_map(GFP_NOFS);
5178 BUG_ON(!em || IS_ERR(em));
5179
5180 em->start = start;
5181 em->len = extent_key->offset;
5182 em->block_len = extent_key->offset;
5183 em->block_start = extent_key->objectid;
5184 em->bdev = root->fs_info->fs_devices->latest_bdev;
5185 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5186
5187 /* setup extent map to cheat btrfs_readpage */
5188 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5189 while (1) {
5190 int ret;
5191 spin_lock(&em_tree->lock);
5192 ret = add_extent_mapping(em_tree, em);
5193 spin_unlock(&em_tree->lock);
5194 if (ret != -EEXIST) {
5195 free_extent_map(em);
5196 break;
5197 }
5198 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
5199 }
5200 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5201
5202 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
5203 }
5204
5205 struct btrfs_ref_path {
5206 u64 extent_start;
5207 u64 nodes[BTRFS_MAX_LEVEL];
5208 u64 root_objectid;
5209 u64 root_generation;
5210 u64 owner_objectid;
5211 u32 num_refs;
5212 int lowest_level;
5213 int current_level;
5214 int shared_level;
5215
5216 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
5217 u64 new_nodes[BTRFS_MAX_LEVEL];
5218 };
5219
5220 struct disk_extent {
5221 u64 ram_bytes;
5222 u64 disk_bytenr;
5223 u64 disk_num_bytes;
5224 u64 offset;
5225 u64 num_bytes;
5226 u8 compression;
5227 u8 encryption;
5228 u16 other_encoding;
5229 };
5230
5231 static int is_cowonly_root(u64 root_objectid)
5232 {
5233 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
5234 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
5235 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
5236 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
5237 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
5238 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
5239 return 1;
5240 return 0;
5241 }
5242
5243 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
5244 struct btrfs_root *extent_root,
5245 struct btrfs_ref_path *ref_path,
5246 int first_time)
5247 {
5248 struct extent_buffer *leaf;
5249 struct btrfs_path *path;
5250 struct btrfs_extent_ref *ref;
5251 struct btrfs_key key;
5252 struct btrfs_key found_key;
5253 u64 bytenr;
5254 u32 nritems;
5255 int level;
5256 int ret = 1;
5257
5258 path = btrfs_alloc_path();
5259 if (!path)
5260 return -ENOMEM;
5261
5262 if (first_time) {
5263 ref_path->lowest_level = -1;
5264 ref_path->current_level = -1;
5265 ref_path->shared_level = -1;
5266 goto walk_up;
5267 }
5268 walk_down:
5269 level = ref_path->current_level - 1;
5270 while (level >= -1) {
5271 u64 parent;
5272 if (level < ref_path->lowest_level)
5273 break;
5274
5275 if (level >= 0)
5276 bytenr = ref_path->nodes[level];
5277 else
5278 bytenr = ref_path->extent_start;
5279 BUG_ON(bytenr == 0);
5280
5281 parent = ref_path->nodes[level + 1];
5282 ref_path->nodes[level + 1] = 0;
5283 ref_path->current_level = level;
5284 BUG_ON(parent == 0);
5285
5286 key.objectid = bytenr;
5287 key.offset = parent + 1;
5288 key.type = BTRFS_EXTENT_REF_KEY;
5289
5290 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5291 if (ret < 0)
5292 goto out;
5293 BUG_ON(ret == 0);
5294
5295 leaf = path->nodes[0];
5296 nritems = btrfs_header_nritems(leaf);
5297 if (path->slots[0] >= nritems) {
5298 ret = btrfs_next_leaf(extent_root, path);
5299 if (ret < 0)
5300 goto out;
5301 if (ret > 0)
5302 goto next;
5303 leaf = path->nodes[0];
5304 }
5305
5306 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5307 if (found_key.objectid == bytenr &&
5308 found_key.type == BTRFS_EXTENT_REF_KEY) {
5309 if (level < ref_path->shared_level)
5310 ref_path->shared_level = level;
5311 goto found;
5312 }
5313 next:
5314 level--;
5315 btrfs_release_path(extent_root, path);
5316 cond_resched();
5317 }
5318 /* reached lowest level */
5319 ret = 1;
5320 goto out;
5321 walk_up:
5322 level = ref_path->current_level;
5323 while (level < BTRFS_MAX_LEVEL - 1) {
5324 u64 ref_objectid;
5325
5326 if (level >= 0)
5327 bytenr = ref_path->nodes[level];
5328 else
5329 bytenr = ref_path->extent_start;
5330
5331 BUG_ON(bytenr == 0);
5332
5333 key.objectid = bytenr;
5334 key.offset = 0;
5335 key.type = BTRFS_EXTENT_REF_KEY;
5336
5337 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5338 if (ret < 0)
5339 goto out;
5340
5341 leaf = path->nodes[0];
5342 nritems = btrfs_header_nritems(leaf);
5343 if (path->slots[0] >= nritems) {
5344 ret = btrfs_next_leaf(extent_root, path);
5345 if (ret < 0)
5346 goto out;
5347 if (ret > 0) {
5348 /* the extent was freed by someone */
5349 if (ref_path->lowest_level == level)
5350 goto out;
5351 btrfs_release_path(extent_root, path);
5352 goto walk_down;
5353 }
5354 leaf = path->nodes[0];
5355 }
5356
5357 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5358 if (found_key.objectid != bytenr ||
5359 found_key.type != BTRFS_EXTENT_REF_KEY) {
5360 /* the extent was freed by someone */
5361 if (ref_path->lowest_level == level) {
5362 ret = 1;
5363 goto out;
5364 }
5365 btrfs_release_path(extent_root, path);
5366 goto walk_down;
5367 }
5368 found:
5369 ref = btrfs_item_ptr(leaf, path->slots[0],
5370 struct btrfs_extent_ref);
5371 ref_objectid = btrfs_ref_objectid(leaf, ref);
5372 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
5373 if (first_time) {
5374 level = (int)ref_objectid;
5375 BUG_ON(level >= BTRFS_MAX_LEVEL);
5376 ref_path->lowest_level = level;
5377 ref_path->current_level = level;
5378 ref_path->nodes[level] = bytenr;
5379 } else {
5380 WARN_ON(ref_objectid != level);
5381 }
5382 } else {
5383 WARN_ON(level != -1);
5384 }
5385 first_time = 0;
5386
5387 if (ref_path->lowest_level == level) {
5388 ref_path->owner_objectid = ref_objectid;
5389 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
5390 }
5391
5392 /*
5393 * the block is tree root or the block isn't in reference
5394 * counted tree.
5395 */
5396 if (found_key.objectid == found_key.offset ||
5397 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
5398 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5399 ref_path->root_generation =
5400 btrfs_ref_generation(leaf, ref);
5401 if (level < 0) {
5402 /* special reference from the tree log */
5403 ref_path->nodes[0] = found_key.offset;
5404 ref_path->current_level = 0;
5405 }
5406 ret = 0;
5407 goto out;
5408 }
5409
5410 level++;
5411 BUG_ON(ref_path->nodes[level] != 0);
5412 ref_path->nodes[level] = found_key.offset;
5413 ref_path->current_level = level;
5414
5415 /*
5416 * the reference was created in the running transaction,
5417 * no need to continue walking up.
5418 */
5419 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
5420 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5421 ref_path->root_generation =
5422 btrfs_ref_generation(leaf, ref);
5423 ret = 0;
5424 goto out;
5425 }
5426
5427 btrfs_release_path(extent_root, path);
5428 cond_resched();
5429 }
5430 /* reached max tree level, but no tree root found. */
5431 BUG();
5432 out:
5433 btrfs_free_path(path);
5434 return ret;
5435 }
5436
5437 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
5438 struct btrfs_root *extent_root,
5439 struct btrfs_ref_path *ref_path,
5440 u64 extent_start)
5441 {
5442 memset(ref_path, 0, sizeof(*ref_path));
5443 ref_path->extent_start = extent_start;
5444
5445 return __next_ref_path(trans, extent_root, ref_path, 1);
5446 }
5447
5448 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
5449 struct btrfs_root *extent_root,
5450 struct btrfs_ref_path *ref_path)
5451 {
5452 return __next_ref_path(trans, extent_root, ref_path, 0);
5453 }
5454
5455 static noinline int get_new_locations(struct inode *reloc_inode,
5456 struct btrfs_key *extent_key,
5457 u64 offset, int no_fragment,
5458 struct disk_extent **extents,
5459 int *nr_extents)
5460 {
5461 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5462 struct btrfs_path *path;
5463 struct btrfs_file_extent_item *fi;
5464 struct extent_buffer *leaf;
5465 struct disk_extent *exts = *extents;
5466 struct btrfs_key found_key;
5467 u64 cur_pos;
5468 u64 last_byte;
5469 u32 nritems;
5470 int nr = 0;
5471 int max = *nr_extents;
5472 int ret;
5473
5474 WARN_ON(!no_fragment && *extents);
5475 if (!exts) {
5476 max = 1;
5477 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
5478 if (!exts)
5479 return -ENOMEM;
5480 }
5481
5482 path = btrfs_alloc_path();
5483 BUG_ON(!path);
5484
5485 cur_pos = extent_key->objectid - offset;
5486 last_byte = extent_key->objectid + extent_key->offset;
5487 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
5488 cur_pos, 0);
5489 if (ret < 0)
5490 goto out;
5491 if (ret > 0) {
5492 ret = -ENOENT;
5493 goto out;
5494 }
5495
5496 while (1) {
5497 leaf = path->nodes[0];
5498 nritems = btrfs_header_nritems(leaf);
5499 if (path->slots[0] >= nritems) {
5500 ret = btrfs_next_leaf(root, path);
5501 if (ret < 0)
5502 goto out;
5503 if (ret > 0)
5504 break;
5505 leaf = path->nodes[0];
5506 }
5507
5508 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5509 if (found_key.offset != cur_pos ||
5510 found_key.type != BTRFS_EXTENT_DATA_KEY ||
5511 found_key.objectid != reloc_inode->i_ino)
5512 break;
5513
5514 fi = btrfs_item_ptr(leaf, path->slots[0],
5515 struct btrfs_file_extent_item);
5516 if (btrfs_file_extent_type(leaf, fi) !=
5517 BTRFS_FILE_EXTENT_REG ||
5518 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
5519 break;
5520
5521 if (nr == max) {
5522 struct disk_extent *old = exts;
5523 max *= 2;
5524 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
5525 memcpy(exts, old, sizeof(*exts) * nr);
5526 if (old != *extents)
5527 kfree(old);
5528 }
5529
5530 exts[nr].disk_bytenr =
5531 btrfs_file_extent_disk_bytenr(leaf, fi);
5532 exts[nr].disk_num_bytes =
5533 btrfs_file_extent_disk_num_bytes(leaf, fi);
5534 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
5535 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5536 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
5537 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
5538 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
5539 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
5540 fi);
5541 BUG_ON(exts[nr].offset > 0);
5542 BUG_ON(exts[nr].compression || exts[nr].encryption);
5543 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
5544
5545 cur_pos += exts[nr].num_bytes;
5546 nr++;
5547
5548 if (cur_pos + offset >= last_byte)
5549 break;
5550
5551 if (no_fragment) {
5552 ret = 1;
5553 goto out;
5554 }
5555 path->slots[0]++;
5556 }
5557
5558 BUG_ON(cur_pos + offset > last_byte);
5559 if (cur_pos + offset < last_byte) {
5560 ret = -ENOENT;
5561 goto out;
5562 }
5563 ret = 0;
5564 out:
5565 btrfs_free_path(path);
5566 if (ret) {
5567 if (exts != *extents)
5568 kfree(exts);
5569 } else {
5570 *extents = exts;
5571 *nr_extents = nr;
5572 }
5573 return ret;
5574 }
5575
5576 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
5577 struct btrfs_root *root,
5578 struct btrfs_path *path,
5579 struct btrfs_key *extent_key,
5580 struct btrfs_key *leaf_key,
5581 struct btrfs_ref_path *ref_path,
5582 struct disk_extent *new_extents,
5583 int nr_extents)
5584 {
5585 struct extent_buffer *leaf;
5586 struct btrfs_file_extent_item *fi;
5587 struct inode *inode = NULL;
5588 struct btrfs_key key;
5589 u64 lock_start = 0;
5590 u64 lock_end = 0;
5591 u64 num_bytes;
5592 u64 ext_offset;
5593 u64 search_end = (u64)-1;
5594 u32 nritems;
5595 int nr_scaned = 0;
5596 int extent_locked = 0;
5597 int extent_type;
5598 int ret;
5599
5600 memcpy(&key, leaf_key, sizeof(key));
5601 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
5602 if (key.objectid < ref_path->owner_objectid ||
5603 (key.objectid == ref_path->owner_objectid &&
5604 key.type < BTRFS_EXTENT_DATA_KEY)) {
5605 key.objectid = ref_path->owner_objectid;
5606 key.type = BTRFS_EXTENT_DATA_KEY;
5607 key.offset = 0;
5608 }
5609 }
5610
5611 while (1) {
5612 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
5613 if (ret < 0)
5614 goto out;
5615
5616 leaf = path->nodes[0];
5617 nritems = btrfs_header_nritems(leaf);
5618 next:
5619 if (extent_locked && ret > 0) {
5620 /*
5621 * the file extent item was modified by someone
5622 * before the extent got locked.
5623 */
5624 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5625 lock_end, GFP_NOFS);
5626 extent_locked = 0;
5627 }
5628
5629 if (path->slots[0] >= nritems) {
5630 if (++nr_scaned > 2)
5631 break;
5632
5633 BUG_ON(extent_locked);
5634 ret = btrfs_next_leaf(root, path);
5635 if (ret < 0)
5636 goto out;
5637 if (ret > 0)
5638 break;
5639 leaf = path->nodes[0];
5640 nritems = btrfs_header_nritems(leaf);
5641 }
5642
5643 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
5644
5645 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
5646 if ((key.objectid > ref_path->owner_objectid) ||
5647 (key.objectid == ref_path->owner_objectid &&
5648 key.type > BTRFS_EXTENT_DATA_KEY) ||
5649 key.offset >= search_end)
5650 break;
5651 }
5652
5653 if (inode && key.objectid != inode->i_ino) {
5654 BUG_ON(extent_locked);
5655 btrfs_release_path(root, path);
5656 mutex_unlock(&inode->i_mutex);
5657 iput(inode);
5658 inode = NULL;
5659 continue;
5660 }
5661
5662 if (key.type != BTRFS_EXTENT_DATA_KEY) {
5663 path->slots[0]++;
5664 ret = 1;
5665 goto next;
5666 }
5667 fi = btrfs_item_ptr(leaf, path->slots[0],
5668 struct btrfs_file_extent_item);
5669 extent_type = btrfs_file_extent_type(leaf, fi);
5670 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
5671 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
5672 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
5673 extent_key->objectid)) {
5674 path->slots[0]++;
5675 ret = 1;
5676 goto next;
5677 }
5678
5679 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5680 ext_offset = btrfs_file_extent_offset(leaf, fi);
5681
5682 if (search_end == (u64)-1) {
5683 search_end = key.offset - ext_offset +
5684 btrfs_file_extent_ram_bytes(leaf, fi);
5685 }
5686
5687 if (!extent_locked) {
5688 lock_start = key.offset;
5689 lock_end = lock_start + num_bytes - 1;
5690 } else {
5691 if (lock_start > key.offset ||
5692 lock_end + 1 < key.offset + num_bytes) {
5693 unlock_extent(&BTRFS_I(inode)->io_tree,
5694 lock_start, lock_end, GFP_NOFS);
5695 extent_locked = 0;
5696 }
5697 }
5698
5699 if (!inode) {
5700 btrfs_release_path(root, path);
5701
5702 inode = btrfs_iget_locked(root->fs_info->sb,
5703 key.objectid, root);
5704 if (inode->i_state & I_NEW) {
5705 BTRFS_I(inode)->root = root;
5706 BTRFS_I(inode)->location.objectid =
5707 key.objectid;
5708 BTRFS_I(inode)->location.type =
5709 BTRFS_INODE_ITEM_KEY;
5710 BTRFS_I(inode)->location.offset = 0;
5711 btrfs_read_locked_inode(inode);
5712 unlock_new_inode(inode);
5713 }
5714 /*
5715 * some code call btrfs_commit_transaction while
5716 * holding the i_mutex, so we can't use mutex_lock
5717 * here.
