2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
18 #include <linux/sched.h>
19 #include <linux/pagemap.h>
20 #include <linux/writeback.h>
21 #include <linux/blkdev.h>
26 #include "print-tree.h"
27 #include "transaction.h"
30 #include "ref-cache.h"
32 #define PENDING_EXTENT_INSERT 0
33 #define PENDING_EXTENT_DELETE 1
34 #define PENDING_BACKREF_UPDATE 2
36 struct pending_extent_op {
47 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
48 btrfs_root *extent_root);
49 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
50 btrfs_root *extent_root);
51 static struct btrfs_block_group_cache *
52 __btrfs_find_block_group(struct btrfs_root *root,
53 struct btrfs_block_group_cache *hint,
54 u64 search_start, int data, int owner);
56 void maybe_lock_mutex(struct btrfs_root *root)
58 if (root != root->fs_info->extent_root &&
59 root != root->fs_info->chunk_root &&
60 root != root->fs_info->dev_root) {
61 mutex_lock(&root->fs_info->alloc_mutex);
65 void maybe_unlock_mutex(struct btrfs_root *root)
67 if (root != root->fs_info->extent_root &&
68 root != root->fs_info->chunk_root &&
69 root != root->fs_info->dev_root) {
70 mutex_unlock(&root->fs_info->alloc_mutex);
74 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
76 return (cache->flags & bits) == bits;
80 * this adds the block group to the fs_info rb tree for the block group
83 int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
84 struct btrfs_block_group_cache *block_group)
87 struct rb_node *parent = NULL;
88 struct btrfs_block_group_cache *cache;
90 spin_lock(&info->block_group_cache_lock);
91 p = &info->block_group_cache_tree.rb_node;
95 cache = rb_entry(parent, struct btrfs_block_group_cache,
97 if (block_group->key.objectid < cache->key.objectid) {
99 } else if (block_group->key.objectid > cache->key.objectid) {
102 spin_unlock(&info->block_group_cache_lock);
107 rb_link_node(&block_group->cache_node, parent, p);
108 rb_insert_color(&block_group->cache_node,
109 &info->block_group_cache_tree);
110 spin_unlock(&info->block_group_cache_lock);
116 * This will return the block group at or after bytenr if contains is 0, else
117 * it will return the block group that contains the bytenr
119 static struct btrfs_block_group_cache *
120 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
123 struct btrfs_block_group_cache *cache, *ret = NULL;
127 spin_lock(&info->block_group_cache_lock);
128 n = info->block_group_cache_tree.rb_node;
131 cache = rb_entry(n, struct btrfs_block_group_cache,
133 end = cache->key.objectid + cache->key.offset - 1;
134 start = cache->key.objectid;
136 if (bytenr < start) {
137 if (!contains && (!ret || start < ret->key.objectid))
140 } else if (bytenr > start) {
141 if (contains && bytenr <= end) {
151 spin_unlock(&info->block_group_cache_lock);
157 * this is only called by cache_block_group, since we could have freed extents
158 * we need to check the pinned_extents for any extents that can't be used yet
159 * since their free space will be released as soon as the transaction commits.
161 static int add_new_free_space(struct btrfs_block_group_cache *block_group,
162 struct btrfs_fs_info *info, u64 start, u64 end)
164 u64 extent_start, extent_end, size;
167 while (start < end) {
168 ret = find_first_extent_bit(&info->pinned_extents, start,
169 &extent_start, &extent_end,
174 if (extent_start == start) {
175 start = extent_end + 1;
176 } else if (extent_start > start && extent_start < end) {
177 size = extent_start - start;
178 ret = btrfs_add_free_space(block_group, start, size);
180 start = extent_end + 1;
188 ret = btrfs_add_free_space(block_group, start, size);
195 static int cache_block_group(struct btrfs_root *root,
196 struct btrfs_block_group_cache *block_group)
198 struct btrfs_path *path;
200 struct btrfs_key key;
201 struct extent_buffer *leaf;
210 root = root->fs_info->extent_root;
212 if (block_group->cached)
215 path = btrfs_alloc_path();
221 * we get into deadlocks with paths held by callers of this function.
222 * since the alloc_mutex is protecting things right now, just
223 * skip the locking here
225 path->skip_locking = 1;
226 first_free = max_t(u64, block_group->key.objectid,
227 BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
228 key.objectid = block_group->key.objectid;
230 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
231 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
234 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
238 leaf = path->nodes[0];
239 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
240 if (key.objectid + key.offset > first_free)
241 first_free = key.objectid + key.offset;
244 leaf = path->nodes[0];
245 slot = path->slots[0];
246 if (slot >= btrfs_header_nritems(leaf)) {
247 ret = btrfs_next_leaf(root, path);
255 btrfs_item_key_to_cpu(leaf, &key, slot);
256 if (key.objectid < block_group->key.objectid)
259 if (key.objectid >= block_group->key.objectid +
260 block_group->key.offset)
263 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
269 add_new_free_space(block_group, root->fs_info, last,
272 last = key.objectid + key.offset;
281 add_new_free_space(block_group, root->fs_info, last,
282 block_group->key.objectid +
283 block_group->key.offset);
285 block_group->cached = 1;
288 btrfs_free_path(path);
293 * return the block group that starts at or after bytenr
295 struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
299 struct btrfs_block_group_cache *cache;
301 cache = block_group_cache_tree_search(info, bytenr, 0);
307 * return the block group that contains teh given bytenr
309 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
313 struct btrfs_block_group_cache *cache;
315 cache = block_group_cache_tree_search(info, bytenr, 1);
320 static int noinline find_free_space(struct btrfs_root *root,
321 struct btrfs_block_group_cache **cache_ret,
322 u64 *start_ret, u64 num, int data)
325 struct btrfs_block_group_cache *cache = *cache_ret;
326 struct btrfs_free_space *info = NULL;
328 u64 search_start = *start_ret;
330 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
334 last = max(search_start, cache->key.objectid);
337 ret = cache_block_group(root, cache);
341 if (cache->ro || !block_group_bits(cache, data))
344 info = btrfs_find_free_space(cache, last, num);
346 *start_ret = info->offset;
351 last = cache->key.objectid + cache->key.offset;
353 cache = btrfs_lookup_first_block_group(root->fs_info, last);
364 static u64 div_factor(u64 num, int factor)
373 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
376 struct list_head *head = &info->space_info;
377 struct list_head *cur;
378 struct btrfs_space_info *found;
379 list_for_each(cur, head) {
380 found = list_entry(cur, struct btrfs_space_info, list);
381 if (found->flags == flags)
387 static struct btrfs_block_group_cache *
388 __btrfs_find_block_group(struct btrfs_root *root,
389 struct btrfs_block_group_cache *hint,
390 u64 search_start, int data, int owner)
392 struct btrfs_block_group_cache *cache;
393 struct btrfs_block_group_cache *found_group = NULL;
394 struct btrfs_fs_info *info = root->fs_info;
402 if (data & BTRFS_BLOCK_GROUP_METADATA)
406 struct btrfs_block_group_cache *shint;
407 shint = btrfs_lookup_first_block_group(info, search_start);
408 if (shint && block_group_bits(shint, data) && !shint->ro) {
409 spin_lock(&shint->lock);
410 used = btrfs_block_group_used(&shint->item);
411 if (used + shint->pinned + shint->reserved <
412 div_factor(shint->key.offset, factor)) {
413 spin_unlock(&shint->lock);
416 spin_unlock(&shint->lock);
419 if (hint && !hint->ro && block_group_bits(hint, data)) {
420 spin_lock(&hint->lock);
421 used = btrfs_block_group_used(&hint->item);
422 if (used + hint->pinned + hint->reserved <
423 div_factor(hint->key.offset, factor)) {
424 spin_unlock(&hint->lock);
427 spin_unlock(&hint->lock);
428 last = hint->key.objectid + hint->key.offset;
431 last = max(hint->key.objectid, search_start);
437 cache = btrfs_lookup_first_block_group(root->fs_info, last);
441 spin_lock(&cache->lock);
442 last = cache->key.objectid + cache->key.offset;
443 used = btrfs_block_group_used(&cache->item);
445 if (!cache->ro && block_group_bits(cache, data)) {
446 free_check = div_factor(cache->key.offset, factor);
447 if (used + cache->pinned + cache->reserved <
450 spin_unlock(&cache->lock);
454 spin_unlock(&cache->lock);
462 if (!full_search && factor < 10) {
472 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
473 struct btrfs_block_group_cache
474 *hint, u64 search_start,
478 struct btrfs_block_group_cache *ret;
479 ret = __btrfs_find_block_group(root, hint, search_start, data, owner);
483 /* simple helper to search for an existing extent at a given offset */
484 int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
487 struct btrfs_key key;
488 struct btrfs_path *path;
490 path = btrfs_alloc_path();
492 maybe_lock_mutex(root);
493 key.objectid = start;
495 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
496 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
498 maybe_unlock_mutex(root);
499 btrfs_free_path(path);
504 * Back reference rules. Back refs have three main goals:
506 * 1) differentiate between all holders of references to an extent so that
507 * when a reference is dropped we can make sure it was a valid reference
508 * before freeing the extent.
510 * 2) Provide enough information to quickly find the holders of an extent
511 * if we notice a given block is corrupted or bad.
513 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
514 * maintenance. This is actually the same as #2, but with a slightly
515 * different use case.
517 * File extents can be referenced by:
519 * - multiple snapshots, subvolumes, or different generations in one subvol
520 * - different files inside a single subvolume
521 * - different offsets inside a file (bookend extents in file.c)
523 * The extent ref structure has fields for:
525 * - Objectid of the subvolume root
526 * - Generation number of the tree holding the reference
527 * - objectid of the file holding the reference
528 * - number of references holding by parent node (alway 1 for tree blocks)
530 * Btree leaf may hold multiple references to a file extent. In most cases,
531 * these references are from same file and the corresponding offsets inside
532 * the file are close together.
534 * When a file extent is allocated the fields are filled in:
535 * (root_key.objectid, trans->transid, inode objectid, 1)
537 * When a leaf is cow'd new references are added for every file extent found
538 * in the leaf. It looks similar to the create case, but trans->transid will
539 * be different when the block is cow'd.
541 * (root_key.objectid, trans->transid, inode objectid,
542 * number of references in the leaf)
544 * When a file extent is removed either during snapshot deletion or
545 * file truncation, we find the corresponding back reference and check
546 * the following fields:
548 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
551 * Btree extents can be referenced by:
553 * - Different subvolumes
554 * - Different generations of the same subvolume
556 * When a tree block is created, back references are inserted:
558 * (root->root_key.objectid, trans->transid, level, 1)
560 * When a tree block is cow'd, new back references are added for all the
561 * blocks it points to. If the tree block isn't in reference counted root,
562 * the old back references are removed. These new back references are of
563 * the form (trans->transid will have increased since creation):
565 * (root->root_key.objectid, trans->transid, level, 1)
567 * When a backref is in deleting, the following fields are checked:
569 * if backref was for a tree root:
570 * (btrfs_header_owner(itself), btrfs_header_generation(itself), level)
572 * (btrfs_header_owner(parent), btrfs_header_generation(parent), level)
574 * Back Reference Key composing:
576 * The key objectid corresponds to the first byte in the extent, the key
577 * type is set to BTRFS_EXTENT_REF_KEY, and the key offset is the first
578 * byte of parent extent. If a extent is tree root, the key offset is set
579 * to the key objectid.
582 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
583 struct btrfs_root *root,
584 struct btrfs_path *path,
585 u64 bytenr, u64 parent,
586 u64 ref_root, u64 ref_generation,
587 u64 owner_objectid, int del)
589 struct btrfs_key key;
590 struct btrfs_extent_ref *ref;
591 struct extent_buffer *leaf;
595 key.objectid = bytenr;
596 key.type = BTRFS_EXTENT_REF_KEY;
599 ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, 1);
607 leaf = path->nodes[0];
608 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
609 ref_objectid = btrfs_ref_objectid(leaf, ref);
610 if (btrfs_ref_root(leaf, ref) != ref_root ||
611 btrfs_ref_generation(leaf, ref) != ref_generation ||
612 (ref_objectid != owner_objectid &&
613 ref_objectid != BTRFS_MULTIPLE_OBJECTIDS)) {
623 static int noinline insert_extent_backref(struct btrfs_trans_handle *trans,
624 struct btrfs_root *root,
625 struct btrfs_path *path,
626 u64 bytenr, u64 parent,
627 u64 ref_root, u64 ref_generation,
630 struct btrfs_key key;
631 struct extent_buffer *leaf;
632 struct btrfs_extent_ref *ref;
636 key.objectid = bytenr;
637 key.type = BTRFS_EXTENT_REF_KEY;
640 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*ref));
642 leaf = path->nodes[0];
643 ref = btrfs_item_ptr(leaf, path->slots[0],
644 struct btrfs_extent_ref);
645 btrfs_set_ref_root(leaf, ref, ref_root);
646 btrfs_set_ref_generation(leaf, ref, ref_generation);
647 btrfs_set_ref_objectid(leaf, ref, owner_objectid);
648 btrfs_set_ref_num_refs(leaf, ref, 1);
649 } else if (ret == -EEXIST) {
651 BUG_ON(owner_objectid < BTRFS_FIRST_FREE_OBJECTID);
652 leaf = path->nodes[0];
653 ref = btrfs_item_ptr(leaf, path->slots[0],
654 struct btrfs_extent_ref);
655 if (btrfs_ref_root(leaf, ref) != ref_root ||
656 btrfs_ref_generation(leaf, ref) != ref_generation) {
662 num_refs = btrfs_ref_num_refs(leaf, ref);
663 BUG_ON(num_refs == 0);
664 btrfs_set_ref_num_refs(leaf, ref, num_refs + 1);
666 existing_owner = btrfs_ref_objectid(leaf, ref);
667 if (existing_owner != owner_objectid &&
668 existing_owner != BTRFS_MULTIPLE_OBJECTIDS) {
669 btrfs_set_ref_objectid(leaf, ref,
670 BTRFS_MULTIPLE_OBJECTIDS);
676 btrfs_mark_buffer_dirty(path->nodes[0]);
678 btrfs_release_path(root, path);
682 static int noinline remove_extent_backref(struct btrfs_trans_handle *trans,
683 struct btrfs_root *root,
684 struct btrfs_path *path)
686 struct extent_buffer *leaf;
687 struct btrfs_extent_ref *ref;
691 leaf = path->nodes[0];
692 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref);
693 num_refs = btrfs_ref_num_refs(leaf, ref);
694 BUG_ON(num_refs == 0);
697 ret = btrfs_del_item(trans, root, path);
699 btrfs_set_ref_num_refs(leaf, ref, num_refs);
700 btrfs_mark_buffer_dirty(leaf);
702 btrfs_release_path(root, path);
706 static int __btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
707 struct btrfs_root *root, u64 bytenr,
708 u64 orig_parent, u64 parent,
709 u64 orig_root, u64 ref_root,
710 u64 orig_generation, u64 ref_generation,
714 struct btrfs_root *extent_root = root->fs_info->extent_root;
715 struct btrfs_path *path;
717 if (root == root->fs_info->extent_root) {
718 struct pending_extent_op *extent_op;
721 BUG_ON(owner_objectid >= BTRFS_MAX_LEVEL);
722 num_bytes = btrfs_level_size(root, (int)owner_objectid);
723 if (test_range_bit(&root->fs_info->extent_ins, bytenr,
724 bytenr + num_bytes - 1, EXTENT_LOCKED, 0)) {
726 ret = get_state_private(&root->fs_info->extent_ins,
729 extent_op = (struct pending_extent_op *)
731 BUG_ON(extent_op->parent != orig_parent);
732 BUG_ON(extent_op->generation != orig_generation);
733 extent_op->parent = parent;
734 extent_op->generation = ref_generation;
736 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
739 extent_op->type = PENDING_BACKREF_UPDATE;
740 extent_op->bytenr = bytenr;
741 extent_op->num_bytes = num_bytes;
742 extent_op->parent = parent;
743 extent_op->orig_parent = orig_parent;
744 extent_op->generation = ref_generation;
745 extent_op->orig_generation = orig_generation;
746 extent_op->level = (int)owner_objectid;
748 set_extent_bits(&root->fs_info->extent_ins,
749 bytenr, bytenr + num_bytes - 1,
750 EXTENT_LOCKED, GFP_NOFS);
751 set_state_private(&root->fs_info->extent_ins,
752 bytenr, (unsigned long)extent_op);
757 path = btrfs_alloc_path();
760 ret = lookup_extent_backref(trans, extent_root, path,
761 bytenr, orig_parent, orig_root,
762 orig_generation, owner_objectid, 1);
765 ret = remove_extent_backref(trans, extent_root, path);
768 ret = insert_extent_backref(trans, extent_root, path, bytenr,
769 parent, ref_root, ref_generation,
772 finish_current_insert(trans, extent_root);
773 del_pending_extents(trans, extent_root);
775 btrfs_free_path(path);
779 int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
780 struct btrfs_root *root, u64 bytenr,
781 u64 orig_parent, u64 parent,
782 u64 ref_root, u64 ref_generation,
786 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
787 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
789 maybe_lock_mutex(root);
790 ret = __btrfs_update_extent_ref(trans, root, bytenr, orig_parent,
791 parent, ref_root, ref_root,
792 ref_generation, ref_generation,
794 maybe_unlock_mutex(root);
798 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
799 struct btrfs_root *root, u64 bytenr,
800 u64 orig_parent, u64 parent,
801 u64 orig_root, u64 ref_root,
802 u64 orig_generation, u64 ref_generation,
805 struct btrfs_path *path;
807 struct btrfs_key key;
808 struct extent_buffer *l;
809 struct btrfs_extent_item *item;
812 path = btrfs_alloc_path();
817 key.objectid = bytenr;
818 key.type = BTRFS_EXTENT_ITEM_KEY;
819 key.offset = (u64)-1;
821 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
825 BUG_ON(ret == 0 || path->slots[0] == 0);
830 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
831 BUG_ON(key.objectid != bytenr);
832 BUG_ON(key.type != BTRFS_EXTENT_ITEM_KEY);
834 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
835 refs = btrfs_extent_refs(l, item);
836 btrfs_set_extent_refs(l, item, refs + 1);
837 btrfs_mark_buffer_dirty(path->nodes[0]);
839 btrfs_release_path(root->fs_info->extent_root, path);
842 ret = insert_extent_backref(trans, root->fs_info->extent_root,
843 path, bytenr, parent,
844 ref_root, ref_generation,
847 finish_current_insert(trans, root->fs_info->extent_root);
848 del_pending_extents(trans, root->fs_info->extent_root);
850 btrfs_free_path(path);
854 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
855 struct btrfs_root *root,
856 u64 bytenr, u64 num_bytes, u64 parent,
857 u64 ref_root, u64 ref_generation,
861 if (ref_root == BTRFS_TREE_LOG_OBJECTID &&
862 owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
864 maybe_lock_mutex(root);
865 ret = __btrfs_inc_extent_ref(trans, root, bytenr, 0, parent,
866 0, ref_root, 0, ref_generation,
868 maybe_unlock_mutex(root);
872 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
873 struct btrfs_root *root)
875 finish_current_insert(trans, root->fs_info->extent_root);
876 del_pending_extents(trans, root->fs_info->extent_root);
880 int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
881 struct btrfs_root *root, u64 bytenr,
882 u64 num_bytes, u32 *refs)
884 struct btrfs_path *path;
886 struct btrfs_key key;
887 struct extent_buffer *l;
888 struct btrfs_extent_item *item;
890 WARN_ON(num_bytes < root->sectorsize);
891 path = btrfs_alloc_path();
893 key.objectid = bytenr;
894 key.offset = num_bytes;
895 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
896 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
901 btrfs_print_leaf(root, path->nodes[0]);
902 printk("failed to find block number %Lu\n", bytenr);
906 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
907 *refs = btrfs_extent_refs(l, item);
909 btrfs_free_path(path);
913 static int get_reference_status(struct btrfs_root *root, u64 bytenr,
914 u64 parent_gen, u64 ref_objectid,
915 u64 *min_generation, u32 *ref_count)
917 struct btrfs_root *extent_root = root->fs_info->extent_root;
918 struct btrfs_path *path;
919 struct extent_buffer *leaf;
920 struct btrfs_extent_ref *ref_item;
921 struct btrfs_key key;
922 struct btrfs_key found_key;
923 u64 root_objectid = root->root_key.objectid;
928 key.objectid = bytenr;
929 key.offset = (u64)-1;
930 key.type = BTRFS_EXTENT_ITEM_KEY;
932 path = btrfs_alloc_path();
933 mutex_lock(&root->fs_info->alloc_mutex);
934 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
938 if (ret < 0 || path->slots[0] == 0)
942 leaf = path->nodes[0];
943 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
945 if (found_key.objectid != bytenr ||
946 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
952 *min_generation = (u64)-1;
955 leaf = path->nodes[0];
956 nritems = btrfs_header_nritems(leaf);
957 if (path->slots[0] >= nritems) {
958 ret = btrfs_next_leaf(extent_root, path);
965 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
966 if (found_key.objectid != bytenr)
969 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
974 ref_item = btrfs_item_ptr(leaf, path->slots[0],
975 struct btrfs_extent_ref);
976 ref_generation = btrfs_ref_generation(leaf, ref_item);
978 * For (parent_gen > 0 && parent_gen > ref_generation):
980 * we reach here through the oldest root, therefore
981 * all other reference from same snapshot should have
982 * a larger generation.
984 if ((root_objectid != btrfs_ref_root(leaf, ref_item)) ||
985 (parent_gen > 0 && parent_gen > ref_generation) ||
986 (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
987 ref_objectid != btrfs_ref_objectid(leaf, ref_item))) {
993 if (*min_generation > ref_generation)
994 *min_generation = ref_generation;
1000 mutex_unlock(&root->fs_info->alloc_mutex);
1001 btrfs_free_path(path);
1005 int btrfs_cross_ref_exists(struct btrfs_trans_handle *trans,
1006 struct btrfs_root *root,
1007 struct btrfs_key *key, u64 bytenr)
1009 struct btrfs_root *old_root;
1010 struct btrfs_path *path = NULL;
1011 struct extent_buffer *eb;
1012 struct btrfs_file_extent_item *item;
1020 BUG_ON(trans == NULL);
1021 BUG_ON(key->type != BTRFS_EXTENT_DATA_KEY);
1022 ret = get_reference_status(root, bytenr, 0, key->objectid,
1023 &min_generation, &ref_count);
1030 old_root = root->dirty_root->root;
1031 ref_generation = old_root->root_key.offset;
1033 /* all references are created in running transaction */
1034 if (min_generation > ref_generation) {
1039 path = btrfs_alloc_path();
1045 path->skip_locking = 1;
1046 /* if no item found, the extent is referenced by other snapshot */
1047 ret = btrfs_search_slot(NULL, old_root, key, path, 0, 0);
1051 eb = path->nodes[0];
1052 item = btrfs_item_ptr(eb, path->slots[0],
1053 struct btrfs_file_extent_item);
1054 if (btrfs_file_extent_type(eb, item) != BTRFS_FILE_EXTENT_REG ||
1055 btrfs_file_extent_disk_bytenr(eb, item) != bytenr) {
1060 for (level = BTRFS_MAX_LEVEL - 1; level >= -1; level--) {
1062 eb = path->nodes[level];
1065 extent_start = eb->start;
1067 extent_start = bytenr;
1069 ret = get_reference_status(root, extent_start, ref_generation,
1070 0, &min_generation, &ref_count);
1074 if (ref_count != 1) {
1079 ref_generation = btrfs_header_generation(eb);
1084 btrfs_free_path(path);
1088 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1089 struct extent_buffer *buf, u32 nr_extents)
1091 struct btrfs_key key;
1092 struct btrfs_file_extent_item *fi;
1100 if (!root->ref_cows)
1103 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1105 root_gen = root->root_key.offset;
1108 root_gen = trans->transid - 1;
1111 level = btrfs_header_level(buf);
1112 nritems = btrfs_header_nritems(buf);
1115 struct btrfs_leaf_ref *ref;
1116 struct btrfs_extent_info *info;
1118 ref = btrfs_alloc_leaf_ref(root, nr_extents);
1124 ref->root_gen = root_gen;
1125 ref->bytenr = buf->start;
1126 ref->owner = btrfs_header_owner(buf);
1127 ref->generation = btrfs_header_generation(buf);
1128 ref->nritems = nr_extents;
1129 info = ref->extents;
1131 for (i = 0; nr_extents > 0 && i < nritems; i++) {
1133 btrfs_item_key_to_cpu(buf, &key, i);
1134 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1136 fi = btrfs_item_ptr(buf, i,
1137 struct btrfs_file_extent_item);
1138 if (btrfs_file_extent_type(buf, fi) ==
1139 BTRFS_FILE_EXTENT_INLINE)
1141 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1142 if (disk_bytenr == 0)
1145 info->bytenr = disk_bytenr;
1147 btrfs_file_extent_disk_num_bytes(buf, fi);
1148 info->objectid = key.objectid;
1149 info->offset = key.offset;
1153 ret = btrfs_add_leaf_ref(root, ref, shared);
1155 btrfs_free_leaf_ref(root, ref);
1161 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1162 struct extent_buffer *orig_buf, struct extent_buffer *buf,
1169 u64 orig_generation;
1171 u32 nr_file_extents = 0;
1172 struct btrfs_key key;
1173 struct btrfs_file_extent_item *fi;
1178 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
1179 u64, u64, u64, u64, u64, u64, u64, u64);
1181 ref_root = btrfs_header_owner(buf);
1182 ref_generation = btrfs_header_generation(buf);
1183 orig_root = btrfs_header_owner(orig_buf);
1184 orig_generation = btrfs_header_generation(orig_buf);
1186 nritems = btrfs_header_nritems(buf);
1187 level = btrfs_header_level(buf);
1189 if (root->ref_cows) {
1190 process_func = __btrfs_inc_extent_ref;
1193 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1196 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1198 process_func = __btrfs_update_extent_ref;
1201 for (i = 0; i < nritems; i++) {
1204 btrfs_item_key_to_cpu(buf, &key, i);
1205 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1207 fi = btrfs_item_ptr(buf, i,
1208 struct btrfs_file_extent_item);
1209 if (btrfs_file_extent_type(buf, fi) ==
1210 BTRFS_FILE_EXTENT_INLINE)
1212 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1218 maybe_lock_mutex(root);
1219 ret = process_func(trans, root, bytenr,
1220 orig_buf->start, buf->start,
1221 orig_root, ref_root,
1222 orig_generation, ref_generation,
1224 maybe_unlock_mutex(root);
1232 bytenr = btrfs_node_blockptr(buf, i);
1233 maybe_lock_mutex(root);
1234 ret = process_func(trans, root, bytenr,
1235 orig_buf->start, buf->start,
1236 orig_root, ref_root,
1237 orig_generation, ref_generation,
1239 maybe_unlock_mutex(root);
1250 *nr_extents = nr_file_extents;
1252 *nr_extents = nritems;
1260 int btrfs_update_ref(struct btrfs_trans_handle *trans,
1261 struct btrfs_root *root, struct extent_buffer *orig_buf,
1262 struct extent_buffer *buf, int start_slot, int nr)
1269 u64 orig_generation;
1270 struct btrfs_key key;
1271 struct btrfs_file_extent_item *fi;
1277 BUG_ON(start_slot < 0);
1278 BUG_ON(start_slot + nr > btrfs_header_nritems(buf));
1280 ref_root = btrfs_header_owner(buf);
1281 ref_generation = btrfs_header_generation(buf);
1282 orig_root = btrfs_header_owner(orig_buf);
1283 orig_generation = btrfs_header_generation(orig_buf);
1284 level = btrfs_header_level(buf);
1286 if (!root->ref_cows) {
1288 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1291 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1295 for (i = 0, slot = start_slot; i < nr; i++, slot++) {
1298 btrfs_item_key_to_cpu(buf, &key, slot);
1299 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1301 fi = btrfs_item_ptr(buf, slot,
1302 struct btrfs_file_extent_item);
1303 if (btrfs_file_extent_type(buf, fi) ==
1304 BTRFS_FILE_EXTENT_INLINE)
1306 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1309 maybe_lock_mutex(root);
1310 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1311 orig_buf->start, buf->start,
1312 orig_root, ref_root,
1313 orig_generation, ref_generation,
1315 maybe_unlock_mutex(root);
1319 bytenr = btrfs_node_blockptr(buf, slot);
1320 maybe_lock_mutex(root);
1321 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1322 orig_buf->start, buf->start,
1323 orig_root, ref_root,
1324 orig_generation, ref_generation,
1326 maybe_unlock_mutex(root);
1337 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1338 struct btrfs_root *root,
1339 struct btrfs_path *path,
1340 struct btrfs_block_group_cache *cache)
1344 struct btrfs_root *extent_root = root->fs_info->extent_root;
1346 struct extent_buffer *leaf;
1348 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1353 leaf = path->nodes[0];
1354 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1355 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1356 btrfs_mark_buffer_dirty(leaf);
1357 btrfs_release_path(extent_root, path);
1359 finish_current_insert(trans, extent_root);
1360 pending_ret = del_pending_extents(trans, extent_root);
1369 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1370 struct btrfs_root *root)
1372 struct btrfs_block_group_cache *cache, *entry;
1376 struct btrfs_path *path;
1379 path = btrfs_alloc_path();
1383 mutex_lock(&root->fs_info->alloc_mutex);
1386 spin_lock(&root->fs_info->block_group_cache_lock);
1387 for (n = rb_first(&root->fs_info->block_group_cache_tree);
1388 n; n = rb_next(n)) {
1389 entry = rb_entry(n, struct btrfs_block_group_cache,
1396 spin_unlock(&root->fs_info->block_group_cache_lock);
1402 last += cache->key.offset;
1404 err = write_one_cache_group(trans, root,
1407 * if we fail to write the cache group, we want
1408 * to keep it marked dirty in hopes that a later
1416 btrfs_free_path(path);
1417 mutex_unlock(&root->fs_info->alloc_mutex);
1421 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1422 u64 total_bytes, u64 bytes_used,
1423 struct btrfs_space_info **space_info)
1425 struct btrfs_space_info *found;
1427 found = __find_space_info(info, flags);
1429 found->total_bytes += total_bytes;
1430 found->bytes_used += bytes_used;
1432 *space_info = found;
1435 found = kmalloc(sizeof(*found), GFP_NOFS);
1439 list_add(&found->list, &info->space_info);
1440 INIT_LIST_HEAD(&found->block_groups);
1441 spin_lock_init(&found->lock);
1442 found->flags = flags;
