Add support for the FITRIM ioctl, which enables user space tools to
issue TRIM/DISCARD requests to the underlying device. Every clean
segment within the specified range will be discarded.
Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>