5718 */
5719 if (is_bad_inode(inode) ||
5720 !mutex_trylock(&inode->i_mutex)) {
5721 iput(inode);
5722 inode = NULL;
5723 key.offset = (u64)-1;
5724 goto skip;
5725 }
5726 }
5727
5728 if (!extent_locked) {
5729 struct btrfs_ordered_extent *ordered;
5730
5731 btrfs_release_path(root, path);
5732
5733 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5734 lock_end, GFP_NOFS);
5735 ordered = btrfs_lookup_first_ordered_extent(inode,
5736 lock_end);
5737 if (ordered &&
5738 ordered->file_offset <= lock_end &&
5739 ordered->file_offset + ordered->len > lock_start) {
5740 unlock_extent(&BTRFS_I(inode)->io_tree,
5741 lock_start, lock_end, GFP_NOFS);
5742 btrfs_start_ordered_extent(inode, ordered, 1);
5743 btrfs_put_ordered_extent(ordered);
5744 key.offset += num_bytes;
5745 goto skip;
5746 }
5747 if (ordered)
5748 btrfs_put_ordered_extent(ordered);
5749
5750 extent_locked = 1;
5751 continue;
5752 }
5753
5754 if (nr_extents == 1) {
5755 /* update extent pointer in place */
5756 btrfs_set_file_extent_disk_bytenr(leaf, fi,
5757 new_extents[0].disk_bytenr);
5758 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
5759 new_extents[0].disk_num_bytes);
5760 btrfs_mark_buffer_dirty(leaf);
5761
5762 btrfs_drop_extent_cache(inode, key.offset,
5763 key.offset + num_bytes - 1, 0);
5764
5765 ret = btrfs_inc_extent_ref(trans, root,
5766 new_extents[0].disk_bytenr,
5767 new_extents[0].disk_num_bytes,
5768 leaf->start,
5769 root->root_key.objectid,
5770 trans->transid,
5771 key.objectid);
5772 BUG_ON(ret);
5773
5774 ret = btrfs_free_extent(trans, root,
5775 extent_key->objectid,
5776 extent_key->offset,
5777 leaf->start,
5778 btrfs_header_owner(leaf),
5779 btrfs_header_generation(leaf),
5780 key.objectid, 0);
5781 BUG_ON(ret);
5782
5783 btrfs_release_path(root, path);
5784 key.offset += num_bytes;
5785 } else {
5786 BUG_ON(1);
5787 #if 0
5788 u64 alloc_hint;
5789 u64 extent_len;
5790 int i;
5791 /*
5792 * drop old extent pointer at first, then insert the
5793 * new pointers one bye one
5794 */
5795 btrfs_release_path(root, path);
5796 ret = btrfs_drop_extents(trans, root, inode, key.offset,
5797 key.offset + num_bytes,
5798 key.offset, &alloc_hint);
5799 BUG_ON(ret);
5800
5801 for (i = 0; i < nr_extents; i++) {
5802 if (ext_offset >= new_extents[i].num_bytes) {
5803 ext_offset -= new_extents[i].num_bytes;
5804 continue;
5805 }
5806 extent_len = min(new_extents[i].num_bytes -
5807 ext_offset, num_bytes);
5808
5809 ret = btrfs_insert_empty_item(trans, root,
5810 path, &key,
5811 sizeof(*fi));
5812 BUG_ON(ret);
5813
5814 leaf = path->nodes[0];
5815 fi = btrfs_item_ptr(leaf, path->slots[0],
5816 struct btrfs_file_extent_item);
5817 btrfs_set_file_extent_generation(leaf, fi,
5818 trans->transid);
5819 btrfs_set_file_extent_type(leaf, fi,
5820 BTRFS_FILE_EXTENT_REG);
5821 btrfs_set_file_extent_disk_bytenr(leaf, fi,
5822 new_extents[i].disk_bytenr);
5823 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
5824 new_extents[i].disk_num_bytes);
5825 btrfs_set_file_extent_ram_bytes(leaf, fi,
5826 new_extents[i].ram_bytes);
5827
5828 btrfs_set_file_extent_compression(leaf, fi,
5829 new_extents[i].compression);
5830 btrfs_set_file_extent_encryption(leaf, fi,
5831 new_extents[i].encryption);
5832 btrfs_set_file_extent_other_encoding(leaf, fi,
5833 new_extents[i].other_encoding);
5834
5835 btrfs_set_file_extent_num_bytes(leaf, fi,
5836 extent_len);
5837 ext_offset += new_extents[i].offset;
5838 btrfs_set_file_extent_offset(leaf, fi,
5839 ext_offset);
5840 btrfs_mark_buffer_dirty(leaf);
5841
5842 btrfs_drop_extent_cache(inode, key.offset,
5843 key.offset + extent_len - 1, 0);
5844
5845 ret = btrfs_inc_extent_ref(trans, root,
5846 new_extents[i].disk_bytenr,
5847 new_extents[i].disk_num_bytes,
5848 leaf->start,
5849 root->root_key.objectid,
5850 trans->transid, key.objectid);
5851 BUG_ON(ret);
5852 btrfs_release_path(root, path);
5853
5854 inode_add_bytes(inode, extent_len);
5855
5856 ext_offset = 0;
5857 num_bytes -= extent_len;
5858 key.offset += extent_len;
5859
5860 if (num_bytes == 0)
5861 break;
5862 }
5863 BUG_ON(i >= nr_extents);
5864 #endif
5865 }
5866
5867 if (extent_locked) {
5868 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5869 lock_end, GFP_NOFS);
5870 extent_locked = 0;
5871 }
5872 skip:
5873 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
5874 key.offset >= search_end)
5875 break;
5876
5877 cond_resched();
5878 }
5879 ret = 0;
5880 out:
5881 btrfs_release_path(root, path);
5882 if (inode) {
5883 mutex_unlock(&inode->i_mutex);
5884 if (extent_locked) {
5885 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5886 lock_end, GFP_NOFS);
5887 }
5888 iput(inode);
5889 }
5890 return ret;
5891 }
5892
5893 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
5894 struct btrfs_root *root,
5895 struct extent_buffer *buf, u64 orig_start)
5896 {
5897 int level;
5898 int ret;
5899
5900 BUG_ON(btrfs_header_generation(buf) != trans->transid);
5901 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5902
5903 level = btrfs_header_level(buf);
5904 if (level == 0) {
5905 struct btrfs_leaf_ref *ref;
5906 struct btrfs_leaf_ref *orig_ref;
5907
5908 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
5909 if (!orig_ref)
5910 return -ENOENT;
5911
5912 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
5913 if (!ref) {
5914 btrfs_free_leaf_ref(root, orig_ref);
5915 return -ENOMEM;
5916 }
5917
5918 ref->nritems = orig_ref->nritems;
5919 memcpy(ref->extents, orig_ref->extents,
5920 sizeof(ref->extents[0]) * ref->nritems);
5921
5922 btrfs_free_leaf_ref(root, orig_ref);
5923
5924 ref->root_gen = trans->transid;
5925 ref->bytenr = buf->start;
5926 ref->owner = btrfs_header_owner(buf);
5927 ref->generation = btrfs_header_generation(buf);
5928
5929 ret = btrfs_add_leaf_ref(root, ref, 0);
5930 WARN_ON(ret);
5931 btrfs_free_leaf_ref(root, ref);
5932 }
5933 return 0;
5934 }
5935
5936 static noinline int invalidate_extent_cache(struct btrfs_root *root,
5937 struct extent_buffer *leaf,
5938 struct btrfs_block_group_cache *group,
5939 struct btrfs_root *target_root)
5940 {
5941 struct btrfs_key key;
5942 struct inode *inode = NULL;
5943 struct btrfs_file_extent_item *fi;
5944 u64 num_bytes;
5945 u64 skip_objectid = 0;
5946 u32 nritems;
5947 u32 i;
5948
5949 nritems = btrfs_header_nritems(leaf);
5950 for (i = 0; i < nritems; i++) {
5951 btrfs_item_key_to_cpu(leaf, &key, i);
5952 if (key.objectid == skip_objectid ||
5953 key.type != BTRFS_EXTENT_DATA_KEY)
5954 continue;
5955 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
5956 if (btrfs_file_extent_type(leaf, fi) ==
5957 BTRFS_FILE_EXTENT_INLINE)
5958 continue;
5959 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
5960 continue;
5961 if (!inode || inode->i_ino != key.objectid) {
5962 iput(inode);
5963 inode = btrfs_ilookup(target_root->fs_info->sb,
5964 key.objectid, target_root, 1);
5965 }
5966 if (!inode) {
5967 skip_objectid = key.objectid;
5968 continue;
5969 }
5970 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5971
5972 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
5973 key.offset + num_bytes - 1, GFP_NOFS);
5974 btrfs_drop_extent_cache(inode, key.offset,
5975 key.offset + num_bytes - 1, 1);
5976 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
5977 key.offset + num_bytes - 1, GFP_NOFS);
5978 cond_resched();
5979 }
5980 iput(inode);
5981 return 0;
5982 }
5983
5984 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
5985 struct btrfs_root *root,
5986 struct extent_buffer *leaf,