1443 found->total_bytes = total_bytes;
1444 found->bytes_used = bytes_used;
1445 found->bytes_pinned = 0;
1446 found->bytes_reserved = 0;
1448 found->force_alloc = 0;
1449 *space_info = found;
1453 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1455 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1456 BTRFS_BLOCK_GROUP_RAID1 |
1457 BTRFS_BLOCK_GROUP_RAID10 |
1458 BTRFS_BLOCK_GROUP_DUP);
1460 if (flags & BTRFS_BLOCK_GROUP_DATA)
1461 fs_info->avail_data_alloc_bits |= extra_flags;
1462 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1463 fs_info->avail_metadata_alloc_bits |= extra_flags;
1464 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1465 fs_info->avail_system_alloc_bits |= extra_flags;
1469 static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags)
1471 u64 num_devices = root->fs_info->fs_devices->num_devices;
1473 if (num_devices == 1)
1474 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
1475 if (num_devices < 4)
1476 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
1478 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
1479 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
1480 BTRFS_BLOCK_GROUP_RAID10))) {
1481 flags &= ~BTRFS_BLOCK_GROUP_DUP;
1484 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
1485 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
1486 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
1489 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
1490 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
1491 (flags & BTRFS_BLOCK_GROUP_RAID10) |
1492 (flags & BTRFS_BLOCK_GROUP_DUP)))
1493 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
1497 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1498 struct btrfs_root *extent_root, u64 alloc_bytes,
1499 u64 flags, int force)
1501 struct btrfs_space_info *space_info;
1505 int ret = 0, waited = 0;
1507 flags = reduce_alloc_profile(extent_root, flags);
1509 space_info = __find_space_info(extent_root->fs_info, flags);
1511 ret = update_space_info(extent_root->fs_info, flags,
1515 BUG_ON(!space_info);
1517 if (space_info->force_alloc) {
1519 space_info->force_alloc = 0;
1521 if (space_info->full)
1524 thresh = div_factor(space_info->total_bytes, 6);
1526 (space_info->bytes_used + space_info->bytes_pinned +
1527 space_info->bytes_reserved + alloc_bytes) < thresh)
1530 while (!mutex_trylock(&extent_root->fs_info->chunk_mutex)) {
1533 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1535 mutex_lock(&extent_root->fs_info->alloc_mutex);
1539 if (waited && space_info->full)
1542 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1543 if (ret == -ENOSPC) {
1544 printk("space info full %Lu\n", flags);
1545 space_info->full = 1;
1550 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1551 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1555 mutex_unlock(&extent_root->fs_info->chunk_mutex);
1560 static int update_block_group(struct btrfs_trans_handle *trans,
1561 struct btrfs_root *root,
1562 u64 bytenr, u64 num_bytes, int alloc,
1565 struct btrfs_block_group_cache *cache;
1566 struct btrfs_fs_info *info = root->fs_info;
1567 u64 total = num_bytes;
1571 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1573 cache = btrfs_lookup_block_group(info, bytenr);
1577 byte_in_group = bytenr - cache->key.objectid;
1578 WARN_ON(byte_in_group > cache->key.offset);
1580 spin_lock(&cache->lock);
1582 old_val = btrfs_block_group_used(&cache->item);
1583 num_bytes = min(total, cache->key.offset - byte_in_group);
1585 old_val += num_bytes;
1586 cache->space_info->bytes_used += num_bytes;
1587 btrfs_set_block_group_used(&cache->item, old_val);
1588 spin_unlock(&cache->lock);
1590 old_val -= num_bytes;
1591 cache->space_info->bytes_used -= num_bytes;
1592 btrfs_set_block_group_used(&cache->item, old_val);
1593 spin_unlock(&cache->lock);
1596 ret = btrfs_add_free_space(cache, bytenr,
1603 bytenr += num_bytes;
1608 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
1610 struct btrfs_block_group_cache *cache;
1612 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
1616 return cache->key.objectid;
1619 int btrfs_update_pinned_extents(struct btrfs_root *root,
1620 u64 bytenr, u64 num, int pin)
1623 struct btrfs_block_group_cache *cache;
1624 struct btrfs_fs_info *fs_info = root->fs_info;
1626 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1628 set_extent_dirty(&fs_info->pinned_extents,
1629 bytenr, bytenr + num - 1, GFP_NOFS);
1631 clear_extent_dirty(&fs_info->pinned_extents,
1632 bytenr, bytenr + num - 1, GFP_NOFS);
1635 cache = btrfs_lookup_block_group(fs_info, bytenr);
1637 len = min(num, cache->key.offset -
1638 (bytenr - cache->key.objectid));
1640 spin_lock(&cache->lock);
1641 cache->pinned += len;
1642 cache->space_info->bytes_pinned += len;
1643 spin_unlock(&cache->lock);
1644 fs_info->total_pinned += len;
1646 spin_lock(&cache->lock);
1647 cache->pinned -= len;
1648 cache->space_info->bytes_pinned -= len;
1649 spin_unlock(&cache->lock);
1650 fs_info->total_pinned -= len;
1658 static int update_reserved_extents(struct btrfs_root *root,
1659 u64 bytenr, u64 num, int reserve)
1662 struct btrfs_block_group_cache *cache;
1663 struct btrfs_fs_info *fs_info = root->fs_info;
1665 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1667 cache = btrfs_lookup_block_group(fs_info, bytenr);
1669 len = min(num, cache->key.offset -
1670 (bytenr - cache->key.objectid));
1672 spin_lock(&cache->lock);
1673 cache->reserved += len;
1674 cache->space_info->bytes_reserved += len;
1675 spin_unlock(&cache->lock);
1677 spin_lock(&cache->lock);
1678 cache->reserved -= len;
1679 cache->space_info->bytes_reserved -= len;
1680 spin_unlock(&cache->lock);
1688 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1693 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1697 ret = find_first_extent_bit(pinned_extents, last,
1698 &start, &end, EXTENT_DIRTY);
1701 set_extent_dirty(copy, start, end, GFP_NOFS);
1707 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1708 struct btrfs_root *root,
1709 struct extent_io_tree *unpin)
1714 struct btrfs_block_group_cache *cache;
1716 mutex_lock(&root->fs_info->alloc_mutex);
1718 ret = find_first_extent_bit(unpin, 0, &start, &end,
1722 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
1723 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1724 cache = btrfs_lookup_block_group(root->fs_info, start);
1726 btrfs_add_free_space(cache, start, end - start + 1);
1727 if (need_resched()) {
1728 mutex_unlock(&root->fs_info->alloc_mutex);
1730 mutex_lock(&root->fs_info->alloc_mutex);
1733 mutex_unlock(&root->fs_info->alloc_mutex);
1737 static int finish_current_insert(struct btrfs_trans_handle *trans,
1738 struct btrfs_root *extent_root)
1743 struct btrfs_fs_info *info = extent_root->fs_info;
1744 struct btrfs_path *path;
1745 struct btrfs_extent_ref *ref;
1746 struct pending_extent_op *extent_op;
1747 struct btrfs_key key;
1748 struct btrfs_extent_item extent_item;
1752 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
1753 btrfs_set_stack_extent_refs(&extent_item, 1);
1754 path = btrfs_alloc_path();
1757 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1758 &end, EXTENT_LOCKED);
1762 ret = get_state_private(&info->extent_ins, start, &priv);
1764 extent_op = (struct pending_extent_op *)(unsigned long)priv;
1766 if (extent_op->type == PENDING_EXTENT_INSERT) {
1767 key.objectid = start;
1768 key.offset = end + 1 - start;
1769 key.type = BTRFS_EXTENT_ITEM_KEY;
1770 err = btrfs_insert_item(trans, extent_root, &key,
1771 &extent_item, sizeof(extent_item));
1774 clear_extent_bits(&info->extent_ins, start, end,
1775 EXTENT_LOCKED, GFP_NOFS);
1777 err = insert_extent_backref(trans, extent_root, path,
1778 start, extent_op->parent,
1779 extent_root->root_key.objectid,
1780 extent_op->generation,
1783 } else if (extent_op->type == PENDING_BACKREF_UPDATE) {
1784 err = lookup_extent_backref(trans, extent_root, path,
1785 start, extent_op->orig_parent,
1786 extent_root->root_key.objectid,
1787 extent_op->orig_generation,
1788 extent_op->level, 0);
1791 clear_extent_bits(&info->extent_ins, start, end,
1792 EXTENT_LOCKED, GFP_NOFS);
1794 key.objectid = start;
1795 key.offset = extent_op->parent;
1796 key.type = BTRFS_EXTENT_REF_KEY;
1797 err = btrfs_set_item_key_safe(trans, extent_root, path,
1800 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1801 struct btrfs_extent_ref);
1802 btrfs_set_ref_generation(path->nodes[0], ref,
1803 extent_op->generation);
1804 btrfs_mark_buffer_dirty(path->nodes[0]);
1805 btrfs_release_path(extent_root, path);
1811 if (need_resched()) {
1812 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1814 mutex_lock(&extent_root->fs_info->alloc_mutex);
1817 btrfs_free_path(path);
1821 static int pin_down_bytes(struct btrfs_trans_handle *trans,
1822 struct btrfs_root *root,
1823 u64 bytenr, u64 num_bytes, int is_data)
1826 struct extent_buffer *buf;
1828 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1832 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1836 /* we can reuse a block if it hasn't been written
1837 * and it is from this transaction. We can't
1838 * reuse anything from the tree log root because
1839 * it has tiny sub-transactions.
1841 if (btrfs_buffer_uptodate(buf, 0) &&
1842 btrfs_try_tree_lock(buf)) {
1843 u64 header_owner = btrfs_header_owner(buf);
1844 u64 header_transid = btrfs_header_generation(buf);
1845 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
1846 header_owner != BTRFS_TREE_RELOC_OBJECTID &&
1847 header_transid == trans->transid &&
1848 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
1849 clean_tree_block(NULL, root, buf);
1850 btrfs_tree_unlock(buf);
1851 free_extent_buffer(buf);
1854 btrfs_tree_unlock(buf);
1856 free_extent_buffer(buf);
1858 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
1865 * remove an extent from the root, returns 0 on success
1867 static int __free_extent(struct btrfs_trans_handle *trans,
1868 struct btrfs_root *root,
1869 u64 bytenr, u64 num_bytes, u64 parent,
1870 u64 root_objectid, u64 ref_generation,
1871 u64 owner_objectid, int pin, int mark_free)
1873 struct btrfs_path *path;
1874 struct btrfs_key key;
1875 struct btrfs_fs_info *info = root->fs_info;
1876 struct btrfs_root *extent_root = info->extent_root;
1877 struct extent_buffer *leaf;
1879 int extent_slot = 0;
1880 int found_extent = 0;
1882 struct btrfs_extent_item *ei;
1885 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1886 key.objectid = bytenr;
1887 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1888 key.offset = num_bytes;
1889 path = btrfs_alloc_path();
1894 ret = lookup_extent_backref(trans, extent_root, path,
1895 bytenr, parent, root_objectid,
1896 ref_generation, owner_objectid, 1);
1898 struct btrfs_key found_key;
1899 extent_slot = path->slots[0];
1900 while(extent_slot > 0) {
1902 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1904 if (found_key.objectid != bytenr)
1906 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1907 found_key.offset == num_bytes) {
1911 if (path->slots[0] - extent_slot > 5)
1914 if (!found_extent) {
1915 ret = remove_extent_backref(trans, extent_root, path);
1917 btrfs_release_path(extent_root, path);
1918 ret = btrfs_search_slot(trans, extent_root,
1921 extent_slot = path->slots[0];
1924 btrfs_print_leaf(extent_root, path->nodes[0]);
1926 printk("Unable to find ref byte nr %Lu root %Lu "
1927 "gen %Lu owner %Lu\n", bytenr,
1928 root_objectid, ref_generation, owner_objectid);
1931 leaf = path->nodes[0];
1932 ei = btrfs_item_ptr(leaf, extent_slot,
1933 struct btrfs_extent_item);
1934 refs = btrfs_extent_refs(leaf, ei);
1937 btrfs_set_extent_refs(leaf, ei, refs);
1939 btrfs_mark_buffer_dirty(leaf);
1941 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1942 struct btrfs_extent_ref *ref;
1943 ref = btrfs_item_ptr(leaf, path->slots[0],
1944 struct btrfs_extent_ref);
1945 BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1);
1946 /* if the back ref and the extent are next to each other
1947 * they get deleted below in one shot
1949 path->slots[0] = extent_slot;
1951 } else if (found_extent) {
1952 /* otherwise delete the extent back ref */
1953 ret = remove_extent_backref(trans, extent_root, path);
1955 /* if refs are 0, we need to setup the path for deletion */
1957 btrfs_release_path(extent_root, path);
1958 ret = btrfs_search_slot(trans, extent_root, &key, path,
1967 #ifdef BIO_RW_DISCARD
1968 u64 map_length = num_bytes;
1969 struct btrfs_multi_bio *multi = NULL;
1973 ret = pin_down_bytes(trans, root, bytenr, num_bytes,
1974 owner_objectid >= BTRFS_FIRST_FREE_OBJECTID);
1980 /* block accounting for super block */
1981 spin_lock_irq(&info->delalloc_lock);
1982 super_used = btrfs_super_bytes_used(&info->super_copy);
1983 btrfs_set_super_bytes_used(&info->super_copy,
1984 super_used - num_bytes);
1985 spin_unlock_irq(&info->delalloc_lock);
1987 /* block accounting for root item */
1988 root_used = btrfs_root_used(&root->root_item);
1989 btrfs_set_root_used(&root->root_item,
1990 root_used - num_bytes);
1991 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1994 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1998 #ifdef BIO_RW_DISCARD
1999 /* Tell the block device(s) that the sectors can be discarded */
2000 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
2001 bytenr, &map_length, &multi, 0);
2003 struct btrfs_bio_stripe *stripe = multi->stripes;
2006 if (map_length > num_bytes)
2007 map_length = num_bytes;
2009 for (i = 0; i < multi->num_stripes; i++, stripe++) {
2010 blkdev_issue_discard(stripe->dev->bdev,
2011 stripe->physical >> 9,
2018 btrfs_free_path(path);
2019 finish_current_insert(trans, extent_root);
2024 * find all the blocks marked as pending in the radix tree and remove
2025 * them from the extent map
2027 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
2028 btrfs_root *extent_root)
2036 struct extent_io_tree *pending_del;
2037 struct extent_io_tree *extent_ins;
2038 struct pending_extent_op *extent_op;
2040 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
2041 extent_ins = &extent_root->fs_info->extent_ins;
2042 pending_del = &extent_root->fs_info->pending_del;
2045 ret = find_first_extent_bit(pending_del, 0, &start, &end,
2050 ret = get_state_private(pending_del, start, &priv);
2052 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2054 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
2057 ret = pin_down_bytes(trans, extent_root, start,
2058 end + 1 - start, 0);
2059 mark_free = ret > 0;
2060 if (!test_range_bit(extent_ins, start, end,
2061 EXTENT_LOCKED, 0)) {
2063 ret = __free_extent(trans, extent_root,
2064 start, end + 1 - start,
2065 extent_op->orig_parent,
2066 extent_root->root_key.objectid,
2067 extent_op->orig_generation,
2068 extent_op->level, 0, mark_free);
2072 ret = get_state_private(extent_ins, start, &priv);
2074 extent_op = (struct pending_extent_op *)
2075 (unsigned long)priv;
2077 clear_extent_bits(extent_ins, start, end,
2078 EXTENT_LOCKED, GFP_NOFS);
2080 if (extent_op->type == PENDING_BACKREF_UPDATE)
2083 ret = update_block_group(trans, extent_root, start,
2084 end + 1 - start, 0, mark_free);
2091 if (need_resched()) {
2092 mutex_unlock(&extent_root->fs_info->alloc_mutex);
2094 mutex_lock(&extent_root->fs_info->alloc_mutex);
2101 * remove an extent from the root, returns 0 on success
2103 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
2104 struct btrfs_root *root,
2105 u64 bytenr, u64 num_bytes, u64 parent,
2106 u64 root_objectid, u64 ref_generation,
2107 u64 owner_objectid, int pin)
2109 struct btrfs_root *extent_root = root->fs_info->extent_root;
2113 WARN_ON(num_bytes < root->sectorsize);
2114 if (root == extent_root) {
2115 struct pending_extent_op *extent_op;
2117 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2120 extent_op->type = PENDING_EXTENT_DELETE;
2121 extent_op->bytenr = bytenr;
2122 extent_op->num_bytes = num_bytes;
2123 extent_op->parent = parent;
2124 extent_op->orig_parent = parent;
2125 extent_op->generation = ref_generation;
2126 extent_op->orig_generation = ref_generation;
2127 extent_op->level = (int)owner_objectid;
2129 set_extent_bits(&root->fs_info->pending_del,
2130 bytenr, bytenr + num_bytes - 1,
2131 EXTENT_LOCKED, GFP_NOFS);
2132 set_state_private(&root->fs_info->pending_del,
2133 bytenr, (unsigned long)extent_op);
2136 /* if metadata always pin */
2137 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
2138 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2139 struct btrfs_block_group_cache *cache;
2141 /* btrfs_free_reserved_extent */
2142 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
2144 btrfs_add_free_space(cache, bytenr, num_bytes);
2145 update_reserved_extents(root, bytenr, num_bytes, 0);
2151 /* if data pin when any transaction has committed this */
2152 if (ref_generation != trans->transid)
2155 ret = __free_extent(trans, root, bytenr, num_bytes, parent,
2156 root_objectid, ref_generation,
2157 owner_objectid, pin, pin == 0);
2159 finish_current_insert(trans, root->fs_info->extent_root);
2160 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
2161 return ret ? ret : pending_ret;
2164 int btrfs_free_extent(struct btrfs_trans_handle *trans,
2165 struct btrfs_root *root,
2166 u64 bytenr, u64 num_bytes, u64 parent,
2167 u64 root_objectid, u64 ref_generation,
2168 u64 owner_objectid, int pin)
2172 maybe_lock_mutex(root);
2173 ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent,
2174 root_objectid, ref_generation,
2175 owner_objectid, pin);
2176 maybe_unlock_mutex(root);
2180 static u64 stripe_align(struct btrfs_root *root, u64 val)
2182 u64 mask = ((u64)root->stripesize - 1);
2183 u64 ret = (val + mask) & ~mask;
2188 * walks the btree of allocated extents and find a hole of a given size.
