https://askubuntu.com/questions/47700/fix-corrupt-ntfs-partition-without-windows

sudo ntfsfix -b -d /dev/sda6

--help shows them

ntfsfix v2015.3.14AR.1 (libntfs-3g)

Usage: ntfsfix [options] device
    Attempt to fix an NTFS partition.

    -b, --clear-bad-sectors Clear the bad sector list
    -d, --clear-dirty       Clear the volume dirty flag
    -h, --help              Display this help
    -n, --no-action         Do not write anything
    -V, --version           Display version information


