btrfs-progs: look up the containing tree root id

Find the tree id of the containing subvolume for a given file or
directory. For subvolume return it's own id.

$ btrfs inspect-internal rootid <path>

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/utils.h b/utils.h
index fdef3f05..19f028f2 100644
--- a/utils.h
+++ b/utils.h
@@ -81,4 +81,6 @@ int is_vol_small(char *file);
 int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 			   int verify);
 int ask_user(char *question);
+int lookup_ino_rootid(int fd, u64 *rootid);
+
 #endif