5987 struct btrfs_block_group_cache *group,
5988 struct inode *reloc_inode)
5989 {
5990 struct btrfs_key key;
5991 struct btrfs_key extent_key;
5992 struct btrfs_file_extent_item *fi;
5993 struct btrfs_leaf_ref *ref;
5994 struct disk_extent *new_extent;
5995 u64 bytenr;
5996 u64 num_bytes;
5997 u32 nritems;
5998 u32 i;
5999 int ext_index;
6000 int nr_extent;
6001 int ret;
6002
6003 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
6004 BUG_ON(!new_extent);
6005
6006 ref = btrfs_lookup_leaf_ref(root, leaf->start);
6007 BUG_ON(!ref);
6008
6009 ext_index = -1;
6010 nritems = btrfs_header_nritems(leaf);
6011 for (i = 0; i < nritems; i++) {
6012 btrfs_item_key_to_cpu(leaf, &key, i);
6013 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
6014 continue;
6015 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6016 if (btrfs_file_extent_type(leaf, fi) ==
6017 BTRFS_FILE_EXTENT_INLINE)
6018 continue;
6019 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6020 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
6021 if (bytenr == 0)
6022 continue;
6023
6024 ext_index++;
6025 if (bytenr >= group->key.objectid + group->key.offset ||
6026 bytenr + num_bytes <= group->key.objectid)
6027 continue;
6028
6029 extent_key.objectid = bytenr;
6030 extent_key.offset = num_bytes;
6031 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
6032 nr_extent = 1;
6033 ret = get_new_locations(reloc_inode, &extent_key,
6034 group->key.objectid, 1,
6035 &new_extent, &nr_extent);
6036 if (ret > 0)
6037 continue;
6038 BUG_ON(ret < 0);
6039
6040 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
6041 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
6042 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
6043 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
6044
6045 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6046 new_extent->disk_bytenr);
6047 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6048 new_extent->disk_num_bytes);
6049 btrfs_mark_buffer_dirty(leaf);
6050
6051 ret = btrfs_inc_extent_ref(trans, root,
6052 new_extent->disk_bytenr,
6053 new_extent->disk_num_bytes,
6054 leaf->start,
6055 root->root_key.objectid,
6056 trans->transid, key.objectid);
6057 BUG_ON(ret);
6058
6059 ret = btrfs_free_extent(trans, root,
6060 bytenr, num_bytes, leaf->start,
6061 btrfs_header_owner(leaf),
6062 btrfs_header_generation(leaf),
6063 key.objectid, 0);
6064 BUG_ON(ret);
6065 cond_resched();
6066 }
6067 kfree(new_extent);
6068 BUG_ON(ext_index + 1 != ref->nritems);
6069 btrfs_free_leaf_ref(root, ref);
6070 return 0;
6071 }
6072
6073 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
6074 struct btrfs_root *root)
6075 {
6076 struct btrfs_root *reloc_root;
6077 int ret;
6078
6079 if (root->reloc_root) {
6080 reloc_root = root->reloc_root;
6081 root->reloc_root = NULL;
6082 list_add(&reloc_root->dead_list,
6083 &root->fs_info->dead_reloc_roots);
6084
6085 btrfs_set_root_bytenr(&reloc_root->root_item,
6086 reloc_root->node->start);
6087 btrfs_set_root_level(&root->root_item,
6088 btrfs_header_level(reloc_root->node));
6089 memset(&reloc_root->root_item.drop_progress, 0,
6090 sizeof(struct btrfs_disk_key));
6091 reloc_root->root_item.drop_level = 0;
6092
6093 ret = btrfs_update_root(trans, root->fs_info->tree_root,
6094 &reloc_root->root_key,
6095 &reloc_root->root_item);
6096 BUG_ON(ret);
6097 }
6098 return 0;
6099 }
6100
6101 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
6102 {
6103 struct btrfs_trans_handle *trans;
6104 struct btrfs_root *reloc_root;
6105 struct btrfs_root *prev_root = NULL;
6106 struct list_head dead_roots;
6107 int ret;
6108 unsigned long nr;
6109
6110 INIT_LIST_HEAD(&dead_roots);
6111 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
6112
6113 while (!list_empty(&dead_roots)) {
6114 reloc_root = list_entry(dead_roots.prev,
6115 struct btrfs_root, dead_list);
6116 list_del_init(&reloc_root->dead_list);
6117
6118 BUG_ON(reloc_root->commit_root != NULL);
6119 while (1) {
6120 trans = btrfs_join_transaction(root, 1);
6121 BUG_ON(!trans);
6122
6123 mutex_lock(&root->fs_info->drop_mutex);
6124 ret = btrfs_drop_snapshot(trans, reloc_root);
6125 if (ret != -EAGAIN)
6126 break;
6127 mutex_unlock(&root->fs_info->drop_mutex);
6128
6129 nr = trans->blocks_used;
6130 ret = btrfs_end_transaction(trans, root);
6131 BUG_ON(ret);
6132 btrfs_btree_balance_dirty(root, nr);
6133 }
6134
6135 free_extent_buffer(reloc_root->node);
6136
6137 ret = btrfs_del_root(trans, root->fs_info->tree_root,
6138 &reloc_root->root_key);
6139 BUG_ON(ret);
6140 mutex_unlock(&root->fs_info->drop_mutex);
6141
6142 nr = trans->blocks_used;
6143 ret = btrfs_end_transaction(trans, root);
6144 BUG_ON(ret);
6145 btrfs_btree_balance_dirty(root, nr);
6146
6147 kfree(prev_root);
6148 prev_root = reloc_root;
6149 }
6150 if (prev_root) {
6151 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
6152 kfree(prev_root);
6153 }
6154 return 0;
6155 }
6156
6157 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
6158 {
6159 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
6160 return 0;
6161 }
6162
6163 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
6164 {
6165 struct btrfs_root *reloc_root;
6166 struct btrfs_trans_handle *trans;
6167 struct btrfs_key location;
6168 int found;
6169 int ret;
6170
6171 mutex_lock(&root->fs_info->tree_reloc_mutex);
6172 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
6173 BUG_ON(ret);
6174 found = !list_empty(&root->fs_info->dead_reloc_roots);
6175 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6176
6177 if (found) {
6178 trans = btrfs_start_transaction(root, 1);
6179 BUG_ON(!trans);
6180 ret = btrfs_commit_transaction(trans, root);
6181 BUG_ON(ret);
6182 }
6183
6184 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
6185 location.offset = (u64)-1;
6186 location.type = BTRFS_ROOT_ITEM_KEY;
6187
6188 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
6189 BUG_ON(!reloc_root);
6190 btrfs_orphan_cleanup(reloc_root);
6191 return 0;
6192 }
6193
6194 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
6195 struct btrfs_root *root)
6196 {
6197 struct btrfs_root *reloc_root;
6198 struct extent_buffer *eb;
6199 struct btrfs_root_item *root_item;
6200 struct btrfs_key root_key;
6201 int ret;
6202
6203 BUG_ON(!root->ref_cows);
6204 if (root->reloc_root)
6205 return 0;
6206
6207 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
6208 BUG_ON(!root_item);
6209
6210 ret = btrfs_copy_root(trans, root, root->commit_root,
6211 &eb, BTRFS_TREE_RELOC_OBJECTID);
6212 BUG_ON(ret);
6213
6214 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
6215 root_key.offset = root->root_key.objectid;
6216 root_key.type = BTRFS_ROOT_ITEM_KEY;
6217
6218 memcpy(root_item, &root->root_item, sizeof(root_item));
6219 btrfs_set_root_refs(root_item, 0);
6220 btrfs_set_root_bytenr(root_item, eb->start);
6221 btrfs_set_root_level(root_item, btrfs_header_level(eb));
6222 btrfs_set_root_generation(root_item, trans->transid);
6223
6224 btrfs_tree_unlock(eb);
6225 free_extent_buffer(eb);
6226
6227 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
6228 &root_key, root_item);
6229 BUG_ON(ret);
6230 kfree(root_item);
6231
6232 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
6233 &root_key);
6234 BUG_ON(!reloc_root);
6235 reloc_root->last_trans = trans->transid;
6236 reloc_root->commit_root = NULL;
6237 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
6238
6239 root->reloc_root = reloc_root;
6240 return 0;
6241 }
6242
6243 /*
6244 * Core function of space balance.
