[PATCH] Variable-size ioctl data handling

Hi,

Could anybody please review and check in the patch 
patch-ioctl-var-size.txt from this PR: 
http://www.freebsd.org/cgi/query-pr.cgi?pr=175425 ?
This patch introduces the generic way to pass variable size ioctl 
argument using the structure like this struct my_struct {int len; ...any 
fields...}.

Thank you,
Yuri