I'm a little unclear on how checkalias() is supposed to work.

I have a system where I'm using the init.root sysctl; "mount -u /"
from inside the chrooted system fails because the inner /dev/raid2a
(or whatever) is a different vnode from the outer /dev/raid2a whence
it was mounted, despite both of them having the same dev_t and type.

There are also, and I seem to recall that PRs already exist on this,
incidents with FSes which happen to contain device nodes being
considered busy despite no evidence of anything on the FS actually in
use, and which I've suspected of being due to similar aliased-device
confusion.

Something is clearly doing something wrong here, but I don't know
what, and I'm not even sure where to start looking.  Pointers are
appreciated.

-- 
(let ((C call-with-current-continuation)) (apply (lambda (x y) (x y)) (map
((lambda (r) ((C C) (lambda (s) (r (lambda l (apply (s s) l))))))  (lambda
(f) (lambda (l) (if (null? l) C (lambda (k) (display (car l)) ((f (cdr l))
(C k)))))))    '((#\J #\d #\D #\v #\s) (#\e #\space #\a #\i #\newline)))))