1 /*
2 * Copyright (C) 2008 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #ifndef __REFCACHE__
19 #define __REFCACHE__
20
21 struct btrfs_extent_info {
22 /* bytenr and num_bytes find the extent in the extent allocation tree */
23 u64 bytenr;
24 u64 num_bytes;
25
26 /* objectid and offset find the back reference for the file */
27 u64 objectid;
28 u64 offset;
29 };
30
31 struct btrfs_leaf_ref {
32 struct rb_node rb_node;
33 struct btrfs_leaf_ref_tree *tree;
34 int in_tree;
35 atomic_t usage;
36
37 u64 root_gen;
38 u64 bytenr;
39 u64 owner;
40 u64 generation;
41 int nritems;
42
43 struct list_head list;
44 struct btrfs_extent_info extents[];
45 };
46
btrfs_leaf_ref_size(int nr_extents)47 static inline size_t btrfs_leaf_ref_size(int nr_extents)
48 {
49 return sizeof(struct btrfs_leaf_ref) +
50 sizeof(struct btrfs_extent_info) * nr_extents;
51 }
52
btrfs_leaf_ref_tree_init(struct btrfs_leaf_ref_tree * tree)53 static inline void btrfs_leaf_ref_tree_init(struct btrfs_leaf_ref_tree *tree)
54 {
55 tree->root = RB_ROOT;
56 INIT_LIST_HEAD(&tree->list);
57 spin_lock_init(&tree->lock);
58 }
59
btrfs_leaf_ref_tree_empty(struct btrfs_leaf_ref_tree * tree)60 static inline int btrfs_leaf_ref_tree_empty(struct btrfs_leaf_ref_tree *tree)
61 {
62 return RB_EMPTY_ROOT(&tree->root);
63 }
64
65 void btrfs_leaf_ref_tree_init(struct btrfs_leaf_ref_tree *tree);
66 struct btrfs_leaf_ref *btrfs_alloc_leaf_ref(struct btrfs_root *root,
67 int nr_extents);
68 void btrfs_free_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref);
69 struct btrfs_leaf_ref *btrfs_lookup_leaf_ref(struct btrfs_root *root,
70 u64 bytenr);
71 int btrfs_add_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref,
72 int shared);
73 int btrfs_remove_leaf_refs(struct btrfs_root *root, u64 max_root_gen,
74 int shared);
75 int btrfs_remove_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref);
76 #endif
77