2189 * The key ins is changed to record the hole:
2190 * ins->objectid == block start
2191 * ins->flags = BTRFS_EXTENT_ITEM_KEY
2192 * ins->offset == number of blocks
2193 * Any available blocks before search_start are skipped.
2195 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
2196 struct btrfs_root *orig_root,
2197 u64 num_bytes, u64 empty_size,
2198 u64 search_start, u64 search_end,
2199 u64 hint_byte, struct btrfs_key *ins,
2200 u64 exclude_start, u64 exclude_nr,
2204 u64 orig_search_start;
2205 struct btrfs_root * root = orig_root->fs_info->extent_root;
2206 struct btrfs_fs_info *info = root->fs_info;
2207 u64 total_needed = num_bytes;
2208 u64 *last_ptr = NULL;
2209 struct btrfs_block_group_cache *block_group;
2210 int chunk_alloc_done = 0;
2211 int empty_cluster = 2 * 1024 * 1024;
2212 int allowed_chunk_alloc = 0;
2214 WARN_ON(num_bytes < root->sectorsize);
2215 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
2217 if (orig_root->ref_cows || empty_size)
2218 allowed_chunk_alloc = 1;
2220 if (data & BTRFS_BLOCK_GROUP_METADATA) {
2221 last_ptr = &root->fs_info->last_alloc;
2222 empty_cluster = 256 * 1024;
2225 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
2226 last_ptr = &root->fs_info->last_data_alloc;
2230 hint_byte = *last_ptr;
2232 empty_size += empty_cluster;
2235 search_start = max(search_start, first_logical_byte(root, 0));
2236 orig_search_start = search_start;
2238 search_start = max(search_start, hint_byte);
2239 total_needed += empty_size;
2242 block_group = btrfs_lookup_block_group(info, search_start);
2244 block_group = btrfs_lookup_first_block_group(info,
2248 * Ok this looks a little tricky, buts its really simple. First if we
2249 * didn't find a block group obviously we want to start over.
2250 * Secondly, if the block group we found does not match the type we
2251 * need, and we have a last_ptr and its not 0, chances are the last
2252 * allocation we made was at the end of the block group, so lets go
2253 * ahead and skip the looking through the rest of the block groups and
2254 * start at the beginning. This helps with metadata allocations,
2255 * since you are likely to have a bunch of data block groups to search
2256 * through first before you realize that you need to start over, so go
2257 * ahead and start over and save the time.
2259 if (!block_group || (!block_group_bits(block_group, data) &&
2260 last_ptr && *last_ptr)) {
2261 if (search_start != orig_search_start) {
2262 if (last_ptr && *last_ptr) {
2263 total_needed += empty_cluster;
2266 search_start = orig_search_start;
2268 } else if (!chunk_alloc_done && allowed_chunk_alloc) {
2269 ret = do_chunk_alloc(trans, root,
2270 num_bytes + 2 * 1024 * 1024,
2275 chunk_alloc_done = 1;
2276 search_start = orig_search_start;
2285 * this is going to seach through all of the existing block groups it
2286 * can find, so if we don't find something we need to see if we can
2287 * allocate what we need.
2289 ret = find_free_space(root, &block_group, &search_start,
2290 total_needed, data);
2291 if (ret == -ENOSPC) {
2293 * instead of allocating, start at the original search start
2294 * and see if there is something to be found, if not then we
2297 if (search_start != orig_search_start) {
2298 if (last_ptr && *last_ptr) {
2300 total_needed += empty_cluster;
2302 search_start = orig_search_start;
2307 * we've already allocated, we're pretty screwed
2309 if (chunk_alloc_done) {
2311 } else if (!allowed_chunk_alloc && block_group &&
2312 block_group_bits(block_group, data)) {
2313 block_group->space_info->force_alloc = 1;
2315 } else if (!allowed_chunk_alloc) {
2319 ret = do_chunk_alloc(trans, root, num_bytes + 2 * 1024 * 1024,
2325 chunk_alloc_done = 1;
2327 search_start = block_group->key.objectid +
2328 block_group->key.offset;
2330 search_start = orig_search_start;
2337 search_start = stripe_align(root, search_start);
2338 ins->objectid = search_start;
2339 ins->offset = num_bytes;
2341 if (ins->objectid + num_bytes >= search_end) {
2342 search_start = orig_search_start;
2343 if (chunk_alloc_done) {
2350 if (ins->objectid + num_bytes >
2351 block_group->key.objectid + block_group->key.offset) {
2352 if (search_start == orig_search_start && chunk_alloc_done) {
2356 search_start = block_group->key.objectid +
2357 block_group->key.offset;
2361 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
2362 ins->objectid < exclude_start + exclude_nr)) {
2363 search_start = exclude_start + exclude_nr;
2367 if (!(data & BTRFS_BLOCK_GROUP_DATA))
2368 trans->block_group = block_group;
2370 ins->offset = num_bytes;
2372 *last_ptr = ins->objectid + ins->offset;
2374 btrfs_super_total_bytes(&root->fs_info->super_copy))
2383 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
2385 struct btrfs_block_group_cache *cache;
2386 struct list_head *l;
2388 printk(KERN_INFO "space_info has %Lu free, is %sfull\n",
2389 info->total_bytes - info->bytes_used - info->bytes_pinned -
2390 info->bytes_reserved, (info->full) ? "" : "not ");
2392 spin_lock(&info->lock);
2393 list_for_each(l, &info->block_groups) {
2394 cache = list_entry(l, struct btrfs_block_group_cache, list);
2395 spin_lock(&cache->lock);
2396 printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used "
2397 "%Lu pinned %Lu reserved\n",
2398 cache->key.objectid, cache->key.offset,
2399 btrfs_block_group_used(&cache->item),
2400 cache->pinned, cache->reserved);
2401 btrfs_dump_free_space(cache, bytes);
2402 spin_unlock(&cache->lock);
2404 spin_unlock(&info->lock);
2407 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2408 struct btrfs_root *root,
2409 u64 num_bytes, u64 min_alloc_size,
2410 u64 empty_size, u64 hint_byte,
2411 u64 search_end, struct btrfs_key *ins,
2415 u64 search_start = 0;
2417 struct btrfs_fs_info *info = root->fs_info;
2418 struct btrfs_block_group_cache *cache;
2421 alloc_profile = info->avail_data_alloc_bits &
2422 info->data_alloc_profile;
2423 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2424 } else if (root == root->fs_info->chunk_root) {
2425 alloc_profile = info->avail_system_alloc_bits &
2426 info->system_alloc_profile;
2427 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2429 alloc_profile = info->avail_metadata_alloc_bits &
2430 info->metadata_alloc_profile;
2431 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2434 data = reduce_alloc_profile(root, data);
2436 * the only place that sets empty_size is btrfs_realloc_node, which
2437 * is not called recursively on allocations
2439 if (empty_size || root->ref_cows) {
2440 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
2441 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2443 BTRFS_BLOCK_GROUP_METADATA |
2444 (info->metadata_alloc_profile &
2445 info->avail_metadata_alloc_bits), 0);
2447 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2448 num_bytes + 2 * 1024 * 1024, data, 0);
2451 WARN_ON(num_bytes < root->sectorsize);
2452 ret = find_free_extent(trans, root, num_bytes, empty_size,
2453 search_start, search_end, hint_byte, ins,
2454 trans->alloc_exclude_start,
2455 trans->alloc_exclude_nr, data);
2457 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
2458 num_bytes = num_bytes >> 1;
2459 num_bytes = num_bytes & ~(root->sectorsize - 1);
2460 num_bytes = max(num_bytes, min_alloc_size);
2461 do_chunk_alloc(trans, root->fs_info->extent_root,
2462 num_bytes, data, 1);
2466 struct btrfs_space_info *sinfo;
2468 sinfo = __find_space_info(root->fs_info, data);
2469 printk("allocation failed flags %Lu, wanted %Lu\n",
2471 dump_space_info(sinfo, num_bytes);
2474 cache = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2476 printk(KERN_ERR "Unable to find block group for %Lu\n", ins->objectid);
2480 ret = btrfs_remove_free_space(cache, ins->objectid, ins->offset);
2485 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
2487 struct btrfs_block_group_cache *cache;
2489 maybe_lock_mutex(root);
2490 cache = btrfs_lookup_block_group(root->fs_info, start);
2492 printk(KERN_ERR "Unable to find block group for %Lu\n", start);
2493 maybe_unlock_mutex(root);
2496 btrfs_add_free_space(cache, start, len);
2497 update_reserved_extents(root, start, len, 0);
2498 maybe_unlock_mutex(root);
2502 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2503 struct btrfs_root *root,
2504 u64 num_bytes, u64 min_alloc_size,
2505 u64 empty_size, u64 hint_byte,
2506 u64 search_end, struct btrfs_key *ins,
2510 maybe_lock_mutex(root);
2511 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
2512 empty_size, hint_byte, search_end, ins,
2514 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2515 maybe_unlock_mutex(root);
2519 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2520 struct btrfs_root *root, u64 parent,
2521 u64 root_objectid, u64 ref_generation,
2522 u64 owner, struct btrfs_key *ins)
2528 u64 num_bytes = ins->offset;
2530 struct btrfs_fs_info *info = root->fs_info;
2531 struct btrfs_root *extent_root = info->extent_root;
2532 struct btrfs_extent_item *extent_item;
2533 struct btrfs_extent_ref *ref;
2534 struct btrfs_path *path;
2535 struct btrfs_key keys[2];
2538 parent = ins->objectid;
2540 /* block accounting for super block */
2541 spin_lock_irq(&info->delalloc_lock);
2542 super_used = btrfs_super_bytes_used(&info->super_copy);
2543 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
2544 spin_unlock_irq(&info->delalloc_lock);
2546 /* block accounting for root item */
2547 root_used = btrfs_root_used(&root->root_item);
2548 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
2550 if (root == extent_root) {
2551 struct pending_extent_op *extent_op;
2553 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2556 extent_op->type = PENDING_EXTENT_INSERT;
2557 extent_op->bytenr = ins->objectid;
2558 extent_op->num_bytes = ins->offset;
2559 extent_op->parent = parent;
2560 extent_op->orig_parent = 0;
2561 extent_op->generation = ref_generation;
2562 extent_op->orig_generation = 0;
2563 extent_op->level = (int)owner;
2565 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2566 ins->objectid + ins->offset - 1,
2567 EXTENT_LOCKED, GFP_NOFS);
2568 set_state_private(&root->fs_info->extent_ins,
2569 ins->objectid, (unsigned long)extent_op);
2573 memcpy(&keys[0], ins, sizeof(*ins));
2574 keys[1].objectid = ins->objectid;
2575 keys[1].type = BTRFS_EXTENT_REF_KEY;
2576 keys[1].offset = parent;
2577 sizes[0] = sizeof(*extent_item);
2578 sizes[1] = sizeof(*ref);
2580 path = btrfs_alloc_path();
2583 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
2587 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2588 struct btrfs_extent_item);
2589 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
2590 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
2591 struct btrfs_extent_ref);
2593 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
2594 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
2595 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
2596 btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
2598 btrfs_mark_buffer_dirty(path->nodes[0]);
2600 trans->alloc_exclude_start = 0;
2601 trans->alloc_exclude_nr = 0;
2602 btrfs_free_path(path);
2603 finish_current_insert(trans, extent_root);
2604 pending_ret = del_pending_extents(trans, extent_root);
2614 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
2616 printk("update block group failed for %Lu %Lu\n",
2617 ins->objectid, ins->offset);
2624 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2625 struct btrfs_root *root, u64 parent,
2626 u64 root_objectid, u64 ref_generation,
2627 u64 owner, struct btrfs_key *ins)
2631 if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
2633 maybe_lock_mutex(root);
2634 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
2635 ref_generation, owner, ins);
2636 update_reserved_extents(root, ins->objectid, ins->offset, 0);
2637 maybe_unlock_mutex(root);
2642 * this is used by the tree logging recovery code. It records that
2643 * an extent has been allocated and makes sure to clear the free
2644 * space cache bits as well
2646 int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
2647 struct btrfs_root *root, u64 parent,
2648 u64 root_objectid, u64 ref_generation,
2649 u64 owner, struct btrfs_key *ins)
2652 struct btrfs_block_group_cache *block_group;
2654 maybe_lock_mutex(root);
2655 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2656 cache_block_group(root, block_group);
2658 ret = btrfs_remove_free_space(block_group, ins->objectid, ins->offset);
2660 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
2661 ref_generation, owner, ins);
2662 maybe_unlock_mutex(root);
2667 * finds a free extent and does all the dirty work required for allocation
2668 * returns the key for the extent through ins, and a tree buffer for
2669 * the first block of the extent through buf.
