/usr/src/linux-source-3.13.0/debian.master/d-i/modules/fs-core-modules is in linux-source-3.13.0 3.13.0-157.207.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | ext2 ?
jfs ?
reiserfs ?
xfs ?
|