Align btrfs st_blocks to how linux calculates it

dissect/target/filesystems/btrfs.py

@@ -181,6 +181,9 @@ def lstat(self) -> fsutil.stat_result:
 
  # Add block information of the filesystem
  st_info.st_blksize = entry.btrfs.sector_size
- st_info.st_blocks = math.ceil(entry.size / st_info.st_blksize)
+
+ st_info.st_blocks = 0
+ if not self.is_dir():
+ st_info.st_blocks = (st_info.st_blksize // 512) * math.ceil(st_info.st_size / st_info.st_blksize)
 
  return st_info

tests/filesystems/test_btrfs.py

@@ -10,9 +10,9 @@
 @pytest.mark.parametrize(
  "sector_size, filesize, expected_blocks",
  [
- (0x1000, 0x343, 0x1),
- (0x1000, 0x1000, 0x1),
- (0x1000, 0x1001, 0x2),
+ (0x1000, 0x343, 0x8),
+ (0x1000, 0x1000, 0x8),
+ (0x1000, 0x1001, 0x10),
  ],
  ids=["lower", "equal", "greater"],
 )
@@ -55,3 +55,27 @@ def test_stat_information_file_blocksize(sector_size: int, filesize: int, expect
 
  assert stat_info.st_blksize == sector_size
  assert stat_info.st_blocks == expected_blocks
+
+
+def test_stat_directory() -> None:
+ """Using btrfs stat information as a base"""
+ entry = INode(Mock(), 42, type=c_btrfs.BTRFS_FT_DIR)
+ entry.btrfs = Mock(sector_size=0x1000)
+ timestamp = c_btrfs.btrfs_timespec()
+ entry.inode = c_btrfs.btrfs_inode_item(
+ mode=0o777,
+ nlink=0,
+ uid=1000,
+ gid=1000,
+ size=0x1000,
+ atime=timestamp,
+ ctime=timestamp,
+ otime=timestamp,
+ mtime=timestamp,
+ )
+
+ fs_entry = BtrfsFilesystemEntry(Mock(), "some/path", entry)
+
+ stat_info = fs_entry.lstat()
+
+ assert stat_info.st_blocks == 0