1 files changed, 77 insertions, 0 deletions

diff --git a/fs/btrfs/ref-cache.h b/fs/btrfs/ref-cache.h
new file mode 100644
index 000000000000..16f3183d7c59
--- /dev/null
+++ b/fs/btrfs/ref-cache.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2008 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+#ifndef __REFCACHE__
+#define __REFCACHE__
+
+struct btrfs_extent_info {
+        /* bytenr and num_bytes find the extent in the extent allocation tree */
+        u64 bytenr;
+        u64 num_bytes;
+
+        /* objectid and offset find the back reference for the file */
+        u64 objectid;
+        u64 offset;
+};
+
+struct btrfs_leaf_ref {
+        struct rb_node rb_node;
+        struct btrfs_leaf_ref_tree *tree;
+        int in_tree;
+        atomic_t usage;
+
+        u64 root_gen;
+        u64 bytenr;
+        u64 owner;
+        u64 generation;
+        int nritems;
+
+        struct list_head list;
+        struct btrfs_extent_info extents[];
+};
+
+static inline size_t btrfs_leaf_ref_size(int nr_extents)
+{
+        return sizeof(struct btrfs_leaf_ref) +
+               sizeof(struct btrfs_extent_info) * nr_extents;
+}
+
+static inline void btrfs_leaf_ref_tree_init(struct btrfs_leaf_ref_tree *tree)
+{
+        tree->root.rb_node = NULL;
+        INIT_LIST_HEAD(&tree->list);
+        spin_lock_init(&tree->lock);
+}
+
+static inline int btrfs_leaf_ref_tree_empty(struct btrfs_leaf_ref_tree *tree)
+{
+        return RB_EMPTY_ROOT(&tree->root);
+}
+
+void btrfs_leaf_ref_tree_init(struct btrfs_leaf_ref_tree *tree);
+struct btrfs_leaf_ref *btrfs_alloc_leaf_ref(struct btrfs_root *root,
+                                            int nr_extents);
+void btrfs_free_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref);
+struct btrfs_leaf_ref *btrfs_lookup_leaf_ref(struct btrfs_root *root,
+                                             u64 bytenr);
+int btrfs_add_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref,
+                       int shared);
+int btrfs_remove_leaf_refs(struct btrfs_root *root, u64 max_root_gen,
+                           int shared);
+int btrfs_remove_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref);
+
+#endif