mnt_{want,drop}_write_file is more suitable than
file_{start,end}_wrtie and also is consistent with
other ioctl operations.
Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>