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);
1154 if (ret == -EEXIST && shared) {
1155 struct btrfs_leaf_ref *old;
1156 old = btrfs_lookup_leaf_ref(root, ref->bytenr);
1158 btrfs_remove_leaf_ref(root, old);
1159 btrfs_free_leaf_ref(root, old);
1160 ret = btrfs_add_leaf_ref(root, ref, shared);
1163 btrfs_free_leaf_ref(root, ref);
1169 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1170 struct extent_buffer *orig_buf, struct extent_buffer *buf,
1177 u64 orig_generation;
1179 u32 nr_file_extents = 0;
1180 struct btrfs_key key;
1181 struct btrfs_file_extent_item *fi;
1186 int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
1187 u64, u64, u64, u64, u64, u64, u64, u64);
1189 ref_root = btrfs_header_owner(buf);
1190 ref_generation = btrfs_header_generation(buf);
1191 orig_root = btrfs_header_owner(orig_buf);
1192 orig_generation = btrfs_header_generation(orig_buf);
1194 nritems = btrfs_header_nritems(buf);
1195 level = btrfs_header_level(buf);
1197 if (root->ref_cows) {
1198 process_func = __btrfs_inc_extent_ref;
1201 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1204 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1206 process_func = __btrfs_update_extent_ref;
1209 for (i = 0; i < nritems; i++) {
1212 btrfs_item_key_to_cpu(buf, &key, i);
1213 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1215 fi = btrfs_item_ptr(buf, i,
1216 struct btrfs_file_extent_item);
1217 if (btrfs_file_extent_type(buf, fi) ==
1218 BTRFS_FILE_EXTENT_INLINE)
1220 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1226 maybe_lock_mutex(root);
1227 ret = process_func(trans, root, bytenr,
1228 orig_buf->start, buf->start,
1229 orig_root, ref_root,
1230 orig_generation, ref_generation,
1232 maybe_unlock_mutex(root);
1240 bytenr = btrfs_node_blockptr(buf, i);
1241 maybe_lock_mutex(root);
1242 ret = process_func(trans, root, bytenr,
1243 orig_buf->start, buf->start,
1244 orig_root, ref_root,
1245 orig_generation, ref_generation,
1247 maybe_unlock_mutex(root);
1258 *nr_extents = nr_file_extents;
1260 *nr_extents = nritems;
1268 int btrfs_update_ref(struct btrfs_trans_handle *trans,
1269 struct btrfs_root *root, struct extent_buffer *orig_buf,
1270 struct extent_buffer *buf, int start_slot, int nr)
1277 u64 orig_generation;
1278 struct btrfs_key key;
1279 struct btrfs_file_extent_item *fi;
1285 BUG_ON(start_slot < 0);
1286 BUG_ON(start_slot + nr > btrfs_header_nritems(buf));
1288 ref_root = btrfs_header_owner(buf);
1289 ref_generation = btrfs_header_generation(buf);
1290 orig_root = btrfs_header_owner(orig_buf);
1291 orig_generation = btrfs_header_generation(orig_buf);
1292 level = btrfs_header_level(buf);
1294 if (!root->ref_cows) {
1296 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
1299 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID)
1303 for (i = 0, slot = start_slot; i < nr; i++, slot++) {
1306 btrfs_item_key_to_cpu(buf, &key, slot);
1307 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1309 fi = btrfs_item_ptr(buf, slot,
1310 struct btrfs_file_extent_item);
1311 if (btrfs_file_extent_type(buf, fi) ==
1312 BTRFS_FILE_EXTENT_INLINE)
1314 bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1317 maybe_lock_mutex(root);
1318 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1319 orig_buf->start, buf->start,
1320 orig_root, ref_root,
1321 orig_generation, ref_generation,
1323 maybe_unlock_mutex(root);
1327 bytenr = btrfs_node_blockptr(buf, slot);
1328 maybe_lock_mutex(root);
1329 ret = __btrfs_update_extent_ref(trans, root, bytenr,
1330 orig_buf->start, buf->start,
1331 orig_root, ref_root,
1332 orig_generation, ref_generation,
1334 maybe_unlock_mutex(root);
1345 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1346 struct btrfs_root *root,
1347 struct btrfs_path *path,
1348 struct btrfs_block_group_cache *cache)
1352 struct btrfs_root *extent_root = root->fs_info->extent_root;
1354 struct extent_buffer *leaf;
1356 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1361 leaf = path->nodes[0];
1362 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1363 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1364 btrfs_mark_buffer_dirty(leaf);
1365 btrfs_release_path(extent_root, path);
1367 finish_current_insert(trans, extent_root);
1368 pending_ret = del_pending_extents(trans, extent_root);
1377 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1378 struct btrfs_root *root)
1380 struct btrfs_block_group_cache *cache, *entry;
1384 struct btrfs_path *path;
1387 path = btrfs_alloc_path();
1391 mutex_lock(&root->fs_info->alloc_mutex);
1394 spin_lock(&root->fs_info->block_group_cache_lock);
1395 for (n = rb_first(&root->fs_info->block_group_cache_tree);
1396 n; n = rb_next(n)) {
1397 entry = rb_entry(n, struct btrfs_block_group_cache,
1404 spin_unlock(&root->fs_info->block_group_cache_lock);
1410 last += cache->key.offset;
1412 err = write_one_cache_group(trans, root,
1415 * if we fail to write the cache group, we want
1416 * to keep it marked dirty in hopes that a later
1424 btrfs_free_path(path);
1425 mutex_unlock(&root->fs_info->alloc_mutex);
1429 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1430 u64 total_bytes, u64 bytes_used,
1431 struct btrfs_space_info **space_info)
1433 struct btrfs_space_info *found;
1435 found = __find_space_info(info, flags);
1437 found->total_bytes += total_bytes;
1438 found->bytes_used += bytes_used;
1440 *space_info = found;
1443 found = kmalloc(sizeof(*found), GFP_NOFS);
1447 list_add(&found->list, &info->space_info);
1448 INIT_LIST_HEAD(&found->block_groups);
1449 spin_lock_init(&found->lock);
1450 found->flags = flags;
1451 found->total_bytes = total_bytes;
1452 found->bytes_used = bytes_used;
1453 found->bytes_pinned = 0;
1454 found->bytes_reserved = 0;
1456 found->force_alloc = 0;
1457 *space_info = found;
1461 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1463 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1464 BTRFS_BLOCK_GROUP_RAID1 |
1465 BTRFS_BLOCK_GROUP_RAID10 |
1466 BTRFS_BLOCK_GROUP_DUP);
1468 if (flags & BTRFS_BLOCK_GROUP_DATA)
1469 fs_info->avail_data_alloc_bits |= extra_flags;
1470 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1471 fs_info->avail_metadata_alloc_bits |= extra_flags;
1472 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1473 fs_info->avail_system_alloc_bits |= extra_flags;
1477 static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags)
1479 u64 num_devices = root->fs_info->fs_devices->num_devices;
1481 if (num_devices == 1)
1482 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
1483 if (num_devices < 4)
1484 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
1486 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
1487 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
1488 BTRFS_BLOCK_GROUP_RAID10))) {
1489 flags &= ~BTRFS_BLOCK_GROUP_DUP;
1492 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
1493 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
1494 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
1497 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
1498 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
1499 (flags & BTRFS_BLOCK_GROUP_RAID10) |
1500 (flags & BTRFS_BLOCK_GROUP_DUP)))
1501 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
1505 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1506 struct btrfs_root *extent_root, u64 alloc_bytes,
1507 u64 flags, int force)
1509 struct btrfs_space_info *space_info;
1513 int ret = 0, waited = 0;
1515 flags = reduce_alloc_profile(extent_root, flags);
1517 space_info = __find_space_info(extent_root->fs_info, flags);
1519 ret = update_space_info(extent_root->fs_info, flags,
1523 BUG_ON(!space_info);
1525 if (space_info->force_alloc) {
1527 space_info->force_alloc = 0;
1529 if (space_info->full)
1532 thresh = div_factor(space_info->total_bytes, 6);
1534 (space_info->bytes_used + space_info->bytes_pinned +
1535 space_info->bytes_reserved + alloc_bytes) < thresh)
1538 while (!mutex_trylock(&extent_root->fs_info->chunk_mutex)) {
1541 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1543 mutex_lock(&extent_root->fs_info->alloc_mutex);
1547 if (waited && space_info->full)
1550 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1551 if (ret == -ENOSPC) {
1552 printk("space info full %Lu\n", flags);
1553 space_info->full = 1;
1558 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1559 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1563 mutex_unlock(&extent_root->fs_info->chunk_mutex);
1568 static int update_block_group(struct btrfs_trans_handle *trans,
1569 struct btrfs_root *root,
1570 u64 bytenr, u64 num_bytes, int alloc,
1573 struct btrfs_block_group_cache *cache;
1574 struct btrfs_fs_info *info = root->fs_info;
1575 u64 total = num_bytes;
1579 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1581 cache = btrfs_lookup_block_group(info, bytenr);
1585 byte_in_group = bytenr - cache->key.objectid;
1586 WARN_ON(byte_in_group > cache->key.offset);
1588 spin_lock(&cache->lock);
1590 old_val = btrfs_block_group_used(&cache->item);
1591 num_bytes = min(total, cache->key.offset - byte_in_group);
1593 old_val += num_bytes;
1594 cache->space_info->bytes_used += num_bytes;
1595 btrfs_set_block_group_used(&cache->item, old_val);
1596 spin_unlock(&cache->lock);
1598 old_val -= num_bytes;
1599 cache->space_info->bytes_used -= num_bytes;
1600 btrfs_set_block_group_used(&cache->item, old_val);
1601 spin_unlock(&cache->lock);
1604 ret = btrfs_add_free_space(cache, bytenr,
1611 bytenr += num_bytes;
1616 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
1618 struct btrfs_block_group_cache *cache;
1620 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
1624 return cache->key.objectid;
1627 int btrfs_update_pinned_extents(struct btrfs_root *root,
1628 u64 bytenr, u64 num, int pin)
1631 struct btrfs_block_group_cache *cache;
1632 struct btrfs_fs_info *fs_info = root->fs_info;
1634 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1636 set_extent_dirty(&fs_info->pinned_extents,
1637 bytenr, bytenr + num - 1, GFP_NOFS);
1639 clear_extent_dirty(&fs_info->pinned_extents,
1640 bytenr, bytenr + num - 1, GFP_NOFS);
1643 cache = btrfs_lookup_block_group(fs_info, bytenr);
1645 len = min(num, cache->key.offset -
1646 (bytenr - cache->key.objectid));
1648 spin_lock(&cache->lock);
1649 cache->pinned += len;
1650 cache->space_info->bytes_pinned += len;
1651 spin_unlock(&cache->lock);
1652 fs_info->total_pinned += len;
1654 spin_lock(&cache->lock);
1655 cache->pinned -= len;
1656 cache->space_info->bytes_pinned -= len;
1657 spin_unlock(&cache->lock);
1658 fs_info->total_pinned -= len;
1666 static int update_reserved_extents(struct btrfs_root *root,
1667 u64 bytenr, u64 num, int reserve)
1670 struct btrfs_block_group_cache *cache;
1671 struct btrfs_fs_info *fs_info = root->fs_info;
1673 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1675 cache = btrfs_lookup_block_group(fs_info, bytenr);
1677 len = min(num, cache->key.offset -
1678 (bytenr - cache->key.objectid));
1680 spin_lock(&cache->lock);
1681 cache->reserved += len;
1682 cache->space_info->bytes_reserved += len;
1683 spin_unlock(&cache->lock);
1685 spin_lock(&cache->lock);
1686 cache->reserved -= len;
1687 cache->space_info->bytes_reserved -= len;
1688 spin_unlock(&cache->lock);
1696 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1701 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1705 ret = find_first_extent_bit(pinned_extents, last,
1706 &start, &end, EXTENT_DIRTY);
1709 set_extent_dirty(copy, start, end, GFP_NOFS);
1715 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1716 struct btrfs_root *root,
1717 struct extent_io_tree *unpin)
1722 struct btrfs_block_group_cache *cache;
1724 mutex_lock(&root->fs_info->alloc_mutex);
1726 ret = find_first_extent_bit(unpin, 0, &start, &end,
1730 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
1731 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1732 cache = btrfs_lookup_block_group(root->fs_info, start);
1734 btrfs_add_free_space(cache, start, end - start + 1);
1735 if (need_resched()) {
1736 mutex_unlock(&root->fs_info->alloc_mutex);
1738 mutex_lock(&root->fs_info->alloc_mutex);
1741 mutex_unlock(&root->fs_info->alloc_mutex);
1745 static int finish_current_insert(struct btrfs_trans_handle *trans,
1746 struct btrfs_root *extent_root)
1751 struct btrfs_fs_info *info = extent_root->fs_info;
1752 struct btrfs_path *path;
1753 struct btrfs_extent_ref *ref;
1754 struct pending_extent_op *extent_op;
1755 struct btrfs_key key;
1756 struct btrfs_extent_item extent_item;
1760 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
1761 btrfs_set_stack_extent_refs(&extent_item, 1);
1762 path = btrfs_alloc_path();
1765 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1766 &end, EXTENT_LOCKED);
1770 ret = get_state_private(&info->extent_ins, start, &priv);
1772 extent_op = (struct pending_extent_op *)(unsigned long)priv;
1774 if (extent_op->type == PENDING_EXTENT_INSERT) {
1775 key.objectid = start;
1776 key.offset = end + 1 - start;
1777 key.type = BTRFS_EXTENT_ITEM_KEY;
1778 err = btrfs_insert_item(trans, extent_root, &key,
1779 &extent_item, sizeof(extent_item));
1782 clear_extent_bits(&info->extent_ins, start, end,
1783 EXTENT_LOCKED, GFP_NOFS);
1785 err = insert_extent_backref(trans, extent_root, path,
1786 start, extent_op->parent,
1787 extent_root->root_key.objectid,
1788 extent_op->generation,
1791 } else if (extent_op->type == PENDING_BACKREF_UPDATE) {
1792 err = lookup_extent_backref(trans, extent_root, path,
1793 start, extent_op->orig_parent,
1794 extent_root->root_key.objectid,
1795 extent_op->orig_generation,
1796 extent_op->level, 0);
1799 clear_extent_bits(&info->extent_ins, start, end,
1800 EXTENT_LOCKED, GFP_NOFS);
1802 key.objectid = start;
1803 key.offset = extent_op->parent;
1804 key.type = BTRFS_EXTENT_REF_KEY;
1805 err = btrfs_set_item_key_safe(trans, extent_root, path,
1808 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1809 struct btrfs_extent_ref);
1810 btrfs_set_ref_generation(path->nodes[0], ref,
1811 extent_op->generation);
1812 btrfs_mark_buffer_dirty(path->nodes[0]);
1813 btrfs_release_path(extent_root, path);
1819 if (need_resched()) {
1820 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1822 mutex_lock(&extent_root->fs_info->alloc_mutex);
1825 btrfs_free_path(path);
1829 static int pin_down_bytes(struct btrfs_trans_handle *trans,
1830 struct btrfs_root *root,
1831 u64 bytenr, u64 num_bytes, int is_data)
1834 struct extent_buffer *buf;
1836 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1840 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1844 /* we can reuse a block if it hasn't been written
1845 * and it is from this transaction. We can't
1846 * reuse anything from the tree log root because
1847 * it has tiny sub-transactions.
1849 if (btrfs_buffer_uptodate(buf, 0) &&
1850 btrfs_try_tree_lock(buf)) {
1851 u64 header_owner = btrfs_header_owner(buf);
1852 u64 header_transid = btrfs_header_generation(buf);
1853 if (header_owner != BTRFS_TREE_LOG_OBJECTID &&
1854 header_owner != BTRFS_TREE_RELOC_OBJECTID &&
1855 header_transid == trans->transid &&
1856 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
1857 clean_tree_block(NULL, root, buf);
1858 btrfs_tree_unlock(buf);
1859 free_extent_buffer(buf);
1862 btrfs_tree_unlock(buf);
1864 free_extent_buffer(buf);
1866 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
1873 * remove an extent from the root, returns 0 on success
1875 static int __free_extent(struct btrfs_trans_handle *trans,
1876 struct btrfs_root *root,
1877 u64 bytenr, u64 num_bytes, u64 parent,
1878 u64 root_objectid, u64 ref_generation,
1879 u64 owner_objectid, int pin, int mark_free)
1881 struct btrfs_path *path;
1882 struct btrfs_key key;
1883 struct btrfs_fs_info *info = root->fs_info;
1884 struct btrfs_root *extent_root = info->extent_root;
1885 struct extent_buffer *leaf;
1887 int extent_slot = 0;
1888 int found_extent = 0;
1890 struct btrfs_extent_item *ei;
1893 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1894 key.objectid = bytenr;
1895 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1896 key.offset = num_bytes;
1897 path = btrfs_alloc_path();
1902 ret = lookup_extent_backref(trans, extent_root, path,
1903 bytenr, parent, root_objectid,
1904 ref_generation, owner_objectid, 1);
1906 struct btrfs_key found_key;
1907 extent_slot = path->slots[0];
1908 while(extent_slot > 0) {
1910 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1912 if (found_key.objectid != bytenr)
1914 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1915 found_key.offset == num_bytes) {
1919 if (path->slots[0] - extent_slot > 5)
1922 if (!found_extent) {
1923 ret = remove_extent_backref(trans, extent_root, path);
1925 btrfs_release_path(extent_root, path);
1926 ret = btrfs_search_slot(trans, extent_root,
1929 extent_slot = path->slots[0];
1932 btrfs_print_leaf(extent_root, path->nodes[0]);
1934 printk("Unable to find ref byte nr %Lu root %Lu "
1935 "gen %Lu owner %Lu\n", bytenr,
1936 root_objectid, ref_generation, owner_objectid);
1939 leaf = path->nodes[0];
1940 ei = btrfs_item_ptr(leaf, extent_slot,
1941 struct btrfs_extent_item);
1942 refs = btrfs_extent_refs(leaf, ei);
1945 btrfs_set_extent_refs(leaf, ei, refs);
1947 btrfs_mark_buffer_dirty(leaf);
1949 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1950 struct btrfs_extent_ref *ref;
1951 ref = btrfs_item_ptr(leaf, path->slots[0],
1952 struct btrfs_extent_ref);
1953 BUG_ON(btrfs_ref_num_refs(leaf, ref) != 1);
1954 /* if the back ref and the extent are next to each other
1955 * they get deleted below in one shot
1957 path->slots[0] = extent_slot;
1959 } else if (found_extent) {
1960 /* otherwise delete the extent back ref */
1961 ret = remove_extent_backref(trans, extent_root, path);
1963 /* if refs are 0, we need to setup the path for deletion */
1965 btrfs_release_path(extent_root, path);
1966 ret = btrfs_search_slot(trans, extent_root, &key, path,
1975 #ifdef BIO_RW_DISCARD
1976 u64 map_length = num_bytes;
1977 struct btrfs_multi_bio *multi = NULL;
1981 ret = pin_down_bytes(trans, root, bytenr, num_bytes,
1982 owner_objectid >= BTRFS_FIRST_FREE_OBJECTID);
1988 /* block accounting for super block */
1989 spin_lock_irq(&info->delalloc_lock);
1990 super_used = btrfs_super_bytes_used(&info->super_copy);
1991 btrfs_set_super_bytes_used(&info->super_copy,
1992 super_used - num_bytes);
1993 spin_unlock_irq(&info->delalloc_lock);
1995 /* block accounting for root item */
1996 root_used = btrfs_root_used(&root->root_item);
1997 btrfs_set_root_used(&root->root_item,
1998 root_used - num_bytes);
1999 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
2002 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
2006 #ifdef BIO_RW_DISCARD
2007 /* Tell the block device(s) that the sectors can be discarded */
2008 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
2009 bytenr, &map_length, &multi, 0);
2011 struct btrfs_bio_stripe *stripe = multi->stripes;
2014 if (map_length > num_bytes)
2015 map_length = num_bytes;
2017 for (i = 0; i < multi->num_stripes; i++, stripe++) {
2018 blkdev_issue_discard(stripe->dev->bdev,
2019 stripe->physical >> 9,
2026 btrfs_free_path(path);
2027 finish_current_insert(trans, extent_root);
2032 * find all the blocks marked as pending in the radix tree and remove
2033 * them from the extent map
2035 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
2036 btrfs_root *extent_root)
2044 struct extent_io_tree *pending_del;
2045 struct extent_io_tree *extent_ins;
2046 struct pending_extent_op *extent_op;
2048 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
2049 extent_ins = &extent_root->fs_info->extent_ins;
2050 pending_del = &extent_root->fs_info->pending_del;
2053 ret = find_first_extent_bit(pending_del, 0, &start, &end,
2058 ret = get_state_private(pending_del, start, &priv);
2060 extent_op = (struct pending_extent_op *)(unsigned long)priv;
2062 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
2065 ret = pin_down_bytes(trans, extent_root, start,
2066 end + 1 - start, 0);
2067 mark_free = ret > 0;
2068 if (!test_range_bit(extent_ins, start, end,
2069 EXTENT_LOCKED, 0)) {
2071 ret = __free_extent(trans, extent_root,
2072 start, end + 1 - start,
2073 extent_op->orig_parent,
2074 extent_root->root_key.objectid,
2075 extent_op->orig_generation,
2076 extent_op->level, 0, mark_free);
2080 ret = get_state_private(extent_ins, start, &priv);
2082 extent_op = (struct pending_extent_op *)
2083 (unsigned long)priv;
2085 clear_extent_bits(extent_ins, start, end,
2086 EXTENT_LOCKED, GFP_NOFS);
2088 if (extent_op->type == PENDING_BACKREF_UPDATE)
2091 ret = update_block_group(trans, extent_root, start,
2092 end + 1 - start, 0, mark_free);
2099 if (need_resched()) {
2100 mutex_unlock(&extent_root->fs_info->alloc_mutex);
2102 mutex_lock(&extent_root->fs_info->alloc_mutex);
2109 * remove an extent from the root, returns 0 on success
2111 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
2112 struct btrfs_root *root,
2113 u64 bytenr, u64 num_bytes, u64 parent,
2114 u64 root_objectid, u64 ref_generation,
2115 u64 owner_objectid, int pin)
2117 struct btrfs_root *extent_root = root->fs_info->extent_root;
2121 WARN_ON(num_bytes < root->sectorsize);
2122 if (root == extent_root) {
2123 struct pending_extent_op *extent_op;
2125 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2128 extent_op->type = PENDING_EXTENT_DELETE;
2129 extent_op->bytenr = bytenr;
2130 extent_op->num_bytes = num_bytes;
2131 extent_op->parent = parent;
2132 extent_op->orig_parent = parent;
2133 extent_op->generation = ref_generation;
2134 extent_op->orig_generation = ref_generation;
2135 extent_op->level = (int)owner_objectid;
2137 set_extent_bits(&root->fs_info->pending_del,
2138 bytenr, bytenr + num_bytes - 1,
2139 EXTENT_LOCKED, GFP_NOFS);
2140 set_state_private(&root->fs_info->pending_del,
2141 bytenr, (unsigned long)extent_op);
2144 /* if metadata always pin */
2145 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
2146 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2147 struct btrfs_block_group_cache *cache;
2149 /* btrfs_free_reserved_extent */
2150 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
2152 btrfs_add_free_space(cache, bytenr, num_bytes);
2153 update_reserved_extents(root, bytenr, num_bytes, 0);
2159 /* if data pin when any transaction has committed this */
2160 if (ref_generation != trans->transid)
2163 ret = __free_extent(trans, root, bytenr, num_bytes, parent,
2164 root_objectid, ref_generation,
2165 owner_objectid, pin, pin == 0);
2167 finish_current_insert(trans, root->fs_info->extent_root);
2168 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
2169 return ret ? ret : pending_ret;
2172 int btrfs_free_extent(struct btrfs_trans_handle *trans,
2173 struct btrfs_root *root,
2174 u64 bytenr, u64 num_bytes, u64 parent,
2175 u64 root_objectid, u64 ref_generation,
2176 u64 owner_objectid, int pin)
2180 maybe_lock_mutex(root);
2181 ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, parent,
2182 root_objectid, ref_generation,
2183 owner_objectid, pin);
2184 maybe_unlock_mutex(root);
2188 static u64 stripe_align(struct btrfs_root *root, u64 val)
2190 u64 mask = ((u64)root->stripesize - 1);
2191 u64 ret = (val + mask) & ~mask;
2196 * walks the btree of allocated extents and find a hole of a given size.
2197 * The key ins is changed to record the hole:
2198 * ins->objectid == block start
2199 * ins->flags = BTRFS_EXTENT_ITEM_KEY
2200 * ins->offset == number of blocks
2201 * Any available blocks before search_start are skipped.
2203 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
2204 struct btrfs_root *orig_root,
2205 u64 num_bytes, u64 empty_size,
2206 u64 search_start, u64 search_end,
2207 u64 hint_byte, struct btrfs_key *ins,
2208 u64 exclude_start, u64 exclude_nr,
2212 u64 orig_search_start;
2213 struct btrfs_root * root = orig_root->fs_info->extent_root;
2214 struct btrfs_fs_info *info = root->fs_info;
2215 u64 total_needed = num_bytes;
2216 u64 *last_ptr = NULL;
2217 struct btrfs_block_group_cache *block_group;
2218 int chunk_alloc_done = 0;
2219 int empty_cluster = 2 * 1024 * 1024;
2220 int allowed_chunk_alloc = 0;
2222 WARN_ON(num_bytes < root->sectorsize);
2223 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
2225 if (orig_root->ref_cows || empty_size)
2226 allowed_chunk_alloc = 1;
2228 if (data & BTRFS_BLOCK_GROUP_METADATA) {
2229 last_ptr = &root->fs_info->last_alloc;
2230 empty_cluster = 256 * 1024;
2233 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
2234 last_ptr = &root->fs_info->last_data_alloc;
2238 hint_byte = *last_ptr;
2240 empty_size += empty_cluster;
2243 search_start = max(search_start, first_logical_byte(root, 0));
2244 orig_search_start = search_start;
2246 search_start = max(search_start, hint_byte);
2247 total_needed += empty_size;
2250 block_group = btrfs_lookup_block_group(info, search_start);
2252 block_group = btrfs_lookup_first_block_group(info,
2256 * Ok this looks a little tricky, buts its really simple. First if we
2257 * didn't find a block group obviously we want to start over.
2258 * Secondly, if the block group we found does not match the type we
2259 * need, and we have a last_ptr and its not 0, chances are the last
2260 * allocation we made was at the end of the block group, so lets go
2261 * ahead and skip the looking through the rest of the block groups and
2262 * start at the beginning. This helps with metadata allocations,
2263 * since you are likely to have a bunch of data block groups to search
2264 * through first before you realize that you need to start over, so go
2265 * ahead and start over and save the time.
2267 if (!block_group || (!block_group_bits(block_group, data) &&
2268 last_ptr && *last_ptr)) {
2269 if (search_start != orig_search_start) {
2270 if (last_ptr && *last_ptr) {
2271 total_needed += empty_cluster;
2274 search_start = orig_search_start;
2276 } else if (!chunk_alloc_done && allowed_chunk_alloc) {
2277 ret = do_chunk_alloc(trans, root,
2278 num_bytes + 2 * 1024 * 1024,
2283 chunk_alloc_done = 1;
2284 search_start = orig_search_start;
2293 * this is going to seach through all of the existing block groups it
2294 * can find, so if we don't find something we need to see if we can
2295 * allocate what we need.
2297 ret = find_free_space(root, &block_group, &search_start,
2298 total_needed, data);
2299 if (ret == -ENOSPC) {
2301 * instead of allocating, start at the original search start
2302 * and see if there is something to be found, if not then we
2305 if (search_start != orig_search_start) {
2306 if (last_ptr && *last_ptr) {
2308 total_needed += empty_cluster;
2310 search_start = orig_search_start;
2315 * we've already allocated, we're pretty screwed
2317 if (chunk_alloc_done) {
2319 } else if (!allowed_chunk_alloc && block_group &&
2320 block_group_bits(block_group, data)) {
2321 block_group->space_info->force_alloc = 1;
2323 } else if (!allowed_chunk_alloc) {
2327 ret = do_chunk_alloc(trans, root, num_bytes + 2 * 1024 * 1024,
2333 chunk_alloc_done = 1;
2335 search_start = block_group->key.objectid +
2336 block_group->key.offset;
2338 search_start = orig_search_start;
2345 search_start = stripe_align(root, search_start);
2346 ins->objectid = search_start;
2347 ins->offset = num_bytes;
2349 if (ins->objectid + num_bytes >= search_end) {
2350 search_start = orig_search_start;
2351 if (chunk_alloc_done) {
2358 if (ins->objectid + num_bytes >
2359 block_group->key.objectid + block_group->key.offset) {
2360 if (search_start == orig_search_start && chunk_alloc_done) {
2364 search_start = block_group->key.objectid +
2365 block_group->key.offset;
2369 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
2370 ins->objectid < exclude_start + exclude_nr)) {
2371 search_start = exclude_start + exclude_nr;
2375 if (!(data & BTRFS_BLOCK_GROUP_DATA))
2376 trans->block_group = block_group;
2378 ins->offset = num_bytes;
2380 *last_ptr = ins->objectid + ins->offset;
2382 btrfs_super_total_bytes(&root->fs_info->super_copy))
2391 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
2393 struct btrfs_block_group_cache *cache;
2394 struct list_head *l;
2396 printk(KERN_INFO "space_info has %Lu free, is %sfull\n",
2397 info->total_bytes - info->bytes_used - info->bytes_pinned -
2398 info->bytes_reserved, (info->full) ? "" : "not ");
2400 spin_lock(&info->lock);
2401 list_for_each(l, &info->block_groups) {
2402 cache = list_entry(l, struct btrfs_block_group_cache, list);
2403 spin_lock(&cache->lock);
2404 printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used "
2405 "%Lu pinned %Lu reserved\n",
2406 cache->key.objectid, cache->key.offset,
2407 btrfs_block_group_used(&cache->item),
2408 cache->pinned, cache->reserved);
2409 btrfs_dump_free_space(cache, bytes);
2410 spin_unlock(&cache->lock);
2412 spin_unlock(&info->lock);
2415 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2416 struct btrfs_root *root,
2417 u64 num_bytes, u64 min_alloc_size,
2418 u64 empty_size, u64 hint_byte,
2419 u64 search_end, struct btrfs_key *ins,
2423 u64 search_start = 0;
2425 struct btrfs_fs_info *info = root->fs_info;
2426 struct btrfs_block_group_cache *cache;
2429 alloc_profile = info->avail_data_alloc_bits &
2430 info->data_alloc_profile;
2431 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2432 } else if (root == root->fs_info->chunk_root) {
2433 alloc_profile = info->avail_system_alloc_bits &
2434 info->system_alloc_profile;
2435 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2437 alloc_profile = info->avail_metadata_alloc_bits &
2438 info->metadata_alloc_profile;
2439 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2442 data = reduce_alloc_profile(root, data);
2444 * the only place that sets empty_size is btrfs_realloc_node, which
2445 * is not called recursively on allocations
2447 if (empty_size || root->ref_cows) {
2448 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
2449 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2451 BTRFS_BLOCK_GROUP_METADATA |
2452 (info->metadata_alloc_profile &
2453 info->avail_metadata_alloc_bits), 0);
2455 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2456 num_bytes + 2 * 1024 * 1024, data, 0);
2459 WARN_ON(num_bytes < root->sectorsize);
2460 ret = find_free_extent(trans, root, num_bytes, empty_size,
2461 search_start, search_end, hint_byte, ins,
2462 trans->alloc_exclude_start,
2463 trans->alloc_exclude_nr, data);
2465 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
2466 num_bytes = num_bytes >> 1;
2467 num_bytes = num_bytes & ~(root->sectorsize - 1);
2468 num_bytes = max(num_bytes, min_alloc_size);
2469 do_chunk_alloc(trans, root->fs_info->extent_root,
2470 num_bytes, data, 1);
2474 struct btrfs_space_info *sinfo;
2476 sinfo = __find_space_info(root->fs_info, data);
2477 printk("allocation failed flags %Lu, wanted %Lu\n",
2479 dump_space_info(sinfo, num_bytes);
2482 cache = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2484 printk(KERN_ERR "Unable to find block group for %Lu\n", ins->objectid);
2488 ret = btrfs_remove_free_space(cache, ins->objectid, ins->offset);
2493 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
2495 struct btrfs_block_group_cache *cache;
2497 maybe_lock_mutex(root);
2498 cache = btrfs_lookup_block_group(root->fs_info, start);
2500 printk(KERN_ERR "Unable to find block group for %Lu\n", start);
2501 maybe_unlock_mutex(root);
2504 btrfs_add_free_space(cache, start, len);
2505 update_reserved_extents(root, start, len, 0);
2506 maybe_unlock_mutex(root);
2510 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2511 struct btrfs_root *root,
2512 u64 num_bytes, u64 min_alloc_size,
2513 u64 empty_size, u64 hint_byte,
2514 u64 search_end, struct btrfs_key *ins,
2518 maybe_lock_mutex(root);
2519 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
2520 empty_size, hint_byte, search_end, ins,
2522 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2523 maybe_unlock_mutex(root);
2527 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2528 struct btrfs_root *root, u64 parent,
2529 u64 root_objectid, u64 ref_generation,
2530 u64 owner, struct btrfs_key *ins)
2536 u64 num_bytes = ins->offset;
2538 struct btrfs_fs_info *info = root->fs_info;
2539 struct btrfs_root *extent_root = info->extent_root;
2540 struct btrfs_extent_item *extent_item;
2541 struct btrfs_extent_ref *ref;
2542 struct btrfs_path *path;
2543 struct btrfs_key keys[2];
2546 parent = ins->objectid;
2548 /* block accounting for super block */
2549 spin_lock_irq(&info->delalloc_lock);
2550 super_used = btrfs_super_bytes_used(&info->super_copy);
2551 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
2552 spin_unlock_irq(&info->delalloc_lock);
2554 /* block accounting for root item */
2555 root_used = btrfs_root_used(&root->root_item);
2556 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
2558 if (root == extent_root) {
2559 struct pending_extent_op *extent_op;
2561 extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
2564 extent_op->type = PENDING_EXTENT_INSERT;
2565 extent_op->bytenr = ins->objectid;
2566 extent_op->num_bytes = ins->offset;
2567 extent_op->parent = parent;
2568 extent_op->orig_parent = 0;
2569 extent_op->generation = ref_generation;
2570 extent_op->orig_generation = 0;
2571 extent_op->level = (int)owner;
2573 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2574 ins->objectid + ins->offset - 1,
2575 EXTENT_LOCKED, GFP_NOFS);
2576 set_state_private(&root->fs_info->extent_ins,
2577 ins->objectid, (unsigned long)extent_op);
2581 memcpy(&keys[0], ins, sizeof(*ins));
2582 keys[1].objectid = ins->objectid;
2583 keys[1].type = BTRFS_EXTENT_REF_KEY;
2584 keys[1].offset = parent;
2585 sizes[0] = sizeof(*extent_item);
2586 sizes[1] = sizeof(*ref);
2588 path = btrfs_alloc_path();
2591 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
2595 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2596 struct btrfs_extent_item);
2597 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
2598 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
2599 struct btrfs_extent_ref);
2601 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
2602 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
2603 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
2604 btrfs_set_ref_num_refs(path->nodes[0], ref, 1);
2606 btrfs_mark_buffer_dirty(path->nodes[0]);
2608 trans->alloc_exclude_start = 0;
2609 trans->alloc_exclude_nr = 0;
2610 btrfs_free_path(path);
2611 finish_current_insert(trans, extent_root);
2612 pending_ret = del_pending_extents(trans, extent_root);
2622 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
2624 printk("update block group failed for %Lu %Lu\n",
2625 ins->objectid, ins->offset);
2632 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2633 struct btrfs_root *root, u64 parent,
2634 u64 root_objectid, u64 ref_generation,
2635 u64 owner, struct btrfs_key *ins)
2639 if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
2641 maybe_lock_mutex(root);
2642 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
2643 ref_generation, owner, ins);
2644 update_reserved_extents(root, ins->objectid, ins->offset, 0);
2645 maybe_unlock_mutex(root);
2650 * this is used by the tree logging recovery code. It records that
2651 * an extent has been allocated and makes sure to clear the free
2652 * space cache bits as well
2654 int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
2655 struct btrfs_root *root, u64 parent,
2656 u64 root_objectid, u64 ref_generation,
2657 u64 owner, struct btrfs_key *ins)
2660 struct btrfs_block_group_cache *block_group;
2662 maybe_lock_mutex(root);
2663 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2664 cache_block_group(root, block_group);
2666 ret = btrfs_remove_free_space(block_group, ins->objectid, ins->offset);
2668 ret = __btrfs_alloc_reserved_extent(trans, root, parent, root_objectid,
2669 ref_generation, owner, ins);
2670 maybe_unlock_mutex(root);
2675 * finds a free extent and does all the dirty work required for allocation
2676 * returns the key for the extent through ins, and a tree buffer for
2677 * the first block of the extent through buf.
2679 * returns 0 if everything worked, non-zero otherwise.
2681 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
2682 struct btrfs_root *root,
2683 u64 num_bytes, u64 parent, u64 min_alloc_size,
2684 u64 root_objectid, u64 ref_generation,
2685 u64 owner_objectid, u64 empty_size, u64 hint_byte,
2686 u64 search_end, struct btrfs_key *ins, u64 data)
2690 maybe_lock_mutex(root);
2692 ret = __btrfs_reserve_extent(trans, root, num_bytes,
2693 min_alloc_size, empty_size, hint_byte,
2694 search_end, ins, data);
2696 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
2697 ret = __btrfs_alloc_reserved_extent(trans, root, parent,
2698 root_objectid, ref_generation,
2699 owner_objectid, ins);
2703 update_reserved_extents(root, ins->objectid, ins->offset, 1);
2705 maybe_unlock_mutex(root);
2709 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
2710 struct btrfs_root *root,
2711 u64 bytenr, u32 blocksize)
2713 struct extent_buffer *buf;
2715 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
2717 return ERR_PTR(-ENOMEM);
2718 btrfs_set_header_generation(buf, trans->transid);
2719 btrfs_tree_lock(buf);
2720 clean_tree_block(trans, root, buf);
2721 btrfs_set_buffer_uptodate(buf);
2722 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2723 set_extent_dirty(&root->dirty_log_pages, buf->start,
2724 buf->start + buf->len - 1, GFP_NOFS);
2726 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
2727 buf->start + buf->len - 1, GFP_NOFS);
2729 trans->blocks_used++;
2734 * helper function to allocate a block for a given tree
2735 * returns the tree buffer or NULL.
2737 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2738 struct btrfs_root *root,
2739 u32 blocksize, u64 parent,
2746 struct btrfs_key ins;
2748 struct extent_buffer *buf;
2750 ret = btrfs_alloc_extent(trans, root, blocksize, parent, blocksize,
2751 root_objectid, ref_generation, level,
2752 empty_size, hint, (u64)-1, &ins, 0);
2755 return ERR_PTR(ret);
2758 buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
2762 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
2763 struct btrfs_root *root, struct extent_buffer *leaf)
2766 u64 leaf_generation;
2767 struct btrfs_key key;
2768 struct btrfs_file_extent_item *fi;
2773 BUG_ON(!btrfs_is_leaf(leaf));
2774 nritems = btrfs_header_nritems(leaf);
2775 leaf_owner = btrfs_header_owner(leaf);
2776 leaf_generation = btrfs_header_generation(leaf);
2778 for (i = 0; i < nritems; i++) {
2782 btrfs_item_key_to_cpu(leaf, &key, i);
2783 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2785 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2786 if (btrfs_file_extent_type(leaf, fi) ==
2787 BTRFS_FILE_EXTENT_INLINE)
2790 * FIXME make sure to insert a trans record that
2791 * repeats the snapshot del on crash
2793 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2794 if (disk_bytenr == 0)
2797 mutex_lock(&root->fs_info->alloc_mutex);
2798 ret = __btrfs_free_extent(trans, root, disk_bytenr,
2799 btrfs_file_extent_disk_num_bytes(leaf, fi),
2800 leaf->start, leaf_owner, leaf_generation,
2802 mutex_unlock(&root->fs_info->alloc_mutex);
2805 atomic_inc(&root->fs_info->throttle_gen);
2806 wake_up(&root->fs_info->transaction_throttle);
2812 static int noinline cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
2813 struct btrfs_root *root,
2814 struct btrfs_leaf_ref *ref)
2818 struct btrfs_extent_info *info = ref->extents;
2820 for (i = 0; i < ref->nritems; i++) {
2821 mutex_lock(&root->fs_info->alloc_mutex);
2822 ret = __btrfs_free_extent(trans, root, info->bytenr,
2823 info->num_bytes, ref->bytenr,
2824 ref->owner, ref->generation,
2826 mutex_unlock(&root->fs_info->alloc_mutex);
2828 atomic_inc(&root->fs_info->throttle_gen);
2829 wake_up(&root->fs_info->transaction_throttle);
2839 int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len,
2844 ret = btrfs_lookup_extent_ref(NULL, root, start, len, refs);
2847 #if 0 // some debugging code in case we see problems here
2848 /* if the refs count is one, it won't get increased again. But
2849 * if the ref count is > 1, someone may be decreasing it at
2850 * the same time we are.
2853 struct extent_buffer *eb = NULL;
2854 eb = btrfs_find_create_tree_block(root, start, len);
2856 btrfs_tree_lock(eb);
2858 mutex_lock(&root->fs_info->alloc_mutex);
2859 ret = lookup_extent_ref(NULL, root, start, len, refs);
2861 mutex_unlock(&root->fs_info->alloc_mutex);
2864 btrfs_tree_unlock(eb);
2865 free_extent_buffer(eb);
2868 printk("block %llu went down to one during drop_snap\n",
2869 (unsigned long long)start);
2880 * helper function for drop_snapshot, this walks down the tree dropping ref
2881 * counts as it goes.
2883 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2884 struct btrfs_root *root,
2885 struct btrfs_path *path, int *level)
2891 struct extent_buffer *next;
2892 struct extent_buffer *cur;
2893 struct extent_buffer *parent;
2894 struct btrfs_leaf_ref *ref;
2899 WARN_ON(*level < 0);
2900 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2901 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
2902 path->nodes[*level]->len, &refs);
2908 * walk down to the last node level and free all the leaves
2910 while(*level >= 0) {
2911 WARN_ON(*level < 0);
2912 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2913 cur = path->nodes[*level];
2915 if (btrfs_header_level(cur) != *level)
2918 if (path->slots[*level] >=
2919 btrfs_header_nritems(cur))
2922 ret = btrfs_drop_leaf_ref(trans, root, cur);
2926 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2927 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2928 blocksize = btrfs_level_size(root, *level - 1);
2930 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
2933 parent = path->nodes[*level];
2934 root_owner = btrfs_header_owner(parent);
2935 root_gen = btrfs_header_generation(parent);
2936 path->slots[*level]++;
2938 mutex_lock(&root->fs_info->alloc_mutex);
2939 ret = __btrfs_free_extent(trans, root, bytenr,
2940 blocksize, parent->start,
2941 root_owner, root_gen,
2944 mutex_unlock(&root->fs_info->alloc_mutex);
2946 atomic_inc(&root->fs_info->throttle_gen);
2947 wake_up(&root->fs_info->transaction_throttle);
2953 * at this point, we have a single ref, and since the
2954 * only place referencing this extent is a dead root
2955 * the reference count should never go higher.
2956 * So, we don't need to check it again
2959 ref = btrfs_lookup_leaf_ref(root, bytenr);
2960 if (ref && ref->generation != ptr_gen) {
2961 btrfs_free_leaf_ref(root, ref);
2965 ret = cache_drop_leaf_ref(trans, root, ref);
2967 btrfs_remove_leaf_ref(root, ref);
2968 btrfs_free_leaf_ref(root, ref);
2972 if (printk_ratelimit()) {
2973 printk("leaf ref miss for bytenr %llu\n",
2974 (unsigned long long)bytenr);
2977 next = btrfs_find_tree_block(root, bytenr, blocksize);
2978 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2979 free_extent_buffer(next);
2981 next = read_tree_block(root, bytenr, blocksize,
2986 * this is a debugging check and can go away
2987 * the ref should never go all the way down to 1
2990 ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
2996 WARN_ON(*level <= 0);
2997 if (path->nodes[*level-1])
2998 free_extent_buffer(path->nodes[*level-1]);
2999 path->nodes[*level-1] = next;
3000 *level = btrfs_header_level(next);
3001 path->slots[*level] = 0;
3005 WARN_ON(*level < 0);
3006 WARN_ON(*level >= BTRFS_MAX_LEVEL);
3008 if (path->nodes[*level] == root->node) {
3009 parent = path->nodes[*level];
3010 bytenr = path->nodes[*level]->start;
3012 parent = path->nodes[*level + 1];
3013 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
3016 blocksize = btrfs_level_size(root, *level);
3017 root_owner = btrfs_header_owner(parent);
3018 root_gen = btrfs_header_generation(parent);
3020 mutex_lock(&root->fs_info->alloc_mutex);
3021 ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
3022 parent->start, root_owner, root_gen,
3024 mutex_unlock(&root->fs_info->alloc_mutex);
3025 free_extent_buffer(path->nodes[*level]);
3026 path->nodes[*level] = NULL;
3035 * helper for dropping snapshots. This walks back up the tree in the path
3036 * to find the first node higher up where we haven't yet gone through
3039 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
3040 struct btrfs_root *root,
3041 struct btrfs_path *path, int *level)
3045 struct btrfs_root_item *root_item = &root->root_item;
3050 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
3051 slot = path->slots[i];
3052 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
3053 struct extent_buffer *node;
3054 struct btrfs_disk_key disk_key;
3055 node = path->nodes[i];
3058 WARN_ON(*level == 0);
3059 btrfs_node_key(node, &disk_key, path->slots[i]);
3060 memcpy(&root_item->drop_progress,
3061 &disk_key, sizeof(disk_key));
3062 root_item->drop_level = i;
3065 struct extent_buffer *parent;
3066 if (path->nodes[*level] == root->node)
3067 parent = path->nodes[*level];
3069 parent = path->nodes[*level + 1];
3071 root_owner = btrfs_header_owner(parent);
3072 root_gen = btrfs_header_generation(parent);
3073 ret = btrfs_free_extent(trans, root,
3074 path->nodes[*level]->start,
3075 path->nodes[*level]->len,
3076 parent->start, root_owner,
3077 root_gen, *level, 1);
3079 free_extent_buffer(path->nodes[*level]);
3080 path->nodes[*level] = NULL;
3088 * drop the reference count on the tree rooted at 'snap'. This traverses
3089 * the tree freeing any blocks that have a ref count of zero after being
3092 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
3098 struct btrfs_path *path;
3101 struct btrfs_root_item *root_item = &root->root_item;
3103 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
3104 path = btrfs_alloc_path();
3107 level = btrfs_header_level(root->node);
3109 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
3110 path->nodes[level] = root->node;
3111 extent_buffer_get(root->node);
3112 path->slots[level] = 0;
3114 struct btrfs_key key;
3115 struct btrfs_disk_key found_key;
3116 struct extent_buffer *node;
3118 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
3119 level = root_item->drop_level;
3120 path->lowest_level = level;
3121 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3126 node = path->nodes[level];
3127 btrfs_node_key(node, &found_key, path->slots[level]);
3128 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
3129 sizeof(found_key)));
3131 * unlock our path, this is safe because only this
3132 * function is allowed to delete this snapshot
3134 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
3135 if (path->nodes[i] && path->locks[i]) {
3137 btrfs_tree_unlock(path->nodes[i]);
3142 wret = walk_down_tree(trans, root, path, &level);
3148 wret = walk_up_tree(trans, root, path, &level);
3153 if (trans->transaction->in_commit) {
3157 atomic_inc(&root->fs_info->throttle_gen);
3158 wake_up(&root->fs_info->transaction_throttle);
3160 for (i = 0; i <= orig_level; i++) {
3161 if (path->nodes[i]) {
3162 free_extent_buffer(path->nodes[i]);
3163 path->nodes[i] = NULL;
3167 btrfs_free_path(path);
3171 static unsigned long calc_ra(unsigned long start, unsigned long last,
3174 return min(last, start + nr - 1);
3177 static int noinline relocate_inode_pages(struct inode *inode, u64 start,
3182 unsigned long first_index;
3183 unsigned long last_index;
3186 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3187 struct file_ra_state *ra;
3188 struct btrfs_ordered_extent *ordered;
3189 unsigned int total_read = 0;
3190 unsigned int total_dirty = 0;
3193 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3195 mutex_lock(&inode->i_mutex);
3196 first_index = start >> PAGE_CACHE_SHIFT;
3197 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
3199 /* make sure the dirty trick played by the caller work */
3200 ret = invalidate_inode_pages2_range(inode->i_mapping,
3201 first_index, last_index);
3205 file_ra_state_init(ra, inode->i_mapping);
3207 for (i = first_index ; i <= last_index; i++) {
3208 if (total_read % ra->ra_pages == 0) {
3209 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
3210 calc_ra(i, last_index, ra->ra_pages));
3214 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
3216 page = grab_cache_page(inode->i_mapping, i);
3221 if (!PageUptodate(page)) {
3222 btrfs_readpage(NULL, page);
3224 if (!PageUptodate(page)) {
3226 page_cache_release(page);
3231 wait_on_page_writeback(page);
3233 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
3234 page_end = page_start + PAGE_CACHE_SIZE - 1;
3235 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
3237 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3239 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3241 page_cache_release(page);
3242 btrfs_start_ordered_extent(inode, ordered, 1);
3243 btrfs_put_ordered_extent(ordered);
3246 set_page_extent_mapped(page);
3248 btrfs_set_extent_delalloc(inode, page_start, page_end);
3249 if (i == first_index)
3250 set_extent_bits(io_tree, page_start, page_end,
3251 EXTENT_BOUNDARY, GFP_NOFS);
3253 set_page_dirty(page);
3256 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3258 page_cache_release(page);
3263 mutex_unlock(&inode->i_mutex);
3264 balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
3268 static int noinline relocate_data_extent(struct inode *reloc_inode,
3269 struct btrfs_key *extent_key,
3272 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3273 struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree;
3274 struct extent_map *em;
3276 em = alloc_extent_map(GFP_NOFS);
3277 BUG_ON(!em || IS_ERR(em));
3279 em->start = extent_key->objectid - offset;
3280 em->len = extent_key->offset;
3281 em->block_start = extent_key->objectid;
3282 em->bdev = root->fs_info->fs_devices->latest_bdev;
3283 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3285 /* setup extent map to cheat btrfs_readpage */
3286 mutex_lock(&BTRFS_I(reloc_inode)->extent_mutex);
3289 spin_lock(&em_tree->lock);
3290 ret = add_extent_mapping(em_tree, em);
3291 spin_unlock(&em_tree->lock);
3292 if (ret != -EEXIST) {
3293 free_extent_map(em);
3296 btrfs_drop_extent_cache(reloc_inode, em->start,
3297 em->start + em->len - 1, 0);
3299 mutex_unlock(&BTRFS_I(reloc_inode)->extent_mutex);
3301 return relocate_inode_pages(reloc_inode, extent_key->objectid - offset,
3302 extent_key->offset);
3305 struct btrfs_ref_path {
3307 u64 nodes[BTRFS_MAX_LEVEL];
3309 u64 root_generation;
3316 struct disk_extent {
3323 static int is_cowonly_root(u64 root_objectid)
3325 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
3326 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
3327 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
3328 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
3329 root_objectid == BTRFS_TREE_LOG_OBJECTID)
3334 static int noinline __next_ref_path(struct btrfs_trans_handle *trans,
3335 struct btrfs_root *extent_root,
3336 struct btrfs_ref_path *ref_path,
3339 struct extent_buffer *leaf;
3340 struct btrfs_path *path;
3341 struct btrfs_extent_ref *ref;
3342 struct btrfs_key key;
3343 struct btrfs_key found_key;
3349 path = btrfs_alloc_path();
3353 mutex_lock(&extent_root->fs_info->alloc_mutex);
3356 ref_path->lowest_level = -1;
3357 ref_path->current_level = -1;
3361 level = ref_path->current_level - 1;
3362 while (level >= -1) {
3364 if (level < ref_path->lowest_level)
3368 bytenr = ref_path->nodes[level];
3370 bytenr = ref_path->extent_start;
3372 BUG_ON(bytenr == 0);
3374 parent = ref_path->nodes[level + 1];
3375 ref_path->nodes[level + 1] = 0;
3376 ref_path->current_level = level;
3377 BUG_ON(parent == 0);
3379 key.objectid = bytenr;
3380 key.offset = parent + 1;
3381 key.type = BTRFS_EXTENT_REF_KEY;
3383 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3388 leaf = path->nodes[0];
3389 nritems = btrfs_header_nritems(leaf);
3390 if (path->slots[0] >= nritems) {
3391 ret = btrfs_next_leaf(extent_root, path);
3396 leaf = path->nodes[0];
3399 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3400 if (found_key.objectid == bytenr &&
3401 found_key.type == BTRFS_EXTENT_REF_KEY)
3405 btrfs_release_path(extent_root, path);
3406 if (need_resched()) {
3407 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3409 mutex_lock(&extent_root->fs_info->alloc_mutex);
3412 /* reached lowest level */
3416 level = ref_path->current_level;
3417 while (level < BTRFS_MAX_LEVEL - 1) {
3420 bytenr = ref_path->nodes[level];
3422 bytenr = ref_path->extent_start;
3424 BUG_ON(bytenr == 0);
3426 key.objectid = bytenr;
3428 key.type = BTRFS_EXTENT_REF_KEY;
3430 ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0);
3434 leaf = path->nodes[0];
3435 nritems = btrfs_header_nritems(leaf);
3436 if (path->slots[0] >= nritems) {
3437 ret = btrfs_next_leaf(extent_root, path);
3441 /* the extent was freed by someone */
3442 if (ref_path->lowest_level == level)
3444 btrfs_release_path(extent_root, path);
3447 leaf = path->nodes[0];
3450 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3451 if (found_key.objectid != bytenr ||
3452 found_key.type != BTRFS_EXTENT_REF_KEY) {
3453 /* the extent was freed by someone */
3454 if (ref_path->lowest_level == level) {
3458 btrfs_release_path(extent_root, path);
3462 ref = btrfs_item_ptr(leaf, path->slots[0],
3463 struct btrfs_extent_ref);
3464 ref_objectid = btrfs_ref_objectid(leaf, ref);
3465 if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
3467 level = (int)ref_objectid;
3468 BUG_ON(level >= BTRFS_MAX_LEVEL);
3469 ref_path->lowest_level = level;
3470 ref_path->current_level = level;
3471 ref_path->nodes[level] = bytenr;
3473 WARN_ON(ref_objectid != level);
3476 WARN_ON(level != -1);
3480 if (ref_path->lowest_level == level) {
3481 ref_path->owner_objectid = ref_objectid;
3482 ref_path->num_refs = btrfs_ref_num_refs(leaf, ref);
3486 * the block is tree root or the block isn't in reference
3489 if (found_key.objectid == found_key.offset ||
3490 is_cowonly_root(btrfs_ref_root(leaf, ref))) {
3491 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3492 ref_path->root_generation =
3493 btrfs_ref_generation(leaf, ref);
3495 /* special reference from the tree log */
3496 ref_path->nodes[0] = found_key.offset;
3497 ref_path->current_level = 0;
3504 BUG_ON(ref_path->nodes[level] != 0);
3505 ref_path->nodes[level] = found_key.offset;
3506 ref_path->current_level = level;
3509 * the reference was created in the running transaction,
3510 * no need to continue walking up.
3512 if (btrfs_ref_generation(leaf, ref) == trans->transid) {
3513 ref_path->root_objectid = btrfs_ref_root(leaf, ref);
3514 ref_path->root_generation =
3515 btrfs_ref_generation(leaf, ref);
3520 btrfs_release_path(extent_root, path);
3521 if (need_resched()) {
3522 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3524 mutex_lock(&extent_root->fs_info->alloc_mutex);
3527 /* reached max tree level, but no tree root found. */
3530 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3531 btrfs_free_path(path);
3535 static int btrfs_first_ref_path(struct btrfs_trans_handle *trans,
3536 struct btrfs_root *extent_root,
3537 struct btrfs_ref_path *ref_path,
3540 memset(ref_path, 0, sizeof(*ref_path));
3541 ref_path->extent_start = extent_start;
3543 return __next_ref_path(trans, extent_root, ref_path, 1);
3546 static int btrfs_next_ref_path(struct btrfs_trans_handle *trans,
3547 struct btrfs_root *extent_root,
3548 struct btrfs_ref_path *ref_path)
3550 return __next_ref_path(trans, extent_root, ref_path, 0);
3553 static int noinline get_new_locations(struct inode *reloc_inode,
3554 struct btrfs_key *extent_key,
3555 u64 offset, int no_fragment,
3556 struct disk_extent **extents,
3559 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
3560 struct btrfs_path *path;
3561 struct btrfs_file_extent_item *fi;
3562 struct extent_buffer *leaf;
3563 struct disk_extent *exts = *extents;
3564 struct btrfs_key found_key;
3569 int max = *nr_extents;
3572 WARN_ON(!no_fragment && *extents);
3575 exts = kmalloc(sizeof(*exts) * max, GFP_NOFS);
3580 path = btrfs_alloc_path();
3583 cur_pos = extent_key->objectid - offset;
3584 last_byte = extent_key->objectid + extent_key->offset;
3585 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
3595 leaf = path->nodes[0];
3596 nritems = btrfs_header_nritems(leaf);
3597 if (path->slots[0] >= nritems) {
3598 ret = btrfs_next_leaf(root, path);
3603 leaf = path->nodes[0];
3606 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3607 if (found_key.offset != cur_pos ||
3608 found_key.type != BTRFS_EXTENT_DATA_KEY ||
3609 found_key.objectid != reloc_inode->i_ino)
3612 fi = btrfs_item_ptr(leaf, path->slots[0],
3613 struct btrfs_file_extent_item);
3614 if (btrfs_file_extent_type(leaf, fi) !=
3615 BTRFS_FILE_EXTENT_REG ||
3616 btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
3620 struct disk_extent *old = exts;
3622 exts = kzalloc(sizeof(*exts) * max, GFP_NOFS);
3623 memcpy(exts, old, sizeof(*exts) * nr);
3624 if (old != *extents)
3628 exts[nr].disk_bytenr =
3629 btrfs_file_extent_disk_bytenr(leaf, fi);
3630 exts[nr].disk_num_bytes =
3631 btrfs_file_extent_disk_num_bytes(leaf, fi);
3632 exts[nr].offset = btrfs_file_extent_offset(leaf, fi);
3633 exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3634 WARN_ON(exts[nr].offset > 0);
3635 WARN_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes);
3637 cur_pos += exts[nr].num_bytes;
3640 if (cur_pos + offset >= last_byte)
3650 WARN_ON(cur_pos + offset > last_byte);
3651 if (cur_pos + offset < last_byte) {
3657 btrfs_free_path(path);
3659 if (exts != *extents)
3668 static int noinline replace_one_extent(struct btrfs_trans_handle *trans,
3669 struct btrfs_root *root,
3670 struct btrfs_path *path,
3671 struct btrfs_key *extent_key,
3672 struct btrfs_key *leaf_key,
3673 struct btrfs_ref_path *ref_path,
3674 struct disk_extent *new_extents,
3677 struct extent_buffer *leaf;
3678 struct btrfs_file_extent_item *fi;
3679 struct inode *inode = NULL;
3680 struct btrfs_key key;
3688 int extent_locked = 0;
3691 memcpy(&key, leaf_key, sizeof(key));
3692 first_pos = INT_LIMIT(loff_t) - extent_key->offset;
3693 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3694 if (key.objectid < ref_path->owner_objectid ||
3695 (key.objectid == ref_path->owner_objectid &&
3696 key.type < BTRFS_EXTENT_DATA_KEY)) {
3697 key.objectid = ref_path->owner_objectid;
3698 key.type = BTRFS_EXTENT_DATA_KEY;
3704 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
3708 leaf = path->nodes[0];
3709 nritems = btrfs_header_nritems(leaf);
3711 if (extent_locked && ret > 0) {
3713 * the file extent item was modified by someone
3714 * before the extent got locked.
3716 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3717 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3718 lock_end, GFP_NOFS);
3722 if (path->slots[0] >= nritems) {
3723 if (++nr_scaned > 2)
3726 BUG_ON(extent_locked);
3727 ret = btrfs_next_leaf(root, path);
3732 leaf = path->nodes[0];
3733 nritems = btrfs_header_nritems(leaf);
3736 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3738 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
3739 if ((key.objectid > ref_path->owner_objectid) ||
3740 (key.objectid == ref_path->owner_objectid &&
3741 key.type > BTRFS_EXTENT_DATA_KEY) ||
3742 (key.offset >= first_pos + extent_key->offset))
3746 if (inode && key.objectid != inode->i_ino) {
3747 BUG_ON(extent_locked);
3748 btrfs_release_path(root, path);
3749 mutex_unlock(&inode->i_mutex);
3755 if (key.type != BTRFS_EXTENT_DATA_KEY) {
3760 fi = btrfs_item_ptr(leaf, path->slots[0],
3761 struct btrfs_file_extent_item);
3762 if ((btrfs_file_extent_type(leaf, fi) !=
3763 BTRFS_FILE_EXTENT_REG) ||
3764 (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3765 extent_key->objectid)) {
3771 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
3772 ext_offset = btrfs_file_extent_offset(leaf, fi);
3774 if (first_pos > key.offset - ext_offset)
3775 first_pos = key.offset - ext_offset;
3777 if (!extent_locked) {
3778 lock_start = key.offset;
3779 lock_end = lock_start + num_bytes - 1;
3781 BUG_ON(lock_start != key.offset);
3782 BUG_ON(lock_end - lock_start + 1 < num_bytes);
3786 btrfs_release_path(root, path);
3788 inode = btrfs_iget_locked(root->fs_info->sb,
3789 key.objectid, root);
3790 if (inode->i_state & I_NEW) {
3791 BTRFS_I(inode)->root = root;
3792 BTRFS_I(inode)->location.objectid =
3794 BTRFS_I(inode)->location.type =
3795 BTRFS_INODE_ITEM_KEY;
3796 BTRFS_I(inode)->location.offset = 0;
3797 btrfs_read_locked_inode(inode);
3798 unlock_new_inode(inode);
3801 * some code call btrfs_commit_transaction while
3802 * holding the i_mutex, so we can't use mutex_lock
3805 if (is_bad_inode(inode) ||
3806 !mutex_trylock(&inode->i_mutex)) {
3809 key.offset = (u64)-1;
3814 if (!extent_locked) {
3815 struct btrfs_ordered_extent *ordered;
3817 btrfs_release_path(root, path);
3819 lock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3820 lock_end, GFP_NOFS);
3821 ordered = btrfs_lookup_first_ordered_extent(inode,
3824 ordered->file_offset <= lock_end &&
3825 ordered->file_offset + ordered->len > lock_start) {
3826 unlock_extent(&BTRFS_I(inode)->io_tree,
3827 lock_start, lock_end, GFP_NOFS);
3828 btrfs_start_ordered_extent(inode, ordered, 1);
3829 btrfs_put_ordered_extent(ordered);
3830 key.offset += num_bytes;
3834 btrfs_put_ordered_extent(ordered);
3836 mutex_lock(&BTRFS_I(inode)->extent_mutex);
3841 if (nr_extents == 1) {
3842 /* update extent pointer in place */
3843 btrfs_set_file_extent_generation(leaf, fi,
3845 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3846 new_extents[0].disk_bytenr);
3847 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
3848 new_extents[0].disk_num_bytes);
3849 ext_offset += new_extents[0].offset;
3850 btrfs_set_file_extent_offset(leaf, fi, ext_offset);
3851 btrfs_mark_buffer_dirty(leaf);
3853 btrfs_drop_extent_cache(inode, key.offset,
3854 key.offset + num_bytes - 1, 0);
3856 ret = btrfs_inc_extent_ref(trans, root,
3857 new_extents[0].disk_bytenr,
3858 new_extents[0].disk_num_bytes,
3860 root->root_key.objectid,
3865 ret = btrfs_free_extent(trans, root,
3866 extent_key->objectid,
3869 btrfs_header_owner(leaf),
3870 btrfs_header_generation(leaf),
3874 btrfs_release_path(root, path);
3875 key.offset += num_bytes;
3881 * drop old extent pointer at first, then insert the
3882 * new pointers one bye one
3884 btrfs_release_path(root, path);
3885 ret = btrfs_drop_extents(trans, root, inode, key.offset,
3886 key.offset + num_bytes,
3887 key.offset, &alloc_hint);
3890 for (i = 0; i < nr_extents; i++) {
3891 if (ext_offset >= new_extents[i].num_bytes) {
3892 ext_offset -= new_extents[i].num_bytes;
3895 extent_len = min(new_extents[i].num_bytes -
3896 ext_offset, num_bytes);
3898 ret = btrfs_insert_empty_item(trans, root,
3903 leaf = path->nodes[0];
3904 fi = btrfs_item_ptr(leaf, path->slots[0],
3905 struct btrfs_file_extent_item);
3906 btrfs_set_file_extent_generation(leaf, fi,
3908 btrfs_set_file_extent_type(leaf, fi,
3909 BTRFS_FILE_EXTENT_REG);
3910 btrfs_set_file_extent_disk_bytenr(leaf, fi,
3911 new_extents[i].disk_bytenr);
3912 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
3913 new_extents[i].disk_num_bytes);
3914 btrfs_set_file_extent_num_bytes(leaf, fi,
3916 ext_offset += new_extents[i].offset;
3917 btrfs_set_file_extent_offset(leaf, fi,
3919 btrfs_mark_buffer_dirty(leaf);
3921 btrfs_drop_extent_cache(inode, key.offset,
3922 key.offset + extent_len - 1, 0);
3924 ret = btrfs_inc_extent_ref(trans, root,
3925 new_extents[i].disk_bytenr,
3926 new_extents[i].disk_num_bytes,
3928 root->root_key.objectid,
3929 trans->transid, key.objectid);
3931 btrfs_release_path(root, path);
3933 inode_add_bytes(inode, extent_len);
3936 num_bytes -= extent_len;
3937 key.offset += extent_len;
3942 BUG_ON(i >= nr_extents);
3945 if (extent_locked) {
3946 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3947 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3948 lock_end, GFP_NOFS);
3952 if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
3953 key.offset >= first_pos + extent_key->offset)
3960 btrfs_release_path(root, path);
3962 mutex_unlock(&inode->i_mutex);
3963 if (extent_locked) {
3964 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
3965 unlock_extent(&BTRFS_I(inode)->io_tree, lock_start,
3966 lock_end, GFP_NOFS);
3973 int btrfs_add_reloc_mapping(struct btrfs_root *root, u64 orig_bytenr,
3974 u64 num_bytes, u64 new_bytenr)
3976 set_extent_bits(&root->fs_info->reloc_mapping_tree,
3977 orig_bytenr, orig_bytenr + num_bytes - 1,
3978 EXTENT_LOCKED, GFP_NOFS);
3979 set_state_private(&root->fs_info->reloc_mapping_tree,
3980 orig_bytenr, new_bytenr);
3984 int btrfs_get_reloc_mapping(struct btrfs_root *root, u64 orig_bytenr,
3985 u64 num_bytes, u64 *new_bytenr)
3988 u64 cur_bytenr = orig_bytenr;
3989 u64 prev_bytenr = orig_bytenr;
3993 ret = get_state_private(&root->fs_info->reloc_mapping_tree,
3994 cur_bytenr, &bytenr);
3997 prev_bytenr = cur_bytenr;
3998 cur_bytenr = bytenr;
4001 if (orig_bytenr == cur_bytenr)
4004 if (prev_bytenr != orig_bytenr) {
4005 set_state_private(&root->fs_info->reloc_mapping_tree,
4006 orig_bytenr, cur_bytenr);
4008 *new_bytenr = cur_bytenr;
4012 void btrfs_free_reloc_mappings(struct btrfs_root *root)
4014 clear_extent_bits(&root->fs_info->reloc_mapping_tree,
4015 0, (u64)-1, -1, GFP_NOFS);
4018 int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans,
4019 struct btrfs_root *root,
4020 struct extent_buffer *buf, u64 orig_start)
4025 BUG_ON(btrfs_header_generation(buf) != trans->transid);
4026 BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
4028 level = btrfs_header_level(buf);
4030 struct btrfs_leaf_ref *ref;
4031 struct btrfs_leaf_ref *orig_ref;
4033 orig_ref = btrfs_lookup_leaf_ref(root, orig_start);
4037 ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems);
4039 btrfs_free_leaf_ref(root, orig_ref);
4043 ref->nritems = orig_ref->nritems;
4044 memcpy(ref->extents, orig_ref->extents,
4045 sizeof(ref->extents[0]) * ref->nritems);
4047 btrfs_free_leaf_ref(root, orig_ref);
4049 ref->root_gen = trans->transid;
4050 ref->bytenr = buf->start;
4051 ref->owner = btrfs_header_owner(buf);
4052 ref->generation = btrfs_header_generation(buf);
4053 ret = btrfs_add_leaf_ref(root, ref, 0);
4055 btrfs_free_leaf_ref(root, ref);
4060 static int noinline invalidate_extent_cache(struct btrfs_root *root,
4061 struct extent_buffer *leaf,
4062 struct btrfs_block_group_cache *group,
4063 struct btrfs_root *target_root)
4065 struct btrfs_key key;
4066 struct inode *inode = NULL;
4067 struct btrfs_file_extent_item *fi;
4069 u64 skip_objectid = 0;
4073 nritems = btrfs_header_nritems(leaf);
4074 for (i = 0; i < nritems; i++) {
4075 btrfs_item_key_to_cpu(leaf, &key, i);
4076 if (key.objectid == skip_objectid ||
4077 key.type != BTRFS_EXTENT_DATA_KEY)
4079 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4080 if (btrfs_file_extent_type(leaf, fi) ==
4081 BTRFS_FILE_EXTENT_INLINE)
4083 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0)
4085 if (!inode || inode->i_ino != key.objectid) {
4087 inode = btrfs_ilookup(target_root->fs_info->sb,
4088 key.objectid, target_root, 1);
4091 skip_objectid = key.objectid;
4094 num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
4096 lock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4097 key.offset + num_bytes - 1, GFP_NOFS);
4098 mutex_lock(&BTRFS_I(inode)->extent_mutex);
4099 btrfs_drop_extent_cache(inode, key.offset,
4100 key.offset + num_bytes - 1, 1);
4101 mutex_unlock(&BTRFS_I(inode)->extent_mutex);
4102 unlock_extent(&BTRFS_I(inode)->io_tree, key.offset,
4103 key.offset + num_bytes - 1, GFP_NOFS);
4110 static int noinline replace_extents_in_leaf(struct btrfs_trans_handle *trans,
4111 struct btrfs_root *root,
4112 struct extent_buffer *leaf,
4113 struct btrfs_block_group_cache *group,
4114 struct inode *reloc_inode)
4116 struct btrfs_key key;
4117 struct btrfs_key extent_key;
4118 struct btrfs_file_extent_item *fi;
4119 struct btrfs_leaf_ref *ref;
4120 struct disk_extent *new_extent;
4129 new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS);
4130 BUG_ON(!new_extent);
4132 ref = btrfs_lookup_leaf_ref(root, leaf->start);
4136 nritems = btrfs_header_nritems(leaf);
4137 for (i = 0; i < nritems; i++) {
4138 btrfs_item_key_to_cpu(leaf, &key, i);
4139 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
4141 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
4142 if (btrfs_file_extent_type(leaf, fi) ==
4143 BTRFS_FILE_EXTENT_INLINE)
4145 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
4146 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
4151 if (bytenr >= group->key.objectid + group->key.offset ||
4152 bytenr + num_bytes <= group->key.objectid)
4155 extent_key.objectid = bytenr;
4156 extent_key.offset = num_bytes;
4157 extent_key.type = BTRFS_EXTENT_ITEM_KEY;
4159 ret = get_new_locations(reloc_inode, &extent_key,
4160 group->key.objectid, 1,
4161 &new_extent, &nr_extent);
4166 BUG_ON(ref->extents[ext_index].bytenr != bytenr);
4167 BUG_ON(ref->extents[ext_index].num_bytes != num_bytes);
4168 ref->extents[ext_index].bytenr = new_extent->disk_bytenr;
4169 ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes;
4171 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
4172 btrfs_set_file_extent_disk_bytenr(leaf, fi,
4173 new_extent->disk_bytenr);
4174 btrfs_set_file_extent_disk_num_bytes(leaf, fi,
4175 new_extent->disk_num_bytes);
4176 new_extent->offset += btrfs_file_extent_offset(leaf, fi);
4177 btrfs_set_file_extent_offset(leaf, fi, new_extent->offset);
4178 btrfs_mark_buffer_dirty(leaf);
4180 ret = btrfs_inc_extent_ref(trans, root,
4181 new_extent->disk_bytenr,
4182 new_extent->disk_num_bytes,
4184 root->root_key.objectid,
4185 trans->transid, key.objectid);
4187 ret = btrfs_free_extent(trans, root,
4188 bytenr, num_bytes, leaf->start,
4189 btrfs_header_owner(leaf),
4190 btrfs_header_generation(leaf),
4196 BUG_ON(ext_index + 1 != ref->nritems);
4197 btrfs_free_leaf_ref(root, ref);
4201 int btrfs_free_reloc_root(struct btrfs_root *root)
4203 struct btrfs_root *reloc_root;
4205 if (root->reloc_root) {
4206 reloc_root = root->reloc_root;
4207 root->reloc_root = NULL;
4208 list_add(&reloc_root->dead_list,
4209 &root->fs_info->dead_reloc_roots);
4214 int btrfs_drop_dead_reloc_roots(struct btrfs_root *root)
4216 struct btrfs_trans_handle *trans;
4217 struct btrfs_root *reloc_root;
4218 struct btrfs_root *prev_root = NULL;
4219 struct list_head dead_roots;
4223 INIT_LIST_HEAD(&dead_roots);
4224 list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots);
4226 while (!list_empty(&dead_roots)) {
4227 reloc_root = list_entry(dead_roots.prev,
4228 struct btrfs_root, dead_list);
4229 list_del_init(&reloc_root->dead_list);
4231 BUG_ON(reloc_root->commit_root != NULL);
4233 trans = btrfs_join_transaction(root, 1);
4236 mutex_lock(&root->fs_info->drop_mutex);
4237 ret = btrfs_drop_snapshot(trans, reloc_root);
4240 mutex_unlock(&root->fs_info->drop_mutex);
4242 nr = trans->blocks_used;
4243 ret = btrfs_end_transaction(trans, root);
4245 btrfs_btree_balance_dirty(root, nr);
4248 free_extent_buffer(reloc_root->node);
4250 ret = btrfs_del_root(trans, root->fs_info->tree_root,
4251 &reloc_root->root_key);
4253 mutex_unlock(&root->fs_info->drop_mutex);
4255 nr = trans->blocks_used;
4256 ret = btrfs_end_transaction(trans, root);
4258 btrfs_btree_balance_dirty(root, nr);
4261 prev_root = reloc_root;
4264 btrfs_remove_leaf_refs(prev_root, (u64)-1, 0);
4270 int btrfs_add_dead_reloc_root(struct btrfs_root *root)
4272 list_add(&root->dead_list, &root->fs_info->dead_reloc_roots);
4276 int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
4278 struct btrfs_root *reloc_root;
4279 struct btrfs_trans_handle *trans;
4280 struct btrfs_key location;
4284 mutex_lock(&root->fs_info->tree_reloc_mutex);
4285 ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL);
4287 found = !list_empty(&root->fs_info->dead_reloc_roots);
4288 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4291 trans = btrfs_start_transaction(root, 1);
4293 ret = btrfs_commit_transaction(trans, root);
4297 location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4298 location.offset = (u64)-1;
4299 location.type = BTRFS_ROOT_ITEM_KEY;
4301 reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
4302 BUG_ON(!reloc_root);
4303 btrfs_orphan_cleanup(reloc_root);
4307 static int noinline init_reloc_tree(struct btrfs_trans_handle *trans,
4308 struct btrfs_root *root)
4310 struct btrfs_root *reloc_root;
4311 struct extent_buffer *eb;
4312 struct btrfs_root_item *root_item;
4313 struct btrfs_key root_key;
4316 BUG_ON(!root->ref_cows);
4317 if (root->reloc_root)
4320 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
4323 ret = btrfs_copy_root(trans, root, root->commit_root,
4324 &eb, BTRFS_TREE_RELOC_OBJECTID);
4327 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4328 root_key.offset = root->root_key.objectid;
4329 root_key.type = BTRFS_ROOT_ITEM_KEY;
4331 memcpy(root_item, &root->root_item, sizeof(root_item));
4332 btrfs_set_root_refs(root_item, 0);
4333 btrfs_set_root_bytenr(root_item, eb->start);
4334 btrfs_set_root_level(root_item, btrfs_header_level(eb));
4335 memset(&root_item->drop_progress, 0, sizeof(root_item->drop_progress));
4336 root_item->drop_level = 0;
4338 btrfs_tree_unlock(eb);
4339 free_extent_buffer(eb);
4341 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
4342 &root_key, root_item);
4346 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
4348 BUG_ON(!reloc_root);
4349 reloc_root->last_trans = trans->transid;
4350 reloc_root->commit_root = NULL;
4351 reloc_root->ref_tree = &root->fs_info->reloc_ref_tree;
4353 root->reloc_root = reloc_root;
4358 * Core function of space balance.
4360 * The idea is using reloc trees to relocate tree blocks in reference
4361 * counted roots. There is one reloc tree for each subvol, all reloc
4362 * trees share same key objectid. Reloc trees are snapshots of the
4363 * latest committed roots (subvol root->commit_root). To relocate a tree
4364 * block referenced by a subvol, the code COW the block through the reloc
4365 * tree, then update pointer in the subvol to point to the new block.
4366 * Since all reloc trees share same key objectid, we can easily do special
4367 * handing to share tree blocks between reloc trees. Once a tree block has
4368 * been COWed in one reloc tree, we can use the result when the same block
4369 * is COWed again through other reloc trees.
4371 static int noinline relocate_one_path(struct btrfs_trans_handle *trans,
4372 struct btrfs_root *root,
4373 struct btrfs_path *path,
4374 struct btrfs_key *first_key,
4375 struct btrfs_ref_path *ref_path,
4376 struct btrfs_block_group_cache *group,
4377 struct inode *reloc_inode)
4379 struct btrfs_root *reloc_root;
4380 struct extent_buffer *eb = NULL;
4381 struct btrfs_key *keys;
4385 int lowest_level = 0;
4389 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID)
4390 lowest_level = ref_path->owner_objectid;
4392 if (is_cowonly_root(ref_path->root_objectid)) {
4393 path->lowest_level = lowest_level;
4394 ret = btrfs_search_slot(trans, root, first_key, path, 0, 1);
4396 path->lowest_level = 0;
4397 btrfs_release_path(root, path);
4401 keys = kzalloc(sizeof(*keys) * BTRFS_MAX_LEVEL, GFP_NOFS);
4403 nodes = kzalloc(sizeof(*nodes) * BTRFS_MAX_LEVEL, GFP_NOFS);
4406 mutex_lock(&root->fs_info->tree_reloc_mutex);
4407 ret = init_reloc_tree(trans, root);
4409 reloc_root = root->reloc_root;
4411 path->lowest_level = lowest_level;
4412 ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 0);
4415 * get relocation mapping for tree blocks in the path
4417 lowest_merge = BTRFS_MAX_LEVEL;
4418 for (level = BTRFS_MAX_LEVEL - 1; level >= lowest_level; level--) {
4420 eb = path->nodes[level];
4421 if (!eb || eb == reloc_root->node)
4423 ret = btrfs_get_reloc_mapping(reloc_root, eb->start, eb->len,
4428 btrfs_item_key_to_cpu(eb, &keys[level], 0);
4430 btrfs_node_key_to_cpu(eb, &keys[level], 0);
4431 nodes[level] = new_bytenr;
4432 lowest_merge = level;
4436 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4437 eb = path->nodes[0];
4438 if (btrfs_header_generation(eb) < trans->transid)
4442 btrfs_release_path(reloc_root, path);
4444 * merge tree blocks that already relocated in other reloc trees
4446 if (lowest_merge != BTRFS_MAX_LEVEL) {
4447 ret = btrfs_merge_path(trans, reloc_root, keys, nodes,
4452 * cow any tree blocks that still haven't been relocated
4454 ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 1);
4457 * if we are relocating data block group, update extent pointers
4458 * in the newly created tree leaf.
4460 eb = path->nodes[0];
4461 if (update_refs && nodes[0] != eb->start) {
4462 ret = replace_extents_in_leaf(trans, reloc_root, eb, group,
4467 memset(keys, 0, sizeof(*keys) * BTRFS_MAX_LEVEL);
4468 memset(nodes, 0, sizeof(*nodes) * BTRFS_MAX_LEVEL);
4469 for (level = BTRFS_MAX_LEVEL - 1; level >= lowest_level; level--) {
4470 eb = path->nodes[level];
4471 if (!eb || eb == reloc_root->node)
4473 BUG_ON(btrfs_header_owner(eb) != BTRFS_TREE_RELOC_OBJECTID);
4474 nodes[level] = eb->start;
4476 btrfs_item_key_to_cpu(eb, &keys[level], 0);
4478 btrfs_node_key_to_cpu(eb, &keys[level], 0);
4481 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4482 eb = path->nodes[0];
4483 extent_buffer_get(eb);
4485 btrfs_release_path(reloc_root, path);
4487 * replace tree blocks in the fs tree with tree blocks in
4490 ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level);
4493 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4494 ret = invalidate_extent_cache(reloc_root, eb, group, root);
4496 free_extent_buffer(eb);
4498 mutex_unlock(&root->fs_info->tree_reloc_mutex);
4500 path->lowest_level = 0;
4506 static int noinline relocate_tree_block(struct btrfs_trans_handle *trans,
4507 struct btrfs_root *root,
4508 struct btrfs_path *path,
4509 struct btrfs_key *first_key,
4510 struct btrfs_ref_path *ref_path)
4515 if (root == root->fs_info->extent_root ||
4516 root == root->fs_info->chunk_root ||
4517 root == root->fs_info->dev_root) {
4519 mutex_lock(&root->fs_info->alloc_mutex);
4522 ret = relocate_one_path(trans, root, path, first_key,
4523 ref_path, NULL, NULL);
4526 if (root == root->fs_info->extent_root)
4527 btrfs_extent_post_op(trans, root);
4529 mutex_unlock(&root->fs_info->alloc_mutex);
4534 static int noinline del_extent_zero(struct btrfs_trans_handle *trans,
4535 struct btrfs_root *extent_root,
4536 struct btrfs_path *path,
4537 struct btrfs_key *extent_key)
4541 mutex_lock(&extent_root->fs_info->alloc_mutex);
4542 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
4545 ret = btrfs_del_item(trans, extent_root, path);
4547 btrfs_release_path(extent_root, path);
4548 mutex_unlock(&extent_root->fs_info->alloc_mutex);
4552 static struct btrfs_root noinline *read_ref_root(struct btrfs_fs_info *fs_info,
4553 struct btrfs_ref_path *ref_path)
4555 struct btrfs_key root_key;
4557 root_key.objectid = ref_path->root_objectid;
4558 root_key.type = BTRFS_ROOT_ITEM_KEY;
4559 if (is_cowonly_root(ref_path->root_objectid))
4560 root_key.offset = 0;
4562 root_key.offset = (u64)-1;
4564 return btrfs_read_fs_root_no_name(fs_info, &root_key);
4567 static int noinline relocate_one_extent(struct btrfs_root *extent_root,
4568 struct btrfs_path *path,
4569 struct btrfs_key *extent_key,
4570 struct btrfs_block_group_cache *group,
4571 struct inode *reloc_inode, int pass)
4573 struct btrfs_trans_handle *trans;
4574 struct btrfs_root *found_root;
4575 struct btrfs_ref_path *ref_path = NULL;
4576 struct disk_extent *new_extents = NULL;
4581 struct btrfs_key first_key;
4584 mutex_unlock(&extent_root->fs_info->alloc_mutex);
4586 trans = btrfs_start_transaction(extent_root, 1);
4589 if (extent_key->objectid == 0) {
4590 ret = del_extent_zero(trans, extent_root, path, extent_key);
4594 ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS);
4600 for (loops = 0; ; loops++) {
4602 ret = btrfs_first_ref_path(trans, extent_root, ref_path,
4603 extent_key->objectid);
4605 ret = btrfs_next_ref_path(trans, extent_root, ref_path);
4612 if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID ||
4613 ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID)
4616 found_root = read_ref_root(extent_root->fs_info, ref_path);
4617 BUG_ON(!found_root);
4619 * for reference counted tree, only process reference paths
4620 * rooted at the latest committed root.
4622 if (found_root->ref_cows &&
4623 ref_path->root_generation != found_root->root_key.offset)
4626 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
4629 * copy data extents to new locations
4631 u64 group_start = group->key.objectid;
4632 ret = relocate_data_extent(reloc_inode,
4641 level = ref_path->owner_objectid;
4644 if (prev_block != ref_path->nodes[level]) {
4645 struct extent_buffer *eb;
4646 u64 block_start = ref_path->nodes[level];
4647 u64 block_size = btrfs_level_size(found_root, level);
4649 eb = read_tree_block(found_root, block_start,
4651 btrfs_tree_lock(eb);
4652 BUG_ON(level != btrfs_header_level(eb));
4655 btrfs_item_key_to_cpu(eb, &first_key, 0);
4657 btrfs_node_key_to_cpu(eb, &first_key, 0);
4659 btrfs_tree_unlock(eb);
4660 free_extent_buffer(eb);
4661 prev_block = block_start;
4664 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
4667 * use fallback method to process the remaining
4671 u64 group_start = group->key.objectid;
4672 ret = get_new_locations(reloc_inode,
4680 btrfs_record_root_in_trans(found_root);
4681 ret = replace_one_extent(trans, found_root,
4683 &first_key, ref_path,
4684 new_extents, nr_extents);
4690 btrfs_record_root_in_trans(found_root);
4691 if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
4692 ret = relocate_tree_block(trans, found_root, path,
4693 &first_key, ref_path);
4696 * try to update data extent references while
4697 * keeping metadata shared between snapshots.
4699 ret = relocate_one_path(trans, found_root, path,
4700 &first_key, ref_path,
4701 group, reloc_inode);
4708 btrfs_end_transaction(trans, extent_root);
4711 mutex_lock(&extent_root->fs_info->alloc_mutex);
4715 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
4718 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
4719 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
4721 num_devices = root->fs_info->fs_devices->num_devices;
4722 if (num_devices == 1) {
4723 stripped |= BTRFS_BLOCK_GROUP_DUP;
4724 stripped = flags & ~stripped;
4726 /* turn raid0 into single device chunks */
4727 if (flags & BTRFS_BLOCK_GROUP_RAID0)
4730 /* turn mirroring into duplication */
4731 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
4732 BTRFS_BLOCK_GROUP_RAID10))
4733 return stripped | BTRFS_BLOCK_GROUP_DUP;
4736 /* they already had raid on here, just return */
4737 if (flags & stripped)
4740 stripped |= BTRFS_BLOCK_GROUP_DUP;
4741 stripped = flags & ~stripped;
4743 /* switch duplicated blocks with raid1 */
4744 if (flags & BTRFS_BLOCK_GROUP_DUP)
4745 return stripped | BTRFS_BLOCK_GROUP_RAID1;
4747 /* turn single device chunks into raid0 */
4748 return stripped | BTRFS_BLOCK_GROUP_RAID0;
4753 int __alloc_chunk_for_shrink(struct btrfs_root *root,
4754 struct btrfs_block_group_cache *shrink_block_group,
4757 struct btrfs_trans_handle *trans;
4758 u64 new_alloc_flags;
4761 spin_lock(&shrink_block_group->lock);
4762 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
4763 spin_unlock(&shrink_block_group->lock);
4764 mutex_unlock(&root->fs_info->alloc_mutex);
4766 trans = btrfs_start_transaction(root, 1);
4767 mutex_lock(&root->fs_info->alloc_mutex);
4768 spin_lock(&shrink_block_group->lock);
4770 new_alloc_flags = update_block_group_flags(root,
4771 shrink_block_group->flags);
4772 if (new_alloc_flags != shrink_block_group->flags) {
4774 btrfs_block_group_used(&shrink_block_group->item);
4776 calc = shrink_block_group->key.offset;
4778 spin_unlock(&shrink_block_group->lock);
4780 do_chunk_alloc(trans, root->fs_info->extent_root,
4781 calc + 2 * 1024 * 1024, new_alloc_flags, force);
4783 mutex_unlock(&root->fs_info->alloc_mutex);
4784 btrfs_end_transaction(trans, root);
4785 mutex_lock(&root->fs_info->alloc_mutex);
4787 spin_unlock(&shrink_block_group->lock);
4791 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4792 struct btrfs_root *root,
4793 u64 objectid, u64 size)
4795 struct btrfs_path *path;
4796 struct btrfs_inode_item *item;
4797 struct extent_buffer *leaf;
4800 path = btrfs_alloc_path();
4804 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4808 leaf = path->nodes[0];
4809 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4810 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4811 btrfs_set_inode_generation(leaf, item, 1);
4812 btrfs_set_inode_size(leaf, item, size);
4813 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4814 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NODATASUM);
4815 btrfs_mark_buffer_dirty(leaf);
4816 btrfs_release_path(root, path);
4818 btrfs_free_path(path);
4822 static struct inode noinline *create_reloc_inode(struct btrfs_fs_info *fs_info,
4823 struct btrfs_block_group_cache *group)
4825 struct inode *inode = NULL;
4826 struct btrfs_trans_handle *trans;
4827 struct btrfs_root *root;
4828 struct btrfs_key root_key;
4829 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4832 root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
4833 root_key.type = BTRFS_ROOT_ITEM_KEY;
4834 root_key.offset = (u64)-1;
4835 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
4837 return ERR_CAST(root);
4839 trans = btrfs_start_transaction(root, 1);
4842 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
4846 err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
4849 err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
4850 group->key.offset, 0);
4853 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
4854 if (inode->i_state & I_NEW) {
4855 BTRFS_I(inode)->root = root;
4856 BTRFS_I(inode)->location.objectid = objectid;
4857 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
4858 BTRFS_I(inode)->location.offset = 0;
4859 btrfs_read_locked_inode(inode);
4860 unlock_new_inode(inode);
4861 BUG_ON(is_bad_inode(inode));
4866 err = btrfs_orphan_add(trans, inode);
4868 btrfs_end_transaction(trans, root);
4872 inode = ERR_PTR(err);
4877 int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
4879 struct btrfs_trans_handle *trans;
4880 struct btrfs_path *path;
4881 struct btrfs_fs_info *info = root->fs_info;
4882 struct extent_buffer *leaf;
4883 struct inode *reloc_inode;
4884 struct btrfs_block_group_cache *block_group;
4885 struct btrfs_key key;
4893 root = root->fs_info->extent_root;
4895 block_group = btrfs_lookup_block_group(info, group_start);
4896 BUG_ON(!block_group);
4898 printk("btrfs relocating block group %llu flags %llu\n",
4899 (unsigned long long)block_group->key.objectid,
4900 (unsigned long long)block_group->flags);
4902 path = btrfs_alloc_path();
4905 reloc_inode = create_reloc_inode(info, block_group);
4906 BUG_ON(IS_ERR(reloc_inode));
4908 mutex_lock(&root->fs_info->alloc_mutex);
4910 __alloc_chunk_for_shrink(root, block_group, 1);
4911 block_group->ro = 1;
4912 block_group->space_info->total_bytes -= block_group->key.offset;
4914 mutex_unlock(&root->fs_info->alloc_mutex);
4916 btrfs_start_delalloc_inodes(info->tree_root);
4917 btrfs_wait_ordered_extents(info->tree_root, 0);
4921 key.objectid = block_group->key.objectid;
4924 cur_byte = key.objectid;
4926 trans = btrfs_start_transaction(info->tree_root, 1);
4927 btrfs_commit_transaction(trans, info->tree_root);
4929 mutex_lock(&root->fs_info->cleaner_mutex);
4930 btrfs_clean_old_snapshots(info->tree_root);
4931 btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
4932 mutex_unlock(&root->fs_info->cleaner_mutex);
4934 mutex_lock(&root->fs_info->alloc_mutex);
4937 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4941 leaf = path->nodes[0];
4942 nritems = btrfs_header_nritems(leaf);
4943 if (path->slots[0] >= nritems) {
4944 ret = btrfs_next_leaf(root, path);
4951 leaf = path->nodes[0];
4952 nritems = btrfs_header_nritems(leaf);
4955 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4957 if (key.objectid >= block_group->key.objectid +
4958 block_group->key.offset)
4961 if (progress && need_resched()) {
4962 btrfs_release_path(root, path);
4963 mutex_unlock(&root->fs_info->alloc_mutex);
4965 mutex_lock(&root->fs_info->alloc_mutex);
4971 if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
4972 key.objectid + key.offset <= cur_byte) {
4978 cur_byte = key.objectid + key.offset;
4979 btrfs_release_path(root, path);
4981 __alloc_chunk_for_shrink(root, block_group, 0);
4982 ret = relocate_one_extent(root, path, &key, block_group,
4986 key.objectid = cur_byte;
4991 btrfs_release_path(root, path);
4992 mutex_unlock(&root->fs_info->alloc_mutex);
4995 btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
4996 invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
4997 WARN_ON(reloc_inode->i_mapping->nrpages);
5000 if (total_found > 0) {
5001 printk("btrfs found %llu extents in pass %d\n",
5002 (unsigned long long)total_found, pass);
5007 /* delete reloc_inode */
5010 /* unpin extents in this range */
5011 trans = btrfs_start_transaction(info->tree_root, 1);
5012 btrfs_commit_transaction(trans, info->tree_root);
5014 mutex_lock(&root->fs_info->alloc_mutex);
5016 spin_lock(&block_group->lock);
5017 WARN_ON(block_group->pinned > 0);
5018 WARN_ON(block_group->reserved > 0);
5019 WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
5020 spin_unlock(&block_group->lock);
5023 mutex_unlock(&root->fs_info->alloc_mutex);
5024 btrfs_free_path(path);
5028 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
5029 struct btrfs_key *key)
5032 struct btrfs_key found_key;
5033 struct extent_buffer *leaf;
5036 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
5041 slot = path->slots[0];
5042 leaf = path->nodes[0];
5043 if (slot >= btrfs_header_nritems(leaf)) {
5044 ret = btrfs_next_leaf(root, path);
5051 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5053 if (found_key.objectid >= key->objectid &&
5054 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
5065 int btrfs_free_block_groups(struct btrfs_fs_info *info)
5067 struct btrfs_block_group_cache *block_group;
5070 mutex_lock(&info->alloc_mutex);
5071 spin_lock(&info->block_group_cache_lock);
5072 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
5073 block_group = rb_entry(n, struct btrfs_block_group_cache,
5076 spin_unlock(&info->block_group_cache_lock);
5077 btrfs_remove_free_space_cache(block_group);
5078 spin_lock(&info->block_group_cache_lock);
5080 rb_erase(&block_group->cache_node,
5081 &info->block_group_cache_tree);
5082 spin_lock(&block_group->space_info->lock);
5083 list_del(&block_group->list);
5084 spin_unlock(&block_group->space_info->lock);
5087 spin_unlock(&info->block_group_cache_lock);
5088 mutex_unlock(&info->alloc_mutex);
5092 int btrfs_read_block_groups(struct btrfs_root *root)
5094 struct btrfs_path *path;
5096 struct btrfs_block_group_cache *cache;
5097 struct btrfs_fs_info *info = root->fs_info;
5098 struct btrfs_space_info *space_info;
5099 struct btrfs_key key;
5100 struct btrfs_key found_key;
5101 struct extent_buffer *leaf;
5103 root = info->extent_root;
5106 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5107 path = btrfs_alloc_path();
5111 mutex_lock(&root->fs_info->alloc_mutex);
5113 ret = find_first_block_group(root, path, &key);
5121 leaf = path->nodes[0];
5122 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5123 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5129 spin_lock_init(&cache->lock);
5130 INIT_LIST_HEAD(&cache->list);
5131 read_extent_buffer(leaf, &cache->item,
5132 btrfs_item_ptr_offset(leaf, path->slots[0]),
5133 sizeof(cache->item));
5134 memcpy(&cache->key, &found_key, sizeof(found_key));
5136 key.objectid = found_key.objectid + found_key.offset;
5137 btrfs_release_path(root, path);
5138 cache->flags = btrfs_block_group_flags(&cache->item);
5140 ret = update_space_info(info, cache->flags, found_key.offset,
5141 btrfs_block_group_used(&cache->item),
5144 cache->space_info = space_info;
5145 spin_lock(&space_info->lock);
5146 list_add(&cache->list, &space_info->block_groups);
5147 spin_unlock(&space_info->lock);
5149 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5152 set_avail_alloc_bits(root->fs_info, cache->flags);
5156 btrfs_free_path(path);
5157 mutex_unlock(&root->fs_info->alloc_mutex);
5161 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
5162 struct btrfs_root *root, u64 bytes_used,
5163 u64 type, u64 chunk_objectid, u64 chunk_offset,
5167 struct btrfs_root *extent_root;
5168 struct btrfs_block_group_cache *cache;
5170 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
5171 extent_root = root->fs_info->extent_root;
5173 root->fs_info->last_trans_new_blockgroup = trans->transid;
5175 cache = kzalloc(sizeof(*cache), GFP_NOFS);
5179 cache->key.objectid = chunk_offset;
5180 cache->key.offset = size;
5181 spin_lock_init(&cache->lock);
5182 INIT_LIST_HEAD(&cache->list);
5183 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
5185 btrfs_set_block_group_used(&cache->item, bytes_used);
5186 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
5187 cache->flags = type;
5188 btrfs_set_block_group_flags(&cache->item, type);
5190 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
5191 &cache->space_info);
5193 spin_lock(&cache->space_info->lock);
5194 list_add(&cache->list, &cache->space_info->block_groups);
5195 spin_unlock(&cache->space_info->lock);
5197 ret = btrfs_add_block_group_cache(root->fs_info, cache);
5200 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
5201 sizeof(cache->item));
5204 finish_current_insert(trans, extent_root);
5205 ret = del_pending_extents(trans, extent_root);
5207 set_avail_alloc_bits(extent_root->fs_info, type);
5212 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
5213 struct btrfs_root *root, u64 group_start)
5215 struct btrfs_path *path;
5216 struct btrfs_block_group_cache *block_group;
5217 struct btrfs_key key;
5220 BUG_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
5221 root = root->fs_info->extent_root;
5223 block_group = btrfs_lookup_block_group(root->fs_info, group_start);
5224 BUG_ON(!block_group);
5226 memcpy(&key, &block_group->key, sizeof(key));
5228 path = btrfs_alloc_path();
5231 btrfs_remove_free_space_cache(block_group);
5232 rb_erase(&block_group->cache_node,
5233 &root->fs_info->block_group_cache_tree);
5234 spin_lock(&block_group->space_info->lock);
5235 list_del(&block_group->list);
5236 spin_unlock(&block_group->space_info->lock);
5239 memset(shrink_block_group, 0, sizeof(*shrink_block_group));
5240 kfree(shrink_block_group);
5243 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
5249 ret = btrfs_del_item(trans, root, path);
5251 btrfs_free_path(path);