shared: test truncate orphan inodes when mounting extN

shared: test truncate orphan inodes when mounting extN

ext4 should hold i_mutex when truncating orhpan inodes, or a WARNING
would be triggered. This commit fixed this issue.

721e3eb ext4: lock i_mutex when truncating orphan inodes

Though it's an ext4 specific issue, there's no harm to test on ext2/3
too, as debugfs is used to set orphan inode list.

This test is based on a script from Lukas Czerner.

Signed-off-by: Eryu Guan <eguan@redhat.com>
Acked-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>