6245 *
6246 * The idea is using reloc trees to relocate tree blocks in reference
6247 * counted roots. There is one reloc tree for each subvol, and all
6248 * reloc trees share same root key objectid. Reloc trees are snapshots
6249 * of the latest committed roots of subvols (root->commit_root).
6250 *
6251 * To relocate a tree block referenced by a subvol, there are two steps.
6252 * COW the block through subvol's reloc tree, then update block pointer
6253 * in the subvol to point to the new block. Since all reloc trees share
6254 * same root key objectid, doing special handing for tree blocks owned
6255 * by them is easy. Once a tree block has been COWed in one reloc tree,
6256 * we can use the resulting new block directly when the same block is
6257 * required to COW again through other reloc trees. By this way, relocated
6258 * tree blocks are shared between reloc trees, so they are also shared
6259 * between subvols.
6260 */
6261 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
6262 struct btrfs_root *root,
6263 struct btrfs_path *path,
6264 struct btrfs_key *first_key,
6265 struct btrfs_ref_path *ref_path,
6266 struct btrfs_block_group_cache *group,
6267 struct inode *reloc_inode)
6268 {
6269 struct btrfs_root *reloc_root;
6270 struct extent_buffer *eb = NULL;
6271 struct btrfs_key *keys;
6272 u64 *nodes;
6273 int level;
6274 int shared_level;
6275 int lowest_level = 0;
6276 int ret;
6277
6278 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
6279 lowest_level = ref_path->owner_objectid;
6280
6281 if (!root->ref_cows) {
6282 path->lowest_level = lowest_level;
6283 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
6284 BUG_ON(ret < 0);
6285 path->lowest_level = 0;
6286 btrfs_release_path(root, path);
6287 return 0;
6288 }
6289
6290 mutex_lock(&root->fs_info->tree_reloc_mutex);
6291 ret = init_reloc_tree(trans, root);
6292 BUG_ON(ret);
6293 reloc_root = root->reloc_root;
6294
6295 shared_level = ref_path->shared_level;
6296 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
6297
6298 keys = ref_path->node_keys;
6299 nodes = ref_path->new_nodes;
6300 memset(&keys[shared_level + 1], 0,
6301 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
6302 memset(&nodes[shared_level + 1], 0,
6303 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
6304
6305 if (nodes[lowest_level] == 0) {
6306 path->lowest_level = lowest_level;
6307 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6308 0, 1);
6309 BUG_ON(ret);
6310 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
6311 eb = path->nodes[level];
6312 if (!eb || eb == reloc_root->node)
6313 break;
6314 nodes[level] = eb->start;
6315 if (level == 0)
6316 btrfs_item_key_to_cpu(eb, &keys[level], 0);
6317 else
6318 btrfs_node_key_to_cpu(eb, &keys[level], 0);
6319 }
6320 if (nodes[0] &&
6321 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6322 eb = path->nodes[0];
6323 ret = replace_extents_in_leaf(trans, reloc_root, eb,
6324 group, reloc_inode);
6325 BUG_ON(ret);
6326 }
6327 btrfs_release_path(reloc_root, path);
6328 } else {
6329 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
6330 lowest_level);
6331 BUG_ON(ret);
6332 }
6333
6334 /*
6335 * replace tree blocks in the fs tree with tree blocks in
6336 * the reloc tree.
6337 */
6338 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
6339 BUG_ON(ret < 0);
6340
6341 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6342 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6343 0, 0);
6344 BUG_ON(ret);
6345 extent_buffer_get(path->nodes[0]);
6346 eb = path->nodes[0];
6347 btrfs_release_path(reloc_root, path);
6348 ret = invalidate_extent_cache(reloc_root, eb, group, root);
6349 BUG_ON(ret);
6350 free_extent_buffer(eb);
6351 }
6352
6353 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6354 path->lowest_level = 0;
6355 return 0;
6356 }
6357
6358 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
6359 struct btrfs_root *root,
6360 struct btrfs_path *path,
6361 struct btrfs_key *first_key,
6362 struct btrfs_ref_path *ref_path)
6363 {
6364 int ret;
6365
6366 ret = relocate_one_path(trans, root, path, first_key,
6367 ref_path, NULL, NULL);
6368 BUG_ON(ret);
6369
6370 return 0;
6371 }
6372
6373 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
6374 struct btrfs_root *extent_root,
6375 struct btrfs_path *path,
6376 struct btrfs_key *extent_key)
6377 {
6378 int ret;
6379
6380 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
6381 if (ret)
6382 goto out;
6383 ret = btrfs_del_item(trans, extent_root, path);
6384 out:
6385 btrfs_release_path(extent_root, path);
6386 return ret;
6387 }
6388
6389 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
6390 struct btrfs_ref_path *ref_path)
6391 {
6392 struct btrfs_key root_key;
6393
6394 root_key.objectid = ref_path->root_objectid;
6395 root_key.type = BTRFS_ROOT_ITEM_KEY;
6396 if (is_cowonly_root(ref_path->root_objectid))
6397 root_key.offset = 0;
6398 else
6399 root_key.offset = (u64)-1;
6400
6401 return btrfs_read_fs_root_no_name(fs_info, &root_key);
6402 }
6403
6404 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
6405 struct btrfs_path *path,
6406 struct btrfs_key *extent_key,
6407 struct btrfs_block_group_cache *group,
6408 struct inode *reloc_inode, int pass)
6409 {
6410 struct btrfs_trans_handle *trans;
6411 struct btrfs_root *found_root;
6412 struct btrfs_ref_path *ref_path = NULL;
6413 struct disk_extent *new_extents = NULL;
6414 int nr_extents = 0;
6415 int loops;
6416 int ret;
6417 int level;
6418 struct btrfs_key first_key;
6419 u64 prev_block = 0;
6420
6421
6422 trans = btrfs_start_transaction(extent_root, 1);
6423 BUG_ON(!trans);
6424
6425 if (extent_key->objectid == 0) {
6426 ret = del_extent_zero(trans, extent_root, path, extent_key);
6427 goto out;
6428 }
6429
6430 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
6431 if (!ref_path) {
6432 ret = -ENOMEM;
6433 goto out;
6434 }
6435
6436 for (loops = 0; ; loops++) {
6437 if (loops == 0) {
6438 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
6439 extent_key->objectid);
6440 } else {
6441 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
6442 }
6443 if (ret < 0)
6444 goto out;
6445 if (ret > 0)
6446 break;
6447
6448 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
6449 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
6450 continue;
6451
6452 found_root = read_ref_root(extent_root->fs_info, ref_path);
6453 BUG_ON(!found_root);
6454 /*
6455 * for reference counted tree, only process reference paths
6456 * rooted at the latest committed root.
