make mountd's -S option the default

[Kirk McKusick]

> Date: Sun, 13 Mar 2016 22:20:47 -0400 (EDT)
> From: Rick Macklem <rmacklem at uoguelph.ca>
> To: FreeBSD Filesystems <freebsd-fs at freebsd.org>
> Subject: make mountd's -S option the default
> 
> Julian Elischer has volunteered to commit the patches that
> make the -S option the default for mountd.
> 
> Without this option, any reload of /etc/exports (which happens
> whenever any file system is mounted on the server) can result in
> error replies to NFS clients, due to the file system being temporarily
> not exported. The only downside I can think of to using this option
> is a delay observed by NFS clients when large /etc/exports files
> are reloaded. (Since without the delay they can get error replies,
> the delay seems preferable.
> 
> There are several PR#s related to these error replies:
> 9619, 131342, 206855 (and probably some others)
> 
> If anyone has a problem with this change in default behaviour,
> please email.
> 
> rick

I believe that putting in -S by default is long overdue.

	Kirk McKusick