Re: bin/698: mount uses mount_* for external fs types, umount should too.

["Simon J. Gerraty" <sjg%juniper.net@localhost>]

David Holland <dholland-bugs%NetBSD.org@localhost> wrote:
>  Log Message:
>  If an external unmount program of the form "umount_TYPE" exists
>  (e.g. umount_ffs, umount_nfs, etc.) exec it instead of calling
>  unmount(2).
>  
>  Closes PR 698.

Thanks.

>  (One might also ask whether there's any real need for this
>  functionality at all any more; this is a fair question, but (a) the
>  change is small and (b) there are certainly cases when doing FS
>  research where you want a custom unmount program; been there & done
>  that.)

Indeed - the case that prompted this PR, was NFS running over SSL to
userland NFS server.  Mount requests authenticated by X509 certs and/or
2 factor authentication.
Performance was poor (putting it mildly) but not an important
consideration.  

AFAIK the system is still in use today ;-)