2671 * returns 0 if everything worked, non-zero otherwise.
2673 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
2674 struct btrfs_root *root,
2675 u64 num_bytes, u64 parent, u64 min_alloc_size,
2676 u64 root_objectid, u64 ref_generation,
2677 u64 owner_objectid, u64 empty_size, u64 hint_byte,
2678 u64 search_end, struct btrfs_key *ins, u64 data)
2682 maybe_lock_mutex(root);
2684 ret = __btrfs_reserve_extent(trans, root, num_bytes,
2685 min_alloc_size, empty_size, hint_byte,
2686 search_end, ins, data);
2688 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
2689 ret = __btrfs_alloc_reserved_extent(trans, root, parent,
2690 root_objectid, ref_generation,
2691 owner_objectid, ins);
2695 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2697 maybe_unlock_mutex(root);
2701 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
2702 struct btrfs_root *root,
2703 u64 bytenr, u32 blocksize)
2705 struct extent_buffer *buf;
2707 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
2709 return ERR_PTR(-ENOMEM);
2710 btrfs_set_header_generation(buf, trans->transid);
2711 btrfs_tree_lock(buf);
2712 clean_tree_block(trans, root, buf);
2713 btrfs_set_buffer_uptodate(buf);
2714 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2715 set_extent_dirty(&root->dirty_log_pages, buf->start,
2716 buf->start + buf->len - 1, GFP_NOFS);
2718 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
2719 buf->start + buf->len - 1, GFP_NOFS);
2721 trans->blocks_used++;
2726 * helper function to allocate a block for a given tree
2727 * returns the tree buffer or NULL.
2729 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2730 struct btrfs_root *root,
2731 u32 blocksize, u64 parent,
2738 struct btrfs_key ins;
2740 struct extent_buffer *buf;
2742 ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
2743 root_objectid, ref_generation, level,
2744 empty_size, hint, (u64)-1, &ins, 0);
2747 return ERR_PTR(ret);
2750 buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
2754 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
2755 struct btrfs_root *root, struct extent_buffer *leaf)
2758 u64 leaf_generation;
2759 struct btrfs_key key;
2760 struct btrfs_file_extent_item *fi;
2765 BUG_ON(!btrfs_is_leaf(leaf));
2766 nritems = btrfs_header_nritems(leaf);
2767 leaf_owner = btrfs_header_owner(leaf);
2768 leaf_generation = btrfs_header_generation(leaf);
2770 for (i = 0; i < nritems; i++) {
2774 btrfs_item_key_to_cpu(leaf, &key, i);
2775 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2777 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2778 if (btrfs_file_extent_type(leaf, fi) ==
2779 BTRFS_FILE_EXTENT_INLINE)
2782 * FIXME make sure to insert a trans record that
2783 * repeats the snapshot del on crash
2785 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2786 if (disk_bytenr == 0)
2789 mutex_lock(&root->fs_info->alloc_mutex);
2790 ret = __btrfs_free_extent(trans, root, disk_bytenr,
2791 btrfs_file_extent_disk_num_bytes(leaf, fi),
2792 leaf->start, leaf_owner, leaf_generation,
2794 mutex_unlock(&root->fs_info->alloc_mutex);
2797 atomic_inc(&root->fs_info->throttle_gen);
2798 wake_up(&root->fs_info->transaction_throttle);
2804 static int noinline cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
2805 struct btrfs_root *root,
2806 struct btrfs_leaf_ref *ref)
2810 struct btrfs_extent_info *info = ref->extents;
2812 for (i = 0; i < ref->nritems; i++) {
2813 mutex_lock(&root->fs_info->alloc_mutex);
2814 ret = __btrfs_free_extent(trans, root, info->bytenr,
2815 info->num_bytes, ref->bytenr,
2816 ref->owner, ref->generation,
2818 mutex_unlock(&root->fs_info->alloc_mutex);
2820 atomic_inc(&root->fs_info->throttle_gen);
2821 wake_up(&root->fs_info->transaction_throttle);
2831 int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len,
2836 ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
2839 #if 0 // some debugging code in case we see problems here
2840 /* if the refs count is one, it won't get increased again. But
2841 * if the ref count is > 1, someone may be decreasing it at
2842 * the same time we are.
2845 struct extent_buffer *eb = NULL;
2846 eb = btrfs_find_create_tree_block(root, start, len);
2848 btrfs_tree_lock(eb);
2850 mutex_lock(&root->fs_info->alloc_mutex);
2851 ret = lookup_extent_ref(NULL, root, start, len, refs);
2853 mutex_unlock(&root->fs_info->alloc_mutex);
2856 btrfs_tree_unlock(eb);
2857 free_extent_buffer(eb);
2860 printk("block %llu went down to one during drop_snap\n",
2861 (unsigned long long)start);
2872 * helper function for drop_snapshot, this walks down the tree dropping ref
2873 * counts as it goes.
2875 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2876 struct btrfs_root *root,
2877 struct btrfs_path *path, int *level)
2883 struct extent_buffer *next;
2884 struct extent_buffer *cur;
2885 struct extent_buffer *parent;
2886 struct btrfs_leaf_ref *ref;
2891 WARN_ON(*level < 0);
2892 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2893 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
2894 path->nodes[*level]->len, &refs);
2900 * walk down to the last node level and free all the leaves
2902 while(*level >= 0) {
2903 WARN_ON(*level < 0);
2904 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2905 cur = path->nodes[*level];
2907 if (btrfs_header_level(cur) != *level)
2910 if (path->slots[*level] >=
2911 btrfs_header_nritems(cur))
2914 ret = btrfs_drop_leaf_ref(trans, root, cur);
2918 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2919 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2920 blocksize = btrfs_level_size(root, *level - 1);
2922 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
2925 parent = path->nodes[*level];
2926 root_owner = btrfs_header_owner(parent);
2927 root_gen = btrfs_header_generation(parent);
2928 path->slots[*level]++;
2930 mutex_lock(&root->fs_info->alloc_mutex);
2931 ret = __btrfs_free_extent(trans, root, bytenr,
2932 blocksize, parent->start,
2933 root_owner, root_gen,
2936 mutex_unlock(&root->fs_info->alloc_mutex);
2938 atomic_inc(&root->fs_info->throttle_gen);
2939 wake_up(&root->fs_info->transaction_throttle);
2945 * at this point, we have a single ref, and since the
2946 * only place referencing this extent is a dead root
2947 * the reference count should never go higher.
2948 * So, we don't need to check it again
2951 ref = btrfs_lookup_leaf_ref(root, bytenr);
2952 if (ref && ref->generation != ptr_gen) {
2953 btrfs_free_leaf_ref(root, ref);
2957 ret = cache_drop_leaf_ref(trans, root, ref);
2959 btrfs_remove_leaf_ref(root, ref);
2960 btrfs_free_leaf_ref(root, ref);
2964 if (printk_ratelimit()) {
2965 printk("leaf ref miss for bytenr %llu\n",
2966 (unsigned long long)bytenr);
2969 next = btrfs_find_tree_block(root, bytenr, blocksize);
2970 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2971 free_extent_buffer(next);
2973 next = read_tree_block(root, bytenr, blocksize,
2978 * this is a debugging check and can go away
2979 * the ref should never go all the way down to 1
2982 ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
2988 WARN_ON(*level <= 0);
2989 if (path->nodes[*level-1])
2990 free_extent_buffer(path->nodes[*level-1]);
2991 path->nodes[*level-1] = next;
2992 *level = btrfs_header_level(next);
2993 path->slots[*level] = 0;
2997 WARN_ON(*level < 0);
2998 WARN_ON(*level >= BTRFS_MAX_LEVEL);
3000 if (path->nodes[*level] == root->node) {
3001 parent = path->nodes[*level];
3002 bytenr = path->nodes[*level]->start;
3004 parent = path->nodes[*level + 1];
3005 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
3008 blocksize = btrfs_level_size(root, *level);
3009 root_owner = btrfs_header_owner(parent);
3010 root_gen = btrfs_header_generation(parent);
3012 mutex_lock(&root->fs_info->alloc_mutex);
3013 ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
3014 parent->start, root_owner, root_gen,
3016 mutex_unlock(&root->fs_info->alloc_mutex);
3017 free_extent_buffer(path->nodes[*level]);
3018 path->nodes[*level] = NULL;
3027 * helper for dropping snapshots. This walks back up the tree in the path
3028 * to find the first node higher up where we haven't yet gone through
3031 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
3032 struct btrfs_root *root,
3033 struct btrfs_path *path, int *level)
3037 struct btrfs_root_item *root_item = &root->root_item;
3042 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
3043 slot = path->slots[i];
3044 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
3045 struct extent_buffer *node;
3046 struct btrfs_disk_key disk_key;
3047 node = path->nodes[i];
3050 WARN_ON(*level == 0);
3051 btrfs_node_key(node, &disk_key, path->slots[i]);
3052 memcpy(&root_item->drop_progress,
3053 &disk_key, sizeof(disk_key));
3054 root_item->drop_level = i;
3057 struct extent_buffer *parent;
3058 if (path->nodes[*level] == root->node)
3059 parent = path->nodes[*level];
3061 parent = path->nodes[*level + 1];
3063 root_owner = btrfs_header_owner(parent);
3064 root_gen = btrfs_header_generation(parent);
3065 ret = btrfs_free_extent(trans, root,
3066 path->nodes[*level]->start,
3067 path->nodes[*level]->len,
3068 parent->start, root_owner,
3069 root_gen, *level, 1);
3071 free_extent_buffer(path->nodes[*level]);
3072 path->nodes[*level] = NULL;
3080 * drop the reference count on the tree rooted at 'snap'. This traverses
3081 * the tree freeing any blocks that have a ref count of zero after being
3084 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
3090 struct btrfs_path *path;
3093 struct btrfs_root_item *root_item = &root->root_item;
3095 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
3096 path = btrfs_alloc_path();
3099 level = btrfs_header_level(root->node);
3101 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
3102 path->nodes[level] = root->node;
3103 extent_buffer_get(root->node);
3104 path->slots[level] = 0;
3106 struct btrfs_key key;
3107 struct btrfs_disk_key found_key;
3108 struct extent_buffer *node;
3110 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
3111 level = root_item->drop_level;
3112 path->lowest_level = level;
3113 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3118 node = path->nodes[level];
3119 btrfs_node_key(node, &found_key, path->slots[level]);
3120 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
3121 sizeof(found_key)));
3123 * unlock our path, this is safe because only this
3124 * function is allowed to delete this snapshot
3126 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
3127 if (path->nodes[i] && path->locks[i]) {
3129 btrfs_tree_unlock(path->nodes[i]);
3134 wret = walk_down_tree(trans, root, path, &level);
3140 wret = walk_up_tree(trans, root, path, &level);
3145 if (trans->transaction->in_commit) {
3149 atomic_inc(&root->fs_info->throttle_gen);
3150 wake_up(&root->fs_info->transaction_throttle);
3152 for (i = 0; i <= orig_level; i++) {
3153 if (path->nodes[i]) {
3154 free_extent_buffer(path->nodes[i]);
3155 path->nodes[i] = NULL;
3159 btrfs_free_path(path);
3163 static unsigned long calc_ra(unsigned long start, unsigned long last,
3166 return min(last, start + nr - 1);
3169 static int noinline relocate_inode_pages(struct inode *inode, u64 start,
3174 unsigned long first_index;
3175 unsigned long last_index;
3178 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3179 struct file_ra_state *ra;
3180 struct btrfs_ordered_extent *ordered;
3181 unsigned int total_read = 0;
3182 unsigned int total_dirty = 0;
3185 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3187 mutex_lock(&inode->i_mutex);
3188 first_index = start >> PAGE_CACHE_SHIFT;
3189 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
3191 /* make sure the dirty trick played by the caller work */
3192 ret = invalidate_inode_pages2_range(inode->i_mapping,
3193 first_index, last_index);
3197 file_ra_state_init(ra, inode->i_mapping);
3199 for (i = first_index ; i <= last_index; i++) {
3200 if (total_read % ra->ra_pages == 0) {
3201 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
3202 calc_ra(i, last_index, ra->ra_pages));
3206 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
3208 page = grab_cache_page(inode->i_mapping, i);
3213 if (!PageUptodate(page)) {
3214 btrfs_readpage(NULL, page);
3216 if (!PageUptodate(page)) {
3218 page_cache_release(page);
3223 wait_on_page_writeback(page);
3225 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
3226 page_end = page_start + PAGE_CACHE_SIZE - 1;
3227 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
3229 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3231 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3233 page_cache_release(page);
3234 btrfs_start_ordered_extent(inode, ordered, 1);
3235 btrfs_put_ordered_extent(ordered);
3238 set_page_extent_mapped(page);
3240 btrfs_set_extent_delalloc(inode, page_start, page_end);
3241 if (i == first_index)
3242 set_extent_bits(io_tree, page_start, page_end,
3243 EXTENT_BOUNDARY, GFP_NOFS);
3245 set_page_dirty(page);
3248 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3250 page_cache_release(page);
3255 mutex_unlock(&inode->i_mutex);
3256 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
3260 static int noinline relocate_data_extent(struct inode *reloc_inode,
3261 struct btrfs_key *extent_key,
3264 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3265 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
3266 struct extent_map *em;
3268 em = alloc_extent_map(GFP_NOFS);
3269 BUG_ON(!em || IS_ERR(em));
3271 em->start = extent_key->objectid - offset;
3272 em->len = extent_key->offset;
3273 em->block_start = extent_key->objectid;
3274 em->bdev = root->fs_info->fs_devices->latest_bdev;
3275 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3277 /* setup extent map to cheat btrfs_readpage */
3278 mutex_lock(&BTRFS_I(reloc_inode)->extent_mutex);
3281 spin_lock(&em_tree->lock);
3282 ret = add_extent_mapping(em_tree, em);
3283 spin_unlock(&em_tree->lock);
3284 if (ret != -EEXIST) {
3285 free_extent_map(em);
3288 btrfs_drop_extent_cache(reloc_inode, em->start,
3289 em->start + em->len - 1, 0);
3291 mutex_unlock(&BTRFS_I(reloc_inode)->extent_mutex);
3293 return relocate_inode_pages(reloc_inode, extent_key->objectid - offset,
3294 extent_key->offset);
3297 struct btrfs_ref_path {
3299 u64 nodes[BTRFS_MAX_LEVEL];
3301 u64 root_generation;
3308 struct disk_extent {
3315 static int is_cowonly_root(u64 root_objectid)
3317 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
3318 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
3319 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
3320 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
3321 root_objectid == BTRFS_TREE_LOG_OBJECTID)
3326 static int noinline __next_ref_path(struct btrfs_trans_handle *trans,
3327 struct btrfs_root *extent_root,
3328 struct btrfs_ref_path *ref_path,
3331 struct extent_buffer *leaf;
3332 struct btrfs_path *path;
3333 struct btrfs_extent_ref *ref;
3334 struct btrfs_key key;
3335 struct btrfs_key found_key;
3341 path = btrfs_alloc_path();
3345 mutex_lock(&extent_root->fs_info->alloc_mutex);
3348 ref_path->lowest_level = -1;
3349 ref_path->current_level = -1;
3353 level = ref_path->current_level - 1;
3354 while (level >= -1) {
3356 if (level < ref_path->lowest_level)
3360 bytenr = ref_path->nodes[level];
3362 bytenr = ref_path->extent_start;
3364 BUG_ON(bytenr == 0);
3366 parent = ref_path->nodes[level + 1];
3367 ref_path->nodes[level + 1] = 0;
3368 ref_path->current_level = level;
3369 BUG_ON(parent == 0);
3371 key.objectid = bytenr;
3372 key.offset = parent + 1;
3373 key.type = BTRFS_EXTENT_REF_KEY;
3375 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3380 leaf = path->nodes[0];
3381 nritems = btrfs_header_nritems(leaf);
3382 if (path->slots[0] >= nritems) {
3383 ret = btrfs_next_leaf(extent_root, path);
3388 leaf = path->nodes[0];
3391 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3392 if (found_key.objectid == bytenr &&
3393 found_key.type == BTRFS_EXTENT_REF_KEY)
3397 btrfs_release_path(extent_root, path);
3398 if (need_resched()) {
3399 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3401 mutex_lock(&extent_root->fs_info->alloc_mutex);
3404 /* reached lowest level */
3408 level = ref_path->current_level;
3409 while (level < BTRFS_MAX_LEVEL - 1) {
3412 bytenr = ref_path->nodes[level];
3414 bytenr = ref_path->extent_start;
3416 BUG_ON(bytenr == 0);
3418 key.objectid = bytenr;
3420 key.type = BTRFS_EXTENT_REF_KEY;
3422 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3426 leaf = path->nodes[0];
3427 nritems = btrfs_header_nritems(leaf);
3428 if (path->slots[0] >= nritems) {
3429 ret = btrfs_next_leaf(extent_root, path);
3433 /* the extent was freed by someone */
3434 if (ref_path->lowest_level == level)
3436 btrfs_release_path(extent_root, path);
3439 leaf = path->nodes[0];
3442 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3443 if (found_key.objectid != bytenr ||
3444 found_key.type != BTRFS_EXTENT_REF_KEY) {
3445 /* the extent was freed by someone */
3446 if (ref_path->lowest_level == level) {
3450 btrfs_release_path(extent_root, path);
3454 ref = btrfs_item_ptr(leaf, path->slots[0],
3455 struct btrfs_extent_ref);
3456 ref_objectid = btrfs_ref_objectid(leaf, ref);
3457 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3459 level = (int)ref_objectid;
3460 BUG_ON(level >= BTRFS_MAX_LEVEL);
3461 ref_path->lowest_level = level;
3462 ref_path->current_level = level;
3463 ref_path->nodes[level] = bytenr;
3465 WARN_ON(ref_objectid != level);
3468 WARN_ON(level != -1);
3472 if (ref_path->lowest_level == level) {
3473 ref_path->owner_objectid = ref_objectid;
3474 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
3478 * the block is tree root or the block isn't in reference
3481 if (found_key.objectid == found_key.offset ||
3482 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
3483 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3484 ref_path->root_generation =
3485 btrfs_ref_generation(leaf, ref);
3487 /* special reference from the tree log */
3488 ref_path->nodes[0] = found_key.offset;
3489 ref_path->current_level = 0;
3496 BUG_ON(ref_path->nodes[level] != 0);
3497 ref_path->nodes[level] = found_key.offset;
3498 ref_path->current_level = level;
3501 * the reference was created in the running transaction,
3502 * no need to continue walking up.
