ioctl and fallocate are being used for TRIMMING effect on block and regular
files, respectively.
This feature is useful for SSDs, where write amplification can be reduced,
and drive life increased. Unlike HDD, SSD has to be explicitly notified of
blocks no longer used.
The interface consists of passing the range to the function, through offset
and length parameters.
Signed-off-by: Raphael S. Carvalho <raphaelsc@cloudius-systems.com>