[PATCH] SELinux: add rootcontext= option to label root inode when mounting

Introduce a new rootcontext= option to FS mounting.  This option will allow
you to explicitly label the root inode of an FS being mounted before that
FS or inode because visible to userspace.  This was found to be useful for
things like stateless linux, see
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=190001



Signed-off-by: Eric Paris <eparis@parisplace.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>