6457 */
6458 if (found_root->ref_cows &&
6459 ref_path->root_generation != found_root->root_key.offset)
6460 continue;
6461
6462 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6463 if (pass == 0) {
6464 /*
6465 * copy data extents to new locations
6466 */
6467 u64 group_start = group->key.objectid;
6468 ret = relocate_data_extent(reloc_inode,
6469 extent_key,
6470 group_start);
6471 if (ret < 0)
6472 goto out;
6473 break;
6474 }
6475 level = 0;
6476 } else {
6477 level = ref_path->owner_objectid;
6478 }
6479
6480 if (prev_block != ref_path->nodes[level]) {
6481 struct extent_buffer *eb;
6482 u64 block_start = ref_path->nodes[level];
6483 u64 block_size = btrfs_level_size(found_root, level);
6484
6485 eb = read_tree_block(found_root, block_start,
6486 block_size, 0);
6487 btrfs_tree_lock(eb);
6488 BUG_ON(level != btrfs_header_level(eb));
6489
6490 if (level == 0)
6491 btrfs_item_key_to_cpu(eb, &first_key, 0);
6492 else
6493 btrfs_node_key_to_cpu(eb, &first_key, 0);
6494
6495 btrfs_tree_unlock(eb);
6496 free_extent_buffer(eb);
6497 prev_block = block_start;
6498 }
6499
6500 mutex_lock(&extent_root->fs_info->trans_mutex);
6501 btrfs_record_root_in_trans(found_root);
6502 mutex_unlock(&extent_root->fs_info->trans_mutex);
6503 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6504 /*
6505 * try to update data extent references while
6506 * keeping metadata shared between snapshots.
6507 */
6508 if (pass == 1) {
6509 ret = relocate_one_path(trans, found_root,
6510 path, &first_key, ref_path,
6511 group, reloc_inode);
6512 if (ret < 0)
6513 goto out;
6514 continue;
6515 }
6516 /*
6517 * use fallback method to process the remaining
6518 * references.
6519 */
6520 if (!new_extents) {
6521 u64 group_start = group->key.objectid;
6522 new_extents = kmalloc(sizeof(*new_extents),
6523 GFP_NOFS);
6524 nr_extents = 1;
6525 ret = get_new_locations(reloc_inode,
6526 extent_key,
6527 group_start, 1,
6528 &new_extents,
6529 &nr_extents);
6530 if (ret)
6531 goto out;
6532 }
6533 ret = replace_one_extent(trans, found_root,
6534 path, extent_key,
6535 &first_key, ref_path,
6536 new_extents, nr_extents);
6537 } else {
6538 ret = relocate_tree_block(trans, found_root, path,
6539 &first_key, ref_path);
6540 }
6541 if (ret < 0)
6542 goto out;
6543 }
6544 ret = 0;
6545 out:
6546 btrfs_end_transaction(trans, extent_root);
6547 kfree(new_extents);
6548 kfree(ref_path);
6549 return ret;
6550 }
6551 #endif
6552
6553 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
6554 {
6555 u64 num_devices;
6556 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
6557 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
6558
6559 num_devices = root->fs_info->fs_devices->rw_devices;
6560 if (num_devices == 1) {
6561 stripped |= BTRFS_BLOCK_GROUP_DUP;
6562 stripped = flags & ~stripped;
6563
6564 /* turn raid0 into single device chunks */
6565 if (flags & BTRFS_BLOCK_GROUP_RAID0)
6566 return stripped;
6567
6568 /* turn mirroring into duplication */
6569 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
6570 BTRFS_BLOCK_GROUP_RAID10))
6571 return stripped | BTRFS_BLOCK_GROUP_DUP;
6572 return flags;
6573 } else {
6574 /* they already had raid on here, just return */
6575 if (flags & stripped)
6576 return flags;
6577
6578 stripped |= BTRFS_BLOCK_GROUP_DUP;
6579 stripped = flags & ~stripped;
6580
6581 /* switch duplicated blocks with raid1 */
6582 if (flags & BTRFS_BLOCK_GROUP_DUP)
6583 return stripped | BTRFS_BLOCK_GROUP_RAID1;
6584
6585 /* turn single device chunks into raid0 */
6586 return stripped | BTRFS_BLOCK_GROUP_RAID0;
6587 }
6588 return flags;
6589 }
6590
6591 static int __alloc_chunk_for_shrink(struct btrfs_root *root,
6592 struct btrfs_block_group_cache *shrink_block_group,
6593 int force)
6594 {
6595 struct btrfs_trans_handle *trans;
6596 u64 new_alloc_flags;
6597 u64 calc;
6598
6599 spin_lock(&shrink_block_group->lock);
6600 if (btrfs_block_group_used(&shrink_block_group->item) +
6601 shrink_block_group->reserved > 0) {
6602 spin_unlock(&shrink_block_group->lock);
6603
6604 trans = btrfs_start_transaction(root, 1);
6605 spin_lock(&shrink_block_group->lock);
6606
6607 new_alloc_flags = update_block_group_flags(root,
6608 shrink_block_group->flags);
6609 if (new_alloc_flags != shrink_block_group->flags) {
6610 calc =
6611 btrfs_block_group_used(&shrink_block_group->item);
6612 } else {
6613 calc = shrink_block_group->key.offset;
6614 }
6615 spin_unlock(&shrink_block_group->lock);
6616
6617 do_chunk_alloc(trans, root->fs_info->extent_root,
6618 calc + 2 * 1024 * 1024, new_alloc_flags, force);
6619
6620 btrfs_end_transaction(trans, root);
6621 } else
6622 spin_unlock(&shrink_block_group->lock);
6623 return 0;
6624 }
6625
6626
6627 int btrfs_prepare_block_group_relocation(struct btrfs_root *root,
6628 struct btrfs_block_group_cache *group)
6629
6630 {
6631 __alloc_chunk_for_shrink(root, group, 1);
6632 set_block_group_readonly(group);
6633 return 0;
6634 }
6635
6636 #if 0
6637 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
6638 struct btrfs_root *root,
6639 u64 objectid, u64 size)
6640 {
6641 struct btrfs_path *path;
6642 struct btrfs_inode_item *item;
6643 struct extent_buffer *leaf;
6644 int ret;
6645
6646 path = btrfs_alloc_path();
6647 if (!path)
6648 return -ENOMEM;
6649
6650 path->leave_spinning = 1;
6651 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
6652 if (ret)
6653 goto out;
6654
6655 leaf = path->nodes[0];
6656 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
6657 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
6658 btrfs_set_inode_generation(leaf, item, 1);
6659 btrfs_set_inode_size(leaf, item, size);
6660 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
6661 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS);
6662 btrfs_mark_buffer_dirty(leaf);
6663 btrfs_release_path(root, path);
6664 out:
6665 btrfs_free_path(path);
6666 return ret;
6667 }
6668
6669 static noinline struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
6670 struct btrfs_block_group_cache *group)
6671 {
6672 struct inode *inode = NULL;
6673 struct btrfs_trans_handle *trans;
6674 struct btrfs_root *root;
6675 struct btrfs_key root_key;
6676 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
6677 int err = 0;
6678
6679 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
6680 root_key.type = BTRFS_ROOT_ITEM_KEY;
6681 root_key.offset = (u64)-1;
6682 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
6683 if (IS_ERR(root))
6684 return ERR_CAST(root);
6685
6686 trans = btrfs_start_transaction(root, 1);
6687 BUG_ON(!trans);
6688
6689 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
6690 if (err)
6691 goto out;
6692
6693 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
6694 BUG_ON(err);
6695
6696 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
6697 group->key.offset, 0, group->key.offset,
6698 0, 0, 0);
6699 BUG_ON(err);
6700
6701 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
6702 if (inode->i_state & I_NEW) {
6703 BTRFS_I(inode)->root = root;
6704 BTRFS_I(inode)->location.objectid = objectid;
6705 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
6706 BTRFS_I(inode)->location.offset = 0;
6707 btrfs_read_locked_inode(inode);
6708 unlock_new_inode(inode);
6709 BUG_ON(is_bad_inode(inode));
6710 } else {
6711 BUG_ON(1);
6712 }
6713 BTRFS_I(inode)->index_cnt = group->key.objectid;
6714
6715 err = btrfs_orphan_add(trans, inode);
6716 out:
6717 btrfs_end_transaction(trans, root);
6718 if (err) {
6719 if (inode)
6720 iput(inode);
6721 inode = ERR_PTR(err);
6722 }
6723 return inode;
6724 }
6725
6726 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
6727 {
6728
6729 struct btrfs_ordered_sum *sums;
6730 struct btrfs_sector_sum *sector_sum;
6731 struct btrfs_ordered_extent *ordered;
6732 struct btrfs_root *root = BTRFS_I(inode)->root;
6733 struct list_head list;
6734 size_t offset;
6735 int ret;
6736 u64 disk_bytenr;
6737
6738 INIT_LIST_HEAD(&list);
6739
6740 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
6741 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
6742
6743 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
6744 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
6745 disk_bytenr + len - 1, &list);
6746
6747 while (!list_empty(&list)) {
6748 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
6749 list_del_init(&sums->list);
6750
6751 sector_sum = sums->sums;
6752 sums->bytenr = ordered->start;
6753
6754 offset = 0;
6755 while (offset < sums->len) {
6756 sector_sum->bytenr += ordered->start - disk_bytenr;
6757 sector_sum++;
6758 offset += root->sectorsize;
6759 }
6760
6761 btrfs_add_ordered_sum(inode, ordered, sums);
6762 }
6763 btrfs_put_ordered_extent(ordered);
6764 return 0;
6765 }
6766
6767 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
6768 {
6769 struct btrfs_trans_handle *trans;
6770 struct btrfs_path *path;
6771 struct btrfs_fs_info *info = root->fs_info;
6772 struct extent_buffer *leaf;
6773 struct inode *reloc_inode;
6774 struct btrfs_block_group_cache *block_group;
6775 struct btrfs_key key;
6776 u64 skipped;
6777 u64 cur_byte;
6778 u64 total_found;
6779 u32 nritems;
6780 int ret;
6781 int progress;
6782 int pass = 0;
6783
6784 root = root->fs_info->extent_root;
6785
6786 block_group = btrfs_lookup_block_group(info, group_start);
6787 BUG_ON(!block_group);
6788
6789 printk(KERN_INFO "btrfs relocating block group %llu flags %llu\n",
6790 (unsigned long long)block_group->key.objectid,
6791 (unsigned long long)block_group->flags);
6792
6793 path = btrfs_alloc_path();
6794 BUG_ON(!path);
6795
6796 reloc_inode = create_reloc_inode(info, block_group);
6797 BUG_ON(IS_ERR(reloc_inode));
6798
6799 __alloc_chunk_for_shrink(root, block_group, 1);
6800 set_block_group_readonly(block_group);
6801
6802 btrfs_start_delalloc_inodes(info->tree_root);
6803 btrfs_wait_ordered_extents(info->tree_root, 0);
6804 again:
6805 skipped = 0;
6806 total_found = 0;
6807 progress = 0;
6808 key.objectid = block_group->key.objectid;
6809 key.offset = 0;
6810 key.type = 0;
6811 cur_byte = key.objectid;
6812
6813 trans = btrfs_start_transaction(info->tree_root, 1);
6814 btrfs_commit_transaction(trans, info->tree_root);
6815
6816 mutex_lock(&root->fs_info->cleaner_mutex);
6817 btrfs_clean_old_snapshots(info->tree_root);
6818 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
6819 mutex_unlock(&root->fs_info->cleaner_mutex);
6820
6821 trans = btrfs_start_transaction(info->tree_root, 1);
6822 btrfs_commit_transaction(trans, info->tree_root);
6823
6824 while (1) {
6825 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6826 if (ret < 0)
6827 goto out;
6828 next:
6829 leaf = path->nodes[0];
6830 nritems = btrfs_header_nritems(leaf);
6831 if (path->slots[0] >= nritems) {
6832 ret = btrfs_next_leaf(root, path);
6833 if (ret < 0)
6834 goto out;
6835 if (ret == 1) {
6836 ret = 0;
6837 break;
6838 }
6839 leaf = path->nodes[0];
6840 nritems = btrfs_header_nritems(leaf);
6841 }
6842
6843 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
6844
6845 if (key.objectid >= block_group->key.objectid +
6846 block_group->key.offset)
6847 break;
6848
6849 if (progress && need_resched()) {
6850 btrfs_release_path(root, path);
6851 cond_resched();
6852 progress = 0;
6853 continue;
6854 }
6855 progress = 1;
6856
6857 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
6858 key.objectid + key.offset <= cur_byte) {
6859 path->slots[0]++;
6860 goto next;
6861 }
6862
6863 total_found++;
6864 cur_byte = key.objectid + key.offset;
6865 btrfs_release_path(root, path);
6866
6867 __alloc_chunk_for_shrink(root, block_group, 0);
6868 ret = relocate_one_extent(root, path, &key, block_group,
6869 reloc_inode, pass);
6870 BUG_ON(ret < 0);
6871 if (ret > 0)
6872 skipped++;
6873
6874 key.objectid = cur_byte;
6875 key.type = 0;
6876 key.offset = 0;
6877 }
6878
6879 btrfs_release_path(root, path);
6880
6881 if (pass == 0) {
6882 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
6883 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
6884 }
6885
6886 if (total_found > 0) {
6887 printk(KERN_INFO "btrfs found %llu extents in pass %d\n",
6888 (unsigned long long)total_found, pass);
6889 pass++;
6890 if (total_found == skipped && pass > 2) {
6891 iput(reloc_inode);
6892 reloc_inode = create_reloc_inode(info, block_group);
6893 pass = 0;
6894 }
6895 goto again;
6896 }
6897
6898 /* delete reloc_inode */
6899 iput(reloc_inode);
6900
6901 /* unpin extents in this range */
6902 trans = btrfs_start_transaction(info->tree_root, 1);
6903 btrfs_commit_transaction(trans, info->tree_root);
6904
6905 spin_lock(&block_group->lock);
6906 WARN_ON(block_group->pinned > 0);
6907 WARN_ON(block_group->reserved > 0);
6908 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
6909 spin_unlock(&block_group->lock);
6910 btrfs_put_block_group(block_group);
6911 ret = 0;
6912 out:
6913 btrfs_free_path(path);
6914 return ret;
6915 }
6916 #endif
6917
6918 static int find_first_block_group(struct btrfs_root *root,
6919 struct btrfs_path *path, struct btrfs_key *key)
6920 {
6921 int ret = 0;
6922 struct btrfs_key found_key;
6923 struct extent_buffer *leaf;
6924 int slot;
6925
6926 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
6927 if (ret < 0)
6928 goto out;
6929
6930 while (1) {
6931 slot = path->slots[0];
6932 leaf = path->nodes[0];
6933 if (slot >= btrfs_header_nritems(leaf)) {
6934 ret = btrfs_next_leaf(root, path);
6935 if (ret == 0)
6936 continue;
6937 if (ret < 0)
6938 goto out;
6939 break;
6940 }
6941 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6942
6943 if (found_key.objectid >= key->objectid &&
6944 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
6945 ret = 0;
6946 goto out;
6947 }
6948 path->slots[0]++;
6949 }
6950 ret = -ENOENT;
6951 out:
6952 return ret;
6953 }
6954
6955 int btrfs_free_block_groups(struct btrfs_fs_info *info)
6956 {
6957 struct btrfs_block_group_cache *block_group;
6958 struct btrfs_space_info *space_info;
6959 struct rb_node *n;
6960
6961 spin_lock(&info->block_group_cache_lock);
6962 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
6963 block_group = rb_entry(n, struct btrfs_block_group_cache,
6964 cache_node);
6965 rb_erase(&block_group->cache_node,
6966 &info->block_group_cache_tree);
6967 spin_unlock(&info->block_group_cache_lock);
6968
6969 btrfs_remove_free_space_cache(block_group);
6970 down_write(&block_group->space_info->groups_sem);
6971 list_del(&block_group->list);
6972 up_write(&block_group->space_info->groups_sem);
6973
6974 WARN_ON(atomic_read(&block_group->count) != 1);
6975 kfree(block_group);
6976
6977 spin_lock(&info->block_group_cache_lock);
6978 }
6979 spin_unlock(&info->block_group_cache_lock);
6980
6981 /* now that all the block groups are freed, go through and
6982 * free all the space_info structs. This is only called during
6983 * the final stages of unmount, and so we know nobody is
6984 * using them. We call synchronize_rcu() once before we start,
6985 * just to be on the safe side.
6986 */
6987 synchronize_rcu();
6988
6989 while(!list_empty(&info->space_info)) {
6990 space_info = list_entry(info->space_info.next,
6991 struct btrfs_space_info,
6992 list);
6993
6994 list_del(&space_info->list);
6995 kfree(space_info);
6996 }
6997 return 0;
6998 }
6999
7000 int btrfs_read_block_groups(struct btrfs_root *root)
7001 {
7002 struct btrfs_path *path;
7003 int ret;
7004 struct btrfs_block_group_cache *cache;
7005 struct btrfs_fs_info *info = root->fs_info;
7006 struct btrfs_space_info *space_info;
7007 struct btrfs_key key;
7008 struct btrfs_key found_key;
7009 struct extent_buffer *leaf;
7010
7011 root = info->extent_root;
7012 key.objectid = 0;
7013 key.offset = 0;
7014 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
7015 path = btrfs_alloc_path();
7016 if (!path)
7017 return -ENOMEM;
7018
7019 while (1) {
7020 ret = find_first_block_group(root, path, &key);
7021 if (ret > 0) {
7022 ret = 0;
7023 goto error;
7024 }
7025 if (ret != 0)
7026 goto error;
7027
7028 leaf = path->nodes[0];
7029 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7030 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7031 if (!cache) {
7032 ret = -ENOMEM;
7033 break;
7034 }
7035
7036 atomic_set(&cache->count, 1);
7037 spin_lock_init(&cache->lock);
7038 spin_lock_init(&cache->tree_lock);
7039 mutex_init(&cache->cache_mutex);
7040 INIT_LIST_HEAD(&cache->list);
7041 INIT_LIST_HEAD(&cache->cluster_list);
7042 cache->sectorsize = root->sectorsize;
7043
7044 /*
7045 * we only want to have 32k of ram per block group for keeping
7046 * track of free space, and if we pass 1/2 of that we want to
7047 * start converting things over to using bitmaps
7048 */
7049 cache->extents_thresh = ((1024 * 32) / 2) /
7050 sizeof(struct btrfs_free_space);
7051
7052 read_extent_buffer(leaf, &cache->item,
7053 btrfs_item_ptr_offset(leaf, path->slots[0]),
7054 sizeof(cache->item));
7055 memcpy(&cache->key, &found_key, sizeof(found_key));
7056
7057 key.objectid = found_key.objectid + found_key.offset;
7058 btrfs_release_path(root, path);
7059 cache->flags = btrfs_block_group_flags(&cache->item);
7060
7061 ret = update_space_info(info, cache->flags, found_key.offset,
7062 btrfs_block_group_used(&cache->item),
7063 &space_info);
7064 BUG_ON(ret);
7065 cache->space_info = space_info;
7066 down_write(&space_info->groups_sem);
7067 list_add_tail(&cache->list, &space_info->block_groups);
7068 up_write(&space_info->groups_sem);
7069
7070 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7071 BUG_ON(ret);
7072
7073 set_avail_alloc_bits(root->fs_info, cache->flags);
7074 if (btrfs_chunk_readonly(root, cache->key.objectid))
7075 set_block_group_readonly(cache);
7076 }
7077 ret = 0;
7078 error:
7079 btrfs_free_path(path);
7080 return ret;
7081 }
7082
7083 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
7084 struct btrfs_root *root, u64 bytes_used,
7085 u64 type, u64 chunk_objectid, u64 chunk_offset,
7086 u64 size)
7087 {
7088 int ret;
7089 struct btrfs_root *extent_root;
7090 struct btrfs_block_group_cache *cache;
7091
7092 extent_root = root->fs_info->extent_root;
7093
7094 root->fs_info->last_trans_log_full_commit = trans->transid;
7095
7096 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7097 if (!cache)
7098 return -ENOMEM;
7099
7100 cache->key.objectid = chunk_offset;
7101 cache->key.offset = size;
7102 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
7103 cache->sectorsize = root->sectorsize;
7104
7105 /*
7106 * we only want to have 32k of ram per block group for keeping track
7107 * of free space, and if we pass 1/2 of that we want to start
7108 * converting things over to using bitmaps
7109 */
7110 cache->extents_thresh = ((1024 * 32) / 2) /
7111 sizeof(struct btrfs_free_space);
7112 atomic_set(&cache->count, 1);
7113 spin_lock_init(&cache->lock);
7114 spin_lock_init(&cache->tree_lock);
7115 mutex_init(&cache->cache_mutex);
7116 INIT_LIST_HEAD(&cache->list);
7117 INIT_LIST_HEAD(&cache->cluster_list);
7118
7119 btrfs_set_block_group_used(&cache->item, bytes_used);
7120 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
7121 cache->flags = type;
7122 btrfs_set_block_group_flags(&cache->item, type);
7123
7124 cache->cached = 1;
7125 ret = btrfs_add_free_space(cache, chunk_offset, size);
7126 BUG_ON(ret);
7127 remove_sb_from_cache(root, cache);
7128
7129 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
7130 &cache->space_info);
7131 BUG_ON(ret);
7132 down_write(&cache->space_info->groups_sem);
7133 list_add_tail(&cache->list, &cache->space_info->block_groups);
7134 up_write(&cache->space_info->groups_sem);
7135
7136 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7137 BUG_ON(ret);
7138
7139 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
7140 sizeof(cache->item));
7141 BUG_ON(ret);
7142
7143 set_avail_alloc_bits(extent_root->fs_info, type);
7144
7145 return 0;
7146 }
7147
7148 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
7149 struct btrfs_root *root, u64 group_start)
7150 {
7151 struct btrfs_path *path;
7152 struct btrfs_block_group_cache *block_group;
7153 struct btrfs_free_cluster *cluster;
7154 struct btrfs_key key;
7155 int ret;
7156
7157 root = root->fs_info->extent_root;
7158
7159 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
7160 BUG_ON(!block_group);
7161 BUG_ON(!block_group->ro);
7162
7163 memcpy(&key, &block_group->key, sizeof(key));
7164
7165 /* make sure this block group isn't part of an allocation cluster */
7166 cluster = &root->fs_info->data_alloc_cluster;
7167 spin_lock(&cluster->refill_lock);
7168 btrfs_return_cluster_to_free_space(block_group, cluster);
7169 spin_unlock(&cluster->refill_lock);
7170
7171 /*
7172 * make sure this block group isn't part of a metadata
7173 * allocation cluster
7174 */
7175 cluster = &root->fs_info->meta_alloc_cluster;
7176 spin_lock(&cluster->refill_lock);
7177 btrfs_return_cluster_to_free_space(block_group, cluster);
7178 spin_unlock(&cluster->refill_lock);
7179
7180 path = btrfs_alloc_path();
7181 BUG_ON(!path);
7182
7183 spin_lock(&root->fs_info->block_group_cache_lock);
7184 rb_erase(&block_group->cache_node,
7185 &root->fs_info->block_group_cache_tree);
7186 spin_unlock(&root->fs_info->block_group_cache_lock);
7187 btrfs_remove_free_space_cache(block_group);
7188 down_write(&block_group->space_info->groups_sem);
7189 /*
7190 * we must use list_del_init so people can check to see if they
7191 * are still on the list after taking the semaphore
7192 */
7193 list_del_init(&block_group->list);
7194 up_write(&block_group->space_info->groups_sem);
7195
7196 spin_lock(&block_group->space_info->lock);
7197 block_group->space_info->total_bytes -= block_group->key.offset;
7198 block_group->space_info->bytes_readonly -= block_group->key.offset;
7199 spin_unlock(&block_group->space_info->lock);
7200 block_group->space_info->full = 0;
7201
7202 btrfs_put_block_group(block_group);
7203 btrfs_put_block_group(block_group);
7204
7205 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
7206 if (ret > 0)
7207 ret = -EIO;
7208 if (ret < 0)
7209 goto out;
7210
7211 ret = btrfs_del_item(trans, root, path);
7212 out:
7213 btrfs_free_path(path);
7214 return ret;
7215 }
Linux 2.6 libata-dev (mirror)