Btrfs: fix double increment of path->slots[0] in btrfs_next_leaf
[deliverable/linux.git] / fs / btrfs / extent-tree.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/pagemap.h>
20 #include <linux/writeback.h>
21 #include <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 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
2391 struct btrfs_root *root)
2392 {
2393 struct btrfs_block_group_cache *cache, *entry;
2394 struct rb_node *n;
2395 int err = 0;
2396 int werr = 0;
2397 struct btrfs_path *path;
2398 u64 last = 0;
2399
2400 path = btrfs_alloc_path();
2401 if (!path)
2402 return -ENOMEM;
2403
2404 while (1) {
2405 cache = NULL;
2406 spin_lock(&root->fs_info->block_group_cache_lock);
2407 for (n = rb_first(&root->fs_info->block_group_cache_tree);
2408 n; n = rb_next(n)) {
2409 entry = rb_entry(n, struct btrfs_block_group_cache,
2410 cache_node);
2411 if (entry->dirty) {
2412 cache = entry;
2413 break;
2414 }
2415 }
2416 spin_unlock(&root->fs_info->block_group_cache_lock);
2417
2418 if (!cache)
2419 break;
2420
2421 cache->dirty = 0;
2422 last += cache->key.offset;
2423
2424 err = write_one_cache_group(trans, root,
2425 path, cache);
2426 /*
2427 * if we fail to write the cache group, we want
2428 * to keep it marked dirty in hopes that a later
2429 * write will work
2430 */
2431 if (err) {
2432 werr = err;
2433 continue;
2434 }
2435 }
2436 btrfs_free_path(path);
2437 return werr;
2438 }
2439
2440 int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
2441 {
2442 struct btrfs_block_group_cache *block_group;
2443 int readonly = 0;
2444
2445 block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
2446 if (!block_group || block_group->ro)
2447 readonly = 1;
2448 if (block_group)
2449 btrfs_put_block_group(block_group);
2450 return readonly;
2451 }
2452
2453 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
2454 u64 total_bytes, u64 bytes_used,
2455 struct btrfs_space_info **space_info)
2456 {
2457 struct btrfs_space_info *found;
2458
2459 found = __find_space_info(info, flags);
2460 if (found) {
2461 spin_lock(&found->lock);
2462 found->total_bytes += total_bytes;
2463 found->bytes_used += bytes_used;
2464 found->full = 0;
2465 spin_unlock(&found->lock);
2466 *space_info = found;
2467 return 0;
2468 }
2469 found = kzalloc(sizeof(*found), GFP_NOFS);
2470 if (!found)
2471 return -ENOMEM;
2472
2473 INIT_LIST_HEAD(&found->block_groups);
2474 init_rwsem(&found->groups_sem);
2475 spin_lock_init(&found->lock);
2476 found->flags = flags;
2477 found->total_bytes = total_bytes;
2478 found->bytes_used = bytes_used;
2479 found->bytes_pinned = 0;
2480 found->bytes_reserved = 0;
2481 found->bytes_readonly = 0;
2482 found->bytes_delalloc = 0;
2483 found->full = 0;
2484 found->force_alloc = 0;
2485 *space_info = found;
2486 list_add_rcu(&found->list, &info->space_info);
2487 return 0;
2488 }
2489
2490 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
2491 {
2492 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
2493 BTRFS_BLOCK_GROUP_RAID1 |
2494 BTRFS_BLOCK_GROUP_RAID10 |
2495 BTRFS_BLOCK_GROUP_DUP);
2496 if (extra_flags) {
2497 if (flags & BTRFS_BLOCK_GROUP_DATA)
2498 fs_info->avail_data_alloc_bits |= extra_flags;
2499 if (flags & BTRFS_BLOCK_GROUP_METADATA)
2500 fs_info->avail_metadata_alloc_bits |= extra_flags;
2501 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
2502 fs_info->avail_system_alloc_bits |= extra_flags;
2503 }
2504 }
2505
2506 static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
2507 {
2508 spin_lock(&cache->space_info->lock);
2509 spin_lock(&cache->lock);
2510 if (!cache->ro) {
2511 cache->space_info->bytes_readonly += cache->key.offset -
2512 btrfs_block_group_used(&cache->item);
2513 cache->ro = 1;
2514 }
2515 spin_unlock(&cache->lock);
2516 spin_unlock(&cache->space_info->lock);
2517 }
2518
2519 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
2520 {
2521 u64 num_devices = root->fs_info->fs_devices->rw_devices;
2522
2523 if (num_devices == 1)
2524 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
2525 if (num_devices < 4)
2526 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
2527
2528 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
2529 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
2530 BTRFS_BLOCK_GROUP_RAID10))) {
2531 flags &= ~BTRFS_BLOCK_GROUP_DUP;
2532 }
2533
2534 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
2535 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
2536 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
2537 }
2538
2539 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
2540 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
2541 (flags & BTRFS_BLOCK_GROUP_RAID10) |
2542 (flags & BTRFS_BLOCK_GROUP_DUP)))
2543 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
2544 return flags;
2545 }
2546
2547 static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data)
2548 {
2549 struct btrfs_fs_info *info = root->fs_info;
2550 u64 alloc_profile;
2551
2552 if (data) {
2553 alloc_profile = info->avail_data_alloc_bits &
2554 info->data_alloc_profile;
2555 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2556 } else if (root == root->fs_info->chunk_root) {
2557 alloc_profile = info->avail_system_alloc_bits &
2558 info->system_alloc_profile;
2559 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2560 } else {
2561 alloc_profile = info->avail_metadata_alloc_bits &
2562 info->metadata_alloc_profile;
2563 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2564 }
2565
2566 return btrfs_reduce_alloc_profile(root, data);
2567 }
2568
2569 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
2570 {
2571 u64 alloc_target;
2572
2573 alloc_target = btrfs_get_alloc_profile(root, 1);
2574 BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
2575 alloc_target);
2576 }
2577
2578 /*
2579 * for now this just makes sure we have at least 5% of our metadata space free
2580 * for use.
2581 */
2582 int btrfs_check_metadata_free_space(struct btrfs_root *root)
2583 {
2584 struct btrfs_fs_info *info = root->fs_info;
2585 struct btrfs_space_info *meta_sinfo;
2586 u64 alloc_target, thresh;
2587 int committed = 0, ret;
2588
2589 /* get the space info for where the metadata will live */
2590 alloc_target = btrfs_get_alloc_profile(root, 0);
2591 meta_sinfo = __find_space_info(info, alloc_target);
2592
2593 again:
2594 spin_lock(&meta_sinfo->lock);
2595 if (!meta_sinfo->full)
2596 thresh = meta_sinfo->total_bytes * 80;
2597 else
2598 thresh = meta_sinfo->total_bytes * 95;
2599
2600 do_div(thresh, 100);
2601
2602 if (meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
2603 meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly > thresh) {
2604 struct btrfs_trans_handle *trans;
2605 if (!meta_sinfo->full) {
2606 meta_sinfo->force_alloc = 1;
2607 spin_unlock(&meta_sinfo->lock);
2608
2609 trans = btrfs_start_transaction(root, 1);
2610 if (!trans)
2611 return -ENOMEM;
2612
2613 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2614 2 * 1024 * 1024, alloc_target, 0);
2615 btrfs_end_transaction(trans, root);
2616 goto again;
2617 }
2618 spin_unlock(&meta_sinfo->lock);
2619
2620 if (!committed) {
2621 committed = 1;
2622 trans = btrfs_join_transaction(root, 1);
2623 if (!trans)
2624 return -ENOMEM;
2625 ret = btrfs_commit_transaction(trans, root);
2626 if (ret)
2627 return ret;
2628 goto again;
2629 }
2630 return -ENOSPC;
2631 }
2632 spin_unlock(&meta_sinfo->lock);
2633
2634 return 0;
2635 }
2636
2637 /*
2638 * This will check the space that the inode allocates from to make sure we have
2639 * enough space for bytes.
2640 */
2641 int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
2642 u64 bytes)
2643 {
2644 struct btrfs_space_info *data_sinfo;
2645 int ret = 0, committed = 0;
2646
2647 /* make sure bytes are sectorsize aligned */
2648 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
2649
2650 data_sinfo = BTRFS_I(inode)->space_info;
2651 again:
2652 /* make sure we have enough space to handle the data first */
2653 spin_lock(&data_sinfo->lock);
2654 if (data_sinfo->total_bytes - data_sinfo->bytes_used -
2655 data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved -
2656 data_sinfo->bytes_pinned - data_sinfo->bytes_readonly -
2657 data_sinfo->bytes_may_use < bytes) {
2658 struct btrfs_trans_handle *trans;
2659
2660 /*
2661 * if we don't have enough free bytes in this space then we need
2662 * to alloc a new chunk.
2663 */
2664 if (!data_sinfo->full) {
2665 u64 alloc_target;
2666
2667 data_sinfo->force_alloc = 1;
2668 spin_unlock(&data_sinfo->lock);
2669
2670 alloc_target = btrfs_get_alloc_profile(root, 1);
2671 trans = btrfs_start_transaction(root, 1);
2672 if (!trans)
2673 return -ENOMEM;
2674
2675 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2676 bytes + 2 * 1024 * 1024,
2677 alloc_target, 0);
2678 btrfs_end_transaction(trans, root);
2679 if (ret)
2680 return ret;
2681 goto again;
2682 }
2683 spin_unlock(&data_sinfo->lock);
2684
2685 /* commit the current transaction and try again */
2686 if (!committed) {
2687 committed = 1;
2688 trans = btrfs_join_transaction(root, 1);
2689 if (!trans)
2690 return -ENOMEM;
2691 ret = btrfs_commit_transaction(trans, root);
2692 if (ret)
2693 return ret;
2694 goto again;
2695 }
2696
2697 printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes"
2698 ", %llu bytes_used, %llu bytes_reserved, "
2699 "%llu bytes_pinned, %llu bytes_readonly, %llu may use "
2700 "%llu total\n", (unsigned long long)bytes,
2701 (unsigned long long)data_sinfo->bytes_delalloc,
2702 (unsigned long long)data_sinfo->bytes_used,
2703 (unsigned long long)data_sinfo->bytes_reserved,
2704 (unsigned long long)data_sinfo->bytes_pinned,
2705 (unsigned long long)data_sinfo->bytes_readonly,
2706 (unsigned long long)data_sinfo->bytes_may_use,
2707 (unsigned long long)data_sinfo->total_bytes);
2708 return -ENOSPC;
2709 }
2710 data_sinfo->bytes_may_use += bytes;
2711 BTRFS_I(inode)->reserved_bytes += bytes;
2712 spin_unlock(&data_sinfo->lock);
2713
2714 return btrfs_check_metadata_free_space(root);
2715 }
2716
2717 /*
2718 * if there was an error for whatever reason after calling
2719 * btrfs_check_data_free_space, call this so we can cleanup the counters.
2720 */
2721 void btrfs_free_reserved_data_space(struct btrfs_root *root,
2722 struct inode *inode, u64 bytes)
2723 {
2724 struct btrfs_space_info *data_sinfo;
2725
2726 /* make sure bytes are sectorsize aligned */
2727 bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
2728
2729 data_sinfo = BTRFS_I(inode)->space_info;
2730 spin_lock(&data_sinfo->lock);
2731 data_sinfo->bytes_may_use -= bytes;
2732 BTRFS_I(inode)->reserved_bytes -= bytes;
2733 spin_unlock(&data_sinfo->lock);
2734 }
2735
2736 /* called when we are adding a delalloc extent to the inode's io_tree */
2737 void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
2738 u64 bytes)
2739 {
2740 struct btrfs_space_info *data_sinfo;
2741
2742 /* get the space info for where this inode will be storing its data */
2743 data_sinfo = BTRFS_I(inode)->space_info;
2744
2745 /* make sure we have enough space to handle the data first */
2746 spin_lock(&data_sinfo->lock);
2747 data_sinfo->bytes_delalloc += bytes;
2748
2749 /*
2750 * we are adding a delalloc extent without calling
2751 * btrfs_check_data_free_space first. This happens on a weird
2752 * writepage condition, but shouldn't hurt our accounting
2753 */
2754 if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {
2755 data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;
2756 BTRFS_I(inode)->reserved_bytes = 0;
2757 } else {
2758 data_sinfo->bytes_may_use -= bytes;
2759 BTRFS_I(inode)->reserved_bytes -= bytes;
2760 }
2761
2762 spin_unlock(&data_sinfo->lock);
2763 }
2764
2765 /* called when we are clearing an delalloc extent from the inode's io_tree */
2766 void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
2767 u64 bytes)
2768 {
2769 struct btrfs_space_info *info;
2770
2771 info = BTRFS_I(inode)->space_info;
2772
2773 spin_lock(&info->lock);
2774 info->bytes_delalloc -= bytes;
2775 spin_unlock(&info->lock);
2776 }
2777
2778 static void force_metadata_allocation(struct btrfs_fs_info *info)
2779 {
2780 struct list_head *head = &info->space_info;
2781 struct btrfs_space_info *found;
2782
2783 rcu_read_lock();
2784 list_for_each_entry_rcu(found, head, list) {
2785 if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
2786 found->force_alloc = 1;
2787 }
2788 rcu_read_unlock();
2789 }
2790
2791 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
2792 struct btrfs_root *extent_root, u64 alloc_bytes,
2793 u64 flags, int force)
2794 {
2795 struct btrfs_space_info *space_info;
2796 struct btrfs_fs_info *fs_info = extent_root->fs_info;
2797 u64 thresh;
2798 int ret = 0;
2799
2800 mutex_lock(&fs_info->chunk_mutex);
2801
2802 flags = btrfs_reduce_alloc_profile(extent_root, flags);
2803
2804 space_info = __find_space_info(extent_root->fs_info, flags);
2805 if (!space_info) {
2806 ret = update_space_info(extent_root->fs_info, flags,
2807 0, 0, &space_info);
2808 BUG_ON(ret);
2809 }
2810 BUG_ON(!space_info);
2811
2812 spin_lock(&space_info->lock);
2813 if (space_info->force_alloc) {
2814 force = 1;
2815 space_info->force_alloc = 0;
2816 }
2817 if (space_info->full) {
2818 spin_unlock(&space_info->lock);
2819 goto out;
2820 }
2821
2822 thresh = space_info->total_bytes - space_info->bytes_readonly;
2823 thresh = div_factor(thresh, 6);
2824 if (!force &&
2825 (space_info->bytes_used + space_info->bytes_pinned +
2826 space_info->bytes_reserved + alloc_bytes) < thresh) {
2827 spin_unlock(&space_info->lock);
2828 goto out;
2829 }
2830 spin_unlock(&space_info->lock);
2831
2832 /*
2833 * if we're doing a data chunk, go ahead and make sure that
2834 * we keep a reasonable number of metadata chunks allocated in the
2835 * FS as well.
2836 */
2837 if (flags & BTRFS_BLOCK_GROUP_DATA) {
2838 fs_info->data_chunk_allocations++;
2839 if (!(fs_info->data_chunk_allocations %
2840 fs_info->metadata_ratio))
2841 force_metadata_allocation(fs_info);
2842 }
2843
2844 ret = btrfs_alloc_chunk(trans, extent_root, flags);
2845 if (ret)
2846 space_info->full = 1;
2847 out:
2848 mutex_unlock(&extent_root->fs_info->chunk_mutex);
2849 return ret;
2850 }
2851
2852 static int update_block_group(struct btrfs_trans_handle *trans,
2853 struct btrfs_root *root,
2854 u64 bytenr, u64 num_bytes, int alloc,
2855 int mark_free)
2856 {
2857 struct btrfs_block_group_cache *cache;
2858 struct btrfs_fs_info *info = root->fs_info;
2859 u64 total = num_bytes;
2860 u64 old_val;
2861 u64 byte_in_group;
2862
2863 /* block accounting for super block */
2864 spin_lock(&info->delalloc_lock);
2865 old_val = btrfs_super_bytes_used(&info->super_copy);
2866 if (alloc)
2867 old_val += num_bytes;
2868 else
2869 old_val -= num_bytes;
2870 btrfs_set_super_bytes_used(&info->super_copy, old_val);
2871
2872 /* block accounting for root item */
2873 old_val = btrfs_root_used(&root->root_item);
2874 if (alloc)
2875 old_val += num_bytes;
2876 else
2877 old_val -= num_bytes;
2878 btrfs_set_root_used(&root->root_item, old_val);
2879 spin_unlock(&info->delalloc_lock);
2880
2881 while (total) {
2882 cache = btrfs_lookup_block_group(info, bytenr);
2883 if (!cache)
2884 return -1;
2885 byte_in_group = bytenr - cache->key.objectid;
2886 WARN_ON(byte_in_group > cache->key.offset);
2887
2888 spin_lock(&cache->space_info->lock);
2889 spin_lock(&cache->lock);
2890 cache->dirty = 1;
2891 old_val = btrfs_block_group_used(&cache->item);
2892 num_bytes = min(total, cache->key.offset - byte_in_group);
2893 if (alloc) {
2894 old_val += num_bytes;
2895 cache->space_info->bytes_used += num_bytes;
2896 if (cache->ro)
2897 cache->space_info->bytes_readonly -= num_bytes;
2898 btrfs_set_block_group_used(&cache->item, old_val);
2899 spin_unlock(&cache->lock);
2900 spin_unlock(&cache->space_info->lock);
2901 } else {
2902 old_val -= num_bytes;
2903 cache->space_info->bytes_used -= num_bytes;
2904 if (cache->ro)
2905 cache->space_info->bytes_readonly += num_bytes;
2906 btrfs_set_block_group_used(&cache->item, old_val);
2907 spin_unlock(&cache->lock);
2908 spin_unlock(&cache->space_info->lock);
2909 if (mark_free) {
2910 int ret;
2911
2912 ret = btrfs_discard_extent(root, bytenr,
2913 num_bytes);
2914 WARN_ON(ret);
2915
2916 ret = btrfs_add_free_space(cache, bytenr,
2917 num_bytes);
2918 WARN_ON(ret);
2919 }
2920 }
2921 btrfs_put_block_group(cache);
2922 total -= num_bytes;
2923 bytenr += num_bytes;
2924 }
2925 return 0;
2926 }
2927
2928 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
2929 {
2930 struct btrfs_block_group_cache *cache;
2931 u64 bytenr;
2932
2933 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
2934 if (!cache)
2935 return 0;
2936
2937 bytenr = cache->key.objectid;
2938 btrfs_put_block_group(cache);
2939
2940 return bytenr;
2941 }
2942
2943 int btrfs_update_pinned_extents(struct btrfs_root *root,
2944 u64 bytenr, u64 num, int pin)
2945 {
2946 u64 len;
2947 struct btrfs_block_group_cache *cache;
2948 struct btrfs_fs_info *fs_info = root->fs_info;
2949
2950 if (pin) {
2951 set_extent_dirty(&fs_info->pinned_extents,
2952 bytenr, bytenr + num - 1, GFP_NOFS);
2953 } else {
2954 clear_extent_dirty(&fs_info->pinned_extents,
2955 bytenr, bytenr + num - 1, GFP_NOFS);
2956 }
2957
2958 while (num > 0) {
2959 cache = btrfs_lookup_block_group(fs_info, bytenr);
2960 BUG_ON(!cache);
2961 len = min(num, cache->key.offset -
2962 (bytenr - cache->key.objectid));
2963 if (pin) {
2964 spin_lock(&cache->space_info->lock);
2965 spin_lock(&cache->lock);
2966 cache->pinned += len;
2967 cache->space_info->bytes_pinned += len;
2968 spin_unlock(&cache->lock);
2969 spin_unlock(&cache->space_info->lock);
2970 fs_info->total_pinned += len;
2971 } else {
2972 spin_lock(&cache->space_info->lock);
2973 spin_lock(&cache->lock);
2974 cache->pinned -= len;
2975 cache->space_info->bytes_pinned -= len;
2976 spin_unlock(&cache->lock);
2977 spin_unlock(&cache->space_info->lock);
2978 fs_info->total_pinned -= len;
2979 if (cache->cached)
2980 btrfs_add_free_space(cache, bytenr, len);
2981 }
2982 btrfs_put_block_group(cache);
2983 bytenr += len;
2984 num -= len;
2985 }
2986 return 0;
2987 }
2988
2989 static int update_reserved_extents(struct btrfs_root *root,
2990 u64 bytenr, u64 num, int reserve)
2991 {
2992 u64 len;
2993 struct btrfs_block_group_cache *cache;
2994 struct btrfs_fs_info *fs_info = root->fs_info;
2995
2996 while (num > 0) {
2997 cache = btrfs_lookup_block_group(fs_info, bytenr);
2998 BUG_ON(!cache);
2999 len = min(num, cache->key.offset -
3000 (bytenr - cache->key.objectid));
3001
3002 spin_lock(&cache->space_info->lock);
3003 spin_lock(&cache->lock);
3004 if (reserve) {
3005 cache->reserved += len;
3006 cache->space_info->bytes_reserved += len;
3007 } else {
3008 cache->reserved -= len;
3009 cache->space_info->bytes_reserved -= len;
3010 }
3011 spin_unlock(&cache->lock);
3012 spin_unlock(&cache->space_info->lock);
3013 btrfs_put_block_group(cache);
3014 bytenr += len;
3015 num -= len;
3016 }
3017 return 0;
3018 }
3019
3020 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
3021 {
3022 u64 last = 0;
3023 u64 start;
3024 u64 end;
3025 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
3026 int ret;
3027
3028 while (1) {
3029 ret = find_first_extent_bit(pinned_extents, last,
3030 &start, &end, EXTENT_DIRTY);
3031 if (ret)
3032 break;
3033 set_extent_dirty(copy, start, end, GFP_NOFS);
3034 last = end + 1;
3035 }
3036 return 0;
3037 }
3038
3039 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
3040 struct btrfs_root *root,
3041 struct extent_io_tree *unpin)
3042 {
3043 u64 start;
3044 u64 end;
3045 int ret;
3046
3047 while (1) {
3048 ret = find_first_extent_bit(unpin, 0, &start, &end,
3049 EXTENT_DIRTY);
3050 if (ret)
3051 break;
3052
3053 ret = btrfs_discard_extent(root, start, end + 1 - start);
3054
3055 /* unlocks the pinned mutex */
3056 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
3057 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3058
3059 cond_resched();
3060 }
3061 return ret;
3062 }
3063
3064 static int pin_down_bytes(struct btrfs_trans_handle *trans,
3065 struct btrfs_root *root,
3066 struct btrfs_path *path,
3067 u64 bytenr, u64 num_bytes, int is_data,
3068 struct extent_buffer **must_clean)
3069 {
3070 int err = 0;
3071 struct extent_buffer *buf;
3072
3073 if (is_data)
3074 goto pinit;
3075
3076 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
3077 if (!buf)
3078 goto pinit;
3079
3080 /* we can reuse a block if it hasn't been written
3081 * and it is from this transaction. We can't
3082 * reuse anything from the tree log root because
3083 * it has tiny sub-transactions.