3504 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
3505 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3506 ref_path->root_generation =
3507 btrfs_ref_generation(leaf, ref);
3512 btrfs_release_path(extent_root, path);
3513 if (need_resched()) {
3514 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3516 mutex_lock(&extent_root->fs_info->alloc_mutex);
3519 /* reached max tree level, but no tree root found. */
3522 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3523 btrfs_free_path(path);
3527 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
3528 struct btrfs_root *extent_root,
3529 struct btrfs_ref_path *ref_path,
3532 memset(ref_path, 0, sizeof(*ref_path));
3533 ref_path->extent_start = extent_start;
3535 return __next_ref_path(trans, extent_root, ref_path, 1);
3538 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
3539 struct btrfs_root *extent_root,
3540 struct btrfs_ref_path *ref_path)
3542 return __next_ref_path(trans, extent_root, ref_path, 0);
3545 static int noinline get_new_locations(struct inode *reloc_inode,
3546 struct btrfs_key *extent_key,
3547 u64 offset, int no_fragment,
3548 struct disk_extent **extents,
3551 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3552 struct btrfs_path *path;
3553 struct btrfs_file_extent_item *fi;
3554 struct extent_buffer *leaf;
3555 struct disk_extent *exts = *extents;
3556 struct btrfs_key found_key;
3561 int max = *nr_extents;
3564 WARN_ON(!no_fragment && *extents);
3567 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
3572 path = btrfs_alloc_path();
3575 cur_pos = extent_key->objectid - offset;
3576 last_byte = extent_key->objectid + extent_key->offset;
3577 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
3587 leaf = path->nodes[0];
3588 nritems = btrfs_header_nritems(leaf);
3589 if (path->slots[0] >= nritems) {
3590 ret = btrfs_next_leaf(root, path);
3595 leaf = path->nodes[0];
3598 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3599 if (found_key.offset != cur_pos ||
3600 found_key.type != BTRFS_EXTENT_DATA_KEY ||
3601 found_key.objectid != reloc_inode->i_ino)
3604 fi = btrfs_item_ptr(leaf, path->slots[0],
3605 struct btrfs_file_extent_item);
3606 if (btrfs_file_extent_type(leaf, fi) !=
3607 BTRFS_FILE_EXTENT_REG ||
3608 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
3612 struct disk_extent *old = exts;
3614 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
3615 memcpy(exts, old, sizeof(*exts) * nr);
3616 if (old != *extents)
3620 exts[nr].disk_bytenr =
3621 btrfs_file_extent_disk_bytenr(leaf, fi);
3622 exts[nr].disk_num_bytes =
3623 btrfs_file_extent_disk_num_bytes(leaf, fi);
3624 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
3625 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3626 WARN_ON(exts[nr].offset > 0);
3627 WARN_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
3629 cur_pos += exts[nr].num_bytes;
3632 if (cur_pos + offset >= last_byte)
3642 WARN_ON(cur_pos + offset > last_byte);
3643 if (cur_pos + offset < last_byte) {
3649 btrfs_free_path(path);
3651 if (exts != *extents)
3660 static int noinline replace_one_extent(struct btrfs_trans_handle *trans,
3661 struct btrfs_root *root,
3662 struct btrfs_path *path,
3663 struct btrfs_key *extent_key,
3664 struct btrfs_key *leaf_key,
3665 struct btrfs_ref_path *ref_path,
3666 struct disk_extent *new_extents,
3669 struct extent_buffer *leaf;
3670 struct btrfs_file_extent_item *fi;
3671 struct inode *inode = NULL;
3672 struct btrfs_key key;
3680 int extent_locked = 0;
3683 memcpy(&key, leaf_key, sizeof(key));
3684 first_pos = INT_LIMIT(loff_t) - extent_key->offset;
3685 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3686 if (key.objectid < ref_path->owner_objectid ||
3687 (key.objectid == ref_path->owner_objectid &&
3688 key.type < BTRFS_EXTENT_DATA_KEY)) {
3689 key.objectid = ref_path->owner_objectid;
3690 key.type = BTRFS_EXTENT_DATA_KEY;
3696 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
3700 leaf = path->nodes[0];
3701 nritems = btrfs_header_nritems(leaf);
3703 if (extent_locked && ret > 0) {
3705 * the file extent item was modified by someone
3706 * before the extent got locked.
3708 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3709 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3710 lock_end, GFP_NOFS);
3714 if (path->slots[0] >= nritems) {
3715 if (++nr_scaned > 2)
3718 BUG_ON(extent_locked);
3719 ret = btrfs_next_leaf(root, path);
3724 leaf = path->nodes[0];
3725 nritems = btrfs_header_nritems(leaf);
3728 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3730 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3731 if ((key.objectid > ref_path->owner_objectid) ||
3732 (key.objectid == ref_path->owner_objectid &&
3733 key.type > BTRFS_EXTENT_DATA_KEY) ||
3734 (key.offset >= first_pos + extent_key->offset))
3738 if (inode && key.objectid != inode->i_ino) {
3739 BUG_ON(extent_locked);
3740 btrfs_release_path(root, path);
3741 mutex_unlock(&inode->i_mutex);
3747 if (key.type != BTRFS_EXTENT_DATA_KEY) {
3752 fi = btrfs_item_ptr(leaf, path->slots[0],
3753 struct btrfs_file_extent_item);
3754 if ((btrfs_file_extent_type(leaf, fi) !=
3755 BTRFS_FILE_EXTENT_REG) ||
3756 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3757 extent_key->objectid)) {
3763 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3764 ext_offset = btrfs_file_extent_offset(leaf, fi);
3766 if (first_pos > key.offset - ext_offset)
3767 first_pos = key.offset - ext_offset;
3769 if (!extent_locked) {
3770 lock_start = key.offset;
3771 lock_end = lock_start + num_bytes - 1;
3773 BUG_ON(lock_start != key.offset);
3774 BUG_ON(lock_end - lock_start + 1 < num_bytes);
3778 btrfs_release_path(root, path);
3780 inode = btrfs_iget_locked(root->fs_info->sb,
3781 key.objectid, root);
3782 if (inode->i_state & I_NEW) {
3783 BTRFS_I(inode)->root = root;
3784 BTRFS_I(inode)->location.objectid =
3786 BTRFS_I(inode)->location.type =
3787 BTRFS_INODE_ITEM_KEY;
3788 BTRFS_I(inode)->location.offset = 0;
3789 btrfs_read_locked_inode(inode);
3790 unlock_new_inode(inode);
3793 * some code call btrfs_commit_transaction while
3794 * holding the i_mutex, so we can't use mutex_lock
3797 if (is_bad_inode(inode) ||
3798 !mutex_trylock(&inode->i_mutex)) {
3801 key.offset = (u64)-1;
3806 if (!extent_locked) {
3807 struct btrfs_ordered_extent *ordered;
3809 btrfs_release_path(root, path);
3811 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3812 lock_end, GFP_NOFS);
3813 ordered = btrfs_lookup_first_ordered_extent(inode,
3816 ordered->file_offset <= lock_end &&
3817 ordered->file_offset + ordered->len > lock_start) {
3818 unlock_extent(&BTRFS_I(inode)->io_tree,
3819 lock_start, lock_end, GFP_NOFS);
3820 btrfs_start_ordered_extent(inode, ordered, 1);
3821 btrfs_put_ordered_extent(ordered);
3822 key.offset += num_bytes;
3826 btrfs_put_ordered_extent(ordered);
3828 mutex_lock(&BTRFS_I(inode)->extent_mutex);
3833 if (nr_extents == 1) {
3834 /* update extent pointer in place */
3835 btrfs_set_file_extent_generation(leaf, fi,
3837 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3838 new_extents[0].disk_bytenr);
3839 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
3840 new_extents[0].disk_num_bytes);
3841 ext_offset += new_extents[0].offset;
3842 btrfs_set_file_extent_offset(leaf, fi, ext_offset);
3843 btrfs_mark_buffer_dirty(leaf);
3845 btrfs_drop_extent_cache(inode, key.offset,
3846 key.offset + num_bytes - 1, 0);
3848 ret = btrfs_inc_extent_ref(trans, root,
3849 new_extents[0].disk_bytenr,
3850 new_extents[0].disk_num_bytes,
3852 root->root_key.objectid,
3857 ret = btrfs_free_extent(trans, root,
3858 extent_key->objectid,
3861 btrfs_header_owner(leaf),
3862 btrfs_header_generation(leaf),
3866 btrfs_release_path(root, path);
3867 key.offset += num_bytes;
3873 * drop old extent pointer at first, then insert the
3874 * new pointers one bye one
3876 btrfs_release_path(root, path);
3877 ret = btrfs_drop_extents(trans, root, inode, key.offset,
3878 key.offset + num_bytes,
3879 key.offset, &alloc_hint);
3882 for (i = 0; i < nr_extents; i++) {
3883 if (ext_offset >= new_extents[i].num_bytes) {
3884 ext_offset -= new_extents[i].num_bytes;
3887 extent_len = min(new_extents[i].num_bytes -
3888 ext_offset, num_bytes);
3890 ret = btrfs_insert_empty_item(trans, root,
3895 leaf = path->nodes[0];
3896 fi = btrfs_item_ptr(leaf, path->slots[0],
3897 struct btrfs_file_extent_item);
3898 btrfs_set_file_extent_generation(leaf, fi,
3900 btrfs_set_file_extent_type(leaf, fi,
3901 BTRFS_FILE_EXTENT_REG);
3902 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3903 new_extents[i].disk_bytenr);
3904 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
3905 new_extents[i].disk_num_bytes);
3906 btrfs_set_file_extent_num_bytes(leaf, fi,
3908 ext_offset += new_extents[i].offset;
3909 btrfs_set_file_extent_offset(leaf, fi,
3911 btrfs_mark_buffer_dirty(leaf);
3913 btrfs_drop_extent_cache(inode, key.offset,
3914 key.offset + extent_len - 1, 0);
3916 ret = btrfs_inc_extent_ref(trans, root,
3917 new_extents[i].disk_bytenr,
3918 new_extents[i].disk_num_bytes,
3920 root->root_key.objectid,
3921 trans->transid, key.objectid);
3923 btrfs_release_path(root, path);
3925 inode_add_bytes(inode, extent_len);
3928 num_bytes -= extent_len;
3929 key.offset += extent_len;
3934 BUG_ON(i >= nr_extents);
3937 if (extent_locked) {
3938 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3939 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3940 lock_end, GFP_NOFS);
3944 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
3945 key.offset >= first_pos + extent_key->offset)
3952 btrfs_release_path(root, path);
3954 mutex_unlock(&inode->i_mutex);
3955 if (extent_locked) {
3956 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3957 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3958 lock_end, GFP_NOFS);
3965 int btrfs_add_reloc_mapping(struct btrfs_root *root, u64 orig_bytenr,
3966 u64 num_bytes, u64 new_bytenr)
3968 set_extent_bits(&root->fs_info->reloc_mapping_tree,
3969 orig_bytenr, orig_bytenr + num_bytes - 1,
3970 EXTENT_LOCKED, GFP_NOFS);
3971 set_state_private(&root->fs_info->reloc_mapping_tree,
3972 orig_bytenr, new_bytenr);
3976 int btrfs_get_reloc_mapping(struct btrfs_root *root, u64 orig_bytenr,
3977 u64 num_bytes, u64 *new_bytenr)
3980 u64 cur_bytenr = orig_bytenr;
3981 u64 prev_bytenr = orig_bytenr;
3985 ret = get_state_private(&root->fs_info->reloc_mapping_tree,
3986 cur_bytenr, &bytenr);
3989 prev_bytenr = cur_bytenr;
3990 cur_bytenr = bytenr;
3993 if (orig_bytenr == cur_bytenr)
3996 if (prev_bytenr != orig_bytenr) {
3997 set_state_private(&root->fs_info->reloc_mapping_tree,
3998 orig_bytenr, cur_bytenr);
4000 *new_bytenr = cur_bytenr;
4004 void btrfs_free_reloc_mappings(struct btrfs_root *root)
4006 clear_extent_bits(&root->fs_info->reloc_mapping_tree,
4007 0, (u64)-1, -1, GFP_NOFS);
4010 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
4011 struct btrfs_root *root,
4012 struct extent_buffer *buf, u64 orig_start)
4017 BUG_ON(btrfs_header_generation(buf) != trans->transid);
4018 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
4020 level = btrfs_header_level(buf);
4022 struct btrfs_leaf_ref *ref;
4023 struct btrfs_leaf_ref *orig_ref;
4025 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
4029 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
4031 btrfs_free_leaf_ref(root, orig_ref);
4035 ref->nritems = orig_ref->nritems;
4036 memcpy(ref->extents, orig_ref->extents,
4037 sizeof(ref->extents[0]) * ref->nritems);
4039 btrfs_free_leaf_ref(root, orig_ref);
4041 ref->root_gen = trans->transid;
4042 ref->bytenr = buf->start;
4043 ref->owner = btrfs_header_owner(buf);
4044 ref->generation = btrfs_header_generation(buf);
4045 ret = btrfs_add_leaf_ref(root, ref, 0);
4047 btrfs_free_leaf_ref(root, ref);
4052 static int noinline invalidate_extent_cache(struct btrfs_root *root,
4053 struct extent_buffer *leaf,
4054 struct btrfs_block_group_cache *group,
4055 struct btrfs_root *target_root)
4057 struct btrfs_key key;
4058 struct inode *inode = NULL;
4059 struct btrfs_file_extent_item *fi;
4061 u64 skip_objectid = 0;
4065 nritems = btrfs_header_nritems(leaf);
4066 for (i = 0; i < nritems; i++) {
4067 btrfs_item_key_to_cpu(leaf, &key, i);
4068 if (key.objectid == skip_objectid ||
4069 key.type != BTRFS_EXTENT_DATA_KEY)
4071 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4072 if (btrfs_file_extent_type(leaf, fi) ==
4073 BTRFS_FILE_EXTENT_INLINE)
4075 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
4077 if (!inode || inode->i_ino != key.objectid) {
4079 inode = btrfs_ilookup(target_root->fs_info->sb,
4080 key.objectid, target_root, 1);
4083 skip_objectid = key.objectid;
4086 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4088 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4089 key.offset + num_bytes - 1, GFP_NOFS);
4090 mutex_lock(&BTRFS_I(inode)->extent_mutex);
4091 btrfs_drop_extent_cache(inode, key.offset,
