libbtrfsutil: add btrfs_util_is_subvolume() and btrfs_util_subvolume_id()

These are the most trivial helpers in the library and will be used to
implement several of the more involved functions.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/libbtrfsutil/python/setup.py b/libbtrfsutil/python/setup.py
index df44809f..1cd3bc00 100755
--- a/libbtrfsutil/python/setup.py
+++ b/libbtrfsutil/python/setup.py
@@ -93,6 +93,7 @@ module = Extension(
         'filesystem.c',
         'module.c',
         'qgroup.c',
+        'subvolume.c',
     ],
     include_dirs=['..'],
     library_dirs=['../..'],