Btrfs: implement the free space B-tree

[sfrench/cifs-2.6.git] / fs / btrfs / free-space-tree.h

diff --git a/fs/btrfs/free-space-tree.h b/fs/btrfs/free-space-tree.h
new file mode 100644 (file)
index 0000000..54ffced
--- /dev/null
+++ b/fs/btrfs/free-space-tree.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2015 Facebook.  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 __BTRFS_FREE_SPACE_TREE
+#define __BTRFS_FREE_SPACE_TREE
+
+/*
+ * The default size for new free space bitmap items. The last bitmap in a block
+ * group may be truncated, and none of the free space tree code assumes that
+ * existing bitmaps are this size.
+ */
+#define BTRFS_FREE_SPACE_BITMAP_SIZE 256
+#define BTRFS_FREE_SPACE_BITMAP_BITS (BTRFS_FREE_SPACE_BITMAP_SIZE * BITS_PER_BYTE)
+
+void set_free_space_tree_thresholds(struct btrfs_block_group_cache *block_group);
+int btrfs_create_free_space_tree(struct btrfs_fs_info *fs_info);
+int btrfs_clear_free_space_tree(struct btrfs_fs_info *fs_info);
+int load_free_space_tree(struct btrfs_caching_control *caching_ctl);
+int add_block_group_free_space(struct btrfs_trans_handle *trans,
+                              struct btrfs_fs_info *fs_info,
+                              struct btrfs_block_group_cache *block_group);
+int remove_block_group_free_space(struct btrfs_trans_handle *trans,
+                                 struct btrfs_fs_info *fs_info,
+                                 struct btrfs_block_group_cache *block_group);
+int add_to_free_space_tree(struct btrfs_trans_handle *trans,
+                          struct btrfs_fs_info *fs_info,
+                          u64 start, u64 size);
+int remove_from_free_space_tree(struct btrfs_trans_handle *trans,
+                               struct btrfs_fs_info *fs_info,
+                               u64 start, u64 size);
+
+/* Exposed for testing. */
+struct btrfs_free_space_info *
+search_free_space_info(struct btrfs_trans_handle *trans,
+                      struct btrfs_fs_info *fs_info,
+                      struct btrfs_block_group_cache *block_group,
+                      struct btrfs_path *path, int cow);
+int __add_to_free_space_tree(struct btrfs_trans_handle *trans,
+                            struct btrfs_fs_info *fs_info,
+                            struct btrfs_block_group_cache *block_group,
+                            struct btrfs_path *path, u64 start, u64 size);
+int __remove_from_free_space_tree(struct btrfs_trans_handle *trans,
+                                 struct btrfs_fs_info *fs_info,
+                                 struct btrfs_block_group_cache *block_group,
+                                 struct btrfs_path *path, u64 start, u64 size);
+int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
+                                 struct btrfs_fs_info *fs_info,
+                                 struct btrfs_block_group_cache *block_group,
+                                 struct btrfs_path *path);
+int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
+                                 struct btrfs_fs_info *fs_info,
+                                 struct btrfs_block_group_cache *block_group,
+                                 struct btrfs_path *path);
+int free_space_test_bit(struct btrfs_block_group_cache *block_group,
+                       struct btrfs_path *path, u64 offset);
+
+#endif