4092 key.offset + num_bytes - 1, 1);
4093 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
4094 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4095 key.offset + num_bytes - 1, GFP_NOFS);
4102 static int noinline replace_extents_in_leaf(struct btrfs_trans_handle *trans,
4103 struct btrfs_root *root,
4104 struct extent_buffer *leaf,
4105 struct btrfs_block_group_cache *group,
4106 struct inode *reloc_inode)
4108 struct btrfs_key key;
4109 struct btrfs_key extent_key;
4110 struct btrfs_file_extent_item *fi;
4111 struct btrfs_leaf_ref *ref;
4112 struct disk_extent *new_extent;
4121 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
4122 BUG_ON(!new_extent);
4124 ref = btrfs_lookup_leaf_ref(root, leaf->start);
4128 nritems = btrfs_header_nritems(leaf);
4129 for (i = 0; i < nritems; i++) {
4130 btrfs_item_key_to_cpu(leaf, &key, i);
4131 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
4133 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4134 if (btrfs_file_extent_type(leaf, fi) ==
4135 BTRFS_FILE_EXTENT_INLINE)
4137 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
4138 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
4143 if (bytenr >= group->key.objectid + group->key.offset ||
4144 bytenr + num_bytes <= group->key.objectid)
4147 extent_key.objectid = bytenr;
4148 extent_key.offset = num_bytes;
4149 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
4151 ret = get_new_locations(reloc_inode, &extent_key,
4152 group->key.objectid, 1,
4153 &new_extent, &nr_extent);
4158 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
4159 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
4160 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
4161 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
4163 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
4164 btrfs_set_file_extent_disk_bytenr(leaf, fi,
4165 new_extent->disk_bytenr);
4166 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4167 new_extent->disk_num_bytes);
4168 new_extent->offset += btrfs_file_extent_offset(leaf, fi);
4169 btrfs_set_file_extent_offset(leaf, fi, new_extent->offset);
4170 btrfs_mark_buffer_dirty(leaf);
4172 ret = btrfs_inc_extent_ref(trans, root,
4173 new_extent->disk_bytenr,
4174 new_extent->disk_num_bytes,
4176 root->root_key.objectid,
4177 trans->transid, key.objectid);
4179 ret = btrfs_free_extent(trans, root,
4180 bytenr, num_bytes, leaf->start,
4181 btrfs_header_owner(leaf),
4182 btrfs_header_generation(leaf),
4188 BUG_ON(ext_index + 1 != ref->nritems);
4189 btrfs_free_leaf_ref(root, ref);
4193 int btrfs_free_reloc_root(struct btrfs_root *root)
4195 struct btrfs_root *reloc_root;
4197 if (root->reloc_root) {
4198 reloc_root = root->reloc_root;
4199 root->reloc_root = NULL;
4200 list_add(&reloc_root->dead_list,
4201 &root->fs_info->dead_reloc_roots);
4206 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
4208 struct btrfs_trans_handle *trans;
4209 struct btrfs_root *reloc_root;
4210 struct btrfs_root *prev_root = NULL;
4211 struct list_head dead_roots;
4215 INIT_LIST_HEAD(&dead_roots);
4216 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
4218 while (!list_empty(&dead_roots)) {
4219 reloc_root = list_entry(dead_roots.prev,
4220 struct btrfs_root, dead_list);
4221 list_del_init(&reloc_root->dead_list);
4223 BUG_ON(reloc_root->commit_root != NULL);
4225 trans = btrfs_join_transaction(root, 1);
4228 mutex_lock(&root->fs_info->drop_mutex);
4229 ret = btrfs_drop_snapshot(trans, reloc_root);
4232 mutex_unlock(&root->fs_info->drop_mutex);
4234 nr = trans->blocks_used;
4235 ret = btrfs_end_transaction(trans, root);
4237 btrfs_btree_balance_dirty(root, nr);
4240 free_extent_buffer(reloc_root->node);
4242 ret = btrfs_del_root(trans, root->fs_info->tree_root,
4243 &reloc_root->root_key);
4245 mutex_unlock(&root->fs_info->drop_mutex);
4247 nr = trans->blocks_used;
4248 ret = btrfs_end_transaction(trans, root);
4250 btrfs_btree_balance_dirty(root, nr);
4253 prev_root = reloc_root;
4256 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
4262 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
4264 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
4268 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
4270 struct btrfs_root *reloc_root;
4271 struct btrfs_trans_handle *trans;
4272 struct btrfs_key location;
4276 mutex_lock(&root->fs_info->tree_reloc_mutex);
4277 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
4279 found = !list_empty(&root->fs_info->dead_reloc_roots);
4280 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4283 trans = btrfs_start_transaction(root, 1);
4285 ret = btrfs_commit_transaction(trans, root);
4289 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4290 location.offset = (u64)-1;
4291 location.type = BTRFS_ROOT_ITEM_KEY;
4293 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
4294 BUG_ON(!reloc_root);
4295 btrfs_orphan_cleanup(reloc_root);
4299 static int noinline init_reloc_tree(struct btrfs_trans_handle *trans,
4300 struct btrfs_root *root)
4302 struct btrfs_root *reloc_root;
4303 struct extent_buffer *eb;
4304 struct btrfs_root_item *root_item;
4305 struct btrfs_key root_key;
4308 BUG_ON(!root->ref_cows);
4309 if (root->reloc_root)
4312 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
4315 ret = btrfs_copy_root(trans, root, root->commit_root,
4316 &eb, BTRFS_TREE_RELOC_OBJECTID);
4319 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4320 root_key.offset = root->root_key.objectid;
4321 root_key.type = BTRFS_ROOT_ITEM_KEY;
4323 memcpy(root_item, &root->root_item, sizeof(root_item));
4324 btrfs_set_root_refs(root_item, 0);
4325 btrfs_set_root_bytenr(root_item, eb->start);
4326 btrfs_set_root_level(root_item, btrfs_header_level(eb));
4327 memset(&root_item->drop_progress, 0, sizeof(root_item->drop_progress));
4328 root_item->drop_level = 0;
4330 btrfs_tree_unlock(eb);
4331 free_extent_buffer(eb);
4333 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
4334 &root_key, root_item);
4338 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
4340 BUG_ON(!reloc_root);
4341 reloc_root->last_trans = trans->transid;
4342 reloc_root->commit_root = NULL;
4343 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
4345 root->reloc_root = reloc_root;
4350 * Core function of space balance.
4352 * The idea is using reloc trees to relocate tree blocks in reference
4353 * counted roots. There is one reloc tree for each subvol, all reloc
4354 * trees share same key objectid. Reloc trees are snapshots of the
4355 * latest committed roots (subvol root->commit_root). To relocate a tree
4356 * block referenced by a subvol, the code COW the block through the reloc
4357 * tree, then update pointer in the subvol to point to the new block.
4358 * Since all reloc trees share same key objectid, we can easily do special
4359 * handing to share tree blocks between reloc trees. Once a tree block has
4360 * been COWed in one reloc tree, we can use the result when the same block
4361 * is COWed again through other reloc trees.
4363 static int noinline relocate_one_path(struct btrfs_trans_handle *trans,
4364 struct btrfs_root *root,
4365 struct btrfs_path *path,
4366 struct btrfs_key *first_key,
4367 struct btrfs_ref_path *ref_path,
4368 struct btrfs_block_group_cache *group,
4369 struct inode *reloc_inode)
4371 struct btrfs_root *reloc_root;
4372 struct extent_buffer *eb = NULL;
4373 struct btrfs_key *keys;
4377 int lowest_level = 0;
4381 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
4382 lowest_level = ref_path->owner_objectid;
4384 if (is_cowonly_root(ref_path->root_objectid)) {
4385 path->lowest_level = lowest_level;
4386 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
4388 path->lowest_level = 0;
4389 btrfs_release_path(root, path);
4393 keys = kzalloc(sizeof(*keys) * BTRFS_MAX_LEVEL, GFP_NOFS);
4395 nodes = kzalloc(sizeof(*nodes) * BTRFS_MAX_LEVEL, GFP_NOFS);
4398 mutex_lock(&root->fs_info->tree_reloc_mutex);
4399 ret = init_reloc_tree(trans, root);
4401 reloc_root = root->reloc_root;
4403 path->lowest_level = lowest_level;
4404 ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 0);
4407 * get relocation mapping for tree blocks in the path
4409 lowest_merge = BTRFS_MAX_LEVEL;
4410 for (level = BTRFS_MAX_LEVEL - 1; level >= lowest_level; level--) {
4412 eb = path->nodes[level];
4413 if (!eb || eb == reloc_root->node)
4415 ret = btrfs_get_reloc_mapping(reloc_root, eb->start, eb->len,
4420 btrfs_item_key_to_cpu(eb, &keys[level], 0);
4422 btrfs_node_key_to_cpu(eb, &keys[level], 0);
4423 nodes[level] = new_bytenr;
4424 lowest_merge = level;
4428 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4429 eb = path->nodes[0];
4430 if (btrfs_header_generation(eb) < trans->transid)
4434 btrfs_release_path(reloc_root, path);
4436 * merge tree blocks that already relocated in other reloc trees
4438 if (lowest_merge != BTRFS_MAX_LEVEL) {
4439 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
4444 * cow any tree blocks that still haven't been relocated
4446 ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 1);
4449 * if we are relocating data block group, update extent pointers
4450 * in the newly created tree leaf.
4452 eb = path->nodes[0];
4453 if (update_refs && nodes[0] != eb->start) {
4454 ret = replace_extents_in_leaf(trans, reloc_root, eb, group,
4459 memset(keys, 0, sizeof(*keys) * BTRFS_MAX_LEVEL);
4460 memset(nodes, 0, sizeof(*nodes) * BTRFS_MAX_LEVEL);
4461 for (level = BTRFS_MAX_LEVEL - 1; level >= lowest_level; level--) {
4462 eb = path->nodes[level];
4463 if (!eb || eb == reloc_root->node)
4465 BUG_ON(btrfs_header_owner(eb) != BTRFS_TREE_RELOC_OBJECTID);
4466 nodes[level] = eb->start;
4468 btrfs_item_key_to_cpu(eb, &keys[level], 0);
4470 btrfs_node_key_to_cpu(eb, &keys[level], 0);
4473 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4474 eb = path->nodes[0];
4475 extent_buffer_get(eb);
4477 btrfs_release_path(reloc_root, path);
4479 * replace tree blocks in the fs tree with tree blocks in
4482 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
4485 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4486 ret = invalidate_extent_cache(reloc_root, eb, group, root);
4488 free_extent_buffer(eb);
4490 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4492 path->lowest_level = 0;
4498 static int noinline relocate_tree_block(struct btrfs_trans_handle *trans,
4499 struct btrfs_root *root,
4500 struct btrfs_path *path,
4501 struct btrfs_key *first_key,
4502 struct btrfs_ref_path *ref_path)
4507 if (root == root->fs_info->extent_root ||
4508 root == root->fs_info->chunk_root ||
4509 root == root->fs_info->dev_root) {
4511 mutex_lock(&root->fs_info->alloc_mutex);
4514 ret = relocate_one_path(trans, root, path, first_key,
4515 ref_path, NULL, NULL);
4518 if (root == root->fs_info->extent_root)
4519 btrfs_extent_post_op(trans, root);
4521 mutex_unlock(&root->fs_info->alloc_mutex);
4526 static int noinline del_extent_zero(struct btrfs_trans_handle *trans,
4527 struct btrfs_root *extent_root,
4528 struct btrfs_path *path,
4529 struct btrfs_key *extent_key)
4533 mutex_lock(&extent_root->fs_info->alloc_mutex);
4534 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
4537 ret = btrfs_del_item(trans, extent_root, path);
4539 btrfs_release_path(extent_root, path);
4540 mutex_unlock(&extent_root->fs_info->alloc_mutex);
4544 static struct btrfs_root noinline *read_ref_root(struct btrfs_fs_info *fs_info,
4545 struct btrfs_ref_path *ref_path)
4547 struct btrfs_key root_key;
4549 root_key.objectid = ref_path->root_objectid;
4550 root_key.type = BTRFS_ROOT_ITEM_KEY;
4551 if (is_cowonly_root(ref_path->root_objectid))
4552 root_key.offset = 0;
4554 root_key.offset = (u64)-1;
4556 return btrfs_read_fs_root_no_name(fs_info, &root_key);
4559 static int noinline relocate_one_extent(struct btrfs_root *extent_root,
4560 struct btrfs_path *path,
4561 struct btrfs_key *extent_key,
4562 struct btrfs_block_group_cache *group,
4563 struct inode *reloc_inode, int pass)
4565 struct btrfs_trans_handle *trans;
4566 struct btrfs_root *found_root;
4567 struct btrfs_ref_path *ref_path = NULL;
4568 struct disk_extent *new_extents = NULL;
4573 struct btrfs_key first_key;
4576 mutex_unlock(&extent_root->fs_info->alloc_mutex);
4578 trans = btrfs_start_transaction(extent_root, 1);
4581 if (extent_key->objectid == 0) {
4582 ret = del_extent_zero(trans, extent_root, path, extent_key);
4586 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
4592 for (loops = 0; ; loops++) {
4594 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
4595 extent_key->objectid);
4597 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
4604 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
4605 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
4608 found_root = read_ref_root(extent_root->fs_info, ref_path);
4609 BUG_ON(!found_root);
4611 * for reference counted tree, only process reference paths
4612 * rooted at the latest committed root.
4614 if (found_root->ref_cows &&
4615 ref_path->root_generation != found_root->root_key.offset)
4618 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4621 * copy data extents to new locations
4623 u64 group_start = group->key.objectid;
4624 ret = relocate_data_extent(reloc_inode,
4633 level = ref_path->owner_objectid;
4636 if (prev_block != ref_path->nodes[level]) {
4637 struct extent_buffer *eb;
4638 u64 block_start = ref_path->nodes[level];
4639 u64 block_size = btrfs_level_size(found_root, level);
4641 eb = read_tree_block(found_root, block_start,
4643 btrfs_tree_lock(eb);
4644 BUG_ON(level != btrfs_header_level(eb));
4647 btrfs_item_key_to_cpu(eb, &first_key, 0);
4649 btrfs_node_key_to_cpu(eb, &first_key, 0);
4651 btrfs_tree_unlock(eb);
4652 free_extent_buffer(eb);
4653 prev_block = block_start;
4656 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
4659 * use fallback method to process the remaining
4663 u64 group_start = group->key.objectid;
4664 ret = get_new_locations(reloc_inode,
4672 btrfs_record_root_in_trans(found_root);
4673 ret = replace_one_extent(trans, found_root,
4675 &first_key, ref_path,
4676 new_extents, nr_extents);
4682 btrfs_record_root_in_trans(found_root);
4683 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
4684 ret = relocate_tree_block(trans, found_root, path,
4685 &first_key, ref_path);
4688 * try to update data extent references while
4689 * keeping metadata shared between snapshots.
4691 ret = relocate_one_path(trans, found_root, path,
4692 &first_key, ref_path,
4693 group, reloc_inode);
4700 btrfs_end_transaction(trans, extent_root);
4703 mutex_lock(&extent_root->fs_info->alloc_mutex);
4707 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
4710 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
4711 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
4713 num_devices = root->fs_info->fs_devices->num_devices;
4714 if (num_devices == 1) {
4715 stripped |= BTRFS_BLOCK_GROUP_DUP;
4716 stripped = flags & ~stripped;
4718 /* turn raid0 into single device chunks */
4719 if (flags & BTRFS_BLOCK_GROUP_RAID0)
4722 /* turn mirroring into duplication */
4723 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
4724 BTRFS_BLOCK_GROUP_RAID10))
4725 return stripped | BTRFS_BLOCK_GROUP_DUP;
4728 /* they already had raid on here, just return */
4729 if (flags & stripped)
4732 stripped |= BTRFS_BLOCK_GROUP_DUP;
4733 stripped = flags & ~stripped;
4735 /* switch duplicated blocks with raid1 */
4736 if (flags & BTRFS_BLOCK_GROUP_DUP)
4737 return stripped | BTRFS_BLOCK_GROUP_RAID1;
4739 /* turn single device chunks into raid0 */
4740 return stripped | BTRFS_BLOCK_GROUP_RAID0;
4745 int __alloc_chunk_for_shrink(struct btrfs_root *root,
4746 struct btrfs_block_group_cache *shrink_block_group,
4749 struct btrfs_trans_handle *trans;
4750 u64 new_alloc_flags;
4753 spin_lock(&shrink_block_group->lock);
4754 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
4755 spin_unlock(&shrink_block_group->lock);
4756 mutex_unlock(&root->fs_info->alloc_mutex);
4758 trans = btrfs_start_transaction(root, 1);
4759 mutex_lock(&root->fs_info->alloc_mutex);
4760 spin_lock(&shrink_block_group->lock);
4762 new_alloc_flags = update_block_group_flags(root,
4763 shrink_block_group->flags);
4764 if (new_alloc_flags != shrink_block_group->flags) {
4766 btrfs_block_group_used(&shrink_block_group->item);
4768 calc = shrink_block_group->key.offset;
4770 spin_unlock(&shrink_block_group->lock);
4772 do_chunk_alloc(trans, root->fs_info->extent_root,
4773 calc + 2 * 1024 * 1024, new_alloc_flags, force);
4775 mutex_unlock(&root->fs_info->alloc_mutex);
4776 btrfs_end_transaction(trans, root);
4777 mutex_lock(&root->fs_info->alloc_mutex);
4779 spin_unlock(&shrink_block_group->lock);
4783 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4784 struct btrfs_root *root,
4785 u64 objectid, u64 size)
4787 struct btrfs_path *path;
4788 struct btrfs_inode_item *item;
4789 struct extent_buffer *leaf;
4792 path = btrfs_alloc_path();
4796 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4800 leaf = path->nodes[0];
4801 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4802 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4803 btrfs_set_inode_generation(leaf, item, 1);
4804 btrfs_set_inode_size(leaf, item, size);
4805 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4806 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NODATASUM);
4807 btrfs_mark_buffer_dirty(leaf);
4808 btrfs_release_path(root, path);
4810 btrfs_free_path(path);
4814 static struct inode noinline *create_reloc_inode(struct btrfs_fs_info *fs_info,
4815 struct btrfs_block_group_cache *group)
4817 struct inode *inode = NULL;
4818 struct btrfs_trans_handle *trans;
4819 struct btrfs_root *root;
4820 struct btrfs_key root_key;
4821 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4824 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4825 root_key.type = BTRFS_ROOT_ITEM_KEY;
4826 root_key.offset = (u64)-1;
4827 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
4829 return ERR_CAST(root);
4831 trans = btrfs_start_transaction(root, 1);
4834 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
4838 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
4841 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
4842 group->key.offset, 0);
4845 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
4846 if (inode->i_state & I_NEW) {
4847 BTRFS_I(inode)->root = root;
4848 BTRFS_I(inode)->location.objectid = objectid;
4849 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
4850 BTRFS_I(inode)->location.offset = 0;
4851 btrfs_read_locked_inode(inode);
4852 unlock_new_inode(inode);
4853 BUG_ON(is_bad_inode(inode));
4858 err = btrfs_orphan_add(trans, inode);
4860 btrfs_end_transaction(trans, root);
4864 inode = ERR_PTR(err);
4869 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
4871 struct btrfs_trans_handle *trans;
4872 struct btrfs_path *path;
4873 struct btrfs_fs_info *info = root->fs_info;
4874 struct extent_buffer *leaf;
4875 struct inode *reloc_inode;
4876 struct btrfs_block_group_cache *block_group;
4877 struct btrfs_key key;
4885 root = root->fs_info->extent_root;
4887 block_group = btrfs_lookup_block_group(info, group_start);
4888 BUG_ON(!block_group);
4890 printk("btrfs relocating block group %llu flags %llu\n",
4891 (unsigned long long)block_group->key.objectid,
4892 (unsigned long long)block_group->flags);
4894 path = btrfs_alloc_path();
4897 reloc_inode = create_reloc_inode(info, block_group);
4898 BUG_ON(IS_ERR(reloc_inode));
4900 mutex_lock(&root->fs_info->alloc_mutex);
4902 __alloc_chunk_for_shrink(root, block_group, 1);
4903 block_group->ro = 1;
4904 block_group->space_info->total_bytes -= block_group->key.offset;
4906 mutex_unlock(&root->fs_info->alloc_mutex);
4908 btrfs_start_delalloc_inodes(info->tree_root);
4909 btrfs_wait_ordered_extents(info->tree_root, 0);
4913 key.objectid = block_group->key.objectid;
4916 cur_byte = key.objectid;
4918 trans = btrfs_start_transaction(info->tree_root, 1);
4919 btrfs_commit_transaction(trans, info->tree_root);
4921 mutex_lock(&root->fs_info->cleaner_mutex);
4922 btrfs_clean_old_snapshots(info->tree_root);
4923 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
4924 mutex_unlock(&root->fs_info->cleaner_mutex);
4926 mutex_lock(&root->fs_info->alloc_mutex);
4929 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4933 leaf = path->nodes[0];
4934 nritems = btrfs_header_nritems(leaf);
4935 if (path->slots[0] >= nritems) {
4936 ret = btrfs_next_leaf(root, path);
4943 leaf = path->nodes[0];
4944 nritems = btrfs_header_nritems(leaf);
4947 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4949 if (key.objectid >= block_group->key.objectid +
4950 block_group->key.offset)
4953 if (progress && need_resched()) {
4954 btrfs_release_path(root, path);
4955 mutex_unlock(&root->fs_info->alloc_mutex);
4957 mutex_lock(&root->fs_info->alloc_mutex);
4963 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
4964 key.objectid + key.offset <= cur_byte) {
4970 cur_byte = key.objectid + key.offset;
4971 btrfs_release_path(root, path);
4973 __alloc_chunk_for_shrink(root, block_group, 0);
4974 ret = relocate_one_extent(root, path, &key, block_group,
4978 key.objectid = cur_byte;
4983 btrfs_release_path(root, path);
4984 mutex_unlock(&root->fs_info->alloc_mutex);
4987 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
4988 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
4989 WARN_ON(reloc_inode->i_mapping->nrpages);
4992 if (total_found > 0) {
4993 printk("btrfs found %llu extents in pass %d\n",
4994 (unsigned long long)total_found, pass);
4999 /* delete reloc_inode */
5002 /* unpin extents in this range */
5003 trans = btrfs_start_transaction(info->tree_root, 1);
5004 btrfs_commit_transaction(trans, info->tree_root);
5006 mutex_lock(&root->fs_info->alloc_mutex);
5008 spin_lock(&block_group->lock);
5009 WARN_ON(block_group->pinned > 0);
5010 WARN_ON(block_group->reserved > 0);
5011 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
5012 spin_unlock(&block_group->lock);
5015 mutex_unlock(&root->fs_info->alloc_mutex);
5016 btrfs_free_path(path);
5020 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
5021 struct btrfs_key *key)
5024 struct btrfs_key found_key;
5025 struct extent_buffer *leaf;
5028 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
5033 slot = path->slots[0];
5034 leaf = path->nodes[0];
5035 if (slot >= btrfs_header_nritems(leaf)) {
5036 ret = btrfs_next_leaf(root, path);
5043 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5045 if (found_key.objectid >= key->objectid &&
5046 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
5057 int btrfs_free_block_groups(struct btrfs_fs_info *info)
5059 struct btrfs_block_group_cache *block_group;
5062 mutex_lock(&info->alloc_mutex);
5063 spin_lock(&info->block_group_cache_lock);
5064 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
5065 block_group = rb_entry(n, struct btrfs_block_group_cache,
5068 spin_unlock(&info->block_group_cache_lock);
5069 btrfs_remove_free_space_cache(block_group);
5070 spin_lock(&info->block_group_cache_lock);
5072 rb_erase(&block_group->cache_node,
5073 &info->block_group_cache_tree);
5074 spin_lock(&block_group->space_info->lock);
5075 list_del(&block_group->list);
5076 spin_unlock(&block_group->space_info->lock);
5079 spin_unlock(&info->block_group_cache_lock);
5080 mutex_unlock(&info->alloc_mutex);
5084 int btrfs_read_block_groups(struct btrfs_root *root)
5086 struct btrfs_path *path;
5088 struct btrfs_block_group_cache *cache;
5089 struct btrfs_fs_info *info = root->fs_info;
5090 struct btrfs_space_info *space_info;
5091 struct btrfs_key key;
5092 struct btrfs_key found_key;
5093 struct extent_buffer *leaf;
5095 root = info->extent_root;
5098 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5099 path = btrfs_alloc_path();
5103 mutex_lock(&root->fs_info->alloc_mutex);
5105 ret = find_first_block_group(root, path, &key);
5113 leaf = path->nodes[0];
5114 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5115 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5121 spin_lock_init(&cache->lock);
5122 INIT_LIST_HEAD(&cache->list);
5123 read_extent_buffer(leaf, &cache->item,
5124 btrfs_item_ptr_offset(leaf, path->slots[0]),
5125 sizeof(cache->item));
5126 memcpy(&cache->key, &found_key, sizeof(found_key));
5128 key.objectid = found_key.objectid + found_key.offset;
5129 btrfs_release_path(root, path);
5130 cache->flags = btrfs_block_group_flags(&cache->item);
5132 ret = update_space_info(info, cache->flags, found_key.offset,
5133 btrfs_block_group_used(&cache->item),
5136 cache->space_info = space_info;
5137 spin_lock(&space_info->lock);
5138 list_add(&cache->list, &space_info->block_groups);
5139 spin_unlock(&space_info->lock);
5141 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5144 set_avail_alloc_bits(root->fs_info, cache->flags);
5148 btrfs_free_path(path);
5149 mutex_unlock(&root->fs_info->alloc_mutex);
5153 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
5154 struct btrfs_root *root, u64 bytes_used,
5155 u64 type, u64 chunk_objectid, u64 chunk_offset,
5159 struct btrfs_root *extent_root;
5160 struct btrfs_block_group_cache *cache;
5162 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
5163 extent_root = root->fs_info->extent_root;
5165 root->fs_info->last_trans_new_blockgroup = trans->transid;
5167 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5171 cache->key.objectid = chunk_offset;
5172 cache->key.offset = size;
5173 spin_lock_init(&cache->lock);
5174 INIT_LIST_HEAD(&cache->list);
5175 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5177 btrfs_set_block_group_used(&cache->item, bytes_used);
5178 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
5179 cache->flags = type;
5180 btrfs_set_block_group_flags(&cache->item, type);
5182 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
5183 &cache->space_info);
5185 spin_lock(&cache->space_info->lock);
5186 list_add(&cache->list, &cache->space_info->block_groups);
5187 spin_unlock(&cache->space_info->lock);
5189 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5192 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
5193 sizeof(cache->item));
5196 finish_current_insert(trans, extent_root);
5197 ret = del_pending_extents(trans, extent_root);
5199 set_avail_alloc_bits(extent_root->fs_info, type);
5204 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
5205 struct btrfs_root *root, u64 group_start)
5207 struct btrfs_path *path;
5208 struct btrfs_block_group_cache *block_group;
5209 struct btrfs_key key;
5212 BUG_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
5213 root = root->fs_info->extent_root;
5215 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
5216 BUG_ON(!block_group);
5218 memcpy(&key, &block_group->key, sizeof(key));
5220 path = btrfs_alloc_path();
5223 btrfs_remove_free_space_cache(block_group);
5224 rb_erase(&block_group->cache_node,
5225 &root->fs_info->block_group_cache_tree);
5226 spin_lock(&block_group->space_info->lock);
5227 list_del(&block_group->list);
5228 spin_unlock(&block_group->space_info->lock);
5231 memset(shrink_block_group, 0, sizeof(*shrink_block_group));
5232 kfree(shrink_block_group);
5235 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
5241 ret = btrfs_del_item(trans, root, path);
5243 btrfs_free_path(path);