btrfs: track the csum, extent, and free space trees in a rb tree

In the future we are going to have multiple copies of these trees.  To
facilitate this we need a way to lookup the different roots we are
looking for.  Handle this by adding a global root rb tree that is
indexed on the root->root_key.  Then instead of loading the roots at
mount time with individually targeted keys, simply search the tree_root
for anything with the specific objectid we want.  This will make it
straightforward to support both old style and new style file systems.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 6 insertions, 12 deletions

diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index a4d1788acd24..5e8bef4b7563 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -71,6 +71,12 @@ struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
 struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
 						 struct btrfs_path *path,
 						 u64 objectid);
+int btrfs_global_root_insert(struct btrfs_root *root);
+void btrfs_global_root_delete(struct btrfs_root *root);
+struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
+				     struct btrfs_key *key);
+struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr);
+struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr);
 
 void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
@@ -103,18 +109,6 @@ static inline struct btrfs_root *btrfs_grab_root(struct btrfs_root *root)
 	return NULL;
 }
 
-static inline struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info,
-						   u64 bytenr)
-{
-	return fs_info->_extent_root;
-}
-
-static inline struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info,
-						 u64 bytenr)
-{
-	return fs_info->_csum_root;
-}
-
 static inline struct btrfs_root *btrfs_block_group_root(struct btrfs_fs_info *fs_info)
 {
 	return btrfs_extent_root(fs_info, 0);