3084 */
3085 if (btrfs_buffer_uptodate(buf, 0) &&
3086 btrfs_try_tree_lock(buf)) {
3087 u64 header_owner = btrfs_header_owner(buf);
3088 u64 header_transid = btrfs_header_generation(buf);
3089 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
3090 header_transid == trans->transid &&
3091 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
3092 *must_clean = buf;
3093 return 1;
3094 }
3095 btrfs_tree_unlock(buf);
3096 }
3097 free_extent_buffer(buf);
3098 pinit:
3099 btrfs_set_path_blocking(path);
3100 /* unlocks the pinned mutex */
3101 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
3102
3103 BUG_ON(err < 0);
3104 return 0;
3105 }
3106
3107
3108 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
3109 struct btrfs_root *root,
3110 u64 bytenr, u64 num_bytes, u64 parent,
3111 u64 root_objectid, u64 owner_objectid,
3112 u64 owner_offset, int refs_to_drop,
3113 struct btrfs_delayed_extent_op *extent_op)
3114 {
3115 struct btrfs_key key;
3116 struct btrfs_path *path;
3117 struct btrfs_fs_info *info = root->fs_info;
3118 struct btrfs_root *extent_root = info->extent_root;
3119 struct extent_buffer *leaf;
3120 struct btrfs_extent_item *ei;
3121 struct btrfs_extent_inline_ref *iref;
3122 int ret;
3123 int is_data;
3124 int extent_slot = 0;
3125 int found_extent = 0;
3126 int num_to_del = 1;
3127 u32 item_size;
3128 u64 refs;
3129
3130 path = btrfs_alloc_path();
3131 if (!path)
3132 return -ENOMEM;
3133
3134 path->reada = 1;
3135 path->leave_spinning = 1;
3136
3137 is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
3138 BUG_ON(!is_data && refs_to_drop != 1);
3139
3140 ret = lookup_extent_backref(trans, extent_root, path, &iref,
3141 bytenr, num_bytes, parent,
3142 root_objectid, owner_objectid,
3143 owner_offset);
3144 if (ret == 0) {
3145 extent_slot = path->slots[0];
3146 while (extent_slot >= 0) {
3147 btrfs_item_key_to_cpu(path->nodes[0], &key,
3148 extent_slot);
3149 if (key.objectid != bytenr)
3150 break;
3151 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3152 key.offset == num_bytes) {
3153 found_extent = 1;
3154 break;
3155 }
3156 if (path->slots[0] - extent_slot > 5)
3157 break;
3158 extent_slot--;
3159 }
3160 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3161 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
3162 if (found_extent && item_size < sizeof(*ei))
3163 found_extent = 0;
3164 #endif
3165 if (!found_extent) {
3166 BUG_ON(iref);
3167 ret = remove_extent_backref(trans, extent_root, path,
3168 NULL, refs_to_drop,
3169 is_data);
3170 BUG_ON(ret);
3171 btrfs_release_path(extent_root, path);
3172 path->leave_spinning = 1;
3173
3174 key.objectid = bytenr;
3175 key.type = BTRFS_EXTENT_ITEM_KEY;
3176 key.offset = num_bytes;
3177
3178 ret = btrfs_search_slot(trans, extent_root,
3179 &key, path, -1, 1);
3180 if (ret) {
3181 printk(KERN_ERR "umm, got %d back from search"
3182 ", was looking for %llu\n", ret,
3183 (unsigned long long)bytenr);
3184 btrfs_print_leaf(extent_root, path->nodes[0]);
3185 }
3186 BUG_ON(ret);
3187 extent_slot = path->slots[0];
3188 }
3189 } else {
3190 btrfs_print_leaf(extent_root, path->nodes[0]);
3191 WARN_ON(1);
3192 printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
3193 "parent %llu root %llu owner %llu offset %llu\n",
3194 (unsigned long long)bytenr,
3195 (unsigned long long)parent,
3196 (unsigned long long)root_objectid,
3197 (unsigned long long)owner_objectid,
3198 (unsigned long long)owner_offset);
3199 }
3200
3201 leaf = path->nodes[0];
3202 item_size = btrfs_item_size_nr(leaf, extent_slot);
3203 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3204 if (item_size < sizeof(*ei)) {
3205 BUG_ON(found_extent || extent_slot != path->slots[0]);
3206 ret = convert_extent_item_v0(trans, extent_root, path,
3207 owner_objectid, 0);
3208 BUG_ON(ret < 0);
3209
3210 btrfs_release_path(extent_root, path);
3211 path->leave_spinning = 1;
3212
3213 key.objectid = bytenr;
3214 key.type = BTRFS_EXTENT_ITEM_KEY;
3215 key.offset = num_bytes;
3216
3217 ret = btrfs_search_slot(trans, extent_root, &key, path,
3218 -1, 1);
3219 if (ret) {
3220 printk(KERN_ERR "umm, got %d back from search"
3221 ", was looking for %llu\n", ret,
3222 (unsigned long long)bytenr);
3223 btrfs_print_leaf(extent_root, path->nodes[0]);
3224 }
3225 BUG_ON(ret);
3226 extent_slot = path->slots[0];
3227 leaf = path->nodes[0];
3228 item_size = btrfs_item_size_nr(leaf, extent_slot);
3229 }
3230 #endif
3231 BUG_ON(item_size < sizeof(*ei));
3232 ei = btrfs_item_ptr(leaf, extent_slot,
3233 struct btrfs_extent_item);
3234 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3235 struct btrfs_tree_block_info *bi;
3236 BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
3237 bi = (struct btrfs_tree_block_info *)(ei + 1);
3238 WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
3239 }
3240
3241 refs = btrfs_extent_refs(leaf, ei);
3242 BUG_ON(refs < refs_to_drop);
3243 refs -= refs_to_drop;
3244
3245 if (refs > 0) {
3246 if (extent_op)
3247 __run_delayed_extent_op(extent_op, leaf, ei);
3248 /*
3249 * In the case of inline back ref, reference count will
3250 * be updated by remove_extent_backref
3251 */
3252 if (iref) {
3253 BUG_ON(!found_extent);
3254 } else {
3255 btrfs_set_extent_refs(leaf, ei, refs);
3256 btrfs_mark_buffer_dirty(leaf);
3257 }
3258 if (found_extent) {
3259 ret = remove_extent_backref(trans, extent_root, path,
3260 iref, refs_to_drop,
3261 is_data);
3262 BUG_ON(ret);
3263 }
3264 } else {
3265 int mark_free = 0;
3266 struct extent_buffer *must_clean = NULL;
3267
3268 if (found_extent) {
3269 BUG_ON(is_data && refs_to_drop !=
3270 extent_data_ref_count(root, path, iref));
3271 if (iref) {
3272 BUG_ON(path->slots[0] != extent_slot);
3273 } else {
3274 BUG_ON(path->slots[0] != extent_slot + 1);
3275 path->slots[0] = extent_slot;
3276 num_to_del = 2;
3277 }
3278 }
3279
3280 ret = pin_down_bytes(trans, root, path, bytenr,
3281 num_bytes, is_data, &must_clean);
3282 if (ret > 0)
3283 mark_free = 1;
3284 BUG_ON(ret < 0);
3285 /*
3286 * it is going to be very rare for someone to be waiting
3287 * on the block we're freeing. del_items might need to
3288 * schedule, so rather than get fancy, just force it
3289 * to blocking here
3290 */
3291 if (must_clean)
3292 btrfs_set_lock_blocking(must_clean);
3293
3294 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
3295 num_to_del);
3296 BUG_ON(ret);
3297 btrfs_release_path(extent_root, path);
3298
3299 if (must_clean) {
3300 clean_tree_block(NULL, root, must_clean);
3301 btrfs_tree_unlock(must_clean);
3302 free_extent_buffer(must_clean);
3303 }
3304
3305 if (is_data) {
3306 ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
3307 BUG_ON(ret);
3308 } else {
3309 invalidate_mapping_pages(info->btree_inode->i_mapping,
3310 bytenr >> PAGE_CACHE_SHIFT,
3311 (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT);
3312 }
3313
3314 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
3315 mark_free);
3316 BUG_ON(ret);
3317 }
3318 btrfs_free_path(path);
3319 return ret;
3320 }
3321
3322 /*
3323 * when we free an extent, it is possible (and likely) that we free the last
3324 * delayed ref for that extent as well. This searches the delayed ref tree for
3325 * a given extent, and if there are no other delayed refs to be processed, it
3326 * removes it from the tree.
3327 */
3328 static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
3329 struct btrfs_root *root, u64 bytenr)
3330 {
3331 struct btrfs_delayed_ref_head *head;
3332 struct btrfs_delayed_ref_root *delayed_refs;
3333 struct btrfs_delayed_ref_node *ref;
3334 struct rb_node *node;
3335 int ret;
3336
3337 delayed_refs = &trans->transaction->delayed_refs;
3338 spin_lock(&delayed_refs->lock);
3339 head = btrfs_find_delayed_ref_head(trans, bytenr);
3340 if (!head)
3341 goto out;
3342
3343 node = rb_prev(&head->node.rb_node);
3344 if (!node)
3345 goto out;
3346
3347 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3348
3349 /* there are still entries for this ref, we can't drop it */
3350 if (ref->bytenr == bytenr)
3351 goto out;
3352
3353 if (head->extent_op) {
3354 if (!head->must_insert_reserved)
3355 goto out;
3356 kfree(head->extent_op);
3357 head->extent_op = NULL;
3358 }
3359
3360 /*
3361 * waiting for the lock here would deadlock. If someone else has it
3362 * locked they are already in the process of dropping it anyway
3363 */
3364 if (!mutex_trylock(&head->mutex))
3365 goto out;
3366
3367 /*
3368 * at this point we have a head with no other entries. Go
3369 * ahead and process it.
3370 */
3371 head->node.in_tree = 0;
3372 rb_erase(&head->node.rb_node, &delayed_refs->root);
3373
3374 delayed_refs->num_entries--;
3375
3376 /*
3377 * we don't take a ref on the node because we're removing it from the
3378 * tree, so we just steal the ref the tree was holding.
3379 */
3380 delayed_refs->num_heads--;
3381 if (list_empty(&head->cluster))
3382 delayed_refs->num_heads_ready--;
3383
3384 list_del_init(&head->cluster);
3385 spin_unlock(&delayed_refs->lock);
3386
3387 ret = run_one_delayed_ref(trans, root->fs_info->tree_root,
3388 &head->node, head->extent_op,
3389 head->must_insert_reserved);
3390 BUG_ON(ret);
3391 btrfs_put_delayed_ref(&head->node);
3392 return 0;
3393 out:
3394 spin_unlock(&delayed_refs->lock);
3395 return 0;
3396 }
3397
3398 int btrfs_free_extent(struct btrfs_trans_handle *trans,
3399 struct btrfs_root *root,
3400 u64 bytenr, u64 num_bytes, u64 parent,
3401 u64 root_objectid, u64 owner, u64 offset)
3402 {
3403 int ret;
3404
3405 /*
3406 * tree log blocks never actually go into the extent allocation
3407 * tree, just update pinning info and exit early.
3408 */
3409 if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
3410 WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
3411 /* unlocks the pinned mutex */
3412 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
3413 update_reserved_extents(root, bytenr, num_bytes, 0);
3414 ret = 0;
3415 } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
3416 ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
3417 parent, root_objectid, (int)owner,
3418 BTRFS_DROP_DELAYED_REF, NULL);
3419 BUG_ON(ret);
3420 ret = check_ref_cleanup(trans, root, bytenr);
3421 BUG_ON(ret);
3422 } else {
3423 ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
3424 parent, root_objectid, owner,
3425 offset, BTRFS_DROP_DELAYED_REF, NULL);
3426 BUG_ON(ret);
3427 }
3428 return ret;
3429 }
3430
3431 static u64 stripe_align(struct btrfs_root *root, u64 val)
3432 {
3433 u64 mask = ((u64)root->stripesize - 1);
3434 u64 ret = (val + mask) & ~mask;
3435 return ret;
3436 }
3437
3438 /*
3439 * walks the btree of allocated extents and find a hole of a given size.
3440 * The key ins is changed to record the hole:
3441 * ins->objectid == block start
3442 * ins->flags = BTRFS_EXTENT_ITEM_KEY
3443 * ins->offset == number of blocks
3444 * Any available blocks before search_start are skipped.
3445 */
3446 static noinline int find_free_extent(struct btrfs_trans_handle *trans,
3447 struct btrfs_root *orig_root,
3448 u64 num_bytes, u64 empty_size,
3449 u64 search_start, u64 search_end,
3450 u64 hint_byte, struct btrfs_key *ins,
3451 u64 exclude_start, u64 exclude_nr,
3452 int data)
3453 {
3454 int ret = 0;
3455 struct btrfs_root *root = orig_root->fs_info->extent_root;
3456 struct btrfs_free_cluster *last_ptr = NULL;
3457 struct btrfs_block_group_cache *block_group = NULL;
3458 int empty_cluster = 2 * 1024 * 1024;
3459 int allowed_chunk_alloc = 0;
3460 struct btrfs_space_info *space_info;
3461 int last_ptr_loop = 0;
3462 int loop = 0;
3463
3464 WARN_ON(num_bytes < root->sectorsize);
3465 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
3466 ins->objectid = 0;
3467 ins->offset = 0;
3468
3469 space_info = __find_space_info(root->fs_info, data);
3470
3471 if (orig_root->ref_cows || empty_size)
3472 allowed_chunk_alloc = 1;
3473
3474 if (data & BTRFS_BLOCK_GROUP_METADATA) {
3475 last_ptr = &root->fs_info->meta_alloc_cluster;
3476 if (!btrfs_test_opt(root, SSD))
3477 empty_cluster = 64 * 1024;
3478 }
3479
3480 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
3481 last_ptr = &root->fs_info->data_alloc_cluster;
3482 }
3483
3484 if (last_ptr) {
3485 spin_lock(&last_ptr->lock);
3486 if (last_ptr->block_group)
3487 hint_byte = last_ptr->window_start;
3488 spin_unlock(&last_ptr->lock);
3489 }
3490
3491 search_start = max(search_start, first_logical_byte(root, 0));
3492 search_start = max(search_start, hint_byte);
3493
3494 if (!last_ptr) {
3495 empty_cluster = 0;
3496 loop = 1;
3497 }
3498
3499 if (search_start == hint_byte) {
3500 block_group = btrfs_lookup_block_group(root->fs_info,
3501 search_start);
3502 if (block_group && block_group_bits(block_group, data)) {
3503 down_read(&space_info->groups_sem);
3504 if (list_empty(&block_group->list) ||
3505 block_group->ro) {
3506 /*
3507 * someone is removing this block group,
3508 * we can't jump into the have_block_group
3509 * target because our list pointers are not
3510 * valid
3511 */
3512 btrfs_put_block_group(block_group);
3513 up_read(&space_info->groups_sem);
3514 } else
3515 goto have_block_group;
3516 } else if (block_group) {
3517 btrfs_put_block_group(block_group);
3518 }
3519 }
3520
3521 search:
3522 down_read(&space_info->groups_sem);
3523 list_for_each_entry(block_group, &space_info->block_groups, list) {
3524 u64 offset;
3525
3526 atomic_inc(&block_group->count);
3527 search_start = block_group->key.objectid;
3528
3529 have_block_group:
3530 if (unlikely(!block_group->cached)) {
3531 mutex_lock(&block_group->cache_mutex);
3532 ret = cache_block_group(root, block_group);
3533 mutex_unlock(&block_group->cache_mutex);
3534 if (ret) {
3535 btrfs_put_block_group(block_group);
3536 break;
3537 }
3538 }
3539
3540 if (unlikely(block_group->ro))
3541 goto loop;
3542
3543 if (last_ptr) {
3544 /*
3545 * the refill lock keeps out other
3546 * people trying to start a new cluster
3547 */
3548 spin_lock(&last_ptr->refill_lock);
3549 if (last_ptr->block_group &&
3550 (last_ptr->block_group->ro ||
3551 !block_group_bits(last_ptr->block_group, data))) {
3552 offset = 0;
3553 goto refill_cluster;
3554 }
3555
3556 offset = btrfs_alloc_from_cluster(block_group, last_ptr,
3557 num_bytes, search_start);
3558 if (offset) {
3559 /* we have a block, we're done */
3560 spin_unlock(&last_ptr->refill_lock);
3561 goto checks;
3562 }
3563
3564 spin_lock(&last_ptr->lock);
3565 /*
3566 * whoops, this cluster doesn't actually point to
3567 * this block group. Get a ref on the block
3568 * group is does point to and try again
3569 */
3570 if (!last_ptr_loop && last_ptr->block_group &&
3571 last_ptr->block_group != block_group) {
3572
3573 btrfs_put_block_group(block_group);
3574 block_group = last_ptr->block_group;
3575 atomic_inc(&block_group->count);
3576 spin_unlock(&last_ptr->lock);
3577 spin_unlock(&last_ptr->refill_lock);
3578
3579 last_ptr_loop = 1;
3580 search_start = block_group->key.objectid;
3581 /*
3582 * we know this block group is properly
3583 * in the list because
3584 * btrfs_remove_block_group, drops the
3585 * cluster before it removes the block
3586 * group from the list
3587 */
3588 goto have_block_group;
3589 }
3590 spin_unlock(&last_ptr->lock);
3591 refill_cluster:
3592 /*
3593 * this cluster didn't work out, free it and
3594 * start over
3595 */
3596 btrfs_return_cluster_to_free_space(NULL, last_ptr);
3597
3598 last_ptr_loop = 0;
3599
3600 /* allocate a cluster in this block group */
3601 ret = btrfs_find_space_cluster(trans, root,
3602 block_group, last_ptr,
3603 offset, num_bytes,
3604 empty_cluster + empty_size);
3605 if (ret == 0) {
3606 /*
3607 * now pull our allocation out of this
3608 * cluster
3609 */
3610 offset = btrfs_alloc_from_cluster(block_group,
3611 last_ptr, num_bytes,
3612 search_start);
3613 if (offset) {
3614 /* we found one, proceed */
3615 spin_unlock(&last_ptr->refill_lock);
3616 goto checks;
3617 }
3618 }
3619 /*
3620 * at this point we either didn't find a cluster
3621 * or we weren't able to allocate a block from our
3622 * cluster. Free the cluster we've been trying
3623 * to use, and go to the next block group
3624 */
3625 if (loop < 2) {
3626 btrfs_return_cluster_to_free_space(NULL,
3627 last_ptr);
3628 spin_unlock(&last_ptr->refill_lock);
3629 goto loop;
3630 }
3631 spin_unlock(&last_ptr->refill_lock);
3632 }
3633
3634 offset = btrfs_find_space_for_alloc(block_group, search_start,
3635 num_bytes, empty_size);
3636 if (!offset)
3637 goto loop;
3638 checks:
3639 search_start = stripe_align(root, offset);
3640
3641 /* move on to the next group */
3642 if (search_start + num_bytes >= search_end) {
3643 btrfs_add_free_space(block_group, offset, num_bytes);
3644 goto loop;
3645 }
3646
3647 /* move on to the next group */
3648 if (search_start + num_bytes >
3649 block_group->key.objectid + block_group->key.offset) {
3650 btrfs_add_free_space(block_group, offset, num_bytes);
3651 goto loop;
3652 }
3653
3654 if (exclude_nr > 0 &&
3655 (search_start + num_bytes > exclude_start &&
3656 search_start < exclude_start + exclude_nr)) {
3657 search_start = exclude_start + exclude_nr;
3658
3659 btrfs_add_free_space(block_group, offset, num_bytes);
3660 /*
3661 * if search_start is still in this block group
3662 * then we just re-search this block group
3663 */
3664 if (search_start >= block_group->key.objectid &&
3665 search_start < (block_group->key.objectid +
3666 block_group->key.offset))
3667 goto have_block_group;
3668 goto loop;
3669 }
3670
3671 ins->objectid = search_start;
3672 ins->offset = num_bytes;
3673
3674 if (offset < search_start)
3675 btrfs_add_free_space(block_group, offset,
3676 search_start - offset);
3677 BUG_ON(offset > search_start);
3678
3679 /* we are all good, lets return */
3680 break;
3681 loop:
3682 btrfs_put_block_group(block_group);
3683 }
3684 up_read(&space_info->groups_sem);
3685
3686 /* loop == 0, try to find a clustered alloc in every block group
3687 * loop == 1, try again after forcing a chunk allocation
3688 * loop == 2, set empty_size and empty_cluster to 0 and try again
3689 */
3690 if (!ins->objectid && loop < 3 &&
3691 (empty_size || empty_cluster || allowed_chunk_alloc)) {
3692 if (loop >= 2) {
3693 empty_size = 0;
3694 empty_cluster = 0;
3695 }
3696
3697 if (allowed_chunk_alloc) {
3698 ret = do_chunk_alloc(trans, root, num_bytes +
3699 2 * 1024 * 1024, data, 1);
3700 allowed_chunk_alloc = 0;
3701 } else {
3702 space_info->force_alloc = 1;
3703 }
3704
3705 if (loop < 3) {
3706 loop++;
3707 goto search;
3708 }
3709 ret = -ENOSPC;
3710 } else if (!ins->objectid) {
3711 ret = -ENOSPC;
3712 }
3713
3714 /* we found what we needed */
3715 if (ins->objectid) {
3716 if (!(data & BTRFS_BLOCK_GROUP_DATA))
3717 trans->block_group = block_group->key.objectid;
3718
3719 btrfs_put_block_group(block_group);
3720 ret = 0;
3721 }
3722
3723 return ret;
3724 }
3725
3726 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
3727 {
3728 struct btrfs_block_group_cache *cache;
3729
3730 printk(KERN_INFO "space_info has %llu free, is %sfull\n",
3731 (unsigned long long)(info->total_bytes - info->bytes_used -
3732 info->bytes_pinned - info->bytes_reserved),
3733 (info->full) ? "" : "not ");
3734 printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu,"
3735 " may_use=%llu, used=%llu\n",
3736 (unsigned long long)info->total_bytes,
3737 (unsigned long long)info->bytes_pinned,
3738 (unsigned long long)info->bytes_delalloc,
3739 (unsigned long long)info->bytes_may_use,
3740 (unsigned long long)info->bytes_used);
3741
3742 down_read(&info->groups_sem);
3743 list_for_each_entry(cache, &info->block_groups, list) {
3744 spin_lock(&cache->lock);
3745 printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
3746 "%llu pinned %llu reserved\n",
3747 (unsigned long long)cache->key.objectid,
3748 (unsigned long long)cache->key.offset,
3749 (unsigned long long)btrfs_block_group_used(&cache->item),
3750 (unsigned long long)cache->pinned,
3751 (unsigned long long)cache->reserved);
3752 btrfs_dump_free_space(cache, bytes);
3753 spin_unlock(&cache->lock);
3754 }
3755 up_read(&info->groups_sem);
3756 }
3757
3758 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
3759 struct btrfs_root *root,
3760 u64 num_bytes, u64 min_alloc_size,
3761 u64 empty_size, u64 hint_byte,
3762 u64 search_end, struct btrfs_key *ins,
3763 u64 data)
3764 {
3765 int ret;
3766 u64 search_start = 0;
3767 struct btrfs_fs_info *info = root->fs_info;
3768
3769 data = btrfs_get_alloc_profile(root, data);
3770 again:
3771 /*
3772 * the only place that sets empty_size is btrfs_realloc_node, which
3773 * is not called recursively on allocations
3774 */
3775 if (empty_size || root->ref_cows) {
3776 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
3777 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3778 2 * 1024 * 1024,
3779 BTRFS_BLOCK_GROUP_METADATA |
3780 (info->metadata_alloc_profile &
3781 info->avail_metadata_alloc_bits), 0);
3782 }
3783 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
3784 num_bytes + 2 * 1024 * 1024, data, 0);
3785 }
3786
3787 WARN_ON(num_bytes < root->sectorsize);
3788 ret = find_free_extent(trans, root, num_bytes, empty_size,
3789 search_start, search_end, hint_byte, ins,
3790 trans->alloc_exclude_start,
3791 trans->alloc_exclude_nr, data);
3792
3793 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
3794 num_bytes = num_bytes >> 1;
3795 num_bytes = num_bytes & ~(root->sectorsize - 1);
3796 num_bytes = max(num_bytes, min_alloc_size);
3797 do_chunk_alloc(trans, root->fs_info->extent_root,
3798 num_bytes, data, 1);
3799 goto again;
3800 }
3801 if (ret) {
3802 struct btrfs_space_info *sinfo;
3803
3804 sinfo = __find_space_info(root->fs_info, data);
3805 printk(KERN_ERR "btrfs allocation failed flags %llu, "
3806 "wanted %llu\n", (unsigned long long)data,
3807 (unsigned long long)num_bytes);
3808 dump_space_info(sinfo, num_bytes);
3809 BUG();
3810 }
3811
3812 return ret;
3813 }
3814
3815 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
3816 {
3817 struct btrfs_block_group_cache *cache;
3818 int ret = 0;
3819
3820 cache = btrfs_lookup_block_group(root->fs_info, start);
3821 if (!cache) {
3822 printk(KERN_ERR "Unable to find block group for %llu\n",
3823 (unsigned long long)start);
3824 return -ENOSPC;
3825 }
3826
3827 ret = btrfs_discard_extent(root, start, len);
3828
3829 btrfs_add_free_space(cache, start, len);
3830 btrfs_put_block_group(cache);
3831 update_reserved_extents(root, start, len, 0);
3832
3833 return ret;
3834 }
3835
3836 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
3837 struct btrfs_root *root,
3838 u64 num_bytes, u64 min_alloc_size,
3839 u64 empty_size, u64 hint_byte,
3840 u64 search_end, struct btrfs_key *ins,
3841 u64 data)
3842 {
3843 int ret;
3844 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
3845 empty_size, hint_byte, search_end, ins,
3846 data);
3847 update_reserved_extents(root, ins->objectid, ins->offset, 1);
3848 return ret;
3849 }
3850
3851 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
3852 struct btrfs_root *root,
3853 u64 parent, u64 root_objectid,
3854 u64 flags, u64 owner, u64 offset,
3855 struct btrfs_key *ins, int ref_mod)
3856 {
3857 int ret;
3858 struct btrfs_fs_info *fs_info = root->fs_info;
3859 struct btrfs_extent_item *extent_item;
3860 struct btrfs_extent_inline_ref *iref;
3861 struct btrfs_path *path;
3862 struct extent_buffer *leaf;
3863 int type;
3864 u32 size;
3865
3866 if (parent > 0)
3867 type = BTRFS_SHARED_DATA_REF_KEY;
3868 else
3869 type = BTRFS_EXTENT_DATA_REF_KEY;
3870
3871 size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
3872
3873 path = btrfs_alloc_path();
3874 BUG_ON(!path);
3875
3876 path->leave_spinning = 1;
3877 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
3878 ins, size);
3879 BUG_ON(ret);
3880
3881 leaf = path->nodes[0];
3882 extent_item = btrfs_item_ptr(leaf, path->slots[0],
3883 struct btrfs_extent_item);
3884 btrfs_set_extent_refs(leaf, extent_item, ref_mod);
3885 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
3886 btrfs_set_extent_flags(leaf, extent_item,
3887 flags | BTRFS_EXTENT_FLAG_DATA);
3888
3889 iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
3890 btrfs_set_extent_inline_ref_type(leaf, iref, type);
3891 if (parent > 0) {
3892 struct btrfs_shared_data_ref *ref;
3893 ref = (struct btrfs_shared_data_ref *)(iref + 1);
3894 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
3895 btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
3896 } else {
3897 struct btrfs_extent_data_ref *ref;
3898 ref = (struct btrfs_extent_data_ref *)(&iref->offset);
3899 btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
3900 btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
3901 btrfs_set_extent_data_ref_offset(leaf, ref, offset);
3902 btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
3903 }
3904
3905 btrfs_mark_buffer_dirty(path->nodes[0]);
3906 btrfs_free_path(path);
3907
3908 ret = update_block_group(trans, root, ins->objectid, ins->offset,
3909 1, 0);
3910 if (ret) {
3911 printk(KERN_ERR "btrfs update block group failed for %llu "
3912 "%llu\n", (unsigned long long)ins->objectid,
3913 (unsigned long long)ins->offset);
3914 BUG();
3915 }
3916 return ret;
3917 }
3918
3919 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
3920 struct btrfs_root *root,
3921 u64 parent, u64 root_objectid,
3922 u64 flags, struct btrfs_disk_key *key,
3923 int level, struct btrfs_key *ins)
3924 {
3925 int ret;
3926 struct btrfs_fs_info *fs_info = root->fs_info;
3927 struct btrfs_extent_item *extent_item;
3928 struct btrfs_tree_block_info *block_info;
3929 struct btrfs_extent_inline_ref *iref;
3930 struct btrfs_path *path;
3931 struct extent_buffer *leaf;
3932 u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
3933
3934 path = btrfs_alloc_path();
3935 BUG_ON(!path);
3936
3937 path->leave_spinning = 1;
3938 ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
3939 ins, size);
3940 BUG_ON(ret);
3941
3942 leaf = path->nodes[0];
3943 extent_item = btrfs_item_ptr(leaf, path->slots[0],
3944 struct btrfs_extent_item);
3945 btrfs_set_extent_refs(leaf, extent_item, 1);
3946 btrfs_set_extent_generation(leaf, extent_item, trans->transid);
3947 btrfs_set_extent_flags(leaf, extent_item,
3948 flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
3949 block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
3950
3951 btrfs_set_tree_block_key(leaf, block_info, key);
3952 btrfs_set_tree_block_level(leaf, block_info, level);
3953
3954 iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
3955 if (parent > 0) {
3956 BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
3957 btrfs_set_extent_inline_ref_type(leaf, iref,
3958 BTRFS_SHARED_BLOCK_REF_KEY);
3959 btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
3960 } else {
3961 btrfs_set_extent_inline_ref_type(leaf, iref,
3962 BTRFS_TREE_BLOCK_REF_KEY);
3963 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
3964 }
3965
3966 btrfs_mark_buffer_dirty(leaf);
3967 btrfs_free_path(path);
3968
3969 ret = update_block_group(trans, root, ins->objectid, ins->offset,
3970 1, 0);
3971 if (ret) {
3972 printk(KERN_ERR "btrfs update block group failed for %llu "
3973 "%llu\n", (unsigned long long)ins->objectid,
3974 (unsigned long long)ins->offset);
3975 BUG();
3976 }
3977 return ret;
3978 }
3979
3980 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
3981 struct btrfs_root *root,
3982 u64 root_objectid, u64 owner,
3983 u64 offset, struct btrfs_key *ins)
3984 {
3985 int ret;
3986
3987 BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
3988
3989 ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
3990 0, root_objectid, owner, offset,
3991 BTRFS_ADD_DELAYED_EXTENT, NULL);
3992 return ret;
3993 }
3994
3995 /*
3996 * this is used by the tree logging recovery code. It records that
3997 * an extent has been allocated and makes sure to clear the free
3998 * space cache bits as well
3999 */
4000 int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
4001 struct btrfs_root *root,
4002 u64 root_objectid, u64 owner, u64 offset,
4003 struct btrfs_key *ins)
4004 {
4005 int ret;
4006 struct btrfs_block_group_cache *block_group;
4007
4008 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
4009 mutex_lock(&block_group->cache_mutex);
4010 cache_block_group(root, block_group);
4011 mutex_unlock(&block_group->cache_mutex);
4012
4013 ret = btrfs_remove_free_space(block_group, ins->objectid,
4014 ins->offset);
4015 BUG_ON(ret);
4016 btrfs_put_block_group(block_group);
4017 ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
4018 0, owner, offset, ins, 1);
4019 return ret;
4020 }
4021
4022 /*
4023 * finds a free extent and does all the dirty work required for allocation
4024 * returns the key for the extent through ins, and a tree buffer for
4025 * the first block of the extent through buf.
4026 *
4027 * returns 0 if everything worked, non-zero otherwise.
4028 */
4029 static int alloc_tree_block(struct btrfs_trans_handle *trans,
4030 struct btrfs_root *root,
4031 u64 num_bytes, u64 parent, u64 root_objectid,
4032 struct btrfs_disk_key *key, int level,
4033 u64 empty_size, u64 hint_byte, u64 search_end,
4034 struct btrfs_key *ins)
4035 {
4036 int ret;
4037 u64 flags = 0;
4038
4039 ret = __btrfs_reserve_extent(trans, root, num_bytes, num_bytes,
4040 empty_size, hint_byte, search_end,
4041 ins, 0);
4042 BUG_ON(ret);
4043
4044 if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
4045 if (parent == 0)
4046 parent = ins->objectid;
4047 flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
4048 } else
4049 BUG_ON(parent > 0);
4050
4051 update_reserved_extents(root, ins->objectid, ins->offset, 1);
4052 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
4053 struct btrfs_delayed_extent_op *extent_op;
4054 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
4055 BUG_ON(!extent_op);
4056 if (key)
4057 memcpy(&extent_op->key, key, sizeof(extent_op->key));
4058 else
4059 memset(&extent_op->key, 0, sizeof(extent_op->key));
4060 extent_op->flags_to_set = flags;
4061 extent_op->update_key = 1;
4062 extent_op->update_flags = 1;
4063 extent_op->is_data = 0;
4064
4065 ret = btrfs_add_delayed_tree_ref(trans, ins->objectid,
4066 ins->offset, parent, root_objectid,
4067 level, BTRFS_ADD_DELAYED_EXTENT,
4068 extent_op);
4069 BUG_ON(ret);
4070 }
4071 return ret;
4072 }
4073
4074 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
4075 struct btrfs_root *root,
4076 u64 bytenr, u32 blocksize,
4077 int level)
4078 {
4079 struct extent_buffer *buf;
4080
4081 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
4082 if (!buf)
4083 return ERR_PTR(-ENOMEM);
4084 btrfs_set_header_generation(buf, trans->transid);
4085 btrfs_set_buffer_lockdep_class(buf, level);
4086 btrfs_tree_lock(buf);
4087 clean_tree_block(trans, root, buf);
4088
4089 btrfs_set_lock_blocking(buf);
4090 btrfs_set_buffer_uptodate(buf);
4091
4092 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
4093 set_extent_dirty(&root->dirty_log_pages, buf->start,
4094 buf->start + buf->len - 1, GFP_NOFS);
4095 } else {
4096 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
4097 buf->start + buf->len - 1, GFP_NOFS);
4098 }
4099 trans->blocks_used++;
4100 /* this returns a buffer locked for blocking */
4101 return buf;
4102 }
4103
4104 /*
4105 * helper function to allocate a block for a given tree
4106 * returns the tree buffer or NULL.
4107 */
4108 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
4109 struct btrfs_root *root, u32 blocksize,
4110 u64 parent, u64 root_objectid,
4111 struct btrfs_disk_key *key, int level,
4112 u64 hint, u64 empty_size)
4113 {
4114 struct btrfs_key ins;
4115 int ret;
4116 struct extent_buffer *buf;
4117
4118 ret = alloc_tree_block(trans, root, blocksize, parent, root_objectid,
4119 key, level, empty_size, hint, (u64)-1, &ins);
4120 if (ret) {
4121 BUG_ON(ret > 0);
4122 return ERR_PTR(ret);
4123 }
4124
4125 buf = btrfs_init_new_buffer(trans, root, ins.objectid,
4126 blocksize, level);
4127 return buf;
4128 }
4129
4130 #if 0
4131 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
4132 struct btrfs_root *root, struct extent_buffer *leaf)
4133 {
4134 u64 disk_bytenr;
4135 u64 num_bytes;
4136 struct btrfs_key key;
4137 struct btrfs_file_extent_item *fi;
4138 u32 nritems;
4139 int i;
4140 int ret;
4141
4142 BUG_ON(!btrfs_is_leaf(leaf));
4143 nritems = btrfs_header_nritems(leaf);
4144
4145 for (i = 0; i < nritems; i++) {
4146 cond_resched();
4147 btrfs_item_key_to_cpu(leaf, &key, i);
4148
4149 /* only extents have references, skip everything else */
4150 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
4151 continue;
4152
4153 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4154
4155 /* inline extents live in the btree, they don't have refs */
4156 if (btrfs_file_extent_type(leaf, fi) ==
4157 BTRFS_FILE_EXTENT_INLINE)
4158 continue;
4159
4160 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
4161
4162 /* holes don't have refs */
4163 if (disk_bytenr == 0)
4164 continue;
4165
4166 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
4167 ret = btrfs_free_extent(trans, root, disk_bytenr, num_bytes,
4168 leaf->start, 0, key.objectid, 0);
4169 BUG_ON(ret);
4170 }
4171 return 0;
4172 }
4173
4174 static noinline int cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
4175 struct btrfs_root *root,
4176 struct btrfs_leaf_ref *ref)
4177 {
4178 int i;
4179 int ret;
4180 struct btrfs_extent_info *info;
4181 struct refsort *sorted;
4182
4183 if (ref->nritems == 0)
4184 return 0;
4185
4186 sorted = kmalloc(sizeof(*sorted) * ref->nritems, GFP_NOFS);
4187 for (i = 0; i < ref->nritems; i++) {
4188 sorted[i].bytenr = ref->extents[i].bytenr;
4189 sorted[i].slot = i;
4190 }
4191 sort(sorted, ref->nritems, sizeof(struct refsort), refsort_cmp, NULL);
4192
4193 /*
4194 * the items in the ref were sorted when the ref was inserted
4195 * into the ref cache, so this is already in order
4196 */
4197 for (i = 0; i < ref->nritems; i++) {
4198 info = ref->extents + sorted[i].slot;
4199 ret = btrfs_free_extent(trans, root, info->bytenr,
4200 info->num_bytes, ref->bytenr,
4201 ref->owner, ref->generation,
4202 info->objectid, 0);
4203
4204 atomic_inc(&root->fs_info->throttle_gen);
4205 wake_up(&root->fs_info->transaction_throttle);
4206 cond_resched();
4207
4208 BUG_ON(ret);
4209 info++;
4210 }
4211
4212 kfree(sorted);
4213 return 0;
4214 }
4215
4216
4217 static int drop_snap_lookup_refcount(struct btrfs_trans_handle *trans,
4218 struct btrfs_root *root, u64 start,
4219 u64 len, u32 *refs)
4220 {
4221 int ret;
4222
4223 ret = btrfs_lookup_extent_refs(trans, root, start, len, refs);
4224 BUG_ON(ret);
4225
4226 #if 0 /* some debugging code in case we see problems here */
4227 /* if the refs count is one, it won't get increased again. But
4228 * if the ref count is > 1, someone may be decreasing it at
4229 * the same time we are.
4230 */
4231 if (*refs != 1) {
4232 struct extent_buffer *eb = NULL;
4233 eb = btrfs_find_create_tree_block(root, start, len);
4234 if (eb)
4235 btrfs_tree_lock(eb);
4236
4237 mutex_lock(&root->fs_info->alloc_mutex);
4238 ret = lookup_extent_ref(NULL, root, start, len, refs);
4239 BUG_ON(ret);
4240 mutex_unlock(&root->fs_info->alloc_mutex);
4241
4242 if (eb) {
4243 btrfs_tree_unlock(eb);
4244 free_extent_buffer(eb);
4245 }
4246 if (*refs == 1) {
4247 printk(KERN_ERR "btrfs block %llu went down to one "
4248 "during drop_snap\n", (unsigned long long)start);
4249 }
4250
4251 }
4252 #endif
4253
4254 cond_resched();
4255 return ret;
4256 }
4257
4258
4259 /*
4260 * this is used while deleting old snapshots, and it drops the refs
4261 * on a whole subtree starting from a level 1 node.
4262 *
4263 * The idea is to sort all the leaf pointers, and then drop the
4264 * ref on all the leaves in order. Most of the time the leaves
4265 * will have ref cache entries, so no leaf IOs will be required to
4266 * find the extents they have references on.
4267 *
4268 * For each leaf, any references it has are also dropped in order
4269 *
4270 * This ends up dropping the references in something close to optimal
4271 * order for reading and modifying the extent allocation tree.
4272 */
4273 static noinline int drop_level_one_refs(struct btrfs_trans_handle *trans,
4274 struct btrfs_root *root,
4275 struct btrfs_path *path)
4276 {
4277 u64 bytenr;
4278 u64 root_owner;
4279 u64 root_gen;
4280 struct extent_buffer *eb = path->nodes[1];
4281 struct extent_buffer *leaf;
4282 struct btrfs_leaf_ref *ref;
4283 struct refsort *sorted = NULL;
4284 int nritems = btrfs_header_nritems(eb);
4285 int ret;
4286 int i;
4287 int refi = 0;
4288 int slot = path->slots[1];
4289 u32 blocksize = btrfs_level_size(root, 0);
4290 u32 refs;
4291
4292 if (nritems == 0)
4293 goto out;
4294
4295 root_owner = btrfs_header_owner(eb);
4296 root_gen = btrfs_header_generation(eb);
4297 sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
4298
4299 /*
4300 * step one, sort all the leaf pointers so we don't scribble
4301 * randomly into the extent allocation tree
4302 */
4303 for (i = slot; i < nritems; i++) {
4304 sorted[refi].bytenr = btrfs_node_blockptr(eb, i);
4305 sorted[refi].slot = i;
4306 refi++;
4307 }
4308
4309 /*
4310 * nritems won't be zero, but if we're picking up drop_snapshot
4311 * after a crash, slot might be > 0, so double check things
4312 * just in case.
4313 */
4314 if (refi == 0)
4315 goto out;
4316
4317 sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
4318
4319 /*
4320 * the first loop frees everything the leaves point to
4321 */
4322 for (i = 0; i < refi; i++) {
4323 u64 ptr_gen;
4324
4325 bytenr = sorted[i].bytenr;
4326
4327 /*
4328 * check the reference count on this leaf. If it is > 1
4329 * we just decrement it below and don't update any
4330 * of the refs the leaf points to.
4331 */
4332 ret = drop_snap_lookup_refcount(trans, root, bytenr,
4333 blocksize, &refs);
4334 BUG_ON(ret);
4335 if (refs != 1)
4336 continue;
4337
4338 ptr_gen = btrfs_node_ptr_generation(eb, sorted[i].slot);
4339
4340 /*
4341 * the leaf only had one reference, which means the
4342 * only thing pointing to this leaf is the snapshot
4343 * we're deleting. It isn't possible for the reference
4344 * count to increase again later
4345 *
4346 * The reference cache is checked for the leaf,
4347 * and if found we'll be able to drop any refs held by
4348 * the leaf without needing to read it in.
4349 */
4350 ref = btrfs_lookup_leaf_ref(root, bytenr);
4351 if (ref && ref->generation != ptr_gen) {
4352 btrfs_free_leaf_ref(root, ref);
4353 ref = NULL;
4354 }
4355 if (ref) {
4356 ret = cache_drop_leaf_ref(trans, root, ref);
4357 BUG_ON(ret);
4358 btrfs_remove_leaf_ref(root, ref);
4359 btrfs_free_leaf_ref(root, ref);
4360 } else {
4361 /*
4362 * the leaf wasn't in the reference cache, so
4363 * we have to read it.
4364 */
4365 leaf = read_tree_block(root, bytenr, blocksize,
4366 ptr_gen);
4367 ret = btrfs_drop_leaf_ref(trans, root, leaf);
4368 BUG_ON(ret);
4369 free_extent_buffer(leaf);
4370 }
4371 atomic_inc(&root->fs_info->throttle_gen);
4372 wake_up(&root->fs_info->transaction_throttle);
4373 cond_resched();
4374 }
4375
4376 /*
4377 * run through the loop again to free the refs on the leaves.
4378 * This is faster than doing it in the loop above because
4379 * the leaves are likely to be clustered together. We end up
4380 * working in nice chunks on the extent allocation tree.
4381 */
4382 for (i = 0; i < refi; i++) {
4383 bytenr = sorted[i].bytenr;
4384 ret = btrfs_free_extent(trans, root, bytenr,
4385 blocksize, eb->start,
4386 root_owner, root_gen, 0, 1);
4387 BUG_ON(ret);
4388
4389 atomic_inc(&root->fs_info->throttle_gen);
4390 wake_up(&root->fs_info->transaction_throttle);
4391 cond_resched();
4392 }
4393 out:
4394 kfree(sorted);
4395
4396 /*
4397 * update the path to show we've processed the entire level 1
4398 * node. This will get saved into the root's drop_snapshot_progress
4399 * field so these drops are not repeated again if this transaction
4400 * commits.
4401 */
4402 path->slots[1] = nritems;
4403 return 0;
4404 }
4405
4406 /*
4407 * helper function for drop_snapshot, this walks down the tree dropping ref
4408 * counts as it goes.
4409 */
4410 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
4411 struct btrfs_root *root,
4412 struct btrfs_path *path, int *level)
4413 {
4414 u64 root_owner;
4415 u64 root_gen;
4416 u64 bytenr;
4417 u64 ptr_gen;
4418 struct extent_buffer *next;
4419 struct extent_buffer *cur;
4420 struct extent_buffer *parent;
4421 u32 blocksize;
4422 int ret;
4423 u32 refs;
4424
4425 WARN_ON(*level < 0);
4426 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4427 ret = drop_snap_lookup_refcount(trans, root, path->nodes[*level]->start,
4428 path->nodes[*level]->len, &refs);
4429 BUG_ON(ret);
4430 if (refs > 1)
4431 goto out;
4432
4433 /*
4434 * walk down to the last node level and free all the leaves
4435 */
4436 while (*level >= 0) {
4437 WARN_ON(*level < 0);
4438 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4439 cur = path->nodes[*level];
4440
4441 if (btrfs_header_level(cur) != *level)
4442 WARN_ON(1);
4443
4444 if (path->slots[*level] >=
4445 btrfs_header_nritems(cur))
4446 break;
4447
4448 /* the new code goes down to level 1 and does all the
4449 * leaves pointed to that node in bulk. So, this check
4450 * for level 0 will always be false.
4451 *
4452 * But, the disk format allows the drop_snapshot_progress
4453 * field in the root to leave things in a state where
4454 * a leaf will need cleaning up here. If someone crashes
4455 * with the old code and then boots with the new code,
4456 * we might find a leaf here.
4457 */
4458 if (*level == 0) {
4459 ret = btrfs_drop_leaf_ref(trans, root, cur);
4460 BUG_ON(ret);
4461 break;
4462 }
4463
4464 /*
4465 * once we get to level one, process the whole node
4466 * at once, including everything below it.
4467 */
4468 if (*level == 1) {
4469 ret = drop_level_one_refs(trans, root, path);
4470 BUG_ON(ret);
4471 break;
4472 }
4473
4474 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
4475 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
4476 blocksize = btrfs_level_size(root, *level - 1);
4477
4478 ret = drop_snap_lookup_refcount(trans, root, bytenr,
4479 blocksize, &refs);
4480 BUG_ON(ret);
4481
4482 /*
4483 * if there is more than one reference, we don't need
4484 * to read that node to drop any references it has. We
4485 * just drop the ref we hold on that node and move on to the
4486 * next slot in this level.
4487 */
4488 if (refs != 1) {
4489 parent = path->nodes[*level];
4490 root_owner = btrfs_header_owner(parent);
4491 root_gen = btrfs_header_generation(parent);
4492 path->slots[*level]++;
4493
4494 ret = btrfs_free_extent(trans, root, bytenr,
4495 blocksize, parent->start,
4496 root_owner, root_gen,
4497 *level - 1, 1);
4498 BUG_ON(ret);
4499
4500 atomic_inc(&root->fs_info->throttle_gen);
4501 wake_up(&root->fs_info->transaction_throttle);
4502 cond_resched();
4503
4504 continue;
4505 }
4506
4507 /*
4508 * we need to keep freeing things in the next level down.
4509 * read the block and loop around to process it
4510 */
4511 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
4512 WARN_ON(*level <= 0);
4513 if (path->nodes[*level-1])
4514 free_extent_buffer(path->nodes[*level-1]);
4515 path->nodes[*level-1] = next;
4516 *level = btrfs_header_level(next);
4517 path->slots[*level] = 0;
4518 cond_resched();
4519 }
4520 out:
4521 WARN_ON(*level < 0);
4522 WARN_ON(*level >= BTRFS_MAX_LEVEL);
4523
4524 if (path->nodes[*level] == root->node) {
4525 parent = path->nodes[*level];
4526 bytenr = path->nodes[*level]->start;
4527 } else {
4528 parent = path->nodes[*level + 1];
4529 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
4530 }
4531
4532 blocksize = btrfs_level_size(root, *level);
4533 root_owner = btrfs_header_owner(parent);
4534 root_gen = btrfs_header_generation(parent);
4535
4536 /*
4537 * cleanup and free the reference on the last node
4538 * we processed
4539 */
4540 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
4541 parent->start, root_owner, root_gen,
4542 *level, 1);
4543 free_extent_buffer(path->nodes[*level]);
4544 path->nodes[*level] = NULL;
4545
4546 *level += 1;
4547 BUG_ON(ret);
4548
4549 cond_resched();
4550 return 0;
4551 }
4552 #endif
4553
4554 struct walk_control {
4555 u64 refs[BTRFS_MAX_LEVEL];
4556 u64 flags[BTRFS_MAX_LEVEL];
4557 struct btrfs_key update_progress;
4558 int stage;
4559 int level;
4560 int shared_level;
4561 int update_ref;
4562 int keep_locks;
4563 };
4564
4565 #define DROP_REFERENCE 1
4566 #define UPDATE_BACKREF 2
4567
4568 /*
4569 * hepler to process tree block while walking down the tree.
4570 *
4571 * when wc->stage == DROP_REFERENCE, this function checks
4572 * reference count of the block. if the block is shared and
4573 * we need update back refs for the subtree rooted at the
4574 * block, this function changes wc->stage to UPDATE_BACKREF
4575 *
4576 * when wc->stage == UPDATE_BACKREF, this function updates
4577 * back refs for pointers in the block.
4578 *
4579 * NOTE: return value 1 means we should stop walking down.
4580 */
4581 static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
4582 struct btrfs_root *root,
4583 struct btrfs_path *path,
4584 struct walk_control *wc)
4585 {
4586 int level = wc->level;
4587 struct extent_buffer *eb = path->nodes[level];
4588 struct btrfs_key key;
4589 u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
4590 int ret;
4591
4592 if (wc->stage == UPDATE_BACKREF &&
4593 btrfs_header_owner(eb) != root->root_key.objectid)
4594 return 1;
4595
4596 /*
4597 * when reference count of tree block is 1, it won't increase
4598 * again. once full backref flag is set, we never clear it.
4599 */
4600 if ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
4601 (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag))) {
4602 BUG_ON(!path->locks[level]);
4603 ret = btrfs_lookup_extent_info(trans, root,
4604 eb->start, eb->len,
4605 &wc->refs[level],
4606 &wc->flags[level]);
4607 BUG_ON(ret);
4608 BUG_ON(wc->refs[level] == 0);
4609 }
4610
4611 if (wc->stage == DROP_REFERENCE &&
4612 wc->update_ref && wc->refs[level] > 1) {
4613 BUG_ON(eb == root->node);
4614 BUG_ON(path->slots[level] > 0);
4615 if (level == 0)
4616 btrfs_item_key_to_cpu(eb, &key, path->slots[level]);
4617 else
4618 btrfs_node_key_to_cpu(eb, &key, path->slots[level]);
4619 if (btrfs_header_owner(eb) == root->root_key.objectid &&
4620 btrfs_comp_cpu_keys(&key, &wc->update_progress) >= 0) {
4621 wc->stage = UPDATE_BACKREF;
4622 wc->shared_level = level;
4623 }
4624 }
4625
4626 if (wc->stage == DROP_REFERENCE) {
4627 if (wc->refs[level] > 1)
4628 return 1;
4629
4630 if (path->locks[level] && !wc->keep_locks) {
4631 btrfs_tree_unlock(eb);
4632 path->locks[level] = 0;
4633 }
4634 return 0;
4635 }
4636
4637 /* wc->stage == UPDATE_BACKREF */
4638 if (!(wc->flags[level] & flag)) {
4639 BUG_ON(!path->locks[level]);
4640 ret = btrfs_inc_ref(trans, root, eb, 1);
4641 BUG_ON(ret);
4642 ret = btrfs_dec_ref(trans, root, eb, 0);
4643 BUG_ON(ret);
4644 ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
4645 eb->len, flag, 0);
4646 BUG_ON(ret);
4647 wc->flags[level] |= flag;
4648 }
4649
4650 /*
4651 * the block is shared by multiple trees, so it's not good to
4652 * keep the tree lock
4653 */
4654 if (path->locks[level] && level > 0) {
4655 btrfs_tree_unlock(eb);
4656 path->locks[level] = 0;
4657 }
4658 return 0;
4659 }
4660
4661 /*
4662 * hepler to process tree block while walking up the tree.
4663 *
4664 * when wc->stage == DROP_REFERENCE, this function drops
4665 * reference count on the block.
4666 *
4667 * when wc->stage == UPDATE_BACKREF, this function changes
4668 * wc->stage back to DROP_REFERENCE if we changed wc->stage
4669 * to UPDATE_BACKREF previously while processing the block.
4670 *
4671 * NOTE: return value 1 means we should stop walking up.
4672 */
4673 static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
4674 struct btrfs_root *root,
4675 struct btrfs_path *path,
4676 struct walk_control *wc)
4677 {
4678 int ret = 0;
4679 int level = wc->level;
4680 struct extent_buffer *eb = path->nodes[level];
4681 u64 parent = 0;
4682
4683 if (wc->stage == UPDATE_BACKREF) {
4684 BUG_ON(wc->shared_level < level);
4685 if (level < wc->shared_level)
4686 goto out;
4687
4688 BUG_ON(wc->refs[level] <= 1);
4689 ret = find_next_key(path, level + 1, &wc->update_progress);
4690 if (ret > 0)
4691 wc->update_ref = 0;
4692
4693 wc->stage = DROP_REFERENCE;
4694 wc->shared_level = -1;
4695 path->slots[level] = 0;
4696
4697 /*
4698 * check reference count again if the block isn't locked.
4699 * we should start walking down the tree again if reference
4700 * count is one.
4701 */
4702 if (!path->locks[level]) {
4703 BUG_ON(level == 0);
4704 btrfs_tree_lock(eb);
4705 btrfs_set_lock_blocking(eb);
4706 path->locks[level] = 1;
4707
4708 ret = btrfs_lookup_extent_info(trans, root,
4709 eb->start, eb->len,
4710 &wc->refs[level],
4711 &wc->flags[level]);
4712 BUG_ON(ret);
4713 BUG_ON(wc->refs[level] == 0);
4714 if (wc->refs[level] == 1) {
4715 btrfs_tree_unlock(eb);
4716 path->locks[level] = 0;
4717 return 1;
4718 }
4719 } else {
4720 BUG_ON(level != 0);
4721 }
4722 }
4723
4724 /* wc->stage == DROP_REFERENCE */
4725 BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
4726
4727 if (wc->refs[level] == 1) {
4728 if (level == 0) {
4729 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4730 ret = btrfs_dec_ref(trans, root, eb, 1);
4731 else
4732 ret = btrfs_dec_ref(trans, root, eb, 0);
4733 BUG_ON(ret);
4734 }
4735 /* make block locked assertion in clean_tree_block happy */
4736 if (!path->locks[level] &&
4737 btrfs_header_generation(eb) == trans->transid) {
4738 btrfs_tree_lock(eb);
4739 btrfs_set_lock_blocking(eb);
4740 path->locks[level] = 1;
4741 }
4742 clean_tree_block(trans, root, eb);
4743 }
4744
4745 if (eb == root->node) {
4746 if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4747 parent = eb->start;
4748 else
4749 BUG_ON(root->root_key.objectid !=
4750 btrfs_header_owner(eb));
4751 } else {
4752 if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
4753 parent = path->nodes[level + 1]->start;
4754 else
4755 BUG_ON(root->root_key.objectid !=
4756 btrfs_header_owner(path->nodes[level + 1]));
4757 }
4758
4759 ret = btrfs_free_extent(trans, root, eb->start, eb->len, parent,
4760 root->root_key.objectid, level, 0);
4761 BUG_ON(ret);
4762 out:
4763 wc->refs[level] = 0;
4764 wc->flags[level] = 0;
4765 return ret;
4766 }
4767
4768 static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
4769 struct btrfs_root *root,
4770 struct btrfs_path *path,
4771 struct walk_control *wc)
4772 {
4773 struct extent_buffer *next;
4774 struct extent_buffer *cur;
4775 u64 bytenr;
4776 u64 ptr_gen;
4777 u32 blocksize;
4778 int level = wc->level;
4779 int ret;
4780
4781 while (level >= 0) {
4782 cur = path->nodes[level];
4783 BUG_ON(path->slots[level] >= btrfs_header_nritems(cur));
4784
4785 ret = walk_down_proc(trans, root, path, wc);
4786 if (ret > 0)
4787 break;
4788
4789 if (level == 0)
4790 break;
4791
4792 bytenr = btrfs_node_blockptr(cur, path->slots[level]);
4793 blocksize = btrfs_level_size(root, level - 1);
4794 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[level]);
4795
4796 next = read_tree_block(root, bytenr, blocksize, ptr_gen);
4797 btrfs_tree_lock(next);
4798 btrfs_set_lock_blocking(next);
4799
4800 level--;
4801 BUG_ON(level != btrfs_header_level(next));
4802 path->nodes[level] = next;
4803 path->slots[level] = 0;
4804 path->locks[level] = 1;
4805 wc->level = level;
4806 }
4807 return 0;
4808 }
4809
4810 static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
4811 struct btrfs_root *root,
4812 struct btrfs_path *path,
4813 struct walk_control *wc, int max_level)
4814 {
4815 int level = wc->level;
4816 int ret;
4817
4818 path->slots[level] = btrfs_header_nritems(path->nodes[level]);
4819 while (level < max_level && path->nodes[level]) {
4820 wc->level = level;
4821 if (path->slots[level] + 1 <
4822 btrfs_header_nritems(path->nodes[level])) {
4823 path->slots[level]++;
4824 return 0;
4825 } else {
4826 ret = walk_up_proc(trans, root, path, wc);
4827 if (ret > 0)
4828 return 0;
4829
4830 if (path->locks[level]) {
4831 btrfs_tree_unlock(path->nodes[level]);
4832 path->locks[level] = 0;
4833 }
4834 free_extent_buffer(path->nodes[level]);
4835 path->nodes[level] = NULL;
4836 level++;
4837 }
4838 }
4839 return 1;
4840 }
4841
4842 /*
4843 * drop a subvolume tree.
4844 *
4845 * this function traverses the tree freeing any blocks that only
4846 * referenced by the tree.
4847 *
4848 * when a shared tree block is found. this function decreases its
4849 * reference count by one. if update_ref is true, this function
4850 * also make sure backrefs for the shared block and all lower level
4851 * blocks are properly updated.
4852 */
4853 int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref)
4854 {
4855 struct btrfs_path *path;
4856 struct btrfs_trans_handle *trans;
4857 struct btrfs_root *tree_root = root->fs_info->tree_root;
4858 struct btrfs_root_item *root_item = &root->root_item;
4859 struct walk_control *wc;
4860 struct btrfs_key key;
4861 int err = 0;
4862 int ret;
4863 int level;
4864
4865 path = btrfs_alloc_path();
4866 BUG_ON(!path);
4867
4868 wc = kzalloc(sizeof(*wc), GFP_NOFS);
4869 BUG_ON(!wc);
4870
4871 trans = btrfs_start_transaction(tree_root, 1);
4872
4873 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
4874 level = btrfs_header_level(root->node);
4875 path->nodes[level] = btrfs_lock_root_node(root);
4876 btrfs_set_lock_blocking(path->nodes[level]);
4877 path->slots[level] = 0;
4878 path->locks[level] = 1;
4879 memset(&wc->update_progress, 0,
4880 sizeof(wc->update_progress));
4881 } else {
4882 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
4883 memcpy(&wc->update_progress, &key,
4884 sizeof(wc->update_progress));
4885
4886 level = root_item->drop_level;
4887 BUG_ON(level == 0);
4888 path->lowest_level = level;
4889 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4890 path->lowest_level = 0;
4891 if (ret < 0) {
4892 err = ret;
4893 goto out;
4894 }
4895 btrfs_node_key_to_cpu(path->nodes[level], &key,
4896 path->slots[level]);
4897 WARN_ON(memcmp(&key, &wc->update_progress, sizeof(key)));
4898
4899 /*
4900 * unlock our path, this is safe because only this
4901 * function is allowed to delete this snapshot
4902 */
4903 btrfs_unlock_up_safe(path, 0);
4904
4905 level = btrfs_header_level(root->node);
4906 while (1) {
4907 btrfs_tree_lock(path->nodes[level]);
4908 btrfs_set_lock_blocking(path->nodes[level]);
4909
4910 ret = btrfs_lookup_extent_info(trans, root,
4911 path->nodes[level]->start,
4912 path->nodes[level]->len,
4913 &wc->refs[level],
4914 &wc->flags[level]);
4915 BUG_ON(ret);
4916 BUG_ON(wc->refs[level] == 0);
4917
4918 if (level == root_item->drop_level)
4919 break;
4920
4921 btrfs_tree_unlock(path->nodes[level]);
4922 WARN_ON(wc->refs[level] != 1);
4923 level--;
4924 }
4925 }
4926
4927 wc->level = level;
4928 wc->shared_level = -1;
4929 wc->stage = DROP_REFERENCE;
4930 wc->update_ref = update_ref;
4931 wc->keep_locks = 0;
4932
4933 while (1) {
4934 ret = walk_down_tree(trans, root, path, wc);
4935 if (ret < 0) {
4936 err = ret;
4937 break;
4938 }
4939
4940 ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
4941 if (ret < 0) {
4942 err = ret;
4943 break;
4944 }
4945
4946 if (ret > 0) {
4947 BUG_ON(wc->stage != DROP_REFERENCE);
4948 break;
4949 }
4950
4951 if (wc->stage == DROP_REFERENCE) {
4952 level = wc->level;
4953 btrfs_node_key(path->nodes[level],
4954 &root_item->drop_progress,
4955 path->slots[level]);
4956 root_item->drop_level = level;
4957 }
4958
4959 BUG_ON(wc->level == 0);
4960 if (trans->transaction->in_commit ||
4961 trans->transaction->delayed_refs.flushing) {
4962 ret = btrfs_update_root(trans, tree_root,
4963 &root->root_key,
4964 root_item);
4965 BUG_ON(ret);
4966
4967 btrfs_end_transaction(trans, tree_root);
4968 trans = btrfs_start_transaction(tree_root, 1);
4969 } else {
4970 unsigned long update;
4971 update = trans->delayed_ref_updates;
4972 trans->delayed_ref_updates = 0;
4973 if (update)
4974 btrfs_run_delayed_refs(trans, tree_root,
4975 update);
4976 }
4977 }
4978 btrfs_release_path(root, path);
4979 BUG_ON(err);
4980
4981 ret = btrfs_del_root(trans, tree_root, &root->root_key);
4982 BUG_ON(ret);
4983
4984 free_extent_buffer(root->node);
4985 free_extent_buffer(root->commit_root);
4986 kfree(root);
4987 out:
4988 btrfs_end_transaction(trans, tree_root);
4989 kfree(wc);
4990 btrfs_free_path(path);
4991 return err;
4992 }
4993
4994 /*
4995 * drop subtree rooted at tree block 'node'.
4996 *
4997 * NOTE: this function will unlock and release tree block 'node'
4998 */
4999 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
5000 struct btrfs_root *root,
5001 struct extent_buffer *node,
5002 struct extent_buffer *parent)
5003 {
5004 struct btrfs_path *path;
5005 struct walk_control *wc;
5006 int level;
5007 int parent_level;
5008 int ret = 0;
5009 int wret;
5010
5011 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5012
5013 path = btrfs_alloc_path();
5014 BUG_ON(!path);
5015
5016 wc = kzalloc(sizeof(*wc), GFP_NOFS);
5017 BUG_ON(!wc);
5018
5019 btrfs_assert_tree_locked(parent);
5020 parent_level = btrfs_header_level(parent);
5021 extent_buffer_get(parent);
5022 path->nodes[parent_level] = parent;
5023 path->slots[parent_level] = btrfs_header_nritems(parent);
5024
5025 btrfs_assert_tree_locked(node);
5026 level = btrfs_header_level(node);
5027 path->nodes[level] = node;
5028 path->slots[level] = 0;
5029 path->locks[level] = 1;
5030
5031 wc->refs[parent_level] = 1;
5032 wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
5033 wc->level = level;
5034 wc->shared_level = -1;
5035 wc->stage = DROP_REFERENCE;
5036 wc->update_ref = 0;
5037 wc->keep_locks = 1;
5038
5039 while (1) {
5040 wret = walk_down_tree(trans, root, path, wc);
5041 if (wret < 0) {
5042 ret = wret;
5043 break;
5044 }
5045
5046 wret = walk_up_tree(trans, root, path, wc, parent_level);
5047 if (wret < 0)
5048 ret = wret;
5049 if (wret != 0)
5050 break;
5051 }
5052
5053 kfree(wc);
5054 btrfs_free_path(path);
5055 return ret;
5056 }
5057
5058 #if 0
5059 static unsigned long calc_ra(unsigned long start, unsigned long last,
5060 unsigned long nr)
5061 {
5062 return min(last, start + nr - 1);
5063 }
5064
5065 static noinline int relocate_inode_pages(struct inode *inode, u64 start,
5066 u64 len)
5067 {
5068 u64 page_start;
5069 u64 page_end;
5070 unsigned long first_index;
5071 unsigned long last_index;
5072 unsigned long i;
5073 struct page *page;
5074 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5075 struct file_ra_state *ra;
5076 struct btrfs_ordered_extent *ordered;
5077 unsigned int total_read = 0;
5078 unsigned int total_dirty = 0;
5079 int ret = 0;
5080
5081 ra = kzalloc(sizeof(*ra), GFP_NOFS);
5082
5083 mutex_lock(&inode->i_mutex);
5084 first_index = start >> PAGE_CACHE_SHIFT;
5085 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
5086
5087 /* make sure the dirty trick played by the caller work */
5088 ret = invalidate_inode_pages2_range(inode->i_mapping,
5089 first_index, last_index);
5090 if (ret)
5091 goto out_unlock;
5092
5093 file_ra_state_init(ra, inode->i_mapping);
5094
5095 for (i = first_index ; i <= last_index; i++) {
5096 if (total_read % ra->ra_pages == 0) {
5097 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
5098 calc_ra(i, last_index, ra->ra_pages));
5099 }
5100 total_read++;
5101 again:
5102 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
5103 BUG_ON(1);
5104 page = grab_cache_page(inode->i_mapping, i);
5105 if (!page) {
5106 ret = -ENOMEM;
5107 goto out_unlock;
5108 }
5109 if (!PageUptodate(page)) {
5110 btrfs_readpage(NULL, page);
5111 lock_page(page);
5112 if (!PageUptodate(page)) {
5113 unlock_page(page);
5114 page_cache_release(page);
5115 ret = -EIO;
5116 goto out_unlock;
5117 }
5118 }
5119 wait_on_page_writeback(page);
5120
5121 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
5122 page_end = page_start + PAGE_CACHE_SIZE - 1;
5123 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
5124
5125 ordered = btrfs_lookup_ordered_extent(inode, page_start);
5126 if (ordered) {
5127 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5128 unlock_page(page);
5129 page_cache_release(page);
5130 btrfs_start_ordered_extent(inode, ordered, 1);
5131 btrfs_put_ordered_extent(ordered);
5132 goto again;
5133 }
5134 set_page_extent_mapped(page);
5135
5136 if (i == first_index)
5137 set_extent_bits(io_tree, page_start, page_end,
5138 EXTENT_BOUNDARY, GFP_NOFS);
5139 btrfs_set_extent_delalloc(inode, page_start, page_end);
5140
5141 set_page_dirty(page);
5142 total_dirty++;
5143
5144 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
5145 unlock_page(page);
5146 page_cache_release(page);
5147 }
5148
5149 out_unlock:
5150 kfree(ra);
5151 mutex_unlock(&inode->i_mutex);
5152 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
5153 return ret;
5154 }
5155
5156 static noinline int relocate_data_extent(struct inode *reloc_inode,
5157 struct btrfs_key *extent_key,
5158 u64 offset)
5159 {
5160 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5161 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
5162 struct extent_map *em;
5163 u64 start = extent_key->objectid - offset;
5164 u64 end = start + extent_key->offset - 1;
5165
5166 em = alloc_extent_map(GFP_NOFS);
5167 BUG_ON(!em || IS_ERR(em));
5168
5169 em->start = start;
5170 em->len = extent_key->offset;
5171 em->block_len = extent_key->offset;
5172 em->block_start = extent_key->objectid;
5173 em->bdev = root->fs_info->fs_devices->latest_bdev;
5174 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5175
5176 /* setup extent map to cheat btrfs_readpage */
5177 lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5178 while (1) {
5179 int ret;
5180 spin_lock(&em_tree->lock);
5181 ret = add_extent_mapping(em_tree, em);
5182 spin_unlock(&em_tree->lock);
5183 if (ret != -EEXIST) {
5184 free_extent_map(em);
5185 break;
5186 }
5187 btrfs_drop_extent_cache(reloc_inode, start, end, 0);
5188 }
5189 unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS);
5190
5191 return relocate_inode_pages(reloc_inode, start, extent_key->offset);
5192 }
5193
5194 struct btrfs_ref_path {
5195 u64 extent_start;
5196 u64 nodes[BTRFS_MAX_LEVEL];
5197 u64 root_objectid;
5198 u64 root_generation;
5199 u64 owner_objectid;
5200 u32 num_refs;
5201 int lowest_level;
5202 int current_level;
5203 int shared_level;
5204
5205 struct btrfs_key node_keys[BTRFS_MAX_LEVEL];
5206 u64 new_nodes[BTRFS_MAX_LEVEL];
5207 };
5208
5209 struct disk_extent {
5210 u64 ram_bytes;
5211 u64 disk_bytenr;
5212 u64 disk_num_bytes;
5213 u64 offset;
5214 u64 num_bytes;
5215 u8 compression;
5216 u8 encryption;
5217 u16 other_encoding;
5218 };
5219
5220 static int is_cowonly_root(u64 root_objectid)
5221 {
5222 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
5223 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
5224 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
5225 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
5226 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
5227 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
5228 return 1;
5229 return 0;
5230 }
5231
5232 static noinline int __next_ref_path(struct btrfs_trans_handle *trans,
5233 struct btrfs_root *extent_root,
5234 struct btrfs_ref_path *ref_path,
5235 int first_time)
5236 {
5237 struct extent_buffer *leaf;
5238 struct btrfs_path *path;
5239 struct btrfs_extent_ref *ref;
5240 struct btrfs_key key;
5241 struct btrfs_key found_key;
5242 u64 bytenr;
5243 u32 nritems;
5244 int level;
5245 int ret = 1;
5246
5247 path = btrfs_alloc_path();
5248 if (!path)
5249 return -ENOMEM;
5250
5251 if (first_time) {
5252 ref_path->lowest_level = -1;
5253 ref_path->current_level = -1;
5254 ref_path->shared_level = -1;
5255 goto walk_up;
5256 }
5257 walk_down:
5258 level = ref_path->current_level - 1;
5259 while (level >= -1) {
5260 u64 parent;
5261 if (level < ref_path->lowest_level)
5262 break;
5263
5264 if (level >= 0)
5265 bytenr = ref_path->nodes[level];
5266 else
5267 bytenr = ref_path->extent_start;
5268 BUG_ON(bytenr == 0);
5269
5270 parent = ref_path->nodes[level + 1];
5271 ref_path->nodes[level + 1] = 0;
5272 ref_path->current_level = level;
5273 BUG_ON(parent == 0);
5274
5275 key.objectid = bytenr;
5276 key.offset = parent + 1;
5277 key.type = BTRFS_EXTENT_REF_KEY;
5278
5279 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5280 if (ret < 0)
5281 goto out;
5282 BUG_ON(ret == 0);
5283
5284 leaf = path->nodes[0];
5285 nritems = btrfs_header_nritems(leaf);
5286 if (path->slots[0] >= nritems) {
5287 ret = btrfs_next_leaf(extent_root, path);
5288 if (ret < 0)
5289 goto out;
5290 if (ret > 0)
5291 goto next;
5292 leaf = path->nodes[0];
5293 }
5294
5295 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5296 if (found_key.objectid == bytenr &&
5297 found_key.type == BTRFS_EXTENT_REF_KEY) {
5298 if (level < ref_path->shared_level)
5299 ref_path->shared_level = level;
5300 goto found;
5301 }
5302 next:
5303 level--;
5304 btrfs_release_path(extent_root, path);
5305 cond_resched();
5306 }
5307 /* reached lowest level */
5308 ret = 1;
5309 goto out;
5310 walk_up:
5311 level = ref_path->current_level;
5312 while (level < BTRFS_MAX_LEVEL - 1) {
5313 u64 ref_objectid;
5314
5315 if (level >= 0)
5316 bytenr = ref_path->nodes[level];
5317 else
5318 bytenr = ref_path->extent_start;
5319
5320 BUG_ON(bytenr == 0);
5321
5322 key.objectid = bytenr;
5323 key.offset = 0;
5324 key.type = BTRFS_EXTENT_REF_KEY;
5325
5326 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
5327 if (ret < 0)
5328 goto out;
5329
5330 leaf = path->nodes[0];
5331 nritems = btrfs_header_nritems(leaf);
5332 if (path->slots[0] >= nritems) {
5333 ret = btrfs_next_leaf(extent_root, path);
5334 if (ret < 0)
5335 goto out;
5336 if (ret > 0) {
5337 /* the extent was freed by someone */
5338 if (ref_path->lowest_level == level)
5339 goto out;
5340 btrfs_release_path(extent_root, path);
5341 goto walk_down;
5342 }
5343 leaf = path->nodes[0];
5344 }
5345
5346 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5347 if (found_key.objectid != bytenr ||
5348 found_key.type != BTRFS_EXTENT_REF_KEY) {
5349 /* the extent was freed by someone */
5350 if (ref_path->lowest_level == level) {
5351 ret = 1;
5352 goto out;
5353 }
5354 btrfs_release_path(extent_root, path);
5355 goto walk_down;
5356 }
5357 found:
5358 ref = btrfs_item_ptr(leaf, path->slots[0],
5359 struct btrfs_extent_ref);
5360 ref_objectid = btrfs_ref_objectid(leaf, ref);
5361 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
5362 if (first_time) {
5363 level = (int)ref_objectid;
5364 BUG_ON(level >= BTRFS_MAX_LEVEL);
5365 ref_path->lowest_level = level;
5366 ref_path->current_level = level;
5367 ref_path->nodes[level] = bytenr;
5368 } else {
5369 WARN_ON(ref_objectid != level);
5370 }
5371 } else {
5372 WARN_ON(level != -1);
5373 }
5374 first_time = 0;
5375
5376 if (ref_path->lowest_level == level) {
5377 ref_path->owner_objectid = ref_objectid;
5378 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
5379 }
5380
5381 /*
5382 * the block is tree root or the block isn't in reference
5383 * counted tree.
5384 */
5385 if (found_key.objectid == found_key.offset ||
5386 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
5387 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5388 ref_path->root_generation =
5389 btrfs_ref_generation(leaf, ref);
5390 if (level < 0) {
5391 /* special reference from the tree log */
5392 ref_path->nodes[0] = found_key.offset;
5393 ref_path->current_level = 0;
5394 }
5395 ret = 0;
5396 goto out;
5397 }
5398
5399 level++;
5400 BUG_ON(ref_path->nodes[level] != 0);
5401 ref_path->nodes[level] = found_key.offset;
5402 ref_path->current_level = level;
5403
5404 /*
5405 * the reference was created in the running transaction,
5406 * no need to continue walking up.
5407 */
5408 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
5409 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
5410 ref_path->root_generation =
5411 btrfs_ref_generation(leaf, ref);
5412 ret = 0;
5413 goto out;
5414 }
5415
5416 btrfs_release_path(extent_root, path);
5417 cond_resched();
5418 }
5419 /* reached max tree level, but no tree root found. */
5420 BUG();
5421 out:
5422 btrfs_free_path(path);
5423 return ret;
5424 }
5425
5426 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
5427 struct btrfs_root *extent_root,
5428 struct btrfs_ref_path *ref_path,
5429 u64 extent_start)
5430 {
5431 memset(ref_path, 0, sizeof(*ref_path));
5432 ref_path->extent_start = extent_start;
5433
5434 return __next_ref_path(trans, extent_root, ref_path, 1);
5435 }
5436
5437 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
5438 struct btrfs_root *extent_root,
5439 struct btrfs_ref_path *ref_path)
5440 {
5441 return __next_ref_path(trans, extent_root, ref_path, 0);
5442 }
5443
5444 static noinline int get_new_locations(struct inode *reloc_inode,
5445 struct btrfs_key *extent_key,
5446 u64 offset, int no_fragment,
5447 struct disk_extent **extents,
5448 int *nr_extents)
5449 {
5450 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
5451 struct btrfs_path *path;
5452 struct btrfs_file_extent_item *fi;
5453 struct extent_buffer *leaf;
5454 struct disk_extent *exts = *extents;
5455 struct btrfs_key found_key;
5456 u64 cur_pos;
5457 u64 last_byte;
5458 u32 nritems;
5459 int nr = 0;
5460 int max = *nr_extents;
5461 int ret;
5462
5463 WARN_ON(!no_fragment && *extents);
5464 if (!exts) {
5465 max = 1;
5466 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
5467 if (!exts)
5468 return -ENOMEM;
5469 }
5470
5471 path = btrfs_alloc_path();
5472 BUG_ON(!path);
5473
5474 cur_pos = extent_key->objectid - offset;
5475 last_byte = extent_key->objectid + extent_key->offset;
5476 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
5477 cur_pos, 0);
5478 if (ret < 0)
5479 goto out;
5480 if (ret > 0) {
5481 ret = -ENOENT;
5482 goto out;
5483 }
5484
5485 while (1) {
5486 leaf = path->nodes[0];
5487 nritems = btrfs_header_nritems(leaf);
5488 if (path->slots[0] >= nritems) {
5489 ret = btrfs_next_leaf(root, path);
5490 if (ret < 0)
5491 goto out;
5492 if (ret > 0)
5493 break;
5494 leaf = path->nodes[0];
5495 }
5496
5497 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5498 if (found_key.offset != cur_pos ||
5499 found_key.type != BTRFS_EXTENT_DATA_KEY ||
5500 found_key.objectid != reloc_inode->i_ino)
5501 break;
5502
5503 fi = btrfs_item_ptr(leaf, path->slots[0],
5504 struct btrfs_file_extent_item);
5505 if (btrfs_file_extent_type(leaf, fi) !=
5506 BTRFS_FILE_EXTENT_REG ||
5507 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
5508 break;
5509
5510 if (nr == max) {
5511 struct disk_extent *old = exts;
5512 max *= 2;
5513 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
5514 memcpy(exts, old, sizeof(*exts) * nr);
5515 if (old != *extents)
5516 kfree(old);
5517 }
5518
5519 exts[nr].disk_bytenr =
5520 btrfs_file_extent_disk_bytenr(leaf, fi);
5521 exts[nr].disk_num_bytes =
5522 btrfs_file_extent_disk_num_bytes(leaf, fi);
5523 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
5524 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5525 exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
5526 exts[nr].compression = btrfs_file_extent_compression(leaf, fi);
5527 exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi);
5528 exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf,
5529 fi);
5530 BUG_ON(exts[nr].offset > 0);
5531 BUG_ON(exts[nr].compression || exts[nr].encryption);
5532 BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
5533
5534 cur_pos += exts[nr].num_bytes;
5535 nr++;
5536
5537 if (cur_pos + offset >= last_byte)
5538 break;
5539
5540 if (no_fragment) {
5541 ret = 1;
5542 goto out;
5543 }
5544 path->slots[0]++;
5545 }
5546
5547 BUG_ON(cur_pos + offset > last_byte);
5548 if (cur_pos + offset < last_byte) {
5549 ret = -ENOENT;
5550 goto out;
5551 }
5552 ret = 0;
5553 out:
5554 btrfs_free_path(path);
5555 if (ret) {
5556 if (exts != *extents)
5557 kfree(exts);
5558 } else {
5559 *extents = exts;
5560 *nr_extents = nr;
5561 }
5562 return ret;
5563 }
5564
5565 static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
5566 struct btrfs_root *root,
5567 struct btrfs_path *path,
5568 struct btrfs_key *extent_key,
5569 struct btrfs_key *leaf_key,
5570 struct btrfs_ref_path *ref_path,
5571 struct disk_extent *new_extents,
5572 int nr_extents)
5573 {
5574 struct extent_buffer *leaf;
5575 struct btrfs_file_extent_item *fi;
5576 struct inode *inode = NULL;
5577 struct btrfs_key key;
5578 u64 lock_start = 0;
5579 u64 lock_end = 0;
5580 u64 num_bytes;
5581 u64 ext_offset;
5582 u64 search_end = (u64)-1;
5583 u32 nritems;
5584 int nr_scaned = 0;
5585 int extent_locked = 0;
5586 int extent_type;
5587 int ret;
5588
5589 memcpy(&key, leaf_key, sizeof(key));
5590 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
5591 if (key.objectid < ref_path->owner_objectid ||
5592 (key.objectid == ref_path->owner_objectid &&
5593 key.type < BTRFS_EXTENT_DATA_KEY)) {
5594 key.objectid = ref_path->owner_objectid;
5595 key.type = BTRFS_EXTENT_DATA_KEY;
5596 key.offset = 0;
5597 }
5598 }
5599
5600 while (1) {
5601 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
5602 if (ret < 0)
5603 goto out;
5604
5605 leaf = path->nodes[0];
5606 nritems = btrfs_header_nritems(leaf);
5607 next:
5608 if (extent_locked && ret > 0) {
5609 /*
5610 * the file extent item was modified by someone
5611 * before the extent got locked.
5612 */
5613 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5614 lock_end, GFP_NOFS);
5615 extent_locked = 0;
5616 }
5617
5618 if (path->slots[0] >= nritems) {
5619 if (++nr_scaned > 2)
5620 break;
5621
5622 BUG_ON(extent_locked);
5623 ret = btrfs_next_leaf(root, path);
5624 if (ret < 0)
5625 goto out;
5626 if (ret > 0)
5627 break;
5628 leaf = path->nodes[0];
5629 nritems = btrfs_header_nritems(leaf);
5630 }
5631
5632 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
5633
5634 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
5635 if ((key.objectid > ref_path->owner_objectid) ||
5636 (key.objectid == ref_path->owner_objectid &&
5637 key.type > BTRFS_EXTENT_DATA_KEY) ||
5638 key.offset >= search_end)
5639 break;
5640 }
5641
5642 if (inode && key.objectid != inode->i_ino) {
5643 BUG_ON(extent_locked);
5644 btrfs_release_path(root, path);
5645 mutex_unlock(&inode->i_mutex);
5646 iput(inode);
5647 inode = NULL;
5648 continue;
5649 }
5650
5651 if (key.type != BTRFS_EXTENT_DATA_KEY) {
5652 path->slots[0]++;
5653 ret = 1;
5654 goto next;
5655 }
5656 fi = btrfs_item_ptr(leaf, path->slots[0],
5657 struct btrfs_file_extent_item);
5658 extent_type = btrfs_file_extent_type(leaf, fi);
5659 if ((extent_type != BTRFS_FILE_EXTENT_REG &&
5660 extent_type != BTRFS_FILE_EXTENT_PREALLOC) ||
5661 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
5662 extent_key->objectid)) {
5663 path->slots[0]++;
5664 ret = 1;
5665 goto next;
5666 }
5667
5668 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5669 ext_offset = btrfs_file_extent_offset(leaf, fi);
5670
5671 if (search_end == (u64)-1) {
5672 search_end = key.offset - ext_offset +
5673 btrfs_file_extent_ram_bytes(leaf, fi);
5674 }
5675
5676 if (!extent_locked) {
5677 lock_start = key.offset;
5678 lock_end = lock_start + num_bytes - 1;
5679 } else {
5680 if (lock_start > key.offset ||
5681 lock_end + 1 < key.offset + num_bytes) {
5682 unlock_extent(&BTRFS_I(inode)->io_tree,
5683 lock_start, lock_end, GFP_NOFS);
5684 extent_locked = 0;
5685 }
5686 }
5687
5688 if (!inode) {
5689 btrfs_release_path(root, path);
5690
5691 inode = btrfs_iget_locked(root->fs_info->sb,
5692 key.objectid, root);
5693 if (inode->i_state & I_NEW) {
5694 BTRFS_I(inode)->root = root;
5695 BTRFS_I(inode)->location.objectid =
5696 key.objectid;
5697 BTRFS_I(inode)->location.type =
5698 BTRFS_INODE_ITEM_KEY;
5699 BTRFS_I(inode)->location.offset = 0;
5700 btrfs_read_locked_inode(inode);
5701 unlock_new_inode(inode);
5702 }
5703 /*
5704 * some code call btrfs_commit_transaction while
5705 * holding the i_mutex, so we can't use mutex_lock
5706 * here.
5707 */
5708 if (is_bad_inode(inode) ||
5709 !mutex_trylock(&inode->i_mutex)) {
5710 iput(inode);
5711 inode = NULL;
5712 key.offset = (u64)-1;
5713 goto skip;
5714 }
5715 }
5716
5717 if (!extent_locked) {
5718 struct btrfs_ordered_extent *ordered;
5719
5720 btrfs_release_path(root, path);
5721
5722 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5723 lock_end, GFP_NOFS);
5724 ordered = btrfs_lookup_first_ordered_extent(inode,
5725 lock_end);
5726 if (ordered &&
5727 ordered->file_offset <= lock_end &&
5728 ordered->file_offset + ordered->len > lock_start) {
5729 unlock_extent(&BTRFS_I(inode)->io_tree,
5730 lock_start, lock_end, GFP_NOFS);
5731 btrfs_start_ordered_extent(inode, ordered, 1);
5732 btrfs_put_ordered_extent(ordered);
5733 key.offset += num_bytes;
5734 goto skip;
5735 }
5736 if (ordered)
5737 btrfs_put_ordered_extent(ordered);
5738
5739 extent_locked = 1;
5740 continue;
5741 }
5742
5743 if (nr_extents == 1) {
5744 /* update extent pointer in place */
5745 btrfs_set_file_extent_disk_bytenr(leaf, fi,
5746 new_extents[0].disk_bytenr);
5747 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
5748 new_extents[0].disk_num_bytes);
5749 btrfs_mark_buffer_dirty(leaf);
5750
5751 btrfs_drop_extent_cache(inode, key.offset,
5752 key.offset + num_bytes - 1, 0);
5753
5754 ret = btrfs_inc_extent_ref(trans, root,
5755 new_extents[0].disk_bytenr,
5756 new_extents[0].disk_num_bytes,
5757 leaf->start,
5758 root->root_key.objectid,
5759 trans->transid,
5760 key.objectid);
5761 BUG_ON(ret);
5762
5763 ret = btrfs_free_extent(trans, root,
5764 extent_key->objectid,
5765 extent_key->offset,
5766 leaf->start,
5767 btrfs_header_owner(leaf),
5768 btrfs_header_generation(leaf),
5769 key.objectid, 0);
5770 BUG_ON(ret);
5771
5772 btrfs_release_path(root, path);
5773 key.offset += num_bytes;
5774 } else {
5775 BUG_ON(1);
5776 #if 0
5777 u64 alloc_hint;
5778 u64 extent_len;
5779 int i;
5780 /*
5781 * drop old extent pointer at first, then insert the
5782 * new pointers one bye one
5783 */
5784 btrfs_release_path(root, path);
5785 ret = btrfs_drop_extents(trans, root, inode, key.offset,
5786 key.offset + num_bytes,
5787 key.offset, &alloc_hint);
5788 BUG_ON(ret);
5789
5790 for (i = 0; i < nr_extents; i++) {
5791 if (ext_offset >= new_extents[i].num_bytes) {
5792 ext_offset -= new_extents[i].num_bytes;
5793 continue;
5794 }
5795 extent_len = min(new_extents[i].num_bytes -
5796 ext_offset, num_bytes);
5797
5798 ret = btrfs_insert_empty_item(trans, root,
5799 path, &key,
5800 sizeof(*fi));
5801 BUG_ON(ret);
5802
5803 leaf = path->nodes[0];
5804 fi = btrfs_item_ptr(leaf, path->slots[0],
5805 struct btrfs_file_extent_item);
5806 btrfs_set_file_extent_generation(leaf, fi,
5807 trans->transid);
5808 btrfs_set_file_extent_type(leaf, fi,
5809 BTRFS_FILE_EXTENT_REG);
5810 btrfs_set_file_extent_disk_bytenr(leaf, fi,
5811 new_extents[i].disk_bytenr);
5812 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
5813 new_extents[i].disk_num_bytes);
5814 btrfs_set_file_extent_ram_bytes(leaf, fi,
5815 new_extents[i].ram_bytes);
5816
5817 btrfs_set_file_extent_compression(leaf, fi,
5818 new_extents[i].compression);
5819 btrfs_set_file_extent_encryption(leaf, fi,
5820 new_extents[i].encryption);
5821 btrfs_set_file_extent_other_encoding(leaf, fi,
5822 new_extents[i].other_encoding);
5823
5824 btrfs_set_file_extent_num_bytes(leaf, fi,
5825 extent_len);
5826 ext_offset += new_extents[i].offset;
5827 btrfs_set_file_extent_offset(leaf, fi,
5828 ext_offset);
5829 btrfs_mark_buffer_dirty(leaf);
5830
5831 btrfs_drop_extent_cache(inode, key.offset,
5832 key.offset + extent_len - 1, 0);
5833
5834 ret = btrfs_inc_extent_ref(trans, root,
5835 new_extents[i].disk_bytenr,
5836 new_extents[i].disk_num_bytes,
5837 leaf->start,
5838 root->root_key.objectid,
5839 trans->transid, key.objectid);
5840 BUG_ON(ret);
5841 btrfs_release_path(root, path);
5842
5843 inode_add_bytes(inode, extent_len);
5844
5845 ext_offset = 0;
5846 num_bytes -= extent_len;
5847 key.offset += extent_len;
5848
5849 if (num_bytes == 0)
5850 break;
5851 }
5852 BUG_ON(i >= nr_extents);
5853 #endif
5854 }
5855
5856 if (extent_locked) {
5857 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5858 lock_end, GFP_NOFS);
5859 extent_locked = 0;
5860 }
5861 skip:
5862 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
5863 key.offset >= search_end)
5864 break;
5865
5866 cond_resched();
5867 }
5868 ret = 0;
5869 out:
5870 btrfs_release_path(root, path);
5871 if (inode) {
5872 mutex_unlock(&inode->i_mutex);
5873 if (extent_locked) {
5874 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
5875 lock_end, GFP_NOFS);
5876 }
5877 iput(inode);
5878 }
5879 return ret;
5880 }
5881
5882 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
5883 struct btrfs_root *root,
5884 struct extent_buffer *buf, u64 orig_start)
5885 {
5886 int level;
5887 int ret;
5888
5889 BUG_ON(btrfs_header_generation(buf) != trans->transid);
5890 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
5891
5892 level = btrfs_header_level(buf);
5893 if (level == 0) {
5894 struct btrfs_leaf_ref *ref;
5895 struct btrfs_leaf_ref *orig_ref;
5896
5897 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
5898 if (!orig_ref)
5899 return -ENOENT;
5900
5901 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
5902 if (!ref) {
5903 btrfs_free_leaf_ref(root, orig_ref);
5904 return -ENOMEM;
5905 }
5906
5907 ref->nritems = orig_ref->nritems;
5908 memcpy(ref->extents, orig_ref->extents,
5909 sizeof(ref->extents[0]) * ref->nritems);
5910
5911 btrfs_free_leaf_ref(root, orig_ref);
5912
5913 ref->root_gen = trans->transid;
5914 ref->bytenr = buf->start;
5915 ref->owner = btrfs_header_owner(buf);
5916 ref->generation = btrfs_header_generation(buf);
5917
5918 ret = btrfs_add_leaf_ref(root, ref, 0);
5919 WARN_ON(ret);
5920 btrfs_free_leaf_ref(root, ref);
5921 }
5922 return 0;
5923 }
5924
5925 static noinline int invalidate_extent_cache(struct btrfs_root *root,
5926 struct extent_buffer *leaf,
5927 struct btrfs_block_group_cache *group,
5928 struct btrfs_root *target_root)
5929 {
5930 struct btrfs_key key;
5931 struct inode *inode = NULL;
5932 struct btrfs_file_extent_item *fi;
5933 u64 num_bytes;
5934 u64 skip_objectid = 0;
5935 u32 nritems;
5936 u32 i;
5937
5938 nritems = btrfs_header_nritems(leaf);
5939 for (i = 0; i < nritems; i++) {
5940 btrfs_item_key_to_cpu(leaf, &key, i);
5941 if (key.objectid == skip_objectid ||
5942 key.type != BTRFS_EXTENT_DATA_KEY)
5943 continue;
5944 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
5945 if (btrfs_file_extent_type(leaf, fi) ==
5946 BTRFS_FILE_EXTENT_INLINE)
5947 continue;
5948 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
5949 continue;
5950 if (!inode || inode->i_ino != key.objectid) {
5951 iput(inode);
5952 inode = btrfs_ilookup(target_root->fs_info->sb,
5953 key.objectid, target_root, 1);
5954 }
5955 if (!inode) {
5956 skip_objectid = key.objectid;
5957 continue;
5958 }
5959 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
5960
5961 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
5962 key.offset + num_bytes - 1, GFP_NOFS);
5963 btrfs_drop_extent_cache(inode, key.offset,
5964 key.offset + num_bytes - 1, 1);
5965 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
5966 key.offset + num_bytes - 1, GFP_NOFS);
5967 cond_resched();
5968 }
5969 iput(inode);
5970 return 0;
5971 }
5972
5973 static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans,
5974 struct btrfs_root *root,
5975 struct extent_buffer *leaf,
5976 struct btrfs_block_group_cache *group,
5977 struct inode *reloc_inode)
5978 {
5979 struct btrfs_key key;
5980 struct btrfs_key extent_key;
5981 struct btrfs_file_extent_item *fi;
5982 struct btrfs_leaf_ref *ref;
5983 struct disk_extent *new_extent;
5984 u64 bytenr;
5985 u64 num_bytes;
5986 u32 nritems;
5987 u32 i;
5988 int ext_index;
5989 int nr_extent;
5990 int ret;
5991
5992 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
5993 BUG_ON(!new_extent);
5994
5995 ref = btrfs_lookup_leaf_ref(root, leaf->start);
5996 BUG_ON(!ref);
5997
5998 ext_index = -1;
5999 nritems = btrfs_header_nritems(leaf);
6000 for (i = 0; i < nritems; i++) {
6001 btrfs_item_key_to_cpu(leaf, &key, i);
6002 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
6003 continue;
6004 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
6005 if (btrfs_file_extent_type(leaf, fi) ==
6006 BTRFS_FILE_EXTENT_INLINE)
6007 continue;
6008 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6009 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
6010 if (bytenr == 0)
6011 continue;
6012
6013 ext_index++;
6014 if (bytenr >= group->key.objectid + group->key.offset ||
6015 bytenr + num_bytes <= group->key.objectid)
6016 continue;
6017
6018 extent_key.objectid = bytenr;
6019 extent_key.offset = num_bytes;
6020 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
6021 nr_extent = 1;
6022 ret = get_new_locations(reloc_inode, &extent_key,
6023 group->key.objectid, 1,
6024 &new_extent, &nr_extent);
6025 if (ret > 0)
6026 continue;
6027 BUG_ON(ret < 0);
6028
6029 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
6030 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
6031 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
6032 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
6033
6034 btrfs_set_file_extent_disk_bytenr(leaf, fi,
6035 new_extent->disk_bytenr);
6036 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
6037 new_extent->disk_num_bytes);
6038 btrfs_mark_buffer_dirty(leaf);
6039
6040 ret = btrfs_inc_extent_ref(trans, root,
6041 new_extent->disk_bytenr,
6042 new_extent->disk_num_bytes,
6043 leaf->start,
6044 root->root_key.objectid,
6045 trans->transid, key.objectid);
6046 BUG_ON(ret);
6047
6048 ret = btrfs_free_extent(trans, root,
6049 bytenr, num_bytes, leaf->start,
6050 btrfs_header_owner(leaf),
6051 btrfs_header_generation(leaf),
6052 key.objectid, 0);
6053 BUG_ON(ret);
6054 cond_resched();
6055 }
6056 kfree(new_extent);
6057 BUG_ON(ext_index + 1 != ref->nritems);
6058 btrfs_free_leaf_ref(root, ref);
6059 return 0;
6060 }
6061
6062 int btrfs_free_reloc_root(struct btrfs_trans_handle *trans,
6063 struct btrfs_root *root)
6064 {
6065 struct btrfs_root *reloc_root;
6066 int ret;
6067
6068 if (root->reloc_root) {
6069 reloc_root = root->reloc_root;
6070 root->reloc_root = NULL;
6071 list_add(&reloc_root->dead_list,
6072 &root->fs_info->dead_reloc_roots);
6073
6074 btrfs_set_root_bytenr(&reloc_root->root_item,
6075 reloc_root->node->start);
6076 btrfs_set_root_level(&root->root_item,
6077 btrfs_header_level(reloc_root->node));
6078 memset(&reloc_root->root_item.drop_progress, 0,
6079 sizeof(struct btrfs_disk_key));
6080 reloc_root->root_item.drop_level = 0;
6081
6082 ret = btrfs_update_root(trans, root->fs_info->tree_root,
6083 &reloc_root->root_key,
6084 &reloc_root->root_item);
6085 BUG_ON(ret);
6086 }
6087 return 0;
6088 }
6089
6090 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
6091 {
6092 struct btrfs_trans_handle *trans;
6093 struct btrfs_root *reloc_root;
6094 struct btrfs_root *prev_root = NULL;
6095 struct list_head dead_roots;
6096 int ret;
6097 unsigned long nr;
6098
6099 INIT_LIST_HEAD(&dead_roots);
6100 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
6101
6102 while (!list_empty(&dead_roots)) {
6103 reloc_root = list_entry(dead_roots.prev,
6104 struct btrfs_root, dead_list);
6105 list_del_init(&reloc_root->dead_list);
6106
6107 BUG_ON(reloc_root->commit_root != NULL);
6108 while (1) {
6109 trans = btrfs_join_transaction(root, 1);
6110 BUG_ON(!trans);
6111
6112 mutex_lock(&root->fs_info->drop_mutex);
6113 ret = btrfs_drop_snapshot(trans, reloc_root);
6114 if (ret != -EAGAIN)
6115 break;
6116 mutex_unlock(&root->fs_info->drop_mutex);
6117
6118 nr = trans->blocks_used;
6119 ret = btrfs_end_transaction(trans, root);
6120 BUG_ON(ret);
6121 btrfs_btree_balance_dirty(root, nr);
6122 }
6123
6124 free_extent_buffer(reloc_root->node);
6125
6126 ret = btrfs_del_root(trans, root->fs_info->tree_root,
6127 &reloc_root->root_key);
6128 BUG_ON(ret);
6129 mutex_unlock(&root->fs_info->drop_mutex);
6130
6131 nr = trans->blocks_used;
6132 ret = btrfs_end_transaction(trans, root);
6133 BUG_ON(ret);
6134 btrfs_btree_balance_dirty(root, nr);
6135
6136 kfree(prev_root);
6137 prev_root = reloc_root;
6138 }
6139 if (prev_root) {
6140 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
6141 kfree(prev_root);
6142 }
6143 return 0;
6144 }
6145
6146 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
6147 {
6148 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
6149 return 0;
6150 }
6151
6152 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
6153 {
6154 struct btrfs_root *reloc_root;
6155 struct btrfs_trans_handle *trans;
6156 struct btrfs_key location;
6157 int found;
6158 int ret;
6159
6160 mutex_lock(&root->fs_info->tree_reloc_mutex);
6161 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
6162 BUG_ON(ret);
6163 found = !list_empty(&root->fs_info->dead_reloc_roots);
6164 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6165
6166 if (found) {
6167 trans = btrfs_start_transaction(root, 1);
6168 BUG_ON(!trans);
6169 ret = btrfs_commit_transaction(trans, root);
6170 BUG_ON(ret);
6171 }
6172
6173 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
6174 location.offset = (u64)-1;
6175 location.type = BTRFS_ROOT_ITEM_KEY;
6176
6177 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
6178 BUG_ON(!reloc_root);
6179 btrfs_orphan_cleanup(reloc_root);
6180 return 0;
6181 }
6182
6183 static noinline int init_reloc_tree(struct btrfs_trans_handle *trans,
6184 struct btrfs_root *root)
6185 {
6186 struct btrfs_root *reloc_root;
6187 struct extent_buffer *eb;
6188 struct btrfs_root_item *root_item;
6189 struct btrfs_key root_key;
6190 int ret;
6191
6192 BUG_ON(!root->ref_cows);
6193 if (root->reloc_root)
6194 return 0;
6195
6196 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
6197 BUG_ON(!root_item);
6198
6199 ret = btrfs_copy_root(trans, root, root->commit_root,
6200 &eb, BTRFS_TREE_RELOC_OBJECTID);
6201 BUG_ON(ret);
6202
6203 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
6204 root_key.offset = root->root_key.objectid;
6205 root_key.type = BTRFS_ROOT_ITEM_KEY;
6206
6207 memcpy(root_item, &root->root_item, sizeof(root_item));
6208 btrfs_set_root_refs(root_item, 0);
6209 btrfs_set_root_bytenr(root_item, eb->start);
6210 btrfs_set_root_level(root_item, btrfs_header_level(eb));
6211 btrfs_set_root_generation(root_item, trans->transid);
6212
6213 btrfs_tree_unlock(eb);
6214 free_extent_buffer(eb);
6215
6216 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
6217 &root_key, root_item);
6218 BUG_ON(ret);
6219 kfree(root_item);
6220
6221 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
6222 &root_key);
6223 BUG_ON(!reloc_root);
6224 reloc_root->last_trans = trans->transid;
6225 reloc_root->commit_root = NULL;
6226 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
6227
6228 root->reloc_root = reloc_root;
6229 return 0;
6230 }
6231
6232 /*
6233 * Core function of space balance.
6234 *
6235 * The idea is using reloc trees to relocate tree blocks in reference
6236 * counted roots. There is one reloc tree for each subvol, and all
6237 * reloc trees share same root key objectid. Reloc trees are snapshots
6238 * of the latest committed roots of subvols (root->commit_root).
6239 *
6240 * To relocate a tree block referenced by a subvol, there are two steps.
6241 * COW the block through subvol's reloc tree, then update block pointer
6242 * in the subvol to point to the new block. Since all reloc trees share
6243 * same root key objectid, doing special handing for tree blocks owned
6244 * by them is easy. Once a tree block has been COWed in one reloc tree,
6245 * we can use the resulting new block directly when the same block is
6246 * required to COW again through other reloc trees. By this way, relocated
6247 * tree blocks are shared between reloc trees, so they are also shared
6248 * between subvols.
6249 */
6250 static noinline int relocate_one_path(struct btrfs_trans_handle *trans,
6251 struct btrfs_root *root,
6252 struct btrfs_path *path,
6253 struct btrfs_key *first_key,
6254 struct btrfs_ref_path *ref_path,
6255 struct btrfs_block_group_cache *group,
6256 struct inode *reloc_inode)
6257 {
6258 struct btrfs_root *reloc_root;
6259 struct extent_buffer *eb = NULL;
6260 struct btrfs_key *keys;
6261 u64 *nodes;
6262 int level;
6263 int shared_level;
6264 int lowest_level = 0;
6265 int ret;
6266
6267 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
6268 lowest_level = ref_path->owner_objectid;
6269
6270 if (!root->ref_cows) {
6271 path->lowest_level = lowest_level;
6272 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
6273 BUG_ON(ret < 0);
6274 path->lowest_level = 0;
6275 btrfs_release_path(root, path);
6276 return 0;
6277 }
6278
6279 mutex_lock(&root->fs_info->tree_reloc_mutex);
6280 ret = init_reloc_tree(trans, root);
6281 BUG_ON(ret);
6282 reloc_root = root->reloc_root;
6283
6284 shared_level = ref_path->shared_level;
6285 ref_path->shared_level = BTRFS_MAX_LEVEL - 1;
6286
6287 keys = ref_path->node_keys;
6288 nodes = ref_path->new_nodes;
6289 memset(&keys[shared_level + 1], 0,
6290 sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1));
6291 memset(&nodes[shared_level + 1], 0,
6292 sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1));
6293
6294 if (nodes[lowest_level] == 0) {
6295 path->lowest_level = lowest_level;
6296 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6297 0, 1);
6298 BUG_ON(ret);
6299 for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) {
6300 eb = path->nodes[level];
6301 if (!eb || eb == reloc_root->node)
6302 break;
6303 nodes[level] = eb->start;
6304 if (level == 0)
6305 btrfs_item_key_to_cpu(eb, &keys[level], 0);
6306 else
6307 btrfs_node_key_to_cpu(eb, &keys[level], 0);
6308 }
6309 if (nodes[0] &&
6310 ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6311 eb = path->nodes[0];
6312 ret = replace_extents_in_leaf(trans, reloc_root, eb,
6313 group, reloc_inode);
6314 BUG_ON(ret);
6315 }
6316 btrfs_release_path(reloc_root, path);
6317 } else {
6318 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
6319 lowest_level);
6320 BUG_ON(ret);
6321 }
6322
6323 /*
6324 * replace tree blocks in the fs tree with tree blocks in
6325 * the reloc tree.
6326 */
6327 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
6328 BUG_ON(ret < 0);
6329
6330 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6331 ret = btrfs_search_slot(trans, reloc_root, first_key, path,
6332 0, 0);
6333 BUG_ON(ret);
6334 extent_buffer_get(path->nodes[0]);
6335 eb = path->nodes[0];
6336 btrfs_release_path(reloc_root, path);
6337 ret = invalidate_extent_cache(reloc_root, eb, group, root);
6338 BUG_ON(ret);
6339 free_extent_buffer(eb);
6340 }
6341
6342 mutex_unlock(&root->fs_info->tree_reloc_mutex);
6343 path->lowest_level = 0;
6344 return 0;
6345 }
6346
6347 static noinline int relocate_tree_block(struct btrfs_trans_handle *trans,
6348 struct btrfs_root *root,
6349 struct btrfs_path *path,
6350 struct btrfs_key *first_key,
6351 struct btrfs_ref_path *ref_path)
6352 {
6353 int ret;
6354
6355 ret = relocate_one_path(trans, root, path, first_key,
6356 ref_path, NULL, NULL);
6357 BUG_ON(ret);
6358
6359 return 0;
6360 }
6361
6362 static noinline int del_extent_zero(struct btrfs_trans_handle *trans,
6363 struct btrfs_root *extent_root,
6364 struct btrfs_path *path,
6365 struct btrfs_key *extent_key)
6366 {
6367 int ret;
6368
6369 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
6370 if (ret)
6371 goto out;
6372 ret = btrfs_del_item(trans, extent_root, path);
6373 out:
6374 btrfs_release_path(extent_root, path);
6375 return ret;
6376 }
6377
6378 static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info,
6379 struct btrfs_ref_path *ref_path)
6380 {
6381 struct btrfs_key root_key;
6382
6383 root_key.objectid = ref_path->root_objectid;
6384 root_key.type = BTRFS_ROOT_ITEM_KEY;
6385 if (is_cowonly_root(ref_path->root_objectid))
6386 root_key.offset = 0;
6387 else
6388 root_key.offset = (u64)-1;
6389
6390 return btrfs_read_fs_root_no_name(fs_info, &root_key);
6391 }
6392
6393 static noinline int relocate_one_extent(struct btrfs_root *extent_root,
6394 struct btrfs_path *path,
6395 struct btrfs_key *extent_key,
6396 struct btrfs_block_group_cache *group,
6397 struct inode *reloc_inode, int pass)
6398 {
6399 struct btrfs_trans_handle *trans;
6400 struct btrfs_root *found_root;
6401 struct btrfs_ref_path *ref_path = NULL;
6402 struct disk_extent *new_extents = NULL;
6403 int nr_extents = 0;
6404 int loops;
6405 int ret;
6406 int level;
6407 struct btrfs_key first_key;
6408 u64 prev_block = 0;
6409
6410
6411 trans = btrfs_start_transaction(extent_root, 1);
6412 BUG_ON(!trans);
6413
6414 if (extent_key->objectid == 0) {
6415 ret = del_extent_zero(trans, extent_root, path, extent_key);
6416 goto out;
6417 }
6418
6419 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
6420 if (!ref_path) {
6421 ret = -ENOMEM;
6422 goto out;
6423 }
6424
6425 for (loops = 0; ; loops++) {
6426 if (loops == 0) {
6427 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
6428 extent_key->objectid);
6429 } else {
6430 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
6431 }
6432 if (ret < 0)
6433 goto out;
6434 if (ret > 0)
6435 break;
6436
6437 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
6438 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
6439 continue;
6440
6441 found_root = read_ref_root(extent_root->fs_info, ref_path);
6442 BUG_ON(!found_root);
6443 /*
6444 * for reference counted tree, only process reference paths
6445 * rooted at the latest committed root.
6446 */
6447 if (found_root->ref_cows &&
6448 ref_path->root_generation != found_root->root_key.offset)
6449 continue;
6450
6451 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6452 if (pass == 0) {
6453 /*
6454 * copy data extents to new locations
6455 */
6456 u64 group_start = group->key.objectid;
6457 ret = relocate_data_extent(reloc_inode,
6458 extent_key,
6459 group_start);
6460 if (ret < 0)
6461 goto out;
6462 break;
6463 }
6464 level = 0;
6465 } else {
6466 level = ref_path->owner_objectid;
6467 }
6468
6469 if (prev_block != ref_path->nodes[level]) {
6470 struct extent_buffer *eb;
6471 u64 block_start = ref_path->nodes[level];
6472 u64 block_size = btrfs_level_size(found_root, level);
6473
6474 eb = read_tree_block(found_root, block_start,
6475 block_size, 0);
6476 btrfs_tree_lock(eb);
6477 BUG_ON(level != btrfs_header_level(eb));
6478
6479 if (level == 0)
6480 btrfs_item_key_to_cpu(eb, &first_key, 0);
6481 else
6482 btrfs_node_key_to_cpu(eb, &first_key, 0);
6483
6484 btrfs_tree_unlock(eb);
6485 free_extent_buffer(eb);
6486 prev_block = block_start;
6487 }
6488
6489 mutex_lock(&extent_root->fs_info->trans_mutex);
6490 btrfs_record_root_in_trans(found_root);
6491 mutex_unlock(&extent_root->fs_info->trans_mutex);
6492 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
6493 /*
6494 * try to update data extent references while
6495 * keeping metadata shared between snapshots.
6496 */
6497 if (pass == 1) {
6498 ret = relocate_one_path(trans, found_root,
6499 path, &first_key, ref_path,
6500 group, reloc_inode);
6501 if (ret < 0)
6502 goto out;
6503 continue;
6504 }
6505 /*
6506 * use fallback method to process the remaining
6507 * references.
6508 */
6509 if (!new_extents) {
6510 u64 group_start = group->key.objectid;
6511 new_extents = kmalloc(sizeof(*new_extents),
6512 GFP_NOFS);
6513 nr_extents = 1;
6514 ret = get_new_locations(reloc_inode,
6515 extent_key,
6516 group_start, 1,
6517 &new_extents,
6518 &nr_extents);
6519 if (ret)
6520 goto out;
6521 }
6522 ret = replace_one_extent(trans, found_root,
6523 path, extent_key,
6524 &first_key, ref_path,
6525 new_extents, nr_extents);
6526 } else {
6527 ret = relocate_tree_block(trans, found_root, path,
6528 &first_key, ref_path);
6529 }
6530 if (ret < 0)
6531 goto out;
6532 }
6533 ret = 0;
6534 out:
6535 btrfs_end_transaction(trans, extent_root);
6536 kfree(new_extents);
6537 kfree(ref_path);
6538 return ret;
6539 }
6540 #endif
6541
6542 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
6543 {
6544 u64 num_devices;
6545 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
6546 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
6547
6548 num_devices = root->fs_info->fs_devices->rw_devices;
6549 if (num_devices == 1) {
6550 stripped |= BTRFS_BLOCK_GROUP_DUP;
6551 stripped = flags & ~stripped;
6552
6553 /* turn raid0 into single device chunks */
6554 if (flags & BTRFS_BLOCK_GROUP_RAID0)
6555 return stripped;
6556
6557 /* turn mirroring into duplication */
6558 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
6559 BTRFS_BLOCK_GROUP_RAID10))
6560 return stripped | BTRFS_BLOCK_GROUP_DUP;
6561 return flags;
6562 } else {
6563 /* they already had raid on here, just return */
6564 if (flags & stripped)
6565 return flags;
6566
6567 stripped |= BTRFS_BLOCK_GROUP_DUP;
6568 stripped = flags & ~stripped;
6569
6570 /* switch duplicated blocks with raid1 */
6571 if (flags & BTRFS_BLOCK_GROUP_DUP)
6572 return stripped | BTRFS_BLOCK_GROUP_RAID1;
6573
6574 /* turn single device chunks into raid0 */
6575 return stripped | BTRFS_BLOCK_GROUP_RAID0;
6576 }
6577 return flags;
6578 }
6579
6580 static int __alloc_chunk_for_shrink(struct btrfs_root *root,
6581 struct btrfs_block_group_cache *shrink_block_group,
6582 int force)
6583 {
6584 struct btrfs_trans_handle *trans;
6585 u64 new_alloc_flags;
6586 u64 calc;
6587
6588 spin_lock(&shrink_block_group->lock);
6589 if (btrfs_block_group_used(&shrink_block_group->item) +
6590 shrink_block_group->reserved > 0) {
6591 spin_unlock(&shrink_block_group->lock);
6592
6593 trans = btrfs_start_transaction(root, 1);
6594 spin_lock(&shrink_block_group->lock);
6595
6596 new_alloc_flags = update_block_group_flags(root,
6597 shrink_block_group->flags);
6598 if (new_alloc_flags != shrink_block_group->flags) {
6599 calc =
6600 btrfs_block_group_used(&shrink_block_group->item);
6601 } else {
6602 calc = shrink_block_group->key.offset;
6603 }
6604 spin_unlock(&shrink_block_group->lock);
6605
6606 do_chunk_alloc(trans, root->fs_info->extent_root,
6607 calc + 2 * 1024 * 1024, new_alloc_flags, force);
6608
6609 btrfs_end_transaction(trans, root);
6610 } else
6611 spin_unlock(&shrink_block_group->lock);
6612 return 0;
6613 }
6614
6615
6616 int btrfs_prepare_block_group_relocation(struct btrfs_root *root,
6617 struct btrfs_block_group_cache *group)
6618
6619 {
6620 __alloc_chunk_for_shrink(root, group, 1);
6621 set_block_group_readonly(group);
6622 return 0;
6623 }
6624
6625 #if 0
6626 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
6627 struct btrfs_root *root,
6628 u64 objectid, u64 size)
6629 {
6630 struct btrfs_path *path;
6631 struct btrfs_inode_item *item;
6632 struct extent_buffer *leaf;
6633 int ret;
6634
6635 path = btrfs_alloc_path();
6636 if (!path)
6637 return -ENOMEM;
6638
6639 path->leave_spinning = 1;
6640 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
6641 if (ret)
6642 goto out;
6643
6644 leaf = path->nodes[0];
6645 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
6646 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
6647 btrfs_set_inode_generation(leaf, item, 1);
6648 btrfs_set_inode_size(leaf, item, size);
6649 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
6650 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS);
6651 btrfs_mark_buffer_dirty(leaf);
6652 btrfs_release_path(root, path);
6653 out:
6654 btrfs_free_path(path);
6655 return ret;
6656 }
6657
6658 static noinline struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
6659 struct btrfs_block_group_cache *group)
6660 {
6661 struct inode *inode = NULL;
6662 struct btrfs_trans_handle *trans;
6663 struct btrfs_root *root;
6664 struct btrfs_key root_key;
6665 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
6666 int err = 0;
6667
6668 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
6669 root_key.type = BTRFS_ROOT_ITEM_KEY;
6670 root_key.offset = (u64)-1;
6671 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
6672 if (IS_ERR(root))
6673 return ERR_CAST(root);
6674
6675 trans = btrfs_start_transaction(root, 1);
6676 BUG_ON(!trans);
6677
6678 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
6679 if (err)
6680 goto out;
6681
6682 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
6683 BUG_ON(err);
6684
6685 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
6686 group->key.offset, 0, group->key.offset,
6687 0, 0, 0);
6688 BUG_ON(err);
6689
6690 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
6691 if (inode->i_state & I_NEW) {
6692 BTRFS_I(inode)->root = root;
6693 BTRFS_I(inode)->location.objectid = objectid;
6694 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
6695 BTRFS_I(inode)->location.offset = 0;
6696 btrfs_read_locked_inode(inode);
6697 unlock_new_inode(inode);
6698 BUG_ON(is_bad_inode(inode));
6699 } else {
6700 BUG_ON(1);
6701 }
6702 BTRFS_I(inode)->index_cnt = group->key.objectid;
6703
6704 err = btrfs_orphan_add(trans, inode);
6705 out:
6706 btrfs_end_transaction(trans, root);
6707 if (err) {
6708 if (inode)
6709 iput(inode);
6710 inode = ERR_PTR(err);
6711 }
6712 return inode;
6713 }
6714
6715 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
6716 {
6717
6718 struct btrfs_ordered_sum *sums;
6719 struct btrfs_sector_sum *sector_sum;
6720 struct btrfs_ordered_extent *ordered;
6721 struct btrfs_root *root = BTRFS_I(inode)->root;
6722 struct list_head list;
6723 size_t offset;
6724 int ret;
6725 u64 disk_bytenr;
6726
6727 INIT_LIST_HEAD(&list);
6728
6729 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
6730 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
6731
6732 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
6733 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
6734 disk_bytenr + len - 1, &list);
6735
6736 while (!list_empty(&list)) {
6737 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
6738 list_del_init(&sums->list);
6739
6740 sector_sum = sums->sums;
6741 sums->bytenr = ordered->start;
6742
6743 offset = 0;
6744 while (offset < sums->len) {
6745 sector_sum->bytenr += ordered->start - disk_bytenr;
6746 sector_sum++;
6747 offset += root->sectorsize;
6748 }
6749
6750 btrfs_add_ordered_sum(inode, ordered, sums);
6751 }
6752 btrfs_put_ordered_extent(ordered);
6753 return 0;
6754 }
6755
6756 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
6757 {
6758 struct btrfs_trans_handle *trans;
6759 struct btrfs_path *path;
6760 struct btrfs_fs_info *info = root->fs_info;
6761 struct extent_buffer *leaf;
6762 struct inode *reloc_inode;
6763 struct btrfs_block_group_cache *block_group;
6764 struct btrfs_key key;
6765 u64 skipped;
6766 u64 cur_byte;
6767 u64 total_found;
6768 u32 nritems;
6769 int ret;
6770 int progress;
6771 int pass = 0;
6772
6773 root = root->fs_info->extent_root;
6774
6775 block_group = btrfs_lookup_block_group(info, group_start);
6776 BUG_ON(!block_group);
6777
6778 printk(KERN_INFO "btrfs relocating block group %llu flags %llu\n",
6779 (unsigned long long)block_group->key.objectid,
6780 (unsigned long long)block_group->flags);
6781
6782 path = btrfs_alloc_path();
6783 BUG_ON(!path);
6784
6785 reloc_inode = create_reloc_inode(info, block_group);
6786 BUG_ON(IS_ERR(reloc_inode));
6787
6788 __alloc_chunk_for_shrink(root, block_group, 1);
6789 set_block_group_readonly(block_group);
6790
6791 btrfs_start_delalloc_inodes(info->tree_root);
6792 btrfs_wait_ordered_extents(info->tree_root, 0);
6793 again:
6794 skipped = 0;
6795 total_found = 0;
6796 progress = 0;
6797 key.objectid = block_group->key.objectid;
6798 key.offset = 0;
6799 key.type = 0;
6800 cur_byte = key.objectid;
6801
6802 trans = btrfs_start_transaction(info->tree_root, 1);
6803 btrfs_commit_transaction(trans, info->tree_root);
6804
6805 mutex_lock(&root->fs_info->cleaner_mutex);
6806 btrfs_clean_old_snapshots(info->tree_root);
6807 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
6808 mutex_unlock(&root->fs_info->cleaner_mutex);
6809
6810 trans = btrfs_start_transaction(info->tree_root, 1);
6811 btrfs_commit_transaction(trans, info->tree_root);
6812
6813 while (1) {
6814 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6815 if (ret < 0)
6816 goto out;
6817 next:
6818 leaf = path->nodes[0];
6819 nritems = btrfs_header_nritems(leaf);
6820 if (path->slots[0] >= nritems) {
6821 ret = btrfs_next_leaf(root, path);
6822 if (ret < 0)
6823 goto out;
6824 if (ret == 1) {
6825 ret = 0;
6826 break;
6827 }
6828 leaf = path->nodes[0];
6829 nritems = btrfs_header_nritems(leaf);
6830 }
6831
6832 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
6833
6834 if (key.objectid >= block_group->key.objectid +
6835 block_group->key.offset)
6836 break;
6837
6838 if (progress && need_resched()) {
6839 btrfs_release_path(root, path);
6840 cond_resched();
6841 progress = 0;
6842 continue;
6843 }
6844 progress = 1;
6845
6846 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
6847 key.objectid + key.offset <= cur_byte) {
6848 path->slots[0]++;
6849 goto next;
6850 }
6851
6852 total_found++;
6853 cur_byte = key.objectid + key.offset;
6854 btrfs_release_path(root, path);
6855
6856 __alloc_chunk_for_shrink(root, block_group, 0);
6857 ret = relocate_one_extent(root, path, &key, block_group,
6858 reloc_inode, pass);
6859 BUG_ON(ret < 0);
6860 if (ret > 0)
6861 skipped++;
6862
6863 key.objectid = cur_byte;
6864 key.type = 0;
6865 key.offset = 0;
6866 }
6867
6868 btrfs_release_path(root, path);
6869
6870 if (pass == 0) {
6871 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
6872 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
6873 }
6874
6875 if (total_found > 0) {
6876 printk(KERN_INFO "btrfs found %llu extents in pass %d\n",
6877 (unsigned long long)total_found, pass);
6878 pass++;
6879 if (total_found == skipped && pass > 2) {
6880 iput(reloc_inode);
6881 reloc_inode = create_reloc_inode(info, block_group);
6882 pass = 0;
6883 }
6884 goto again;
6885 }
6886
6887 /* delete reloc_inode */
6888 iput(reloc_inode);
6889
6890 /* unpin extents in this range */
6891 trans = btrfs_start_transaction(info->tree_root, 1);
6892 btrfs_commit_transaction(trans, info->tree_root);
6893
6894 spin_lock(&block_group->lock);
6895 WARN_ON(block_group->pinned > 0);
6896 WARN_ON(block_group->reserved > 0);
6897 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
6898 spin_unlock(&block_group->lock);
6899 btrfs_put_block_group(block_group);
6900 ret = 0;
6901 out:
6902 btrfs_free_path(path);
6903 return ret;
6904 }
6905 #endif
6906
6907 static int find_first_block_group(struct btrfs_root *root,
6908 struct btrfs_path *path, struct btrfs_key *key)
6909 {
6910 int ret = 0;
6911 struct btrfs_key found_key;
6912 struct extent_buffer *leaf;
6913 int slot;
6914
6915 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
6916 if (ret < 0)
6917 goto out;
6918
6919 while (1) {
6920 slot = path->slots[0];
6921 leaf = path->nodes[0];
6922 if (slot >= btrfs_header_nritems(leaf)) {
6923 ret = btrfs_next_leaf(root, path);
6924 if (ret == 0)
6925 continue;
6926 if (ret < 0)
6927 goto out;
6928 break;
6929 }
6930 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6931
6932 if (found_key.objectid >= key->objectid &&
6933 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
6934 ret = 0;
6935 goto out;
6936 }
6937 path->slots[0]++;
6938 }
6939 ret = -ENOENT;
6940 out:
6941 return ret;
6942 }
6943
6944 int btrfs_free_block_groups(struct btrfs_fs_info *info)
6945 {
6946 struct btrfs_block_group_cache *block_group;
6947 struct btrfs_space_info *space_info;
6948 struct rb_node *n;
6949
6950 spin_lock(&info->block_group_cache_lock);
6951 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
6952 block_group = rb_entry(n, struct btrfs_block_group_cache,
6953 cache_node);
6954 rb_erase(&block_group->cache_node,
6955 &info->block_group_cache_tree);
6956 spin_unlock(&info->block_group_cache_lock);
6957
6958 btrfs_remove_free_space_cache(block_group);
6959 down_write(&block_group->space_info->groups_sem);
6960 list_del(&block_group->list);
6961 up_write(&block_group->space_info->groups_sem);
6962
6963 WARN_ON(atomic_read(&block_group->count) != 1);
6964 kfree(block_group);
6965
6966 spin_lock(&info->block_group_cache_lock);
6967 }
6968 spin_unlock(&info->block_group_cache_lock);
6969
6970 /* now that all the block groups are freed, go through and
6971 * free all the space_info structs. This is only called during
6972 * the final stages of unmount, and so we know nobody is
6973 * using them. We call synchronize_rcu() once before we start,
6974 * just to be on the safe side.
6975 */
6976 synchronize_rcu();
6977
6978 while(!list_empty(&info->space_info)) {
6979 space_info = list_entry(info->space_info.next,
6980 struct btrfs_space_info,
6981 list);
6982
6983 list_del(&space_info->list);
6984 kfree(space_info);
6985 }
6986 return 0;
6987 }
6988
6989 int btrfs_read_block_groups(struct btrfs_root *root)
6990 {
6991 struct btrfs_path *path;
6992 int ret;
6993 struct btrfs_block_group_cache *cache;
6994 struct btrfs_fs_info *info = root->fs_info;
6995 struct btrfs_space_info *space_info;
6996 struct btrfs_key key;
6997 struct btrfs_key found_key;
6998 struct extent_buffer *leaf;
6999
7000 root = info->extent_root;
7001 key.objectid = 0;
7002 key.offset = 0;
7003 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
7004 path = btrfs_alloc_path();
7005 if (!path)
7006 return -ENOMEM;
7007
7008 while (1) {
7009 ret = find_first_block_group(root, path, &key);
7010 if (ret > 0) {
7011 ret = 0;
7012 goto error;
7013 }
7014 if (ret != 0)
7015 goto error;
7016
7017 leaf = path->nodes[0];
7018 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7019 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7020 if (!cache) {
7021 ret = -ENOMEM;
7022 break;
7023 }
7024
7025 atomic_set(&cache->count, 1);
7026 spin_lock_init(&cache->lock);
7027 spin_lock_init(&cache->tree_lock);
7028 mutex_init(&cache->cache_mutex);
7029 INIT_LIST_HEAD(&cache->list);
7030 INIT_LIST_HEAD(&cache->cluster_list);
7031 read_extent_buffer(leaf, &cache->item,
7032 btrfs_item_ptr_offset(leaf, path->slots[0]),
7033 sizeof(cache->item));
7034 memcpy(&cache->key, &found_key, sizeof(found_key));
7035
7036 key.objectid = found_key.objectid + found_key.offset;
7037 btrfs_release_path(root, path);
7038 cache->flags = btrfs_block_group_flags(&cache->item);
7039
7040 ret = update_space_info(info, cache->flags, found_key.offset,
7041 btrfs_block_group_used(&cache->item),
7042 &space_info);
7043 BUG_ON(ret);
7044 cache->space_info = space_info;
7045 down_write(&space_info->groups_sem);
7046 list_add_tail(&cache->list, &space_info->block_groups);
7047 up_write(&space_info->groups_sem);
7048
7049 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7050 BUG_ON(ret);
7051
7052 set_avail_alloc_bits(root->fs_info, cache->flags);
7053 if (btrfs_chunk_readonly(root, cache->key.objectid))
7054 set_block_group_readonly(cache);
7055 }
7056 ret = 0;
7057 error:
7058 btrfs_free_path(path);
7059 return ret;
7060 }
7061
7062 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
7063 struct btrfs_root *root, u64 bytes_used,
7064 u64 type, u64 chunk_objectid, u64 chunk_offset,
7065 u64 size)
7066 {
7067 int ret;
7068 struct btrfs_root *extent_root;
7069 struct btrfs_block_group_cache *cache;
7070
7071 extent_root = root->fs_info->extent_root;
7072
7073 root->fs_info->last_trans_log_full_commit = trans->transid;
7074
7075 cache = kzalloc(sizeof(*cache), GFP_NOFS);
7076 if (!cache)
7077 return -ENOMEM;
7078
7079 cache->key.objectid = chunk_offset;
7080 cache->key.offset = size;
7081 cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
7082 atomic_set(&cache->count, 1);
7083 spin_lock_init(&cache->lock);
7084 spin_lock_init(&cache->tree_lock);
7085 mutex_init(&cache->cache_mutex);
7086 INIT_LIST_HEAD(&cache->list);
7087 INIT_LIST_HEAD(&cache->cluster_list);
7088
7089 btrfs_set_block_group_used(&cache->item, bytes_used);
7090 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
7091 cache->flags = type;
7092 btrfs_set_block_group_flags(&cache->item, type);
7093
7094 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
7095 &cache->space_info);
7096 BUG_ON(ret);
7097 down_write(&cache->space_info->groups_sem);
7098 list_add_tail(&cache->list, &cache->space_info->block_groups);
7099 up_write(&cache->space_info->groups_sem);
7100
7101 ret = btrfs_add_block_group_cache(root->fs_info, cache);
7102 BUG_ON(ret);
7103
7104 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
7105 sizeof(cache->item));
7106 BUG_ON(ret);
7107
7108 set_avail_alloc_bits(extent_root->fs_info, type);
7109
7110 return 0;
7111 }
7112
7113 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
7114 struct btrfs_root *root, u64 group_start)
7115 {
7116 struct btrfs_path *path;
7117 struct btrfs_block_group_cache *block_group;
7118 struct btrfs_free_cluster *cluster;
7119 struct btrfs_key key;
7120 int ret;
7121
7122 root = root->fs_info->extent_root;
7123
7124 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
7125 BUG_ON(!block_group);
7126 BUG_ON(!block_group->ro);
7127
7128 memcpy(&key, &block_group->key, sizeof(key));
7129
7130 /* make sure this block group isn't part of an allocation cluster */
7131 cluster = &root->fs_info->data_alloc_cluster;
7132 spin_lock(&cluster->refill_lock);
7133 btrfs_return_cluster_to_free_space(block_group, cluster);
7134 spin_unlock(&cluster->refill_lock);
7135
7136 /*
7137 * make sure this block group isn't part of a metadata
7138 * allocation cluster
7139 */
7140 cluster = &root->fs_info->meta_alloc_cluster;
7141 spin_lock(&cluster->refill_lock);
7142 btrfs_return_cluster_to_free_space(block_group, cluster);
7143 spin_unlock(&cluster->refill_lock);
7144
7145 path = btrfs_alloc_path();
7146 BUG_ON(!path);
7147
7148 spin_lock(&root->fs_info->block_group_cache_lock);
7149 rb_erase(&block_group->cache_node,
7150 &root->fs_info->block_group_cache_tree);
7151 spin_unlock(&root->fs_info->block_group_cache_lock);
7152 btrfs_remove_free_space_cache(block_group);
7153 down_write(&block_group->space_info->groups_sem);
7154 /*
7155 * we must use list_del_init so people can check to see if they
7156 * are still on the list after taking the semaphore
7157 */
7158 list_del_init(&block_group->list);
7159 up_write(&block_group->space_info->groups_sem);
7160
7161 spin_lock(&block_group->space_info->lock);
7162 block_group->space_info->total_bytes -= block_group->key.offset;
7163 block_group->space_info->bytes_readonly -= block_group->key.offset;
7164 spin_unlock(&block_group->space_info->lock);
7165 block_group->space_info->full = 0;
7166
7167 btrfs_put_block_group(block_group);
7168 btrfs_put_block_group(block_group);
7169
7170 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
7171 if (ret > 0)
7172 ret = -EIO;
7173 if (ret < 0)
7174 goto out;
7175
7176 ret = btrfs_del_item(trans, root, path);
7177 out:
7178 btrfs_free_path(path);
7179 return ret;
7180 }
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