cvs commit: src/sbin/mount Makefile mount.c

[Craig Rodrigues]

On Sat, Feb 03, 2007 at 12:59:43AM +0100, Pawel Jakub Dawidek wrote:
> Should we also restart mountd(8) on successful umount(8)?

Your fix to mount(8) is a good one, since the existing behavior
of mount(8) is to SIGHUP mountd, based on the pid 
in /var/run/mountd.pid.

I don't like how these sneaky behaviors with non-obvious side-effects
sneak into existing utilities like mount(8).....but that's what we have
today.

A sneaky side effect of the existing behavior, is that when you
SIGHUP mountd, it deletes all existing NFS exports, re-reads
/etc/exports, and then re-creates all the NFS exports.
Some people find this very annoying, especially when you
are already using an NFS export ( http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/9619 ).

I am looking at some patches from Andrey Simonenko which fix this
problem, but they are quite intrusive changes to userland and kernel,
so it is slow going on my part.

So for now, I would recommend leaving umount alone, to avoid adding
new side effects, even though based on existing behavior, it seems logical
to add it.

However, if this behavior is necessary for ZFS, then I won't oppose
modifying umount to SIGHUP mountd. :)

It seems a lot of cruft has accumulated in a simple utility like
mount(8) over the years!
-- 
Craig Rodrigues        
rodrigc at crodrigues.org