nilfs2: add FITRIM ioctl support for nilfs2
nilfs2: add FITRIM ioctl support for nilfs2

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 <307809eb270e82590481d18cc726355b9a856b2d@gmx.net>
Signed-off-by: Ryusuke Konishi <f414f2bdd839fdc054376382fa67e9bc2fbf206f@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs