misc/137629: background_dhclient rc.conf option causing double nfs mounts

[Jochen Keil]

>Number:         137629
>Category:       misc
>Synopsis:       background_dhclient rc.conf option causing double nfs mounts
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Aug 10 10:30:02 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator:     Jochen Keil
>Release:        7.2-RELEASE
>Organization:
>Environment:
FreeBSD monolith.lokal.lan 7.2-STABLE FreeBSD 7.2-STABLE #0: Wed Aug  5 10:11:22 CEST 2009     root at monolith.lokal.lan:/usr/obj/usr/src/sys/MONOLITH  i386
>Description:
One or more NFS mountpoints listed in fstab similar to this one:
192.168.1.1:/pub  /pub  nfs  ro,-b,-i  0  0

set background_dhclient="YES" in /etc/rc.conf.

This will result in /pub (and other mountpoints) getting mounted twice on boot.
Output from mount looks something like that:
$ mount
[..]
192.168.1.1:/pub on /pub (nfs, read-only)
[..]
192.168.1.1:/pub on /pub (nfs, read-only)

Setting background_dhclient="NO" fixes the problem.
>How-To-Repeat:
Set background_dhclient="YES" in /etc/rc.conf and put a NFS mount with option "-b" into /etc/fstab.
>Fix:
Set background_dhclient="NO" in /etc/rc.conf

>Release-Note:
>Audit-Trail:
>Unformatted: